JP2015165015A - Polyimide resin composition, polyimide film using the resin composition, and device film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide resin composition giving a polyimide film having such properties that upon removing a carrier substrate from a device film laminate including the polyimide film, the substrate can be easily and efficiently removed without damaging a device film obtained by the removal and that the polyimide film has an appearance with colorless and transparent properties or the like.SOLUTION: The resin composition comprises a polyimide resin and/or a polyimide resin precursor, and a surfactant. The amount of the surfactant in the resin composition is less than 0.4 mass% with respect to the polyimide resin and/or the polyimide resin precursor; and the surfactant is nonionic and comprises an element selected from H, C, N, O, P, S, and Se. The polyimide resin and/or the polyimide resin precursor contain at least one structure selected from a cyclic aliphatic skeleton, a fluorinated skeleton, and a biphenyl skeleton.

Description

  The present invention is a polyimide resin composition used in the manufacture of flexible devices and the like, and the polyimide film obtained from the polyimide resin composition has excellent releasability and is compatible with appearance such as colorless transparency Relates to the composition.

  Currently, glass substrates are mainly used as element substrates in the field of display devices such as liquid crystal displays, organic EL displays and electronic paper, the field of light receiving devices such as solar cells, and the field of light emitting devices such as organic EL lighting. In these fields, weight reduction and thinning are required, but there is a problem that when the glass substrate is reduced in weight and thickness, the strength is lowered and the glass substrate is easily broken.

Therefore, a plastic film has attracted attention as an alternative to a glass substrate that is generally used for the above-mentioned applications.
Examples of commonly used plastic films include PEN (polyethylene naphthalate resin), PES (polyether sulfone resin), PET (polyethylene terephthalate resin), BCB (benzocyclobutene resin), and the like. However, these substrates have problems such as low heat resistance and complexity of the film forming process.
On the other hand, polyimide films are attracting attention as substrates for flexible devices such as displays, organic EL, photoelectric conversion elements and the like because they are excellent in heat resistance, have little change in physical properties in a wide temperature range, and are tough.

When forming a device constituent member on a plastic film, the following steps (A) to (C) are used.
(A) A plastic film is formed on a carrier substrate (hereinafter, a plastic film formed on a carrier substrate is referred to as a plastic film laminate). (B) A device constituent member is formed on the plastic film laminate (hereinafter, a device constituent member formed on the plastic film laminate is referred to as a device film laminate). (C) The carrier substrate is peeled from the device film laminate (hereinafter, the carrier substrate is peeled from the device film laminate is referred to as a device film). The schematic diagram of the said device film laminated body is shown in FIG.

  As the step (C), a method of peeling by immersion treatment, a method of peeling using a laser or the like, a method of forming a pressure-sensitive adhesive layer between a carrier substrate and a plastic film, and the like are used. However, in these methods, the device component formed on the plastic film and the plastic film itself are damaged, and as a result, the performance and production efficiency of the device film may be lowered. Further, since the manufacturing process becomes complicated, further improvement is required.

  As the step (C), a method of adding an additive such as a surfactant to a polymer solution which is a raw material of a plastic film is proposed. For example, Patent Document 1 describes a film-forming polymer solution containing a fluorosurfactant, and a polyimide film obtained by a casting method is excellent in surface smoothness and peelability from a casting surface. It has been shown.

  Patent Document 2 describes a film-forming polymer composition containing an organic siloxane such as a silicone varnish, and the polyimide film produced from this polymer composition has excellent peelability from the casting surface. It is shown.

JP 59-191760 JP 47-33063 A

  However, when a device constituent member is formed on a polyimide film manufactured using the polymer solution described in Patent Document 1, the fluorine-based surfactant remaining in the polyimide film is used to form a device configuration such as a barrier layer or a sealing layer. Adhesiveness with a member is inhibited, and as a result, the performance of the device film tends to be lowered. In addition, when the formation process of the device constituent member such as an electrode or a transistor is higher than the polyimide film manufacturing temperature, during the formation process of the device constituent member, the fluorosurfactant remaining in the polyimide film becomes outgas, It tends to reduce the performance of the device component.

  In addition, according to the study by the present inventors, when a polyimide film is produced using a film-forming polymer composition containing an organic oxane such as silicone varnish as in Patent Document 2, sufficient releasability is obtained. For this, a large amount of organosiloxane must be added. In that case, however, it has been found that the produced polyimide film may be whitened. In other words, when colorless transparency is required for the polyimide film, it became clear that it is difficult to achieve both the peelability of the polyimide film from the carrier substrate and the appearance of the polyimide film, such as colorless transparency and haze. .

  The present invention makes it easy to peel the carrier substrate from the device film laminate without causing the performance deterioration of the device component even after the device component is formed on the polyimide film laminate. It aims at providing the polyimide resin composition which makes external appearances, such as colorless transparency, compatible.

  In view of the above circumstances, the present inventors diligently studied a polyimide resin composition that can be easily and efficiently carried out when peeling a carrier substrate from a device film laminate. As a result, the inventors have found that the object of the present invention can be achieved by using a polyimide resin composition containing a polyimide resin and / or a polyimide resin precursor and a specific surfactant, thereby completing the present invention.

The present invention relates to the following items.
[1] A resin composition comprising a polyimide resin and / or a polyimide resin precursor and a surfactant, wherein the amount of the surfactant in the resin composition is relative to the polyimide resin and / or the polyimide resin precursor A polyimide resin composition characterized by being less than 0.4% by mass and having a nonionic property, wherein the surfactant comprises an element selected from H, C, N, O, P, S and Se.
[2] The polyimide resin composition according to [1], wherein the polyimide resin and / or polyimide resin precursor includes at least one selected from a cyclic aliphatic skeleton, a fluorinated skeleton, and a biphenyl skeleton.
[3] A polyimide film formed by casting the polyimide resin composition according to [1] or [2].
[4] A polyimide film laminate in which the polyimide film according to [3] is formed on a carrier substrate.
[5] A device film laminate in which a device constituent member is further formed on the polyimide film laminate of [4].
[6] A device film obtained by peeling the carrier substrate from the device film laminate according to [5].

By using the polyimide resin composition of this invention, when peeling a carrier substrate from a device film laminated body, it can carry out easily and efficiently, without damaging a device film. Moreover, since the polyimide film obtained using the polyimide resin composition of the present invention does not cause whitening or the like, it is particularly useful for flexible displays that require optical properties such as colorless transparency.
Hereinafter, in the present invention, a film obtained from the polyimide resin composition of the present invention is referred to as a polyimide film. Moreover, what formed the polyimide film on the carrier substrate is called a polyimide film laminated body.
In addition, as described above, a device layer formed by forming a device constituent member such as a barrier layer, a sealing layer, an electrode, a transistor, a color filter, and a polarizing film on the polyimide film laminate is referred to as a device film laminate. What peeled the carrier substrate from the film laminated body is called a device film.
In addition, as an example of the schematic diagram of the device film laminate using the polyimide film of the present invention, in FIG. 1 described above, the plastic film is changed to a polyimide film, and the plastic film laminate is changed to a polyimide film laminate. Can be mentioned.

It is a schematic diagram which shows an example of a device film laminated body. It is a schematic diagram of the structure cross section of the organic electroluminescent element using a polyimide film.

  Hereinafter, embodiments of the present invention will be described in detail. What is described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to the following embodiment unless it exceeds the gist.

  The polyimide resin composition of the present invention contains a polyimide resin and / or a polyimide resin precursor, and a surfactant. In addition to the polyimide resin and / or polyimide resin precursor and surfactant, the polyimide resin composition may be a solvent, an antioxidant, a lubricant, a colorant, a stabilizer, an ultraviolet absorber, an antistatic agent, a flame retardant. , Plasticizers or mold release agents, leveling agents, antifoaming agents, and the like. Moreover, you may mix | blend inorganic type fillers or organic type fillers, such as powder form, a granular form, plate shape, and fibrous form, as long as the objective of invention is not impaired as needed. These additive components may be added at any stage of any process for producing the polyimide resin composition.

  Examples of inorganic fillers include oxides such as silica, diatomaceous earth, barium ferrite, beryllium oxide, pumice and pumice balloon; hydroxides such as aluminum hydroxide, magnesium hydroxide and basic magnesium carbonate; calcium carbonate Carbonates such as magnesium carbonate, dolomite, and dawsonite; sulfates and sulfites such as calcium sulfate, barium sulfate, ammonium sulfate, and calcium sulfite; talc, clay, mica, asbestos, glass fiber, glass balloon, glass beads, calcium silicate Silicates such as carbon fiber, carbon black, graphite and carbon hollow spheres; powders of molybdenum sulfide, zinc borate, barium metaborate, calcium borate, sodium borate, boron fiber, etc. Shape, granular, board , Fibrous inorganic fillers; powdered, granular, fibrous, whisker-like metal fillers of metal elements, metal compounds, alloys, etc .; silicon carbide, silicon nitride, zirconia, aluminum nitride, titanium carbide, potassium titanate, etc. Powdered, granular, fibrous, and whisker-like ceramic fillers.

On the other hand, examples of organic fillers include shell fibers such as fir shells, carbon nanotubes, fullerenes, wood flour, cotton, jute, paper strips, cellophane pieces, aromatic polyamide fibers, cellulose fibers, nylon fibers, polyester fibers, Polypropylene fiber, thermosetting resin powder, rubber and the like can be mentioned.
As a filler, what processed into flat form, such as a nonwoven fabric, may be used, and several materials may be mixed and used.

  When producing the polyimide film of the present invention by using a casting method or the like for the polyimide resin composition, the polyimide resin composition preferably contains a solvent. The solvent is not particularly limited. Examples of the solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone; dimethyl sulfoxide, γ-butyrolactone, Aprotic solvents such as anisole, diglyme, cyclohexanone, 1,4-dioxane; and the like. Among these, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and γ-butyrolactone are particularly preferable from the viewpoint of compatibility with the polyimide resin and the polyimide resin precursor. Moreover, when a polyimide resin is included in the polyimide resin composition, it is preferable that anisole is included in order to suppress whitening due to moisture absorption during the formation of the coating film. These solvents may be one kind or a mixture of two or more kinds.

  The concentration of the polyimide resin and / or the polyimide resin precursor in the polyimide resin composition is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more, and usually 80% by mass or less, preferably Is 50 mass% or less. By adjusting the concentration of the polyimide resin and / or the polyimide resin precursor in the polyimide resin composition within this range, good coating properties tend to be achieved.

The viscosity of the polyimide resin composition of the present invention is not particularly limited, but is usually 10 mPa · s or more, preferably 1.0 × 10 ² mPa · s or more. Moreover, it is 5.0 * 10 < ⁴ > mPa * s or less normally, Preferably it is 2.0 * 10 < ⁴ > mPa * s or less. By adjusting the viscosity of the polyimide resin composition within the above range, when a polyimide film is formed from the polyimide resin composition, good coating properties are achieved, and solvent removal (drying) tends to be facilitated. .
In addition, the viscosity of a polyimide resin composition shall be measured at 25 degreeC using an E-type viscosity meter. The viscosity can be measured by a known method, for example, according to the method described in International Publication No. 99/60622.

<Surfactant>
The polyimide resin composition of the present invention contains a surfactant at less than 0.4% by mass with respect to the polyimide resin and / or polyimide resin precursor, and the amount of the surfactant is H, If it consists of an element chosen from C, N, O, P, S and Se and it is nonionic, there will be no restriction | limiting in particular in molecular weight. By using the surfactant of the present invention, the performance and productivity of the device film are improved, and the device film can be obtained without impairing the performance of the device constituent member.

The factors for obtaining the effects of the present invention are considered as follows.
In general, alkaline metals such as Na, alkaline earth metals such as Ca, and halogens such as Cl contained in cationic surfactants, anionic surfactants, amphoteric surfactants, etc. are polyimide films. There is a possibility that the performance of the device constituent member formed on the laminate is lowered. For example, when an alkali metal or the like enters a TFT layer having a transistor function, these may become carriers and semiconductor characteristics may deteriorate. Among nonionic surfactants, surfactants containing F or Si elements may hinder the adhesion between the polyimide film and device components such as a barrier layer and a sealing layer formed thereon. is there.
The surfactant used in the present invention is presumed that the effect of the present invention was obtained by specifying an element that does not contain the above-described elements and that can obtain a useful device film. The surfactant of the present invention is composed of an element selected from H, C, N, O, P, S, and Se, so that the performance of the device constituent member is not deteriorated, and the polyimide film and the device constituent member are moderate. Adhesiveness can be obtained.
The surfactant of the present invention is nonionic. By being nonionic, the ionic substance derived from the surfactant does not move to the device constituent member and does not adversely affect the device constituent member. Therefore, it is presumed that the effect of the present invention was obtained. Moreover, the storage stability of a polyimide resin composition is acquired because it is nonionic, and it exists in the tendency for the mechanical physical property of the polyimide film obtained from this polyimide resin composition to improve.

  As addition amount of surfactant, it is less than 0.4 mass% with respect to a polyimide resin and / or a polyimide resin precursor. Preferably it is 0.38 mass% or less, More preferably, it is 0.35 mass% or less. Moreover, it is preferably 0.0001% by mass or more, more preferably 0.005% by mass or more, and particularly preferably 0.01% by mass or more. When the addition amount is in the above range, the peelability of the carrier substrate from the device film laminate tends to be improved while the adhesion between the device constituent member and the polyimide film is obtained. Moreover, when colorless transparency is requested | required of a polyimide film, whitening of a polyimide film is suppressed and it exists in the tendency for an optical characteristic to become favorable.

The surfactant used in the present invention preferably has a 5% weight loss temperature above 200 ° C. under nitrogen. Moreover, it is preferable to have at 500 degrees C or less. By having a 5% weight reduction temperature in a specific temperature range, the surfactant is thermally decomposed by heating during the process of forming the polyimide film or forming the device constituent member on the polyimide film, and from the device film laminate It tends to prevent the peelability of the carrier substrate from decreasing. Further, in the step of forming the device constituent member on the polyimide film, the outgassing of the surfactant remaining in the polyimide film is suppressed, and the production yield and performance of the device film tend not to be hindered.
Note that the 5% weight loss temperature above 200 ° C. under nitrogen can be measured using a differential thermothermal gravimetric simultaneous measurement device or the like. The measuring method can be adjusted as appropriate, and the measurement may be performed at a temperature increase rate of 10 ° C./min in an atmospheric pressure nitrogen atmosphere.

Nonionic surfactants used in the present invention include the following, and may be used alone or in combination.
Examples of the nonionic surfactant used in the present invention include ether type, ester type, ether / ester type, polyhydric alcohol type, amide type, and polymer type.
Among the above, ether type, ester type or polymer type is preferable. By using these, good releasability is obtained, and because it is excellent in compatibility with the polyimide resin and / or polyimide resin precursor, white turbidity and surface irregularity formation of the resulting polyimide film are suppressed, transparency, It tends to be excellent in surface smoothness.

Examples of the ether type include polyoxyalkylene alkyl ethers, and examples include polyoxyethylene ethers and polyoxypropylene ethers.
Polyoxyethylene ethers include polyoxyethylene alkyl allyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene alkylamine, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene Examples thereof include ethylene stearyl ether.
Among these, polyoxyethylene ether is preferable, and polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, or polyoxyethylene oleyl ether is more preferable.
By using these, good releasability is obtained, and because it is excellent in compatibility with the polyimide resin and / or polyimide resin precursor, white turbidity and surface irregularity formation of the resulting polyimide film are suppressed, transparency, It tends to be excellent in surface smoothness.

Examples of the ester type include sorbitan fatty acid ester, glycerin fatty acid ester, sucrose fatty acid ester, sucrose benzoic acid ester, sucrose derivative, fatty acid ester and the like. Among these, sorbitan fatty acid ester, sucrose benzoate ester or sucrose derivative is preferable.
By using these, good releasability is obtained, and because it is excellent in compatibility with the polyimide resin and / or polyimide resin precursor, white turbidity and surface irregularity formation of the resulting polyimide film are suppressed, transparency, It tends to be excellent in surface smoothness.

  Examples of the ether / ester type include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene hydrogenated castor oil ether, and the like.

Examples of the polyhydric alcohol type include alkyl glucoside and alkyl polyglucoside.
Examples of the amide type include alkyl alkanolamides.

Examples of the polymer type include polyvinyl pyrrolidone, polyalkylene polyamine alkylene oxide adduct, polyalkylene polyimine alkylene oxide adduct, and the like. Among these, polyvinyl pyrrolidone or polyalkylene polyamine alkylene oxide adduct is preferable.
By using these, good releasability is obtained, and because it is excellent in compatibility with the polyimide resin and / or polyimide resin precursor, white turbidity and surface irregularity formation of the resulting polyimide film are suppressed, transparency, It tends to be excellent in surface smoothness.

  Specific examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as emulgen 123P, emulgen 130K, emulgen 150, emulgen 430, emulgen 409PV, emulgen 705, emulgen 707, and emulgen 709 (manufactured by Kao Corporation); Sorbitan fatty acid esters such as Daiichi Kogyo Seiyaku Co., Ltd., New Coal 20, New Coal 60, New Coal 80 (Nihon Emulsifier Co., Ltd.); Sucrose benzoic acid esters such as Monopet SB (Daiichi Kogyo Seiyaku Co., Ltd.); Sucrose fatty acid esters such as DK Ester F-110 (Daiichi Kogyo Seiyaku); polyvinylpyrrolidone such as Pitzkor K-30, Pitzkor K-40, Pitzkor K-90 (Daiichi Kogyo Seiyaku); Etc.

As the surfactant of the present invention, it is preferable to select a surfactant that is compatible with the polyimide resin composition. High compatibility with the polyimide resin composition is preferable in that a film having good surface smoothness and colorless transparency can be obtained.
For example, when a polyoxyethylene alkyl ether type surfactant is used, it is preferable to use a surfactant having an HLB value of 16 or less. When the HLB value is larger than 16, the compatibility of the surfactant is lowered depending on the polyimide structure of the polyimide resin composition, and the polyimide film may be whitened.

  In addition to the surfactant used in the present invention, a silicone compound or the like may be used in combination as a leveling agent or an easily peelable auxiliary agent. These silicone compounds may be used alone or in combination.

  The addition amount of the silicone compound is preferably 1 ppm or more, more preferably 2 ppm or more with respect to the polyimide resin and / or the polyimide resin precursor. Moreover, Preferably it is 20000 ppm or less, More preferably, it is 10,000 ppm or less. It exists in the tendency for the peelability of the carrier substrate from a device film laminated body to improve, while the adhesiveness of a device structural member and a polyimide film is acquired because the addition amount of a silicone type compound exists in the said range. Moreover, since the polyimide film tends to be difficult to whiten, it is particularly useful when the polyimide film is required to be colorless and transparent. Furthermore, when a device constituent member is formed on a polyimide film, the silicone-based compound is unlikely to be outgassed, and the yield and performance of device film production tend not to decrease.

Examples of silicone compounds include, but are not limited to, polyether-modified siloxane, polyether-modified polydimethylsiloxane, polyether-modified hydroxyl group-containing polydimethylsiloxane, polyether-modified polymethylalkylsiloxane, and polyester-modified polydimethylsiloxane. Polyester-modified hydroxyl group-containing polydimethylsiloxane, polyester-modified polymethylalkylsiloxane, aralkyl-modified polymethylalkylsiloxane, highly polymerized silicone, amino-modified silicone, amino-derivative silicone, phenyl-modified silicone, polyether-modified silicone, and the like.
Among these, it is desirable that the silicone compound has a 5% weight loss temperature of 200 ° C. or higher. When the 5% weight loss temperature is within this range, it prevents the silicone compound from being thermally decomposed during the production of the polyimide film or during the formation of the device constituent member, thereby reducing the peelability of the device film. There is a tendency. Moreover, in the process of forming the device constituent member on the polyimide film, the outgassing of the silicone compound remaining in the polyimide film is suppressed, and the production yield and performance of the device film tend not to be hindered.

  There is no restriction | limiting in particular as a method of analyzing the surface active agent and silicone type compound in a polyimide resin composition and a polyimide film. For example, nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR method), liquid chromatography (LC), gas chromatography (GC), mass spectrometry (MS), time-of-flight secondary Examples include ion mass spectrometry (TOF-SIMS), a method combining these, and the like.

<Polyimide resin and polyimide resin precursor>
The polyimide resin composition of the present invention contains a polyimide resin and / or a polyimide resin precursor. This refers to polyimide resin only, polyimide resin precursor only, and mixtures thereof. The imidation ratio of the polyimide resin is not particularly limited, and the polyimide resin of the present invention includes those containing an amic acid structure in the main chain of the polyimide resin. In the present invention, the polyimide resin precursor refers to a polyamic acid resin and a polyamic acid ester resin.

  Although the ratio of the polyimide resin and the polyimide resin precursor in the polyimide resin composition is not particularly limited, the ratio of the polyimide resin precursor to the polyimide resin is usually 30% by mass or less, preferably 20% by mass or less, more preferably. Is 10% by mass or less. When the amount of the polyimide resin precursor is within an appropriate range with respect to the polyimide resin, the polyimide resin and the polyimide resin precursor are not phase separated, and whitening tends to be suppressed. Moreover, it exists in the tendency for the colorless transparency of the polyimide film obtained to become high by mixing uniformly and not phase-separating.

  The polyimide resin and polyimide resin precursor of the present invention preferably contain at least one selected from a cyclic aliphatic skeleton, a fluorinated skeleton, and a biphenyl skeleton. By including the biphenyl skeleton, it tends to be a polyimide film having a low coefficient of linear expansion and excellent thermal properties having a high glass transition temperature. Moreover, by including a cycloaliphatic skeleton and a fluorinated skeleton, it becomes a polyimide film having colorless transparency and high total light transmittance, and tends to have excellent optical properties.

The cycloaliphatic skeleton, the fluorinated skeleton, and the biphenyl skeleton are not particularly limited, but may be a skeleton derived from a tetracarboxylic dianhydride, a diamine compound, and a diisocyanate compound, which are raw materials for the polyimide resin and the polyimide resin precursor. preferable.
The skeleton of the polyimide resin is the substituent R ¹ and R ² portion of the polyimide resin represented by the general formula (1) described later, and the polyimide resin precursor represented by the general formulas (6) to (8). substituents ^{R 10, R 11, R 14} , it is preferable to have each part of R ^15, R ¹⁸ and R ^19.

Specific examples of the cyclic aliphatic skeleton include a skeleton derived from a cyclic aliphatic tetracarboxylic dianhydride, a cyclic aliphatic diamine compound, and a cyclic isocyanate compound. These specific examples are shown in the raw material of the polyimide resin and polyimide resin precursor mentioned later.
The fluorinated skeleton is a skeleton having a fluorine atom, and preferably has an aromatic ring. Specific examples include aromatic tetracarboxylic dianhydrides having fluorine atoms, and skeletons derived from aromatic diamine compounds having fluorine atoms. These specific examples are shown in the raw material of the polyimide resin and polyimide resin precursor mentioned later.
Specific examples of the biphenyl skeleton include a skeleton derived from a compound having a biphenyl skeleton in an aromatic tetracarboxylic dianhydride and an aromatic diamine compound described later.

<Polyimide resin>
The polyimide resin of the present invention has the following structure.

[In the general formula (1), R ¹ represents a tetravalent organic group,
R ² represents a divalent organic group,
n represents an integer of 1 or more, and when n is 2 or more, a plurality of R ¹ and R ² present in one molecule of the structure represented by the general formula (1) may be the same or different. . ]

(N)
n is an integer of 1 or more, and the upper limit is not particularly limited as long as the effects of the present invention are not impaired. It is preferable from the point of the toughness of the polyimide film obtained to determine n so that it may become 40000 or more.
Note that the plurality of tetravalent organic groups R ¹ and the plurality of divalent organic groups R ² may all have the same structure or different structures.

(R ¹ )
R ¹ represents a tetravalent organic group and is not particularly limited as long as it does not impair the effects of the present invention. A specific example of R ¹ is a tetravalent organic group derived from tetracarboxylic dianhydride. Examples of tetracarboxylic dianhydrides include aromatic tetracarboxylic dianhydrides, fluorine-containing aromatic tetracarboxylic dianhydrides and aliphatic tetracarboxylic acids which will be described later as raw materials for the polyimide resin of the present invention. And dianhydrides.

When the obtained polyimide film is required to have heat resistance, dimensional stability, etc., it is preferable to use an aromatic tetracarboxylic dianhydride residue having a biphenyl skeleton among R ^{1 in} the general formula (1). Among them, it is particularly preferable to have a 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride residue.
When colorless transparency is required for the polyimide film, among the R ^{1 in} the general formula (1), an aromatic tetracarboxylic dianhydride containing a cyclic aliphatic tetracarboxylic dianhydride residue or a fluorine group. In particular, a structure represented by the general formula (2) (1,1′-bicyclohexane-3,3 ′, 4 constituted by a tetracarboxylic acid residue having a bicyclohexane skeleton) is preferably used. , 4′-tetracarboxylic acid-3,3 ′, 4,4′-dianhydride residue). By using the structure represented by the general formula (2), there is a tendency that effects of reduction in coloring of the polyimide film, ultraviolet resistance and improvement in solubility are obtained. In addition, the solubility is relatively high and the solution concentration tends to be freely adjusted. Moreover, the total light transmittance is high, and it becomes a low retardation and becomes a polyimide film excellent in optical characteristics.

If the colorless and transparent of the polyimide film used as the film for the substrate is high, it is possible to obtain a high-performance display device and a light receiving device with high photoelectric conversion efficiency. For example, it can correspond to a see-through device. In addition, when used as a device substrate for an organic EL display, a bottom emission type light extraction structure that can be easily manufactured can be adopted, so that a device for a large-sized organic EL display can be easily obtained. In addition, since it does not affect the original color of the display, a high-performance device can be obtained.
In particular, since the polyimide resin represented by the general formula (2) tends to absorb less light having a wavelength suitable for power generation of a solar cell, when used as a device substrate on the light-receiving surface side of the solar cell, Even when it has the same layer structure as the solar cell using the glass substrate, the photoelectric conversion rate tends not to be remarkably lowered.

[In the general formula (2), R ³ represents a divalent organic group,
a represents an integer of 1 or more. When a is 2 or more, a plurality of R ³ present in one molecule of the structure represented by the general formula (2) may be the same or different. ]

The divalent organic group represented by R ^{3 in} the general formula (2) has the same meaning as R ^{2 in the} general formula (1), and the substituents and preferred examples that may be included are also synonymous. Moreover, a of General formula (2) is synonymous with n of General formula (1), and its preferable range is also synonymous.

  As a tetracarboxylic dianhydride that is a raw material of the polyimide film represented by the general formula (2), 1,1′-bicyclohexane-3,3 ′, 4,4′-tetracarboxylic acid-3,3 ′, In addition to 4,4′-dianhydride, various properties such as heat resistance of the polyimide film according to the present embodiment, and further, when colorless transparency is required, other tetracarboxylic acids are added to the extent that colorless transparency is not impaired. An acid dianhydride may be mixed and used as a raw material. 1 type may be sufficient as the tetracarboxylic dianhydride mixed, and 2 or more types may be sufficient as it.

(R ² )
R ² is not particularly limited as long as it is a divalent organic group. Specific examples thereof include a structural unit obtained by removing an amino group from a diamine compound, which will be described later as a raw material for the polyimide resin of the present invention. . Examples of the diamine compound include aromatic diamine compounds, aromatic diamine compounds containing a fluorine group, and aliphatic diamine compounds.

Among the above-mentioned, R ² is not only a divalent organic group represented by the general formula (3) having excellent heat resistance and a tough polyimide film, but also having solubility in an organic solvent. It is preferable in terms of improvement. Moreover, the colorless transparency of a polyimide film becomes high and it exists in the tendency which can reduce the coloring by time-dependent deterioration.

[In General Formula (3), Ring A ²⁰ and Ring A ²¹ are each independently an optionally substituted aromatic group, an optionally substituted alicyclic hydrocarbon group or a substituted group. A heterocyclic group optionally having a group;
p and q each independently represent an integer of 0 or more and 10 or less. However, neither p nor q is 0.
X ⁴ is a direct bond, an oxygen atom, a sulfur atom, an alkylene group which may have a substituent, a sulfonyl group, a sulfinyl group, a sulfide group, a carbonyl group, an aromatic group which may have a substituent,- NH-C (= O) - group shown, an -NH- group or a -O-C _z H _2z -O- group (z is an integer of from 1 to 5).
Y ¹⁰ and Y ¹¹ each independently represent a direct bond, an oxygen atom, a sulfur atom, an alkylene group which may have a substituent, a sulfonyl group, a sulfinyl group, a sulfide group or a carbonyl group.
When p and / or q is 2 or more, the plurality of Y ¹⁰ , Y ¹¹ , ring A ²⁰ and ring A ²¹ may be different from each other. ]

(Ring A ²⁰ and Ring A ²¹ )
(Aromatic group)
The aromatic groups of the ring A ²⁰ and the ring A ²¹ of the general formula (3) are not particularly limited, but each independently includes, for example, an aromatic hydrocarbon group and an aromatic group which may have a substituent. Group heterocyclic group. Examples of the substituent that may be included include a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a hydroxyl group.
Among the aromatic groups of ring A ²⁰ and ring A ²¹ , those having 5 or more carbon atoms are preferable, and those having 30 or less and further 25 or less tend to obtain high mechanical properties and heat resistance of the polyimide film. preferable.

Examples of the aromatic hydrocarbon group for ring A ²⁰ and ring A ²¹ include a phenylene group, a biphenylene group, a naphthylene group, a phenanthrene group, a triphenylene group, a terphenylene group, a pinylene group, and a fluorene group.
Examples of the aromatic heterocyclic group for ring A ²⁰ and ring A ²¹ include a pyridylene group, a quinolylene group, a thiophene ring, a furan ring, a pyrrole ring, a pyrazole ring, a thiazole ring, and an oxazole ring.
Among these, a benzene ring, a biphenylene ring, a terphenyl ring, a benzotriazole ring or a benzoxazole ring tends to obtain high mechanical properties and heat resistance of the polyimide film.

(Alicyclic hydrocarbon group)
The alicyclic hydrocarbon group for ring A ²⁰ and ring A ²¹ is derived from an aliphatic ring and is not particularly limited. Specific examples include those having 3 to 30 carbon atoms such as cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, norbornane ring, norbornene ring, hydrindane ring, decahydronaphthalene ring, adamantane ring and the like. It is done. Among these, a cyclohexane ring, a cyclopentane ring or a norbornane ring is preferable from the viewpoint of mechanical properties and heat resistance of the polyimide film.

(Heterocyclic group)
The heterocyclic group of the ring A ²⁰ and the ring A ²¹ does not have an unsaturated bond, includes one or more heteroatoms in a three-membered ring or more, and is not particularly limited. Specific examples include an aziridine ring and a thiolane ring. Examples of the substituent that the heterocyclic group of ring A ²⁰ and ring A ²¹ may have include a halogen atom, an alkyl group, an alkoxy group, and a hydroxyl group.

Regarding the aromatic group, alicyclic hydrocarbon group, or heterocyclic group that is ring A ²⁰ and ring A ²¹ , the position of bonding to Y ¹⁰ , Y ¹¹ , or X ⁴ is not particularly limited.

(P, q)
p and q are each independently an integer of 0 or more, preferably 1 or more, and are an integer of 10 or less, preferably 5 or less.

(X ⁴⁾
X ⁴ is a direct bond, an oxygen atom, a sulfur atom, an alkylene group which may have a substituent, a sulfonyl group, a sulfinyl group, a sulfide group, a carbonyl group, an aromatic group which may have a substituent,- NH-C (= O) - , - NH- or an -O-C _z H _2z -O-. However, z shows the integer of 1-5. Among these, from the viewpoint of high mechanical properties and heat resistance of the polyimide film, a direct bond, an oxygen atom, an alkylene group which may have a substituent, a sulfinyl group, or a sulfonyl group is preferable, an oxygen atom, An alkylene group or a sulfinyl group which may have a substituent is particularly preferable.

The alkylene group for X ⁴ is not particularly limited, but is preferably an alkylene group having 1 to 20 carbon atoms from the viewpoint of mechanical properties and heat resistance of the polyimide film, and an alkylene group having 1 to 10 carbon atoms. More preferably. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, and a 2,2-propanediyl group.
Examples of the substituent that the alkylene group of X ⁴ may have include an alkyl group having 1 to 5 carbon atoms, a hydroxy group, an alkoxy group, an amino group, a carboxyl group, and an epoxy group. These substituents may be further substituted with a halogen atom such as a fluorine atom or a chlorine atom.

The aromatic group for X ⁴ is not particularly limited, and examples thereof include an aromatic hydrocarbon group and an aromatic heterocyclic group which may have a substituent. Specifically it has the same meanings as those mentioned ring A ^20, also synonymous substituents which may have. The aromatic hydrocarbon group for X ⁴ preferably has 6 or more carbon atoms, preferably 30 or less, and more preferably 25 or less. By being in these ranges, the mechanical properties and heat resistance of the polyimide film tend to be improved.
In addition, the aromatic heterocyclic group represented by X ⁴ preferably has 2 or more carbon atoms, preferably 30 or less, and more preferably 25 or less, from the viewpoint of mechanical properties and heat resistance of the polyimide film.
Among the aromatic groups of X ⁴ , a phenylene group, a naphthylene group, or a pyridylene group is particularly preferable from the viewpoint of mechanical properties and heat resistance of the polyimide film.

(Y ¹⁰ and Y ¹¹⁾
Y ¹⁰ and Y ¹¹ each independently represent a direct bond, an oxygen atom, a sulfur atom, an alkylene group which may have a substituent, a sulfonyl group, a sulfinyl group, a sulfide group or a carbonyl group. Among these, a direct bond or an oxygen atom is preferable.
When p or q is 2 or more, there are a plurality of Y ¹⁰ and Y ^{11 in} R ² , but these plurality of Y ¹⁰ and Y ¹¹ may have the same structure or different structures. May be. Here, as the alkylene group which may have a substituent, the same alkylene groups as those described for the alkylene group of X ⁴ can be used.

  Among the general formula (3), the structure represented by the following general formula (4) or (5) is particularly preferable from the viewpoint of high mechanical properties and heat resistance of the polyimide film.

The general formula (4) corresponds to the case where p = 2 and q = 2 in the general formula (3).
X ^{5 in the} general formula (4) has the same meaning as x ^{4 in the} general formula (3). In addition, ring A ²² and ring A ²³ in general formula (4) have the same meaning as ring A ^{20 in} general formula (3), respectively, and ring A ²⁴ and ring A ²⁵ in general formula (4) are each in general formula It is synonymous with ring A ^{21 in} (3).
Y ¹² and Y ^{13 in} the general formula (4) are respectively synonymous with Y ^{10 in the} general formula (3), and Y ¹⁴ and Y ^{15 in} the general formula (4) are respectively Y ¹¹ and Y ^{11 in the} general formula (3). It is synonymous.
Similarly to general formula (3), ring A ²² to ring A ²⁵ and Y ^{12 to} Y ¹⁵ in general formula (4) may be the same or different.

In the general formula (4), the ring A ²² , the ring A ²³ , the ring A ²⁴ and the ring A ²⁵ are each independently an aromatic group which may have a substituent. It is preferable from the viewpoint of heat resistance. Among these, a phenylene group is more preferable, and a substituent that may be present is preferably a halogen atom such as a chlorine atom.
Further, from the viewpoint of mechanical properties and heat resistance of the polyimide film, Y ¹² and Y ¹³ are preferably a direct bond, an oxygen atom or a sulfur atom, and Y ¹⁴ and Y ¹⁵ are preferably a direct bond.

The general formula (5) corresponds to the case where p = 1 and q = 1 in the general formula (3).
X ^{6 in the} general formula (5) has the same meaning as x ^{4 in the} general formula (3). In addition, ring A ²⁶ and ring A ²⁷ in general formula (5) have the same meanings as ring A ²⁰ and ring A ^{21 in} general formula (3), respectively.
Y ¹⁶ and Y ^{17 in} the general formula (5) have the same meanings as Y ¹⁰ and Y ^{11 in} the general formula (3), respectively.
In particular, from the viewpoint of mechanical properties and heat resistance of the polyimide film, ring A ²⁶ and ring A ²⁷ are preferably the same structure, and Y ¹⁰ and Y ¹¹ are more preferably the same structure.

Ring A ²⁶ and Ring A ²⁷ in the general formula (5) each independently have an aromatic group or a substituent which may have a substituent from the viewpoint of mechanical properties and heat resistance of the polyimide film. It is preferably an alicyclic hydrocarbon group. Among these, an aromatic group which may have a substituent is preferable, and a phenylene group which may have a substituent is more preferable. Further, the substituent that may have is preferably a halogen atom such as a chlorine atom.
Y ¹⁶ is preferably a direct bond, an oxygen atom or a sulfur atom from the viewpoint of mechanical properties and heat resistance of the polyimide film, and Y ¹⁷ is preferably a direct bond.

Among the above-mentioned, R ² is preferably a divalent group obtained by removing an amino group from the following compounds, from the viewpoint that heat resistance, mechanical strength and colorless transparency can be achieved at the same time.
Specifically, 4,4′-diaminodiphenyl ether, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, bis (4- (4-aminophenoxy) phenyl) sulfone, 4,4′- Diamino-2,2′-dimethylbiphenyl, N- (4-aminophenoxy) -4-aminobenzamide, 2- (4-aminophenyl) -6-aminobenzoxazole, 2- (4-aminophenyl) -5 Aminobenzoxazole, 5-amino-2- (4-aminophenyl) -1H-benzimidazole, 4,4′-methylenebis (cyclohexylamine), 2,2-bis (4- (4-aminophenoxy) phenyl) hexa Fluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-diaminodiphenylsulfo Etc. The. These diamines may be used alone or in combination of two or more.

<Polyimide resin precursor>
The polyimide resin precursor of the present invention refers to a polyamic acid resin and / or a polyamic acid ester resin. The polyimide resin precursor of the present invention contains at least one selected from repeating units represented by the following general formulas (6) to (8). Moreover, the abundance ratio of the general formulas (6) to (8) in the polyimide resin precursor of the present invention is not particularly limited.

In the general formulas (6) to (8), R ¹⁰ , R ¹⁴ and R ¹⁸ are each independently synonymous with R ¹ in the general formula (1), and may have a substituent and a preferred group. It is synonymous.
R ¹¹ , R ¹⁵ and R ¹⁹ are each independently synonymous with R ² in the general formula (1), and the substituents and preferred groups that may be present are also synonymous.

R ¹² , R ¹³ , R ¹⁶ , R ¹⁷ , R ²⁰ and R ²¹ represent a hydrogen atom or an alkyl group which may have a substituent. Although there is no special restriction | limiting as an alkyl group, Usually, it is a C1-C14 alkyl group, A C1-C10 alkyl group is preferable, a methyl group, an ethyl group, n-propyl group, isopropyl group, n- A butyl group or an isobutyl group is more preferable, and a methyl group or an ethyl group is still more preferable. Examples of the substituent that the alkyl group may have include a halogen atom.

<Raw material of polyimide resin and polyimide resin precursor>
Examples of the raw material for the polyimide resin of the present invention include tetracarboxylic dianhydrides, diamine compounds, and diisocyanate compounds. Moreover, tetracarboxylic dianhydride, a diamine compound, etc. are mentioned as a raw material of a polyimide resin precursor.
Examples of tetracarboxylic dianhydrides include aromatic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides having fluorine atoms, and aliphatic tetracarboxylic dianhydrides. Examples of the diisocyanate compound include aromatic diisocyanate compounds and aliphatic diisocyanate compounds. Examples of the diamine compound include aromatic diamine compounds, aromatic diamine compounds containing a fluorine group, and aliphatic diamine compounds. Specific examples are shown below.

(Tetracarboxylic dianhydrides)
(Aromatic tetracarboxylic dianhydrides)
The aromatic tetracarboxylic dianhydrides include a tetracarboxylic dianhydride having one aromatic ring in the molecule, a tetracarboxylic dianhydride having a biphenyl skeleton, and two independent aromatic rings (biphenyl). And tetracarboxylic dianhydrides having a condensed aromatic ring, and the like.

  Examples of the tetracarboxylic dianhydride having one aromatic ring in the molecule include pyromellitic dianhydride and 1,2,3,4-benzenetetracarboxylic dianhydride.

  Examples of tetracarboxylic dianhydrides having a biphenyl skeleton include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 2,2 ′, 6,6′-biphenyltetracarboxylic dianhydride. Etc.

  Examples of tetracarboxylic dianhydrides having two or more independent aromatic rings (excluding the biphenyl skeleton) include, for example, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2, 3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis ( 2,3-dicarboxyphenyl) ether dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic Dianhydrides, 4,4-oxydiphthalic dianhydride, 4,4- (p-phenylenedioxy) diphthalic dianhydride, 4,4- (m-phenylenedioxy) diphthalic dianhydride, etc. It is done.

  Examples of the tetracarboxylic dianhydride having a condensed aromatic ring include 1,2,5,6-naphthalenedicarboxylic dianhydride, 1,4,5,8-naphthalenedicarboxylic dianhydride, 2,3, 6,7-naphthalenedicarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, and 1,2,7, Examples include 8-phenanthrenetetracarboxylic dianhydride.

(Aromatic tetracarboxylic dianhydrides having fluorine atoms)
Examples of the aromatic tetracarboxylic dianhydride containing a fluorine group include 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride. 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,4-difluoropyromellitic dianhydride, 1, 4-ditrifluoromethylpyromellitic dianhydride etc. are mentioned.

(Aliphatic tetracarboxylic dianhydride)
Examples of the aliphatic tetracarboxylic dianhydride include a chain aliphatic tetracarboxylic dianhydride and a cyclic aliphatic tetracarboxylic dianhydride.

  Examples of the chain aliphatic tetracarboxylic dianhydride include ethylene tetracarboxylic dianhydride, butanetetracarboxylic dianhydride, meso-butane-1,2,3,4-tetracarboxylic dianhydride, etc. Is mentioned.

Examples of the cycloaliphatic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2 , 4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3 , 4-Tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 1,2,3 , 4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, tricyclo [6.4.0.0 ^2,7 ] dodecane-1,8: 2,7-tetracarboxylic dianhydride Thing, bi Cyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid And dianhydrides, 3,3 ′, 4,4′-biscyclohexanetetracarboxylic dianhydride, 1,1′-bicyclohexane-3,3 ′, 4,4′-tetracarboxylic dianhydride, and the like. It is done.

(Diisocyanate compound)
(Aromatic diisocyanate compound)
Examples of the aromatic diisocyanate compound include 4,4′-diisocyanato-3,3′-dimethylbiphenyl, 2,2-bis (4-isocyanatophenyl) hexafluoropropane, 4,4′-diisocyanato-3,3. '-Dimethyldiphenylmethane, 1,5-diisocyanatonaphthalene, methylenediphenyl 4,4'-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,3-bis (isocyanatomethyl) ) Benzene, toluene diisocyanate and the like.

(Aliphatic diisocyanate compound)
Examples of the aliphatic diisocyanate compound include a chain aliphatic diisocyanate compound and a cycloaliphatic diisocyanate compound.
Examples of the chain aliphatic diisocyanate compound include hexamethylene diisocyanate and isophorone diisocyanate. Examples of the cycloaliphatic diisocyanate compound include 1,3-bis (isocyanatomethyl) cyclohexane.

(Diamine compound)
(Aromatic diamine compound)
The aromatic diamine compound includes a diamine compound having one aromatic ring in the molecule, a diamine compound having a biphenyl skeleton, a diamine compound having two independent aromatic rings (excluding the biphenyl skeleton), and three independent diamine compounds. Examples thereof include a diamine compound having an aromatic ring, a diamine compound having four independent aromatic rings, and a diamine compound having a condensed aromatic ring.

  Examples of the diamine compound having one aromatic ring include 1,4-phenylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, 3-aminobenzylamine, 2,5-dimethyl-1,4. -Phenylenediamine, p-xylylenediamine, m-xylylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine and the like.

  Examples of the diamine compound having a biphenyl skeleton include 4,4′-diamino-3,3′-dimethylbiphenyl, 4,4′-diamino-2,2′-dimethylbiphenyl, 4,4′-diamino-3, 3'-dihydroxybiphenyl and the like can be mentioned.

  Examples of the diamine compound having two independent aromatic rings include 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 1,3-bis (4-aminophenoxy) neopentane, and bis (4-amino- 3-carboxyphenyl) methane, 4,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfide, N- (4-aminophenoxy) -4-aminobenzamide, 2,7-diaminofluorene, 1,1- Bis (4-aminophenyl) cyclohexane, bis (3-aminophenyl) sulfone, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 3 , 3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane Tan, 4,4′-diaminodiphenylmethane, 4,4′-ethylenedianiline, 4,4′-methylenebis (2,6-diethylaniline), 4,4′-methylenebis (2-ethyl-6-methylaniline) 4,4′-diamino-2,2′-dimethoxybiphenyl, 2,3′-diaminodiphenyl ether, bis (4-aminophenoxy) methane, 1,3′-bis (4-aminophenoxy) propane, 1,4 '-Bis (4-aminophenoxy) butane, 1,5'-bis (4-aminophenoxy) pentane, 2,2-bis (3-amino-4-hydroxyphenyl) propane, bis (3-amino-4- Hydroxyphenyl) sulfone, N, N-bis (4-aminophenyl) piperazine and the like.

  Examples of the diamine compound having three independent aromatic rings include 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, and 1,4-bis (4-amino). Phenoxy) -2,5-di-t-butylbenzene, 1,4-bis (4-aminophenoxy) -2,3,5-trimethylbenzene, N, N-bis (4-aminophenyl) terephthalamide, 1 , 3-bis (3-aminophenoxy) benzene, α, α'-bis (4-aminophenyl) -1,4-diisopropylbenzene, 1,3-bis [1- (4-aminophenyl) -1-methyl Ethyl] benzene and the like.

  Examples of the diamine compound having four independent aromatic rings include 2,2-bis (4- (4-aminophenoxy) phenyl) propane, bis (4- (4-aminophenoxy) phenyl) sulfone, and bis (4 -(3-aminophenoxy) phenyl) sulfone, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4 '-(9-fluorenylidene) dianiline, 4,4'-(biphenyl-2,5-diylbis) Oxy) bisaniline, 4,4′-bis (4-aminobenzamide) -3,3′-dihydroxybiphenyl, 4,4′-bis (4-aminophenoxy) benzophenone, and the like.

  Examples of the diamine compound having a condensed aromatic ring include 2- (4-aminophenyl) -6-aminobenzoxazole, 2- (4-aminophenyl) -5-aminobenzoxazole, and 5-amino-2- (4 -Aminophenyl) -1H-benzimidazole, 1,5-diaminonaphthalene, 3,7-diamino-2,8-dimethyldibenzothiophene 5,5-dioxide and the like.

(Aromatic diamine compounds having fluorine atoms)
Examples of the aromatic diamine compound having a fluorine atom include 5-trifluoromethyl-1,3-benzenediamine, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4 ′. -Diamino-2,2'-bis (trifluoromethyl) biphenyl ether, 2,2'-bis (4-aminophenyl) hexafluoropropane, 2,2'-bis (3-aminophenyl) hexafluoropropane, 4 , 4′-diaminooctafluorobiphenyl, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 4,4 '-Diamino-2- (trifluoromethyl) diphenyl ether, 1,4-bis {4-amino-2- (trifluoromethyl) phenoxy Si} benzene, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis [4- {4-amino-2- (trifluoromethyl) phenoxy} phenyl] hexafluoro Examples include propane.

(Aliphatic diamine compound)
Examples of the aliphatic diamine compound include a chain aliphatic diamine compound and a cyclic aliphatic diamine compound.
Examples of the cycloaliphatic diamine compound include 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 4,4′-methylenebis (2-methylcyclohexylamine) and the like.

  In the above raw material, when the heat resistance and dimensional stability of the resulting polyimide film are required, it is preferable to use an aromatic tetracarboxylic dianhydride and an aromatic diamine compound. By using these as raw materials, the polyimide film tends to have a glass transition point of 300 ° C. or higher, and the linear expansion coefficient tends to be 10 ppm or lower.

In the above raw materials, when colorless transparency is required as the performance of the polyimide film, the following combinations are listed as preferred examples.
A. B. Combinations of aromatic tetracarboxylic dianhydrides and aliphatic diamines or aliphatic diisocyanates Aliphatic tetracarboxylic dianhydrides and aromatic diamines and / or aliphatic diamines C.I. C. Combinations of aliphatic tetracarboxylic dianhydrides with aromatic diisocyanates and / or aliphatic diisocyanates Combinations of aromatic tetracarboxylic dianhydrides having fluorine atoms and aromatic diamines having fluorine atoms or aromatic diisocyanates having fluorine atoms

  When colorless transparency is required for the polyimide film, it is preferable to use a fluorine atom-containing one or a cycloaliphatic tetracarboxylic dianhydride residue, particularly a tetracarboxylic acid residue having a bicyclohexane skeleton. It is preferable to use 1,1′-bicyclohexane-3,3 ′, 4,4′-tetracarboxylic acid-3,3 ′, 4,4′-dianhydride residue.

<Method for producing polyimide resin and polyimide resin precursor>
(Production method of polyimide resin precursor)
The polyamic acid resin, which is the polyimide resin precursor of the present invention, can be obtained by reacting at least one of the tetracarboxylic dianhydrides and at least one of the diamine compounds in a suitable solvent.
In addition, the polyamic acid ester resin, which is the polyimide resin precursor of the present invention, is obtained by diesterifying the tetracarboxylic dianhydride by ring-opening using an alcohol such as methanol, ethanol, isopropanol, or n-propanol. The obtained diester can be obtained by reacting with the diamine compound in a suitable solvent. Furthermore, the polyamic acid ester resin can also be obtained by esterifying the carboxylic acid group of the polyamic acid resin obtained as described above by reacting with the alcohol as described above.

Reaction of the said tetracarboxylic dianhydride and the said diamine compound can be performed on conventionally known conditions. There are no particular limitations on the order of addition or addition method of the tetracarboxylic dianhydride and the diamine compound. For example, a polyimide resin precursor can be obtained by sequentially adding tetracarboxylic dianhydride and a diamine compound to a solvent and stirring at an appropriate temperature.
The amount of the diamine compound is usually 0.8 mol or more, preferably 1 mol or more with respect to 1 mol of tetracarboxylic dianhydride. On the other hand, it is 1.2 mol or less normally, Preferably it is 1.1 mol or less. By making the quantity of a diamine compound into such a range, it exists in the tendency for the yield of the polyimide resin precursor obtained to improve.

  The concentration of the tetracarboxylic dianhydride and the diamine compound in the solvent can be appropriately set according to the reaction conditions and the viscosity of the polyimide resin precursor solution. For example, the total weight of the tetracarboxylic dianhydride and the diamine compound is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more with respect to the total amount of the solution, while usually 70%. It is not more than mass%, preferably not more than 30 mass%. By setting the amount of the reaction substrate in such a range, a polyimide resin precursor can be obtained at low cost and high yield.

The temperature at which the tetracarboxylic dianhydride and the diamine compound are reacted is not particularly limited, but is usually 0 ° C. or higher, preferably 20 ° C. or higher. On the other hand, it is usually 100 ° C. or lower, preferably 80 ° C. or lower. The atmosphere may be air or an inert atmosphere. When the polyimide film is required to be colorless and transparent, it is preferably heated in an inert atmosphere such as nitrogen in order to suppress coloring.
The reaction time is not particularly limited, but is usually 1 hour or longer, preferably 2 hours or longer, and is usually 100 hours or shorter, preferably 24 hours or shorter. By performing the reaction under such conditions, a polyimide resin precursor can be obtained at low cost and high yield.

  Solvents used for the reaction with tetracarboxylic dianhydride and diamine compound include hydrocarbon solvents such as hexane, cyclohexane, heptane, benzene, toluene, xylene, mesitylene; carbon tetrachloride, methylene chloride, chloroform, 1, 2 -Halogenated hydrocarbon solvents such as dichloroethane, chlorobenzene, dichlorobenzene and fluorobenzene; ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane and methoxybenzene; ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone; N, Amide solvents such as N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone; aprotic polar solvents such as dimethyl sulfoxide, γ-butyrolactone, anisole; pyridine, picoli , Lutidine, quinoline, heterocyclic solvents isoquinoline; phenol, phenolic solvents such as cresol; but like, but it is not particularly limited. As the solvent, one kind of substance can be used, or two or more kinds of substances can be mixed and used.

  The polyimide resin precursor obtained by reacting the tetracarboxylic dianhydride and the diamine compound is dissolved in the solvent described above, or the solvent used for the reaction with the tetracarboxylic dianhydride and the diamine compound. By leaving it dissolved in, it can be used as a polyimide resin composition used in the present invention.

(Method for producing polyimide resin)
The polyimide resin of the present invention is a method of subjecting a polyamic acid resin or polyamic acid ester resin, which is a polyimide resin precursor, to dehydration cyclization or dealcoholization cyclization in the presence of a solvent, a tetracarboxylic dianhydride and a diisocyanate compound in the presence of a solvent. It is obtained by the method of reacting below (hereinafter collectively referred to as imidization).

  The imidization method is not particularly limited, and can be performed using any conventionally known method. Examples thereof include thermal imidization that causes thermal cyclization and chemical imidization that causes chemical cyclization. These imidation reactions may be used alone or in combination. Hereinafter, an example of the imidization method will be described, but the present invention is not limited to this method.

(Heated imide)
Below, the method of the heat imidation in a solution is demonstrated.
A polyimide resin can be obtained by heating a polyimide resin precursor in the presence of a solvent, or heating a tetracarboxylic dianhydride and a diisocyanate compound in the presence of a solvent.
When the polyimide resin precursor is heated in the presence of a solvent, it is preferable that water or alcohol generated by imidization is discharged out of the reaction system in order to inhibit the ring closure reaction. For example, a method of discharging water out of the system by azeotropically boiling an organic solvent such as toluene or xylene with water is often used.

  Examples of the solvent used when imidizing by heating include a solvent used in the reaction for obtaining the polyamic acid resin or the polyamic acid ester resin. Among them, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone are highly soluble in polyimide resin precursors and polyimide resins, and have high boiling points and imides. This is preferable because the chemical reaction proceeds efficiently.

  In the case where the polyimide resin precursor is heated in the presence of a solvent, the concentration of the polyimide resin precursor in the imidization reaction solution is not particularly limited. Usually, it is 5% by mass or more, preferably 10% by mass or more, and more preferably 20% by mass or more. Moreover, it is 80 mass% or less normally, Preferably it is 60 mass% or less, More preferably, it is 40 mass% or less. 20 mass% or more is preferable in terms of high production efficiency, and 40 mass% or less is preferable in that the solution viscosity is easy to handle with ordinary production equipment.

  When the tetracarboxylic dianhydride and the diisocyanate compound are heated in the presence of a solvent, the amounts of the tetracarboxylic dianhydride and the diisocyanate compound in the imidization reaction solution are not particularly limited. For example, the total weight of the tetracarboxylic dianhydride and the diisocyanate compound is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more, based on the amount of the imidization reaction solution, Usually, it is 70 mass% or less, Preferably it is 30 mass% or less. By setting it as such a range, it exists in the tendency for it to become a solution viscosity with a sufficient yield and easy to handle with normal manufacturing equipment.

  The imidation reaction temperature is not particularly limited, but is usually 50 ° C or higher, preferably 80 ° C or higher, more preferably 120 ° C or higher, and usually 300 ° C or lower, preferably 280 ° C or lower, more preferably 250 ° C or lower. . It is preferable in that the imidization reaction proceeds efficiently when the temperature is 120 ° C or higher, and it is preferable in that the side reaction other than the imidization reaction is suppressed when the temperature is 250 ° C or lower. The pressure during the reaction may be normal pressure, increased pressure, or reduced pressure. The atmosphere may be air or an inert atmosphere. When the polyimide film is required to be colorless and transparent, it is preferably heated in an inert atmosphere such as nitrogen in order to suppress coloring.

  Moreover, tertiary amines etc. can also be added as a catalyst which accelerates | stimulates imidation. Specifically, trimethylamine, triethylamine, tripropylamine, tributylamine, tritanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N- Methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline, isoquinoline and the like can be used as a catalyst. The amount of the catalyst used is preferably from 0.1 to 100 mol%, more preferably from 1 to 10 mol%, based on the carboxyl group or ester group. When the amount of the catalyst used is in such a range, the reaction tends to be performed at a low cost and with a high yield.

(Chemical imidization)
The case where chemical imidation is used as the imidation method will be described below. The chemical imidization of the present invention refers to heating the polyimide resin precursor in the presence of a solvent by adding a dehydrating condensing agent.
As the solvent used when imidizing the polyimide resin precursor, the solvents mentioned in the heating imidization can be used.

  Although there is no restriction | limiting in particular in the density | concentration of the polyimide resin precursor of an imidation reaction solution, Usually, 5 mass% or more, Preferably it is 10 mass% or more, More preferably, it is 20 mass% or more. Moreover, it is 80 mass% or less normally, Preferably it is 60 mass% or less, More preferably, it is 40 mass% or less. 20% by mass or more is preferable in terms of high production efficiency, and 40% or less is preferable in that the solution viscosity is easy to handle in normal production equipment.

The imidation reaction temperature is not particularly limited, but is usually 50 ° C. or higher, preferably 80 ° C. or higher, more preferably 120 ° C. or higher, and usually 300 ° C. or lower, preferably 280 ° C. or lower, more preferably 250 ° C. It is as follows. It is preferable in that the imidization reaction proceeds efficiently when it is 50 ° C. or higher, and it is preferable in that the side reaction other than the imidization reaction is suppressed when it is 300 ° C. or lower.
The pressure during the reaction may be normal pressure, increased pressure, or reduced pressure. The atmosphere may be air or an inert atmosphere. When the polyimide film is required to be colorless and transparent, it is preferably heated in an inert atmosphere such as nitrogen in order to suppress coloring.
Further, a tertiary amine or the like can be added as a catalyst for promoting imidization in the same manner as in the heating imidization.

  N, N-2-substituted carbodiimides such as N, N-dicyclohexylcarbodiimide and N, N-diphenylcarbodiimide; acid anhydrides such as acetic anhydride and trifluoroacetic anhydride; chlorides such as thionyl chloride and tosyl chloride Acetyl chloride, acetyl bromide, propionyl iodide, acetyl fluoride, propionyl chloride, propionyl bromide, propionyl iodide, propionyl fluoride, isobutyryl chloride, isobutyryl bromide, isobutyryl iodide, isobutyryl fluoride N-butyryl chloride, n-butyryl bromide, n-butyryl iodide, n-butyryl fluoride, mono-, di-, tri-chloroacetyl chloride, mono-, di-, tri-bromoa Tyl chloride, mono-, di-, tri-iodoacetyl chloride, mono-, di-, tri-fluoroacetyl chloride, chloroacetic anhydride, phenylphosphonic dichloride, thionyl chloride, thionyl bromide, thionyl iodide or thionyl fluoride Halogenated compounds such as phosphorus compounds such as phosphorus trichloride, triphenyl phosphite, and diethylphosphoric acid amide can be added.

  The amount of these dehydrating condensing agents used is usually 0.5 mol, preferably 1 mol or more, and usually 20 mol or less, preferably 10 mol or less, per 1 mol of the repeating unit of the polyimide resin precursor. These can be used alone or in combination of two or more.

  Moreover, the polyimide resin precursor and polyimide resin used by this invention may be terminal-capped as needed. By end-capping, the polymerizability of each resin end is lowered, and the viscosity of the polyimide resin precursor and the polyimide resin tends to be stabilized.

The terminal sealing method is not limited, and any conventionally known method may be used. Moreover, you may seal in any step which prepares a polyimide resin precursor and a polyimide resin.
A preferable method includes a method using a terminal blocking agent. Any conventionally known end capping agent may be used.
Examples of the terminal blocking agent used for sealing the terminal amino group include phthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 4-methylcyclohexane-1,2-dicarboxylic anhydride, (2-methyl-2 -Propenyl) acid anhydrides such as succinic anhydride; organic acid chlorides such as benzoic acid chloride.
Examples of the end capping agent for capping the terminal acid anhydride group include amine compounds such as 3-aminophenylacetylene, aniline, and cyclohexylamine.

<Method for producing polyimide resin composition>
The method for producing the polyimide resin composition of the present invention is not particularly limited, and a surfactant may be added to the solvent containing the polyimide resin and / or the polyimide resin precursor described above, and the polyimide resin and / or the polyimide resin. A new solvent may be added to the precursor and the surfactant. The surfactant may be used in a solid state or in a state dissolved in a solvent. Moreover, in order to improve the solubility of surfactant, you may heat separately the polyimide resin composition containing an additive.
Among these, it is preferable to add a surfactant to a solvent containing a polyimide resin and / or a polyimide resin precursor and stir because the process is simple.

<Manufacturing method of polyimide film>
Although the manufacturing method of the polyimide film of this invention is not specifically limited, The method of apply | coating a polyimide resin composition on a carrier substrate and forming a polyimide film may be used.
Examples of the coating method include die coating, spin coating, screen printing, spray method, casting method, coater method, spraying method, dipping method, calendar method, casting method and the like.
Among these, in order to efficiently produce a thin device and a flexible device that can be bent, it is preferable to use a casting method. In particular, this is a particularly suitable method for efficiently producing display devices such as liquid crystal displays, organic EL displays and electronic paper, light receiving devices such as solar cells, and light emitting devices such as organic EL lighting.

  The method for volatilizing the solvent contained in the polyimide resin composition is not particularly limited. Usually, the solvent is volatilized by heating the carrier substrate coated with the polyimide resin composition. The heating method is not particularly limited, and examples thereof include hot air heating, vacuum heating, infrared heating, microwave heating, heating by contact using a hot plate or a hot roll, and the like.

  The heating temperature in this case may be a suitable temperature depending on the type of solvent, but is usually 40 ° C. or higher, preferably 60 ° C. or higher, and is usually 400 ° C. or lower, preferably 350 ° C. or lower, more preferably. Is 300 ° C. or lower. When the solvent removal temperature is 40 ° C. or higher, it is preferable in that the solvent is sufficiently volatilized. In addition, when the solvent removal temperature is 300 ° C. or lower, since the organic solvent does not volatilize rapidly, bubbles or the like can be prevented from being generated in the obtained polyimide film. This is preferable because the possibility of reducing the appearance and quality of the resulting polyimide film can be reduced. The heating atmosphere may be in air or in an inert atmosphere, and is not particularly limited. However, when the polyimide film is required to be colorless and transparent, it is heated in an inert atmosphere such as nitrogen to suppress coloring. It is preferable.

  The carrier substrate used in the production method of the present invention is preferably hard and heat resistant. That is, it is preferable to use a material that does not deform under the temperature conditions required in the manufacturing process. Specifically, the carrier substrate is preferably composed of a material having a glass transition temperature of usually 200 ° C. or higher, preferably 250 ° C. or higher. In order to reduce the manufacturing cost of the device, it is also preferable to use an inexpensive carrier substrate. From such a viewpoint, preferable examples of the material of the carrier substrate include glass, ceramic, metal, silicon wafer and the like.

  Although it does not specifically limit as a glass substrate used as a material of a carrier substrate, For example, a blue plate glass (alkali glass), high silicate glass, soda lime glass, lead glass, aluminoborosilicate glass, non-alkali Glass (borosilicate glass, Corning Eagle XG, etc.), aluminosilicate glass, etc. are mentioned.

  The polyimide resin composition of the present invention is inexpensive, but even when glass having very strong adhesion to the polyimide film layer is used as a carrier substrate, the polyimide film layer and the device formed on the polyimide film layer are damaged. It can peel without giving. Therefore, a device can be manufactured at a low cost in a shorter process.

  The thickness of the carrier substrate is not particularly limited, but is usually 0.3 mm or more, preferably 0.5 mm or more, and is usually 5.0 cm or less, preferably 2.0 cm or less. When the thickness of the carrier substrate is in such a range, the impact resistance of the carrier substrate can be improved and the device manufacturing cost can be reduced.

<Polyimide film>
The thickness of the polyimide film of this invention can be suitably adjusted according to a use. The thickness of the polyimide film can be controlled by adjusting the coating amount of the polyimide resin composition.
The thickness of the polyimide film is usually 1 μm or more, preferably 2 μm or more, and is usually 300 μm or less, preferably 200 μm or less. When the thickness is 1 μm or more, the polyimide film tends to obtain sufficient strength. This is preferable in that the strength of the device film is improved and the device film is hardly damaged, and the handling property is improved. Moreover, it becomes possible to make a device film thin by making thickness into 200 micrometers or less.

  The coefficient of thermal expansion of the polyimide film is preferably 100 ppm / K or less, more preferably 70 ppm / K or less, and most preferably the same thermal expansion as that of the carrier substrate. . When the coefficient of thermal expansion is in such a range, in the step of forming the device constituent member on the polyimide film laminate, peeling of the polyimide film from the carrier substrate due to temperature change in the step tends to be prevented. Moreover, when forming a polyimide film on a carrier substrate, there exists a tendency for the curvature of a polyimide film laminated body to become small.

The polyimide film is preferably less colored and heat resistant, and preferably has high mechanical strength. Moreover, it is preferable to have colorless transparency as needed. In the present specification, being colorless and transparent means that in a film having a thickness of 1 to 100 μm, the transmittance of light at 500 nm is usually 70% or more, preferably 80% or more, particularly preferably 85% or more. Say. A polyimide film having a high light transmittance is suitably used in applications requiring translucency, such as a photoelectric conversion element.
In this specification, the total light transmittance at 500 nm according to JIS K 7136-1 is used as the transmittance.

  When the polyimide film is particularly required to be colorless, the yellowness (yellow index (YI)) when the film thickness is 50 ± 5 μm is usually −10 or more, preferably −5 or more, more preferably − 1 or more. On the other hand, it is usually 20 or less, preferably 15 or less, more preferably 10 or less, and still more preferably 5 or less.

  The polyimide film of the present invention preferably has a softening transition temperature of 200 ° C. or higher. More preferably, it is 250 degreeC or more, Most preferably, it is 300 degreeC or more. By being in this range, since the polyimide film is not softened in the step of forming the device constituent member, the yield of device film production tends to be improved.

The polyimide film of the present invention preferably has a glass transition temperature (Tg) of 150 ° C. or higher, more preferably 200 ° C. or higher, more preferably 250 ° C. or higher. When the glass transition temperature is high, the thermal influence on the device constituent member is lowered and the heat resistance tends to be improved.
The polyimide film depends on the required device film and the type of device component, but preferably has mechanical strength such as the following tensile strength, tensile elastic modulus, and tensile elongation. When the polyimide film has such mechanical strength, a more durable device film tends to be obtained.
The tensile strength of the polyimide film of the present invention is not particularly limited, but is usually 50 MPa or more, preferably 70 MPa or more, and is usually 400 MPa or less, preferably 300 MPa or less.
The tensile elastic modulus of the polyimide film of the present invention is not particularly limited, but is usually 1000 MPa or more, preferably 1500 MPa, while it is usually 20 GPa or less, preferably 10 GPa or less.
The tensile elongation of the polyimide film of the present invention is not particularly limited, but is usually 10% GL or more, preferably 20% GL, and is usually 300% GL or less, preferably 200% GL or less. .

<Method for forming device constituent member>
A method for forming a device constituent member such as an organic EL layer, a photoelectric conversion layer, a barrier layer, a sealing layer, an electrode, a transistor, a color filter, a polarizing film, or a silicon oxide film on the polyimide film of the present invention is not particularly limited. After forming the device constituent member on the polyimide film of the polyimide film laminate, the carrier substrate can be peeled from the device film laminate to obtain a device film used for each application such as display, light reception, and light emission.
Before forming the device constituent member, the polyimide film laminate may be washed or surface-treated as necessary. Moreover, you may laminate | stack various barrier layers on a polyimide film laminated body before forming a device structural member as needed. These methods are not limited.
Examples of cleaning include UV ozone cleaning, plasma cleaning, sputter cleaning, ion cleaning, heat cleaning, dry ice jet cleaning and other dry cleaning; water cleaning, alkali cleaning, acid cleaning, detergent cleaning, solvent cleaning, liquid jet cleaning, etc. Wet cleaning.
As an example of laminating various barrier layers, a method of coating a gas barrier polymer, laminating a metal such as platinum or aluminum, an inorganic oxide such as alumina or titanium oxide, a metal nitride, etc. And a method of coating an organic barrier layer or an organic / inorganic composite barrier layer.

  Necessary device constituent members are formed on the polyimide film of the polyimide film laminate formed by the above-described method in accordance with uses such as display, light reception, and light emission. For example, when manufacturing a TFT liquid crystal display device film, a TFT such as amorphous silicon may be formed. A TFT can also be formed by forming a gate metal layer, a silicon nitride gate dielectric layer, and an ITI pixel electrode. Further, a structure necessary for the liquid crystal display can be formed on the TFT by a known method.

The display device is not limited to the above-mentioned TFT liquid crystal display, and includes organic EL displays, liquid crystal displays, electronic paper applications and the like.
Moreover, a solar cell device etc. are mentioned as a light receiving device, The illumination etc. which used organic EL are mentioned as a light emitting device.
Moreover, when manufacturing a solar cell device, a solar cell using, for example, crystalline silicon, amorphous silicon, a compound semiconductor material, an organic compound material, or the like may be formed on a polyimide film laminate. For example, a solar cell can be formed by forming a transparent electrode, a crystalline silicon, an amorphous silicon, a photoelectric conversion layer containing an organic material, a counter electrode, or the like. Furthermore, a structure necessary for the solar cell can be formed on the solar cell by a known method.
In addition, you may perform the process etc. which process the process which forms layers other than a circuit, a member other than a circuit, and a member with respect to the device film laminated body in which the device structural member was formed.

<Method of peeling carrier substrate from device film laminate>
The method of peeling the carrier substrate from the device film laminate to obtain the device film is not particularly limited, but the method of physically peeling is particularly preferred in that it can be peeled without impairing the performance of the polyimide film and the device constituent member.

The method of physically peeling is, for example, a method of obtaining a device film by separating the peripheral edge of a device constituent member in a device film laminate, and obtaining a device film by sucking the peripheral edge of the device constituent member in the device film laminate. Examples thereof include a method and a method of obtaining a device film by fixing the periphery of a device constituent member in a device film laminate and moving only the carrier substrate.
In order to use such a method of physically peeling, the peeling strength between the carrier substrate and the device film needs to be larger than 0 N / m in the peeling test according to JIS K 6854-2. When it is 0 N / m, the polyimide film may be displaced or peeled off from the carrier substrate in the step of forming the device constituent member on the polyimide film laminate.
In an actual manufacturing process, a method of cutting the device film laminate with a laser, a cutter, or the like and then peeling it off can be mentioned. In that case, it is preferable that the device film is not peeled until the cut is made, and the peel strength after the cut is preferably a smaller value.
Therefore, the peel strength between the carrier substrate and the polyimide film is greater than 0 N / m, preferably 0.5 N / m or more, more preferably 1 N / m or more, and usually 1.0 × 10 ³ N / m or less. Furthermore, 7.0 × 10 ² N / m or less is preferable. The same applies to the peel strength between the carrier substrate and the device film. When the peel strength is in the above range, the polyimide film tends not to peel or shift from the carrier substrate in the step of forming the device constituent member. Moreover, it exists in the tendency which can peel a carrier substrate easily from a device film laminated body, without damaging a device structural member.

  Applications of the device film of the present invention include display devices such as liquid crystal displays, organic EL displays and electronic paper, light receiving devices such as solar cells, and light emitting devices such as organic EL lighting. In particular, it is optimal for application to applications where thinning, lightening, and flexibility are desired.

<Example of device film of the present invention>
An example of a device formed on the polyimide film of the present invention is an organic electroluminescent element. A glass substrate is generally used as the substrate of the organic electroluminescence device. However, by using the polyimide film of the present invention instead of the glass substrate, flexible organic electroluminescence without changing the manufacturing method in the conventional glass substrate and without adversely affecting the characteristics of the organic electroluminescence device. An element can be easily manufactured.
That is, the polyimide film laminate of the present invention is handled as a glass substrate in a conventional production method, and a device constituent member of an organic electroluminescent element is formed on the polyimide film surface side to form a device film laminate. Thereafter, by peeling the carrier substrate from the device film laminate, a flexible organic electroluminescent element having a polyimide film as the device film can be produced.
Hereinafter, the organic electroluminescent element using the polyimide film of the present invention and the production method thereof will be described in detail.

(Organic electroluminescent device using the polyimide film of the present invention and method for producing the same)
FIG. 2 is a schematic cross-sectional view showing a structure example suitable for the organic electroluminescent element 10 using the polyimide film of the present invention. In FIG. 2, reference numeral 1 is a polyimide film, reference numeral 2 is an anode, and reference numeral 3 is a hole. Reference numeral 4 denotes a hole transport layer, reference numeral 5 denotes a light emitting layer, reference numeral 6 denotes a hole blocking layer, reference numeral 7 denotes an electron transport layer, reference numeral 8 denotes an electron injection layer, and reference numeral 9 denotes a cathode.
A known material can be applied as a material applied to these structures, and there is no particular limitation. In addition, when citing a publication, a paper or the like, the contents can be appropriately applied and applied within the common sense of those skilled in the art.

(Display device and lighting device)
A display device or a lighting device can be manufactured using an organic electroluminescent element using the polyimide film of the present invention as a substrate. There is no restriction | limiting in particular about the format and structure of a display apparatus or an illuminating device, It can assemble in accordance with a conventional method using the organic electroluminescent element which used the polyimide film of this invention for the board | substrate.
For example, a display device and a lighting device are formed by a method as described in “Organic EL Display” (Ohm, published on August 20, 2004, Shizushi Tokito, Chiba Adachi, Hideyuki Murata). be able to.

(Effect when the polyimide film of the present invention is used for a substrate of an organic electroluminescence device)
By using the polyimide film of the present invention, it is easy to peel off the carrier substrate from the device film laminate, so that it is difficult to physically damage the organic electroluminescent element at the time of peeling. In addition, when a wet film forming method is employed in the manufacturing process of the organic electroluminescent element, the film may be heated to 200 ° C. or higher in a drying process after the film formation. Even in such a case, by using the polyimide film of the present invention for the substrate, the generation of outgas from the polyimide film is suppressed, the generation of defects in the organic electroluminescence device can be suppressed, and the light emission characteristics and life characteristics are improved. Can be maintained.
Since the organic electroluminescence device is required to have uniform light emission, the surface roughness is required to be high smoothness of 10 nm or less. Since the polyimide film of the present invention has high smoothness, the organic electroluminescence device can emit light uniformly.
Usually, when peeling a carrier substrate from a device film laminate, a polyimide film is deformed and peeled. When the polyimide film is deformed, a phenomenon in which the organic electroluminescent element is destroyed due to elongation or tearing of the polyimide film can be considered. Since the polyimide film of the present invention is excellent in releasability, it is possible to peel off the carrier substrate without destroying the organic electroluminescent element.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. The following measurements in the examples were performed according to the following methods.

[Peelability]
The releasability after cutting with a cutter in a polyimide film formed on a glass substrate was confirmed using the following indicators.
(Double-circle): The polyimide film peeled naturally.
○: The polyimide film was easily peeled off.
Δ: It was difficult to remove the polyimide film.
X: The polyimide film did not peel

<Synthesis Example 1>
(Synthesis of 1,1′-bicyclohexane-3,3 ′, 4,4′-tetracarboxylic acid-3,3 ′, 4,4′-dianhydride (H-BPDA))

  1,1′-biphenyl-3, obtained by dissolving 150 g of 1,1′-biphenyl-3,3 ′, 4,4′-tetracarboxylic dianhydride in a solution of 593 g of water and 83.3 g of sodium hydroxide , 3 ′, 4,4′-tetracarboxylic acid tetrasodium salt aqueous solution was subjected to nuclear hydrogenation at 10 MPaG and 120 ° C. using a Ru / C catalyst. Subsequently, 429 g of a 49% aqueous sulfuric acid solution was added dropwise to precipitate and filtered to obtain 157 g (yield 81%) of dicyclohexyl-3,3 ′, 4,4′-tetracarboxylic acid.

  Into a 300 ml three-necked flask equipped with a thermometer, a stirrer and a Dimroth condenser, dicyclohexyl-3,3 ′, 4,4′-tetracarboxylic acid (H-BTC) obtained above under nitrogen is obtained. 7 g (0.98 mol) and 90 g of acetic anhydride were added. This was heated with stirring and reacted at reflux temperature (130 ° C. to 140 ° C.) for 3 hours. After the reaction, it was cooled to 10 ° C. and filtered to obtain white crystals. The obtained crystals were washed with toluene and dried with a vacuum dryer to obtain 1,1′-bicyclohexane-3,3 ′, 4,4′-tetracarboxylic acid-3,3 ′, 4. , 4'-dianhydride (H-BPDA) containing composition 23.5g (yield 78%) was obtained.

<Synthesis Example 2>
(Preparation of polyimide resin precursor solution 1)
1,1′-bicyclohexane-3,3 ′, 4,4′-tetracarboxylic acid-3,3 ′, 4,4′-dianhydride (H-BPDA) 60.0 g obtained in Synthesis Example 1 (196 mmol) was added to N, N-dimethylacetamide (127.5 g), and the mixture was stirred at room temperature under a nitrogen stream. A solution prepared by dissolving 39.6 g (198 mmol) of 4,4′-diaminodiphenyl ether (ODA) (manufactured by Tokyo Chemical Industry Co., Ltd.) in 171.3 g of N, N-dimethylacetamide was added and stirred at 80 ° C. for 6 hours. The objective polyimide resin precursor solution 1 was obtained.

<Synthesis Example 3>
(Preparation of polyimide resin solution 1)
In a 4-necked flask equipped with a dry nitrogen gas inlet tube, a cooler, a Dean-Stark aggregator filled with toluene, and a stirrer, polyimide resin precursor solution 1 (50 g) obtained in Synthesis Example 2 and 7.5 g of toluene were added. In addition, the inside of the three-necked flask was made into a nitrogen atmosphere. The external temperature was heated to 190 ° C., and water generated during imidization was distilled off azeotropically with toluene. When heating, refluxing, and stirring were continued for 6 hours, generation of water was not observed. Subsequently, the mixture was heated for 7 hours while distilling off toluene and triethylamine to obtain a polyimide resin solution 1.

<Example 1>
A blue glass plate (125 × 125 mm, 18 mm thickness) was used as the carrier substrate. This glass plate was washed with an alkaline surfactant and distilled water before use.
0.18 g of ether type nonionic surfactant polyoxyethylene lauryl ether (constituent elements: C, O, H / Emulgen 123P (manufactured by Kao Corporation)) is dissolved in N, N-dimethylacetamide (2.82 g). A 6% surfactant solution 1 was prepared.
A 25% by weight polyimide resin solution 1 (10 g) synthesized in Synthesis Example 3 and a 6% surfactant solution 1 (0.042 g) were used as a surfactant with respect to the polyimide resin contained in the polyimide resin solution 1. The polyimide resin composition 1 was obtained by mixing and stirring so that the concentration was 0.10% by mass. Using a film applicator, this polyimide resin composition was applied on a soda glass plate with a thickness of 254 μm. Then, it was dried at 80 ° C. for 10 minutes in a nitrogen atmosphere, then heated to 300 ° C. at 2 ° C./min, and heated at 300 ° C. for 30 minutes to form a polyimide film laminate on which a polyimide film was formed on a blue plate glass plate. Was made. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 2>
Example 1 except that Emulgen 123P described in Example 1 was changed to polyoxyethylene alkyl ether of ether type nonionic surfactant (constituent elements: C, O, H / Emulgen 709 (manufactured by Kao Corporation)). In the same manner, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 3>
Emulgen 123P described in Example 1 was changed to sorbitan monooleate (constituent elements: C, O, H / Sorgen 40 (Daiichi Kogyo Seiyaku Co., Ltd.)), an ester-type nonionic surfactant, and the polyimide resin solution A polyimide film laminate was obtained in the same manner as in Example 1 except that the surfactant was mixed with the polyimide resin contained in 1 so that the concentration of the surfactant was 0.15% by mass. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 4>
Example 3 except that Sorgen 40 described in Example 3 was changed to sorbitan laurate (constituent elements: C, O, H / New Coal 20 (manufactured by Nippon Emulsifier Co., Ltd.)), an ester-type nonionic surfactant. In the same manner, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 5>
Example 3 except that Sorgen 40 described in Example 3 was changed to sorbitan stearate (constituent elements: C, O, H / New Coal 60 (manufactured by Nippon Emulsifier Co., Ltd.)), an ester type nonionic surfactant. In the same manner, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 6>
Example 3 except that Sorgen 40 described in Example 3 was changed to sorbitan oleate (constituent elements: C, O, H / New Coal 80 (manufactured by Nippon Emulsifier Co., Ltd.)), an ester type nonionic surfactant. In the same manner, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 7>
Except for changing Sorgen 40 described in Example 3 to a sucrose fatty acid ester of an ester-type nonionic surfactant (constituent elements: C, O, H / DK ester F-110 (Daiichi Kogyo Seiyaku Co., Ltd.)) A polyimide film laminate was obtained in the same manner as Example 3. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 8>
Implemented except that Sorgen 40 described in Example 3 was changed to sucrose benzoate (constituent elements: C, O, H / Monopet SB (Daiichi Kogyo Seiyaku Co., Ltd.)), an ester-type nonionic surfactant. In the same manner as in Example 3, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 9>
Implemented except that Solgen 40 described in Example 3 was changed to polyvinyl pyrrolidone (constituent elements: C, O, H / Pitzkor K-30 (Daiichi Kogyo Seiyaku Co., Ltd.)) as a polymeric nonionic surfactant. In the same manner as in Example 3, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 10>
The procedure was carried out except that Solgen 40 described in Example 3 was changed to polyvinyl pyrrolidone (constituent elements: C, O, H / Pitzkor K-90 (Daiichi Kogyo Seiyaku Co., Ltd.)), a polymer type nonionic surfactant. In the same manner as in Example 3, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 11>
Emulgen 123P described in Example 1 was changed to ether type nonionic surfactant polyoxyethylene lauryl ether (constituent elements: C, O, H / Emulgen 130K (manufactured by Kao Corporation)). A polyimide film laminate was obtained in the same manner as in Example 1 except that the concentration of the surfactant was 0.35% by mass with respect to the contained polyimide resin. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 12>
Same as Example 11 except that Emulgen 130K described in Example 11 was changed to polyoxyethylene lauryl ether of ether type nonionic surfactant (constituent elements: C, O, H / Emulgen 150 (manufactured by Kao Corporation)). Thus, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 13>
The same as Example 11 except that Emulgen 130K described in Example 11 was changed to polyoxyethylene oleyl ether (constituent elements: C, O, H / Emulgen 430 (manufactured by Kao Corporation)), an ether type nonionic surfactant. Thus, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 14>
The same as Example 11 except that Emulgen 130K described in Example 11 was changed to polyoxyethylene oleyl ether of ether type nonionic surfactant (constituent elements: C, O, H / Emulgen 409PV (manufactured by Kao Corporation)). Thus, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 15>
The same as Example 11 except that Emulgen 130K described in Example 11 was changed to polyoxyethylene alkyl ether of ether type nonionic surfactant (constituent elements: C, O, H / Emulgen 705 (manufactured by Kao Corporation)). Thus, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 16>
The same as Example 11 except that Emulgen 130K described in Example 11 was changed to polyoxyethylene alkyl ether of ether type nonionic surfactant (constituent elements: C, O, H / Emulgen 707 (manufactured by Kao Corporation)). Thus, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 17>
Polyoxyethylene alkyl ether of ether type nonionic surfactant (constituent elements: C, O, H / Emulgen 707 (manufactured by Kao Corporation) 0.18 g was dissolved in N, N-dimethylacetamide (2.82 g), 6 % Surfactant solution 2 was prepared, 0.18 g of polyether-modified silicone SH3771 (manufactured by Dow Corning Toray) was dissolved in N, N-dimethylacetamide (2.82 g), and a 6% silicone varnish solution was prepared. Created.
The polyimide resin solution 1 (10 g) having a concentration of 25% by mass synthesized in Synthesis Example 3 and this 6% surfactant solution 2 (0.125 g) are 0.30% by mass with respect to the polyimide resin contained in the polyimide resin solution 1. The 6% silicone varnish solution (0.042 g) was mixed so as to be 0.10% by mass with respect to the polyimide resin contained in the polyimide resin solution 1 and stirred. Otherwise in the same manner as in Example 1, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 18>
Emulgen 707 described in Example 17 was changed to polyoxyethylene lauryl ether of ether type nonionic surfactant (constituent elements: C, O, N, H / Emulgen 150 (manufactured by Kao Corporation)), and the polyimide resin solution A polyimide film laminate was obtained in the same manner as in Example 17, except that the surfactant was mixed with the polyimide resin contained in 1 so that the concentration of the surfactant was 0.20% by mass. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 19>
Emulgen 707 described in Example 17 was changed to an ester-type nonionic surfactant sucrose benzoate (constituent elements: C, O, N, H / Monopet SB (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)) It mixes so that the density | concentration of surfactant may be set to 0.15 mass% with respect to the polyimide resin contained in the said polyimide resin solution 1, and 6% silicone varnish solution is with respect to the polyimide resin contained in the polyimide resin solution 1. A polyimide film laminate was obtained in the same manner as in Example 17 except for mixing so as to be 0.05% by mass. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 20>
Monopet SB described in Example 19 was changed to a polymeric nonionic surfactant polyvinylpyrrolidone (constituent elements: C, O, N, H / Pitzkor K-30 (Daiichi Kogyo Seiyaku Co., Ltd.)). A polyimide film laminate was obtained in the same manner as Example 19 except for the above. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Example 21>
Monopet SB described in Example 19 was changed to a polymeric nonionic surfactant polyvinylpyrrolidone (constituent elements: C, O, N, H / Pitzkor K-90 (Daiichi Kogyo Seiyaku Co., Ltd.)). A polyimide film laminate was obtained in the same manner as Example 19 except for the above. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Comparative Example 1>
Emulgen 123P described in Example 1 was changed to anionic surfactant sodium lauryl sulfate (constituent elements: C, O, H, S, Na / Emar 2FG (manufactured by Kao Corporation)), and the polyimide resin solution 1 A polyimide film laminate was obtained in the same manner as in Example 1 except that the concentration of the surfactant was 0.15% by mass with respect to the polyimide resin contained in. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Comparative Example 2>
Comparative Example 1 except that Emar 2FG described in Comparative Example 1 was changed to sodium lauryl sulfate (constituent elements: C, O, H, S, Na / Emar 10G (manufactured by Kao Corporation)) as an anionic surfactant. In the same manner, a polyimide film laminate was obtained. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Comparative Example 3>
Emar 2FG described in Comparative Example 1 was changed to a nonionic surfactant polyoxyethylene fatty acid diester (constituent elements: C, O, H / Ionet DS-300 (manufactured by Sanyo Kasei Co., Ltd.)), and the polyimide resin solution 1 A polyimide film laminate was obtained in the same manner as in Comparative Example 1 except that the surfactant was mixed with the polyimide resin contained in the solution so that the concentration of the surfactant was 0.40% by mass. The polyimide film of the obtained polyimide film laminate was colorless and transparent. Moreover, the peelability of the said polyimide film was confirmed according to said method. The evaluation results are shown in Table 1.

<Comparative Example 4>
Emar 2FG described in Comparative Example 1 was changed to nonionic surfactant polyoxyethylene lauryl ether (constituent elements: C, O, H / Emulgen 130K (manufactured by Kao Corporation)) and contained in the polyimide resin solution 1 A polyimide film laminate was obtained in the same manner as in Comparative Example 1 except that the surfactant was mixed with the polyimide resin so that the concentration of the surfactant was 0.50% by mass. The obtained polyimide film was whitened.

<Comparative Example 5>
Emul 2FG described in Comparative Example 1 was changed to polyoxyethylene lauryl ether (constituent elements: C, O, H / Emulgen 150 (manufactured by Kao Corporation)), a nonionic surfactant, and contained in the polyimide resin solution 1 A polyimide film laminate was obtained in the same manner as in Comparative Example 1 except that the surfactant was mixed with the polyimide resin so that the concentration of the surfactant was 0.50% by mass. The obtained polyimide film was whitened.

<Comparative Example 6>
Emul 2FG described in Comparative Example 1 was changed to nonionic surfactant polyoxyethylene oleyl ether (constituent elements: C, O, H / Emulgen 430 (manufactured by Kao Corporation)) and contained in the polyimide resin solution 1 A polyimide film laminate was obtained in the same manner as in Comparative Example 1 except that the surfactant was mixed with the polyimide resin so that the concentration of the surfactant was 0.50% by mass. The obtained polyimide film was whitened.

In Examples 1-21, the polyimide film which was colorless and transparent and excellent in peelability was obtained. Therefore, also when a device structural member is formed on the polyimide film shown in Examples 1-21, a carrier substrate can be peeled from a device film laminated body, without impairing a device structural member.
On the other hand, Comparative Examples 1 and 2 using an anionic surfactant containing Na, which is a metal element, could not peel the polyimide film. Moreover, as shown to Comparative Examples 3-6, when the nonionic surfactant was added 0.4% or more, the produced polyimide film was whitened. Therefore, when a device structural member was formed on the polyimide film shown in Comparative Examples 1 and 2, it was found that there was a high possibility of damaging the device structural member during peeling. Moreover, it turned out that the polyimide film shown to Comparative Examples 4-6 has inadequate optical characteristics.

DESCRIPTION OF SYMBOLS 1 Polyimide film 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer
6 Hole blocking layer 7 Electron transport layer 8 Electron injection layer 9 Cathode 10 Organic electroluminescent device 11 Carrier substrate 12 Plastic film 13 Device component 14 Plastic film laminate 15 Device film laminate 16 Device film

Claims (6)

A resin composition comprising a polyimide resin and / or a polyimide resin precursor, and a surfactant,
The amount of the surfactant in the resin composition is less than 0.4% by mass with respect to the polyimide resin and / or the polyimide resin precursor,
A polyimide resin composition, wherein the surfactant comprises an element selected from H, C, N, O, P, S, and Se, and is nonionic. The polyimide resin composition according to claim 1, wherein the polyimide resin and / or the polyimide resin precursor includes at least one selected from a cyclic aliphatic skeleton, a fluorinated skeleton, and a biphenyl skeleton. The polyimide film which forms the polyimide resin composition of Claim 1 or 2 using the casting method. A polyimide film laminate, wherein the polyimide film according to claim 3 is formed on a carrier substrate. A device film laminate in which a device constituent member is further formed on the polyimide film laminate of claim 4. A device film obtained by peeling a carrier substrate from the device film laminate according to claim 5.

Images