JP2009292902A - Biaxially oriented polyarylene sulfide film and adhesive material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive material which has heat resistance, uses, as a base film, a biaxially oriented polyarylene sulfide film having excellent heat resistance, dimensional stability, low moisture absorption, and chemical resistance, and excels in the adhesion between the base film and an adhesive layer provided on the film surface. <P>SOLUTION: As the base film which is provided with the adhesive layer on at least one film surface and is used in the adhesive material, the biaxially oriented polyarylene sulfide film is used having a surface free energy value of at least one surface of the film surfaces of ≥50 mN/m. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention has heat resistance such as an electricity storage device (for example, an electrolytic capacitor, an electric double capacitor, a lithium ion battery), an element fixing tape, a carrier tape for TAB mounted with a semiconductor chip, an adhesive tape for fixing a lead frame, and a flexible printed circuit board. The present invention relates to a biaxially oriented polyarylene sulfide film that can be suitably used for the adhesive material, and an adhesive material provided with an adhesive layer on the biaxially oriented polyarylene sulfide film.

  Biaxially oriented polyarylene sulfide film has features such as excellent heat resistance, flame retardancy, rigidity, chemical resistance, electrical insulation and low moisture absorption, especially electric / electronic equipment, mechanical parts and automobiles. Specifically, it is suitably used as a process film such as an electrical insulating material, a molding material, a circuit board material, a circuit / optical member, a protective film, and a heat-resistant adhesive material.

  In recent years, taking advantage of its heat resistance and low hygroscopicity, electricity storage devices (for example, electrolytic capacitors, electric double capacitors, lithium ion batteries, etc.) element fixing tapes, TAB carrier tapes mounted with semiconductor chips and lead frame fixing adhesive tapes, Application of a polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) film to a heat-resistant adhesive material such as a flexible printed circuit board is in progress. However, while PPS film is excellent in heat resistance and chemical resistance, its surface is inactive, so it has poor adhesion to other substances. When used as a heat resistant adhesive tape, PPS film and adhesive layer There has been a problem such as peeling of the PPS film, and improvement in the adhesion of the PPS film surface has been strongly desired. As means for improving the adhesiveness in order to solve the adhesive improvement on the surface of the PPS film, it is disclosed to perform a corona discharge treatment on the surface of the PPS film (Patent Documents 1 and 2). Although these films described in Patent Documents 1 and 2 have improved adhesiveness as compared to untreated films, they are not disclosed that they can be used as adhesive materials, and further, the tensile elongation at break is insufficient and the flexibility is not disclosed. However, there are problems such as cracking and cracking due to insufficient toughness in use conditions and processing steps that require the use of adhesive materials, and there is room for improvement in use as an adhesive material.

On the other hand, as a method for improving the tensile elongation at break of a PPS film, a resin composition or film in which another thermoplastic resin is mixed in a polyarylene sulfide resin has been proposed. For example, PPS is used as polyarylene sulfide and nylon 11 and nylon 12 are dispersed in the PPS with an average dispersion diameter of 1 μm or less (see Patent Document 3), and a composition comprising PPS, polyamide and epoxy resin (patent) Reference 4), compositions composed of PPS and polyamide (see Patent Documents 5 and 6), films composed of PPS and polyetherimide (refer to Patent Document 7), films composed of PPS and polysulfone (refer to Patent Document 8), and the like. Although it is disclosed, the film-forming stability is not sufficient, and blending via a compatibilizing agent to control the dispersion state of PPS and other thermoplastic resins suppresses the variation in physical properties in the film surface. And the film (refer patent document 9) which improves the elongation of a PPS film and improves toughness is disclosed. However, since there is a concern about the heat resistance of the alloy component and the compatibilizing agent, it cannot be said to be sufficient for use in adhesive materials that require heat resistance.
JP-A-57-187327 Japanese Patent Laid-Open No. 2002-12198 JP-A-3-81367 JP 59-155462 A JP-A 63-189458 JP 2001-302918 A Japanese Patent Laid-Open No. 4-146935 JP-A-62-112161 JP 2006-321977 A

  An object of the present invention is to solve the above problems by making use of the excellent heat resistance, dimensional stability, low hygroscopicity, and chemical resistance of polyarylene sulfide films, while making electrical and electronic equipment, mechanical parts, and automobile parts. In detail, electrical insulating materials, molding materials, circuit board materials, process films and protective films such as circuits and optical members, among others, power storage devices (for example, electrolytic capacitors, electric double capacitors, lithium ion batteries, etc.), element stop tapes, and semiconductors Biaxially oriented polymer that can be suitably used as a base film for adhesive materials, particularly suitable for applications requiring heat resistance, such as carrier tapes for TAB mounting chips, adhesive tapes for fixing lead frames, and flexible printed circuit boards. An arylene sulfide film is provided.

  The present invention for achieving the above object is a base film of an adhesive material in which an adhesive layer is provided on at least one side of a film, and the surface free energy value of at least one side of the surface is 50 mN / m or more A biaxially oriented polyarylene sulfide film as described above is used as a skeleton.

  According to the present invention, as described below, a biaxially oriented polyarylene sulfide film having excellent heat resistance, dimensional stability, low hygroscopicity, and chemical resistance is used as a base film, and adhesion to an adhesive layer In addition, it is possible to obtain a heat-resistant adhesive material having excellent processability. The film of the present invention can be used for an electricity storage device (for example, an electrolytic capacitor, an electric double capacitor, a lithium ion battery, etc.), an element fixing tape, a TAB carrier tape mounted with a semiconductor chip, an adhesive tape for fixing a lead frame, a flexible printed circuit board, etc. It can be suitably used as a base film for an adhesive material that requires heat resistance.

  Hereinafter, the biaxially oriented polyarylene sulfide film of the present invention and an adhesive material using the same will be described.

  The polyarylene sulfide used 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 the group consisting of hydrogen, alkyl groups, alkoxy groups and halogen groups, and R1 and R2 may be the same or different.)
As the repeating unit of 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, and random thereof. Examples thereof include copolymers, block copolymers, and mixtures thereof. A particularly preferred polyarylene sulfide is preferably polyphenylene sulfide (PPS) from the viewpoint of film properties and economy. In the present invention, as the repeating unit of the polyarylene sulfide, a paraarylene sulfide unit represented by the following structural unit is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 95 mol% or more. Is preferred. The most preferred embodiment is a polyarylene sulfide which is substantially a homopolymer. If it 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 polyarylene sulfide, may be impaired. Moreover, there exists a possibility that the flatness of a film may worsen.

  The melt viscosity of the polyarylene sulfide resin of the present invention is not particularly limited as long as it can be formed into a film, but at a temperature of 315 ° C. and a shear rate of 1,000 (1 / sec), 100 to 20, It is preferably in the range of 000 poise, more preferably in the range of 1000 to 10,000 poise.

  In the present invention, polyphenylene sulfide can be preferably used as the polyarylene sulfide, but the PPS can be obtained by various methods, for example, a method for obtaining a polymer having a relatively small molecular weight described in JP-B No. 45-3368, or And a method for obtaining a polymer having a relatively large molecular weight described in JP-B-52-12240 and JP-A-61-7332. Also, PPS resin can be crosslinked / high molecular weight by heating in air, heat treatment in an inert gas atmosphere such as nitrogen or reduced pressure, washing with organic solvent, hot water and acid aqueous solution, acid anhydride, amine In addition, it can be used after various treatments such as activation with a functional group-containing compound such as isocyanate and a functional group disulfide compound.

  The polyarylene sulfide used in the present invention includes thermoplastic resins other than polyarylene sulfide, such as polyamide, polyetherimide, polyethersulfone, polysulfone, polyphenylene ether, polyester, and polyarylate, as long as the object of the present invention is not impaired. One or more of various polymers such as polyamide imide, polycarbonate, polyolefin, and polyether ether ketone can be added. The melting point or glass transition temperature of the thermoplastic resin is preferably not higher than the melting point of polyarylene sulfide. Examples of such thermoplastic resins include polyarylate, polyetherimide, polyethersulfone, polysulfone, polyphenylene ether, polyamideimide, polycarbonate, and polycycloolefin.

  In addition, for the purpose of improving slipperiness, wear resistance, scratch resistance, etc., the polyarylene sulfide used in the present invention includes organic or inorganic particles such as clay, mica, titanium oxide, calcium carbonate, kaolin, talc, So-called precipitation by wet or dry silica, colloidal silica, inorganic particles such as calcium phosphate, barium sulfate, alumina and zirconia, organic particles containing acrylic acid, styrene, etc., catalyst added during polymerization reaction of polyarylene sulfide, etc. Internal particles. Although there is no restriction | limiting in particular in content, 20 wt% or less of a film weight is preferable and it is more preferable to set it as 10 wt% or less. Further, organic lubricants such as heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, flame retardants, pigments, dyes, fatty acid esters and waxes may be added within the range not impairing the object of the present invention. Good.

  The biaxially oriented polyarylene sulfide film of the present invention needs to have a surface free energy value of 50 mN / m or more on at least one surface thereof. More preferably, it is 60 mN / m or more, More preferably, it is 65 mN / m or more. When the surface free energy value is less than 50 mN / m, the adhesion between the film and the adhesive layer becomes insufficient, and it is used as an adhesive material in which the adhesive layer is provided on the biaxially oriented polyarylene film of the present invention. In such a case, there arises a problem that the film and the adhesive layer are peeled off.

  Here, the value of the surface free energy uses water, ethylene glycol, formamide, and methylene iodide as four types of liquids whose surface free energy and its components (dispersing force, polar force, hydrogen bonding force) are known. Using a contact angle meter CA-D (manufactured by Kyowa Interface Science Co., Ltd.), the contact angle (θ) of each liquid on the film is obtained. From the known values for the binding force (according to Panzer's method IV (see Japan Adhesion Association Vol. 15, No. 3, page 96)), the following formula derived from the extended Fowkes equation and Young's equation is used. The values of dispersion force, polarity force, and hydrogen bonding force on the film surface are obtained.

(Γ _S ^d · γ _L ^d ) ^1/2 + (γ _S ^p · γ _L ^p ) ^1/2 + (γ _S ^h · γ _L ^h ) ^1/2 = (1 + cos θ) / 2
Here, γ _L ^d , γ _L ^p , and γ _L ^h represent the dispersion force, polar force, and hydrogen bonding force (known) of the measurement liquid, respectively, θ represents the contact angle of the measurement liquid on the measurement surface, Further, γ _S ^d , γ _S ^p , and γ _S ^h represent the values of the components of the dispersion force, polar force, and hydrogen bonding force on the film surface, respectively. Film is obtained by measuring θ for at least three kinds of measurement liquids whose dispersion force, polar force, and hydrogen bonding force are known, substituting them into the above equations, and solving the equations obtained for each measurement solution as simultaneous equations. Determine the surface dispersion, polarity, and hydrogen bonding. In the present invention, the surface free energy is defined as the sum of the polar force component and the hydrogen bond force component determined for the film surface.

  In the biaxially oriented polyarylene sulfide film of the present invention, the contact angle θ of methylene iodide on the surface having a surface free energy value of 50 mN / m or more is preferably 20 ° or less. More preferably, it is 15 ° or less, and further preferably 10 ° or less. When the contact angle θ of methylene iodide is 20 ° or less, the adhesion between the film and the adhesive layer provided on the film surface is very good. In the biaxially oriented polyarylene sulfide film of the present invention, as a simple means for setting the contact angle θ of methylene iodide on the surface to 20 ° or less, the oxygen concentration is 10% by volume or less, more preferably 5 as described later. For example, a corona discharge treatment under a nitrogen atmosphere of not more than volume% can be mentioned.

  In the biaxially oriented polyarylene sulfide film of the present invention, the contact angle θ of ethylene glycol on the surface having a surface free energy value of 50 mN / m or more is preferably 15 ° or less. More preferably, it is 13 ° or less, and further preferably 10 ° or less. When the contact angle θ of ethylene glycol on at least one surface of the film is 15 ° or less, the adhesion between the film and the adhesive layer provided on the film surface is very good. In the biaxially oriented polyarylene sulfide film film of the present invention, as a simple means for setting the contact angle θ of ethylene glycol on the surface to 15 ° or less, the oxygen concentration is 10% by volume or less, more preferably 5 as described later. For example, a corona discharge treatment in a mixed gas atmosphere of carbon dioxide gas and nitrogen gas having a volume% or less may be performed.

  The biaxially oriented polyarylene sulfide film of the present invention is suitably used as an adhesive material in which an adhesive layer is provided on at least one surface of the film. As the types of adhesives that can be used, for example, epoxy resins, phenol resins, acrylonitrile resins, butadiene resins, polyimide resins, polyamide resins, polyamideimide resins, and silicone resins are preferable. The adhesive material using the biaxially oriented polyarylene sulfide film of the present invention includes an electricity storage device (for example, an electrolytic capacitor, an electric double capacitor, a lithium ion battery, etc.), an element fixing tape, a TAB carrier tape and a lead frame on which a semiconductor chip is mounted. From the viewpoint of being suitably used for applications requiring heat resistance, such as fixing adhesive tapes and flexible printed circuit boards, an adhesive layer of a silicone resin having excellent heat resistance is particularly preferable. Here, the thickness of the adhesive layer is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 20 μm or less, and further preferably 3 μm or more and 15 μm or less. When the thickness of the adhesive layer is 1 μm or less, the adhesiveness of the heat-resistant adhesive material may be insufficient. On the other hand, when the thickness of the adhesive layer exceeds 20 μm, the thickness of the entire heat-resistant adhesive material becomes large, and handling properties may deteriorate in processing steps such as bonding.

  Since the biaxially oriented polyarylene sulfide film of the present invention can have toughness in use conditions and processing steps that require flexibility, the tensile breaking elongation in at least one direction in the film plane is 100% or more. Preferably there is. More preferably, it is 110% or more, More preferably, it is 120% or more. Further, it is desirable that the preferable range is satisfied also in the direction orthogonal to the direction, and it is more preferable that the preferable range is satisfied in any direction in the film plane. If the tensile breaking elongation in the direction in any film plane is less than 100%, problems such as cracking and cracking are likely to occur due to insufficient toughness in use situations requiring flexibility. The upper limit of the tensile elongation at break is not particularly limited, but setting it to 200% or more may cause the draw ratio during film formation to be extremely low, and the flatness of the film deteriorates in the drawing process. There is a risk.

As a method for setting such a preferable tensile breaking elongation range, for example, the film forming area ratio is stretched in the longitudinal direction and the width direction so as to be 13 times or less, and the heat setting after stretching is performed in two or more steps having different temperatures. The heat setting temperature of the first stage is 160 ° C. or more and 220 ° C. or less, and the heat setting temperature of the latter stage is 240 ° C. or more and 280 ° C. or less. After heat setting, it is 8% or less in the width direction, preferably 2-5 % Relaxation treatment is appropriately adjusted below the melting point of polyarylene sulfide.

  Further, the biaxially oriented polyarylene sulfide film of the present invention preferably has a tensile breaking stress in either the longitudinal direction or the width direction of 300 MPa or less, more preferably 280 MPa or less, still more preferably 250 MPa or less. If the tensile breaking stress exceeds 300 MPa, the film may be damaged during processing or use, or it may not be practically usable. The other tensile rupture stress in the longitudinal direction or the width direction of the film is not particularly limited, but is preferably 350 MPa or less, more preferably 300 MPa or less.

  In the present invention, from the viewpoint of improving workability, it is a preferred embodiment that both the average tensile breaking stress in the longitudinal direction and the width direction of the film is 300 MPa or less, more preferably 280 MPa or less, and still more preferably 250 MPa or less.

  In addition, the biaxially oriented polyarylene sulfide film of the present invention has both heat shrinkage ratios in the longitudinal direction and the width direction of the film at 260 ° C. for 10 minutes of heating (hereinafter described as 260 ° C. for 10 minutes). It is preferably 0% or more and 10% or less, more preferably 0% or more and 8% or less. When the heat shrinkage rate at 260 ° C. for 10 minutes is less than 0%, the film cannot be sufficiently shrunk in the relaxation treatment after film-forming heat setting, and the film loosens in the tenter oven and breaks at the temperature partition plate of the tenter oven. The flatness of the film may deteriorate. When the film has a thermal shrinkage rate of more than 10%, when used in a heated atmosphere, the film may undergo large thermal shrinkage and may not be practically usable.

  In the present invention, from the viewpoint of film flatness, it is preferable that the thermal shrinkage rates in the longitudinal direction and the width direction of the film at 250 ° C. for 10 minutes are both 0% or more and 10% or less. More preferably, it is 0% or more and 8% or less.

  In the present invention, in order to improve the tensile breaking elongation of the biaxially oriented polyarylene sulfide film, it is preferable to reduce the film-forming area ratio to 13 times or less, but the film-forming stretch ratio remains in the conventional film-forming conditions. If it is lowered only, the flatness of the film may be deteriorated. In the present invention, it is possible to improve the tensile elongation at break while maintaining the flatness by using two or more stages of heat setting. In the flatness of the film, the heat shrinkage rate in the width direction of the film at 260 ° C. for 10 minutes is preferably 0% or more, more preferably the heat shrinkage rate in the film width direction at 250 ° C. for 10 minutes is 0. When it is at least%, good flatness is obtained.

  In the present invention, the minute endothermic peak temperature just below the melting point of the biaxially oriented polyarylene sulfide film is preferably 250 ° C. or higher, more preferably 255 ° C. or higher, and further preferably 260 ° C. or higher. When the minute endothermic peak temperature just below the melting point is less than 250 ° C., the heat resistance characteristic of polyarylene sulfide may be reduced. For example, when used at 200 ° C. to 240 ° C., the heat shrinkage of the film in the heating step Due to this, the flatness may be deteriorated.

  The minute endothermic peak temperature just below the melting point is a minute endothermic peak that appears before crystal melting by suggestive scanning calorimetry (DSC) measurement, and is observed at a temperature corresponding to the heat treatment temperature of the film. This is because an incomplete part melts.

  In order to make the minute endothermic peak just below the melting point within the scope of the present invention, it can be achieved by performing a heat setting temperature of 250 ° C. or more and a heat setting time of 5 seconds or more by tenter heat setting in film formation.

  In the present invention, from the viewpoint of improving the flatness, it is preferable that the thermal shrinkage rates in the longitudinal direction and the width direction of the film at 250 ° C. for 10 minutes are both 0% or more and 10% or less.

  The biaxially oriented polyarylene sulfide film of the present invention preferably has a center line average roughness (Ra) of 10 nm to 200 nm and a maximum height (Rmax) of 1000 nm or less. When Ra is less than 10 nm, sufficient slipperiness cannot be imparted to the film, and curling is generated during film formation or processing becomes 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 the adhesive layer is provided on the surface of the film, the adhesiveness between the film and the adhesive layer becomes insufficient. It may be difficult to obtain the effects of the invention. The lower limit of Rmax is not particularly limited, but is suitably set to 300 nm or less from the viewpoint of imparting appropriate slipperiness.

  The orientation of the biaxially oriented polyarylene sulfide film of the present invention can be measured by laser Raman spectroscopy. “Oriented” means that the orientation parameter obtained by laser Raman spectroscopy is in the range of 2.0 to 8.0. More preferably, it is 2.5-6.0. When the orientation parameter exceeds 8.0, the molecular chain orientation may proceed excessively or the crystallization may proceed excessively, resulting in damage during processing or use of the film, or in practical use. On the other hand, when the orientation parameter is less than 2.0, the molecular chain orientation may be insufficient or the progress of crystallization may be insufficient, which may reduce the heat resistance of the structure.

  For the measurement by the laser Raman spectroscopy, a conventional method can be used. For example, a laser Raman apparatus (PDP320 (manufactured by Photon Design)) is used, the microprobe objective lens is 100 times, and the objective lens is in the near infrared region (1064). ˜1300 nm), NA 0.95, and chromatic aberration correction can be used. Cross slit 1 mm, spot diameter 1 μm, light source Nd-YAG (wavelength 1064 nm, output: 1 W), diffraction grating Spectrograph 300 g / mm, slit: 100 μm, detector InGaAs (Roper Scientific 512) is preferably used.

The film used for the measurement was sampled and embedded in an epoxy resin, and a film cross section was prepared 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 calculated by measuring 5 samples for each of the longitudinal direction and the width direction with the central point of each sample as the measurement point. . The measurement is performed through a polarizer placed in a polarization direction parallel to the polarization direction of incident light, the sample is rotated, and a polarization direction perpendicular to the polarization direction parallel to the film surface is displayed with respect to the polarization direction of the laser light. A spectrum was obtained. The orientation parameter was calculated by the following formula.
(Orientation parameter) = (I1575 / I740) (Parallel) / (I1575 / I740) (Vertical)
I1575 / I740 (parallel): in the Raman spectrum measured in a parallel polarization direction to the film surface, obtained by dividing the Raman band near 1575 cm ^-1 in the Raman band intensity near 740 cm ^-1.
I1575 / I740 (vertical): in the Raman spectrum measured with polarization direction perpendicular to the film surface, obtained by dividing the Raman band near 1575 cm ^-1 in the Raman band intensity near 740 cm ^-1.

  The thickness of the biaxially oriented polyarylene sulfide film of the present invention varies depending on the use, etc., but is preferably 1 μm or more and 500 μm, more preferably 6 μm or more and 500 μm or less. Preferably it is the range of 10-300 micrometers, More preferably, it is the range of 20-200 micrometers.

  Moreover, it is preferable that melting | fusing point of the biaxially oriented polyarylene sulfide film of this invention is 250 degreeC or more, More preferably, it is 260 degreeC or more, More preferably, it is 280 degreeC or more.

  Further, 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 within the range not impairing the object of the present invention. Good.

  Next, the method for producing the biaxially oriented polyarylene sulfide film of the present invention will be described by taking the production of a biaxially oriented polyphenylene sulfide film using PPS as the polyarylene sulfide as an example. Of course, it is not limited.

  The PPS resin can be obtained, for example, by reacting sodium sulfide and p-dichlorobenzene 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 can be added as a polymerization degree adjusting agent, and the reaction is performed at 230 to 280 ° C. After the polymerization, the polymer is cooled, and the polymer is filtered as a water slurry through a filter to obtain a granular polymer. This is stirred in an aqueous solution such as acetate at 30 to 100 ° C. for 10 to 60 minutes, washed several times with ion exchange water at 30 to 80 ° C. and dried to obtain a PPS powder. The 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 dried under a reduced pressure of 5 torr or less. Since the polymer thus obtained is a substantially linear PPS polymer, stable film formation and stretching are possible. 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 Further, a heat stabilizer and an antioxidant may be added.

  The PPS resin can be crosslinked / high molecular weight by heating. For example, until a desired melt viscosity is obtained at a predetermined temperature in a heating container in an oxidizing gas atmosphere such as air or oxygen or in a mixed gas atmosphere of the oxidizing gas and an inert gas such as nitrogen or argon. The method of heating can be mentioned. The treatment temperature is usually selected from 170 to 280 ° C, more preferably from 200 to 270 ° C, and the treatment time is usually selected from 0.5 to 100 hours, more preferably from 2 to 50 hours. By controlling both of these, it is possible to obtain a viscosity advantageous for film formation. The processing apparatus may be a normal hot air dryer or a heating apparatus with a rotary or stirring blade. From the viewpoint of efficiency and quality uniformity, it is preferable to use a processing apparatus with a rotary or stirring blade.

  As the PPS resin used in the present invention, it is preferable to use a deionized one. Specific examples of the deionization process include an acid aqueous solution cleaning process, a hot water cleaning process, and an organic solvent cleaning process, and two or more methods may be used in combination.

  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 / sulfone solvents such as dimethyl sulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, ether solvents such as dimethyl ether, dipropyl ether, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene chloride, dichloroethane, Halogen solvents such as tetrachloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, Phenol, cresol, alcohol phenol based solvents such as polyethylene glycol, 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 And 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. However, a PPS resin subjected to an acid aqueous solution cleaning treatment (hereinafter sometimes referred to as an acid-terminated PPS resin) has a high melt crystallization temperature, and crystallization may proceed after melt extrusion. If it increases, crystallization proceeds on the cast drum after melt extrusion, so that film breakage may occur in the subsequent stretching step, and film formation stability may deteriorate.

  On the other hand, it is considered that a PPS resin that has been washed with an aqueous calcium salt solution such as an aqueous calcium acetate solution replaces a part of the terminal component with a Ca terminal component (hereinafter sometimes referred to as a Ca terminal PPS resin). Ca-terminated PPS resins and PPS resins that are not acid-washed (sometimes referred to as Na-terminated PPS resins) have a lower melt crystallization temperature and a lower crystallization rate than acid-terminated PPS resins. When forming a film, it may be preferable to use it as a raw material in order to suppress crystallization of the polymer after melt extrusion. In the present invention, a PPS resin that has been washed with an aqueous calcium acetate solution is preferably used from the viewpoint of film formation stability.

  As a method for reducing the oligomer component of the PPS resin, a method of pre-drying before melt extrusion and a method of pre-melt kneading (pelletizing) are used, but a method of pre-kneading (pelletizing) is preferable. The addition is preferably used for oligomer reduction.

  Next, the PPS pellets are vacuum-dried at 180 ° C. for 3 hours or more, and the molten portion of the extruder is put into an extruder heated to a temperature of 300 to 350 ° C., preferably 320 to 340 ° C. Thereafter, the molten polymer passed through the extruder is passed through a filter, and the molten polymer is discharged into a sheet form using a die of a T die. The set temperature of the filter part and the die is preferably 3 to 20 ° C higher than the temperature of the melting part of the extruder, more preferably 5 to 15 ° C. This sheet-like material is brought into close contact with a cooling drum having a surface temperature of 20 to 70 ° C. to be cooled and solidified to obtain a substantially non-oriented unstretched film.

  Next, this unstretched 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.

  In the following, a sequential biaxial stretching method will be described as a specific example. In sequential biaxial stretching, an unstretched polyphenylene sulfide film is heated with a heating roll group, and the stretching ratio is determined from the longitudinal direction (from the viewpoint of obtaining a film having good flatness). (MD direction) 3.0 to 4.2 times, preferably 3.1 to 4.1 times, and more preferably 3.2 to 4.0 times in one or more stages (MD) Stretching). The stretching temperature ranges from Tg (glass transition temperature of polyarylene sulfide) to (Tg + 40) ° C., preferably (Tg + 2) to (Tg + 30) ° C. In the case of PPS, the stretching temperature is 95 ° C to 135 ° C, and more preferably 97 ° C to 125 ° C. Thereafter, it is cooled by a cooling roll group of 20 to 50 ° C.

  For stretching in the width direction (TD direction) following stretching in the MD direction, for example, a method using a tenter is generally used. 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 (glass transition temperature of polyarylene sulfide) to (Tg + 40) ° C., more preferably (Tg + 2) to (Tg + 30) ° C. In the case of PPS, it is 95 ° C to 135 ° C, more preferably 97 ° C to 125 ° C. The draw ratio is in the range of 3.0 to 4.2 times, preferably 3.1 to 4.1 times, and more preferably 3.2 to 4.0 times from the viewpoint of obtaining a film with good flatness. Further, the area magnification (product of the magnification in the MD direction and the magnification in the TD direction) is preferably 9 times or more and 18 times or less, more preferably 9.6 times or more and 14 times or less. When the area stretch ratio is less than 9, planarity may be deteriorated. Here, in order to improve the tensile elongation at break, the longitudinal direction (MD direction) is 3 to 4 times, preferably 3.1 to 3.4 times, more preferably 3.2 to 3.3 times. Stretching in one step or two or more steps, appropriately combining in the range of 3 to 4 times, preferably 3.1 to 3.6 times, more preferably 3.2 to 3.5 times in the width direction (TD direction) The area magnification (product of the magnification in the MD direction and the magnification in the TD direction) is preferably 9 times or more and 13 times or less, and more preferably 9.6 times or more and 12 times or less. In the case of stretching such that the area magnification exceeds 13 times, the tensile elongation at break may be less than 100%.

  Next, this stretched film is heat-set under tension. The preferred heat setting temperature in the case of one-stage heat setting is 250 to 280 ° C., and the total time of the heat setting step and the relaxation treatment step is 1 to 10 seconds when the thickness of the biaxially oriented polyphenylene sulfide is less than 50 μm, preferably Is 3-8 seconds. When the thickness of the biaxially oriented polyphenylene sulfide exceeds 50 μm, the total time of the heat setting step and the relaxation treatment step is 5 to 60 seconds, preferably 10 to 30 seconds. A more preferable heat treatment is multistage heat setting. In this case, the heat setting temperature of the first stage is 160 to 220 ° C., preferably 180 to 220 ° C. When the thickness of the biaxially oriented polyphenylene sulfide is less than 50 μm, the treatment time is preferably 1 to 15 seconds, more preferably. Is 1 to 8 seconds. Further, even when the thickness of the biaxially oriented polyphenylene sulfide is 50 μm or more, the treatment time for the first stage heat setting is preferably 1 to 15 seconds, and more preferably 1 to 8 seconds. The maximum temperature of the subsequent heat setting performed subsequently is 250 to 280 ° C, preferably 260 to 280 ° C. Further, this film is subjected to a relaxation treatment in the width direction at 250 to 280 ° C, more preferably 260 to 280 ° C. The relaxation rate is preferably 0.1 to 8%, more preferably 2 to 5%. When the thickness of the biaxially oriented polyphenylene sulfide is less than 50 μm, the total time of the subsequent heat setting step and the relaxation treatment step at 250 ° C. or higher is preferably 1 to 15 seconds, and more preferably 2 to 10 seconds. When the thickness of the biaxially oriented polyphenylene sulfide is 50 μm or more, the total time of the subsequent heat setting step and the relaxation treatment step at 250 ° C. or higher is preferably 1 to 30 seconds, more preferably 5 to 20 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.

  Furthermore, in the present invention, as a method of setting the surface free energy value in a desired range, one or both surfaces of the film may be subjected to corona discharge treatment. The discharge treatment may be performed during the film production process or at a stage after the film is produced. Here, examples of the corona discharge treatment method include corona discharge treatment carried out in the air, corona discharge treatment carried out in a nitrogen atmosphere, and corona discharge treatment carried out in a mixed gas atmosphere of carbon dioxide gas and nitrogen gas. From the viewpoint of improving adhesiveness with the adhesive layer, it is preferable to perform the corona discharge treatment in a nitrogen atmosphere or a mixed gas atmosphere of carbon dioxide gas and nitrogen gas. Further, the corona discharge treatment mentioned here may be performed singly or in combination. Here, the corona discharge treatment in a mixed gas atmosphere of carbon dioxide gas and nitrogen gas is a treatment in which a carbonyl functional group or a nitrogen-containing functional group is effectively introduced to the treated film surface to activate the surface. Further, the corona discharge treatment under a nitrogen atmosphere is a treatment in which nitrogen-containing functional groups are effectively introduced into the treated film surface by the discharge treatment and the surface is activated. Under the mixed gas atmosphere with these nitrogen gases, the nitrogen atmosphere may be an atmosphere in which a desired functional group can be effectively introduced to the surface of the treated film, preferably the oxygen concentration is 10% by volume or less, more preferably The atmosphere is 5% by volume or less. When the oxygen concentration is high, it becomes the same as normal discharge treatment in air, and there is a tendency that functional groups derived from oxygen atoms are selectively introduced into the treatment surface, or radical generation occurs on the film surface due to the influence of oxygen. The accompanying chain breakage tends to occur, and the film may have poor adhesion to the adhesive layer. Here, the oxygen concentration can be measured by an oxygen concentration meter near the drum of the corona treatment apparatus.

The treatment strength during the corona discharge treatment of the present invention can be appropriately selected within the range where the effects of the present invention are not impaired, but is preferably 20 W · min / m ² or more and 300 W · min / m ² or less. The effect of the present invention can be easily obtained by setting it to preferably 25 W · min / m ² or more and 200 W · min / m ² or less, and more preferably 30 W · min / m ² or more and 100 W · min / m ² or less. When the treatment strength is too weak, it is difficult to obtain the effect of the discharge treatment, and when the treatment strength is too strong, adverse effects such as excessive treatment of the treated surface or damage to the treated surface are likely to occur.

  In addition, as the treatment intensity of the discharge treatment, an “E value” defined by the following equation can be used. The E value cannot be simply compared when the processing apparatuses are different, and can be compared by creating a master curve with wettability as an index, for example. The E value in the present invention is expressed as a value when a high-frequency power source (AGI-024 type, manufactured by Kasuga Electric Co., Ltd.) is used.

E value = [(applied voltage) × (applied current)] / [(processing speed) × (electrode width)]
Here, the applied voltage (V), the applied current (A), the processing speed (m / min), and the electrode width (m).

  Next, in order to obtain an adhesive material, an adhesive layer is provided on at least one surface of the obtained film. Examples of the method of providing the adhesive layer include a method of applying and drying an adhesive solution and a method of laminating the adhesive layer. When using a silicone-based pressure-sensitive adhesive, the thickness is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 20 μm or less, and even more preferably 3 μm or more and 15 μm or less.

The characteristic value measurement method and evaluation method of the present invention are as follows.
(1) Breaking strength, breaking elongation According to the method prescribed | regulated to ASTM-D882, it measured using the Instron type tensile tester. The measurement was performed under the following conditions, and an average value was taken for each of the 10 samples.

Measuring device: Orientec Co., Ltd. film strong elongation automatic measuring device “Tensilon AMF / RTA-100”
Sample size: width 10mm x length 150mm
Between test lengths: 100 mm
Tensile speed: 300 mm / min Measurement environment: 23 ° C.
(2) Contact angle θ of methylene iodide and contact angle θ of ethylene glycol
Water, ethylene glycol, formamide, and methylene iodide were used as four types of liquids having known values of surface free energy and each of its components (dispersion force, polar force, hydrogen bonding force) at 23 ° C. and 65% RH. The contact angle (θ / 2) on the film surface of each liquid was measured with a contact angle meter CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). A measurement was performed five times on one measurement surface, and a value obtained by doubling the average value of the contact angles (θ / 2) was defined as the contact angle (θ).
(3) Surface free energy The value of the contact angle obtained in the above (2) and the known value of each liquid (Numerical values of Method IV by Panzer (described in Journal of Japan Adhesion Association Vol. 15, No. 3, p96)) Then, the value of each component was calculated using the following formula introduced from the extended Fowkes formula and the Young formula.
(Γ _S ^d · γ _L ^d ) ^1/2 + (γ _S ^p · γ _L ^p ) ^1/2 + (γ _S ^h · γ _L ^h ) ^1/2 = (1 + cos θ) / 2
Here, γ _L ^d , γ _L ^p , and γ _L ^h represent the values (known) of the components of the dispersion force, polar force, and hydrogen bonding force of the measurement liquid, respectively, and θ represents the measurement liquid on the measurement surface. The contact angle is represented, and γ _S ^d , γ _S ^p , and γ _S ^h represent values of components of the dispersion force, the polar force, and the hydrogen bonding force on the film surface, respectively. By solving the simultaneous equation obtained by substituting the known value and θ into the above equation, the values of the three components of the measurement surface are obtained. In the present invention, the sum of the values of the respective components of the obtained dispersion force, polarity force, and hydrogen bonding force is defined as the surface free energy value.
(4) Glass transition temperature It 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
(5) Melting temperature of resin In the same manner as in (4) above, a differential scanning calorimeter DSC (RDC220) manufactured by Seiko Instruments Inc. was used according to JIS K7121-1987, and a disk station (SSC / 5200) manufactured by the same company was used as a data analysis device. Then, 5 mg of the sample was heated from room temperature to 340 ° C. at a heating rate of 20 ° C./min on an aluminum tray, melted and held at 340 ° C. for 5 minutes, rapidly solidified and held for 5 minutes, and then heated from room temperature. The temperature was raised at a rate of 20 ° C./min. At that time, the peak temperature of the endothermic peak of melting observed was defined as the melting temperature (Tm).
(6) Slight endothermic peak temperature just below the melting point In the same manner as in (4) above, a differential scanning calorimeter DSC (RDC220) manufactured by Seiko Instruments Inc. according to JIS K7121-1987, a disk station (SSC / 5200) manufactured by Seiko Instruments Inc. The temperature of 5 mg of the sample was raised from room temperature to 340 ° C. at a heating rate of 20 ° C./min on an aluminum pan, at which time the peak temperature of the endothermic peak of melting having a heat of fusion of 30 j / g or more of crystals. Was the melting temperature (Tm), and the slight endothermic peak immediately below the Tm was taken as Tmeta.
(7) Heat shrinkage rate Heat treatment was performed under the following conditions in a hot air oven heated to 250 ° C or 260 ° C, and the heat shrinkage rate was calculated according to the following formula. The dimensional evaluation was performed using a profile projector model V-16A manufactured by Nippon Optical Co., Ltd., the dimensions up to 1/1000 mm were read, and the values at 1/100 mm were rounded to the values of 1/10 mm.

Sample size: width 10mm x length 150mm
Between test lengths: 100 mm
Heat treatment temperature: 250 ° C or 260 ° C
Heat treatment time: 10 minutes Sample state: Tensile stress shrinkage (%) = {(dimension before heat treatment) − (dimension after heat treatment)} / (dimension before heat treatment) × 100
(8) 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.
(9) 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.
(10) Adhesiveness between the film and the adhesive layer In an atmosphere of 23 ° C. × 65% RH, on the adhesive layer side of the adhesive material, 1 mm width is cut vertically and horizontally to make 100 squares, A Nichiban No. 405 cellophane adhesive tape with a width of 18 mm was firmly pressure-bonded by hand and allowed to stand for 30 seconds. Thereafter, the cellophane pressure-sensitive adhesive tape was rapidly peeled off in the 45 ° direction, and the coating film residual rate of the adhesive on the film surface was visually confirmed. An adhesive layer having a residual rate of 100% was indicated by “◎”, a residual rate of 90% or more was indicated by “◯”, and an adhesive layer having a residual rate less than that was indicated by “X”. ◎ and ○ pass, × fail.
(11) Workability Using a Scott Scratch Resistance Tester (manufactured by Toyo Seiki), a fir tree test according to JIS-K-6328-1981 was carried out. Use a sample with an adhesive material cut to a width of 10 mm and a length of 200 mm, measure it under a load of 2.5 kg, and visually check whether the film and the adhesive layer are cleaved, or until the film itself breaks. Find the number of times. Judgment was made according to the following criteria. ◎ and ○ are acceptable, and △ and × are unacceptable.

◎: 100 times or more ○: 40 times or more and less than 100 times Δ: 20 times or more and less than 40 times ×: Less than 20 times.
(12) Adhesiveness of adhesive material The adhesive material was cut into a size of 10 mm in width and 200 mm in length, and a rolled copper foil having a thickness of 12 μm was laminated on the adhesive layer side of the adhesive material, and 270 in a nitrogen atmosphere. A hot-press cure was carried out for 20 minutes under the conditions of 5 ° C. at 5 ° C. to prepare a copper-clad plate. The copper paste was subjected to a rub test according to JIS-K-6328-1981 using a Scott Scratch Resistance Tester (manufactured by Toyo Seiki). Measured with a load of 2.5 kg, whether the cleavage between the copper foil and the adhesive layer can be confirmed visually, the cleavage between the film and the adhesive layer can be confirmed, or the number of times until the film itself breaks is determined. Judgment was made according to the following criteria. ◎ and ○ are acceptable, and △ and × are unacceptable.

◎: 100 times or more ○: 40 times or more and less than 100 times Δ: 20 times or more and less than 40 times ×: Less than 20 times.

Reference Example 1 Preparation of PPS Resin In a 70 liter autoclave equipped with a stirrer, 8267.37 g (70.00 mol) of 47.5% sodium hydrosulfide, 2957.21 g (70.97 mol) of 96% sodium hydroxide, N-methyl-2-pyrrolidone (NMP) 11434.50 g (115.50 mol), sodium acetate 2583.00 g (31.50 mol), and ion-exchanged water 10500 g were charged, and the temperature was increased to 245 ° C. while passing nitrogen at normal pressure. After gradually heating over 3 hours to distill 14780.1 g of water and 280 g of NMP, the reaction vessel was cooled to 160 ° C. 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, 10235.46 g (69.63 mol) of p-dichlorobenzene and 900.00 g (91.00 mol) of NMP were added, the reaction vessel was sealed under nitrogen gas, and stirred at 240 rpm while stirring at 0.6 ° C. / The temperature was raised to 238 ° C. at a rate of minutes. 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 26300 g of NMP, the solvent and solid matter were filtered off with a sieve (80 mesh), and the resulting particles were washed with 31900 g of NMP and filtered off. This was washed several times with 56000 g of ion-exchanged water and filtered, then washed with 70000 g of 0.05 wt% aqueous calcium acetate and filtered. After washing with 70000 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 resin had a melt viscosity of 2000 poise (310 ° C., shear rate of 1000 / s), a glass transition temperature of 90 ° C., and a melting point of 280 ° C.
Reference Example 2 Preparation of Particle Master Chip 92 parts by weight of the PPS resin prepared in Reference Example 1 and 8 parts by weight of calcium carbonate powder having an average particle diameter of 1.2 μm were rotated in the same direction with a twin-screw kneading extruder (Nippon Steel) Manufactured, manufactured by Komatsu, screw diameter 30 mm, screw length / screw diameter = 45.5), melt-extruded at 330 ° C., residence time 30 seconds, screw rotation speed 300 rpm, discharged into a strand, temperature 25 ° C. After cooling with water, cutting was performed immediately to prepare a particle master chip (containing 8% of particles).

(Example 1)
96 parts by weight of the PPS resin prepared in Reference Example 1 and 4 parts by weight of the particle master chip prepared in Reference Example 2 were blended and dried under reduced pressure at 180 ° C. for 3 hours, and then the melted portion was heated to 320 ° C. It was fed to a single screw extruder. After the polymer melted by the extruder is filtered through a filter set at a temperature of 330 ° C., it is melt extruded from a die of a T die set at a temperature of 310 ° C. and cast while applying an electrostatic charge to a cast drum having a surface temperature of 25 ° C. Cooled and solidified to produce an unstretched film.

This unstretched film was heated 3.9 times in the longitudinal direction of the film at a film temperature of 101 ° C. at a film temperature of 101 ° C. using a difference in peripheral speed of the roll after preheating using a longitudinal stretching machine comprising a plurality of heated roll groups Stretched at a magnification. Thereafter, both ends of the film are gripped with clips, guided to a tenter, stretched in the width direction of the film at a stretching temperature of 101 ° C. and a stretching ratio of 3.7 times, and subsequently heat treated at a temperature of 260 ° C. for 4 seconds (1 Step heat treatment was performed, followed by heat treatment at 260 ° C. for 4 seconds (second step heat treatment). Subsequently, 8% relaxation treatment was performed laterally in a 260 ° C. relaxation treatment zone for 4 seconds, followed by cooling to 115 ° C. through a cooling process at 115 ° C., and then the film edge was removed to produce a 25 μm thick film. did. The film thus obtained was corona only on one side at a treatment strength E value = 30 W · min / m ² in a gas atmosphere in which carbon dioxide gas and nitrogen gas were mixed at a volume ratio of 1: 4 (oxygen concentration 0% by volume). Discharge treatment was performed to obtain a biaxially oriented polyphenylene sulfide film. Next, a silicone-based pressure-sensitive adhesive (SD-4588L manufactured by Toray Dow Corning Silicone Co., Ltd.) was applied to the surface side subjected to corona discharge treatment so as to have a thickness of 5 μm to obtain an adhesive material. . The characteristics of the biaxially oriented PPS film and the adhesive material obtained in this example are as shown in Table 1, the surface free energy value is high, and the contact angle θ of ethylene glycol is within the preferred range of the present invention. Also, the adhesiveness between the film and the adhesive layer was good, and the adhesive material was excellent in adhesiveness and workability.

(Example 2)
A biaxially oriented PPS film and an adhesive material were prepared in the same manner as in Example 1 except that the corona discharge treatment was performed under a nitrogen atmosphere (oxygen concentration was 0% by volume). The characteristics of the biaxially oriented PPS film and the adhesive material obtained in this example are as shown in Table 1. The surface free energy value is high, and the contact angle θ of methylene iodide is within the preferable range of the present invention. In addition, the adhesion between the film and the adhesive layer was good, and the adhesive material was excellent in adhesion and workability.

(Example 3)
A biaxially oriented PPS film and an adhesive material were produced in the same manner as in Example 1 except that the corona discharge treatment was performed in the atmosphere (oxygen concentration was 21% by volume). The characteristics of the biaxially oriented PPS film and the adhesive material obtained in this example are as shown in Table 1. Although the surface free energy value is high, the contact angle θ of methylene iodide and the contact angle θ of ethylene glycol However, this is outside the preferred range of the present invention, and the adhesion between the film and the adhesive layer is somewhat inferior, but at a level that does not cause any problems in use, and is suitable as an adhesive material.

(Examples 4, 5 and Comparative Example 2)
A biaxially oriented PPS film and an adhesive material were produced in the same manner as in Example 2 except that the treatment strength (E value) of the corona discharge treatment was changed to the values shown in Table 1. The characteristics of the biaxially oriented PPS films and adhesive materials obtained in Examples 4 and 5 are as shown in Table 1. The present invention has a high surface free energy value, and the contact angle θ of methylene iodide is high. Within the preferable range of the present invention, the adhesiveness between the base film and the adhesive layer was good, and the heat resistant adhesive material was excellent in workability. On the other hand, the biaxially oriented PPS film of Comparative Example 2 whose E value is outside the scope of the present invention has a low surface free energy value, poor adhesion between the film and the adhesive layer, and adhesion as a heat resistant adhesive material. Processing aptitude was insufficient.

(Example 6)
A biaxially oriented PPS film and an adhesive material were produced in the same manner as in Example 1 except that oxygen gas was mixed with a mixed gas of carbon dioxide gas and nitrogen gas to adjust the oxygen concentration to 5% by volume as corona discharge treatment. The characteristics of the biaxially oriented PPS film and heat-resistant adhesive material obtained in this example are as shown in Table 1, the surface free energy is high, and the contact angle θ of ethylene glycol is within the preferred range of the present invention. Further, the adhesion between the base film and the adhesive layer was good, and the adhesive material was excellent in adhesion and workability.

(Example 7)
A biaxially oriented PPS film and an adhesive material were produced in the same manner as in Example 2 except that oxygen gas was mixed in a nitrogen atmosphere as the corona discharge treatment to adjust the oxygen concentration to 15% by volume. The characteristics of the biaxially oriented PPS film and the adhesive material obtained in this example are as shown in Table 1. The surface free energy value is high, but the contact angle θ of methylene iodide and the contact angle θ of ethylene glycol However, this is outside the preferred range of the present invention, and the adhesion between the film and the adhesive layer is somewhat inferior, but at a level that does not cause any problems in use, and is suitable as an adhesive material.

(Example 8)
A biaxially oriented PPS film and an adhesive material were produced in the same manner as in Example 1 except that the stretching ratio in the film forming step of the biaxially oriented PPS film was changed to the magnification shown in Table 1. The characteristics of the biaxially oriented PPS base film and the heat-resistant adhesive material obtained in this example are as shown in Table 1. The surface free energy value is high, and the contact angle θ of ethylene glycol is preferable in the present invention. It was within the range, the adhesiveness between the film and the adhesive layer was good, and it was excellent as an adhesive material. Furthermore, the tensile elongation at break of the biaxially oriented PPS film was within the preferred range of the present invention, and the processability as a heat-resistant adhesive material was extremely excellent.

Example 9
A biaxially oriented PPS base film and an adhesive material were prepared in the same manner as in Example 1 except that the stretching ratio and heat setting temperature in the film forming step of the biaxially oriented PPS film were changed to the ratio and heat setting temperature shown in Table 1. Produced. The characteristics of the biaxially oriented PPS film and heat-resistant adhesive material obtained in this example are as shown in Table 1, the surface free energy is high, and the contact angle θ of ethylene glycol is within the preferred range of the present invention. In addition, the adhesion between the film and the adhesive layer was also good, and it was also excellent as an adhesive material. Furthermore, the tensile elongation at break of the biaxially oriented PPS film was within the preferred range of the present invention, and the processability as an adhesive material was extremely excellent.

(Comparative Example 1)
A biaxially oriented PPS film and an adhesive material were produced in the same manner as in Example 1 except that the corona discharge treatment was not performed. The characteristics of the biaxially oriented PPS film and the adhesive material obtained in this comparative example are as shown in Table 1, the value of the surface free energy is low, the adhesiveness between the film and the adhesive layer is poor, and the adhesive material As a result, adhesiveness and processability were insufficient.

  The biaxially oriented polyarylene sulfide film of the present invention has excellent heat resistance, dimensional stability, low hygroscopicity, and excellent adhesion to the adhesive layer without impairing chemical resistance, and electrical / electronic equipment and mechanical parts. In particular, automotive parts, etc., electrical insulation materials, molding materials, circuit board materials, process films and protective films such as circuits and optical members, especially storage devices (for example, electrolytic capacitors, electric double capacitors, lithium ion batteries, etc.) Also, it can be suitably used as a base material for adhesive materials such as a carrier tape for TAB on which a semiconductor chip is mounted, an adhesive tape for fixing a lead frame, and a flexible printed circuit board.

Claims (9)

A biaxially oriented polyarylene sulfide film having a surface free energy value of at least one side of the surface of 50 mN / m or more. 2. The biaxially oriented polyarylene sulfide film according to claim 1, wherein a contact angle θ of methylene iodide on a surface having a surface free energy value of 50 mN / m or more is 20 ° or less. 2. The biaxially oriented polyarylene sulfide film according to claim 1, wherein a contact angle θ of ethylene glycol on a surface having a surface free energy value of 50 mN / m or more is 15 ° or less. The biaxially oriented polyarylene sulfide film according to any one of claims 1 to 3, wherein the polyarylene sulfide is polyphenylene sulfide. The biaxially oriented polyarylene sulfide film according to any one of claims 1 to 4, wherein a tensile breaking elongation in at least one direction in the film plane is 100% or more. The biaxially oriented polyarylene sulfide film according to any one of claims 1 to 5, wherein the film is subjected to corona discharge treatment on one side or both sides of the film in an atmosphere having an oxygen concentration of 10% by volume or less. The biaxially oriented polyarylene sulfide film according to claim 6, wherein a treatment atmosphere of the corona discharge treatment is a nitrogen atmosphere. The biaxially oriented polyarylene sulfide film according to claim 6, wherein a treatment atmosphere of the corona discharge treatment is a mixed gas atmosphere of carbon dioxide gas and nitrogen. An adhesive material comprising an adhesive layer provided on at least one surface of the biaxially oriented polyarylene sulfide film according to claim 1.