TWI774855B - Polyimide film, method for producing polyimide film, laminate, surface material for display, touch panel member, liquid crystal display device, and organic electroluminescence display device - Google Patents

Abstract

Provided is a polyimide film comprising a polyimide and an UV absorber, wherein the UV absorber is absent in one side of the polyimide film and is localized in another side thereof, and wherein a transmittance is 18% or less at a wavelength of 380 nm and 85% or more at a wavelength of 450 nm.

Description

Polyimide film, method for producing polyimide film, laminate, surface material for display, touch panel member, liquid crystal display device, and organic electroluminescence display device

Embodiments of the present invention relate to a polyimide film, a method for producing the polyimide film, a laminate, a surface material for a display, a touch panel member, a liquid crystal display device, and an organic electroluminescence display device.

Thin plate glass is excellent in hardness, heat resistance, etc., but on the other hand, it is difficult to bend, easily broken when dropped, has problems in workability, and has the disadvantage of being heavier than plastic products. Therefore, in recent years, from the viewpoint of processability and weight reduction, resin products such as resin substrates and resin films have gradually replaced glass products, and research into resin products as glass replacement products has been conducted in the industry.

For example, with the rapid progress of electronic devices such as displays such as liquid crystals and organic ELs, and touch panels, thinning or weight reduction of devices is required, and flexibility is also required. In these devices, various electronic components, such as thin transistors and transparent electrodes, were previously formed on a relatively thin plate glass. By changing the thin plate glass to a resin film, the impact resistance of the panel itself can be achieved. strengthening, flexibility, thinning or lightweighting.

Polyimide resins have excellent properties such as heat resistance, dimensional stability, and insulating properties, so they are popularly used as insulating materials for electronic parts such as chip coating films in semiconductor devices or substrates for flexible printed wiring boards. In recent years, as a glass replacement product, research has been conducted on resin products using polyimide resins with improved transparency. However, polyimide resin generally has absorption in the ultraviolet region, so there is a problem of easy discoloration in the case of outdoor use, and it is required to improve the weather resistance. In Patent Document 1, as a resin film having high transparency even after a light irradiation test, for example, it is described that a polyimide-based polymer having high transparency is used and an ultraviolet absorber is contained in the resin film. middle. prior art literature Patent Literature

Patent Document 1: International Publication No. 2017/014279

[The problem to be solved by the invention]

However, the weather resistance of the known polyimide film is not sufficient, and the industry demands to further improve the weather resistance of the polyimide film. In addition, the inventors of the present invention found that the conventional polyimide film containing the ultraviolet absorber was more prone to creases when folded than the polyimide film not containing the ultraviolet absorber. On the other hand, for a flexible display mounted on a mobile device with a foldable screen, it is required to return to its original state when it is flattened even if it continues to be bent for a long time or is repeatedly bent. . Therefore, the base material and surface material for flexible displays are also required to have recovery properties after being bent for a long time (hereinafter, sometimes referred to as static bending resistance) and recovery properties after repeated bending. (Hereinafter, it may be referred to as dynamic deflection resistance).

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a resin film which is excellent in weather resistance and suppresses a decrease in flexural resistance. Another object of the present invention is to provide a method for producing the above-mentioned resin film, a laminate having the above-mentioned resin film, a surface material for a display as the above-mentioned resin film or the above-mentioned laminate, and a touch panel having the above-mentioned resin film or the above-mentioned laminate A member, a liquid crystal display device, and an organic electroluminescence display device. [Technical means to solve the problem]

One aspect of the present invention provides a polyimide film comprising a polyimide and an ultraviolet absorber, wherein the ultraviolet absorber is absent on one side and is eccentrically present on the other side, and The transmittance of the polyimide film at a wavelength of 380 nm is less than 18%, and the transmittance at a wavelength of 450 nm is more than 85%.

One aspect of the present invention provides a polyimide film having at least one polyimide layer (a) containing polyimide and not containing an ultraviolet absorber on one side, and at least one layer (a) on the other side. The layer contains a polyimide layer (b) of polyimide and a UV absorber.

One aspect of the present invention provides a polyimide film, wherein the total thickness of the polyimide layer (a) is the same as or greater than the total thickness of the polyimide layer (b) Aggregate thickness of layer (b).

One aspect of the present invention provides a polyimide film in which the total thickness of the polyimide layers (b) is 0.5 μm or more.

One aspect of the present invention provides a polyimide film in which the content of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) is 0.8 mass % or more and 60 mass % the following.

One aspect of the present invention provides a polyimide film in which the polyimide layer (a) and the polyimide layer (b) that exist adjacent to each other contain the same polyimide.

One aspect of the present invention provides a polyimide film in which the polyimide layer (a) and the polyimide layer (b) that are adjacent to each other contain the same polyimide, And the said polyimide layer (a) and the said polyimide layer (b) which exist adjacent to each other each contain the polyimide which has the structure represented by following general formula (1).

（通式（1）中，R¹ 表示作為具有芳香族環或脂肪族環之四羧酸殘基的四價基，R² 表示作為二胺殘基之二價基，R² 之總量之2.5莫耳%以上且50莫耳%以下為於主鏈具有矽原子之二胺殘基，R² 之總量之50莫耳%以上且97.5莫耳%以下為不具有矽原子且具有芳香族環或脂肪族環之二胺殘基；n表示重複單位數）General formula (1)

(In the general formula (1), R ¹ represents a tetravalent group that is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, R ² represents a divalent group that is a diamine residue, and the sum of the total amount of R ² 2.5 mol % or more and 50 mol % or less are diamine residues having silicon atoms in the main chain, and 50 mol % or more and 97.5 mol % or less of the total amount of R ² do not have silicon atoms and are aromatic Diamine residue of ring or aliphatic ring; n represents the number of repeating units)

One aspect of the present invention provides a polyimide film, wherein the diamine residue having a silicon atom in the main chain of R ² in the general formula (1) is one or two in the main chain. Diamine residues of silicon atoms.

One aspect of the present invention provides a polyimide film in which the polyimide contained in the polyimide layer (a) on the outermost surface on one side and the polyimide on the outermost surface on the other side The polyimide contained in the imide layer (b) is different from each other.

One aspect of the present invention provides a polyimide film in which the polyimide contained in the polyimide layer (a) on the outermost surface on one side and the polyimide on the outermost surface on the other side The polyimide contained in the imide layer (b) is different from each other, and the polyimide layer (a) located on the outermost surface of one surface side contains the polyimide having the structure represented by the general formula (1). imine.

One aspect of the present invention provides a polyimide film in which the polyimide contained in the polyimide layer (a) on the outermost surface on one side and the polyimide on the outermost surface on the other side The polyimide layer (b) contained in the polyimide layer is different from each other, and the polyimide layer (b) located on the outermost surface of the other surface side contains a polyimide having a structure represented by the following general formula (2). Polyimide.

（通式（2）中，R³ 表示選自由焦蜜石酸二酐殘基、2,3,3',4'-聯苯四羧酸二酐殘基及3,3',4,4'-聯苯四羧酸二酐殘基所組成之群中之至少1種四價基，R⁴ 表示作為二胺殘基之二價基；n'表示重複單位數）General formula (2)

(In the general formula (2), R ³ represents a residue selected from the group consisting of pyromic acid dianhydride residues, 2,3,3',4'-biphenyltetracarboxylic dianhydride residues and 3,3',4,4 '-At least one tetravalent group in the group consisting of biphenyltetracarboxylic dianhydride residues, R ⁴ represents a divalent group as a diamine residue; n' represents the number of repeating units)

One aspect of the present invention provides a polyimide film, wherein, in the polyimide having the structure represented by the above-mentioned general formula (2), R ⁴ in the above-mentioned general formula (2) includes an aromatic ring having an aromatic ring. Or diamine residue of aliphatic ring.

One aspect of the present invention provides a polyimide film including a polyimide including an aromatic ring having a perfluoroalkyl group.

One aspect of the present invention provides a polyimide film in which both the Young's modulus of one side and the Young's modulus of the other side are 2.4 GPa or more.

One aspect of the present invention provides a polyimide film in which the melting point of the ultraviolet absorber is 100°C or higher.

One aspect of the present invention provides a polyimide film in which the ultraviolet absorber has a linear or branched saturated aliphatic hydrocarbon group having 1 or more and 15 or less carbon atoms.

One aspect of the present invention provides a polyimide film, wherein the ultraviolet absorber is a compound represented by the following general formula (I).

（通式（I）中，R²¹ 、R²² 、R²³ 及R²⁴ 分別獨立地表示氫原子、鹵素原子或碳數1以上且4以下之烷基，R²⁵ 、R²⁶ 、R²⁷ 、R²⁸ 及R²⁹ 分別獨立地表示氫原子、羥基、可經苯基或一價之聚矽氧烷基取代之碳數1以上且15以下之直鏈狀或支鏈狀之烷基、或-R³⁰ -A-R³¹ ，R³⁰ 表示碳數1以上且15以下之直鏈狀或支鏈狀之伸烷基（alkylene），A表示伸苯基或二價之聚矽氧烷基，R³¹ 表示碳數1以上且15以下之直鏈狀或支鏈狀之烷基，R²⁵ 、R²⁶ 、R²⁷ 、R²⁸ 及R²⁹ 之至少一者表示可經苯基或一價之聚矽氧烷基取代之碳數1以上且15以下之直鏈狀或支鏈狀之烷基、或-R³⁰ -A-R³¹ ；上述苯基及上述伸苯基可經碳數1以上且15以下之直鏈狀或支鏈狀之烷基取代）General formula (I)

(In the general formula (I), R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 or more and 4 or less carbon atoms, R ²⁵ , R ²⁶ , R ²⁷ , and R ²⁸ and R ²⁹ each independently represent a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 15 carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group, or -R ³⁰ -AR ³¹ , R ³⁰ represents a linear or branched alkylene with a carbon number of 1 or more and 15 or less, A represents a phenylene or a divalent polysiloxane, and R ³¹ represents a carbon A linear or branched alkyl group of 1 or more and 15 or less, at least one of R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ represents a phenyl group or a monovalent polysiloxane group Substituted linear or branched alkyl group with 1 to 15 carbon atoms, or -R ³⁰ -AR ³¹ ; the above-mentioned phenyl group and the above-mentioned phenylene group may be substituted by a linear or branched carbon number of 1 or more and 15 or less. or branched chain alkyl substitution)

One aspect of the present invention provides a method for producing a polyimide film, comprising the steps of: forming a polyimide layer (a) containing polyimide and not containing an ultraviolet absorber; and forming a polyimide layer (b) containing polyimide and an ultraviolet absorber in such a manner as to exist adjacent to the above-mentioned polyimide layer (a); The step of forming the above-mentioned polyimide layer (b) has the following steps: preparing a UV absorbent-containing polyimide resin composition containing a polyimide, a UV absorbent and an organic solvent; and Coating the above-mentioned UV absorber-containing polyimide resin composition to form a UV absorber-containing polyimide resin coating film; The polyimide film has at least one layer of the polyimide layer (a) on one side and at least one layer of the polyimide layer (b) on the other side, and has a transmittance at a wavelength of 380 nm. 18% or less, and the transmittance at a wavelength of 450 nm is more than 85%.

A first aspect of the present invention provides a laminate comprising the polyimide film of the first aspect of the present invention, and a functional layer containing at least one polymer of a radically polymerizable compound and a cationically polymerizable compound.

One aspect of the present invention provides a layered product, wherein the radically polymerizable compound is a compound having two or more (meth)acryloyl groups in one molecule, and the cationically polymerizable compound is a compound having two or more (meth)acryloyl groups in one molecule. A compound of at least one of two or more epoxy groups and oxetanyl groups.

One aspect of the present invention provides a surface material for a display, which is the polyimide film of the first aspect of the present invention or the laminate of the first aspect of the present invention.

An aspect of the present invention provides a surface material for a display for a flexible display, which is the polyimide film of the first embodiment of the present invention or the laminate of the first embodiment of the present invention.

Furthermore, one aspect of the present invention provides a touch panel member comprising: the polyimide film of the first aspect of the present invention or the laminate of the first aspect of the present invention; A transparent electrode that is disposed on one surface side of the polyimide film or the laminate and is composed of a plurality of conductive parts; and A plurality of lead wires electrically connected to at least one side of the end of the conductive portion.

Further, an aspect of the present invention provides a liquid crystal display device comprising: the polyimide film of the first embodiment of the present invention or the laminate of the first embodiment of the present invention; and The liquid crystal display part which is arrange|positioned at one surface side of the said polyimide film or the said laminated body, and has a liquid crystal layer between the opposing substrates.

Further, an embodiment of the present invention provides an organic electroluminescence display device comprising: the polyimide film of the first embodiment of the present invention or the laminate of the first embodiment of the present invention; and The organic electroluminescence display part which is arrange|positioned at one surface side of the said polyimide film or the said laminated body, and has an organic electroluminescence layer between the opposing substrates. [Effect of invention]

According to the embodiment of the present invention, it is possible to provide a resin film which is excellent in weather resistance and suppresses a decrease in flexural resistance. Further, according to an embodiment of the present invention, there can be provided a method for producing the resin film described above, a laminate having the resin film, a surface material for a display as the resin film or the laminate, and the resin film or laminate having the above-mentioned laminate. touch panel components, liquid crystal display devices, and organic electroluminescence display devices.

I. Polyimide film The polyimide film of the present invention contains polyimide and an ultraviolet absorber, and the ultraviolet absorber does not exist on one side but exists on the other side, The transmittance at the wavelength of 380 nm is less than 18%, and the transmittance at the wavelength of 450 nm is more than 85%.

The polyimide film of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the polyimide film of the present invention. The polyimide film 10 of the present invention shown in FIG. 1 does not have an ultraviolet absorber on one side S1, and has an ultraviolet absorber on the other side S2.

The transmittance of the polyimide film of the present invention at a wavelength of 380 nm is less than 18%, and the transmittance at a wavelength of 450 nm is more than 85%. Thereby, transparency becomes favorable, and it can be used suitably as a transparent resin material. In terms of improving the weather resistance, the transmittance of the polyimide film of the present invention at a wavelength of 380 nm is further preferably 15% or less, more preferably 11% or less, and still more preferably 7% or less. In the polyimide film of the present invention, the transmittance at a wavelength of 380 nm can be determined by, for example, the type and content of the ultraviolet absorber contained in the polyimide film, and the polyimide layer containing the ultraviolet absorber. Adjust the thickness, etc. Specifically, for example, the transmittance at a wavelength of 380 nm can be reduced by increasing the concentration of the ultraviolet absorber in the polyimide layer containing the ultraviolet absorber or increasing the thickness of the polyimide layer containing the ultraviolet absorber. Moreover, from the viewpoint of improving transparency, the transmittance of the polyimide film of the present invention at a wavelength of 450 nm is more preferably 86% or more, more preferably 87% or more. In the polyimide film of the present invention, the transmittance at a wavelength of 450 nm can be adjusted by, for example, the type of polyimide contained in the polyimide film. Specifically, for example, the transmittance at a wavelength of 450 nm can be improved by using the polyimide contained in the polyimide film, which is preferable in terms of the following light transmittance. The above-mentioned transmittance can preferably be achieved when the thickness of the polyimide film of the present invention is 20 μm or more and 100 μm or less. Furthermore, in the present invention, the transmittance at the wavelength of 380 nm and the transmittance at the wavelength of 450 nm can use an ultraviolet-visible-near-infrared spectrophotometer (for example, a model manufactured by Nippon Shoko Co., Ltd.: V-7100) to measure.

The reason why the polyimide film of the present invention is excellent in weather resistance and suppresses a decrease in flexural resistance is estimated as follows. In the conventional polyimide film containing an ultraviolet absorber, if the content of the ultraviolet absorber is increased in order to improve the weather resistance, the flex resistance is poor, and it is difficult to sufficiently improve the weather resistance in order to maintain the flex resistance. It is inferred that the conventional polyimide film containing UV absorber has poorer flexural resistance than the polyimide film without UV absorber because the UV absorber acts as a plasticizer, and the polyimide film The whole is prone to plastic deformation. On the other hand, it is considered that the polyimide film of the present invention does not contain an ultraviolet absorber on one side and is partially present on the other side, and has no ultraviolet absorber or a sufficiently small content of the ultraviolet absorber on one side. On the other side, the content of the ultraviolet absorber is relatively increased. In addition, the region containing no ultraviolet absorber or a sufficiently low content of the ultraviolet absorber suppresses plastic deformation and improves the flex resistance of the polyimide film. Therefore, it is considered that it is comparable to the conventional polyimide film containing the ultraviolet absorber. The ratio suppresses the decrease in flexural resistance. Moreover, although the polyimide film of this invention does not contain an ultraviolet absorber uniformly in the whole film, it can absorb the light of the ultraviolet region efficiently on the side where the ultraviolet absorber is concentrated, and is considered to be excellent in weather resistance.

Hereinafter, the polyimide film of the present invention will be described in detail. The polyimide film of the present invention contains polyimide and an ultraviolet absorber. The ultraviolet absorber does not exist on one side but exists on the other side. The transmittance at a wavelength of 380 nm is less than 18%, and the wavelength of 380 nm is less than 18%. The transmittance at 450 nm is 85% or more, and other structures may be provided within the range that does not impair the effect of the present invention.

1. Composition of polyimide film The polyimide film of the present invention has no ultraviolet absorber on one side, and has an ultraviolet absorber on the other side. The absence of ultraviolet absorber on one side of the polyimide film can be analyzed by cutting out a test piece from one side of the polyimide film using a thermal decomposition gas chromatography device (GC-MS). Specifically, the polyimide film was cut into slices having a size of 10 mm×10 mm, and the surface was cut so that the presence or absence of the ultraviolet absorber remained on the surface to prepare a test piece. The prepared test piece was analyzed by GC-MS. When the UV absorber did not reach the detection limit (1 ppm), it was deemed that there was no UV absorber on the surface of the polyimide film. The thickness of the said test piece can be set to about 10 micrometers, for example.

In the polyimide film of the present invention, in terms of weather resistance and flexibility resistance, when the total content of the ultraviolet absorbers contained in the entire film is 100% by mass, self-existing The total content of the ultraviolet absorber contained in the above-mentioned other surface of the ultraviolet absorber to the surface having a thickness of 50% of the entire thickness of the film is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 100% by mass. Furthermore, in terms of improving the flexural resistance, when the total content of the ultraviolet absorbers contained in the entire film is 100% by mass, the thickness of the entire film from the other side where the ultraviolet absorber is partially stored is 80 mass % or more is preferable, as for the total content of the ultraviolet absorber contained in the surface with a thickness of 40%, 90 mass % or more is more preferable, and 100 mass % is still more preferable. Furthermore, when the total content of the ultraviolet absorbers contained in the entire film is set to 100% by mass, the ultraviolet rays contained in the film from the other surface of the ultraviolet absorber to the surface having a thickness of 25% of the entire thickness of the film The total content of the absorbent is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 100% by mass. In addition, the quantity of the ultraviolet absorber contained in the area|region up to the specific thickness of a film can be measured by GC-MS using the sample which cut|disconnected the film to a specific thickness. The quantification of the ultraviolet absorber in the sample obtained by GC-MS is performed, for example, by the following method. The polyimide film was cut to a predetermined thickness, the obtained sample was added to N,N-dimethylformamide (DMF) in an amount of 5% by mass concentration, and the sample was dissolved in DMF. Prepare sample solutions. For this sample solution, a GC-MS apparatus (eg, 6890/5973 GC/MS from Agilent) was used in a column: InertCapWax inner diameter 250 μm × length 30 m × film thickness 0.25 μm (manufactured by GL Science), sample injection amount : 0.2 μL, ionization method: GC-MS measurement was carried out under the conditions of EI. This GC-MS measurement was performed three times, and the measurement result was taken as the average value of the three times. In addition, regarding the ultraviolet absorber having the same structure as the ultraviolet absorber contained in the sample, a calibration curve can be prepared, and the content of the ultraviolet absorber in the sample can be obtained using the calibration curve as a reference. Furthermore, the structure of the ultraviolet absorber contained in the sample can be specified by GC-MS connected to a blowing gas trapping device (heating desorption device).

In addition, in terms of flexibility resistance, when the total content of the ultraviolet absorbers contained in the entire film is 100% by mass, from the above-mentioned surface where the ultraviolet absorber does not exist to the entire thickness of the film is 50%. 10 mass % or less is preferable, 5 mass % or less is more preferable, and 0 mass % is still more preferable.

Moreover, in the polyimide film of the present invention, the ultraviolet absorber is not particularly limited as long as it does not exist on one side and exists on the other side, and it is not particularly limited in terms of weather resistance and flexibility resistance. In other words, it is preferable to have at least one polyimide layer (a) containing polyimide and no ultraviolet absorber on one side, and at least one layer containing polyimide and ultraviolet absorbing agent on the other side. The polyimide layer (b) of the agent. In addition, in this invention, the layer containing different kinds of components is made into a mutually different layer. In the present invention, the case where the polyimide layer (a) having two or more layers includes, for example, one that has different types of polyimide contained in the build-up layer on one side and does not contain an ultraviolet absorber. In the case of a configuration consisting of two or more polyimide layers. Moreover, the said polyimide layer (b) which has two or more layers is mentioned, for example, the other surface side has a laminated layer containing polyimide and an ultraviolet absorber, and the polyimide and ultraviolet absorber contained in the layer can be mentioned. At least one of the two or more layers of polyimide layers whose types are different from each other is the case. In the polyimide film of the present invention, it is preferable to have only one layer of the polyimide layer (a) described above on one surface side, and to have the polyimide layer (a) together with the polyimide layer, especially in terms of thinning and optical properties. The imine layer (a) has only one layer of the above-mentioned polyimide layer (b) adjacent to the other surface side.

The polyimide film 10 of the present invention shown in FIG. 1 has a polyimide layer (a) 1 containing polyimide and no ultraviolet absorber on one side S1 side, and has a polyimide layer (a) 1 containing polyimide on the other side S2 side Polyimide layer of imine and UV absorber (b) 2. The polyimide film 10 ′ of the present invention shown in FIG. 2 has polyimide layers (a) 1a and 1b containing polyimide and not containing an ultraviolet absorber on one side S1 side in order from the side S1 side , on the other side S2 side from this side S2 side, there are polyimide layers (b) 2a, 2b containing polyimide and an ultraviolet absorber in this order.

Furthermore, in the polyimide film of the present invention, the interface between the layers can be obtained from electrons such as scanning electron microscope (SEM), transmission electron microscope (TEM), scanning transmission electron microscope (STEM), etc. The cross section in the thickness direction observed by a microscope was obtained. Typically, the layer formed using the ultraviolet absorber-containing polyimide precursor resin composition or the ultraviolet absorber-containing polyimide resin composition contains the ultraviolet absorber, and thus becomes the above-mentioned layer. The polyimide layer (b), the polyimide layer formed using the polyimide precursor resin composition or the polyimide resin composition that does not contain the ultraviolet absorber, is free from the ultraviolet absorber. The above-mentioned polyimide layer (a). When the content of the ultraviolet absorber has a gradient and the interface is unclear in the vicinity of the interface between the polyimide layer (a) containing no ultraviolet absorber and the polyimide layer (b) containing the ultraviolet absorber, the above The boundary between the polyimide layer (a) and the above-mentioned polyimide layer (b) can be set as a plane in a direction perpendicular to the thickness direction of the polyimide film, which can be divided into areas containing the ultraviolet absorber and areas not containing the ultraviolet absorber. The area of the ultraviolet absorber, and the plane in contact with the area containing the ultraviolet absorber.

When the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), in terms of weather resistance and flex resistance, it is more It is preferable that the total thickness of the said polyimide layer (a) is the same as the total thickness of the said polyimide layer (b), or is larger than the total thickness of the said polyimide layer (b). In particular, in terms of improving the flex resistance, the total thickness of the polyimide layer (b) is preferably 40% or less, more preferably 30% or less, and still more preferably the total thickness of the polyimide film. Preferably, it is 25% or less, and more preferably, it is 20% or less. On the other hand, in terms of improving the weather resistance, the total thickness of the polyimide layer (b) is preferably 1% or more, more preferably 2% or more, with respect to the entire thickness of the polyimide film, and further More preferably, it is 3% or more, particularly preferably 5% or more. In addition, the film thickness of each polyimide layer and polyimide film can be measured by observing the cross section which cut|disconnected the polyimide film in the thickness direction with a scanning electron microscope (SEM). In the present invention, after embedding, curing and fixing a test piece cut from a polyimide film of 5 mm×5 mm with resin, the thickness direction of the fixed sample is 50 nm or more and 150 nm or less using a microtome. The left and right intervals were cut, and in each section, the thickness of each polyimide layer or polyimide film was measured at three arbitrary points, the number averaged was performed, and the obtained value was used as the film thickness.

When the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), the above-mentioned polyimide layer ( The total thickness of a) is preferably 10 μm or more and 120 μm or less, and more preferably 20 μm or more and 100 μm or less. Furthermore, in terms of weather resistance, the total thickness of the polyimide layers (b) is preferably 0.2 μm or more, more preferably 0.5 μm or more, and still more preferably 1 μm or more. In terms of flexibility, it is preferably 40 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, and particularly preferably 15 μm or less.

The thickness of the polyimide film of the present invention may be appropriately selected depending on the application, and in terms of mechanical strength and weather resistance of the film, preferably 20 μm or more, and more preferably 30 μm. On the other hand, from the viewpoint of deflection resistance, it is preferably 200 μm or less, more preferably 150 μm or less, and still more preferably 100 μm or less. If the thickness of the entire film is too thin, the strength may be lowered, or it may become difficult to store the ultraviolet absorber. Since the load on the film becomes large, there exists a possibility that bending resistance may fall.

2. Composition of polyimide film The polyimide film of the present invention contains at least a polyimide and an ultraviolet absorber, and may also contain other additives different from the ultraviolet absorber or other additives other than the polyimide resin as necessary within the scope of impairing the effects of the present invention. Resin and other optional components are added.

(1) Polyimide The polyimide is obtained by reacting a tetracarboxylic acid component and a diamine component. Preferably, it is imidized to obtain a polyamic acid by the polymerization of a tetracarboxylic acid component and a diamine component. The imidization can be performed by thermal imidization or by chemical imidization. Moreover, it can also manufacture by the method of using thermal imidization and chemical imidization together. Furthermore, the polyimide film of the present invention may contain one kind of polyimide or a mixture of two or more kinds of polyimide. When the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), each polyimide layer may contain one type of polyimide. Or mix and contain two or more kinds of polyimides.

As a specific example of the tetracarboxylic acid component, tetracarboxylic dianhydride is suitably used, and examples thereof include cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, dicyclohexane-3,4,3', 4'-Tetracarboxylic dianhydride, Pyromic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,2',3,3'-benzophenone Tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis(3, 4-Dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4 -Dicarboxyphenyl) stilbene dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4 -Dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis( 2,3-Dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis[(3,4-dicarboxy)benzyl]phthalic anhydride , 1,4-bis[(3,4-dicarboxy)benzyl]phthalic anhydride, 2,2-bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl} Propane dianhydride, 2,2-bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}propane dianhydride, bis{4-[4-(1,2-dicarboxy)benzene Oxy]phenyl}ketone dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, 4,4'-bis[4-(1,2- Dicarboxy)phenoxy]biphthalic anhydride, 4,4'-bis[3-(1,2-dicarboxy)phenoxy]biphthalic anhydride, bis{4-[4-(1,2- Dicarboxy)phenoxy]phenyl}ketone dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, bis{4-[4-(1, 2-Dicarboxy)phenoxy]phenyl}stilbene dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}stilbene dianhydride, bis{4-[4-( 1,2-Dicarboxy)phenoxy]phenyl}thioether dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}thioether dianhydride, 4,4' -(hexafluoroisopropylidene)diphthalic anhydride, 3,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3'-(hexafluoroisopropylidene)diphthalic anhydride Phthalic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride , 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylene tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 1,2, 7,8-Phenanthrenetetracarboxylic dianhydride, etc. These may be used individually or in mixture of 2 or more types.

Specific examples of the diamine component include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4 ,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl Thioether, 3,3'-diaminodiphenyl selenium, 3,4'-diaminodiphenyl sine, 4,4'-diaminodiphenyl sine, 3,3'-diamine Benzophenone, 4,4'-Diaminobenzophenone, 3,4'-Diaminobenzophenone, 4,4'-Diaminobenzylaniline, 3,3'-Diaminobenzophenone Aminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-bis(3-aminophenyl)propane, 2, 2-bis(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)- 1,1,1,3,3,3-Hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2-(3 -Aminophenyl)-2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 1,1-bis(3-aminophenyl)-1- Phenylethane, 1,1-bis(4-aminophenyl)-1-phenylethane, 1-(3-aminophenyl)-1-(4-aminophenyl)-1- Phenylethane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy) ) benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminobenzyl)benzene, 1,3-bis(4-aminobenzyl) ) benzene, 1,4-bis(3-aminobenzyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(3-aminobenzyl), α-Dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amino-α,α-dimethyl) Benzyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(3-amino-α,α-ditrifluoromethylbenzyl) base)benzene, 1,3-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene, 1,4-bis(3-amino-α,α-ditrifluoromethylbenzyl) base)benzene, 1,4-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene, 2,6-bis(3-aminophenoxy)benzonitrile, 2,6 -Bis(3-aminophenoxy)pyridine, N,N'-bis(4-aminophenyl)terephthalamide, 9,9-bis(4-aminophenyl)pyridine, 2 ,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 3,3'-dichloro-4 ,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl , 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl Benzene, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy) ) phenyl] sulfide, bis[4-(4-aminophenoxy)phenyl] sulfide,

Bis[4-(3-aminophenoxy)phenyl] bis[4-(4-aminophenoxy)phenyl] bis[4-(3-aminophenoxy)benzene base] ether, bis[4-(4-aminophenoxy)phenyl]ether, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[ 4-(4-Aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexa Fluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1,3-bis[4-(3 -Aminophenoxy)benzyl]benzene, 1,3-bis[4-(4-aminophenoxy)benzyl]benzene, 1,4-bis[4-(3-amine phenylphenoxy)benzyl]benzene, 1,4-bis[4-(4-aminophenoxy)benzyl]benzene, 1,3-bis[4-(3-aminobenzene] oxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4- Bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-aminophenoxy)-α,α-dimethyl Benzyl]benzene, 4,4'-bis[4-(4-aminophenoxy)benzyl]diphenyl ether, 4,4'-bis[4-(4-amino-α, α-Dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylene , 4,4'-bis[4-(4-aminophenoxy)phenoxy]diphenylene, 3,3'-diamino-4,4'-diphenoxybenzophenone , 3,3'-diamino-4,4'-diphenyloxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 3,3'-diphenyloxybenzophenone Amino-4-biphenoxybenzophenone, 6,6'-bis(3-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spiro Bisindane, 6,6'-bis(4-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobisindane, 1,3-bis( 3-Aminopropyl)tetramethyldisiloxane, 1,3-bis(4-aminobutyl)tetramethyldisiloxane, α,ω-bis(3-aminopropyl)poly Dimethylsiloxane, α,ω-bis(3-aminobutyl)polydimethylsiloxane, bis(aminomethyl)ether, bis(2-aminoethyl)ether, bis( 3-aminopropyl) ether, bis(2-aminomethoxy)ethyl]ether, bis[2-(2-aminoethoxy)ethyl]ether, bis[2-(3-amine propoxy)ethyl]ether,

1,4-cyclohexanediamine, trans-1,4-bismethylenecyclohexanediamine, 2,6-bis(aminomethyl)bicyclo[2,2,1]heptane, 2, 5-bis(aminomethyl)bicyclo[2,2,1]heptane, and can also be used to replace part or all of the hydrogen atoms on the aromatic ring of the above-mentioned diamines with fluoro, methyl, Diamines substituted with methoxy, trifluoromethyl, or trifluoromethoxy. In addition, these diamines may be used alone or in combination of two or more.

In addition, from the viewpoint of improving light transmittance and improving surface hardness, the polyimide preferably contains an aromatic ring and is selected from the group consisting of (i) a fluorine atom, (ii) an aliphatic ring, and ( iii) A polyimide of at least one of the group consisting of a structure in which aromatic rings are linked by a sulfonyl group or a fluorine atom-substituted alkylene group. When the polyimide contains an aromatic ring, the orientation is improved, the rigidity is improved, and thus the surface hardness is improved, but the transmittance tends to decrease due to the absorption wavelength of the aromatic ring. When the polyimide contains (i) a fluorine atom, the light transmittance is improved in that the electronic state in the polyimide skeleton is less likely to undergo charge transfer. When the polyimide contains (ii) an aliphatic ring, the light transmittance is improved in that the transfer of electric charges in the skeleton can be inhibited by cutting off the conjugation of π electrons in the skeleton of the polyimide. . If the polyimide contains (iii) a structure in which aromatic rings are linked to each other by an alkylene group that can be substituted by a sulfonyl group or a fluorine atom, the polyimide skeleton can be fused by π electrons in the polyimide skeleton. The light transmittance is improved because the conjugation is cut and the transfer of the charges in the skeleton is inhibited.

Among them, it is preferable to use a polyimide containing an aromatic ring and containing a fluorine atom in terms of improving the light transmittance and improving the surface hardness. When the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), from the viewpoints of improving light transmittance and improving surface hardness, it is preferably At least any one of the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b) contains a polyimide containing an aromatic ring and a fluorine atom, more preferably the above-mentioned polyimide layer (a) ) and the above-mentioned polyimide layer (b) both contain polyimide containing an aromatic ring and containing a fluorine atom.

In addition, from the viewpoint of improving the surface hardness of the above-mentioned polyimide, when the total of the tetracarboxylic acid residues and the diamine residues is 100 mol %, the tetracarboxylic acid residues having an aromatic ring are The total of the diamine residues having an aromatic ring is preferably 50 mol % or more, more preferably 60 mol % or more, and still more preferably 75 mol % or more. Here, the tetracarboxylic acid residue refers to a residue obtained by removing four carboxyl groups from a tetracarboxylic acid, and represents the same structure as a residue obtained by removing an acid dianhydride structure from a tetracarboxylic dianhydride. In addition, the diamine residue refers to a residue obtained by removing two amine groups from diamine.

Moreover, it is preferable that at least one of the tetracarboxylic acid residue and the diamine residue contain an aromatic ring and a fluorine atom from the viewpoint of improving the surface hardness and the light transmittance of the above-mentioned polyimide, and more preferably An aromatic ring and a fluorine atom are contained for both the tetracarboxylic acid residue and the diamine residue. Among them, the above-mentioned polyimide contains a tetracarboxylic acid residue having an aromatic ring and a fluorine atom, and a tetracarboxylic acid residue having an aromatic ring and a fluorine atom, when the total of the tetracarboxylic acid residue and the diamine residue is 100 mol%. The total of the diamine residues is preferably 50 mol% or more, more preferably 60 mol% or more, and still more preferably 75 mol% or more.

Furthermore, it is preferable that the polyimide used in the present invention contains a polyimide containing an aromatic ring having a perfluoroalkyl group from the viewpoint of easily improving the light transmittance and reducing the haze value. When the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), it is relatively easy to improve the light transmittance and reduce the haze value. It is preferable that the above-mentioned polyimide layer (b) containing at least an ultraviolet absorber contains a polyimide containing an aromatic ring having a perfluoroalkyl group. When the polyimide contains an aromatic ring having a perfluoroalkyl group, the compatibility between the polyimide and the ultraviolet absorber is easily improved, the haze value at the time of film formation is reduced, and the characteristics as an optical film can be improved. It is inferred that by making the polyimide contain an aromatic ring having a perfluoroalkyl group, it is easy to have a bulky and sparse (low density) structure, and it is easy to expand the distance between the molecular chains of the polyimide resin, and it is easy to reduce the polyimide resin. The interaction between the molecular chains of the imine resin, so the ultraviolet absorber becomes easy to exist in the gaps generated between the molecular chains of the polyimide resin, thereby improving the compatibility between the polyimide and the ultraviolet absorber, so The haze value during film formation is reduced. Although it does not specifically limit as said perfluoroalkyl group, C1 or more and 3 or less perfluoroalkyl groups are preferable. In addition, from the viewpoint of further improving the light transmittance of the film, the polyimide film of the present invention may contain both the polyimide layer (a) and the polyimide layer (b) described above. Polyimides with aromatic rings of perfluoroalkyl groups. Among them, the polyimide used in the present invention contains tetracarboxylic acid residues having an aromatic ring having a perfluoroalkyl group and The total amount of diamine residues including an aromatic ring having a perfluoroalkyl group is preferably 50 mol % or more, more preferably 60 mol % or more, and still more preferably 75 mol % or more.

The polyimide film of the present invention may not contain polyimide containing fluorine atoms. In the case of containing polyimide containing fluorine atoms, the content ratio of fluorine atoms is in terms of light transmittance and fog reduction. From the viewpoint of degree value, the ratio (F/C) of the number of fluorine atoms (F) to the number of carbon atoms (C) measured on the surface of the polyimide by X-ray photoelectron spectroscopy is preferably 0.01 or more, More preferably, it is 0.05 or more. On the other hand, if the content ratio of fluorine atoms is too high, the inherent heat resistance of polyimide, etc. may be lowered. Therefore, the ratio (F/C) of the number of fluorine atoms (F) to the number of carbon atoms (C) is described above. 1 or less is preferable, and 0.8 or less is more preferable. In the present invention, the above ratio obtained by the measurement of X-ray photoelectron spectroscopy (XPS) can be obtained from the value of atomic % of each atom measured using an X-ray photoelectron spectroscopy apparatus (eg, Theta Probe of Thermo Scientific Corporation). out.

Furthermore, when the polyimide film of the present invention contains polyimide containing fluorine atoms, the content ratio (mass) of the fluorine atoms in all the polyimides contained in the polyimide film of the present invention %), from the viewpoint of easily improving the light transmittance of the polyimide film and reducing the haze value, it is more preferably 5 mass % or more and 45 mass % or less, and still more preferably 10 mass % or more and 40 mass % the following. When the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), from the viewpoint of easily reducing the haze value, the above-mentioned polyimide layer (b) The content ratio (mass %) of fluorine atoms in all the polyimides contained is more preferably 5 mass % or more and 45 mass % or less, and still more preferably 10 mass % or more and 40 mass % or less. Here, the content ratio (mass %) of fluorine atoms in all the polyimide contained in the polyimide film can be obtained from the molecular weight added during the production of the polyimide, and it can be The decomposition product of polyimide obtained by decomposing the sample in an aqueous solution or supercritical methanol was determined using high performance liquid chromatography, gas chromatography mass spectrometer, NMR, elemental analysis, XPS/ESCA and TOF-SIMS.

In addition, as the above-mentioned polyimide, it is preferable to use 50% or more of hydrogen atoms bonded to carbon atoms contained in the polyimide from the viewpoint of light transmittance and heat resistance. Polyimide with hydrogen atom of aromatic ring. The ratio of the hydrogen atoms (number) directly bonded to the aromatic ring among all the hydrogen atoms (number) bonded to the carbon atoms contained in the polyimide is more preferably 60% or more, and more preferably above 70%. When 50% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are contained in the polyimide which is directly bonded to the hydrogen atoms of the aromatic ring, even if the heating step in the atmosphere is carried out For example, even if it is stretched at a temperature of 200° C. or higher, it is preferable in that there are few changes in optical properties, especially transmittance or yellowness YI value. It is inferred that more than 50% of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are directly bonded to the hydrogen atoms of the aromatic ring. The reactivity of the polyimide with oxygen is low, so the polyimide The chemical structure is not easily changed. Polyimide films are mostly used in devices that require processing steps accompanied by heating due to their high heat resistance. When % or more is a polyimide directly bonded to a hydrogen atom of an aromatic ring, it is not necessary to carry out these subsequent steps in an inactive environment in order to maintain transparency, so it is possible to reduce equipment costs and environmental control costs. the advantages of the cost. In the present invention, the ratio of the hydrogen atoms (number) directly bonded to the aromatic ring among all the hydrogen atoms (number) bonded to carbon atoms contained in the polyimide may be equal to that of the polyimide. The decomposition product was determined using high performance liquid chromatography, gas chromatography mass spectrometry and NMR. For example, the sample can be decomposed with an alkaline aqueous solution or supercritical methanol, the obtained decomposed product of polyimide can be separated by high performance liquid chromatography, and the separated product can be separated by gas chromatography mass spectrometer and NMR. Qualitative analysis was carried out on each peak, and high-performance liquid chromatography was used for quantitative analysis, thereby obtaining the hydrogen atoms directly bonded to the aromatic ring among all the hydrogen atoms (number) contained in the polyimide ( number) ratio.

Moreover, as said polyimide, the polyimide containing a silicon atom can be used suitably from a viewpoint of improving the bending resistance of a polyimide film. Examples of the polyimide containing a silicon atom include polyimide containing a tetracarboxylic acid residue having a silicon atom or a diamine residue having a silicon atom. Particularly, in terms of flexibility, the Preferred is a polyimide containing a diamine residue having a silicon atom.

In the polyimide containing the diamine residue having a silicon atom, the ratio of the diamine residue having a silicon atom in 100 mol% of the total amount of the diamine residues, simultaneously realizes the performance of the polyimide film. From the viewpoint of surface hardness and flex resistance, it is preferably 2.5 mol % or more and 50 mol % or less, more preferably 3 mol % or more and 45 mol % or less, and still more preferably 5 mol % More than 40 mol% or less.

As a diamine residue which has a silicon atom, the diamine residue which has a silicon atom in a main chain is preferable. The diamine residue having a silicon atom in the main chain may be a residue obtained by removing two amine groups from the diamine having a silicon atom in the main chain. As a diamine residue which has a silicon atom in a main chain, the diamine represented by following general formula (A) is mentioned, for example.

（通式（A）中，L分別獨立為直接鍵或-O-鍵，R¹⁰ 分別獨立地表示可具有取代基且可含有氧原子或氮原子之碳數1以上且20以下之一價烴基；R¹¹ 分別獨立地表示可具有取代基且可含有氧原子或氮原子之碳數1以上且20以下之二價烴基；k為0以上且200以下之數；具有多個之L、R¹⁰ 及R¹¹ 彼此可相同亦可不同）General formula (A)

(In the general formula (A), L each independently represents a direct bond or -O- bond, and R ¹⁰ each independently represents a carbon number of 1 or more and 20 or less, which may have a substituent and may contain an oxygen atom or a nitrogen atom. ; R ¹¹ each independently represents a divalent hydrocarbon group with a carbon number of 1 or more and 20 or less that may have a substituent and may contain an oxygen atom or a nitrogen atom; k is a number of 0 or more and 200 or less; There are multiple L, R ¹⁰ and R ¹¹ may be the same or different from each other)

Examples of the monovalent hydrocarbon group represented by R ¹⁰ include an alkyl group having 1 to 20 carbon atoms, an aryl group, and a combination thereof. The alkyl group may be any of linear, branched and cyclic, and may also be linear or a combination of branched and cyclic. The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, isopropyl, butyl, and isobutyl. base, tertiary butyl, pentyl, hexyl, etc. As said cyclic alkyl group, a C3 or more and 10 or less cycloalkyl group is preferable, and a cyclopentyl group, a cyclohexyl group, etc. are mentioned specifically,. The aryl group is preferably an aryl group having 6 or more carbon atoms and 12 or less carbon atoms, and specific examples thereof include a phenyl group, a tolyl group, a naphthyl group, and the like. Moreover, as a monovalent hydrocarbon group represented by ^R10 , an aralkyl group (aralkyl) may be sufficient, for example, a benzyl group, a phenylethyl group, a phenylpropyl group, etc. are mentioned. Examples of the hydrocarbon group which may contain an oxygen atom or a nitrogen atom include at least one of the following divalent hydrocarbon group and the above-mentioned monovalent hydrocarbon group using an ether bond, a carbonyl bond, an ester bond, an amide bond, and an imine bond (-NH-). One is the foundation of a bond. The substituent which the monovalent hydrocarbon group represented by R ¹⁰ may have is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include halogen atoms such as a fluorine atom and a chlorine atom, and a hydroxyl group.

The monovalent hydrocarbon group represented by R ¹⁰ is preferably an alkyl group having 1 or more and 3 or less carbon atoms, or an alkyl group having 6 or more and 10 or less carbon atoms, in terms of both improvement in flexural resistance and compatibility of surface hardness. The aryl group is more preferably an alkyl group having 1 or more and 3 or less carbon atoms. The alkyl group having 1 to 3 carbon atoms is more preferably a methyl group, and the aryl group having 6 to 10 carbon atoms is more preferably a phenyl group.

Examples of the divalent hydrocarbon group represented by R ¹¹ include an alkylene group having 1 to 20 carbon atoms, an arylene group, and a group of a combination thereof. The alkylene group may be any of linear, branched and cyclic, and may also be linear or a combination of branched and cyclic. The alkylene group having 1 to 20 carbon atoms is preferably an alkylene group having 1 to 10 carbon atoms, for example, methylene group, ethylidene group, various propylidene groups, various butylene groups, A combination of a linear or branched alkylene group such as a cyclohexyl group and a cyclic alkylene group, etc. As the above-mentioned arylene group, an arylene group having 6 or more carbon atoms and 12 or less carbon atoms is preferable, and examples thereof include a phenylene group, a biextendenyl group, a naphthylene group, and the like, and the following aromatic ring may be further substituted. base. As the divalent hydrocarbon group which may contain an oxygen atom or a nitrogen atom, the above-mentioned divalent hydrocarbon groups are bonded to each other by at least one of an ether bond, a carbonyl bond, an ester bond, an amide bond, and an imine bond (-NH-). the basis of. The substituent which the divalent hydrocarbon group represented by R ¹¹ may have may be the same as the substituent which the monovalent hydrocarbon group represented by R ¹⁰ may have.

The divalent hydrocarbon group represented by R ¹¹ is preferably an alkylene group having 1 or more and 6 or less carbon atoms, or an alkylene group having 6 or more and 10 carbon atoms in view of the compatibility between the improvement of flexural resistance and the surface hardness. The following arylene group is more preferably an alkylene group having 2 or more and 4 or less carbon atoms, and the alkylene group is preferably linear or branched.

In the general formula (A), k is a number of 0 or more and 200 or less, preferably 0 or more and 100 or less, more preferably 0 or more and 10 or less, still more preferably 0 or more and 6 or less The number is more preferably a number of 0 or more and 4 or less, more preferably a number of 0 or more and 2 or less, and particularly preferably 0 or 1.

Among the above-mentioned diamine residues having a silicon atom in the main chain, a diamine residue having one or two silicon atoms in the main chain is preferable. As a diamine which has one silicon atom in a main chain, the diamine represented by the following general formula (A-1) in which k=0 among the diamines represented by the said general formula (A) is mentioned, for example. Moreover, as a diamine which has two silicon atoms in a main chain, the diamine represented by the following general formula (A-2) in which k=1 in the diamine represented by the said general formula (A) is mentioned, for example.

通式（A-2）

（通式（A-1）及通式（A-2）中，L分別獨立為直接鍵或-O-鍵，R¹⁰ 分別獨立地表示可具有取代基且可含有氧原子或氮原子之碳數1以上且20以下之一價烴基；R¹¹ 分別獨立地表示可具有取代基且可含有氧原子或氮原子之碳數1以上且20以下之二價烴基；具有多個之L、R¹⁰ 及R¹¹ 彼此可相同亦可不同）General formula (A-1)

General formula (A-2)

(In general formula (A-1) and general formula (A-2), L is each independently a direct bond or -O- bond, and R ¹⁰ is each independently a carbon that may have a substituent and may contain an oxygen atom or a nitrogen atom A monovalent hydrocarbon group of 1 or more and 20 or less; R ¹¹ each independently represents a divalent hydrocarbon group with a carbon number of 1 or more and 20 or less, which may have a substituent and may contain an oxygen atom or nitrogen atom; There are multiple L, R ¹⁰ and R ¹¹ may be the same or different from each other)

The molecular weight of the diamine residue having a silicon atom in the main chain is preferably 3,000 or less, and more preferably 2,000 or less, in terms of suppressing the mobility of molecules and imparting flex resistance, and both in terms of surface hardness. , more preferably 1000 or less, more preferably 800 or less, still more preferably 500 or less, still more preferably 300 or less.

Moreover, as the above-mentioned diamine residue having one or two silicon atoms in the main chain, it is preferable to have two of two silicon atoms in terms of light transmittance, flex resistance, and surface hardness The amine residue is preferably selected from the group consisting of 1,3-bis(3-aminopropyl)tetramethyldisiloxane residue, In the group consisting of 1,3-bis(4-aminobutyl)tetramethyldisiloxane residues and 1,3-bis(5-aminopentyl)tetramethyldisiloxane residues at least one of them. In addition, these may be used individually or in mixture of 2 or more types.

The content ratio of each repeating unit in the polyimide, the content ratio (mol%) of each tetracarboxylic acid residue or each diamine residue can be obtained from the molecular weight added during the production of polyimide, and, The decomposition product of the polyimide obtained in the same manner as above can be determined by using high performance liquid chromatography, gas chromatography mass spectrometry, NMR, elemental analysis, XPS/ESCA and TOF-SIMS.

Moreover, when the polyimide film of the present invention has the polyimide layer (a) and the polyimide layer (b), the polyimide layer (a) that exists adjacent to each other If the polyimide contained in each of the above-mentioned polyimide layers (b) is the same as each other, the adhesion between the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b) that exist adjacent to each other is excellent. It is better in this respect.

The polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), and the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer that exist adjacent to each other When the polyimides contained in each of the amine layers (b) are the same as each other, the polyimides are used in terms of improving the flexibility resistance, interlayer adhesion, and light transmittance. , preferably containing a polyimide having a structure represented by the following general formula (1).

（通式（1）中，R¹ 表示作為具有芳香族環或脂肪族環之四羧酸殘基之四價基，R² 表示作為二胺殘基之二價基，R² 之總量之2.5莫耳%以上且50莫耳%以下為於主鏈具有矽原子之二胺殘基，R² 之總量之50莫耳%以上且97.5莫耳%以下為不具有矽原子且具有芳香族環或脂肪族環之二胺殘基；n表示重複單位數）General formula (1)

(In the general formula (1), R ¹ represents a tetravalent group as a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, R ² represents a divalent group as a diamine residue, and the sum of the total amount of R ² 2.5 mol % or more and 50 mol % or less are diamine residues having silicon atoms in the main chain, and 50 mol % or more and 97.5 mol % or less of the total amount of R ² do not have silicon atoms and are aromatic Diamine residue of ring or aliphatic ring; n represents the number of repeating units)

R ¹ of the above general formula (1) can be appropriately selected from the above-mentioned tetracarboxylic acid components from the residue of the tetracarboxylic dianhydride having an aromatic ring after removing the acid dianhydride structure, or from the tetracarboxylic acid having an aliphatic ring. The residue from which the acid dianhydride structure is removed from the dianhydride, among them, is preferably selected from the group consisting of a cyclohexanetetracarboxylic dianhydride residue and a cyclopentanetetracarboxylic dianhydride residue in terms of flexibility , dicyclohexane-3,4,3',4'-tetracarboxylic dianhydride residue, cyclobutane tetracarboxylic dianhydride residue, 4,4'-(hexafluoroisopropylidene) di-ortho Phthalic anhydride residue, 3,4'-(hexafluoroisopropylidene)diphthalic anhydride residue, 3,3'-(hexafluoroisopropylidene)diphthalic anhydride residue At least one tetravalent group in the group consisting of 4,4'-oxydiphthalic anhydride residues, and 3,4'-oxydiphthalic anhydride residues, but no particular limited. In the above-mentioned R ¹ , the total content of these preferred residues is preferably 50 mol% or more, more preferably 70 mol% or more, and more preferably 90 mol% or more. Especially in terms of light transmittance and surface hardness, the above R ¹ is more preferably selected from the group consisting of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride residues, 3,4'-(hexafluoroisopropylidene Fluoroisopropylidene) diphthalic anhydride residue, 3,3'-(hexafluoroisopropylidene) diphthalic anhydride residue, 4,4'-oxydiphthalic anhydride residue and at least one tetravalent group in the group consisting of 3,4'-oxydiphthalic anhydride residues.

In the polyimide having the structure represented by the above general formula (1), the ratio of the diamine residue having a silicon atom in the main chain is 2.5 mol % or more and 50 mol % or less of the total amount of R ² , from the viewpoint of improving flex resistance and improving interlayer adhesion, preferably 5 mol % or more of the total amount of R ² , and may be 10 mol % or more. On the other hand, from the viewpoint of improving hardness and light transmittance, R ² in the above general formula (1) is preferably 45 mol % of the total amount of R ² in the diamine residue having a silicon atom in the main chain Below, more preferably, it is 40 mol% or less. Furthermore, if 2.5 mol % or more and 50 mol % or less of the total amount of R ² are satisfied, it is a diamine residue having a silicon atom in the main chain, and 50 mol % or more and 97.5 mol % of the total amount of R ² are satisfied. % and below are diamine residues that do not have silicon atoms and have aromatic or aliphatic rings, then R ² in the above general formula (1) may also include diamine residues that have silicon atoms in the main chain and do not. Other diamine residues having a silicon atom and having an aromatic ring or an aliphatic ring are different from the diamine residue. The other diamine residue is preferably 10 mol % or less of the total amount of R ² , more preferably 5 mol % or less, still more preferably 3 mol % or less, particularly preferably 1 mol % or less. As this other diamine residue, the diamine residue etc. which do not have a silicon atom and do not have an aromatic ring or an aliphatic ring are mentioned, for example. Moreover, it is preferable not to contain the diamine residue which has 3 or more silicon atoms in a main chain from a viewpoint of improving a tensile elastic modulus and improving surface hardness. Among them, it is preferably 2.5 mol % or more and 50 mol % or less of the total amount of R ² , more preferably 3 mol % or more and 45 mol % or less, 5 mol % or more and 40 mol % or less. In the total amount (100 mol %) of diamine residues having silicon atoms in the main chain, R ² , the residue of the above-mentioned molar % (x mol %) of diamine residues having silicon atoms in the main chain ( 100%-x%), that is, 50 mol% or more and 97.5 mol% or less, preferably 55 mol% or more and 97 mol% or less, 60 mol% or more and 95 mol% or less, do not have silicon atoms And have an aromatic ring or aliphatic ring diamine residue.

The diamine residue having a silicon atom in the main chain in the above R ² is the same as that described in relation to the above-mentioned polyimide containing a silicon atom, and among them, one or two silicon atoms in the main chain is preferred. diamine residue.

The diamine residue that does not have a silicon atom and has an aromatic ring in the above R ² can be a residue obtained by removing two amine groups from the diamine that does not have a silicon atom and has an aromatic ring. As the diamine having no silicon atom and having an aromatic ring, for example, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4'- Diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4 '-Diamino diphenyl sulfide, 3,3'-diamino diphenyl sulfide, 3,4'-diamino diphenyl sulfide, 4,4'-diamino diphenyl sulfide, 3,3'-Diaminobenzophenone, 4,4'-Diaminobenzophenone, 3,4'-Diaminobenzophenone, 4,4'-Diaminobenzophenone Aniline, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-bis(3-amine phenyl)propane, 2,2-bis(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane 3-Aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3- Hexafluoropropane, 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 1,1-bis(3- Aminophenyl)-1-phenylethane, 1,1-bis(4-aminophenyl)-1-phenylethane, 1-(3-aminophenyl)-1-(4- Aminophenyl)-1-phenylethane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis (3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene 4-Aminobenzyl)benzene, 1,4-bis(3-aminobenzyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis (3-Amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amine base-α,α-dimethylbenzyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(3-amino-α, α-Ditrifluoromethylbenzyl)benzene, 1,3-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene, 1,4-bis(3-amino-α, α-Ditrifluoromethylbenzyl)benzene, 1,4-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene, 2,6-bis(3-aminophenoxy) ) benzonitrile, 2,6-bis(3-aminophenoxy)pyridine, N,N'-bis(4-aminophenyl)terephthalamide, 9,9-bis(4- Aminophenyl) phenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (2 ,2'-bis(trifluoromethyl)benzidine), 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diphenyl Aminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-bis (3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[ 4-(4-Aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl] ] sulfide, bis[4-(3-aminophenoxy)phenyl] bis[4-(4-aminophenoxy)phenyl] bis(4-(3-aminophenoxy)phenyl] bis[4-(3-aminobenzene) oxy)phenyl] ether, bis[4-(4-aminophenoxy)phenyl]ether, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2, 2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3 ,3-hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1,3-bis[ 4-(3-Aminophenoxy)benzyl]benzene, 1,3-bis[4-(4-aminophenoxy)benzyl]benzene, 1,4-bis[4- (3-Aminophenoxy)benzyl]benzene, 1,4-bis[4-(4-aminophenoxy)benzyl]benzene, 1,3-bis[4-(3 -aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-aminophenoxy)-α, α-Dimethylbenzyl]benzene, 4,4'-bis[4-(4-aminophenoxy)benzyl]diphenyl ether, 4,4'-bis[4-(4-amine] base-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy] Diphenyl bismuth, 4,4'-bis[4-(4-aminophenoxy)phenoxy]diphenyl bismuth, 3,3'-diamino-4,4'-diphenoxy Benzophenone, 3,3'-diamino-4,4'-diphenyloxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 3, 3'-Diamino-4-biphenoxybenzophenone, 6,6'-bis(3-aminophenoxy)-3,3,3',3'-tetramethyl-1, 1'-spirobisindane, 6,6'-bis(4-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobisindane, etc., and A diamine obtained by substituting a part or all of the hydrogen atoms on the aromatic ring of the above-mentioned diamine with a substituent selected from a fluoro group, a methyl group, a methoxy group, a trifluoromethyl group, or a trifluoromethoxy group. These may be used individually or in mixture of 2 or more types.

The diamine residue having no silicon atom and having an aliphatic ring in R ² of the above general formula (1) can be set as the residue after removing two amine groups from the diamine having no silicon atom and having an aliphatic ring . As the diamine having no silicon atom and having an aliphatic ring, for example, 1,4-cyclohexanediamine, trans-1,4-bismethylenecyclohexanediamine, 2,6-bis(amine (aminomethyl)bicyclo[2,2,1]heptane, 2,5-bis(aminomethyl)bicyclo[2,2,1]heptane, and the like. These may be used individually or in mixture of 2 or more types.

As a diamine residue having no silicon atom and having an aromatic ring or an aliphatic ring in R ² of the above general formula (1), among them, in terms of light transmittance, flex resistance and surface hardness, And the aspect that the silicon atom in the film is easy to exist, is preferably selected from 1,4-cyclohexanediamine residue, trans-1,4-bismethylenecyclohexanediamine residue, 4 ,4'-diaminodiphenyl residue, 3,4'-diaminodiphenyl residue, 2,2-bis(4-aminophenyl)propane, 2,2-bis( 4-aminophenyl) hexafluoropropane residue, and at least one divalent group in the group consisting of the divalent group represented by the following general formula (3), especially for both light transmittance and surface hardness. On the other hand, it is more preferable to be selected from the group consisting of 4,4'-diaminodiphenyl residues, 3,4'-diaminodiphenyl residues, 2,2-bis(4-amino Phenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane residue, and at least one divalent group in the group consisting of a divalent group represented by the following general formula (3) , more preferably a divalent group represented by the following general formula (3). As a divalent group represented by the following general formula (3), it is more preferable that R ⁵ and R ⁶ are perfluoroalkyl groups, among them, perfluoroalkyl groups having 1 to 3 carbon atoms are preferable, and more preferable are trifluoromethyl or perfluoroethyl. Moreover, as the alkyl group in R ⁵ and R ⁶ in the following general formula (3), an alkyl group having 1 or more and 3 or less carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.

（通式（3）中，R⁵ 及R⁶ 分別獨立地表示氫原子、烷基、或全氟烷基）General formula (3)

(In the general formula (3), R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group, or a perfluoroalkyl group)

In the structure represented by the above-mentioned general formula (1), n represents the number of repeating units, and is 1 or more. The number n of repeating units in the polyimide is preferably appropriately selected according to the structure so as to exhibit the desired Young's modulus and glass transition temperature, and is usually 10 to 2000, more preferably 15 to 1000, but There is no particular limitation. Furthermore, R ¹ in each repeating unit may be the same or different from each other, and R ² in each repeating unit may be the same or different from each other.

Moreover, about the polyimide having the structure represented by the above-mentioned general formula (1), the number average molecular weight is preferably 10,000 or more, and more preferably 20,000 in terms of strength and flex resistance when formed into a film. or more, more preferably 30,000 or more, particularly preferably 50,000 or more. The upper limit is not particularly limited, but from the viewpoint of easy synthesis and easy acquisition, it is preferably 10,000,000 or less, and more preferably 500,000 or less. Furthermore, the number average molecular weight of the polyimide can be measured in the same manner as the number average molecular weight of the polyimide precursor described below.

In addition, the weight average molecular weight of the polyimide having the structure represented by the above general formula (1) is preferably 20,000 or more, more preferably 30,000 in terms of strength and flex resistance when formed into a film. or more, more preferably 40,000 or more, particularly preferably 80,000 or more. The upper limit is not particularly limited, but from the viewpoint of easy synthesis and easy acquisition, it is preferably 10,000,000 or less, and more preferably 500,000 or less. The weight average molecular weight of the polyimide can be determined by gel permeation chromatography (GPC). Specifically, polyimide was prepared as an N-methylpyrrolidone (NMP) solution with a concentration of 0.2% by weight, and the developing solvent was a 30 mmol% LiBr-NMP solution with a water content of 500 ppm or less, manufactured by Tosoh A GPC device (HLC-8120, using a column: GPC LF-804 manufactured by SHODEX) was used for the measurement under the conditions of a sample injection volume of 50 μL, a solvent flow rate of 0.4 mL/min, and 40°C. The weight average molecular weight is determined based on a polystyrene standard sample having the same concentration as the sample.

The polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), and the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer that exist adjacent to each other When the polyimides contained in the amine layers (b) are the same as each other, in terms of light transmittance and flexibility resistance, among all the polyimides contained in the polyimide film of the present invention, The content ratio of the polyimide having the structure represented by the general formula (1) is preferably 60 mass % or more, more preferably 70 mass % or more, and still more preferably 80 mass % or more.

Moreover, when the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), if the above-mentioned polyimide layer ( The polyimide contained in a) is different from the polyimide contained in the above-mentioned polyimide layer (b) located on the outermost surface of the other side. The polyimide contained in each of (a) and the polyimide layer (b) is preferable in that the properties of each polyimide layer are adjusted, and the flexural resistance and surface hardness are easily improved.

The polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), and the polyimide layer (a) on the outermost surface on one side contains the polyimide layer (a). In the case where the polyimide and the polyimide contained in the polyimide layer (b) located on the outermost surface of the other side are different from each other, the interlayer adhesion, flex resistance, It is preferable that the said polyimide layer (a) located in the outermost surface of one surface side contains the polyimide which has the structure represented by the said General formula (1) from the viewpoint of translucency. In this case, all the polyimides contained in the polyimide layer (a) have the above-mentioned general formula (1) in terms of light transmittance, flex resistance, and interlayer adhesion. ) of the structure represented by the polyimide content ratio is preferably 60 mass % or more, more preferably 70 mass % or more, and still more preferably 80 mass % or more.

In addition, the polyimide film of the present invention has the polyimide layer (a) and the polyimide layer (b), and the polyimide layer (a) located on the outermost surface of one side is provided with the polyimide layer (a). In the case where the polyimide contained is different from the polyimide contained in the polyimide layer (b) located on the outermost surface of the other side, it is preferable to be located at the surface hardness. The said polyimide layer (b) of the outermost surface of the other surface side contains the polyimide which has the structure represented by following general formula (2). In this case, among all the polyimides contained in the polyimide layer (b), the content ratio of the polyimide having the structure represented by the following general formula (2) is preferably 60% by mass Above, more preferably 70 mass % or more, still more preferably 80 mass % or more.

（通式（2）中，R³ 表示選自由焦蜜石酸二酐殘基、2,3,3',4'-聯苯四羧酸二酐殘基及3,3',4,4'-聯苯四羧酸二酐殘基所組成之群中之至少1種四價基，R⁴ 表示作為二胺殘基之二價基；n'表示重複單位數）General formula (2)

(In the general formula (2), R ³ represents a residue selected from the group consisting of pyromic acid dianhydride residues, 2,3,3',4'-biphenyltetracarboxylic dianhydride residues and 3,3',4,4 '-At least one tetravalent group in the group consisting of biphenyltetracarboxylic dianhydride residues, R ⁴ represents a divalent group as a diamine residue; n' represents the number of repeating units)

The diamine residue in R ⁴ of the general formula (2) is not particularly limited, but it is preferable to include an aromatic ring in terms of flexibility resistance, light transmittance, and surface hardness. Or the diamine residue of an aliphatic ring, it is more preferable to contain the diamine residue which does not have a silicon atom and has an aromatic ring or an aliphatic ring. As the diamine residue having an aromatic ring or an aliphatic ring in R ⁴ of the above general formula (2), for example, a polyimide having a structure represented by the above general formula (1) can be preferably used The same as those described for the diamine residue having no silicon atom and having an aromatic ring or an aliphatic ring are used. In the polyimide having the structure represented by the above general formula (2), in terms of flexibility resistance, light transmittance, and surface hardness, those having an aromatic ring or an aliphatic ring are preferred. The ratio of the diamine residues is preferably 50 mol % or more, more preferably 60 mol % or more, and still more preferably 70 mol % or more of the total amount of R ⁴ .

In the structure represented by the said general formula (2), n' represents the number of repeating units, and is 1 or more. The number of repeating units n' in the polyimide is preferably appropriately selected according to the structure in such a manner that the desired Young's modulus and glass transition temperature are exhibited, usually 10-2000, more preferably 15-1000, However, it is not particularly limited. Furthermore, R ³ in each repeating unit may be the same or different from each other, and R ⁴ in each repeating unit may be the same or different from each other.

Moreover, about the polyimide having the structure represented by the above-mentioned general formula (2), the number average molecular weight is preferably 10,000 or more, more preferably 20,000 in terms of strength and flex resistance when formed into a film or more, more preferably 30,000 or more, particularly preferably 50,000 or more. The upper limit is not particularly limited, but from the viewpoint of easy synthesis and easy acquisition, it is preferably 10,000,000 or less, and more preferably 500,000 or less.

In addition, with regard to the polyimide having the structure represented by the above-mentioned general formula (2), the weight-average molecular weight is preferably 20,000 or more, more preferably 30,000, in terms of strength and flex resistance when formed into a film. or more, more preferably 40,000 or more, particularly preferably 80,000 or more. The upper limit is not particularly limited, but from the viewpoint of easy synthesis and easy acquisition, it is preferably 10,000,000 or less, and more preferably 500,000 or less.

In addition, the polyimide used in the present invention may contain a polyimide structure in part as long as the effect of the present invention is not impaired. Examples of the polyamide structure that can be contained include a polyamide imide structure containing a tricarboxylic acid residue such as 1,2,4-tricarboxylic acid anhydride, or a dicarboxylic acid residue such as terephthalic acid. based on the polyamide structure. Moreover, in this invention, it is preferable that the polyimide contained in the polyimide layer containing the polyimide having the structure represented by the above-mentioned general formula (1) has the structure represented by the above-mentioned general formula (1). It is 95% or more of the total number of repeating units of the polyimide, more preferably 98% or more, and still more preferably 100%. In the present invention, the polyimide layer contained in the polyimide layer containing the polyimide having the structure represented by the general formula (2) is preferably a polyimide having the structure represented by the general formula (2). The total number of repeating units of the imine is 95% or more, more preferably 98% or more, and still more preferably 100%. Examples of structures different from the structure represented by the above-mentioned general formula (1) or the structure represented by the above-mentioned general formula (2) include, for example, a case containing a tetracarboxylic acid residue without an aromatic ring or an aliphatic ring, and the like, or polyamide structure.

The polyimide used in the present invention preferably has a glass transition temperature in a temperature range of 150°C or higher and 400°C or lower, from the viewpoint of both heat resistance and moderate baking temperature. By making the said glass transition temperature 150 degreeC or more, it is excellent in heat resistance, More preferably, it is 200 degreeC or more, More preferably, it is 250 degreeC or more, More preferably, it is 270 degreeC or more. Moreover, by making glass transition temperature 400 degrees C or less, a baking temperature can be lowered|hung, and it is more preferable that it is 380 degrees C or less. Moreover, it is preferable that the polyimide used in the present invention has one peak of the tanδ curve in a temperature range of 150°C or higher and 400°C or lower. In addition, the polyimide used in the present invention preferably does not have the peak of the tanδ curve in the temperature range of -150°C or higher and 0°C or lower, thereby improving the tensile elasticity of the polyimide film at room temperature. modulus, which can increase the surface hardness. In addition, the polyimide used in the present invention may further have a peak of a tanδ curve in a temperature range exceeding 0°C and less than 150°C. In addition, the above-mentioned glass transition temperature is obtained from the peak temperature of the temperature-tanδ (tanδ = loss elastic modulus (E'')/storage elastic modulus (E')) curve obtained by dynamic viscoelasticity measurement . The glass transition temperature of polyimide refers to the temperature at which the maximum value of the peak is the maximum peak when there are multiple peaks of the tanδ curve. The dynamic viscoelasticity measurement can be performed, for example, with a dynamic viscoelasticity measuring apparatus RSA III (TA Instruments Japan Co., Ltd.), with a measurement range of -150°C to 400°C, a frequency of 1 Hz, and a temperature increase rate of 5°C/min. . In addition, the sample width can be set to 5 mm, and the distance between the chucks can be set to 20 mm, and the measurement can be performed. When analyzing the peaks and inflection points, the data were digitized without visual evaluation, and analyzed based on the numerical values. In the present invention, the peak of the tanδ curve refers to an inflection point that is a maximum value, and the peak width between the peaks and valleys is 3°C or more. Regarding noise and other slight fluctuations from measurement, Not to be interpreted as the above-mentioned peaks.

The content ratio of the polyimide in the total solid content of the polyimide film of the present invention is preferably 90% by mass or more in terms of flex resistance and surface hardness. From the viewpoint of sufficiently containing an ultraviolet absorber to improve weather resistance, it is preferably 99.9 mass % or less. Moreover, when the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), the total solid content of the above-mentioned polyimide layer (a) The content ratio of the polyimide among them is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 99% by mass or more, in terms of flex resistance. In addition, the content ratio of the polyimide in the total solid content of the polyimide layer (b) is preferably 40 mass % or more, more preferably 45 mass %, in terms of flex resistance % or more, more preferably 55 mass % or more, still more preferably 65 mass % or more, may be 80 mass % or more, and may be 90 mass % or more, on the other hand, the ultraviolet absorber is sufficiently contained to improve weather resistance From a viewpoint, it is preferably 99.2 mass % or less, more preferably 98 mass % or less, still more preferably 96 mass % or less, still more preferably 91 mass % or less, and still more preferably 87 mass % or less. In addition, in this invention, the so-called solid content means all components other than a solvent.

(2) UV absorber The ultraviolet absorber used in the present invention can be appropriately set so that the transmittance at a wavelength of 380 nm of the polyimide film of the present invention is 18% or less, and the transmittance at a wavelength of 450 nm is 85% or more. The type and content are not particularly limited. In addition, as the ultraviolet absorber used in the present invention, as long as it has a maximum absorption wavelength at a wavelength of 250 nm or more and 380 nm or less, and satisfies any one of the following conditions (i) and (ii), it is not limited to general It is used as what is included in the ultraviolet absorber. Condition (i) Absorbance at wavelength 380 nm is above 0.005, absorbance at wavelength over 380 nm and below 780 nm in visible light region is less than absorbance at wavelength 380 nm, and absorbance at wavelength 450 nm is below 0.1 Condition (ii) The molar absorptivity at a wavelength of 380 nm is 50 or more and 500,000 or less, and the molar absorptivity at a wavelength of 450 nm is less than or equal to 10 and 500,000 at a wavelength of 380 nm In addition, the absorbance and molar absorption coefficient of the ultraviolet absorber can be obtained by dissolving the ultraviolet absorber in a solvent by ultraviolet-visible spectroscopy (UV-vis). As a solvent for dissolving the ultraviolet absorber when the absorbance is determined, a solvent capable of dissolving the ultraviolet absorber can be appropriately selected and used from solvents in which absorbance is not detected at a wavelength of 380 nm or more and 780 nm or less. Specifically, a solvent whose absorption wavelength is in the ultraviolet region and on the shorter wavelength side, such as acetonitrile, can be preferably used, and dimethylacetamide (DMAc) and the like can also be suitably used. Moreover, the density|concentration of the solution used for absorbance measurement is usually adjusted so that a solvent may become 100 mL with respect to 1 mg of an ultraviolet absorber.

Examples of the ultraviolet absorber used in the present invention include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, Sankou-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, and hindered amines. Commercially available products such as ultraviolet absorbers, benzoate-based ultraviolet absorbers, malonate-based ultraviolet absorbers, and oxaniline-based ultraviolet absorbers can also be used. Among them, preferably at least one selected from the group consisting of benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, and three-well-based ultraviolet absorbers, in terms of transmittance and ultraviolet absorptivity, In terms of reducing the yellowness, at least one selected from the group consisting of a benzotriazole-based ultraviolet absorber and a three-well-based ultraviolet absorber is more preferred, and a benzotriazole-based ultraviolet absorber is more preferred. agent. In addition, in this invention, an ultraviolet absorber may be used individually by 1 type, and may mix and use 2 or more types.

Examples of benzotriazole-based ultraviolet absorbers include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tertiarybutyl) -5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tertiary pentylphenyl)benzotriazole, 2-(2' -Hydroxy-5'-tertiary octylphenyl)benzotriazole, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tertiary octylphenol ], 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2'-hydroxy-5'-tertiary butyl) phenyl)-2H-benzotriazole, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-( 2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2,2 '-Methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(3,5-di Tertiary butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazole-2 -yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-benzotriazol-2-yl-4,6-ditertiary butylphenol, 2-[5 -Chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tertiary butyl)phenol, 2-(2H-benzotriazol-2-yl)-4,6- Di-tertiary butylphenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazole -2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidomethyl)phenol, 3-(3-(2H-benzotriazole- 2-yl)-5-tertiary butyl-4-hydroxyphenyl) methyl propionate/polyethylene glycol 300 reaction product, 2-(2H-benzotriazol-2-yl)-6- (straight-chain and side-chain dodecyl)-4-methylphenol, etc.

Examples of commercially available benzotriazole-based ultraviolet absorbers include Tinuvin PS, Tinuvin 109, Tinuvin 1130, Tinuvin 171, Tinuvin 326, Tinuvin 328, Tinuvin 384-2, Tinuvin 99-2, Tinuvin 900, Tinuvin 928, Tinuvin Carboprotect (the above is manufactured by BASF); Sumisorb 200, Sumisorb 250, Sumisorb 300, Sumisorb 340, Sumisorb 350 (the above are manufactured by Sumika Chemtex Co., Ltd.); LA-29, LA-31, LA-32, LA -36 (the above are manufactured by ADEKA Co., Ltd.); JF-77, JF-79, JF-80, JF-83, JF-832, JAST-500 (the above are manufactured by Chengbei Chemical Industry Co., Ltd.); KEMISORB 71, KEMISORB 73, KEMISORB 74, KEMISORB 79, KEMISORB 279 (the above are manufactured by Chemipro Kasei Co., Ltd.); SEESORB 701, SEESORB 703, SEESORB 704, SEESORB 706, SEESORB 707, SEESORB 709 (the above are manufactured by Shipro Kasei Co., Ltd.), etc. .

Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-n-octyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxydibenzophenone Benzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone , 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 1,4-bis(4-benzyl-3-hydroxyphenoxy)-butane, etc.

Examples of commercially available benzophenone-based ultraviolet absorbers include Chimassorb 8a-3himassorb 90 (manufactured by BASF); Adekastab 1413 (manufactured by ADEKA); SEESORB 100, SEESORB 101, SEESORB 101S, SEESORB 102, and SEESORB 103 , SEESORB 105, SEESORB 106, SEESORB 107, SEESORB 151 (the above are manufactured by Shipro Kasei Co., Ltd.); Sumisorb 130 (by Sumika Chemtex Co., Ltd.); Co., Ltd.), etc.

As a three-well type ultraviolet absorber, for example, 2-(4,6-diphenyl-1,3,5-three-well-2-yl)-5-[(hexyl)oxy]-phenol, 2 -(4,6-Bis(2,4-Dimethylphenyl)-1,3,5-Triwell-2-yl)-5-hydroxyphenyl, 2,4-Bis[2-hydroxy-4 -Butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triple, 2-(4,6-diphenyl-1,3,5-triple In-2-yl)-5-[2-(2-ethylhexyloxy)ethoxy]phenol, 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methyl) phenyl)-1,3,5-Three wells, etc.

Examples of commercially available three-well UV absorbers include Tinuvin 460, Tinuvin 479, Tinuvin 477, Tinuvin 400, Tinuvin 405, and Tinuvin 1577ED (the above are manufactured by BASF); Adekastab LA-46, Adekastab LA-F70 (The above are manufactured by ADEKA Corporation) and so on.

The above-mentioned ultraviolet absorbers usually have a maximum absorption wavelength at a wavelength of more than 250 nm and less than 380 nm, and the absorbance at a wavelength of 380 nm is more than 0.005. The absorbance at 450 nm is below 0.1. The absorbance of the above-mentioned ultraviolet absorber at a wavelength of 380 nm is more preferably 0.01 or more, and still more preferably 0.02 or more. Moreover, it is more preferable that the absorbance of the wavelength 450 nm of the said ultraviolet absorber is 0.01 or less, and it is still more preferable that it is 0.005 or less.

Moreover, as said ultraviolet absorber, from a viewpoint of drying a solvent in manufacture, it is preferable that a melting point is 75 degreeC or more, and it is more preferable that a melting point is 100 degreeC or more. On the other hand, in terms of solubility, the melting point of the ultraviolet absorber is preferably 200°C or lower.

In addition, as the above-mentioned ultraviolet absorber, it is easy to improve the light transmittance of the polyimide film of the present invention by having good compatibility with polyimide, especially with polyimide containing silicon atoms. From a viewpoint, what has a C1-15 linear or branched saturated aliphatic hydrocarbon group is preferable. The above-mentioned saturated aliphatic hydrocarbon group is from the viewpoint that the compatibility between the ultraviolet absorber and the polyimide becomes better, the reduction of the optical properties of the polyimide film containing the ultraviolet absorber is easily suppressed, and the light transmittance is easily improved. An alkyl group or an alkylene group is preferable, and an alkyl group is more preferable. Moreover, the carbon number of the said saturated aliphatic hydrocarbon group is more preferably 6 or more, still more preferably 7 or more, still more preferably 8 or more.

Among them, as an ultraviolet absorber having a linear or branched saturated aliphatic hydrocarbon group with a carbon number of 1 or more and 15 or less, it has good compatibility with polyimide and is easy to suppress the optical properties of the polyimide film. The compound represented by the following general formula (I) can be preferably used from the viewpoint of easily improving the light transmittance.

（通式（I）中，R²¹ 、R²² 、R²³ 及R²⁴ 分別獨立地表示氫原子、鹵素原子或碳數1以上且4以下之烷基，R²⁵ 、R²⁶ 、R²⁷ 、R²⁸ 及R²⁹ 分別獨立地表示氫原子、羥基、可經苯基或一價之聚矽氧烷基取代之碳數1以上且15以下之直鏈狀或支鏈狀之烷基、或-R³⁰ -A-R³¹ ，R³⁰ 表示碳數1以上且15以下之直鏈狀或支鏈狀伸烷基，A表示伸苯基或二價之聚矽氧烷基，R³¹ 表示碳數1以上且15以下之直鏈狀或支鏈狀之烷基，R²⁵ 、R²⁶ 、R²⁷ 、R²⁸ 及R²⁹ 之至少一者表示可經苯基或一價之聚矽氧烷基取代之碳數1以上且15以下之直鏈狀或支鏈狀之烷基、或-R³⁰ -A-R³¹ ；上述苯基及上述伸苯基可經碳數1以上且15以下之直鏈狀或支鏈狀之烷基取代）General formula (I)

(In the general formula (I), R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 or more and 4 or less carbon atoms, R ²⁵ , R ²⁶ , R ²⁷ , and R ²⁸ and R ²⁹ each independently represent a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 15 carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group, or -R ³⁰ -AR ³¹ , R ³⁰ represents a linear or branched alkylene group with 1 or more carbon atoms and 15 or less, A represents a phenylene group or a divalent polysiloxane group, R ³¹ represents a carbon number of 1 or more and Linear or branched alkyl group below 15, at least one of R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ represents the number of carbons that can be substituted by phenyl or monovalent polysiloxane A linear or branched alkyl group of 1 or more and 15 or less, or -R ³⁰ -AR ³¹ ; the above-mentioned phenyl and the above-mentioned phenylene may be linear or branched with a carbon number of 1 or more and 15 or less the alkyl substitution)

Examples of the halogen atom in R ²¹ , R ²² , R ²³ and R ²⁴ in the general formula (I) include chlorine atom, fluorine atom, bromine atom, etc. Among them, chlorine atom is preferable. The alkyl group having 1 or more and 4 or less carbon atoms in R ²¹ , R ²² , R ²³ and R ²⁴ in the general formula (I) may be any of linear, branched or cyclic, preferably It is linear or branched, preferably methyl or ethyl. Among them, in terms of compatibility with polyimide, R ²¹ , R ²² , R ²³ and R ²⁴ in the general formula (I) are preferably a hydrogen atom or a halogen atom, more preferably R ²¹ , R ²³ and R ²⁴ are hydrogen atoms, and R ²² is a hydrogen atom or a halogen atom, more preferably both are hydrogen atoms. From the viewpoint that the compatibility with polyimide becomes good, the reduction of the optical properties of the polyimide film is easily suppressed, and the light transmittance is easily improved, R ²⁵ , R ²⁶ , The alkyl group in R ²⁷ , R ²⁸ and R ²⁹ , the alkylene group in R ³⁰ , and the alkyl group in R ³¹ are more preferably 6 or more carbon atoms, more preferably 7 or more, particularly preferably 8 or more. In addition, the alkyl group in R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ in the general formula (I), the alkyl group in R ³⁰ and the alkyl group in R ³¹ are straight or branched chains It is preferably branched from the viewpoint of compatibility with polyimide. The monovalent polysiloxane group among R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ in the above general formula (I) refers to the removal of one hydrogen atom at the end of the main chain of the polysiloxane. The remaining group, the divalent polysiloxane group in A refers to the remaining group after removing one hydrogen atom from both ends of the main chain of the polysiloxane. Among them, the above-mentioned monovalent or divalent polysiloxane group is preferably a monovalent or divalent dimethyl polysiloxane group in terms of compatibility with polyimide. Moreover, it is preferable that the repetition number of the siloxane unit in the said polysiloxane group is 1 or more and 200 or less, More preferably, it is 3 or more and 200 or less. R ²⁵ in the above general formula (I) is preferably a hydrogen atom or a hydroxyl group, more preferably a hydroxyl group. Preferably, at least one of R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ in the above general formula (I) represents a carbon number of 1 or more and 15 or less which may be substituted by a phenyl group or a monovalent polysiloxane group. A chain or branched alkyl group, or -R ³⁰ -AR ³¹ , and the remainder represents a hydrogen atom. It is especially preferable that R ²⁸ represents a linear or branched alkyl group having 1 to 15 carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group, or -R ³⁰ -AR ³¹ , R ²⁶ , R ²⁷ and R ²⁹ each independently represent a hydrogen atom, or a linear or branched alkyl group having 1 to 15 carbon atoms that may be substituted by a phenyl group or a monovalent polysiloxane group, or— R ³⁰ -AR ³¹ , particularly preferably R ²⁶ represents a hydrogen atom, or a linear or branched alkyl group having 1 to 15 carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group , or -R ³⁰ -AR ³¹ , R ²⁷ and R ²⁹ represent a hydrogen atom. Furthermore, it is more preferable that R ²⁸ represents a linear or branched alkyl group having 1 to 15 carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group, and R ²⁶ represents a hydrogen atom, or A linear or branched alkyl group having 1 or more and 15 or less carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group, and R ²⁷ and R ²⁹ represent a hydrogen atom. Among them, in terms of compatibility with polyimide, the above-mentioned linear or branched alkyl group having 1 or more and 15 or less carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group Preferably one or two hydrogen atoms in the alkyl group are substituted with a phenyl group or a monovalent polysiloxane group, or without a substituent, more preferably one hydrogen atom in the alkyl group is substituted It is a phenyl group or a monovalent polysiloxane group, or has no substituent, and particularly preferably has no substituent. In addition, the phenyl group in R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ in the general formula (I), and the phenylene group in A may have a straight chain having 1 or more and 15 or less carbon atoms. Or branched alkyl substitution.

Among the compounds represented by the above-mentioned general formula (I), those having good compatibility with polyimide are preferred from the viewpoint of easily suppressing the decrease in optical properties of the polyimide film and easily improving the light transmittance. It is a compound represented by the following general formula (I-1).

（通式（I-1）中，X¹ 表示氫原子或氯原子，Y¹ 表示氫原子、或碳數1以上且15以下之直鏈狀或支鏈狀之烷基，Y² 表示碳數1以上且15以下之直鏈狀或支鏈狀之烷基）General formula (I-1)

(In the general formula (I-1), X ¹ represents a hydrogen atom or a chlorine atom, Y ¹ represents a hydrogen atom, or a linear or branched alkyl group having 1 to 15 carbon atoms, and Y ² represents a carbon number 1 or more and 15 or less linear or branched alkyl)

Among the alkyl groups in Y ¹ and Y ² in the general formula (I-1), the compatibility with polyimide becomes good, the reduction of the optical properties of the polyimide film is easily suppressed, and it is easy to From the viewpoint of improving the light transmittance, the number of carbon atoms is more preferably 6 or more, still more preferably 7 or more, particularly preferably 8 or more. In addition, the alkyl groups in Y ¹ and Y ² in the general formula (I-1) are linear or branched, and are preferably branched in terms of compatibility with polyimide . In the same respect, X ¹ in the above-mentioned general formula (I-1) is preferably a hydrogen atom.

In the polyimide film of the present invention, by eccentrically containing the ultraviolet absorber on one side, even if the content of the ultraviolet absorber is small, excellent weather resistance can be exhibited. For example, the polyimide film can be The content ratio of the ultraviolet absorber in the total solid content may be 10 mass % or less, in a more preferable aspect, it may be 8 mass % or less, and in a further more preferable aspect, it may be less than 5 mass %. By reducing the content of the ultraviolet absorber in the polyimide film, transparency and optical properties can be improved, and a reduction in flex resistance can be suppressed. Furthermore, in terms of weather resistance, the content ratio of the ultraviolet absorber in the total solid content of the polyimide film is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and still more preferably 0.5 mass % %above.

Moreover, when the polyimide film of the present invention has the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b), from the viewpoint of improving weather resistance, the above-mentioned polyimide layer The content of the above-mentioned ultraviolet absorber in the total solid content contained in (b) is preferably 0.8 mass % or more, more preferably 2 mass % or more, still more preferably 4 mass % or more, and still more preferably 9 mass % % or more, more preferably 13 mass % or more, and on the other hand, from the viewpoint of suppressing the reduction in flexural resistance, preferably 60 mass % or less, more preferably 55 mass % or less, and still more preferably 45 mass % mass % or less. Furthermore, in terms of improving the transparency and optical properties of the polyimide film, the content of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) is preferably 35% by mass. the following. In the case where the total thickness of the above-mentioned polyimide layer (b) is 10% or less relative to the overall thickness of the polyimide film, even if the content of the ultraviolet absorber in the polyimide layer (b) is increased, Since it is easy to suppress the reduction of the flexural resistance, for example, the content of the above-mentioned ultraviolet absorber in the total solid content contained in the polyimide layer (b) may be 40 mass % or more, or 50 mass %. above. In addition, the content of the above-mentioned ultraviolet absorber contained in the above-mentioned polyimide layer (b) can be obtained from the addition amount when manufacturing the above-mentioned polyimide layer (b), and can be obtained from the polyimide film by using It was calculated|required from the film thickness confirmation of the said polyimide layer (b) by cross-sectional observation using electron microscopes, such as SEM, and the quantitative analysis of the ultraviolet absorber by the said GC-MS.

(3) Arbitrary addition of ingredients In addition to the above-mentioned polyimide and the above-mentioned ultraviolet absorber, the polyimide film of the present invention may optionally contain other additives different from the above-mentioned ultraviolet absorber, or other optional components such as resins other than the above-mentioned polyimide. . As said other additive, for example, a silica filler for smooth winding, or a surfactant for improving film-forming property and defoaming property, etc. are mentioned.

Examples of the other resins mentioned above include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyamide resins, polyamide imide resins, and polyamide resins. Phenyl sulfide resin, polyether ether ketone resin, polyether tungsten resin, polycarbonate resin, polyether imide resin, epoxy resin, phenol resin, glass-epoxy resin, polyphenylene ether resin, acrylic resin, Polyolefin resins such as polyethylene and polypropylene, polycyclic olefins such as polynorbornene, etc. The polyimide film of the present invention preferably does not contain other resins other than polyimide. When the polyimide film of the present invention contains other resins other than polyimide, the content of the other resins is relatively The total solid content in the polyimide film is preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 0.5% by mass or less.

4. Characteristics of polyimide film The polyimide film of the present invention has the above-mentioned specific transmittance, and more preferably has the following characteristics.

The total light transmittance measured according to JIS K7361-1 of the polyimide film of the present invention is preferably 85% or more. When the transmittance is high in this way, the transparency becomes good, and it can be suitably used as a glass substitute material. The above-mentioned total light transmittance of the polyimide film of the present invention measured in accordance with JIS K7361-1 is further preferably 88% or more, more preferably 89% or more, and particularly preferably 90% or more. The total light transmittance can preferably be achieved when the thickness of the polyimide film is 20 μm or more and 100 μm or less. The total light transmittance measured according to JIS K7361-1 can be measured by, for example, a haze meter (for example, HM150 manufactured by Murakami Color Institute). In a single-layer polyimide film, according to the measured value of the total light transmittance of a certain thickness, the conversion value of the total light transmittance of different thicknesses can be obtained by the Lambert-Beer law.

The polyimide film of the present invention preferably has a yellowness (YI value) of 30 or less as calculated based on JIS K7373-2006. Since the yellowness is reduced in this way, the coloring of the yellow tint can be suppressed, the light transmittance can be improved, and it can be used as a glass substitute material. The above-mentioned yellowness (YI value) calculated based on JIS K7373-2006 is preferably 20 or less, more preferably 15 or less, still more preferably 10 or less, still more preferably 8 or less, and still more preferably 6 or less. The yellowness (YI value) can preferably be achieved when the thickness of the polyimide film is 20 μm or more and 100 μm or less in thickness. Furthermore, the yellowness (YI value) can be based on JIS K7373-2006, using an ultraviolet-visible-near-infrared spectrophotometer (for example, V-7100 of Nippon Shoko Co., Ltd.), by spectrophotometric method, using auxiliary illuminator C, 2-degree field of view, based on the transmittance measured at intervals of 1 nm in the range from 250 nm to 800 nm, the tristimulus values X, Y, and Z in the XYZ color system are obtained, and from the X, Y, and Z The values of Y and Z are calculated according to the following equations. YI=100 (1.2769X-1.0592Z)/Y Further, the polyimide film of the present invention preferably has the yellowness (YI value) below the upper limit value before the following weather resistance test. The so-called polyimide film before the weather resistance test typically refers to the one immediately after production, but it should be stored in such a way that the change in the YI value of the polyimide film is within the range of ±0.2 immediately after production. can be. Furthermore, in a single-layer polyimide film, according to the measured value of the yellowness of a certain thickness, the yellowness of different thicknesses can be equal to 1 in the sample of a certain film thickness between 250 nm and 800 nm. nm is the measured transmittance of each wavelength at the interval. Similar to the above-mentioned total light transmittance, the conversion value of each transmittance of each wavelength with different thicknesses is obtained by the Lambert-Beer law, and based on the conversion The value is calculated and used.

In addition, the polyimide film of the present invention was prepared by irradiating the surface on the side where the ultraviolet absorber was biased for 24 hours with a UVB313 nm lamp at an output of 1 W/m ² /nm using a QUV weather resistance tester. A weather resistance test is performed, and the difference (ΔYI) of the YI value before and after the weather resistance test is preferably 3.0 or less, more preferably 2.5 or less, and still more preferably 2.0 or less. The difference (ΔYI) of the above YI values is calculated by the following formula ΔYI=(YI value after weather resistance test)−(YI value before weather resistance test). In the above formula, the YI value before and after the weather resistance test is in accordance with the rule B of JIS Z8401:1999, which is rounded to the second decimal place. The value of ΔYI is in accordance with the rule B of JIS Z8401:1999, Sets the value rounded to the first decimal place.

In addition, from the viewpoint that the polyimide film of the present invention can be suitably used as a glass substitute material by suppressing the coloration of yellow tinge and improving the light transmittance, the yellowness ( The value obtained by dividing the YI value) by the film thickness (μm) (YI value/film thickness (μm)) is preferably 0.10 or less, more preferably 0.07 or less, still more preferably 0.05 or less, still more preferably 0.04 or less, More preferably, it is 0.03 or less. Here, the above-mentioned yellowness (YI value) is the yellowness (YI value) of the polyimide film before the weather resistance test. In addition, in the present invention, the value obtained by dividing the above-mentioned yellowness (YI value) by the film thickness (μm) (YI value/film thickness (μm)) is based on the rule B of JIS Z8401:1999, and is rounded up to The value in the 2nd place after the decimal point.

In terms of light transmittance, the haze value of the polyimide film of the present invention is preferably 10 or less, more preferably 8 or less, still more preferably 5 or less, and still more preferably 2 or less. The haze value can preferably be achieved when the thickness of the polyimide film is 20 μm or more and 100 μm or less. The said haze value can be measured by the method based on JIS K-7136, for example, it can be measured by the haze meter HM150 by Murakami Color Technology Laboratory.

Furthermore, in terms of surface hardness of the polyimide film of the present invention, both the Young's modulus of one side and the Young's modulus of the other side are preferably 2.4 GPa or more, and more preferably both are 3.0 GPa or more. Among them, from the viewpoint of further increasing the surface hardness of at least one surface, the Young's modulus of at least one surface is preferably 4.0 GPa or more, more preferably 5.0 GPa or more, and still more preferably 6.0 GPa or more. In addition, in the present invention, the Young's modulus is measured at a temperature of 25° C. using a nanoindentation method in accordance with ISO14577. Specifically, as the measuring device, PICODENTOR HM500 manufactured by Fischer Instruments Co., Ltd. was used, and a Vickers indenter was used as the measuring indenter. Eight points were measured at arbitrary points on the surface of the polyimide film, and the numbers were averaged, and the obtained value was used as the Young's modulus. In addition, the measurement conditions were made into the maximum indentation depth: 1000 nm, the loading time: 20 second, and the creep time: 5 second.

In addition, the polyimide film of the present invention is preferably measured on a test piece of 15 mm×40 mm with the stretching speed set to 10 mm/min and the distance between the chucks set to 20 mm in accordance with JIS K7127. The tensile modulus of elasticity obtained at 25°C was 1.8 GPa or more. If the tensile modulus of elasticity at 25° C. (room temperature) is thus high, it is easy to maintain sufficient surface hardness as a protective film even at room temperature, so it can be suitably used as a surface material. The above tensile modulus of elasticity is particularly preferably 2.0 GPa or more, more preferably 2.2 GPa or more, and still more preferably 2.4 GPa or more. On the other hand, from the viewpoint of improving the bending resistance, the tensile modulus of elasticity is preferably 5.2 GPa or less. From the viewpoint of improving the flexural resistance, the tensile modulus of elasticity may be 4.0 GPa or less, or 3.5 GPa or less. The above-mentioned tensile modulus of elasticity was cut out from a polyimide film with a width of 15 mm × length of 40 mm using a tensile testing machine (for example, Shimadzu: Autograph AG-X 1N, load cell: SBL-1KN). A test piece with a direction of 40 mm x 15 mm in the direction perpendicular to the stretching direction), according to JIS K7127, at 25°C, the stretching speed is set to 10 mm/min, and the distance between the chucks is set to 20 mm. to measure. When the test piece is cut out from the film, it is preferable to cut out a portion of the film with a uniform film thickness, for example, it is preferable to cut out from the vicinity of the central portion of the film. As a standard for uniform film thickness of the film, for example, a digital linear gauge (model PDN12 digital gauge manufactured by Ozaki Seisakusho Co., Ltd.) is used to measure the film thickness of a total of 5 points in the four corners and the center of the cut film. , the difference between the average film thickness at 5 points and the film thickness at each point is within 6% of the average film thickness.

In the polyimide film of the present invention, the pencil hardness of the surface on the side where the ultraviolet absorber is biased is preferably 2B or more, more preferably B or more, and still more preferably HB or more. The pencil hardness of the above-mentioned polyimide film can be measured by using the test specified in JIS-S-6006 after adjusting the humidity of the measurement sample at a temperature of 25°C and a relative humidity of 60% for 2 hours. Use a pencil to conduct the pencil hardness test (0.98 N load) specified in JIS K5600-5-4 (1999) on the surface of the polyimide film on the side where the ultraviolet absorber is biased. Pencil hardness was evaluated. For example, a pencil scratch coating hardness tester manufactured by Toyo Seiki Co., Ltd. can be used.

In the polyimide film of the present invention, from the viewpoint of being excellent in flexural resistance, in the case of performing a static flexural test according to the following static flexural test method, the inner angle measured by the test is relatively high. It is preferably 120° or more, and more preferably 125° or more. [Static Flexure Test Method] A test piece cut into a 15 mm×40 mm polyimide film is bent at half of the long side so that the side where the ultraviolet absorber is biased becomes the inside, and the length of the test piece is folded. The two ends of the side are arranged in such a way that a metal sheet with a thickness of 6 mm (100 mm × 30 mm × 6 mm) is sandwiched from the upper and lower surfaces, and the overlap between the two ends of the test piece and the metal sheet on the upper and lower surfaces is determined. It was fixed with tape so that each would be 10 mm, and in this state, the test piece was clamped from top to bottom with a glass plate (100 mm × 100 mm × 0.7 mm), and the test piece was fixed in a state of being flexed with an inner diameter of 6 mm. At this time, a dummy test piece was sandwiched between the metal piece and the glass plate where the test piece did not exist, and the glass plates were fixed with tape so that the glass plates would become parallel. After the test piece fixed in such a flexed state was allowed to stand for 24 hours in an environment of 60±2°C and 93±2% relative humidity (RH), the glass plate and the fixing tape were removed, and the test was released. force exerted by the sheet. Then, one end of the test piece was fixed, and the inner angle of the test piece was measured 30 minutes after the force applied to the test piece was released.

In addition, in the polyimide film of the present invention, from the viewpoint of being excellent in flexural resistance, when a dynamic flexural test is performed according to the following dynamic flexural test method, the inner angle of the test piece is preferably 140° or more, more preferably 150° or more, still more preferably 155° or more, and still more preferably 160° or more. [Dynamic deflection test method] The test piece of the polyimide film cut into the size of 20 mm × 100 mm was fixed to the durability test system in the constant temperature and humidity chamber (U-shaped stretch test fixture DMX-FS without load of the planar body manufactured by Yuasa system) with tape. ). In a state where the test piece is flexed in the same manner as in the above-mentioned static flexure test, that is, in a state where the surface on the side where the ultraviolet absorber is concentrated becomes the inside, the two ends of the long side of the test piece are flexed. After setting the distance between parts to be 6 mm (fixed in the state of flexing with an inner diameter of 6 mm), under the environment of 60±2°C, 93±2% relative humidity (RH), it will be self-flat open state The above-mentioned folded state was defined as one deflection, and the deflection was repeated 200,000 times at the number of deflections of 90 times in 1 minute. Then, the test piece was removed, one end of the obtained test piece was fixed, and the inner angle of the test piece was measured 30 minutes after repeated 200,000 deflections.

The polyimide film of the present invention preferably has a glass transition temperature in the temperature range of 150°C or higher and 400°C or lower from the viewpoint of achieving both heat resistance and moderate baking temperature, and in particular, from the viewpoint of improving heat resistance More preferably, it is 200 degreeC or more, More preferably, it is 250 degreeC or more, and on the other hand, it is more preferable that it is 380 degrees C or less from a viewpoint which can lower a baking temperature. Moreover, it is preferable that the polyimide film of this invention has one peak of a tan delta curve in the temperature range of 150 degreeC or more and 400 degrees C or less. In addition, the glass transition temperature of a polyimide film can be calculated|required by the same method as the glass transition temperature of the said polyimide. Moreover, it is preferable that the polyimide film of this invention does not have the peak of a tan delta curve in the temperature range of -150 degreeC or more and 0 degreeC or less. In the case of a diamine residue with a longer siloxane bond in the main chain, there is a peak of the tanδ curve in such a lower temperature region, but with the case of a diamine residue with a longer siloxane bond in the main chain Compared with the polyimide film containing the diamine residue, the decrease of the tensile modulus of elasticity at room temperature is suppressed, and the surface hardness sufficient as a protective film can be maintained.

Moreover, in the polyimide film of the present invention, from the viewpoint of reducing optical strain, the birefringence in the thickness direction at a wavelength of 590 nm is preferably 0.040 or less, more preferably 0.020 or less. Thereby, when the polyimide film of the present invention is used as a surface material for a display, the deterioration of the display quality of the display can be suppressed. The birefringence in the thickness direction at a wavelength of 590 nm is preferably smaller, preferably 0.015 or less, more preferably 0.010 or less, and still more preferably less than 0.008. In addition, when a film with a birefringence exceeding 0.040 in the thickness direction at a wavelength of 590 nm is placed on the surface of the display, and the display is observed with polarized sunglasses, there is a case where rainbow unevenness occurs, which reduces visibility. On the other hand, if the birefringence in the thickness direction of the film provided on the display surface is 0.040 or less, the occurrence of rainbow unevenness when viewing the display while wearing polarized sunglasses can be suppressed. Furthermore, when the birefringence of the said thickness direction of the film provided on the display surface is 0.020 or less, the color reproducibility at the time of oblique observation of a display improves. Furthermore, the birefringence of the polyimide film of the present invention in the thickness direction at a wavelength of 590 nm can be obtained by the following method. First, measure the retardation value (Rth) in the thickness direction of the polyimide film at 25°C with light with a wavelength of 590 nm using a retardation measuring device (such as the product name "KOBRA-WR" manufactured by Oji Scientific Instruments Co., Ltd.). . The thickness direction retardation value (Rth) measures the retardation value of 0-degree incidence and the retardation value of 40-degree oblique incidence, and calculates the thickness direction retardation value Rth from these retardation values. The retardation value of the said 40-degree oblique incidence was measured by making the light with a wavelength of 590 nm incident on the film from the direction inclined by 40 degrees from the normal line of the film. The birefringence in the thickness direction of the polyimide film can be obtained by substituting it into the formula: Rth/d. The above d represents the film thickness (nm) of the polyimide film. Furthermore, the retardation value in the thickness direction is based on the refractive index of the slow axis direction in the in-plane direction of the film (the direction in which the refractive index in the in-plane direction of the film becomes the largest) as nx, and the fast-axis direction in the in-plane direction of the film (the direction of the film surface). When the refractive index in the inner direction becomes the smallest direction) is set as ny, and the refractive index in the thickness direction of the film is set as nz, it can be expressed as Rth[nm]={(nx+ny)/2-nz}×d .

In addition, as a preferred form, the ratio of the number of fluorine atoms (F) to the number of carbon atoms (C) of the polyimide film measured by X-ray photoelectron spectroscopy on the surface of the film without the ultraviolet absorber (F/C) is preferably 0.01 or more and 1 or less, more preferably 0.05 or more and 0.8 or less, and still more preferably 0.1 or more and 0.8 or less. The number of fluorine atoms (F ) to the number of carbon atoms (C) (F/C) is preferably 0.01 or more and 1 or less, more preferably 0.05 or more and 1 or less, still more preferably 0.1 or more and 0.9 or less. Furthermore, on the surface of the film without the ultraviolet absorber, the ratio (F/N) of the number of fluorine atoms (F) to the number of nitrogen atoms (N) measured by X-ray photoelectron spectroscopy of the polyimide film was higher than that of the polyimide film. It is preferably 0.1 or more and 20 or less, and more preferably 0.5 or more and 15 or less. The number of fluorine atoms (F ) to the number of nitrogen atoms (N) (F/N) is preferably 0.01 or more and 20 or less, and more preferably 0.1 or more and 15 or less. In addition, on the surface of the film without the ultraviolet absorber, the ratio (F/Si) of the number of fluorine atoms (F) to the number of silicon atoms (Si) measured by X-ray photoelectron spectroscopy of the polyimide film was higher than that of the polyimide film. It is preferably 1 or more and 150 or less, and more preferably 3 or more and 120 or less. The number of fluorine atoms (F ) to the number of silicon atoms (Si) (F/Si) is preferably 1 or more and 150 or less, and more preferably 3 or more and 120 or less.

5. The use of polyimide film The application of the polyimide film of the present invention is not particularly limited, and it can be used as a substrate or a surface material of glass products such as thin plate glass previously used. Since the polyimide film of the present invention is excellent in weather resistance and suppresses a decrease in flexural resistance, it is particularly suitable for use as a display substrate or a surface material that can cope with curved surfaces that can be used outdoors. Moreover, when using the polyimide film of this invention as a surface material, it is preferable to use the surface on the side of the said ultraviolet absorber biased as an outer side from the point which is easy to exhibit weather resistance. When the polyimide film of the present invention is used as a surface material for a display, it is preferable to use the surface on the side where the above-mentioned ultraviolet absorber is biased as the visible side from the viewpoint of easily exhibiting weather resistance. Specifically, the polyimide film of the present invention can be suitably used for, for example, thin and flexible flexible organic EL displays, mobile terminals such as smart phones or watch terminals, display devices inside automobiles, Flexible panels used in watches, etc. In addition, the polyimide film of the present invention can also be applied to components for image display devices such as liquid crystal display devices and organic EL display devices, or components for touch panels, flexible printed substrates, surface protection films, or solar panels such as substrate materials. Components for cell panels, components for optical waveguides, and other semiconductor-related components.

II. Manufacturing method of polyimide film The method for producing the polyimide film of the present invention is not particularly limited as long as it can obtain the above-mentioned method for producing the polyimide film of the present invention. For example, the following method for producing a polyimide film having : the step of forming the polyimide layer (a) containing the polyimide and not containing the ultraviolet absorber (hereinafter referred to as the polyimide layer (a) forming step); and The step of forming the polyimide layer (b) containing the polyimide and the ultraviolet absorber so as to exist adjacent to the above-mentioned polyimide layer (a) (hereinafter referred to as the formation of the polyimide layer (b)) step); The polyimide film has at least one layer of the polyimide layer (a) on one side and at least one layer of the polyimide layer (b) on the other side, and has a transmittance at a wavelength of 380 nm. 18% or less, and the transmittance at a wavelength of 450 nm is more than 85%.

In the manufacturing method of the polyimide film of the present invention, the imidization of the polyimide precursor can be performed by either thermal imidization or chemical imidization. The method of imidization by thermal imidization is preferable in terms of reducing the birefringence of the polyimide film, and the method of imidization by chemical imidization is as follows. Preferably, that is, since there is no high temperature heat treatment such as thermal imidization, it is performed at a relatively low temperature, thereby inhibiting the oxidation of the polyimide, resulting in a reduction in the yellowness of the polyimide film.

From the viewpoint of improving the weather resistance of the polyimide film by suppressing decomposition of the ultraviolet absorber due to heat, the polyimide layer (b) described above is preferably formed by using a polyimide containing a pre-synthesized polyimide film. A method of composing an ultraviolet absorber-containing polyimide resin with an ultraviolet absorber. As a method of synthesizing polyimide in advance, a method of imidizing a polyimide precursor by chemical imidization can be suitably used. As the preferred manufacturing method of the polyimide film of the present invention, for example, the following manufacturing method of the polyimide film can be enumerated, which has the following steps: forming a polyimide layer (a) containing polyimide and free of UV absorbers; and forming a polyimide layer (b) containing polyimide and an ultraviolet absorber in such a manner as to exist adjacent to the above-mentioned polyimide layer (a); The step of forming the above-mentioned polyimide layer (b) has the following steps: preparing a UV absorbent-containing polyimide resin composition containing a polyimide, a UV absorbent and an organic solvent; and Coating the above-mentioned UV absorber-containing polyimide resin composition to form a UV absorber-containing polyimide resin coating film; The polyimide film has at least one layer of the polyimide layer (a) on one side and at least one layer of the polyimide layer (b) on the other side, and has a transmittance at a wavelength of 380 nm. 18% or less, and the transmittance at a wavelength of 450 nm is more than 85%.

Furthermore, in the manufacturing method of the polyimide film of the present invention, the formation of each polyimide layer can be performed layer by layer, or a multi-layer coating formed by laminating a coating film containing a polyimide precursor can also be formed. After filming, the formation of each polyimide layer is performed simultaneously by carrying out imidization of the polyimide precursor in the multilayer coating film. For example, in the method for producing a polyimide film of the present invention, after forming the polyimide layer (a), the polyimide layer (b) may be formed on one surface of the polyimide layer (a). ), the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b) can also be formed simultaneously. In the case where the polyimide layer (a) and the polyimide layer (b) are simultaneously formed, it is preferable to carry out the imide when the polyimide layer (a) is formed by the same method. imidization and imidization in the formation of the above-mentioned polyimide layer (b). When thermal imidization is performed during the formation of the polyimide layer (a) and the polyimide layer (b), the polyimide layer (a) and the polyimide layer (b) are simultaneously formed. The method for the amine layer (b) includes, for example, a method of forming the amide for the polyimide layer (b) on one surface of the coating film before the imidization of the polyimide layer (a). After the pre-coating film is formed, the polyimide precursor in each pre-imide coating film is imidized by heating the whole to form the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer. The imine layer (b). Moreover, the said polyimide layer (a) and the said polyimide layer (b) can also be formed simultaneously, for example by a multilayer extrusion method. For example, when thermal imidization is performed during the formation of the polyimide layer (a) and the polyimide layer (b), the polyimide can be simultaneously formed by a multilayer extrusion method or the like. After the amine layer (a) is imidized with the pre-coating film and the above-mentioned polyimide layer (b) is imidized with the pre-coating film, the whole is heated to make each imidized pre-coating film. The obtained polyimide precursor is imidized to form the polyimide layer (a) and the polyimide layer (b) at the same time. In addition, the above-mentioned polyimide layer may be simultaneously formed by simultaneously forming a polyimide resin coating film containing no ultraviolet absorber and a polyimide resin coating film containing a ultraviolet absorber by a multilayer extrusion method or the like. (a) with the above polyimide layer (b).

1. Polyimide layer (a) forming step <Method a-1> As a method of forming the above-mentioned polyimide layer (a), for example, as the method a-1, the following method, which has: A step of preparing a polyimide precursor resin composition containing a polyimide precursor and an organic solvent (hereinafter, referred to as the step of preparing a polyimide precursor resin composition); The step of coating the above-mentioned polyimide precursor resin composition on a support to form a polyimide precursor resin coating film (hereinafter, the step of forming a polyimide precursor resin coating film); and The step of imidizing the above-mentioned polyimide precursor by heating (hereinafter, referred to as an imidization step). The above-mentioned method a-1 can reduce the birefringence of the polyimide layer (a) and also reduce the birefringence of the entire polyimide film, and by easily reducing the polyimide layer (a). The residual solvent amount in a) is preferable in that the flex resistance of the polyimide film can be easily improved. Hereinafter, each step in the above-mentioned method a-1 will be described in detail.

(1) Preparation steps of polyimide precursor resin composition Polyimide Precursor The resin composition contains a polyimide precursor and an organic solvent, and may also contain any additional components as required. The polyimide precursor is a polyimide obtained by the polymerization of a tetracarboxylic acid component and a diamine component. The tetracarboxylic acid component and the diamine component used in the polyimide precursor are not particularly limited, and for example, the tetracarboxylic dianhydride and the diamine residue which are the tetracarboxylic acid residues of the above-mentioned polyimide can be listed, respectively. base diamine.

The number-average molecular weight of the polyimide precursor is preferably 2,000 or more, and more preferably 4,000 or more, in terms of strength at the time of film formation. On the other hand, when the number average molecular weight is too large, the viscosity may increase and the workability may be lowered, and it is preferably 1,000,000 or less, and more preferably 500,000 or less. The number average molecular weight of the polyimide precursor can be determined by NMR (eg, AVANCE III manufactured by BRUKER). For example, after coating the polyimide precursor solution on a glass plate and drying it at 100°C for 5 minutes, 10 mg of the solid content was dissolved in 7.5 mL of dimethylsulfoxide-d6 solvent, and NMR measurement was carried out. The number average molecular weight was calculated from the ratio of the peak intensities of the hydrogen atoms bonded to the aromatic ring.

Moreover, the weight-average molecular weight of the polyimide precursor is preferably 2,000 or more, more preferably 4,000 or more, in terms of strength at the time of film formation. On the other hand, when the weight average molecular weight is too large, the viscosity may increase and the workability such as filtration may be lowered, and it is preferably 1,000,000 or less, and more preferably 500,000 or less. The weight average molecular weight of the polyimide precursor can be determined by gel permeation chromatography (GPC). Specifically, the polyimide precursor was prepared as an N-methylpyrrolidone (NMP) solution with a concentration of 0.5 wt %, a 10 mmol% LiBr-NMP solution with a water content of 500 ppm or less was used as the developing solvent, and Tosoh A manufactured GPC device (HLC-8120, using a column: GPC LF-804 manufactured by SHODEX) was used for the measurement under the conditions of a sample injection amount of 50 μL, a solvent flow rate of 0.5 mL/min, and 40°C. The weight average molecular weight is determined based on a polystyrene standard sample having the same concentration as the sample.

The said polyimide precursor solution is obtained by making the said tetracarboxylic dianhydride and the said diamine react in a solvent. The solvent for synthesizing the polyimide precursor (polyamide acid) is not particularly limited as long as it can dissolve the above-mentioned tetracarboxylic dianhydride and diamine. For example, an aprotic polar solvent or a water-soluble alcohol-based solvent can be used. Wait. In the present invention, it is particularly preferable to use N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylidene Phosphatamide, 1,3-dimethyl-2-imidazolidinone and other organic solvents containing nitrogen atoms, γ-butyrolactone and the like. Among them, it is preferable to use an organic solvent containing a nitrogen atom, and it is more preferable to use N,N-dimethylacetamide, N-methyl-2-pyrrolidone or a combination thereof. In addition, an organic solvent means the solvent containing a carbon atom.

In addition, when two or more kinds of diamines are combined to prepare the above-mentioned polyimide precursor solution, acid dianhydride can be added to the mixed solution of two or more kinds of diamines to synthesize polyamide acid. Two or more kinds of diamine components can be added to the reaction liquid stepwise at an appropriate molar ratio, and the sequence of incorporating each raw material into the polymer chain can be controlled to some extent. In the case of using a diamine having a silicon atom, for example, it can be prepared by adding 0.5 mol ratio of acid dianhydride to the reaction solution in which the diamine having a silicon atom is dissolved. It is reacted to synthesize the diamine with silicon atom and the amide acid obtained by the reaction of both ends of the acid dianhydride, put all or a part of the remaining diamine there, and add the acid dianhydride to make the polyamide Acid polymerization. When the polymerization is carried out by this method, the diamine having a silicon atom is introduced into the polyamic acid in a form linked via one acid dianhydride. By polymerizing the polyamide by this method, the positional relationship of the amide having a silicon atom is specified to a certain extent, and it is preferable in that it is easy to obtain a film with excellent flexibility resistance.

When the molar number of the diamine in the above-mentioned polyimide precursor solution (polyamide acid solution) is set to X, and the molar number of the tetracarboxylic dianhydride is set to Y, it is preferable to set Y/ X is 0.9 or more and 1.1 or less, more preferably 0.95 or more and 1.05 or less, still more preferably 0.97 or more and 1.03 or less, and particularly preferably 0.99 or more and 1.01 or less. By setting it as such a range, the molecular weight (polymerization degree) of the obtained polyamic acid can be suitably adjusted. The order of the polymerization reaction can be appropriately selected and used by a known method, and is not particularly limited. In addition, the polyimide precursor solution obtained by the synthesis reaction can be used directly, and other components can be mixed therein as needed, or the solvent of the polyimide precursor solution can be dried and dissolved in other solvents to obtain use.

From the viewpoint of forming a uniform coating film and polyimide layer, the viscosity of the polyimide precursor solution at 25° C. is preferably 500 cps or more and 100,000 cps or less. The viscosity of the polyimide precursor solution can be measured using a viscometer (eg TVE-22HT, Toki Sangyo Co., Ltd.) at 25°C with a sample volume of 0.8 mL.

The above-mentioned polyimide precursor resin composition may contain optional additional components as required. Examples of the above-mentioned optional additives include silica fillers for smooth winding, surfactants for improving film-forming properties and defoaming properties, and the like. Ultraviolet rays as described above for the polyimide film can be used. Any additional components other than the absorbent are the same.

The organic solvent used in the above-mentioned polyimide precursor resin composition is not particularly limited as long as it can dissolve the above-mentioned polyimide precursor. For example, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphamide, 1 , 3-dimethyl-2-imidazolidinone and other organic solvents containing nitrogen atoms, γ-butyrolactone, etc., among them, organic solvents containing nitrogen atoms are preferably used.

From the viewpoint of forming a uniform coating film and a polyimide layer having a strength that can be handled, the content of the polyimide precursor in the above-mentioned polyimide precursor resin composition is based on the solid content of the resin composition. The content of the components is preferably 90% by mass or more, and the upper limit may be appropriately adjusted depending on the components to be contained. From the viewpoint of forming a uniform coating film and polyimide layer, the organic solvent in the polyimide precursor resin composition is preferably 40% by mass or more, and more preferably 50% by mass in the resin composition. % or more, and preferably 99% by mass or less.

In addition, from the viewpoint that the storage stability of the polyimide precursor resin composition becomes good and the productivity can be improved, the moisture content of the polyimide precursor resin composition is preferably 1000 ppm or less. . When a large amount of water is contained in the polyimide precursor resin composition, the polyimide precursor may be easily decomposed. In addition, the moisture content of a polyimide precursor resin composition can be calculated|required using a Karl-Fischer Moisture Titrator (for example, the trace moisture analyzer CA-200 type|mold by Mitsubishi Chemical Corporation). In order to make the moisture content 1000 ppm or less as described above, it is preferable to dehydrate the organic solvent used, or to operate in an environment with a humidity of 5% or less after the use of the moisture content is managed by a manager.

From the viewpoint of forming a uniform coating film and polyimide layer, the viscosity of the polyimide precursor resin composition at 25° C. is preferably 500 cps or more and 100,000 cps or less. The viscosity of the polyimide precursor resin composition can be measured in the same manner as the viscosity of the polyimide precursor solution described above.

(2) Formation step of polyimide precursor resin coating film In the step of coating the above-mentioned polyimide precursor resin composition on the support to form the polyimide precursor resin coating film, as the support used, as long as the surface is smooth and has heat resistance and solvent resistance There is no particular limitation on the material of sex. For example, inorganic materials, such as a glass plate, a metal plate whose surface is mirror-finished, etc. are mentioned. In addition, the shape of the support is selected according to the coating method, and for example, it may be a plate shape, a roll shape, a belt shape, a sheet shape that can be wound into a roll, or the like.

The above-mentioned coating means is not particularly limited as long as it is a method that can coat with a target film thickness, and for example, a die coater, a comma coater, a roll coater, and a gravure coater can be used. known ones, such as a coating machine, a curtain coater, a spray coater, and a lip coater. The coating can be performed by a single-sheet coating device or by a roll-to-roll coating device.

After the polyimide precursor resin composition is coated on the support, it is dried at a temperature below 150°C, preferably above 30°C and below 120°C, until the surface becomes non-sticky, and the above composition is applied. solvent removal. By making the said drying temperature 150 degrees C or less, the imidization of a polyamic acid can be suppressed.

The drying time may be appropriately adjusted according to the film thickness of the polyimide precursor resin coating film, the type of solvent, and the drying temperature, and is usually 1 to 60 minutes, preferably 2 to 30 minutes. When it exceeds the said upper limit, it is unfavorable from the viewpoint of the manufacturing efficiency of a polyimide film. On the other hand, when it falls below the said lower limit, there exists a possibility that the external appearance etc. of the obtained polyimide film may be affected by the rapid drying of a solvent.

The drying method of the solvent is not particularly limited as long as the solvent can be dried at the above-mentioned temperature, and for example, an oven, a drying furnace, a hot plate, and infrared heating can be used. In the case where high management of optical properties is necessary, the environment in which the solvent is dried is preferably an inert gas environment. In an inert gas atmosphere, preferably a nitrogen atmosphere, the oxygen concentration is preferably 100 ppm or less, more preferably 50 ppm or less. If the heat treatment is performed in the atmosphere, the film may be oxidized and colored, or the performance may be lowered.

(3) imidization step In the step of imidizing the polyimide precursor by heating, the imidization temperature may be appropriately selected according to the structure of the polyimide precursor. Usually, it is preferable to set temperature increase starting temperature to 30 degreeC or more, and it is more preferable to set it to 100 degreeC or more. On the other hand, it is preferable to set temperature increase completion temperature to 250 degreeC or more.

The heating rate is preferably appropriately selected according to the film thickness of the polyimide layer to be formed, and when the film thickness of the polyimide layer is thick, the heating rate is preferably slow. From the viewpoint of the production efficiency of the polyimide film, it is preferably 5°C/min or more, and more preferably 10°C/min or more. On the other hand, the upper limit of the temperature increase rate is usually 50°C/min, preferably 40°C/min or less, and more preferably 30°C/min or less. It is preferable to set it as the said temperature rise rate from the point which can suppress the whitening accompanying an imidization reaction, and can improve light transmittance by suppressing the appearance defect and intensity|strength fall of a film.

The temperature rise may be carried out continuously or in steps, but it is preferably carried out continuously from the viewpoint of suppressing poor appearance and strength reduction of the film and controlling whitening accompanying the imidization reaction. In addition, the temperature increase rate can be fixed in all the above-mentioned temperature ranges, or it can be changed in the middle.

The environment at the time of raising the temperature of the imidization is preferably an inert gas environment. In an inert gas atmosphere, preferably a nitrogen atmosphere, the oxygen concentration is preferably 100 ppm or less, more preferably 50 ppm or less. If the heat treatment is performed in the atmosphere, the film may be oxidized to cause discoloration or decrease in performance. However, in the case where more than 50% of the hydrogen atoms bonded to carbon atoms contained in the polyimide are hydrogen atoms directly bonded to the aromatic ring, the influence of oxygen on the optical properties is small, even if no oxygen is used. In an active gas environment, polyimide with higher light transmittance can also be obtained.

The heating method for imidization is not particularly limited as long as the temperature can be raised at the above-mentioned temperature, and for example, an oven, a heating furnace, infrared heating, electromagnetic induction heating, and the like can be used.

In order to obtain the final polyimide film, the reaction is preferably carried out until the imidization is 90% or more, more preferably 95% or more, and more preferably 100%. In order to carry out the reaction until the imidization of 90% or more, and more preferably 100%, it is preferable to hold the temperature for a certain period of time at the temperature increase end temperature, and the holding time is preferably set to generally 1 minute to 180 minutes, and more preferably 5 minutes. minutes to 150 minutes.

In the above-mentioned method a-1, at least the above-mentioned polyimide precursor resin coating film and the imidized post-imide coating film obtained by imidizing the above-mentioned polyimide precursor resin coating film may be further included. One performs the extension step of extension.

In the case of performing the extension step in the above-mentioned method a-1, in the above-mentioned imidization step, it is particularly preferable to set the imidization rate of the polyimide precursor to 50% or more before the extension step. By setting the imidization rate to 50% or more before the elongation step, even in the case where elongation is performed after the step, and then the imidization is performed by heating at a higher temperature for a certain period of time. Poor appearance or whitening of the film can be suppressed. Among them, from the viewpoint of improving the surface hardness of the polyimide film, it is preferable to set the imidization rate to 80% or more in the imidization step before the stretching step, and it is preferable to allow the reaction to proceed. 90% or more, more preferably 100%. It is presumed that by extending after imidization, the rigid polymer chains are easily aligned, and thus the strength and surface hardness are improved. In addition, the measurement of the imidization rate can be performed by the analysis etc. of the spectrum obtained by infrared measurement (IR).

In the case where there is an extending step in the above method a-1, in terms of improving the strength and surface hardness of the polyimide film, it is preferable to include a step of extending the coating film after imidization.

When the above-mentioned method a-1 has an extension step, it is preferable to simultaneously perform heating at 80° C. or higher and a step of extending 101% or more and 10000% or less when the initial size before extension is set to 100%. The heating temperature during elongation is preferably within the range of ±50°C of the glass transition temperature of the polyimide or the polyimide precursor, preferably within the range of ±40°C of the glass transition temperature. If the stretching temperature is too low, the film may not be deformed and the orientation may not be sufficiently induced. On the other hand, if the stretching temperature is too high, the alignment obtained by stretching may be relaxed due to the temperature, and there is a possibility that a sufficient alignment cannot be obtained. The extension step can also be performed concurrently with the imidization step. In terms of improving the strength and surface hardness of the polyimide layer, the imidization rate is preferably 80% or more, further 90% or more, further 95% or more, and especially substantially 100% imidization. The coating film is then stretched after imidization.

The stretching ratio of the stretching performed by the stretching step is preferably 101% or more and 10000% or less, and more preferably 101% or more and 500% or less. By extending in the above range, the strength and surface hardness of the polyimide layer can be further improved.

The fixing method of the polyimide layer during the stretching is not particularly limited, and it is selected according to the type of the stretching device and the like. In addition, the stretching method is not particularly limited. For example, a stretching device having a conveying device such as a tenter can be used, and the stretching can be performed while passing through a heating furnace. The polyimide layer can be stretched in only one direction (longitudinal or lateral), and can also be stretched in two directions by simultaneous biaxial stretching, successive biaxial stretching, and oblique stretching.

<Method a-2> As another method of forming the above-mentioned polyimide layer (a), for example, as the method a-2, the following method, which has: A step of preparing a polyimide resin composition containing polyimide and an organic solvent (hereinafter, referred to as a polyimide resin composition preparation step); A step of applying the above-mentioned polyimide resin composition to a support to form a polyimide resin coating film (hereinafter, referred to as a polyimide resin coating film forming step). The above-mentioned method a-2 is preferable in that the yellowness (YI value) of the polyimide layer (a) can be easily reduced, and the yellowness (YI value) of the entire polyimide film can also be reduced. Hereinafter, each step in the above-mentioned method a-2 will be described in detail.

(1) Preparation steps of polyimide resin composition The polyimide used in the preparation step of the polyimide resin composition is preferably selected from the above-mentioned polyimides having a solvent solubility of 5% by mass or more in an organic solvent at 25°C. amine is used. The imidization of the polyimide is preferably carried out by chemical imidization using a chemical imidizing agent. In the case of chemical imidization, known compounds such as amines such as pyridine and β-picolinic acid, carbodiimides such as dicyclohexylcarbodiimide, and acid anhydrides such as acetic anhydride can also be used as dehydration catalysts. The acid anhydride is not limited to acetic anhydride, and examples thereof include propionic anhydride, n-butyric anhydride, benzoic anhydride, trifluoroacetic anhydride, and the like, but are not particularly limited. These dehydration catalysts may be used alone or in combination of two or more. If the amines remain in the film, the optical properties, especially the yellowness (YI value) will decrease. Therefore, in the case of using the above-mentioned amines, it is preferable to purify the components other than polyimide by reprecipitation or the like. They were removed to less than 100 ppm of the total weight of the polyimide, instead of directly casting the reaction solution obtained from the reaction of the precursor to the polyimide to form a film.

In the preparation step of the polyimide resin composition, as the organic solvent used in the reaction solution for the chemical imidization of the polyimide precursor, for example, the above-mentioned polyimide in the above-mentioned method a-1 can be used. The same as those described in the preparation steps of the amine precursor resin composition. In the preparation step of the polyimide resin composition, as the organic solvent used for redissolving the purified polyimide from the reaction solution, for example, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetic acid can be mentioned. Esters, ethylene glycol mono-n-butyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, o-dichlorobenzene, xylene, cresol, chlorobenzene, isobutyl acetate, isoamyl acetate, acetic acid n-Butyl, n-propyl acetate, n-pentyl acetate, cyclohexanol, cyclohexanone, dioxane, tetrachloroethylene, toluene, methyl isobutyl ketone, methyl cyclohexanol, methyl cyclohexanone , methyl n-butanone, dichloromethane, dichloroethane and these mixed solvents, etc., among which, can be preferably used selected from dichloromethane, n-butyl acetate, propylene glycol monomethyl ether acetate and this At least one of the group consisting of mixed solvents such as these.

The above-mentioned polyimide resin composition may contain optional additional components as needed. As the above-mentioned optional additive components, the same ones as those described in the above-mentioned preparation step of the polyimide precursor resin composition in the above-mentioned method a-1 can be used.

Regarding the content of polyimide in the solid content of the above-mentioned polyimide resin composition, from the viewpoint of forming a uniform coating film and a polyimide layer having a strength that can be handled, the content of the polyimide in the resin composition is 90 mass % or more is preferable in a solid content, and 99.9 mass % or less is preferable from a viewpoint of containing an ultraviolet absorber sufficiently on the other hand. In addition, from the viewpoint of forming a uniform coating film and polyimide layer, the organic solvent in the polyimide resin composition is preferably 40% by mass or more, and more preferably 50% by mass in the resin composition. % or more, and preferably 99% by mass or less.

Moreover, from the viewpoint of improving the storage stability of the polyimide resin composition and improving the productivity, it is preferable that the water content of the polyimide resin composition is 1000 ppm or less. As a method for making the water content of the above-mentioned polyimide resin composition to be 1000 ppm or less, the same method as the method described in the above-mentioned preparation step of the above-mentioned polyimide precursor resin composition in the above-mentioned method a-1 can be used. method.

(2) Polyimide resin coating film forming steps In the step of coating the above-mentioned polyimide resin composition on the support to form a polyimide resin coating film, as the above-mentioned support and the above-mentioned coating method, the polyimide and the above-mentioned method a-1 can be used. The same as those described in the step of forming the amine precursor resin coating film. After coating the above-mentioned polyimide resin composition, the surface is preferably dried until it becomes non-sticky. As a drying temperature, it is preferable to set it as 40 degreeC or more and 150 degrees C or less under normal pressure. It is preferable to set it as the range of 10 degreeC or more and 100 degrees C or less under reduced pressure. After drying the surface until it becomes non-sticky, it is preferable to heat at 100° C. or more and 300° C. or less in an inert gas atmosphere in order to reduce the residual solvent. In an inert gas atmosphere, preferably a nitrogen atmosphere, the oxygen concentration is preferably 100 ppm or less, more preferably 50 ppm or less. If the heat treatment is performed at 260° C. or higher in the atmosphere, the polyimide may be oxidized to cause discoloration or lower performance.

In the said method a-2, you may further have the extending|stretching process of extending|stretching the said polyimide resin coating film. This extending step can be performed by the same method as the extending step described in the above-mentioned method a-1.

In the manufacturing method of the polyimide film having the above-mentioned polyimide layer (a) having two or more layers, for example, by using any one of the above-mentioned forming methods of the above-mentioned polyimide layer (a), it is possible to further The formation of the said polyimide layer (a) is performed, and the said polyimide layer (a) of two or more layers is formed. Moreover, in this invention, the preliminarily formed film-like polyimide molding can also be used as the said polyimide layer (a).

2. Polyimide layer (b) forming step <Method b-1> As a method of forming the above-mentioned polyimide layer (b), for example, as method b-1, the following method, which has: The steps of preparing a UV absorber-containing polyimide precursor resin composition containing a polyimide precursor, a UV absorber and an organic solvent (hereinafter, referred to as the UV absorber-containing polyimide precursor resin composition) preparation steps); The step of coating the above-mentioned UV absorber-containing polyimide precursor resin composition to form a UV absorber-containing polyimide precursor resin coating film (hereinafter, UV absorber-containing polyimide precursor resin coating film forming step); and The step of imidizing the above-mentioned polyimide precursor by heating (hereinafter, referred to as imidization step).

In addition, the ultraviolet absorber used in the above-mentioned polyimide layer (b) is the same as the ultraviolet absorber described in the above-mentioned polyimide film of the present invention.

The preparation step of the ultraviolet absorbent-containing polyimide precursor resin composition in the above-mentioned method b-1 is in the preparation step of the polyimide precursor resin composition in the above-mentioned method a-1. The precursor resin composition further contains an ultraviolet absorber, and the content of each component is appropriately adjusted, except that it can be set as the same as the above-mentioned preparation steps of the polyimide precursor resin composition. Furthermore, the ultraviolet absorber is preferably added after synthesizing the polyimide precursor. The above-mentioned method b-1 is the same as the above-mentioned method a-1, in that the birefringence of the polyimide layer (b) can be reduced, and the birefringence of the entire polyimide film can also be reduced, and It is preferable at the point that the flex resistance of the polyimide film can be easily improved by easily reducing the residual solvent amount in the polyimide layer (b). In the above-mentioned method b-1, with regard to the content of the polyimide precursor in the above-mentioned ultraviolet absorbent-containing polyimide precursor resin composition, a uniform coating film and a polyimide with an operable strength are formed. From the viewpoint of the imine layer and the improvement of the deflection resistance of the polyimide film, the solid content of the resin composition is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably It is 55 mass % or more, more preferably 65 mass % or more, may be 80 mass % or more, and may be 90 mass % or more, on the other hand, from the viewpoint of sufficiently containing the ultraviolet absorber, preferably 99.2 The mass % or less is more preferably 98 mass % or less, still more preferably 96 mass % or less, still more preferably 91 mass % or less, and still more preferably 87 mass % or less. The content of the ultraviolet absorber in the above-mentioned ultraviolet absorber-containing polyimide precursor resin composition is preferably 0.8% by mass or more in the solid content of the resin composition in terms of weather resistance, and more Preferably it is 2 mass % or more, more preferably 4 mass % or more, still more preferably 9 mass % or more, still more preferably 13 mass % or more, on the other hand, from the viewpoint of suppressing the decrease in the deflection resistance , preferably 60 mass % or less, more preferably 55 mass % or less, still more preferably 45 mass % or less, and in terms of improving the transparency and optical properties of the polyimide film, preferably 35 mass % %the following. In addition, the content of the ultraviolet absorber in the above-mentioned ultraviolet absorber-containing polyimide precursor resin composition with respect to 100 parts by mass of the polyimide precursor is preferably 2 mass parts in terms of weather resistance part or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more. On the other hand, from the viewpoint of bending resistance and suppression of whitening of the polyimide film, it is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, still more preferably 100 parts by mass or less, More preferably, it is 70 parts by mass or less, and furthermore, from the viewpoint of improving the transparency and optical properties of the polyimide film, it is more preferably 50 parts by mass or less. From the viewpoint of forming a uniform coating film and polyimide layer, the organic solvent in the above-mentioned ultraviolet absorber-containing polyimide precursor resin composition is preferably 40% by mass or more in the resin composition, and further 50 mass % or more is preferable, and 99 mass % or less is preferable.

The step of forming the UV absorbent-containing polyimide precursor resin coating film in the above-mentioned method b-1 can be set to be the same as the forming step of the polyimide precursor resin coating film in the above-mentioned method a-1. Furthermore, the above-mentioned ultraviolet absorber-containing polyimide precursor resin composition is applied on the above-mentioned polyimide layer (a) or on the coating film which becomes the above-mentioned polyimide layer (a). In addition, the imidization step in the above-mentioned method b-1 may be the same as the imidization step in the above-mentioned method a-1.

For example, when the formation of the polyimide layer (a) is performed by the method a-1 and the formation of the polyimide layer (b) is performed by the method b-1, the above-mentioned polyimide layer (b) can be formed The polyimide layer (b) may be formed after the polyimide layer (a), or the polyimide layer (b) may be formed simultaneously with the formation of the polyimide layer (a). On the other hand, when the formation of the polyimide layer (a) is performed by the method a-2 and the formation of the polyimide layer (b) is performed by the method b-1, it is preferable After forming the above-mentioned polyimide layer (a), the above-mentioned polyimide layer (b) is formed on the formed above-mentioned polyimide layer (a).

<Method b-2> Moreover, as another method of forming the above-mentioned polyimide layer (b), for example, as method b-2, the following method, which has: A step of preparing a UV absorber-containing polyimide resin composition containing a polyimide, a UV absorber, and an organic solvent (hereinafter, referred to as the UV absorber-containing polyimide resin composition preparation step); and The step of coating the above-mentioned UV absorber-containing polyimide resin composition to form a UV absorber-containing polyimide resin composition coating film (hereinafter, referred to as UV absorber-containing polyimide resin coating film formation) step). As a method of forming the above-mentioned polyimide layer (b), the above-mentioned method b-2 is preferable in particular from the viewpoint of suppressing the decomposition of the ultraviolet absorber and improving the weather resistance of the polyimide film.

The preparation step of the ultraviolet absorbent-containing polyimide resin composition in the above-mentioned method b-2 is in the preparation step of the polyimide resin composition in the above-mentioned method a-2, so that the polyimide resin composition in the In addition to containing an ultraviolet absorber, and adjusting the content of each component appropriately, it can be set as the same as the above-mentioned preparation procedure of the polyimide resin composition. The above-mentioned method b-2 is the same as the above-mentioned method a-2, it is easy to reduce the yellowness (YI value) of the polyimide layer (b), and the yellowness (YI value) of the whole polyimide film can also be reduced. It is better in this respect. In the above-mentioned method b-2, regarding the content of the polyimide in the above-mentioned ultraviolet absorber-containing polyimide resin composition, a uniform coating film and a polyimide layer having an operable strength are formed. From the viewpoint of improving the flexibility resistance of the polyimide film, the solid content of the resin composition is preferably 40% by mass or more, more preferably 45% by mass or more, and still more preferably 55% by mass. Above, more preferably 65 mass % or more, may be 80 mass % or more, and may be 90 mass % or more, on the other hand, from the viewpoint of sufficiently containing the ultraviolet absorber to improve the weather resistance, it is preferably 99.2 The mass % or less is more preferably 98 mass % or less, still more preferably 96 mass % or less, still more preferably 91 mass % or less, and still more preferably 87 mass % or less. The content of the ultraviolet absorber in the above-mentioned ultraviolet absorber-containing polyimide resin composition is preferably 0.8% by mass or more in the solid content of the resin composition in terms of weather resistance, and more preferably 2 mass % or more, more preferably 4 mass % or more, more preferably 9 mass % or more, still more preferably 13 mass % or more. 60 mass % or less is preferable, 55 mass % or less is more preferable, 45 mass % or less is more preferable, and 35 mass % or less is more preferable in terms of improving the transparency and optical properties of the polyimide film . In addition, the content of the ultraviolet absorber in the above-mentioned ultraviolet absorber-containing polyimide resin composition relative to 100 parts by mass of the polyimide is preferably 2 parts by mass or more in terms of weather resistance, and more It is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and still more preferably 15 parts by mass or more. On the other hand, from the viewpoint of bending resistance and suppression of whitening of the polyimide film, it is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, still more preferably 100 parts by mass or less, More preferably, it is 70 parts by mass or less, and still more preferably, it is 50 parts by mass or less in terms of improving the transparency and optical properties of the polyimide film. The organic solvent in the above-mentioned ultraviolet absorber-containing polyimide resin composition is preferably 40% by mass or more in the resin composition from the viewpoint of forming a uniform coating film and polyimide layer, and further 50 mass % or more is preferable, and 99 mass % or less is preferable.

The UV absorbent-containing polyimide resin coating film forming step in the above-mentioned method b-2 can be set to be the same as the polyimide resin coating film forming step in the above-mentioned method a-2. Furthermore, the said ultraviolet absorber-containing polyimide resin composition is coated on the said polyimide layer (a) or the coating film which becomes the said polyimide layer (a).

When the formation of the above-mentioned polyimide layer (a) is performed by the above-mentioned method a-1, and the above-mentioned polyimide layer (b) is formed by the above-mentioned method b-2, the above-mentioned polyimide layer is suppressed. In terms of the decomposition of the ultraviolet absorber in the amine layer (b) and the improvement of the weather resistance of the polyimide film, it is preferred that after the polyimide layer (a) is formed, the polyimide layer (a) formed The above-mentioned polyimide layer (b) is formed on the imine layer (a). When the above-mentioned polyimide layer (a) is formed by the above-mentioned method a-2, and the above-mentioned polyimide layer (b) is formed by the above-mentioned method b-2, it can become the above-mentioned polyimide layer. The polyimide resin coating film containing the ultraviolet absorber formed on the polyimide resin coating film of the imine layer (a) to become the above-mentioned polyimide layer (b) may also be formed simultaneously by a multilayer extrusion method or the like. The polyimide resin coating film that becomes the polyimide layer (a) and the ultraviolet absorber-containing polyimide resin coating film that becomes the polyimide layer (b). In the method for producing the polyimide film of the present invention by chemical imidization using a multilayer extrusion method, the polyimide film of the present invention can be obtained, for example, by, on a support The polyimide resin composition containing the polyimide synthesized by chemical imine and the polyimide resin composition containing the ultraviolet absorber are simultaneously extruded to carry out casting coating on the support, Thereby, a multi-layer structure having a polyimide resin coating film to become the polyimide layer (a) and a polyimide resin coating film containing an ultraviolet absorber to become the polyimide layer (b) is formed. multi-layer coating film, and if necessary, heating the multi-layer coating film to remove the residual solvent.

In addition, in the above-mentioned method b-1, in the above-mentioned method b-1, the above-mentioned polyimide The amine precursor preferably contains: a polyimide precursor containing an aromatic ring having a perfluoroalkyl group. In the above-mentioned method b-2, the polyimide preferably contains: a polyimide precursor containing a perfluoroalkyl group The aromatic ring of the polyimide. It is inferred that if the polyimide precursor or polyimide contains an aromatic ring having a perfluoroalkyl group, it is likely to have a bulky and sparse (low density) structure, and it is easy to expand the polyimide precursor in the composition. The distance between the molecular chains of the polyimide or polyimide is easy to reduce the interaction between the polyimide precursor or the molecular chain of the polyimide, so it is easy to improve the polyimide precursor or polyimide and the organic Due to the compatibility of the solvent, the UV absorber is likely to exist in the polyimide precursor or the gaps between the molecular chains of the polyimide, thereby reducing the haze value during film formation.

Moreover, the manufacturing method of the polyimide film of the present invention may also include an extension step for forming the coating film before or after imidization to be the polyimide layer (a) described above. It stretches with the laminated body which becomes the coating film before imidization of the said polyimide layer (b) or after imidization. This extending step can be performed by the same method as the extending step described in the above-mentioned method a-1. Moreover, in the manufacturing method of the polyimide film which has the above-mentioned polyimide layer (b) of two or more layers, for example, any one of the forming methods of the above-mentioned polyimide layer (b) can be used. The formation of the said polyimide layer (b) is further performed, and the said polyimide layer (b) of two or more layers is formed.

Moreover, the manufacturing method of the polyimide film of this invention may further have the process of performing surface treatment, such as saponification treatment, glow discharge treatment, corona discharge treatment, ultraviolet treatment, flame treatment, for example.

III. Laminate The laminate system of the present invention has the above-mentioned polyimide film of the present invention and a functional layer containing at least one polymer of a radically polymerizable compound and a cationically polymerizable compound.

Since the above-mentioned polyimide film of the present invention is used in the laminate system of the present invention, the weather resistance is excellent, the reduction of the flexural resistance is suppressed, and a desired function is imparted by having a functional layer.

1. Polyimide film As the polyimide film used in the laminate of the present invention, the polyimide film of the present invention described above can be used, so the description here is omitted.

2. Functional layer The functional layer of the layered product of the present invention is a layer intended to exhibit certain functions. Specifically, for example, a layer that exhibits functions such as hard coat properties, antireflection properties, antistatic properties, and antifouling properties can be used, and known ones can be used. functional layer. Among the functional layers used in the present invention, those that function as a hard coat layer are preferred from the viewpoint of improving the surface hardness of the layered product of the present invention. Here, the term "hard coat layer" refers to a layer for increasing surface hardness, and specifically, refers to a hardness of "H" or higher in the pencil hardness test specified in JIS 5600-5-4 (1999). By.

The functional layer used in the present invention contains at least one polymer of a radically polymerizable compound and a cationically polymerizable compound as a binder component, and as long as the effect of the present invention is not impaired, optional additional components may be included. Here, the polymer contained in the functional layer also includes a polymer obtained by polymerizing at least one of the radical polymerizable compound and the cationic polymerizable compound in the composition for the functional layer described below in the curing step when the functional layer is formed. Any one of the obtained polymer and a polymer obtained by polymerizing at least one of a radically polymerizable compound and a cationically polymerizable compound before forming a functional layer, preferably a composition for a functional layer A polymer obtained by polymerizing at least one of the radically polymerizable compound and the cationically polymerizable compound in the hardening step at the time of forming the functional layer. Moreover, the said functional layer may contain unreacted monomers, oligomers, etc. as a binder component in addition to the said polymer in the range which does not impair the effect.

(1) Radically polymerizable compounds The radically polymerizable compound is a compound having a radically polymerizable group. The radically polymerizable group possessed by the above-mentioned radically polymerizable compound is not particularly limited as long as it is a functional group capable of generating a radical polymerization reaction, and examples thereof include a group containing a carbon-carbon unsaturated double bond, and the like. Specifically, a vinyl group, a (meth)acryloyl group, etc. are mentioned. In addition, when the said radically polymerizable compound has two or more radically polymerizable groups, these radically polymerizable groups may be the same or different from each other.

From the viewpoint of improving the hardness of the functional layer, the number of radically polymerizable groups contained in one molecule of the radically polymerizable compound is preferably two or more, and more preferably three or more. Among the above-mentioned radically polymerizable compounds, compounds having a (meth)acryloyl group are preferred in terms of high reactivity, and in terms of adhesiveness and permeability between the polyimide film and the functional layer. In terms of optical properties and surface hardness, a compound having two or more (meth)acryloyl groups in one molecule is preferred. As a compound having 2 or more (meth)acryloyl groups in 1 molecule, for example, a compound having 2 to 6 (meth)acryloyl groups in 1 molecule can be preferably used, which is called a polyfunctional acrylate monolayer. Compounds of monomers or oligomers, or called urethane (metha)crylate, polyester (meth)acrylate, epoxy (meth)acrylate, have several in the molecule Multifunctional (meth)acrylate monomers and oligomers such as multifunctional monomers and oligomers with molecular weights of (meth)acryloyl groups ranging from hundreds to thousands. Moreover, the polyfunctional (meth)acrylate polymer which has 2 or more (meth)acryloyl groups in the side chain in a (meth)acrylate polymer can also be used suitably. By making the functional layer contain at least one polymer selected from the above-mentioned polyfunctional (meth)acrylate monomers, oligomers, and polymers, the hardness and flex resistance of the functional layer can be improved, and furthermore, the adhesion to the polymer can be improved. Adhesion of imide film. In addition, in this specification, a (meth)acryloyl group represents each of an acryl group and a methacryloyl group, and a (meth)acrylate represents each of an acrylate and a methacrylate.

Specific examples of the radical polymerizable compound include vinyl compounds such as divinylbenzene; ethylene glycol di(meth)acrylate, bisphenol A epoxy di(meth)acrylate, 9 ,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]phenyl, alkylene oxide modified bisphenol A di(meth)acrylate (e.g. ethoxylated (cyclic Ethylene oxide modified) bisphenol A di(meth)acrylate, etc.), trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, neotaerythritol Tri(meth)acrylate, Neotaerythritol tetra(meth)acrylate, Dipivalerythritol tri(meth)acrylate, Dipivalerythritol tetra(meth)acrylate, Dipivalerythritol Polyol polyacrylates such as alcohol penta(meth)acrylate, dipivalerythritol hexa(meth)acrylate, bisphenol A diglycidyl ether diacrylate, hexanediol diglycidyl ether two Epoxy acrylates such as acrylates, acrylates obtained by the reaction of polyisocyanates with hydroxyl-containing acrylates such as hydroxyethyl acrylate, etc.

(2) Cationic polymerizable compound The cationically polymerizable compound refers to a compound having a cationically polymerizable group. The cationically polymerizable group contained in the cationically polymerizable compound is not particularly limited as long as it is a functional group capable of causing a cationic polymerization reaction, and examples thereof include epoxy groups, oxetanyl groups, vinyl ether groups, and the like. Furthermore, when the said cationically polymerizable compound has two or more cationically polymerizable groups, these cationically polymerizable groups may be the same or different from each other.

From the viewpoint of improving the hardness of the functional layer, the number of the cationically polymerizable groups contained in one molecule of the cationically polymerizable compound is preferably two or more, and more preferably three or more. In addition, as the above-mentioned cationically polymerizable compound, among them, a compound having at least one of an epoxy group and an oxetanyl group as a cationically polymerizable group is preferable, in terms of the adhesion between the polyimide film and the functional layer, and From the viewpoint of light transmittance and surface hardness, a compound having at least one of two or more epoxy groups and oxetanyl groups in one molecule is more preferable. From the viewpoint of small shrinkage accompanying the polymerization reaction, a cyclic ether group such as an epoxy group and an oxetanyl group is preferable. In addition, the compound having the epoxy group in the cyclic ether group has a compound that can easily obtain various structures, does not adversely affect the durability of the obtained functional layer, and can easily control the compatibility with the radical polymerizable compound. advantage. In addition, the oxetanyl group in the cyclic ether group has the following advantages compared with the epoxy group: the degree of polymerization is higher, and the toxicity is low, and the combination of the obtained functional layer and the compound having the epoxy group will be accelerated. The network formation rate obtained by the cationically polymerizable compound in the coating film does not allow unreacted monomers to remain in the film to form an independent network even in the region where the radically polymerizable compound is mixed.

Examples of the cationically polymerizable compound having an epoxy group include, for example, using hydrogen peroxide, peroxide, polyglycidyl ether of a polyhydric alcohol having an alicyclic ring, or a compound having a cyclohexene ring or a cyclopentene ring with Alicyclic epoxy resins obtained by epoxidizing appropriate oxidizing agents such as acids; polyglycidyl ethers of aliphatic polyols, or their alkylene oxide adducts, polyglycidyl esters of aliphatic long-chain polyacids, (methyl) base) aliphatic epoxy resins such as homopolymers and copolymers of glycidyl acrylate; by bisphenols such as bisphenol A, bisphenol F or hydrogenated bisphenol A, or their alkylene oxide adducts, Glycidyl ethers produced by the reaction of derivatives such as caprolactone adducts with epichlorohydrin, and glycidyl ether-type epoxy resins derived from bisphenols such as novolak epoxy resins.

As said alicyclic epoxy resin, 3, 4- epoxy cyclohexane carboxylic acid-3, 4- epoxy cyclohexyl methyl ester (UVR-6105, UVR-6107, UVR-6110), bis- 3,4-Epoxycyclohexylmethyl adipate (UVR-6128) (above, trade name in parentheses, manufactured by Dow Chemical).

Moreover, as said glycidyl ether type epoxy resin, sorbitol polyglycidyl ether (Denacol EX-611, Denacol EX-612, Denacol EX-614, Denacol EX-614B, Denacol EX-622), polyglycerol, Polyglycidyl ether (Denacol EX-512, Denacol EX-521), neopentylerythritol polyglycidyl ether (Denacol EX-411), diglycerol polyglycidyl ether (Denacol EX-421), glycerol polyglycidyl ether ( Denacol EX-313, Denacol EX-314), trimethylolpropane polyglycidyl ether (Denacol EX-321), resorcinol diglycidyl ether (Denacol EX-201), neopentyl glycol diglycidyl ether (Denacol EX-211), 1,6-hexanediol diglycidyl ether (Denacol EX-212), hydrobisphenol A diglycidyl ether (Denacol EX-252), ethylene glycol diglycidyl ether (Denacol EX-252) EX-810, Denacol EX-811), polyethylene glycol diglycidyl ether (Denacol EX-850, Denacol EX-851, Denacol EX-821), propylene glycol glycidyl ether (Denacol EX-911), polypropylene glycol glycidyl Ether (Denacol EX-941, Denacol EX-920), Allyl Glycidyl Ether (Denacol EX-111), 2-Ethylhexyl Glycidyl Ether (Denacol EX-121), Phenyl Glycidyl Ether (Denacol EX- 141), phenol glycidyl ether (Denacol EX-145), butyl phenyl glycidyl ether (Denacol EX-146), diglycidyl phthalate (Denacol EX-721), hydroquinone diglycidyl ether ( Denacol EX-203), diglycidyl terephthalate (Denacol EX-711), glycidyl phthalimide (Denacol EX-731), dibromophenyl glycidyl ether (Denacol EX-147 ), dibromoneopentyl glycol diglycidyl ether (Denacol EX-221) (above, trade names in parentheses, manufactured by Nagase chemteX).

Moreover, as other commercially available epoxy resins, Epikote 825, Epikote 827, Epikote 828, Epikote 828EL, Epikote 828XA, Epikote 834, Epikote 801, Epikote 801P, Epikote 802, Epikote 815, Epikote 815XA, Epikote 816A、Epikote 819、Epikote 834X90、Epikote 1001B80、Epikote 1001X70、Epikote 1001X75、Epikote 1001T75、Epikote 806、Epikote 806P、Epikote 807、Epikote 152、Epikote 154、Epikote 871、Epikote 191P、Epikote YX310、Epikote DX255、Epikote YX8000 , Epikote YX8034, etc. (the above are trade names, manufactured by Japan Epoxy Resins).

Examples of the cationically polymerizable compound having an oxetanyl group include 3-ethyl-3-hydroxymethyloxetane (OXT-101), 1,4-bis-3-ethyloxetane Cyclobutan-3-ylmethoxymethylbenzene (OXT-121), Bis-1-ethyl-3-oxetanyl methyl ether (OXT-221), 3-ethyl-3-2-ethyl Hexyloxymethyloxetane (OXT-212), 3-ethyl-3-phenoxymethyloxetane (OXT-211) (above, trade names in parentheses, and East Asia Synthetic manufacture), or trade names Etanacol EHO, Etanacol OXBP, Etanacol OXTP, Etanacol OXMA (the above are trade names, manufactured by Ube Industries).

(3) Polymerization initiator The at least one polymer of the radical polymerizable compound and the cationic polymerizable compound contained in the functional layer can be, for example, by adding a polymerization initiator to at least one of the radical polymerizable compound and the cationic polymerizable compound as required. It can be obtained by polymerizing it by a known method.

As the above-mentioned polymerization initiator, a radical polymerization initiator, a cationic polymerization initiator, a radical and a cationic polymerization initiator, etc. can be appropriately selected and used. These polymerization initiators are decomposed by at least one of light irradiation and heating, and generate radicals or cations, so that radical polymerization and cationic polymerization proceed.

The radical polymerization initiator should just be capable of releasing a substance that initiates radical polymerization by at least one of light irradiation and heating. For example, the photoradical polymerization initiators include imidazole derivatives, bisimidazole derivatives, N-arylglycine derivatives, organic azide compounds, titanocenes, aluminate complexes, Organic peroxides, N-alkoxypyridinium salts, 9-oxosulfakou-yamaguchi derivatives, etc. More specifically, 1,3-bis(tertiary butyldioxycarbonyl)diphenyl ketone, 3,3',4,4'-tetrakis(tertiary butyldioxycarbonyl) benzophenone, 3-phenyl-5-isoazolinone, 2-mercaptobenzimidazole, Bis(2,4,5-triphenyl)imidazole, 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name Irgacure 651, manufactured by Ciba Japan Co., Ltd.), 1-Hydroxy-cyclohexyl-phenyl-one (trade name Irgacure 184, manufactured by Ciba Japan Co., Ltd.), 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)- Butan-1-one (trade name Irgacure 369, manufactured by Ciba Japan Co., Ltd.), bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-( 1H-pyrrol-1-yl)-phenyl)titanium (trade name Irgacure 784, manufactured by Ciba Japan Co., Ltd.) and the like, but not limited to these.

In addition to the above, commercially available products can also be used, and specific examples include Irgacure 907, Irgacure 379, Irgacure 819, Irgacure 127, Irgacure 500, Irgacure 754, Irgacure 250, Irgacure 1800, and Irgacure manufactured by Ciba Japan Co., Ltd. 1870, Irgacure OXE01, DAROCUR TPO, DAROCUR1173, SpeedcureMBB, SpeedcurePBZ, SpeedcureITX, SpeedcureCTX, SpeedcureEDB, Esacure ONE, Esacure KIP150, Esacure KTO46, KAYACURE DETX-S, KAYACURE manufactured by Nihon SiberHegner Co., Ltd. CTX, KAYACURE BMS, KAYACURE DMBI, etc.

Moreover, the cationic polymerization initiator should just be able to release the substance which starts cationic polymerization by at least any one of light irradiation and heating. Examples of the cationic polymerization initiator include: sulfonic acid esters, imide sulfonic acid esters, dialkyl-4-hydroxy perionate salts, p-nitrobenzyl arylsulfonic acid esters, silanol-aluminum complexes, ( n ⁶ -benzene) (n ⁵ -cyclopentadienyl) iron (II), etc., and more specifically, benzoin tosylate, 2,5-dinitrobenzyltoluenesulfonate acid ester, N-toluenesulfonylphthalimide, etc., but not limited to these.

As both a radical polymerization initiator and a cationic polymerization initiator, aromatic iodonium salts, aromatic periconium salts, aromatic diazonium salts, aromatic phosphonium salts, three well compounds, Iron-aromatic complexes, etc., and more specifically, chlorides of iodonium such as diphenyl iodonium, xylyl iodonium, bis(p-tertiary butylphenyl) iodonium, and bis(p-chlorophenyl) iodonium , bromide, fluoroborate, hexafluorophosphate, hexafluoroantimonate and other iodonium salts, triphenyl perionium, 4-tert-butyltriphenyl perionium, tris(4-methylphenyl) perionium and other perium Chloride, bromide, fluoroborate, hexafluorophosphate, hexafluoroantimonate and other peronium salts, 2,4,6-tris(trichloromethyl)-1,3,5-three wells, 2- Phenyl-4,6-bis(trichloromethyl)-1,3,5-three-well, 2-methyl-4,6-bis(trichloromethyl)-1,3,5-three-well, etc. 2,4,6-substituted-1,3,5 three-well compound, etc., but not limited to these.

(4) Additives In addition to the above polymers, the functional layer used in the present invention may also contain additives such as antistatic agents, antiglare agents, antifouling agents, inorganic or organic fine particles for improving hardness, leveling agents, and various sensitizers as required.

Furthermore, regarding at least one polymer of a radically polymerizable compound and a cationically polymerizable compound contained in the functional layer used in the present invention, a Fourier transform infrared spectrophotometer (FTIR) can be used for the decomposition product of the polymer. ), thermal decomposition gas chromatography (GC-MS), or a combination of high performance liquid chromatography, gas chromatography mass spectrometry, NMR, elemental analysis, XPS/ESCA and TOF-SIMS, etc.

3. The composition of the laminate The laminated body of the present invention is not particularly limited as long as it has the above-mentioned polyimide film and the above-mentioned functional layer, and the above-mentioned functional layer may be laminated on one surface side of the above-mentioned polyimide film, or the above-mentioned polyimide film may be laminated. The two area layers of the imide film have the above-mentioned functional layers. In addition to the above-mentioned polyimide film and the above-mentioned functional layer, the layered product of the present invention may have, for example, a function for improving the adhesion between the above-mentioned polyimide film and the above-mentioned functional layer within the range that does not impair the effect of the present invention. other layers such as a primer coat. Moreover, the laminated body of this invention may exist adjacent to the said polyimide film and the said functional layer. Among these, it is preferable that the said functional layer is located in the surface of the said polyimide layer (b) side of a polyimide film in terms of weather resistance and abrasion resistance.

The overall thickness of the layered product of the present invention may be appropriately selected depending on the application, and in terms of strength, it is preferably 30 μm or more, and more preferably 40 μm or more. On the other hand, in terms of deflection resistance, it is preferably 300 μm or less, and more preferably 250 μm or less. Moreover, in the layered product of the present invention, the thickness of each functional layer is preferably 2 μm or more and 80 μm or less, and more preferably 3 μm or more and 50 μm or less.

4. Characteristics of laminated body The pencil hardness of the surface on the side of the functional layer of the layered product of the present invention is preferably HB or more, more preferably F or more, and still more preferably H or more. The pencil hardness of the layered product of the present invention can be measured in the same manner except that the load is set to 9.8 N in the method for measuring the pencil hardness of the polyimide film described above.

The total light transmittance of the laminate of the present invention measured in accordance with JIS K7361-1 is preferably 85% or more, more preferably 88% or more, and still more preferably 90% or more. Since the transmittance is so high, the transparency becomes good, and it can be used as a glass substitute material. The above-mentioned total light transmittance of the laminate of the present invention can be measured in the same manner as the total light transmittance measured in accordance with JIS K7361-1 of the above-mentioned polyimide film.

The above-mentioned yellowness (YI value) of the laminate of the present invention calculated based on JIS K7373-2006 is preferably 30 or less, more preferably 20 or less, and still more preferably 16 or less. The above-mentioned yellowness (YI value) of the laminate of the present invention can be measured in the same manner as the above-mentioned yellowness (YI value) calculated according to JIS K7373-2006 of the above-mentioned polyimide film.

In terms of light transmittance, the haze value of the layered product of the present invention is preferably 10 or less, more preferably 8 or less, and still more preferably 5 or less. The haze value of the laminate of the present invention can be measured in the same manner as the haze value of the polyimide film described above.

The birefringence of the laminate of the present invention in the thickness direction at a wavelength of 590 nm is preferably 0.040 or less, more preferably 0.020 or less, and still more preferably 0.015 or less. The birefringence of the laminate of the present invention can be measured in the same manner as the birefringence of the polyimide film in the thickness direction at a wavelength of 590 nm.

5. Use of laminates The use of the laminate of the present invention is not particularly limited, and for example, it can be used for the same use as the use of the polyimide film of the present invention described above.

6. Manufacturing method of laminated body As the manufacturing method of the laminated body of the present invention, for example, the following manufacturing method can be mentioned, which comprises the following steps: A coating film of a functional layer-forming composition containing at least one of a radically polymerizable compound and a cationically polymerizable compound is formed on at least one side of the polyimide film of the present invention; and The said coating film is hardened.

The said composition for functional layer formation contains at least 1 type of a radically polymerizable compound and a cationic polymerizable compound, and may further contain a polymerization initiator, a solvent, an additive, etc. as needed. Here, the radically polymerizable compounds, cationically polymerizable compounds, polymerization initiators, and additives contained in the above-mentioned functional layer-forming composition may be the same as those described for the above-mentioned functional layers, and the solvent may be any known solvent. Use appropriately.

As a method of forming a coating film of the composition for forming a functional layer on at least one side of a polyimide film, for example, by a known coating means, coating the above-mentioned composition for forming a functional layer on at least one side of a polyimide film can be mentioned. method of composition. The above-mentioned coating means is not particularly limited as long as it is a method capable of coating with a desired film thickness, and examples thereof include the same means as those for coating the above-mentioned polyimide precursor resin composition on a support. In addition, the coating amount of the curable resin composition for functional layers varies depending on the performance required for the obtained laminate, but it is preferably adjusted appropriately so that the film thickness after drying becomes 3 μm or more and 25 μm or less. , the coating amount is preferably in the range of 3 g/m ² or more and 30 g/m ² or less, and particularly preferably in the range of 5 g/m ² or more and 25 g/m ² or less. Moreover, in terms of weather resistance and scratch resistance, it is preferable to apply the functional layer-forming composition to the surface of the polyimide film on the side where the ultraviolet absorber is concentrated.

The coating film of the said curable resin composition for functional layers removes a solvent by drying as needed. Examples of the drying method include drying under reduced pressure, drying by heating, and a method of combining these dryings. Moreover, when drying under normal pressure, it is preferable to perform drying at 30 degreeC or more and 110 degrees C or less.

The coating film obtained by coating the above-mentioned curable resin composition for functional layers and drying it as necessary, corresponds to the polymerizable groups of the radically polymerizable compound and the cationically polymerizable compound contained in the curable resin composition. By curing the coating film by at least one of light irradiation and heating, a functional layer containing at least one polymer of a radical polymerizable compound and a cationic polymerizable compound can be formed on at least one side of the polyimide film .

Light irradiation mainly uses ultraviolet rays, visible light, electron beams, ionizing radiation, and the like. In the case of ultraviolet curing, ultraviolet rays emitted from ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arcs, xenon arcs, metal halide lamps, etc. are used. The irradiation dose of the energy ray source is about 50 to 5000 mJ/cm ² in terms of the cumulative exposure dose at the ultraviolet wavelength of 365 nm. In the case of heating, the treatment is usually performed at a temperature of 40°C or higher and 120°C or lower. Moreover, reaction can also be performed by leaving to stand at room temperature (25 degreeC) for 24 hours or more.

IV. Surface Materials for Displays The surface material for a display of the present invention is the polyimide film of the present invention described above or the laminate of the present invention described above.

The surface material for a display of the present invention is used so as to be located on the surface of various displays, and among them, it is preferably used so that the side where the ultraviolet absorber of the polyimide film of the present invention is biased becomes the visible side. . The surface material for a display of the present invention is excellent in weather resistance and suppresses a decrease in flexural resistance similarly to the polyimide film of the present invention and the laminate of the present invention described above, and thus can be suitably used for outdoor use. The display application can also be suitably used for a flexible display application.

The surface material for a display of the present invention can be used for various known displays without particular limitation. For example, it can be used for the displays described above regarding the use of the polyimide film of the present invention.

Furthermore, when the surface material for a display of the present invention is the laminate of the present invention, in terms of weather resistance and scratch resistance, it is preferable that the surface on the side of the functional layer is the surface on the more front side. The surface material for a display of the present invention is arranged in such a way. Moreover, the surface material for displays of this invention may have a fingerprint adhesion prevention layer on the outermost surface.

Moreover, it does not specifically limit as a method to arrange|position the surface material for displays of this invention on the surface of a display, For example, the method of passing through an adhesive layer, etc. are mentioned. As said adhesive layer, the previously well-known adhesive layer which can be used for the adhesiveness of the surface material for displays can be used.

V. Touch Panel Components The touch panel member of the present invention includes the polyimide film of the present invention described above or the laminate of the present invention described above; A transparent electrode that is disposed on one surface side of the polyimide film or the laminate and is composed of a plurality of conductive parts; and A plurality of lead wires electrically connected to at least one side of the end of the conductive portion.

Since the touch panel member of the present invention is provided with the polyimide film or laminate of the present invention described above, it is excellent in weather resistance and suppresses a reduction in flexural resistance, so that it can be suitably used for flexible displays, especially suitable for use in flexible displays. It is used as a flexible display that can be used even outdoors. Moreover, since the touch panel member of this invention is equipped with the polyimide film or laminated body of this invention mentioned above, it is excellent in optical characteristics. The laminate of the present invention used in the touch panel member of the present invention preferably has a hard coat layer containing at least one polymer of a radically polymerizable compound and a cationically polymerizable compound adjacent to both surfaces of the polyimide film . Moreover, although the touch panel member of this invention is not specifically limited, It is preferable that the said transparent electrode and one surface side of the said laminated body are contacted and laminated|stacked. For example, the touch panel member of the present invention can be used by being disposed on the surface of various displays. Moreover, the touch panel member of this invention, and the polyimide film or laminated body of this invention as a surface material can be arrange|positioned in order on the surface of various displays, and it can be used.

Hereinafter, the touch panel member of the present invention will be described using an example of the laminate of the present invention, but the polyimide film of the present invention may be similarly used in place of the laminate of the present invention. 4 is a schematic top view of one side of an example of the touch panel member of the present invention, FIG. 5 is a schematic top view of the other side of the touch panel member shown in FIG. 4 , and FIG. 6 is a schematic view of the touch panel member shown in FIGS. 4 and 5 A-A' section view. The touch panel member 20 shown in FIGS. 4 , 5 , and 6 includes the laminate 11 of the present invention, a first transparent electrode 4E arranged in contact with one surface of the laminate 11 , and a surface in contact with the other surface of the laminate 11 . The configured second transparent electrode 5E. In the first transparent electrode 4E, a plurality of first conductive portions 41 that are short strip-shaped electrode sheets extending in a manner of extending along the x-axis direction are arranged at a predetermined interval. In the first conductive portion 41 , a first lead wire 7 electrically connected to the first conductive portion 41 is connected to any one of the ends in the longitudinal direction. Preferably, a first terminal 71 for electrical connection with an external circuit is provided at the end of the first lead wire 7 extending to the end edge 21 of the laminate 11 . The first conductive portion 41 and the first lead wire 7 are generally connected in the inactive area 23 located outside the active area 22 that can be visually recognized by a user of the touch panel. For the connection between the first conductive portion 41 and the first lead wire 7, for example, as shown in FIG. Specifically, the connection portion 24 can be formed by extending the conductive material layer from the longitudinal end of the first conductive portion 41 to a specific position in the inactive region 23 . Furthermore, by overlapping at least a part of the first lead wire 7 on the connection portion 24 , a connection structure between the first conductive portion 41 and the first lead wire 7 can be formed. The connection between the first conductive portion 41 and the first lead wire 7 is not limited to the structure of forming the connection portion 24 as shown in FIG. 4 . For example, although the illustration is omitted, the end of the first conductive portion 41 in the longitudinal direction may be extended to the inactive region 23 , and within the inactive region 23 , the end of the first conductive portion 41 extending to the inactive region 23 may be extended. The portion covers the first lead wire 7 so that the two are electrically connected. 4 shows a form in which any one of the longitudinal ends of the first conductive portion 41 is connected to the first lead wire 7, but in the present invention, it may be set to one first conductive portion. Both ends of the portion 41 in the longitudinal direction are respectively electrically connected to the first lead wires 7 .

As shown in FIG. 5 , the touch panel member 20 includes a second transparent electrode 5E arranged in contact with the other surface of the laminate 11 . In the second transparent electrode 5E, a plurality of short strip-shaped electrode pieces extending along the y-axis direction, that is, the second conductive portions 51 are arranged at a predetermined interval in the x-axis direction. In the second conductive portion 51 , a second lead wire 8 electrically connected to the second conductive portion 51 is connected to one of its longitudinal ends. The second lead wire 8 is extended to a position where the end edge 21 of the first lead wire 7 is extended and does not overlap the first terminal 71 in the end edge of the laminated body 11 . Preferably, a second terminal 81 for electrical connection with an external circuit is provided at the end of the second lead wire 8 extending to the end edge 21 of the laminate 11 . The electrical connection between the second conductive portion 51 and the second lead wire 8 can be applied in the same form as the electrical connection between the first lead wire 7 and the first conductive portion 41 .

Furthermore, as shown in FIG. 4 and FIG. 5, the pattern in which the first lead wire 7 is formed as a long wire and the second lead wire 8 is formed as a short wire is only one embodiment of the touch panel member of the present invention, For example, it may be a pattern in which the first lead wire 7 is a short wire and the second lead wire 8 is a long wire. Moreover, the extending direction of the first lead wire 7 and the extending direction of the second lead wire 8 are not limited to the directions shown in FIGS. 4 and 5 , and can be arbitrarily designed.

The conductive portion of the touch panel member of the present invention can be appropriately selected and applied to the touch panel member constituting the transparent electrode, and the pattern of the conductive portion is not limited to those shown in FIG. 4 and FIG. 5 . For example, by the electrostatic capacitance method, the pattern of the transparent electrode that can detect the change in capacitance caused by the contact of a finger or the like or a state close to the contact can be appropriately selected and applied. The material of the conductive portion is preferably a translucent material, for example, indium oxide-based transparent electrode materials mainly composed of indium tin oxide (ITO), indium oxide, indium zinc oxide (IZO), etc., Transparent conductive films, such as tin (SnO ₂ ) and zinc oxide (ZnO) as main components, conductive polymer compounds such as polyaniline and polyacetylene, etc., are not limited to these. In addition, the first conductive portion 41 and the second conductive portion 51 may be formed using the same type of conductive material, or may be formed using a different type of material. In particular, if the first conductive portion 41 and the second conductive portion 51 are formed using the same type of conductive material, it is preferable from the viewpoint that the generation of warpage and strain of the touch panel member can be more effectively suppressed. The thickness of the above-mentioned conductive portion is not particularly limited. For example, when the conductive portion is formed by a photo-etching method, it can be generally formed to be about 10 nm to 500 nm.

The conductive material constituting the lead-out line included in the touch panel member of the present invention may be light-transmitting or not. In general, the lead wires can be formed using metal materials such as silver or copper with high conductivity. Specifically, a metal element, a metal composite, a composite of a metal and a metal compound, and a metal alloy are mentioned. As a metal element, the element of silver, copper, gold, chromium, platinum, aluminum, etc. can be illustrated. As the metal composite, MAM (three-layer structure of molybdenum, aluminum, and molybdenum), etc. can be exemplified. As a composite of a metal and a metal compound, a laminated body of chromium oxide and chromium, etc. can be illustrated. As the metal alloy, a silver alloy or a copper alloy is widely used. Moreover, APC (alloy of silver, palladium, and copper) etc. can be illustrated as a metal alloy. Moreover, about the said lead wire, a resin component may be mixed suitably in the said metal material. In the touch panel member of the present invention, the terminals provided at the ends of the lead wires can be formed using, for example, the same material as the above lead wires. The thickness and width of the lead lines are not particularly limited. For example, when the lead lines are formed by photolithography, generally, the thickness is about 10 nm to 1000 nm, and the width is 5 μm to 200 nm. μm or so. On the other hand, when forming a lead wire by printing such as screen printing, generally, the thickness is formed to be about 5 μm to 20 μm, and the width dimension is formed to be about 20 μm to 300 μm.

The touch panel member of this invention is not limited to the form shown in FIG. 4 - FIG. 6, For example, the 1st transparent electrode and the 2nd transparent electrode may be respectively laminated|stacked on a different laminated body, and it may be comprised. 7 and 8 are schematic plan views each showing an example of the conductive member provided with the laminate of the present invention. The first conductive member 201 shown in FIG. 7 includes the laminate 11 of the present invention, and a first transparent electrode 4E disposed in contact with one surface of the laminate 11 , and the first transparent electrode 4E has a plurality of first conductive portions 41. The second conductive member 202 shown in FIG. 8 has the laminated body 11 ′ of the present invention and a second transparent electrode 5E arranged in contact with one surface of the laminated body 11 ′. The second transparent electrode 5E has a plurality of second conductive members Section 51. FIG. 9 is a schematic cross-sectional view showing another example of the touch panel member of the present invention. The touch panel member 20 ′ shown in FIG. 9 includes the first conductive member 201 shown in FIG. 7 and the second conductive member shown in FIG. 8 . Component 202 . In the touch panel member 20 ′, the surface of the first conductive member 201 without the first transparent electrode 4E and the surface of the second conductive member 202 with the transparent electrode 5E are bonded via the adhesive layer 6 . Furthermore, in the present invention, for example, as an adhesive layer for adhering the laminate of the present invention and the touch panel member of the present invention, and an adhesive layer for adhering the touch panel members of the present invention to each other, the present invention is applied. The adhesive layer for bonding the touch panel member and the display device, etc., can be appropriately selected and used for the previously known bonding layer used for optical members. In the conductive member used in the touch panel member of the present invention, the structures and materials of the transparent electrodes, lead wires and terminals can be the same as the transparent electrodes, lead wires and terminals used in the touch panel member of the present invention described above.

VI. Liquid crystal display device The liquid crystal display device of the present invention includes the polyimide film of the present invention or the laminate of the present invention, and a liquid crystal layer disposed between the opposing substrates on one surface side of the polyimide film or the laminate. The completed liquid crystal display.

Since the liquid crystal display device of the present invention includes the polyimide film of the present invention or the laminate of the present invention, the liquid crystal display device of the present invention is excellent in weather resistance and suppresses a decrease in flexural resistance, so that it is particularly suitable for use as a flexible display. , especially suitable for use as a flexible display that can be used outdoors. Moreover, since the liquid crystal display device of this invention is equipped with the polyimide film or laminated body of this invention mentioned above, it is excellent in optical characteristics. The laminate of the present invention used in the liquid crystal display device of the present invention preferably has a hard coat layer containing at least one polymer of a radically polymerizable compound and a cationically polymerizable compound adjacent to both surfaces of the polyimide film . Moreover, the liquid crystal display device of this invention may be provided with the touch panel member of this invention mentioned above. In addition, the opposite substrate of the liquid crystal display device of the present invention may be provided with the polyimide film or the laminate of the present invention.

Hereinafter, the liquid crystal display device of the present invention will be described by using the above-mentioned laminate of the present invention, but the polyimide film of the present invention may be similarly used in place of the above-mentioned laminate of the present invention. FIG. 10 is a schematic cross-sectional view showing an example of the liquid crystal display device of the present invention. The liquid crystal display device 100 shown in FIG. 10 includes a laminate 11 of the present invention, a touch panel member 20 having a first transparent electrode 4E on one side and a second transparent electrode 5E on the other side of the laminate 11 ′ of the present invention, and The liquid crystal display unit 30 . In the liquid crystal display device 100 , the laminate 11 is used as a surface material, and the laminate 11 and the touch panel member 20 are bonded together via the adhesive layer 6 .

The liquid crystal display portion used in the liquid crystal display device of the present invention has a liquid crystal layer formed between the substrates arranged opposite to each other, and the structure used in the conventionally known liquid crystal display device can be adopted. The driving method of the liquid crystal display device of the present invention is not particularly limited, and generally, a driving method used in liquid crystal display devices can be adopted, for example, a TN method, an IPS method, an OCB method, and an MVA method. As the opposing substrate used in the liquid crystal display device of the present invention, it can be appropriately selected and used according to the driving method of the liquid crystal display device, etc., and a polyimide film or a laminate of the present invention can also be used. As the liquid crystal constituting the liquid crystal layer, various liquid crystals having different dielectric anisotropy and mixtures thereof can be used according to the driving method of the liquid crystal display device of the present invention. As a formation method of a liquid crystal layer, the method generally used as a manufacturing method of a liquid crystal cell can be used, for example, a vacuum injection method, a liquid crystal drop method, etc. are mentioned. After the liquid crystal layer is formed by the above method, the enclosed liquid crystal can be aligned by slowly cooling the liquid crystal cell to normal temperature. In the liquid crystal display device of the present invention, coloring layers of various colors or light shielding portions for defining pixels may be further provided between the substrates arranged opposite to each other. In addition, the liquid crystal display unit may have a backlight unit including a light-emitting element or a phosphor at a position opposite to the side where the touch panel member exists on the outer side of the opposing substrate. Moreover, you may have a polarizing plate on the outer surface of the board|substrate arrange|positioned facing each other.

FIG. 11 is a schematic cross-sectional view showing another example of the liquid crystal display device of the present invention. The liquid crystal display device 200 shown in FIG. 11 includes a laminate 11 of the present invention, a first conductive member 201 having a first transparent electrode 4E on one surface of the laminate 11' of the present invention, and the laminate 11 of the present invention The touch panel member 20 ′ including the second conductive member 202 of the second transparent electrode 5E and the liquid crystal display portion 30 are provided on one surface of ″. In the liquid crystal display device 200 , the laminate 11 and the first conductive member 201 and the first conductive member 201 and the second conductive member 202 are bonded via the adhesive layer 6 , respectively. The structure of the touch panel member 20' can be set to be the same as that of the touch panel member 20' shown in FIG. 9, for example. As the conductive member used in the liquid crystal display device of the present invention, the same conductive member as the conductive member used in the touch panel member of the present invention can be used.

VII. Organic Electroluminescence Display Device The organic electroluminescence display device of the present invention includes the polyimide film of the present invention or the laminate of the present invention, and the polyimide film or the laminate of the present invention, which is disposed on one surface side of the polyimide film or the laminate. An organic electroluminescence display part formed from an organic electroluminescence layer.

Since the organic electroluminescence display device of the present invention is provided with the polyimide film of the present invention or the laminate of the present invention, it is excellent in weather resistance and suppresses a decrease in flex resistance, so it can be particularly suitably used as a flexible It is suitable for flexible display applications, especially flexible display applications that can be used outdoors. Moreover, since the organic electroluminescence display device of this invention is equipped with the polyimide film or laminated body of this invention mentioned above, it is excellent in optical characteristics. Preferably, the laminate of the present invention used in the organic electroluminescence display device of the present invention is adjacent to both surfaces of the polyimide film and has at least one polymer containing a radically polymerizable compound and a cationically polymerizable compound. Hard coater. In addition, the organic electroluminescence display device of the present invention may be provided with the touch panel member of the present invention described above. Moreover, the opposite substrate of the organic electroluminescence display device of the present invention may be provided with the polyimide film or laminate of the present invention.

FIG. 12 is a schematic cross-sectional view showing an example of the organic electroluminescence display device of the present invention. The organic electroluminescence display device 300 shown in FIG. 12 includes the laminate 11 of the present invention, and a touch panel member having a first transparent electrode 4E on one side of the laminate 11 ′ of the present invention and a second transparent electrode 5E on the other side 20 , and an organic electroluminescence display portion 40 . In the organic electroluminescence display device 300 , the laminate 11 is used as a surface material, and the laminate 11 and the touch panel member 20 are bonded via the adhesive layer 6 .

The organic electroluminescence display part (organic EL display part) used in the organic electroluminescence display device (organic EL display device) of the present invention has an organic electroluminescence layer (organic EL display part) formed between the substrates arranged opposite to each other. layer), the structure used in the previously known organic EL display device can be adopted. The organic EL display unit may further include a support substrate, an organic EL element including an organic EL layer, an anode layer and a cathode layer sandwiching the organic EL layer, and a sealing substrate for sealing the organic EL element. As the above-mentioned organic EL layer, any one having at least an organic EL light-emitting layer may be used. For example, a hole injection layer, a hole transport layer, an organic EL light-emitting layer, and an electron transport layer which are laminated in this order from the anode layer side may be used. and the structure of the electron injection layer. The organic EL display device of the present invention can be applied to, for example, both a passively driven organic EL display and an active driven organic EL display. As the counter substrate used in the organic EL display device of the present invention, it can be appropriately selected and used according to the driving method of the organic EL display device, etc., and the laminate of the present invention can also be used.

13 is a schematic cross-sectional view showing another example of the organic electroluminescence display device of the present invention. The organic electroluminescence display device 400 shown in FIG. 13 includes the laminate 11 of the present invention, the first conductive member 201 having the first transparent electrode 4E on one surface of the laminate 11 ′ of the present invention, and the laminate 11 ′ of the present invention. One surface of the laminated body 11 ″ includes the touch panel member 20 ′ of the second conductive member 202 of the second transparent electrode 5E, and the organic electroluminescence display portion 40 . In the organic electroluminescence display device 400 , the laminate 11 and the first conductive member 201 and the first conductive member 201 and the second conductive member 202 are bonded via the adhesive layer 6 , respectively. The structure of the touch panel member 20' can be set to be the same as that of the touch panel member 20' shown in FIG. 9, for example. As the conductive member used in the organic electroluminescence display device of the present invention, the same conductive member as the conductive member used in the touch panel member of the present invention can be used. Example

Hereinafter, unless otherwise specified, measurement or evaluation was performed at 25°C. [Evaluation method] <Weight Average Molecular Weight of Polyimide Precursor> The weight-average molecular weight of the polyimide precursor is obtained by preparing the polyimide precursor into an N-methylpyrrolidone (NMP) solution with a concentration of 0.5% by mass, and passing the solution through a syringe filter (pore size: 0.45 μm) and filtration, using a 10 mmol% LiBr-NMP solution with a water content of 500 ppm or less as a developing solvent, using a GPC apparatus (HLC-8120 manufactured by Tosoh, using a column: GPC LF-804 manufactured by SHODEX), the sample was The measurement was performed under the conditions of an injection volume of 50 μL, a solvent flow rate of 0.5 mL/min, and 40°C. The weight-average molecular weight of the polyimide precursor is set as the relative value measured based on the polystyrene standard sample with the same concentration as the sample (weight-average molecular weight: 364,700, 204,000, 103,500, 44,360, 27,500, 13,030, 6,300, 3,070) Converted to standard polystyrene. The dissolution time was compared with the calibration curve, and the weight average molecular weight was obtained.

<Viscosity of polyimide precursor solution> The viscosity of the polyimide precursor solution was measured using a viscometer (TVE-22HT, Dongji Industrial Co., Ltd.) at 25°C with a sample volume of 0.8 mL.

<Weight average molecular weight of polyimide> The weight-average molecular weight of polyimide was obtained by preparing polyimide as a N-methylpyrrolidone (NMP) solution with a concentration of 0.2% by weight, and passing the solution through a syringe filter (pore size: 0.45 μm). Filtration, using a 30 mmol% LiBr-NMP solution with a water content of 500 ppm or less as a developing solvent, using a GPC apparatus (HLC-8120 manufactured by Tosoh, using a column: GPC LF-804 manufactured by SHODEX), the injection volume of the sample is 50 μL , The solvent flow rate is 0.4 mL/min, and the measurement is carried out under the conditions of 40 °C. The weight-average molecular weight of polyimide is determined based on the polystyrene standard sample with the same concentration as the sample (weight-average molecular weight: 364,700, 204,000, 103,500, 44,360, 27,500, 13,030, 6,300, 3,070) relative to Conversion value of standard polystyrene. The dissolution time was compared with the calibration curve, and the weight average molecular weight was obtained. <Viscosity of polyimide solution> The viscosity of the polyimide solution was measured using a viscometer (TVE-22HT, Toki Sangyo Co., Ltd.) at 25°C with a sample volume of 0.8 mL.

<The content ratio of fluorine atoms in polyimide (mass %)> The fluorine atom content ratio (mass %) of the polyimide contained in the polyimide layer (b) was calculated from the added molecular weight. The polyimide used in the polyimide layers (b) of Examples 1 to 15 is based on 4,4'-(hexafluoroisopropylidene)diphthalic anhydride ( 6FDA) 1 mol, using 2,2'-bis(trifluoromethyl)benzidine (TFMB) 0.95 mol as the diamine component, and 1,3-bis(3-aminopropyl)tetramethyl Disiloxane (AprTMOS) is 0.05 mol, so it can be calculated by the following method. The molecular weight of 1 mole of polyimide repeating unit is based on From 6FDA: (C) 12.01 × 19 + (F) 19.00 × 6 + (O) 16.00 × 4 + (H) 1.01 × 6 = 412.25 From TFMB: {(C)12.01×14+(F)19.00×6+(N)14.01×2+(H)1.01×6}×0.95=300.41 From AprTMOS: {(C) 12.01 × 10 + (O) 16.00 × 1 + (N) 14.01 × 2 + (Si) 28.09 × 2 + (H) 1.01 × 24} × 0.05 = 12.23, It is calculated as 412.25+300.41+12.23=724.89. The content ratio (mass %) of fluorine atoms in 1 mole of polyimide repeating unit is obtained as {(19.00×6)+(19.00×6×0.95)}/724.89×100=30.7 (mass %).

＜Film thickness＞ The film thickness of each polyimide layer and the whole of the polyimide film was measured by observing the cross section of the polyimide film cut in the thickness direction with a scanning electron microscope (SEM). Specifically, a test piece cut from a polyimide film of 5 mm × 5 mm was embedded, cured and fixed with epoxy resin, and then a microtome (LEICA manufactured by Leica) was used in the thickness direction of the fixed sample. EM UC7) is cut with a width of 50 nm or more and about 150 nm. In each section, the thickness of each polyimide layer and polyimide film is measured at three arbitrary points, and the number is averaged. The value obtained is taken as the film thickness.

<Weather resistance test> For the polyimide layer (b) side surface of the polyimide film cut into a test piece of 55 mm × 75 mm, a QUV weather resistance tester (QUV Accelerated manufactured by Q-LAB Co., Ltd.) was used. Weathering Tester), and irradiated with a UVB313 nm lamp for 24 hours at an output set to 1 W/m ² /nm to conduct a weather resistance test. Before and after the weather resistance test, the YI value (yellowness) of the polyimide film was measured, and the difference (ΔYI) of the YI value was obtained. Furthermore, in Comparative Examples 1, 9, and 10, the surface on the side of the comparative polyimide layer (b) was irradiated. The surface in contact with the plate is irradiated. The YI value (yellowness) is based on JIS K7373-2006, using an ultraviolet-visible-near-infrared spectrophotometer (V-7100 of Nippon Spectrophotometer Co., Ltd.), by spectrophotometric method, using auxiliary illuminator C, 2-degree field of view, The transmittance is measured at intervals of 1 nm in the range from 250 nm to 800 nm, and the tristimulus values X, Y, and Z in the XYZ color system are obtained based on the transmittance. The value is calculated according to the following formula. YI=100 (1.2769X－1.0592Z)/Y

＜Penetration rate＞ In the process of measuring the YI value of the polyimide film before the above weather resistance test, the transmittance at a wavelength of 380 nm and the transmittance at a wavelength of 450 nm were measured.

＜Haze＞ The haze value was measured with a haze meter (HM150 by Murakami Color Technology Laboratory) in accordance with JIS K-7136.

<Static flexural test> Hereinafter, the method of the static deflection test will be described with reference to FIG. 3 . A test piece 10 cut into a polyimide film of 15 mm × 40 mm was bent at half of the long side so that the side of the polyimide layer (b) became the inside, and the test piece 10 was The two ends of the long side are arranged to sandwich the metal sheet 3 (100 mm × 30 mm × 6 mm) with a thickness of 6 mm from the upper and lower surfaces, and the two ends of the test piece 10 and the metal sheet 2 are placed on the upper and lower sides. Fix the surface with tape so that the overlapping amount of the surface is 10 mm. In this state, sandwich the glass plates (100 mm × 100 mm × 0.7 mm) 4a and 4b from the top and bottom, and the test piece 10 has an inner diameter of 6 mm. Fixed in a flexed state. At this time, dummy test pieces 5a, 5b are sandwiched between the metal piece 3 and the glass plates 4a, 4b where the test piece 10 does not exist, and the glass plates 4a, 4b are fixed with tape so that the glass plates 4a, 4b become parallel. In addition, in the comparative examples 1, 9, and 10, the comparative polyimide layer (b) side was bent so that the side of the comparative polyimide layer became the inner side, and in the comparative examples 2 to 8 and 11, the polyimide film was not formed when the polyimide film was formed. The surface in contact with the glass plate is bent so that it becomes the inside. After the test piece 10 fixed in such a flexed state is allowed to stand for 24 hours in an environment of 60° C. and 93% relative humidity (RH), the glass plate and the fixing tape are removed, and the test piece 10 is released. applied force. Then, one end of the test piece 10 was fixed, and the inner angle of the test piece 30 minutes after the force applied to the test piece 10 was released was measured. When the film is completely restored to the original state without being affected by the static flexure test, the above-mentioned inner angle becomes 180°.

<Dynamic deflection test> The test pieces cut into a size of 20 mm × 100 mm were fixed to the durability test system in the constant temperature and hygrostat (U-shaped expansion test fixture DMX-FS manufactured by Yuasa system without load). In the state where the test piece is folded in the same way as in the above-mentioned static flexure test, that is, in the state where the polyimide layer (b) side is folded inward, the distance between the two ends of the long side of the test piece is After setting it to 6 mm, in an environment of 60°C and 93% relative humidity (RH), from the flat open state to the above-mentioned folded state, it is set as 1 deflection, 90 times in 1 minute. The number of deflections was repeated for 200,000 deflections. In addition, in the comparative examples 1, 9, and 10, the comparative polyimide layer (b) side was bent so that the side of the comparative polyimide layer became the inner side, and in the comparative examples 2 to 8 and 11, the polyimide film was not formed when the polyimide film was formed. The surface in contact with the glass plate is bent so that it becomes the inside. Then, 30 minutes after the test piece was removed, one end of the obtained test piece was fixed, and the inner angle of the test piece was measured. When the film is completely restored to the original state without being affected by the dynamic deflection test, the above-mentioned inner angle becomes 180°.

<Young's modulus> For the front and back of the test piece cut into a polyimide film of 15 mm×15 mm, at a temperature of 25° C., according to ISO14577, the nano-indentation method was used for measurement. Specifically, as the measuring device, PICODENTOR HM500 manufactured by Fischer Instruments Co., Ltd. was used, and a Vickers indenter was used as the measuring indenter. About the front and back of a test piece, 8 places of arbitrary points were measured respectively, and the numerical average was performed, and the obtained value was made into the Young's modulus of each layer. In addition, the measurement conditions were set as the maximum indentation depth: 1000 nm, the loading time: 20 seconds, and the creep time: 5 seconds.

<tensile elastic modulus> Under the conditions of temperature 25°C and relative humidity 60%, the test piece of the polyimide film cut into 15 mm × 40 mm was subjected to humidity adjustment for 2 hours, and the stretching speed was set to 8 mm/min according to JIS K7127. , set the distance between the chucks to 20 mm, and measure the tensile modulus of elasticity at 25°C. A tensile testing machine (manufactured by Shimadzu Corporation: Autograph AG-X 1N, load cell: SBL-1KN) was used. Moreover, when measuring the said tensile elastic modulus, the breaking strength at the time of film breaking was measured. The said test piece was cut out from the center part vicinity of a film. Use a digital linear gauge (model PDN12 digital gauge manufactured by Ozaki Seisakusho Co., Ltd.) to measure the film thickness of 5 points in total at the four corners and the center of the cut film, and use the average film thickness of the 5 points and the film thickness of each point. The difference is within 6% of the average film thickness.

＜Pencil Hardness＞ The pencil hardness was measured by using the test pencil specified in JIS-S-6006 after adjusting the humidity of the measurement sample at a temperature of 25°C and a relative humidity of 60% for 2 hours, using Toyo Seiki The Pencil Scratch Coating Film Hardness Tester manufactured by Co., Ltd. conducts the pencil hardness test (0.98 N load) specified in JIS K5600-5-4 (1999) on the surface of the polyimide layer (b) side, and tests the The highest pencil hardness without damage was evaluated. In addition, in Comparative Examples 1, 9, and 10, the pencil hardness test was performed on the surface on the side of the comparative polyimide layer (b). The pencil hardness test is carried out on the surface in contact with the glass plate.

(Synthesis Example 1) In a 5 L separable flask, dissolve 2903 g of dehydrated dimethylacetamide, and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (AprTMOS) 16.0 g g (0.07 mol) of the solution was controlled to have a liquid temperature of 30°C. At this time, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride ( 6FDA) 14.6 g (0.03 mol), stirred with a mechanical stirrer for 30 minutes. To this, 400 g (1.25 mol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) was added, and after confirming complete dissolution, 4,4 '-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) 565 g (1.27 mol), to synthesize polyimide precursor solution 1 in which polyimide precursor 1 was dissolved (solid content 25 weight%). The molar ratio (TFMB:AprTMOS) of TFMB and AprTMOS used in the polyimide precursor 1 was 95:5. The viscosity of the polyimide precursor solution 1 (solid content 25% by weight) at 25° C. was 95,300 cps, and the weight-average molecular weight of the polyimide precursor 1 measured by GPC was 183,000.

(Synthesis example 2) In a 500 mL separable flask, dissolve dehydrated dimethylacetamide (200 g), and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (AprTMOS) ) 1.27 g (5.11 mmol) of the solution was controlled to have a liquid temperature of 30°C. At this time, 4,4'-(hexafluoroisopropylidene)diphthalate was slowly added so that the temperature rose to 2°C or less. Acid anhydride (6FDA) 1.14 g (2.56 mmol) was stirred with a mechanical stirrer for 1 hour. To this, 31.1 g (97.1 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) was added, and after confirming that it was completely dissolved, 4,4 '-(Hexafluoroisopropylidene)diphthalic anhydride (6FDA) 43.9 g (98.7 mmol), to synthesize polyimide precursor solution 1' in which polyimide precursor 1' was dissolved (solid composition 28% by weight). The molar ratio (TFMB:AprTMOS) of TFMB and AprTMOS used in the polyimide precursor 1' was 95:5. The above-mentioned polyimide precursor solution 1' was lowered to room temperature, 109 g of dehydrated dimethylacetamide was added, and the mixture was stirred until it became uniform. Next, 32.1 g (405 mmol) of pyridine and 41.4 g (405 mmol) of acetic anhydride were added as catalysts, and the mixture was stirred at room temperature for 24 hours to synthesize a polyimide solution. The obtained polyimide solution was transferred to a 5 L separable flask, 313 g of butyl acetate was added, and the mixture was stirred until it became uniform. Then, 696 g of methanol was slowly added to obtain a slightly cloudy solution. To the turbid solution, 1620 g of methanol was added at one time to obtain a white slurry. The above slurry was filtered and washed with methanol five times to obtain polyimide 1 (69.6 g). The weight average molecular weight of polyimide 1 measured by GPC was 192,000. Polyimide 1 was dissolved in butyl acetate to prepare polyimide solution 1 with a solid content of 15% by weight. The viscosity of the polyimide solution 1 (solid content: 15% by weight) at 25°C was 5000 cps.

Furthermore, the polyimide 1 was dissolved in a mixed solvent mixed at a ratio of butyl acetate/PGMEA=8/2 to prepare a polyimide solution 1' with a solid content of 25% by mass. The viscosity of the polyimide solution 1' (solid content: 25% by weight) at 25°C was 40,000 cps.

(Synthesis Example 3) In a 500 mL separable flask, 300 g of dehydrated dimethylacetamide and 44.61 g (139 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dissolved. The liquid temperature of the above solution was controlled to 30°C, and 29.99 g (138 mmol) of pyrometic acid dianhydride (PMDA) was slowly added in several times so that the temperature rose to below 2°C to synthesize the dissolved polyimide precursor. The polyimide precursor solution 2' of material 1 (solid content: 20% by weight). The above solution was lowered to room temperature, 43.5 g (550 mmol) of pyridine and 56.2 g (550 mmol) of acetic anhydride were added as catalysts, and the mixture was stirred at room temperature for 24 hours to synthesize a polyimide solution. The obtained polyimide solution was transferred to a 5 L separable flask, 273 g of butyl acetate was added, and the mixture was stirred until it became uniform. Then, 671 g of methanol was slowly added, and a slightly cloudy solution was obtained. To the turbid solution, 1570 g of methanol was added at one time to obtain a white slurry. The above slurry was filtered and washed with methanol five times to obtain polyimide 2 (67.1 g). The weight average molecular weight of polyimide 2 measured by GPC was 83,000. Polyimide 2 was dissolved in butyl acetate to prepare polyimide solution 2 with a solid content of 15% by weight. The viscosity of the polyimide solution 2 (solid content: 15% by weight) at 25°C was 4000 cps.

[Table 1]

Hereinafter, the abbreviations in each table are as follows. ・TFMB: 2,2'-bis(trifluoromethyl)benzidine ・AprTMOS: 1,3-bis(3-aminopropyl)tetramethyldisiloxane ・6FDA: 4,4'-(hexafluoroisopropylidene)diphthalic anhydride ・PMDA: Pyromelic acid dianhydride

(Example 1) By using the polyimide precursor solution 1 obtained in Synthesis Example 1, the following procedures (1) to (3) were carried out to produce a monolayer having a thickness of 80 μm as the polyimide layer (a). Polyimide film 1. (1) Coat the polyimide precursor solution 1 on a glass plate and dry in a circulating oven at 120°C for 10 minutes. (2) Under a nitrogen gas flow (oxygen concentration of 100 ppm or less), the temperature was raised to 350°C at a temperature increase rate of 10°C/min, kept at 350°C for 1 hour, and then cooled to room temperature. (3) Peel off from the glass plate to obtain a single-layer polyimide film 1 .

Next, to the polyimide solution 1 obtained in Synthesis Example 2, an ultraviolet absorber (Sumika Chemtex) represented by the following chemical formula (i) was added so as to be 3.0 parts by mass with respect to 100 parts by mass of the polyimide 1. Trade name manufactured by Co., Ltd.: Sumisorb 340, melting point 102°C, absorbance at 380 nm 0.023, absorbance at 450 nm 0.002), to obtain a UV absorber-containing polyimide resin composition 1. The obtained UV absorbent-containing polyimide resin composition 1 was subjected to the following procedures (4) and (5) on the single-layer polyimide film 1 obtained above, whereby the single-layer polyimide film 1 was subjected to the following procedures. A polyimide layer (b) was formed on one surface of the imide film 1, and the polyimide film 1 of Example 1 was produced. (4) Coat the polyimide resin composition containing the ultraviolet absorber on the single-layer polyimide film 1, and dry it in a circulating oven at 40°C for 10 minutes. (5) Under a nitrogen gas flow (oxygen concentration of 100 ppm or less), the temperature was raised to 200°C at a temperature increase rate of 10°C/min, kept at 200°C for 1 hour, and then cooled to room temperature. In addition, the content rate of the ultraviolet absorber in the total solid content of the polyimide film 1 of Example 1 was 0.14 mass %. Moreover, content of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) which the polyimide film 1 has was 2.91 mass %.

Chemical formula (i)

(Examples 2 to 7) In Example 1, they were used in the polyimide solution 1 at 5 parts by mass, 10 parts by mass, 15 parts by mass, 20 parts by mass, 25 parts by mass, and 50 parts by mass relative to 100 parts by mass of polyimide 1, respectively. The ultraviolet absorber-containing polyimide resin compositions 2 to 7 obtained by adding an ultraviolet absorber (Sumisorb 340) in parts by mass are used instead of the ultraviolet absorber-containing polyimide resin composition 1, and are shown in Table 1. The polyimide films 2 to 7 of Examples 2 to 7 were produced in the same manner as in Example 1, except that the polyimide layer (b) was formed with the thickness shown in 2. The content ratio of the ultraviolet absorber in the total solid content of the polyimide films 2 to 7 and the content ratio of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) are shown in Table 2.

(Comparative Example 1) In Example 1, a polyimide solution 1 containing no ultraviolet absorber was used instead of the polyimide resin composition 1 containing an ultraviolet absorber, and a comparative polyimide was formed in such a manner that the thickness shown in Table 2 was obtained. Except for the amine layer (b), a comparative polyimide film 1 of Comparative Example 1 was produced in the same manner as in Example 1.

(Examples 8 to 10) In Example 1, the ultraviolet absorber-containing polyimide obtained by adding an ultraviolet absorber (Sumisorb 340) to the polyimide solution 1 in an amount of 50 parts by mass relative to 100 parts by mass of the polyimide 1 was used. The imine resin composition was substituted for the polyimide resin composition 1 containing the ultraviolet absorber, and the polyimide layer (b) was formed in such a manner that the thickness of Table 2 was obtained. 1 The polyimide films 8 to 10 of Examples 8 to 10 were produced in the same manner. The content ratio of the ultraviolet absorber in the total solid content of the polyimide films 8 to 10 and the content ratio of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) are shown in Table 2.

(Comparative Example 2) By performing the following procedures (1) to (3) using the polyimide solution 1' obtained in Synthesis Example 2, a monolayer comparative polyimide film 2 having the thickness shown in Table 2 was produced. (1) Coat the polyimide solution 1' on a glass plate and dry it in a circulating oven at 40°C for 10 minutes. (2) Under a nitrogen gas flow (oxygen concentration of 100 ppm or less), the temperature was raised to 200°C at a temperature increase rate of 10°C/min, kept at 200°C for 1 hour, and then cooled to room temperature. (3) The single-layer comparative polyimide film 2 was obtained by peeling from the glass plate.

(Comparative Examples 3 to 8) In Comparative Example 2, it was used in the polyimide solution 1' in the amount of 1 part by mass, 2 parts by mass, 3 parts by mass, 4 parts by mass, 5 parts by mass, 100 parts by mass of polyimide 1, The ultraviolet absorber-containing polyimide resin composition obtained by adding the ultraviolet absorber (Sumisorb 340) in an amount of 10 parts by mass was used in place of the polyimide solution 1', except that the same procedure as in Comparative Example 2 was carried out. The comparative polyimide films 3-8 were obtained in a single-layer manner. The content ratio of the ultraviolet absorber in the total solid content of the polyimide films 3 to 8 was compared, and the content ratio of the ultraviolet absorber in the total solid content contained in the comparative polyimide layer (b) was compared. shown in Table 2.

(Examples 11 to 14) By carrying out the following procedures (1) to (3) using the polyimide solution 1 obtained in Synthesis Example 2, a monolayer having a thickness of 80 μm±5 μm as the polyimide layer (a) was produced The polyimide film. (1) Coat the polyimide solution 1 on a glass plate and dry it in a circulating oven at 40°C for 10 minutes. (2) Under a nitrogen gas flow (oxygen concentration of 100 ppm or less), the temperature was raised to 200°C at a temperature increase rate of 10°C/min, kept at 200°C for 1 hour, and then cooled to room temperature. (3) Peeling from the glass plate to obtain a single-layer polyimide film 2 .

Next, with respect to the polyimide solution 1 obtained in Synthesis Example 2, 5 parts by mass, 10 parts by mass, 20 parts by mass, and 25 parts by mass were added to 100 parts by mass of the polyimide 1, respectively. The same compositions of the above-mentioned UV absorbent-containing polyimide resin compositions 2, 3, 5, and 6 obtained with a UV absorber (Sumisorb 340) were respectively placed on the single-layer polyimide film 2 obtained above. , and the following procedures (4) and (5) were carried out, whereby a polyimide layer (b) was formed on one side of the single-layer polyimide film 2, and the polyimide films of Examples 11 to 14 were produced. 11 to 14. (4) Coat the polyimide resin composition containing the ultraviolet absorber on the single-layer polyimide film 2 obtained above, and dry it in a circulating oven at 40° C. for 10 minutes. (5) Under a nitrogen gas flow (oxygen concentration of 100 ppm or less), the temperature was raised to 200°C at a temperature increase rate of 10°C/min, kept at 200°C for 1 hour, and then cooled to room temperature. Furthermore, the content ratio of the ultraviolet absorber in the total solid content of the polyimide films 11 to 14 and the content of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) were The ratios are shown in Table 2.

(Comparative Example 9) In Example 11, the polyimide solution 1 containing no ultraviolet absorber was used instead of the polyimide resin composition containing the ultraviolet absorber, and the comparative polyimide layer was formed so as to have the thickness shown in Table 2. (b) Except for this, a comparative polyimide film 9 of Comparative Example 9 was obtained in the same manner as in Example 11.

(Comparative Example 10) In Example 1, a comparative ultraviolet absorber-containing polymer obtained by adding an ultraviolet absorber (Sumisorb 340) to the polyimide solution 1 in an amount of 0.7 parts by mass relative to 100 parts by mass of the polyimide 1 was used. In addition to forming the comparative polyimide layer (b) so as to have the thickness shown in Table 2 in place of the polyimide resin composition 1 containing the ultraviolet absorber, the imide resin composition 10 was used A comparative polyimide film 10 of Comparative Example 10 was produced in the same manner as in Example 1. The content ratio of the ultraviolet absorber in the total solid content of the comparative polyimide film 10 and the content ratio of the ultraviolet absorber in the total solid content contained in the comparative polyimide layer (b) are shown in Table 2.

(Comparative Example 11) In Example 1, except that the formation of the polyimide layer (b) was not performed, a comparative polyimide film 11 of Comparative Example 11 was produced in the same manner as in Example 1.

(Example 15) In Example 1, when the polyimide layer (b) was formed, the polyimide solution 2 obtained in Synthesis Example 3 was used instead of the polyimide solution 1, and the amount of polyimide solution 1 was used relative to 100 parts by mass. The amine 2 was replaced by the ultraviolet absorber-containing polyimide resin composition 1 obtained by adding the ultraviolet absorber (Sumisorb 340) so that the ultraviolet absorber (Sumisorb 340) was added in place of the ultraviolet absorber-containing polyimide resin composition 1. The polyimide film 15 of Example 15 was obtained in the same manner as in Example 1. The content ratio of the ultraviolet absorber in the total solid content of the polyimide film 15 and the content ratio of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) are shown in Table 2. .

[Table 2]

In addition, in the table, UVA means an ultraviolet absorber, and PI means a polyimide.

According to Table 2, the polyimide films of Examples 1 to 15 in which the ultraviolet absorber does not exist on one side and are partially present on the other side are compared with the polyimide films 1, 2, 9, and 11 that do not contain the ultraviolet absorber. , or the comparative polyimide film 10 with less UV absorber content and a transmittance of more than 18% at a wavelength of 380 nm, the change in YI (ΔYI) before and after the weather resistance test is smaller, and the weather resistance is improved. In addition, it was shown that the polyimide films of Examples 1 to 15 absorb the ultraviolet rays with respect to the comparative polyimide films of Comparative Examples 3 to 8 in which the monolayer polyimide film uniformly contains the ultraviolet absorber. The content of the agent is very small, but it has excellent weather resistance. Furthermore, it was shown that the polyimide films of Examples 1 to 15 are excellent in flexural resistance and the reduction of flexural resistance is suppressed as compared with the comparative polyimide films of Comparative Examples 3 to 8. Among them, the polyimide films of Examples 1 to 10 were imidized by thermal imidization to form a polyimide layer (a) without an ultraviolet absorber, and the flex resistance was further improved. . The reason for this is presumed to be that the residual solvent amount in the polyimide layer (a) was further reduced. In addition, the polyimide film obtained in Example 15 has high tensile modulus and Young's modulus of the polyimide layer (b) side, and the polyimide layer (b) side The surface hardness has been improved.

(Example 16) To the 40 mass % methyl isobutyl ketone solution of neotaerythritol triacrylate, 10 mass parts of 1-hydroxy-cyclohexyl groups were added with respect to 100 mass parts of neotaerythritol triacrylate -Phenyl-ketone (Irgacure 184 manufactured by BASF), and a resin composition for hard coat layer was prepared. The polyimide film of Example 4 was cut into 10 cm × 10 cm, and the above-mentioned resin composition for hard coating was coated on the surface of the polyimide layer (b) side, and the resin composition was applied at a rate of 200 mJ/ The exposure amount of cm ² was irradiated with ultraviolet rays to cure it to form a hard coat layer as a cured film with a film thickness of 10 μm, and a laminate was produced.

(Examples 17 to 21) In Example 1, the coating amount of the polyimide precursor solution 1 was adjusted so that the thickness of the polyimide layer (a) was as shown in Table 3, and further, it was used in the polyimide solution 1 with The ultraviolet absorber-containing polyimide resin composition obtained by adding an ultraviolet absorber (Sumisorb 340) in an amount of 20 parts by mass relative to 100 parts by mass of polyimide 1 was used instead of the ultraviolet absorber-containing polyimide resin The polyimide films of Examples 17 to 21 were produced in the same manner as in Example 1, except that the composition 1 was used to form the polyimide layer (b) with the thickness shown in Table 3. 17-21. The content ratio of the ultraviolet absorber in the total solid content of the polyimide films 17 to 21 and the content ratio of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) are shown in table 3.

[table 3]

It is clear from Table 3 that the polyimide layer (a) containing polyimide and no ultraviolet absorber is provided on one side, and the polyimide layer (a) containing polyimide and ultraviolet absorber is provided on the other side. In the polyimide film of the present invention of the imine layer (b), even if the ratio of the thicknesses of the polyimide layer (a) and the polyimide layer (b) is changed, the YI ratio before and after the weather resistance test is changed. The change (ΔYI) is also small, the weather resistance is excellent, and the reduction of the flexural resistance is suppressed compared with the single-layer polyimide film containing the ultraviolet absorber. Moreover, when the content ratio of the ultraviolet absorber in the above-mentioned polyimide layer (b) is the same, even if the ratio of the thickness of the above-mentioned polyimide layer (a) and the above-mentioned polyimide layer (b) is different , ΔYI is also the same, on the other hand, the smaller the ratio of the thickness of the polyimide layer (b) is, the more the flex resistance of the polyimide film is improved.

(Examples 22 to 25) In Example 1, the coating amount of the polyimide precursor solution 1 was adjusted so that the thickness of the polyimide layer (a) was as shown in Table 4, and further, it was used in the polyimide solution 1 with The ultraviolet absorber-containing polyimide resin composition obtained by adding an ultraviolet absorber (Sumisorb 340) in an amount of 120 parts by mass relative to 100 parts by mass of the polyimide 1 was used instead of the polyimide containing a ultraviolet absorber Resin composition 1, and the coating amount of the polyimide resin composition containing the ultraviolet absorber was adjusted so that the thickness of the polyimide layer (b) was as shown in Table 4. In the same manner as in Example 1, the polyimide films 22 to 25 of Examples 22 to 25 were obtained. The content ratio of the ultraviolet absorber in the total solid content of the polyimide films 22 to 25 and the content ratio of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) are shown in Table 4.

(Examples 26 to 28) In Example 1, the coating amount of the polyimide precursor solution 1 was adjusted so that the thickness of the polyimide layer (a) was as shown in Table 4, and further, it was used in the polyimide solution 1 with An ultraviolet absorber represented by the following chemical formula (ii) (trade name: Sumisorb 350 manufactured by Sumika Chemtex Co., Ltd., melting point 77°C) was added in an amount of 70 parts by mass relative to 100 parts by mass of polyimide 1 The ultraviolet absorber-containing polyimide resin composition was replaced by the ultraviolet absorber-containing polyimide resin composition 1, and the polyimide layer (b) was adjusted so that the thickness of the polyimide layer (b) was as shown in Table 4. The polyimide films 26 to 28 of Examples 26 to 28 were produced in the same manner as in Example 1, except for the coating amount of the polyimide resin composition of the ultraviolet absorber. The content ratio of the ultraviolet absorber in the total solid content of the polyimide films 26 to 28 and the content ratio of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) are shown in Table 4.

Chemical formula (ii)

[Table 4]

It can be clearly seen from Table 4 that the polyimide film of the present invention has a small change in YI (ΔYI) before and after the weather resistance test even if the type and content of the ultraviolet absorber are changed, and the polyimide film of the present invention has excellent weather resistance. Compared with the single-layer polyimide film, the reduction of flex resistance is suppressed. Among them, in the case of using Sumisorb 340, an ultraviolet absorber having a linear or branched saturated aliphatic hydrocarbon group having a carbon number of 6 or more and 15 or less, increase the content of the ultraviolet absorber in the polyimide layer (b) The optical characteristics are not easy to deteriorate over time. Therefore, it is clear that by adjusting the content of the ultraviolet absorber in the polyimide layer (b) and the thickness of the polyimide layer (b), it is easy to simultaneously improve the weather resistance and the flex resistance of the polyimide film state.

Furthermore, from the polyimide films 1 to 28 obtained in Examples 1 to 28 and the comparative polyimide films 3 to 8 and 10 obtained in Comparative Examples 3 to 8 and 10, 10 were cut out in two places. In the area of mm × 10 mm, 2 sections were made for each membrane. One of the two slices was cut so that one side was left, and the other was cut so that the other side was left to prepare a test piece. The presence or absence of the ultraviolet absorber in each test piece was confirmed using GC-MS connected to a blowing trap device (heating desorption device). Specifically, a sample tube into which the test piece was placed was installed in a blowing trap device (product name JTD505-III, Nippon Analytical Industries Co., Ltd.), and the temperature was kept at 200° C. for 30 minutes for heating, and the trapping at -60° C. was used. The generated gas was trapped in a tube, and the trapped gas was heated at 315°C to be scattered and sent to a GC-MS device (6890/5973 GC/MS of Agilent), and the components of the generated organic gas were analyzed. Qualitative analysis to confirm the presence or absence of UV absorbers. In addition, analysis conditions are as follows. (Conditions for blowing air capture device) Total split ratio (intake volume/exhaust volume): 1:10 Carrier gas: Helium 1.0 mL/min quant (GC-MS conditions) Column: UA-5 inner diameter 250 μm x length 30 m x film thickness 0.25 μm (manufactured by Frontier Laboratories) Heating conditions: After holding at 50°C for 5 minutes, the temperature was raised to 320°C at 10°C/min, and held at 320°C for 3 minutes

As a result, in the polyimide films 1 to 28 of Examples 1 to 28 and the comparative polyimide 10 of Comparative Example 10, no ultraviolet absorber was detected on one side, and ultraviolet rays were detected only on one side. absorbent. Comparative Examples 3 to 8 In the polyimide films 3 to 8, the ultraviolet absorbers were detected on both sides.

1, 1a, 1b‧‧‧polyimide layer (a) 2, 2a, 2b‧‧‧polyimide layer (b) 10, 10'‧‧‧Polyimide film 3‧‧‧Metal 4a, 4b‧‧‧glass plate 5a, 5b‧‧‧ Dummy test piece 11, 11', 11''‧‧‧Laminate 4E‧‧‧First transparent electrode 41‧‧‧First conductive part 5E‧‧‧Second transparent electrode 51‧‧‧Second conductive part 6‧‧‧Additional layer 7‧‧‧First pinout 71‧‧‧First terminal 8‧‧‧Second lead wire 81‧‧‧Second terminal 20, 20'‧‧‧touch panel components 21‧‧‧Edge of laminated body 22‧‧‧Effective area 23‧‧‧Invalid area 24‧‧‧Connection 201‧‧‧First Conductive Member 202‧‧‧Second conductive member 30‧‧‧LCD display 40‧‧‧Organic Electroluminescence Display Section 100, 200‧‧‧LCD device 300, 400‧‧‧Organic electroluminescence display device

FIG. 1 is a schematic cross-sectional view showing an example of the polyimide film of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the polyimide film of the present invention. Figure 3 is a diagram for explaining the method of the static deflection test. 4 is a schematic plan view of one surface of an example of the touch panel member of the present invention. FIG. 5 is a schematic plan view of the other side of the touch panel member shown in FIG. 4 . FIG. 6 is an AA' cross-sectional view of the touch panel member shown in FIGS. 4 and 5 . FIG. 7 is a schematic plan view showing an example of a conductive member including the laminate of the present invention. FIG. 8 is a schematic plan view showing another example of the conductive member including the laminate of the present invention. FIG. 9 is a schematic cross-sectional view showing another example of the touch panel member of the present invention. FIG. 10 is a schematic cross-sectional view showing an example of the liquid crystal display device of the present invention. FIG. 11 is a schematic cross-sectional view showing another example of the liquid crystal display device of the present invention. FIG. 12 is a schematic cross-sectional view showing an example of the organic electroluminescence display device of the present invention. 13 is a schematic cross-sectional view showing another example of the organic electroluminescence display device of the present invention.

1‧‧‧Polyimide layer (a)

2‧‧‧Polyimide layer (b)

10‧‧‧Polyimide film

S1‧‧‧One side

S2‧‧‧The other side

Claims (29)

A polyimide film, which contains polyimide and an ultraviolet absorber, wherein the ultraviolet absorber does not exist on one side and exists on the other side, and the transmittance of the polyimide film at a wavelength of 380 nm is 18% below, and the transmittance at a wavelength of 450 nm is 85% or more, and has at least one polyimide layer (a) containing polyimide and no ultraviolet absorber on one side, and has at least one layer on the other side. One layer is a polyimide layer (b) containing polyimide and a UV absorber. The polyimide film according to claim 1, wherein the total thickness of the polyimide layer (a) is the same as or greater than the total thickness of the polyimide layer (b) (b) Total thickness. The polyimide film according to claim 1 or 2, wherein the total thickness of the polyimide layers (b) is 0.5 μm or more. The polyimide film according to claim 1 or 2, wherein the content of the ultraviolet absorber in the total solid content contained in the polyimide layer (b) is 0.8 mass % or more and 60 mass % %the following. The polyimide film according to claim 1 or 2, wherein the polyimide layer (a) and the polyimide layer (b) that are adjacent to each other contain the same polyimide. . The polyimide film according to claim 5, wherein the polyimide layer (a) and the polyimide layer (b), which are adjacent to each other, each contain a compound having the following general formula (1). The polyimide represented by the structure, the general formula (1)

(In the general formula (1), R ¹ represents a tetravalent group that is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, R ² represents a divalent group that is a diamine residue, and the sum of the total amount of R ² 2.5 mol % or more and 50 mol % or less are diamine residues having silicon atoms in the main chain, and 50 mol % or more and 97.5 mol % or less of the total amount of R ² do not have silicon atoms and are aromatic Diamine residues of cyclic or aliphatic rings; n represents the number of repeating units). The polyimide film according to claim 6, wherein, in the polyimide having the structure represented by the above-mentioned general formula (1), the above-mentioned R ² in the above-mentioned general formula (1) is in the main chain The diamine residue having a silicon atom is a diamine residue having 1 or 2 silicon atoms in the main chain. The polyimide film according to claim 1 or 2, wherein the polyimide contained in the polyimide layer (a) on the outermost surface on one side and the polyimide on the outermost surface on the other side The polyimide contained in the polyimide layer (b) is different from each other. The polyimide film according to claim 8, wherein the polyimide layer (a) on the outermost surface on one surface side contains a polyimide having a structure represented by the following general formula (1),

(In the general formula (1), R ¹ represents a tetravalent group that is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, R ² represents a divalent group that is a diamine residue, and the sum of the total amount of R ² 2.5 mol % or more and 50 mol % or less are diamine residues having silicon atoms in the main chain, and 50 mol % or more and 97.5 mol % or less of the total amount of R ² do not have silicon atoms and are aromatic Diamine residues of cyclic or aliphatic rings; n represents the number of repeating units). The polyimide film according to claim 9, wherein, in the polyimide having the structure represented by the above general formula (1), the above-mentioned R ² in the above general formula (1) is in the main chain The diamine residue having a silicon atom is a diamine residue having 1 or 2 silicon atoms in the main chain. The polyimide film according to claim 8, wherein the polyimide layer (b) on the outermost surface on the other surface side contains a polyimide having a structure represented by the following general formula (2) ,

(In the general formula (2), R ³ represents a residue selected from the group consisting of pyromic acid dianhydride residues, 2,3,3',4'-biphenyltetracarboxylic dianhydride residues and 3,3',4,4 At least one tetravalent group in the group consisting of '-biphenyltetracarboxylic dianhydride residues, R ⁴ represents a divalent group as a diamine residue; n' represents the number of repeating units). The polyimide film according to claim 11, wherein, in the polyimide having the structure represented by the above general formula (2), R ⁴ in the above general formula (2) includes an aromatic ring or Alicyclic diamine residue. The polyimide film according to claim 9, wherein the polyimide layer (b) on the outermost surface on the other side contains a polyimide having a structure represented by the following general formula (2) , the general formula (2)

(In the general formula (2), R ³ represents a residue selected from the group consisting of pyromic acid dianhydride residues, 2,3,3',4'-biphenyltetracarboxylic dianhydride residues and 3,3',4,4 At least one tetravalent group in the group consisting of '-biphenyltetracarboxylic dianhydride residues, R ⁴ represents a divalent group as a diamine residue; n' represents the number of repeating units). The polyimide film according to claim 13, wherein, in the polyimide having the structure represented by the above general formula (2), R ⁴ in the above general formula (2) contains an aromatic ring or Alicyclic diamine residue. The polyimide film according to claim 10, wherein the polyimide layer (b) on the outermost surface on the other side contains a polyimide having a structure represented by the following general formula (2) ,

(In the general formula (2), R ³ represents a residue selected from the group consisting of pyromic acid dianhydride residues, 2,3,3',4'-biphenyltetracarboxylic dianhydride residues and 3,3',4,4 At least one tetravalent group in the group consisting of '-biphenyltetracarboxylic dianhydride residues, R ⁴ represents a divalent group as a diamine residue; n' represents the number of repeating units). The polyimide film according to claim 15, wherein, in the polyimide having the structure represented by the above general formula (2), R ⁴ in the above general formula (2) contains an aromatic ring or Alicyclic diamine residue. The polyimide film as claimed in claim 1 or 2, comprising: including a perfluoroalkyl group The aromatic ring of the polyimide. The polyimide film according to claim 1 or 2, wherein the Young's modulus of one side and the Young's modulus of the other side are both 2.4GPa or more. The polyimide film according to claim 1 or 2, wherein the melting point of the ultraviolet absorber is 100°C or higher. The polyimide film according to claim 1 or 2, wherein the ultraviolet absorber has a linear or branched saturated aliphatic hydrocarbon group having 1 to 15 carbon atoms. The polyimide film according to claim 1 or 2, wherein the ultraviolet absorber is a compound represented by the following general formula (I),

(In the general formula (I), R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 or more and 4 or less carbon atoms, and R ²⁵ , R ²⁶ , R ²⁷ , and R ²⁸ and R ²⁹ each independently represent a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 15 carbon atoms which may be substituted by a phenyl group or a monovalent polysiloxane group, or -R ³⁰ -AR ³¹ , R ³⁰ represents a linear or branched alkylene with a carbon number of 1 or more and 15 or less, A represents a phenylene or a divalent polysiloxane, and R ³¹ represents a carbon A linear or branched alkyl group of 1 or more and 15 or less, at least one of R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ represents a phenyl group or a monovalent polysiloxane group Substituted linear or branched alkyl group with 1 to 15 carbon atoms, or -R ³⁰ -AR ³¹ ; the above-mentioned phenyl group and the above-mentioned phenylene group may be substituted by a linear or branched carbon number of 1 or more and 15 or less. or branched alkyl substituted). A kind of manufacture method of polyimide film, it has the following steps: Forming a polyimide layer (a) containing polyimide and not containing an ultraviolet absorber; The polyimide layer (b); the step of forming the above-mentioned polyimide layer (b) has the following steps: preparing a polyimide resin containing a polyimide, an ultraviolet absorber and an organic solvent containing an ultraviolet absorber. and coating the above-mentioned ultraviolet absorbent-containing polyimide resin composition to form a ultraviolet absorbent-containing polyimide resin coating film; the polyimide film has at least one layer of the above-mentioned polyimide resin on one side The amine layer (a) has at least one layer of the polyimide layer (b) on the other side, and has a transmittance of 18% or less at a wavelength of 380 nm and a transmittance of 85% or more at a wavelength of 450 nm. A laminate comprising the polyimide film according to any one of claims 1 to 21, and a functional layer containing at least one polymer of a radically polymerizable compound and a cationically polymerizable compound. The layered product according to claim 23, wherein the radically polymerizable compound is a compound having two or more (meth)acryloyl groups in one molecule, and the cationically polymerizable compound is a compound having two or more (meth)acryloyl groups in one molecule. A compound of at least one of more than one epoxy group and oxetanyl. A surface material for a display, which is the polyimide film described in any one of claims 1 to 21, or at least 1 having the polyimide film and a radically polymerizable compound and a cationically polymerizable compound. A laminate of functional layers of polymers. The surface material for a display according to claim 25, which is used for a flexible display. A touch panel member comprising: the polyimide film described in any one of claims 1 to 21, or the polyimide film and a radically polymerizable compound containing a cationically polymerizable compound A laminate of functional layers of at least one polymer of a compound; a transparent electrode disposed on one surface side of the polyimide film or the laminate and composed of a plurality of conductive parts; and a transparent electrode that is electrically connected to the conductive parts A plurality of lead wires on at least one side of the end. A liquid crystal display device comprising: the polyimide film described in any one of claims 1 to 21, or the polyimide film and at least one of a radically polymerizable compound and a cationically polymerizable compound A laminate of a functional layer of a polymer; and a liquid crystal display portion comprising a liquid crystal layer disposed on one surface side of the polyimide film or the laminate and having a liquid crystal layer between opposing substrates. An organic electroluminescence display device comprising: the polyimide film described in any one of claims 1 to 21, or a combination of the polyimide film and a radically polymerizable compound and a cationically polymerizable compound A laminate of at least one functional layer of a polymer; and an organic electroluminescence display portion provided on one surface side of the polyimide film or the laminate and having an organic electroluminescence layer between opposing substrates.

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