LCP extruded film for stretching, heat-shrinkable LCP stretched film, insulating material for circuit boards, and metal foil-clad laminates

Abstract

It exhibits excellent stretchability during stretching, thereby reducing anisotropy and anisotropy in dimensional change rates. A stretchable LCP extruded film capable of producing heat-shrinkable LCP stretched films with a small tail value. We provide things like [unclear / etc.]. [Solution] An LCP extruded film for stretching treatment containing a thermoplastic liquid crystal polymer, and a constant temperature bath Tensile test (compliant with JIS K7161-1:2014, 200℃, tensile speed 200 mm / m) In the stress-strain curve measured in, the T of the LCP extruded film for stretching treatment The yield strength X (MPa) and fracture strength Y (MPa) in direction D satisfy the following equation (1). LCP extruded film for stretching. 0.75 ≤ breaking point strength Y / yield point strength X ≤ 1.50 ···(1)

Description

[Technical Field]

[0001] This invention relates to LCP extruded film for stretching, heat-shrinkable LCP stretched film, and circuit board film. This relates to insulating materials and metal foil-clad laminates, etc. [Background technology]

[0002] Conventionally, insulating materials for circuit boards have been made from thermosetting resins such as epoxy resins and inorganic fillers. A varnish-impregnated composite material is made by impregnating glass cloth with varnish containing agents, etc., and then heat-pressing it. This is known. However, this manufacturing method has limitations, for example, in terms of resin flowability during varnish impregnation and heat pressing. In terms of curability during molding, etc., the manufacturing process has little tolerance and is less productive. Also, heat Curable resins readily absorb moisture, and their dimensions change as they absorb moisture, resulting in varnish. The dimensional accuracy (heat-induced dimensional accuracy) of the impregnated composite material is inferior.

[0003] On the other hand, liquid crystal polymers (LCPs) are in a molten or solution state. It is a polymer that exhibits liquid crystalline properties. In particular, it is a thermotropic liquid that exhibits liquid crystalline properties in the molten state. Crystal polymers are extrudeable and possess high gas barrier properties, high film strength, high heat resistance, and high thermal insulation properties. It possesses excellent properties such as a fine edge, low water absorption rate, and low dielectric properties in the high-frequency range. Therefore, it is thermoplastic. Films using liquid crystal polymers are used in gas barrier film materials, electronic materials, and electrical applications. Its practical application is being considered for gas insulating material applications.

[0004] However, when single-layer extrusion molding is actually performed, the high performance of thermoplastic liquid crystal polymers Due to its high degree of liquid crystal alignment, thermoplastic liquid crystal polymer films have high industrial value. In other words, to obtain a thermoplastic liquid crystal polymer film with excellent thickness accuracy, good appearance and surface flatness. It turned out that this was difficult.

[0005] Therefore, for example, Patent Document 1 describes using a three-layer co-extrusion die instead of a single-layer extrusion die, A fully aromatic polyester-based thermotropic liquid crystal polymer is used as the intermediate layer, and polypolymer is used as both outer layers. Olefin resin or polycarbonate resin is simultaneously extruded, and the intermediate layer is thermoplastic liquid crystal poly A three-layer laminated film is formed, in which the outer layers are thermoplastic resin layers, and the thermoplastic resin layers of both outer layers are formed. By peeling off the plastic resin layer and extracting the intermediate layer as a film, it is possible to achieve excellent thickness accuracy and appearance. It has been disclosed that a thermoplastic liquid crystal polymer film with good surface flatness can be obtained.

[0006] Furthermore, for example, Patent Document 2 describes the thermoplastic liquid crystal polymer film described in Patent Document 1. Regarding the MD direction (Machine Direction; longitudinal direction), the TD direction (Transverse Direction) It was discovered that the strength in the lateral direction (n) was not sufficient for practical use, and a multi-manifold system was developed. By using a three-layer co-extrusion die with a feed block system instead of an extrusion die, The thermoplastic liquid crystal polymer film is in the TD direction and MD direction (Machine Direction; longitudinal direction) It is disclosed that the anisotropy of the intensity in the direction is mitigated. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 63-31729 [Patent Document 2] Japanese Patent Application Publication No. 2-178016 [Overview of the project]

Problems to be Solved by the Invention

[0008] Insulating materials for circuit boards using liquid crystal polymers are excellent in high-frequency characteristics and low dielectric properties, and thus have recently been in the spotlight as insulating materials for flexible printed wiring boards (FPCs), flexible printed wiring board laminates, fiber-reinforced flexible laminates, etc. in the upcoming fifth-generation mobile communication system (5G), millimeter-wave radar, etc.

[0009] In the technologies described in Patent Documents 1 and 2 mentioned above, it is said that a thermoplastic liquid crystal polymer film with excellent thickness accuracy, good appearance, and surface flatness can be realized. However, in reality, although the generation of peeling of the skin layer and peeling of fibrillated fibers caused by the highly molecular orientation of the thermoplastic liquid crystal polymer on the film surface can be suppressed, the thermoplastic liquid crystal polymer films described in Patent Documents 1 and 2 are still highly molecularly oriented as a whole film and could not withstand practical use as an insulating material for circuit boards.

[0010] Specifically, in the application of insulating materials for circuit boards, a thermoplastic liquid crystal polymer film may have a metal foil such as copper foil thermocompression-bonded to one side and / or both sides thereof and be used as a metal foil-clad laminate. Then, when this metal foil is pattern-etched to form fine wiring, etc., a metal foil-clad laminate can be used as a material for circuit boards such as electronic circuit boards and multi-layer boards. Therefore, a high degree of dimensional stability is required for the thermoplastic liquid crystal polymer film that supports the metal foil. However, the thermoplastic liquid crystal polymer films described in Patent Documents 1 and 2 ​​​​​​​​​The difference in the dimensional change rates in the TD direction and the MD direction after etching of the thermotropic liquid crystal polymer film is still large, and it has not been able to meet the requirements for application to recent ultra-fine processing.

[0011] The present invention has been made in view of the above problems. The object of the present invention is to provide an LCP extrusion film for stretching treatment that is excellent in stretching properties during stretching treatment, and thereby enables the realization of a heat-shrinkable LCP stretched film with small anisotropy of the dimensional change rate and the absolute value of the dimensional change rate. Another object of the present invention is to provide a heat-shrinkable LCP stretched film with small anisotropy of the dimensional change rate and the absolute value of the dimensional change rate, and an insulating material for a circuit board and a metal foil-clad laminate using the same.

Means for Solving the Problems

[0012] As a result of intensive studies to solve the above problems, the present inventors have found that an LCP extrusion film having predetermined tensile properties is excellent in stretching properties during stretching treatment, and by stretching this, a heat-shrinkable LCP stretched film with small anisotropy of the dimensional change rate and the absolute value of the dimensional change rate can be realized, and the present invention has been completed.

[0013] That is, the present invention provides various specific embodiments shown below. (1) An LCP extrusion film for stretching treatment containing a thermoplastic liquid crystal polymer, in the stress-strain curve measured by a constant temperature bath tensile test (in accordance with JIS K7161-1:2014, 200 ° C, tensile speed 200 mm / min), the yield point strength X (MPa) and the breaking point strength Y (MPa) in the TD direction of the LCP extrusion film for stretching treatment satisfy the following formula (1). LCP extrusion film for stretching treatment. 0.75 ≤ breaking point strength Y / yield point strength X ≤ 1.50 ···(1)

[0014] (2) The LCP extruded film for stretching has a coefficient of linear expansion in the TD direction of 5 to 55 ppm / K is the LCP extruded film for stretching described in (1).

[0015] (3) The LCP extruded film for stretching is a T-die extruded film (1) or (2 LCP extruded film for stretching treatment as described above.

[0016] (4) The LCP extruded film for stretching is a laminated extruded film having an outer layer, an intermediate layer, and an outer layer. The intermediate layer obtained by removing the two outer layers from the film is one of the following (1) to (3): LCP extruded film for stretching.

[0017] (5) The LCP extruded film for stretching is made in accordance with JIS K5600-5-6. In adhesion tests using the loss-cut method, the film surface does not have a skin layer that can be peeled off with tape. LCP extruded film for stretching as described in any one of items 1) to (4).

[0018] (6) The LCP extruded film for stretching has a thickness of 15 μm or more and 300 μm or less. LCP extruded film for stretching treatment as described in any one of items (1) to (5).

[0019] (7) The LCP extruded film for stretching further contains an inorganic filler (1)~( LCP extruded film for stretching as described in any one of item 6).

[0020] (8) The stretched LCP extruded film for stretching described in any one of items (1) to (7) Furthermore, the coefficient of linear expansion of the stretched body in the TD direction is -20 ppm / K or more and less than 0 ppm / K. Within the range, the linear expansion coefficient in the MD direction of the stretched material is -20 ppm / K or greater and 0 ppm / A heat-shrinkable LCP stretched film with a temperature range of less than K.

[0021] (9) The stretched body is 1.3 to 2 in the TD direction relative to the LCP extruded film for stretching. A heat-shrinkable LCP stretched film according to (8) having a stretching ratio of 0.5 times.

[0022] (10)(8) or (9) The heat-shrinkable LCP stretched film and the heat-shrinkable LCP The laminate comprises a stretched film with at least one woven fabric provided on at least one side. insulating material for circuit boards.

[0023] (11)(8) or (9) The heat-shrinkable LCP stretched film and the heat-shrinkable LCP A metal foil-clad laminate comprising a stretched film with metal foil provided on one and / or both sides.

[0024] (14)(8) or (9) contains at least one heat-shrinkable LCP stretched film and woven fabric. A laminate comprising a metal foil provided on one side and / or both sides of the laminate, Tension laminate. [Effects of the Invention]

[0025] According to one aspect of the present invention, the stretchability during stretching is excellent, thereby reducing the anisotropy of the dimensional change rate. Furthermore, a stretching process that enables the realization of a heat-shrinkable LCP stretched film with a small absolute value of dimensional change rate. This makes it possible to realize LCP extruded films and the like. Furthermore, according to one aspect of the present invention, dimensions A novel heat-shrinkable LCP stretched film with small anisotropy in the rate of change and small absolute values ​​in the rate of dimensional change. Furthermore, insulating materials for circuit boards and metal foil-clad laminates can be realized using these materials. Therefore, according to various aspects of the present invention, highly reliable products suitable for recent ultra-fine machining can be produced. This can be achieved. [Brief explanation of the drawing]

[0026] [Figure 1] This graph shows an example of a stress-strain curve in the TD direction of the LCP extruded film for stretching treatment according to the present invention. [Figure 2] This graph shows an example of a stress-strain curve in the TD direction of the LCP extruded film for stretching treatment according to the present invention. [Figure 3] This graph shows an example of a stress-strain curve in the TD direction for a conventional LCP extruded film used for stretching. [Figure 4] This figure shows a co-extrusion method for stretching an LCP extruded film according to one embodiment. [Figure 5] This figure shows a co-extrusion method for stretching an LCP extruded film according to one embodiment. [Figure 6] This figure shows a co-extrusion method for stretching an LCP extruded film according to one embodiment. [Figure 7] This is a schematic cross-sectional view showing an insulating material for a circuit board in one embodiment. [Figure 8] This is a schematic cross-sectional view showing a metal foil-clad laminate in one embodiment. [Figure 9] This is a schematic cross-sectional view showing a metal foil-clad laminate in one embodiment. [Modes for carrying out the invention]

[0027] The embodiments of the present invention will be described in detail below with reference to the drawings. Unless otherwise specified, the positional relationships of the elements shall be based on those shown in the drawings. The dimensional ratios of the surfaces are not limited to those shown in the illustration. However, the following embodiments are based on this. These are illustrative examples for illustrating the invention, and the present invention is not limited to these examples. The present invention can be implemented with modifications without departing from its essence. In this specification, for example, the notation of a numerical range "1 to 100" means that its lower limit is "1" and This should include both the upper limit value "100" and the upper limit value. The same applies to the notation of other numerical ranges. .

[0028] (LCP extruded film for stretching) The LCP extruded film for stretching in this embodiment contains a thermoplastic liquid crystal polymer, and the stretching process This is an LCP extruded film (stretched LCP extruded film) that can be uniformly stretched during processing.

[0029] As mentioned earlier, conventional LCP extruded films have a skin layer on the film surface. Delamination and peeling of fibrillated fibers occur on the film surface of the thermoplastic liquid crystal polymer. The molecules were extremely oriented in that region. This was due to shear stress from the side of the apparatus during extrusion. As a result, the thermoplastic liquid crystal polymer is highly oriented on the surface of the extruded product. It is presumed that this is the case. And, conventional technology in which thermoplastic liquid crystal polymers are highly oriented Even with LCP extruded films, stretching treatment can improve the anisotropy of the dimensional change rate and It was expected that this would enable the creation of LCP stretched films with a small absolute value of dimensional change rate. However, according to the inventors' findings, conventional LCP extruded films have a stretching process during stretching. It has very little suitability, and it is practically difficult to obtain industrially useful LCP stretched films. It was found that, specifically, conventional LCP extruded films are stretched in the TD direction, for example. Even a stretching process with a stretching ratio of 1.1 times can result in uneven stretching, for example, in the TD direction. Increasing the stretching ratio to 1.2 times can cause film breakage, indicating that the film is not suitable for stretching. It did not exist. On the other hand, by improving as shown in Patent Documents 1 and 2, thermoplastic liquid crystal It was confirmed that the extreme molecular orientation on the polymer film surface was alleviated, At the same time, controlling only the molecular orientation of thermoplastic liquid crystal polymers on the film surface is not enough to control the circuit The inventors' knowledge revealed that they could not create a material that could withstand the required performance as an insulating material for a substrate. This was revealed by observation.

[0030] The LCP extruded film for stretching treatment (the LCP extruded film to be stretched) of this embodiment is This was considered from that perspective. That is, the LCP extruded film for stretching in this embodiment. (The stretched LCP extruded film) has predetermined tensile properties so that it can move at least in the TD direction It possesses excellent stretchability, and therefore enables uniform stretching, which was difficult with conventional technology. And, by stretching this stretched LCP extruded film, the film surface and To reduce molecular orientation and internal strain of thermoplastic liquid crystal polymers occurring within the film. This results in a thermal shrinkage LC with low anisotropy and absolute value of dimensional change rate. P-stretched film can be realized.

[0031] The thermoplastic liquid crystal polymer contained in the stretched LCP extruded film is known in the industry. Any material can be used, and its type is not particularly limited. Liquid crystal polymers are optically anisotropic. These are polymers that form a molten phase, and typical examples include thermotropic liquid crystal compounds. The properties of the anisotropic fused phase can be determined using known methods such as polarization testing using orthogonal polarizers. Therefore, it can be confirmed. More specifically, the confirmation of the anisotropic molten phase can be done using Leitz polarization. Using a microscope, the sample placed on the Leitz hot stage was examined under a nitrogen atmosphere at 40x magnification. This can be done by observing.

[0032] Specific examples of thermoplastic liquid crystal polymers include aromatic or aliphatic dihydroxy compounds, fragrances Aliphatic or aliphatic dicarboxylic acids, aromatic hydroxycarboxylic acids, aromatic diamines, aromatic hydroxycarboxylic acids Examples include those obtained by polycondensation of monomers such as roxyamines and aromatic aminocarboxylic acids. These are not the only examples. Thermoplastic liquid crystal polymers are preferably copolymers. Specifically... These are monomers such as aromatic hydroxycarboxylic acids, aromatic diamines, and aromatic hydroxyamines. Aromatic polyamide resin obtained by polycondensation of aromatic diols, aromatic carboxylic acids, aromatic (Total) aromatic polyester resins obtained by polycondensation of monomers such as hydroxycarboxylic acids; etc. These include, but are not limited to, a single type or two or more types. It can be used in any combination and ratio.

[0033] Thermoplastic liquid crystal polymers are generally classified into Type I and Type II from the perspective of their thermal distortion temperature (TDUL). They are classified into types III, etc. The LCP extruded film for stretching in this embodiment is Even thermoplastic liquid crystal polymers of this type can be suitably used, depending on the application. They can be selected and used as appropriate. For example, they are suitable for use with lead-free solder at temperatures of around 230-260°C. For electronic circuit board applications, TDUL is a high-temperature resistant I-type with a temperature of approximately 250-350°C. This thermoplastic liquid crystal polymer, Type II, has a relatively high heat resistance of approximately 240-250°C. Thermoplastic liquid crystal polymers are preferably used.

[0034] Among these, those exhibiting thermotropic liquid crystal-like properties and having a melting point of 250°C or higher are preferred. Alternatively, a (fully) aromatic polyester resin with a melting point of 280°C to 380°C is preferably used. Examples of such (all) aromatic polyester resins include aromatic diols, aromatic Synthesized from monomers such as hydroxycarboxylic acids and other hydroxycarboxylic acids, exhibiting liquid crystalline properties upon melting. All aromatic polyester resins are known. A typical example is ethylene Polycondensate of terephthalate and parahydroxybenzoic acid, phenol and phthalic acid and para Polycondensation with hydroxybenzoic acid, 2,6-hydroxynaphthoic acid and parahydroxybenzoic acid Examples include polycondensation products with aromatic acids, but are not limited to these. Polyester resins can be used individually or in any combination and ratio of two or more types. This is possible. Depending on the required performance, a relatively high melting point or high heat distortion temperature and high heat resistance can be used. Aromatic polyester resins are used, or materials with a relatively low melting point or low heat distortion temperature are used for molding. Aromatic polyester resins with excellent workability can be used.

[0035] A preferred embodiment is 6-hydroxy-2-naphthoic acid and its derivatives (hereinafter referred to as It is sometimes simply referred to as "monomer component A." ) has as its basic structure, parahydroxy Benzoic acid, terephthalic acid, isophthalic acid, 6-naphthalenedicarboxylic acid, 4,4'-bifluic acid Enol, bisphenol A, hydroquinone, 4,4-dihydroxybiphenol, eth One or more selected from the group consisting of lenterephthalate and its derivatives are used as monomers. There is at least one component (hereinafter sometimes simply referred to as "monomer component B") Examples include (all) aromatic polyester resins. In a molten state, the linear chains of the molecules in the resin are arranged in a regular manner, forming an anisotropic molten phase, typically... It exhibits otropic liquid crystal-like properties, and possesses mechanical properties, electrical properties, high-frequency properties, heat resistance, and absorption properties. It will possess excellent basic performance in terms of moisture resistance and other factors.

[0036] Furthermore, the (all) aromatic polyester resin of the preferred embodiment described above has a minimum essential unit. Any configuration can be adopted as long as it contains monomer component A and monomer component B. For example, even if it has two or more monomer components A, it may have three or more monomer components A. It may also be used. Furthermore, the (all) aromatic polyester resin of the preferred embodiment described above may be mono Other monomer components other than monomer component A and monomer component B (hereinafter simply referred to as "monomer") It may contain the following: -Component C (which may be referred to as "component C"). One embodiment of the (all) aromatic polyester resin is derived solely from monomer component A and monomer component B. Even in polycondensates of two or more elements, monomer component A, monomer component B and monomer component It may also be a polycondensate of three or more monomer components consisting of C. Therefore, other than monomer components A and B mentioned above, specifically aromatic or Aliphatic dihydroxy compounds and their derivatives; aromatic or aliphatic dicarboxylic acids and their derivatives Forms; aromatic hydroxycarboxylic acids and their derivatives; fragrance diamines, aromatic hydroxyamines Examples include ammonium compounds or aromatic aminocarboxylic acids and their derivatives; however, the examples are not limited to these. It is not possible. Other monomer components may be used individually or in any combination and ratio of two or more. It can be used in [location / service].

[0037] In this specification, "derivative" refers to a monomer component that contains halogens. Atoms (e.g., fluorine, chlorine, bromine, iodine), alkyl groups with 1 to 5 carbon atoms. Groups (e.g., methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, iso Aryl groups such as butyl groups, s-butyl groups, t-butyl groups, etc., phenyl groups, hydroxyl groups, carbon 1 to 5 alkoxy groups (e.g., methoxy group, ethoxy group, etc.), carbonyl group, -O-, Those that have modified groups such as -S-, -CH2-, etc. introduced (hereinafter referred to as "having substituents") It is sometimes referred to as a "monomer component." ) Here, "derivative" means the above-mentioned derivative. Acylated compounds, ester derivatives, or acid compounds of monomer components A and B, which may have decorative groups. They may also be ester-forming monomers such as chloromethyl compounds.

[0038] In one particularly preferred embodiment, parahydroxybenzoic acid and its derivatives and 6-hydroxybenzoic acid C-2-naphthoic acid and its derivatives in binary polycondensates; parahydroxybenzoic acid and so A ternary system of derivatives of 6-hydroxy-2-naphthoic acid and its derivatives and monomer component C The above polycondensates; parahydroxybenzoic acid and its derivatives and 6-hydroxy-2-naphtho E acids and their derivatives, terephthalic acid, isophthalic acid, 6-naphthalenedicarboxylic acid, 4, 4'-Biphenol, Bisphenol A, Hydroquinone, 4,4-Dihydroxybiphen One or more selected from the group consisting of ethanol, ethylene terephthalate, and derivatives thereof. A ternary or higher polycondensate consisting of; parahydroxybenzoic acid and its derivatives and 6-hydroxy C-2-naphthoic acid and its derivatives, terephthalic acid, isophthalic acid, 6-naphthalenediacid Rubonic acid, 4,4'-biphenol, bisphenol A, hydroquinone, 4,4-dihydrogen Selected from the group consisting of roxybiphenol, ethylene terephthalate, and derivatives thereof. Examples include polycondensates of quaternary or greater systems consisting of one or more elements and one or more monomer components C; These have relatively low melting points compared to, for example, homopolymers of p-hydroxybenzoic acid. It can be obtained as having these properties, and therefore thermoplastic liquid crystal polymers using these properties are This results in excellent formability when heat-pressed onto the adherend.

[0039] (Total) lowering the melting point of aromatic polyester resin, LCP extruded film for stretching or To improve the moldability of the stretched body when it is heat-pressed onto the adherend, or for LCP extrusion for stretching treatment From the perspective of obtaining high peel strength when a film or its stretched form is heat-pressed onto a metal foil The molar ratio of monomer component A to the (total) aromatic polyester resin is 1 Preferably, the concentration is 0 mol% to 90 mol%, and more preferably 30 mol% to 85 mol%. More preferably, 50 mol% to 80 mol%. Similarly, (all) aromatic polyester The molar ratio of monomer component B to the resin is between 10 mol% and 90 mol%. Preferably, 15 mol% or more and 70 mol% or less, more preferably 20 mol% or more and 50 mol% The following are even more preferable. Also, substances that may be included in the (all) aromatic polyester resin. The content of component C is preferably 10 mol% or less in terms of molar ratio, and more preferably 8 mol%. It is less than 1% of 5 mol%, more preferably less than 5 mol%, and particularly preferably less than 3 mol%.

[0040] Furthermore, known methods can be applied to the synthesis of (whole) aromatic polyester resins. , and not particularly limited. Known polycondensation that forms ester bonds with the monomer components described above. Legal methods such as melt polymerization, melt acidolysis, and slurry polymerization can be applied. When applying these polymerization methods, the acylation or acetylation step is performed according to the conventional method. That's fine.

[0041] The LCP extruded film for stretching may further contain an inorganic filler. By incorporating a film, an LCP extruded film for stretching is realized with a reduced coefficient of linear expansion. Specifically, this can be done in the MD direction, TD direction, and ZD direction (Z-axis direction; film thickness). This makes it easier to obtain LCP extruded films for stretching that have reduced anisotropy in the coefficient of linear expansion (in the direction of expansion). Such LCP extruded films for stretching are, for example, rigid bases required for multilayer lamination. It is particularly useful in applications such as boards.

[0042] Inorganic fillers can be those known in the industry, and their types are not particularly limited. For example, kaolin, calcined kaolin, calcined clay, uncalcined clay, silica (for example, natural silica) Lica, fused silica, amorphous silica, hollow silica, wet silica, synthetic silica, aero Zill, etc.), aluminum compounds (e.g., boehmite, aluminum hydroxide, alumina, etc.) Idrotalcite, aluminum borate, aluminum nitride, etc.), magnesium compounds ( For example, magnesium aluminometasilicate, magnesium carbonate, magnesium oxide, water Magnesium oxide, etc.), calcium compounds (e.g., calcium carbonate, calcium hydroxide, Calcium sulfate, calcium sulfite, calcium borate, etc.), molybdenum compounds (e.g.) Molybdenum oxide, zinc molybdate, etc.), talc (e.g., natural talc, calcined talc, etc.), Mica, titanium dioxide, zinc oxide, zirconium oxide, barium sulfate, zinc borate Barium metaborate, sodium borate, boron nitride, aggregated boron nitride, silicon nitride, Examples include carbon nitride, strontium titanate, barium titanate, zinc stanate, and other stannate salts. However, these are not the only options. One type can be used alone, or two types can be used together. The above can also be used in combination. Among these, from the viewpoint of dielectric properties, etc., silicon Ka is preferable.

[0043] Furthermore, the inorganic fillers used here are those that have undergone surface treatment known in this industry. This is also acceptable. Surface treatment can improve moisture resistance, adhesive strength, dispersibility, etc. The treatment agents include silane coupling agents, titanate coupling agents, and sulfonic acid esters. Examples include, but are not limited to, carboxylates, phosphate esters, etc. .

[0044] The median diameter (d50) of the inorganic filler can be set appropriately according to the required performance, and is not particularly limited It is not done. From the viewpoint of kneadability and handling during preparation, and the effect of reducing the coefficient of linear expansion, inorganic fillers The d50 is preferably 0.01 μm or more and 50 μm or less, and more preferably 0.03 μm or less. The particle size is 50 μm or less, more preferably 0.1 μm or more and 50 μm or less. In this case, the median diameter (d50) of the inorganic filler is determined by the particle size distribution of the laser diffraction / scattering method. Using a measuring device (LA-500 manufactured by Horiba, Ltd.), volume bases were determined by laser diffraction and scattering. It refers to the value measured in a specific order.

[0045] The amount of inorganic filler will be determined considering the balance of other essential and optional components. The settings can be adjusted as appropriate depending on the performance, and are not particularly limited. Factors such as kneadability and handling during preparation, and the coefficient of linear expansion are considered. From the perspective of reduction effects, etc., in terms of solid content relative to the total amount of LCP extruded film for stretching, The total content of the filler is preferably 1% by mass or more and 45% by mass or less, and more preferably The total amount is 3% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 35% by mass or less. It is below.

[0046] The LCP extruded film for stretching treatment is, to the extent that it does not excessively impair the effects of the present invention, as described above. Resin components other than thermoplastic liquid crystal polymers (hereinafter referred to simply as "other resin components") It may contain, for example, thermosetting resins or thermoplastic resins. The LCP extruded film for processing is made of materials known in the industry, to the extent that it does not excessively impair the effects of the present invention. Additives, such as higher fatty acids with 10 to 25 carbon atoms, higher fatty acid esters, and higher fatty acid amides. Release agents such as higher fatty acid metal salts, polysiloxanes, and fluororesins; colorants such as dyes and pigments. Agents; organic fillers; antioxidants; heat stabilizers; light stabilizers; UV absorbers; flame retardants; antistatic agents It may contain surfactants, rust inhibitors, defoamers, fluorescent agents, etc. These additives are Each of these additives can be used individually or in combination of two or more. It can be included in the molten resin composition prepared during the molding of LCP extruded film for stretching treatment. The content of these resin components and additives is not particularly limited, but it is important for moldability and thermal stability. From these perspectives, the amounts are set at 0.01 to 10 for each of the total amount of LCP extruded film for stretching. Preferably, each is mass%; more preferably, each is 0.1 to 7 mass%; and even more preferably, each It is 0.5 to 5% by mass.

[0047] The LCP extruded film for stretching in this embodiment has predetermined tensile properties, thus, compared to conventional techniques Unlike other methods, it has good stretchability in the TD direction at least and allows for uniform stretching during the stretching process. Specifically, the LCP extruded film for stretching in this embodiment undergoes a constant temperature bath tensile test ( Measured according to JIS K7161-1:2014, at 200°C and a tensile speed of 200 mm / min. In the defined stress-strain curve, the TD direction of the LCP extruded film for stretching treatment The slab strength X (MPa) and the rupture strength Y (MPa) satisfy the following equation (1). 0.75 ≤ breaking point strength Y / yield point strength X ≤ 1.50 ···(1)

[0048] Here, the tensile test conducted in accordance with JIS K7161-1:2014 is performed on the test specimen. The test specimen is moved along its main axis at a constant speed until it breaks (perpendicular to the cross-section of the test specimen). This is a tensile test (at a constant speed) that measures the force and elongation applied to the test specimen. The point strength X (MPa) is the strongest point within the yield region of the stress-strain curve obtained in the above tensile test. This indicates a high point; the higher this value, the greater the force required to deform the material. The breaking point strength Y (MPa) represents the stress immediately before the test specimen breaks in the tensile test described above. The higher the value of Y, the greater the force required to break the material. On the other hand, the ratio of breaking point strength Y to yield strength is also important. Point strength X is the stress-strain curve obtained in a tensile test, and is the difference between the fracture point strength Y and the yield point strength. This represents the intensity ratio of degree X. Figures 1 and 2 show the present invention satisfying 0.75 ≤ Y / X ≤ 1.50. This graph shows an example of a stress-strain curve in the TD direction of an LCP extruded film for stretching. Furthermore, Figure 3 shows a conventional LCP extruded film for stretching treatment corresponding to Y / X < 0.75. This graph shows an example of a stress-strain curve in the TD direction. Comparing Figures 1 to 3, As can be understood, the LCP extruded film for stretching of the present invention is superior to the prior art in terms of breaking down Because the strength ratio of point strength Y to yield strength X is relatively large, it exhibits uniform tensile properties under a constant load. Furthermore, the displacement (horizontal axis) from the yield strength X to the fracture strength Y correlates with the elongation ratio. Furthermore, the large amount of displacement indicates that a high stretch ratio can be applied. In other words, the LCP extruded film for stretching according to this embodiment that satisfies the above formula (1) is a conventional technology Unlike other methods, it allows for relatively uniform stretching and can be applied to relatively high stretching ratios. It is understood that this is the case.

[0049] The value of the fracture point strength Y / yield point strength X in the TD direction is not particularly limited, but is preferably 0. It is 80 or more and 1.50 or less, more preferably 0.85 or more and 1.50 or less, and further Preferably, it is 0.90 or more and 1.35 or less, and particularly preferably 0.90 or more and 1.20 or less. The larger this value, the greater the tendency for uniform stretchability in the TD direction to be. In this context, the values ​​of fracture point strength Y / yield point strength X are determined as described later, from the perspective of ensuring measurement accuracy. The average value obtained from five tensile tests conducted under the conditions described in the examples is used.

[0050] Furthermore, the value of the fracture point strength Y / yield point strength X in the MD direction is not particularly limited. When uniform stretchability is required, the value of the fracture point strength Y / yield point strength X in the MD direction is 0 Preferably, it is between 0.75 and 1.50, and more preferably between 0.80 and 1.50. More preferably 0.85 to 1.50, and particularly preferably 0.90 to 1.5 It is 0 or less. The larger this value, the greater the tendency for uniform stretchability in the MD direction to be improved.

[0051] As LCP extruded films for stretching, melt extruded films such as T-die extruded films are used. Preferably used. In addition, as the LCP extruded film for stretching, a thermoplastic resin layer, A laminated structure in which a thermoplastic liquid crystal polymer layer and a thermoplastic resin layer are arranged in at least this order. A thermoplastic liquid crystal polymer layer, which is the intermediate layer (core layer) of the three-layer co-extruded film having the above characteristics, is also preferred. It is used. In this case, by removing the thermoplastic resin layers of both outer layers of the three-layer co-extruded film. Used as a single-layer thermoplastic liquid crystal polymer film (LCP extruded film for stretching). It is possible. The extruded film of thermoplastic liquid crystal polymer is made of thermoplastic liquid crystal polymer fibers. Compared to woven and nonwoven fabrics, it is possible to manufacture uniform products at a lower cost.

[0052] The thickness of the LCP extruded film for stretching can be set as appropriate according to requirements and is not particularly limited. No. Considering handling and productivity during extrusion molding, a thickness of 15 μm to 300 μm is preferred. More preferably 18 μm to 250 μm, and even more preferably 20 μm to 20 It is 0 μm or less.

[0053] On the other hand, the LCP extruded film for stretching in this embodiment undergoes linear expansion in the MD direction and the TD direction. It is preferable that the molecular orientation of the thermoplastic liquid crystal polymer, expressed by a coefficient, is sufficiently reduced. As mentioned earlier, the LCP extruded films described in prior art patent documents 1 and 2 are three During co-extrusion of layers, the thermoplastic liquid crystal polymer is protected by the thermoplastic resin layers on both outer layers. The molecular orientation is slightly relaxed, thereby affecting the MD orientation of the resulting thermoplastic liquid crystal polymer film. It appears that the anisotropy of the strength in the directional and TD directions has been mitigated. However, in reality The LCP extruded films described in Patent Documents 1 and 2 have a coefficient of linear expansion in the MD direction of -20p. While a stable value of around pm / K is obtained, the coefficient of linear expansion in the TD direction is 55 ppm. It exceeds this level, sometimes reaching around 100 ppm / K. This is also clear from this. Thus, the LCP extruded films described in the prior art patent documents 1 and 2 are such that the entire film and Therefore, the molecular orientation of the thermoplastic liquid crystal polymer remains largely intact, or internal strain is present. It is easy to see that a large portion of the structure remains intact.

[0054] The LCP extruded film for stretching in this embodiment has a linear expansion coefficient in the MD direction and the TD direction ( The CTE (α2, 23~200℃) should preferably be in the range of -30~55 ppm / K. LCP extruded films for stretching that have a coefficient of linear expansion within this range have low internal strain, etc. In a reduced state, the anisotropy of the dimensional change rate is smaller compared to those that are not reduced, and the dimensional It can become an LCP extruded film for stretching with a sufficiently small absolute value of the rate of change. The coefficient of linear expansion (CTE, α2, 23~200℃) in the MD direction of LCP extruded film is that of metals. From the perspective of improving adhesion to the foil, a range of -30 to 10 ppm / K is preferred. Furthermore, it is more preferable that the concentration be within the range of -25 to 5 ppm / K, and more preferably -20 to 0 ppm / K. It is even more preferable that it be within the range. Also, the TD direction of the LCP extruded film for stretching. The coefficient of linear expansion (CTE, α2, 23~200℃) is considered from the perspective of improving adhesion to metal foil, etc. Therefore, it is preferable that it be within the range of 0 to 55 ppm / K, and within the range of 5 to 55 ppm / K. It is more preferable that the concentration be within the range of 5 to 50 ppm / K. In this specification, the coefficient of linear expansion (CTE, α2, 23~200℃) is defined as JIS K This refers to values ​​measured by the TMA method compliant with 7197 in the temperature range of 23-200°C. Furthermore, other detailed measurement conditions shall follow the conditions described in the examples below.

[0055] On the other hand, the dielectric properties of the LCP extruded film for stretching in this embodiment are appropriate according to the desired performance. It can be set as appropriate and is not particularly limited. From the viewpoint of obtaining higher dielectric properties, the relative permittivity ε r (36 The frequency (GHz) is preferably 3.0 to 3.7, and more preferably 3.0 to 3.5. Similarly, the dielectric loss tangent tanδ (36 GHz) is preferably between 0.0010 and 0.0050. More preferably, it is 0.0010 or more and 0.0045 or less. , relative permittivity ε r (36GHz) and dielectric loss tangent tanδ(36GHz) are defined in JIS K64. This refers to the value at 36 GHz measured using the cavity resonator contact method compliant with 71. Also, Other detailed measurement conditions shall follow the conditions described in the examples below.

[0056] (Method for manufacturing LCP extruded film for stretching) The LCP extruded film for stretching in this embodiment is made of the thermoplastic liquid crystal polymer described above, and A resin composition containing optional components such as inorganic fillers or other resin components as needed is prepared to a predetermined thickness. It can be obtained by extrusion molding. Extrusion methods can be applied using various known methods. It is possible, and the type is not particularly limited. For example, the T-die method or the inflation method; for example, the multi-die method. Co-extrusion methods using the manifold or feedblock; for example, two-layer co-extrusion. Multilayer co-extrusion methods, such as the three-layer co-extrusion method, can be applied in any combination.

[0057] Among these, the film surface (film surface S1) and the inside of the film (film surface From the viewpoint of ease of controlling the molecular orientation of the thermoplastic liquid crystal polymer in S2), a preferred one In one embodiment, the above-mentioned resin composition is extruded using a T-die (hereinafter, simply This is sometimes called the "T-die extrusion method." ) The material is extruded from a T-die and formed into a film. Then, if necessary, cooling treatment, crimping treatment, pressurized heating treatment, etc. are performed to prepare for the predetermined stretching process. One method for obtaining LCP extruded film is described. Specifically, a first surface layer containing thermoplastic resin Resin composition A for the intermediate layer containing a thermoplastic liquid crystal polymer, The resin composition C for the second surface layer, which contains the resin, is prepared separately and then extruded from the co-extrusion die of the extruder. These are co-extruded to extrude a three-layer co-extruded molten material, and the intermediate layer is a thermoplastic liquid crystal polymer. A co-extrusion method is preferred in which an LCP extruded film for stretching is formed as one layer. According to extrusion molding, the thermoplastic layer of the intermediate layer is protected by the thermoplastic resin layers of both outer layers. The molecular orientation of the thermoplastic liquid crystal polymer in the liquid crystal polymer layer is relaxed. A preferred embodiment of a method for manufacturing LCP extruded film for stretching is described in detail.

[0058] Figures 4 to 6 show the preferred method for manufacturing the stretched LCP extruded film of this embodiment described above. This figure shows one possible embodiment. Here, the thermoplastic liquid crystal polymer described above, and as needed The above resin composition B, which contains optional components such as inorganic fillers and other resin components, is then extruded using the T-type extruder. From (i), it is melt-extruded into a film. At this time, heat is applied to both sides of the above-mentioned film-like molten extruded material. By co-extruding resin compositions A and C containing a plastic resin, a first outer layer containing a thermoplastic resin is formed. A release layer, an intermediate layer (LCP layer) containing a thermoplastic liquid crystal polymer, and a thermoplastic resin containing a A co-extruded molten product (3-layer laminated film) of a predetermined thickness, having two outer layers (release layers), is produced. This co-extruded molten material is drawn out by a take-up roll and sent to a cooling roll and a crimping roll. Subsequently, the first outer layer and the second outer layer are peeled off from the intermediate layer, and the thermoplastic resin layers of both outer layers and the middle layer are separated. The thermoplastic liquid crystal polymer layer (LCP extruded film for stretching) in the interlayer is then carried along by the winding roll. They are reeled in.

[0059] The preparation of resin composition B containing the above-mentioned thermoplastic liquid crystal polymer can be carried out according to a conventional method. The process is not particularly limited. Each of the above components may be processed by, for example, kneading, melt kneading, granulation, extrusion molding, etc. It can be manufactured and processed by known methods such as molding or injection molding. When mixing, a single-screw or twin-screw extruder or various kneaders are commonly used. A kneading device can be used. When supplying each component to these melting and kneading devices, liquid crystal particles can be used. Rimmer, other resin components, inorganic fillers, additives, etc. are pre-mixed in a tumbler or Henschel mixer. Dry blending may be performed using a mixing device such as a siphon. During melt mixing, the syringe of the mixing device The setting temperature can be set as appropriate and is not particularly limited, but generally it is the melting point of the liquid crystal polymer. A range of 360°C or less is preferred, and more preferably 10°C or more above the melting point of the liquid crystal polymer. It is below 60℃.

[0060] The preparation of resin compositions A and C, which contain thermoplastic resins, can also be carried out according to conventional methods, and there are no particular limitations. Not specified. Examples of thermoplastic resins include polyethylene, polypropylene, and polymethyl Lupentene, polyolefin resins such as ethylene-α-olefin copolymers, PMMA, etc. Acrylic resins, polyamide resins, acrylonitrile-butadiene-styrene copolymers (ABS resin), polystyrene (PS), polyvinyl chloride, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polycarbonate (PC), poly Examples include ether ether ketone (PEEK) and polyphenyl sulfide (PPS). However, it is not limited to these. When it is made into a co-extruded molten product, polycarbonate and the like Whether it is a polar resin or a non-polar resin such as polymethylpentene, it is effective as a release layer. These thermoplastic resins are included in the LCP extruded film for stretching described above. Other resin components or inorganic fillers may be added. Even if product A and resin composition C have the same resin composition, they may have different resin compositions. It is also possible to include the same thermoplastic resin or different thermoplastic resins. Furthermore, resin compositions A and C, which contain thermoplastic resins, can be subjected to processes such as kneading, melt kneading, granulation, and extrusion. It can be manufactured and processed by known methods such as molding, pressing, or injection molding. When performing melt-mixing, commonly used single-screw or twin-screw extruders and various kneaders are used. - Mixing equipment such as the above can be used. When supplying each component to these melting and mixing equipment Thermoplastic resins, other resin components, inorganic fillers, additives, etc. are pre-treated in tumblers and hexagonal molds. Dry blending may be performed using a mixing device such as a molten mixer. During melting and kneading, a kneading device is used. The cylinder temperature setting should be set appropriately to a temperature below which the thermoplastic resin does not deteriorate due to thermal decomposition. While not particularly limited, generally a temperature above the melting point of the thermoplastic resin is preferred, and more preferably... The melting point of the thermoplastic resin is 10°C or higher.

[0061] The setting conditions for co-extrusion depend on the type and composition of the resin composition used and the target extruded film. The settings can be set appropriately according to the desired performance, etc., and are not particularly limited. For example, the cylinder of an extruder The set temperature depends on the type and composition of the resin composition used, and the desired performance of the extruded film. The temperature can be set appropriately depending on the circumstances, and is not particularly limited, but 230 to 360°C is preferred. Preferably, the temperature is 280-350°C.

[0062] Similarly, the die width (mm) of a T-die also depends on the type and composition of the resin composition used, and the size of the die. The setting can be appropriately determined according to the desired performance of the target extruded film, and is not particularly limited. Generally, 200 to 2000 mm is preferred, and more preferably 400 to 1500 mm. ru.

[0063] Furthermore, for example, the lip opening (mm) of a T-die is similarly affected by the type and combination of resin compositions used. The setting can be appropriately determined according to the desired performance of the extruded film, and is not particularly limited. However, generally, 0.1 to 3.0 (mm) is preferred, and more preferably 0.2 to 2.0 ( It is (mm).

[0064] And, for example, the shear rate of the lip wall of the T-die (sec -1 Similarly, the resin components used The settings should be adjusted appropriately according to the type and composition of the product, the desired performance of the extruded film, etc. While not particularly limited, generally 100-1500 (sec) -1 ) is preferable, and more preferable 150-1000 (sec) -1 )

[0065] Also, the total discharge volume (mm) of the resin composition of the T-die 3 Similarly, the resin composition used ( / sec) The settings can be adjusted as appropriate depending on the type and composition of the material, the desired performance of the extruded film, etc. While not limited to this range, generally 500-15000 (mm) 3 ( / sec) is preferred, and more preferably The range is 1500-10000 (mm 3 ( / sec)

[0066] On the other hand, the melt viscosity (Pa·sec) of thermoplastic liquid crystal polymers is similarly determined by the resin composition used. The settings can be adjusted as appropriate depending on the type and composition of the material, the desired performance of the extruded film, etc. While not limited to these, generally 10 to 300 (Pa·sec) is preferred, more The melt viscosity of thermoplastic liquid crystal polymers is 20-250 (Pa·sec). The sec) conforms to JIS K7199 and uses a Capillograph 1D (manufactured by Toyo Seiki Seisakusho Co., Ltd.). Using this, the cylinder length is 10.00 mm, the cylinder diameter is 1.00 mm, and the barrel diameter is 9. Under conditions of 55mm, under the conditions used in the manufacture of LCP extruded film for stretching (die temperature, and ri This refers to the value measured by the shear rate of the top wall.

[0067] Similarly, the take-up speed (mm / sec) of the co-extruded film also depends on the type of resin composition used. The type and composition, the desired performance of the extruded film, etc., can be set appropriately, and there are no particular limitations. Although not specified, generally 15 to 1000 (mm / sec) is preferred, and more preferably 20 It is approximately 500 (mm / sec).

[0068] Here, from the perspective of reducing the molecular orientation of thermoplastic liquid crystal polymers in the MD direction during co-extrusion It is desirable that the shear stress (kPa) during co-extrusion be low. This makes it easier for thermoplastic liquid crystal polymers to be highly oriented in the MD direction, and also makes it easier for internal strain to remain. in the direction, when the shear stress during coextrusion is small, in both the film surface and the film interior the molecular orientation of the thermoplastic liquid crystal polymer tends to be reduced, and internal strain also tends not to remain . The shear stress (kPa) during coextrusion is a value represented by the product of the shear rate (sec -1 ) of the lip wall surface and the melt viscosity (Pa·sec) of the thermoplastic liquid crystal polymer, and the shear rate is a value calculated based on the total discharge amount of the resin composition, die width, and lip opening during coextrusion . Therefore, the shear stress during coextrusion can be controlled by adjusting these respective values . Specifically, the shear stress during coextrusion is preferably 40 kPa or less, more preferably 38 kPa or less, and even more preferably 36 kPa or less. The lower limit value is not particularly limited, but considering productivity and the like, 5 kPa or more is preferable, and more preferably 1 0 kPa or more.

[0069] Also, from the perspective of reducing the molecular orientation of the thermoplastic liquid crystal polymer in the MD direction during coextrusion, the drawdown ratio during coextrusion is desirably low. When the drawdown ratio during coextrusion is large, the thermoplastic liquid crystal polymer tends to be highly oriented in the MD direction, and internal strain also tends to remain. When the drawdown ratio during coextrusion is small, in both the film surface and the film interior, the molecular orientation of the thermoplastic liquid crystal polymer tends to be reduced, and internal strain also tends not to remain . The drawdown ratio is a value represented by the take-up speed (mm / sec) / the flow rate (mm / sec) of the thermoplastic liquid crystal polymer, and the flow rate of the thermoplastic liquid crystal polymer is a value calculated based on the total discharge amount of the resin composition, die width, and lip opening during coextrusion. Thus Therefore, the drawdown ratio during co-extrusion can be controlled by adjusting each of these values. Specifically, the drawdown ratio during co-extrusion is preferably 3.5 or less, and more preferably... Or 3.3 or less, more preferably 3.1 or less. The lower limit is not particularly limited Although not required, considering productivity and other factors, a value of 1.0 or higher is preferable, and more preferably 1.2 or higher. be.

[0070] The thickness of the resulting LCP extruded film for stretching can be set appropriately according to the requirements, in particular Not limited. Considering handling and productivity during extrusion molding, 15 μm to 300 μm. The lower part is preferable, more preferably 18 μm to 250 μm, and even more preferably 20 μm. The size is 200 μm or less.

[0071] The melting point (melting temperature) of the resulting LCP extruded film for stretching is not particularly limited, From the standpoint of heat resistance and processability of the film, the melting point (melting temperature) should be between 200 and 400°C. This is preferable, and in particular, from the viewpoint of improving the thermocompression adhesion to metal foil, 250 to 360°C is preferred. More preferably 260-355°C, even more preferably 270-350°C, particularly preferred The temperature is 275-345°C. In this specification, LCP extrusion film for stretching treatment The melting point of the material was determined using a DSC8500 (manufactured by PerkinElmer) to eliminate the thermal history. To observe the values, the extruded film was heated at a rate of 20°C / min in the temperature range of 30-400°C. After heating (1st heating), cool at a rate of 50°C / min (1st cooling) (ling), followed by a second heating at a heating rate of 20°C / min (2nd heating) This refers to the melting peak temperature in differential scanning calorimetry (DSC) when ) is performed. For other aspects, the measurement conditions described in the examples below shall be followed.

[0072] Furthermore, the extruded LCP extruded film for stretching can be used as is. However, by performing a pressurized heating process as needed, its orientation (anisotropy) can be further improved. This can reduce or further release internal strain, thereby reducing the anisotropy of the dimensional change rate. LCP extruded films for stretching with reduced stretching properties and films with smaller absolute values ​​of dimensional change. It is also possible to create LCP extruded films for stretching.

[0073] The heat and pressure treatment is carried out using methods known in the industry, such as contact heat treatment, non-contact heat treatment, etc. Any type of device can be used, and the type is not particularly limited. For example, a non-contact heater, an oven, Known machines such as blowing machines, hot rolls, cooling rolls, hot presses, and double belt hot presses. It can be heat-set using a container. At this time, if necessary, LCP extrusion for stretching can be performed. A release film or porous film known in this industry is placed on the surface of the film, and then heat treatment is performed. This can be done. Also, when performing this heat treatment, from the viewpoint of controlling orientation, the stretching treatment L A double belt press machine is used to press CP extruded film by placing release film or porous film on both sides. The endless belt pair is sandwiched and heat-pressed, and then a release film or porous film is applied. A hot-press molding method for removing film is preferably used. For example, a hot-press molding method is described in Japanese Patent Application Publication No. 201. This can be done by referring to No. 0-221694, etc. LC for stretching treatment using the above resin composition. When hot-pressing P extruded film between the endless belt pair of a double belt press machine As for the temperature, in order to control the crystalline state of the LCP extruded film for stretching, the liquid crystal polymer It is preferable to carry out the procedure at a temperature higher than the melting point and 70°C higher than the melting point, and more preferably at a temperature higher than the melting point. More preferably, the temperature is 5°C higher than the melting point and 60°C higher than the melting point. The temperature is between 10°C above the melting point and 50°C above the melting point. The conditions can be set appropriately according to the desired performance and are not particularly limited, but a surface pressure of 0.5~ It is preferable to carry out the process under conditions of 10 MPa and a heating temperature of 250 to 430°C, and more preferably... Under conditions of a surface pressure of 0.6 to 8 MPa and a heating temperature of 260 to 400°C, more preferably a surface pressure of 0. This is under conditions of 7-6 MPa and a heating temperature of 270-370°C. On the other hand, non-contact heaters and When using a microwave oven, for example, the process can be carried out under conditions of 200-320°C for 1-20 hours. preferable.

[0074] (LCP stretched film) The LCP extruded film for stretching described above is subjected to uniaxial and / or biaxial stretching. To be used in the form of CP stretched film 100 (stretched LCP extruded film for stretching treatment). This can be done. At this time, even if the LCP stretched film 100 is heat-shrinkable in the TD direction, it will not expand in the heat. It may be tensile, but it is preferable that it be heat-shrinkable in the TD direction. The stretched film 100 may be either heat-shrinkable or heat-expandable in the MD direction, but M It is preferable that it is heat-shrinkable in the D direction. In this specification, heat-shrinkable LCP stretching The film is an LCP stretched film that exhibits heat shrinkage in the TD and MD directions. This means that it is thermally shrinkable, and the coefficient of linear expansion (ppm / K), which will be described later, is negative. This is supported by [the following].

[0075] The setting conditions during the stretching process depend on the type and composition of the resin composition used and the desired LCP stretching. The settings can be appropriately determined according to the desired performance of the film 100, and are not particularly limited. Uniaxial stretching In such cases, for example, the LCP extruded film for stretching described above is moved in the TD direction (Transverse It can be stretched 1.3 to 2.5 times in the direction (lateral direction) at 90 to 180°C, and It is preferable to perform a heat treatment (heat set) at, for example, 100-240°C for 1-600 seconds afterward. The stretch ratio in the TD direction is preferably 1.4 to 2.4 times, and 1.5 to 2.3 times is preferable. Preferably, 1.6 to 2.3 times is more preferable. In the case of biaxial stretching, for example, as described above The LCP extruded film for stretching is preferably in the MD direction (Machine Direction; longitudinal direction). ) is stretched to 1.3 to 2.5 times its original size at 70 to 180°C to form a uniaxially oriented film, and then further T Stretch 1.1 to 2.5 times in the D direction (Transverse Direction) at 90 to 180°C. This can be done, followed by a heat treatment (heat setting) at, for example, 100-240°C for 1-600 seconds. It is preferable to perform the following. At this time, simultaneous biaxial stretching can be performed instead of sequential stretching. The stretching ratio is not particularly limited, but it improves film transportability, release properties, and the occurrence of thickness unevenness and wrinkles. From the perspective of suppressing growth, etc., the total stretch ratio in the MD direction × TD direction (the stretch ratio in the MD direction is m) Furthermore, when the stretching ratio in the TD direction is n, the stretching ratio expressed as m × n is 1.3 times or more. Preferably, more preferably 1.4 times or more, even more preferably 1.5 times or more, particularly preferably It is 1.6 times or more. While there is no particular upper limit, a guideline is 6.0 times or less. Preferably 5.0 times or less, more preferably less than 4.0 times, and even more preferably 3.0 It is less than double. Also, when heat setting, methods known in the industry, such as contact heat treatment, Non-contact heat treatment can be performed, and the type is not particularly limited. For example, non-contact heat treatment Heaters, ovens, blowers, hot rolls, cooling rolls, hot presses, double belt hot presses Heat setting can be done using known equipment such as a heat setter. At this time, if necessary, L A release film or porous film known in the industry is placed on the surface of the CP stretched film 100. This allows for heat and pressure treatment.

[0076] The MD direction of the stretched LCP film 100 (stretched body of LCP extruded film for stretching treatment) and The coefficient of linear expansion in the TD direction (CTE, α2, 23~200℃) is set appropriately according to the desired performance. It is possible, and is not limited to, reducing the anisotropy of the rate of dimensional change and the absolute value of the rate of dimensional change. From the perspective of improving adhesion to metal foil, etc., the range is -20 to 0 ppm / K. It is preferable that the concentrations be within the range of -15 to 0 ppm / K, and more preferably within that range. Furthermore, it is more preferable that each is within the range of -13 to 0 ppm / K, and each - A concentration within the range of 10 to 0 ppm / K is particularly preferable.

[0077] (Insulating material for circuit boards) Figure 7 is a schematic cross-sectional view showing the main parts of the insulating material 200 for circuit boards according to this embodiment. The insulating material 200 for circuit boards in the form of the above-mentioned LCP stretched film 100 (for stretching treatment) A woven fabric WF is provided on one and / or both sides of the stretched CP extruded film. It comprises a laminated structure.

[0078] Specifically, the insulating material 200 for circuit boards is LCP stretched film 100, woven fabric WF, and The LCP stretched film 100 is arranged in a laminated structure (3-layer structure) in at least this order. It comprises a laminate. In this laminate, one of the LCP stretched films 100 is woven The other LCP stretched film 100 is provided on the surface side of the WF fabric, and the other LCP stretched film 100 is provided on the back side of the WF fabric. These three layers are heat-sealed together, thereby forming a three-layer laminate. Here, a laminated structure with three layers is given as an example, but the present invention relates to one of the LCP stretched fills. Even in a two-layer laminated structure with the 100 layer omitted, LCP stretched film 100 and woven fabric WF Needless to say, this can also be done with laminated structures of four or more layers, which are further stacked. do not have.

[0079] Hereinafter, in this specification, "woven fabric W on one side and / or both sides of LCP stretched film 100" "F is provided" means that, as in this embodiment, the surface of the woven fabric WF is covered with an LCP stretched film 100 In addition to the embodiment in which it is directly placed, the illustration shows the LCP stretched film 100 and the woven fabric WF being placed between them. Any layer (e.g., primer layer, adhesive layer, etc.) intervenes, and the LCP stretched film 100 This means that it includes configurations in which the elements are positioned at a distance from the woven fabric WF.

[0080] Woven fabric WF is a fabric made by weaving fibers. The type of fiber used in woven fabric WF is not particularly limited. It can be used with any of the following: inorganic fibers, organic fibers, or organic-inorganic hybrid fibers. In particular, inorganic fiber woven fabric WF is preferably used. Inorganic fiber woven fabric WF is LCP By heat-pressing the stretched film 100, the anisotropy of the dimensional change rate in the MD direction and TD direction is reduced. This can be kept small, and in a more preferred embodiment, the dimensional change rates in the MD and TD directions themselves can be It can be made smaller. Commercially available products can be used as woven WF, and in this industry It can be manufactured by known methods.

[0081] Examples of inorganic fibers include E glass, D glass, L glass, M glass, S glass, and T glass. Glass, Q glass, UN glass, NE glass, spherical glass, glass fibers, quartz, etc. Examples include inorganic fibers other than glass, ceramic fibers such as silica, etc., but are not limited to these. It is not fixed. Inorganic fiber woven fabrics WF are woven fabrics that have undergone fiber opening and weave tightening treatments, and dimensional stability It is preferable from the viewpoint of mechanical strength, dimensional stability, water absorption, etc. Glass cloth is preferred. From the viewpoint of improving the heat-pressure bonding with the LCP stretched film 100, Glass cloth that has undergone fiber opening and pore filling treatment is preferred. Also, epoxy silane treatment is preferred. Glass cloths that have been surface-treated with silane coupling agents such as aminosilane treatment are also suitably used. It is possible to use it. Furthermore, woven fabric WF can be used either individually or in appropriate combinations of two or more types. It is possible to be there.

[0082] The thickness of the woven WF can be set appropriately according to the required performance and is not particularly limited. Lamination properties and processing From the viewpoint of properties, mechanical strength, etc., 10 to 300 μm is preferred, and more preferably 10 to 20 The particle size is 0 μm, more preferably 15 to 180 μm.

[0083] The total thickness of the insulating material 200 for circuit boards can be set appropriately according to the required performance, and is not particularly limited. No. From the viewpoint of lamination, processability, mechanical strength, etc., 30 to 500 μm is preferred, and more preferably... The particle size is preferably 50-400 μm, more preferably 70-300 μm, and especially preferably 90- It is 250 μm.

[0084] The insulating material 200 for the circuit board of this embodiment adopts the above-described configuration, in the MD direction Furthermore, the anisotropy of the dimensional change rate in the TD direction is small, and in a more preferred embodiment, the MD direction and the TD direction It can reduce the dimensional change rate itself, and moreover, it has excellent dielectric properties in the high-frequency range. It has the remarkable advantages of being easy to manufacture and having excellent productivity.

[0085] The insulating material 200 for circuit boards described above can be manufactured by appropriately applying known manufacturing methods. The manufacturing method is not particularly limited. For example, LCP stretched film 10 0 and woven fabric WF are laminated, heated and pressurized, and the LCP stretched film 100 and woven fabric WF are By thermocompression bonding, an insulating material 200 for circuit boards can be obtained. In addition, LCP stretched film The lum 100, woven fabric WF, and LCP stretched film 100 are layered in this order to form a laminate. The laminate is then heated and pressurized while being held between the plates using a press machine or a double belt press machine. Furthermore, a method of thermo-pressing the insulating material 200 for the circuit board is also preferred. Note that the processing temperature during thermocompression bonding The degree can be set appropriately according to the required performance and is not particularly limited, but is between 200 and 400. °C is preferred, more preferably 250-360°C, and even more preferably 270-350°C. Yes. The processing temperature during heat bonding is the surface temperature of the LCP stretched film 100 of the laminate mentioned above. The value measured by temperature shall be used. Furthermore, the pressurization conditions shall be set appropriately according to the desired performance. It is possible, and is not particularly limited, but for example, at a surface pressure of 0.5 to 10 MPa for 1 to 240 minutes, Preferably, the surface pressure is 0.8 to 8 MPa for 1 to 120 minutes.

[0086] (Metal foil-clad laminate) Figure 8 is a schematic cross-sectional view showing the main part of the metal foil-clad laminate 300 of this embodiment. The metal foil laminate 300 is made of the above-mentioned LCP stretched film 100 and this LCP stretched film It comprises a metal foil MF provided on one side and / or both sides of the lum 100.

[0087] Specifically, the metal foil laminated board 300 consists of metal foil MF, LCP stretched film 100, and Double-sided metal foil having a laminated structure (3-layer structure) in which metal foil MF is arranged in at least this order. It is a laminated board. These three layers are heat-pressed together, thereby forming a three-layer laminated structure. In this embodiment, a double-sided metal foil laminate is shown, but LCP stretched film is also used. The present invention can also be implemented in a configuration in which the metal foil MF is provided on only one surface of M100. Yes. In other words, although a three-layer laminate is given as an example here, the present invention is one of the metal foil MF Even in a two-layer laminated structure that omits the LCP stretched film 100 and woven fabric WF further Needless to say, this is also possible with laminated structures consisting of four or more layers stacked together.

[0088] Figure 9 is a schematic cross-sectional view showing the main part of the metal foil-clad laminate 400 of this embodiment. The metal foil laminate 400 is made of the above-mentioned LCP stretched film 100 and this LCP stretched film Laminate having at least the above-mentioned woven fabric WF provided on one and / or both sides of Rum 100 It comprises a body and metal foil MF provided on one and / or both sides of this laminate.

[0089] Specifically, the metal foil laminate 400 consists of metal foil MF, LCP stretched film 100, and woven fabric. WF, LCP stretched film 100, and metal foil MF are arranged in at least this order in a compound This is a double-sided metal foil laminate with a layered structure (5-layer structure). These 5 layers are heat-pressed together. As a result, a laminate with a five-layer structure is formed. In this embodiment, although a double-sided metal foil clad laminate is shown, the present invention is also applicable to a mode in which the metal foil MF is provided only on one surface. That is, here a laminate with a five-layer structure is exemplified, but the present invention is applicable even to a laminate with a four-layer structure in which one metal foil MF is omitted, or a laminate with a six-layer or more structure in which an LCP stretched film 100, an insulating material 200 for a circuit board, and a woven fabric WF are further laminated. Needless to say, it is also feasible.

[0090] The material of the metal foil MF is not particularly limited, and examples include gold, silver, copper, copper alloy, nickel, nickel alloy, aluminum, aluminum alloy, iron, iron alloy, etc. Among these, copper foil, aluminum foil, stainless steel foil, and alloy foil of copper and aluminum are preferable, and copper foil is more preferable. Any copper foil manufactured by a rolling method, an electrolytic method, or the like can be used, but electrolytic copper foil or rolled copper foil with a relatively large surface roughness is preferable.

[0091] The thickness of the metal foil MF can be appropriately set according to the desired performance and is not particularly limited. Usually, 1. 5 to 1000 μm is preferable, more preferably 2 to 500 μm, still more preferably 5 to 1 50 μm, and particularly preferably 7 to 100 μm. As long as the effects of the present invention are not impaired, the metal foil MF may be subjected to surface treatment such as chemical surface treatment such as pickling. Note that the type and thickness of the metal foil MF may be the same or different.

[0092] The metal foil MF is provided on the surface of the LCP stretched film 100 or the insulating material 200 for a circuit board. ​​The law may be carried out in accordance with common law, and is not particularly limited. LCP stretched film 100 Alternatively, a metal foil MF is laminated onto an insulating material 200 for circuit boards, and the two layers are bonded or pressed together. Methods include physical methods such as sputtering and vapor deposition (dry methods), electroless plating and electroless plating after electroless plating. This may be done using any of the following methods: chemical methods such as deplating (wet methods), or by applying a metal paste. Furthermore, LCP stretched film 100 and insulating material for circuit boards 200 and one or more metal foils MF Laminates formed by stacking these materials can be used in, for example, multi-stage presses, multi-stage vacuum presses, continuous molding machines, and autoclaving machines. By using a heat pressing machine or the like, metal foil-clad laminates 300 and 400 can be obtained. It can also be done this way.

[0093] The metal foil laminates 300 and 400 described above can be manufactured by appropriately applying known manufacturing methods. The manufacturing method is not particularly limited. For example, LCP stretched film 100 and circuit board insulating material 200 and metal foil MF are layered together to form LCP stretched film 1 A laminate is formed by placing metal foil MF on top of 00, and this laminate is used in the double belt press machine One method is to heat-press the material while sandwiching it between a pair of dress belts. As mentioned above, The LCP stretched film 100 used in the embodiment has different dimensional change rates in the MD direction and the TD direction. The directional properties are small, and in a more preferred embodiment, the dimensional change rates in the MD and TD directions themselves are small. Therefore, high peel strength to metal foil MF can be obtained.

[0094] The temperature during the heat-compression bonding of metal foil MF can be set appropriately according to the required performance, and is not limited to It is not done, but the temperature is 50°C lower than the melting point of the liquid crystal polymer and 50°C higher than the melting point. The following is preferable: a temperature 40°C lower than the melting point and 40°C higher than the melting point. Preferably, the temperature is 30°C lower than the melting point and more preferably 30°C higher than the melting point. It is preferable that the temperature be at least 20°C lower than the melting point and at least 20°C higher than the melting point. The temperature during the heat-pressing of the metal foil MF is the same as the surface temperature of the LCP stretched film 100 mentioned above. The value measured in degrees shall be used. Furthermore, the crimping conditions at this time shall be set appropriately according to the desired performance. This is possible, and is not particularly limited, but for example, when using a double belt press machine, the surface pressure is 0.5 It is preferable to perform the procedure under conditions of ~10 MPa and a heating temperature of 200~360°C.

[0095] The metal foil-clad laminates 300 and 400 of this embodiment consist of an LCP stretched film 100 and metal foil M As long as it has a two-layer heat-sealed body with F, it has another laminated structure or further laminated structure It may also be possible. For example, a two-layer structure of metal foil MF / LCP stretched film 100; metal foil MF / LCP stretched film 100 / metal foil MF, LCP stretched film 100 / metal foil MF / LC A three-layer structure such as P-oriented film 100; metal foil MF / LCP-oriented film 100 / woven fabric 4-layer structure such as WF / LCP stretched film 100; metal foil MF / LCP stretched film 1 00 / Metal foil MF / LCP stretched film 100 / Metal foil MF, Metal foil MF / LCP stretched film Five-layer structure such as film 100 / woven fabric WF / LCP stretched film 100 / metal foil MF; etc. , can be made into a multilayer structure. Also, multiple (for example, 2 to 50) metal foil-clad laminates 3 00 and 400 can also be laminated and heat-pressed together.

[0096] In the metal foil-clad laminates 300 and 400 of this embodiment, the LCP stretched film 100 and gold The peel strength with the attached foil MF is not particularly limited, but from the perspective of achieving higher peel strength is preferably 0.8 (N / mm) or more, more preferably 1.0 (N / mm ) or more, and still more preferably 1.2 (N / mm) or more. As described above, in the metal foil laminated plates 300 and 400 of the present embodiment , high peel strength can be achieved. Therefore, for example, peeling between the LCP stretched film 100 and the metal foil MF can be suppressed in the heating process of substrate manufacturing . In addition, manufacturing conditions excellent in process margin and productivity can be applied in obtaining peel strength equivalent to the prior art . Therefore, deterioration of the basic performance of the liquid crystal polymer can be suppressed while maintaining the same level of peel strength as in the prior art .

[0097] And the metal foil laminated plates 300 and 400 of the present embodiment can be used as materials for circuit boards such as electronic circuit boards and multilayer boards by pattern etching at least a part of the metal foil MF . Further, the metal foil laminated plates 300 and 400 of the present embodiment have excellent dielectric characteristics in the high-frequency range, small anisotropy in the dimensional change rates in the MD direction and the TD direction, and in a more preferable aspect, the dimensional change rates in the MD direction and the TD direction themselves are small, excellent in dimensional stability, and easy to manufacture and excellent in productivity. Therefore, it becomes a particularly useful material as an insulating material for flexible printed wiring boards (FPCs) etc. in the fifth-generation mobile communication system (5G), millimeter-wave radars, etc .

Examples

Examples

[0098] Hereinafter, the features of the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited thereto. That is, the materials, usage amounts, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention . ​​​This can be done. Furthermore, the values ​​of the various manufacturing conditions and evaluation results in the following examples are the actual results of the present invention. This has meaning as a preferred upper limit or preferred lower limit in the method of application, and is preferred The desired numerical range is a combination of the upper or lower limit mentioned above and the values ​​of the following examples or the values ​​of the examples themselves. The range defined by the combination is also clear.

[0099] [Melting viscosity] Under the following conditions, the melt viscosity [Pa·sec] of the LCP extruded film for stretching was determined as follows: It was measured. Measuring instrument: Capillograph 1D (manufactured by Toyo Seiki Seisakusho Co., Ltd.) Equipment used: Cylinder length 10.00mm, cylinder diameter 1.00mm, barrel diameter 9.55mm Measurement conditions: Temperature [°C] and shear rate [se] during extrusion molding of LCP extruded film for stretching treatment. c -1 ]

[0100] [Yield strength X and failure strength Y] Under the following conditions, a tensile test was performed on the LCP extruded film for stretching, determining the yield strength X and breaking point. The failure point strength Y was determined. Compliant with JIS K7161-1:2014 Tensile testing machine: Strograph VE1D (manufactured by Toyo Seiki Seisakusho Co., Ltd.) Sample size: dumbbell type Pre-test conditioning: 23°C, 50RH for 24 hours Measurement temperature: 200℃ Tensile speed: 200 mm / min Distance between gauge lines: 50mm Measurement results: Average of 5 measurements

[0101] [Coefficient of linear expansion] In accordance with JIS K7197, the TMA method is used to produce LCP extruded film and LCP for stretching. The coefficient of linear thermal expansion of each stretched film was measured. Measuring instrument: TMA 4000SE (manufactured by NETZSCH) Measurement method: Tensile mode Measurement conditions: Sample size 25mm x 4mm x 50μm thickness Chuck spacing: 20mm Temperature range: 23-200℃ (2nd RUN) Heating rate: 5°C / min Atmosphere: Nitrogen (flow rate 50 ml / min) Test load 5gf *The value from 2ndRUN was used to see the value after the thermal history had been eliminated.

[0102] [Tape peel test] Regarding the film surface of LCP extruded film for stretching, JIS K5600-5-6 Adhesion tests were conducted using the cross-cut method in accordance with the standards, and the presence or absence of a skin layer was confirmed in each case. At this time, use Nichiban's cellophane tape (registered trademark) measuring 24mm wide x 50mm long. If there is no peeling in the grid pattern after removing the tape, it is called "no skin layer", and if there is peeling... The case was defined as "with a skin layer." ○ No skin layer × Skin layer present

[0103] (Examples 1-3) As an intermediate layer, a type I thermoplastic liquid crystal polymer (monomer composition is p-hydroxybenzoic acid 79) is used. mol%, 20 mol% 6-hydroxy-2-naphthoic acid, 1 mol% terephthalic acid Polymer, temperature 330°C, and shear rate 500 sec -1 The melt viscosity is 70 Pa·sec. Polycarbonate PC (Teijin Panlite L-1225L) is used as the surface layer on both sides of the intermediate layer. Using these, under conditions of a shear stress of 40 kPa and a drawdown ratio of 2.0, the die width 6 From a two-type three-layer extruder equipped with T-dies of 00mm and lip opening of 0.2~1.0mm Each resin is co-extruded at 330°C using the casting method, and the intermediate layer has the thickness shown in Table 1. A two-type, three-layer film was formed. From the formed two-type, three-layer film, the polycarbonate on both surface layers... The films were peeled off at the winding line and stretched according to Examples 1-3, which have a melting point of 315°C. Each LCP extruded film was obtained.

[0104] The LCP extruded films obtained from Examples 1-3 for stretching were subjected to a uniaxial stretching machine at 130°C. Each material is stretched to 2.0 times its original length in the TD direction (total stretching ratio: 2.0 times), and then heated at 130°C for 30 seconds. By setting them together, the LCP stretched films of Examples 1 to 3 were obtained. Then, each one Glass cloth (IPC No. #1037) is placed between the LCP stretched films of the pairs of Examples 1-3. With each part sandwiched in place, a heat press is used to perform a heat-sealing process at 300°C for 5 minutes. Thus, insulating materials for circuit boards were obtained for Examples 1 to 3.

[0105] (Comparative Example 1) Under conditions of shear stress of 50 kPa and drawdown ratio of 6.0, the die width was 600 mm and the liter Liquid is extracted from a single-layer extruder equipped with a T-die with a piping opening of 0.2 to 1.0 mm using the T-die casting method. The procedure is the same as in Example 1, except that the crystalline polymer is extruded at 330°C, and the polymer has a melting point of 315°C. A stretching-type LCP extruded film for Comparative Example 1 was obtained.

[0106] The process is the same as in Example 1, except that the LCP extruded film for stretching obtained in Comparative Example 1 is used. We attempted to obtain an LCP stretched film, but we were unable to achieve uniform stretching.

[0107] The results are shown in Table 1.

[0108] [Table 1]

[0109] (Examples 4-6) As an intermediate layer, a type II thermoplastic liquid crystal polymer (monomer composition is p-hydroxybenzoic acid 7) A copolymer of 4 mol% and 26 mol% 6-hydroxy-2-naphthoic acid, at a temperature of 300°C and shear rate 500 sec -1 The melt viscosity is 80 Pa·sec), and the surface layers on both sides of the intermediate layer are used. Using polycarbonate PC (Teijin Panlight L-1225L), shearing Under conditions of a stress of 40 kPa and a drawdown ratio of 2.0, the die width was 600 mm and the lip opening was 600 mm. Each tree is produced using the T-die casting method from a two-type, three-layer extruder equipped with T-dies of 0.2 to 1.0 mm. The fat is co-extruded at 300°C to form a two-layer, three-part film in which the intermediate layer has the thickness described in Table 2. The two types of three-layer films were molded, and the polycarbonate films on both surfaces were taken from the molded film on the winding line. Each was peeled off, and the LCP extruded films for stretching treatment of Examples 4-6, each having a melting point of 280°C, were obtained. They each obtained something.

[0110] The LCP extruded films obtained from Examples 4-6 for stretching were subjected to a uniaxial stretching machine at 130°C. Each material is stretched to 2.0 times its original length in the TD direction (total stretching ratio: 2.0 times), and then heated at 130°C for 30 seconds. By setting them together, the LCP stretched films of Examples 4 to 6 were obtained. Then, each one Glass cloth (IPC No. #1037) is placed between the LCP stretched films of the paired Examples 4-6. With each part sandwiched in place, a heat press is used to perform a heat-pressing process at 300°C for 5 minutes. Thus, insulating materials for circuit boards were obtained for Examples 4 to 6.

[0111] (Comparative Example 2) Under conditions of shear stress of 60 kPa and drawdown ratio of 6.0, the die width was 600 mm and the liter Liquid is extracted from a single-layer extruder equipped with a T-die with a piping opening of 0.2 to 1.0 mm using the T-die casting method. The procedure is the same as in Example 4, except that the crystalline polymer is extruded at 300°C, and the result has a melting point of 280°C. A stretching-type LCP extruded film for Comparative Example 2 was obtained.

[0112] The process is the same as in Example 4, except that the LCP extruded film for stretching obtained in Comparative Example 2 is used. We attempted to obtain an LCP stretched film, but we were unable to achieve uniform stretching.

[0113] The results are shown in Table 2.

[0114] [Table 2] [Industrial applicability]

[0115] The LCP extruded film of the present invention is suitable for electronic circuit boards, multilayer substrates, high heat dissipation substrates, and flexible Widely used in applications such as printed circuit boards, antenna substrates, optoelectronic mixed-signal substrates, and IC packages. Furthermore, it is effectively usable, particularly suitable for ultra-fine machining and highly reliable, making it suitable for fifth-generation migration. Flexible printed circuit boards (FP) used in 5G and millimeter-wave radar systems, etc. It can be used particularly widely and effectively as an insulating material such as C) or as a metal foil-clad laminate. [Explanation of Symbols]

[0116] X...Yield point strength Y ···Breakpoint strength 100 ···LCP stretched film 200 ···Insulating material for circuit boards 300 ··Metal foil-clad laminate 400 ··Metal foil-clad laminate WF ···Woven fabric MF ···metal foil

Claims

1. This is an LCP extruded film for stretching containing a thermoplastic liquid crystal polymer. Constant temperature bath tensile test (compliant with JIS K7161-1:2014, 200°C, tensile speed 200°C) In the stress-strain curve measured in mm / min, the LCP extrusion for stretching treatment The yield strength X (MPa) and fracture strength Y (MPa) of the lum in the TD direction are given by the following formula (1) ； 0.75 ≤ breaking point strength Y / yield point strength X ≤ 1.50 ... (1) Satisfying LCP extruded film for stretching

2. The LCP extruded film for stretching has a linear expansion coefficient in the TD direction of 5 to 55 ppm / K. be The LCP extruded film for stretching treatment according to claim 1.

3. The LCP extruded film for stretching is a T-die extruded film. The LCP extruded film for stretching treatment according to claim 1 or 2.

4. The LCP extruded film for stretching is a laminated extruded film having an outer layer, an intermediate layer, and an outer layer. The intermediate layer is obtained by removing the two outer layers from the film. An LCP extruded film for stretching treatment according to any one of claims 1 to 3.

5. The LCP extruded film for stretching is a cross-woven film conforming to JIS K5600-5-6. Adhesion tests using the cutting method show that the film surface does not have a skin layer that can be peeled off with tape. An LCP extruded film for stretching treatment according to any one of claims 1 to 4.

6. The LCP extruded film for stretching has a thickness of 15 μm or more and 300 μm or less. An LCP extruded film for stretching treatment according to any one of claims 1 to 5.

7. The LCP extruded film for stretching further contains an inorganic filler. An LCP extruded film for stretching treatment according to any one of claims 1 to 6.

8. The stretched body comprises an LCP extruded film for stretching according to any one of claims 1 to 7, The linear expansion coefficient of the stretched body in the TD direction is in the range of -20 ppm / K or more and less than 0 ppm / K. Located inside, The linear expansion coefficient of the stretched body in the MD direction is in the range of -20 ppm / K or more and less than 0 ppm / K. Inside, Heat-shrinkable LCP stretched film.

9. The stretched body is 1.3 to 2.5 degrees in the TD direction relative to the LCP extruded film for stretching. Having a stretching ratio of twice as much The heat-shrinkable LCP stretched film according to claim 8.

10. The heat-shrinkable LCP stretched film and the heat-shrinkable LCP stretched film according to claim 8 or 9 The laminate comprises having at least one woven fabric provided on at least one side of the material. Insulating material for circuit boards.

11. The heat-shrinkable LCP stretched film and the heat-shrinkable LCP stretched film according to claim 8 or 9 The film is provided with metal foil on one and / or both sides. Metal foil-clad laminate.

12. A laminate comprising at least the heat-shrinkable LCP stretched film and woven fabric described in claim 8 or 9. The laminate comprises a body and metal foil provided on one and / or both sides of the laminate, Metal foil-clad laminate.

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