JP5720355B2 - Polyimide film manufacturing apparatus and method for manufacturing polyimide film - Google Patents

Description

  The present invention relates to a polyimide film manufacturing apparatus and a polyimide film manufacturing method.

  The polyimide film has high heat resistance and high electrical insulation, and even a thin film satisfies the rigidity, heat resistance, and electrical insulation necessary for handling. For this reason, it is widely used in industrial fields, such as an electrical insulation film, a heat insulation film, and a base film of a flexible circuit board.

  The polyimide film is formed by coating a polyimide precursor solution such as polyamic acid on a support in the form of a film and drying it by heating to form a self-supporting film having self-supporting properties. It is manufactured by heating to complete imidization.

  In addition, for the purpose of imparting various physical properties such as surface modification of the polyimide film and heat resistance, for example, as described in Patent Document 1, an organic solution is applied to the surface of the self-supporting film and dried by heating. It has been conventionally practiced to imidize after removing a part or all of the solvent of the applied organic solution.

JP 2009-6542 A

  Conventionally, the organic solution applied to the surface of the self-supporting film has been dried by passing it through a drying furnace having a high atmospheric temperature.

  However, in the conventional method of drying by passing the inside of the drying furnace with a high atmospheric temperature, the drying efficiency is poor, and it is necessary to lengthen the furnace length of the drying furnace, or the atmosphere temperature in the drying furnace is made higher. There is a problem that operation cost and equipment cost increase.

  An object of the present invention is to provide a polyimide film production apparatus and a polyimide film production method capable of producing a polyimide film having surface modification and various physical properties with high productivity.

  It was thought that when hot air was blown onto the self-supporting film coated with the organic solution and dried, the applied organic solution was caused to flow on the self-supporting film by the hot air. However, the present inventors diligently examined the drying conditions, and even when hot air was blown onto the self-supporting film coated with the organic solution, the organic solution was not unexpectedly repelled and was applied in a short time. The present inventors have found that the organic solution can be dried and have completed the present invention.

That is, the polyimide film manufacturing apparatus of the present invention is
A casting furnace for drying a casting cast with a polyimide precursor solution on a support to form a self-supporting film having self-supporting property;
A coater furnace having an organic solution coating device for applying an organic solution on both sides or one side of the self-supporting film that has passed through the casting furnace, and a dryer for blowing hot air on the self-supporting film coated with the organic solution;
And a curing furnace that completes imidization by heating the self-supporting film that has passed through the coater furnace.

  In the polyimide film manufacturing apparatus of the present invention, the distance (d) from the tip of the dryer that blows hot air to the surface of the self-supporting film is preferably 10 to 35 mm.

  In the polyimide film manufacturing apparatus of the present invention, at least a part of the upper dryer disposed on the upper surface side of the self-supporting film and the lower dryer disposed on the lower surface side of the self-supporting film face each other. Are preferably arranged.

  In the dryer of the polyimide film manufacturing apparatus of the present invention, it is preferable that a plurality of hot air jets are arranged at an angle with respect to the traveling direction of the self-supporting film on a horizontal head.

Moreover, the manufacturing method of the polyimide film of the present invention is a manufacturing method of a polyimide film using the polyimide film manufacturing apparatus,
A casting step of casting a polyimide precursor solution on a support surface and drying to form a self-supporting film having self-supporting property;
The surface for treating the surface of the self-supporting film by applying the organic solution to one or both sides of the self-supporting film obtained in the casting step and then drying the organic solution applied to the self-supporting film. Processing steps;
A curing step for heating the self-supporting film obtained in the surface treatment step to complete imidization,
In the surface treatment step, hot air is blown on at least one surface of the self-supporting film on the self-supporting film coated with the organic solution, and the organic solution applied to the self-supporting film is dried. It is characterized by that.

  In the method for producing a polyimide film of the present invention, in the surface treatment step, after applying an organic solution to one surface of the self-supporting film, hot air is simultaneously sprayed on both surfaces of the self-supporting film to perform the drying. It is preferable.

  In the method for producing a polyimide film of the present invention, in the surface treatment step, after applying an organic solution to one surface of the self-supporting film, hot air is applied to at least the application surface of the organic solution of the self-supporting film. It is preferable to perform the drying by spraying.

  According to the present invention, for the self-supporting film coated with the organic solution, hot air is blown on at least one surface of the self-supporting film, and the organic solution applied to the self-supporting film is dried. The organic solution can be dried in a short time. Moreover, since the hot air temperature can be lowered as compared with the conventional method of passing through a drying furnace having a high atmospheric temperature and drying, the amount of energy used can be reduced and the running cost is excellent. Moreover, since the drying equipment can be reduced in size, the equipment cost can be greatly reduced.

It is a schematic block diagram of 1st Embodiment of the polyimide film manufacturing apparatus of this invention. It is a schematic block diagram of the coater furnace used for the polyimide film manufacturing apparatus. (A) is an enlarged view of a drying apparatus, (b) is AA sectional drawing of (a). It is a schematic block diagram of the coater furnace used by 2nd Embodiment of the polyimide film manufacturing apparatus of this invention. It is a schematic block diagram of the drying apparatus of the same coater furnace. It is a schematic block diagram of the coater furnace used by 3rd Embodiment of the polyimide film manufacturing apparatus of this invention. It is a schematic block diagram of the drying apparatus of the same coater furnace. It is a schematic block diagram of the drying apparatus used in each test example of an Example.

  1st Embodiment of the polyimide film manufacturing apparatus of this invention is described using FIG.

  The polyimide film manufacturing apparatus shown in FIG. 1 includes a die 2 for extruding a polyimide precursor solution 1, a support 3 for casting the polyimide precursor solution 1 extruded from the tip of the die 2, and a cast polyimide precursor casting. A casting furnace 4 for heating and drying the product 1a to form a self-supporting film 1b, a coater furnace 5 for applying a surface treatment by applying an organic solution to the self-supporting film, and a surface-treated self passing through the coating furnace 5 The support film 1c is heat-treated to complete imidization and to obtain a polyimide film 1d.

  There is no limitation in particular as the support body 3, A metal belt, a metal drum, etc. can be used.

  Referring also to FIG. 2, the coater furnace 5 includes a first organic solution coating device 11a, a first drying device 12a, and a self-supporting film 1b that apply an organic solution to one surface S1 of the self-supporting film 1b. A second organic solution coating device 11b and a second drying device 12b for coating the organic solution on the other surface S2 are arranged in order along the traveling direction A of the self-supporting film 1b.

  In the drying device 12a (12b), dryers 13a and 13b are arranged at positions facing each other through the self-supporting film 1b at predetermined intervals from the upper surface and the lower surface of the self-supporting film 1b. That is, hot air can be simultaneously blown onto the upper and lower surfaces of the self-supporting film 1b being conveyed. In this embodiment, one dryer is provided on each of the upper surface and the lower surface of the self-supporting film 1b, but two or more dryers may be provided in series.

  The distance (d) from the tip of the dryer 13a (13b) that blows hot air to the surface 1b of the self-supporting film is preferably 10 to 35 mm from the viewpoint of the dry state.

  Referring also to FIG. 3, the dryer 13 a (13 b) has a head 20 having a space into which hot air is sent and having a plurality of hot air jets on one side arranged in the horizontal direction. doing. The hot air injection ports 21 are arranged in a number of parallel rows, preferably at an angle θ with respect to the traveling direction A of the self-supporting film 1b. The angle θ is preferably 1 to 10 °, and more preferably 2 to 5 °.

  The hot air injection port 21 is arranged at an angle with respect to the traveling direction A of the self-supporting film 1b, so that the temperature distribution on the surface of the self-supporting film 1b is uniform (the heat history is uniform in the width direction). And uneven drying is less likely to occur. The cause of this is not necessarily clear, but when the ejection hole is not at an angle with respect to the film traveling direction, hot air is continuously blown to the position facing the outlet, so the ejection hole in the film width direction. Although the temperature distribution occurs at an arrangement pitch of, the angle of the air outlets has the same effect as the position of the air outlets moving sequentially in the film width direction as the film advances, and the temperature distribution is Presumed to be uniform.

  Although there is no restriction | limiting in particular about the shape of the hot air injection nozzle 21, Typically, a round hole, a square hole, etc. are mentioned.

  Next, taking the case where the said polyimide film manufacturing apparatus is used as an example, the manufacturing method of the polyimide film of this invention is demonstrated.

[Casting process]
The polyimide precursor solution 1 is extruded from the tip of the die 2 and cast on the support 3 to form a film-like polyimide precursor casting 1a.

  The polyamic acid solution which is a polyimide precursor solution can be obtained by reacting a tetracarboxylic acid component and a diamine component by a known method. For example, it can be produced by polymerizing a tetracarboxylic acid component and a diamine component in an organic solvent usually used for producing polyimide.

  Examples of the tetracarboxylic acid component include aromatic tetracarboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and the like. Specific examples include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-oxydiphthalic dianhydride, diphenylsulfone-3. , 4,3 ′, 4′-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1, Aromatic tetracarboxylic dianhydrides such as 1,3,3,3-hexafluoropropane dianhydride are exemplified.

  Examples of the diamine component include aromatic diamines, aliphatic diamines, and alicyclic diamines. Specific examples include p-phenylenediamine, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, m-tolidine, p-tolidine, 5-amino-2- (p-aminophenyl) benzoxazole, 4 , 4′-diaminobenzanilide, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,3 '-Bis (3-aminophenoxy) biphenyl, 3,3'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) ) Biphenyl, bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4-aminophenoxy) phene Ether], bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) And aromatic diamines such as phenyl] propane.

  Examples of the combination of the tetracarboxylic acid component and the diamine component include the following 1) to 3) from the viewpoints of mechanical properties and heat resistance.

1) 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine, or p-phenylenediamine and 4,4-diaminodiphenyl ether (for example, PPD / DADE (molar ratio) ) Is preferably 100/0 to 85/15.)).
2) 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride (for example, s-BPDA / PMDA (molar ratio) is 0/100 to 90/10) P-phenylenediamine, or p-phenylenediamine and 4,4-diaminodiphenyl ether (for example, PPD / DADE (molar ratio) is preferably 90/10 to 10/90). Combination.
3) pyromellitic dianhydride, p-phenylenediamine and 4,4-diaminodiphenyl ether (for example, PPD / DADE (molar ratio) is preferably 90/10 to 10/90). Combination.

  A known solvent can be used as the organic solvent, and examples thereof include N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide and the like. These organic solvents may be used alone or in combination of two or more.

  When imidation is completed by thermal imidation of the polyimide precursor solution, an imidization catalyst, an organic phosphorus-containing compound, inorganic fine particles, and the like may be added to the polyamic acid solution as necessary.

  When the polyimide precursor solution is completely imidized by chemical imidization, a cyclization catalyst, a dehydrating agent, inorganic fine particles, and the like may be added to the polyamic acid solution as necessary.

  Examples of the imidization catalyst include a substituted or unsubstituted nitrogen-containing heterocyclic compound, an N-oxide compound of the nitrogen-containing heterocyclic compound, a substituted or unsubstituted amino acid compound, an aromatic hydrocarbon compound having a hydroxyl group, or an aromatic Heterocyclic compounds are mentioned.

  Examples of the cyclization catalyst include aliphatic tertiary amines, aromatic tertiary amines, and heterocyclic tertiary amines.

  Examples of the dehydrating agent include aliphatic carboxylic acid anhydrides and aromatic carboxylic acid anhydrides.

  The inorganic fine particles include fine particle titanium dioxide powder, silicon dioxide (silica) powder, magnesium oxide powder, aluminum oxide (alumina) powder, inorganic oxide powder such as zinc oxide powder, fine particle silicon nitride powder, titanium nitride Examples thereof include inorganic nitride powder such as powder, inorganic carbide powder such as silicon carbide powder, and inorganic salt powder such as particulate calcium carbonate powder, calcium sulfate powder and barium sulfate powder. These inorganic fine particles may be used in combination of two or more. In order to uniformly disperse these inorganic fine particles, a means known per se can be applied.

  Examples of the organic fine particles include polyimide particles and crosslinked resin particles.

  The solid content concentration (polymer component) of the polyimide precursor solution is not particularly limited as long as the concentration is within a viscosity range suitable for film production by casting. 10 mass%-30 mass% are preferable, 15 mass%-27 mass% are more preferable, and 16 mass%-24 mass% are still more preferable.

  The polyimide precursor casting 1a is introduced into a casting furnace 4 and dried by heating to form a self-supporting film 1b having self-supporting properties.

  Here, having self-supporting means a state having a strength that can be peeled off from the support 3.

  The drying conditions (heating conditions) for forming the self-supporting film 1b are not particularly limited, but in the thermal imidization, it can be produced by heating at a temperature of 100 to 180 ° C. for about 2 to 60 minutes.

  The self-supporting film 1b only needs to have the solvent removed and / or imidized to such an extent that it can be peeled off from the support 3. In the thermal imidization, it is preferable to carry out such that the heating loss is 20 to 50% by mass. If the loss on heating is in the range of 20 to 50% by mass, the mechanical properties of the self-supporting film are sufficient.

Here, the loss on heating of the self-supporting film 1b is a value obtained by the following equation from the mass W1 of the self-supporting film and the mass W2 of the cured film.
Heat loss (mass%) = {(W1-W2) / W1} × 100

  The self-supporting film 1b that has passed through the casting furnace 4 is peeled off from the support 3 and sent to the coater furnace 5 to perform a surface treatment process. The method for peeling the self-supporting film 1b from the support 3 is not particularly limited, and examples thereof include a method of cooling the self-supporting film 1b and applying a tension via a roll to peel it.

[Surface treatment process]
In the surface treatment step, the organic solution is applied to one side or both sides of the self-supporting film 1b, and then the applied organic solution is dried to treat the surface of the self-supporting film.

  The organic solution applied to the self-supporting film can be appropriately selected and used depending on the purpose of application such as surface modification of the film.

  For example, (1) only an organic solvent, (2) an organic solvent containing a surface treatment agent, (3) an organic solvent containing inorganic fine particles, (4) an organic solvent containing a surface treatment agent and inorganic fine particles, (5 Only polyimide precursor solution such as polyamic acid, (6) polyimide precursor solution such as polyamic acid containing surface treatment agent, (7) polyimide precursor solution such as polyamic acid containing inorganic fine particles, (8) surface Polyimide precursor solution such as polyamic acid containing treatment agent and inorganic fine particles, (9) organic fine particles such as polyimide particles, (10) polyimide precursor solution such as polyamic acid containing organic fine particles, (11) surface treatment And a polyimide precursor solution such as polyamic acid containing an agent and organic fine particles.

  As the organic solution, in addition to the organic solvent used for the polyimide precursor solution described above, alcohols such as methanol, ethanol and propanol, ketones such as acetone, aromatic hydrocarbons such as benzene, toluene and ethylbenzene, hexane, Organic solvents such as aliphatic or alicyclic hydrocarbons such as heptane, octane and cyclohexane, and ethers can be used. These organic solvents can be used alone or in combination of two or more. Well, it may contain a small amount of water. The same thing as the organic solvent of a polyimide precursor solution is especially preferable.

  Examples of the surface treatment agent include various coupling agents such as a silane coupling agent, a borane coupling agent, an aluminum coupling agent, an aluminum chelating agent, a titanate coupling agent, an iron coupling agent, and a copper coupling agent. The processing agent which improves adhesiveness and adhesiveness, such as a chelating agent, can be mentioned. It can select suitably according to the intended purpose. In particular, when a silane coupling agent is used as the surface treatment agent, excellent effects such as improved adhesion can be obtained. Although it does not specifically limit as a silane coupling agent, At least 1 component chosen from an aminosilane coupling agent, an epoxy silane coupling agent, a mercapto silane coupling agent, etc. can be used. Among them, epoxy silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; N-β -(Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) ) -Γ-aminopropyltriethoxysilane, N- (aminocarbonyl) -γ-aminopropyltriethoxysilane, N- [β- (phenylamino) -ethyl] -γ-aminopropyltriethoxysilane, and other aminosilane-based cups Ring agent: γ-mercaptopropyltrimethoxysilane, γ-mercap Triethoxysilane, .gamma.-mercaptopropyl methyl dimethoxy silane, mercapto-based silane coupling agents such as .gamma.-mercaptopropyl methyldiethoxysilane are preferred. Moreover, since it is easy to hydrolyze, the silane coupling agent which contains a methoxy group as an alkoxy group is preferable. Particularly preferred are N-phenyl-γ-aminopropyltrimethoxysilane and γ-mercaptopropyltrimethoxysilane.

  As said inorganic fine particle, the thing similar to the inorganic fine particle used for the above-mentioned polyimide precursor solution can be suitably selected according to a use purpose.

  Referring also to FIG. 2, the organic solution is applied from the first organic solution applying apparatus 11 a to the surface S <b> 1 of the self-supporting film 1 b that is conveyed with a certain tension applied by the conveying roller 15.

  The application of the organic solution to the self-supporting film 1b is not particularly limited as long as it can be applied uniformly. For example, a known coating method such as gravure coating, spin coating, silk screen, dip coating, spray coating, bar coating, knife coating, roll coating, blade coating, or die coating is used. be able to. The coating amount of the organic solution can be appropriately selected depending on the purpose of use.

  The self-supporting film 1b1 coated with the organic solution on the surface S1 is conveyed to the first drying device 12a, where the organic solution coated on the surface S1 is dried.

  In the present invention, the drying treatment of the organic solution is performed by blowing hot air on at least one surface of the self-supporting film 1b1. Hot air may be ejected from either the dryer 13a or the dryer 13b, and the hot air may be blown onto only one of the upper surface or the lower surface of the self-supporting film 1b1 to dry. It is preferable to blow hot air on the upper and lower surfaces of the self-supporting film 1b1 conveyed to the drying device 12a and simultaneously dry the hot air. By performing the drying treatment by simultaneously blowing hot air on the upper and lower surfaces of the self-supporting film 1b1, the surface temperature of the self-supporting film 1b1 can be quickly raised, and the organic solution can be efficiently dried in a shorter time. For this reason, the furnace length of the drying apparatus 12a can be made shorter. Further, when the organic solution applied to the surface of the self-supporting film 1b1 is dried, a part of the self-supporting film 1b1 may be evaporated and contracted, and the inside of the drying apparatus is supported while being supported by a transport roller or the like. When transported, due to shrinkage during drying, fine scratches and the like may occur on the roller contact surface, but by simultaneously blowing hot air on the upper and lower surfaces of the self-supporting film 1b1, the self-supporting film 1b1 Since it is transported in a state of being floated by hot air without fluttering, it can be transported through the drying apparatus without being supported by a transport roller or the like, and a polyimide film having a good surface state can be easily obtained.

  30-150 degreeC is preferable and, as for the temperature of the hot air sprayed on the self-supporting film 1b, 40-120 degreeC is more preferable. Even if the hot air temperature is 150 ° C. or higher, there is no problem. However, according to the method of the present invention, even if the hot air temperature is low, the organic solution can be sufficiently dried in a short time, so that energy is wasted. When the temperature is lower than 30 ° C., it may take time to dry the organic solution or uneven drying may occur.

The gas flow rate and gas flow rate of hot air blown from the dryer to the self-supporting film 1b are appropriately adjusted. For example, the gas flow rate is ^{2 to 20} Nm ³ / m ² · min, and the gas flow rate is the area of the injection surface. It is 0.2 to 5 m / sec in terms of per unit.

  The self-supporting film 1b2 unloaded from the first organic solution coating apparatus 11a is transported while applying a certain tension by the transport roller 15, and is organically applied to the surface S2 of the self-supporting film 1b from the second organic solution coating apparatus 11b. The solution is applied. Then, the self-supporting film 1b3 having the organic solution applied to the surface S2 is conveyed to the second drying device 12b, and is applied to at least one surface of the self-supporting film 1b3 in the same manner as the first drying device 12a. Hot air is blown to dry the organic solution applied to the surface S2.

  The surface-treated self-supporting film 1c carried out from the second drying device 12b is sent to the curing furnace 6 to perform a curing process.

[Cure process]
In the curing step, the self-supporting film 1c surface-treated in the coater furnace 5 is introduced into the curing furnace 6, and heat treatment is performed to complete solvent removal and imidization, thereby obtaining a polyimide film 1d.

  As a method for heating the self-supporting film 1c, a known method can be used. As an example of the heating method, it is appropriate to first gradually perform imidization of the polymer and evaporation / removal of the solvent at a temperature of about 100 ° C. to 400 ° C. for about 0.05 to 5 hours, particularly 0.1 to 3 hours. It is. In particular, the heating method is a stepwise primary heat treatment at a relatively low temperature of about 100 ° C to about 170 ° C for about 0.5 to 30 minutes, and then at a temperature of 170 ° C to 220 ° C for about 0.5 The secondary heat treatment is preferably performed for ˜30 minutes, and then the third heat treatment is performed at a high temperature of 220 ° C. to 400 ° C. for about 0.5 to 30 minutes. If necessary, the fourth high-temperature heat treatment may be performed at a high temperature of 400 ° C. to 550 ° C., preferably 450 to 520 ° C.

  At the time of the heat treatment for completing imidization, in the curing furnace 6, at least the edges in the direction perpendicular to the longitudinal direction of the long solidified film, that is, the width direction of the film, are fixed with pin tenters, clips, frames, etc. Then, heat treatment may be performed by expanding or contracting in the width direction or the length direction as necessary.

  The polyimide film 1d after finishing the curing step may be wound up in a roll shape by a winding device or the like.

  According to the present invention, since hot air is blown onto at least one surface of the self-supporting film on the self-supporting film coated with the organic solution, the surface temperature of the self-supporting film is quickly raised and applied. The organic solution can be dried in a short time. In particular, the organic solution can be efficiently dried in a shorter time by spraying hot air on the upper surface and the lower surface of the self-supporting film at the same time for drying treatment. For this reason, the furnace length of the drying apparatus 12a can be shortened, and an installation cost is reduced. In addition, since the hot air temperature can be lowered compared with the conventional method of passing through a drying furnace having a high atmospheric temperature and drying, the amount of energy used can be reduced and the running cost is excellent. Furthermore, since the self-supporting film 1b1 can be transported in a state where it is floated by hot air without fluttering, it can be transported inside the drying apparatus without being supported by a transport roller or the like, and a polyimide film having a good surface condition can be easily obtained. Become. In particular, a mode in which a dry air current is pressed from both sides against the same position of the self-supporting film (at least a part of the upper dryer 13a and the lower dryer 13b disposed on the lower surface side of the self-supporting film is opposed to each other. The self-supporting film can be transported more smoothly.

  In the surface treatment step, the organic solution is applied to one surface of the self-supporting film, and then dried by blowing hot air from a dryer disposed on at least the surface opposite to the organic solution application surface of the self-supporting film. May be.

  In the surface treatment step, after the first organic solution is applied to one surface of the self-supporting film, the dryer disposed on at least the surface of the self-supporting film opposite to the application surface of the first organic solution. Then, the second organic solution is applied to the other surface of the self-supporting film on which the first organic solution is not applied, and at least the second organic solution is applied to the self-supporting film. You may dry by blowing a hot air from the dryer arrange | positioned on the surface opposite to the surface.

  Although the thickness of the polyimide film obtained by this invention is not specifically limited, 3-100 micrometers is preferable and 5-75 micrometers is more preferable. The polyimide film obtained by the present invention is a printed wiring board, a flexible printed circuit board, a TAB tape, a COF tape, a cover substrate such as a chip member such as an IC chip, a liquid crystal display, an organic electroluminescence display, an electronic paper, a solar cell. It can be used as a material for electronic parts and electronic devices such as a base substrate and a cover substrate.

  A second embodiment of the polyimide film manufacturing apparatus of the present invention will be described with reference to FIG.

  In this polyimide film manufacturing apparatus, the coater furnace 5a includes a first organic solution coating device 11a, a first drying device 22a, and a self-supporting film 1b that apply an organic solution to one surface S1 of the self-supporting film 1b. A second organic solution coating device 11b and a second drying device 22b that apply the organic solution to the other surface S2 are arranged in order along the traveling direction A of the self-supporting film 1b.

  In the drying device 22a (22b), dryers 23a and 23b are arranged along the traveling direction A of the self-supporting film 1b in the order of the opposite side of the organic solution coating surface and the organic solution coating surface side. As shown in FIG. 5, in the dryers 23a and 23b, a part of the front end side of the dryer 23a and a part of the base end side of the dryer 23b may face each other through a self-supporting film.

  3rd embodiment of the polyimide film manufacturing apparatus of this invention is described using FIG.

  In this polyimide film manufacturing apparatus, the coater furnace 5a has a first organic solution coating device 11a, a first drying device 32a, and a self-supporting film 1b for applying an organic solution to one surface S1 of the self-supporting film 1b. A second organic solution coating device 11b and a second drying device 32b that apply an organic solution to the other surface S2 are arranged in order along the traveling direction A of the self-supporting film 1b.

  In the drying device 32a (32b), dryers 33, 33 are alternately arranged in the order of the organic solution application surface side and the organic solution application surface side along the traveling direction A of the self-supporting film 1b. Yes. As shown in FIG. 7, in the dryers 33a and 33b, a part of the tip end side of the dryer 33a and a part of the base end side of the dryer 33b may face each other through a self-supporting film.

(Example)
3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine were reacted to prepare a polyamic acid solution (N, N-dimethylacetamide 18% by mass). Silica filler (average particle size: 0.08 μm, “ST-ZL” manufactured by Nissan Chemical Co., Ltd.) was added to the obtained polyamic acid solution so as to be 0.5% with respect to the monomer concentration, and the polyimide precursor was added. A body solution was prepared. The obtained polyimide precursor solution is cast on a stainless steel substrate so that the film thickness after drying is 12.5 μm, dried with hot air at 120 ° C., and peeled from the substrate to obtain a self-supporting film. It was. On one side (surface S1) of this self-supporting film, 5% by mass of N, N-dimethylacetamide obtained from 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine, An organic solution containing 3% by mass of γ-phenylaminopropyltrimethoxysilane was applied at a coating amount of 7 g / m ² and dried under the conditions shown in Table 1 to evaluate the dry state and the presence or absence of dry marks. . The dry state was a good one that did not leave a tack when touched by a finger. In addition, the presence or absence of drying marks was evaluated by visually observing the surface state of the film, evaluating those with uneven color due to surface irregularities as having dry marks, and evaluating those without color unevenness as having no drying marks. The results are shown in Table 1.

(Comparative example)
The same operation as in the example was performed except that the drying process was performed in a box where the atmospheric temperature was 90 ° C. and no hot air was blown. The results are shown in Table 1.

  FIG. 8A shows a dryer in which the dryers 51 and 52 are arranged to face each other through the self-supporting film 1b1, and FIGS. 8B and 8C show that the dryers 51 and 52 are in progress. FIG. 8B shows a dryer arranged in the order of the direction opposite to the application surface of the organic solution (surface S2 side) and the application surface side of the organic solution (surface S1 side) along the direction A. A part on the front end side of 51 and a part on the base end side of the dryer are arranged to face each other through a self-supporting film.

  It was able to dry in a short time by spraying hot air on the self-supporting film coated with the organic solution and drying it. Especially, the dry state was favorable even if the film temperature was 50 degrees C or less by spraying hot air simultaneously on both surfaces of a self-supporting film, and drying (Example 1 and Example 2). Furthermore, there was no drying mark and the surface condition was very good. Moreover, in Examples 3-7, although the drying trace was seen slightly, it was a level which is satisfactory practically.

1: Polyimide precursor solution 1a: Polyimide precursor cast 1b: Self-supporting film 1d: Polyimide film 2: Die 3: Support body 4: Cast furnace 5: Coater furnace 6: Cure furnace 11a, 11b: Application of organic solution Apparatus 12a, 12b, 22a, 22b, 32a, 32b: Drying apparatus 13a, 13b, 23a, 23b, 33a, 33b: Dryer 15: Conveying roller 20: Head 21: Hot air injection port

Claims (6)

A casting furnace for drying a casting cast with a polyimide precursor solution on a support to form a self-supporting film having self-supporting property;
A coater furnace having an organic solution coating apparatus for applying an organic solution on both sides or one side of the self-supporting film that has passed through the casting furnace, and a dryer for blowing hot air on both sides of the self-supporting film coated with the organic solution; ,
A polyimide film manufacturing apparatus comprising: a curing furnace for heating the self-supporting film that has passed through the coater furnace to complete imidization.   The polyimide film manufacturing apparatus of Claim 1 whose distance (d) from the front-end | tip of the said dryer which blows off hot air to the surface of the said self-supporting film is 10-35 mm.   The at least one part of the upper dryer arrange | positioned by the upper surface side of the said self-supporting film and the lower dryer arrange | positioned by the lower surface side of the said self-supporting film is arrange | positioned facing. Or the polyimide film manufacturing apparatus of 2.   The polyimide according to any one of claims 1 to 3, wherein the dryer has a horizontal head and a plurality of hot-air jets arranged at an angle with respect to a traveling direction of the self-supporting film. Film manufacturing equipment. A method for producing a polyimide film using the polyimide film production apparatus according to any one of claims 1 to 4,
A casting step of casting a polyimide precursor solution on a support surface and drying to form a self-supporting film having self-supporting property;
The surface for treating the surface of the self-supporting film by applying the organic solution to one or both sides of the self-supporting film obtained in the casting step and then drying the organic solution applied to the self-supporting film. Processing steps;
A curing step for heating the self-supporting film obtained in the surface treatment step to complete imidization,
In the surface treatment step, to self-supporting film coated with the organic solution, by blowing hot air on both sides of the self-supporting film, drying the said organic solution coated on the self-supporting film A method for producing a polyimide film. 6. The polyimide film according to claim 5, wherein, in the surface treatment step, after the organic solution is applied to one surface of the self-supporting film, the drying is performed by simultaneously blowing hot air onto both surfaces of the self-supporting film. Production method.