JP2002321235A - Polyimide film manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyimide film manufacturing apparatus capable of effectively performing surface treatment for imparting adhesiveness without generating coating irregularity by using a taper roll as a drain roll and setting the diameter of the roll to ϕ120 or more. SOLUTION: In manufacturing equipment for performing surface treatment liquid immersion treatment in a stage of a gel film 28, a pair of the drain rolls 26 for pressing the gel film 28 from both surfaces thereof are formed as taper rolls and the diameter of each of the rolls is set to ϕ120 or more to provide an apparatus for effectively treating the surface of the film with a surface treatment liquid without generating coating irregularity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a polyimide film, and more particularly to an apparatus for applying a surface treatment liquid for imparting adhesiveness. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing apparatus that eliminates warping at the time and improves unevenness in surface treatment.

[0002]

2. Description of the Related Art Polyimide is known to have excellent properties such as heat resistance, cold resistance, chemical resistance, electrical insulation, and mechanical strength. Widely used for base films of wiring boards. In particular, in applications such as flexible wiring boards and electrical insulating films, specifically, a polyimide film is bonded to a copper foil via an adhesive to form a copper-clad laminate, or directly by a PVD method or the like without using an adhesive. It is widely used for laminating metals to form a metal laminate, prepreg by adhesive coating, and compounding with a fluororesin. Therefore, the adhesive ability of the film is an important property, and not only the initial adhesive strength, but also the adhesive strength after heat treatment or high-temperature high-humidity treatment is an important property, and various improvements in adhesiveness have been made. It is planned.

As a technique for imparting adhesiveness to a polymer film, post-treatment after film production includes, for example, flame treatment, corona treatment, ultraviolet treatment, alkali treatment, sand blast treatment, plasma treatment and the like. In these general techniques, a method applied for the purpose of improving the adhesiveness while maintaining the properties of the polyimide film is selected, and various surface treatments using a liquid such as a coupling agent or an alkaline solution are used to impart the adhesiveness of the polyimide film. Have been.

The surface treatment currently performed includes a method of mixing a surface treatment agent into a polyimide precursor solution and a method of applying a surface treatment agent to a manufactured polyimide film.

Specifically, in the above-mentioned method, in a polyimide production step, a surface coupling agent is mixed in an organic solvent solution of a polyamic acid, which is a polyimide precursor, and then cast and applied, followed by heating. This is a method for producing a film. Further, the above method is a method of applying a surface treatment agent to a polyimide film produced by casting and heating a polyimide precursor and heating the film, and then, through a drying step, improving the adhesiveness of the film.

However, the above method has a problem that a large amount of the surface treatment agent is consumed because the surface treatment agent is required not only on the film surface but also inside the film. Embrittlement of the resulting film is a major problem. Also, the above method
Since it is difficult for the surface treatment agent to sufficiently penetrate into the finished film, there is a problem that the effect of the surface treatment agent on improving the adhesiveness is small, and particularly, environmental resistance, that is, adhesion under high temperature and high temperature and high humidity. There was a problem that the property is low. On the other hand, Japanese Patent Application Laid-Open No. 2000-204178 has developed a method and an apparatus for treating a gel film with a surface treating agent in order to solve the above problem and sufficiently exhibit the effect of improving the adhesive force by the surface treating agent. Is disclosed in JP-A-2000-204.
In the invention of Japanese Patent No. 178, the running film bends at the time of liquid draining nip, unevenness of liquid draining occurs, unevenness occurs in the obtained polyimide film, occurrence of dark portions in the film, embrittlement of the film, etc. Some of the physical properties differed greatly, and the production equipment was not satisfactory.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have studied a polyimide film manufacturing apparatus, and in particular, an apparatus for applying a surface treatment liquid for imparting adhesiveness. The present invention has been completed by developing a manufacturing apparatus which improves deflection, eliminates deflection at the time of liquid removal nip, and improves processing unevenness in surface treatment.

A first aspect of the present invention is to provide a surface treatment liquid immersion tank for treating a treatment liquid on the surface of a gel film formed by casting and heating an organic solvent solution containing a polyimide precursor substance. A jetting means for blowing a gas onto the surface of the gel film coated with the processing liquid, a pair of draining rolls for pressing the gel film from both front and back, and heat-treating the gel film coated with the processing liquid. In a polyimide film manufacturing apparatus having a heat treatment apparatus, one or both rolls of the draining roll is a tapered roll having a diameter at the center part larger than that at the end part, and the diameter of the draining roll is This is a polyimide film manufacturing apparatus having a content of φ120 or more.

A second aspect of the present invention is an apparatus for producing a polyimide film, comprising a pinch roll for holding both ends of a gel film from the surface treatment liquid immersion tank from both sides.

A third aspect of the present invention is that a traveling roll for guiding and immersing the gel film is installed in the surface treatment liquid immersion tank, and the surface layer of the liquid removal roll is made of a fluororesin. This is a manufacturing apparatus for a polyimide film.

A fourth aspect of the present invention is an apparatus for producing a polyimide film, wherein a gel film is pulled up substantially vertically from the surface treatment liquid immersion tank.

A fifth aspect of the present invention is an apparatus for producing a polyimide film, wherein the taper angle θ of the taper roll is 0.00005 to 0.01 in tan θ.

A sixth aspect of the present invention is an apparatus for producing a polyimide film, wherein the taper angle θ of the tapered roll is 0.0001 to 0.005 in tan θ.

[0013] A seventh aspect of the present invention is that the jetting means maintains a gas jetting angle at which the residual liquid of the surface treatment liquid on the film surface near both ends of the gel film can be moved in the center direction, and from the side of the film end. An apparatus for producing a polyimide film, wherein the apparatus is arranged as a pair toward the center of the film.

According to an eighth aspect of the present invention, the jetting means is held at an angle of 10 to 90 degrees with respect to the film width direction and at an angle of 10 to 90 degrees with respect to the film advancing direction. An apparatus for producing a polyimide film, wherein the gas is set so as to hit both ends of the gel film.

A ninth aspect of the present invention is that the pinch rolls for supporting the film edge are provided at both ends of the gel film, each pinch the film edge from both sides of the film, and the pinch rolls for the film moving direction. An apparatus for producing a polyimide film, wherein the apparatus is held at an angle of not less than 90 degrees.

A tenth aspect of the present invention is an apparatus for producing a polyimide film, characterized in that the draining roll of the surface treatment liquid is installed so as to be in contact with a surface inside 30 mm from both ends of the gel film. .

An eleventh aspect of the present invention is the production of a polyimide film, characterized in that the jetting means is an air nozzle set so that air can be jetted onto the film surface at least 30 mm from both ends of the gel film. Device. A twelfth aspect of the present invention is that the film supporting pinch roll is at least 30 m from both ends of the gel film.
An apparatus for producing a polyimide film, wherein the apparatus is set so as to hold a film surface in a range of m.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus for producing a polyimide film according to the present invention will be described based on an example of an embodiment, but the present invention is not limited thereto.

In general, since a polyimide film is insoluble and infusible, a solvent casting method in which an organic solvent solution of a polyamic acid as a precursor thereof is applied by casting onto a support such as a drum or a belt is used. This method is also used in the apparatus for manufacturing a polyimide film according to (1).

Hereinafter, an apparatus for producing a polyimide film according to the present invention will be specifically described.

The polyimide film according to the present invention is obtained from various known raw materials, and is not particularly limited. The polyimide film is mainly composed of an organic tetracarboxylic dianhydride and an organic diamine as raw materials. It is obtained via a polyamic acid varnish obtained by polymerizing in an organic solvent solution by using substantially equimolar amounts.

The polyamic acid varnish is basically composed of an aromatic tetracarboxylic dianhydride represented by pyromellitic dianhydride, 4,4′-diaminodiphenyl ether,
And a polyamic acid composition obtained by polymerizing an aromatic diamine represented by paraphenylenediamine in an organic polar solvent and uniformly dissolving in the organic polar solvent. The polyamic acid varnish contains calcium hydrogen phosphate for the purpose of forming a stable polyimide film.
Fillers such as silica, mica, titanium oxide, alumina, and glass beads may be added. The polymerization reaction is not limited by a known method. As an example of the polymerization method, one or two kinds of diamines are dispersed in an organic solvent as a solution or a slurry in an atmosphere of an inert gas such as argon or nitrogen. At least one or more tetracarboxylic dianhydrides are added to this solution in a solid state, in an organic solvent solution state, or in a slurry state to obtain a polyamic acid varnish. The reaction temperature at this time is from −20 ° C. to 50 ° C., preferably 20 ° C. or less. The reaction time is
It is preferably from 1 hour to 6 hours. In addition, in this reaction, contrary to the above addition order, first, tetracarboxylic dianhydride is dissolved or diffused in an organic solvent, and a solution of the diamine in a solid or organic solvent or a slurry is added to the solution. Is also good. The reaction may be carried out simultaneously, and the order of adding the acid dianhydride component and the diamine component is not limited. As the aromatic tetracarboxylic dianhydride component, pyromellitic dianhydride, 2,3,6,7
-Naphthalenetetracarboxylic dianhydride, 3,3 ',
4,4'-biphenyltetracarboxylic dianhydride, 1,
2,5,6-naphthalenetetracarboxylic dianhydride,
2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, oxydiphthalic dianhydride, 2,2-
Bis (3,4-dicarboxylphenyl) propane dianhydride, p-phenylenebis (trimellitic acid monoester acid anhydride), 1,4-naphthalenebis (trimellitic acid monoester acid anhydride), 2,6 -Naphthalenebis (trimellitic acid monoester anhydride), 4,4'-
Aromatic diester tetracarboxylic dianhydrides such as biphenylene bis (trimellitic acid monoester anhydride) and the like may be mentioned, and one kind or two or more kinds may be used.
As the aromatic diamine component, 4,4′-diaminodiphenyl ether, paraphenylenediamine, metaphenylenediamine, 4,4′-diaminodiphenylmethane,
4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, 3,3'-dimethyl-4,4'-diaminobiphenyl 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 4,4′-bis (4-aminophenoxy) biphenyl, 3,3′-dimethoxybenzidine,
Examples thereof include diaminonaphthalene, and one or more kinds may be used. Examples of the organic polar solvent used for the polymerization reaction of the polyamic acid include, for example, dimethyl sulfoxide, sulfoxide solvents such as diethyl sulfoxide,
Formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide; acetamido solvents such as N, N-dimethylacetamide and N, N-diethylacetamide; N-methyl-2-pyrrolidone;
Pyrrolidone-based solvents such as vinyl-2-pyrrolidone, phenol-based solvents such as phenol, o-, m-, or p-cresol, xylenol, halogenated phenol, and catechol; or hexamethylphosphoramide, γ
-Butyrolactone, etc., and it is desirable to use them alone or as a mixture, but it is also possible to use some aromatic hydrocarbons such as xylene and toluene. The concentration of the solid polyamic acid in the varnish is preferably 10 to 30 wt%, more preferably 1 to 30 wt%.
The content is preferably 5 to 25 wt%, more preferably 15 to 20 wt%. If the concentration of polyamic acid solids in the varnish falls below this range, the mechanical properties of the resulting polyimide film need to be increased by increasing the belt temperature to dry on the endless belt until it has self-supporting properties. Greatly decreases. If the concentration of the polyamic acid solids in the varnish exceeds this range, the viscosity of the varnish increases, and the resulting polyimide film has significant thickness variations and bubbles. After mixing the polyamic acid varnish obtained by the above method and the chemical imidizing agent, the polyimide film is continuously extruded as a smooth thin film curtain from a slit die, cast on an endless belt, and dried and cooled to form a self-supporting film. A gel film having a supporting property is formed. The gel film is further heated to obtain a polyimide film having the desired mechanical properties. In the above method, the viscosity of the resin solution composition obtained by mixing the polyamic acid varnish and the chemical imidizing agent in the die is preferably 450 poise or less, more preferably 300 poise or less, and particularly preferably 50 to 300 poise. is there. If the viscosity is more than this range, the dispersion of the film thickness becomes remarkably high, and the entrainment of bubbles is apt to occur, which is not preferable. Further, when the poise is 50 poise or less, it is difficult to stably form a film in the present invention using a casting method using a die. This viscosity is a value measured by a B-type viscometer. Examples of the organic solvent that can be used in the present invention include, for example, sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, and N, N-dimethyl. Acetamide, N, N
Acetamide solvents such as diethylacetamide, N
-Methyl-2-pyrrolidone, pyrrolidone-based solvents such as N-vinyl-2-pyrrolidone, phenol, o-, m-,
Or phenolic solvents such as p-cresol, xylenol, halogenated phenol, catechol, etc., or hexamethylphosphoramide, γ-butyrolactone, etc., and these are preferably used alone or as a mixture. It is also possible to use some aromatic hydrocarbons such as toluene. In addition, when preparing the polyamic acid solution, or after preparing the polyamic acid solution, or by using a dehydrating agent and a catalyst by a chemical method, an antioxidant, a light stabilizer, a flame retardant, an antistatic agent, a heat stabilizer, an ultraviolet absorber Agents, or inorganic fillers, or other reinforcing agents, and the like. As a dehydrating agent used for chemical imidization, organic carboxylic anhydride, N, N'-
Examples thereof include dialkylcarbodiimides, lower fatty acid halides, halogenated lower fatty acid anhydrides, arylphosphonic dihalides, and thionyl halides, and among them, organic carboxylic anhydrides are preferable. Here, as the organic carboxylic acid anhydride, acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, a mixture thereof and an anhydride thereof, and an aromatic monocarboxylic acid such as benzoic acid, naphthoic acid And a mixture with anhydrides of carbonic acid and formic acid and aliphatic ketene (ketene and dimethylketene). Among them, acetic anhydride is preferable. As the chemical imidization catalyst, a tertiary amine is preferable, and trimethylamine, triethylamine, triethylenediamine, pyridine, picoline, quinoline, isoquinoline, lutidine, and the like can be mentioned. More preferably, pyridine, β-picoline, γ-picoline, Quinoline and isoquinoline. Next, the manufacturing process of the polyimide film according to the present invention will be described. The production method for imidizing the polyamic acid, which is a polyimide precursor, and finally producing a polyimide film product is a belt chamber or a drum chamber in which a gel film is obtained by casting and coating on an endless belt or a casting drum, and post-heating. It is divided into a tenter room for curing. One example of the production process of the polyimide film according to the present invention is shown in FIG. 1. First, in the process in the belt chamber 10, a process of extruding a polyimide precursor mixed by a mixer into a film shape by a T-die 12 is performed, followed by reaction curing. In the chamber, a film-like polyimide precursor extruded from the T-die 12 is formed into a film on an endless belt or a casting drum 14. The precursor formed in a film shape is imidized by being heated by a heating means while being moved by the rotation of the belt or the drum 14. In the belt chamber, products generated by the reaction, mainly water, organic solvents and the like evaporate. The heating means adjusts the temperature of the atmosphere and the rotation speed of the belt or drum to prevent the danger of igniting the flammable volatile components evaporating from the resin or to prevent the resin itself from igniting. For example, heating by hot air, hot air, or radiant heat, belt heating, or the like can be used. According to these steps, while the polyimide precursor film is imidized and heated and dried until the film has a self-supporting property, the film is peeled off from the endless belt or the casting drum 14 and the gel film 16 according to the present invention is removed. Get. By the way, when the imidation is carried out while the normal film is conveyed through the above process, the shape and the surface state of the gel film 16 are best kept, the difficulty on the surface such as peeling and wrinkling of the film is prevented, and the self-supporting property is improved. As an index for producing a film having no problem in transportation and processing, measurement of a residual volatile matter amount is performed. In the present invention, the amount of residual volatiles in the film is determined by the following equation (1). Amount of residual volatile matter (%) = 100 × W0 / (W−W0) Formula 1 W: Weight before drying W0: Weight after heat treatment at 450 ° C. for 20 minutes Peeled from a support such as an endless belt or drum. The residual volatile content of the film is in the range of 5 to 500%, preferably 20 to 300%, more preferably 20 to 300%.
It is in the range of 200%, most preferably in the range of 20-100%. It is preferable to use a film in this range, and it is difficult to achieve a predetermined effect when the film is moved. Also, using infrared absorption spectrometry, Equation 2 (C / D) × 100 / (E / F)... Equation 2 In Equation 2, C, D, E, and F represent the following. C: Absorption peak height of gel film at 1370 cm −1 D: Absorption peak height of gel film at 1500 cm −1 E: Absorption peak height of polyimide film at 1370 cm −1 F: Absorption peak of polyimide film at 1500 cm −1 The imidation ratio of the gel film calculated from the height is in the range of 50% or more, preferably 80% or more, and more preferably 85% or more.
%, Most preferably 90% or more. It is preferable to use a film in this range. The gel film obtained as described above undergoes the gel film surface treatment liquid immersion step 18 used in the present invention. More specifically, the gel film 16 is immersed in the surface treatment liquid immersion tank 22 while being guided by the guide roll 20 in the surface treatment liquid immersion step 18. The gel film treated with the surface treatment liquid is sprayed with compressed air by an air nozzle 24 as a spraying means, and then rolls 26 serving as a draining roll of the treatment liquid.
The surface treatment liquid can be more uniformly attached. The gel film 28 that has passed through the surface treatment liquid immersion step 18 is
0 is introduced. In the tenter chamber 30, the gel film 28 is heated at a fixed end. For example,
As shown in FIG. 1, the film 28 is moved in the tenter chamber 30 by moving the pin sheet 34 to which the film is fixed with the pins by the rotation of the pin conveyor 36. In the tenter chamber 30, the gel film is further imidized by gradually heating in a heating furnace 38 for performing heat curing. The heating furnace 38 is usually gradually heated from a temperature of about 200 ° C. to complete imidization to polyimide,
A polyimide film 32 is obtained. FIG. 2 is a schematic view showing a surface treatment liquid immersion step in the polyimide film manufacturing apparatus according to the present invention. Arrow X is the direction of travel of gel film 16. The gel film 16 that has passed through the belt chamber 10 is immersed in the surface treatment liquid immersion tank 22 filled with the surface treatment liquid while being guided by the guide roll 20. Although the surface treatment liquid is not particularly limited, since the gel film 16 is further heated after passing through this surface treatment liquid immersion step,
It is desirable that the surface treatment liquid has heat resistance that does not deteriorate even at the heating temperature. The surface treatment liquid used in the present invention is not particularly limited, and may be water, an organic solvent, an alkali solution, an aqueous solution or an organic solution containing various coupling agents, a polyamic acid solution, or a polyimide solution. Examples of the coupling agent include a silane-based, titanium-based, aluminum-based, or zirconaluminum-based coupling agent, and these coupling agents may be used alone or as a mixture of several types.
In particular, it is preferable to use a titanium coupling agent. In particular, the following general formula (1)

Embedded image Is preferably used. The coupling agent is dissolved in a solvent and used as a solution. Examples of the solution include alcohols such as methanol, ethanol, propanol, isopropanol or solmix which is a mixed solvent thereof, acetone, MEK, Examples thereof include ketone solvents such as pentanone and 3-pentanone, and aromatic hydrocarbon solvents such as toluene and xylene. These may be used alone or as a mixture of several types. Further, the concentration of the coupling agent solution is preferably from 0.005 wt% to 30 wt%, and particularly preferably from 0.01 wt% to 5 wt%. If the concentration of the coupling agent is too high, unevenness is observed on the surface of the polyimide film and the color of the film becomes dark, which is not preferable in appearance. On the other hand, if the concentration of the coupling agent is too low, a sufficient effect may not be exhibited. Further, as the surface treatment liquid, as the chemical imidization catalyst, a chemical imidization catalyst such as trimethylamine, triethylamine, triethylenediamine, pyridine, picoline, quinoline, isoquinoline, lutidine, or a chemical mixture of a dehydrating agent and the above chemical imidization catalyst is used. An imidizing reagent may be used.

The immersed gel film 28 is pulled up while being guided by a guide roll. FIG. 3 is a perspective view showing a processing means of the gel film 28 after being pulled up. It is preferable that the gel film 28 be pulled up substantially vertically so as not to cause wrinkles or deviations in the film 28.

Next, compressed gas is jetted to both ends of the gel film 28 by jetting means. The jetting means is applied to the front and back surfaces of both ends of the film, and may be, for example, an air nozzle 24, and the compressed gas may be an inert gas such as nitrogen or argon, or air. By injecting the compressed gas, the surface treatment liquid attached to the edge of the gel film 28 is brought to the center. As shown in the front view of FIG. 4A, the injection means such as an air nozzle has an angle α with respect to the film surface of 10 degrees or more and 90 degrees.
Preferably, the angle β with respect to the film advancing direction X is maintained at an angle of 10 degrees or more and 90 degrees or less, as shown in the side view of FIG. Further, it is preferable that the jetted air is configured to hit the end of the gel film 28. Specifically, it is preferable to set the position and the air pressure so that air can be jetted onto the film surface 30 mm from at least both ends of the gel film 28.

In order to obtain a uniform polyimide film, the end portion having a relatively uneven thickness and drying degree is easily cut when the surface treatment liquid remains, There is a possibility that running muscles may be generated when the vehicle travels. Therefore, in order to prevent this, it is effective to install the gas injection means at the above angle.

Next, the gel film 28 is removed by a nip formed by a pair of surface treatment liquid draining rolls, i.e., a liquid removal roll 26, to remove excess surface treatment liquid remaining on the film surface.

One of the pair of draining rolls 26 or one of the pair of rolls is preferably a tapered roll whose central portion is larger in diameter than both ends as shown in FIG. Diameter (outer diameter of both ends of the roll) is φ12
It is preferably 0 or more. It is a tapered roll, and the roll diameter is φ120 or more, eliminating the occurrence of deflection in the running film at the nip by giving the roll strength, eliminating the occurrence of liquid drainage unevenness, and the occurrence of unevenness or film in the obtained polyimide film. In this case, it is possible to eliminate the occurrence of dark-colored portions and the occurrence of portions having greatly different physical properties such as embrittlement portions of the film. Further, in the liquid draining rolls 26 which are respectively disposed so as to face both surfaces of the film, the two rolls may have the same diameter or different diameters, and only one side of the liquid draining roll may be used. In the case of a tapered roll, it is preferable that the diameter of the tapered roll is larger than the diameter of the other roll. The taper angle θ of the roll 26 as the taper roll shown in FIG.
0005 to 0.01, more preferably 0.00005 to 0.005 in tan θ,
More preferably, tan θ is 0.0001 to 0.001.
It is. The draining roll 26 is not particularly limited as long as it has water repellency and is basically a material that does not react with the organic solvent and the surface treatment liquid of the gel film. In particular, the roll is made of a fluororesin or a synthetic resin. Alternatively, a rubber roll coated with a fluororesin, or a fluororesin sheet or tube wound is preferable. Rolls made of these materials are less likely to wrinkle the film and have a good drainage of the surface treatment liquid as compared with other materials. In addition, the draining rolls 26 are used in pairs, and the gel film immersed in the surface treatment liquid passes through the gap between the rolls in a roll-to-roll system. The nip pressure of the draining roll depends on the structure of the polyimide, the mechanical properties involved, and the film thickness. In general, when the film has a thickness of 25 μm, a cylinder pressure of 2 to 3 kgf is applied. Preferably.

The surface treatment liquid draining roll 26
However, it is preferable to install the gel film 28 so as to hit the film surface 30 mm inside from both ends of the gel film 28. Since the film edge is non-uniform as compared with the film in the above range, the nip causes wrinkles on the film surface, and it is difficult to perform the surface treatment. This is because it is necessary and sufficient to perform the processing.

Depending on the structure of the polyimide film and the mechanical properties and thickness of the polyimide film, if the wrinkles are relatively large, the curl at the end is large, or if the running is poor, the gel film may be used. It is preferred to support the 28 ends. Specifically, as a film edge support means,
For example, as shown in FIG. 3, it can be supported by a pair of pinch rolls 40. The pinch roll 40 shown in FIG.
The configuration is such that the roll portion is fixed to a support so that the roll portion can be moved in accordance with the movement of the gel film 28 while holding the front and back surfaces of the end portion 8. The pinch rolls 40 support both ends of the gel film 28, and may be basically provided at a plurality of locations.

The pinch roll 4 for supporting the film edge portion
With a value of 0, a stable film width without wrinkles can be obtained, and furthermore, the curl at the end can be corrected and the thickness can be made constant. Further, in order to eliminate wrinkles of the film and to lubricate the running, the film end supporting pinch roll 40 sandwiches the film ends from the both sides of the gel film in pairs, and as shown in FIG. Preferably, the angle δ is maintained at an angle δ of 10 degrees or more and 90 degrees or less with respect to the film traveling direction (arrow X).

The gel film 28 thus surface-treated is supplied to a tenter chamber 30 for performing a heat treatment step. As described above, by installing the surface treatment step before the heating step in the tenter chamber 30, the drying step of the surface treatment agent can be performed simultaneously with the heat treatment step of the tenter chamber 30.

The surface-treated gel film 28 has its ends fixed and is heated in a tenter chamber 30. For example, the tenter room 30 is constituted by a heating furnace and an annealing furnace,
The film 28 moves in the tenter chamber 30 by moving the pin sheet to which the film is fixed by the pin by the rotation drive of the pin conveyor. Heating furnace 3 for heat curing
8 by gradually heating the gel film 2
8 is further imidized. In the heating furnace 38, usually 20
The temperature is gradually raised from about 0 ° C. to complete the imidization to polyimide.

The temperature of the heat treatment is gradually increased to a maximum temperature of 4.
It is preferable that the temperature be in the range of 00 ° C. to 650 ° C. More preferably, the range is 450 ° C. or more and 620 ° C. or less. For the temperature gradient that reaches the maximum temperature,
There is no particular limitation as long as the heat treatment is performed within the above temperature range.
The heat treatment time is several seconds to several tens of minutes, preferably 1 minute to 5 minutes, and is appropriately set in relation to the heat treatment temperature.

In the heat curing step, the completely imidized polyimide film is gradually cooled in an annealing furnace.

The polyimide film obtained by the above production method means a film in a broad sense including a sheet having a thickness of several μm to several hundred μm, and the thickness can be selected according to the application. For example, when used as a base film of a flexible printed wiring board, 12.5 μm
Films of the order of m to 50 μm can be applied.

The above-mentioned production method incorporates a surface treatment step in the film production step. Specifically, a dipping step of the surface treatment liquid in a surface treatment liquid having a residual liquid treatment means is added in the production step. This can effectively contribute to the improvement of the adhesive strength of the polyimide film as the final product.

Although one example of the embodiment of the apparatus for producing a polyimide film according to the present invention has been described above, the present invention is not limited to only these embodiments, and other known post-treatment methods may be used if necessary. For example, a flame treatment, a corona treatment, an ultraviolet treatment, an alkali treatment, a primer treatment, a sand blast treatment, a plasma treatment, and the like can be further applied, and the knowledge of a person skilled in the art without departing from the spirit of the present invention. Based on the above, various improvements, changes, and modifications can be made.

EXAMPLES Hereinafter, a specific example of a method for producing a polyimide film using the apparatus for producing a polyimide film according to the present invention will be described. The present invention is not limited to these examples. (Example 1) Polyamic acid was repeatedly added to a polyamic acid solution obtained by using 4,4′-diaminodiphenyl ether as an aromatic diamine and pyromellitic dianhydride as an aromatic tetracarboxylic dianhydride. 5.5 mol of acetic anhydride and 0.55 mol of isoquinoline were added as imidizing agents to the molecular weight per unit, and the mixture was sufficiently stirred to prepare a dope solution for film formation at about 0 ° C. The dope liquid obtained above was continuously cast from a T-die onto a smooth metal endless belt at a thickness of about 600 μm,
Hot air drying was performed while rotating the belt. At this time, the temperature of the belt chamber was set to 120 ° C. for 4 minutes and the cooling pulley temperature was set to 80 ° C., and the belt was peeled off from the endless belt. The residual volatile matter amount of this gel film was 46%. Next, the obtained gel film was introduced into a surface treatment liquid immersion tank filled with a 0.2 wt% dihydroxytitanium bislactate / butyl alcohol solution. The immersed film is pulled up vertically, blown dry by blowing compressed air with an air nozzle from both ends to 50 mm, and then dried. Then, the taper angle θ coated with Teflon (registered trademark) is 0 at tan θ. The film was nipped with a nip roll of 0.0002 at a nip pressure of 4 kgf, and the residual liquid amount on each side of the film was adjusted to about 2 g / m ² . Pinch rolls were used at both ends before and after the nip roll. At this time, no wrinkles were generated in the running gel film. Next, these films were subjected to heat treatment in a tenter room at 300 ° C. to 580 ° C. for a total time of about 4 minutes. Thereafter, the temperature was gradually lowered to room temperature in a cooling chamber to obtain a polyimide film of 50 μm. No coating unevenness was observed on the obtained polyimide film, and the surface state was good. (Comparative Example 1) A polyimide film of 50 µm was obtained in the same manner as in Example 1, except that a nip roll having no taper was not used. The resulting film had many dripping marks and coating unevenness, and was poor in appearance. (Comparative Example 2) In the same manner as in Example 1, except that a nip roll having a roll diameter of φ60 was used,
Was obtained. The resulting film had poor appearance due to streaks and coating unevenness due to liquid dripping generated by nip wrinkles generated by the liquid removing roll.

According to the polyimide film obtained as described above, the adhesiveness can be effectively improved by the surface treatment agent. By including the heat treatment step in the tenter chamber, the step can be omitted.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for producing a polyimide film according to the present invention.

FIG. 2 is a schematic diagram of a surface treatment liquid immersion step in the apparatus for producing a polyimide film according to the present invention.

FIG. 3 is a perspective view of a part of a surface treatment liquid immersion step.

FIG. 4 is a front view (a) and a side view (b) of a method of installing an air nozzle.

FIG. 5 is a front view of a method of installing a pinch roll.

FIG. 6 is a side view of the draining roll.

[Explanation of symbols]

 10; Belt chamber 12; T die 14; Endless belt 16, 28; Gel film 18; Surface treatment liquid immersion step 20; Guide roll 22; Surface treatment liquid immersion tank 24; Air nozzle 26; Surface treatment liquid dipping roll 30; Chamber 32; Polyimide film 40; Pinch roll

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 7:00 B29L 7:00 (72) Inventor Masanori Hamamura 1-25-1 Hiei Tsuji, Otsu City, Shiga Prefecture (72) ) Inventor Renichi Akahori 2- 23-6 Okokita, Otsu-shi, Shiga F-term (reference) 4F040 AA22 AB13 AC02 BA47 CC15 CC19 DA05 DA12 DB13 DB30 4F042 AA22 BA06 BA10 BA19 BA25 CA01 DB02 DD09 DD32 DD45 DE01 DF23 DF30 ED01 ED05 4205 AA40 AG01 AM27 GA07 GB02 GC07 GW05 GW31

Claims (12)

[Claims] 1. A surface treatment liquid immersion tank for treating a treatment liquid on a surface of a gel film formed by casting and heating an organic solvent solution containing a polyimide precursor substance, and applying the treatment liquid to the surface of the gel film. Spraying means for blowing compressed gas onto the surface of the gel film applied to the surface of the gel film, a pair of draining rolls for pressing the gel film from both front and back surfaces, and a heat treatment apparatus for heat-treating the gel film coated with the treatment liquid And one or both of the draining rolls are tapered rolls whose central portion is larger in diameter than the end portion, and the draining roll diameter is φ120 or more. An apparatus for producing a polyimide film. 2. The polyimide film production apparatus according to claim 1, further comprising a pinch roll for holding both ends of the gel film coming out of the surface treatment liquid immersion tank from both sides. 3. A running roll for guiding and immersing the gel film in the surface treatment liquid immersion tank, and a surface layer of the liquid removal roll is made of a fluororesin. An apparatus for producing a polyimide film according to claim 1. 4. The apparatus for producing a polyimide film according to claim 1, wherein a gel film is pulled up substantially vertically from the surface treatment liquid immersion tank. 5. The taper roll having a taper angle θ of t
The polyimide film manufacturing apparatus according to any one of claims 1 to 4, wherein anθ is 0.00005 to 0.01. 6. The taper roll has a taper angle θ of ta.
The polyimide film manufacturing apparatus according to any one of claims 1 to 4, wherein nθ is 0.0001 to 0.005. 7. The gas jetting means maintains a gas jetting angle capable of moving the surface treatment liquid remaining liquid on the film surface near both ends of the gel film in the center direction, and from the film end side toward the film center direction. The apparatus for producing a polyimide film according to any one of claims 1 to 6, wherein the air nozzles are arranged as a pair. 8. The jetting means is held at an angle of not less than 10 degrees and not more than 90 degrees with respect to the film width direction and at an angle of not less than 10 degrees and not more than 90 degrees with respect to the film advancing direction. The apparatus for producing a polyimide film according to claim 7, wherein the air nozzles are set so as to correspond to both ends of the polyimide film. 9. The pinch rolls for supporting the film edge are provided at both ends of the gel film, sandwiching the film edge from each side of the film in pairs, and 10 to 90 degrees with respect to the film advancing direction. The apparatus for producing a polyimide film according to any one of claims 4 to 8, wherein the polyimide film is held at an angle. 10. The method according to claim 4, wherein the draining roll of the surface treatment liquid is provided so as to hit a surface inside 30 mm from both ends of the gel film. Polyimide film production equipment. 11. The air nozzle according to claim 3, wherein said jetting means is an air nozzle set so as to jet air onto a film surface at least 30 mm from both ends of the gel film. An apparatus for producing a polyimide film according to any of the above items 12. The film supporting pinch roll,
The polyimide film manufacturing apparatus according to any one of claims 4 to 11, wherein the apparatus is set so as to be able to hold at least a film surface within a range of 30 mm from both ends of the gel film.