Polyarylene sulfide film

Abstract

The present invention provides a polyarylene sulfide film having excellent transparency and color tone. The present invention is a polyarylene sulfide film which contains, as a main component, a polyarylene sulfide (PAS)-based resin, has a spectral light transmittance Ta at a wavelength of 550 nm of at least 75%, and has a b value of at most 5.0.

Description

[Technical Field]

[0001] The present invention relates to a polyarylene sulfide film. [Background technology]

[0002] In recent years, glass has been under consideration as a circuit board material that requires transparency. However, glass substrates have drawbacks such as being easily broken, being heavy, and being difficult to make thin. In addition, glass substrates do not have sufficient flexibility for use in car windshields and other parts that come into contact with curved surfaces indoors and outdoors.

[0003] Polyarylene sulfide resins possess excellent heat resistance, flame retardancy, rigidity, chemical resistance, electrical insulation, and low moisture absorption, making them particularly suitable for use in electrical and electronic devices, mechanical components, and automotive parts. The trend toward higher speeds and larger capacities in the electrical and electronic component fields has led to a demand for materials with low transmission loss. Polyarylene sulfide films, such as polyphenylene sulfide (PPS) films, are being increasingly used as circuit materials, taking advantage of their low transmission loss and low moisture absorption. However, PPS films have poor transparency and color tone. Therefore, when used as transparent circuit boards, for example, PPS films can easily impair visibility due to their transparency and color tone. Therefore, improvements in transparency and color tone are desirable.

[0004] To date, there has been insufficient research into techniques for improving the color tone of PPS films. For example, a technique for rubbing PPS films to improve transparency and slipperiness has been disclosed (Patent Document 1). Furthermore, a technique for reducing the content of impurities by-produced during polymerization reactions to improve volatile content and color tone has been disclosed (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-67748 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-138206 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology described in Patent Document 1 has a problem in that it is insufficient to improve the color tone of PPS resin, and the technology described in Patent Document 2 has a problem in that it does not provide sufficient transparency when applied to film applications.

[0007] An object of the present invention is to solve the above-mentioned problems, that is, to provide a polyarylene sulfide film excellent in transparency and color tone. [Means for solving the problem]

[0008] In order to solve the above problems, the polyarylene sulfide film of the present invention has the following configuration: Namely, the polyarylene sulfide film contains a polyarylene sulfide (PAS) resin as a main constituent component, and has a spectral light transmittance Ta at a wavelength of 550 nm of 75% or more and a b value of 5.0 or less. [Effects of the Invention]

[0009] The polyarylene sulfide film of the present invention has excellent transparency and color tone. Therefore, by taking advantage of these properties, it can be suitably used as various parts that particularly require transparency, such as automobile components, battery components, display components, industrial packaging materials, decorative materials, and electric and electronic materials, such as transparent circuit boards, transparent antenna boards, high-frequency transparent circuit boards, and high-frequency transparent antenna boards. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the present invention, the polyarylene sulfide film is a film obtained by melt-molding a resin composition containing a polyarylene sulfide (hereinafter, PAS)-based resin as a main component into a sheet, and may be preferably biaxially stretched and heat-treated.

[0011] In the present invention, "having a PAS resin as the main constituent" means that the PAS resin accounts for 50% by mass or more, preferably 60% by mass or more, and more preferably 70% by mass or more. If the PAS resin content is less than 50% by mass, the heat resistance, dimensional stability, and mechanical properties that are characteristic of PAS films may be impaired.

[0012] The PAS resin used in the present invention is a copolymer having a repeating unit of -(Ar-S)-, where Ar includes units represented by the following formulae (A) to (K).

[0013] [ka]

[0014] (R1 and R2 are substituents selected from hydrogen, alkyl groups, alkoxy groups, and halogen groups, and R1 and R2 may be the same or different.) Among the repeating units of the above formula, the p-arylene sulfide unit is preferred. Representative examples of these include polyphenylene sulfide, polysulfone, polyether sulfone, polyphenylene sulfide sulfone, and polyphenylene sulfide ketone. From the viewpoints of film properties and economic efficiency, the p-phenylene sulfide unit is particularly preferred.

[0015] The polyarylene sulfide resin used in the present invention preferably comprises p-phenylene sulfide units represented by the following structural formula as the main structural unit, accounting for 80 mol % to 99.9 mol % of all repeating units. By making the PAS resin used in the present invention have the above composition, it is possible to achieve excellent heat resistance and chemical resistance.

[0016] [ka]

[0017] The PAS resin used in the present invention can also be copolymerized with copolymer units in an amount of 0.01 mol % to 20 mol % of the repeating units.

[0018] Preferred copolymerized units include the following, and a particularly preferred copolymerized unit is an m-phenylene sulfide unit.

[0019] [ka]

[0020] [ka]

[0021] [ka]

[0022] (where X represents an alkylene, CO, or SO2 unit.)

[0023] [ka]

[0024] [ka]

[0025] (where R represents an alkyl, nitro, phenylene, or alkoxy group.) In the main structural unit of the PAS resin used in the present invention, the mode of copolymerization with the copolymerization unit is not particularly limited, but a random copolymer is preferred.

[0026] The PAS resin composition constituting the PAS film of the present invention may contain various additives such as antioxidants, heat stabilizers, antistatic agents, and antiblocking agents, as long as the effects of the present invention are not impaired.

[0027] The PAS film of the present invention must have a light transmittance (Ta) at a wavelength of 550 nm of 75% or more. By ensuring that Ta is 75% or more, a film with excellent transparency can be obtained. If Ta is less than 75%, the film becomes more cloudy, and transparency may decrease when used as a transparent circuit board or a protective substrate for optical components. The light transmittance at a wavelength of 550 nm is more preferably 78% or more, and even more preferably 80% or more. Methods for achieving a light transmittance at a wavelength of 550 nm within the above range include a method for controlling particles and other resins contained in the film to improve runnability, as described below, and a method for removing impurities by subjecting the polymerized polymer or the resulting film to a solvent washing treatment, as described below.

[0028] In the PAS film of the present invention, it is preferable that the light transmittance (Tb) at a wavelength of 400 nm and the light transmittance (Tc) at a wavelength of 600 nm satisfy the following formula (i). Tc-Tb≦8.2% Equation (i).

[0029] The above characteristics mean that there are fewer impurities that absorb light in the wavelength range of 400 to 600 nm, resulting in a film with little coloration. Furthermore, if the Tc-Tb ratio exceeds 8.2%, the film may be colored and have a lower color tone when used as a substrate material. More preferably, Tc-Tb is ≦8.0%. The Tc-Tb ratio can be controlled within the above range by reducing the remaining impurities in the PAS film through a cleaning process, as described below. In the present invention, impurities refer to substances that absorb light in the 400 to 600 nm range, such as the polymerization solvent N-methyl-2-pyrrolidone (NMP), and polymerization by-products such as sodium hydrogen sulfide (NaSH) and 4-chlorobenzenethiolate. Light transmittance at wavelengths of 550 nm, 400 nm, and 600 nm can be evaluated using the method described below.

[0030] The PAS film of the present invention must have a b-value, which is an index of yellowness, of 5.0 or less. By setting the b-value to 5.0 or less, a film with excellent color tone can be obtained. If the b-value exceeds 5.0, when used as a transparent circuit board or a protective substrate for optical components, the color tone may cause deterioration in visibility, leading to overlooking of defects. The b-value is more preferably 3.0 or less, even more preferably 2.5 or less, and most preferably 2.0 or less. There is no particular lower limit, but from the viewpoint of productivity, it is preferably 0.0 or more. To obtain a polyarylene sulfide film with a b-value within the above range, for example, a method can be used in which the polymerized polymer or the obtained film is washed with a solvent to remove impurities, as described below.

[0031] The PAS film of the present invention preferably has an L value, which is an index of brightness, of 85 or more. By setting the L value within the above range, a film with excellent color tone can be obtained. If the L value is less than 85, when used as a transparent circuit board or a protective substrate for optical components, the brightness may be low and visibility may be impaired. More preferably, the L value is 90 or more. To obtain a PAS film with an L value within the above range, control can be achieved by controlling the particles or other resins contained in the film, as described below, or by the film layer structure, as described below. The L value can be evaluated by the method described below.

[0032] The washing treatment in the present invention is a process in which polymer powder after polymerization or a film obtained by melt-molding a polymer into a sheet and then biaxially stretching and heat-treating the polymer is immersed in a solvent while being heated for a predetermined time. For the polymer powder in the present invention, a method in which an alkali metal sulfide such as sodium sulfide and a polyhaloaromatic compound such as p-dichlorobenzene are reacted in an organic amide solvent such as NMP (JP-B-45-3368) is used, but is not particularly limited thereto. In particular, the method of washing the polymer powder obtained by polymerization with a solvent is preferred from the viewpoints of productivity and efficiency.

[0033] Examples of the washing solvent used in the washing treatment include acetone, toluene, and NMP. NMP is particularly preferred from the viewpoint of removing residual impurities, as it is used as a polymerization solvent.

[0034] Next, the present invention will be explained using a cleaning method using NMP as an example, but the present invention is not limited to this.

[0035] In the present invention, the temperature of the solvent during washing is preferably 100°C or higher and 200°C or lower. By setting the temperature during washing within the above range, the temperature is above the glass transition temperature of the resin, and molecular chain motion begins, allowing remaining impurities to be efficiently removed, resulting in a film with excellent transparency and color tone. If the temperature is lower than 100°C, the molecular chains are constrained, which may result in remaining impurities and a decrease in color tone. If the temperature exceeds 200°C, the mobility of the resin becomes too high, and the extracted impurities may be re-incorporated into the resin, resulting in a decrease in color tone. The solvent temperature during washing in the present invention is more preferably 125°C or higher and 175°C or lower.

[0036] In the present invention, the washing treatment time of the solvent is preferably 5 hours or more. By setting the washing treatment time within the above range, deterioration of the solvent can be suppressed and impurities can be efficiently removed. If it is less than 5 hours, impurities may not be completely extracted, which may result in coloration and a decrease in color tone. The upper limit of the treatment time is not particularly limited, but is preferably 30 hours or less from the viewpoint of productivity. The washing treatment time of the present invention is more preferably 10 hours or more, and even more preferably 20 hours or more.

[0037] Furthermore, in the present invention, it is preferable to incorporate fine bubbles into the cleaning solvent. In the present invention, fine bubbles are bubbles with a diameter of 100 μm or less. The method for incorporating fine bubbles into the cleaning solvent is not particularly limited, but a known device such as that exemplified in JP-A-2007-21343 can be used. By incorporating fine bubbles into the solvent, the cleaning solvent increases the wettability of the polymer powder or film, facilitating penetration, thereby achieving efficient cleaning. Examples of gas species to be incorporated into the fine bubbles include nitrogen (N2), oxygen (O2), and carbon dioxide (CO2), but any of these may be used. Oxygen is particularly preferable for promoting adsorption through interaction with the functional groups of the resin.

[0038] The PAS film of the present invention preferably has a surface roughness (Ra) of 10 nm or more and 200 nm or less on at least one film surface. SRa is a three-dimensional surface roughness parameter, meaning the average roughness at the center plane when the surface roughness curve is approximated by a sine curve, and is defined as the center plane average roughness. The center plane average roughness is a three-dimensional extension of the center line average roughness (Ra), a two-dimensional roughness parameter described in JIS-B0601-1994, and is calculated by dividing the volume enclosed by the surface profile curve and the center plane by the measured area. When the center plane is the XY plane, the vertical direction is the Z axis, and the measured surface profile curve is f(x, y), it is defined by the following formula (ii): where Lx is the measured length in the X direction, and Ly is the measured length in the Y direction.

[0039]

number

[0040] By setting the SRa within the above range, a film with excellent runnability can be obtained. If the surface roughness (Ra) of the film surface is less than 10 nm, the surface is smooth, which may increase friction during transport and reduce runnability. If the surface roughness (SRa) of the film surface exceeds 200 nm, light reflection due to surface irregularities may occur, resulting in reduced transparency. The surface roughness (SRa) of the film surface is more preferably 10 nm or more and 100 nm or less, and even more preferably 20 nm or more and 50 nm or less. The surface roughness (SRa) of the film surface can be controlled to fall within the above range by controlling the particles and other resins contained in the film, as described below, and can also be controlled by the film's layer structure, as described below. The surface roughness (SRa) of the film surface can be evaluated by the method described below.

[0041] The PAS film of the present invention has a depth volume (Vv) of 50 μm from a reference surface on at least one film surface. 3 More than 800μm 3 It is preferable that the depth volume (Vv) is equal to or less than 1 / 2 of the total volume of each recessed portion from the reference surface in one field of view, as measured by a VertScan manufactured by Ryoka Systems Co., Ltd. using the measurement method described below. The reference surface in this invention refers to the surface where the depth volume and protrusion volume are equal, and is a surface that is automatically set by the VertScan analysis software. A smaller depth volume (Vv) indicates fewer recesses on the film surface.

[0042] By setting the depth volume (Vv) within the range of the upper limit or less, the film surface has few recesses and has excellent surface quality, and by setting the depth volume (Vv) to the lower limit or more, excessive friction during transport can be suppressed, and running properties during processing can be improved. The depth volume (Vv) is more preferably 100 μm 3 More than 600μm 3 More preferably, it is 150 μm or less. 3 More than 400μm 3The depth volume (Vv) of the film surface can be set within the above range by a method of controlling the particles or other resins contained in the film, as described below, or by a method of controlling the film's layer structure, as described below. The depth volume (Vv) of the film surface can be evaluated by a method described below.

[0043] The PAS film of the present invention has a depth volume (Vv) (unit: μm 3 ) and the number of protrusions (n) (unit: pieces) preferably satisfy the following formula (iii): In the present invention, the number of protrusions is the number of protrusions per field of view measured by VertScan and obtained when the threshold value is used as the reference plane. 0.01≦Vv / n≦3.0 Equation (iii).

[0044] Vv / n represents the depth volume for one protrusion. For example, when there is a scratch on the film surface, Vv / n tends to increase if the scratch is large and Vv / n tends to decrease if the scratch is small. By setting Vv / n to the lower limit or more, excessive friction during transport can be prevented, and running properties during processing can be improved. Furthermore, by setting Vv / n to the upper limit or less, surface quality can be improved. Vv / n is more preferably 0.1 μm 3 / pcs or more 1.5μm 3 / or less, more preferably 0.1 μm 3 / pcs or more 0.5μm 3 / or less. Vv / n can be set within the above range by controlling the particles or other resins contained in the film, which will be described later, or by controlling the film's layer structure, which will be described later. Vv / n can be evaluated by the method described later.

[0045] The PAS film of the present invention preferably has a glossiness of 140% or more and less than 200% on at least one film surface. By achieving a glossiness within the above range, the surface has minimal surface irregularities that optically diffusely reflect light, resulting in high surface smoothness. When a metal layer is formed by vapor deposition, sputtering, plating, or other methods for use as a circuit, the surface is less likely to be uneven, resulting in a circuit with excellent transmission characteristics. Furthermore, when a metal layer is formed by vapor deposition or sputtering for use as a reflective film, the metal layer is less likely to be uneven. By maintaining a glossiness below the aforementioned upper limit, it is possible to prevent excessive surface irregularities from occurring, which could lead to the metal layer transferring the film's surface irregularities and thereby reducing transmission characteristics and reflection efficiency. Furthermore, by maintaining a glossiness above the aforementioned lower limit, it is possible to prevent a surface that is too smooth, resulting in increased friction during transportation and reduced runnability during processing.

[0046] The PAS film of the present invention contains particles and / or dispersions, and the void formation ratio of the particles and dispersions is preferably 10% or less. In the present invention, the void formation ratio refers to the ratio of particles and dispersions that form voids around their periphery, each void having a size of 10% or more of the cross-sectional area of ​​the particle or dispersion in an FE-SEM image of the film cross section, and is a value measured by the method described below. By maintaining the void formation ratio within the above range, it is possible to suppress light diffusion and light reflection within the film, thereby preventing deterioration of film transparency and improving color tone. The void formation ratio is more preferably 5.0% or less, and even more preferably 3.0% or less. The void formation ratio can be controlled within the above range by controlling the particles or other resins contained in the film as described below, or by the film layer structure described below.

[0047] To control the surface properties of the above-mentioned film, the PAS film may contain inactive particles or a thermoplastic resin (X) other than the PAS resin for surface control. When inactive particles are contained, examples include inorganic particles such as silica, alumina, calcium carbonate, barium carbonate, barium titanate, barium sulfate, calcium silicate, magnesium oxide, titanium oxide, and zinc oxide. When other thermoplastic resins are contained, polyarylates, polyphenylene ethers, polyetherimides, polysulfones, polyphenylsulfones, and polyethersulfones can be used. However, polysulfones, polyphenylsulfones, and polyethersulfones are preferred in terms of their affinity with the PAS resin. In the present invention, the incorporation of other thermoplastic resins is preferred in terms of achieving transparency, color tone, and runnability.

[0048] The PAS film of the present invention has a peak at 1145 cm in the infrared absorption spectrum obtained by Fourier transform infrared spectroscopy (FT-IR). -1 ~1160cm -1 It is preferable that the film has at least one absorption peak between these ranges. The absorption peak in the above range refers to a peak due to the stretching vibration of the S=O bond, and since the affinity between the PAS resin and the thermoplastic resin (X) is increased, the film is finely and uniformly dispersed in the PAS resin, resulting in transparency, and the thermoplastic resin (X) can impart surface roughness to the film, resulting in a film that is both transparent and has good runnability. The absorption peak in the above range can be achieved by incorporating a resin having sulfonic acid groups, such as polysulfone, polyphenylsulfone, or polyethersulfone, into the thermoplastic resin (X) at a predetermined concentration.

[0049] The PAS film of the present invention has a PAS resin content of W I and the content of thermoplastic resin (X) different from PAS resin W II When the total of the above is taken as 100 parts by mass, the content W of the thermoplastic resin (X) IIIn order to achieve both runnability and transparency, the content W of the thermoplastic resin (X) is preferably 0.01 parts by mass or more and 5.0 parts by mass or less. II is 0.2 parts by mass or more and 1.0 parts by mass or less. By making the content of the thermoplastic resin (X) equal to or less than the upper limit mentioned above, it is possible to prevent the transparency from being deteriorated due to the difference in refractive index of the resin. In addition, the content W of the thermoplastic resin (X) II By making the value equal to or greater than the lower limit mentioned above, it is possible to prevent the film from running smoothly and the quality from being reduced.

[0050] The PAS film of the present invention preferably has two or more layers primarily composed of a PAS resin, with at least one outermost layer being a layer (layer A) primarily composed of a PAS resin and containing at least one other thermoplastic resin (X) different from the PAS resin. By constructing two or more layers, the film can have multiple properties, including transparency, color tone, runnability, and surface quality. Examples of lamination structures include multilayer structures such as A / B, A / B / A, A / B / A / B, and A / B / A / B / A, where layer B is the layer primarily composed of a PAS resin.

[0051] The PAS film of the present invention preferably has three or more layers primarily composed of a PAS resin, with both outermost layers being layers (A layers) primarily composed of a PAS resin and containing at least one other thermoplastic resin (X) different from the PAS resin, as this allows for multiple properties to be simultaneously maintained and controlled. Examples of lamination structures include multilayer structures such as A / B / A and A / B / A / B / A. In the present invention, a three-layer structure of A / B / A is more preferred from the viewpoints of transparency, color tone, surface quality, and runnability.

[0052] In the PAS film of the present invention, the layer A has a peak at 1145 cm in an infrared absorption spectrum obtained by Fourier transform infrared spectroscopy (FT-IR). -1 ~1160cm -1 It is preferable that the wavelength of the light having at least one absorption peak be between the wavelengths.

[0053] In the PAS film of the present invention, it is preferable that the PAS film contains, in the layer A, a thermoplastic resin (X) different from the PAS resin that is incompatible with the PAS resin and that the thermoplastic resin (X) different from the PAS resin is dispersed in the PAS resin. In the present invention, the phrase "the thermoplastic resin (X) different from the PAS resin that is incompatible with the PAS resin and that the thermoplastic resin (X) different from the PAS resin is dispersed in the PAS resin" refers to a sea-island structure formed by the PAS resin and the thermoplastic resin (X) different from the PAS resin, with the PAS resin constituting the sea component and the thermoplastic resin (X) different from the PAS resin constituting the island component. By including a dispersion incompatible with the PAS resin in the layer A, which is primarily composed of a PAS resin, it is possible to form and control surface irregularities, resulting in a film with excellent transparency, runnability, and quality. The shape of the dispersion is not particularly limited. The cross section of the film can be observed with a transmission electron microscope (TEM) or a scanning electron microscope (SEM) to confirm its shape, and examples of shapes include circular, elliptical, spindle-shaped, and irregular.

[0054] The PAS film of the present invention preferably has an aspect ratio of 5.0 to 15.0 as determined by the measurement method described below. In the present invention, the aspect ratio refers to a value calculated from the ratio of the major axis to the minor axis of the dispersed diameter of the thermoplastic resin (X) present as a dispersed phase in the PAS resin. An aspect ratio within the above range indicates a strong interaction between the PAS resin and the thermoplastic resin (X). Therefore, this is preferable because it prevents void formation, which is a factor in reducing transparency during the stretching process, and improves transparency. By setting the aspect ratio of the dispersion at or above the aforementioned lower limit, it is possible to prevent void formation during the stretching process, which would otherwise reduce transparency. On the other hand, by setting the aspect ratio of the dispersion at or below the aforementioned upper limit, it is possible to eliminate the need for extremely high stretch ratios and prevent productivity from being reduced due to breakage during the film formation process. The lower limit of the aspect ratio is more preferably 7.0 or higher. The upper limit of the aspect ratio is more preferably 12.0 or lower, and even more preferably 10.0 or lower. The aspect ratio can be controlled by the stretching ratio among the film-forming conditions described later.

[0055] In the PAS film of the present invention, the major axis of the dispersion is preferably 200 to 2000 nm. By setting the major axis of the dispersion within the above range, surface irregularities can be formed, which is preferable, as it improves runnability and surface quality. By setting the major axis of the dispersion to be equal to or greater than the above-mentioned lower limit, the formation of surface irregularities is reduced, resulting in a smooth surface, which in turn prevents increased friction during transport and reduced runnability and surface quality. On the other hand, by setting the major axis of the dispersion to be equal to or less than the above-mentioned upper limit, it is possible to prevent deterioration of transparency due to light diffusion by the dispersion. The major axis of the dispersion is more preferably 400 to 1000 nm. The major axis of the dispersion can be controlled by the stretching ratio among the film-forming conditions described below. In the present invention, the major axis of the dispersion can be calculated by the method described below.

[0056] In the PAS film of the present invention, the thickness ratio of the layer A is preferably 0.1% to 10% of the total film thickness. By setting the thickness ratio of the layer A within the above range, it is possible to easily form dense surface irregularities and reduce the amount of dispersion in the entire film, which is preferable because it improves transparency and color tone surface quality. By setting the thickness ratio of the layer A to be equal to or greater than the above-mentioned lower limit, the formation of surface irregularities is reduced and the surface becomes smooth, which prevents increased friction during transport and deterioration of runnability and surface quality. Furthermore, by setting the thickness ratio of the layer A to be equal to or less than the above-mentioned upper limit, the surface irregularities are formed densely, resulting in excellent transparency. The thickness ratio of the layer A is more preferably 0.5% to 5.0%, more preferably 1.0% to 3.0%. The thickness ratio of the layer A can be controlled by the extrusion conditions among the film-forming conditions. In the present invention, the thickness ratio of the layer A can be calculated using the method described below.

[0057] The thickness of the polyarylene sulfide film of the present invention is not particularly limited, but from the viewpoint of film formability, it is preferably 10 to 150 μm, more preferably 20 to 125 μm, and even more preferably 25 to 100 μm.

[0058] The method for producing the polyarylene sulfide film of the present invention will be explained using an example of a film production method in which polyphenylene sulfide resin (hereinafter sometimes abbreviated as PPS resin) is used as the polyarylene sulfide-based resin, but the present invention is not limited to this example.

[0059] Sodium sulfide and p-dichlorobenzene are combined and reacted under high temperature and pressure in an amide-based polar solvent such as N-methyl-2-pyrrolidone (NMP). Copolymerization components such as m-dichlorobenzene and trihalobenzene can also be added as needed. Caustic potassium or alkali metal carboxylates are added as polymerization modifiers, and the polymerization reaction is carried out at 230-290°C. After polymerization, the polymer is cooled, and the polymer is made into a water slurry and filtered through a filter to obtain wet granular polymer. An amide-based polar solvent is added to the granular polymer, which is then stirred and washed at 30-100°C. It is then washed several times with ion-exchanged water at 30-80°C, washed several times with an aqueous solution of a metal salt such as calcium acetate, and dried to obtain polyphenylene sulfide polymer powder.

[0060] In the present invention, when washing the polymer powder, the obtained polymer powder is washed in an NMP solvent at a temperature of 100 to 200°C for 6 to 24 hours, and then washed several times with pure water at 30 to 80°C to obtain a washed polymer powder. This polymer powder is fed into a vented extruder and melt-extruded into a strand shape, cooled with water at a temperature of 25°C, and then cut into chips to form PPS chips.

[0061] A masterbatch is prepared by mixing the polymer powder and / or washed polymer powder obtained above as the polyarylene sulfide resin with inorganic particles and / or other thermoplastic resin (X) in any desired ratio. In the present invention, a preferred method for preparing the masterbatch is to use a device that applies shear stress, such as a twin-screw extruder, to form the masterbatch. In this case, the kneading step is preferably carried out so that the resin temperature is in the range of 5°C to 80°C above the melting point of the PAS resin (I), more preferably 10°C to 80°C above the melting point of the PAS resin (I), and even more preferably 15°C to 70°C above the melting point of the PAS resin (I). The screw rotation speed is preferably in the range of 100 rpm to 1500 rpm. The dispersion diameter of the dispersed phase can be controlled by setting the resin temperature and screw rotation speed within the desired range.

[0062] In the present invention, PPS chips, optionally dried under reduced pressure at 180°C for 3 hours, are mixed with a masterbatch in a predetermined ratio, fed into a full-flight single-screw extruder with a melting zone set at 300-350°C, passed through a filter, and then extruded from a T-die nozzle and rapidly cooled and solidified by applying a static charge to a cooling drum with a surface temperature of 20-70°C, to obtain a substantially unoriented unstretched film.When a laminated film with two or more layers is produced, the above two types of chips are fed into separate melt extrusion devices and heated to above the melting point of each resin. The melted raw materials are then placed in a confluence device between the melt extrusion device and the die outlet, and laminated in a molten state in a two-layer configuration (a layer primarily composed of PPS and a layer primarily composed of PPS and containing at least one other thermoplastic resin different from PPS) or a three-layer configuration (a layer primarily composed of PPS and containing at least one other thermoplastic resin different from PPS, a layer primarily composed of PPS and a layer primarily composed of PPS and containing at least one other thermoplastic resin different from PPS) at an arbitrary lamination ratio (e.g., 0.3:24.4:0.3 or 0.3:24.7), and extruded through the slit-shaped die outlet. This sheet-like material is then placed on a cooling drum (surface temperature: 20-70°C) with the PPS layer facing the cooling drum, and cooled and solidified to obtain a substantially unoriented two-layer or three-layer laminate sheet. Having the above-described laminate structure allows for: Next, when biaxially stretching, the unstretched film obtained above is biaxially stretched using a sequential biaxial stretching machine or a simultaneous biaxial stretching machine at a temperature above the glass transition temperature (Tg) of the polyarylene sulfide resin and below the cold crystallization temperature (Tcc), followed by a single-stage or multi-stage heat treatment at a temperature in the range of 150 to 280°C to obtain a biaxially oriented film. Stretching methods that can be used include sequential biaxial stretching (a stretching method that combines stretching in one direction at a time, such as stretching in the longitudinal direction followed by stretching in the width direction), simultaneous biaxial stretching (a method of stretching in the longitudinal direction and the width direction simultaneously), or a combination thereof. Here, sequential biaxial stretching, in which stretching in the longitudinal direction is performed first and then in the width direction, is exemplified.

[0063] The unstretched film is heated by a group of heating rolls and stretched in the machine direction (MD) by 2.0 to 4.5 times, more preferably 2.8 to 4.2 times, in one or more stages (MD stretching). The stretching temperature is in the range of Tg to Tcc, preferably (Tg + 5) to (Tcc - 10)°C. The film is then cooled by a group of cooling rolls at 20 to 50°C.

[0064] As a method of stretching in the width direction (TD direction) following MD stretching, for example, a method using a tenter is common. Both ends of the film are held with clips and introduced into the tenter, where it is stretched in the width direction (TD stretching). The stretching temperature is preferably Tg to Tcc, more preferably in the range of (Tg + 5) to (Tcc - 10) °C. From the viewpoint of the flatness of the film, the stretching ratio is preferably 3.0 to 5.0 times, and more preferably 3.0 to 4.5 times.

[0065] Next, the stretched film is heat-set under tension (heat setting treatment). The heat setting treatment is a single-stage or multi-stage heat treatment at a temperature in the range of 150 to 280°C, and the film is cooled to room temperature, and if necessary, relaxed in the longitudinal and transverse directions while being wound up to obtain a biaxially oriented polyarylene sulfide film.

[0066] In the present invention, when the film is subjected to a washing treatment, the obtained polyarylene sulfide film is washed in an NMP solvent at a temperature of 100 to 200°C for 5 to 30 hours, and then washed with pure water at 30 to 80°C 3 to 5 times to obtain the polyarylene sulfide film of the present invention.

[0067] The polyarylene sulfide film of the present invention has excellent transparency and color tone, as well as excellent running properties and quality of the film surface, and can therefore be suitably used as an automobile component, a battery component, an electric / electronic material, in particular as various parts and industrial packaging materials that require transparency, such as a protective material for the lower plate of a flexible printed circuit board, and as a capacitor material that requires surface quality.

[0068] Furthermore, the polyarylene sulfide film of the present invention may be coated on one or both sides with various coating agents in-line or off-line for the purpose of improving weather resistance and adhesiveness, or for surface protection.

[0069] A conductive film is formed on the 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, and examples include those made by laminating one or more metal films such as Ag films, metal oxide films such as ITO (indium tin oxide) films, and resin films containing conductive particles. Methods for forming conductors include well-known methods, such as sputtering and paste printing, but are not particularly limited thereto. Well-known methods for patterning circuit boards include photolithographic etching and screen printing. Furthermore, circuit boards can be obtained by forming through-holes, as needed, using drills, lasers, melt-through methods, or the like.

[0070] A circuit board using the polyarylene sulfide film of the present invention is useful as a transparent antenna substrate because of its excellent transparency and color tone.

[0071] [Method of measuring characteristics] (1) Light transmittance at wavelengths of 550 nm, 400 nm, and 600 nm Measurement was carried out using the following device, and the light transmittance at each wavelength was calculated using the following formula. Equipment: UV measuring instrument U-3410 (Hitachi Instruments) Wavelength range: 300nm to 800nm Measurement speed: 120nm / min Measurement mode: Transmittance Light transmittance (%)=(Tr1 / Tr0)×100 Here, Tr1 is the intensity of light that has passed through the sample, and Tr0 is the intensity of light that has passed through the air at the same distance but has not passed through the sample.

[0072] (2) Yellowness (b value) Using a spectrophotometer CM-3600d (KONICA-MINOLTA), tristimulus values ​​X, Y, and Z were measured by the transmission method in accordance with JIS-Z-8722 (2000). From these values, lightness (L value) and yellowness (b value) of the Hunter Lab color system were calculated using the following formula: b value=7.0×(Y-0.847×Z) / Y1 / 2.

[0073] (3) Surface roughness (SRa) The average centerline roughness (SRa) was determined under the following conditions using a Surfcorder ET30HK manufactured by Kosaka Laboratory. Stylus curvature radius: 2μm Cutoff: 0.25mm Measurement length: 0.5mm Measurement interval: 5 μm Number of measurements: 40.

[0074] (4) Depth volume (Vv), number of protrusions (n) The measurements were performed using a VertScan2.0 R5300GL-Lite-AC manufactured by Ryoka Systems Co., Ltd. The photographed image was subjected to surface correction using a polynomial fourth-order approximation using the attached analysis software, and the depth volume (Vv) and number of protrusions (n) were determined using a threshold of 0 nm. The measurement conditions were as follows: Measurements were performed on both sides of the film with n = 100, and the average values ​​were used as the depth volume (Vv) and number of protrusions (n) for each side. For Examples 26 and 52, measurements were performed on the surface of layer A with n = 100, and the average values ​​were used as the depth volume (Vv) and number of protrusions (n) for each side. Manufacturer: Ryoka Systems Co., Ltd. Device name:VertScan2.0 R5300GL-Lite-AC Measurement conditions: CCD camera SONY HR-57 1 / 2 inch Objective lens: 5x Intermediate lens: 0.5x Wavelength filter: 530nm white Measurement mode: Wave Measurement software: VS-Measure Version 5.5.1 Analysis software: VS-Viewer Version 5.5.1 Measurement area: 0.561mm x 0.561mm.

[0075] (5) Glossiness In accordance with JIS K-7105 (1981), the film surface was measured at an incident angle of 60° and an acceptance angle of 60° using a digital variable angle glossmeter UGV-5D manufactured by Suga Test Instruments Co., Ltd. The average value of data from five points was taken as the gloss (%). Measurements were performed on both sides of the film, and the value of the surface that achieved the highest gloss is shown in the table.

[0076] (6) Fourier transform infrared spectroscopy (FT-IR) Using a PerkinElmer Frontier FT-IR spectrometer with a UATR IR unit, the spectral intensity is measured by the attenuated total reflection (ATR) method using diamond / ZnSe as the medium crystal. The spectrometer resolution is 1 cm. -1 The spectrum is measured with 16 integration times. Spectral intensity is expressed as absorbance (arb.unit) at each wavelength. When measuring the spectrum of the surface layer of a film, the surface layer of the film is brought into close contact with the medium crystal and measurement is carried out. The medium crystal and sample are brought into close contact by applying pressure using a jig attached to the device. The pressure is increased while observing the spectrum of the sample, and measurement is carried out at the point when the spectral shape does not change due to the pressure. Spectral intensity is calculated as absorbance (arb.unit) at each wavelength.

[0077] In the present invention, in the case of a single-layer film, measurement is carried out from one of the surfaces by the above method, and the infrared absorption spectrum obtained is -1 ~1160cm -1 In the case of a laminated film, measurements are taken using the above method from the surface of the outermost layer, which is Layer A, and the presence or absence of an absorption peak is determined. If the laminated structure is unknown, measurements are taken using the above method from both surfaces and the presence or absence of an absorption peak is determined.

[0078] (7) Scanning electron microscope (SEM) observation of cut surface After embedding the film in epoxy resin, the film cross section was cut using a microtome parallel to the longitudinal direction and perpendicular to the film surface without crushing the film in the thickness direction. The cut film cross section was then fixed to the specimen stage of a scanning electron microscope under conditions that would prevent thermal deterioration of the material. Cross-sectional ion milling was performed using a Hitachi High-Technologies Corporation IM4000PLUS ion milling system, followed by platinum deposition. The resulting film cross section was then observed and images were obtained using a JEOL Ltd. JSM-6700F field emission scanning electron microscope at an accelerating voltage of 3.0 kV and a working distance of 8.0 mm.

[0079] (7-1) Void formation ratio of particles and dispersions To calculate the void formation ratio of particles and dispersions, observation was performed at a magnification of 30,000x, and the obtained images were analyzed. The observation location was determined randomly at a position on the film cross section where particles or dispersions could be observed, with the top and bottom of the image parallel to the thickness direction of the film and the left and right direction of the image parallel to the film surface.

[0080] The image obtained was analyzed using image analysis software (Mountec Corporation, MacView ver. 4.0) to calculate the area of ​​each particle (D1), the area of ​​the dispersion (D1'), the area of ​​the voids around the particle (D2), and the area of ​​the voids around the dispersion (D2'). If the D2 area was 10% or more of the D1 area, the particle was judged to have formed voids, and if the D2' area was 10% or more of the D1' area, the dispersion was judged to have formed voids. Measurements were carried out on 100 particles and 100 dispersions each for evaluation, and the void formation ratio was calculated from the number of particles and dispersions in which voids were formed. Void formation ratio = (number of void-forming particles + number of void-forming dispersions) / number of measurement points (200 points) × 100.

[0081] (7-2) Major axis and aspect ratio of dispersion The major axis and aspect ratio of the dispersions were observed at a magnification of 30,000x, and the resulting images were analyzed. The images were imported into an image analyzer (Leica Microsystems, Leica Application Suite LAS ver. 4.6), and 20 dispersions were randomly selected. The circumscribed circle of each dispersion was calculated, and the average diameter was used as the dispersion size. The major and minor axes of the dispersed phase were also measured, and the aspect ratio was calculated.

[0082] (7-3) Layer A thickness and layer A ratio The lamination thickness and lamination ratio of Layer A were observed at a magnification of 5000x, and the thickness of Layer A on the film was measured at five random locations based on the analysis of the obtained images, and the average value was taken as the layer thickness of Layer A.

[0083] Additionally, the overall thickness of the film was observed at a magnification of 3000x, and an image was taken that allowed the entire thickness of the film to be observed. The overall thickness of the film was measured from the image obtained through observation. If the entire thickness of the film could not be seen at the above magnification, images were taken at several points in the thickness direction and the images were stitched together to confirm the overall picture. A total of five randomly selected locations were used as samples for thickness measurement, and the average of the measurements for the five samples was taken as the film thickness of that sample.

[0084] (8) Transparency White dots with a diameter decreasing in 10 μm increments from 200 μm to 10 μm were printed on black construction paper. Each film was placed on the black construction paper, and the diameter of the white dot that could be seen from the top of the film was judged according to the following criteria. C was judged to have poor transparency. AA: Visible up to 10 μm (Excellent transparency) A: Visible up to 50 μm (good transparency) B: Visible up to 100 μm (normal transparency) C: Not visible even at 100 μm (poor transparency).

[0085] (9) Color tone A color sample was created on white paper using dots 0.5 mm in diameter, varying the RGB color model. Dots were printed with R (red) 255, G (green) 255, and B (blue) 0, increasing B in increments of 10 from R255, G255, and B250 to create a color sample. Each film was then placed on top of the white paper, and the color dots were judged to be visible at a position 100 cm from the top of the film, using the following criteria. D was judged to be poor color tone. AA: R255, G255, B240 or higher visible (excellent color tone) A: Visible up to R255, G255, B230 (good color tone) B: Visible up to R255, G255, B200 (inferior color tone) C: Visible up to R255, G255, B180 (color tone is poor) D: Visible up to R255, G255, B170 (severe color tone issues).

[0086] (10) Runnability Using a friction tester manufactured by Toyo Tester Kogyo, the initial resistance value was measured in accordance with ASTM-D1894 (1999) when one side of the film was placed in contact with the back side and rubbed against the other in the MD direction. The maximum value was taken as the static friction coefficient μs. However, if the initial resistance value was too large and exceeded the upper limit of the measurement value (5.0), it was deemed unmeasurable. Samples were cut into rectangular shapes measuring 80 mm wide and 200 mm long, and five sets (10 pieces) were cut out. Five measurements were taken and the average value was calculated. The runnability was evaluated based on the static friction coefficients calculated using the following criteria: D was determined as poor runnability. A:μs=0.50 or less (good running performance) B: μs=0.50 or more, 0.60 or less (normal running performance) C: μs = over 0.60 and below 0.70 (slightly poor running performance) D: μs=more than 0.70 (poor running performance).

[0087] (11) Surface quality 1m 2 The film was illuminated with an LED light source, and the number of scratches visible on the surface were counted using transmitted light. 2The surface quality was judged based on the number of scratches around the surface according to the following criteria. AA:50 pieces / m 2 less than A:50 pieces / m 2 More than 100 pieces / m 2 less than B: 100 pieces / m 2 More than 150 pieces / m 2 less than C: 150 pieces / m 2 More than 200 pieces / m 2 less than D:200 pieces / m 2 That's all. [Example]

[0088] (Reference Example 1) Manufacturing method of PPS resin (granules) A 1-liter autoclave equipped with a process stirrer was charged with 1.00 mol of 47% sodium hydrosulfide, 1.03 mol of 96% sodium hydroxide, 1.65 mol of N-methyl-2-pyrrolidone (NMP), 0.45 mol of sodium acetate, and 150 g of ion-exchanged water. The mixture was gradually heated to 225°C over approximately 3 hours while stirring at 240 rpm and passing nitrogen through at atmospheric pressure. After distilling off 211 g of water and 4 g of NMP, the reaction vessel was cooled to 160°C.

[0089] 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 increased from 200°C to 235°C at a rate of 0.6°C / min. After reaching 235°C, the reaction was continued at 235°C for 95 minutes. The temperature was then increased to 270°C at a rate of 0.8°C / min and maintained at that temperature 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, the mixture was cooled to 200°C at a rate of 1.0°C / min and then rapidly cooled to near room temperature. The contents were removed, diluted with 0.4 L of NMP, and stirred at 85°C for 30 minutes. The solvent and solids were then filtered through an 80-mesh sieve. Following the post-treatment step, 0.5 L of NMP was added to the resulting solid, which was stirred at 85°C for 30 minutes and then filtered. The resulting solid was washed three times with 0.9 L of warm water and filtered. The resulting particles were then washed twice with 1 L of warm water and filtered to obtain polymer particles. These were then 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) with a melting point of 280°C and a mass-average molecular weight of 70,000.

[0090] (Reference Example 2) Manufacturing method of PPS pellets The PPS resin (granules) produced in Reference Example 1 was fed into a vented co-rotating twin-screw kneading extruder heated to 320°C, melt-extruded and discharged in the form of strands, which were then cooled with water at a temperature of 25°C and immediately cut to produce PPS pellets 1.

[0091] (Reference Example 3) Preparation of master pellets (MB1) of PPS granules and thermoplastic resin A co-rotating, vented twin-screw kneading extruder equipped with one kneading paddle kneading section was heated to 320°C, and 90 parts by mass of the PPS granules obtained in Reference Example 1 and 10 parts by mass of polyethersulfone (PESU: Solvay Advanced Polymers, Inc., Veradel 3600) were fed into the feed port. The mixture was melt-kneaded at a screw rotation speed of 200 rpm, discharged in the form of a strand, cooled with water at 25°C, and immediately cut to produce master pellets (MB1) containing 10 parts by mass of PESU.

[0092] (Reference Example 4) Preparation of master pellets (MB2) of PPS granules and particles A particle masterbatch (MB2) with a particle content of 10% by mass was prepared in the same manner as in Reference Example 3, except that a mixture of 90% by mass of the PPS resin (granules) prepared in Reference Example 1 and 10% by mass of calcium carbonate (average particle diameter 1.0 μm) as inert particles was melt-kneaded.

[0093] (Reference Example 5) Preparation of master pellets (MB3) from PPS granules and thermoplastic resin A co-rotating, vented twin-screw kneading extruder equipped with one kneading paddle kneading section was heated to 320°C, and 90 parts by mass of the PPS granules obtained in Reference Example 1 and 10 parts by mass of polyphenylsulfone (PPSU: Solvay Advanced Polymers K.K., Radel R5600-NT) were fed through the feed port. The mixture was melt-kneaded at a screw rotation speed of 200 rpm, discharged in the form of a strand, cooled with water at a temperature of 25°C, and immediately cut to produce master pellets (MB3) containing 10 parts by mass of PPSU.

[0094] Examples 1 to 12 The PPS resin (granules) produced in Reference Example 1 was washed under the conditions shown in Table 1-1 using NMP as a solvent, and then washed three times with pure water at 40°C to obtain washed PPS granules. These washed PPS granules were fed into a vented co-rotating twin-screw kneading extruder heated to 320°C, melt-extruded, and discharged in the form of strands. These strands were then cooled with water at 25°C and immediately cut to produce washed PPS pellets.

[0095] The PPS pellets (washed) and PPS master pellets were mixed uniformly in the ratio shown in Table 1, dried under reduced pressure at 180°C for 3 hours, and then fed into a single-screw extruder whose melting section was heated to 315°C.

[0096] The molten polymer was then passed through a fiber-sintered stainless steel metal filter (20 μm cut) and melt-extruded through a T-die nozzle set at 310°C. The extrusion was then applied to a casting drum at a surface temperature of 25°C while applying a static charge, resulting in a 350 μm-thick unstretched film. The unstretched film was then stretched 3.5 times in the longitudinal direction at a stretching temperature of 105°C using a longitudinal stretching machine consisting of a group of heated rolls, utilizing the difference in the peripheral speed of the rolls. The film was then held at both ends with clips and introduced into a tenter, where it was stretched 3.5 times in the transverse direction at a stretching temperature of 100°C. The film was subsequently heat-treated at 280°C, followed by a 2% relaxation treatment. After cooling to room temperature, the film edges were removed to yield a 25 μm-thick polyarylene sulfide film. The physical properties and characteristics of the resulting film are shown in Table 1-1.

[0097] Example 13 A polyarylene sulfide film was obtained in the same manner as in Example 1, except that the PPS resin (granules) was not subjected to a washing treatment.

[0098] Example 14 A polyarylene sulfide film was obtained in the same manner as in Example 1, except that the PPS resin (granules) was not subjected to a washing treatment and was supplied as PPS pellets 1 alone.

[0099] (Comparative Example 1) A polyarylene sulfide film was obtained in the same manner as in Example 1, except that PPS pellets 1 and the master batch were mixed to have the composition and ratio shown in Table 1-1, and a washing treatment was carried out under the conditions shown in Table 1-1.

[0100] (Comparative Example 2) A polyarylene sulfide film was obtained in the same manner as in Example 1, except that the PPS resin (granules) was not washed, only PPS pellets 1 were used, and the PPS pellets 1 were mixed with a master batch to achieve the composition and ratio shown in Table 1-1.

[0101] (Examples 15 to 25) The PPS resin (granules) produced in Reference Example 1 was washed under the conditions shown in Table 1-2 using NMP as a solvent, and then washed three times with pure water at 40°C to obtain washed PPS granules. These washed PPS granules were fed into a vented co-rotating twin-screw kneading extruder heated to 320°C, melt-extruded, and discharged in the form of strands. These strands were then cooled with water at 25°C and immediately cut to produce washed PPS pellets.

[0102] Washed PPS pellets and PPS master pellets were used to prepare the raw materials for layers A and B, with the compositions and ratios shown in Table 1-2. Each raw material was vacuum-dried separately at 180°C for 3 hours and then fed separately into two single-screw extruders heated to 315°C. The molten material was then passed through a lamination device at the top of the die to form a three-layer structure (A / B / A) with the lamination ratio shown in Table 1-2. The extruded material was then extruded through a T-die die and rapidly solidified by applying an electrostatic charge to a casting drum at a surface temperature of 25°C, resulting in a 350 μm-thick unstretched film. The resulting unstretched film was then stretched 3.5 times in the longitudinal direction at 105°C using a longitudinal stretching machine consisting of multiple heated rolls, utilizing the difference in peripheral speed between the rolls. The film was then held at both ends by clips and introduced into a tenter, where it was stretched 3.5 times in the transverse direction at 100°C. The film was subsequently heat-treated at 280°C, then relaxed by 2%, and cooled to room temperature. The film edges were then removed to obtain a 25µm-thick polyarylene sulfide film. The physical properties and characteristics of the obtained film are shown in Table 1-1.

[0103] Example 26 A polyarylene sulfide film was obtained in the same manner as in Example 16, except that the lamination structure of the lamination device was A / B 2 layers and the lamination ratio was as shown in Table 1-2.

[0104] Example 27 A polyarylene sulfide film was obtained in the same manner as in Example 16, except that the PPS resin (granules) was not washed and was used as PPS pellets 1.

[0105] (Comparative Example 3) A polyarylene sulfide film was obtained in the same manner as in Example 15, except that raw materials were supplied so as to have the composition and ratio shown in Table 1-2.

[0106] (Examples 28 to 39) PPS pellets 1 and PPS master pellets were homogeneously mixed in the ratio shown in Table 2-1, dried under reduced pressure at 180°C for 3 hours, and then fed into a single-screw extruder with the melt section heated to 315°C. The molten polymer was then passed through a fiber-sintered stainless steel metal filter (20 μm cut) and melt-extruded from a T-die nozzle set at 310°C. The extruded polymer was then cooled and solidified in close contact with a cast drum at a surface temperature of 25°C while applying a static charge, yielding an unstretched film with a thickness of 350 μm. The unstretched film was then stretched 3.5 times in the longitudinal direction at 105°C using a longitudinal stretching machine consisting of multiple heated rolls, utilizing the difference in peripheral speed between the rolls. The film was then held at both ends by clips and introduced into a tenter, where it was stretched 3.5 times in the width direction at 100°C. Subsequently, the film was subjected to a heat treatment at 280° C., followed by a 2% relaxation treatment, and then cooled to room temperature. The film edges were then removed to obtain a polyarylene sulfide film having a thickness of 25 μm.

[0107] The obtained film was washed using NMP as a washing solvent under the conditions shown in Table 2-1, and then washed five times with pure water at a temperature of 40°C to obtain a washed polyarylene sulfide film. The physical properties and characteristics of the obtained film are shown in Table 2-1.

[0108] Comparative Example 4 A polyarylene sulfide film was obtained in the same manner as in Example 28, except that PPS pellets 1 and the master batch were mixed to have the composition and ratio shown in Table 2-1, and a washing treatment was carried out under the conditions shown in Table 2-1.

[0109] (Examples 40 to 50) PPS pellets 1 and PPS master pellets were used to prepare the raw materials for layers A and B, with the compositions and ratios shown in Table 2-2. Each raw material was vacuum-dried separately at 180°C for 3 hours and then fed separately into two single-screw extruders heated to 315°C. The molten material was then passed through a lamination device above the die to form a three-layer structure (A / B / A) with the lamination ratio shown in Table 2-2. The extruded material was then extruded through a T-die die and rapidly solidified by applying an electrostatic charge to a casting drum at a surface temperature of 25°C, resulting in a 350 μm-thick unstretched film. The resulting unstretched film was then stretched 3.5 times in the longitudinal direction at 105°C using a longitudinal stretching machine consisting of multiple heated rolls, utilizing the difference in the roll peripheral speed. The film was then held at both ends by clips and introduced into a tenter, where it was stretched 3.5 times in the transverse direction at 100°C. Subsequently, the film was subjected to a heat treatment at 280° C., followed by a 2% relaxation treatment, and then cooled to room temperature. The film edges were then removed to obtain a polyarylene sulfide film having a thickness of 25 μm.

[0110] The obtained film was washed using NMP as a washing solvent under the conditions shown in Table 2-2, and then washed five times with pure water at a temperature of 40°C to obtain a washed polyarylene sulfide film. The physical properties and characteristics of the obtained film are shown in Table 2-2.

[0111] Example 51 A polyarylene sulfide film was obtained in the same manner as in Example 41, except that the lamination structure of the lamination device was A / B 2 layers and the lamination ratio was as shown in Table 2-2.

[0112] (Comparative Example 5) A polyarylene sulfide film was obtained in the same manner as in Example 41, except that raw materials were supplied so as to have the composition and ratio shown in Table 2-2.

[0113] [Table 1-1]

[0114] [Table 1-2]

[0115] [Table 2-1]

[0116] [Table 2-2] [Industrial Applicability]

[0117] The polyarylene sulfide film of the present invention has excellent transparency and color tone, and can therefore be suitably used as a transparent circuit substrate or a transparent antenna substrate.

Claims

1. A polyarylene sulfide film having a polyarylene sulfide (PAS) resin as a main constituent, having a spectral light transmittance Ta of 75% or more at a wavelength of 550 nm, a b value of 5.0 or less, and a surface roughness (Ra) of 10 nm or more and 200 nm or less on at least one film surface.

2. 2. The polyarylene sulfide film according to claim 1, wherein the b value is 3.0 or less.

3. 3. The polyarylene sulfide film according to claim 1, wherein the spectral transmittance Tb at a wavelength of 400 nm and the spectral transmittance Tc at a wavelength of 600 nm satisfy the following formula (i): Tc-Tb≦8.2% Formula (i)

4. The depth volume (Vv) from the reference surface on at least one of the film surfaces is 50 μm ３ 800 μm or more ３ The polyarylene sulfide film according to any one of claims 1 to 3, wherein:

5. 5. The polyarylene sulfide film according to claim 1, wherein the depth volume (Vv) from the reference plane and the number of protrusions (n) on at least one film surface satisfy the following formula (iii): 0.01≦Vv / n≦3.0 Formula (iii)

6. 6. The polyarylene sulfide film according to claim 1, wherein the gloss of at least one film surface is 140% or more but less than 200%.

7. 7. The polyarylene sulfide film according to claim 1, which contains particles and / or dispersions, and the void formation ratio of said particles and dispersions is 10% or less.

8. In the infrared absorption spectrum obtained by Fourier transform infrared spectroscopy (FT-IR), －１ ~1160cm －１ 8. The polyarylene sulfide film according to claim 1, having at least one absorption peak between

9. The polyarylene sulfide film according to any one of claims 1 to 8, which has two or more layers containing a polyarylene sulfide resin as a main constituent, and at least one of the outermost layers is a layer (layer A) containing a polyarylene sulfide resin as a main component and at least one other thermoplastic resin (X) different from the polyarylene sulfide resin.

10. The polyarylene sulfide film according to any one of claims 1 to 8, which has three or more layers containing a polyarylene sulfide resin as a main component, and both outermost layers are layers (A layers) containing a polyarylene sulfide resin as a main component and at least one other thermoplastic resin (X) different from the polyarylene sulfide resin.

11. The layer A has a peak at 1145 cm in an infrared absorption spectrum obtained by Fourier transform infrared spectroscopy (FT-IR). －１ ~1160cm －１ The polyarylene sulfide film according to claim 9 or 10, having at least one absorption peak between

12. The polyarylene sulfide film according to any one of claims 9 to 11, wherein the thermoplastic resin (X) different from the polyarylene sulfide is incompatible with the polyarylene sulfide-based resin, and the thermoplastic resin (X) different from the polyarylene sulfide is contained as a dispersion in the polyarylene sulfide-based resin.

13. The polyarylene sulfide film according to claim 12, wherein the aspect ratio of the dispersion is 5.0 or more and 15.0 or less, and the major axis of the dispersion is 200 to 2000 nm.

14. The polyarylene sulfide film according to any one of claims 9 to 13, wherein the thickness ratio of the layer A to the total thickness of the film is 0.1% or more and 10% or less.

15. The polyarylene sulfide film according to any one of claims 1 to 14, which is used as a transparent circuit substrate.

16. The polyarylene sulfide film according to any one of claims 1 to 14, which is used as a transparent antenna substrate.

Images