JP2023050160A - Biaxially-oriented polyarylene sulfide film - Google Patents

Abstract

To provide a polyarylene sulfide film having excellent transparency.SOLUTION: A biaxially-oriented polyarylene sulfide film is primarily composed of polyarylene sulfide (PAS), and has a crystal size of 90Å or less, obtained by applying the Scherrer equation to a half peak width of the (200) diffraction peak of polyarylene sulfide crystal determined by X-ray diffraction.SELECTED DRAWING: None

Description

The present invention relates to biaxially oriented polyarylene sulfide films.

In recent years, glass has been studied as a circuit board material that requires transparency. However, glass substrates have drawbacks such as being fragile, heavy, and difficult to make thin. In addition, they do not have sufficient materials for flexible applications such as car windshields and parts that come into contact with curved surfaces indoors and outdoors. .

Polyarylene sulfide has properties such as excellent heat resistance, flame resistance, rigidity, chemical resistance, electrical insulation, and low moisture absorption, making it particularly suitable for electrical and electronic equipment, mechanical parts, and automobile parts. It is used. In the field of electrical and electronic parts, materials with low transmission loss are in demand due to the trend toward higher speed and larger capacity. Taking advantage of its high transmission loss and low hygroscopicity, it is being applied to circuit materials. However, since PPS films have low transparency in terms of haze, for example, when used as a transparent circuit board, visibility tends to deteriorate due to the transparency of the PPS film. Improvements in transparency are desired.

In the past, a technique for subjecting a PPS film to a rubbing treatment has been disclosed as a method for improving the transparency and slipperiness of the PPS film (Patent Document 1). In addition, a technique is disclosed in which zinc oxide particles whose particle size and dispersibility are controlled are included to improve transparency and slipperiness. (Patent document 2)
On the other hand, a technique has been disclosed in which the crystal size of a sheet using polyphenylene sulfide is controlled to be large to improve the thermal and mechanical properties (Patent Document 3).

JP 2013-67748 A JP-A-5-320380 JP-A-7-205373

However, although the techniques described in Patent Document 1 and Patent Document 2 disclose techniques for improving transparency at a thickness of 25 μm, haze at a thickness of 30 μm or more, which is required for a film for circuit boards. There was a problem that it was insufficient to improve the transparency shown in . In addition, the technology described in Patent Document 2 has a problem of insufficient transparency when applied to film applications.

Further, the technique described in Patent Document 3 is a technique for controlling the crystal size of a sheet obtained by impregnating a glass fiber material with PPS. There was a problem that the crystal size of was not controllable.

An object of the present invention is to solve the above problems. That is, the object is to provide a biaxially oriented polyarylene sulfide film having excellent transparency.

As a result of studies to solve the above problems, the present inventors found that the transparency can be improved by reducing the crystal size in the biaxially oriented polyarylene sulfide film. provides a biaxially oriented polyarylene sulfide film.
A preferable aspect of the present invention is as follows.
(1) Polyarylene sulfide (PAS) is the main component, and the crystal size obtained by applying Schller's formula to the half width of the (200) diffraction peak of polyarylene sulfide crystals determined by X-ray diffraction is 90 Å or less. A biaxially oriented polyarylene sulfide film.
(2) The biaxially oriented polyarylene sulfide film according to (1), which has a thickness of 30 μm or more.
(3) The biaxially oriented polyarylene sulfide film according to (1) or (2), wherein at least one film surface has a glossiness of 200% or more.
(4) The biaxially oriented polyarylene sulfide film according to any one of (1) to (3), wherein at least one film surface has a glossiness of 200% or more.
(5) The biaxially oriented polyarylene sulfide film according to (1) to (4), which has a haze of 10% or less.
(6) It has two or more layers containing polyarylene sulfide as a main component, and at least one of the outermost layers contains polyarylene sulfide as a main component and at least one other thermoplastic resin different from polyarylene sulfide. The biaxially oriented polyarylene sulfide film according to any one of (1) to (5), which has a layer (A layer).
(7) of (1) to (6), wherein the layer A contains a dispersion incompatible with polyarylene sulfide, and the thickness ratio of the layer A is 0.1% or more and 10% or less of the total thickness of the film; A biaxially oriented polyarylene sulfide film according to any one.
(8) A transparent circuit substrate using the biaxially oriented polyarylene sulfide film according to any one of (1) to (7).
(9) A transparent antenna substrate using the biaxially oriented polyarylene sulfide film according to any one of (1) to (7).
(10) An insulating film using the biaxially oriented polyarylene sulfide film described in (1) to (7).
(11) Metal film laminated film having a metal film on at least one side of the biaxially oriented polyarylene sulfide film described in (1) to (7) (12) Using the metal laminated film described in (11), Film capacitor.
(13) A power control unit having the film capacitor according to (12).
(14) An electric vehicle having the power control unit according to (13).
(15) An electric aircraft having the power control unit according to (13).

The polyarylene sulfide film of the present invention is excellent in transparency and surface quality. Therefore, by making use of such characteristics, various parts requiring transparency, such as automobile members, battery members, display members, industrial packaging materials, design materials, electrical/electronic materials, and electrical insulating materials, can be used. It can be suitably used as an insulating film including a circuit board, a transparent antenna substrate, a high frequency transparent circuit substrate, a high frequency transparent antenna substrate, and a capacitor material that requires surface quality.

The biaxially oriented polyarylene sulfide film of the present invention comprises a resin composition containing a polyarylene sulfide (hereinafter referred to as PAS) resin as a main component.

In the present invention, containing a PAS-based resin as a main constituent means that the PAS-based resin is contained in an amount of 50% by mass or more. It preferably contains 60% by mass or more, more preferably 70% by mass or more. If the content of the PAS-based resin is less than 50% by mass, the heat resistance, dimensional stability and mechanical properties characteristic of the PAS film may be impaired.

The PAS-based resin used in the present invention is a homopolymer or copolymer having -(Ar-S)- repeating units. Examples of Ar include units represented by the following formulas (A) to (K).

(R1 and R2 are substituents selected from hydrogen, an alkyl group, an alkoxy group and a halogen group, and R1 and R2 may be the same or different)
Among the above formulas, the repeating unit is preferably a p-arylene sulfide unit, and representative examples thereof include polyphenylene sulfide, polysulfone, polyether sulfone, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, etc., and are particularly preferred. As the p-arylene sulfide unit, a p-phenylene sulfide unit is preferably exemplified from the viewpoint of film properties and economy.

The polyarylene sulfide resin used in the present invention preferably comprises p-arylene sulfide units represented by the following structural formula as main structural units in 97 mol % or more of all repeating units. Preferably, it is 98 mol % or more. When the main component is 97 mol % or more, crystallinity, glass transition temperature, etc. are increased, and excellent heat resistance, electrical properties, and chemical resistance can be achieved.

Moreover, a unit containing a copolymerizable sulfide bond may be contained in less than 3 mol % of the repeating units. Examples of such repeating units include trifunctional units, ether units, sulfone units, ketone units, meta-bond units, aryl units having substituents such as alkyl groups, biphenyl units, terphenylene units, vinylene units, and carbonate units. etc., and one or more of them can coexist. In this case, the constitutional unit may be in the form of random copolymerization or block copolymerization.

Polyarylene sulfide resins can be prepared by known synthesis methods, and in the case of polyphenylene sulfide, reference example 1 described later can be exemplified. However, it is not limited to this.

To the PAS-based resin composition constituting the biaxially oriented polyarylene sulfide film of the present invention, various additives such as antioxidants, heat stabilizers, antistatic agents and antiblocking agents are added to the extent that the effects of the present invention are not impaired. agents may be included.

In the biaxially oriented polyarylene sulfide film of the present invention, the crystal size obtained by applying Schller's formula to the half width of the (200) diffraction peak of the polyarylene sulfide crystal determined by X-ray diffraction is 90 Å or less. is necessary. It is preferably 80 Å or less, more preferably 30 Å or more and 70 Å or less. When the crystal size is 90 Å or less, light scattering due to crystals is suppressed, and a biaxially stretched polyarylene sulfide film with low haze and high transparency can be obtained even if the film thickness is large. On the other hand, the heat resistance can be improved by making the crystal size equal to or larger than the above size.

The crystal size referred to in the present invention is determined by the X-ray diffraction method. Specifically, the diffraction pattern is measured by the reflection method, and the half width of the (200) diffraction peak of the polyarylene sulfide crystal is It means the apparent crystal size obtained by applying the Schller equation.

The method for controlling the crystal size of the biaxially stretched polyarylene sulfide film is not particularly limited. For example, in the process of producing a biaxially stretched polyarylene sulfide film, after stretching in the biaxial direction, the film is stretched in the longitudinal direction at a temperature of (the melting point of the polyarylene sulfide resin −10° C.) or higher (the melting point of the polyarylene sulfide resin +10° C.). And/or a preferred method is to stretch the film by 1.01 times to 1.80 times or less in the width direction, heat-treat the film at the same temperature, and then subject the film to a high-temperature stretching step. By drawing at a temperature near the melting point of the polyarylene sulfide resin, the crystals are partially melted and deformed to reduce the crystal size.

The biaxially oriented polyarylene sulfide film of the present invention must be a biaxially oriented film. By using a polyarylene sulfide film as a biaxially oriented film, it is possible to improve mechanical strength and flatness and reduce unevenness in thickness. When used as an industrial packaging material, the biaxial orientation treatment is necessary from the viewpoint of improving the properties of the film.

Here, the fact that the polyarylene sulfide film of the present invention is a biaxially oriented film is a parameter indicating the sharpness of resonance of the polyarylene sulfide film measured using a molecular orientation meter (manufactured by Oji Scientific Instruments, MOA-6015). It means that the average value of 10 measurements of (Q value) is 4300 or more.

The method of biaxial orientation treatment includes a sequential biaxial stretching method (a method of stretching in one direction at a time, such as a method of stretching in the longitudinal direction and then stretching in the width direction), which will be exemplified in the manufacturing method described later. An axial stretching method (a method of stretching in the longitudinal direction and the width direction at the same time) or a method combining them may be used.

Although the thickness of the biaxially oriented polyarylene sulfide film of the present invention is not particularly limited, the film thickness is preferably 1 μm or more from the viewpoint of film-forming properties. The biaxially oriented polyarylene sulfide of the present invention is preferably adjusted appropriately depending on the application, but for circuit substrates, the thickness is preferably 30 μm or more, more preferably 50 μm or more. Although the upper limit is not particularly defined, it is preferably 200 μm or less from the viewpoint of film formability.

The term "thickness" as used in the present invention refers to a value measured by observing the cross section of the film with a scanning electron microscope.

Although the method for making the biaxially oriented polyarylene sulfide film have such a thickness is not particularly limited, for example, it can be obtained by adjusting the amount of resin extruded from an extruder, the film forming speed and the draw ratio in the film production process. can be done.

The biaxially oriented polyarylene sulfide film of the present invention preferably has a glossiness of 140% or more on at least one film surface. When the glossiness is within the above range, it means that there are few surface irregularities that optically diffusely reflect light on the surface, and there are few scratches and foreign matter on the film surface. As a result, when a metal layer is formed by vapor deposition, sputtering, plating, etc., for use as a circuit or capacitor, it is difficult to cause unevenness on the surface, and the capacitor has excellent transmission characteristics and a circuit that suppresses insulation failure due to scratches. can be obtained. If the glossiness is less than 140%, the surface may have many irregularities, and when used as a circuit material, the transparency may be poor, or the surface may be scratched and defective, resulting in poor quality. Although there is no upper limit for the glossiness, it is 240% or less from the viewpoint of film-forming properties. The glossiness is more preferably 160% or higher, still more preferably 180% or higher, and most preferably 200% or higher. Glossiness can be measured by the method described later.
As a preferred mode of the method of adjusting the glossiness to the preferred range described above, it can be obtained by controlling the surface unevenness without forming voids according to the lamination structure and stretching conditions of the production method described below. When particles and/or dispersions are not blended, voids are not formed, but surface running properties are poor, scratches and defects are likely to occur on the surface, and surface glossiness is not increased, resulting in poor surface quality.

The haze of the biaxially oriented polyarylene sulfide film of the present invention is preferably 10% or less, more preferably 5% or less, even more preferably 3% or less. By setting the haze of the biaxially oriented polyarylene sulfide film within the above range, light diffusion inside the film can be suppressed, light can be efficiently transmitted and used, and defects can be detected during the production process of products using the film. Alignment becomes possible, and utilization as an optical film becomes possible. When the haze of the polyarylene sulfide film is more than 10%, the defect detectability becomes insufficient, and problems may occur in optical applications as described above.

The haze referred to in the present invention is a value measured according to JIS-K7136 (2000).

As a method for adjusting the haze to the above range, it is preferable to set the crystal size obtained by applying Schller's formula to the half width of the (200) diffraction peak of the polyarylene sulfide crystal obtained by the X-ray diffraction method to be 90 Å or less. mentioned.

The biaxially oriented polyarylene sulfide film of the present invention has two or more layers containing a PAS-based resin as a main component, and at least one of the outermost layers contains a PAS-based resin as a main component and is different from the PAS-based resin. It is preferable to have a layer (A layer) containing at least one thermoplastic resin (X). By constructing two or more layers, it is possible to control surface unevenness mainly using the outermost layer, and not only has surface runnability, but also can suppress scratches on the surface, transparency, It can have multiple properties such as color tone, runnability, and suppression of insulation failure due to surface quality. As for the laminate structure, when the layer having a PAS-based resin as a main component is the B layer, A/B, A/B/A, A/B/A/B, A/B/A/B/A and the like. In the biaxially oriented polyarylene sulfide film of the present invention, from the viewpoint of chemical resistance and the like, the outermost layer is preferably a layer containing a PAS resin as a main component. Moreover, from the same point of view, it is preferable not to have a coating layer.

In the present invention, a three-layer structure of A/B/A is more preferable from the viewpoint of transparency, color tone, surface quality, and runnability.

In order to achieve such a structure, two types of resin raw materials, a resin containing a PAS-based resin as a main component and a resin containing a PAS-based resin as a main component and containing another thermoplastic resin different from the PAS-based resin, are used in the film manufacturing process. , Separate melt extruders are supplied, and after heating and melting above the melting point of each resin, a layer containing a PAS-based resin as a main component and a PAS-based Layers containing resin as the main component and other thermoplastic resin different from PAS resin are combined so as to be laminated in the thickness direction, and the unstretched sheet extruded from the nozzle outlet on the slit is biaxially stretched. can be obtained.

In the biaxially oriented polyarylene sulfide film of the present invention, in the layer A, another thermoplastic resin (X) different from the PAS-based resin is incompatible with the PAS-based resin, and It is preferably included as a dispersion. By including a dispersion incompatible with the PAS-based resin in the layer A, the main component of which is the PAS-based resin, the unevenness of the surface can be formed and controlled to obtain a film with excellent transparency, runnability and quality. be able to.

In the present invention, the thermoplastic resin (X) is incompatible with the PAS-based resin and contained as a dispersion in the PAS-based resin means that the PAS-based resin and the thermoplastic resin (X) form a sea-island structure. , that the PAS-based resin constitutes the sea component and the thermoplastic resin (X) constitutes the island component.

Examples of the thermoplastic resin (X) incompatible with the PAS-based resin include polysulfone, polyphenylsulfone, polyethersulfone, polyetherimide, nylon 6, and nylon 46 when the PAS-based resin is polyphenylene sulfide. be done. In particular, polysulfone, polyphenylsulfone, and polyethersulfone have good dispersibility in polyphenylene sulfide and do not form voids at the interface during stretching during film formation, which is preferable from the viewpoint of transparency, and the size of the dispersion can be reduced. polyether sulfone is more preferred.

Moreover, the shape of the dispersion is not particularly limited. The cross-section of the film can be observed by a transmission electron microscope (TEM) or a scanning electron microscope (SEM) to confirm its shape, and examples thereof include circular, elliptical, spindle-shaped, and irregular shapes.

In the biaxially oriented polyarylene sulfide film of the present invention, when the total of the content of the PAS resin in the layer A and the content of the thermoplastic resin (X) different from the PAS resin is 100 parts by mass, , the content WII of the thermoplastic resin (X) is preferably 0.01 parts by mass or more and 3.0 parts by mass or less. In order to achieve both runnability and transparency, the content WII of the thermoplastic resin (X) is more preferably 0.1 parts by mass or more and 1.0 parts by mass or less, and still more preferably 0.2 parts by mass or more. It is 0.5 parts by mass or less. By making the content of the thermoplastic resin (X) equal to or less than the upper limit described above, it is possible to suppress the deterioration of transparency due to the difference in the refractive index of the resin. Further, by setting the content WII of the thermoplastic resin (X) to the above-mentioned lower limit or more, it is possible to suppress deterioration of the surface quality due to scratches due to deterioration of running properties when the film is formed.

In the biaxially oriented polyarylene sulfide film of the present invention, the thickness ratio of the layer A is preferably 0.1% or more and 10% or less with respect to the total thickness of the film. By setting the thickness ratio of the A layer within the above range, it is possible to make it easier to form surface irregularities densely, and it is possible to reduce the amount of the dispersion in the entire film, so that the transparency and color tone surface quality can be improved. preferable. By setting the thickness ratio of the layer A to the above lower limit or more, the formation of unevenness on the surface is reduced and the surface becomes smooth. . In addition, by setting the thickness ratio of the layer A to the above upper limit or less, the surface unevenness is formed densely, so that the transparency is excellent. The thickness ratio of the A layer is more preferably 0.5% or more and 5.0% or less, and more preferably 1.0% or more and 3.0% or less.

In the present invention, the thickness ratio of the A layer can be obtained by measuring the lamination thickness of the A layer and the thickness of the entire film from a scanning electron microscope SEM image on the cut surface of the film, and calculating the ratio. When there are a plurality of A layers, the value obtained by determining the ratio of the total thickness of the A layers to the total thickness of the film.

The thickness ratio of the A layer can be controlled by adjusting the discharge ratio of the extruder that supplies the resins of the A layer and the B layer in the film manufacturing process to the lamination ratio.

The biaxially oriented polyarylene sulfide film of the present invention is excellent in transparency and color tone, as well as in running property and quality of the film surface. , various parts and industrial packaging materials that require transparency, such as lower plate protection materials for flexible printed circuit boards, insulating films such as capacitor materials that require surface quality, transparent circuit boards, and transparent antenna substrates. It can be suitably used as a material.

The biaxially oriented polyarylene sulfide film of the present invention may be coated with various coating agents on both sides or one side in-line or off-line for the purpose of improving weather resistance and adhesiveness and protecting the surface.

A conductive film is formed on the biaxially oriented polyarylene sulfide film thus obtained to produce a circuit board. When used as a transparent circuit, the conductive film is preferably a transparent or translucent conductor. Examples include metal films such as Ag films, metal oxide films such as ITO (indium tin oxide) films, and conductive fine particles. A film produced by laminating one or more resin films containing A method of forming a thin wire conductor in a mesh form as a conductive film is also effective for improving the transparency.

A method for forming the conductor includes well-known methods such as sputtering and paste printing, but is not particularly limited. Patterning of the circuit board includes well-known methods such as photolithographic etching and screen printing. Furthermore, the circuit board is obtained by forming through holes by a drill, laser, fusion penetration method, or the like, if necessary.

A circuit board using the biaxially oriented polyarylene sulfide film of the present invention is useful as a transparent antenna substrate because of its excellent transparency and color tone.

The method for producing the biaxially oriented polyarylene sulfide film of the present invention will be described by taking as an example a method for producing a film using a polyphenylene sulfide resin (hereinafter sometimes abbreviated as PPS resin) as the polyarylene sulfide resin. However, the invention is not limited to this example.

Sodium sulfide and p-dichlorobenzene are blended and reacted at high temperature and high pressure in an amide-based polar solvent such as N-methyl-2-pyrrolidone (NMP). Copolymerization components such as m-dichlorobenzene and trihalobenzene can be included as necessary. Caustic potash, carboxylic acid alkali metal salts, etc. are added as polymerization degree modifiers, and the polymerization reaction is carried out at 230 to 290°C. After the polymerization, the polymer is cooled, and the polymer is made into an aqueous slurry and filtered through a filter to obtain a wet granular polymer. Add an amide-based polar solvent to the granular polymer, stir and wash at a temperature of 30 to 100° C., wash several times with ion-exchanged water at 30 to 80° C., and wash several times with an aqueous solution of a metal salt such as calcium acetate. After washing, it is dried to obtain polyphenylene sulfide polymer powder.

In the present invention, when the polymer powder is washed, the obtained polymer powder is washed in an NMP solvent at a temperature of 100 to 200°C for 6 to 24 hours, and washed with pure water at 30 to 80°C for several hours. Wash twice to obtain polymer powder (washed). This polymer powder is put into a vented extruder, melt-extruded into strands, cooled with water at a temperature of 25° C., and cut into chips to obtain PPS chips.

The polymer powder and/or the polymer powder (washed) obtained above as the polyarylene sulfide resin, inorganic particles and/or other thermoplastic resin (X) are mixed in an arbitrary ratio to prepare a masterbatch. The concentration of the inorganic particles and/or other thermoplastic resin (X) in the masterbatch is preferably 1% by mass to 25% by mass, more preferably 5% by mass to 10% by mass. If the amount is more than 25% by mass, the dispersibility may deteriorate and the dispersed diameter may become large. If it is less than 1% by mass, the amount of the masterbatch used may increase during use due to dilution, which may not be preferable from the viewpoint of cost. The method of producing the masterbatch in the present invention is preferably a method of forming a masterbatch using an apparatus such as a twin-screw extruder which is subjected to shear stress. In this case, in the kneading section, it is preferable to knead so that the resin temperature ranges from (melting point of PAS resin + 5 ° C.) to (melting point of PAS resin + 80 ° C.), more preferably (melting point of PAS resin + 10 °C) or more (melting point of PAS resin +80 °C), more preferably (melting point of PAS resin +15 °C) or more (melting point of PAS resin +70 °C) or less. Moreover, it is preferable to make screw rotation speed into the range of 100 rpm or more and 1500 rpm or less. The dispersed diameter of the dispersed phase can be controlled by setting the resin temperature and the screw rotation speed within preferable ranges.

After mixing the PPS chips dried under reduced pressure at 180°C for 3 hours and the masterbatch at a predetermined ratio, in the case of a single layer, a full-flight single-screw extruder with the melting zone set at 300°C to 350°C. After passing through a filter, it is then discharged from a T-die type nozzle and brought into close contact with a cooling drum with a surface temperature of 20 ° C. to 70 ° C. while applying an electrostatic charge to rapidly solidify and solidify. An unstretched film in an oriented state is obtained.

In the case of forming a laminated film having two or more layers, the PPS chips and chips obtained by mixing PPS chips and a masterbatch at a predetermined ratio are supplied to separate single-screw extruders and heated to the melting point of each resin or higher. Each raw material melted by heating is in a molten state in a merging device provided between the melt extruder and the mouthpiece outlet, and (a layer containing PPS as a main component) / (a layer containing PPS as a main component and other than PPS) Layer containing at least one thermoplastic resin), or (Layer containing PPS as the main component and at least one other thermoplastic resin different from PPS) / (Layer containing PPS as the main component) / (A layer containing PPS as a main component and at least one other thermoplastic resin different from PPS), and any lamination ratio (for example, 0.3:24.4:0.3 or 0.3: 24.7) and extruded from the spinneret outlet on the slit. This sheet-like material is brought into close contact with a cooling drum having a surface temperature of 20° C. to 70° C. and solidified by cooling to obtain a substantially non-oriented two-layer laminated unstretched film or three-layer laminated unstretched film.

A desired thickness can be obtained by adjusting the amount of resin extruded from the extruder, the film-forming speed, and the stretching ratio.

The unstretched film obtained above is then biaxially stretched. Stretching methods include sequential biaxial stretching (stretching in one direction at a time, such as stretching in the longitudinal direction and then stretching in the width direction), simultaneous biaxial stretching (stretching in the longitudinal direction and the width direction). stretching at the same time), or a combination thereof. Here, a sequential biaxial stretching method is exemplified in which stretching is performed first in the longitudinal direction and then in the width direction.

An unstretched film is heated by a group of heating rolls, and is stretched in the longitudinal direction (MD direction) by 2.0 to 4.5 times, more preferably 2.8 to 4.2 times in one stage or two or more stages. Draw (MD draw). The stretching temperature is preferably in the range of Tg to Tcc, more preferably (Tg+5°C) to (Tcc-10°C). After that, it is cooled by a group of cooling rolls at 20°C to 50°C.

As a stretching method in the width direction (TD direction) following MD stretching, for example, a method using a tenter is common. Both ends of the film are gripped with clips, guided to a tenter, and stretched in the width direction (TD stretching). The stretching temperature is preferably from Tg to Tcc, more preferably from (Tg+5°C) to (Tcc-10°C). The draw ratio is preferably 3.0 to 5.0 times, preferably 3.0 to 4.5 times, from the viewpoint of flatness of the film.

Next, it was stretched 1.01 times to 1.80 times or less in the longitudinal direction and/or the width direction at a temperature of (melting point of polyarylene sulfide resin −10° C.) or higher (melting point of polyarylene sulfide resin +10° C.) or lower. It is preferable to pass through a high temperature drawing process after heat-treating at the same temperature later. A more preferable temperature is (melting point of polyarylene sulfide resin) or more and (melting point of polyarylene sulfide resin+5° C.) or less, and a more preferable magnification is 1.3 to 1.5 times in the width direction. Since the crystals are partially melted and deformed in this step, the crystal size can be controlled to a desired size, and the haze can be reduced. Furthermore, in this step, by applying stretching in a temperature range where the resin has high fluidity, stretching can be performed without forming fine voids at the interfaces of particles and/or dispersions formed by MD stretching and TD stretching. By suppressing the surface unevenness due to voids, the surface unevenness becomes gentle and the surface glossiness can be increased.
If the draw ratio is less than 1.01 times, a sufficient effect cannot be obtained, and if it exceeds 1.8 times, tearing may occur during drawing. Also, relaxation treatment may be performed in the longitudinal and/or width direction during the heat treatment.

Next, the film is cooled to room temperature and, if necessary, subjected to relaxation treatment in the longitudinal and/or transverse direction, and wound up to obtain a biaxially oriented polyarylene sulfide film.
Next, a metal film laminated film using the biaxially oriented polyarylene sulfide film of the present invention, a film capacitor using the same, and production methods thereof will be described.

The metal film laminated film of the present invention has a metal film on at least one side of the biaxially oriented polyarylene sulfide film of the present invention. This metal film laminated film can be obtained by providing a metal film on at least one side of the biaxially oriented polyarylene sulfide film according to the present invention.

In the present invention, the method of applying the metal film is not particularly limited, but for example, aluminum or an alloy of aluminum and zinc is deposited on at least one side of the biaxially oriented polyarylene sulfide film to form an internal electrode of the film capacitor. A method of providing a metal film such as a vapor deposition film is preferably used. At this time, other metal components such as nickel, copper, gold, silver, chromium, etc. can be vapor-deposited simultaneously or sequentially with aluminum. Also, a protective layer can be provided on the deposited film with oil or the like. When the surface roughness of the biaxially oriented polyarylene sulfide film is different between the front and back surfaces, it is preferable to form a metal film laminated film by providing a metal film on the smooth surface side from the viewpoint of increasing the voltage resistance.

In the present invention, if necessary, after forming the metal film, the metal film laminated film can be annealed at a specific temperature or subjected to heat treatment. Also, for insulation or other purposes, at least one surface of the metal film laminated film can be coated with a resin such as polyphenylene oxide.

The film capacitor of the present invention uses the metal film laminated film of the present invention. That is, the film capacitor of the present invention has the metal film laminated film of the present invention.

For example, the film capacitor of the present invention can be obtained by laminating or winding the above metal film laminated film of the present invention by various methods. A preferred method for manufacturing a wound film capacitor is as follows.

Aluminum is deposited under reduced pressure on one side of the biaxially oriented polyarylene sulfide film. At that time, vapor deposition is performed in stripes having margins running in the longitudinal direction. Next, a blade is inserted into the center of each vapor-deposited portion and the center of each margin portion on the surface to form a slit, thereby producing a tape-shaped take-up reel having a margin on one side of the surface. A tape-shaped take-up reel having a margin on the left or right is wound by stacking two reels each of the left margin and the right margin so that the vapor-deposited portion protrudes from the margin in the width direction, and a wound body is obtained. get

When vapor deposition is performed on both sides, vapor deposition is performed in stripes having a margin running in the longitudinal direction on one surface, and stripes are deposited on the other surface so that the margin in the longitudinal direction is positioned in the center of the vapor deposition on the back side. evaporate in a shape. Next, a blade is inserted in the center of the margins on the front and back sides to form a slit to produce a tape-shaped take-up reel having margins on one side on both sides (for example, if there is a margin on the right side on the front side, a margin on the left side on the back side). Two sheets of the obtained reel and one undeposited laminated film are superimposed and wound so that the metallized film protrudes from the laminated film in the width direction to obtain a wound body.

As a method of obtaining the film capacitor of the present invention from the metal layer laminated film of the present invention, for example, the core material is removed from the wound body produced as described above and pressed, and metallikon is thermally sprayed on both end surfaces to form external electrodes. and a method of welding a lead wire to a metallicon to form a wound film capacitor. Film capacitors are used in a wide variety of applications, including electric vehicles such as electric vehicles, hybrid vehicles, and fuel cell vehicles, power control unit applications for electric aircraft such as drones, railroad vehicle applications, solar and wind power generation applications, and general home appliance applications. Therefore, the film capacitor of the present invention can also be suitably used for these applications. In addition, the polypropylene film of the present invention can be used in various applications such as packaging films, release films, process films, sanitary products, agricultural products, building products, medical products, etc. In particular, film processing includes a heating step. It can be preferably used for the purpose.

A power control unit, an electric vehicle, and an electric aircraft according to the present invention will be described below. The power control unit of the present invention has the film capacitor of the present invention. A power control unit is a system that manages power in an electric vehicle, an electric aircraft, or the like that has a mechanism driven by electric power. By mounting the film capacitor of the present invention in a power control unit, it becomes possible to reduce the size of the power control unit itself, improve heat resistance, and improve efficiency, resulting in improved fuel efficiency.

The electric vehicle of the present invention has the power control unit of the present invention. Here, an electric vehicle refers to a vehicle having a mechanism driven by electric power, such as an electric vehicle, a hybrid vehicle, and a fuel cell vehicle. As described above, the power control unit of the present invention can be miniaturized and has excellent heat resistance and efficiency.

The electric aircraft of the invention has the power control unit of the invention. Here, an electric aircraft refers to an aircraft having a mechanism driven by electric power, such as a manned electric aircraft and a drone. As described above, the power control unit of the present invention can be miniaturized and has excellent heat resistance and efficiency.

[Method for measuring characteristics]
(1) Crystal Size The crystal size was determined by measuring the diffraction pattern by a reflection method, employing a method in which the sample was rotated in-plane to eliminate the orientation effect of the sample. The X-ray generator, X-ray source, goniometer, slit system, 2θ scanning speed, chart speed, and measurement sample were carried out in the same manner as in determining the degree of crystallinity.

The apparent crystal size (ACS) was calculated from the half width of the PPS (200) diffraction peak using Scheller's formula.

ACS(Å)=kλ/(β cos θ)
β={B ² −(B′) ² } ^1/2
where k = Scheller constant (k = 1)
λ = X-ray wavelength (λ = 1.5418 Å)
2θ = Bragg angle (°)
β=half width after correction (radian)
B = measured half width (radian)
B'=half width (radian) of standard sample for correction (Si single crystal).
(2) Glossiness According to JIS K-7105 (1981), the film surface was measured using a digital variable angle gloss meter UGV-5D manufactured by Suga Test Instruments Co., Ltd. under the conditions of an incident angle of 60° and a light receiving angle of 60°. The average value of the point data was defined as glossiness (%). Measurements were made on both sides of the film, and the value of the surface with the highest glossiness was shown in the table.

(3) Overall thickness of film, thickness of A layer and thickness ratio of A layer After embedding the film in epoxy resin, crush the cross section of the film in the thickness direction parallel to the longitudinal direction of the film and perpendicular to the film surface with a microtome. disconnected without Next, the cross section of the cut film is fixed to a sample stage of a scanning electron microscope under conditions that do not cause material deterioration due to heat, and the cross section is subjected to ion rimming using an ion milling device IM4000PLUS manufactured by Hitachi High-Technologies Corporation. Subsequently, Pt vapor deposition was performed. Then, the cross section of the obtained film was observed using an electrolytic emission scanning electron microscope JSM-6700F manufactured by JEOL Ltd. under the conditions of an accelerating voltage of 3.0 kV and a working distance of 8.0 mm to obtain an image. .

The thickness of the A layer was observed under conditions of an observation magnification of 5000 times, and the thickness of the A layer of the film was measured at arbitrary 5 points from the analysis of the obtained image, and the average value was taken as the thickness of the A layer. When there were a plurality of A layers, the thickness of each A layer was obtained, and the total thickness of all A layers was taken as the A layer thickness.

Further, the thickness of the entire film is observed under the condition of an observation magnification of 3000 times, and an image in which the entire thickness direction of the film can be observed is collected. The thickness of the entire film was measured from the image obtained by observation. If the entire thickness direction of the film cannot be confirmed at the above magnification, several images are taken in the thickness direction and the images are joined to confirm the overall image. Samples used for the thickness measurement were selected at random locations at a total of 5 locations, and the average of the measured values of the 5 samples was taken as the total film thickness of the sample.

The ratio of the thickness of the A layer to the total thickness of the film obtained by the above-described method was obtained and defined as the thickness ratio of the A layer.

(4) Haze The haze of the entire film was measured using the following equipment.
Apparatus: Turbidity meter NDH5000 (manufactured by Nippon Denshoku Industries Co., Ltd.)
Light source: White LED 5V3W (rated)
Light receiving element: Si photodiode with V(λ) filter
Measurement light flux: φ14 mm (incidence aperture φ25 mm)
Optical conditions: Compliant with JIS-K7136 (2000) (5) Runnability Using a Toyo Tester Kogyo friction measuring instrument, according to ASTM-D1894 (1999), one side of the film and its back side were in contact. The initial rising resistance value was measured when the MD directions were rubbed against each other, and the maximum value was taken as the static friction coefficient μs. However, when the initial rise was large and exceeded the upper limit (5.0) of the measured value, the measurement was considered impossible. Five sets (10 pieces) of samples were cut into rectangles having a width of 80 mm and a length of 200 mm. Measurement was performed 5 times and an average value was obtained. The running performance was judged according to the following criteria from the obtained coefficient of static friction. D was judged to have poor runnability.
A: μs = 0.50 or less (good runnability)
B: µs = more than 0.50 and 0.60 or less (normal runnability)
C: µs = more than 0.60 and 0.70 or less (slightly inferior in runnability)
D: more than μs = 0.70 (poor runnability)
(6) A strip-shaped sample with a length of 200 mm and a width of 10 mm was cut out in the longitudinal direction of the heat-resistant film and used. Breaking elongation was measured at 25° C. and 65% RH using a tensile tester according to the method specified in ASTM-D882-97. The initial tension chuck distance was 100 mm, and the tension speed was 300 m/min. The measurement was performed 20 times by changing the sample, and the average value (X) of the elongation at break was obtained. In addition, a strip-shaped sample with a length of 200 mm and a width of 10 mm in the longitudinal direction of the film was placed in a gear oven, left in an atmosphere of 200 ° C., naturally cooled, and subjected to a tensile test under the same conditions as above. was performed 20 times, and the average value (Y) of the elongation at break was obtained. From the obtained average values (X) and (Y) of the breaking elongation, the elongation retention rate was obtained by the following equation.
Elongation retention rate (%) = (Y/X) x 100
The treatment time in the gear oven until the elongation retention rate became 50% or less was defined as the half life time of the elongation at break. Heat resistance was evaluated according to the following criteria. A and B pass.
A: Elongation half life is 120 hours or more.
B: Elongation half life is 80 hours or more and less than 120 hours.
C: Elongation half life is less than 80 hours.
(7) Insulation evaluation Cut the film into squares of size 25 cm × 25 cm, and after conditioning the humidity in a room of 23 ° C. and 65% Rh for 24 hours, based on JIS C2151 (2006), AC dielectric breakdown tester (Kasuga The dielectric breakdown voltage (kV) per unit thickness was measured at a frequency of 60 Hz and a boost rate of 1000 V/sec using an AC 30 kV (manufactured by Denki Co., Ltd.). Then, the thickness (μm) of the peripheral portion of the portion where the dielectric breakdown occurred and the hole was opened was measured. Next, the obtained dielectric breakdown voltage was divided by the thickness (μm) to calculate the dielectric breakdown voltage per unit thickness (V/μm). The measurement was performed 10 times, and the average value was taken as the dielectric breakdown voltage (V/μm) per unit thickness. Based on the value of the dielectric breakdown voltage obtained, the insulation was judged according to the following criteria.

AA: Dielectric breakdown voltage of 270 V/μm or more
A: Dielectric breakdown voltage of 240 V/μm or more B: Dielectric breakdown voltage of 210 V/μm or more C: Dielectric breakdown voltage of 180 V/μm or more D: Dielectric breakdown voltage of less than 180 V/μm

(Reference Example 1) Production process of PPS resin (granules) Process In a 1-liter autoclave equipped with a stirrer, 1.00 mol of 47% sodium hydrosulfide, 1.03 mol of 96% sodium hydroxide, and N-methyl-2-pyrrolidone. (NMP) 1.65 mol, sodium acetate 0.45 mol, and ion-exchanged water 150 g were charged, stirred at 240 rpm, and gradually heated to 225° C. over about 3 hours while passing nitrogen under normal pressure, and 211 g of water and After distilling off 4 g of NMP, the reactor was cooled to 160°C.

Next, 1.00 mol of p-dichlorobenzene (p-DCB) and 1.31 mol of NMP were added. The reaction vessel was then sealed under nitrogen gas. While stirring at 240 rpm, the temperature was raised from 200° C. to 235° C. at a rate of 0.6° C./minute, and after reaching 235° C., the reaction was continued at 235° C. for 95 minutes. After that, the temperature was raised to 270° C. at a rate of 0.8° C./min and held for 100 minutes. After reaching 270° C., 1 mol of water was injected into the system over 15 minutes. After 100 minutes at 270°C, it was cooled to 200°C at a rate of 1.0°C/min, and then rapidly cooled to near room temperature. The content was taken out, diluted with 0.4 liter of NMP, stirred at 85° C. for 30 minutes, and the solvent and solids were separated by filtration through a sieve (80 mesh). In the post-treatment step, 0.5 liter of NMP was added to the resulting solid, stirred at 85°C for 30 minutes, and filtered. The obtained solid was washed with 0.9 liter of warm water three times and filtered. Furthermore, 1 liter of warm water was added to the obtained particles, and the particles were washed twice and filtered to obtain polymer particles. This was dried with hot air at 80°C and then dried under reduced pressure at 120°C to obtain polyphenylene sulfide (PPS) resin granules (PPS granules) having a melting point of 280°C and a mass average molecular weight of 70,000.

(Reference Example 2) Production method of PPS pellets (PPS-1) The PPS resin (granules) prepared in Reference Example 1 was charged into a vented co-rotating twin-screw kneading extruder heated to 320°C and melted. The mixture was extruded into strands, cooled with water at 25° C., and immediately cut to prepare PPS pellets (PPS-1).

(Reference Example 3) Preparation of PPS granules and thermoplastic resin master pellets (MB-1) A co-rotating vented twin-screw kneading extruder provided with one kneading paddle kneading section was heated to 320°C. 90 parts by mass of the PPS granules obtained in Reference Example 1 and 10 parts by mass of polyethersulfone (PESU: Solvay Advanced Polymers Co., Ltd., Veradel 3600) were supplied from the feed port, and melt-kneaded at a screw rotation speed of 200 rpm. , extruded in a strand shape, cooled with water at a temperature of 25° C., and immediately cut to prepare master pellets (MB-1) containing 10 parts by mass of PESU.

(Example 1)
The PPS pellets (PPS-1) prepared in Reference Example 2 and the PPS master pellets (MB-1) prepared in Reference Example 3 were uniformly mixed at the ratio shown in Table 1, and dried under reduced pressure at 180°C for 3 hours. , fed into a single screw extruder with the melt zone heated to 315°C.

Next, the molten polymer is passed through a fiber sintered stainless metal filter (20 μm cut) and melted and extruded from a T-die mouthpiece set at a temperature of 310° C., and then adhered to a cast drum with a surface temperature of 25° C. while applying an electrostatic charge. It was solidified by cooling to obtain an unstretched film having a thickness of 950 μm. Next, the obtained unstretched film is stretched in the longitudinal direction of the film at a stretching temperature of 105° C. by using a longitudinal stretching machine consisting of a plurality of heated rolls and utilizing the difference in peripheral speed of the rolls at a magnification of 3.6 times in the longitudinal direction of the film. Stretched. Thereafter, both ends of the film were held by clips, and the film was led to a tenter and stretched at a stretching temperature of 100° C. in the width direction at a magnification of 3.6 times. Subsequently, as a post-high-temperature stretching step, the film was stretched 1.4 times in the width direction at 285°C, heat-treated at 285°C, subjected to 2% relaxation treatment, cooled to room temperature, and film edges were removed to obtain a thickness of 50 µm. of polyarylene sulfide film was obtained. Table 1 shows the physical properties and characteristics of the obtained film.

(Example 2)
Raw materials for layers A and B were prepared so that the PPS pellets (PPS-1) prepared in Reference Example 2 and the PPS master pellets (MB-1) prepared in Reference Example 3 had the compositions and ratios shown in Table 1, After vacuum-drying the raw materials separately at 180°C for 3 hours, they were separately supplied to two single-screw extruders heated to 315°C, and three layers (laminated In the configuration A/B/A), the lamination ratio is guided to be as shown in Table 1, and then discharged from a T-die type nozzle, and while static charge is applied to a cast drum with a surface temperature of 25 ° C., it is adhered and rapidly cooled and solidified to obtain a thickness. An unstretched film of 950 μm was obtained. Next, the obtained unstretched film is stretched in the longitudinal direction of the film at a stretching temperature of 105° C. by using a longitudinal stretching machine consisting of a plurality of heated rolls and utilizing the difference in peripheral speed of the rolls at a magnification of 3.6 times in the longitudinal direction of the film. Stretched. Thereafter, both ends of the film were held by clips, and the film was led to a tenter and stretched at a stretching temperature of 100° C. in the width direction at a magnification of 3.6 times. Subsequently, as a post-high temperature stretching step, the film is stretched in the width direction at the temperature and magnification shown in Table 1, heat-treated at the same temperature, subjected to 2% relaxation treatment, cooled to room temperature, and the film edge is removed. A polyarylene sulfide film having a thickness of 50 μm was obtained. Table 1 shows the physical properties and characteristics of the obtained film.

(Example 3)
A biaxially oriented polyarylene sulfide film having a thickness of 50 μm was obtained in the same manner as in Example 2 except that the unstretched film had a thickness of 800 μm and the composition, ratio, and stretching conditions shown in Table 1 were applied.

(Examples 4-5)
A biaxially oriented polyarylene sulfide film having a thickness of 50 μm was obtained in the same manner as in Example 2 except that the unstretched film had a thickness of 950 μm and the composition, ratio, and stretching conditions shown in Table 1 were applied.

(Example 6)
A biaxially oriented polyarylene sulfide film having a thickness of 100 μm was obtained in the same manner as in Example 2 except that the unstretched film had a thickness of 1900 μm and the composition, ratio, and stretching conditions shown in Table 1 were applied.

(Example 7)
A biaxially oriented polyarylene sulfide film having a thickness of 50 μm was produced in the same manner as in Example 2 except that the unstretched film had a thickness of 950 μm, the composition, ratio, and post-high-temperature stretching conditions were as shown in Table 1, and heat treatment was not performed. Obtained.

(Examples 8-9)
A biaxially oriented polyarylene sulfide film having a thickness of 50 μm was obtained in the same manner as in Example 2 except that the lamination ratio shown in Table 1 was used.
(Examples 10-11)
A biaxially oriented polyarylene sulfide film having a thickness of 50 μm was obtained in the same manner as in Example 2 except that the composition of the A layer was changed to the ratio shown in Table 1.

(Comparative example 1)
A polyarylene sulfide film was obtained in the same manner as in Example 1, except that the PPS pellets 1 and the masterbatch were mixed so as to have the composition and ratio shown in Table 1, and the mixture was stretched under the conditions shown in Table 1.

(Comparative example 2)
A polyarylene sulfide film was obtained in the same manner as in Example 2, except that the PPS pellets 1 and the masterbatch were mixed so as to have the composition and ratio shown in Table 1, and the mixture was stretched under the conditions shown in Table 1.

Since the polyarylene sulfide film of the present invention is excellent in transparency, it can be suitably used as a transparent circuit substrate and a transparent antenna substrate.

Claims (15)

Polyarylene sulfide (PAS) is the main component, and the crystal size obtained by applying Schller's equation to the half width of the (200) diffraction peak of the polyarylene sulfide crystal obtained by X-ray diffraction is 90 Å or less. Axially oriented polyarylene sulfide film. 2. The biaxially oriented polyarylene sulfide film according to claim 1, having a thickness of 30 [mu]m or more. 3. The biaxially oriented polyarylene sulfide film according to claim 1, wherein at least one film surface has a glossiness of 140% or more. 4. The biaxially oriented polyarylene sulfide film according to claim 3, wherein at least one film surface has a glossiness of 200% or more. 3. The biaxially oriented polyarylene sulfide film according to claim 1, which has a haze of 10% or less. A layer (A layer). 7. The biaxially oriented polyarylene according to claim 6, wherein the layer A contains a dispersion incompatible with polyarylene sulfide, and the thickness ratio of the layer A is 0.1% or more and 10% or less with respect to the total thickness of the film. sulfide film. 3. The biaxially oriented polyarylene sulfide film according to claim 1, which is used for a transparent circuit board. 3. The biaxially oriented polyarylene sulfide film according to claim 1, which is used for a transparent antenna substrate. An insulating film using the biaxially oriented polyarylene sulfide film according to claim 1 or 2. A metal film laminated film comprising a metal film on at least one surface of the biaxially oriented polyarylene sulfide film according to claim 1 or 2. A film capacitor using the metal laminated film according to claim 11 . A power control unit comprising a film capacitor according to claim 12. An electric vehicle comprising the power control unit according to claim 13. An electric aircraft, comprising a power control unit according to claim 13.