JP2008280508A - Biaxially oriented polyarylene sulfide film, metallized film and capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biaxially oriented polyarylene sulfide film having excellent heat resistance, dimensional stability, electric properties and planarity; to provide a polyarylene sulfide film capable of forming a capacitor high in reliability even when using at a high temperature and high voltage when being applied particularly to a capacitor because of having high electric properties together with an excellent self-healing property (SH property); to provide its metallized film; and to provide a capacitor using the same. <P>SOLUTION: The biaxially oriented polyarylene film is characterized in that when a dielectric breakdown voltage at 23°C is defined as V(23) (V/μm) and that at 150°C is defined as V(150) (V/μm), the relations: V(150)/V(23)≥0.85 and V(150)≥300 are satisfied. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a biaxially oriented polyarylene sulfide film having excellent heat resistance, dimensional stability, electrical properties and planar properties, a biaxially oriented polyarylene sulfide film for capacitors, a metallized biaxially oriented polyarylene sulfide film, and It relates to the capacitor used. Specifically, it has excellent electrical characteristics such as withstand voltage at high temperatures, so it can be used for electrical insulation materials such as capacitors, motors, transformers, circuit board materials, lithium ion battery materials, fuel cell materials, diaphragms, etc. In particular, when used as a capacitor, the self-healing property (self-healing property, SH property) is also improved, so that a polyarylene sulfide film and metallized film that can form a highly reliable capacitor even when used at high temperatures and high voltages. And a capacitor using the same.

  A biaxially oriented polyphenylene sulfide film (hereinafter sometimes abbreviated as a PPS film) is disclosed in Patent Document 1 and the like. Further, Patent Document 2 proposes that a capacitor having excellent heat resistance, frequency characteristics, temperature characteristics, etc. can be provided by using a PPS film as a capacitor dielectric. However, the capacitor as described above has a narrow range of manufacturing conditions in its manufacturing process, i.e., winding, cutting, molding, and the like. There is a drawback that the number of defective products due to destruction increases. Furthermore, the capacitor often suffers from short circuit without self-healing (self-healing) when low-voltage breakdown occurs, and further has a defect such as an increased defect rate and low reliability during use.

  In order to solve this problem, Patent Documents 3 to 5 propose using a PPS laminated film in which a polyester resin or a polyolefin resin is laminated on at least one side of a PPS film as a capacitor. However, these conventional PPS laminated films do not have sufficient adhesion between the polyester and polyolefin resin layers and the PPS layer, and are often easily peeled off during the capacitor manufacturing process, and have sufficient quality for self-healing (SH). It was difficult to obtain. In addition, a film in which a resin other than PPS such as polyester or polyolefin is laminated cannot be substantially self-recovered, and a trimming edge or an out-of-product film cannot be used again as a film raw material.

  Patent Document 6 proposes a PPS laminated film obtained by laminating an amorphous polyester resin composition in order to improve SH properties. In this method, an amorphous polyester resin layer is formed on a PPS layer in-line and off-line. However, when the glass transition temperature Tg is 90 ° C. at the highest and used at a high temperature of 100 ° C. or higher, the humidity is particularly low. There has been a problem that heat resistance and reliability when used in a high environment are lowered.

  Patent Document 7 proposes a PPS film in which the entire thickness direction portion of the film is substantially composed of PPS and the surface layer portion is more amorphous than the inner layer portion in order to improve the SH property. In this method, the surface of the PPS film is melted and made amorphous by frame treatment or the like, or an amorphous PPS resin is laminated, but in any case, the flatness deteriorates when the film becomes thin, for example, 3 μm or less. There is a problem that productivity may be deteriorated, and SH property is also insufficient.

  Patent Document 8 proposes a PPS film in which a ceramic layer is provided on at least one side of a PPS film. However, sufficient self-healing characteristics (SH property) cannot be obtained unless the deposited layer has a thickness of, for example, 100 nm. Poor productivity and surface roughness due to loss of heat of vapor deposition of the film may cause problems.

There has also been a proposal to improve the properties of the polyphenylene sulfide film by polymer blend or alloy (Patent Documents 9 to 12). Patent Document 9 proposes a blend of PPS and polyetherimide, and Patent Document 11 proposes a blend of PPS and polyarylate. However, in Patent Document 9, it is said that the tear resistance of the film is improved by simply blending PPS and polyetherimide with a twin screw extruder, but the dispersion major axis of polyetherimide is 30 μm simply by blending two kinds of polymers. The control is limited to the following, and no mention is made of improvement of electrical characteristics and capacitor characteristics. Patent Document 11 aims to improve the slipperiness of the film by a simple blend of PPS and polyarylate, and does not mention dispersion diameter control, and does not mention improvement of electrical characteristics and capacitor characteristics. . On the other hand, Patent Document 10 proposes to improve the withstand voltage by compatibilizing PPS with polyetherimide to improve the glass transition temperature of the PPS film to 95 ° C. or more. Although not mentioned, even if the performance improvement of small low-pressure capacitors such as chip capacitors can be achieved by increasing the heat resistance temperature by the increase of the glass transition temperature, for example, high temperature and high performance such as a capacitor for inverters in hybrid cars. When used for a large-capacity winding capacitor used under a voltage, the performance may be insufficient. Furthermore, in Patent Document 12, blending is performed via a compatibilizing agent to control the dispersion state of PPS and other thermoplastic resins, thereby suppressing variation in physical properties of the film and improving the toughness by improving the elongation of the PPS film. Although it is disclosed that there is no mention of improvement of electrical characteristics and capacitor characteristics, there is room for improvement.
JP 54-142275 A JP-A-57-187327 Japanese Patent Application No.2-168861 JP-A-4-219236 JP-A-5-318665 JP 2000-218738 A JP 2002-20508 A JP-A 63-189458 Japanese Patent Application Laid-Open No. 62-155812 JP 2001-261959 A JP-A-1-266146 JP 2006-321977 A

  In order to solve the above problems, an object of the present invention is to provide a biaxially oriented polyarylene sulfide film having excellent heat resistance, dimensional stability, electrical properties, and planarity. In other words, it has excellent electrical characteristics such as withstand voltage at high temperatures, so it can be used suitably for electrical insulation materials such as capacitors, motors, transformers, circuit board materials, lithium ion battery materials, fuel cell materials, diaphragms, etc. This is to provide a sulfide film. Especially when used as a capacitor, it has high electrical characteristics and excellent self-healing (SH), so it can form a highly reliable capacitor even when used at high temperature and high voltage. It is to provide a polyarylene sulfide film, a metallized film, and a capacitor using the same. More specifically, it is not only used for small capacitors such as chip capacitors where PPS films have been used in the past, but also for high-speed railway and hybrid car inverter capacitors that require high reliability at high temperatures and high voltages. Another object of the present invention is to provide a capacitor film that can also be used for a large-capacity wound capacitor used at a high temperature and a high voltage, this metallized film, and a capacitor using the same.

In order to achieve the above object, the present invention provides a dielectric breakdown voltage V (23) (V / μm) at 23 ° C. and a dielectric breakdown voltage V (150) (V / μm) at 150 ° C. of V (150) / V (23) ≧ 0.85
And V (150) ≧ 300
A biaxially oriented polyarylene sulfide film.
Or, in the elongation-stress curve at 23 ° C. in the longitudinal direction and the width direction of the film, the differential coefficient in the section of elongation 2% and (elongation at break−5%) is always 0 or more in any direction. It is a biaxially oriented polyarylene film.
The biaxially oriented polyarylene sulfide film of the present invention is
(1) The breaking elongation at 23 ° C. in the longitudinal direction and the width direction of the film is both 30% or more and less than 80%, and the breaking strength is 230 MPa or more and 500 MPa or less,
(2) The breaking elongation at 23 ° C. in the longitudinal direction and the width direction of the film is both 30% or more and less than 80%, and the breaking strength is 230 MPa or more and 500 MPa or less,
(3) A film made of a thermoplastic resin containing polyarylene sulfide and another thermoplastic resin A different from polyarylene sulfide, wherein the thermoplastic resin A forms a dispersed phase, and the average dispersion of the dispersed phase The diameter is 50 to 500 nm, the glass transition temperature of the film is observed at 80 ° C. or higher and lower than 95 ° C., and is not observed at 95 ° C. or higher and 130 ° C. or lower.
(4) The content of polyarylene sulfide is 70 to 99.5 parts by weight and the content of thermoplastic resin A is 0.5 when the sum of the contents of polyarylene sulfide and thermoplastic resin A is 100 parts by weight. ~ 30 parts by weight,
(5) The thermoplastic resin A is an amorphous resin, and its glass transition temperature is 150 ° C. or higher and not higher than the melting point of polyarylene sulfide.
(6) The thermoplastic resin A is at least one polymer selected from the group consisting of polyarylate, polyphenylene ether, polyetherimide, polyethersulfone and polysulfone,
(7) Kneading a raw material containing 0.05 to 3 parts by weight of a polyarylene sulfide, a thermoplastic resin A, and a compatibilizer having at least one group selected from the group consisting of an epoxy group, an amino group, and an isocyanate group Melt-forming the resin composition obtained,
(8) The polyarylene sulfide is polyphenylene sulfide.
(9) The biaxially oriented polyarylene sulfide film is for a capacitor,
(10) A manufacturing method in which stretching in the longitudinal direction and the width direction is performed so that the area magnification is 11 times or more, and the heat setting after the drawing is performed in two or more steps having different temperatures. The temperature is set to (immediately before the stretching temperature + 5 ° C.) or more and 240 ° C. or less, and the maximum value of the heat setting temperature in the subsequent stage is set to (the heat setting temperature of the first stage + 20 ° C.) or more (the melting point of the polyarylene sulfide constituting the film−5 ° C. ) Production method of polyarylene sulfide film as described below (11) A metallized film obtained by forming a metal layer on at least one surface of a biaxially oriented polyarylene sulfide film.
(12) A capacitor comprising a metallized film wound or laminated.
Each as a preferred embodiment.

  According to the present invention, as described below, a biaxially oriented polyarylene sulfide film having excellent heat resistance, dimensional stability, electrical properties, and planarity is obtained, which is excellent in electrical properties such as withstand voltage at high temperatures. Therefore, it can be used for electrical insulation materials such as capacitors, motors, transformers, circuit board materials, lithium ion battery materials, fuel cell materials, diaphragms, etc. Especially when used for capacitors, it has high electrical characteristics and excellent self-healing By having the property (SH property), it is possible to obtain a polyarylene sulfide film capable of forming a large and small capacitor with high reliability even when used at a high temperature and a high voltage, and a capacitor using the same.

Hereinafter, the biaxially oriented polyarylene sulfide film of the present invention, the biaxially oriented polyarylene sulfide film for capacitors, the metallized biaxially oriented polyarylene sulfide film, and the capacitors using these will be described.
The biaxially oriented polyarylene film of the present invention has excellent heat resistance, dimensional stability, electrical characteristics, and planarity, and particularly has high electrical characteristics and excellent self-recovery (SH property) when used for capacitors. By doing so, a highly reliable capacitor can be formed even when used at high temperature and high voltage.

The biaxially oriented polyarylene sulfide film in the present invention has a high electrical property especially at high temperatures when used for a capacitor, and from the viewpoint of developing excellent self-healing property (SH property), a dielectric breakdown voltage at 23 ° C. V (23) (V / μm) and dielectric breakdown voltage V (150) (V / μm) at 150 ° C. V (150) / V (23) ≧ 0.85
And V (150) ≧ 300
It is essential. More preferably, V (150) / V (23) ≧ 0.9, and further preferably V (150) / V (23) ≧ 0.95.

  Further, V (150) ≧ 350 is preferable, and V (150) ≧ 400 is more preferable. The upper limit of V (150) of the biaxially oriented polyarylene sulfide film of the present invention is not particularly set. However, when it is 1000 (V / μm) or more, the SH property does not function when the capacitor is used, and it causes penetration failure. Sometimes.

  In order to express such properties, in the present invention, the polyarylene sulfide molecular chains are highly oriented in the stretching process during film formation, and the molecular temperature is maintained by controlling the temperature of the heat setting process that is subsequently performed. Hold the chain tension and fix the structure. For example, in the stretching step, the stretching temperature is set to (Tg (glass transition temperature of polyarylene sulfide)) to (Tg + 40), preferably (Tg + 5 ° C.) to (Tg + 20 ° C.) in both the longitudinal direction and the width direction. The direction is 3 times or more, preferably 3.5 times or more and the area magnification is 11 times or more, and the heat setting temperature after stretching is 170 to (Tm (melting point of polyarylene sulfide) -5 ° C.) ° C., preferably 200 to One-stage heat setting at 250 ° C., more preferably, heat setting after stretching is performed in two or more steps with different temperatures, and the heat setting temperature of the first stage is (the previous stretching temperature + 5 ° C.) to 240 ° C. Preferably, it is set to (preceding stretching temperature + 30 ° C.) to 220 ° C., and the maximum value of the heat setting temperature in the latter stage is set to (first stage heat fixing temperature + 20 ° C.) to (Tm−5 ° C.). 8% or less in, preferably in the range of the present invention by performing appropriately adjusted 2-5% relaxation treatment in less than a subsequent stage of the highest value of the heat setting temperature. Here, heat setting refers to a step of applying predetermined heat in a state where a film is stretched by applying tension in the longitudinal direction and the width direction. In particular, in order to set the dielectric breakdown voltage V (150) at 150 ° C. to 300 V / μm or more, the kind and content of the thermoplastic resin A different from the polyarylene sulfide, and the average dispersion diameter of the dispersed phase are preferable in the present invention. It is preferable to adjust to be within the range.

The biaxially oriented polyarylene sulfide film of the present invention has a melt specific resistance at 310 ° C. of the resin composition constituting the film of 1 × 10 ⁸ Ω · cm to 1 × 10 ¹¹ Ω · cm, in particular. It is preferable from the viewpoint of obtaining a film excellent in electrical insulation under high temperature and high voltage, and particularly preferably 5 × 10 ⁸ Ω · cm to 1 × 10 ¹¹ Ω · cm.

Further, the volume specific resistance of the biaxially oriented polyarylene film of the present invention at 150 ° C. and DC 500 V applied is preferably 1.0 × 10 ¹⁴ Ω · cm or more, more preferably 1.0 × 10 ¹⁵ Ω · cm. cm or more. When a capacitor is produced using this film with a volume resistivity of less than 1.0 × 10 ¹⁴ Ω · cm at 150 ° C. and DC 500 V applied, at a temperature higher than the glass transition temperature of the film, that is, higher than 95 ° C. In some cases, the leakage current of the capacitor increases and stability at high temperatures is poor. The upper limit of the volume resistivity of the biaxially oriented polyarylene sulfide film is not particularly set, but when it is 1.0 × 10 ¹⁶ Ω · cm or more, the casting process by the electrostatic application method may be difficult during melt film formation. .

  In order to make the melt specific resistance and volume resistivity of the biaxially oriented polyarylene sulfide film of the present invention within the above preferred ranges, the metal component in the film is 1 to 10000 ppm, preferably 10 to 1000 ppm or less, 30 to 500 ppm or less. More preferably it is. For this reason, it is preferable to control the excess metal ions in the polyarylene sulfide and the metal components and metal ion components contained in the thermoplastic resin A and the particles.

The biaxially oriented polyarylene sulfide film of the present invention has a differential coefficient in the section of elongation 2% and (elongation at break-5%) in the elongation-stress curve at 23 ° C. in the longitudinal direction and the width direction of the film. However, it is necessary that all directions are always 0 or more. The differential coefficient in any direction is more preferably 0.1 (MPa /%) or more, and further preferably 0.5 (MPa /%) or more. When the differential coefficient is negative, not only the strength of the film decreases, but also the heat resistance, dimensional stability, electrical characteristics, planar characteristics, etc. decrease, or the difference in breakdown voltage between 150 ° C. and 23 ° C. is large. Or may be unfavorable because the SH property becomes poor. The cause of this is not necessarily clear, but the degree of relaxation of the amorphous molecular chains that make up the film is large, especially because the polyarylene sulfide molecular chains have high mobility above the glass transition point of the polyarylene sulfides. I believe. On the other hand, when the differential coefficient always exceeds 10 (MPa /%), the elongation of the film becomes less than 30%, which is not preferable.
In order to express such properties, in the present invention, the polyarylene sulfide molecular chains are highly oriented in the stretching process during film formation, and the molecular temperature is maintained by controlling the temperature of the heat setting process that is subsequently performed. Hold the chain tension and fix the structure.

  In order to make it within the scope of the present invention, for example, in the stretching step, the stretching temperature is set to (Tg (glass transition temperature of polyarylene sulfide)) to (Tg + 40), preferably (Tg + 5 ° C.) to ( Tg + 20 ° C.), the stretching ratio is 3 times or more in both the longitudinal direction and the width direction, preferably 3.5 times or more, the area ratio is 11 times or more, more preferably 12 times or more, and the heat setting temperature after stretching is 170 to ( Tm (melting point of polyarylene sulfide) −5 ° C.) ° C., preferably 200 to 250 ° C., one-stage heat setting, more preferably, heat setting after stretching is carried out in two or more steps with different temperatures. The heat setting temperature of the stage is (immediately preceding stretching temperature + 5 ° C.) to 240 ° C., preferably (the immediately preceding stretching temperature + 30 ° C.) to 220 ° C., and the maximum value of the heat fixing temperature of the rear stage is (first stage (Fixing temperature + 20 ° C.) to (Tm−5 ° C.), and after heat fixing, the relaxation treatment of 8% or less, preferably 2 to 5% in the width direction is appropriately adjusted below the maximum value of the heat fixing temperature in the subsequent stage. Is preferred.

  In particular, in order to ensure that the differential coefficient is always 0 or more in the longitudinal and width directions in the elongation-stress curve, the thermoplastic resin A different from the polyarylene sulfide is included, and the type, content, and average dispersed diameter of the dispersed phase are determined. It is preferable to adjust so that it may become in the preferable range of invention.

The biaxially oriented polyarylene sulfide film of the present invention preferably has a breaking elongation in the longitudinal direction and in the width direction of 30% or more and less than 80%, more preferably 35% or more and less than 65%, still more preferably 40% or more and 55%. Is less than. When the elongation at break of the film is less than 30%, it is easy to break at the time of film slitting, and cracking is likely to occur during processing such as bending, and particularly when used for a capacitor, it is easy to break when manufacturing a wound capacitor. Processing becomes difficult. On the other hand, when the elongation at break of the film is 80% or more, when used for a capacitor, low voltage breakdown may occur or the SH property may be insufficient, resulting in a capacitor with poor reliability.
The biaxially oriented polyarylene sulfide film of the present invention has a breaking strength in the longitudinal direction and the width direction of 230 MPa to 500 MPa, more preferably 250 MPa to 450 MPa, and further preferably 270 MPa to 400 MPa. When the breaking strength of the film is less than 230 MPa, cracking may occur easily during processing such as bending, and the withstand voltage at high temperatures may be reduced. Especially when used for capacitors, when manufacturing a wound capacitor In some cases, the capacitor is liable to break, making it difficult to process, or causing low-voltage breakdown, resulting in an insufficient SH property and an unreliable capacitor. On the other hand, in order to obtain a film exceeding 500 MPa, it is necessary to make the draw ratio at the time of film formation extremely high, and film tearing tends to occur at the time of drawing in the film forming process, which may not be preferable.

  The biaxially oriented polyarylene sulfide film of the present invention preferably has a Young's modulus in the longitudinal direction and the width direction of 3 GPa or more and less than 7 GPa, more preferably 3.2 GPa or more and less than 6 GPa, and even more preferably 3.5 GPa or more and 5 GPa. Is less than. When either of the Young's modulus in the longitudinal direction and the width direction of the film is less than 3 GPa, the withstand voltage at high temperatures may be low, and particularly when used for capacitors, low voltage breakdown is likely to occur, and the SH property is low. This is not preferable because it may be insufficient and the capacitor may be inferior in reliability. On the other hand, when the Young's modulus in the longitudinal direction and the width direction of the film exceeds 7 GPa, it is necessary to make the stretch ratio during film formation extremely high, which is not preferable because the film is easily broken during stretching in the film forming process. There is a case.

  In the biaxially oriented polyarylene sulfide film of the present invention, the orientation parameters in the longitudinal direction and the width direction obtained by laser Raman spectroscopy are preferably in the range of 3 to 7, respectively. Whether the polyarylene sulfide film is biaxially oriented can be determined by the fact that the orientation parameters in the longitudinal direction and the width direction obtained by laser Raman spectroscopy are in the above ranges, respectively. A more preferable range of the orientation parameter is 3.5 to 6.5, and a more preferable range is 4 to 6. Orientation parameters by laser Raman spectroscopy reflect molecular orientation and crystal content. When the orientation parameter exceeds 7, the molecular chain orientation proceeds too much or crystallization progresses too much, and the tensile elongation at break becomes small. Especially when it is used for a capacitor, it breaks when manufacturing a wound capacitor. It becomes easy to do and processing becomes difficult. On the other hand, when the orientation parameter is less than 3, the molecular orientation becomes insufficient, and the withstand voltage at high temperature may be lowered. Especially when it is used for a capacitor, low voltage breakdown is likely to occur, and the SH property becomes insufficient and is reliable. This is not preferable because the capacitor can be inferior. The orientation parameters of the polyarylene sulfide film by laser Raman spectroscopy are, for example, the stretching temperature and stretching ratio in longitudinal stretching, the preheating temperature before transverse stretching, the stretching temperature and stretching ratio in transverse stretching, and the heat setting temperature after stretching. By making it the preferred range of the present invention, it can be made the range of the present invention.

  The biaxially oriented polyarylene sulfide film of the present invention includes polyarylene sulfide and another thermoplastic resin A different from polyarylene sulfide, and the thermoplastic resin A forms a dispersed phase, and the average dispersion of the dispersed phase It is preferable that the diameter is 50 to 500 nm and the glass transition temperature of the film is observed at 80 ° C. or higher and lower than 95 ° C., but not observed at 95 ° C. or higher and 130 ° C. or lower. In the present invention, polyarylene sulfide forms a continuous phase (sea phase or matrix), other thermoplastic resin A forms a dispersed phase (island phase or domain), and an average value of the average dispersed diameter of the dispersed phase. Is preferably 50 to 500 nm, more preferably 60 to 300 nm, and even more preferably 70 to 200 nm. When the polyarylene sulfide forms a continuous phase, the excellent properties of the heat resistance, chemical resistance and mechanical properties of the polyarylene sulfide can be greatly reflected in the film. By making the average dispersion diameter in the above range, the molecular chain orientation of the biaxially oriented polyarylene sulfide film can be easily increased, and when used as a capacitor dielectric, the difference in withstand voltage between 150 ° C. and 23 ° C. is 50 V / It is easy to make it as small as [mu] m or less, and it is possible to achieve a high withstand voltage even at 150 [deg.] C. Furthermore, it is possible to impart SH properties to the film. When the average value of the average dispersion diameter of the dispersed phase is less than 50 nm, the effect of reducing the difference in withstand voltage at 150 ° C. and 23 ° C. when used as a dielectric of the capacitor of the present invention may be insufficient. is there. On the other hand, if the average value of the average dispersion diameter is larger than 500 nm, the heat resistance and flatness of the film are deteriorated, and the film is easily broken during stretching.

  The average dispersion diameter of the disperse phase here is (a) a direction parallel to the longitudinal direction and perpendicular to the film surface, (a) a direction parallel to the width direction and perpendicular to the film surface, and (c) relative to the film surface. This is a number average of dispersed particle diameters observed with respect to a plane cut in a parallel direction. The maximum length (la) and the maximum length (lb) in the film thickness direction of the disperse phase appearing on the cut surface of (a), and the maximum length in the film thickness direction of the disperse phase appearing on the cut surface of (a). (Lc), the maximum length in the width direction (ld), and the maximum length (le) in the film longitudinal direction and the maximum length in the width direction (lf) of the dispersed phase appearing on the cut surface of (c) Phase shape index I = (number average value of lb + number average value of le) / 2, shape index J = (number average value of ld + number average value of lf) / 2, shape index K = (number average value of la + Lc number average value) / 2, and the average dispersion diameter of the dispersed phase is (I + J + K) / 3.

  For measurement, a sample was prepared by an ultrathin section method, observed using a transmission electron microscope under a condition of an applied voltage of 100 kV, photographed at 20,000 times, and the obtained photograph was imaged. An average dispersion diameter of 100 arbitrary dispersed particles is calculated by taking the image into an analyzer and performing image processing as necessary.

  The shape of the dispersed phase of the thermoplastic resin A is preferably spherical or elongated island shape, oval shape or fiber shape. The aspect ratio of the dispersed phase is preferably in the range of 1-20. A more preferable range of the aspect ratio of the dispersed phase is 1 to 10, and a more preferable range is 1 to 5. By setting the aspect ratio of these island components in the above range, it is preferable because a biaxially oriented polyarylene sulfide film with improved tensile elongation can be easily obtained. Here, the aspect ratio means the ratio of the average major axis / average minor axis of the dispersed phase. The aspect ratio can be measured using a technique such as a transmission electron microscope or a scanning electron microscope. For example, a sample is prepared by an ultrathin section method, observed using a transmission electron microscope under a condition of a pressurization voltage of 100 kV, photographed at 20,000 times, and the obtained photograph as an image analyzer. The aspect ratio can be calculated by capturing the image as-and performing image processing (details of the measurement method will be described later).

  In the present invention, the glass transition temperature (Tg) of the biaxially oriented polyarylene film is observed to be 80 ° C. or higher and lower than 95 ° C. when a resin component other than polyarylene sulfide is included, while 95 ° C. or higher and 130 ° C. or lower. It is necessary not to be observed. When Tg is less than 80 ° C., the heat resistance of the film is lowered. When Tg is observed to be 95 ° C. or higher and 130 ° C. or lower, the SH property is insufficient when the film is used as a dielectric of a capacitor.

  When the biaxially oriented polyarylene sulfide film of the present invention contains another thermoplastic resin A different from the polyarylene sulfide, the polyarylene sulfide and the thermoplastic resin A content is 100 parts by weight. It is preferable that the content of arylene sulfide is 70 to 99.5 parts by weight, the content of thermoplastic resin A is 0.5 to 30 parts by weight, the content of polyarylene sulfide is 80 to 98 parts by weight, and thermoplasticity. The resin A content is more preferably 2 to 20 parts by weight, the polyarylene sulfide content is 90 to 97 parts by weight, and the thermoplastic resin A content is more preferably 3 to 10 parts by weight. . When the content of the thermoplastic resin A different from polyarylene sulfide exceeds 30 parts by weight, the heat resistance, mechanical properties and electrical properties of the biaxially oriented polyarylene sulfide may be impaired, and the film formability is poor. May be inferior. When the content of the thermoplastic resin A is less than 1 part by weight, it becomes difficult to impart excellent planar characteristics and SH properties when used as a capacitor dielectric.

  The polyarylene sulfide referred to in the present invention is a homopolymer or copolymer having a repeating unit of-(Ar-S)-. Ar includes structural 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.)
As the repeating unit of the polyarylene sulfide used in the present invention, the structural formula represented by the above formula (A) is preferable, and representative examples thereof include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, Examples thereof include random copolymers, block copolymers, and mixtures thereof. Particularly preferred polyarylene sulfide is preferably polyphenylene sulfide (PPS) from the viewpoint of film properties and economy, and a p-phenylene sulfide unit represented by the following structural formula is preferably used as the main structural unit of the polymer. It is a resin containing mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more. When the p-phenylene sulfide component is less than 80 mol%, the crystallinity and thermal transition temperature of the polymer are low, and the heat resistance, dimensional stability, mechanical properties, dielectric properties, etc., which are the characteristics of PPS, may be impaired.

  In the PPS resin, if the repeating unit is less than 20 mol%, preferably less than 10 mol%, other units containing copolymerizable sulfide bonds may be included. Examples of the repeating unit of less than 20 mol%, preferably less than 10 mol% of the repeating unit include, for example, an aryl group having a substituent such as a trifunctional unit, an ether unit, a sulfone unit, a ketone unit, a meta bond unit, or an alkyl group. -Units, biphenyl units, terphenylene units, vinylene units, carbonate units and the like are listed as examples, and specific examples include the following structural units. One or more of these can coexist. In this case, the structural unit may be either a random type or a block type copolymerization method.

  PPS consisting essentially of p-phenylene sulfide or PPS consisting of 1 mol% or less of trifunctional components and 99 mol% or more of p-phenylene sulfide is used as a film raw material for cost, film-forming properties, particularly at high temperatures. Most preferable from the viewpoint of performance and the like. In this case, the obtained PPS resin has a melting point of 280 ° C. or higher and lower than 290 ° C., and a glass transition temperature of 90 ° C. or higher and lower than 95 ° C.

  The melt viscosity of the PPS resin and the PPS resin composition is not particularly limited as long as melt kneading is possible, but the range is 100 to 2000 Pa · s at a temperature of 310 ° C. and a shear rate of 1,000 (1 / sec). It is preferable that it is in the range of 200 to 1,000 Pa · s.

  The PPS used in the present invention can be obtained by various methods, for example, a method for obtaining a polymer having a relatively small molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-7332. Can be produced by a method for obtaining a polymer having a relatively large molecular weight as described in Japanese Patent Publication No. JP-A.

  In the present invention, the obtained PPS resin is subjected to crosslinking / polymerization by heating in air, heat treatment under an inert gas atmosphere such as nitrogen or reduced pressure, washing with an organic solvent, hot water, an acid aqueous solution, etc., acid anhydride It can also be used after various treatments such as activation with functional group-containing compounds such as products, amines, isocyanates and functional group disulfide compounds.

  Next, although the manufacturing method of PPS resin is illustrated, in this invention, it is not limited to this in particular. For example, sodium sulfide and p-dichlorobenzene are reacted in an amide polar solvent such as N-methyl-2-pyrrolidone (NMP) under high temperature and high pressure. If necessary, a copolymer component such as trihalobenzene can be included. Caustic potash or alkali metal carboxylate is added as a polymerization degree adjusting agent, and a polymerization reaction is performed at 230 to 280 ° C. After the polymerization, the polymer is cooled, and the polymer is filtered through a filter as a water slurry to obtain a granular polymer. This is stirred in an aqueous solution such as acetic acid or acetate at 30 to 100 ° C. for 10 to 60 minutes, washed with ion exchange water several times at 30 to 80 ° C. and dried to obtain a PPS powder. This powder polymer is washed with NMP at an oxygen partial pressure of 10 torr or less, preferably 5 torr or less, then washed several times with ion-exchanged water at 30 to 80 ° C., and under reduced pressure of 5 torr or less. dry. Since the polymer thus obtained is a substantially linear PPS polymer, stable stretch film formation becomes possible. Of course, if necessary, other polymer compounds, inorganic and organic compounds such as silicon oxide, magnesium oxide, calcium carbonate, titanium oxide, aluminum oxide, crosslinked polyester, crosslinked polystyrene, mica, talc and kaolin and thermal decomposition inhibitors, Heat stabilizers and antioxidants may be added.

  As a specific method for crosslinking / high molecular weight by heating PPS resin, under an oxidizing gas atmosphere such as air or oxygen or a mixed gas atmosphere of the oxidizing gas and an inert gas such as nitrogen or argon. A method of heating until a desired melt viscosity is obtained at a predetermined temperature in a heating container can be exemplified. The heat treatment temperature is usually selected from 170 to 280 ° C, more preferably from 200 to 270 ° C, and the heat treatment time is usually selected from 0.5 to 100 hours, more preferably from 2 to 50 hours. However, by controlling both of these, a target viscosity level can be obtained. The heat treatment apparatus may be a normal hot air dryer or a heating apparatus with a rotary type or a stirring blade, but in order to efficiently and uniformly perform the treatment, use a heating apparatus with a rotary type or a stirring blade. Is preferred.

  As a specific method for heat-treating the PPS resin under an inert gas atmosphere such as nitrogen or under reduced pressure, a heat treatment temperature of 150 to 280 ° C., preferably 200 to 200 ° C. under an inert gas atmosphere such as nitrogen or under reduced pressure. A method of heat treatment at 270 ° C. and a heating time of 0.5 to 100 hours, preferably 2 to 50 hours can be exemplified. The heat treatment apparatus may be a normal hot air drier or a heating apparatus with a rotary or stirring blade, but it is preferable to use a heating apparatus with a rotary or stirring blade for efficient and more uniform treatment. . The PPS resin used in the present invention is preferably a substantially linear PPS that does not undergo high molecular weight by thermal oxidative crosslinking treatment in order to achieve the goal of improving tensile elongation at break.

  The PPS resin used in the present invention may be a PPS resin that has been subjected to deionization treatment or demetallation component treatment, or an alkaline earth metal salt such as Ca in PPS. Specific examples of the deionization treatment or demetallation component treatment include acid aqueous solution washing treatment, hot water washing treatment, organic solvent washing treatment, entrainer treatment, and the like. A combination of methods may be used.

  The following method can be illustrated as a specific method for the organic solvent cleaning treatment of the PPS resin. That is, the organic solvent is not particularly limited as long as it does not have an action of decomposing the PPS resin. For example, nitrogen-containing polar solvents such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, Sulfoxide and sulfone solvents such as dimethyl sulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, and acetophenone, ether solvents such as dimethyl ether, dipropyl ether, and tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, dichloride Halogen solvents such as ethylene, dichloroethane, tetrachloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentaanol, ethylene glycol, propylene glycol, E Bruno - le, cresol - Le, polyethylene glycol - alcohol phenol based solvents such as Le, benzene, and aromatic hydrocarbon solvents such as toluene and xylene. Among these organic solvents, N-methylpyrrolidone, acetone, dimethylformamide and chloroform are particularly preferably used. These organic solvents are used alone or in combination of two or more.

  As a method of washing with an organic solvent, there is a method of immersing a PPS resin in an organic solvent, and it is possible to appropriately stir or heat as necessary. There is no restriction | limiting in particular about the washing | cleaning temperature at the time of wash | cleaning PPS resin with an organic solvent, Arbitrary temperature can be selected in the range of normal temperature-300 degreeC. As the cleaning temperature increases, the cleaning efficiency tends to increase, but usually a sufficient effect is obtained at a temperature of room temperature to 150 ° C. The PPS resin that has been washed with an organic solvent is preferably washed several times with water or warm water in order to remove the remaining organic solvent.

  The following method can be illustrated as a specific method of the hot water washing process of PPS resin. That is, it is preferable that the water to be used is distilled water or deionized water in order to exhibit a preferable chemical modification effect of the PPS resin by hot water washing. The operation of the hot water treatment is usually performed by adding a predetermined amount of PPS resin to a predetermined amount of water, and heating and stirring at normal pressure or in a pressure vessel. The ratio of the PPS resin to water is preferably larger, but usually a bath ratio of 200 g or less of PPS resin is selected for 1 liter of water.

  The following method can be illustrated as a specific method of the acid aqueous solution washing treatment of the PPS resin. That is, there is a method of immersing the PPS resin in an acid or an acid aqueous solution, and it is possible to appropriately stir or heat as necessary. The acid to be used is not particularly limited as long as it does not have an action of decomposing PPS resin. For example, aliphatic saturated monocarboxylic acids such as formic acid, acetic acid, propionic acid and butyric acid, and halogen-substituted fatty acids such as chloroacetic acid and dichloroacetic acid. Saturated carboxylic acids, aliphatic unsaturated monocarboxylic acids such as acrylic acid and crotonic acid, aromatic carboxylic acids such as benzoic acid and salicylic acid, dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, phthalic acid and fumaric acid, Examples include inorganic acidic compounds such as sulfuric acid, phosphoric acid, hydrochloric acid, carbonic acid, and silicic acid. Of these, acetic acid and hydrochloric acid are preferably used. It is preferable to wash the acid-treated PPS resin several times with water or warm water in order to remove the remaining acid or salt. The water used for washing is preferably distilled water or deionized water in the sense that the effect of the preferred chemical modification of the PPS resin is not impaired by the acid treatment. When the acid aqueous solution cleaning treatment is performed, the acid terminal component of the PPS resin is increased, and when mixed with another thermoplastic resin A, the dispersibility is enhanced, and the average dispersion diameter of the dispersed phase is easily reduced. This is preferable. In addition, the acid aqueous solution cleaning treatment may reduce the amount of metal in the PPS, and may improve the electrical insulation particularly under high temperature and high voltage, which may be preferable.

  In the present invention, PPS obtained by introducing antari earth metal salt such as Ca into PPS may be used. Examples of the method of introducing the alkaline earth metal salt include a method of adding an alkaline earth metal salt after removing residual oligomers and residual salts by washing with an organic solvent or washing with warm water or hot water. The alkaline earth metal salt is preferably introduced into the PPS in the form of an alkaline earth metal ion such as acetate, hydroxide or carbonate. It is preferable to remove excess alkaline earth metal salt by washing with warm water. The alkaline earth metal ion concentration at the time of introducing the alkaline earth metal ion is preferably 0.001 mmol or more, more preferably 0.01 mmol or more with respect to 1 g of PPS. As temperature, 50 degreeC or more is preferable, 75 degreeC or more is more preferable, and 90 degreeC or more is especially preferable. Although there is no upper limit temperature, it is usually preferably 280 ° C. or lower from the viewpoint of operability. The bath ratio (the weight of the cleaning solution with respect to the dry PPS weight) is preferably 0.5 or more, more preferably 3 or more, and still more preferably 5 or more.

  As a specific method for entrainer treatment of PPS resin, when melt-extruding PPS resin or a resin composition containing PPS, a medium inert to the resin composition is fed to an extruder, and after melt-kneading By sucking from the vent of the extruder, impurities such as metals and metal salt components are collected together with the medium, and the ions and metal components in the PPS resin or PPS resin composition are reduced. Examples of the medium inert to PPS include organic solvents and supercritical carbon dioxide in the organic solvent cleaning treatment described above. As a medium inert to the resin composition, a medium having no action such as decomposing the thermoplastic resin A can be appropriately selected. For example, when the thermoplastic resin A is a polyetherimide, ethylene glycol or Examples include propylene glycol. As the extruder used in this treatment, it is preferable to use a twin-screw extruder having a high kneading ability in order to increase the contact opportunity between the resin component and the medium and facilitate the dispersion of ions or metal components in the medium.

  When the biaxially oriented polyarylene sulfide film of the present invention contains a thermoplastic resin A different from polyarylene sulfide, examples of the thermoplastic resin A include polyamide, polyetherimide, polyethersulfone, polysulfone, and polyphenylene. Various polymers such as ether, polyester, polyarylate, polyamideimide, polycarbonate, polyolefin, polyetheretherketone, and blends containing at least one of these polymers can be used. The thermoplastic resin A is preferably an amorphous resin having a glass transition temperature Tg of 150 ° C. or higher and a melting point (Tm) of polyarylene sulfide of 170 ° C. or higher (Tm-20) ° C. or lower. A resin is further preferable, and an amorphous resin having a temperature of 180 ° C. or higher and (Tm-50) ° C. or lower is most preferable. When the Tg of the thermoplastic resin A is less than 150 ° C., it may be difficult to obtain the effect of improving heat resistance and electrical characteristics when the film is used as a capacitor dielectric. Further, when the Tg of the thermoplastic resin A is equal to or higher than the melting point (Tm) of the polyarylene sulfide, or when the thermoplastic resin exhibits crystallinity in the film, the SH property when used as a capacitor dielectric may be inferior. The thermoplastic resin A is a polymer selected from the group consisting of polyarylate, polyphenylene ether, polyetherimide, polyethersulfone, and polysulfone, or at least one selected from the viewpoints of the blendability of polyarylene sulfide and the manifestation of the effects of the present invention. In particular, it is excellent in dispersibility in polyarylene sulfide in the case of polyetherimide, and excellent in electrical characteristics in the case of a biaxially oriented polyarylene sulfide film due to a small amount of impurities and metal components. It is preferable.

  The polyetherimide is not particularly limited, but for example, as shown by the following general formula, a polymer which is a structural unit containing an ether bond in the polyimide constituent component can be preferably exemplified.

In the above formula, R1 is a divalent organic group selected from the group consisting of a divalent aromatic or aliphatic group having 2 to 30 carbon atoms, and an alicyclic group, It is the same divalent organic group as R.
Examples of R1 and R2 include aromatic groups represented by the following formula groups:

Can be mentioned.

  The most preferable polyarylene sulfide resin in the present invention is PPS composed of p-phenylene sulfide as described above, or PPS resin composed of 1 mol% or less of trifunctional components and 99 mol% or more of p-phenylene sulfide. The melting point is 280-290 ° C. In the present invention, since the glass transition temperature is preferably not higher than the melting point (Tm) of polyarylene sulfide, 280 ° C. or lower, more preferably 260 ° C. or lower is used. From the viewpoint of compatibility with polyarylene sulfide, melt moldability, and the like, 2,2-bis [4- (2,3-diene) having a structural unit represented by the following formula is easily obtained. Carboxyphenoxy) phenyl] propane dianhydride and m-phenylenediamine or p-phenylenediamine Condensate is preferable.

  Polyetherimide having this structural unit is available from GE Plastics under the trade name "Ultem" (registered trademark). For example, “Ultem 1000” and “Ultem 1010” may be mentioned as polyetherimide having a structural unit (former formula) containing a unit derived from m-phenylenediamine. Moreover, "Ultem CRS5000" is mentioned as a polyetherimide which has a structural unit (the latter formula) containing the unit derived from p-phenylenediamine.

  Other examples of the thermoplastic resin A contained in the biaxially oriented polyarylene sulfide film of the present invention include polysulfone and polyethersulfone having a sulfone group in the molecular skeleton. As polysulfone and polyethersulfone, various known ones can be used. From the viewpoint of miscibility with polyarylene sulfide, examples of the terminal group of polyethersulfone include a chlorine atom, an alkoxy group, and a phenolic hydroxyl group. As the thermoplastic resin A, polyphenylene ether and polyarylate having a molecular structure similar to that of polyarylene sulfide are preferably exemplified.

  In the present invention, the timing of mixing the polyarylene sulfide and the other thermoplastic resin A is not particularly limited. However, prior to melt extrusion, the mixture of the polyarylene sulfide and the other thermoplastic resin A is pre-melted and kneaded (pelletized). There are a method of forming a master chip and a method of mixing and melt-kneading at the time of melt extrusion. Of these, a method of pre-kneading into a master chip using a high-shear mixer with high shear stress such as a twin screw extruder is preferably exemplified. In that case, the mixed master chip raw material may be put into an ordinary single-screw extruder to form a melt film, or may be directly sheeted without forming a master chip in a state where high shear is applied. In particular, a method of pre-melt-kneading (pelletizing) each resin mixture to form a master chip before melt extrusion is preferably exemplified. In this case, the weight fraction of polyarylene sulfide and thermoplastic resin A is 99.5. It is preferable to prepare a blend raw material of /0.5 to 70/30. In the case of mixing with a twin screw extruder, from the viewpoint of reducing poor dispersion, it is preferable to equip a screw with a triple twin screw type or a double twin screw type, and the kneading part has a melting point of PPS resin +5 to 55 ° C. A resin temperature range is preferred. A more preferable temperature range is the melting point of the PPS resin + 10 to 45 ° C., and a more preferable temperature range is the melting point of the PPS resin + 10 to 35 ° C. Setting the temperature range of the kneading part to a preferable range makes it easy to increase the shear stress and increases the effect of reducing defective dispersion, and the dispersed diameter of the dispersed phase can be controlled within the preferable range of the present invention. The residence time at that time is preferably in the range of 1 to 5 minutes. Moreover, it is preferable that screw rotation speed shall be 100-500 rotation / min, More preferably, it is the range of 200-400 rotation / min. By setting the screw rotation speed within a preferable range, high shear stress is easily added, and the dispersion diameter of the dispersed phase can be controlled within the preferable range of the present invention. Further, the ratio of (screw shaft length / screw shaft diameter) of the twin screw extruder is preferably in the range of 20 to 60, more preferably in the range of 30 to 50. Further, in the twin screw, it is preferable to provide a kneading part by a kneading paddle or the like in order to increase the kneading force, and the kneading part is preferably formed in a screw shape having two or more, more preferably three or more. At this time, the mixing order of the raw materials is not particularly limited, and a method in which all raw materials are blended and then melt-kneaded by the above method, a part of the raw materials are blended and then melt-kneaded by the above method, and the remaining raw materials are blended. Any method such as a method of melt kneading or a method of mixing a part of raw materials and mixing the remaining raw materials using a side feeder during melt kneading by a single-screw or biaxial extruder may be used. Further, a method using a supercritical fluid described in Journal of Plastics Processing Society of Japan, “Molding”, Vol. 15, No. 6, pp. 382 to 385 (2003) can be preferably exemplified.

  In the present invention, in order to control the dispersion diameter of the thermoplastic resin A domain, a compound having at least one group selected from an epoxy group, an amino group, and an isocyanate group is used as a polyarylene sulfide as a compatibilizing agent. It is preferable to add 0.1 to 5 parts by weight with respect to 100 parts by weight of the total of the thermoplastic resin A. More preferably, 0.2 to 3 parts by weight is added, and still more preferably 0.3 to 2 parts by weight. If the added amount of the compatibilizer is less than 0.1 parts by weight, the compatibility between the polyarylene sulfide and the thermoplastic resin A becomes poor, and the effects of the present invention may not be obtained. On the other hand, if the amount of the compatibilizer exceeds 5 parts by weight, the reactivity between the polyarylene sulfide and the thermoplastic resin A is excessively increased, and the melt viscosity may increase and film extrusion may become difficult. is there.

  Specific examples of such compatibilizers include bisphenol A, resorcinol, hydroquinone, pyrocatechol, bisphenol F, saligenin, 1,3,5-trihydroxybenzene, bisphenol S, trihydroxy- Diphenyldimethylmethane, 4,4′-dihydroxybiphenyl, 1,5-dihydroxynaphthalene, cashew phenol, 2.2.5.5. -Glycidyl ethers of bisphenols such as tetrakis (4-hydroxyphenyl) hexane, those using halogenated bisphenol instead of bisphenol, diglycidyl ethers of butanediol, etc. Compounds, glycidyl ester compounds such as glycidyl phthalate, glycidyl epoxy resins such as glycidyl amine compounds such as N-glycidyl aniline, linear epoxy compounds such as epoxidized polyolefin and epoxidized soybean oil, vinylcyclohexene dioxide, di Examples thereof include cyclic non-glycidyl epoxy resins such as cyclopentadiene dioxide. In addition, other novolac type epoxy resins are also included. The novolak type epoxy resin has two or more epoxy groups and is usually obtained by reacting novolak type phenol resin with epichlorohydrin. A novolac type phenol resin is obtained by a condensation reaction of phenols with formaldehyde. There are no particular restrictions on the phenols used as raw materials, but examples include phenol, o-cresol, m-cresol, p-cresol, bisphenol A, resorcinol, p-tertiary-butylphenol, bisphenol F, bisphenol S, and condensates thereof. It is done.

  As the most preferable example of the compatibilizing agent used in the biaxially oriented polyarylene sulfide film of the present invention, alkoxysilane having one or more functional groups selected from an epoxy group, an amino group and an isocyanate group can be mentioned. Specific examples of such compounds include epoxy group-containing alkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Compounds, ureido group-containing alkoxysilane compounds such as γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ- (2-ureidoethyl) aminopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane Γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, γ-isocyanate pro Isocyanate group-containing alkoxysilane compounds such as ruethyldiethoxysilane, γ-isocyanate-propyltrichlorosilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltri Examples include amino group-containing alkoxysilane compounds such as methoxysilane and γ-aminopropyltrimethoxysilane. Among them, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyl When an isocyanato group-containing alkoxysilane compound such as dimethoxysilane, γ-isocyanate-propylethyldiethoxysilane, or γ-isocyanate-propyltrichlorosilane is used, the average dispersion of the dispersed phase of the biaxially oriented polyarylene sulfide film It becomes easy to control the diameter within a preferable range of the present invention.

  In the present invention, when alkoxysilane is used as a compatibilizing agent, an alkoxysilane-derived alcohol may be generated during kneading or extrusion. In order to obtain a resin composition with a small amount of alcohol generated as a raw material for film formation, using a twin-screw extruder having at least two kneading parts, once compatibilized with polyphenylene sulfide and thermoplastic resin A A preferred method is to melt and knead the agent and then melt and knead it once more. In addition, in the second and subsequent melt kneading, 0.02 parts by weight or more, more preferably 0.1 to 5 parts by weight of water is added to 100 parts by weight of the total of polyphenylene sulfide and the thermoplastic resin A. May be preferred. By this method, hydrolysis of the alkoxysilane compound is promoted, and the amount of alcohol generated from the resulting resin composition can be reduced. In order to stabilize the film formation, it is possible to remove as much as possible from the raw material chips for film formation obtained by kneading the impurities and oligomers in the polyarylene sulfide, the thermoplastic resin A, and the alcohol generated by the reaction of the compatibilizing agent. For this purpose, it is preferable to provide a vacuum vent after the kneading zone of the extruder during melt kneading. The method of adding water is not particularly limited, but a method of side-feeding water using a liquid feeding device such as a gear pump or a plunger pump from the middle of the extruder, or once melting and kneading and further melting once or more. When kneading, a preferable method is to mix water or side feed from the middle of the extruder.

  When an alkoxysilane having one or more functional groups selected from an epoxy group, an amino group, and an isocyanate group is used, a siloxane bond is easily formed between the polyarylene sulfide and the thermoplastic resin A, and in the vicinity of the interface of the dispersed phase. Siloxane bonds are likely to exist. Silicon atoms can be detected in the vicinity of the interface of the dispersed phase using a TEM-EDX method or the like. In the present invention, it is preferable that a silicon (Si) atom resulting from a siloxane bond is included in the interface of the dispersed phase made of the thermoplastic resin A.

The biaxially oriented polyarylene sulfide film of the present invention has a melt specific resistance at 310 ° C. of the resin composition constituting the film of 1 × 10 ⁸ Ω · cm to 1 × 10 ¹¹ Ω · cm, particularly at high temperature. From the viewpoint of obtaining a film excellent in electrical insulation under high voltage, it is particularly preferably 5 × 10 ⁸ Ω · cm to 1 × 10 ¹¹ Ω · cm. As described above, the PPS resin used in the present invention may preferably have a reduced amount of metal using part or all of the deionized or demetalized component treated from the viewpoint of increasing the withstand voltage. is there. Specific examples of the method include an acid aqueous solution cleaning process, a hot water cleaning process, an organic solvent cleaning process, and an entrainer process. These processes may be used in combination of two or more methods. . It is also preferable to select a thermoplastic resin A having a small amount of metal and ions, or to perform an entrainer treatment when creating a master chip. The above range can be achieved by combining these methods. From the viewpoint of the electrical characteristics of the film, particularly the high temperature characteristics when it is used as a capacitor, it is preferable that the melt specific resistance is high. On the other hand, although there is no particular upper limit for the melt specific resistance, the thermal stability of the resin at the time of melting may be deteriorated or it is preferably 1 × 10 ¹¹ Ω · cm or less from the electrostatic castability at the time of film formation. .

  The biaxially oriented polyarylene sulfide film of the present invention preferably has a friction coefficient of 0.2 or more and 0.8 or less. More preferably, it is 0.25 or more and 0.6 or less, and further preferably 0.3 or more and less than 0.5. When the friction coefficient is less than 0.2, sufficient slipperiness cannot be imparted to the film, and curling flaws occur during film formation, or wrinkles occur when manufacturing a wound capacitor, It becomes difficult. On the other hand, when the coefficient of friction exceeds 0.8, the surface becomes very rough, and when a deposited film such as aluminum or zinc is formed on the surface of the film, the deposited film has uneven thickness, or a film is used as a wound capacitor. Use as a film for capacitors due to air intervening between them leading to instability of electrical characteristics and lowering of withstand voltage, electric field concentration during use, and melting or burning of film and metal thin film layer. In this case, it becomes difficult to improve the performance of the capacitor.

  The biaxially oriented polyarylene sulfide film of the present invention preferably has a center line average roughness Ra of 20 nm to 200 nm and a maximum height Rmax of 1000 nm or less. When Ra is less than 30 nm, sufficient slipperiness cannot be imparted to the film, and curling flaws occur during film formation, or wrinkles occur when manufacturing a wound capacitor, making processing difficult. . On the other hand, when Ra is larger than 200 nm, or when Rmax is larger than 1000 nm, the roughness of the surface is large, and when a deposited film such as aluminum or zinc is formed on the surface of the film, unevenness in the deposited film thickness occurs, When a capacitor is used, air intervenes between the films, causing instability of electrical characteristics, lowering the withstand voltage, electric field concentration occurring during use, melting or burning of the film and metal thin film layer, When used as a capacitor film, it may be difficult to improve the performance of the capacitor. The lower limit of Rmax is not particularly limited, but is set to 300 nm from the viewpoint of imparting appropriate slipperiness.

  The biaxially oriented polyarylene sulfide film of the present invention contains particles so as to achieve the friction coefficient range and surface roughness of the above film in order to impart slipperiness to the film and improve processability. Can do. Examples of particles include inert particles such as inorganic particles such as titanium oxide, calcium carbonate, silica, alumina and zirconia, and organic particles such as silicon particles, crosslinked acrylic particles and crosslinked polystyrene particles, and calcium acetate during polymer polymerization. It is also possible to deposit particles in the course of polymer polymerization using lithium or lithium acetate. The average particle diameter of the particles is preferably not more than the film thickness, more preferably not more than 2/3 of the film thickness, and still more preferably not more than 1/2. In the present invention, it is preferable that coarse particles having a particle diameter of 2 μm or more or a film thickness or more are not included. When coarse particles are included, the film formation may be inferior in stability, or particles may fall off from the film during use of the capacitor, resulting in an insulation defect and impairing the reliability of the capacitor. For this reason, inert particles such as inorganic particles and organic particles are made into a slurry in a solvent at the time of PPS polymerization and dispersed with a medium stirring type dispersion device such as a sand grinder or an ultrasonic dispersion device, and then classified with a wet classification device or a filter. It is preferable to filter out and remove coarse particles.

  In the present invention, when the thermoplastic resin A is included, a fine projection structure may be formed on the surface depending on the dispersion state. In this case, the above friction coefficient range is achieved without substantially adding particles. There is. Since the protrusion height tends to decrease as the average dispersion diameter of the thermoplastic resin A decreases, the inorganic or organic particles described above are added to impart the necessary processability when the average dispersion diameter is less than 200 nm. It may be necessary to add.

  In the film of the present invention, a plasticizer, a weathering agent, an antioxidant, a heat stabilizer, an ultraviolet stabilizer, a lubricant, an antistatic agent, a whitening agent, as long as the effects of the present invention are not impaired. Coloring agents, conductive agents, rust preventives, etc. may be added.

  The thickness of the biaxially oriented polyarylene sulfide film of the present invention is preferably 500 μm or less, although it varies depending on the application. In the case of a capacitor application, 0.5 to 20 μm is preferable, and 1 to 10 μm is more preferable. In the case of an electrically insulating film, the thickness is more preferably in the range of 10 to 300 μm, and still more preferably in the range of 20 to 200 μm, from the viewpoint of workability.

  The biaxially oriented polyarylene sulfide film of the present invention is directly coated with a polyarylene sulfide or other polymer layer such as polyester, polyolefin, polyamide, polyimide, polyvinylidene chloride or acrylic polymer. Or you may laminate | stack and use through layers, such as an adhesive agent.

  In addition, the biaxially oriented polyarylene sulfide film of the present invention may be subjected to any processing such as heat treatment, molding, surface treatment, lamination, coating, printing, embossing and etching as necessary. Good.

  The biaxially oriented polyarylene sulfide film of the present invention can be used for capacitor dielectrics, motors, transformers and other electrical insulating materials and molding materials, circuit board materials, circuit / optical member processes, release films and protective films, lithium Used for ion battery materials, fuel cell materials, diaphragms, etc. In particular, since it has excellent electrical insulation performance at high temperatures, it can be preferably used for capacitors, electrical insulation materials, circuit boards and the like. Furthermore, since it is excellent in SH property when used as a capacitor dielectric, a capacitor having high safety and heat resistance is preferable.

  Next, regarding the method for producing a biaxially oriented polyarylene sulfide film of the present invention, a biaxial structure comprising poly-p-phenylene sulfide as polyarylene sulfide and polyetherimide “Ultem 1010” manufactured by GE Plastics as thermoplastic resin A. The production of an oriented polyphenylene fide film will be described as an example. Of course, the present invention is not limited to the following description.

  In the case where polyphenylene sulfide (PPS) and polyetherimide (PEI) are mixed, a method of pre-melting and kneading (pelletizing) a mixture of the respective resins before melt extrusion is preferably exemplified.

  In the present invention, it is preferable that the PPS and PEI are first charged into a twin-screw kneading extruder to prepare a blend raw material having a weight fraction of PPS and PEI of 99.5 / 0.5 to 70/30. The mixing / kneading method of the resin composition of the blend raw material is not particularly limited, and various mixing / kneading means are used. For example, each may be separately fed to the melt extruder and mixed, or only the powder raw material is preliminarily dry mixed using a mixer such as a Henschel mixer, a ball mixer, a blender or a tumbler, It may be melt kneaded in a melt kneader. Then, it is preferable from a viewpoint of the quality of a film and film forming property that the said blend raw material is thrown into an extruder with PPS and these collection | recovery raw materials as needed, and is made into the target composition. When preparing the raw material, it is also preferable to filter the resin in the melt-extrusion process in order to reduce foreign matter contamination in the film as much as possible. In order to remove foreign substances and denatured polymers in the extruder, it is preferable to use various filters, for example, filters made of materials such as sintered metal, porous ceramic, sand and wire mesh. Moreover, you may provide a gear pump as needed in order to improve fixed_quantity | feed_rate supply property.

  The more specific conditions of the manufacturing method of said preferable biaxially oriented polyphenylene sulfide film are as follows.

  First, PPS pellets or granules and PEI pellets are mixed at a constant ratio, supplied to a vent type twin-screw kneading extruder, and melt-kneaded to obtain a blend chip. It is preferable to use a high-shear mixer with high shear stress, such as a twin-screw extruder, and from the viewpoint of reducing poor dispersion, a screw equipped with a triple-screw or double-screw type is preferable. In this case, the residence time is preferably in the range of 1 to 5 minutes. Moreover, it is preferable that it is a resin temperature range of 290-350 degreeC in a kneading part, and a more preferable temperature range is 295-330 degreeC. Setting the resin temperature range of the kneading part to a preferable range makes it easy to increase the shear stress and increases the effect of reducing defective dispersion, and the dispersed diameter of the dispersed phase can be controlled within the preferable range of the present invention. Moreover, it is preferable that screw rotation speed shall be 100-500 rotation / min, More preferably, it is the range of 200-400 rotation / min. By setting the screw rotation speed within a preferable range, high shear stress is easily added, and the dispersion diameter of the dispersed phase can be controlled within the preferable range of the present invention. Further, the ratio of (screw shaft length / screw shaft diameter) of the twin screw extruder is preferably in the range of 20 to 60, more preferably in the range of 30 to 50. Furthermore, in the twin screw, it is preferable to provide a kneading part by a kneading paddle or the like in order to increase the kneading force, and a screw shape in which two or more kneading parts are provided and a normal feed screw is provided between the kneading parts. It is more preferable to make it.

  In mixing PPS and PEI, if a mixed composition of PPS and PEI or a compatibilizing agent is added, poor dispersion may be reduced and compatibility may be increased.

  Thereafter, a blend chip made of PPS and PEI obtained by the above pelletizing operation, and optionally mixed PPS and a raw material mixed with recovered raw material and particles after film formation at a certain ratio, and mixed at 180 ° C. 3 After drying at a reduced pressure of 10 mmHg or less for an hour or more, it is put into an extruder heated to a temperature of 300 to 350 ° C., preferably 320 to 340 ° C. Thereafter, the molten polymer that has passed through the extruder is passed through a filter, and then the molten polymer is discharged into a sheet shape using a die of a T die. This sheet-like material is closely adhered to a cooling drum having a surface temperature of 20 to 70 ° C. to be cooled and solidified to obtain an unstretched polyphenylene sulfide film that is substantially amorphous and non-oriented.

  Next, this unstretched polyphenylene sulfide film is biaxially stretched and biaxially oriented. Stretching methods include sequential biaxial stretching methods (stretching methods that combine stretching in each direction, such as a method of stretching in the width direction after stretching in the longitudinal direction), and simultaneous biaxial stretching methods (in the longitudinal direction and the width direction). The method of extending | stretching simultaneously), or the method which combined them can be used.

  Here, a sequential biaxial stretching method in which stretching in the longitudinal direction and then in the width direction is performed first is used.

  An unstretched polyphenylene sulfide film is heated with a group of heating rolls, and the stretching ratio is 3 to 5 times, preferably 3.3 to 4.7 times, more preferably 3.times. In the longitudinal direction (MD direction) from the viewpoint of improving electrical properties. The film is stretched 5 to 4.5 times in one or more stages (MD stretching). The stretching temperature is in the range of Tg (glass transition temperature of PPS) to (Tg + 40) ° C., preferably (Tg + 5) to (Tg + 20) ° C. Thereafter, it is cooled by a cooling roll group of 20 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. The both ends of this film are gripped with clips, guided to a tenter, and stretched in the width direction (TD stretching). The stretching temperature is preferably Tg to (Tg + 40) ° C., more preferably (Tg + 5) to (Tg + 20) ° C. The draw ratio is in the range of 3 to 5 times, preferably 3.3 to 4.7 times, more preferably 3.5 to 4.5 times from the viewpoint of improving electrical characteristics, and the area ratio (MD direction ratio and TD). The product of the magnification in the direction) is preferably 11 times or more, more preferably 12 times or more, and still more preferably 13 times or more. In the case of stretching such that the area magnification exceeds 25 times, the film may be easily broken during film formation, and the elongation of the film may be less than 30%.

Next, this stretched film is heat-set under tension. The preferable heat setting temperature in the case of one-stage heat setting is 170 to 275 ° C., preferably 200 to 250 ° C., and the heat setting time is 1 second to 100 seconds, preferably 1 second to 60 seconds, more preferably 1 second to 30 seconds. As more preferable conditions, heat setting after stretching is performed in two or more steps having different temperatures, and the heat setting temperature of the first step is (previous stretching temperature + 5 ° C.) to 240 ° C. The maximum value is preferably set to (the first stage heat setting temperature + 5 ° C.) to (the melting point of the polyarylene sulfide constituting the film−5 ° C.) or less, and more preferably the first stage heat setting temperature is (Stretching temperature + 5 ° C.) to 220 ° C., and the maximum value of the heat setting temperature in the subsequent stage is (the heat setting temperature of the first stage + 30 ° C.) to (the melting point of the polyarylene sulfide constituting the film−5 ° C.) or less. preferable. In the case of multi-stage heat fixation, the first stage of heat fixation is 1 second to 100 seconds, preferably 1 second to 60 seconds, more preferably 1 second to 30 seconds, and the heat fixation at the highest temperature in the subsequent stage is 1 second to 100 seconds. Seconds, preferably 1 second to 60 seconds, more preferably 1 second to 30 seconds, so that the total heat setting time does not exceed 200 seconds, preferably 120 seconds, more preferably 60 seconds. Further, this film is subjected to a relaxation treatment in the width direction in a temperature zone of 40 to 275 ° C., more preferably a stretching temperature or more and a heat setting temperature or less (the highest heat setting temperature in the case of multistage heat setting). The relaxation rate is preferably 0.1 to 8%, more preferably 1.5 to 6%, and still more preferably 2 to 5%. The relaxation treatment is performed in the above temperature range over 1 second to 100 seconds, preferably 1 second to 60 seconds, more preferably 1 second to 30 seconds.

Further, the film is cooled and rolled up to room temperature, if necessary, in the longitudinal and width directions, if necessary, to obtain the desired biaxially oriented polyphenylene sulfide film.
The metallized film of the present invention is a biaxially oriented film in which a metal layer is formed on at least one surface, and a metal thin film formed by a method such as vacuum deposition or sputtering can be used. . Such metals include, but are not limited to, aluminum, zinc, tin, titanium, nickel, or alloys thereof.

The film capacitor of the present invention can be produced by a known method such as a winding method or a lamination method. As the conductor of such a capacitor, the above metallized film can be used.
Next, a method for manufacturing the capacitor of the present invention will be described. When metal foil is used as the internal electrode of the capacitor, the metal foil and the laminated film of the present invention are alternately rolled up by winding the foil or by inserting a tab in the middle of winding, etc. And a capacitor element or a capacitor mother element are obtained by winding the electrodes so that the electrodes can be drawn out to the outside.

When a metal thin film is used as the internal electrode of the capacitor, the above-described film of the present invention is first metallized. The metallization method is preferably a vapor deposition method. The metal to be deposited is preferably a metal mainly composed of aluminum. At the time of metallization, the adhesion between the metal thin film and the film can be improved by treatment such as corona discharge treatment or plasma treatment on the surface of the film to be metallized in advance. The resistance value of the metal layer is preferably in the range of 0.5 to 100Ω / □. If the resistance value is less than 0.5Ω / □, the original capacitor characteristics may not be obtained, for example, the self-healing property tends to deteriorate or the insulation resistance tends to deteriorate. If it exceeds 100Ω / □, the equivalent resistance may increase directly, or the dielectric loss tangent (tan δ) may tend to deteriorate. Since the effect of this invention is easy to express, 1-50 ohm / square is more preferable, and 2-30 ohm / square is still more preferable.
It is usual to provide a non-metalized part (so-called margin) by tape mask, oil margin or laser beam so that the counter electrode is not short-circuited during metallization or after metallization. A non-metallized band can also be provided using a laser beam or the like. After that, the tape may be slit into a narrow tape shape so that a margin part comes to one end.
Next, a capacitor element is manufactured. When obtaining a wound type capacitor, the metallized film is slit into a narrow tape shape with a margin at one end, and two sheets are stacked, or a double-sided metallized film and a non-metallized film are stacked. It is a common practice to wind individual elements individually. There is also a method of winding a single composite film in which a second dielectric is provided on a double-sided metallized film by a coating method or the like.

In the case of a multilayer capacitor, the capacitor mother element is obtained by winding it on a large-diameter drum or flat plate. When manufacturing a wound type capacitor, it is common to press-mold the capacitor mother element obtained as described above. At this time, it can also heat to the temperature below 100 degreeC or more and the melting | fusing point of a film. After that, the external electrode mounting process (by metal spraying, conductive resin, etc.), if necessary, resin or oil impregnation process, when using a leaded type capacitor, the lead wire mounting process and the exterior process can be used to obtain the capacitor. it can.
In the case of multilayer capacitors, molding is performed by applying pressure in the thickness direction of the film, such as heat treatment of a large-diameter drum or mother element wound on a flat plate, clamping with a ring, or pressing with a parallel plate. . The temperature range in that case is from normal temperature to below the melting point of the film. Thereafter, the capacitor can be obtained through an external electrode attaching step (metal spraying, using a conductive resin), individual element cutting steps, and if necessary, a resin or oil impregnation step.

  The shape of the capacitor of the present invention may be any of the above. Further, the capacitor of the present invention can be developed for both AC and DC applications.

The characteristic value measurement method and effect evaluation method of the present invention are as follows.
(1) Average dispersion diameter and aspect ratio of the dispersed phase The film is (a) a direction parallel to the longitudinal direction and perpendicular to the film surface, (b) a direction parallel to the width direction and perpendicular to the film surface, and (c) a film surface. The sample was cut in a parallel direction, and a sample was prepared by an ultrathin section method. In order to clarify the contrast of the dispersed phase, it may be stained with osmic acid, ruthenic acid, phosphotungstic acid, or the like. When the thermoplastic resin A is polyamide, dyeing with phosphotungstic acid is used. The cut surface was observed using a transmission electron microscope (H-7100FA type, manufactured by Hitachi) under the condition of an applied voltage of 100 kV, and a photograph was taken at 20,000 times. The obtained photograph was taken into an image analyzer as an image, 100 arbitrary dispersed phases were selected, and image processing was performed, whereby the size of each dispersed phase was determined as follows. The maximum thickness (la) and the maximum length (lb) in the film thickness direction of each dispersed phase appearing on the cut surface of (a), and the maximum thickness (lb) in the longitudinal direction of each dispersed phase appearing on the cut surface of (a) The maximum length (lc), the maximum length (ld) in the width direction, the maximum length (le) in the film longitudinal direction and the maximum length (lf) in the width direction of each dispersed phase appearing on the cut surface of (c). Asked. Next, the shape index of the dispersed phase I = (average value of lb + average value of le) / 2, shape index J = (average value of ld + average value of lf) / 2, shape index K = (average value of la + lc In the case of (average value) / 2, the average dispersion diameter of the dispersed phase was (I + J + K) / 3. Further, from I, J, and K, the average major axis L was determined as the maximum value and the average minor axis D was determined as the minimum value, and the aspect ratio of the dispersed phase was L / D.
(2) Glass transition temperature and melting point of film Measured according to JIS K7121-1987. Using a differential scanning calorimeter DSC (RDC220) manufactured by Seiko Instruments Inc. and a disk station (SSC / 5200) manufactured by Seiko Instruments Inc. as a data analysis device, 5 mg of the sample was melted and held at 350 ° C. for 5 minutes on an aluminum tray, and rapidly cooled and solidified. The temperature was raised from room temperature at a heating rate of 20 ° C./min. The glass transition temperature (Tg) was calculated by the following formula.
Glass transition temperature = (extrapolated glass transition start temperature + extrapolated glass transition end temperature) / 2
(3) Glass transition temperature and melting temperature of polyarylene sulfide and thermoplastic resin A The glass transition temperature of the raw material chip of polyarylene sulfide and thermoplastic resin A is measured according to JIS K7121-1987 in the same manner as (2) above. did.

As for the melting temperature, a differential scanning calorimeter DSC (RDC220) manufactured by Seiko Instruments Inc. and a disk station (SSC / 5200) manufactured by Seiko Instruments Inc. were used as a data analysis device, and a sample 5 mg was heated from room temperature to 340 ° C. on an aluminum pan. The temperature was raised at 20 ° C./minute, melted and held at 340 ° C. for 5 minutes, rapidly solidified and held for 5 minutes, and then heated from room temperature at a heating rate of 20 ° C./minute. At that time, the peak temperature of the endothermic peak of melting observed was defined as the melting temperature (Tm).
(4) Mechanical properties (breaking elongation, breaking strength, Young's modulus) of film and differential coefficient of elongation-stress curve Measured using an Instron type tensile tester according to the method defined in ASTM-D882-97. did. The measurement was performed under the following conditions, and the number of samples was 10 in each of the longitudinal direction and the width direction. Breaking elongation, breaking strength, and Young's modulus are the averages of the remaining 6 measurements of breaking elongation, breaking strength, and Young's modulus, excluding the highest and lowest, respectively, by measuring the elongation from the lowest to the highest in the tensile test. Value. In addition, for the two measurements in the middle of the permutation of elongation in each of the longitudinal direction and the width direction, a differential coefficient is obtained for each data sampling point (excluding sampling points at both ends), and the elongation is 2% in each direction (breaking The average value of the lowest values of each measurement in the section of the point elongation (%)-5%) was taken, and the smaller value was compared as the lowest differential coefficient γmin.

Measuring device: Orientec Co., Ltd. film strong elongation automatic measuring device "Tensilon AMF / RTA-100"
Sample size: width 10mm x test length 50mm
Tensile speed: 300 mm / min Measurement environment: Temperature 23 ° C., humidity 65% RH
Data sampling interval: Every 0.4% elongation Calculation method of differential coefficient γ The elongation (%) and stress (MPa) at the Nth measurement point are E (N) and S (N), respectively. The differential coefficient γ (N) of the Nth measurement point is calculated.
γ (N) = {S (N + 1) −S (N)} / {E (N + 1) −E (N)}
Determination of differential coefficient C: γmin <0
B: 0 ≦ γmin <0.5
A: 0.5 ≦ γmin
(5) Dielectric breakdown voltage and standard deviation of film The film was measured under the conditions of an environmental temperature of 23 ° C. and 65% RH and 150 ° C. according to the method defined in JIS C-2151-1990. For the measurement, an aluminum foil electrode having a thickness of 100 μm and a 10 cm square was used for the cathode, a brass electrode having a diameter of 25 mm and a weight of 500 g was used for the anode, and a film was sandwiched between them. The pressure was increased at a rate of 2 seconds, and the dielectric breakdown was considered when 10 mA or more flowed. This measurement was performed 30 times, and the average value of the values divided by the film thickness was taken as the dielectric breakdown voltage of the film. The standard deviation in the value measured 30 times at this time was calculated.

(6) Melting specific resistance After putting 300 g of a substance to be measured (film) into a glass container into which a pair of copper parallel plate electrodes having a facing area of 15 cm ² (3 cm × 5 cm) and a distance between the electrodes of 0.5 cm are inserted, this Immerse the container in a heated silicon bath. A substance to be measured is melted and stored at 310 ° C. for 2 hours in a nitrogen gas atmosphere, and a DC voltage of 5 KV is applied between both electrodes from a DC high voltage generator. The melt specific resistance (ρ) was determined according to the following equation from the indicated values of the ammeter and voltmeter, the electrode area, and the distance between the electrodes.
ρ = V × S / (I × D)
ρ: Melting specific resistance (Ω · cm)
V: Applied voltage (V)
S: Area of electrode (cm ² )
I: Measurement current (A)
D: Distance between electrodes (cm)
Number of measurements: measured three times, and the average value is calculated.
(7) Melt Viscosity Using a flow tester CFT-500 (manufactured by Shimadzu Corporation), the base length was 10 mm, the base diameter was 1.0 mm, the preheating time was set to 5 minutes, and the measurement was performed at 310 ° C.

The melt viscosity at a shear rate of 1000 / s is a correlation line obtained by measuring the melt viscosities at shear rates of 500 to 1000 / s and 1000 to 2000 / s with n = 2, respectively, and linearly approximating them on a log-log plot. The value at a shear rate of 1000 / s.
(8) Centerline average roughness Ra, maximum height Rmax, number of protrusions Using an atomic force microscope, 20 fields of view were measured at different locations under the following conditions. For the obtained image, the three-dimensional surface roughness (Roughness Analysis) was calculated, and the center line average roughness Ra and the maximum protrusion height Rmax were measured. The conditions were as follows. The threshold value of the protrusion height was set to 50 nm, and the number of protrusions having a height equal to or higher than the threshold value was determined and measured.
Measuring device: NanoScope III AFM (manufactured by Digital Instruments)
Cantilever: Silicon single crystal scanning mode: Tapping mode Scanning range: 50 μm
Scanning speed: 0.5Hz
Peak Thresh ref (reference threshold): ZERO
Peak Threshold: 50nm
(9) Friction coefficient A film slit into a tape having a width of 1/2 inch. Running on a stainless steel guide pin (surface roughness: 100 nm Ra) using a tape running tester (running speed 250 m / min, Winding angle 60 °, exit side tension 90 g, number of running times 1). At this time, the entry side tension was Ti, and the following formula, μk = 2.20 log (90 / Ti) was used.
(10) Film thickness Using an electronic micrometer (K-312A type) manufactured by Anritsu Corporation under an atmosphere of 23 ° C. and 65% RH, the film thickness was measured at a needle pressure of 30 g.
(11) Degree of orientation by laser Raman spectroscopy Microscopic Raman measurement conditions by the laser Raman scattering method are as follows.
Laser Raman system: Near-infrared Raman spectrometer (Photon Design)
Microprobe: Objective lens × 20
Cross slit: 500 μm
Spot diameter: 5 μm
Light source: Nd-YAG (wavelength 1064 nm, output: 500 mW)
Diffraction grating: Spectrograph 300gr / mm
Slit: 100 μm
Detector: InGaAs (Nippon Roper)
The film used for measurement was sampled and embedded in an epoxy resin, and then a film cross section was taken out with a microtome. The film cross section was adjusted to be parallel to the film longitudinal direction or the width direction, and the average value was obtained by measuring five samples for each of the longitudinal direction and the width direction with the central point of each sample as the measurement point. . Measurements were taken at 1570 cm ⁻¹ Raman peak intensity (I) with longitudinal or width polarization parallel to the film plane and 740 cm ⁻¹ Raman peak intensity (I _ND ) with polarization perpendicular to the film plane. seeking the ratio I / I _ND of polyarylene - sulfide film orientation parameters - data - and the.
(11) Average particle diameter of particles in film On the surface of a measurement film fixed on a sample stage of a scanning electron microscope, using a sputtering apparatus, the vacuum is 10 ⁻³ Torr, the voltage is 0.25 kV, and the current is 12.5 mA. For 10 minutes. Next, the surface is sputtered with gold using the same apparatus, and photographs of 10,000 to 30,000 times are taken with a scanning electron microscope. The average particle diameter of the particles in the film is determined from the above formula by determining the area equivalent circle diameter (Di) of 100 or more n particles from the above photograph. Here, the area equivalent circle diameter (Di) is the diameter of each circumscribed circle.

(12) Particle Concentration in Film Particle Concentration in Film Dissolve the film in α-chloronaphthalene, separate the particles by heating when heated, and express the ratio (part by weight) relative to the total weight of the film. In addition, it can be quantified using infrared spectroscopy, fluorescent X-ray method, or SEM-XMA as required. (13) Capacitor characteristics (a) Preparation of capacitor Surface resistance is 10Ω / □ on one side of the film. Aluminum was vapor-deposited so that At that time, vapor deposition was performed in a stripe shape having a margin portion running in the longitudinal direction (repetition of a vapor deposition portion width of 80 mm and a margin portion width of 10 mm). The deposited film was slit at the center of each vapor deposition part and the center of the margin part, and wound into a tape having a width of 45 mm having a 5 mm margin part on the left or right. The obtained tapes were stacked one on the left margin and the other on the right margin, and wound to obtain a wound body having a capacitance of 5 μF. At that time, the two films were shifted and wound so that the vapor deposition part protruded 5 mm from the margin part in the width direction. The core material was removed from these wound bodies and pressed as it was for 5 minutes at 200 ° C., 25 kg / cm ² temperature and pressure. Further, metallicon was sprayed on both end faces to form external electrodes, and lead wires were welded to the metallicon to obtain capacitor elements. The obtained element was heat-treated at 220 ° C. for 2 hours, and then packaged with a powder epoxy resin (average jacket thickness 0.5 mm) to prepare a capacitor.
(B) Evaluation of withstand voltage (step-up DC breakdown voltage test)
Connect the lead wire of the capacitor element to a 2KV power source (manufactured by HEIDEN lab .: Model HD2K2P-PS), start up at 150 ° C., step up every 100V at 400V and LCR meter (Ando Electric Co., Ltd.) A capacity of 1 kHz was measured with TYPE AG 4311). The holding time at each step was 10 minutes.

A test was carried out with 12 capacitor elements for each level of the film, and the average value of the applied voltage value in the step immediately before the capacity decreased by 10% or more with respect to the capacity before the voltage application was taken as the withstand voltage.
(C) Evaluation of self-healing property (SH property) In the DC withstanding voltage evaluation described above, a capacitor element causing dielectric breakdown in the step immediately after the capacity is reduced by 10% or more is regarded as SH property failure, and the failure rate (%) is calculated. Judgment was made based on the following criteria. ○ is a pass.
○: Defect rate less than 10% Δ: Defect rate 10% or more and less than 50% X: Defect rate 50% or more (d) Heat resistance 30 capacitors are placed in an oven at 150 ° C. Equipped with a switch to stop, connected in parallel with the DC power generator, and continuously applying a voltage of 250V / μm for 1000 hours, the broken capacitor element is regarded as a withstand voltage defective element, and the defect rate (%) is judged according to the following criteria did. ◎ and ○ are acceptable.

◎: Defect rate less than 2% ○: Defect rate 2% or more and less than 10% △: Defect rate 10% or more and less than 20% ×: Defect rate 20% or more (e) Resistance of metal layer 100 mm electrode by 4-terminal method The resistance of the metal layer was measured, and the measured value was divided by the measurement width and the distance between the electrodes, and the resistance value of the metal layer per 10 mm width and 10 mm distance between the electrodes was calculated. The unit is displayed as Ω / □.

(Reference Example 1) Poly-p-phenylene sulfide (PPS-1) in a 70 liter autoclave equipped with a polymerization stirrer, 47.5 wt% sodium hydrosulfide 8,267.37 g (70.00 mol), 96 wt% Sodium hydroxide 2,957.21 g (70.97 mol), N-methyl-2-pyrrolidone (NMP) 11,434.50 g (115.50 mol), sodium acetate 2,583.00 g (31.50 mol) And 10,500 g of ion-exchanged water were charged and gradually heated to 245 ° C. over about 3 hours while passing nitrogen at normal pressure. After distilling 14,780.1 g of water and 280 g of NMP, the reaction vessel was brought to 160 ° C. Cooled down. The amount of water remaining in the system per mole of the charged alkali metal sulfide was 1.06 mol including the water consumed for the hydrolysis of NMP. The amount of hydrogen sulfide scattered was 0.02 mol per mol of the charged alkali metal sulfide.

  Next, 10,235.46 g (69.63 mol) of p-dichlorobenzene and 9,09.0.00 g (91.00 mol) of NMP were added, the reaction vessel was sealed under nitrogen gas, and the mixture was stirred at 240 rpm. The temperature was raised to 238 ° C. at a rate of 6 ° C./min. After reacting at 238 ° C. for 95 minutes, the temperature was raised to 270 ° C. at a rate of 0.8 ° C./min. After reacting at 270 ° C. for 100 minutes, 1,260 g (70 mol) of water was injected over 15 minutes and cooled to 250 ° C. at a rate of 1.3 ° C./minute. Then, after cooling to 200 ° C. at a rate of 1.0 ° C./min, it was rapidly cooled to near room temperature.

The contents were taken out, diluted with 26,300 g of NMP, the solvent and solid matter were filtered off with a sieve (80 mesh), and the resulting particles were washed with 31,900 g of NMP and filtered off. This was washed 3 times with 56,000 g of ion-exchanged water and filtered, and then washed with 70,000 g of 0.05 wt% acetic acid aqueous solution and filtered. After washing with 70,000 g of ion-exchanged water and filtering, the resulting hydrous PPS particles were dried with hot air at 80 ° C. and dried under reduced pressure at 120 ° C. The obtained PPS had a melt viscosity of 200 Pa · s (310 ° C., shear rate of 1,000 / s), a glass transition temperature of 93 ° C., and a melting point of 285 ° C.
(Reference Example 2) Polymerization of poly-p-phenylene sulfide (PPS-2) A PPS resin was prepared in the same manner as in Reference Example 1 except that an aqueous solution of calcium acetate was used instead of an aqueous solution of acetic acid in the washing step of the reference example. . The obtained PPS resin had a melt viscosity of 210 Pa · s (310 ° C., shear rate of 1,000 / s), a glass transition temperature of 93 ° C., and a melting point of 285 ° C.
(Reference Example 3) Polymerization of poly-p-phenylene sulfide (PPS-3) In the reaction step of Reference Example 1, the reaction time at 238 ° C was 100 minutes, the reaction time at 270 ° C was 125 minutes, and an acetic acid aqueous solution was used. Instead, a PPS resin was prepared in the same manner as in Reference Example 1 except that an aqueous calcium acetate solution was used. The obtained PPS resin had a melt viscosity of 250 Pa · s (310 ° C., shear rate of 1,000 / s), a glass transition temperature of 93 ° C., and a melting point of 285 ° C.
Reference Example 4 Preparation of Particle Master Chip 8 parts by weight of silica spherical fine particles having an average particle diameter of 0.55 μm (“Sea Hoster KEP-50” manufactured by Nippon Shokubai Co., Ltd.) with respect to 92 parts by weight of the PPS resin prepared in Reference Example 1. It mix | blends so that it may become, It introduce | transduces into the same direction rotation type biaxial kneading extruder with a vent (Nippon Steel Works, screw diameter 30mm, screw length / screw diameter = 45.5), Residence time 30 seconds, Screw rotation speed 300 The mixture was melt-extruded at 330 ° C. at a speed of rotation / minute, discharged into a strand, cooled with water at a temperature of 25 ° C., and immediately cut to produce a particle master chip (containing 8% particles).
Example 1
The PPS-1 resin prepared in Reference Example 1 was dried under reduced pressure of 1 mmHg at 180 ° C. for 3 hours, and polyetherimide (“Ultem 1010” manufactured by GE Plastics) (PEI) as thermoplastic resin A at 120 ° C. It was dried separately under reduced pressure of 1 mmHg for 3 hours. Further, 2.4 parts by weight of γ-isocyanatopropyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., “KBE9007”) is added to 70 parts by weight of the PPS-1 resin and 30 parts by weight of PEI, and then kneaded. Vented co-rotating twin-screw kneading extruder with three paddle kneading parts (manufactured by Nippon Steel Works, screw diameter 30 mm, screw length / screw diameter = 45.5), residence time 90 seconds, screw It was melt extruded at 330 ° C. at a rotation speed of 300 rpm, discharged into a strand, cooled with water at a temperature of 25 ° C., and immediately cut to produce a blend chip.
The resulting PPS / PEI (70/30 parts by weight) blend chip raw material 17 parts by weight, the PPS-2 resin 73 parts by weight prepared in Reference Example 2 and the particle master chip 10 parts by weight were dry blended, and 7 ° C. at 7O 0 C. After drying for 1 hour under a reduced pressure of 1 mmHg, the molten part was supplied to a full flight single screw extruder heated to 320 ° C.

  Next, the polymer melted by the extruder is filtered through a filter set at a temperature of 320 ° C., melt-extruded from a die of a T die set at a temperature of 320 ° C., and then adhered while applying an electrostatic charge to a cast drum having a surface temperature of 25 ° C. It was cooled and solidified to produce an unstretched polyphenylene sulfide film.

  This unstretched polyphenylene sulfide film is stretched in the longitudinal direction of the film at a stretching temperature of 99 ° C. and a stretching speed of 30000% / min by using a longitudinal stretching machine composed of a plurality of heated roll groups and utilizing the peripheral speed difference of the rolls. The film was stretched at a magnification of 3.6 times. Thereafter, both ends of the film are gripped by clips and guided to a tenter, and stretched in the width direction of the film at a stretching temperature of 100 ° C., a stretching speed of 1100% / min, and a stretching ratio of 3.7 times, and subsequently a temperature of 240 After heat treatment at 15 ° C. for 15 seconds, in the cooling zone controlled at 180 ° C., 2% relaxation treatment was performed in the transverse direction for 2 seconds to cool to room temperature, and then the film edge was removed, wound up, and the thickness was 3.0 μm. A biaxially oriented polyphenylene sulfide film was obtained.

The measurement, evaluation results and capacitor characteristics of the composition and characteristics of the obtained biaxially oriented polyphenylene sulfide film are as shown in Table 3. This biaxially oriented polyphenylene sulfide film is excellent in dielectric breakdown voltage and also has capacitor characteristics. It was good.
(Examples 2, 27, Comparative Examples 1, 2, 4)
Biaxially oriented polyphenylene sulfide in the same manner as in Example 1, except that the amount of PEI added to the thermoplastic resin A, the type and amount of the compatibilizer, the film forming conditions, and the thickness were changed as shown in Tables 1 and 2. A film and a capacitor using the film were prepared. Measurements, evaluation results and capacitor characteristics for the properties of the obtained biaxially oriented polyphenylene sulfide film are as shown in Tables 3 and 4, respectively. The biaxially oriented polyphenylene sulfide films of Examples 2 and 27 have a dielectric breakdown voltage. Excellent and capacitor characteristics were also good. On the other hand, the biaxially oriented polyphenylene sulfide films of Comparative Examples 1 and 2 were tried to form a film in the same manner as in Example 1. However, the differential coefficient of the obtained film had a negative value after the yield point, The withstand voltage was lower than the withstand voltage at room temperature, and the SH property of the device was inferior. In Comparative Example 4, a sample that could be evaluated due to frequent film breaks could not be collected.
(Examples 3-16, 22-26, Comparative Example 3)
The amount of PEI added to the thermoplastic resin A, the type and amount of the compatibilizing agent, and the thickness were changed as shown in Table 1, and further, in the film forming conditions, the heat treatment performed continuously after stretching in the width direction is shown in Tables 1 and 2. A biaxially oriented polyphenylene sulfide film and a capacitor using the biaxially oriented polyphenylene sulfide film were prepared in the same manner as in Example 1 except that each of the two heat setting temperatures described was performed for 7.5 seconds. Measurements, evaluation results and capacitor characteristics for the properties of the obtained biaxially oriented polyphenylene sulfide film are as shown in Tables 3 and 4, and any of the biaxially oriented polyphenylene sulfide films of Examples 3 to 16 and 22 to 26 Although the film formation conditions were superior or inferior, all had excellent breakdown voltage and good capacitor characteristics. On the other hand, the biaxially oriented polyphenylene sulfide film of Comparative Example 3 was formed in the same manner as in Example 3, but the results were inferior to the SH property of the device.
(Example 17)
A biaxially oriented polyphenylene sulfide film and a capacitor using the same were prepared in the same manner as in Example 3 except that polyarylate (“U polymer” U100 manufactured by Unitika) (PAR) was used as the thermoplastic resin A. The measurement, evaluation results, and capacitor characteristics of the biaxially oriented polyphenylene sulfide film obtained are as shown in Table 1. This biaxially oriented polyphenylene sulfide film is excellent in dielectric breakdown voltage and also has capacitor characteristics. It was good.
(Example 18)
A biaxially oriented polyphenylene sulfide film and a capacitor using the same were prepared in the same manner as in Example 3 except that polyphenylene ether (YPX-100A manufactured by Mitsubishi Gas Chemical Company) (PPE) was used as the thermoplastic resin A. The measurement, evaluation results, and capacitor characteristics of the biaxially oriented polyphenylene sulfide film obtained are as shown in Table 1. This biaxially oriented polyphenylene sulfide film is excellent in dielectric breakdown voltage and also has capacitor characteristics. It was good.
(Example 19)
A biaxially oriented polyphenylene sulfide film and a capacitor using the same were prepared in the same manner as in Example 3 except that polyethersulfone (“RADEL” A-200A manufactured by Amoco) (PES) was used as the thermoplastic resin A. The measurement, evaluation results, and capacitor characteristics of the biaxially oriented polyphenylene sulfide film obtained are as shown in Table 1. This biaxially oriented polyphenylene sulfide film is excellent in dielectric breakdown voltage and also has capacitor characteristics. It was good.
(Example 20)
A biaxially oriented polyphenylene sulfide film having a thickness of 3.5 μm and a capacitor using the same were prepared in the same manner as in Example 3 except that polysulfone (“UDEL” P-1700 manufactured by Amoco) (PSF) was used as the thermoplastic resin A. Created. The measurement, evaluation results, and capacitor characteristics of the biaxially oriented polyphenylene sulfide film obtained are as shown in Table 1. This biaxially oriented polyphenylene sulfide film is excellent in dielectric breakdown voltage and also has capacitor characteristics. It was good.
(Example 21)
A biaxially oriented polyphenylene sulfide film and a capacitor using the same were prepared in the same manner as in Example 3 except that nylon 610 resin (nylon resin “Amilan CM2001” manufactured by Toray Industries, Inc.) (polyamide (PA)) was used as thermoplastic resin A. Created. The measurement, evaluation results, and capacitor characteristics of the obtained biaxially oriented polyphenylene sulfide film are as shown in Table 1. This biaxially oriented polyphenylene sulfide film has a slightly lower dielectric breakdown voltage. The characteristics were sufficiently high and there were no problems in actual use.
(Example 27, Comparative Example 6)
The PPS-2 resin prepared in Reference Example 2 was dried at 180 ° C. under reduced pressure of 1 mmHg for 3 hours, and the same direction rotating twin-screw kneading extruder with three kneading paddle kneading sections (manufactured by Nippon Steel Works). , Screw diameter 30 mm, screw length / screw diameter = 45.5), melt-extruded at 330 ° C., residence time 90 seconds, screw rotation speed 300 rpm, discharged into a strand, water at a temperature of 25 ° C. After cooling, the cutting was performed immediately to prepare a blend chip.
90 parts by weight of the obtained PPS chip raw material and 10 parts by weight of the particle master chip prepared in Reference Example 4 were dry blended, dried at 180 ° C. for 7 hours under a reduced pressure of 1 mmHg, and then the molten part was heated to 320 ° C. It was fed to a full flight single screw extruder.

Next, the polymer melted by the extruder is filtered through a filter set at a temperature of 320 ° C., melt-extruded from a die of a T die set at a temperature of 320 ° C., and then adhered while applying an electrostatic charge to a cast drum having a surface temperature of 25 ° C. It was cooled and solidified to produce an unstretched polyphenylene sulfide film. A biaxially oriented polyphenylene sulfide film and a capacitor using the same were prepared in the same manner as in Example 1 except for the stretching conditions in Table 2. The measurement, evaluation results, and capacitor characteristics for the composition and properties of the obtained biaxially oriented polyphenylene sulfide film are as shown in Table 4. This biaxially oriented polyphenylene sulfide film has a slightly lower dielectric breakdown voltage. The characteristics were sufficiently high and there were no problems in actual use. On the other hand, film formation was attempted in Comparative Example 6 in the same manner as in Example 1, but the results were inferior in heat resistance and SH property of the element.
(Example 28)
A biaxially oriented polyphenylene sulfide film and a biaxially oriented polyphenylene sulfide film, respectively, in the same manner as in Example 27, except that the heat treatment performed continuously after stretching in the width direction under the film forming conditions was performed for each of the two heat setting temperatures shown in Table 2 for 7.5 seconds. The capacitor which used it was made. The measurement, evaluation results, and capacitor characteristics of the obtained biaxially oriented polyphenylene sulfide film were as shown in Table 4. The dielectric breakdown voltage was excellent, and the capacitor characteristics were also good (Example 29). )
Table 2 shows that 10 parts by weight of the PPS-1 resin prepared in Reference Example 1 and 80 parts by weight of the PPS-2 resin prepared in Reference Example 2 were used in place of the PPS-2 resin of Example 28. A biaxially oriented polyphenylene sulfide film and a capacitor using the same were prepared in the same manner as in Example 28 except for the film forming conditions. The measurement, evaluation results, and capacitor characteristics for the composition and properties of the obtained biaxially oriented polyphenylene sulfide film are as shown in Table 4. This biaxially oriented polyphenylene sulfide film has a slightly lower dielectric breakdown voltage. The characteristics were sufficiently high and there were no problems in actual use.
(Example 30)
A biaxially oriented polyphenylene sulfide film was used in the same manner as in Example 28 except that PPS-3 prepared in Reference Example 3 was used in place of the PPS-2 resin of Example 28 and the film forming conditions shown in Table 2 were used. And the capacitor which used it was made. The measurement, evaluation results, and capacitor characteristics for the composition and properties of the obtained biaxially oriented polyphenylene sulfide film are as shown in Table 4. This biaxially oriented polyphenylene sulfide film has a slightly lower dielectric breakdown voltage. The characteristics were sufficiently high and there were no problems in actual use.
(Example 31)
The PPS-1 resin prepared in Reference Example 1 was dried under reduced pressure of 1 mmHg at 180 ° C. for 3 hours, and polyetherimide (“Ultem 1010” manufactured by GE Plastics) (PEI) as thermoplastic resin A at 120 ° C. It was dried separately under reduced pressure of 1 mmHg for 3 hours. Further, 2.4 parts by weight of γ-isocyanatopropyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., “KBE9007”) is added to 70 parts by weight of the PPS-1 resin and 30 parts by weight of PEI, and then kneaded. It is put into a co-rotating twin-screw kneading extruder with a vacuum vent provided with three paddle kneading parts (manufactured by Nippon Steel Works, screw diameter 30 mm, screw length / screw diameter = 45.5), and the residence time is 90 seconds. The melt was extruded at 330 ° C. at a screw rotation speed of 300 rpm and discharged into a strand shape, cooled with water at a temperature of 25 ° C., and then immediately cut to produce a blend chip.
The resulting PPS / PEI (70/30 parts by weight) blend chip raw material 17 parts by weight, 73 parts by weight of the PPS-2 resin prepared in Reference Example 2 and 10 parts by weight of the particle master chip were dry blended, and the resin 100 parts by weight. What added 0.3 part by weight of water per part was charged into the above twin screw kneading extruder, melted and extruded at a residence time of 90 seconds, screw rotation speed of 300 rotations / minute, 330 ° C., and discharged in a strand form, After cooling with water at a temperature of 25 ° C., it was immediately cut to produce a blend chip.
A biaxially oriented polyphenylene sulfide film having a thickness of 3.0 μm and a capacitor using the same were prepared in the same manner as in Example 1 except that this was extruded as a raw material. The measurement, evaluation results, and capacitor characteristics of the obtained biaxially oriented polyphenylene sulfide film are as shown in Table 4. This biaxially oriented polyphenylene sulfide film is excellent in dielectric breakdown voltage and also has capacitor characteristics. It was good.
(Example 32)
The blend chip raw material of Example 31 was extruded, and under the same film forming conditions as Example 3, a biaxially oriented polyphenylene sulfide film having a thickness of 3.0 μm and a capacitor using the same were prepared. The measurement, evaluation results, and capacitor characteristics of the obtained biaxially oriented polyphenylene sulfide film are as shown in Table 4. This biaxially oriented polyphenylene sulfide film is excellent in dielectric breakdown voltage and also has capacitor characteristics. It was good.
(Example 33)
The thickness is the same as in Example 32 except that the average particle diameter of the silica spherical fine particles of the particle master chip prepared in Reference Example 3 is changed to 1.2 μm and the particle concentration in the film is changed to the concentration shown in Table 4. A 3.0 μm biaxially oriented polyphenylene sulfide film and a capacitor using the same were prepared. The biaxially oriented polyphenylene sulfide film of this example had excellent dielectric breakdown voltage and good capacitor characteristics.
(Example 34)
Example 32 and Example 32 except that the silica spherical fine particles of the particle master chip prepared in Reference Example 3 were changed to calcium carbonate powder particles having an average particle diameter of 1.2 μm, and the particle concentration in the film was changed to the concentration shown in Table 4. Similarly, a biaxially oriented polyphenylene sulfide film having a thickness of 3.0 μm and a capacitor using the same were prepared. The biaxially oriented polyphenylene sulfide film of this example had excellent dielectric breakdown voltage and good capacitor characteristics.
(Example 35)
The silica spherical fine particles of the particle master chip prepared in Reference Example 3 were changed to calcium carbonate powder particles (two particle system) having an average particle diameter of 1.0 μm and an average particle diameter of 0.25 μm, and the particle concentration in the film is shown in Table 4. A biaxially oriented polyphenylene sulfide film having a thickness of 3.0 μm and a capacitor using the same were prepared in the same manner as in Example 32 except that the concentration was changed to the indicated concentration. The biaxially oriented polyphenylene sulfide film of this example had excellent dielectric breakdown voltage and good capacitor characteristics.
(Comparative Example 5)
A biaxially oriented polyphenylene sulfide film was used in the same manner as in Example 27 except that PPS-1 prepared in Reference Example 1 was used instead of the PPS-2 resin of Example 27 and the film forming conditions shown in Table 2 were used. As shown in Table 4, the heat resistance and the SH property of the device were inferior.

  The biaxially oriented polyarylene sulfide film of the present invention is to provide a biaxially oriented polyarylene sulfide film having excellent heat resistance, dimensional stability, electrical properties, and planarity, and particularly when used as a capacitor, By having the characteristics and excellent self-healing property (SH property), it can be suitably used as a highly reliable film for a capacitor even when used at high temperature and high voltage. Furthermore, the capacitor using the biaxially oriented polyarylene sulfide film of the present invention can be suitably used as a small-sized and high-capacity high-performance capacitor.

Claims (13)

The breakdown voltage V (23) (V / μm) at 23 ° C. and the breakdown voltage V (150) (V / μm) at 150 ° C. satisfy the following formulas (1) and (2) at the same time. A biaxially oriented polyarylene sulfide film characterized by
V (150) / V (23) ≧ 0.85 (1)
V (150) ≧ 300 (2) In the elongation-stress curve at 23 ° C. in the longitudinal direction and the width direction of the film, the differential coefficient in the section between the elongation 2% and (elongation at break−5%) is always 0 or more in both the longitudinal direction and the width direction. Biaxially oriented polyarylene film. The biaxially oriented polyarylene sulfide film according to 1 or 2, wherein the breaking elongation at 23 ° C in the longitudinal direction and the width direction of the film is 30% or more and less than 80%, and the breaking strength is 230 MPa or more and 500 MPa or less. A film made of a thermoplastic resin containing polyarylene sulfide and another thermoplastic resin A different from polyarylene sulfide, wherein the thermoplastic resin A forms a dispersed phase, and the average dispersed diameter of the dispersed phase is 50 The glass transition temperature of the film is observed at 80 ° C. or higher and lower than 95 ° C., and is not observed at 95 ° C. or higher and 130 ° C. or lower. Axial-oriented polyarylene sulfide film. When the sum of the contents of polyarylene sulfide and thermoplastic resin A is 100 parts by weight, the content of polyarylene sulfide is 70 to 99.5 parts by weight, and the content of thermoplastic resin A is 0.5 to 30 parts by weight. The biaxially oriented polyarylene sulfide film according to claim 4, which is a part. The biaxially oriented polyarylene sulfide film according to claim 4 or 5, wherein the thermoplastic resin A is an amorphous resin and has a glass transition temperature of 150 ° C or higher and a melting point of polyarylene sulfide or lower. The biaxially oriented polyarylene sulfide according to any one of claims 4 to 6, wherein the thermoplastic resin A is at least one polymer selected from the group consisting of polyarylate, polyphenylene ether, polyetherimide, polyethersulfone and polysulfone. the film. Contains 0.05 to 3 parts by weight of a compatibilizer having at least one group selected from the group consisting of an epoxy group, an amino group and an isocyanate group based on 100 parts by weight of the sum of polyarylene sulfide and thermoplastic resin A The biaxially oriented polyarylene sulfide film according to any one of claims 4 to 7, wherein a resin composition obtained by kneading raw materials is melt-formed. The biaxially oriented polyarylene sulfide film according to claim 4, wherein the polyarylene sulfide is polyphenylene sulfide. The biaxially oriented polyarylene sulfide film according to any one of claims 1 to 9, wherein the biaxially oriented polyarylene sulfide film is for a capacitor. It is a manufacturing method of the polyarylene sulfide film in any one of Claims 1-10, Comprising: It stretches in a longitudinal direction and the width direction so that an area magnification may be 11 times or more, and heat setting after extending | stretching differs in temperature 2 This is a manufacturing method that is performed in steps of more than one stage, and the heat setting temperature of the first stage is (preceding temperature + 5 ° C.) to 240 ° C. and the maximum value of the heat setting temperature of the rear stage is (the first stage of heat setting). (Temperature + 20 ° C.) A method for producing a polyarylene sulfide film that is not less than (the melting point of the polyarylene sulfide constituting the film is −5 ° C.) or less. A metallized film obtained by forming a metal layer on at least one surface of the biaxially oriented polyarylene sulfide film according to claim 1. A capacitor formed by winding or laminating the metallized film according to claim 12.