Polyarylene sulfide film
阅读说明：本技术 聚芳撑硫醚膜 (Polyarylene sulfide film ) 是由 松井一直 高桥健太 吉田昌平 福田一友 青山滋 于 2019-03-08 设计创作，主要内容包括：本发明的课题是提供热膨胀系数或热收缩率低、电绝缘性高的聚芳撑硫醚膜。解决手段是一种聚芳撑硫醚膜,其具有以聚芳撑硫醚系树脂(A)作为主要构成成分,并包含与树脂(A)不同的热塑性树脂(B)的层(P1层),热塑性树脂(B)具有选自下述化学式中的结构。(其中,式中的R<Sub>1</Sub>～R<Sub>6</Sub>各自为H、OH、甲氧基、乙氧基、三氟甲基、碳原子数1～13的脂肪族基、碳原子数6～10的芳香族基中的任一者。)<Image he="385" wi="700" file="DDA0002671336730000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The subject of the invention is to provide a polyarylene sulfide film with low thermal expansion coefficient or thermal shrinkage rate and high electrical insulation. The solution is a polyarylene sulfide film having a layer (P1 layer) containing a polyarylene sulfide resin (A) as a main component and a thermoplastic resin (B) different from the resin (A)) The thermoplastic resin (B) has a structure selected from the following chemical formulae. (wherein, R in the formula 1 ～R 6 Each of which is H, OH, methoxy group, ethoxy group, trifluoromethyl group, aliphatic group having 1 to 13 carbon atoms, or aromatic group having 6 to 10 carbon atoms. ))
1. A polyarylene sulfide film having a P1 layer, wherein the P1 layer is a layer which comprises a polyarylene sulfide resin (A) as a main component and a thermoplastic resin (B) different from the resin (A), the thermoplastic resin (B) having a structure selected from the following chemical formulas,
wherein R in the formula1～R6Each of which is H, OH, methoxy group, ethoxy group, trifluoromethyl group, aliphatic group having 1 to 13 carbon atoms, or aromatic group having 6 to 10 carbon atoms.
2. The polyarylene sulfide film according to claim 1, having a thermal expansion coefficient C in ppm/° C, an insulation breakdown voltage R in kV, and a thickness t in μm, and satisfying the following formulae (1) and (2),
C＜80 (1)
R＞0.17×t+1.0 (2)。
3. the polyarylene sulfide film according to claim 1 or 2, wherein the P1 layer is a layer in which the thermoplastic resin (B) is present as a dispersed phase in the polyarylene sulfide resin (A).
4. The polyarylene sulfide film according to any one of claims 1 to 3, wherein Tc-Tg, which is the difference between the lowest glass transition temperature Tg and the cold crystallization temperature Tc measured in the second Run, 2nd Run, in Differential Scanning Calorimetry (DSC) measurement, is greater than 45 ℃.
5. The polyarylene sulfide film according to any one of claims 1 to 4, which has a glass transition temperature of 200 ℃ or higher as measured by DSC.
6. The polyarylene sulfide film according to any one of claims 1 to 5, wherein the thermoplastic resin (B) has a sulfonyl group.
7. The polyarylene sulfide film according to any one of claims 1 to 6, wherein the content WB1 of the thermoplastic resin (B) is 0.1 part by weight or more and less than 50 parts by weight, based on 100 parts by weight of the total of the content WA1 of the polyarylene sulfide resin (A) in the P1 layer and the content WB1 of the thermoplastic resin (B) different from the resin (A).
8. The polyarylene sulfide film according to any one of claims 1 to 7, which has a retention rate of breaking strength in at least 1 direction of 75% or more after standing in an oven at 200 ℃ for 1000 hours.
9. The polyarylene sulfide film according to any one of claims 1 to 8, wherein the peak temperature of the highest tan observed in the dynamic viscoelasticity (DMA) measurement is 200 ℃ or higher.
10. The polyarylene sulfide film according to claim 3, wherein the ratio of the major axis to the minor axis in the dispersion diameter of the thermoplastic resin (B) is 1.05 or more.
11. The polyarylene sulfide film according to any one of claims 1 to 10, which has a thickness of 1093cm measured by FT-IR-1Absorbance of (3 cm) of-1) And 1385cm-1Absorbance of (1385 cm)-1) The orientation degree parameter Op ═ I (1093 cm) calculated by the above ratio-1)/I(1385cm-1) Wherein the orientation degree parameter OpM in the longitudinal direction and the orientation degree parameter OpT in the width direction satisfy the following formula,
(OpM/OpT)＜1.0 (3)。
12. the polyarylene sulfide film according to any one of claims 1 to 11, wherein the average dispersion diameter of the thermoplastic resin (B) is more than 0.5. mu.m.
13. The polyarylene sulfide film according to any one of claims 1 to 12, which has a thermal shrinkage rate of 5.0% or less in a transport direction, which is a longitudinal direction after heat treatment at a temperature of 250 ℃ for 10 minutes.
14. The method for producing a polyarylene sulfide film according to any one of claims 1 to 13, wherein the stretching ratio in the width direction is higher than the stretching ratio in the longitudinal direction.
Technical Field
The present invention relates to a polyarylene sulfide film containing a polyarylene sulfide resin as a main component.
Background
Polyarylene sulfide (hereinafter abbreviated as PPS) films are widely used for capacitor dielectrics, copper-clad laminates, flexible printed boards, electronic parts such as insulating tapes, automobile parts such as motor insulators, and the like because of their excellent properties as engineering plastics, such as excellent heat resistance, electrical insulation, and moist heat resistance. However, in recent years, as electronic devices have been reduced in size and increased in capacity, operating power has increased and heat generation has increased, and therefore PPS films are desired to have higher electrical insulation properties, a low coefficient of thermal expansion, and a low thermal shrinkage.
Disclosure of Invention
Problems to be solved by the invention
The present invention provides a PPS film which can be suitably used for capacitors, insulating tapes, motor insulation, and circuit boards and has both high electrical insulation and a low coefficient of thermal expansion or a low thermal shrinkage.
Means for solving the problems
(1) A polyarylene sulfide film having a P1 layer, wherein the P1 layer is a layer which comprises a polyarylene sulfide resin (A) as a main component and a thermoplastic resin (B) different from the resin (A), and the thermoplastic resin (B) has a structure selected from the following skeletons.
(wherein, R in the formula1～R6Each of which is H, OH, methoxy group, ethoxy group, trifluoromethyl group, aliphatic group having 1 to 13 carbon atoms, or aromatic group having 6 to 10 carbon atoms. )
(2) The polyarylene sulfide film according to
C＜80 (1)
R＞0.17×t+1.0 (2)
(3) The polyarylene sulfide film according to (1) or (2), wherein the P1 layer is a layer in which the thermoplastic resin (B) is present as a dispersed phase in the polyarylene sulfide resin (A),
(4) the polyarylene sulfide film according to any one of (1) to (3), wherein a difference (Tcc-Tg) between a lowest glass transition temperature (Tg) and a cold crystallization temperature (Tcc) measured in a second Run (2nd Run) in a Differential Scanning Calorimetry (DSC) measurement is greater than 45 ℃.
(5) The polyarylene sulfide film according to any one of (1) to (4), which has a glass transition temperature of 200 ℃ or higher as measured by DSC.
(6) The polyarylene sulfide film according to any one of (1) to (5), wherein the thermoplastic resin (B) has a sulfonyl group.
(7) The polyarylene sulfide film according to any one of (1) to (6), wherein the content WB1 of the thermoplastic resin (B) is 0.1 part by weight or more and less than 50 parts by weight, based on 100 parts by weight of the total of the content WA1 of the polyarylene sulfide resin (A) in the P1 layer and the content WB1 of the thermoplastic resin (B) different from the resin (A).
(8) The polyarylene sulfide film according to any one of (1) to (7), which has a retention rate of breaking strength in at least 1 direction of 75% or more after standing in an oven at 200 ℃ for 1000 hours.
(9) The polyarylene sulfide film according to any one of (1) to (8), wherein the peak temperature of the highest tan observed in dynamic viscoelasticity (DMA) measurement is 200 ℃ or higher.
(10) The polyarylene sulfide film according to any one of claims (1) to (9), wherein a ratio of a major axis to a minor axis in a dispersion diameter of the thermoplastic resin (B) is 1.05 or more.
(11) The polyarylene sulfide film according to any one of (1) to (10), which has a thickness of 1093cm measured by FT-IR-1Absorbance (I (1093 cm)-1) And 1385cm-1Absorbance of (1) (1385 cm)-1) Orientation degree parameter (Op ═ I (1093 cm)) calculated from the ratio-1)/I(1385cm-1) In the longitudinal direction (OpM) and the width direction (OpT) satisfy the following expression.
(OpM/OpT)＜1.0 (3)
(12) The polyarylene sulfide film according to any one of (1) to (11), wherein the average dispersion diameter of the thermoplastic resin (B) is more than 0.5. mu.m.
(13) The polyarylene sulfide film according to any one of (1) to (12), which has a thermal shrinkage rate of 5.0% or less in the longitudinal direction (transport direction) after heat treatment at a temperature of 250 ℃ for 10 minutes.
(14) The method for producing a polyarylene sulfide film according to any one of (1) to (13), wherein the stretching magnification in the width direction is higher than the stretching magnification in the longitudinal direction.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, a polyarylene sulfide film having both high electrical insulation and a low coefficient of thermal expansion or a low thermal shrinkage can be provided. In particular, the resin composition can be suitably used for electronic parts such as a capacitor dielectric, a copper-clad laminate, a flexible printed circuit board, and an insulating tape, and automobile parts such as a motor insulator.
Drawings
FIG. 1 is a conceptual diagram of the thermoplastic resin (B) present in the polyarylene sulfide resin (A) as a spherical dispersed phase
FIG. 2 is a conceptual diagram of the thermoplastic resin (B) present in the polyarylene sulfide resin (A) as a spindle-shaped dispersed phase
FIG. 3 is a conceptual diagram of the presence of the thermoplastic resin (B) in the polyarylene sulfide resin (A) as an amorphous dispersed phase
Detailed Description
The polyarylene sulfide film of the present invention needs to have a layer (P1 layer) containing a polyarylene sulfide resin (a) as a main component and a thermoplastic resin (B) different from the resin (a), the thermoplastic resin (B) having a structure selected from the following chemical formulae.
(wherein, R in the formula1～R6H, OH, A respectivelyAny one of an oxy group, an ethoxy group, a trifluoromethyl group, an aliphatic group having 1 to 13 carbon atoms, and an aromatic group having 6 to 10 carbon atoms. )
The polyarylene sulfide resin (a) in the present invention is a homopolymer or a copolymer containing a repeating unit of- (Ar-S) -as a main constituent unit, and preferably 80 mol% or more of the repeating unit. Ar is a group containing an aromatic ring in which a bond is present in the aromatic ring, and examples thereof include divalent repeating units represented by the following formulae (F) to (Q), and among them, a repeating unit represented by the formula (F) is particularly preferable.
(wherein R1 and R2 in the formula are substituents selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms and a halogen group, and R1 and R2 may be the same or different.)
The repeating unit may contain a small amount of a branching unit or a crosslinking unit represented by the following formulae (R) to (U) as long as the repeating unit is a main constituent unit. The copolymerization amount of the branched unit or the crosslinking unit is preferably in the range of 0 to 5 mol%, more preferably 0 to 1 mol%, based on 1 mol of the- (Ar-S) -unit.
The polyarylene sulfide resin (a) used for the film of the present invention may be any of a random copolymer, a block copolymer, and a mixture thereof having the above repeating unit.
In the film of the present invention, the melt viscosity of the polyarylene sulfide resin (a) is not particularly limited, but is preferably in the range of 100 to 2,000Pa · s, and more preferably in the range of 200 to 1,000Pa · s, at a temperature of 310 ℃ and a shear rate of 1,000 (1/sec).
Representative examples of the polyarylene sulfide resin (a) include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers and block copolymers thereof, and mixtures thereof. The polyarylene sulfide resin (a) is particularly preferably polyphenylene sulfide containing a p-phenylene sulfide unit represented by the following formula (V) as a main constituent unit of the polymer, preferably 80 mol% or more, more preferably 85 mol% or more, and further preferably 90 mol% or more. If the content of the p-phenylene sulfide unit is less than 80 mol%, the crystallinity, heat transfer temperature, and the like of the polymer are low, and the heat resistance, dimensional stability, mechanical properties, and the like, which are characteristics of the polyarylene sulfide resin (a), may be impaired.
The method for producing the polyarylene sulfide resin (A) is not particularly limited, and it is preferable to include a step of treating with an aqueous solution containing an alkaline earth metal such as Ca in order to lower the crystallization rate of the polyarylene sulfide, as disclosed in, for example, Japanese patent application laid-open Nos. 3-74433 and 2002-332351. The polyarylene sulfide resin (a) containing a group having an aromatic ring other than a phenylene group can be obtained by using a monomer obtained by replacing the aromatic ring other than the phenylene group with a phenylene group.
The polyarylene sulfide resin (a) used for the film of the present invention can be used after various treatments such as "crosslinking/high molecular weight by heating in air, heat treatment under an inert gas atmosphere such as nitrogen or under reduced pressure, washing with an organic solvent, hot water, an aqueous acid solution, and the like, and activation with a functional group-containing compound such as an acid anhydride, an amine, an isocyanate, and a functional group disulfide compound" are performed as long as the characteristics of the present invention are not impaired.
The present invention is a film containing polyarylene sulfide as a main component. The main constituent component means that the polyarylene sulfide resin (a) accounts for 50 parts by mass or more based on 100 parts by weight of the entire resin composition. The film may be any of an unstretched film, a uniaxially stretched film, and a biaxially stretched film, and is preferably a biaxially stretched film from the viewpoint of long-term heat resistance and productivity. As a method for obtaining a biaxially stretched film as a film, a sequential biaxial stretching method (a stretching method in which stretching in each direction is combined such as a method of stretching in a longitudinal direction and then stretching in a width direction), a simultaneous biaxial stretching method (a method of stretching in both the longitudinal direction and the width direction), or a method in which these are combined can be used.
The thermoplastic resin (B) used for the polyarylene sulfide film of the present invention preferably contains at least 1 structure of the following chemical formula, more preferably contains the chemical formulas (a), (B), (C), and (D), and still more preferably contains the chemical formulas (a) and (D). Particularly, the chemical formula (a) is preferable because it contributes to a reduction in the coefficient of thermal expansion, an improvement in electrical insulation, and an improvement in film formability (particularly, stretchability), and it is presumed that: the thermoplastic resin (B) containing the chemical formula (A) interacts with the PPS resin. In addition, when the thermoplastic resin (B) does not contain a structure represented by the following chemical formula, not only a sufficient thermal expansion coefficient and electrical insulation cannot be obtained, but also peeling may occur at the interface with the thermoplastic resin B when the resin kneaded with the polyarylene sulfide is formed into a film and stretched, which may lead to breakage of the film, and thus is not preferable.
(wherein, R in the formula1～R6Each of which is H, OH, methoxy group, ethoxy group, trifluoromethyl group, aliphatic group having 1 to 13 carbon atoms, or aromatic group having 6 to 10 carbon atoms. )
As the thermoplastic resin (B), various polymers such as polyamide, polyetherimide, polyethersulfone, polyphenylsulfone, polysulfone, polyphenylene ether, polyester, polyarylate, polyamideimide, polycarbonate, and polyether ether ketone, and a blend containing at least one of these polymers can be used. From the viewpoint of heat resistance and electrical insulation, the thermoplastic resin (B) is preferably a resin selected from the group consisting of polyphenylsulfone, polyethersulfone, polyphenylene ether, polysulfone, and polyetherimide, and more preferably polyphenylsulfone or polyethersulfone.
In the present invention, the time for mixing the polyarylene sulfide resin (a) and the thermoplastic resin (B) is not particularly limited, but there is a method comprising: a method in which a mixture of the polyarylene sulfide resin (a) and the thermoplastic resin (B) is subjected to preliminary melt kneading (granulation) and masterbatch is obtained before melt extrusion; a method of mixing and melt-kneading the components in melt extrusion. Among them, a method of performing master batch using a device for applying a shear stress such as a twin-screw extruder is preferable. In this case, the kneading is preferably carried out in the kneading section so that the resin temperature range is from +5 ℃ to 80 ℃ inclusive of the melting point of the polyarylene sulfide resin (a), more preferably from +10 ℃ to 80 ℃ inclusive of the melting point of the polyarylene sulfide resin (a), and still more preferably from +15 ℃ to 70 ℃ inclusive of the melting point of the polyarylene sulfide resin (a). The screw rotation speed is preferably in the range of 100rpm to 500rpm, more preferably 150rpm to 400 rpm. By setting the resin temperature and the screw rotation speed in the preferred ranges, the dispersion diameter of the dispersed phase can be controlled. The ratio (screw axis length/screw axis diameter) of the twin-screw extruder is preferably in the range of 20 to 60, and more preferably in the range of 30 to 50.
The polyarylene sulfide film of the present invention preferably has a thermal expansion coefficient (C) (ppm/. degree. C.), an insulation breakdown voltage (R) (kV), and a thickness (t) (μm) satisfying the following formulae (1) and (2). More preferably, the compounds satisfy the formulae (34) and (45), and still more preferably satisfy the formulae (56) and (67). When the thermal expansion coefficient (C) is 80 or more, film deformation may occur in an off-line processing step accompanying heat treatment or in use in a high-temperature environment, which is not preferable. When the insulation breakdown voltage (R) does not satisfy the relationship of the following formula, sufficient electrical insulation properties as a motor insulating material and an electric/electronic component may not be obtained.
C＜80 (1)
R＞0.17×t+1.0 (2)
C＜78 (34)
R＞0.17×t+1.2 (45)
C＜77 (56)
R＞0.17×t+1.5 (67)
Further, a method of producing a biaxially stretched film containing a thermoplastic resin having any one of the structures described in chemical formula (1) as a method of satisfying the following formulas in terms of thermal expansion coefficient and insulation breakdown voltage. The biaxially stretched film can be determined by whether or not the orientation degree parameter (Q) measured by a molecular orientation meter is 4300 or more. The orientation degree parameter (Q) is more preferably 4500 or more, and still more preferably 4700 or more. In the case of an unstretched film or a uniaxially stretched film, the degree of orientation of molecular chains is insufficient, and the thermal expansion coefficient and the electrical insulation property may not be satisfied. The value of the orientation degree parameter (Q) is not particularly limited to an upper limit, but 5500 or less is a substantial upper limit as a film which can be stably formed without cracking or the like.
In the polyarylene sulfide film of the present invention, the P1 layer is preferably a layer in which the thermoplastic resin (B) is present as a dispersed phase in the polyarylene sulfide resin (a). The dispersed phase herein means an island component of a sea-island structure composed of the polyarylene sulfide resin (a) and the thermoplastic resin (B). The shape of the thermoplastic resin (B) means that the thermoplastic resin (B) is present in the polyarylene sulfide film of the present invention in a circular, elliptical, spindle, amorphous or other state, and the shape can be confirmed by observing the cross section of the film with a Transmission Electron Microscope (TEM), a Scanning Electron Microscope (SEM) or the like.
The polyarylene sulfide films of the invention preferably have a Differential Scanning Calorimetry (DSC) with a difference (Tc-Tg 1) between the lowest glass transition temperature (Tg1) and the cold crystallization temperature (Tc) measured in the second Run (2nd Run) of greater than 45 ℃. More preferably more than 48 deg.C, still more preferably more than 50 deg.C. When the (Tcc-Tg1) is 45 ℃ or lower, crystallization excessively proceeds in the stretching step and the heat treatment step, and cracking or the like may occur, and stable film formation may not be achieved, which is not preferable. The (Tcc-Tg1) exceeding 45 ℃ can be achieved by containing a thermoplastic resin having any structure described in chemical formula (1).
The cold crystallization temperature here is a temperature of an exothermic peak in a differential scanning calorimetry measurement chart of the second Run (2nd Run) obtained by heating a resin at a temperature rise rate of 20 ℃/min from 25 ℃ to 350 ℃ (first Run, 1st Run) in accordance with JIS K-7122(1987), maintaining the resin in this state for 5 minutes at a temperature rise rate of 20 ℃/min, then quenching the resin so as to be 25 ℃ or less, raising the temperature again from 25 ℃ to 350 ℃ (second Run, 2nd Run) at a temperature rise rate of 20 ℃/min, and setting the temperature of the exothermic peak as the cold crystallization temperature.
The polyarylene sulfide film of the present invention preferably has a glass transition temperature (Tg2) of 200 ℃ or higher at the highest in DSC measurement. More preferably 210 ℃ or higher, and still more preferably 220 ℃ or higher. When the Tg2 is less than 200 ℃, the coefficient of thermal expansion of the resulting polyarylene sulfide film may become large, which is not preferable. The upper limit of Tg2 is not particularly limited, but if it exceeds 340 ℃ which is the extrusion temperature of the polyarylene sulfide resin (a), the melt viscosity may become too high to melt-form a film, and therefore the upper limit of Tg2 is preferably substantially 340 ℃ or less.
The thermoplastic resin (B) contained in the polyarylene sulfide film of the present invention preferably has a sulfonyl group. When the sulfonyl group is not contained, heat resistance and mechanical properties may be lowered, which is not preferable.
In the polyarylene sulfide film of the present invention, it is preferable that the content WB1 of the thermoplastic resin (B) is 0.1 part by weight or more and less than 50 parts by weight, when the total of the content WA1 of the polyarylene sulfide resin (a) in the P1 layer and the content WB1 of the thermoplastic resin (B) different from the resin (a) is 100 parts by weight. The content WB1 of the thermoplastic resin (B) is more preferably 0.1 part by weight or more and less than 30 parts by weight, and the content WB1 of the thermoplastic resin (B) is more preferably 0.1 part by weight or more and less than 15 parts by weight. When the content of the thermoplastic resin (B) is 50 parts by mass or more, the film may be broken frequently during stretching and the film may not be stably formed, which is not preferable. Further, when the content of the thermoplastic resin (B) is less than 0.1 part by weight, an increase in the thermal expansion coefficient and a decrease in the dielectric breakdown voltage may be caused, which is not preferable.
In the polyarylene sulfide film of the present invention, a single layer may be used, such as a layer (P1 layer) containing the polyarylene sulfide resin (a) as a main component and a thermoplastic resin (B) different from the resin (a), but a layer made of the resin (a) or a layer made of the resin (B) may be provided as the P2 layer on at least one surface of the P1 layer. Further, a P2 layer may be formed by laminating a layer having a smaller proportion of the thermoplastic resin (B) than the P1 layer, when the resin component of the P2 layer is 1000. Further, not only a 3-layer structure such as a P2 layer/P1 layer/P2 layer or a P1 layer/P2 layer/P1 layer, but also a structure in which 5 or more layers of a P1 layer and a P2 layer are alternately stacked may be used. The lamination structure is preferable because it contributes to improvement of mechanical properties and film formability.
The polyarylene sulfide film of the present invention preferably has a Young's modulus of 2.0GPa or more. More preferably 2.5GPa or more, and still more preferably 3.0GPa or more. If the Young's modulus is less than 2.0GPa, not only the hardness of the film is reduced and the workability is deteriorated, but also the film may be deformed during the processing step, which is not preferable.
The polyarylene sulfide film of the present invention preferably has an elongation at break of 10% or more. More preferably 20% or more, still more preferably 30% or more, still more preferably 80% or more, and most preferably 100% or more. If the elongation at break is less than 10%, the film is not only brittle and the handling properties are reduced, but also the film is likely to break during the processing step, which is not preferable. Here, considering the conveying step during processing, it is preferable that the elongation at break in the longitudinal direction is higher than that in the width direction, and this may be achieved by increasing the stretch ratio in the width direction as compared with the stretch ratio in the longitudinal direction. In addition, the elongation at break may be increased by performing a stretching process at a low stretching ratio, and the elongation at break may be further increased by subjecting the film to an off-line heat treatment (annealing treatment) in the biaxial stretching process.
The polyarylene sulfide film of the present invention preferably has a breaking strength retention rate of 75% or more after heating for 1000 hours in an oven at 200 ℃. More preferably 80% or more, and still more preferably 85% or more. The breaking strength retention ratio is a value represented by the following formula, and when the breaking strength retention ratio is less than 75%, the heat resistance as a film is low, and the film may break when used for a long time in a high-temperature environment, which is not preferable. In order to maintain the breaking strength retention ratio within the above range, the thermoplastic resin (B) can be obtained by including a thermoplastic resin (B) having any one of the structures described in chemical formula (1).
Breaking strength retention (%) — (breaking strength after heating)/(breaking strength before heating) × 100
The polyarylene sulfide film in the present invention preferably has a peak temperature of tan of 200 ℃ or higher, which is observed when the film is measured at a frequency of 1Hz in dynamic viscoelasticity (DMA) measurement. More preferably 210 ℃ or higher, and still more preferably 215 ℃ or higher. When the peak temperature of tan is lower than 200 ℃, the coefficient of thermal expansion of the polyarylene sulfide film to be obtained may become large, which is not preferable. The peak temperature of tan is not particularly limited, but if it exceeds 340 ℃ which is the extrusion temperature of the polyarylene sulfide resin (a), the melt viscosity may be too high to melt film-form, and therefore the upper limit value of tan is preferably substantially 340 ℃ or less.
The polyarylene sulfide film in the present invention preferably has a ratio of the major axis to the minor axis of 1.05 or more in the dispersion diameter of the thermoplastic resin (B) present as a dispersed phase in the polyarylene sulfide resin (a). More preferably 2.00 or more, still more preferably 3.50 or more, and most preferably 4.00 or more. When the ratio of the major axis to the minor axis is less than 1.05, peeling may occur at the interface between the polyarylene sulfide resin (a) and the thermoplastic resin (B) during film stretching, resulting in occurrence of cracking or the like, or reduction in elongation at break of the resulting stretched film, which is not preferable. It is considered that the larger the ratio of the major axis to the minor axis, the stronger the interaction between the polyarylene sulfide resin (a) and the thermoplastic resin (B) and the more contributes to the improvement of the electrical characteristics, thermal characteristics and dimensional stability, and therefore, this is preferable. Therefore, although the upper limit is not particularly set, it is assumed from the stretching magnification that the ratio of the major axis to the minor axis is estimated to be about 20.00 and becomes a substantial upper limit.
The polyarylene sulfide film in the present invention is preferably 1093cm as measured by FT-IR-1Absorbance (I (1093 cm)-1) And 1385cm-1Absorbance of (1) (1385 cm)-1) Orientation degree parameter (Op ═ I (1093 cm)) calculated from the ratio-1)/I(1385cm-1) In the longitudinal direction (OpM) and the width direction (OpT) satisfy the following expression. More preferably, the following formula (8) is satisfied, still more preferably, the following formula (9) is satisfied, still more preferably, the following formula (10) is satisfied, and still more preferably, the following formula (11) is satisfied. When the orientation parameter is 1.0 or more, the thermal shrinkage in the longitudinal direction becomes large, and the film is undesirably wrinkled in a reflow process or the like when used as a circuit board. The oriented film can be obtained by including the thermoplastic resin (B) having any structure described in chemical formula (1) in the polyarylene sulfide film of the present invention, biaxially stretching the film at a stretching ratio in the width direction higher than that in the longitudinal direction, and heat-treating the biaxially oriented film at a temperature of 200 ℃ or higher to thermally crystallize the film so that the orientation parameter satisfies the following formula (3). Here, when OpM/OpT is greater than 1.00, it means that the orientation in the longitudinal direction (conveyance direction, MD direction) is stronger than the orientation in the width direction (TD direction), and when OpM/OpT is less than 1.00, it means that the orientation in the width direction (TD direction) is stronger than the orientation in the longitudinal direction (MD direction).
(OpM/OpT)＜1.00 (3)
(OpM/OpT)＜0.95 (8)
(OpM/OpT)＜0.92 (9)
(OpM/OpT)＜0.90 (10)
(OpM/OpT)＜0.85 (11)
The average dispersion diameter of the thermoplastic resin (B) of the polyarylene sulfide film in the present invention is preferably more than 0.5. mu.m. The dispersion diameter is more preferably 0.8 μm or more, and still more preferably 1.0 μm or more. The average dispersion diameter is a diameter that is determined by confirming a dispersion form of a cross section of the film by Transmission Electron Microscope (TEM) observation, Scanning Electron Microscope (SEM) observation, or the like, and if the cross section is a perfect circle, the diameter of the circle may be determined as a dispersion diameter, and if the cross section is a deformed dispersion form such as an ellipse or a spindle, the diameter of a circumscribed circle may be determined as a dispersion diameter. The average dispersion diameter is larger than 0.5. mu.m, and this is achieved by preparing a base particle composed only of the polyarylene sulfide resin (A) and the thermoplastic resin (B) and using the same for film formation. Further, a technique of reducing the dispersion diameter by adding a compatibilizer having a reactive group terminal such as an epoxy group or an isocyanate group is known, but when the compatibilizer is contained, long-term durability at high temperature may be lowered, which is not preferable.
The polyarylene sulfide film in the present invention preferably has a thermal shrinkage of 5.0% or less in the longitudinal direction (the transport direction, MD direction) after heat treatment at a temperature of 250 ℃ for 10 minutes. More preferably 3.5% or less, still more preferably 2.5% or less, and still more preferably 1.0% or less. When the heat shrinkage rate is more than 5.0%, the film may be wrinkled or curled in the reflow step when used as a circuit board, which is not preferable. In order to achieve a heat shrinkage of 5% or less, the heat shrinkage can be achieved by including a thermoplastic resin (B) having any structure described in chemical formula (1) in a polyarylene sulfide film, biaxially stretching the film at a stretch ratio in the width direction that is higher than the stretch ratio in the longitudinal direction, and heat-treating the biaxially oriented film at a temperature of 200 ℃ or higher to thermally crystallize the film. Further, the heat shrinkage rate may be further reduced by heat-treating (annealing) the obtained biaxially oriented polyarylene sulfide film in an oven capable of raising the temperature to 220 ℃ or higher and conveying the film at a tension of 30N or lower. If the temperature is lower than 220 ℃, sufficient heat treatment is not performed, and the heat shrinkage at a temperature of 250 ℃ may not be sufficiently reduced, which is not preferable. When the transport tension is greater than 30N, excessive tension may be applied to the film during the heat treatment, which may cause wrinkles in the film surface, which is not preferable.
In the polyarylene sulfide film of the present invention, other components such as a heat-resistant stabilizer (hindered phenol-based, hydroquinone-based, phosphite-based, and substituted products thereof), a weather-resistant agent (resorcinol-based, salicylate-based, benzotriazole-based, benzophenone-based, hindered amine-based, etc.), a release agent and a lubricant (montanic acid and metal salts thereof, esters thereof, half esters thereof, stearyl alcohol, stearamide, various bisamides, diurea, polyethylene wax, etc.), a pigment (cadmium sulfide, phthalocyanine, carbon black for coloring, etc.), a dye (nigrosine), etc.), a plasticizer (octyl paraben, N-butylbenzenesulfonamide, etc.), an antistatic agent (alkylsulfate-based anionic antistatic agent, quaternary ammonium salt-based cationic antistatic agent, nonionic antistatic agent such as polyoxyethylene sorbitan monostearate, etc.) may be added within a range not to impair the effects of the present invention, Betaine amphoteric antistatic agents, etc.), flame retardants (for example, hydroxides such as red phosphorus, phosphate esters, melamine cyanurate, magnesium hydroxide, aluminum hydroxide, etc., ammonium polyphosphate, brominated polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated epoxy resins, or a combination of these bromine flame retardants and antimony trioxide), other polymers (for example, polyamide imide, polyarylate, polyether sulfone, polyether imide, polysulfone, polyphenylene oxide, etc., amorphous resins, elastomers, etc.).