JP5546304B2 - Method for producing adhesive film and flexible metal-clad laminate - Google Patents

Description

  The present invention relates to a method for producing an adhesive film and a flexible metal-clad laminate having excellent moisture absorption solder resistance obtained by bonding a metal foil to the adhesive film.

  2. Description of the Related Art In recent years, electronic devices have been rapidly improved in performance, function, and size, and accordingly, there is an increasing demand for downsizing and weight reduction of electronic components used in electronic devices. In response to the above requirements, semiconductor device packaging methods and wiring boards on which they are mounted are required to have higher density, higher functionality, and higher performance.

  A flexible printed wiring board (hereinafter also referred to as FPC) generally uses a thin insulating film having flexibility as a substrate (base film), and a metal foil is heated and pressure-bonded to the surface of the substrate via various adhesive materials. Thus, a circuit pattern is formed on the metal-clad laminate bonded together, and a cover layer is applied to the surface. In a flexible printed wiring board (three-layer FPC) composed of three layers of an insulating film, an adhesive layer, and a metal foil, a polyimide film or the like has been widely used as an insulating film. This is because polyimide has excellent heat resistance and electrical characteristics. Moreover, as the adhesive layer, a thermosetting adhesive such as epoxy resin or acrylic resin is generally used.

  However, in order to obtain a high-density, high-function, and high-performance FPC as described above, it is necessary to improve the performance of the above-mentioned insulating adhesive and insulating film used as the material and use them. It is necessary. Specifically, the adhesive layer and the like are required to have high heat resistance and mechanical strength, and to be excellent in workability, adhesion, low moisture absorption, electrical characteristics, and dimensional stability.

  On the other hand, thermosetting resins such as epoxy resins and acrylic resins that have been conventionally used as adhesive layers are excellent in low-temperature workability because they can be bonded at a relatively low temperature, and also from an economical viewpoint. However, at present, for example, other characteristics typified by heat resistance are insufficient.

  In order to solve the above problem, a two-layer FPC using a polyimide material for an adhesive layer has been proposed (see, for example, Patent Document 1). In addition, although it can be said that the FPC obtained by the method using a polyimide material for the adhesive layer is strictly three layers, the two polyimide layers are regarded as a single body to form a two-layer FPC. This two-layer FPC is superior in heat resistance, electrical characteristics, and dimensional stability compared to a three-layer FPC using an epoxy resin or an acrylic resin as an adhesive layer, and has attracted attention as a material that can meet the required characteristics in the future. ing.

  On the other hand, a drawback in using a polyimide material is a high water absorption rate based on the properties of polyimide. This is a problem that also applies to a two-layer FPC. When the water absorption rate of the FPC is high, it may adversely affect the mounting of components using solder. Specifically, moisture taken into the material from the atmosphere is suddenly released out of the system by heating at the time of component mounting, resulting in swelling and whitening of the FPC, and between the materials in the FPC There may be problems with adhesion and electrical properties. In order to avoid such a problem relating to moisture-absorbing solder resistance, for example, it is possible to take measures to preliminarily dry the FPC and remove moisture before the mounting process. However, since the number of processes increases, there is a problem in terms of productivity.

  In order to solve the above problems, an adhesive film in which the properties of thermoplastic polyimide used for the adhesive layer are controlled has been proposed. Specifically, by increasing the glass transition temperature of the thermoplastic polyimide contained in the adhesive layer provided on one side or both sides of the heat-resistant base film, improving the heat resistance of the adhesive layer and lowering the water absorption rate, The amount of moisture taken into the film is reduced (see, for example, Patent Document 2 or Patent Document 3). In addition, when processing the adhesive film and the metal foil, a countermeasure on the processing surface such as removing moisture by pre-drying the adhesive film has been proposed (see, for example, Patent Document 4).

  By these methods, the moisture-absorbing solder resistance, which was a drawback when using a polyimide material, is improved. However, with the recent increase in awareness of the environment, there are an increasing number of cases where lead-free solder is used in semiconductor mounting. Since lead-free solder has a melting point of about 40 ° C. higher than eutectic solder currently used, the temperature applied to the material used in the mounting process inevitably rises. For this reason, the current situation is that the resistance to moisture-absorbing solder required for the material is stricter than before. In addition, when used as a multilayer FPC application, moisture tends to be trapped inside the material due to multilayering, and therefore, defects tend to occur at a lower solder temperature than in the case of a single layer FPC. The materials used in the above are required to have more severe moisture-absorbing solder resistance.

Japanese Patent Laid-Open No. 2-180682 JP 2000-129228 A JP 2001-260272 A JP 2001-270037 A

  The present invention has been made in view of the above problems, and its purpose is to control the properties of thermoplastic polyimide used as an adhesive, and to use an adhesive film excellent in moisture-absorbing solder resistance and the use thereof. It is in providing the obtained flexible metal-clad laminate.

  In general, it is known that the imidization temperature of the thermoplastic polyimide is effective as high as possible from the viewpoint of leaving no solvent component in the film after imidization and baking. However, when the thermoplastic polyimide according to the present invention is imidized at a high temperature, sufficient moisture-absorbing solder resistance cannot be obtained.

  As a result of intensive studies in view of the above-mentioned problems, the present inventor used a specific monomer in a specific molar ratio in the thermoplastic polyimide composition used for the adhesive layer, and imidized at a low temperature, thereby producing an adhesive film and the same. The present inventors have found that the moisture absorption solder resistance of the flexible metal-clad laminate obtained by using this can be improved, and have completed the present invention.

That is, the present invention is an adhesive film in which an adhesive layer containing a thermoplastic polyimide is provided on at least one surface of a heat-resistant polyimide film, and the thermoplastic polyimide satisfies the following (A) and (B): It is related with the manufacturing method of the adhesive film characterized by imidating the polyimide precursor at the temperature of 320-400 degreeC.
(A) The thermoplastic polyimide is mainly composed of pyromellitic dianhydride and 2,2-bis- [4- (4-aminophenoxy) phenyl] propane, and other than pyromellitic dianhydride Diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane and / or a diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane In 100 mol% of the diamine component, 5 to 30 mol%,
(B) The total number of moles of acid dianhydride other than pyromellitic dianhydride and diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane is 5 to 50%.

  As a preferred embodiment, the acid dianhydride other than the pyromellitic dianhydride is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, and a method for producing an adhesive film About.

  As a preferred embodiment, the diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane is 4,4′-oxydianiline, and the method for producing an adhesive film is characterized in that About.

  In a preferred embodiment, when a metal foil is laminated on the adhesive film to form a metal-clad laminate, the metal foil peeling strength is 10 N / cm or more when peeled in the direction of 180 degrees. Regarding the method.

As a preferred embodiment, the thermoplastic polyimide has a storage elastic modulus of 1 × 10 ⁸ Pa or more at 280 ° C. and a storage elastic modulus of less than 1 × 10 ⁸ Pa at 350 ° C. .

  As a preferred embodiment, the present invention relates to a method for producing an adhesive film, wherein the heat-resistant polyimide film contains a thermoplastic polyimide block component in an amount of 20 to 60 mol% of the whole polyimide.

  As a preferred embodiment, the present invention relates to a method for producing an adhesive film, wherein the repeating unit n of the block component of the thermoplastic polyimide is 3 to 99.

  A preferred embodiment relates to a method for producing an adhesive film, which is formed by casting the polyimide precursor solution on a support by coextrusion.

  As a preferred embodiment, a chemical dehydrating agent and a catalyst are contained in any one of the solution layer containing the thermoplastic polyimide precursor and the solution layer containing the heat-resistant polyimide precursor. The present invention relates to a method for producing an adhesive film.

Furthermore, the present invention relates to an adhesive film produced by the method for producing an adhesive film described above.

  Furthermore, the present invention relates to a flexible metal-clad laminate obtained by bonding a metal foil to the adhesive film described above.

  The adhesive film obtained by the present invention and the flexible metal-clad laminate produced by bonding a metal foil to the adhesive film are excellent in moisture absorption solder resistance while maintaining excellent adhesiveness.

  Embodiments of the present invention will be described below.

The adhesive film according to the present invention is an adhesive film in which an adhesive layer containing a thermoplastic polyimide is provided on at least one surface of a heat-resistant polyimide film, and the thermoplastic polyimide satisfies the following (A) and (B): And it is the manufacturing method of the adhesive film characterized by imidating the polyimide precursor at the temperature of 320-400 degreeC.
(A) The thermoplastic polyimide is mainly composed of pyromellitic dianhydride and 2,2-bis- [4- (4-aminophenoxy) phenyl] propane, and other than pyromellitic dianhydride Diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane and / or a diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane In 100 mol% of the diamine component, 5 to 30 mol%,
(B) The total number of moles of acid dianhydride other than pyromellitic dianhydride and diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane is 5 to 50%.

  The reason why the acid dianhydride other than the pyromellitic dianhydride is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride does not decrease the storage elastic modulus at the hygroscopic solder test temperature. preferable.

  The reason why the diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane is 4,4′-oxydianiline does not decrease the storage elastic modulus at the hygroscopic solder test temperature. Is more preferable.

  The thickness of the heat-resistant polyimide film can be appropriately selected depending on the application. In general, in a two-layer FPC, the insulating layer thickness (the thickness obtained by adding the heat-resistant polyimide film and the adhesive layer) is 1 mil (25 μm), 12.5 μm) is preferably used. Therefore, the thickness of the heat-resistant polyimide film is preferably in the range of 4 to 22 μm, more preferably in the range of 6 to 20 μm.

  The heat-resistant polyimide film according to the present invention is produced using polyamic acid as a precursor. Any known method can be used as a method for producing the polyamic acid. Usually, the polyamic acid obtained by dissolving a substantially equimolar amount of an aromatic dianhydride and an aromatic diamine in an organic solvent is obtained. The organic solvent solution is produced by stirring under controlled temperature conditions until the polymerization of the acid dianhydride and the diamine is completed. These polyamic acid solutions are usually obtained at a concentration of 5 to 35% by weight, preferably 10 to 30% by weight. When the concentration is in this range, an appropriate molecular weight and solution viscosity are obtained.

As the polymerization method, any known method and a combination thereof can be used. The characteristic of the polymerization method in the polymerization of polyamic acid is the order of addition of the monomers, and the physical properties of the polyimide obtained can be controlled by controlling the order of addition of the monomers. Therefore, in the present invention, any method of adding monomers may be used for the polymerization of polyamic acid. The following method is mentioned as a typical polymerization method. That is,
1) A method in which an aromatic diamine is dissolved in an organic polar solvent, and this is reacted with a substantially equimolar aromatic tetracarboxylic dianhydride for polymerization.
2) An aromatic tetracarboxylic dianhydride is reacted with a small molar amount of an aromatic diamine compound in an organic polar solvent to obtain a prepolymer having acid anhydride groups at both ends. Subsequently, a method of polymerizing with an aromatic diamine compound so that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar in all steps,
3) An aromatic tetracarboxylic dianhydride and an excess molar amount of the aromatic diamine compound are reacted in an organic polar solvent to obtain a prepolymer having amino groups at both ends. Subsequently, after adding an aromatic diamine compound here, using the aromatic tetracarboxylic dianhydride so that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar in all steps. How to polymerize,
4) A method in which an aromatic tetracarboxylic dianhydride is dissolved and / or dispersed in an organic polar solvent and then polymerized using an aromatic diamine compound so as to be substantially equimolar,
5) A method of polymerizing by reacting a mixture of substantially equimolar aromatic tetracarboxylic dianhydride and aromatic diamine in an organic polar solvent,
And so on. These methods may be used singly or in combination.

  It is essential that the heat-resistant polyimide film of the present invention contains a thermoplastic polyimide block component in its molecule in an amount of 20 to 60 mol% of the whole polyimide. For the purpose of ideally forming the block component, after forming the block component of the thermoplastic polyimide precursor, the method of forming the non-thermoplastic polyimide precursor using the remaining diamine and / or acid dianhydride is used. preferable. Under the present circumstances, it is preferable to use combining the method of said 1) -5) partially.

  In the present invention, the thermoplastic polyimide block component refers to a component that melts when the high molecular weight film is heated to about 350 ° C. to 500 ° C. and does not retain the shape of the film. As a more specific determination method for the thermoplastic polyimide block component, the molar ratio of the diamine to be used and the acid dianhydride is added to an appropriate solvent so that the molar ratio is virtually 100: 97 to 97: 100. A solution is prepared, and then the polyamic acid solution is coated on a smooth support so that the final thickness is 10 to 30 μm and the length of one side is 25 cm or more. Specific examples of the smooth support include PET film, aluminum foil, and copper foil. Examples of the method for applying the final thickness to 10 to 30 μm include a bar coater, a comma coater, and a doctor blade. Furthermore, the coating film of the polyamic acid solution coated on the support is dried until it is self-supporting, peeled off from the support, fixed to a metal frame, and imidization and drying are substantially terminated. To produce a single layer sheet of polyimide. Examples of the drying and imidization methods include hot air and far infrared rays, and the temperature conditions are appropriately selected depending on the solvent species and the molecular structure of the polyamic acid. The polyimide single-layer sheet thus obtained was fixed to a square metal frame having an inner side of 20 cm each so that the center of the polyimide single-layer sheet and the metal frame substantially coincided, and 350 ° C. to 500 ° C. In the atmosphere of 5 minutes or more so that the film is substantially horizontal. At that time, if the center of the film is thermally deformed by 1 cm or more vertically downward, the block component made of the polyimide is determined to be thermoplastic.

  The melting temperature is further preferably 250 to 450 ° C, particularly preferably 300 to 400 ° C. If this temperature is too low, it will be difficult to finally obtain a heat-resistant polyimide film, and if this temperature is too high, it will be difficult to obtain excellent adhesion, which is an effect of the present invention.

  Furthermore, the thermoplastic polyimide block component is contained in an amount of 20 to 60 mol%, preferably 25 to 55 mol%, particularly preferably 30 to 50 mol% of the whole polyimide.

  If the thermoplastic polyimide block component is below this range, moisture absorption solder heat resistance will deteriorate, and at the same time it will be difficult to develop the excellent adhesiveness of the present invention. It becomes difficult.

  Here, the mol% of the thermoplastic polyimide block component, that is, the content of the thermoplastic polyimide block component in the present invention was synthesized by using the thermoplastic polyimide block component excessively with respect to the acid component. In the case of synthesis by the following calculation formula (1), the acid component is calculated according to the following calculation formula (2) when synthesized in excess with respect to the diamine component.

(Thermoplastic polyimide block component content) = a / b × 100 Formula (1)
a: Amount of diamine contained in thermoplastic polyimide block component (mol)
b: Total diamine amount (mol)
(Thermoplastic polyimide block component content) = a / b × 100 Formula (2)
a: Amount of acid component contained in thermoplastic polyimide block component (mol)
b: Total acid component amount (mol)

  Further, the repeating unit n of the thermoplastic polyimide block component is preferably 3 to 99, more preferably 4 to 90. When the repeating unit n is less than this range, excellent adhesiveness is hardly exhibited and the hygroscopic expansion coefficient tends to be large. On the other hand, if the repeating unit n exceeds this range, the storage stability of the polyimide precursor solution tends to deteriorate, and the reproducibility of polymerization tends to decrease, such being undesirable.

  The thermoplastic polyimide block component in the present invention preferably has a glass transition temperature (Tg) in the range of 150 to 300 ° C. in the high molecular weight body. Tg can be obtained from the inflection point value of the storage elastic modulus measured by a dynamic viscoelasticity measuring device (DMA).

The monomer that forms the thermoplastic polyimide block component of the present invention will be described.
Examples that can be preferably used as the diamine main component constituting the thermoplastic polyimide block component of the present invention include 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3. '-Diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 4,4'-oxydianiline, 3,3'-oxydianiline, 3,4'-oxydianiline, 4,4'-diaminodiphenyldiethyl Silane, 4,4′-diaminodiphenylsilane, 4,4′-diaminodiphenylethylphosphine oxide, 4,4′-diaminodiphenyl N-methylamine, 4,4′-diaminodiphenyl N-phenylamine, 1,4- Diaminobenzene (p-phenylenediamine), bis {4- (4-aminophenoxy) Enyl} sulfone, bis {4- (3-aminophenoxy) phenyl} sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 1,3- Bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 3, Examples include 3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis (4-aminophenoxyphenyl) propane, and these can be used alone or in combination. These examples are examples that are suitably used as the main component, and any diamine can be used as the accessory component. Examples of diamines that can be particularly preferably used among these are 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 1,3-bis (3-amino). Phenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis (4 -Aminophenoxyphenyl) propane.

  Among these, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is particularly preferable because the adhesiveness can be easily controlled within a suitable range.

  Examples that can be suitably used as the acid component constituting the thermoplastic polyimide block component include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride and the like can be mentioned, and these can be used alone or in combination. In the present invention, at least 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 4,4′-oxydiphthalic acid It is preferable to use at least one acid dianhydride selected from the group consisting of anhydrides as an essential component. By using these acid dianhydrides, high adhesion to the adhesive polyimide layer, which is the effect of the present invention, can be easily obtained.

  In this invention, the suitable example of the diamine and acid dianhydride which are used when making it react with a thermoplastic polyimide block component (in this stage, a thermoplastic polyimide precursor block component) and manufacturing a heat resistant polyimide precursor is given. . Although various characteristics change depending on the combination of diamine and acid dianhydride, it cannot be specified unconditionally, but ultimately, a diamine or an acid that becomes a heat-resistant polyimide is used. As such a diamine, it is preferable to use a rigid component such as paraphenylenediamine and a derivative thereof, benzidine and a derivative thereof as a main component. By using these diamines having a rigid structure, it becomes non-thermoplastic and it is easy to achieve a high elastic modulus. Moreover, it is preferable to use pyromellitic dianhydride as a main component as an acid component. As is well known, pyromellitic dianhydride tends to give a non-thermoplastic polyimide because of its rigid structure.

  Here, the heat-resistant polyimide film in the present invention refers to a film that melts and maintains the shape of the film when the high molecular weight film is heated to about 350 ° C to 500 ° C. As a more specific method for determining a heat-resistant polyimide film, a polyamic acid solution is prepared by adding a molar ratio of a diamine to be used and an acid dianhydride to an appropriate solvent so that the molar ratio is virtually 100: 97 to 97: 100. Then, the polyamic acid solution is applied onto a smooth support so that the final thickness is 10 to 30 μm and the length of one side is 25 cm or more. Specific examples of the smooth support include PET film, aluminum foil, and copper foil. Examples of the method for applying the final thickness to 10 to 30 μm include a bar coater, a comma coater, and a doctor blade. Furthermore, the coating film of the polyamic acid solution coated on the support is dried until it is self-supporting, peeled off from the support, fixed to a metal frame, and imidization and drying are substantially terminated. To produce a single layer sheet of polyimide. Examples of the drying and imidization methods include hot air and far infrared rays, and the temperature conditions are appropriately selected depending on the solvent species and the molecular structure of the polyamic acid. The polyimide single-layer sheet thus obtained was fixed to a square metal frame having an inner side of 20 cm each so that the center of the polyimide single-layer sheet and the metal frame substantially coincided, and 350 ° C. to 500 ° C. In the atmosphere of 5 minutes or more so that the film is substantially horizontal. At that time, if the thermal deformation at the center of the film is less than 1 cm in the vertically downward direction, the film made of the polyimide is determined to be heat resistant.

  In the present invention, from the viewpoint of ease of polymerization control and convenience of the apparatus, after first synthesizing a thermoplastic polyimide precursor block component, diamine and acid dianhydride are further added at an appropriately designed molar fraction to provide heat resistance. It is preferable to use a polymerization method using a polyimide precursor.

  As a preferred solvent for synthesizing a polyimide precursor (hereinafter referred to as polyamic acid), any solvent that dissolves polyamic acid can be used, but amide solvents, that is, N, N-dimethylformamide, N, N -Dimethylacetamide, N-methyl-2-pyrrolidone and the like, and N, N-dimethylformamide and N, N-dimethylacetamide can be particularly preferably used.

The thermoplastic polyimide contained in the adhesive polyimide layer according to the present invention preferably has a storage elastic modulus at 280 ° C. of 1 × 10 ⁸ Pa or more in order to improve solder heat resistance. In addition, at the temperature at which the adhesive film and the metal foil are bonded when the flexible metal-clad laminate is manufactured, the adhesive layer needs to be sufficiently softened in order to exhibit adhesiveness. The thermoplastic polyimide contained in the polyimide layer preferably has a storage elastic modulus at 350 ° C. of less than 1 × 10 ⁸ Pa. Furthermore, it is preferable that the thermoplastic polyimide contained in the adhesive layer has a storage elastic modulus at 300 ° C. of 1 × 10 ⁷ Pa or more and a storage elastic modulus at 340 ° C. of less than 1 × 10 ⁸ Pa. Furthermore, it is preferable that the thermoplastic polyimide contained in the adhesive layer has a storage elastic modulus at 300 ° C. of 3 × 10 ⁷ Pa or more and a storage elastic modulus at 340 ° C. of less than 8 × 10 ⁷ Pa. When the storage modulus of the adhesive polyimide layer at the solder test temperature is low, moisture in the adhesive film is suddenly released outside the system through the adhesive layer, resulting in whitening in the adhesive film or flexible metal-clad laminate And can cause blistering. Moreover, when the storage elastic modulus is large at the temperature to be bonded to the metal foil, the copper foil adhesion strength is lowered, and problems such as peeling of the copper foil occur when the obtained copper clad laminate is processed. In addition, the low storage elastic modulus at the temperature to be bonded to the metal foil is a necessary condition for the good adhesion strength of the copper foil, and even if the storage elastic modulus is small, the adhesion strength is due to poor matching with the copper foil. May be low.

  In addition, a filler can be added for the purpose of improving various film properties such as slidability, thermal conductivity, conductivity, corona resistance, and loop stiffness. Any filler may be used, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica and the like.

The particle size of the filler is not particularly limited because it is determined by the film characteristics to be modified and the kind of filler to be added, but generally the average particle size is 0.05 to 100 μm, preferably 0.1. It is -75 micrometers, More preferably, it is 0.1-50 micrometers, Most preferably, it is 0.1-25 micrometers. If the particle size is below this range, the modification effect is less likely to appear. If the particle size is above this range, the surface properties may be greatly impaired or the mechanical properties may be greatly deteriorated. Further, the number of added parts of the filler is not particularly limited because it is determined by the film properties to be modified, the filler particle diameter, and the like. Generally, the addition amount of the filler is 0.01 to 100 parts by weight, preferably 0.01 to 90 parts by weight, and more preferably 0.02 to 80 parts by weight with respect to 100 parts by weight of the polyimide. If the amount of filler added is less than this range, the effect of modification by the filler hardly appears, and if it exceeds this range, the mechanical properties of the film may be greatly impaired. Addition of filler
1. 1. A method of adding to a polymerization reaction solution before or during polymerization 2. A method of kneading fillers using three rolls after the completion of polymerization. Any method such as preparing a dispersion containing filler and mixing it with a polyamic acid organic solvent solution may be used, but a method of mixing a dispersion containing filler with a polyamic acid solution, particularly immediately before film formation. This method is preferable because the contamination by the filler in the production line is minimized. When preparing a dispersion containing a filler, it is preferable to use the same solvent as the polymerization solvent for the polyamic acid. Further, in order to disperse the filler satisfactorily and stabilize the dispersion state, a dispersant, a thickener and the like can be used within a range not affecting the film physical properties.

  A conventionally well-known method can be used about the method of manufacturing a polyimide film from these polyamic-acid solutions. This method includes a thermal imidization method and a chemical imidization method, and either method may be used to produce a film, but the imidization by the chemical imidation method is more preferably used in the present invention. It tends to be easy to obtain a polyimide film having various characteristics.

Moreover, the production process of the polyimide film particularly preferable in the present invention is as follows.
a) reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride in an organic solvent to obtain a polyamic acid solution;
b) casting a film-forming dope containing the polyamic acid solution on a support;
c) a step of peeling the gel film from the support after heating on the support;
d) further heating to imidize and dry the remaining amic acid,
It is preferable to contain.

  In the above step, a curing agent containing a dehydrating agent typified by an acid anhydride such as acetic anhydride and an imidation catalyst typified by a tertiary amine such as isoquinoline, β-picoline or pyridine may be used. .

  In the present invention, any one of the solution layer containing a thermoplastic polyimide precursor and the solution layer containing a heat-resistant polyimide precursor contains a chemical dehydrating agent and a catalyst to improve productivity. It is preferable for ensuring the mechanical strength of the film.

  Hereinafter, taking the chemical imide method as an example, the production process of the polyimide film will be described. However, the present invention is not limited to the following examples.

  The film forming conditions and heating conditions can vary depending on the type of polyamic acid, the thickness of the film, and the like.

A film forming dope is obtained by mixing a dehydrating agent and an imidization catalyst in a polyamic acid solution at a low temperature. Subsequently, this film-forming dope is cast into a film on a support such as a glass plate, an aluminum foil, an endless stainless steel belt, or a stainless drum, and the temperature on the support is 80 ° C. to 200 ° C., preferably 100 ° C. to 180 ° C. By heating in the region, the dehydrating agent and imidization catalyst are activated to partially cure and / or dry and then peel from the support to obtain a polyamic acid film (hereinafter referred to as a gel film).
The gel film is in the intermediate stage of curing from polyamic acid to polyimide, has a self-supporting property, and has the following formula (3)
(A−B) × 100 / B (Equation 3)
(However, in Formula (3), A and B represent the following.
A: Weight of the gel film B: Weight after heating the gel film at 450 ° C. for 20 minutes)
The volatile content calculated from is in the range of 5 to 500% by weight, preferably 5 to 200% by weight, more preferably 5 to 150% by weight. It is preferable to use a film in this range, and problems such as film breakage, uneven film color due to drying unevenness, and characteristic variations may occur during the baking process.

  The preferable amount of the dehydrating agent is 0.5 to 5 mol, preferably 1.0 to 4 mol, relative to 1 mol of the amic acid unit in the polyamic acid.

  Moreover, the preferable quantity of an imidation catalyst is 0.05-3 mol with respect to 1 mol of amic acid units in a polyamic acid, Preferably it is 0.2-2 mol.

  If the dehydrating agent and the imidization catalyst are below the above ranges, chemical imidization may be insufficient, and may break during firing or mechanical strength may decrease. Moreover, when these amounts exceed the above range, the progress of imidization becomes too fast, and it may be difficult to cast into a film, which is not preferable.

  The end of the gel film is fixed to avoid shrinkage during curing, water, residual solvent, residual conversion agent and catalyst are removed, and the remaining amic acid is completely imidized to obtain the present invention. A polyimide film is obtained.

  At this time, it is preferable to finally heat at a temperature of 300 to 650 ° C. for 5 to 400 seconds. Above this temperature and / or for a long time, the film may suffer from thermal degradation and may cause problems. Conversely, if the temperature is lower than this temperature and / or the time is shorter, the predetermined effect may not be exhibited.

  Moreover, in order to relieve the internal stress remaining in the film, heat treatment can be performed under the minimum tension necessary for transporting the film. This heat treatment may be performed in the film manufacturing process, or may be provided separately. The heating conditions vary depending on the characteristics of the film and the apparatus used, and therefore cannot be determined in general. The internal stress can be relaxed by heat treatment at a temperature of 450 ° C. or lower for 1 to 300 seconds, preferably 2 to 250 seconds, particularly preferably 5 to 200 seconds.

  Since polyimide is a material having high water absorption among plastics, it is preferable to use a heat-resistant polyimide film having as low water absorption as possible in order to further improve moisture-absorbing solder resistance when used as a material for FPC. Specifically, it is preferable to use a heat-resistant polyimide film having a water absorption rate of 1.7% or less. If a heat-resistant polyimide film having a low water absorption rate is used, the absolute amount of moisture that moves through the material during solder immersion can be reduced, leading to improved moisture absorption solder resistance.

  Further, the thickness of the adhesive layer in the adhesive film according to the present invention is not limited, but may be appropriately selected in consideration of the thickness of the entire adhesive film, the surface roughness of the metal foil to be bonded, The range of 1-12 micrometers is preferable, Furthermore, the range of 1.3-10 micrometers is preferable, Furthermore, the range of 1.5-8 micrometers is more preferable. Even if the adhesive layer is made thicker than the above range, the adhesive strength is not proportionally improved, and conversely, it may be difficult to control the linear expansion coefficient as the adhesive film. If the adhesive layer is thinner than the above range, the adhesive layer may not sufficiently bite into the irregularities on the surface of the metal foil, resulting in poor adhesion.

  Moreover, the thermoplastic polyimide of this invention can control various characteristics by limiting the raw material ratio to be used.

  The adhesive film of the present invention swells and whitens even when it is dampened in moisture-absorbing solder resistance (for example, 85 ° C. and 85% RH for 24 hours and then immersed in a 300 ° C. solder bath for 10 seconds). The level at which the appearance abnormality does not occur, etc.) can be improved.

  When a metal foil is laminated on the adhesive film of the present invention to form a metal-clad laminate, the metal foil peel strength is preferably 10 N / cm or more when peeled in the 180 ° direction. When the metal foil peeling strength is less than 10 N / cm, problems such as peeling of the copper foil occur when the obtained copper-clad laminate is processed.

  The heat-resistant polyimide film of the present invention preferably contains a thermoplastic polyimide block component in an amount of 20 to 60 mol% of the total polyimide. By using a heat-resistant film in this range, it becomes possible to improve moisture-absorbing solder heat resistance. The reason for this has not been clarified yet, but is presumed as follows. Defects in the moisture absorption solder heat resistance test, that is, whitening and foaming, are caused by rapid expansion at the interface between the metal foil and the polyimide layer when the moisture absorbed in the polyimide layer is immersed in a heated solder bath. This is a phenomenon that occurs. By introducing the block component of the thermoplastic polyimide layer into the high heat resistant polyimide layer, the water vapor transmission rate is remarkably improved, thereby preventing the rapid expansion of moisture at the interface between the metal foil and the polyimide layer. ing. Furthermore, the thermoplastic polyimide block component is contained in an amount of 20 to 60 mol%, preferably 25 to 55 mol%, particularly preferably 30 to 50 mol% of the whole polyimide.

  If the thermoplastic polyimide block component is below this range, it will be difficult to develop the excellent adhesiveness of the present invention, and if it exceeds this range, it will be difficult to finally form a high heat-resistant polyimide film.

  The repeating unit n of the block component of the thermoplastic polyimide of the present invention is preferably 3 to 99. Furthermore, 4-90 is more preferable. When the repeating unit n is less than this range, excellent adhesiveness is hardly exhibited and the hygroscopic expansion coefficient tends to be large. On the other hand, if the repeating unit n exceeds this range, the storage stability of the polyimide precursor solution tends to deteriorate, and the reproducibility of polymerization tends to decrease, such being undesirable.

  It is preferably formed by casting the polyimide precursor solution of the present invention on a support by coextrusion. The co-extrusion method is more advantageous than the sequential casting method because it is superior in productivity and because there are fewer steps of defects such as contamination due to fewer steps. Among the co-extrusion methods, in the thermal curing method in which imidization is carried out substantially only by heating, the steps of volatilization / removal of the solvent and imidization in the film forming step take a long time. Therefore, the chemical dehydrating agent and the catalyst are contained in any one of the solution layer containing the thermoplastic polyimide precursor and the solution layer containing the heat-resistant polyimide precursor, so that productivity is improved as compared with the thermal curing method. As a result, the metal-clad laminate can be provided at low cost. If the storage modulus of the adhesive layer at the solder test temperature is low, moisture in the adhesive film is suddenly released outside the system through the adhesive layer, resulting in whitening or swelling in the adhesive film or flexible metal-clad laminate. Can cause

  The method for producing an adhesive film according to the present invention is not particularly limited. For example, (i) a method of forming an adhesive layer on one or both sides of a heat-resistant polyimide film to be a core, and (ii) forming the adhesive layer into a sheet shape And (iii) a method in which the core layer and the adhesive layer are simultaneously formed by multilayer extrusion or the like. Among these, in the case of adopting the method (i), if the polyamic acid that is a precursor of the thermoplastic polyimide contained in the adhesive layer is completely imidized, the solubility in an organic solvent may be reduced. Therefore, it may be difficult to provide the adhesive layer on the heat-resistant polyimide film. Therefore, from the above viewpoint, it is more preferable to prepare a solution containing polyamic acid which is a precursor of thermoplastic polyimide, apply this to a heat-resistant polyimide film as a core, and then imidize. . When the thermoplastic polyimide is soluble, it may be used after imidization. Also, the imidization means is not limited to the thermal curing method and the chemical curing method, and a conventionally known method may be used.

  The flexible metal-clad laminate according to the present invention can be obtained by bonding a metal foil to the adhesive film. The metal foil to be used is not particularly limited, but when the flexible metal-clad laminate of the present invention is used for electronic equipment / electric equipment, for example, copper or copper alloy, stainless steel or its alloy, nickel Alternatively, a metal foil made of nickel alloy (including 42 alloy), aluminum, or aluminum alloy can be used. In general flexible metal-clad laminates, copper foil such as rolled copper foil and electrolytic copper foil is frequently used, but it can also be preferably used in the present invention. In addition, the antirust layer, the heat-resistant layer, or the contact bonding layer may be apply | coated to the surface of these metal foil.

  In the present invention, the thickness of the metal foil is not particularly limited, and may be any thickness as long as a sufficient function can be exhibited depending on the application.

  The method for bonding the adhesive film and the metal foil is not particularly limited, and for example, a continuous process using a hot roll laminating apparatus having a pair of metal rolls or a double belt press (DBP) can be used. Among these, it is preferable to use a hot roll laminating apparatus having a pair of metal rolls because the apparatus configuration is simple and advantageous in terms of maintenance cost. The “heat roll laminating apparatus having a pair of metal rolls” herein may be an apparatus having a metal roll for heating and pressurizing a material, and the specific apparatus configuration is particularly limited. It is not a thing.

  The temperature at which the adhesive film and the metal foil are bonded is preferably a glass transition temperature (Tg) of the thermoplastic polyimide contained in the adhesive layer of the adhesive film + 50 ° C. or higher and a melting point (Tm) −50 ° C. or higher, The thermoplastic polyimide contained in the adhesive layer of the adhesive film is more preferably Tg + 100 ° C. or higher and Tm−20 ° C. or higher. If it is Tg + 50 degreeC or more and the temperature of Tm-50 degreeC or more, an adhesive film and metal foil can be heat-laminated favorably. Moreover, when laminating | stacking metal foil continuously, if it is Tg + 100 degreeC or more and Tm-20 degreeC or more, the lamination speed | rate can be raised and the productivity can be improved more.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to these. In addition, the hygroscopic solder resistance and the peel strength of the metal foil of the flexible metal-clad laminate in which the metal foil is bonded to the thermoplastic polyimide used in the adhesive layers in Examples and Comparative Examples are measured or evaluated as follows. did.

[Hygroscopic solder resistance of flexible metal-clad laminate]
The double-sided flexible metal-clad laminates obtained in the examples and comparative examples were cut into 3.5 cm squares, and one side (for convenience, the A side) had a 2.5 cm square copper foil layer left in the center of the sample. On the opposite side (for convenience, B side), five samples were prepared by removing the excess copper foil layer by etching treatment so that the copper foil layer remained on the entire surface. The obtained sample was 40 ° C., 90% R.D. H. The sample was left for 96 hours under the humidification conditions, and a moisture absorption treatment was performed. After the moisture absorption treatment, the sample was immersed in a solder bath at 260 ° C., 280 ° C., or 300 ° C. for 10 seconds. For the sample after solder immersion, the copper foil layer on the B side is completely removed by etching, and the appearance of the part where the copper foil overlaps is unchanged (good), whitening of the adhesive film layer, swelling, copper When any peeling of the foil layer was confirmed, it was set as x (bad).

[Metal foil peel strength of flexible metal-clad laminate]
A sample was prepared according to “6.5 peel strength” of JIS C6471, and a 5 mm wide metal foil part was peeled off at a peeling angle of 180 degrees and 50 mm / min, and the load was measured. Furthermore, as the adhesive strength in a high temperature and high humidity environment, the substrate was left to stand at 121 ° C., humidity 95%, 2 atm oven for 96 hours, allowed to reach room temperature, and then evaluated by 90 ° peel strength. .

[Measurement of storage modulus of polyimide film with adhesive layer only]
The polyimide film obtained from the polyimide precursor resin of each synthesis example was used with a DMS6100 manufactured by Seiko Electronics Co., Ltd. (sample size width: 9 mm, length: 50 mm), and the temperature rising rate was 1, 5, and 10 Hz. Measurements were made at a temperature range of 20 to 400 ° C. at 3 ° C./min, and the storage elastic modulus values at 280 ° C. and 350 ° C. were read.

(Synthesis Example 1; Synthesis of thermoplastic polyimide precursor)
807.2 g of N, N-dimethylformamide (hereinafter also referred to as DMF), 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) in a glass flask having a capacity of 2000 ml 111.0 g was added, and 57.2 g of pyromellitic dianhydride (hereinafter also referred to as PMDA) was added while stirring under a nitrogen atmosphere, followed by stirring at 25 ° C. for 1 hour. A solution in which 1.8 g of PMDA was dissolved in 22.8 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 2: Synthesis of thermoplastic polyimide precursor)
Add 807.3 g of DMF and 110.4 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 4.0 g of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter also referred to as BPDA) and stirring under a nitrogen atmosphere, 53.9 g of PMDA was added, and 25 ° C. For 1 hour. A solution prepared by dissolving 1.8 g of PMDA in 22.7 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 3; Synthesis of thermoplastic polyimide precursor)
Add 807.5 g of DMF and 109.7 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 7.9 g of BPDA while stirring under a nitrogen atmosphere, 50.7 g of PMDA was added and stirred at 25 ° C. for 1 hour. A solution in which 1.7 g of PMDA was dissolved in 22.5 g of DMF was separately prepared, and this was gradually added to the reaction solution while being careful of the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 4; Synthesis of thermoplastic polyimide precursor)
Add 802.6 g of DMF and 107.9 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 8.5 g of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (hereinafter also referred to as BTDA), stirring 7.7 g of BPDA under a nitrogen atmosphere and stirring under a nitrogen atmosphere While adding 47.0 g of PMDA, the mixture was stirred at 25 ° C. for 1 hour. A solution prepared by dissolving 1.8 g of PMDA in 23.3 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 5: Synthesis of thermoplastic polyimide precursor)
Add 807.6 g of DMF and 109.0 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml, and stir in a nitrogen atmosphere. While adding 11.7 g of BPDA and stirring under a nitrogen atmosphere, 47.5 g of PMDA was added and stirred at 25 ° C. for 1 hour. A solution in which 1.7 g of PMDA was dissolved in 22.4 g of DMF was separately prepared, and this was gradually added to the reaction solution while being careful of the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 6; Synthesis of thermoplastic polyimide precursor)
Add 807.7 g of DMF and 108.4 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 15.5 g of BPDA and stirring under a nitrogen atmosphere, 44.4 g of PMDA was added and stirred at 25 ° C. for 1 hour. A solution in which 1.7 g of PMDA was dissolved in 22.3 g of DMF was separately prepared, and this was gradually added to the reaction solution while being careful of the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 7; Synthesis of thermoplastic polyimide precursor)
Add 808.0 g of DMF and 107.1 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 23.0 g of BPDA while stirring under a nitrogen atmosphere, 38.1 g of PMDA was added and stirred at 25 ° C. for 1 hour. A solution in which 1.7 g of PMDA was dissolved in 22.0 g of DMF was separately prepared, and this was gradually added to the reaction solution while being careful of the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 8; Synthesis of thermoplastic polyimide precursor)
Add 808.5 g of DMF and 104.7 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 37.5 g of BPDA and stirring under a nitrogen atmosphere, 26.1 g of PMDA was added and stirred at 25 ° C. for 1 hour. A solution in which 1.7 g of PMDA was dissolved in 21.5 g of DMF was separately prepared, and this was gradually added to the reaction solution while being careful of the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 9: Synthesis of thermoplastic polyimide precursor)
Add 809.0 g of DMF and 102.3 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 51.3 g of BPDA and stirring under a nitrogen atmosphere, 16.3 g of PMDA was added and stirred at 25 ° C. for 1 hour. A solution in which 1.6 g of PMDA was dissolved in 21.0 g of DMF was separately prepared, and this was gradually added to the above reaction solution while being careful of the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 10; Synthesis of thermoplastic polyimide precursor)
Add 807.8 g of DMF and 108.3 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 12.8 g of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (hereinafter also referred to as BTDA), while stirring under a nitrogen atmosphere, 47.2 g of PMDA was added, and at 25 ° C. Stir for 1 hour. A solution in which 1.7 g of PMDA was dissolved in 22.3 g of DMF was separately prepared, and this was gradually added to the reaction solution while being careful of the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 11; Synthesis of thermoplastic polyimide precursor)
Add 773.7 g of DMF and 127.9 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. Then, 14.3 g of oxydiphthalic dianhydride (hereinafter also referred to as ODPA) was added, and 55.7 g of PMDA was added while stirring in a nitrogen atmosphere, followed by stirring at 25 ° C. for 1 hour. A solution in which 2.0 g of PMDA was dissolved in 26.3 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 12; Synthesis of thermoplastic polyimide precursor)
Add 806.8 g of DMF and 107.3 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml, and stir in a nitrogen atmosphere. While adding 2.8 g of 4,4′-oxydianiline (hereinafter also referred to as “4,4′-ODA”), stirring under a nitrogen atmosphere, adding 58.2 g of PMDA and stirring at 25 ° C. for 1 hour did. A solution prepared by dissolving 1.8 g of PMDA in 22.7 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 13; Synthesis of thermoplastic polyimide precursor)
Add 806.4 g of DMF and 103.4 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask having a capacity of 2000 ml, and stir in a nitrogen atmosphere. While adding 5.6 g of 4,4′-oxydianiline (hereinafter also referred to as “4,4′-ODA”), while stirring under a nitrogen atmosphere, add 59.2 g of PMDA and stir at 25 ° C. for 1 hour. did. A solution prepared by dissolving 1.8 g of PMDA in 23.6 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 14; Synthesis of thermoplastic polyimide precursor)
Add 804.7 g of DMF and 86.4 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml, and stir in a nitrogen atmosphere. While adding 18.1 g of 4,4′-oxydianiline (hereinafter also referred to as “4,4′-ODA”) and stirring under a nitrogen atmosphere, 63.6 g of PMDA was added and the mixture was heated at 25 ° C. for 1 hour. Stir. A solution in which 2.0 g of PMDA was dissolved in 25.4 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 15: Synthesis of thermoplastic polyimide precursor)
Add 802.6 g of DMF and 66.7 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml, and stir in a nitrogen atmosphere. While adding 32.5 g of 4,4′-oxydianiline (hereinafter also referred to as “4,4′-ODA”), stirring under a nitrogen atmosphere, adding 68.7 g of PMDA and stirring at 25 ° C. for 1 hour did. A solution in which 2.0 g of PMDA was dissolved in 25.4 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 16; Synthesis of thermoplastic polyimide precursor)
Add 807.0 g of DMF and 106.6 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 2.7 g of 4,4′-oxydianiline (hereinafter, also referred to as 4,4′-ODA), adding 4.0 g of BPDA while stirring under a nitrogen atmosphere, and stirring with PMDA, Was added and stirred at 25 ° C. for 1 hour. A solution in which 1.8 g of PMDA was dissolved in 23.1 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 17; Synthesis of thermoplastic polyimide precursor)
Add 807.1 g of DMF and 106.0 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 2.7 g of 4,4′-oxydianiline (hereinafter also referred to as 4,4′-ODA), adding 8.0 g of BPDA while stirring in a nitrogen atmosphere, and stirring with PMDA 51.6 g was added and stirred at 25 ° C. for 1 hour. A solution in which 1.8 g of PMDA was dissolved in 22.9 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Synthesis Example 18; Synthesis of thermoplastic polyimide precursor)
Add 805.4 g of DMF and 89.7 g of 2,2-bis- [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as BAPP) to a glass flask with a capacity of 2000 ml and stir in a nitrogen atmosphere. While adding 14.6 g of 4,4′-oxydianiline (hereinafter also referred to as “4,4′-ODA”), adding 8.6 g of BPDA while stirring under a nitrogen atmosphere, stirring PMDA under a nitrogen atmosphere, Was added and stirred at 25 ° C. for 1 hour. A solution prepared by dissolving 1.9 g of PMDA in 24.6 g of DMF was separately prepared, and this was gradually added to the above reaction solution while paying attention to the viscosity and stirred. When the viscosity reached 1000 poise, the addition and stirring were stopped to obtain a polyamic acid solution.

(Comparative Example 1)
After diluting the polyamic acid solution obtained in Synthesis Example 1 with DMF to a solid content concentration of 8.5% by weight, non-thermoplasticity comprising 17 μm pyromellitic dianhydride and 4,4′-oxydianiline A polyamic acid solution was applied to both sides of the polyimide film so that the final single-sided thickness of the thermoplastic polyimide layer (being an adhesive layer) was 4 μm, and then heated at 140 ° C. for 1 minute. Subsequently, imidization was performed by heating at 340 ° C. for 20 seconds to obtain an adhesive film.

  18 μm rolled copper foil (BHY-22B-T; manufactured by Nikko Metal) on both sides of the obtained adhesive film, and protective materials (125 μm pyromellitic dianhydride and 4,4′-oxydianiline on both sides) A non-thermoplastic polyimide film) and heated continuously using a hot roll laminator at a lamination temperature of 360 ° C., a lamination pressure of 196 N / cm (20 kgf / cm), and a lamination speed of 1.0 m / min. Lamination was performed to produce a flexible metal-clad laminate according to the present invention.

  Next, after diluting the polyamic acid solution obtained in Synthesis Example 1 with DMF until the solid content concentration becomes 11%, it is cast on aluminum foil so that the final thickness becomes 10 μm, and heated at 140 ° C. for 2 minutes. It was. Subsequently, imidization was performed by heating at 340 ° C. for 1 minute to obtain a polyimide film having only an adhesive layer.

(Comparative Example 2)
An adhesive film, a flexible metal-clad laminate, and an adhesive were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 2 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

( Reference Example 1 )
An adhesive film, a flexible metal-clad laminate, and an adhesive were prepared in the same manner as in Comparative Example 1, except that the polyamic acid solution obtained in Synthesis Example 3 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

( Reference Example 2 )
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 4 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

( Reference Example 3 )
Instead of the polyamic acid solution obtained in Synthesis Example 1, the same procedure as in Comparative Example 1 was performed except that the polyamic acid solution obtained in Synthesis Example 5 was used, and the adhesive film, flexible metal-clad laminate and adhesion A polyimide film with only a layer was obtained.

( Reference Example 4 )
An adhesive film, a flexible metal-clad laminate, and an adhesive were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 6 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

( Reference Example 5 )
An adhesive film, a flexible metal-clad laminate, and an adhesive were prepared in the same manner as in Comparative Example 1, except that the polyamic acid solution obtained in Synthesis Example 7 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

( Reference Example 6 )
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1, except that the polyamic acid solution obtained in Synthesis Example 8 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Comparative Example 3)
An adhesive film, a flexible metal-clad laminate, and an adhesive were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 9 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Comparative Example 4)
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 10 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Comparative Example 5)
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 11 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Example 7)
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 12 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Example 8)
The same procedure as in Comparative Example 1 was performed except that the polyamic acid solution obtained in Synthesis Example 13 was used instead of the polyamic acid solution obtained in Synthesis Example 1, and an adhesive film, a flexible metal-clad laminate, and an adhesive were bonded. A polyimide film with only a layer was obtained.

Example 9
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1, except that the polyamic acid solution obtained in Synthesis Example 14 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Comparative Example 6)
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 15 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Comparative Example 7)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 5 was used, and imidation of the adhesive film was heated at 300 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

( Reference Example 10 )
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 5 was used, and imidization of the adhesive film was heated at 360 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

( Reference Example 11 )
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 5 was used, and imidization of the adhesive film was heated at 390 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Comparative Example 8)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 5 was used, and imidation of the adhesive film was heated at 420 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Comparative Example 9)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 13 was used, and imidization of the adhesive film was heated at 300 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Example 12)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 13 was used, and imidation of the adhesive film was heated at 360 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Example 13)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 13 was used, and imidization of the adhesive film was heated at 390 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Comparative Example 10)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 13 was used, and imidation of the adhesive film was heated at 420 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Comparative Example 11)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 9 was used, and imidation of the adhesive film was heated at 300 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Comparative Example 12)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 9 was used, and imidization of the adhesive film was heated at 360 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Comparative Example 13)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 9 was used, and imidization of the adhesive film was heated at 390 ° C. for 20 seconds. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Comparative Example 14)
Instead of the polyamic acid solution obtained in Synthesis Example 1, the polyamic acid solution obtained in Synthesis Example 9 was used, and imidization of the adhesive film was heated at 420 ° C. for 20 seconds, and was the same as Comparative Example 1. The operation was performed to obtain an adhesive film and a flexible metal-clad laminate.

(Example 14)
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1, except that the polyamic acid solution obtained in Synthesis Example 16 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Example 15)
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1, except that the polyamic acid solution obtained in Synthesis Example 17 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

(Example 16)
An adhesive film, a flexible metal-clad laminate, and an adhesive film were prepared in the same manner as in Comparative Example 1 except that the polyamic acid solution obtained in Synthesis Example 18 was used instead of the polyamic acid solution obtained in Synthesis Example 1. A polyimide film with only a layer was obtained.

  Table 1 shows the characteristic results of the flexible metal-clad laminates obtained in each example and comparative example. Table 2 shows the characteristic results of the films having only the adhesive layers obtained in the respective Examples and Comparative Examples.

Claims (10)

An adhesive film in which an adhesive layer containing a thermoplastic polyimide is provided on at least one surface of a heat-resistant polyimide film, the thermoplastic polyimide satisfying the following (A) and (B), and the polyimide precursor is 320 to A method for producing an adhesive film, which is imidized at a temperature of 400 ° C .:
(A) The thermoplastic polyimide is mainly composed of pyromellitic dianhydride and 2,2-bis- [4- (4-aminophenoxy) phenyl] propane, and 2,2-bis- [ A diamine other than 4- (4-aminophenoxy) phenyl] propane is contained in 5 to 30 mol% of 100 mol% of the diamine component ,
(B) The total number of moles of acid dianhydride other than pyromellitic dianhydride and diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane is 5 to 50%. The method for producing an adhesive film according to claim 1 , wherein the diamine other than 2,2-bis- [4- (4-aminophenoxy) phenyl] propane is 4,4'-oxydianiline. . When the metallic foil and laminated metal-clad laminate to the adhesive film, any one of the claims 1-2, characterized in that the metal foil peeling strength is 180 degree direction separation at 10 N / cm or more The manufacturing method of the adhesive film of description. The said thermoplastic polyimide is storage elastic modulus 1 * 10 < ⁸ > Pa or more in 280 degreeC, and is less than 1 * 10 < ⁸ > Pa storage elastic modulus in 350 degreeC , The any one of Claims 1-3 characterized by the above-mentioned. Method for producing an adhesive film. The said heat resistant polyimide film contains 20-60 mol% of block components of thermoplastic polyimide of the whole polyimide, The manufacturing method of the adhesive film of any one of Claims 1-4 characterized by the above-mentioned. The method for producing an adhesive film according to any one of claims 1 to 5 , wherein the repeating unit n of the block component of the thermoplastic polyimide is 3 to 99. It forms by casting the said polyimide precursor solution on a support body by coextrusion, The manufacturing method of the adhesive film of any one of Claims 1-6 characterized by the above-mentioned. Solution layer containing the thermoplastic polyimide precursor, and any one layer of a solution layer containing a heat resistant polyimide precursor of claim 1, wherein the chemical dehydrating agent and a catalyst is contained The manufacturing method of the adhesive film of any one of Claims 1. An adhesive film produced by the method for producing an adhesive film according to claim 1 . A flexible metal-clad laminate obtained by bonding a metal foil to the adhesive film according to claim 9 .