WO2017002664A1

WO2017002664A1 - Polyimide film, organic electroluminescent element, transparent conductive laminate, touch panel, solar cell, and display device

Info

Publication number: WO2017002664A1
Application number: PCT/JP2016/068351
Authority: WO
Inventors: 伸一小松; 松本　隆也
Original assignee: Ｊｘエネルギー株式会社
Priority date: 2015-06-30
Filing date: 2016-06-21
Publication date: 2017-01-05
Also published as: JP2017014377A; CN107709409A; TW201718724A; KR20180022853A

Abstract

A polyimide film comprising a polyimide that includes, relative to the total amount of repeating units, at least 30 mol% of a repeating unit represented by general formula (1) (in formula (1), R¹, R², and R³ each independently represent a hydrogen atom, or the like, R¹⁰ represents a specific group, and n is an integer of 0–12). The polyimide film has a tensile strength of at least 125 MPa and a breaking elongation of at least 15%.

Description

Polyimide film, organic electroluminescence element, transparent conductive laminate, touch panel, solar cell, and display device

The present invention relates to a polyimide film, an organic electroluminescence element, a transparent conductive laminate, a touch panel, a solar cell, and a display device.

In recent years, in the field of display equipment such as a display using an organic electroluminescence element and a liquid crystal display, as a material to be used for the substrate, etc., it has a high light transmission like glass and has a sufficiently high heat resistance. At the same time, the emergence of light and flexible materials has been demanded. And as a material used for such a glass substitute use etc., the film which has high heat resistance, and consists of a light and flexible polyimide attracts attention.

As such polyimide, for example, aromatic polyimide (for example, trade name “Kapton” manufactured by DuPont) is known. However, although such aromatic polyimide is a polyimide having sufficient flexibility and high heat resistance, it exhibits a brown color and can be used for glass replacement applications and optical applications that require light transmission. It wasn't.

Therefore, in recent years, development of an alicyclic polyimide having sufficient light transmittance for use in glass substitute applications and the like has been promoted. For example, in International Publication No. 2011/099518 (Patent Document 1) Polyimides having repeating units described by a specific general formula are disclosed. And such a polyimide as described in patent document 1 had sufficient light transmittance and high heat resistance. However, even in the above-mentioned Patent Document 1, there is no particular description regarding mechanical strength (toughness) such as polyimide tensile strength and elongation at break.

International Publication No. 2011/099518

The present invention has been made in view of the above-mentioned problems of the prior art, has a high balance of tensile strength and elongation characteristics, and has higher toughness based on tensile strength and elongation at break. It is an object of the present invention to provide a polyimide film that can be used, and an organic electroluminescence device using the polyimide film. Furthermore, an object of this invention is to provide the transparent conductive laminated body using the said polyimide film, the touchscreen using the transparent conductive laminated body, a solar cell, and a display apparatus.

As a result of intensive studies to achieve the above object, the inventors of the present invention comprise a polyimide film containing a polyimide unit containing 30 mol% or more of a repeating unit represented by the following general formula (1) with respect to all repeating units. By using a film, the tensile strength and elongation characteristics of the film (characteristics that exhibit sufficient elongation before breaking) are well balanced at a higher level, and the toughness based on tensile strength and breaking elongation is higher. As a result, the present invention has been completed.

That is, the polyimide film of the present invention has the following general formula (1):

Wherein ^{^{(1), R 1, R}} 2, R 3 are each independently a hydrogen atom, represents one selected from the group consisting of alkyl groups and fluorine atoms having 1 to 10 carbon ^{atoms, R 10} is The following general formulas (101) to (102):

And n represents an integer of 0 to 12. ]
It is made of a polyimide containing 30 mol% or more of the repeating unit represented by the following formula, and has a tensile strength of 125 MPa or more and an elongation at break of 15% or more.

In the polyimide film of the present invention, it is preferable that the polyimide contains 40 mol% or more of the repeating unit represented by the general formula (1) with respect to all repeating units.

The organic electroluminescent element of the present invention comprises the polyimide film of the present invention.

The transparent conductive laminate of the present invention comprises the polyimide film of the present invention and a thin film made of a conductive material laminated on the polyimide film.

Furthermore, the touch panel, solar cell, and display device of the present invention each comprise the transparent conductive laminate of the present invention.

According to the present invention, there is provided a polyimide film that has a good balance of tensile strength and elongation characteristics at a higher level, and that can have higher toughness based on tensile strength and elongation at break, and It is possible to provide the used organic electroluminescence element. Moreover, according to this invention, it becomes possible to provide the transparent conductive laminated body using the said polyimide film, the touchscreen using the transparent conductive laminated body, a solar cell, and a display apparatus.

It is a schematic longitudinal cross-sectional view which shows suitable one Embodiment of the organic electroluminescent element of this invention. 2 is a graph showing an infrared absorption spectrum (IR spectrum) of the polyimide film obtained in Example 1. FIG.

Hereinafter, the present invention will be described in detail on the basis of preferred embodiments thereof.

[Polyimide film]
The polyimide film of the present invention has the following general formula (1):

Wherein ^{^{(1), R 1, R}} 2, R 3 are each independently, a hydrogen atom, a one selected from the group consisting of alkyl groups and fluorine atoms of 1-10 carbon ^{atoms, R 10} is The following general formulas (101) to (102):

The alkyl group that can be selected as R ¹ , R ² , or R ^{3 in the} general formula (1) is an alkyl group having 1 to 10 carbon atoms. When the number of carbon atoms exceeds 10, the glass transition temperature is lowered and a sufficiently high heat resistance cannot be achieved. Further, the number of carbon atoms of the alkyl group that can be selected as R ¹ , R ² , or R ³ is preferably 1 to 6 and is preferably 1 to 5 from the viewpoint of easier purification. Is more preferably 1 to 4, particularly preferably 1 to 3. Further, such an alkyl group that can be selected as R ¹ , R ² , or R ³ may be linear or branched. Further, such an alkyl group is more preferably a methyl group or an ethyl group from the viewpoint of ease of purification.

R ¹ , R ² and R ^{3 in the} general formula (1) are each independently a hydrogen atom or a carbon number of 1 to 10 from the viewpoint that higher heat resistance can be obtained when a polyimide is produced. In particular, from the viewpoints of easy availability of raw materials and easier purification, each independently represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group. It is more preferably a group, and particularly preferably a hydrogen atom or a methyl group. Moreover, it is especially preferable that several R < ¹ >, R < ² >, R < ³ > in such a formula is the same from viewpoints, such as the ease of refinement | purification.

The groups that can be selected as R ¹⁰ in the general formula (1) are groups represented by the general formulas (101) to (102). Such R ¹⁰ is preferably a group represented by the above general formula (101) from the viewpoint of tensile strength, elongation at break, and heat resistance, and includes tensile strength, elongation at break, retardation in thickness direction (Rth). ) Is preferably a group represented by the general formula (102). In the present invention, as the repeating unit represented by the general formula (1), two or more kinds of repeating units having different types of R ¹⁰ may be included.

In the general formula (1), n represents an integer of 0 to 12. When such a value of n exceeds the upper limit, purification becomes difficult. Further, the upper limit value of the numerical value range of n in the general formula (1) is more preferably 5 and particularly preferably 3 from the viewpoint of easier purification. Further, the lower limit of the numerical range of n in the general formula (1) is more stable from the viewpoint of the stability of the raw material compound used when forming the repeating unit represented by the general formula (1). From the viewpoint of producing a polyimide, it is more preferably 1 and particularly preferably 2. Thus, n in the general formula (1) is particularly preferably an integer of 2 to 3.

Furthermore, in this invention, the said polyimide contains 30 mol% or more of repeating units represented by the said General formula (1) with respect to all the repeating units. Content of the repeating unit represented by the general formula (1) (when plural types of repeating units represented by the general formula (1) are included (for example, selected as R ¹ , R ² , R ³ , R ¹⁰ etc. In the case where two or more repeating units represented by the formula (1) having different types of groups are included), the total amount thereof is 30 mol% or more based on all repeating units. Polyimide having a sufficiently high tensile strength and a sufficiently high value of elongation at break can be obtained in a well-balanced manner, whereby a polyimide film having a higher degree of toughness (mechanical strength) (high toughness) Polyimide film) can be obtained. As the content of the repeating unit represented by the general formula (1) (total amount of the repeating unit represented by the general formula (1)), the tensile strength is set to a higher value while the elongation at break is higher. In terms of heat resistance, transparency, and thickness direction retardation (Rth), it is more preferably 40 mol% or more, and 50 mol% or more with respect to all repeating units in the polyimide. Is more preferably 70 mol% or more, particularly preferably 90 mol% or more.

As described above, in the present invention, the polyimide only needs to contain the repeating unit represented by the general formula (1) in an amount of 30 mol% or more based on the total repeating units, and contains other repeating units. It may be. Such other repeating units are not particularly limited, and known repeating units capable of constituting polyimide can be appropriately used. Moreover, as another repeating unit that can be used together with the repeating unit represented by the general formula (1), from the viewpoint of heat resistance, transparency, and thickness direction retardation (Rth), the following general formula (2 ):

[In the formula (2), R ¹ , R ² and R ³ each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and a fluorine atom, and R ^a represents An aryl group having 6 to 40 carbon atoms (excluding the groups represented by the above general formulas (101) to (102)), and n represents an integer of 0 to 12. ]
The repeating unit represented by can be particularly preferably used. Incidentally, ^R ^1, R 2, ^{R 3} and n in the general formula (2) has the same definition as ^R ^1, R 2, ^{R 3} and n in formula (1) (their preferred Are the same as R ¹ , R ² , R ³ and n in the general formula (1).

R ^a in the general formula (2) is an aryl group having 6 to 40 carbon atoms other than the groups represented by the general formulas (101) to (102) (where R ^a is the above general formula In the case of the group represented by (101) to (102), it is the same as the repeating unit represented by the general formula (1), and therefore, R ^a in the formula (2) The groups represented by (101) to (102) are excluded.)

The number of carbon atoms of the aryl group that can be selected as R ^a in the general formula (2) is more preferably 6 to 40 (more preferably 6 to 30, and still more preferably 12 to 20). When such a carbon number exceeds the said upper limit, it exists in the tendency for heat resistance and tensile strength to fall.

As the ^{R a} in the general formula (2), from the viewpoints of heat resistance, tensile strength, the following general formula (201) to (204):

[In the formula (203), R ^b represents one selected from the group consisting of a hydrogen atom, a fluorine atom, a methyl group, an ethyl group and a trifluoromethyl group, and in the formula (204), Q represents a formula: —O—, —S—, —CO—, —CONH—, —COO—, —C ₆ H ₄ —, —C ₁₀ H ₆ —, —NHCO—C ₆ H ₄ —CONH—, —CONH—C ₆ _{_{_{_{H 4 -NHCO -, - OCO-}}}} C 6 H 4 -COO -, - COO-C 6 H 4 -OCO -, - O-C 10 H 6 -O -, - OCO-C 10 H 6 -COO-, _{_{_{-COO-C 10 H 6 -OCO -}}} , - CONH-C 10 H 6 -NHCO -, - NHCO-C 10 H 6 -CONH -, - SO 2 -, - C (CF 3) 2 -, - C ( _{_{_{CH 3) 2 -, - CH}}} 2 -, - O-C 6 H 4 -C (CH 3) 2 -C 6 _{_{_{4 -O -, - O-C}}} 6 H 4 -SO 2 -C 6 H 4 -O-, _{_{_{_{and, -C (CH 3) 2 -C}}}} 6 H 4 -C (CH 3) 2 - is represented by 1 type selected from the group which consists of groups is shown. ]
It is preferable that it is at least 1 sort (s) of group represented by these. In addition, as ^{Rb in} such General formula (203), a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is more preferable from a heat resistant viewpoint, and a hydrogen atom is especially preferable. Q in the general formula (204) is more preferably a group represented by the formula: —CONH—, —COO—, —C ₆ H ₄ —, from the viewpoint of heat resistance and tensile strength. A group represented by —, —C ₆ H ₄ — is more preferred, and a group represented by —CONH— is particularly preferred.

Further, the group represented by the general formula of such may be selected as ^{R a} (201) ~ (204), represented heat resistance, from the viewpoint of tensile strength, the general formula (203) or (204) The group is more preferable, and the group represented by the general formula (204) is still more preferable.

Among the repeating units represented by the general formula (2), R ^a is represented by the general formula (204) from the viewpoint that the tensile strength of the polyimide can be made higher. And a repeating unit in which Q in the general formula (204) is a group represented by —CONH— or —C ₆ H ₄ — is more preferable, and R ^a is represented by the above general formula (204). And a repeating unit in which Q in the general formula (204) is a group represented by —CONH— is particularly preferable.

When the polyimide contains a repeating unit represented by the general formula (2), the content of the repeating unit represented by the general formula (2) is 10 to 70 mol% with respect to all the repeating units. It is preferably 20 to 60% by mole. When the content of the repeating unit represented by the general formula (2) is less than the lower limit, the effect obtained by containing the repeating unit represented by the general formula (2) (particularly the tensile strength is higher). Tend to be insufficient). On the other hand, when the content of the repeating unit represented by the general formula (2) exceeds the upper limit, the value of elongation at break tends to decrease and the mechanical strength tends to decrease.

Further, the polyimide film of the present invention needs to have a tensile strength of 125 MPa or more. When such tensile strength is less than the lower limit, a film having higher toughness cannot be obtained. Further, from the same viewpoint, the tensile strength of such a polyimide film is more preferably 130 MPa or more, and further preferably 135 MPa or more. In addition, although it does not restrict | limit especially as an upper limit of the tensile strength of such a polyimide film, It is preferable that it is 1000 Mpa or less. When such tensile strength exceeds the upper limit, processing tends to be difficult.

Also, the polyimide film of the present invention needs to have an elongation at break of 15% or more. When the elongation at break is less than the lower limit, a film having higher toughness cannot be obtained. Further, from the same viewpoint, the breaking elongation of such a polyimide film is more preferably 20% or more, and further preferably 25% or more. In addition, although it does not restrict | limit especially as an upper limit of the breaking elongation of such a polyimide film, It is preferable that it is 300% or less. If such elongation at break exceeds the upper limit, the processing tends to be difficult.

Moreover, regarding the polyimide film of the present invention, the values obtained as follows can be adopted as the tensile strength and elongation at break. In such measurement, first, the product name “Super Dumbbell Cutter (Model: SDMK-1000-D, compliant with JIS K7139 (issued in 2009) A22 standard)” manufactured by Dumbbell Co., Ltd. A measurement sample is prepared by attaching to a container (duplicator made by Dumbbell Co., Ltd. (model SDL-200)) and cutting a polyimide film (thickness: 13 μm). In addition, the measurement sample obtained in this way is basically a dumbbell shape that conforms to the standard of type A22 (scale test piece) described in JIS K7139 (issued in 2009) except that the thickness is 13 μm. The test piece has a total length of 75 mm, a distance between tab portions: 57 mm, a length of the parallel portion: 30 mm, a radius of the shoulder: ≧ 30 mm, a width of the end portion: 10 mm, and a parallel portion in the center. The width is 5 mm and the thickness is 13 μm. When used, the width between the gripping tools is 57 mm and the width of the gripping portion is 10 mm (the same width as the entire width of the end portion). Next, using a Tensilon type universal testing machine (for example, model number “UCT-10T” manufactured by A & D Co., Ltd.), the measurement sample has a width of 57 mm between the gripping tools and a width of the gripping portion of 10 mm (test After placing the measurement sample under the conditions of load full scale: 0.05 kN, test speed: 300 mm / min, and tensile strength (at the time of breaking) Stress [unit: MPa]) and the value of elongation at break (unit:%) are determined (such a test is a test based on JIS K7162 (issued in 1994)). The value (%) of the elongation at break is the distance between the tab portions of the sample before the start of the tensile test (= width between grips: 57 mm) L ₀ , the distance between the tab portions of the sample until the sample breaks in the tensile test ( Assuming that the width between gripping tools when broken: 57 mm + α) is L, the following formula:
[Elongation at break (%)] = {(L−L ₀ ) / L ₀ } × 100
Can be calculated.

Further, such a polyimide preferably has an imidization ratio of 90% or more, more preferably 95% or more, and particularly preferably 96 to 100%. When such an imidation ratio is less than the lower limit, heat resistance tends to decrease, coloring is observed, and voids and blisters tend to occur in the film during heating. Such an imidation ratio can be calculated as follows. That is, the polyimide to be measured is dissolved in a heavy solvent such as deuterated chloroform (preferably deuterated chloroform), and ¹ H-NMR measurement is performed. From the ¹ H-NMR graph, NH of around 10 ppm (10 ppm ± 1 ppm) is obtained. It can be calculated by obtaining an integral value of H of COOH and H of COOH around 12 ppm (12 ppm ± 1 ppm). In this case, the integral ratio (imidation ratio) was prepared by first preparing a sample in which the acid dianhydride and diamine of the raw material compound were dissolved in a heavy solvent in which they were soluble (such as DMSO-d ₆ ). ¹ H-NMR spectra were measured, and in the ¹ H-NMR graphs, the H position (chemical shift) and integrated value of acid dianhydride and the H position (chemical shift) and integrated value of diamine were measured. Using the position and integral value of H of the acid dianhydride and the position and integral value of H of the diamine as a reference, NH of about 10 ppm in the ¹ H-NMR graph of the polyimide to be measured is obtained. A value calculated by relative comparison is adopted for the integrated value of H and H of COOH near 12 ppm. In the measurement of the imidization rate, the amount of polyimide for measuring the ¹ H-NMR spectrum is 0.01 to 5.0 mass% with respect to the heavy solvent (preferably heavy chloroform). The amount of the acid dianhydride of the compound and the amount of the diamine are used so as to be 0.01 to 5.0 mass% with respect to the soluble heavy solvent (DMSO-d ₆ or the like), respectively. In measuring the imidization rate, the amount of polyimide, the amount of acid dianhydride of the raw material compound, and the amount of diamine (the above concentration) are measured at the same concentration. In the ¹ H-NMR measurement, an NMR measuring instrument (manufactured by VARIAN, trade name: UNITY INOVA-600) is employed as a measuring apparatus.

Further, such a polyimide preferably has a 5% weight loss temperature (Td 5%) of 400 ° C. or more, more preferably 450 to 550 ° C. If such a 5% weight loss temperature is less than the lower limit, sufficient heat resistance tends to be difficult to achieve, and if it exceeds the upper limit, it tends to be difficult to produce a polyimide having such characteristics. It is in. Note that such a 5% weight reduction temperature is obtained by setting the scanning temperature to 30 ° C. to 550 ° C. while flowing nitrogen gas in a nitrogen gas atmosphere, and the rate of temperature increase is 10 ° C./min. It can be determined by measuring the temperature at which the weight of the used sample is reduced by 5% by heating under the above conditions. In addition, for such measurement, for example, a thermogravimetric analyzer (“TG / DTA220” manufactured by SII Nano Technology Co., Ltd.) can be used as a measuring device.

Further, such a polyimide preferably has a glass transition temperature (Tg) of 250 ° C. or higher, more preferably 300 to 500 ° C. If the glass transition temperature (Tg) is less than the lower limit, sufficient heat resistance tends to be difficult to achieve, and if it exceeds the upper limit, it tends to be difficult to produce a polyimide having such characteristics. It is in. In addition, such a glass transition temperature (Tg) can be simultaneously measured by the same method as a softening temperature measurement, using a thermomechanical analyzer (trade name "TMA8311" manufactured by Rigaku) as a measuring device. In the measurement of such a glass transition temperature, it is preferable to perform the measurement by scanning a range of 30 ° C. to 550 ° C. in a nitrogen atmosphere under a temperature increase rate of 5 ° C./min.

Further, such a polyimide preferably has a softening temperature of 250 to 550 ° C, more preferably 350 to 550 ° C, and still more preferably 360 to 510 ° C. When the softening temperature is lower than the lower limit, the heat resistance is lowered. For example, when a polyimide film is used as a substrate for a transparent electrode of a solar cell, a liquid crystal display device, or an organic EL display device, In the heating process, it tends to be difficult to sufficiently suppress the deterioration of the quality of the film (substrate) (such as occurrence of cracks). On the other hand, when the upper limit is exceeded, the heat of the polyamic acid is produced when the polyimide is produced. A sufficient solid phase polymerization reaction does not proceed simultaneously with the ring-closing condensation reaction, and when the film is formed, it tends to be a brittle film.

In addition, the softening temperature of such a polyimide can be measured as follows. That is, a film made of polyimide having a size of 5 mm in length, 5 mm in width and 0.013 mm (13 μm) in thickness was prepared as a measurement sample, and a thermomechanical analyzer (trade name “TMA8311” manufactured by Rigaku) was used as a measurement device. Under a nitrogen atmosphere, using a temperature rising rate of 5 ° C./min, a transparent quartz pin (tip diameter: 0.5 mm) is applied to the film under a temperature range of 30 ° C. to 550 ° C. under a pressure of 500 mN. Can be measured simultaneously with the glass transition temperature (Tg) (by the so-called penetration method). In such measurement, the softening temperature is calculated based on the measurement data in accordance with the method described in JIS K 7196 (1991).

In addition, the polyimide forming such a film preferably has a thermal decomposition temperature (Td) of 450 ° C. or higher, more preferably 480 to 600 ° C. If such a thermal decomposition temperature (Td) is less than the lower limit, sufficient heat resistance tends to be difficult to achieve, and if it exceeds the upper limit, it is difficult to produce a polyimide having such characteristics. There is a tendency. In addition, such a thermal decomposition temperature (Td) was measured using a TG / DTA220 thermogravimetric analyzer (manufactured by SII Nanotechnology Co., Ltd.) in a nitrogen atmosphere under a heating rate of 10 ° C./min. It can be determined by measuring the temperature at the intersection of the tangent lines drawn on the decomposition curve before and after thermal decomposition under the conditions of

Furthermore, the number average molecular weight (Mn) of such a polyimide is preferably 1,000 to 1,000,000, more preferably 10,000 to 500,000 in terms of polystyrene. If such a number average molecular weight is less than the lower limit, it is difficult to achieve sufficient heat resistance, it does not sufficiently precipitate from the polymerization solvent during production, and it tends to be difficult to obtain polyimide efficiently, When the upper limit is exceeded, the viscosity increases, and it takes a long time to dissolve or requires a large amount of solvent, which tends to make processing difficult.

The weight average molecular weight (Mw) of the polyimide forming such a film is preferably 1000 to 5000000 in terms of polystyrene. Moreover, as a lower limit of the numerical range of such a weight average molecular weight (Mw), it is more preferable that it is 5000, It is further more preferable that it is 10,000, It is especially preferable that it is 20000. Moreover, as an upper limit of the numerical range of a weight average molecular weight (Mw), it is more preferable that it is 5000000, It is further more preferable that it is 500,000, It is especially preferable that it is 100,000. If such a weight average molecular weight is less than the lower limit, it is difficult to achieve sufficient heat resistance, and does not sufficiently precipitate from the polymerization solvent during production, and it tends to be difficult to obtain polyimide efficiently, When the upper limit is exceeded, the viscosity increases, so that it takes a long time to dissolve or a large amount of solvent is required, which tends to make processing difficult.

Furthermore, the molecular weight distribution (Mw / Mn) of such polyimide is preferably 1.1 to 5.0, and more preferably 1.5 to 3.0. If the molecular weight distribution is less than the lower limit, it tends to be difficult to produce, while if it exceeds the upper limit, it tends to be difficult to obtain a uniform film. The molecular weight (Mw or Mn) and molecular weight distribution (Mw / Mn) of such a polyimide are measured by a gel permeation chromatography (GPC) measuring device (Degasser: DG-2080-54 manufactured by JASCO, Liquid pump: PU-2080 manufactured by JASCO, interface: LC-NetII / ADC manufactured by JASCO, column: GPC column KF-806M (x2) manufactured by Shodex, column oven: 860-CO manufactured by JASCO, RI detector : Data measured using RI-2031 manufactured by JASCO, column temperature 40 ° C., chloroform solvent (flow rate 1 mL / min.) Can be obtained by conversion with polystyrene.

Further, such a polyimide preferably has a linear expansion coefficient of 0 to 100 ppm / K, and more preferably 10 to 70 ppm / K. When such a linear expansion coefficient exceeds the upper limit, peeling tends to occur due to thermal history when combined with a metal or an inorganic material having a linear expansion coefficient range of 5 to 20 ppm / K. Moreover, when the linear expansion coefficient is less than the lower limit, the solubility and the film characteristics tend to be lowered.

As a method for measuring the linear expansion coefficient of such a polyimide, after forming a polyimide film having a size of 76 mm in length, 52 mm in width, and 13 μm in thickness, the film is vacuum-dried (at 120 ° C. for 1 hour) to form a nitrogen atmosphere. Using a dry film obtained by heat treatment at 200 ° C. for 1 hour as a measurement sample and using a thermomechanical analyzer (trade name “TMA8310” manufactured by Rigaku) as a measuring device, the sample is pulled in a nitrogen atmosphere. Using a mode (49 mN) and a temperature increase rate of 5 ° C./min, the change in the length of the sample in the longitudinal direction from 50 ° C. to 200 ° C. was measured, and 1 in the temperature range of 50 ° C. to 200 ° C. The value obtained by calculating the average value of the length change per ° C is adopted.

Furthermore, it is preferable that the polyimide in such a film can be dissolved in a low boiling point casting solvent. If it is the film which consists of such a polyimide, it also becomes possible to prepare more easily. The casting solvent mentioned here has a boiling point of 200 from the viewpoint of solubility, volatility, transpiration, removability, film formability, productivity, industrial availability, recyclability, presence of existing equipment, and price. It is preferred that the solvent be at most 0 ° C. (more preferably 20 to 150 ° C., still more preferably 30 to 120 ° C., particularly preferably 40 to 100 ° C., most preferably 60 ° C. to 100 ° C.). Moreover, as such a solvent having a boiling point of 200 ° C. or lower, a halogen-based solvent having a boiling point of 200 ° C. or lower is more preferable, and dichloromethane (methylene chloride), trichloromethane (chloroform), carbon tetrachloride, dichloroethane, trichloroethylene, tetrachloroethylene, Tetrachloroethane, chlorobenzene, and o-dichlorobenzene are more preferable, and dichloromethane (methylene chloride) and trichloromethane (chloroform) are particularly preferable. In addition, you may utilize such a casting solvent individually by 1 type or in combination of 2 or more types.

Further, such a polyimide film preferably has a sufficiently high transparency, and has a total light transmittance of 80% or more (more preferably 85% or more, particularly preferably 87% or more). More preferred. Moreover, as such a polyimide film, the thing whose haze (turbidity) is 5 or less (further preferably 4 or less, especially preferably 3 or less) is more preferable from a viewpoint that a thing with higher transparency is preferable. Furthermore, such a polyimide film is more preferably one having a yellowness (YI) of 10 or less (more preferably 8 or less, particularly preferably 6 or less) from the viewpoint that a film with higher transparency is preferable. Such total light transmittance, haze (turbidity), and yellowness (YI) can be easily achieved by appropriately selecting the type of polyimide. In addition, such a total light transmittance, haze (turbidity), and yellowness (YI) are measured by forming a polyimide film having a length of 76 mm, a width of 52 mm, and a thickness of 13 μm as a measurement sample. A value measured using a product name “Haze Meter NDH-5000” manufactured by Nippon Denshoku Industries Co., Ltd. is adopted as the apparatus.

The form of such a polyimide film is not particularly limited as long as it is in the form of a film, and can be appropriately designed into various shapes (disc shape, cylindrical shape (film processed into a cylindrical shape), etc.).

Furthermore, the thickness of the polyimide film of the present invention is not particularly limited, but is preferably 1 to 500 μm, more preferably 10 to 200 μm. If the thickness is less than the lower limit, the strength tends to be reduced and handling tends to be difficult.On the other hand, if the upper limit is exceeded, multiple coatings may be required or processing may be complicated. Tend to occur.

In addition, when the polyimide film of the present invention is used in a display device, it has the effect of suppressing the decrease in contrast and improving the viewing angle. Therefore, the thickness direction retardation (Rth) measured at a wavelength of 590 nm has a thickness of 10 μm. It is preferable that the film has a thickness of −1000 to 1000 nm (more preferably −500 to 500 nm, still more preferably −250 to 250 nm). In addition, the “thickness direction retardation (Rth)” of the polyimide film of the present invention is the refractive index of the polyimide film measured as described below using the product name “AxoScan” manufactured by AXOMETRICS as a measuring device. 589 nm) is input to the measuring device, and then the retardation in the thickness direction of the polyimide film is measured using light with a wavelength of 590 nm under the conditions of temperature: 25 ° C. and humidity: 40%. Based on the measured value of retardation (measured value by automatic measurement (automatic calculation) of the measuring device), it can be obtained by converting into a retardation value per 10 μm of film thickness. The size of the polyimide film of the measurement sample is not particularly limited as long as it is larger than the photometric part (diameter: about 1 cm) of the stage of the measuring instrument. However, the length is 76 mm, the width is 52 mm, and the thickness is 13 μm. Is preferred.

In addition, the value of “refractive index of the polyimide film (589 nm)” used for the measurement of retardation (Rth) in the thickness direction is an unstretched film made of the same type of polyimide as the polyimide forming the film to be measured for retardation. After forming the film, the unstretched film is used as a measurement sample (in the case where the film to be measured is an unstretched film, the film can be used as it is as a measurement sample). Using a refractive index measuring device (trade name “NAR-1T SOLID” manufactured by Atago Co., Ltd.) as a measuring device, using a light source of 589 nm and a temperature condition of 23 ° C., the in-plane direction (what is the thickness direction)? It can be obtained by measuring the refractive index for light of 589 nm in the vertical direction). Since the measurement sample is unstretched, the refractive index in the in-plane direction of the film is constant in any direction in the plane, and by measuring the refractive index, the intrinsic refractive index of the polyimide can be measured. (Nx = Ny when the refractive index in the in-plane delay axis direction is Nx and the in-plane refractive index perpendicular to the delay axis direction is Ny because the measurement sample is not stretched). Thus, the intrinsic refractive index (589 nm) of polyimide is measured using an unstretched film, and the obtained measurement value is used for the measurement of retardation (Rth) in the thickness direction described above. Here, the size of the polyimide film of the measurement sample is not particularly limited as long as it is a size that can be used in the refractive index measurement device, and may be 1 cm square (1 cm in length and width) and 13 μm in thickness.

Such a polyimide film of the present invention has a sufficiently high tensile strength and a sufficiently high value of elongation at break in a more balanced manner (with higher toughness based on these). ), Since the mechanical strength becomes higher, for example, films for flexible wiring boards, heat-resistant insulating tapes, wire enamels, semiconductor protective coating agents, liquid crystal alignment films, transparent conductive films for organic EL, displays Substrate materials (TFT substrate, display substrate such as transparent electrode substrate (eg, transparent conductive film for organic EL)), organic EL lighting film, flexible substrate film, flexible organic EL substrate film, flexible transparent conductive film, Transparent conductive film for organic thin film solar cell, Transparent conductive film for dye-sensitized solar cell, Lexical Bull gas barrier film, a substrate material for a touch panel (touch panel film, etc.), a front film for flexible displays, back film or the like for a flexible display, is particularly useful. In addition, since the polyimide film of the present invention has higher toughness and higher mechanical strength as described above, it is used for the above-described purposes (in particular, display substrate materials (TFT substrates). When used for display substrates such as transparent electrode substrates) and substrate materials for touch panels (films for touch panels, etc.), the final product (for example, an organic EL element, etc.) is derived from its mechanical strength. ) Can be improved sufficiently.

The method for producing such a polyimide film is not particularly limited, and in order to produce a film made of polyimide containing the above repeating unit, the following general formula (3):

Wherein ^{^{(3), R 1, R}} 2, R 3, n are as defined ^{^{^{R 1, R 2, R 3}}} , n in the general formula (1). ]
A tetracarboxylic dianhydride represented by the following general formulas (301) to (302):

The content of the repeating unit represented by the general formula (1) in the obtained polyimide is 30 mol% with respect to all the repeating units. A polyimide film is produced by appropriately adopting a known method (for example, a method for producing a polyimide described in International Publication No. 2011/099518, International Publication No. 2014/034760) and reacting them. The method can be adopted.

As a method for producing such a polyimide film, for example, in the presence of a polymerization solvent, a tetracarboxylic dianhydride represented by the above general formula (3) and the above general formulas (301) to (301) 302) an aromatic diamine containing at least one of the diamine compounds represented by (at least one of the diamine compounds represented by the general formulas (301) to (302) depending on the design of the target polyimide). The diamine compound may contain only one kind, or at least one of the diamine compounds represented by the general formulas (301) to (302) may be mixed with another diamine compound. And the following general formula (4):

Wherein ^{^{(4), R 1, R}} 2, R 3, n is the formula ^{^{(1) R 1, R 2}} , R 3, n and are as defined in (also Formula those its preferred ( ^{^{^{1) R 1, R 2,}}} R 3, the same meaning as n ^{in.), R 10} has the same meaning as ^{R 10} in the general formula (1) (formula others its preferred (1) Synonymous with R ^{10 in the} middle). ]
30 mol% or more (more preferably 40 mol% or more, more preferably 50 mol% or more, particularly preferably 70 mol% or more, most preferably 90 mol% or more) with respect to all repeating units. ) After forming the contained polyamic acid, a solution of the polyamic acid containing the polyamic acid is applied onto the surface of a substrate (for example, a glass substrate), and then the polyamic acid is imidized to form the group. The repeating unit represented by the general formula (1) laminated on the material is 30 mol% or more (more preferably 40 mol% or more, still more preferably 50 mol% or more, particularly preferably based on all repeating units). Is a method of forming a film comprising polyimide containing 70 mol% or more, most preferably 90 mol% or more (hereinafter sometimes simply referred to as “method (A)”). It can be suitably used.

Regarding the tetracarboxylic dianhydride represented by the general formula (3), R ¹ , R ² and R ³ in the formula (3) are each independently a hydrogen atom or an alkyl having 1 to 10 carbon atoms. 1 is selected from the group consisting of a group and a fluorine atom, and n is an integer of 0 to 12. ^R ^1,

R

^{2, R} 3, n in the general formula (3) is similar to the ^R ^1,

R

^{2, R} 3, n in the general formula (1), the suitable The thing is the same as that of the suitable thing of R < ¹ >, R < ² >, R < ³ >, n in the said General formula (1). The method for producing the tetracarboxylic dianhydride represented by the general formula (3) is not particularly limited, and a known method can be appropriately employed. For example, International Publication No. 20111 / You may employ | adopt the method as described in 099517, the method as described in international publication 2011/099518, etc.

In addition, as the tetracarboxylic dianhydride represented by the general formula (3), the following general formula (5) can be used from the viewpoint of adjusting film properties, thermophysical properties, mechanical properties, optical properties, and electrical properties. ):

Wherein ^{^{(5), R 1, R}} 2, R 3, n has the same definition as ^{^{^{R 1, R 2, R 3}}} , n in the general formula (3). ]
Compound (A) represented by the following general formula (6):

Wherein ^{^{(6), R 1, R}} 2, R 3, n are as defined ^{^{^{R 1, R 2, R 3}}} , n in the general formula (3). ]
The compound (B) containing at least one of the compounds (B) and the total amount of the compounds (A) and (B) is preferably 90 mol% or more. In the compound (A) represented by the general formula (5), two norbornane groups are in trans configuration, and the carbonyl group of cycloalkanone is in the endo configuration with respect to each of the two norbornane groups. It is an isomer of tetracarboxylic dianhydride represented by the general formula (3). Further, the compound (B) represented by the general formula (6) has a configuration in which two norbornane groups are in cis configuration and the carbonyl group of cycloalkanone is endo in each of the two norbornane groups. It is an isomer of tetracarboxylic dianhydride represented by the above general formula (3). In addition, the manufacturing method of the tetracarboxylic dianhydride containing such an isomer in the above ratio is not particularly limited, and a known method can be appropriately employed. For example, it is described in International Publication No. 2014/034760. These methods may be appropriately adopted.

Moreover, as aromatic diamine made to react with the tetracarboxylic dianhydride represented by General formula (3), in the polyimide obtained, the repeating unit represented by the general formula (1) is based on all repeating units. 30 mol% or more (more preferably 40 mol% or more, more preferably 50 mol% or more, particularly preferably 70 mol% or more, most preferably 90 mol% or more) The diamine compound (1,4-bis (4-aminophenoxy) benzene) represented by (301) and the diamine compound (4,4′-bis (4-aminophenoxy) represented by the general formula (302) It is necessary to use at least one of (biphenyl). From such a viewpoint, the content of at least one of the diamine compounds represented by the general formulas (301) to (302) is 30 mol% or more (more preferably 40 mol% or more, and still more preferably 50 mol). % Or more, particularly preferably 70 mol% or more, most preferably 90 mol% or more). As the diamine compounds represented by the general formulas (301) to (302), commercially available products may be used.

Furthermore, in the method for producing such a polyimide film, when the repeating unit represented by the general formula (2) is contained as another repeating unit, the tetracarboxylic acid represented by the general formula (3) is used. As the aromatic diamine to be reacted with the acid dianhydride, it is preferable to use a mixture in which at least one of the diamine compounds represented by the general formulas (301) to (302) is mixed with another diamine compound. .

Such other diamine compound is not particularly limited, and a known aromatic diamine compound used for the production of polyimide can be appropriately used. Among these other diamine compounds, from the viewpoint of heat resistance and transparency, the formula: H ₂ N—R ^a —NH ₂ [wherein R ^a is an aryl group having 6 to 40 carbon atoms (however, the above general formula) (Excluding the groups represented by formulas (101) to (102)). ] The diamine compound represented by this is more preferable. Incidentally, R ^a in the formula of such other diamine compound has the same meaning as R ^a in the general formula (2) (The same applies to those that preferred.). Examples of such other diamine compounds include 4,4′-diaminobenzanilide, 4,4 ″ -diamino-p-terphenyl, and 4-aminobenzoic acid 4- Aminophenyl is more preferred, and 4,4′-diaminobenzanilide is particularly preferred. Such other diamine compounds can be used singly or in combination of two or more. Moreover, you may utilize suitably a commercially available thing as such other aromatic diamine.

The polymerization solvent used in the method (A) includes tetracarboxylic dianhydride represented by the general formula (3) and the aromatic diamine (represented by the general formulas (301) to (302)). (A mixture of at least one of the diamine compounds represented by the general formulas (301) to (302) and another diamine compound). )) And an organic solvent capable of dissolving both.

Examples of such organic solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, propylene carbonate, tetramethylurea, 1,3- Aprotic polar solvents such as dimethyl-2-imidazolidinone, hexamethylphosphoric triamide, pyridine; phenol solvents such as m-cresol, xylenol, phenol, halogenated phenol; tetrahydrofuran, dioxane, cellosolve, glyme And ether solvents such as diglyme; aromatic solvents such as benzene, toluene and xylene; ketone solvents such as cyclopentanone and cyclohexanone; and nitrile solvents such as acetonitrile and benzonitrile. Such polymerization solvents (organic solvents) may be used alone or in combination of two or more.

Moreover, in the said method (A), the usage-amount of the tetracarboxylic dianhydride represented by the said General formula (3) and the said aromatic diamine is with respect to 1 equivalent of amino groups which the said aromatic diamine has. The acid anhydride group of the tetracarboxylic dianhydride represented by the general formula (3) is preferably 0.2 to 2 equivalents, and more preferably 0.8 to 1.2 equivalents. When such a use ratio is less than the lower limit, the polymerization reaction does not proceed efficiently, and a high molecular weight polyamic acid tends not to be obtained. On the other hand, when the upper limit is exceeded, a high molecular weight polyamic acid is obtained as described above. It tends to be impossible.

Furthermore, in the said method (A), as the usage-amount of the said polymerization solvent (organic solvent), the total amount of the tetracarboxylic dianhydride represented by the said General formula (3) and the said aromatic diamine is a reaction solution. The amount is preferably 0.1 to 50% by mass (more preferably 10 to 30% by mass) with respect to the total amount. If the amount of such an organic solvent used is less than the lower limit, it tends to be impossible to obtain polyamic acid efficiently. On the other hand, if it exceeds the upper limit, stirring tends to be difficult due to the increase in viscosity.

Moreover, in the said method (A), it does not restrict | limit especially as a method with which the tetracarboxylic dianhydride represented by the said General formula (3) and the said aromatic diamine are made, Tetracarboxylic dianhydride and A known method capable of performing the reaction of the aromatic diamine can be appropriately employed. For example, the aromatic diamine is dissolved in a solvent under an inert atmosphere such as nitrogen, helium or argon under atmospheric pressure conditions. Thereafter, a method may be employed in which the tetracarboxylic dianhydride represented by the above general formula (3) is added and then reacted for 10 to 48 hours. In such a reaction, the temperature condition is preferably about −20 to 100 ° C. If the reaction time or reaction temperature is less than the lower limit, it tends to be difficult to cause sufficient reaction. On the other hand, if the upper limit is exceeded, the probability of mixing a substance (such as oxygen) that degrades the polymer increases and the molecular weight increases. It tends to decrease.

Further, In said method (A), relates to the polyamic acid formed as an intermediate, ^R 1 in the general formula (4) ^in,

R

^{2, R} 3, n is ^R 1 in the general formula (1), is R ^2, ^R 3, same meanings as n, is synonymous with the preferred ones also for the general formula (1) ^R ^1,

R

^{2, R} 3, n. Further, R ¹⁰ in the general formula (4) has the same meaning as R ¹⁰ in the general formula (1), it is also the same as the preferable examples. Thus, R ¹⁰ in the general formula (4) is one group selected from the groups represented by the general formulas (101) to (102).

Further, in the method (A), the polyamic acid formed as an intermediate preferably has an intrinsic viscosity [η] of 0.05 to 3.0 dL / g, preferably 0.1 to 2.0 dL. / G is more preferable. When the intrinsic viscosity [η] is smaller than 0.05 dL / g, when a film-like polyimide is produced using the intrinsic viscosity [η], the resulting film tends to be brittle, while 3.0 dL / g is reduced. When it exceeds, the viscosity is too high and the processability is lowered, and for example, when a film is produced, it is difficult to obtain a uniform film.

Further, the intrinsic viscosity [η] of such polyamic acid can be measured as follows. That is, first, N, N-dimethylacetamide is used as a solvent, and the polyamic acid is dissolved in the N, N-dimethylacetamide so as to have a concentration of 0.5 g / dL, and a measurement sample (solution) is obtained. obtain. Next, using the measurement sample, the viscosity of the measurement sample is measured using a kinematic viscometer under a temperature condition of 30 ° C., and the obtained value is adopted as the intrinsic viscosity [η]. In addition, as such a kinematic viscometer, an automatic viscosity measuring device (trade name “VMC-252”) manufactured by Koiso Co., Ltd. is used.

Moreover, it does not restrict | limit especially as a base material used for the said method (A), According to the shape etc. of the film which consists of the target polyimide, the base material (it can use for the formation of a film) For example, a glass plate or a metal plate) can be used as appropriate.

Furthermore, in the method (A), the method of applying the polyamic acid solution on the substrate is not particularly limited, and examples thereof include spin coating, spray coating, dip coating, dropping, and gravure printing. In addition, known methods such as a screen printing method, a relief printing method, a die coating method, a curtain coating method, and an ink jet method can be appropriately employed.

In the method (A), the method for imidizing the polyamic acid is not particularly limited, and may be any method that can imidize polyamic acid, and is not particularly limited, and is a known method (International Publication No. 2011/099518, The imidization method and the like described in International Publication No. 2014/034760 can be appropriately employed. As a method for imidizing such polyamic acid, for example, polyamic acid containing a repeating unit represented by the above general formula (4) is used at 60 to 400 ° C. (more preferably 60 to 370 ° C., still more preferably 150 ° C. It is preferable to employ a method of imidizing by performing a heat treatment under a temperature condition of ˜360 ° C. or a method of imidizing using a so-called “imidizing agent”.

In such a method (A), the polymerization solvent (organic solvent) is isolated without isolating the polyamic acid containing the repeating unit represented by the general formula (4) before imidating the polyamic acid. ), The tetracarboxylic dianhydride represented by the general formula (3) is reacted with the aromatic diamine, and the resulting reaction solution (the repeating unit represented by the general formula (4) is represented by The reaction solution containing the polyamic acid contained) is used as it is, and after applying the reaction solution on a substrate, the solvent is removed by drying treatment, and then imidization is performed by applying the heat treatment. May be. The temperature condition in such a drying method is preferably 0 to 180 ° C., more preferably 60 to 150 ° C. In addition, you may isolate and utilize the polyamic acid containing the repeating unit represented by the said General formula (4) from the said reaction liquid, In that case, it does not restrict | limit especially as a polyamic acid isolation method, Polyamide A known method capable of isolating the acid can be appropriately employed. For example, a method of isolating the acid as a reprecipitate may be employed.

By such a method (A), the polyimide film of the present invention can be obtained while being laminated on the substrate. In the case where the polyimide film thus obtained is peeled from the substrate and collected, the peeling method is not particularly limited, and a known method can be appropriately employed. For example, high-temperature water (for example, A method of peeling the polyimide film from the base material by immersing a laminate in which the polyimide film is laminated on the base material in water at 80 ° C. or higher may be employed.

[Organic electroluminescence device]
The organic electroluminescent element of the present invention comprises the polyimide film of the present invention.

As such an organic electroluminescence element, other configurations are not particularly limited except that, for example, the polyimide film of the present invention is provided, and those having a known configuration can be appropriately used. In addition, the organic electroluminescence device is not particularly limited, but for example, from the viewpoint of improving the yield during production, a device provided with the polyimide film of the present invention as a substrate for laminating transparent electrodes is preferable. .

Hereinafter, an embodiment of an organic EL element that can be suitably used as the organic electroluminescence element (organic EL element) of the present invention will be briefly described with reference to the drawings. In the following description and drawings, the same or corresponding elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

FIG. 1 is a schematic longitudinal sectional view of a preferred embodiment of the organic electroluminescence element (organic EL element) of the present invention. The organic EL element 1 of the embodiment shown in FIG. 1 includes a polyimide film 11, a gas barrier layer 12, a transparent electrode layer 13, an organic layer 14, and a metal electrode layer 15.

The polyimide film 11 in such an organic EL element is made of the polyimide film of the present invention. In the present embodiment, such a polyimide film 11 is used as a substrate (substrate for transparent electrode lamination) of an organic EL element.

In addition, the gas barrier layer 12 is a layer that is preferably used to suppress the permeation of gas into the element by increasing the permeation preventing performance of gas (including water vapor). Such a gas barrier layer 12 is not particularly limited, but for example, a layer made of an inorganic material such as SiN, SiO ₂ , SiC, SiO _x N _y , TiO ₂ , or Al ₂ O ₃ , an ultrathin plate glass, or the like is preferably used. can do. Such a gas barrier layer 12 may be laminated by appropriately arranging (forming) a known gas barrier layer on the polyimide film 11.

The thickness of the gas barrier layer 12 is not particularly limited, but is preferably in the range of 0.01 to 5000 μm, and more preferably in the range of 0.1 to 100 μm. If the thickness is less than the lower limit, sufficient gas barrier properties tend not to be obtained. On the other hand, if the thickness exceeds the upper limit, the thickness tends to be increased and characteristics such as flexibility and flexibility tend to disappear.

The transparent electrode layer 13 is a layer used as a transparent electrode of the organic EL element. The material of the transparent electrode layer 13 is not particularly limited as long as it can be used for the transparent electrode of the organic EL element. For example, indium oxide, zinc oxide, tin oxide, and a composite thereof can be used. Some indium tin oxide (ITO), gold, platinum, silver and copper are used. Among these, ITO is preferable from the viewpoint of balance between transparency and conductivity.

The thickness of the transparent electrode layer 13 is preferably in the range of 20 to 500 nm. If the thickness is less than the lower limit, the conductivity tends to be insufficient. On the other hand, if the thickness exceeds the upper limit, the transparency is insufficient and the emitted EL light tends not to be taken out sufficiently.

A so-called thin film transistor (TFT) layer may be formed between the gas barrier layer 12 and the transparent electrode layer 13. By providing the TFT layer in this manner, a device (TFT element) having a transparent electrode connected to the TFT can be formed. There is no particular limitation on the material (oxide semiconductor, amorphous silicon, polysilicon, organic transistor, etc.) and configuration of such a TFT layer, and the TFT layer can be appropriately designed based on a known TFT configuration. Moreover, when a TFT layer is provided on a laminate of the polyimide film 11 and the gas barrier layer 12, these laminates can be used as a so-called TFT substrate. In addition, it does not restrict | limit especially as a manufacturing method of such a TFT layer, A well-known method can be employ | adopted suitably, for example, low temperature polysilicon method, high temperature polysilicon method, amorphous silicon method, oxide semiconductor method etc. A manufacturing method may be adopted.

The organic layer 14 is not particularly limited as long as it can be used for forming an organic EL element, and the structure thereof is not particularly limited, and an organic layer that can be used for an organic layer of a known organic EL element is appropriately used. Can do. Further, the configuration of the organic layer 14 is not particularly limited, and a known configuration can be appropriately adopted. For example, a laminate including a hole transport layer, a light emitting layer, and an electron transport layer may be used as the organic layer.

As a material for such a hole transport layer, a known material capable of forming a hole transport layer can be appropriately used. For example, naphthyldiamine (α-NPD), triphenylamine, triphenyldiamine Derivatives (TPD), derivatives such as benzidine, pyrazoline, styrylamine, hydrazone, triphenylmethane, carbazole, and the like can be used.

The light emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode layer and the like. The material of the light emitting layer is not particularly limited, and the light emitting layer of the organic EL element is formed. For example, a trisphenylpyridinatoiridium (III) complex (Ir (ppy) ₃ ) may be used in 4,4′-N, N′-dicarbazole-biphenyl (CBP). Doped material, 8-hydroxyquinoline aluminum (Alq ₃ , green, small molecule), bis- (8-hydroxy) quinaldine aluminum phenoxide (Alq ′ ₂ OPh, blue, small molecule), 5, 10, 15, 20- tetraphenyl-21H, 23H-porphine (TPP, red, small molecule) poly (9,9-dioctylfluorene-2,7-diyl) (PFO, blue, polymer), poly [2-methoxy-5- (2′-ethylhexyloxy) -1,4- (1-cyanvinylene) phenylene] ( A known material that emits light when a voltage is applied, such as a material made of a fluorescent organic solid such as MEH-CN-PPV, red, or a polymer) or anthracene, can be used as appropriate.

Furthermore, the material for the electron transport layer is not particularly limited, and a known material capable of forming the electron transport layer can be used as appropriate. For example, an aluminum quinolinol complex (Alq), a phenanthroline derivative, an oxadi An azole derivative, a triazole derivative, a phenylquinoxaline derivative, or a silole derivative can be used.

In the case where the organic layer 14 is a laminate composed of a hole transport layer, a light emitting layer, and an electron transport layer, the thicknesses of the hole transport layer, the light emitting layer, and the electron transport layer are not particularly limited. The range is preferably 50 nm (hole transport layer), 5 to 200 nm (light emitting layer), and 5 to 200 nm (electron transport layer). The total thickness of the organic layer 14 is preferably in the range of 20 to 600 nm.

The metal electrode layer 15 is an electrode made of metal. As a material of such a metal electrode, a substance having a small work function can be appropriately used, and is not particularly limited, and examples thereof include aluminum, MgAg, MgIn, and AlLi. The thickness of the metal electrode layer 15 is preferably in the range of 50 to 500 nm. If the thickness is less than the lower limit, the conductivity tends to decrease. On the other hand, if the thickness exceeds the upper limit, peeling tends to occur or cracks tend to occur.

In addition, although the manufacturing method in particular of such an organic EL element is not restrict | limited, For example, after preparing the polyimide film of the said invention, the said gas barrier layer, the said transparent electrode, the said on the surface of this polyimide film You may employ | adopt the method of manufacturing by laminating | stacking an organic layer and the said metal electrode sequentially.

A method for laminating the gas barrier layer 12 on the surface of the polyimide film 11 is not particularly limited, and a known method such as a vapor deposition method or a sputtering method can be appropriately employed. From this point of view, it is preferable to employ a sputtering method. Moreover, as a method of laminating the transparent electrode layer 13 on the surface of the gas barrier layer 12, a known method such as a vapor deposition method or a sputtering method can be appropriately employed, and among them, from the viewpoint of forming a dense film, It is preferable to employ a sputter method.

Further, the method for laminating the organic layer 14 on the surface of the transparent electrode layer 13 is not particularly limited. For example, as described above, the organic layer is a laminate composed of a hole transport layer, a light emitting layer, and an electron transport layer. In this case, these layers may be sequentially laminated on the transparent electrode layer 13. In addition, it does not restrict | limit especially as a method of laminating | stacking each layer in such an organic layer 14, A well-known method can be utilized suitably, For example, a vapor deposition method, a sputtering method, the apply | coating method etc. are employable. . Among these methods, it is preferable to employ a vapor deposition method from the viewpoint of sufficiently preventing decomposition, deterioration and modification of the organic layer.

Furthermore, the method for laminating the metal electrode layer 15 on the organic layer 14 is not particularly limited, and a known method can be appropriately used. For example, a vapor deposition method, a sputtering method, or the like can be employed. Among these methods, it is preferable to employ a vapor deposition method from the viewpoint of sufficiently preventing decomposition, deterioration and modification of the organic layer 14 formed previously.

In addition, by manufacturing the organic EL element in this way, an organic EL element using the polyimide film 11 as a substrate for supporting a so-called element portion can be formed, and thus the yield is derived from its mechanical strength. It is possible to improve the flexibility and to make the flexibility sufficiently high.

As mentioned above, although one suitable embodiment of the organic EL element of the present invention was described, the organic EL element of the present invention is not limited to the above-mentioned embodiment. For example, in the above embodiment, the organic layer 14 is composed of a laminate of a hole transport layer, a light emitting layer, and an electron transport layer, but the form of the organic layer is not particularly limited, and is publicly known. The structure of the organic layer can be adopted as appropriate, for example, an organic layer composed of a laminate of a hole injection layer and a light emitting layer; an organic layer composed of a laminate of a light emitting layer and an electron injection layer; An organic layer composed of a laminate of a light emitting layer and an electron injection layer; or an organic layer composed of a laminate of a buffer layer, a hole transport layer and an electron transport layer can be used. In addition, the material of each layer in the other form of such an organic layer is not particularly limited, and a known material can be appropriately used. For example, a perylene derivative or the like may be used as the material for the electron injection layer, a triphenylamine derivative or the like may be used as the material for the hole injection layer, and copper phthalocyanine, PEDOT or the like may be used as the material for the anode buffer layer. May be used. Moreover, even if it is a layer which is not arrange | positioned in the said embodiment, as long as it is a layer which can be utilized for an organic EL element, you may arrange | position suitably, for example, the charge injection to the organic layer 14, or a hole From the viewpoint of facilitating the injection, a highly active alkaline earth such as a metal fluoride such as lithium fluoride (LiF) or Li ₂ O ₃ , Ca, Ba, or Cs is formed on the transparent electrode layer 13 or the organic layer 14. A layer made of a similar metal, an organic insulating material, or the like may be provided.

[Transparent conductive laminate]
The transparent conductive laminate of the present invention comprises the polyimide film of the present invention and a thin film made of a conductive material laminated on the polyimide film.

Thus, the transparent conductive laminate of the present invention is formed by laminating a thin film made of the conductive material on the polyimide film of the present invention. In such a transparent conductive laminate, the total light transmittance is preferably 78% or more (more preferably 80% or more, still more preferably 82% or more) from the viewpoint of being transparent. Such total light transmittance can be easily achieved by appropriately selecting the type of the polyimide film according to the present invention and the type of the conductive material. As such total light transmittance, a value measured using a trade name “Haze Meter NDH-5000” manufactured by Nippon Denshoku Industries Co., Ltd. can be used as a measuring device.

The conductive material is not particularly limited as long as it is a conductive material, and a known conductive material that can be used for a solar cell, an organic EL element, a transparent electrode of a liquid crystal display device, or the like. Can be used as appropriate, for example, metals such as gold, silver, chromium, copper, tungsten; metal oxides such as tin, indium, zinc, cadmium, titanium, and other elements (eg, tin, tellurium, cadmium, molybdenum) , Tungsten, fluorine, zinc, germanium, aluminum, and the like (for example, Indium Tin Oxide (ITO (In ₂ O ₃ : Sn)), Fluorine doped Tin Oxide (FTO (SnO ₂ : F))), Aluminum doped Zinc Oxide (AZO (ZnO: Al)), Indium d ped Zinc Oxide (IZO (ZnO: I)), Germanium doped Zinc Oxide (GZO (ZnO: Ge)), etc.); and the like. Further, among these conductive materials, it is preferable to use ITO (particularly preferably, ITO containing 3 to 15% by mass of tin) because transparency and conductivity can be exhibited at a higher level in a balanced manner. .

The film thickness of such a thin film made of a conductive material (conductive thin film) can be appropriately changed depending on the application and is not particularly limited, but is 1 to 2000 nm. It is preferably 10 nm to 1000 nm, more preferably 20 nm to 500 nm, and particularly preferably 20 nm to 200 nm. If the thickness of such a conductive thin film is less than the lower limit, the surface resistance value is not sufficiently low, and the photoelectric conversion efficiency tends to decrease when used in a solar cell. There is a tendency that the production efficiency decreases due to a decrease in film formation time or a long film formation time.

A method of laminating a thin film made of such a conductive material on the polyimide film of the present invention is not particularly limited, and a known method can be appropriately used. For example, a sputtering method on the polyimide film, A method of laminating the thin film on the polyimide film by forming a thin film of the conductive material by a vapor deposition method such as a vacuum deposition method, an ion plating method, or a plasma CVD method may be employed. As described above, when laminating the thin film on the polyimide film, a gas barrier film is previously formed on the polyimide film, and the thin film is laminated on the polyimide film via the gas barrier film. May be. Further, such a gas barrier film is not particularly limited, and a known film that can be used for a solar cell, an organic EL element, a transparent electrode of a liquid crystal display device, or the like can be appropriately used, and a formation method thereof is also a known method. Can be used as appropriate.

In such a transparent conductive laminate of the present invention, since the polyimide film has higher toughness, for example, a transparent electrode of a solar cell, a display device (organic EL display device, liquid crystal display device, etc.) It is particularly useful for transparent electrodes and the like, and enables the yield of those final products to be more sufficiently improved.

[Touch panel, solar cell, display device]
The touch panel, solar cell, and display device of the present invention each include the transparent conductive laminate of the present invention.

The “display device” here is not particularly limited as long as the transparent conductive laminate can be used, and examples thereof include a liquid crystal display device and an organic EL display device. Moreover, as such a touch panel, a solar cell, and a display device, other configurations are not particularly limited, except that each of the touch panel, the solar cell, and the display device includes the transparent conductive laminate of the present invention. Can be adopted as appropriate. As such a configuration, for example, a configuration in which a touch panel includes a transparent electrode and another transparent electrode arranged with a gap interposed therebetween, and a solar cell includes a transparent electrode, a semiconductor layer, and a conductive layer for a counter electrode. The organic EL display device includes a transparent electrode, an organic layer, and a conductive layer for a counter electrode, and the liquid crystal display device includes a transparent electrode, a liquid crystal layer, and a conductive layer for a counter electrode. The structure which includes is mentioned. Moreover, it does not restrict | limit especially as a material of each layer, such as an organic layer, a liquid crystal layer, and a semiconductor layer, A well-known material can be utilized suitably. In the touch panel, solar cell, and display device of the present invention, it is preferable that the transparent conductive laminate of the present invention is used as the transparent electrode. Thus, by using the transparent conductive laminate of the present invention as the transparent electrode, a high temperature that is normally employed in the manufacturing process of touch panels, solar cells, and display devices (liquid crystal display devices and organic EL display devices). Even if it is exposed to the conditions, the transparent electrode layer (thin film made of a conductive material) is sufficiently suppressed from cracking, etc., so that it produces high quality touch panels, solar cells, and display devices with high yield. It becomes possible to do.

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

First, the chemical formulas of aromatic diamines used in Examples and Comparative Examples and the abbreviations of the compounds are shown below.

Next, a method for evaluating the characteristics of the polyimide film and the like obtained in each example and each comparative example will be described.

<Identification of molecular structure>
Identification of the molecular structure of the compound obtained in each Example and each Comparative Example was performed by IR measurement using an IR measuring device (trade name: FT / IR-4100, manufactured by JASCO Corporation).

<Measurement of intrinsic viscosity [η]>
As described above, the intrinsic viscosity [η] value (unit: dL / g) of the polyamic acid obtained as an intermediate in each Example and each Comparative Example is an automatic viscosity measuring device (trade name “ VMC-252 ") and a measurement sample with a concentration of 0.5 g / dL using N, N-dimethylacetamide as a solvent, and measurement at a temperature of 30 ° C.

<Measurement of tensile strength and elongation at break>
In each example and each comparative example, the tensile strength (unit: MPa) and elongation at break (unit:%) of the polyimide film (thickness: 13 μm) were measured as follows. That is, first, a product name “Super Dumbbell Cutter (Model: SDMK-1000-D, JIS K7139) manufactured by Dumbbell Co., Ltd. is used for the SD type lever type sample cutter (Dubell Co., Ltd. (Model SDL-200)). (Compliant with A22 standard of 2009)), the size of the polyimide film is as follows: total length: 75 mm, distance between tab portions: 57 mm, parallel portion length: 30 mm, shoulder radius: 30 mm, Width of end part: 10mm, width of central parallel part: 5mm, thickness: cut to 13μm, dumbbell-shaped test piece (except for JIS K7139 type A22 (scale test piece except for thickness 13μm)) (According to the standard) was prepared as a measurement sample. Next, using a Tensilon type universal testing machine (for example, model number “UCT-10T” manufactured by A & D Co., Ltd.), the width of the measurement sample is 57 mm, and the width of the grip portion is 10 mm (end The tensile strength and breaking elongation values are obtained by performing a tensile test by pulling the measurement sample under the conditions of full load of load: 0.05 kN, test speed: 300 mm / min. It was. Such a test was a test based on JIS K7162 (issued in 1994). Further, the value (%) of the elongation at break is the distance between the tab portions of the sample before the start of the tensile test (= the width between the gripping tools: 57 mm) L ₀ , and the distance between the tab portions of the sample until the sample breaks in the tensile test ( The width between the gripping tools when broken: 57 mm + α), where L is the following formula:
[Elongation at break (%)] = {(L−L ₀ ) / L ₀ } × 100
Was calculated.

<Measurement of glass transition temperature (Tg)>
The value (unit: ° C.) of the glass transition temperature (Tg) of the compound (compound that forms a film) obtained in each example and each comparative example is the polyimide film produced in each example and each comparative example. , Using a thermomechanical analyzer (trade name “TMA8311” manufactured by Rigaku) as a measuring device, adopting the same method (same conditions) as the following softening temperature measurement, and simultaneously measuring the softening temperature It was measured.

<Measurement of softening temperature>
The value (unit: ° C.) of the softening temperature (softening point) of the compounds (compounds forming the film) obtained in each Example and each Comparative Example is determined using the polyimide film produced in each Example and each Comparative Example. , Using a thermomechanical analyzer (trade name “TMA8311” manufactured by Rigaku) as a measuring device under a nitrogen atmosphere, at a temperature rising rate of 5 ° C./min, and in a temperature range (scanning temperature) of 30 ° C. to 550 ° C. The film was measured by inserting a transparent quartz pin (tip diameter: 0.5 mm) into the film at a pressure of 500 mN (measurement by a so-called penetration method). In such measurement, the softening temperature was calculated based on the measurement data in accordance with the method described in JIS K7196 (1991) except that the measurement sample was used.

<Measurement of 5% weight loss temperature (Td 5%)>
The value (unit: ° C.) of 5% weight loss temperature (Td 5%) of the compound obtained in each example, etc. was determined using a thermogravimetric analyzer (SII) using the polyimide film produced in each example and each comparative example. “TG / DTA220” manufactured by I Nano Technology Co., Ltd.), the scanning temperature was set to 30 ° C. to 550 ° C., and nitrogen gas was allowed to flow in a nitrogen atmosphere at 10 ° C./min. The temperature was determined by measuring the temperature at which the weight of the sample used was reduced by 5%.

<Measurement of total light transmittance, haze (turbidity) and yellowness (YI)>
The value of the total light transmittance (unit:%), haze (turbidity: HAZE), and yellowness (YI) were measured by Nippon Denshoku Industries, Ltd. using the polyimide film produced in each example and each comparative example. It was determined by carrying out measurement in accordance with JIS K7361-1 (issued in 1997) using a trade name “Haze Meter NDH-5000” manufactured by Co., Ltd.

<Measurement of refractive index>
The refractive index of the polyimide film produced in each example and each comparative example (refractive index for light of 589 nm) is the same as the method employed in each example and each comparative example (unstretched film). A 1 cm square (1 cm length and width 1 cm) film having a thickness of 13 μm was cut out and used as a measurement sample. The refractive index (inherent refractive index of polyimide) in the in-plane direction (direction perpendicular to the thickness direction) with respect to 589 nm light was measured at a temperature condition of 23 ° C.

<Thickness direction retardation (Rth)>
The thickness direction retardation (Rth) value (unit: nm) was measured using the polyimide film (length: 76 mm, width: 52 mm, thickness: 13 μm) produced in each example and each comparative example as it was as a measurement sample. As a product name “AxoScan” manufactured by AXOMETRICS Co., Ltd., and inputting the value of the refractive index of each polyimide film (the refractive index of the film with respect to the light of 589 nm determined by the above refractive index measurement), temperature: 25 After measuring retardation in the thickness direction using light having a wavelength of 590 nm under the conditions of ° C. and humidity: 40%, the measured value of the retardation in the thickness direction (measured value by automatic measurement of the measuring device) was used. It was determined by converting to a retardation value per 10 μm of film thickness.

(Example 1)
<Preparation process of tetracarboxylic dianhydride>
In accordance with the method described in Synthesis Example 1, Example 1 and Example 2 of International Publication No. 2011/099518, the following general formula (7):

A tetracarboxylic dianhydride represented by the formula (norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acid Anhydride) was prepared.

<Preparation process of polyamic acid>
First, a 30 ml three-necked flask was heated with a heat gun and sufficiently dried. Next, the atmosphere gas in the three-necked flask that was sufficiently dried was replaced with nitrogen, and the inside of the three-necked flask was changed to a nitrogen atmosphere. Next, after adding 0.2631 g (0.90 mmol: Wakayama Seika Kogyo Co., Ltd .: 4,4-BAB) as an aromatic diamine to the three-necked flask, 1,4-bis (4-aminophenoxy) benzene Further, 2.7 g of N, N-dimethylacetamide was added and stirred to dissolve the aromatic diamine (4,4-BAB) in the N, N-dimethylacetamide to obtain a solution. .

Next, 0.3359 g (0.90 mmol) of the compound represented by the above general formula (7) was added to the three-necked flask containing the solution under a nitrogen atmosphere, and then room temperature (25 ° C. under a nitrogen atmosphere). ) For 12 hours to obtain a reaction solution. In this way, polyamic acid was formed in the reaction solution.

A part of the reaction solution (N, N-dimethylacetamide solution of polyamic acid: polyamic acid solution) was used to prepare an N, N-dimethylacetamide solution with a polyamic acid concentration of 0.5 g / dL. Then, as described above, the intrinsic viscosity [η] of the polyamic acid as the reaction intermediate was measured, and the intrinsic viscosity [η] of the polyamic acid was 0.98 dL / g.

<Preparation process of film made of polyimide>
A large slide glass (trade name “S9213” manufactured by Matsunami Glass Industrial Co., Ltd., length: 76 mm, width 52 mm, thickness 1.3 mm) was prepared as a glass substrate, and the reaction solution (polyamic acid solution) obtained as described above was prepared. Was spin-coated on the surface of the glass substrate so that the thickness of the heat-cured coating film was 13 μm, thereby forming a coating film on the glass substrate. Thereafter, the glass substrate on which the coating film was formed was placed on a hot plate at 60 ° C. and allowed to stand for 2 hours, and the solvent was evaporated and removed from the coating film (solvent removal treatment).

After performing such a solvent removal treatment, the glass substrate on which the coating film has been formed is put into an inert oven in which nitrogen is flowing at a flow rate of 3 L / min, and in the inert oven, at 25 ° C. in a nitrogen atmosphere. After standing at temperature conditions for 0.5 hours, heating at 135 ° C temperature conditions for 0.5 hours, further heating at 340 ° C temperature conditions (final heating temperature) for 1 hour to cure the coating film, A polyimide-coated glass in which a thin film (polyimide film) made of polyimide was coated on the glass substrate was obtained.

Next, the polyimide-coated glass thus obtained is immersed in hot water at 90 ° C., and the polyimide film is peeled off from the glass substrate to obtain a polyimide film (length 76 mm, width 52 mm, thickness 13 μm). Size film).

In addition, in order to identify the molecular structure of the compound forming the polyimide film thus obtained, an IR spectrum was measured using an IR measuring machine (trade name: FT / IR-4100, manufactured by JASCO Corporation). did. The IR spectrum obtained as a result of such measurement is shown in FIG. As is clear from the results shown in FIG. 2, C═O stretching vibration of imide carbonyl was observed at 1701 cm ⁻¹ in the compound constituting the film formed in Example 1. From the molecular structure identified based on such results, it was confirmed that the obtained film was made of polyimide.

In addition, the obtained polyimide is a repeating unit represented by the above general formula (1) (R ¹ , R ² , R ³ in the formula are all hydrogen atoms, and n is 2 from the type of monomer used). And the content of R ¹⁰ is a repeating unit which is a group represented by the above general formula (101) was 100 mol% of polyimide with respect to all repeating units. Moreover, regarding the obtained polyimide film, the evaluation results of properties (Tg, softening temperature, etc. obtained by the above-described property evaluation method) are shown in Table 1.

(Example 2)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.3316 g (0.90 mmol: 4,4′-bis (4-aminophenoxy) biphenyl: The same method as in Example 1 was used except that the final heating temperature in the inert oven was changed from 340 ° C. to 320 ° C. in the preparation process of the polyimide film using Nippon Pure Chemicals Co., Ltd .: APBP). Adopted to obtain a polyimide film. In addition, when the molecular structure of the compound which forms the film obtained similarly to Example 1 was identified, it confirmed that it was a polyimide. In addition, the polyimide thus obtained has a repeating unit represented by the above general formula (1) (R ¹ , R ² and R ³ in the formula are all hydrogen atoms, based on the type of monomer used). , N is 2, and R ¹⁰ is a polyimide having a content of 100 mol% with respect to all repeating units, the content of which is a group represented by the general formula (102). Table 1 shows the intrinsic viscosity [η] of the polyamic acid and the evaluation results of the properties of the polyimide film (Tg, softening temperature, etc. determined by the above-described property evaluation method).

(Comparative Example 1)
In the preparation process of polyamic acid, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.2045 g (0.90 mmol: Nippon Pure Chemicals Co., Ltd.) is used instead of 1,4-bis (4-aminophenoxy) benzene. A polyimide film was obtained by employing the same method as in Example 1 except that DABAN was used. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 2)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl 2882 g (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: 6FDA), and in the polyamic acid preparation step, instead of stirring at room temperature (25 ° C.) for 12 hours in a nitrogen atmosphere when obtaining a reaction solution, temperature The conditions were changed and stirred at 60 ° C. for 12 hours in a nitrogen atmosphere. Further, in the process of preparing a film made of polyimide, the final heating temperature in the inert oven was changed from 340 ° C. to 360 ° C. The same method as in Example 1 was adopted to obtain a polyimide film. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 3)
In the preparation process of polyamic acid, instead of using 1,4-bis (4-aminophenoxy) benzene as an aromatic diamine, 0.2631 g (0.90 mmol: Wakayama) of 1,3-bis (4-aminophenoxy) benzene Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 300 ° C. in the step of preparing a film made of polyimide using TPE-R). A polyimide film was obtained using the same method. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 4)
In the preparation process of polyamic acid, instead of using 1,4-bis (4-aminophenoxy) benzene as an aromatic diamine, 0.3695 g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane ( 0.90 mmol: manufactured by Wakayama Seika Kogyo Co., Ltd .: BAPP), and in the process of preparing a film made of polyimide, except that the final heating temperature in the inert oven was changed from 340 ° C. to 300 ° C. The same method as in Example 1 was adopted to obtain a polyimide film. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 5)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as an aromatic diamine, 0.3892 g (0.90 mmol: 0.90 mmol: bis [4- (4-aminophenoxy) phenyl] sulfone is used. Wakayama Seika Kogyo Co., Ltd .: BAPS), and in the process of preparing a film made of polyimide, the same as in Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 300 ° C. By adopting the method, a polyimide film was obtained. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 6)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.1802 g of 4,4′-diaminodiphenyl ether (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: 4,4′-DDE), and in the step of preparing a film made of polyimide, the same method as in Example 1 was used except that the final heating temperature in the inert oven was changed from 340 ° C. to 300 ° C. Adopted to obtain a polyimide film. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 7)
Instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine in the preparation process of the polyamic acid, 0.3892 g (0.90 mmol: 0.90 mmol: bis [4- (3-aminophenoxy) phenyl] sulfone is used. Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 300 ° C. in the preparation process of the film made of polyimide using Wakayama Seika Kogyo Co., Ltd. (BAPS-M). A polyimide film was obtained by employing the same method. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 8)
Instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine in the preparation process of the polyamic acid, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane A polyimide film was obtained in the same manner as in Example 1 except that 4666 g (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: Bis-AF) was used. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 9)
In the preparation process of polyamic acid, instead of using 1,4-bis (4-aminophenoxy) benzene as an aromatic diamine, 0.2631 g (0.90 mmol: Mitsui) of 1,3-bis (3-aminophenoxy) benzene Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 300 ° C. in the step of preparing a film made of polyimide, using Fine Chemical Co., Ltd .: 3,3-BAB). A polyimide film was obtained using the same method. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Comparative Example 10)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.1911 g (0.90 mmol of Wakayama Seika Kogyo Co., Ltd .: m-tolidine) was used. In addition, in the process of preparing a film made of polyimide, the same method as in Example 1 was adopted except that the final heating temperature in the inert oven was changed from 340 ° C. to 350 ° C. A film was obtained. In addition, the evaluation result of the characteristic of a polyamic acid and a polyimide film is shown in Table 1.

(Example 3)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.2105 g (0.72 mol: 4) of 1,4-bis (4-aminophenoxy) benzene was used. , 4-BAB) and 0.0409 g (0.18 mol: DABAN) of 4,4′-diaminobenzanilide (molar ratio of 4,4-BAB to DABAN ([4,4-BAB]: [DABAN] ) Is 80:20), and the same method as in Example 1 is adopted except that the final heating temperature in the inert oven is changed from 340 ° C. to 350 ° C. in the step of preparing the film made of polyimide. Thus, a polyimide film was obtained. In addition, when the molecular structure of the compound which forms the film obtained similarly to Example 1 was identified, it confirmed that it was a polyimide. In addition, the polyimide thus obtained has a repeating unit represented by the above general formula (1) (R ¹ , R ² and R ³ in the formula are all hydrogen atoms, based on the type of monomer used). , N is 2, and R ¹⁰ is a polyimide having a content of 80 mol% with respect to all repeating units, the content of R ¹⁰ being a group represented by the general formula (101). Table 2 shows the intrinsic viscosity [η] of the polyamic acid and the evaluation results of the properties of the polyimide film (Tg, softening temperature, etc. determined by the above-described property evaluation method).

Example 4
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.2653 g (0.72 mol: 0.74 mol: 4,4′-bis (4-aminophenoxy) biphenyl) is used. APBP) and 0.0409 g (0.18 mol: DABAN) of 4,4′-diaminobenzanilide (molar ratio of APBP to DABAN ([APBP]: [DABAN]) is 80:20), and A polyimide film was obtained by adopting the same method as in Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 350 ° C. in the preparation process of the polyimide film. In addition, when the molecular structure of the compound which forms the film obtained similarly to Example 1 was identified, it confirmed that it was a polyimide. In addition, the polyimide thus obtained has a repeating unit represented by the above general formula (1) (R ¹ , R ² and R ³ in the formula are all hydrogen atoms, based on the type of monomer used). , N is 2, and R ¹⁰ is a polyimide having a content of 80 mol% with respect to all the repeating units, which is a repeating unit which is a group represented by the general formula (102). Table 2 shows the intrinsic viscosity [η] of the polyamic acid and the evaluation results of the properties of the polyimide film (Tg, softening temperature, etc. determined by the above-described property evaluation method).

(Example 5)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.1990 g (0.54 mol: 0.54 mol: 4,4′-bis (4-aminophenoxy) biphenyl) was used. (APBP) and 0.0818 g (0.36 mol: DABAN) of 4,4′-diaminobenzanilide (molar ratio of APBP to DABAN ([APBP]: [DABAN]) is 60:40), and A polyimide film was obtained by adopting the same method as in Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 350 ° C. in the preparation process of the polyimide film. In addition, when the molecular structure of the compound which forms the film obtained similarly to Example 1 was identified, it confirmed that it was a polyimide. In addition, the polyimide thus obtained has a repeating unit represented by the above general formula (1) (R ¹ , R ² and R ³ in the formula are all hydrogen atoms, based on the type of monomer used). , N is 2, and R ¹⁰ is a polyimide having a content of 60 mol% with respect to all repeating units, the content of R ¹⁰ being a group represented by the general formula (102). Table 2 shows the intrinsic viscosity [η] of the polyamic acid and the evaluation results of the properties of the polyimide film (Tg, softening temperature, etc. determined by the above-described property evaluation method).

(Example 6)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as an aromatic diamine, 0.1326 g (0.36 mol: 0.36 mol: 4,4′-bis (4-aminophenoxy) biphenyl is used. (APBP) and 0.1227 g (0.54 mol: DABAN) of 4,4′-diaminobenzanilide (molar ratio of APBP to DABAN ([APBP]: [DABAN]) is 40:60), and A polyimide film was obtained by adopting the same method as in Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 350 ° C. in the preparation process of the polyimide film. In addition, when the molecular structure of the compound which forms the film obtained similarly to Example 1 was identified, it confirmed that it was a polyimide. In addition, the polyimide thus obtained has a repeating unit represented by the above general formula (1) (R ¹ , R ² and R ³ in the formula are all hydrogen atoms, based on the type of monomer used). , N is 2, and R ¹⁰ is a polyimide having a content of 40 mol% with respect to all the repeating units, which is a repeating unit which is a group represented by the general formula (102). Table 2 shows the intrinsic viscosity [η] of the polyamic acid and the evaluation results of the properties of the polyimide film (Tg, softening temperature, etc. determined by the above-described property evaluation method).

(Comparative Example 11)
In the polyamic acid preparation step, instead of using 1,4-bis (4-aminophenoxy) benzene as the aromatic diamine, 0.0663 g (0.18 mol: 0.18 mol: 4,4′-bis (4-aminophenoxy) biphenyl is used. APBP) and 0.1636 g (0.72 mol: DABAN) of 4,4′-diaminobenzanilide (molar ratio of APBP to DABAN ([APBP]: [DABAN]) is 20:80), and A polyimide film was obtained by adopting the same method as in Example 1 except that the final heating temperature in the inert oven was changed from 340 ° C. to 350 ° C. in the preparation process of the polyimide film. In addition, the polyimide thus obtained has a repeating unit represented by the above general formula (1) based on the type of monomer used (wherein R ¹ , R ² and R ³ are all hydrogen atoms). , N is 2, and R ¹⁰ is a polyimide having a content of 20 mol% with respect to all repeating units, the content of R ¹⁰ being a group represented by the general formula (102). Further, the intrinsic viscosity [η] of the polyamic acid and the evaluation results of the properties of the polyimide film (Tg, softening temperature, etc. determined by the above-described property evaluation method) are shown in Table 2 (in Table 2, for reference) The results of Examples 1 and 2 are also shown.)

As is clear from the results shown in Tables 1 and 2, all of the polyimide films (Examples 1 to 6) of the present invention have a tensile strength of 125 MPa or more and a breaking elongation of 15% or more. Thus, it was confirmed that the tensile strength and elongation characteristics (elongation characteristics until breaking) were balanced at a higher level and had higher toughness. In addition, since all of the polyimide films of the present invention (Examples 1 to 8) have a Tg of 295 ° C. or higher, a softening temperature of 470 ° C. or higher, and a 5% weight loss temperature of 494 ° C. or higher, It was confirmed that it has a high heat resistance. Further, it was confirmed that all the polyimide films of the present invention (Examples 1 to 8) had a total light transmittance of 87% or more and had sufficiently high transparency. From these results, the polyimide film (polyimide film of the present invention) obtained in each example has high heat resistance and sufficient transparency, and higher toughness (high toughness: more High mechanical strength). Further, as is clear from the results shown in Table 2, the tensile strength and the elongation characteristics are exhibited in a balanced manner at a higher level by containing 40 mol% or more of the repeating unit represented by the general formula (1). It has been found that it exhibits higher toughness (higher mechanical strength).

On the other hand, the polyimide films obtained in Comparative Examples 1 to 11 have a tensile strength of less than 125 MPa or a breaking elongation of less than 15%, and the tensile strength and the elongation characteristics are not necessarily sufficiently high. It was not something that could be demonstrated in a well-balanced manner. From these results, the polyimide films obtained in the respective comparative examples are not necessarily sufficient in toughness and sufficient in mechanical strength as compared with the polyimide films of the present invention (Examples 1 to 6). It turns out that it is not.

As described above, according to the present invention, the polyimide has a balance of tensile strength and elongation characteristics at a higher level and can have higher toughness based on tensile strength and elongation at break. It becomes possible to provide a film and an organic electroluminescence device using the film. Moreover, according to this invention, it becomes possible to provide the transparent conductive laminated body using the said polyimide film, the touchscreen using the transparent conductive laminated body, a solar cell, and a display apparatus.

Moreover, since the polyimide film of the present invention has higher toughness and is superior in mechanical strength, for example, when used for a substrate material such as an organic EL display, a liquid crystal display or a touch panel, Due to its excellent mechanical strength, it is possible to sufficiently improve the yield of the final product. From such a viewpoint, the polyimide film of the present invention is, for example, a flexible wiring board film, a heat-resistant insulating tape, a wire enamel, a semiconductor protective coating agent, a liquid crystal alignment film, and a transparent conductive film for organic EL (organic electroluminescence). Film for organic EL lighting, flexible substrate film, substrate film for flexible organic EL, flexible transparent conductive film, transparent conductive film for organic thin film solar cell, transparent conductive film for dye-sensitized solar cell, flexible gas barrier film It is particularly useful as a film for touch panels, a front film for flexible displays, a back film for flexible displays, and the like.

DESCRIPTION OF SYMBOLS 1 ... Organic EL element, 11 ... Polyimide film, 12 ... Gas barrier layer, 13 ... Transparent electrode layer, 14 ... Organic layer, 15 ... Metal electrode layer.

Claims

The following general formula (1):

Wherein (1), R 1, R 2, R 3 are each independently a hydrogen atom, represents one selected from the group consisting of alkyl groups and fluorine atoms having 1 to 10 carbon atoms, R 10 is The following general formulas (101) to (102):

And n represents an integer of 0 to 12. ]
The polyimide film which consists of a polyimide which contains 30 mol% or more of the repeating unit represented by these with respect to all the repeating units, and whose tensile strength is 125 Mpa or more and whose elongation at break is 15% or more.
The polyimide film according to claim 1, wherein the polyimide contains 40 mol% or more of the repeating unit represented by the general formula (1) with respect to all repeating units.
An organic electroluminescence device comprising the polyimide film according to claim 1.
A transparent conductive laminate comprising the polyimide film according to claim 1 or 2 and a thin film made of a conductive material laminated on the polyimide film.
A touch panel comprising the transparent conductive laminate according to claim 4.
A solar cell comprising the transparent conductive laminate according to claim 4.
A display device comprising the transparent conductive laminate according to claim 4.