CN113396180B - Liquid crystal polyester powder, liquid crystal polyester composition, method for producing film, and method for producing laminate - Google Patents

Abstract

The liquid crystal polyester powder of the present invention comprises a liquid crystal polyester having a number average molecular weight of 10000 or less and has an average particle diameter of 0.5 to 20 [ mu ] m.

Description

Liquid crystal polyester powder, liquid crystal polyester composition, method for producing film, and method for producing laminate

technical field

The present invention relates to a liquid crystal polyester powder, a liquid crystal polyester composition, a method for producing a film, and a method for producing a laminate.

This application claims priority based on Japanese Patent Application No. 2019-025664 filed in Japan on February 15, 2019 and Japanese Patent Application No. 2019-141072 filed in Japan on July 31, 2019, and the contents thereof are cited in this application middle.

Background technique

Insulating materials are used in printed circuit boards on which electronic components are mounted. In recent years, along with the development of communication systems, etc., further improvements in physical properties such as dielectric properties of insulating materials have been expected.

For example, Patent Document 1 describes an insulating resin composition containing a silyl group-containing epoxy resin, a curing agent, and an inorganic filler such as silica for the purpose of reducing dielectric loss.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2017-66360.

Contents of the invention

The problem to be solved by the invention

However, as in the method described in Patent Document 1, when the inorganic filler is added to the resin composition, there is a problem that the adhesion strength with the metal foil or the mechanical strength of the insulating base material decreases.

In addition, considering application to next-generation mobile communication systems, there is a high possibility that existing substrate materials may not have sufficient dielectric properties at high frequencies.

Since liquid crystal polyester films have excellent high-frequency characteristics and low water absorption, they are attracting attention as electronic substrate materials.

An object of the present invention is to provide a liquid crystal polyester powder and a liquid crystal polyester composition capable of producing a liquid crystal polyester film having good quality as a film for electronic parts.

Another object of the present invention is to provide a method for producing a liquid crystal polyester film and a method for producing a laminate that can produce a liquid crystal polyester film having good quality as a film for electronic components.

means to solve the problem

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have found that a high-quality liquid crystal polyester film can be produced by including a liquid crystal polyester powder having a predetermined molecular weight and having a predetermined average particle diameter, thereby completing the invention.

That is, one aspect of the present invention is the following liquid crystal polyester powder, liquid crystal polyester composition, method for producing a film, and method for producing a laminate.

<1> A liquid crystal polyester powder, wherein the liquid crystal polyester powder contains a liquid crystal polyester having a number average molecular weight of 10000 or less, and the average particle diameter of the liquid crystal polyester powder is 0.5 to 20 μm.

<2> The liquid crystal polyester powder as described in <1>, wherein the relative dielectric constant of the liquid crystal polyester powder is 3 or less at a frequency of 1 GHz, and the liquid crystal polyester powder has a relative dielectric constant of 3 or less at a frequency of 1 GHz. The dielectric loss tangent is 0.005 or less.

<3> The liquid crystalline polyester powder according to the above <1> or <2>, wherein the liquid crystalline polyester has a structural unit containing a naphthalene structure.

<4> The liquid crystal polyester powder as described in <3>, wherein the content of the structural unit containing a naphthalene structure is 40 moles relative to the total amount of all structural units in the liquid crystal polyester (100 mol%) %above.

<5> The liquid crystal polyester powder according to <3> or <4>, wherein the liquid crystal polyester has 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 (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

Ar ¹ represents 2,6-naphthalenediyl, 1,4-phenylene or 4,4'-biphenylene.

Ar ² and Ar ³ independently represent 2,6-naphthalenediyl, 2,7-naphthalenediyl, 1,4-phenylene, 1,3-phenylene or 4,4'-biphenylene .

The hydrogen atoms in the groups represented by Ar ¹ , Ar ² or Ar ³ are independently substituted or not substituted by halogen atoms, alkyl groups with 1 to 10 carbon atoms or aryl groups with 6 to 20 carbon atoms .

<6> A liquid crystal polyester composition comprising a medium and the liquid crystal polyester powder according to any one of <1> to <5>.

<7> A method for producing a liquid crystal polyester film, wherein the method for producing a liquid crystal polyester film comprises: coating the liquid crystal polyester composition described in <6> on a support, and performing heat treatment, thereby A step of obtaining a liquid crystal polyester film containing a liquid crystal polyester.

<8> A method for producing a laminate, wherein the method for producing a laminate comprises: coating the liquid crystal polyester composition described in <6> on a support, and performing heat treatment to form a liquid crystal polyester a liquid crystal polyester film, thereby obtaining a laminate comprising the support and the liquid crystal polyester film.

That is, the present invention includes the following aspects.

<1> A liquid crystal polyester powder, wherein the liquid crystal polyester powder contains a liquid crystal polyester having a number average molecular weight of 10000 or less, and the average particle diameter of the liquid crystal polyester powder is 0.5 to 20 μm.

<2> The liquid crystal polyester powder as described in <1>, wherein the relative dielectric constant of the liquid crystal polyester powder is 3 or less at a frequency of 1 GHz, and the liquid crystal polyester powder has a relative dielectric constant of 3 or less at a frequency of 1 GHz. The dielectric loss tangent is 0.005 or less.

<3> The liquid crystalline polyester powder according to the above <1> or <2>, wherein the liquid crystalline polyester has a structural unit containing a naphthalene structure.

<4> The liquid crystal polyester powder as described in <3>, wherein the content of the structural unit containing a naphthalene structure is 40 moles relative to the total amount of all structural units in the liquid crystal polyester (100 mol%) %above.

<5> The liquid crystal polyester powder according to <3> or <4>, wherein the liquid crystal polyester has 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 (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

Ar ¹ represents 2,6-naphthalenediyl, 1,4-phenylene or 4,4'-biphenylene.

Ar ² and Ar ³ independently represent 2,6-naphthalenediyl, 2,7-naphthalenediyl, 1,4-phenylene, 1,3-phenylene or 4,4'-biphenylene .

The hydrogen atoms in the groups represented by Ar ¹ , Ar ² or Ar ³ are independently substituted or not substituted by halogen atoms, alkyl groups with 1 to 10 carbon atoms or aryl groups with 6 to 20 carbon atoms .

<6> The liquid crystalline polyester powder according to any one of <1> to <5>, wherein the liquid crystalline polyester powder is insoluble in an aprotic solvent.

<7> A liquid crystal polyester composition comprising a medium and the liquid crystal polyester powder according to any one of <1> to <6>.

<8> The liquid crystal polyester composition according to the above <7>, wherein the medium is an aprotic solvent.

<9> A method for producing a liquid crystal polyester film, wherein the method for producing a liquid crystal polyester film comprises: coating the liquid crystal polyester composition described in <7> or <8> on a support, A step of performing heat treatment to obtain a liquid crystal polyester film containing liquid crystal polyester.

<10> A method for producing a laminate, wherein the method for producing a laminate comprises: coating the liquid crystal polyester composition described in <7> or <8> on a support, performing heat treatment, and forming A liquid crystal polyester film containing a liquid crystal polyester, thereby obtaining a laminate comprising the support and the liquid crystal polyester film.

The effect of the invention

According to the present invention, there can be provided a liquid crystal polyester powder and a liquid crystal polyester composition capable of producing a liquid crystal polyester film having good quality as a film for electronic parts.

Moreover, according to this invention, the manufacturing method of a liquid crystal polyester film and the manufacturing method of a laminated body which can manufacture the liquid crystal polyester film which has the favorable quality as a film for electronic components can be provided.

Description of drawings

FIG. 1 is a schematic diagram showing a production process of a liquid crystal polyester film and a laminate according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the structure of a film according to one embodiment of the present invention.

FIG. 3 is a schematic diagram showing the structure of a laminate according to one embodiment of the present invention.

Detailed ways

Embodiments of the liquid crystal polyester powder, the liquid crystal polyester composition, the method for producing a film, and the method for producing a laminate of the present invention will be described below.

"Liquid Crystal Polyester Powder"

The liquid crystal polyester powder according to the embodiment includes a liquid crystal polyester having a number average molecular weight of 10,000 or less, and has an average particle diameter of 0.5 to 20 μm. The liquid crystal polyester powder of the embodiment is suitable as a raw material for the method for producing the liquid crystal polyester film or laminate of the embodiment. According to the liquid crystal polyester powder satisfying the above-mentioned requirements, a liquid crystal polyester film having good quality as a film for electronic parts can be produced. The isotropy, thickness, and appearance of the film (whether holes or through-holes are generated) can be mentioned as the quality standard. Details of the liquid crystal polyester film will be described later.

The average particle diameter of the liquid crystal polyester powder is 20 μm or less, preferably 18 μm or less, more preferably 15 μm or less, and still more preferably 10 μm or less. When the average particle diameter of the liquid crystalline polyester exceeds 20 μm, it is difficult to obtain a liquid crystalline polyester film with good appearance. For example, as shown in Examples described later, when the average particle diameter of the liquid crystal polyester exceeds 20 μm, through holes may be formed in the produced liquid crystal polyester film. Formation of through-holes tends to occur in a thickness range of 50 μm or less, which is a good thickness range for a film for electronic components. That is, by setting the average particle diameter of the liquid crystalline polyester to 20 μm or less, it is possible to easily manufacture a film having both a good thickness and an appearance as a film for electronic components.

In addition, the average particle diameter of the liquid crystalline polyester powder is preferably 0.5 μm or more, more preferably 3 μm or more, and still more preferably 5 μm or more, from the viewpoint of powder handling properties.

The upper limit and lower limit of the average particle diameter of the above-mentioned liquid crystal polyester powder can be freely combined. As an example of the numerical range of the average particle diameter value of the liquid crystal polyester powder, it may be 0.5 μm to 20 μm, may be 3 μm to 18 μm, may be 5 μm to 15 μm, may be 5 μm to 10 μm .

In this specification, "average particle diameter" refers to the particle diameter value (50% Cumulative volume particle size D ₅₀ ).

As a method of controlling the particle size within the above range, for example, when using a jet mill, it can be controlled by changing the rotation speed of the classifying rotor, the pressure of the crushing nozzle, the processing speed, and the like.

In addition, in the method for producing a liquid crystal polyester film or laminate according to an embodiment described later, since it is not necessary to dissolve liquid crystal polyester powder in a solvent, powder of liquid crystal polyester having excellent dielectric properties can be used as a raw material. From the liquid crystalline polyester powder having excellent dielectric properties, a liquid crystalline polyester film having excellent dielectric properties can be produced.

In this specification, "dielectric characteristics" refer to characteristics related to relative permittivity and dielectric loss tangent.

The relative permittivity of the liquid crystal polyester powder according to the embodiment at a frequency of 1 GHz is preferably 3 or less, preferably 2.9 or less, preferably 2.8 or less, more preferably less than 2.8, further preferably 2.78 or less, especially preferably 2.76 or less. In addition, the relative dielectric constant of the liquid crystal polyester powder may be 2.5 or more, 2.6 or more, or 2.7 or more.

The upper limit and lower limit of the value of the above-mentioned relative permittivity of the above-mentioned liquid crystal polyester powder can be freely combined. An example of the numerical range of the relative permittivity of the liquid crystal polyester powder may be 2.5 to 3, 2.6 to 2.78, or 2.7 to 2.76.

The liquid crystal polyester powder according to the embodiment has a dielectric loss tangent of preferably 0.005 or less at a frequency of 1 GHz, preferably 0.004 or less, more preferably 0.003 or less, further preferably 0.0025 or less, and especially preferably 0.002 or less. In addition, the dielectric loss tangent of the liquid crystal polyester powder may be 0.0003 or more, 0.0005 or more, or 0.001 or more.

The upper limit and lower limit of the value of the dielectric loss tangent of the liquid crystalline polyester powder can be freely combined. As an example of the numerical range of the value of the above-mentioned dielectric loss tangent of the above-mentioned liquid crystal polyester powder, it may be 0.0003 to 0.005, may be 0.0005 to 0.004, may be 0.001 to 0.003, may be 0.001 or more And 0.0025 or less, may be 0.001 or more and 0.002 or less.

The relative permittivity and dielectric loss tangent of the liquid crystal polyester powder at a frequency of 1 GHz can be measured under the following conditions by a volumetric method using an impedance analyzer.

A tablet having a diameter of 1 cm and a thickness of 0.5 cm was produced by melting the powder of liquid crystal polyester microparticles at a temperature 5° C. higher than the melting point measured by a flow tester, followed by cooling and solidification. The relative permittivity and dielectric loss tangent of the obtained tablet were measured at 1 GHz under the following conditions.

Determination method: volumetric method.

Electrode model: 16453A.

Measurement environment: 23°C, 50%RH.

Applied voltage: 1V.

It should be noted that the relative permittivity and dielectric loss tangent of the liquid crystal polyester powder according to the embodiment may be different from those of a liquid crystal polyester film produced using the powder as a raw material. This is considered to be due to the difference in the molecular weights of the liquid crystal polyesters contained.

The liquid crystal polyester powder is preferably insoluble in a medium contained in the liquid crystal polyester composition described later, and more preferably insoluble in a protic solvent.

Here, whether or not it is insoluble in a medium can be confirmed by performing the following test. In the following test methods, the case where the medium is an aprotic solvent will be described.

experiment method

Liquid crystal polyester powder (5 parts by weight) was stirred in an aprotic solvent (medium) (95 parts by weight) at a temperature of 180° C. and stirred for 6 hours using an anchor blade at 200 rpm, and then cooled to room temperature. Next, after filtration using a membrane filter with a mesh size of 5 μm and a pressure filter, residues on the membrane filter were confirmed. At this time, when the presence of a solid substance was not confirmed, it was judged to be soluble in an aprotic solvent (medium). When a solid substance having a minor diameter of 5 μm or more was confirmed, it was judged to be insoluble in an aprotic solvent (medium). Solid matter having a short diameter of 5 μm or more can be confirmed by microscopic observation.

With respect to 100 mass % of the liquid crystal polyester powder of the embodiment, the content ratio of the liquid crystal polyester may be 50 to 100 mass %, or may be 80 to 95 mass %.

The number average molecular weight of the liquid crystal polyester in the liquid crystal polyester powder according to the embodiment is 10,000 or less, more preferably 3,000 to 10,000, still more preferably 4,000 to 8,000, and especially preferably 5,000 to 7,000. When the number-average molecular weight of the liquid crystal polyester in the liquid crystal polyester powder exceeds 10,000, the liquid crystal polyester composition becomes gel-like, making it difficult to perform film-forming processing with excellent isotropy. In addition, the smaller the number average molecular weight of the liquid crystal polyester, the more likely the thermal conductivity in the thickness direction of the film after heat treatment will be improved. Therefore, it is preferable that when the number average molecular weight of the liquid crystal polyester is more than the above-mentioned lower limit value, the thermal conductivity of the film after heat treatment The heat resistance or strength/rigidity of the film was good.

In the present specification, the "number average molecular weight" is an absolute value measured using a gel permeation chromatography-multi-angle light scattering photometer.

Hereinafter, details of the liquid crystal polyester contained in the liquid crystal polyester powder according to the embodiment will be described.

(liquid crystal polyester)

The liquid crystal polyester is a liquid crystal polyester that exhibits liquid crystallinity in a molten state, and is preferably melted at a temperature of 450° C. or lower. It should be noted that the liquid crystal polyester may be liquid crystal polyester amide, liquid crystal polyester ether, liquid crystal polyester carbonate, or liquid crystal polyester imide. The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester having only a structural unit derived from an aromatic compound as a raw material monomer.

It should be noted that "derived from" in this specification means that in order to polymerize the raw material monomers, the chemical structure of the functional group that contributes to the polymerization changes, and no other structural changes occur.

Typical examples of liquid crystal polyesters include the following.

1) At least one compound selected from the group consisting of (i) aromatic hydroxycarboxylic acid, (ii) aromatic dicarboxylic acid and (iii) aromatic diol, aromatic hydroxylamine and aromatic diamine Polymerized (condensed) liquid crystal polyester.

2) A liquid crystal polyester obtained by polymerizing a plurality of aromatic hydroxycarboxylic acids.

3) A liquid crystal polyester obtained by polymerizing (i) an aromatic dicarboxylic acid and (ii) at least one compound selected from the group consisting of aromatic diols, aromatic hydroxylamines, and aromatic diamines.

4) Liquid crystal polyester obtained by polymerizing (i) polyester such as polyethylene terephthalate and (ii) aromatic hydroxycarboxylic acid.

Here, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxylamines, and aromatic diamines may each independently be replaced with a part or all of them by their polymerizable derivatives.

Examples of polymerizable derivatives of compounds having carboxyl groups such as aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids include substances (esters) in which carboxyl groups are converted into alkoxycarbonyl or aryloxycarbonyl groups, substances in which carboxyl groups are converted Substances that convert to haloformyl groups (acid halides) and substances that convert carboxyl groups to acyloxycarbonyl groups (acid anhydrides). Examples of polymerizable derivatives of compounds having hydroxyl groups such as aromatic hydroxycarboxylic acids, aromatic diols, and aromatic hydroxylamines include those obtained by acylation of hydroxyl groups to convert them to acyloxy groups (acylates). As an example of the polymerizable derivative of the compound which has an amino group, such as an aromatic hydroxylamine and an aromatic diamine, the thing (acylate) which acylated an amino group and converted into an amido group is mentioned.

The liquid crystal polyester preferably has a structural unit containing a divalent aromatic hydrocarbon group.

Examples of liquid crystal polyesters having a structural unit containing a divalent aromatic hydrocarbon group include 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 (3). A liquid crystal polyester having a structural unit of the following formula (2), or a liquid crystal polyester having a structural unit represented by the following formula (2) and a structural unit represented by the following formula (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

Ar ¹ , Ar ² and Ar ³ each independently represent a divalent aromatic hydrocarbon group.

The hydrogen atoms in the groups represented by Ar ¹ , Ar ² or Ar ³ are independently substituted or not substituted by halogen atoms, alkyl groups with 1 to 10 carbon atoms or aryl groups with 6 to 20 carbon atoms .

Among Ar ¹ , Ar ² and Ar ³ , examples of the divalent aromatic hydrocarbon group include phenylene, naphthylene, biphenylene and the like.

Here, among Ar ¹ , Ar ² and Ar ³ , examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, 2-ethylhexyl, The number of carbon atoms in n-octyl, n-decyl, etc. is usually 1-10. Examples of the aryl group include phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl and 2-naphthyl, and the number of carbon atoms is usually 6-20. In the case where the hydrogen atom is substituted by these groups, in each of the groups represented by Ar ¹ , Ar ² or Ar ³ , the number thereof is independently usually 2 or less, preferably 1 or less .

The liquid crystalline polyester more preferably has a structural unit containing a naphthalene structure.

As the liquid crystal polyester having a structural unit containing a divalent naphthalene structure, for example, 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 (3) can be cited. A liquid crystal polyester having a structural unit of the following formula (2), or a liquid crystal polyester having a structural unit represented by the following formula (2) and a structural unit represented by the following formula (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

[Ar ¹ , Ar ² and Ar ³ each independently represent a divalent aromatic hydrocarbon group (however, at least one of the plurality of Ar ¹ , Ar ² and Ar ³ is a naphthylene group).

The hydrogen atoms in the groups represented by Ar ¹ , Ar ² or Ar ³ are independently substituted or not substituted by halogen atoms, alkyl groups with 1 to 10 carbon atoms or aryl groups with 6 to 20 carbon atoms . ]

The Ar ¹ , Ar ² and Ar ³ may each independently represent a naphthylene group or a phenylene group (however, at least one of the plurality of Ar ¹ , Ar ² and Ar ³ is a naphthylene group).

The liquid crystal polyester has a structural unit represented by the above formula (1), a structural unit represented by the above formula (2), and a structural unit represented by the above (3), and among the plurality of Ar ¹ , Ar ² and Ar ³ When at least one is a naphthylene group, it is preferable that at least one of the plurality of Ar ¹ and/or Ar ² is a naphthylene group.

In the case where the liquid crystal polyester has a structural unit represented by the above formula (2) and a structural unit represented by the above formula (3), and at least one of a plurality of Ar ² and Ar ³ is a naphthylene group, preferably a plurality of At least one of Ar ² is naphthylene.

The naphthylene groups in Ar ¹ , Ar ² and Ar ³ are preferably 2,6-naphthalenediyl or 2,7-naphthalenediyl, more preferably 2,6-naphthalenediyl.

In the liquid crystal polyester, the content of the structural unit containing the naphthalene structure is 100 mol% relative to the total amount of all structural units in the liquid crystal polyester (by dividing the mass of each structural unit constituting the liquid crystal polyester by the formula of each structural unit Quantity, the material equivalent (mole) of each structural unit is obtained, and the value of these totals) is preferably 40 mol% or more, more preferably 50 mol% or more, and even more preferably 60 mol% or more. By making content of the structural unit containing a naphthalene structure more than the said lower limit, the relative dielectric constant of a liquid crystal polyester can be further reduced.

In the liquid crystalline polyester, the content of the structural unit containing a naphthalene structure is preferably 90 mol% or less, more preferably 80 mol% or less, relative to 100 mol% of the total amount of all structural units in the liquid crystalline polyester. By making the content of the structural unit containing a naphthalene structure below the above-mentioned upper limit, the reaction stability at the time of production of the liquid crystalline polyester can be ensured.

As an example of the numerical range of the content of the structural unit containing the naphthalene structure, it may be 40 mol% or more and 90 mol% or less, may be 50 mol% or more and 80 mol% or less, may be 60 mol% or more and 80 mol% or less.

Among the structural units represented by the above formulas (1) to (3), the liquid crystal polyester may be a liquid crystal polyester comprising a structural unit represented by the above formula (2) and a structural unit represented by the above formula (3), and may be It is a liquid crystal polyester having all types of structural units represented by the above formulas (1) to (3).

Among the structural units represented by the above formulas (1) to (3), the liquid crystal polyester can be a liquid crystal polyester composed of a structural unit represented by the above formula (2) and a structural unit represented by the above formula (3), and can be It is a liquid crystal polyester composed of all kinds of structural units represented by the above formulas (1) to (3).

As the liquid crystal polyester having a structural unit represented by the above formulas (1) to (3), for example, a structural unit represented by the following formula (1), a structural unit represented by the following formula (2) and a A liquid crystalline polyester having a structural unit represented by the following formula (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

Ar ¹ , Ar ² and Ar ³ each independently represent a naphthalenediyl group, a phenylene group or a biphenylene group.

The hydrogen atoms in the groups represented by Ar ¹ , Ar ² or Ar ³ are independently substituted or not substituted by halogen atoms, alkyl groups with 1 to 10 carbon atoms or aryl groups with 6 to 20 carbon atoms .

The above-mentioned liquid crystal polyesters include the following liquid crystal polyesters.

A liquid crystal polyester having 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 (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

Ar ¹ represents 2,6-naphthalenediyl, 1,4-phenylene or 4,4'-biphenylene.

Ar ² and Ar ³ independently represent 2,6-naphthalenediyl, 2,7-naphthalenediyl, 1,4-phenylene, 1,3-phenylene or 4,4'-biphenylene .

The hydrogen atoms in the groups represented by Ar ¹ , Ar ² or Ar ³ are independently substituted or not substituted by halogen atoms, alkyl groups with 1 to 10 carbon atoms or aryl groups with 6 to 20 carbon atoms .

As the liquid crystal polyester having a structural unit represented by the above formulas (1) to (3), for example, a structural unit represented by the following formula (1), a structural unit represented by the following formula (2) and a A liquid crystalline polyester having a structural unit represented by the following formula (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

Ar ¹ represents a naphthalene diyl group, Ar ² represents a naphthalene diyl group or a phenylene group, and Ar ³ represents a phenylene group.

The hydrogen atoms in the groups represented by Ar ¹ , Ar ² or Ar ³ are independently substituted or not substituted by halogen atoms, alkyl groups with 1 to 10 carbon atoms or aryl groups with 6 to 20 carbon atoms .

When the liquid crystalline polyester has all kinds of structural units represented by the above formulas (1) to (3), the ratio of the preferable content of each structural unit in the liquid crystalline polyester can be listed as follows.

The ratio of the content of the structural unit (1) in the liquid crystal polyester is preferably 30 mol% or more and 80 mol% or less, more preferably 40 mol% or more and 100 mol% of the total amount of all structural units in the liquid crystalline polyester. 70 mol% or less, more preferably 45 mol% or more and 65 mol% or less.

In addition, the proportion of the content of the structural unit (2) in the liquid crystal polyester is preferably 10 mol% or more and 35 mol% or less, more preferably 15 mol% relative to the total amount of all structural units in the liquid crystalline polyester (100 mol%) It is more than or equal to 30 mol %, More preferably, it is 17.5 mol % or more and 27.5 mol % or less.

In addition, the proportion of the content of the structural unit (3) in the liquid crystal polyester is preferably 10 mol% or more and 35 mol% or less, more preferably 15 mol% with respect to 100 mol% of the total amount of all structural units in the liquid crystalline polyester. It is more than or equal to 30 mol %, More preferably, it is 17.5 mol % or more and 27.5 mol % or less.

In addition, the content of the structural unit (2) and the content of the structural unit (3) in the liquid crystal polyester are preferably equal, and in the case of different contents, the difference between the content of the structural unit (2) and the structural unit (3) is preferably 5 mol% or less.

In an example of a liquid crystal polyester having high heat resistance or high melt tension, Ar ¹ of the structural unit (1) is 2,6-naphthalenediyl (for example, a structural unit derived from 2-hydroxy-6-naphthoic acid) The ratio of the content is preferably not less than 40 mol% and not more than 74.8 mol%, more preferably not less than 40 mol% and not more than 64.5 mol%, with respect to the total amount of all structural units in the liquid crystal polyester, still more preferably not less than 50 mol% and not more than 50 mol%. 58 mol% or less.

In the liquid crystal polyester, Ar ² of the structural unit (2) is the ratio of the content of 2,6-naphthalenediyl (for example, a structural unit derived from 2,6-naphthalene dicarboxylic acid), relative to that in the liquid crystal polyester The total amount of all structural units is preferably 10.0 mol% to 35 mol%, more preferably 12.5 mol% to 30 mol%, and still more preferably 15 mol% to 25 mol%.

In addition, in the liquid crystal polyester, the ratio of ^Ar2 of the structural unit (2) to the content of 1,4-phenylene (for example, a structural unit derived from terephthalic acid) relative to the total structure in the liquid crystal polyester The total amount of units is preferably not less than 0.2 mol% and not more than 15 mol%, more preferably not less than 0.5 mol% and not more than 12 mol%, and still more preferably not less than 2 mol% and not more than 10 mol%.

In the liquid crystal polyester, Ar of the structural unit ( ³ ) is the ratio of the content of 1,4-phenylene (for example, a structural unit derived from hydroquinone), relative to the total structural unit in the liquid crystal polyester The total amount is preferably 12.5 mol % to 30 mol %, more preferably 17.5 mol % to 30 mol %, further preferably 20 mol % to 25 mol %.

In liquid crystal polyester, in structural unit (2), Ar ² is the content of 2,6-naphthalenediyl, relative to Ar ² being 2,6-naphthalenediyl and Ar ² being 1,4-phenylene The total amount of, for example, the content of structural units derived from 2,6-naphthalene dicarboxylic acid, relative to the total amount of structural units derived from 2,6-naphthalene dicarboxylic acid and structural units derived from terephthalic acid , preferably 0.5 mole times or more, more preferably 0.6 mole times or more.

The compounding ratio of each structural unit relative to the total amount of 100 mol% of all structural units in the liquid crystalline polyester may be a compounding ratio relative to the total amount of 100 mol% of all structural units derived from aromatic compounds in the liquid crystalline polyester.

The sum of the contents of the above structural units of the liquid crystalline polyester does not exceed 100 mol%.

The liquid crystalline polyester of the embodiment can be produced, for example, by melt polycondensation of monomers imparting structural units.

In this case, it is preferable to use an ester-forming derivative thereof as each of the above-mentioned monomers in order to rapidly perform melt polycondensation.

Here, as an example of an ester-forming derivative, if it is a compound having a carboxyl group such as an aromatic hydroxycarboxylic acid or an aromatic dicarboxylic acid, a carboxyl group is converted into a haloformyl group, a carboxyl group is converted into an acyloxycarbonyl group, etc. Substances, carboxyl converted to alkoxycarbonyl or aryloxycarbonyl substances.

Moreover, if it is a compound which has a hydroxyl group, such as an aromatic hydroxycarboxylic acid and an aromatic diol, the thing which converted a hydroxyl group into an acyloxy group is mentioned. Among them, it is preferable to use a substance in which a hydroxyl group is converted to an acyloxy group, that is, as an ester-forming derivative of an aromatic hydroxycarboxylic acid, an aromatic acyloxycarboxylic acid whose hydroxyl group is acylated is preferably used. As an ester-forming derivative of alcohol, an aromatic diacyloxy compound whose hydroxyl group has been acylated is preferably used. The acylation is preferably acetylated with acetic anhydride, and the ester-forming derivative produced by this acetylation is capable of deacetic acid polycondensation.

The melt polymerization can be carried out in the presence of a catalyst, and as examples of the catalyst, metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate and antimony trioxide, and As nitrogen-containing heterocyclic compounds such as 4-(dimethylamino)pyridine and 1-methylimidazole, nitrogen-containing heterocyclic compounds are preferably used. In addition, melt polymerization may further perform solid phase polymerization as needed.

The flow start temperature of the liquid crystal polyester in the liquid crystal polyester powder according to the embodiment is preferably 250°C or higher, more preferably 250°C or higher and 350°C or lower, and still more preferably 260°C or higher and 330°C or lower. The higher the flow initiation temperature of the liquid crystal polyester, the easier it is to improve the heat resistance or the strength and rigidity, but when it is too high, the pulverization becomes poor and it becomes difficult to obtain a powder with a target particle size.

The flow initiation temperature is also called viscous flow temperature or flow temperature, and is obtained by melting the liquid crystal polyester while raising the temperature at a rate of 4°C/min under a load of 9.8MPa (100kg/cm ² ) using a capillary rheometer. When extruded from a nozzle with an inner diameter of 1 mm and a length of 10 mm, the temperature at which a viscosity of 4800 Pa s (48000 poise) is exhibited becomes a standard for the molecular weight of liquid crystal polyester (refer to Koide Naoyuki, "Liquid Crystal Polymers-Synthesis· Molding and Application-(Liquid Crystal Polyma - Synthesis, Molding and Application-)", CMC Co., Ltd. (Syemsy Corporation, Inc., June 5, 1987, p.95).

For example, powders of liquid crystal polyesters having a number average molecular weight of 10,000 or less produced by the above-mentioned method for producing liquid crystal polyesters can be pulverized using a jet mill or the like as needed to obtain an average particle diameter of 0.5 to 20 μm. way of liquid crystal polyester powder.

The liquid crystal polyester powder of the embodiment may be a liquid crystal polyester powder containing a liquid crystal polyester having a number average molecular weight of 10000 or less and having an average particle diameter of 0.5 to 20 μm (however, due to the structure derived from 2-hydroxy-6-naphthoic acid unit, a structural unit derived from 2,6-naphthalene dicarboxylic acid, a structural unit derived from terephthalic acid, and a structural unit derived from hydroquinone, and has a volume average particle diameter of 9 μm Except liquid crystal polyester powder).

The liquid crystal polyester powder of the embodiment may be a liquid crystal polyester powder containing a liquid crystal polyester having a number average molecular weight of 10000 or less and having an average particle diameter of 0.5 to 20 μm (however, by making 2-hydroxy-6-naphthoic acid (5.5 mol ), 2,6-naphthalene dicarboxylic acid (1.75 moles), terephthalic acid (0.5 moles), hydroquinone (2.475 moles), acetic anhydride (12 moles) and 1-methylimidazole as a catalyst The polymer obtained by the reaction is composed of liquid crystal polyester, and the liquid crystal polyester powder with a volume average particle diameter of 9 μm is excluded).

The liquid crystal polyester powder of the embodiment may be a liquid crystal polyester powder containing a liquid crystal polyester having a number average molecular weight of 10000 or less and having an average particle diameter of 0.5 to 20 μm (however, the structure derived from 2-hydroxy-6-naphthoic acid unit, a structural unit derived from 2,6-naphthalene dicarboxylic acid, a structural unit derived from terephthalic acid, and a structural unit derived from hydroquinone, obtained by pulverizing a liquid crystal polyester having a flow initiation temperature of 265°C Except liquid crystal polyester powder with a volume average particle diameter of 9 μm).

The liquid crystal polyester powder of the embodiment may be a liquid crystal polyester powder containing a liquid crystal polyester having a number average molecular weight of 10,000 or less and having an average particle diameter of 0.5 to 20 μm (however, containing a structure derived from 2-hydroxy-6-naphthoic acid). Units, structural units derived from 2,6-naphthalene dicarboxylic acid, structural units derived from terephthalic acid, and structural units derived from hydroquinone, except liquid crystal polyester powders with a volume average particle diameter of 9 μm) .

The liquid crystal polyester powder of the embodiment may be a liquid crystal polyester powder containing a liquid crystal polyester having a number average molecular weight of 10000 or less and having an average particle diameter of 0.5 to 20 μm (however, 2-hydroxy-6-naphthoic acid (5.5 moles) , 2,6-naphthalene dicarboxylic acid (1.75 moles), terephthalic acid (0.5 moles), hydroquinone (2.475 moles), acetic anhydride (12 moles) and 1-methylimidazole as a catalyst The obtained polymer and liquid crystal polyester powder having a volume average particle diameter of 9 μm are excluded).

The liquid crystal polyester powder of the embodiment may be a liquid crystal polyester powder containing a liquid crystal polyester having a number average molecular weight of 10,000 or less and having an average particle diameter of 0.5 to 20 μm (however, it will contain a liquid crystal polyester derived from 2-hydroxy-6-naphthoic acid). Structural unit, a structural unit derived from 2,6-naphthalene dicarboxylic acid, a structural unit derived from terephthalic acid, and a structural unit derived from hydroquinone, obtained by pulverizing a liquid crystal polyester having a flow initiation temperature of 265°C Except liquid crystal polyester powder with a volume average particle diameter of 9 μm).

The liquid crystal polyester powder of the embodiment may be a liquid crystal polyester powder containing a liquid crystal polyester having a number average molecular weight of 10000 or less and having an average particle diameter of 0.5 to 20 μm (however, 2-hydroxy-6-naphthoic acid (5.5 mol ), 2,6-naphthalene dicarboxylic acid (1.75 moles), terephthalic acid (0.5 moles), hydroquinone (2.475 moles), acetic anhydride (12 moles) and 1-methylimidazole as a catalyst Except liquid crystal polyester powder obtained by pulverizing a polymer obtained by the reaction with a flow start temperature of 265° C. and having a volume average particle diameter of 9 μm).

It should be noted that the "volume average particle diameter" here refers to the particle size distribution measurement device (for example, Horiba Co., Ltd. HORIBA Co., Ltd.) under the condition that the refractive index of pure water is 1.333. "LA-950V2") is a value measured for a liquid crystal polyester powder dispersion obtained by ultrasonically dispersing 0.01 g of liquid crystal polyester powder in about 10 g of pure water for 5 minutes. "Volume average particle size" refers to the particle size value at the point where the cumulative volume is 50% when the whole is 100% in the volume-based cumulative particle size distribution curve measured by a scattering type particle size distribution measuring device (50% cumulative Volume particle size D ₅₀ ).

In addition, although acetic acid derived from acetic anhydride, which is a raw material of liquid crystal polyester, may remain in the liquid crystal polyester powder of the embodiment, the upper limit of the amount of residual acetic acid that can be contained in 100% by mass of the liquid crystal polyester powder of the embodiment is , from the viewpoint of mechanical properties after processing into a film, it is preferably 1% by mass or less, more preferably 500 mass ppm or less, and even more preferably 300 mass ppm or less. In addition, the lower limit of the amount of residual acetic acid contained in 100% by mass of the liquid crystal polyester powder according to the embodiment is preferably 30 mass ppm or more, more preferably 50 mass ppm or more, and still more preferably 100 mass ppm from the viewpoint of pulverization. above ppm.

The upper limit and lower limit of the residual acetic acid amount that can be contained in 100% by mass of the liquid crystal polyester powder can be freely combined. As an example of the numerical range of the value of the amount of residual acetic acid that can be contained in 100% by mass of the above-mentioned liquid crystal polyester powder, it can be 30 mass ppm or more and 1 mass % or less, can be 50 mass ppm or more and 500 mass ppm or less, can be It is 100 mass ppm or more and 300 mass ppm or less.

According to the liquid crystal polyester powder of the embodiment, a liquid crystal polyester film having good quality as a film for electronic components can be produced. The isotropy, thickness, and appearance of the film (whether holes or through-holes are generated) can be mentioned as the quality standard.

When the number average molecular weight of the liquid crystal polyester in the liquid crystal polyester powder of the embodiment is a relatively small value of 10,000 or less, the liquid crystal polyester composition becomes suitable for coating, and the liquid crystal polyester film during heat treatment The melted state of the film becomes good, and film processing capable of producing a liquid crystal polyester film with excellent isotropy becomes possible. In addition, since the average particle diameter of the liquid crystal polyester powder according to the embodiment is 0.5 to 20 μm, it has an appropriate thickness for use as a film for electronic components, and a high-quality polyester film with suppressed generation of holes or through holes can be obtained.

According to the liquid crystal polyester powder of the embodiment, a liquid crystal polyester film excellent in isotropy can be produced.

Conventionally, liquid crystal polyester films are generally produced by a melt molding method or a casting method in which liquid crystal polyester is melted.

The melt molding method is a method of molding a film by extruding a kneaded product from an extruder. However, in the film produced by the melt molding method, the liquid crystal polyester molecules are more aligned along the direction of the extrusion direction (the direction perpendicular to the extrusion direction and the thickness direction of the film, Transverse Direction (TD)) than in the transverse direction with respect to the extrusion direction. The film direction (also called the extrusion direction, Machine Direction (MD)) is oriented, so it is difficult to obtain a liquid crystal polyester with excellent isotropy.

On the other hand, according to the liquid crystal polyester powder of the embodiment, a liquid crystal polyester film excellent in isotropy can be produced. The liquid crystal polyester powder of the embodiment is suitable as a raw material for the method for producing a liquid crystal polyester film of the embodiment, and by applying this method, it is possible to easily produce a liquid crystal having excellent isotropy without the above-mentioned extrusion molding operation. polyester film.

Here, "excellent isotropy" of the liquid crystal polyester film means that the value of the molecular orientation (MOR) of the liquid crystal polyester film is within the range of 1 to 1.1.

According to the liquid crystal polyester powder of the embodiment, a liquid crystal polyester film having both dielectric properties and isotropy can be produced.

The orientation of the liquid crystal polyester of the liquid crystal polyester film produced by the solution casting method is more isotropic than that of the liquid crystal polyester film formed by the melt molding method. However, to apply the solution casting method, there is a limitation that a liquid crystal polyester having a property of being soluble in a solvent must be used. In a liquid crystal polyester whose solubility in a solvent is improved, for example, by increasing the polarity or the like, the dielectric properties may be lowered.

As described above, it is difficult to make the dielectric properties and isotropy of a liquid crystal polyester film at a high level at the same time.

On the other hand, according to the liquid crystal polyester powder of the embodiment, a liquid crystal polyester film having both dielectric properties and isotropy can be produced. The liquid crystal polyester powder of the embodiment is suitable as a raw material for the method for producing a liquid crystal polyester film of the embodiment, and by applying this method, it is possible to easily produce a liquid crystal polyester film having excellent isotropy without dissolving the liquid crystal polyester powder in a solvent. liquid crystal polyester film. In addition, since a liquid crystal polyester excellent in dielectric properties can be used as a raw material, a liquid crystal polyester film excellent in dielectric properties and isotropy can be easily produced.

"Liquid Crystal Polyester Composition"

The liquid crystal polyester composition of the embodiment contains a medium and the liquid crystal polyester powder of the embodiment. The liquid crystal polyester composition is suitable for the production of the liquid crystal polyester film described later.

The liquid crystal polyester composition of the embodiment preferably contains an aprotic solvent and a liquid crystal polyester powder insoluble in the aprotic solvent.

As for the liquid crystal polyester powder, the examples described in the above-mentioned "Liquid Crystal Polyester Powder" can be mentioned, so the description is omitted.

The medium is not particularly limited as long as it does not dissolve the liquid crystal polyester powder, but is preferably a dispersion medium. In addition, the medium is preferably a fluid, more preferably a liquid.

The "dispersion" here is a term for distinguishing from the state in which the liquid crystal polyester powder is dissolved (excluding the state in which the liquid crystal polyester powder is dissolved in the liquid crystal polyester composition). The distribution of the liquid crystal polyester powder in the composition may have uneven parts. The state of the liquid crystal polyester powder in the composition may be any state as long as the liquid crystal polyester composition can be coated on a support in the method for producing a liquid crystal polyester film described later.

Examples of the medium include dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, 1-chlorobutane , chlorobenzene, o-dichlorobenzene and other halogenated hydrocarbons; p-chlorophenol, pentachlorophenol, pentafluorophenol and other halogenated phenols; diethyl ether, tetrahydrofuran, 1,4-dioxane and other ethers; acetone, cyclohexanone, etc. Ketones; 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; Urea compounds such as tetramethylurea; Nitro compounds such as nitromethane and nitrobenzene; Sulfur compounds such as methyl sulfoxide and sulfolane; and phosphorus compounds such as hexamethylphosphoric acid amide and tri-n-butyl phosphoric acid, two or more of them can be used.

As the medium, from the perspective of low corrosion and easy handling, it is preferred to use aprotic compounds, especially aprotic compounds without halogen atoms as the main component, and the proportion of aprotic compounds to the entire medium is preferably 50 to 100. % by mass, more preferably 70 to 100% by mass, still more preferably 90 to 100% by mass. In addition, as the aprotic compound, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, tetramethylurea, and N-methylpyrrolidone, or γ-butyrolactone are preferably used. isoester, more preferably N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.

In addition, the medium is preferably a medium mainly composed of a compound having a boiling point of 220° C. or lower at 1 atmosphere, and the ratio of the compound having a boiling point of 220° C. or lower at 1 atmosphere to the entire medium is preferably 50 to 100. % by mass, more preferably 70 to 100% by mass, still more preferably 90 to 100% by mass. As the aprotic compound, a compound having a boiling point of 220° C. or lower at 1 atmosphere is preferably used.

With respect to the total amount of solids contained in the liquid crystal polyester composition, the ratio of the liquid crystal polyester powder may be, for example, 50 to 100 mass%, 70 to 100 mass%, or 90 to 100 mass%. .

The proportion of the liquid crystal polyester powder contained in the liquid crystal polyester composition is preferably 0.1 to 60% by mass, more preferably 1 to 50% by mass, and even more preferably 3 to 40% by mass relative to the total amount of the liquid crystal polyester powder and the medium. Mass % is especially preferably 5-30 mass %.

The liquid crystal polyester composition can be obtained by mixing the medium, liquid crystal polyester powder, and other components used as necessary, all together or in an appropriate order.

The liquid crystal polyester composition may contain one or more of other components such as fillers, additives, and resins other than the liquid crystal polyester.

Examples of fillers include inorganic fillers such as silica, alumina, titanium oxide, barium titanate, strontium titanate, aluminum hydroxide, and calcium carbonate; and cured epoxy resins, cross-linked benzoguanamine resins, cross-linked The content of organic fillers such as biacrylate resins may be 0, preferably 100 parts by mass or less, based on 100 parts by mass of liquid crystal polyester.

Examples of additives include leveling agents, antifoaming agents, antioxidants, ultraviolet absorbers, flame retardants, and colorants, and their content can be 0, preferably 5 parts by mass relative to 100 parts by mass of liquid crystal polyester the following.

Examples of resins other than liquid crystal polyesters include polypropylene, polyamide, polyesters other than liquid crystal polyesters, polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether, and Its modified products, thermoplastic resins other than liquid crystal polyester such as polyetherimide; elastomers such as copolymers of glycidyl methacrylate and polyethylene; and phenolic resins, epoxy resins, polyimide resins, The content of thermosetting resins such as cyanate resins may be 0, preferably 20 parts by mass or less, based on 100 parts by mass of liquid crystal polyester.

In the liquid crystal polyester composition of the embodiment, the liquid crystal polyester of the above embodiment may be contained in an amount of more than 70% by mass and not more than 100% by mass relative to the total of 100% by mass of the liquid crystal polyester contained, and may contain 80 to 100% by mass The liquid crystal polyester of the above-mentioned embodiment. As the liquid crystal polyester, the liquid crystal polyester listed in the liquid crystal polyester powder of the embodiment may be mentioned, and among the liquid crystal polyester described in the paragraph of the above embodiment (liquid crystal polyester), it may be a liquid crystal polyester not corresponding to the following (X ) component of the liquid crystal polyester, for example, the liquid crystal polyester of the above-mentioned 1) to 4), has the structural unit represented by the above formula (1), the structural unit represented by the above formula (2) and the structure unit represented by the above formula (3) A liquid crystal polyester having a structural unit of the above formula (2), or a liquid crystal polyester having a structural unit represented by the above formula (2) and a structural unit represented by the above formula (3).

The liquid crystal polyester composition of the embodiment may be a liquid crystal polyester composition containing a medium and a liquid crystal polyester powder (however, the content of the liquid crystal polyester soluble in an aprotic solvent is less than 5% by mass).

The liquid crystal polyester composition of the embodiment may be a liquid crystal polyester composition containing a medium and a liquid crystal polyester powder (however, when the liquid crystal polyester powder is contained as a resin powder, the liquid crystal polyester except for esters).

As the liquid crystal polyester soluble in an aprotic solvent, there may be a liquid crystal polyester containing a structural unit derived from 4-hydroxyacetanilide.

As a liquid crystal polyester soluble in an aprotic solvent, a structural unit derived from 6-hydroxy-2-naphthoic acid, a structural unit derived from 4-hydroxyacetanilide, and a structural unit derived from isophthalic acid can be used. Composed of liquid crystal polyester.

As a liquid crystal polyester soluble in an aprotic solvent, 6-hydroxy-2-naphthoic acid (5.0 moles), 4-hydroxyacetanilide (2.5 moles), isophthalic acid (2.5 moles) and acetic anhydride (8.4 moles) The polymer obtained by reacting the mixture is a liquid crystal polyester.

Hereinafter, liquid crystal polyesters soluble in aprotic solvents will be described.

"(X) Ingredient"

The component (X) is a liquid crystalline polyester soluble in an aprotic solvent. Here, "soluble in an aprotic solvent" can be confirmed by performing the following test.

experiment method

The liquid crystalline polyester is stirred in an aprotic solvent at a temperature of 120° C. to 180° C. for 1 hour to 6 hours, and then cooled to room temperature (23° C.). Next, after filtration using a 5 μm membrane filter and a pressure filter, residues on the membrane filter were confirmed. At this time, when the presence of a solid substance was not confirmed, it was judged to be soluble in an aprotic solvent.

More specifically, 1 part by mass of liquid crystalline polyester was stirred in 99 parts by mass of an aprotic solvent at 140°C for 4 hours, and then cooled to 23°C. Next, after filtration using a 5 μm membrane filter and a pressure filter, residues on the membrane filter were confirmed. At this time, when the presence of a solid substance was not confirmed, it was judged to be soluble in an aprotic solvent.

The liquid crystalline polyester (X) preferably contains, as a structural unit, structural units represented by the following formulas (X1), (X2) and (X3).

As one aspect, with respect to the total content of all structural units constituting the component (X), the content of the structural unit represented by the formula (X1) is 30 to 80 mol%, and the content of the structural unit represented by the formula (X2) is 35% by mole. ~10 mol%, and the content of the structural unit represented by the formula (X3) is 35~10 mol%.

However, the total content of the structural unit represented by formula (X1), the structural unit represented by formula (X2) and the structural unit represented by formula (X3) does not exceed 100 mol%.

(X1)-O-Ar1-CO-

(X2)-CO-Ar2-CO-

(X3)-X-Ar3-Y-

(In X1～X3, Ar1 represents 1,4-phenylene, 2,6-naphthalenediyl or 4,4'-biphenylene. Ar2 represents 1,4-phenylene, 1,3-phenylene Phenyl or 2,6-naphthalenediyl. Ar3 represents 1,4-phenylene or 1,3-phenylene. X represents -NH-, Y represents -O- or NH-.)

The structural unit (X1) is a structural unit derived from an aromatic hydroxycarboxylic acid, the structural unit (X2) is a structural unit derived from an aromatic dicarboxylic acid, and the structural unit (X3) is derived from an aromatic diamine or has a phenolic hydroxyl group structural units of aromatic amines. (X) As a component, ester or amide-forming derivatives of the above structural units may be used instead of the above structural units.

In this embodiment, it is preferred that the Ar1 is 2,6-naphthalenediyl, the Ar2 is 1,3-phenylene, the Ar3 is 1,4-phenylene, and the Y is -O- .

As ester-forming derivatives of carboxylic acids, for example, substances in which the carboxyl group is changed to highly reactive derivatives such as acid chlorides and acid anhydrides that accelerate the reaction to form polyesters, and carboxyl groups formed with alcohols or ethylene glycol, etc. Esters are substances that produce polyesters through transesterification reactions, etc.

Examples of the ester-forming derivatives of phenolic hydroxyl groups include esters of phenolic hydroxyl groups and carboxylic acids, and the like.

Examples of amide-forming derivatives of amino groups include those in which amino groups form amides with carboxylic acids, and the like.

Although the following are mentioned as a repeating structural unit of (X)component used in this embodiment, it is not limited to these.

As the structural unit represented by the formula (X1), for example, a structural unit derived from p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid or 4'-hydroxy-4-biphenylcarboxylic acid, etc., two kinds The above-mentioned structural units may be included in all structural units. Among these structural units, it is preferable to use the component (X) containing a structural unit derived from 6-hydroxy-2-naphthoic acid.

The content of the structural unit (X1) is 30 mol% or more and 80 mol% or less, preferably 40 mol% or more and 70 mol% or less, more preferably 45 mol% with respect to the content of all structural units constituting the component (X) % or more and 65 mol% or less.

When there are many structural units (X1), there exists a tendency for the solubility to a solvent to fall remarkably, and when there are too few, there exists a tendency for liquid crystallinity not to be shown. That is, when the content of the structural unit (X1) is within the above range, the solubility in a solvent is favorable and liquid crystallinity is easily exhibited.

As the structural unit represented by the formula (X2), for example, a structural unit derived from terephthalic acid, isophthalic acid, or 2,6-naphthalene dicarboxylic acid, etc., two or more of the structural units, Can be included in all structural units. Among these structural units, it is preferable to use a liquid crystalline polyester including a structural unit derived from isophthalic acid from the viewpoint of solubility in a solvent.

The content of the structural unit (X2) is preferably 10 mol% or more and 35 mol% or less, more preferably 15 mol% or more and 30 mol% or less, and especially preferably 17.5 mol% or more and 27.5 mol% or less. When there are too many structural units (X2), there exists a tendency for liquid crystallinity to fall, and when there are few, there exists a tendency for the solubility to a solvent to fall. That is, when the content of the structural unit (X2) is within the above range, the liquid crystallinity becomes favorable, and the solubility in a solvent also becomes favorable.

As the structural unit represented by the formula (X3), for example, a structural unit derived from 3-aminophenol, 4-aminophenol, 1,4-phenylenediamine or 1,3-phenylenediamine, etc., two kinds The above-mentioned structural units may be included in all structural units.

Among these structural units, it is preferable to use a liquid crystalline polyester comprising a structural unit derived from 4-aminophenol from the viewpoint of reactivity.

The content of the structural unit (X3) is preferably 10 mol% to 35 mol% with respect to the content of all structural units constituting the component (X), more preferably 15 mol% to 30 mol%, especially preferably 17.5 mol% or more and 27.5 mol% or less. When there are too many structural units (3), there exists a tendency for liquid crystallinity to fall, and when there are few, it exists in the tendency for the solubility to a solvent to fall. That is, when the content of the structural unit (X3) is within the above range, the liquid crystallinity becomes favorable, and the solubility in a solvent also becomes favorable.

The structural unit (X3) is preferably used in an amount substantially equal to that of the structural unit (X2), and by making the content of the structural unit (X3) -10 to +10 mol% relative to the content of the structural unit (X2), it is also possible to The degree of polymerization of liquid crystalline polyester is controlled.

The method for producing component (X) of the present embodiment is not particularly limited, for example, a method in which an acylate and an aromatic dicarboxylic acid are subjected to ester/amide exchange (polycondensation) to melt polymerize, etc., wherein the acylate The compound is an aromatic hydroxy acid corresponding to the structural unit (X1), an aromatic amine having a phenolic hydroxyl group corresponding to the structural unit (X3), or a phenolic hydroxyl group or amino group of an aromatic diamine, and is formed due to excess fatty acid anhydride An acylate obtained by acylation; the aromatic dicarboxylic acid is an aromatic dicarboxylic acid corresponding to the structural unit (X2) (see JP-A-2002-220444 and JP-A-2002-146003).

In the acylation reaction, the amount of fatty acid anhydride added is preferably 1.0 to 1.2 equivalents, more preferably 1.05 to 1.1 equivalents, based on the total amount of phenolic hydroxyl groups and amino groups. When the amount of fatty acid anhydride added is too small, during transesterification/amidation (polycondensation), there is a tendency for the acylate or raw material monomers to sublimate, and the reaction system tends to be easily clogged. The coloring tends to be noticeable. That is, when the addition amount of the fatty acid anhydride is within the above range, the reaction of the acylate or the raw material monomer during transesterification/amidation (polycondensation) is good, and the obtained liquid crystalline polyester will not be excessively colored.

The acylation reaction is preferably carried out at 130-180°C for 5 minutes to 10 hours, more preferably at 140-160°C for 10 minutes-3 hours.

The fatty acid anhydride used in the acylation reaction is not particularly limited, for example, acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, 2-ethylhexanoic anhydride, monochloroacetic anhydride, Acid anhydride, dichloroacetic anhydride, trichloroacetic anhydride, monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, glutaric anhydride, maleic anhydride, Succinic anhydride, β-bromopropionic anhydride, etc., and two or more of these may be used in combination. In this embodiment, it is preferably acetic anhydride, propionic anhydride, butyric anhydride, or isobutyric anhydride, more preferably acetic anhydride.

In transesterification/amidation (polycondensation), the acyl group of the acylate is preferably 0.8 to 1.2 times the equivalent of the carboxyl group.

Transesterification/amidation (polycondensation) is preferably performed while raising the temperature to 400°C at a rate of 0.1 to 50°C/min, more preferably while raising the temperature to 350°C at a rate of 0.3 to 5°C/min.

When the acylate and carboxylic acid are transesterified/amidated (polycondensation), by-product fatty acid and unreacted fatty acid anhydride are preferably distilled out of the system by evaporation or the like.

In addition, acylation reaction and transesterification/amidation exchange (polycondensation) can be performed in presence of a catalyst. As the catalyst, catalysts conventionally known as polyester polymerization catalysts can be used, for example, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, antimony trioxide Metal salt catalysts such as N,N-dimethylaminopyridine, N-methylimidazole and other organic compound catalysts.

Among these catalysts, heterocyclic compounds containing at least two nitrogen atoms, such as N,N-dimethylaminopyridine and N-methylimidazole, are preferably used (see JP-A-2002-146003).

The catalyst is usually charged when the monomers are charged, and it is not necessarily necessary to remove it after acylation, and the transesterification can be directly performed without removing the catalyst.

Polycondensation by transesterification/amidation is usually carried out by melt polymerization, but melt polymerization and solid phase polymerization may be used in combination. Solid-phase polymerization is preferably carried out by a known solid-phase polymerization method after extracting the polymer in a melt polymerization step and pulverizing it into powder or flakes. Specifically, for example, a method of heat-treating in a solid phase state for 1 to 30 hours at 20 to 350° C. in an inert atmosphere such as nitrogen, and the like are exemplified. The solid-phase polymerization may be performed while stirring, or may be performed in a state of standing without stirring. In addition, by providing an appropriate stirring mechanism, the melt polymerization tank and the solid phase polymerization tank can also be made into the same reaction tank. After the solid-state polymerization, the obtained liquid crystalline polyester can be pelletized and shaped by a known method. In addition, pulverization can also be performed by a known method.

Production of liquid crystalline polyester can be performed using, for example, a batch device, a continuous device, or the like.

When the liquid crystalline polyester (X) is powdery, the volume average particle diameter is preferably 100 to 2000 μm. The volume average particle diameter of the powdery liquid crystalline polyester (X) can be measured by a dry sieving method (for example, RPS-105 manufactured by Seishin Co., Ltd.).

As one aspect, it is preferable that content of (X)component is 5-10 mass % with respect to the gross mass of a liquid crystalline polyester liquid composition.

[Example of Production of Liquid Crystalline Polyester (X)]

Add 940.9 g (5.0 moles) of 6-hydroxy-2-naphthoic acid and 377.9 g (2.5 moles) of 4-hydroxyacetanilide to a reactor equipped with a stirring device, a torque measuring instrument, a nitrogen inlet pipe, a thermometer and a reflux cooler , 415.3g (2.5 moles) of isophthalic acid and 867.8g (8.4 moles) of acetic anhydride, after replacing the gas in the reactor with nitrogen, under nitrogen flow, while stirring, it takes 60 The temperature was raised to 140°C in minutes, and refluxed at 140°C for 3 hours. Next, while distilling off by-produced acetic acid and unreacted acetic anhydride, the temperature was raised from 150°C to 300°C over 5 hours, and kept at 300°C for 30 minutes, then the contents were taken out from the reactor and cooled to room temperature (23°C ). The obtained solid matter is pulverized using a pulverizer to obtain a powdery liquid crystalline polyester (X-1). The flow initiation temperature of the liquid crystalline polyester (X-1) may be 193.3°C.

The liquid crystalline polyester (X-1) is heated from room temperature (23°C) to 160°C over 2 hours and 20 minutes under a nitrogen atmosphere, then from 160°C to 180°C over 3 hours and 20 minutes, and heated at 180°C. After holding at °C for 5 hours to carry out solid-state polymerization, it was cooled to 23 °C and then pulverized with a pulverizer to obtain a powdery liquid crystalline polyester (X-2). The flow initiation temperature of the liquid crystalline polyester (X-2) may be 220°C.

By raising the temperature of the liquid crystalline polyester (X-2) from room temperature to 180°C over 1 hour and 25 minutes under a nitrogen atmosphere, and then raising the temperature from 180°C to 255°C over 6 hours and 40 minutes, and maintaining at 255°C for 5 hours , to perform solid phase polymerization, and then cooled to 23° C. to obtain a powdery liquid crystalline polyester (X) with a volume average particle diameter of 871 μm. The volume average particle diameter of the liquid crystalline polyester (X) was measured with RPS-105 manufactured by Shinsei Corporation. The flow initiation temperature of the liquid crystalline polyester (X) may be 302°C.

[Preparation of liquid crystalline polyester solution (X')]

Liquid crystalline polyester can be prepared by adding 8 parts by mass of liquid crystalline polyester (X) to 92 parts by mass of N-methylpyrrolidone (boiling point (1 atmosphere) 204°C) and stirring at 140°C for 4 hours under a nitrogen atmosphere. Solution (X'). The viscosity of the liquid crystalline polyester solution (X') may be 955 mPa·s.

"Manufacturing method of liquid crystal polyester film"

The method for producing a liquid crystal polyester film according to the embodiment includes the steps of applying the liquid crystal polyester composition according to the embodiment on a support, followed by heat treatment, to obtain a liquid crystal polyester film containing liquid crystal polyester.

This manufacturing method may include the following steps.

A step of applying the liquid crystal polyester composition of the embodiment on a support to form a precursor of a liquid crystal polyester film on the support (coating step).

A step of heat-treating the precursor of the liquid crystal polyester film to obtain a liquid crystal polyester film (heat treatment step).

In the method for producing a liquid crystal polyester film, in the coating step, after coating the liquid crystal polyester composition of the embodiment on the support, a step of removing the medium from the coated liquid crystal polyester composition (drying) may be included. process).

That is, the manufacturing method of the liquid crystal polyester film of the embodiment may include coating the liquid crystal polyester composition of the embodiment on the support, removing the medium from the coated liquid crystal polyester composition, and performing heat treatment, thereby obtaining the liquid crystal polyester film containing Process of liquid crystal polyester film of liquid crystal polyester.

Moreover, in the manufacturing method of a liquid crystal polyester film, the process (separation process) of separating a support body from the said laminated body may be included further. In addition, since the liquid crystal polyester film can be suitably used as a film for electronic components even if it is formed as a laminated body on a support body, a separation process is not an essential process in the manufacturing process of a liquid crystal polyester film.

Hereinafter, an example of the manufacturing method of the liquid crystal polyester film which concerns on embodiment is demonstrated, referring drawings.

FIG. 1 is a schematic diagram showing an example of a production process of a liquid crystal polyester film and a laminate according to an embodiment.

First, the liquid crystal polyester composition 30 is coated on the support 12 (FIG. 1(a) coating step). The liquid crystal polyester composition 30 includes a liquid crystal polyester powder 1 and a medium 3 . The coating of the liquid crystal polyester liquid composition on the support can be carried out by methods such as roll coating, dip coating, spray coating, spin coating, curtain coating, slot coating and screen printing, and can be suitably selected. A method that enables smooth and uniform coating on the surface of the support. In addition, in order to make the distribution of the liquid crystal polyester powder uniform, an operation of stirring the liquid crystal polyester composition may be performed before coating.

As the support body 12, it is preferable that it is a plate shape, a sheet shape, or a film shape, for example, a glass plate, a resin film, or a metal foil is mentioned. Among them, a resin film or a metal foil is preferable, and copper foil is particularly preferable because it has excellent heat resistance, is easy to apply a liquid composition, and is easy to remove from a liquid crystal polyester film.

Examples of commercially available polyimide (PI) films include "U-PILEX S" and "U-PILEX R" from Ube Industries, Ltd., and "Kapton" from Toray DuPont Co., Ltd. , and "IF30", "IF70" and "LV300" of SKC Kolon Polyimide Company (SKC KOLON PI). The thickness of the resin film is preferably not less than 25 μm and not more than 75 μm, more preferably not less than 50 μm and not more than 75 μm. The thickness of the metal foil is preferably from 3 μm to 75 μm, more preferably from 5 μm to 30 μm, still more preferably from 10 μm to 25 μm.

Next, the medium 3 is removed from the liquid crystal polyester composition 30 coated on the support 12 ( FIG. 1( b ) drying step). The liquid crystal polyester composition from which the medium 3 has been removed becomes the liquid crystal polyester film precursor 40 to be heat-treated. It should be noted that the medium 3 does not need to be completely removed from the liquid crystal polyester composition, and a part of the medium contained in the liquid crystal polyester composition may be removed, or all of the medium may be removed. The proportion of the solvent contained in the liquid crystal polyester film precursor 40 is preferably 50% by mass or less, more preferably 3% by mass or more and 12% by mass or less, and still more preferably 5% by mass, relative to the total mass of the liquid crystal polyester film precursor. Mass % or more and 10 mass % or less. By making the solvent content in the liquid crystal polyester film precursor more than the said lower limit, the risk that the thermal conductivity of a liquid crystal polyester film will fall can be reduced. Moreover, by making the solvent content in a liquid crystal polyester film precursor below the said upper limit, the risk of the appearance deterioration of a liquid crystal polyester film by foaming etc. at the time of heat processing is reduced.

The removal of the medium is preferably carried out by evaporating the medium, and examples of this method include heating, decompression, and ventilation, and these may be combined. In addition, the removal of the media may be performed continuously or individually. From the standpoint of productivity and operability, the removal of the medium is preferably performed continuously under heating, and more preferably performed continuously under heating while ventilating. The temperature for removing the medium is preferably lower than the melting point of the liquid crystal polyester powder, for example, 40°C to 200°C, preferably 60°C to 200°C. The time to remove the medium is appropriately adjusted so that the content of the medium in the liquid crystal polyester film precursor is 3 to 12% by mass, for example. The time for removing the medium is, for example, not less than 0.2 hours and not more than 12 hours, preferably not less than 0.5 hours and not more than 8 hours.

To the laminated body precursor 22 that has support body 12 and liquid crystal polyester film precursor 40 obtained in this way, heat treatment is carried out, obtain has support body 12 and liquid crystal polyester film 10 (liquid crystal polyester film precursor 40 forms through heat treatment) film) laminated body 20 (FIG. 1(c) heat treatment step). At this time, the liquid crystal polyester film 10 formed on the support was obtained.

The heat treatment conditions include, for example, raising the temperature from the boiling point of the medium to -50°C to the heat treatment temperature, and then performing heat treatment at a temperature equal to or higher than the melting point of the liquid crystalline polyester.

During this temperature rise, there are cases where the polymerization reaction of the liquid crystal polyester proceeds by heating, but by accelerating the temperature rise rate until reaching the heat treatment temperature, the increase in the molecular weight of the liquid crystal polyester in the liquid crystal polyester powder can be suppressed to a certain extent, and the liquid crystal polyester Melting of the powder becomes good, and a high-quality film can be easily obtained. The rate of temperature rise from the solvent boiling point -50°C to the heat treatment temperature is preferably 3°C/min or higher, more preferably 5°C/min or higher.

The heat treatment temperature is preferably equal to or higher than the melting point of the liquid crystal polyester, more preferably higher than the melting point of the liquid crystal polyester, and even more preferably the melting point of the liquid crystal polyester + 5° C. or higher as the heat treatment temperature. The heat treatment temperature can be appropriately determined according to the type of liquid crystal polyester, and as an example, it is preferably 230°C to 400°C, more preferably 300°C to 380°C, and still more preferably 320°C to 350°C. By performing heat treatment at a temperature higher than the melting point of the liquid crystal polyester, the liquid crystal polyester powder can be melted favorably, and a high-quality liquid crystal polyester film can be formed. It can be confirmed that the liquid crystal polyester powder can be melted by making the liquid crystal polyester film precursor 40 transparent.

In addition, the medium boiling point mentioned here means the boiling point under the pressure at the time of temperature rise. In addition, when heating the laminate precursor 22 from below the boiling point of the medium - 50°C, the temperature increase rate may be determined within the range from reaching the boiling point of the medium - 50°C to the heat treatment temperature. The time to reach the boiling point of the medium -50° C. is arbitrary. In addition, the time after reaching the heat treatment temperature was regarded as the heat treatment time. The heat treatment time may be, for example, not less than 0.5 hours, not less than 1 hour and not more than 24 hours, or not less than 3 hours and not more than 12 hours.

Like the removal of the medium, the heat treatment can be carried out continuously or individually, but from the viewpoint of productivity or operability, it is preferably carried out continuously, and it is more preferable to carry out continuously after removing the medium. .

Next, the liquid crystal polyester film 10 can be obtained as a monolayer film by separating the liquid crystal polyester film 10 from the laminated body 20 having the support body 12 and the liquid crystal polyester film 10 ( FIG. 1( d ) separation step). What is necessary is just to separate the liquid crystal polyester film 10 from the laminated body 20 by peeling the liquid crystal polyester film 10 from the laminated body 20, when using a glass plate as the support body 12. When using a resin film as the support body 12, what is necessary is just to carry out by peeling the resin film or the liquid crystal polyester film 10 from the laminated body 20. When using a metal foil as the support body 12, what is necessary is just to etch and remove a metal foil, and to isolate|separate from the laminated body 20. When a resin film, especially a polyimide film is used as a support, the polyimide film or liquid crystal polyester film can be easily peeled off from the laminate 20, and a liquid crystal polyester film with good appearance can be obtained. When a metal foil is used as the support, the laminate 20 can be used as a metal-clad laminate for a printed wiring board without separating the liquid crystal polyester film from the laminate 20 .

According to the manufacturing method of the liquid crystal polyester film of embodiment, the liquid crystal polyester film excellent in isotropy can be manufactured.

In the conventional melt molding method, a thin film of liquid crystalline polyester is produced by making the melted liquid crystalline polyester into a film shape. In contrast, in the above-mentioned production method of the embodiment, the liquid crystalline polyester is thinly arranged in advance on the support. After the liquid crystal polyester powder is melted, it is very different from the existing film production method.

In the method for producing a liquid crystal polyester film or a laminate according to the embodiment, since the liquid crystal polyester powder is thinly placed on the support beforehand to form a film, extrusion molding or the like is not performed to cause molecular orientation deviation. The physical force of the important factor can produce a liquid crystal polyester film with excellent isotropy.

In addition, by setting the number-average molecular weight of the liquid crystal polyester in the liquid crystal polyester powder to a relatively small value of 10,000 or less, it is possible to produce a liquid crystal polyester composition having properties suitable for coating. The molten state of the film becomes good, and it is suitable as a high-quality liquid crystal polyester film excellent in isotropy for electronic component film applications.

In addition, by using liquid crystal polyester powder with an average particle diameter of 0.5 to 20 μm as a raw material, it is possible to easily produce a high-quality polyester film that has an appropriate thickness for use as a film for electronic components and suppresses the occurrence of holes or through-holes .

Moreover, in the liquid crystal polyester composition, since there is no limitation that the liquid crystal polyester powder should be soluble in the medium, it is possible to use a liquid crystal polyester with excellent dielectric properties, and it is easy to obtain a liquid crystal polymer with excellent dielectric properties and isotropy. Ester film.

"Manufacturing method of laminated body"

The method for producing a laminate according to an embodiment includes coating the liquid crystal polyester composition according to the embodiment on a support, and performing heat treatment to form a liquid crystal polyester film containing liquid crystal polyester, thereby obtaining a liquid crystal polyester film comprising the support and the liquid crystal polyester. A laminate of liquid crystal polyester films.

This manufacturing method may include the following steps.

A step of applying the liquid crystal polyester composition of the embodiment on a support to form a liquid crystal polyester film precursor on the support (coating step).

A step of heat-treating the liquid crystal polyester film precursor to obtain a laminate including the support and the liquid crystal polyester film (heat treatment step).

As in the above-mentioned method for producing a liquid crystal polyester film, in the method for producing a laminate, in the coating step, after coating the liquid crystal polyester composition of the embodiment on the support, the liquid crystal polyester composition obtained from the coating may be included. The step of removing the medium from the composition (drying step).

That is, the manufacturing method of the laminated body of the embodiment may include coating the liquid crystal polyester composition of the embodiment on the support, removing the medium from the coated liquid crystal polyester composition, and performing heat treatment to form a liquid crystal polyester a liquid crystal polyester film to obtain a laminate comprising the support and the liquid crystal polyester film.

FIG. 1 is a schematic diagram showing an example of a production process of a liquid crystal polyester film and a laminate according to an embodiment. The manufacturing method of the laminated body shown in FIG. 1 is the same as that described in the above-mentioned "Method for Manufacturing Liquid Crystal Polyester Film" except that the above-mentioned separation step (FIG. 1(d)) is not performed, so the description is omitted.

According to the manufacturing method of the laminated body of embodiment, the laminated body which has the liquid crystal polyester film of embodiment can be manufactured.

"membrane"

In the method for producing the above-mentioned liquid crystal polyester film or laminate, although the liquid crystal polyester powder is used as a raw material, a thermoplastic resin excellent in dielectric properties is used instead of the liquid crystal polyester as a raw material, and excellent dielectric properties and isotropy can be obtained. membrane.

FIG. 2 is a schematic diagram showing the structure of the film 11 according to the embodiment.

The film of the embodiment includes a thermoplastic resin, has a relative permittivity of 3 or less at a frequency of 1 GHz, a dielectric loss tangent of 0.005 or less at a frequency of 1 GHz, and a degree of molecular orientation (MOR) measured using a microwave orientation meter. The value is in the range of 1 to 1.1.

A film that satisfies the above-mentioned requirements has good quality as a film for electronic components. The quality criteria are the above-mentioned relative permittivity, dielectric loss tangent, and degree of molecular orientation (isotropy of the film), and in addition, thickness and appearance (whether holes or through-holes are generated) are considered.

As an example, the values of relative permittivity and dielectric loss tangent of the film can be controlled by the type of thermoplastic resin. In addition, as an example, the degree of isotropy of the film can be controlled by the production method of the film.

The film of the embodiment has a relative permittivity at a frequency of 1 GHz of 3 or less, preferably 2.9 or less, more preferably 2.8 or less, still more preferably 2.7 or less, particularly preferably 2.6 or less. In addition, the relative dielectric constant of the film may be 2.3 or more, 2.4 or more, or 2.5 or more.

The upper limit and the lower limit of the value of the above-mentioned relative permittivity of the above-mentioned film can be freely combined. As an example of the numerical range of the value of the above-mentioned relative permittivity of the above-mentioned film, it can be 2.3 to 3, can be 2.4 to 2.9, can be 2.5 to 2.8, can be 2.5 to 2.7, It may be 2.5 or more and 2.6 or less.

The film of the embodiment has a dielectric loss tangent at a frequency of 1 GHz of 0.005 or less, preferably 0.004 or less, more preferably 0.003 or less, still more preferably 0.002 or less, particularly preferably 0.001 or less. The dielectric loss tangent of the liquid crystal polyester film may be 0.0003 or more, 0.0005 or more, or 0.0007 or more.

The upper limit and lower limit of the value of the dielectric loss tangent of the above film can be freely combined. As an example of the numerical range of the value of the dielectric loss tangent of the above film, it may be 0.0003 to 0.005, 0.0005 to 0.004, 0.0007 to 0.003, 0.0007 to 0.002. , may be not less than 0.0007 and not more than 0.001.

The relative permittivity and dielectric loss tangent of the film at a frequency of 1 GHz can be measured by a volumetric method using an impedance analyzer under the following conditions.

The film was melted at 350°C by using a flow tester, and then cooled and solidified to produce a tablet with a diameter of 1 cm and a thickness of 0.5 cm. The relative permittivity and dielectric loss tangent of the obtained tablet were measured at 1 GHz under the following conditions.

Determination method: volumetric method.

Electrode model: 16453A.

Measurement environment: 23°C, 50%RH.

Applied voltage: 1V.

The value of the degree of molecular orientation (MOR) of the film of the embodiment measured using a microwave orientation meter is in the range of 1 to 1.1, preferably in the range of 1 to 1.08, more preferably in the range of 1 to 1.06, and even more preferably in the range of 1 to 1.04 range.

The degree of molecular orientation (MOR) is measured with a microwave molecular orientation meter (for example, MOA-5012A, manufactured by Oji Scientific Instruments, Ltd.). The microwave molecular orientation meter is a device that utilizes the principle that the transmission intensity of microwaves is different in the orientation direction and the vertical direction according to the orientation of molecules. Specifically, the sample was irradiated with microwaves having a constant frequency (12 GHz was used) while rotating the sample, and the intensity of transmitted microwaves varying with molecular orientation was measured, and the ratio of the maximum value/minimum value was expressed as MOR. The interaction of the microwave electric field with a constant frequency and the dipoles constituting the molecule is related to the inner product of the two vectors. Due to the anisotropy of the dielectric constant of the sample, the microwave intensity varies with the angle of the sample configuration, so the degree of orientation can be known.

The film according to the embodiment has a coefficient of linear expansion measured in a temperature range of 50 to 100°C under the condition of a heating rate of 5°C/min, preferably 85 ppm/°C or less, more preferably 50 ppm/°C or less, and even more preferably 40 ppm/°C. °C or lower, particularly preferably 30 ppm/°C or lower. The lower limit of the linear expansion coefficient is not particularly limited, for example, it is 0 ppm/°C or more. In addition, for example, when the copper foil and the film are laminated, since the linear expansion coefficient of the copper foil is 18 ppm/°C, the linear expansion coefficient of the film according to the embodiment is preferably a value close to this value. That is, the coefficient of linear expansion of the film according to the embodiment is preferably 0 ppm/°C to 50 ppm/°C, more preferably 10 ppm/°C to 40 ppm/°C, and still more preferably 20 ppm/°C to 30 ppm/°C. When the coefficient of linear expansion differs depending on the direction or location of the film, a higher value is adopted as the coefficient of linear expansion of the film. The coefficient of linear expansion of the film can be measured using a thermomechanical analyzer (for example, manufactured by Rigaku Corporation, model: TMA8310). The film of the embodiment satisfying the above numerical range has a low coefficient of linear expansion and high dimensional stability.

A film excellent in isotropy has a small difference in linear expansion coefficient between different measurement directions.

In the film of the embodiment, among the linear expansion coefficients, the difference between the linear expansion coefficient of MD and the linear expansion coefficient of TD (MD-TD in the case of MD>TD, TD-MD in the case of TD>MD) ), preferably 2 ppm/°C or less, more preferably 1 ppm/°C or less. In films produced by casting, MD is the coating direction of the dispersion. As shown in the above calculation of the difference in the coefficient of linear expansion, in fact, it is only necessary to clarify the coefficient of linear expansion in different directions. Therefore, when the MD and TD of the film are unknown, in the arbitrary direction of the film as the MD, the When the direction intersecting MD at 90° is TD, the direction may be set such that the difference in the coefficients of linear expansion in the respective directions is the largest.

The film of the embodiment satisfying the above numerical range has excellent isotropy in linear expansion and high dimensional stability in the longitudinal and transverse directions.

In the film of the embodiment, as an appearance suitable for a film for electronic components, it is preferable that there are no holes or through-holes. When there are holes or through-holes, there is a possibility that the plating solution may infiltrate into the holes or through-holes during plating. The liquid crystal polyester film produced using the liquid crystal polyester powder of the embodiment as a raw material is a high quality liquid crystal polyester film that suppresses the occurrence of holes or through holes while having a good thickness as a film for electronic components.

The thickness of the film according to the embodiment is not particularly limited, but a good thickness of the film for electronic components is preferably 5 to 50 μm, more preferably 7 to 40 μm, still more preferably 10 to 33 μm, and especially preferably 15 to 20 μm.

In addition, in this specification, "thickness" is the average value of the value obtained by measuring the thickness of 10 randomly selected places according to JIS standard (K7130-1992).

A film excellent in dielectric properties can be obtained by selecting a raw material resin excellent in dielectric properties from arbitrary thermoplastic resins.

The content rate of the thermoplastic resin may be 50-100 mass % with respect to 100 mass % of the total mass of the film of embodiment, and may be 80-95 mass %.

Examples of thermoplastic resins include polypropylene, polyamide, polyester, polysulfone, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and polyetherimide.

From the viewpoint of having particularly excellent dielectric properties, liquid crystal polyester is preferable as the thermoplastic resin. As the liquid crystal polyester, the liquid crystal polyester described in the above "Liquid Crystal Polyester Powder" can be mentioned, so the description is omitted.

The content ratio of the liquid crystal polyester may be 50 to 100 mass % with respect to 100 mass % of the total mass of the film of the embodiment, and may be 80 to 95 mass %.

In the case where the film of the embodiment contains a liquid crystal polyester, the liquid crystal polyester of the above embodiment may be contained in an amount exceeding 70% by mass and not more than 100% by mass relative to 100% by mass of the total liquid crystal polyester contained in the film. 80 to 100% by mass of the liquid crystal polyester of the above-mentioned embodiment. The liquid crystal polyesters include the liquid crystal polyesters listed in the liquid crystal polyester powders of the above-mentioned embodiments, for example, the liquid crystal polyesters of the above-mentioned 1) to 4), which have a structural unit represented by the above formula (1), represented by A liquid crystal polyester having a structural unit represented by the above formula (2) and a structural unit represented by the above formula (3), or a liquid crystal having a structural unit represented by the above formula (2) and a structural unit represented by the above formula (3) polyester.

The film of the embodiment comprises a thermoplastic resin, and may have a relative permittivity of 3 or less at a frequency of 1 GHz, a dielectric loss tangent of 0.005 or less at a frequency of 1 GHz, and a molecular orientation measured using a microwave orientation meter ( MOR) value in the range of 1 to 1.1 film (however, in the case of containing liquid crystal polyester as a thermoplastic resin, with respect to the total of liquid crystal polyester 100% by mass, liquid crystal polyester soluble in aprotic solvent content is less than 5% by mass).

The film of the embodiment comprises a thermoplastic resin, and may have a relative permittivity of 3 or less at a frequency of 1 GHz, a dielectric loss tangent of 0.005 or less at a frequency of 1 GHz, and a molecular orientation measured using a microwave orientation meter ( MOR) in the range of 1 to 1.1 (except for those containing liquid crystal polyester soluble in aprotic solvents).

Here, examples of the liquid crystal polyester soluble in the aprotic solvent include those listed in the liquid crystal polyester powder of the embodiment.

The method for producing the film of the embodiment is not particularly limited, and the film of the embodiment can be produced by the above-mentioned <<Method for Producing a Crystalline Polyester Film>>. In the "Method for Producing a Crystalline Polyester Film" described above, liquid crystalline polyester was used as a raw material for explanation, but in this method, by understanding liquid crystalline polyester as any thermoplastic resin, it is possible to produce the crystalline polyester film containing any thermoplastic resin. membrane.

The film of embodiment can be suitably used for film uses for electronic components, such as a printed wiring board. The film of the embodiment can be used as a substrate (for example, a flexible substrate), a laminate (for example, a flexible copper-clad laminate), a printed circuit board, a printed wiring board, a printed circuit board, etc., provided with the film as an insulating material. supply.

"Layers"

The laminated body of the embodiment includes a metal layer and the film of the embodiment laminated on the metal layer.

FIG. 3 is a schematic diagram showing the structure of a laminated body 21 according to one embodiment of the present invention. The laminated body 21 includes a metal layer 13 and a film 11 laminated on the metal layer 13 .

Since the above-mentioned ones are mentioned about the film provided with a laminated body, description is abbreviate|omitted.

The metal layer provided with the laminate includes those listed as the support in the above-mentioned "Method for Producing a Liquid Crystal Polyester Film" and "Method for Producing a Laminate", among which a metal foil is preferable. As the metal constituting the metal layer, copper is preferred from the viewpoint of conductivity and cost, and as the metal foil, copper foil is preferred.

The thickness of the laminated body of the embodiment is not particularly limited, but is preferably 5 to 130 μm, more preferably 10 to 70 μm, and still more preferably 15 to 60 μm.

The method of manufacturing the laminated body of the embodiment is not particularly limited, and the laminated body of the embodiment can be manufactured by the aforementioned <<Method for Manufacturing a Laminated Body>>. In the above-mentioned "Method for Producing a Laminated Body", the liquid crystalline polyester was used as a raw material, but in this method, by understanding the liquid crystalline polyester as an arbitrary thermoplastic resin, an embodiment including a film containing an arbitrary thermoplastic resin can be produced. of stacks.

The laminated body of embodiment can be suitably used for film uses for electronic components, such as a printed wiring board.

[Example]

The present invention will be described in more detail by showing examples below, but the present invention is not limited to the following examples.

＜Measurement method＞

[Measurement of flow start temperature of liquid crystal polyester]

Using a flow tester ("CFT-500 type" of Shimadzu Corporation), about 2 g of liquid crystal polyester is filled into a cylinder equipped with a nozzle having an inner diameter of 1 mm and a length of 10 mm, and the pressure is controlled at 9.8 MPa ( Under a load of 100 kg/cm ² ), the temperature (FT) at which the liquid crystalline polyester was melted while raising the temperature at a rate of 4°C/min, extruded from a nozzle, and exhibited a viscosity of 4800 Pa·s (48000P) was measured.

[Measurement of melting point of liquid crystal polyester]

Using a differential scanning calorimeter (Shimadzu Corporation's "DSC-50"), the temperature was raised at a heating rate of 10°C/min, the position of the endothermic peak was confirmed, and the temperature at the apex of the endothermic peak was measured , as the melting point of the liquid crystal polyester.

[Measurement of molecular weight of liquid crystal polyester contained in liquid crystal polyester microparticle powder]

Gel permeation chromatography-multi-angle light scattering photometer (differential refractometer (manufactured by Shimadzu Corporation: RID-20A), multi-angle light scattering detector (EOS manufactured by Wyatt Technology, USA) was used. , Filter column (manufactured by Showa Denko: Shodex K-G, K-806M (2 pieces), K-802 (1 piece) (φ8.0mm×30cm)) and solvent (pentafluorophenol/chloroform (weight ratio 35/65)) ) to measure the number average molecular weight of the liquid crystal polyester contained in the liquid crystal polyester microparticle powder. Add 2 mg of sample to 1.4 g of pentafluorophenol, dissolve at 80°C for 2 hours, add 2.6 g of chloroform after cooling to room temperature, and further dilute to 2 times with a solvent (pentafluorophenol/chloroform (weight ratio 35/65)) After that, it was filtered using a filter with a pore size of 0.45 μm to prepare a sample solution for measurement.

[Analysis of the amount of residual acetic acid contained in liquid crystal polyester fine particle powder]

The amount of residual acetic acid in the liquid crystal polyester microparticle powder was analyzed using a headspace gas chromatograph (manufactured by Shimadzu Corporation: GC-2014) under extraction conditions of 120° C. for 20 hours and analysis conditions of 200° C. for 1 hour.

[Measurement of Relative Permittivity and Dielectric Loss Tangent of Liquid Crystal Polyester Microparticle Powder]

By melting the powder of liquid crystal polyester microparticles at a temperature 5°C higher than the melting point measured by a flow tester ("CFT-500 type" of Shimadzu Corporation) and then cooling and solidifying, a 1 cm diameter and a thickness 0.5 cm tablet. The relative permittivity and dielectric loss tangent of the obtained tablet were measured at 1 GHz under the following conditions.

Measuring method: volumetric method (device: impedance analyzer (manufactured by Agilent, model: E4991A)).

Electrode model: 16453A.

Measurement environment: 23°C, 50%RH.

Applied voltage: 1V.

[Measurement of Average Particle Size of Liquid Crystal Polyester Microparticle Powder]

Weigh 0.01 g of liquid crystal polyester microparticle powder and disperse it in about 10 g of pure water. The prepared liquid crystal polyester microparticle powder dispersion was dispersed for 5 minutes using ultrasonic waves. Using a scattering particle size distribution measuring device (“LA-950V2” from Horiba Co., Ltd.), under the condition that the refractive index of pure water is 1.333, the volume-based cumulative particle size distribution of liquid crystal polyester fine particle powder is measured, and the average Particle size (D ₅₀ ).

[Measurement of Relative Permittivity and Dielectric Loss Tangent of Liquid Crystal Polyester Film]

A tablet having a diameter of 1 cm and a thickness of 0.5 cm was produced by melting the liquid crystal polyester film at 350° C. using a flow tester (“CFT-500” manufactured by Shimadzu Corporation) and then cooling and solidifying it. The relative permittivity and dielectric loss tangent of the obtained tablet were measured at 1 GHz under the following conditions.

Measuring method: volumetric method (apparatus: impedance analyzer (manufactured by Agilent Corporation, model: E4991A)).

Electrode model: 16453A.

Measurement environment: 23°C, 50%RH.

Applied voltage: 1V.

[Measurement of Molecular Orientation Degree of Liquid Crystal Polyester Film]

The film was cut into 5 cm squares and placed on a stand, and the degree of molecular orientation was measured using a molecular orientation meter (manufactured by Oji Scientific Instruments Co., Ltd., model: MOA-5012A) at a frequency of 12 GHz and a rotation speed of 1 rpm.

[Measurement of linear expansion coefficient of liquid crystal polyester film]

The linear expansion coefficient from 50°C to 100°C was measured at a temperature increase rate of 5°C/min using a thermomechanical analyzer (manufactured by Rigaku Co., Ltd., model: TMA8310). The flow direction (MD) and the direction perpendicular|vertical (TD) of the liquid crystal polyester film were measured. In addition, in the liquid crystal polyester film of each Example or the comparative example produced by the casting method, the flow direction (MD) means the coating direction of a dispersion liquid.

＜Manufacture of Liquid Crystal Polyester Microparticle Powder＞

[Example 1]

Production of Liquid Crystal Polyester (A)

In the reactor equipped with stirring device, torque measuring instrument, nitrogen gas introduction pipe, thermometer and reflux cooler, add 2-hydroxyl-6-naphthoic acid 1034.99g (5.5 moles), 2,6-naphthalene dicarboxylic acid 378.33g ( 1.75 moles), terephthalic acid 83.07g (0.5 moles), hydroquinone 272.52g (2.475 moles, 0.225 moles excess relative to the total molar amount of 2,6-naphthalene dicarboxylic acid and terephthalic acid), ethyl 1226.87 g (12 moles) of an acid anhydride and 0.17 g of 1-methylimidazole as a catalyst. After replacing the gas in the reactor with nitrogen, the temperature was raised from room temperature to 145° C. over 15 minutes while stirring under a nitrogen gas flow, and refluxed at 145° C. for 1 hour.

Next, 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, and kept at 310° C. for 3 hours. Then, the solid liquid crystal polyester was taken out, and the liquid crystal polymer was The ester was cooled to room temperature to obtain a liquid crystalline polyester (A).

The flow start temperature of the liquid crystal polyester (A) was 268°C. The liquid crystalline polyester (A) was pulverized using a shredder VM-16 manufactured by Orient Pulverizer Co., Ltd. to obtain a powder of the liquid crystalline polyester (A) with an average particle diameter of 394 μm.

Production of Liquid Crystal Polyester Microparticle Powder

Next, using a jet mill ("KJ-200" manufactured by Kurimoto Iron Works, diameter of crushing nozzle: 4.5 mm), set the rotating speed of the classifying rotor at 10,000 rpm, the pressure of the crushing nozzle at 0.64 MPa, and the processing speed at 2.1 kg/hour to crush the liquid crystal polymer. powder of the ester (A), thereby obtaining the liquid crystal polyester microparticle powder of Example 1. The average particle diameter of the liquid crystal polyester microparticle powder was 8 μm. In addition, when the melting point of the liquid crystal polyester microparticle powder of Example 1 was measured using a differential scanning calorimeter, it was 290°C.

[Example 2]

In addition to setting the processing conditions of the jet mill ("KJ-200" manufactured by Kurimoto Iron Works Co., Ltd.) to 10,000 rpm of the classification rotor, 0.63 MPa of the crushing nozzle pressure, and 2.6 kg/hour of processing speed to crush the liquid crystal polyester powder, and Production of the Liquid Crystal Polyester Microparticle Powder of Example 1 In the same manner, the liquid crystal polyester microparticle powder of Example 2 was obtained. The average particle diameter of the liquid crystal polyester microparticle powder was 10 μm.

[Example 3]

In addition to setting the processing conditions of the jet mill ("KJ-200" manufactured by Kurimoto Iron Works Co., Ltd.) to 10,000 rpm of the classification rotor, 0.60 MPa of the crushing nozzle pressure, and 4.0 kg/hour of processing speed to crush the liquid crystal polyester powder, and Production of the Liquid Crystal Polyester Microparticle Powder of Example 1 In the same manner, the liquid crystal polyester microparticle powder of Example 3 was obtained. The average particle diameter of the liquid crystal polyester microparticle powder was 15 μm.

[Comparative example 1]

Except that instead of the jet mill, a freezing/impact mill (Linrex Mill manufactured by Hosokawa Micron) was used, and the processing speed was set at 10 kg/hour to pulverize the liquid crystal polyester powder, the same liquid crystal powder as in Example 1 was obtained. Production of Polyester Microparticle Powder In the same manner, liquid crystal polyester microparticle powder of Comparative Example 1 was obtained. The average particle diameter of the liquid crystal polyester microparticle powder was 27 μm.

[Comparative example 2]

Manufacture of Liquid Crystal Polyester (D)

The powder of the liquid crystal polyester (A) obtained in Example 1 was filled in a tray made of SUS (stainless steel), and heat-treated at 290° C. for 6 hours to obtain a liquid crystal polyester (D).

Production of Liquid Crystal Polyester Microparticle Powder

Next, except using a jet mill ("KJ-200" manufactured by Kurimoto Iron Works Co., Ltd.), the liquid crystal polyester (D) was pulverized by setting the rotating speed of the classification rotor at 10000 rpm, the pulverizing nozzle pressure at 0.60 MPa, and the processing speed at 0.1 kg/hour. Except for the powder, the liquid crystalline polyester fine particle powder of Comparative Example 2 was obtained in the same manner as the production of the liquid crystalline polyester fine particle powder of Example 1. The average particle diameter of the liquid crystal polyester microparticle powder was 7 μm.

The relative permittivity and dielectric loss tangent were measured for each of the obtained liquid crystal polyester fine particle powders.

Table 1 shows the above-mentioned items and their measurement results.

＜Manufacture of liquid crystal polyester film＞

[Examples 1-1 to 3-1, Comparative Examples 1-1 to 2-1]

Preparation of dispersion

Add 8 parts by weight of each liquid crystal polyester microparticle powder in the above-mentioned Examples 1 to 3 and Comparative Examples 1 to 2 to 92 parts by weight of N-methyl 2-pyrrolidone (boiling point (1 atmosphere) 204 ° C), using a new base Stirring was performed using a stirring defoaming machine AR-500 manufactured by Shinky Co., Ltd. to obtain each dispersion.

Manufacture of liquid crystal polyester film

Each of the above-mentioned dispersions was prepared using a film applicator with a micrometer ("SA204" of SHEEN) and an automatic coating device ("Type I" of Tester Sangyo Co., Ltd. (Tester Industry Co., Ltd.) ), was cast on the roughened surface of copper foil (manufactured by Mitsui Metal Mining Co., Ltd., 3EC-VLP, 18 μm) so that the thickness of the cast film was 300 μm, and dried at 40° C. under normal pressure (1 atmosphere) for 4 hours. Remove the solvent from the cast film. In Comparative Example 2-1, the dispersion became gelatinous and could not be casted, so it was not possible to form a film.

After the above drying, the temperature was further raised from room temperature to 310° C. at a rate of 7° C./min in a hot air oven under a nitrogen atmosphere, and kept at this temperature for 6 hours for heat treatment, thereby obtaining a liquid crystal polyester film with copper foil.

The obtained liquid crystal polyester film with copper foil was immersed in an aqueous ferric chloride solution, and the copper foil was removed by etching to obtain a single-layer film.

The appearance of each film was confirmed. The liquid crystal polyester film of Comparative Example 1-1 had a large number of pores on the surface, had poor appearance, and was of unsuitable quality as a film for electronic components.

Table 1 shows the above-mentioned items and their measurement results.

[Table 1]

※Film cannot be made

In Comparative Example 2-1, in which the liquid crystal polyester microparticle powder of Comparative Example 2 containing liquid crystal polyester having a number average molecular weight not in the range of 10,000 or less was used as a raw material, a liquid crystal polyester film could not be produced. On the other hand, the liquid crystal polyester films of Examples 1-1 to 3-1 can be produced by using the liquid crystal polyester microparticle powder of Examples 1 to 3 containing liquid crystal polyester having a number average molecular weight in the range of 10,000 or less as a raw material. .

In addition, the liquid crystal polyester film of Comparative Example 1-1 produced from the liquid crystal polyester fine particle powder of Comparative Example 1 whose average particle size did not satisfy the range of 0.5 to 20 μm as a raw material had a large number of pores on the surface, resulting in poor appearance. In contrast, the liquid crystal polyester films of Examples 1-1 to 3-1 produced from the liquid crystal polyester fine particle powders of Examples 1 to 3 having an average particle diameter in the range of 0.5 to 20 μm were thin and had an excellent appearance. Also excellent.

The appearance evaluation results of the liquid crystal polyester films of Examples 1-1 to 3-1 and Comparative Example 1-1, in Table 1, no holes were found and the appearance was excellent was recorded as "G", and a large number of holes were generated. And those with poor appearance were recorded as "F".

＜Manufacture of liquid crystal polyester film＞

The liquid crystal polyester films of Examples 1-1 to 1-5 were produced by using the liquid crystal polyester microparticle powder of the liquid crystal polyester (A) obtained in Example 1 above as a raw material and changing the heat treatment conditions. In addition, the liquid crystal polyester film of Example 1-1 was obtained by the same manufacturing method as the said Example 1-1.

[Example 1-1]

Preparation of dispersion

8 parts by weight of the liquid crystal polyester microparticle powder of the liquid crystal polyester (A) manufactured in the above-mentioned embodiment 1 was dropped into 92 parts by weight of N-methyl 2-pyrrolidone, and the stirring defoamer AR- Stir at 500 to obtain a dispersion.

Manufacture of liquid crystal polyester film

Each of the above-mentioned dispersion liquids was coated on a copper foil (Mitsui Produced by Metal Mining Co., Ltd., 3EC-VLP, 18 μm) on a roughened surface, after casting so that the thickness of the cast film becomes 300 μm, the solvent was removed from the cast film by drying at 40°C under normal pressure (1 atmosphere) for 4 hours. .

After the above-mentioned drying, the temperature was further raised from room temperature to 310° C. at 7° C./min in a hot air oven under a nitrogen environment, and kept at this temperature for 6 hours for heat treatment, thereby obtaining the copper foil of Example 1-1. Liquid crystal polyester film.

[Example 1-2]

Except that the above-mentioned heat treatment conditions were changed from room temperature to 330° C. at a rate of 7° C./min, the copper-coated polyester film of Example 1-2 was obtained in the same manner as the production of the liquid crystal polyester film with copper foil in Example 1-1 above. Foil of liquid crystal polyester film.

[Example 1-3]

Except that the above-mentioned heat treatment conditions were changed from room temperature to 310° C. at a rate of 4° C./min, the copper-coated polyester film of Example 1-3 was obtained in the same manner as the production of the liquid crystal polyester film with copper foil in Example 1-1 above. Foil of liquid crystal polyester film.

[Example 1-4]

Except that the above-mentioned heat treatment conditions were changed from room temperature to 300° C. at a rate of 7° C./min, the copper-coated polyester film of Example 1-4 was obtained in the same manner as the production of the liquid crystal polyester film with copper foil in Example 1-1 above. Foil of liquid crystal polyester film.

[Example 1-5]

Except that the above-mentioned heat treatment conditions were changed from room temperature to 310° C. at a rate of 3° C./min, the copper-coated polyester film of Example 1-5 was obtained in the same manner as the production of the liquid crystal polyester film with copper foil in Example 1-1 above. Foil of liquid crystal polyester film.

[Comparative example 3]

A liquid crystal polyester soluble in an organic solvent was produced and used as a raw material, and a liquid crystal polyester film of Comparative Example 3 was produced as follows.

Production of Liquid Crystal Polyester (B)

Add 940.9 g (5.0 moles) of 6-hydroxy-2-naphthoic acid and 377.9 g (2.5 moles) of 4-hydroxyacetanilide to a reactor equipped with a stirring device, a torque measuring instrument, a nitrogen inlet pipe, a thermometer and a reflux cooler , 415.3g (2.5 moles) of isophthalic acid and 867.8g (8.4 moles) of acetic anhydride, after the gas in the reactor was replaced with nitrogen, under nitrogen flow, while stirring, it took 60 minutes to heat up from room temperature to 140 °C, and reflux at 140 °C for 3 hours.

Next, while distilling off by-produced acetic acid and unreacted acetic anhydride, the temperature was raised from 150°C to 300°C over 5 hours and kept at 300°C for 30 minutes, then the contents were taken out from the reactor and cooled to room temperature. The obtained solid substance was pulverized using a pulverizer to obtain a powdery liquid crystal polyester (B1). The flow start temperature of the 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 raised from 160° C. to 180° C. over 3 hours and 20 minutes, and kept at 180° C. for 5 hours. hours to carry out solid-phase polymerization, then cooled, and then pulverized with a pulverizer to obtain a powdery liquid crystal polyester (B2). The flow initiation temperature of the liquid crystal polyester (B2) was 220°C.

The liquid crystal polyester (B2) obtained above was heated from room temperature to 180°C over 1 hour and 25 minutes under a nitrogen atmosphere, then raised from 180°C to 255°C over 6 hours and 40 minutes, and kept at 255°C for 5 Hours, to carry out solid-state polymerization and then cooling to obtain powdery liquid crystal polyester (B). The flow initiation temperature of the liquid crystal polyester (B) was 302°C. In addition, the melting point of the liquid crystal polyester (B) was measured to be 311° C. using a differential scanning calorimeter.

Preparation of liquid crystal polyester solution

8 parts by mass of liquid crystal polyester (B) was added to 92 parts by mass of N-methylpyrrolidone (boiling point (1 atm) 204° C.) and stirred at 140° C. for 4 hours under a nitrogen atmosphere to prepare a liquid crystal polyester solution. The viscosity of this liquid crystal polyester solution was 955 mPa·s.

Manufacture of liquid crystal polyester film

The liquid crystal polyester solution was coated on copper foil (Mitsui Co., Ltd. Produced by Metal Mining Co., Ltd., 3EC-VLP, 18 μm) on a roughened surface, after casting so that the thickness of the cast film becomes 300 μm, the solvent was removed from the cast film by drying at 40°C under normal pressure (1 atmosphere) for 4 hours. . In addition, the second cast was performed on the surface of the dried liquid crystal polyester (B) so that the cast film had a thickness of 300 μm, and dried at 40° C. The solvent was removed from the film.

After the above drying, the temperature was further raised from room temperature to 270°C at a rate of 1°C/min in a hot air oven under a nitrogen atmosphere, and kept at this temperature for 2 hours for heat treatment, thereby obtaining the liquid crystal with copper foil of Comparative Example 3 polyester film.

[Comparative example 4]

Manufacture of Liquid Crystal Polyester (C)

The powder of the liquid crystal polyester (A) obtained in Example 1 above was filled in a SUS tray, and heat-treated at 280° C. for 6 hours to obtain a liquid crystal polyester (C). The flow start temperature of the obtained liquid crystal polyester (C) was 306°C.

Manufacture of liquid crystal polyester film

100 parts by weight of the obtained liquid crystal polyester (C) was pelletized at 325° C. using a twin-screw extruder (“PCM-30” manufactured by Ikegai Iron Works Co., Ltd.) to obtain pellets. In addition, as a result of measuring the melting point of the pellets using a differential scanning calorimeter, it was 319°C.

After melt-extruding the obtained pellets using a single-screw extruder, inflation film-forming was performed using an annular inflation die with a die diameter of 30 mm and a slit pitch of 0.25 mm. At this time, film formation was performed while filtering the dissolved liquid crystal polyester using a filter device (leaf disc filter, manufactured by Nippon Seisen Co., Ltd.) connected to the inlet of the annular inflation die. For the filter device, 16 pieces of NASLON Filter (NASLON Filter) LF4-0 NF2M-05D2 (manufactured by Nippon Seisen Co., Ltd., filter precision 5.0 μm, leaf disk type) are used in cascade.

The liquid crystal polyester film of Comparative Example 4 was obtained by extruding from an annular inflation die heated to 340° C. under the condition that the draw ratio of TD to the draw ratio of MD was 4.3.

The liquid crystal polyester films with copper foil obtained in Examples 1-1 to 1-5 and Comparative Examples 3 to 4 were immersed in an aqueous ferric chloride solution, and the copper foil was removed by etching to obtain a single-layer film.

Table 2 shows the above items and their measurement results.

[Table 2]

※The left column is the value of the linear expansion coefficient of MD, and the right column is the value of the TD linear expansion coefficient.

Since the liquid crystal polyester films of Examples 1-1 to 1-5 are obtained by casting the dispersion liquid of liquid crystal polyester particle powder on copper foil and then performing heat treatment (abbreviated as "dispersion liquid casting" in the table), , so it has excellent dielectric properties and a low degree of molecular orientation (MOR), which has excellent properties.

Since the liquid crystal polyester film of Comparative Example 3 is obtained by casting a solution of liquid crystal polyester particle powder on a copper foil (abbreviated as "solution casting" in the table), it is non-oriented, but due to the In the solution casting method, there is a limitation of using a liquid crystal polyester soluble in a solvent as a raw material, so the dielectric properties tend to be poor.

Since the liquid crystal polyester film of Comparative Example 4 was obtained by an inflation method, the degree of molecular orientation (MOR) tended to be high, and there was also a difference in linear expansion between MD and TD.

Each configuration in each embodiment, a combination thereof, and the like are examples, and additions, omissions, substitutions, and other changes to configurations can be made without departing from the gist of the present invention. In addition, this invention is not limited to each embodiment, and is limited only by the range of a claim (claim).

Explanation of reference signs

1: liquid crystal polyester powder; 3: medium; 30: liquid crystal polyester composition; 10: liquid crystal polyester film; 11: film; 12: support; 13: metal layer; 20, 21: laminate; 22: laminate body precursor; 40: liquid crystal polyester film precursor.

Claims (8)

1. A liquid-crystalline polyester composition comprising a medium and a liquid-crystalline polyester powder insoluble in the medium, wherein,

the liquid crystal polyester powder comprises a liquid crystal polyester having a number average molecular weight of 10000 or less,

and the average particle diameter of the liquid crystal polyester powder is 0.5 to 20 mu m.

2. The liquid crystalline polyester composition according to claim 1, wherein,

the relative dielectric constant of the liquid crystal polyester powder at a frequency of 1GHz is 3 or less, and the dielectric loss tangent of the liquid crystal polyester powder at a frequency of 1GHz is 0.005 or less.

3. The liquid-crystalline polyester composition according to claim 1 or 2, wherein,

the liquid crystal polyester has a structural unit containing a naphthalene structure.

4. The liquid-crystalline polyester composition according to claim 3, wherein,

the content of the structural unit containing a naphthalene structure is 40 mol% or more with respect to 100 mol% of the total of all structural units in the liquid crystal polyester.

5. The liquid-crystalline polyester composition according to claim 3, wherein,

the liquid crystal polyester has 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 (3),

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-O-Ar ³ -O-

Ar ¹ represents 2, 6-naphthalenediyl, 1, 4-phenylene, or 4,4' -biphenylene; ar (Ar) ² And Ar is a group ³ Each independently represents 2, 6-naphthalenediyl, 2, 7-naphthalenediyl, 1, 4-phenylene, 1, 3-phenylene or 4,4' -biphenylene; from Ar ¹ 、Ar ² Or Ar ³ The hydrogen atoms in the groups are independently substituted or not substituted with a halogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms.

6. The liquid-crystalline polyester composition according to claim 1 or 2, wherein,

the medium is an aprotic solvent.

7. A method for producing a liquid crystal polyester film, wherein,

the method for producing the liquid crystal polyester film comprises the following steps: a process for preparing a liquid-crystalline polyester film comprising the liquid-crystalline polyester by applying the liquid-crystalline polyester composition according to any one of claims 1 to 6 to a support and heat-treating the applied liquid-crystalline polyester composition.

8. A method for producing a laminate, wherein,

the method for producing the laminate comprises: a process for producing a laminate comprising the support and the liquid crystal polyester film, wherein the liquid crystal polyester composition according to any one of claims 1 to 6 is applied to the support and heat-treated to form a liquid crystal polyester film containing a liquid crystal polyester.

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