KR20170026300A - Method for producing polyimide substrate film with functional layer, long polyimide substrate film with functional layer, long polyimide laminate and long polyimide laminate with functional layer - Google Patents

Abstract

Provided is a method for producing a polyimide substrate film having a functional layer, which is capable of being prevented from being mixed with a foreign material, is easily peeled off from a carrier film, and is provided with the functional layer thereon. According to the method for producing a polyimide substrate film having a functional layer, a first heat treatment is performed by first solution application onto a continuously supplied carrier. Then, a second heat treatment is performed on the same by second solution application. Then, a long polyimide laminate provided with first and second polyimide hardened layers is obtained. Subsequently, the functional layer is formed on the polyimide substrate film based on one side of the polyimide hardened layer as the polyimide substrate film and the other side of the polyimide hardened layer as the carrier film. Then, the carrier film is separated and the polyimide substrate film provided with the functional layer is obtained.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a polyimide substrate film on which a functional layer is formed, a long polyimide substrate film on which a functional layer is formed, a long polyimide laminate and a long polyimide laminate having a functional layer formed thereon POLYIMIDE SUBSTRATE FILM WITH FUNCTIONAL LAYER, LONG POLYIMIDE LAMINATE AND LONG POLYIMIDE LAMINATE WITH FUNCTIONAL LAYER}

The present invention relates to a method for producing a polyimide substrate film on which a functional layer is formed and a long polyimide substrate film on which a functional layer is formed. More specifically, the present invention relates to a flexible display such as a liquid crystal display device and an organic EL display, The present invention relates to a method for producing a polyimide substrate film in which a functional layer having a functional layer for forming a paper, a touch panel, a solar cell, a color filter and the like is formed and a long polyimide substrate film on which a functional layer is formed, A long polyimide laminate for obtaining a long polyimide substrate film formed with a functional layer and a long polyimide laminate having a functional layer formed thereon.

Display devices such as liquid crystal display devices and organic EL display devices are used for various display applications ranging from large displays such as televisions to small displays such as cellular phones, PCs and smart phones. For example, in this organic EL display device, a thin film transistor (hereinafter referred to as TFT) is formed on a glass substrate that is a supporting substrate, and an electrode, a light emitting layer, and an electrode are sequentially formed, And is hermetically sealed with a separate glass substrate or multilayer thin film.

Here, by replacing the glass substrate, which is a supporting substrate, with a resin substrate, thinness, lightness, and flexibility can be realized, and the use of the display device can be further widened.

For example, Patent Document 1 discloses a polyimide useful as a plastic substrate for a flexible display, and an invention related to the precursor thereof, wherein a tetracarboxylic acid including an alicyclic structure such as cyclohexylphenyltetracarboxylic acid and the like are used, And polyimide obtained by reacting with diamine has excellent transparency. In addition, attempts have been made to reduce the weight of the supporting substrate by using a flexible resin. For example, in the following non-patent documents 1 and 2, an organic EL display device in which polyimide having high transparency is applied to a supporting substrate has been proposed have.

Thus, it is known that a resin substrate such as polyimide is useful for a flexible substrate for a flexible display. However, since the resin substrate generally has poor dimensional stability, transparency, heat resistance, moisture resistance and gas barrier properties as compared with glass, it is in the research stage at present and various studies have been made.

For example, in Non-Patent Document 3, after a predetermined functional layer is formed on a resin substrate coated and fixed on glass, a laser is irradiated from the glass side by a method called an EPLaR (Electronics Plastic by Laser Release) A method of forcibly separating a resin substrate having a layer from a glass has been proposed.

In addition, in Non-Patent Document 4, a predetermined functional layer is formed on a polyimide substrate obtained by applying a polyamic acid (polyimide precursor) solution on a glass via a release layer and curing, and then a polyimide substrate A method of peeling has been proposed. In this method, the polyamic acid solution is applied at a larger area than the release layer, the periphery of the polyimide substrate after curing is directly fixed to the glass, and the periphery is left on the glass, The cut is put and the polyimide substrate formed through the release layer is separated from the glass.

The techniques disclosed in Non-Patent Documents 3 and 4 are all to ensure the handling and dimensional stability of a resin substrate by forming a resin substrate on glass and forming a functional layer on the resin substrate. However, in these methods, since a special means is adopted in separating the resin substrate from the glass, there is a problem such as low productivity. That is, in the method using the EPLaR process described in the non-patent document 3, it takes time to separate the resin substrate from the glass, and there is a fear that the surface property of the resin substrate may be adversely affected. In addition, in the method described in Non-Patent Document 4, in addition to the increase in the number of steps, an area that can not be used as a resin substrate is generated and waste is generated. Therefore, there is a strong demand for the development of a technique that can be used as an industrially helpful means while taking advantage of the advantages of a resin substrate.

As a method for solving such a problem, there has been proposed a polyimide laminate having a polyimide film instead of glass on the back surface side of the polyimide substrate, wherein the interface between the polyimide substrate and the polyimide film has a specific performance, A polyimide laminate is disclosed in which a predetermined functional layer is formed on the front surface side and then the polyimide film is detachable (see Patent Document 2). This polyimide laminate is a polyimide film which is used as a supporting substrate instead of glass in the above Non-Patent Document 3 and Non-Patent Document 4. The polyamide acid solution is applied to the surface of the polyimide film and heat- Thereby forming a polyimide substrate. The polyimide laminate thus obtained can secure handling properties and dimensional stability, and can also be used as a polyimide film to easily separate the polyimide substrate from the supporting substrate. Thus, the touch panel or the display device And the like.

Japanese Patent Application Laid-Open No. 2008-231327 Japanese Patent Application Laid-Open No. 2014-61685

 S. An et. "2.8-inch WQVGA Flexible AMOLED Using Low Temperature Polysilicon TFT on Plastic Substrates ", SID2010 DIGEST, p706 (2010)  Oishi et. quot; Transparent PI for flexible display ", IDW '11 FLX2 / FMC4-1  E. I. Haskal et. al. "Flexible OLED Displays Made with the EPLaR Process ", Proc. Eurodisplay '07, pp.36-39 (2007)  Cheng-Chung Lee et. al. "A Novel Approach to Make Flexible Active Matrix Displays ", SID10 Digest, pp.810-813 (2010)

According to the method described in Patent Document 2, since the polyimide substrate can be easily separated from the supporting substrate while securing handling properties and dimensional stability, the polyimide film can be used as the resin substrate instead of the conventional glass substrate It is thought that the application is promoted. However, as in the method described in Patent Document 2, when a polyamide acid (polyimide precursor) solution or a polyimide resin solution is coated on the polyimide film as a supporting substrate and heat treatment is performed to obtain a polyimide substrate film If foreign matter such as particles adheres to the polyimide film constituting the supporting substrate, the polyimide film may be mixed into the polyimide substrate film as it is.

For example, in a manufacturing process of a flexible device such as a liquid crystal display device, an organic EL display, an organic EL light, an electronic paper, a touch panel, a solar cell, a color filter and the like, a highly clean environment is required. For example, The characteristics of the flexible device may be remarkably lowered due to the incorporation thereof. Further, it is required to make the polyimide substrate film itself thinner due to the high performance, miniaturization and thinness of the flexible device. However, if the polyimide substrate film is thin, the polyimide substrate film may be broken in peeling from the supporting substrate, There is room for further improvement.

As a result, the inventors of the present invention have made intensive investigations into the above problems. As a result, the inventors have found that the first and second solutions made of a polyimide precursor or a polyimide resin solution are applied to the carrier body, 2 Heat treatment is carried out to obtain a long polyimide laminate in which a carrier film and a polyimide substrate film are laminated so that foreign matter can be prevented as much as possible and the peelability of the carrier film and the polyimide substrate film is good, And the present invention has been completed.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a polyimide substrate film which is capable of preventing foreign matter from entering the polyimide substrate film and which is excellent in peeling property from the carrier film, A method for producing a mid substrate film, and a polyimide substrate film on which a functional layer obtained by the method is formed.

Another object of the present invention is to provide a polyimide laminate for obtaining a polyimide substrate film on which such a functional layer is formed, and a polyimide laminate on which a functional layer is formed.

That is, the gist of the present invention is as follows.

(1) A first solution comprising a polyimide precursor or a polyimide resin solution is applied onto a continuously fed carrier, and a first heat treatment is performed to form at least a fixed dry surface on the surface of the first solution, And a second polyimide cured layer composed of a first solution and a second solution, the first polyimide cured layer being formed of a first solution and the second polyimide cured layer being formed of a second solution by applying a second solution comprising a polyimide precursor or a polyimide resin solution, , A long polyimide laminate separated from the carrying body in the longitudinal direction of the carrying body is obtained,

One of the first and second polyimide hardened layers in the elongated polyimide laminate is used as a polyimide substrate film and the other is used as a carrier film to form a functional layer on a polyimide substrate film, And separating the film to obtain a polyimide substrate film having a functional layer.

(2) After the long polyimide laminate is once wound around a take-up roll, the functional layer is continuously formed on the polyimide substrate film while the polyimide laminate is unwound, or the polyimide laminate is unwound (1) wherein a functional layer is formed on a polyimide substrate film for each polyimide laminate on a sheet by cutting the polyimide film into a sheet with a predetermined length.

(3) In order to obtain the elongated polyimide laminate, the carrier may be separated before performing the second heat treatment, or separated from the functional layer after the second heat treatment, To form a polyimide substrate film.

(4) The method for producing a polyimide substrate film as described in any one of (1) to (3), wherein the carrier is a metal drum, an endless belt, or a rolled long rolled substrate.

(5) The polyimide substrate according to any one of (1) to (4), wherein the carrier film comprises a first polyimide cured layer and the polyimide substrate film is a second polyimide cured layer, ≪ / RTI >

(6) The polyimide substrate according to any one of (1) to (4), wherein the polyimide substrate film comprises a first polyimide cured layer and the carrier film is a second polyimide cured layer, ≪ / RTI >

(7) applying a first solution of a polyimide resin solution onto the carrier, and performing a first heat treatment at a temperature of 60 ° C to 300 ° C at a maximum temperature to form a fixed dry surface on the surface of the first solution A method for producing a polyimide substrate film in which the functional layer according to any one of (1) to (6) is formed.

(8) A first solution comprising a polyimide precursor is coated on the carrier, and a first heat treatment is performed at a maximum temperature of 100 ° C to 450 ° C to form a first polyimide cured layer composed of the first solution A method for producing a polyimide substrate film in which the functional layer according to any one of (1) to (6) is formed.

(9) The method for producing a polyimide substrate film according to any one of (1) to (8), wherein the maximum temperature of the heat treatment in the second heat treatment is 100 ° C to 450 ° C.

(10) The multilayer printed wiring board according to any one of the above (1) to (10), wherein the interlayer adhesive strength between the first polyimide hardened layer and the second polyimide hardened layer is 1 to 20 N / m, and the thickness of the first or second polyimide hardened layer Wherein the functional layer according to any one of (1) to (9) is formed on the surface of the polyimide substrate film.

(11) The process for producing a polyimide substrate film in which the functional layer according to any one of (1) to (10), wherein the first or second polyimide hardened layer made of the polyimide substrate film has a total light transmittance of 80% .

(12) A laminate as described in any one of (1) to (11), wherein the longitudinally-extending substrate is a polyimide film, a SUS foil, a copper foil, or a composite in which two or more of these are laminated, A method for producing a polyimide substrate film having a functional layer formed thereon.

(13) The method according to any one of (1) to (12), wherein at least two kinds of the first solution of the polyimide precursor or the polyimide resin solution are used and the first solution is applied and applied to form the first polyimide cured layer Wherein the polyimide substrate film is a polyimide film.

(14) The method according to any one of (1) to (12), wherein at least two kinds of the second solution of the polyimide precursor or the polyimide resin solution are used and the second solution is coated to form the second polyimide cured layer Wherein the polyimide substrate film is a polyimide film.

(15) A method for producing a polyimide precursor or a polyimide resin solution, which comprises the steps of: preparing a carrier film comprising a polyimide precursor or a polyimide resin solution and a polyimide cured layer obtained by curing one of the first and second solutions; The functional layer is continuously formed on the polyimide substrate film in the longitudinal direction of the elongated polyimide laminate in which the polyimide substrate film made of the polyimide cured layer having the other side thereof cured is laminated, The total light transmittance is 80% or more, the interface with the carrier film has a surface roughness with an arithmetic average roughness Ra of 0 to 5 nm, and the interlayer between the carrier film and the polyimide substrate film And an adhesive strength of 1 to 20 N / m.

(16) The elongated polyimide laminate according to (15), wherein the functional layer is an ITO film.

(17) The elongated polyimide laminate according to (15), wherein the functional layer is a TFT, is formed.

(18) The light emitting device according to (18), wherein the functional layer is any one selected from the group consisting of a transparent conductive layer, a wiring layer, a conductive layer, a gas barrier layer, a thin film transistor, an electrode layer, a light emitting layer, an adhesive layer, a pressure sensitive adhesive layer, A functional layer according to (15), wherein the functional layer is a layer containing one or a combination of two or more types of paper.

(19) A method for producing a polyimide precursor, comprising the steps of: preparing a carrier film comprising a polyimide precursor or a polyimide resin solution and a polyimide cured layer obtained by curing one of the first and second solutions; and a first or second solution comprising a polyimide precursor or a polyimide resin solution Wherein the interlaminar bond strength between the carrier film and the polyimide substrate film is 1 to 20 N / m, and the polyimide substrate film is a polyimide substrate film Has a thickness of 1 to 50 占 퐉 and has a total light transmittance of 80% or more.

(20) A functional layer is continuously formed in a longitudinal direction of a long polyimide substrate film comprising a polyimide precursor or a polyimide resin solution and a polyimide cured layer obtained by curing the solution, wherein the polyimide substrate film has a thickness Characterized in that the total light transmittance is 80% or more and the surface on the opposite side to the functional layer has a surface roughness with an arithmetic average roughness Ra of 0 to 5 nm. Substrate film.

(Effects of the Invention)

According to the present invention, it is possible to prevent foreign matter from being mixed into the polyimide substrate film, and also to provide a polyimide substrate on which a functional layer having a functional layer is formed on the polyimide substrate film, A film can be obtained. Among them, the polyimide substrate film is excellent in heat resistance and can be applied to a heat treatment process at a high temperature, so that it can be provided for manufacturing various flexible devices using a functional layer.

Further, in obtaining a polyimide substrate film having such a functional layer formed thereon, in the present invention, after obtaining a long polyimide laminate, the present invention is applied to the formation of a functional layer on the polyimide substrate film constituting the polyimide laminate (Handling property) and dimensional stability are ensured.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a roll-to-roll type coating and drying curing apparatus used for obtaining a polyimide laminate. Fig.
Fig. 2 is a schematic explanatory diagram showing an endless belt type coating and drying curing apparatus used for obtaining a polyimide laminate.
Fig. 3 is a schematic explanatory diagram showing a metal drum type coating and drying curing apparatus used for obtaining a polyimide laminate.
4 is a schematic diagram showing a continuous production apparatus of a roll-to-roll system for forming a functional layer in a polyimide laminate.

Hereinafter, the present invention will be described in detail.

In the present invention, first, a first solution made of a polyimide precursor or a polyimide resin solution is coated on a continuously fed carrier, and a first heat treatment is performed to form at least a fixed dry surface on the surface of the first solution, Then, a second polyimide precursor or a polyimide resin solution is applied and then subjected to a second heat treatment to form a first polyimide cured layer composed of the first solution and a second polyimide cured layer composed of the second solution And the elongated polyimide laminate separated from the carrier is obtained in the longitudinal direction of the carrying body.

In the present invention, the use of the carrier to be continuously supplied means that the first and second solutions made of the polyimide precursor or the polyimide resin solution are used to form the first polyimide cured layer and the second polyimide In order to obtain a long polyimide laminate in which these polyimide cured layers are laminated.

That is, a polyimide laminate obtained by applying a first solution onto a carrier to be continuously supplied, performing a first heat treatment to form at least a fixed dry surface, applying a second solution thereon, and performing a second heat treatment The MD (Machine Direction) side becomes a long laminated film with respect to the TD (Transverse Direction) side. Such a long polyimide laminate can be transported in a roll-to-roll process in a post-process, and the functional layer can be continuously formed, for example, after winding the polyimide laminate once have. Therefore, the number of steps is reduced compared with the case where a sheet-shaped polyimide laminate is obtained by using a carrier supplied intermittently, for example, and a functional layer is formed by a batch process. Therefore, And a flexible device using the functional layer can be manufactured efficiently.

The carrier to be continuously supplied is not particularly limited, and examples thereof include a metal drum, an endless belt, and an elongated substrate wound in a roll form. Among them, from the viewpoint of productivity, it is preferable to use an endless belt or an elongated substrate rolled in a roll form, more preferably an elongated substrate wound in a roll form. Of these, in the case of a long substrate rolled up in a rolled form, it is preferable because a longer polyimide laminate can be obtained as the MD is longer, but from the viewpoint of productivity and the like, preferably (MD side length) / (TD side length) And more preferably at least 2,000. Further, in the case of the endless belt, the longer the MD side is, the higher the productivity is, but the apparatus becomes expensive and the size and weight of the apparatus increase. The length of the endless belt from the balance of these is preferably about 10 to 50 m.

Here, the material forming the carrier may be any material capable of withstanding the temperature of the first heat treatment in which at least the first solution is applied to form a fixed dry surface. Specifically, in the case of a rolled-up elongated substrate, in addition to strength and heat resistance, a polyimide film having excellent flexibility, SUS foil, and copper foil may be used, or a composite thereof may be used. Among them, a polyimide film is preferable. Further, in the case of the endless belt, it is preferable that the endless belt is made of SUS.

Then, a first solution comprising a polyimide precursor or a polyimide resin solution is applied onto the continuously supplied carrier, and a first heat treatment is performed to form a fixed dry surface at least on the surface of the solution. The term " fixed drying " refers to a state in which an object does not adhere to the contact object when the object is brought into contact with the surface of the object. For example, when the first solution is applied, The structure of the first solution is not attached.

Further, in order to put the first solution applied on the carrier at least in a fixed dry state, at least a part of the solvent in the first solution applied by the first heat treatment is dried so as to volatilize. At this time, if the first solution is a polyimide resin solution, at least a part of the solution may be imidized. If the first heat treatment is insufficient, the dried dry surface is not formed and is mixed with the second solution, swelling occurs later in the polyimide laminate, or the polyimide substrate film and the carrier film can not be separated from each other There is a concern. In some cases, the carrier can not be separated later.

Although the first heat treatment is different depending on the kind of the first solution to be used, when the first solution is made of a polyimide resin solution, it is not necessary to carry out the imidization reaction, It is preferable to carry out the first heat treatment at a maximum temperature of 150 to 250 deg. C to form a bonded dry surface on the surface of the first solution applied to the carrier. In this case, it is preferable that the first solution which has been dried by the first heat treatment in the fixed dry state has a solid concentration of preferably 95 to 99.5 mass%, more preferably 99 to 99.5 mass%.

On the other hand, when the first solution is made of a polyimide precursor, it is preferable that at least its surface is imidized. From this viewpoint, the first polyimide cured layer made of the first solution may be formed by carrying out a first heat treatment with a maximum temperature of preferably 100 ° C to 450 ° C, more preferably 180 ° C to 360 ° C. At that time, the polyimide precursor is preferably " almost completely imidized " to form the first polyimide cured layer. Here, " almost completely imidized " refers to a state in which the imidization rate is 90% or more. In this case, it is necessary to carry out the heat treatment at a higher temperature than in the fixed dry state by the above-mentioned drying. The polyimide substrate film and the carrier film are more easily separated by imidization almost completely. In this case, it is preferable to set the maximum temperature to 300 to 360 ° C. The first solution comprising the polyimide precursor may be imidized by adding a so-called " imidation catalyst " such as pyridine, acetic anhydride or N-methylimidazole. Imidization is likely to proceed even at a relatively low temperature by adding an imidation catalyst.

When " almost completely imidized ", the solid content concentration of the first solution becomes almost 100% by mass. However, if the heat treatment is performed rapidly, the solvent may volatilize rapidly from the first solution, which may cause problems such as foaming of the first solution coated on the carrier. Therefore, in the first heat treatment, it is preferable to raise the temperature stepwise from the relatively low temperature state before reaching the maximum temperature. In this case, it is preferable to use a continuous heat treatment apparatus constituted of a plurality of furnaces, the temperature of which gradually increases from the furnace on the sample inlet side to the furnace on the outlet side. As another method, a method in which a maximum temperature of the heat treatment is preliminarily heated at 90 to 180 DEG C by a heat treatment apparatus (preheat treatment), then passed through a separate heat treatment apparatus, and heat treatment (posttreatment) . In the latter case, the post-heat treatment temperature is to be heat-treated at a temperature higher than the pre-heat treatment temperature.

When applying the first solution on the carrier, a known coating method can be used. Specifically, a knife coater, a die coater, a lip coater and the like can be mentioned, but a lip coater is preferable because it is a closed type and has a wide range of viscosity to cope with.

After at least a fixed dry surface is formed on the surface of the first solution applied on the carrier as described above, a second solution comprising a polyimide precursor or a polyimide resin solution is applied and subjected to a second heat treatment to form a first A first polyimide cured layer made of a solution and a second polyimide cured layer made of a second solution are formed. In this second heat treatment, the first polyimide cured layer and the second polyimide cured layer may be formed after the solvent of the applied second solution is dried and once fixed and dried (in the first heat treatment, the first polyimide And if the hardened layer is formed, the second polyimide hardened layer is formed in this second heat treatment). By forming the second polyimide cured layer (or the first and second polyimide cured layers) once in the fixed drying state, the peelability at the interface of these polyimide cured layers can be further increased.

The heat treatment condition for bringing the second solution into a fixed dry state with respect to the second heat treatment is the same as the heat treatment condition for setting the first solution to a fixed dry state in the first heat treatment. In the case where the second polyimide hardened layer (or the first and second polyimide hardened layers) is formed and the second solution is made of the polyimide precursor, the " substantially completely " , And it is preferable that the maximum temperature of the heat treatment in the second heat treatment is set to 100 ° C to 450 ° C. More preferably 180 ° C to 360 ° C, and still more preferably 300 ° C to 360 ° C. On the other hand, when the second solution is made of a polyimide resin solution, it is preferable that the maximum temperature of the heat treatment is set to 150 to 250 캜.

By the second heat treatment, a long polyimide laminate separated from the carrier is obtained in the longitudinal direction of the carrying body by providing the first polyimide hardened layer and the second polyimide hardened layer . Here, in obtaining the elongated polyimide laminate, the carrier may be separated for performing the second heat treatment, or may be separated after performing the second heat treatment. Figs. 1 to 3 schematically show the shape until the elongated polyimide laminate is obtained. 1 is an example of a case where a long substrate 2 wound in a rolled form is used as a carrier. In this embodiment, the second solution applied by using the second mono pump 6 is applied by a lip coater (not shown) 2 After the second heat treatment is performed by the heat treatment device 7, the elongated substrate 2 is separated. 3 is an example of a case in which the metal drum 12 is used as a carrier. Fig. 2 shows an example in which the endless belt 11 is used as a carrier. Fig. 3 shows an example in which the metal drum 12 is used as a carrier. After the first heat treatment is performed by the first heat treatment apparatus 5, the carrier (endless belt 11, metal drum 12) is separated. In order to separate the carrier before the second heat treatment, it is preferable to form the first polyimide hardened layer by the first heat treatment, and it is preferable that the first polyimide hardened layer is formed by the first heat treatment, The bonding strength between the first polyimide cured layers is preferably 1 to 100 N / m, and more preferably 10 to 50 N / m. The first heat treatment refers to the application of the first solution, and the second heat treatment refers to application after the second solution is applied, and each of them may include a plurality of heat treatments. Arrows in the figure indicate the traveling direction of the transporting object or the like.

As a preferable mode for obtaining a long polyimide laminate, there is a method in which a winding roll (winding portion) 1 shown in FIG. 1, a lip coater (not shown), a continuous drying furnace and a heat treatment apparatus (RTR) type coating and drying curing apparatus provided with winding rolls (winding units) 9 and 10 for a carrier and a polyimide laminate, It is good to use. That is, the elongated substrate 2 wound in a roll form is attached to a winding roll (winding portion) 1, and the first and second solutions coated with the mono pumps 4 and 6 while applying the solution are coated with a lip coater, And the polyimide laminate 8 is formed on the elongate substrate 2 by heat treatment. The elongated base material 2 and the polyimide laminate 8 are wound around the winding rolls 9 and 10, respectively, while separating the elongated substrate 2 and the polyimide laminated body 8 from each other, Roll in a roll. The continuous drying furnace is a furnace in which two or more drying furnaces are connected, and the temperature of each drying furnace can be individually adjusted. It is preferable that the set temperature of the drying furnace is set to be gradually increased from the furnace side of the winding section to the furnace of the winding section side. For example, the furnace at the take-out portion side is set at 130 캜, the furnace at the take-up portion side is set at 400 캜, and the furnace at the take-up portion side is set to any one of 130 캜 to 400 캜. Further, the continuous furnace is a furnace in which two or more furnaces are connected, and the temperature of each furnace can be individually adjusted. It is preferable that the set temperature of the furnace is set so as to gradually increase from the furnace side of the take-up unit side to the furnace side of the take-up unit side. For example, the furnace at the take-out portion side is set at 130 캜, the furnace at the take-up portion side is set at 400 캜, and the furnace at the take-up portion side is set to any one of 130 캜 to 400 캜.

Further, after the polyimide laminate is formed on the carrier, the carrier-polyimide laminate is peeled off in the coating drying and curing apparatus, the elongated substrate is wound in a rolled form in the winding unit for the long base material, The polyimide laminate in the winding section for the laminate is wound in a roll shape. With this method, it is possible to increase the working efficiency in a post-process in which the wound polyimide laminate is transported to form a functional layer. Also, the work efficiency when disposing or reusing the wound carrier is also good. Alternatively, after the polyimide laminate is formed on the elongated substrate, the elongated substrate and the polyimide laminate may be separately rolled up into a rolled form in a state in which the elongated substrate and the polyimide laminate are separately laminated, And then the elongated substrate-polyimide laminate was peeled off. Thereafter, the elongated substrate was rolled up in a winding section for the elongate substrate, and the elongated substrate was wound in the form of a roll, The polyimide laminate may be wound in a rolled state in the winding section.

The polyimide laminate thus obtained was obtained by forming one of the first and second polyimide cured layers as a polyimide substrate film and the other as a carrier film to form a functional layer on a polyimide substrate film And the carrier film is separated to obtain a polyimide substrate film having a functional layer. That is, the carrier film may be made of the first polyimide hardened layer, the polyimide substrate film may be made of the second polyimide hardened layer, the polyimide substrate film may be made of the first polyimide hardened layer, And a second polyimide cured layer. Preferably, in view of the fact that the surface smoothness of the polyimide substrate film is not influenced by the surface smoothness of the carrier, in the former case (the carrier film is the first polyimide cured layer and the polyimide substrate film is the second polyimide cured layer) It is good.

The thickness of the polyimide substrate film is preferably 1 to 50 占 퐉, preferably 1 to 20 占 퐉, in view of maintaining the strength as a polyimide substrate and making it possible to produce a thin flexible device. More preferably, Is preferably 1 to 15 mu m. If the thickness of the polyimide substrate film is more than 50 占 퐉, the thin film may deviate from the purpose when the thin flexible device is manufactured. Conversely, if the thickness is less than 1 占 퐉, the strength of the flexible device tends to become insufficient. The thickness of the carrier film is preferably 30 to 200 mu m from the viewpoint of workability assurance when the functional layer is formed. If the thickness exceeds 200 탆, winding becomes difficult. On the other hand, if it is less than 30 탆, there is a fear that processing becomes difficult. The first and second solutions to be applied may be adjusted so as to have a thickness of the same.

Further, regarding the bonding strength between the layers of the carrier film and the polyimide substrate film, these layers are not peeled off at the time of forming the functional layer, and when the carrier film is separated after the functional layer is formed, The bonding strength between these layers is preferably 1 to 20 N / m, more preferably 1.5 to 15 N / m.

In the present invention, after the first solution for forming the carrier film is applied to the carrier and at least the fixed dry surface is formed, the second solution for forming the polyimide substrate film is applied twice more to form a plurality of polyimide layers May be formed on the polyimide substrate film. At this time, each time the second solution is applied, heat treatment may be performed at 60 ° C to 300 ° C to divide the second heat treatment plural times and finally imidize them, or the second solution may be divided into a plurality of circuits, Heat treatment may be carried out at 60 ° C to 300 ° C to bring the coated surface to a fixed dry state, and then imidization may be performed finally. In the former case, the polyimide substrate film can be separately separated into individual polyimide layers, and in the latter case, a polyimide substrate film having a plurality of polyimide layers having different characteristics can be obtained.

When the first solution for forming the carrier film is applied to the carrier, application of the first solution may be performed more than once to form a carrier film having a plurality of polyimide layers. In this case, each time the first solution is applied, the first heat treatment may be performed to obtain a fixed dry state, or the first solution may be applied a plurality of times and the first heat treatment may be performed all at once to form a fixed dry surface on the outermost surface . In the case of the former, each characteristic of the plurality of polyimide layers is easily given individually for each layer, and in the latter case, it is easy to assign the respective characteristics integrally to each layer. Production efficiency is also high.

However, when a flexible device such as a bottom emissive type organic EL display device is manufactured using the polyimide substrate film on which the functional layer of the present invention is formed, the total light transmittance defined in JIS J 7375: 2008 is preferably 80% or more , Preferably 85% or more. Likewise, when the flexible device is a touch panel, it is preferable that the total light transmittance of the polyimide substrate film at a thickness of 20 占 퐉 is 90% or more, considering the necessity of visibility of the display.

The difference (CTE) between the CTE of the polyimide substrate film and the CTE of the carrier film is preferably -25 ppm / K to 25 ppm / K. And more preferably -10 ppm / K to 10 ppm / K. When the CTE difference is within these ranges, interlayer delamination and warpage between the carrier and the polyimide laminate can be preferably suppressed in obtaining the polyimide laminate, and a functional layer is formed on the polyimide substrate film The interlayer peeling and warpage can be suppressed preferably.

The surface of the polyimide substrate film forming the interface with the carrier film preferably has an arithmetic mean roughness (Ra) of 0 nm to 5 nm, more preferably 0.3 to 3 nm, and further preferably 0.3 to 2 nm good. In the present invention, since both the first and second polyimide hardened layers constituting the carrier film and the polyimide substrate film are formed by the casting method, the flatness of these interfaces can be ensured. When the surface roughness of the polyimide substrate film forming the interface with the carrier film is within these ranges, there is no possibility that the polyimide substrate film is peeled off when the polyimide laminate is formed or when the functional layer is formed, It is possible to reliably prevent the polyimide substrate film or the functional layer from being damaged when the film is separated.

Similarly, regarding the surface of the carrier film forming the interface with the polyimide substrate film, the arithmetic mean roughness (Ra) is preferably 0 nm to 5 nm, more preferably 0.3 to 3 nm, still more preferably 0.3 to 2 nm . The surface of the carrier to which the first solution is applied preferably has an arithmetic mean roughness (Ra) of from 0 to 3.5 nm, more preferably from 0.3 to 3 nm, and still more preferably from 0.3 to 2 nm. If the surface roughness of the carrying body to which the first solution is applied is within these ranges, it is possible to prevent unintentional peeling in obtaining the polyimide laminate or to prevent damage when separating the carrying body from the polyimide laminate . In addition, the arithmetic mean roughness (Ra) is calculated from the measurement value measured using an atomic force microscope (AFM) under the conditions specified in JIS B0601: 2013.

In the present invention, the polyimide forming the carrier film is not particularly limited, but is preferably an acid anhydride compound selected from the group consisting of anhydrous pyromellitic acid (PMDA), 2,3,2 ' Biphenyltetracarboxylic acid dianhydride (BPDA), or 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA) is used as the diamine compound and 4 , 4'-diaminodiphenyl ether (4,4'-DAPE), 2,2'-dimethyl-4,4'-diaminobiphenyl (m- 4-aminophenoxy) phenyl] propane (BAPP). Among them, the acid anhydride compound is preferably PMDA and the diamine compound is 4,4'-DAPE.

In the present invention, the carrier film serves as a die sheet when the functional layer is formed on the polyimide substrate film side. Even when the handleability and dimensional stability of the polyimide substrate film are secured in the process of manufacturing the functional layer After the flexible device is manufactured, it is removed. Therefore, even if transparency is low, it does not matter at all. By using the polyimide laminate of the present invention, it is possible to obtain a flexible device which can form a predetermined functional layer on a polyimide substrate film precisely and reliably, and realize a thin, lightweight, and flexible polyimide laminate . That is, the carrier film may be separated and removed immediately after the functional layer is formed through various process steps, and may be integrated with the polyimide substrate film in a certain period of time, bonded to another device member, . Examples of the device member include glass, a plastic plate, a film, a circuit board, and a casing.

On the other hand, as the polyimide forming the polyimide substrate film, a polyimide substrate film forming the functional layer is preferably a film of 4,4'-oxydiphthalic anhydride (ODPA) as the acid anhydride compound, (CBDA), 1,2,3,4-cyclohexanetetracarboxylic acid dianhydride (CHDA), or 2, 3, 4-cyclobutane tetracarboxylic acid dianhydride , 2-bis (3,4-anhydrodicarboxyphenyl) hexafluoropropane (6FDA), and 4,4'-diamino-2,2'-bis (tri Diaminobiphenyl (m-TB), or 4,4 '- (hexafluoroisopropylidene) dianiline (4-fluoromethyl) biphenyl (TFMB), 2,2'- , And 46F). Among them, the acid anhydride compound is preferably at least one of 6FDA, PMDA and CBDA, and the diamine compound is at least one of TFMB and 4,46F.

Examples of the solvent of the polyimide precursor or polyimide resin solution constituting the first and second solutions include N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc) (DMSO), dimethyl sulfate, sulfolane, butylolactone, cresol, phenol, halogenated phenol, cyclohexanone, dioxane, tetrahydrofuran, diglycine, triglyceride, carbonate (dimethyl carbonate, diethyl carbonate , Ethyl methyl carbonate, ethylene carbonate, propylene carbonate, etc.).

The polyimide precursor solution or polyimide solution may contain a mold release agent if necessary. Further, additives such as a catalyst, an antioxidant, a heat stabilizer, an antistatic agent, a flame retardant, an ultraviolet absorber and a lubricant may be included.

As the functional layer to be formed on the polyimide substrate film, a device capable of securing the function of a known flexible device can be applied. For example, an organic EL / TFT, a photoelectric conversion device, an electronic paper driving device, a color filter, Photoelectric conversion devices, and the like. As an example, when an organic EL display is manufactured as a flexible device, a TFT for image driving may be used as the functional layer. The material of the TFT is a silicon semiconductor or an oxide semiconductor. When a conventional flexible substrate is not used, a barrier layer of an inorganic component is formed on a hard substrate such as a plate glass, and a TFT is formed thereon. (300 占 폚 range to 400 占 폚 range) is required in formation of the polyimide, but the back surface of the polyimide can withstand the high temperature treatment. When a touch panel is manufactured as a flexible device, an electrode layer such as a transparent conductive film or a metal mesh may be used as the functional layer. Examples of the transparent conductive film include ITO (tin-doped indium oxide), SnO, ZnO, and IZO. When these electrode layers are formed, a conductive layer having a small resistance value can be obtained by performing heat treatment at 200 DEG C or more, but the back surface of polyimide can withstand high temperature processing. In addition, when the transparent conductive film is used as the functional layer, not limited to the touch panel, it is also referred to as a " transparent conductive layer ".

As a preferable mode for forming the functional layer on the polyimide substrate film of the polyimide laminate, after the long polyimide laminate is once wound around the take-up roll, the polyimide laminate is unwound, It is preferable to continuously form the functional layer on the substrate film. Further, the wound polyimide laminate may be cut into sheets in a predetermined length while being unwound to form a functional layer on the polyimide substrate film for each sheet-shaped polyimide laminate.

After the functional layer is formed on the polyimide substrate film, the carrier film of the polyimide laminate is separated to obtain a polyimide substrate film having the functional layer. Here, the method for separating the carrier film is not particularly limited, and a known method can be used. At that time, the carrier film may be peeled off by a mechanical means such as a claw holding tool such as a tweezers for forming a peeling claw portion, a suction plate, and air jetting to the peeling portion after forming the peeling end portion. For example, a carrier film is peeled off by picking up the end portion of the carrier film with a tweezers, and a polyimide substrate film having a functional layer is peeled off from the peeling portion using another tool (tweezers, sticks, blades, Separate it completely. Alternatively, instead of the tweezers, the tool may be pierced at the interface of the polyimide substrate film on which the carrier film-functional layer is formed by using a needle-like, hook-shaped or insect-leg-shaped tool to peel the end of the carrier film, The formed polyimide substrate film may be sucked with a suction plate to peel off the carrier film. Such a method of using the suction plate is a preferable method in that the polyimide substrate film on which the functional layer is formed at the same time as peeling can be stably gripped and transported. The suction plate may have a flat shape or a curved shape such as a semicircular shape. Further, after the end portion of the carrier film is peeled off by any of the above-described methods, a suction plate or compressed air may be sprayed to peel off the carrier film.

Here, the case of manufacturing the touch panel using the elongated polyimide laminate of the present invention will be described as an example. In this example, the continuous production apparatus of the RTR type shown in Fig. 4 is used, and this continuous production apparatus comprises a take-up roll (take-up unit) 13 for unwinding the elongated polyimide laminate 8 wound in a roll form, (Guide roll) 14, a process processing section 15, and a winding roll (winding section) The polyimide laminate 8 unwound from the unwinding roll 13 is transferred to the surface of the polyimide laminate on the side of the polyimide substrate film on the surface of the polyimide laminate in the process processing section 15 via the transport roll 14 for preventing wrinkles and wind- ITO is deposited as a functional layer at 100 to 400 캜 to form a functional layer (ITO) on the polyimide laminate. Thereafter, the polyimide laminate 16 having the functional layer is wound in a rolled state by the winding roll 17 via the transport roll 14.

Instead of depositing ITO by the process processing section 15, ITO may be formed on a resin film support such as polyethylene terephthalate or polyethylene, and the ITO surface may be adhered to the surface of the polyimide substrate film in the polyimide laminate And then the resin film support is peeled off to form ITO on the polyimide laminate.

Next, the polyimide laminate 16 on which the functional layer wound on a roll is formed is unwound and cut into a sheet with a predetermined length. The size of the sheet can be determined arbitrarily according to the size of the touch panel to be manufactured. ITO in the polyimide laminate on which the functional layer on the cut sheet is formed is processed into a circuit shape to be used as a touch panel by etching. A known method can be used for etching. For example, a liquid or film-like photoresist (a negative type or a positive type) may be laminated on the surface of ITO. In the case of a liquid photoresist, after the lamination, the solvent may be volatilized and dried by heat treatment. Then, a well-known photomask patterned in a circuit shape is laminated on the photoresist, exposed with a known exposure apparatus, and developed with a known developer. The developer can be appropriately selected from an aqueous alkaline solution, an organic solvent and the like by using the photoresist to be used. As a result of the development, a photoresist corresponding to the shape of a circuit used as a touch panel is left on the surface of the ITO. Then, the etching solution is contacted to remove the ITO in the portion where the photoresist is not laminated. As the etching solution, a known etching solution can be used, and examples thereof include iron chloride-based or chloride-based etching solutions. Then, the remaining photoresist is peeled off and washed with water. Further, the carrier film is peeled off using a tweezers or the like to obtain a polyimide substrate film on which ITO is used as a touch panel.

4, after the ITO is formed on the polyimide laminate and processed into a circuit shape to be used as a touch panel by etching, a polyimide film The intermediate laminate is wound up by a take-up roll 17 and then cut into sheets in an arbitrary size in accordance with the size of the touch panel to be produced in the same manner as described above. Further, the carrier film is peeled off and ITO So as to obtain the formed polyimide substrate film.

As another mode for manufacturing a touch panel using a long polyimide laminate according to the present invention, silver or copper nanowires (hereinafter referred to as " nanowires ") may be replaced with known ultraviolet light curing type The functional layer may be formed by laminating using an adhesive. In this case, in the process processing section 15 of the continuous manufacturing apparatus of the RTR system, an ultraviolet curable resin is applied to the surface of the polyimide laminate on the side of the polyimide substrate film and dried to laminate the nanowires in the form of a circuit. When stacking, grooves may be formed in the shape of a circuit, and nanowires may be provided in the grooves. Then, the ultraviolet light curable adhesive is cured by irradiating ultraviolet light to adhere the nanowire to the polyimide laminate, and the polyimide laminate 16 having the functional layer is wound in a roll form by the take-up roll 17. Then, the polyimide laminate 16 on which the functional layer was formed was unwound, cut into sheets in an arbitrary length as in the case of the above-mentioned production example, and the carrier film was peeled off, Thereby obtaining a polyimide substrate film. At this time, the end face of the nanowire may be smoothly polished or the like.

Further, in the present invention, a long polyimide laminate is cut into sheets in advance according to the size of a flexible device such as a touch panel manufactured, and ITO is formed on the sheet-like polyimide laminate, The film may be processed into the shape of a circuit used as a touch panel and the carrier film may be peeled off to obtain a polyimide substrate film on which ITO is used as a touch panel or the like.

On the other hand, a case of producing a coverlay film using the elongated polyimide laminate of the present invention will be described as an example. The polyimide laminate 8 is unrolled from the unwinding roll 13 by using the RTR continuous production apparatus shown in Fig. 4 and is fed to the process processing unit 15 via the transport roll 14, An adhesive layer is formed as a functional layer on the surface of the polyimide laminate on the polyimide substrate film side. Examples of the method for forming the adhesive layer include known resin materials such as epoxy resin, acrylic resin, polyimide resin and silicone resin, which are raw materials for the adhesive layer using a coating apparatus such as a lip coater, Known pressure-sensitive adhesive (pressure-sensitive adhesive) such as hot melt adhesive, rubber adhesive and the like is applied and dried. Then, the polyimide laminate having the adhesive layer formed by the winding roll 17 is rolled up into a roll, and cut into sheets in an arbitrary size according to the size of the coverlay film to be produced, and the carrier film is peeled off as a coverlay film Thereby obtaining a polyimide substrate film on which an adhesive layer to be used is formed. When the pressure-sensitive adhesive is used as the adhesive layer, the pressure-sensitive adhesive layer may be referred to as a pressure-sensitive adhesive layer. In the case of using the pressure sensitive adhesive layer as the functional layer of the present invention, in the case of manufacturing the touch panel, after the ITO is formed on the polyimide laminate and the cover layer is laminated thereon, Can also be used.

In the present invention, in obtaining a polyimide substrate film having a functional layer such as a polyimide substrate film having the adhesive layer formed thereon, in the above-described continuous manufacturing apparatus of the RTR system, a winding roll for winding the carrier film is separately provided And a polyimide substrate film on which a long functional layer is formed may be wound. That is, after the functional layer is formed on the polyimide laminate in the process processing section, the carrier film is peeled off in the continuous production apparatus of the RTR system and wound up by a take-up roll (not shown) for the carrier film, 17, a polyimide substrate film on which a functional layer is formed is wound. The polyimide substrate film on which the wound functional layer is formed may be cut into sheets in accordance with the size of the flexible device, if necessary.

In the case of producing an organic EL display using the elongated polyimide laminate according to the present invention, for example, the organic EL display is cut into sheets in accordance with the size of the organic EL display in which the polyimide laminate is manufactured in advance, A glass sheet is laminated on the side of the carrier film side of the polyimide laminate. Then, a TFT, an electrode layer, a light emitting layer, and an electrode layer are sequentially formed as a functional layer on the side of the polyimide substrate film side, these functional layers are hermetically sealed with a glass substrate or a multilayer thin film, A polyimide substrate film on which a functional layer usable as a display is formed is obtained. That is, the forming temperature when the TFT is formed is 300 to 500 캜.

In the case of manufacturing a liquid crystal display device using the elongated polyimide laminate according to the present invention, a known resist ink for a color filter made of a vinyl ester resin, a phenol resin, an acrylic resin, As shown in FIG.

In the case of manufacturing the various flexible devices using the long polyimide laminate of the present invention, the following functional layers may be mounted in order to improve respective characteristics. Namely, known compounds such as melamine resin, urethane resin, acrylic resin, silicone resin, silane compound and metal oxide may be mounted as a hard coat layer in order to improve the friction resistance of the polyimide substrate film. A known gas barrier layer such as alumina or silica may be mounted on the polyimide substrate film to suppress permeation of oxygen or water vapor. In order to control the optical properties, dimensional stability, etc. of the polyimide substrate film, a known transparent resin such as a cyclic olefin resin or an ester resin may be mounted as a transparent resin layer.

Further, in addition to the above-mentioned functional layers, it is also possible to use copper, silver, gold, titanium, tungsten, ITO, etc. for the purpose of exchanging electronic signals between flexible devices, between flexible device and output devices or between flexible device- May be mounted as a wiring layer.

As described above, the polyimide substrate film provided with the functional layer obtained by the present invention has excellent smoothness and little foreign matter. In addition to various flexible devices such as a touch panel, an electronic paper, and a solar cell as well as a flexible display such as an organic EL in addition to a thin film having a small thickness and excellent light transmittance, a deposition mask, a fan-out wafer level package ) And the like.

(Example)

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

<1. Various physical properties measurement and performance test method>

[Measurement of Peel Strength]

The peel strength between the carrier body and the carrier film and the peeling strength between the carrier film and the polyimide substrate film were obtained by processing these laminated bodies into a vertically elongated rectangular shape having a width of 1 mm to 10 mm and a length of 10 mm to 25 mm, The carrier film was peeled in the direction of 180 占 using a tensile tester (Strograph-M1) manufactured by KIKAISHO Co., Ltd. to measure the peel strength. Further, the peel strength was high, and it was determined that "peeling was impossible" when peeling was difficult.

[Transmittance]

The polyimide substrate film was cut out to a size of 5 cm x 5 cm, and the total light transmittance was measured using HAZE METER NDH-5000 manufactured by Nippon Denshoku Kogyo Co.,

[Surface roughness Ra]

The surface roughness Ra of the carrier, the carrier film, and the polyimide substrate film was divided into 3 cm x 3 cm, and the surface roughness Ra (JIS B0601: 2013) was measured using an AFM manufactured by Burka Co., .

[CTE]

The CTEs of the carrier, the carrier film, and the polyimide substrate film were each cut into 3 mm x 15 mm, and subjected to a thermomechanical analysis (TMA) apparatus manufactured by Seiko Instruments Inc. under a load of 5.0 g, / min) in a temperature range of 30 占 폚 to 260 占 폚, and CTE (占 10 ^-6 / K) was measured from the elongation of the polyimide film relative to the temperature.

&Lt; 2. Synthesis of polyamic acid (polyimide precursor) solution >

The raw materials, aromatic diamino compounds, acid anhydrides of aromatic tetracarboxylic acids, and solvents used for synthesis of the polyamic acid (polyimide precursor) solution to be treated in the following Synthesis Examples, Examples and Comparative Examples are shown below.

[An aromatic diamino compound]

4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl (TFMB)

4,4'-diaminodiphenyl ether (4,4'-DAPE)

[Acid anhydride of aromatic tetracarboxylic acid]

· Anhydrous pyromellitic acid (PMDA)

· 2,2-bis (3,4-anhydrodicarboxyphenyl) hexafluoropropane (6FDA)

〔solvent〕

N, N-dimethylacetamide (DMAc)

(Synthesis Example 1)

Under a stream of nitrogen, TFMB (9.4 g) was added to 127.5 g of solvent DMAc with stirring in a 300 ml separable flask, warmed and dissolved at 50 캜. Then, 6FDA (13.09 g) was added. Thereafter, the solution was stirred for 3 hours at room temperature to carry out a polymerization reaction to obtain 200 g of pale brown viscous polyamic acid A varnish. The polyamic acid A varnish is cured under the heating conditions described later to obtain a polyimide resin A (CTE: 70 ppm / K).

(Synthesis Example 2)

4,4'-DAPE (10.753 g) was added to 170 g of solvent DMAc with stirring in a 300 ml separable flask under nitrogen flow, and the mixture was warmed and dissolved at 50 캜. PMDA (11.747 g) was then added. Thereafter, the solution was stirred for 3 hours at room temperature to carry out a polymerization reaction to obtain 200 g of pale brown viscous polyamic acid B varnish. The polyamic acid B varnish was cured under the heating conditions described below to obtain a polyimide resin B (CTE: 69 ppm / K).

&Lt; 3. Formation of PI layer by application >

The respective materials handled in the following examples and comparative examples are shown below.

· Long substrate (carrier)

Polyimide film (UFIREX S, manufactured by Ube Industries Ltd.), thickness: 0.75 mm, CTE: 18 ppm / K.

Polyimide film (CAPTON 300H made by Toray DuPont), thickness 75 mu m, CTE: 27 ppm / K.

(Example 1)

(Not shown) shown in Fig. 1, a continuous coater (not shown), and a continuous coater 2 as shown in Fig. 1 were used as the long base material 2, (First heat treatment device 5 and second heat treatment device 7) provided with a continuous furnace and a continuous furnace, and a roll-to-roll type furnace having a winding section 9 and 10 for a carrier and a polyimide laminate The polyamic acid B varnish coated from the mono pump 4 was applied at a speed of 8 m / min with a coating drying and curing apparatus so as to have a film thickness of 500 m. This was passed through a continuous drying furnace (first heat treatment apparatus 5) composed of a plurality of rolls and dried at 90 DEG C for 2 minutes and at 130 DEG C for 1 minute, and was constituted by a plurality of rolls, (Polyimide cured layer) B is formed by passing the mixture through a furnace in which the temperature is gradually increased (first heat treatment apparatus 5) and stepwise from 130 占 폚 to 400 占 폚 in total for 20 minutes in total did.

Then, the polyamic acid A varnish was applied from the mono pump 6, and the polyamic acid A varnish was applied on the polyimide B so as to have a film thickness of 150 占 퐉. Then, a continuous drying furnace (a second heat treatment (7)), dried at 90 占 폚 for 2 minutes, and at 130 占 폚 for 1 minute, and the continuous furnace is constituted by a plurality of furnaces and the temperature is gradually increased from the furnace on the sample inlet side to the furnace on the outlet side 2 heat treatment apparatus 7) and heated stepwise from 130 占 폚 to 400 占 폚 in total for 10 minutes to form a polyimide (polyimide cured layer) A. Then, the laminated body 8 of polyimide B and polyimide A was wound up with the take-up part 10 while separating the long base material 2, the epi-Lex S, to obtain a roll-shaped polyimide laminate according to the first embodiment.

The thickness of each layer of the obtained polyimide laminate (8) was 50 占 퐉 for polyimide B and 15 占 퐉 for polyimide A. Also, the peel strength between Eupylex S (elongated substrate) and polyimide B was 0.12 N / m, and the peel strength between polyimide B-polyimide A was 0.10 N / m. On the other hand, the surface roughness Ra of the polyimide A after peeling at each interface was 1.0 nm, the surface roughness Ra of the polyimide B was 1.0 nm, and the surface roughness Ra of the dipyrite S was 1.15 nm. The light transmittance of polyimide A was 91%.

Next, a roll-to-roll method (roll-to-roll method) including the winding unit 13, the conveying roll 14, the process processing unit 15, and the winding unit 17 shown in Fig. , A functional layer was formed as follows. That is, the polyimide multilayer body 8 is transported at a speed of 5 m / min to unwind the polyimide A film in the longitudinal direction so that the polyimide A film becomes a polyimide substrate film, Was introduced into the installed process processing unit 15, and ITO having a thickness of 50 nm was formed on the polyimide A side by sputtering in the process processing unit 15 by continuous treatment. Then, the polyimide laminate 16 on which the functional layer with the ITO was formed was wound up in a rolled state by the winding section 17. Then,

The polyimide laminate 16 on which the functional layer obtained above was formed was cut into a sheet of 370 mm x 450 mm while unwinding it, and the formed ITO was subjected to X-ray transparent circuit processing. At that time, the intersection of the Y circuit and the X circuit did not form a circuit.

Then, an overcoat was applied to the intersection of the Y circuit and the X circuit, heat treatment was performed at 250 占 폚 to cure the overcoat layer, and bridge processing was performed over the overcoat layer using silver paste to complete the XY circuit. Overcoat was applied again to the entire surface, and annealing treatment was performed at 270 占 폚 to cure the overcoat layer and crystallize ITO.

Then, OCA (Optically Clear Adhesive Tape, 8146-2 made by 3M) was adhered to the surface of the overcoat layer which was applied again, and the cover glass was adhered thereon. Thereafter, polyimide B having a carrier film was mechanically peeled off to complete a touch panel substrate having flexibility.

(Comparative Example 1)

The above-mentioned capton 300H (width 520 mm x length 1100 m x thickness 75 m, surface roughness Ra = 4.0 nm) wound in a roll form was unwound at a speed of 8 m / min by a roll-to-roll type coating and drying curing apparatus shown in Fig. 1 , Polyamic acid A varnish was applied from the mono pump 4 so as to have a film thickness of 150 mu m and dried at 90 DEG C for 2 minutes and at 130 DEG C for 1 minute through a continuous drying furnace composed of a plurality of nozzles The sample was passed through a continuous furnace composed of a plurality of furnaces and gradually increasing in temperature from the furnace on the sample inlet side to the furnace on the outlet side so as to be gradually heated from 130 占 폚 to 400 占 폚 in a stepwise manner for 10 minutes in total, Mid A was formed. Then, a laminate of capton 300H and polyimide A was wound up to obtain a roll-shaped polyimide laminate according to Comparative Example 1. [

Here, since the obtained polyimide laminate in roll form could not peel polyimide A from capton 300H, no functional layer was formed. The surface roughness Ra of the exposed surface of polyimide A was 1.0 nm.

1: Rolling up (release)
2: elongated substrate (carrier)
3: Feed roll (guide roll)
4: first mono pump
5: First heat treatment apparatus
6: second mono pump
7: Second heat treatment apparatus
8: polyimide laminate
9: Wound roll for conveying body (winding section)
10: Winding roll for polyimide laminate (winding part)
11: Endless belt (carrier)
12: metal drum (carrier)
13: Rolling up (rolling)
14: Feed roll (guide roll)
15: Process processor
16: Polyimide laminate with functional layer formed
17: Winding roll (Winding part)

Claims (20)

A first solution comprising a polyimide precursor or a polyimide resin solution is coated on a carrier to be supplied continuously and a first heat treatment is performed to form at least a fixed dry surface on the surface of the first solution and then a polyimide precursor or And a second polyimide cured layer made of a first solution and a second polyimide cured layer made of a second solution by applying a second solution comprising a polyimide resin solution and performing a second heat treatment, A long polyimide laminate separated from the carrier is obtained in the longitudinal direction,
One of the first and second polyimide hardened layers in the elongated polyimide laminate is used as a polyimide substrate film and the other is used as a carrier film to form a functional layer on a polyimide substrate film, And separating the film to obtain a polyimide substrate film having a functional layer. The method according to claim 1,
After the elongated polyimide laminate is once wound around a take-up roll, the functional layer is continuously formed on the polyimide substrate film while the polyimide laminate is being unwound, or the polyimide laminate is unwound, To form a functional layer for forming a functional layer on the polyimide substrate film for each polyimide laminate on the sheet. 3. The method according to claim 1 or 2,
Wherein the carrier body is separated before performing the second heat treatment or a functional layer separated after the second heat treatment is performed in obtaining the elongated polyimide laminate. 3. The method according to claim 1 or 2,
Wherein the carrier comprises a metal drum, an endless belt, or a functional layer that is a long substrate rolled in a rolled form. 3. The method according to claim 1 or 2,
Wherein the carrier film comprises a first polyimide cured layer, and the polyimide substrate film is a functional layer comprising a second polyimide cured layer. 3. The method according to claim 1 or 2,
Wherein the polyimide substrate film is made of a first polyimide cured layer and the carrier film is a functional layer made of a second polyimide cured layer. 3. The method according to claim 1 or 2,
A first solution comprising a polyimide resin solution is coated on the carrier and subjected to a first heat treatment at a temperature of 60 to 300 DEG C to form a functional layer for forming a fixed dry surface on the surface of the first solution A method for producing a polyimide substrate film. 3. The method according to claim 1 or 2,
A first solution comprising a polyimide precursor is coated on the carrier and a first heat treatment is performed at a temperature of 100 ° C to 450 ° C to form a first polyimide cured layer of a first solution A method for producing a polyimide substrate film. 3. The method according to claim 1 or 2,
Wherein a maximum temperature of the heat treatment in the second heat treatment is 100 占 폚 to 450 占 폚. 3. The method according to claim 1 or 2,
Wherein the interlayer adhesion strength between the first polyimide cured layer and the second polyimide cured layer is 1 to 20 N / m and the thickness of the first or second polyimide cured layer made of a polyimide substrate film is 1 to 50 m Wherein the polyimide substrate film is a polyimide film. 3. The method according to claim 1 or 2,
Wherein the first or second polyimide hardened layer of the polyimide substrate film is formed with a functional layer having a total light transmittance of 80% or more. 3. The method according to claim 1 or 2,
Wherein the carrier body is made of a rolled-up elongated substrate, and the elongated substrate is a polyimide film, a SUS foil, a copper foil, or a composite in which two or more thereof are laminated. 3. The method according to claim 1 or 2,
Wherein a functional layer for forming a first polyimide cured layer is formed by using at least two kinds of first solutions made of the polyimide precursor or polyimide resin solution and coating them in an overlaid manner to form a first polyimide cured layer. 3. The method according to claim 1 or 2,
Wherein a functional layer for forming a second polyimide cured layer is formed by using at least two kinds of second solutions made of the polyimide precursor or polyimide resin solution and coating them in an overlaid manner to form a second polyimide cured layer. A carrier film made of a polyimide precursor or a polyimide resin solution and a polyimide cured layer obtained by curing one of the first and second solutions and a second film made of a polyimide precursor or a polyimide resin solution The functional layer is continuously formed on the polyimide substrate film in the longitudinal direction of the elongated polyimide laminate in which the polyimide substrate film composed of the polyimide cured layer having been cured is laminated and the polyimide substrate film has a thickness of 1 The total light transmittance is 80% or more, and the interface with the carrier film has a surface roughness with an arithmetic average roughness Ra of 0 to 5 nm, and the interlaminar bond strength between the carrier film and the polyimide substrate film is 1 to 20 N / m. 16. The method of claim 15,
Wherein the functional layer is an ITO film. 16. The method of claim 15,
Wherein the functional layer is a TFT. 16. The method of claim 15,
The functional layer may be any one selected from the group consisting of a transparent conductive layer, a wiring layer, a conductive layer, a gas barrier layer, a thin film transistor, an electrode layer, a light emitting layer, an adhesive layer, a pressure sensitive adhesive layer, a transparent resin layer, a color filter resist, Wherein the functional layer is a layer including a combination of two or more types of polyimide. A carrier film made of a polyimide precursor or a polyimide resin solution and a polyimide cured layer obtained by curing one of the first and second solutions and a second film made of a polyimide precursor or a polyimide resin solution Wherein the interlayer adhesive strength between the carrier film and the polyimide substrate film is 1 to 20 N / m, and the thickness of the polyimide substrate film is less than the thickness of the polyimide substrate film And a total light transmittance of 80% or more. A functional layer is continuously formed in a longitudinal direction of a long polyimide substrate film comprising a polyimide precursor or a solution of a polyimide resin solution and made of a polyimide cured layer, and the polyimide substrate film has a thickness of 1 to 50 탆, a total light transmittance at a thickness of 20 탆 of 80% or more, and a surface on the side opposite to the functional layer has a surface roughness with an arithmetic average roughness Ra of 0 to 5 nm Formed long polyimide substrate film.

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