JP2019119084A - Light permeable film with protective film, and protective film - Google Patents

Abstract

To provide a light permeable film excellent in smoothness with a protective film, and a protective film.SOLUTION: A light permeable film 10 with a protective film includes a foldable light permeable film 20 having at least a resin substrate 21 and a protective film 30 detachably attached to the surface 20A of the light permeable film 20. The protective film 30 has a thickness of 30 μm or more and a haze value of 10% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light transmitting film with a protective film and a protective film.

  Conventionally, image display devices such as smartphones and tablet terminals are known, but at present, development of foldable image display devices is being carried out. Usually, a smartphone, a tablet terminal or the like is covered with a cover glass. When a cover glass is used for the image display device, although the hardness is excellent, there is a high possibility of breakage when trying to fold. For this reason, using a foldable optical film instead of a cover glass is examined for a foldable image display apparatus (for example, refer to patent documents 1).

JP, 2016-125063, A

  In order to form such an optical film, a foldable light transmitting film composed only of a resin substrate or a foldable light composed of a resin substrate and a resin layer laminated on at least one surface of the resin substrate Permeable films are used. The light transmitting film is usually wound in a roll, and is drawn out at the time of use. However, when the light transmitting film is wound in a roll, the light transmitting films stick to each other, making the drawing difficult. become. In addition, a light transmitting film provided with a resin substrate is easily scratched and is expensive. Because of this, a protective film is often attached to at least one side of the light transmitting film. The protective film is releasably bonded to the light transmitting film, and is peeled off during processing of the light transmitting film.

  In the light transmitting film, excellent smoothness is required for the purpose of obtaining high transparency and improving the appearance quality, but it is wound in a state where the protective film is attached to the light transmitting film, When pressure is applied, the asperity shape on the surface of the protective film is transferred, and therefore, when the protective film is peeled from the light transmitting film, there is a problem that asperities appear on the surface of the resin substrate. In particular, when the protective film is directly attached to the resin base of the light transmitting film, the asperities appear notably on the surface of the resin base. In addition, although the unevenness of the surface of the light transmitting film can be corrected by treating the light transmitting film at a high temperature, it is inefficient that it is important that the unevenness does not appear on the surface of the light transmitting film .

  The present invention has been made to solve the above problems. That is, it is an object of the present invention to provide a light transmitting film with a protective film and a protective film capable of obtaining a light transmitting film having excellent smoothness.

  According to one aspect of the present invention, there is provided a light with a protective film comprising: a foldable light transmitting film comprising at least a resin substrate; and a protective film releasably attached to at least one side of the light transmitting film. It is a transparent film, Comprising: The thickness of the said protective film is 30 micrometers or more, and the haze value of the said protective film is 10% or less. The light transmissive film with a protective film is provided.

  In the light transmitting film with a protective film, the protective film may be peelably attached to both sides of the light transmitting film.

  In the light transmitting film with a protective film, the first surface of the resin substrate constitutes the first surface of the light transmitting film, and the protective film is formed on the first surface of the resin substrate. It may be pasted so as to be peelable.

  In the light transmitting film with a protective film, the light transmitting film may further include a resin layer provided on at least one side of the resin base.

  In the light transmitting film with a protective film, the protective film includes a base film made of a polyester resin and an adhesive layer provided on the surface of the base film on the side of the light transmitting film. It is also good.

  In the light transmitting film with a protective film, the resin substrate may be a substrate made of a polyimide resin, a polyamide resin, or a mixture thereof.

  In the light transmitting film with a protective film, the light transmitting film with a protective film may be wound in a roll.

  According to another aspect of the present invention, there is provided a protective film that can be attached to a foldable light transmissive film comprising at least a resin substrate, wherein the thickness of the protective film is 30 μm or more, and the haze of the protective film A protective film is provided whose value is 10% or less.

  According to one aspect and another aspect of the present invention, a light transmitting film with a protective film and a protective film capable of obtaining a light transmitting film having excellent smoothness can be provided.

It is a schematic block diagram of a light transmission film with a protective film concerning an embodiment. It is the figure which showed typically the mode of the continuous folding test. It is the figure which showed typically the mode of the folding stationary test. It is a schematic block diagram of the other light transmission film with a protective film which concerns on embodiment. It is a schematic block diagram of the other light transmission film with a protective film which concerns on embodiment. It is a schematic block diagram of the optical film which concerns on embodiment. It is a schematic block diagram of the image display apparatus which concerns on embodiment.

  Hereinafter, a light transmitting film with a protective film and a protective film according to an embodiment of the present invention will be described with reference to the drawings. In the present specification, the terms "film", "sheet" and the like are not distinguished from one another based only on the difference in designation. Thus, for example, "film" is used in a sense that it also includes a member also called a sheet. FIG. 1 is a schematic configuration view of a light transmitting film with a protective film according to the present embodiment, FIG. 2 is a view schematically showing a state of a continuous folding test, and FIG. It is the figure shown typically, and FIG. 4 and FIG. 5 is a schematic block diagram of the other light transmissive film with a protective film which concerns on this embodiment.

<<< Light transmitting film with protective film >>>
The protective film-carrying light transmitting film 10 shown in FIG. 1 comprises a foldable light transmitting film 20 comprising at least a resin substrate 21 and a first surface 20 A of the light transmitting film 20 (hereinafter simply referred to as “surface 20 A And the first surface of the light transmitting film 20. The first protective film 30 may be releasably attached to the first protective film 30 (hereinafter, may simply be referred to as the “protective film 30”). A second protective film 40 (hereinafter simply referred to as "protective film 40") releasably attached to the second surface 20B opposite to 20A (hereinafter sometimes simply referred to as "surface 20B"). (Sometimes called)). That is, in the light transmitting film 10 with a protective film shown in FIG. 1, the protective films 30 and 40 are provided on both sides of the light transmitting film 20. Each of the protective films 30 and 40 has a thickness of 30 μm or more and a haze value of 10% or less as described later, and thus satisfies the requirements of the present invention. The light transmitting film with protective film may not be provided with the protective film satisfying the requirements of the present invention on both sides as long as the protective film satisfying the requirements of the present invention is provided on at least one side of the light transmitting film. For example, as long as the light transmitting film 10 with a protective film of FIG. 1 includes the protective film 30, the protective film 40 may not be provided. In addition, the light transmitting film 10 with a protective film may be wound in a roll.

  The surface 20A of the light transmitting film 20 is a first surface 21A of the resin base 21 (hereinafter, may be simply referred to as "surface 21A"). Further, as described later, since the light transmitting film 20 shown in FIG. 1 is composed of only the resin base 21, the surface 20 B of the light transmitting film 20 is a first surface of the resin base 21. A second surface 21B opposite to 21A (hereinafter, also simply referred to as "surface 21B") is provided. Therefore, in the light transmitting film 10 with protective film, the protective film 30 is peelably attached to the surface 21 A of the resin base 21, and the protective film 40 is peeled off to the surface 21 B of the resin base 21. It is pasted possible. In the case where both surfaces of the light transmitting film are releasably attached and the protective film is releasably attached to the surface of the resin substrate, at least one of the protective films is on one side of the resin substrate It is sufficient that the protective films are releasably attached, and it is not necessary for both protective films to be releasably attached to both sides of the resin substrate.

<< light transmitting film >>
The light transmitting film 20 is a film having a light transmitting property. In the present specification, the “light transmitting film” may be any of an intermediate-stage film used in producing an optical film and an optical film which is a finished product, as long as it has a light transmitting property. . The light transmitting film 20 shown in FIG. 1 is an intermediate-stage film used when manufacturing the optical film 100. Further, "light transmitting" means a property of transmitting light, and for example, the total light transmittance is 50% or more, preferably 70% or more, more preferably 80% or more, particularly preferably 90% or more. Including a certain thing. The light transmissive property does not necessarily have to be transparent and may be translucent.

  The light transmitting film 20 shown in FIG. 1 is composed of only the resin base 21. Since the light transmitting film 20 is composed only of the resin base 21, the following description of the light transmitting film 20 also applies to the resin base 21. The light transmitting film 20 has a single-layer structure of the resin base 21, but may have a laminated structure of a resin base and a resin layer provided on at least one side of the resin base.

  The light transmitting film 20 is foldable. Specifically, even when the light transmitting film 20 is repeatedly subjected to a folding test (continuous folding test) described below 100,000 times, Preferably, the light transmitting film 20 does not break or break, and it is more preferable that the light transmitting film 20 does not break or break even when the continuous folding test is repeated 200,000 times. It is further preferable that the light transmitting film 20 does not break or break even when repeated 1,000,000 times. When the light transmitting film 20 is repeatedly subjected to a continuous folding test 100,000 times and cracks occur in the light transmitting film 20, the foldability of the light transmitting film 20 becomes insufficient.

  The continuous folding test is performed as follows. In addition, the continuous folding test of the light transmissive film 20 shall be performed in the state which peeled the protective films 30 and 40. FIG. As shown in FIG. 2A, in the continuous folding test, first, the side portion 20C of the light transmitting film 20 and the side portion 20D facing the side portion 20C are respectively fixed by the fixing portions 50 arranged in parallel. Fix it. In addition, although the light transmissive film 20 may be arbitrary shapes, it is preferable that the light transmissive film 20 in a continuous folding test is a rectangle (for example, a rectangle of 30 mm x 100 mm). Moreover, as shown to FIG. 2 (A), the fixing | fixed part 50 is slidable in the horizontal direction.

  Next, as shown in FIG. 2 (B), the light transmitting film 20 is deformed to be folded by moving the fixing portions 50 so as to be close to each other, and further as shown in FIG. 2 (C) After moving the fixing portion 50 to a position where the distance between the two opposing side portions fixed by the fixing portion 50 of the light transmitting film 20 is 30 mm, the fixing portion 50 is moved in the reverse direction to transmit light The deformation of the film 20 is eliminated.

  By moving the fixing portion 50 as shown in FIGS. 2A to 2C, the light transmitting film 20 can be folded by 180 degrees. In addition, a continuous folding test is performed so that the bent portion 20E of the light transmitting film 20 does not protrude from the lower end of the fixing portion 50, and the distance when the fixing portion 50 approaches closest is controlled to 30 mm. The distance between the two opposing sides of the elastic film 20 can be 30 mm. In this case, the outer diameter of the bending portion 20E is considered to be 30 mm. In addition, since the thickness of the light transmitting film 20 is a sufficiently small value as compared with the distance (30 mm) between the fixing portions 50, the result of the continuous folding test of the light transmitting film 20 is the same as that of the light transmitting film 20. It can be considered that it is not affected by the difference in thickness. In the light transmitting film 20, it is preferable that cracking or breakage does not occur when the test of folding 180 ° repeatedly for 100,000 times so that the distance between opposing side portions of the light transmitting film 20 is 30 mm. No cracking or breakage occurs when the continuous folding test of 180 ° folding is repeated 100,000 times so that the distance between opposing sides of the light transmitting film 20 is 20 mm, 15 mm, 10 mm, 6 mm, 3 mm, or 2 mm. Is more preferable (the smaller the distance between the side portions, the more preferable).

  In the light transmitting film 20, as shown in FIG. 3A, the side portion 20C of the light transmitting film 20 and the side portion 20D facing the side portion 20C are divided into the side portion 20C and the side portion 20D. Each sheet is fixed by fixing parts 55 disposed in parallel so that the distance is 30 mm, and in a state where light transmitting film 20 is folded, a folding and standing test is performed by leaving at 70 ° C. for 240 hours. As shown in B), the folded state is released by removing the fixing part 55 from the side part 20D after the folding and standing test, and after 30 minutes at room temperature, the light transmitting film 20 becomes natural in the light transmitting film 20. It is preferable that opening angle (theta) of the transparent film 20 is 100 degrees or more, when opening angle (theta) which is an opening angle is measured. The larger the opening angle θ, the better the restorability, and the maximum is 180 °. In addition, the folding stationary test of the light transmissive film 20 shall be performed in the state which peeled the protective films 30 and 40. FIG.

  The haze value (total haze value) of the light transmitting film 20 is preferably 3% or less. When the haze value of the light transmitting film 20 is 3% or less, the surface 21A and the surface 21B of the resin base 21 have less unevenness, and therefore, the smoothness is more excellent. The haze value of the light transmitting film 20 is obtained by peeling the protective films 30 and 40 from the light transmitting film 10 with a protective film cut out to a size of 50 mm × 100 mm, which is a state of the light transmitting film 20 alone, Measure in accordance with JIS K7136: 2000 using a haze meter (product name "HM-150", Murakami Color Research Laboratory Co., Ltd.) with no curl or wrinkle and no fingerprints or dust. be able to. The haze value of the light transmitting film is an arithmetic mean value of the values obtained by measuring three times for one light transmitting film. In the present specification, “to measure three times” means to measure three different places instead of measuring the same place three times. In the case where the light transmitting film can not be cut into the above size, for example, since the entrance opening at the time of measurement of HM-150 is 20 mmφ, a sample size having a diameter of 21 mm or more is required. Therefore, the light transmitting film may be cut out to a size of 22 mm × 22 mm or more. When the size of the light transmitting film is small, the light source spot is shifted little by little within the range where the light source spot does not go out, or the angle is changed to three measurement points. The haze value of the light transmitting film 20 is more preferably in the order of 2% or less and 1% or less (the smaller the numerical value, the more preferable).

  The total light transmittance of the light transmitting film 20 is preferably 85% or more. If the total light transmittance of the light transmitting film 20 is 85% or more, sufficient optical performance can be obtained. The total light transmittance is obtained by peeling the protective films 30 and 40 from the light transmitting film 10 with a protective film cut out to a size of 50 mm × 100 mm, and is a state of the light transmitting film 20 alone, without curling or wrinkles. And in the absence of fingerprints and dust, etc., using a haze meter (product name “HM-150”, Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K7361-1: 1997. it can. The total light transmittance of the light transmitting film is an arithmetic mean of the values obtained by measuring three times for one light transmitting film. In the case where the light transmitting film can not be cut into the above size, for example, since the entrance opening at the time of measurement of HM-150 is 20 mmφ, a sample size having a diameter of 21 mm or more is required. Therefore, the light transmitting film may be cut out to a size of 22 mm × 22 mm or more. When the size of the light transmitting film is small, the light source spot is shifted little by little within the range where the light source spot does not go out, or the angle is changed to three measurement points. The total light transmittance of the light transmitting film 20 is more preferably in the order of 88% or more and 90% or more (the larger the numerical value, the more preferable).

  The light transmissive film 20 preferably has a yellow index (YI) of 15 or less. If YI of the light transmitting film 20 is 15 or less, the yellowishness of the light transmitting film 20 can be suppressed, and the invention can be applied to applications where transparency is required. The yellow index (YI) is a light with a protective film cut into a size of 50 mm x 100 mm using a spectrophotometer (product name "UV-3100 PC", manufactured by Shimadzu Corporation, light source: tungsten lamp and deuterium lamp) The protective films 30, 40 are peeled off from the transparent film 10, and the chromaticity tristimulus values X, Y, Z are calculated according to the arithmetic equation described in JIS Z 8722: 2009 from the values measured in the state of the transparent film 20 alone. It is a value calculated according to an arithmetic expression described in ASTM D1925: 1962 from tristimulus values X, Y, Z. The upper limit of the yellow index (YI) of the light transmitting film 20 is more preferably in the order of less than 10 and less than 1.5 (the smaller the numerical value, the more preferable).

  In order to adjust the yellow index (YI) of the light transmitting film 20, for example, the resin base 21 may contain a blue dye that is a complementary color of yellow, or it may be provided on at least one side of the resin base A blue pigment may be contained in a thin layer (for example, resin layers 71, 91, 92 described later). By using a polyimide base material as the resin base 21, even if yellowness is a problem, by including a blue pigment in the resin base 21, the yellow color of the light transmitting film is obtained. The index (YI) can be lowered.

  The blue dye may be either a pigment or a dye, but for example, when the light transmitting film 20 is used in an organic light emitting diode display device, one having both light resistance and heat resistance is preferable. As the above-mentioned blue pigment, polycyclic organic pigments, metal complex organic pigments, etc. have a lower degree of molecular breakage due to ultraviolet rays than the molecular dispersion of dyes, and are extremely excellent in light resistance, and therefore applications requiring light resistance etc. And more specifically, phthalocyanine-based organic pigments and the like are preferably mentioned. However, since the pigment is dispersed in particles in the solvent, and thus the transparency is inhibited due to particle scattering, it is preferable to put the particle size of the pigment dispersion in the Rayleigh scattering region. On the other hand, when the transparency of the light transmitting film is regarded as important, it is preferable to use a dye which is molecularly dispersed in a solvent as the blue dye.

  The application of the light transmitting film 20 is not particularly limited, but as the application of the light transmitting film 20, for example, a smartphone, a tablet terminal, a personal computer (PC), a wearable terminal, digital signage, television, car navigation, etc. There is an image display device.

  The light transmitting film 20 may be cut into a desired size, but may be rolled. When the light transmitting film 20 is cut to a desired size, the size of the light transmitting film is not particularly limited, and is appropriately determined according to the size of the display surface of the image display device. Specifically, the size of the light transmitting film 20 may be, for example, 2.8 inches or more and 500 inches or less. In the present specification, "inch" means the length of a diagonal when the optical film has a square shape, means the diameter when the optical film has a circular shape, and the minor axis when it has an elliptical shape. It means the average value of the sum of the major diameter and the major diameter. Here, when the optical film has a rectangular shape, the aspect ratio of the optical film at the time of obtaining the above-mentioned inch is not particularly limited as long as there is no problem as the display screen of the image display device. For example, vertical: horizontal = 1: 1, 4: 3, 16:10, 16: 9, 2: 1 and the like can be mentioned. However, especially in automotive applications and digital signage, which are rich in design, it is not limited to such an aspect ratio. Moreover, when the size of the light transmitting film 20 is large, it is cut out from an arbitrary position into an A5 size (148 mm × 210 mm), and then cut out into the size of each measurement item.

<Resin base material>
The resin base 21 is a base made of a resin. The thickness of the resin base 21 is preferably 10 μm or more and 100 μm or less. If the thickness of the resin substrate 21 is 10 μm or more, curling can be suppressed, and sufficient hardness can be obtained, and wrinkles are generated even when the light transmitting film is manufactured by Roll to Roll. It is difficult to do so and there is no risk of deteriorating the appearance. On the other hand, if the thickness of the resin substrate 21 is 100 μm or less, the folding performance of the light transmitting film is good, and the requirements of the continuous folding test can be satisfied, and the weight reduction of the light transmitting film Preferred. The thickness of the resin base 21 is obtained by photographing the cross section of the resin base 21 using a scanning electron microscope (SEM), measuring the thickness of the resin base 21 at 10 points in the image of the cross section, and It is an arithmetic mean value of thickness. The lower limit of the resin base 21 is more preferably 20 μm or more, and the upper limit of the resin base 21 is more preferably 80 μm or less.

  Examples of the resin constituting the resin base 21 include polyimide resins, polyamide imide resins, polyamide resins, or a mixture of two or more of these resins. Among these, not only cracking or breakage is less likely to occur in the continuous folding test, but it also has excellent hardness and transparency, is also excellent in heat resistance, and is further excellent in hardness and transparency by firing. From the viewpoint of being capable of imparting, polyimide resins, polyamide resins, or mixtures thereof are preferred.

  The polyimide resin is obtained by reacting a tetracarboxylic acid component and a diamine component. It is preferable to obtain and polyimidate a polyamic acid by polymerizing a tetracarboxylic acid component and a diamine component. The imidization may be performed by thermal imidization or chemical imidization. Moreover, it can also manufacture by the method which used heat | fever imidation and chemical imidation together. The polyimide-based resin may be an aliphatic polyimide-based resin, but is preferably a polyimide-based resin containing an aromatic ring. The polyimide resin containing an aromatic ring is one containing an aromatic ring in at least one of the tetracarboxylic acid component and the diamine component.

  As a specific example of the tetracarboxylic acid component, tetracarboxylic acid dianhydride is suitably used, and cyclohexanetetracarboxylic acid dianhydride, cyclopentanetetracarboxylic acid dianhydride, dicyclohexane-3,4,3 ', 4 '-Tetracarboxylic acid dianhydride, pyromellitic acid dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic acid dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic acid dianhydride , 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxy) Phenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3 4-dicarboxyphenyl) sulfone 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) benzoyl] benzene dianhydride, 1 , 4-Bis [(3,4-dicarboxy) benzoyl] benzene dianhydride, 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) phenoxy] phenyl} ketone dianhydride, bis {4- [3- (1,2- (1,2-di) Dicarboxy) phenoxy] phenyl} ketone dianhydride, 4,4'-bis [4- (1,2-dicarboxy) phenoxy] biphenyl dianhydride, 4,4'-bis [3- (1,2- (1,2-di) Dicarboxy) phenoxy] biphenyl dianhydride, 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} sulfone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl } Rufone dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} sulfide dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfide Anhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, 3,4'-(hexafluoroisopropylidene) diphthalic anhydride, 3,3 '-(hexafluoroisopropylidene) diphthalic anhydride 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 1 2,2,3,4-benzenetetracarboxylic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracenetetracarboxylic acid Dianhydride, 1,2,7,8-phenanthrene tetracarboxylic acid dianhydride, and the like. These may be used alone or in combination of two or more.

  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 sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzanilide, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3, 4 ' Diaminodiphenylmethane, 2,2-di (3-aminophenyl) propane, 2,2-di (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2, 2-di (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-di (4-aminophenyl) -1,1,1,3,3,3- Hexafluoropropane, 2- (3-aminophenyl) -2- (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 1,1-di (3-aminophenyl)- 1-phenylethane, 1,1-di (4-aminophenyl) -1-phenylethane, 1- (3-aminophenyl) -1- (4-aminophenyl) -1-phenylethane, 1,3-bis (3-aminophenoxy) bee Zen, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-amino Benzoyl) benzene, 1,3-bis (4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4-aminobenzoyl) benzene, 1,3-bis (3 -Amino-α, α-dimethylbenzyl) benzene, 1,3-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (3-amino-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-ditrifluoromethyl) Benzyl) benzene, 2,6-bis (3-aminophenoxy) benzonitrile, 2,6-bis (3-aminophenoxy) pyridine, N, N'-bis (4-aminophenyl) terephthalamide, 9,9- Bis (4-aminophenyl) fluorene, 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, 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] sulfone, bis [4- (4- Aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) 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) benzoyl] benzene, 1,3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,4-bis [4 -(3-Aminophenoxy) benzoyl] benzene, 1,4-bis [4- (4-aminophenoxy) benzoyl] 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) benzoyl] diphenyl ether, 4,4′- Bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenyl sulfone, 4,4 ′ -Bis [4- (4-aminophenoxy) phenoxy] diphenyl sulfone, 3,3'-diamino-4,4'-diphenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 3, 3'-Diamino-4-phenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone, 6,6'-bis (3-aminophen) Noxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane, 6,6'-bis (4-aminophenoxy) -3,3,3', 3'-tetramethyl-1 , 1′-spirobiindane, 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-aminopropyl) ethyl] ether, trans-cyclo Xandiamine, trans-1,4-bismethylenecyclohexanediamine, 2,6-bis (aminomethyl) bicyclo [2,2,1] heptane, 2,5-bis (aminomethyl) bicyclo [2,2,1] Heptane, or diamine in which some or all of the hydrogen atoms on the aromatic ring of the above diamine are substituted with a substituent selected from fluoro, methyl, methoxy, trifluoromethyl or trifluoromethoxy is also used can do. These may be used alone or in combination of two or more.

  From the viewpoint of improving the light transmittance and the rigidity, the polyimide resin contains an aromatic ring, and (i) a fluorine atom, (ii) an aliphatic ring, and (iii) an aromatic ring It is preferable that it is a polyimide-type resin containing at least 1 selected from the group which consists of a coupling group which cut | disconnects electronic conjugation of each other. When the polyimide-based resin contains an aromatic ring, the orientation is enhanced and the rigidity is improved, but the transmittance tends to decrease due to the absorption wavelength of the aromatic ring. When the polyimide-based resin contains (i) a fluorine atom, light transmittance can be improved because the charge transfer of the electronic state in the polyimide skeleton can be made difficult. In addition, when the polyimide-based resin contains (ii) an aliphatic ring, it is possible to inhibit the movement of charges in the skeleton by breaking the conjugation of π electrons in the polyimide skeleton, thereby improving the light transmittance. . Furthermore, in the case where the polyimide-based resin contains a linking group that cleaves electron conjugation of (iii) aromatic rings, inhibiting transfer of charge in the skeleton by cleaving conjugation of π electrons in the polyimide skeleton The light transmission is improved from the point of being able to. Such a linking group for cleaving the electronic conjugation between the aromatic rings is, for example, an ether bond, a thioether bond, a carbonyl bond, a thiocarbonyl bond, an amide bond, a sulfonyl bond, a sulfinyl bond, and fluorine-substituted And a divalent linking group such as an alkylene group which may be substituted.

  Among these, polyimide resins containing an aromatic ring and containing a fluorine atom are preferably used from the viewpoint of improving the light transmittance and the rigidity. The content ratio of fluorine atoms in the polyimide resin containing fluorine atoms is determined by the ratio (F / C) of the number of fluorine atoms (F) to the number of carbon atoms (C) when the surface of the polyimide resin is measured by X-ray photoelectron spectroscopy. Is preferably 0.01 or more, and more preferably 0.05 or more. On the other hand, if the content ratio of fluorine atoms is too high, the inherent heat resistance of the polyimide-based resin may be lowered, so the ratio of the number of fluorine atoms (F) to the number of carbon atoms (C) (F / C) Is preferably 1 or less, and more preferably 0.8 or less. Here, the above ratio by the measurement of X-ray photoelectron spectroscopy (XPS) can be determined from the value of atomic% of each atom measured using an X-ray photoelectron spectrometer (for example, Theta Probe, manufactured by Thermo Scientific) .

  In addition, it is a polyimide resin in which 70% or more of the hydrogen atoms bonded to carbon atoms contained in the polyimide resin are hydrogen atoms bonded directly to the aromatic ring, thereby improving the light transmittance and rigidity It is preferably used from the point of improving the The percentage of hydrogen atoms (number) directly bonded to the aromatic ring in all hydrogen atoms (number) bonded to carbon atoms contained in the polyimide resin is preferably 80% or more, and more preferably 85% or more It is more preferable that When 70% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are hydrogen atoms bonded directly to the aromatic ring, they are stretched at, for example, 200 ° C. or more even after the heating step in the air. Even if it does, it is preferable from the point with few changes of optical characteristics, especially total light transmittance and yellow index (YI). If 70% or more of the hydrogen atoms bonded to carbon atoms contained in the polyimide resin are polyimides that are hydrogen atoms bonded directly to the aromatic ring, the reactivity with oxygen is low. It is presumed that the chemical structure is unlikely to change. Substrates made of polyimide resins take advantage of their high heat resistance and are often used for devices that require processing steps involving heating, but 70% of hydrogen atoms bonded to carbon atoms contained in polyimide resins If the above is a polyimide resin that is a hydrogen atom directly bonded to an aromatic ring, there is no need to carry out these subsequent steps under an inert atmosphere to maintain transparency, so equipment cost and atmosphere There is an advantage that control costs can be reduced. Here, the ratio of hydrogen atoms (number) directly bonded to the aromatic ring in all hydrogen atoms (number) bonded to carbon atoms contained in the polyimide resin is high-performance liquid chromatography, gas chromatography of the decomposition product of polyimide It can be determined using a tograph mass spectrometer and NMR. For example, the sample is decomposed with an aqueous alkaline solution or supercritical methanol, and the resulting decomposition product is separated by high performance liquid chromatography, and the qualitative analysis of each separated peak is carried out by gas chromatography mass spectrometry, NMR, etc. The ratio of hydrogen atoms (number) directly bonded to the aromatic ring in all hydrogen atoms (number) in the polyimide can be determined by performing measurement using high performance liquid chromatography.

  Moreover, as a polyimide resin, it is chosen from the group which consists of a structure represented by following General formula (1) and following General formula (3) from a point which improves light transmittance and rigidity. It is preferred to have at least one structure.

上記一般式（１）において、Ｒ^１はテトラカルボン酸残基である４価の基、Ｒ^２は、ｔｒａｎｓ−シクロヘキサンジアミン残基、ｔｒａｎｓ−１，４−ビスメチレンシクロヘキサンジアミン残基、４，４’−ジアミノジフェニルスルホン残基、３，４’−ジアミノジフェニルスルホン残基、および下記一般式（２）で表される２価の基からなる群から選ばれる少なくとも１種の２価の基を表す。ｎは繰り返し単位数を表し、１以上である。本明細書において、「テトラカルボン酸残基」とは、テトラカルボン酸から、４つのカルボキシル基を除いた残基をいい、テトラカルボン酸二無水物から酸二無水物構造を除いた残基と同じ構造を表す。また、「ジアミン残基」とは、ジアミンから２つのアミノ基を除いた残基をいう。

In the above general formula (1), R ¹ is a tetravalent group which is a tetracarboxylic acid residue, R ² is a trans-cyclohexanediamine residue, trans-1,4-bismethylenecyclohexanediamine residue, 4,4 Represents at least one divalent group selected from the group consisting of a '-diaminodiphenyl sulfone residue, a 3,4'-diaminodiphenyl sulfone residue, and a divalent group represented by the following general formula (2) . n represents the number of repeating units and is 1 or more. In the present specification, “tetracarboxylic acid residue” refers to a residue obtained by removing four carboxyl groups from a tetracarboxylic acid, and a residue obtained by removing an acid dianhydride structure from a tetracarboxylic acid dianhydride Represents the same structure. Moreover, a "diamine residue" means the residue remove | excluding two amino groups from diamine.

上記一般式（２）において、Ｒ^３およびＲ^４はそれぞれ独立して、水素原子、アルキル基、またはパーフルオロアルキル基を表す。

In the above general formula (2), R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group or a perfluoroalkyl group.

上記一般式（３）において、Ｒ^５はシクロヘキサンテトラカルボン酸残基、シクロペンタンテトラカルボン酸残基、ジシクロヘキサン−３，４，３’，４’−テトラカルボン酸残基、および４，４'−（ヘキサフルオロイソプロピリデン）ジフタル酸残基からなる群から選ばれる少なくとも１種の４価の基、Ｒ^６は、ジアミン残基である２価の基を表す。ｎ’は繰り返し単位数を表し、１以上である。

In the above general formula (3), R ⁵ is a cyclohexanetetracarboxylic acid residue, a cyclopentanetetracarboxylic acid residue, a dicyclohexane-3,4,3 ′, 4′-tetracarboxylic acid residue, and 4,4 ′ At least one tetravalent group selected from the group consisting of-(hexafluoroisopropylidene) diphthalic acid residue, and R ⁶ represents a divalent group which is a diamine residue. n 'represents the number of repeating units and is 1 or more.

R ¹ in the above general formula (1) is a tetracarboxylic acid residue, which can be a residue obtained by removing the acid dianhydride structure from the tetracarboxylic acid dianhydride as exemplified above. As R ¹ in the above general formula (1), among them, from the viewpoint of improving light transmittance and rigidity, 4,4 ′-(hexafluoroisopropylidene) diphthalic acid residue, 3,3 ′, 4,4'-biphenyltetracarboxylic acid residue, pyromellitic acid residue, 2,3 ', 3,4'-biphenyltetracarboxylic acid residue, 3,3', 4,4'-benzophenonetetracarboxylic acid residue Selected from the group consisting of a group, 3,3 ', 4,4'-diphenyl sulfone tetracarboxylic acid residue, 4,4'-oxydiphthalic acid residue, cyclohexane tetracarboxylic acid residue, and cyclopentane tetracarboxylic acid residue It is preferable to include at least one of the following: 4,4 '-(hexafluoroisopropylidene) diphthalic acid residue, 4,4'-oxydiphthalic acid residue, and 3,3', 4,4'- The It is preferable to include at least one selected from the group consisting of phenyl sulfone tetracarboxylic acid residues.

In R ¹ , the total content of these suitable residues is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more.

And R ¹ represents a group consisting of 3,3 ′, 4,4′-biphenyltetracarboxylic acid residue, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid residue, and pyromellitic acid residue. Group of tetracarboxylic acid residues (group A) suitable for improving rigidity such as at least one selected; 4,4 '-(hexafluoroisopropylidene) diphthalic acid residue, 2,3' , 3,4'-biphenyl tetracarboxylic acid residue, 3,3 ', 4,4'-diphenyl sulfone tetracarboxylic acid residue, 4,4'-oxydiphthalic acid residue, cyclohexane tetracarboxylic acid residue, and cyclo It is also preferable to use it in combination with a group of tetracarboxylic acid residues (group B) suitable for improving transparency such as at least one selected from the group consisting of pentanetetracarboxylic acid residues. There.

  In this case, the content ratio of the tetracarboxylic acid residue group (group A) suitable for improving the rigidity and the tetracarboxylic acid residue group (group B) suitable for improving the transparency is 0.05 mol of tetracarboxylic acid residue group (group A) suitable for improving the rigidity with respect to 1 mol tetracarboxylic acid residue group (group B) suitable for improving transparency It is preferably 9 mol or more, more preferably 0.1 mol to 5 mol, and still more preferably 0.3 mol to 4 mol.

As R ² in the above general formula (1), among them, from the viewpoint of improving light transmittance and rigidity, 4,4′-diaminodiphenyl sulfone residue, 3,4′-diaminodiphenyl sulfone residue And at least one divalent group selected from the group consisting of divalent groups represented by the above general formula (2), and further preferably a 4,4'-diaminodiphenyl sulfone residue, 3 , 4'-diaminodiphenyl sulfone residue, and at least one divalent selected from the group consisting of the divalent groups represented by the above general formula (2) in which R ³ and R ⁴ are perfluoroalkyl groups. Is preferably a group of

As R ⁵ in the above general formula (3), among them, from the viewpoint of improving light transmittance and rigidity, 4,4 ′-(hexafluoroisopropylidene) diphthalic acid residue, 3,3 ′, It is preferable to contain a 4,4'-diphenyl sulfone tetracarboxylic acid residue and an oxydiphthalic acid residue.

In R ^5, these preferred residues, preferably contains more than 50 mol%, preferably it contains more than 70 mol%, it is preferable to include even more than 90 mol%.

R ⁶ in the general formula (3) is a diamine residue, which can be a residue obtained by removing two amino groups from the diamine as exemplified above. The ^{R 6} in the general formula (3), among others, from the viewpoint of improving optical transparency, and to improve the rigidity, 2,2'-bis (trifluoromethyl) benzidine residues, bis [4- (4 -Aminophenoxy) phenyl] sulfone residue, 4,4'-diaminodiphenyl sulfone residue, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane residue, bis [4- (3- Aminophenoxy) phenyl] sulfone residue, 4,4'-diamino-2,2'-bis (trifluoromethyl) diphenyl ether residue, 1,4-bis [4-amino-2- (trifluoromethyl) phenoxy] Benzene residue, 2,2-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane residue, 4,4'-diamino-2- (tril From a trifluoromethyl) diphenyl ether residue, a 4,4'-diaminobenzanilide residue, an N, N'-bis (4-aminophenyl) terephthalamide residue, and a 9,9-bis (4-aminophenyl) fluorene residue It is preferable to include at least one divalent group selected from the group consisting of the following: 2,2'-bis (trifluoromethyl) benzidine residue, bis [4- (4-aminophenoxy) phenyl] sulfone residue It is preferable to include at least one bivalent group selected from the group consisting of a group and a 4,4'-diaminodiphenyl sulfone residue.

In R ⁶ , the total content of these suitable residues is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more.

In addition, as R ⁶ , a bis [4- (4-aminophenoxy) phenyl] sulfone residue, a 4,4′-diaminobenzanilide residue, an N, N′-bis (4-aminophenyl) terephthalamide residue, Group of diamine residues suitable for improving rigidity such as at least one member selected from the group consisting of paraphenylene diamine residues, metaphenylene diamine residues, and 4,4'-diaminodiphenylmethane residues (group C) and 2,2'-bis (trifluoromethyl) benzidine residue, 4,4'-diaminodiphenyl sulfone residue, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane residue Group, bis [4- (3-aminophenoxy) phenyl] sulfone residue, 4,4'-diamino-2,2'-bis (trifluoromethyl) diphenyl Ether residue, 1,4-bis [4-amino-2- (trifluoromethyl) phenoxy] benzene residue, 2,2-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexa At least one member selected from the group consisting of fluoropropane residue, 4,4'-diamino-2- (trifluoromethyl) diphenyl ether residue, and 9,9-bis (4-aminophenyl) fluorene residue It is also preferable to mix and use a diamine residue group (group D) suitable for improving the transparency.

  In this case, the content ratio of the diamine residue group (group C) suitable for improving the rigidity and the diamine residue group (group D) suitable for improving the transparency improves the transparency. 0.05 mol or more and 9 mol or less of diamine residue groups (group C) suitable for improving the rigidity with respect to 1 mol of diamine residues group (group D) suitable for The molar ratio is preferably 0.1 to 5 mol, more preferably 0.3 to 4 mol.

  In the structures represented by the above general formula (1) and the above general formula (3), n and n 'each independently represent the number of repeating units and is 1 or more. The number n of repeating units in the polyimide may be appropriately selected according to the structure so as to indicate a preferable glass transition temperature described later, and is not particularly limited. The average number of repeating units is usually 10 to 2,000, and preferably 15 to 1,000.

  In addition, the polyimide resin may partially include a polyamide structure. Examples of the polyamide structure which may be contained include a polyamideimide structure containing a tricarboxylic acid residue such as trimellitic anhydride, and a polyamide structure containing a dicarboxylic acid residue such as terephthalic acid.

  From the viewpoint of heat resistance, the polyimide resin preferably has a glass transition temperature of 250 ° C. or higher, and more preferably 270 ° C. or higher. On the other hand, the glass transition temperature is preferably 400 ° C. or less, more preferably 380 ° C. or less, from the viewpoint of ease of stretching and reduction of the baking temperature.

Specifically, as a polyimide resin, the compound which has a structure represented by a following formula is mentioned, for example. In the following formula, n is a repeating unit and represents an integer of 2 or more.

  The polyamide resin is a concept including not only aliphatic polyamide but also aromatic polyamide (aramid). As a polyamide-type resin, the compound which has frame | skeleton represented by following formula (21)-(23) is mentioned, for example. In the following formulas, n is a repeating unit and represents an integer of 2 or more.

  A commercially available thing may be used for a substrate which consists of a polyimide system resin or a polyamide system resin denoted by the above-mentioned formula (4)-(20) and (23). As a commercial item of the base material which consists of the above-mentioned polyimide system resin, neoprim made by Mitsubishi Gas Chemical Co., Ltd. etc. is mentioned, for example, As a commercial item of the base material which consists of the above-mentioned polyamide system resin, For example, Miktron etc. are mentioned.

Moreover, you may use what was synthesize | combined by the well-known method as a polyimide-type resin or polyamide-type resin represented by said Formula (4)-(20) and (23). For example, a synthesis method of a polyimide-based resin represented by the above formula (4) is described in JP 2009-132091A, and specifically, 4,4′-hexa represented by the following formula (24) It can be obtained by reacting fluoropropylidenebisphthalic acid dianhydride (FPA) with 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl (TFDB).

  The weight average molecular weight of the polyimide resin or the polyamide resin is preferably in the range of 3,000 to 500,000, more preferably in the range of 5,000 to 300,000, and in the range of 10,000 to 200,000. Is more preferred. When the weight average molecular weight is less than 3,000, sufficient strength may not be obtained, and when it exceeds 500,000, the viscosity increases and the solubility decreases, so that the substrate is smooth and the film thickness is uniform. It can not be obtained. In addition, in this specification, a "weight average molecular weight" is the polystyrene conversion value measured by gel permeation chromatography (GPC).

  Among the above-mentioned polyimide resins and polyamide resins, polyimide resins or polyamide resins having a structure in which intramolecular or intermolecular charge transfer does not easily occur are preferable because they have excellent transparency. Fluorinated polyimide resins such as the above formulas (4) to (11), polyimide resins having an alicyclic structure such as the above formulas (13) to (16), and polyamides having halogen groups such as the above formula (23) Resin is mentioned.

  In addition, fluorinated polyimide resins such as the above formulas (4) to (11) have high heat resistance because they have a fluorinated structure, and heat during the production of a substrate made of polyimide resins It has excellent transparency because it is not colored by.

  The resin substrate 21 is a fluorinated polyimide resin represented by the above formulas (4) to (11) or an aramid resin having a halogen group such as the above formula (23) or the like from the viewpoint of being able to improve the hardness. It is preferable to use the base material which consists of. Among these, from the viewpoint of being able to further improve the hardness, it is more preferable to use a substrate made of the polyimide resin represented by the above formula (4).

<< First Protective Film >>
The protective film 30 is attached to the surface 21 A of the resin base 21. The thickness of the protective film 30 is 30 μm or more. If the thickness of the protective film 30 is 30 μm or more, curling can be suppressed. The thickness of the protective film 30 can be measured by the same method as the thickness of the resin base 21. In the case of shipping in the state of the light transmitting film 10 with a protective film, in order to suppress curling of the light transmitting film 10 with a protective film, the thickness of the protective film 30 is preferably 50 μm or more. The upper limit of the thickness of the protective film 30 is preferably 250 μm or less from the viewpoint of handling at the time of peeling and easiness of cutting.

  The haze value (all haze values) of the protective film 30 is 10% or less. If the haze value of the protective film 30 is 10% or less, unevenness on the surface 20A of the light transmitting film 20 is reduced, and the light transmitting film 20 having excellent smoothness can be obtained. The haze value of the protective film 30 is such that the protective film 30 is peeled off from the light transmitting film 10 with protective film cut out to a size of 50 mm × 100 mm, and the protective film 30 is in a single state without curling or wrinkles. The base film 31 side of the protective film 30 by a method according to JIS K7136: 2000 using a haze meter (product name "HM-150", manufactured by Murakami Color Research Laboratory) in the absence of fingerprints and dust It can be measured from The haze value of the protective film 30 is taken as the arithmetic mean value of the values obtained by measuring the protective film 30 three times. In the case where the protective film can not be cut into the above-mentioned size, for example, since the entrance opening at the time of measurement of HM-150 is 20 mmφ, a sample size which has a diameter of 21 mm or more is required. For this reason, you may cut out a protective film suitably in the magnitude | size of 22 mm x 22 mm or more. If the size of the protective film is small, slightly shift the light source spot within a range that does not deviate, or change the angle to three measurement points. The haze value of the protective film 30 is more preferably in the order of 5% or less and 3% or less (the smaller the numerical value, the more preferable). In the present specification, the mere “haze value” means all haze values and is different from the external haze value described later.

  Since the total haze value of the protective film 30 is 10% or less, the external haze on the surface in contact with the surface 21A of the resin base 21 in the protective film 30 is also 10% or less. The external haze value is a value obtained by subtracting the internal haze from the total haze value. The external haze value can be determined using a haze meter (product name "HM-150", manufactured by Murakami Color Research Laboratory, Inc.). Specifically, first, the haze value (total haze value) of the protective film 30 is determined according to the method of measuring the total haze value. After that, the surface of the protective film 30 in contact with the surface 21A of the resin base 21 has a thickness of 25 μm through a transparent optical adhesive layer (product name “Pana Clean PD-S1”, Panac Corporation). Affix a 60 μm triacetyl cellulose base material (product name “TD60UL”, manufactured by Fujifilm Corporation). Thereby, the concavo-convex shape of the surface of the protective film 30 is crushed and the surface of the protective film 30 is flattened. Then, in this state, the internal haze value is determined by measuring the haze value by the same method as the measurement method of the total haze value, and the external haze value is determined by subtracting the internal haze from the total haze value. The external haze value of the protective film 30 is more preferably in the order of 5% or less and 3% or less (the smaller the numerical value, the more preferable).

  The protective film 30 includes a base film 31 and an adhesive layer 32 provided on the surface of the base film 31 on the resin base 21 side. Although the protective film 30 shown by FIG. 1 is provided with the adhesion layer 32, depending on a protective film, the adhesion layer may not be provided.

<Base film>
The base film 31 is preferably made of a polyester resin in order to reduce unevenness of the surface 21A. Examples of polyester resins include at least one resin such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like. Among these, polyethylene terephthalate is preferable in terms of transparency and cost.

  The thickness of the base film 31 is preferably 30 μm or more for the same reason as the thickness of the protective film 30. The thickness of the base film 31 can be measured by the same method as the thickness of the resin base 21. When conveying or shipping in the state of the light transmitting film 10 with a protective film, the thickness of the base film 31 is preferably 50 μm or more in order to suppress curling of the light transmitting film 10 with a protective film. The upper limit of the thickness of the base film 31 is preferably 250 μm or less from the viewpoint of handling at the time of peeling and easiness of cutting.

<Adhesive layer>
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 32 is not particularly limited as long as it has desired adhesiveness, and a general pressure-sensitive adhesive used for a protective film can be used. Such pressure-sensitive adhesives include, for example, acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, or mixtures thereof. Among these, acrylic pressure-sensitive adhesives are preferable in that it is easy to adjust appropriate adhesion.

  The thickness of the adhesive layer 32 is preferably in the range of 1 μm to 50 μm. If the film thickness of the adhesive layer 32 is 1 μm or more, the protective film 30 can be reliably attached to the resin substrate 21. If the film thickness of the adhesive layer 32 is 50 μm or less, the surface of the adhesive layer 32 is It is possible to smooth and prevent so-called tear-off phenomenon in which the adhesive layer 32 is torn at the time of peeling. The film thickness of the adhesive layer 32 can be measured by the same method as the thickness of the resin base 21. The lower limit of the film thickness of the adhesive layer 32 is more preferably 5 μm or more, and the upper limit is more preferably 30 μm or less.

<< Second Protective Film >>
The protective film 40 is attached to the surface 21 B of the resin base 21. The thickness of the protective film 40 is 30 μm or more. If the thickness of the protective film 40 is 30 μm or more, curling can be suppressed. The thickness of the protective film 40 can be measured by the same method as the thickness of the resin base 21. When conveying or shipping in the state of the light transmitting film 10 with a protective film, in order to suppress curling of the light transmitting film 10 with a protective film, the thickness of the protective film 40 is preferably 50 μm or more. The upper limit of the thickness of the protective film 40 is preferably 250 μm or less from the viewpoint of handling at the time of peeling and easiness of cutting.

  The thickness of the protective film 40 may be different from the thickness of the protective film 30. By the difference in thickness of the protective film 30 and the protective film 40, the curl can be adjusted.

  The haze value (all haze values) of the protective film 40 is 10% or less. If the haze value of the protective film 40 is 10% or less, unevenness on the surface 20B of the light transmitting film 20 is reduced, and the light transmitting film 20 having more excellent smoothness can be obtained. The haze value of the protective film 40 is obtained by peeling the protective film 40 from the light transmitting film 10 with protective film cut out to a size of 50 mm × 100 mm, and using the protective film 40 alone as a haze meter (product name “HM-150 And Murakami Color Research Laboratory Co., Ltd.) according to JIS K7136: 2000. The haze value of the protective film 40 is taken as the arithmetic mean of the values obtained by measuring the protective film 40 three times. In the case where the protective film can not be cut into the above-mentioned size, for example, since the entrance opening at the time of measurement of HM-150 is 20 mmφ, a sample size which has a diameter of 21 mm or more is required. For this reason, you may cut out a protective film suitably in the magnitude | size of 22 mm x 22 mm or more. If the size of the protective film is small, slightly shift the light source spot within a range that does not deviate, or change the angle to three measurement points. The haze value of the protective film 40 is more preferably in the order of 5% or less and 3% or less (the smaller the numerical value, the more preferable).

  Since the total haze value of the protective film 40 is 10% or less, the external haze of the surface of the protective film 40 in contact with the surface 20B of the light transmitting film 20 is also 10% or less. The external haze value of the protective film 40 can be determined by the same method as the external haze value of the protective film 30. The external haze value of the protective film 40 is more preferably in the order of 5% or less and 3% or less (the smaller the numerical value, the more preferable).

  The protective film 40 includes a base film 41 and an adhesive layer 42 provided on the surface of the base film 41 on the resin base 21 side.

<Base film and adhesive layer>
Since the base film 41 is the same as the base film 31 and the adhesive layer 42 is the same as the adhesive layer 32, the description will be omitted here.

<<< Other transparent films with protective film >>>
The light transmitting film 10 with a protective film shown in FIG. 1 includes the protective film 30 attached to the surface 21A of the resin substrate 21 and the protective film 40 attached to the surface 21B. As shown in FIG. 4, the protective film may be provided on only one side of the light transmitting film.

  The light transmitting film 60 with a protective film shown in FIG. 4 has a foldable light transmitting film 70 including a resin base 21 and a resin layer 71, and a first surface 70A of the light transmitting film 70 (hereinafter referred to as And a protective film 30 releasably attached to the surface 70A. In FIG. 4, the protective film is not provided on the second surface 70 B side of the light transmitting film 70, but the protective film is peelably attached to the first surface 70 A of the light transmitting film 70. A protective film similar to the protective film 40 may be peelably attached to the second surface 70 B of the light transmitting film 70 as well as 30. In addition, in FIG. 4, members denoted with the same reference numerals as those in FIG. 1 are the same as the members shown in FIG. 1, and therefore the description will be omitted except for the following.

  The surface 70 A of the light transmitting film 70 is the first surface 21 A of the resin base 21. Therefore, in the light transmitting film 60 with protective film, the protective film 30 is peelably attached to the surface 21 A of the resin base 21. Further, since the light transmitting film 70 shown in FIG. 4 includes the resin layer 71 in addition to the resin base 21, the second surface 70 B of the light transmitting film 70 (hereinafter simply referred to as “the surface 70 B” Is sometimes referred to as “surface 71 A” on the side opposite to the surface on the resin base 21 side in the resin layer 71.

  In addition, in the light transmitting film 10 with a protective film shown in FIG. 1, the protective film 30 is peelably attached to the surface 21A of the resin substrate 21, but as shown in FIG. It may be releasably attached to the surface of the resin layer.

  The light transmitting film 80 with a protective film shown in FIG. 5 comprises: a foldable light transmitting film 90 comprising a resin base 21 and resin layers 91 and 92 provided on both sides of the resin base 21; The protective film 30 is provided so as to be releasably attached to the first surface 90A of the permeable film 90 (hereinafter sometimes simply referred to as “surface 90A”). In FIG. 5, the protective film is not provided on the side of the second surface 90B of the light transmitting film 90, but the protective film is peelably attached to the first surface 90A of the light transmitting film 90. A protective film similar to the protective film 40 may be peelably attached to the second surface 90B of the light transmitting film 90 as well as 30. In FIG. 5, members denoted with the same reference numerals as in FIG. 1 are the same as the members shown in FIG. 1, and therefore the description will be omitted except for the following.

  The surface 90 A of the light transmitting film 90 is the surface 91 A of the resin layer 91. Therefore, in the light transmitting film 90 with protective film, the protective film 30 is peelably attached to the surface 91 A of the resin layer 91. Also, the surface 90 B of the light transmitting film 90 is the surface 92 A of the resin layer 92.

<< light transmitting film >>
The light transmitting films 70, 90 are foldable. Specifically, even if the above-described folding test (continuous folding test) is repeatedly performed 100,000 times on the light transmitting films 70 and 90, the light transmitting films 70 and 90 are broken or broken. It is preferable not to occur, and even when the continuous folding test is repeated 300,000 times, it is more preferable that the light transmitting films 70 and 90 do not break or break, and it is a case where it is repeatedly performed 1,000,000 times. Even more preferably, the light transmitting films 70, 90 do not break or break. The continuous folding test may be performed such that the light transmitting films 70 and 90 may be folded so that the resin layers 71 and 92 are on the inside, and the light transmitting films 70 may be such that the resin layers 71 and 92 are on the outside. , 90 may be folded, but in any case, it is preferable that the light transmitting films 70, 90 do not break or break. Since the conditions of the continuous folding test are the same as the conditions of the continuous folding test described in the section of the light transmitting film 20, the description will be omitted.

  Also in the light transmitting films 70 and 90, the folding and standing test described above is performed, and then the folded state is released, and when the opening angle is measured, the opening angle θ of the light transmitting films 70 and 90 is It is preferable that it is 100 degrees or more. The conditions of the folding stationary test are the same as the conditions of the folding stationary test described in the section of the light transmitting film 20, and the measurement conditions of the opening angle are also the measuring of the opening angle described in the section of the light transmitting film 20 Since the conditions are the same, the description will be omitted.

  The haze value (total haze value) of the light transmitting films 70 and 90 is preferably 3% or less. When the haze value of the light transmitting film 20 is 3% or less, the unevenness of the surfaces 70A and 90A of the light transmitting films 70 and 90 is small, and the film has excellent smoothness. The measurement conditions of the haze value are the same as the measurement conditions of the haze value described in the section of the light transmitting film 20, and thus the description thereof is omitted here. The haze values of the light transmitting films 70 and 90 are more preferably in the order of 2% or less and 1% or less (the smaller the numerical value, the more preferable).

  The total light transmittance of the light transmitting films 70 and 90 is preferably 85% or more. If the total light transmittance of the light transmitting films 70 and 90 is 85% or more, sufficient optical performance can be obtained. Since the measurement conditions of the total light transmittance are the same as the measurement conditions of the total light transmittance described in the section of the light transmitting film 20, the description will be omitted here. The total light transmittance of the light transmitting film 70 is more preferably in the order of 88% or more and 90% or more (the larger the numerical value, the more preferable).

  The light transmitting films 70 and 90 preferably have a yellow index (YI) of 15 or less. If YI of the light transmitting films 70 and 90 is 15 or less, the yellowishness of the light transmitting film 70 can be suppressed, and the invention can be applied to applications where transparency is required. Since the measurement conditions of the yellow index are the same as the measurement conditions of the yellow index described in the section of the light transmitting film 20, the description is omitted here. The upper limit of the yellow index (YI) of the light transmitting film 70 is more preferably in the order of less than 10 and less than 1.5 (the smaller the numerical value, the more preferable).

<< Resin layer >>
The resin layers 71, 91, 92 are layers made of resin. The resin layers 71 and 92 are laminated on the surface 21 B of the resin base 21, and the resin layer 91 is laminated on the surface 21 A of the resin base 21. When a protective film is attached to the surface of the resin layer as in the resin layer 91, as the thickness of the resin layer is thinner, unevenness tends to appear on the surface of the resin layer due to the influence of the protective film. Therefore, when the protective film of the present invention is attached to the surface of the resin layer, it is particularly effective when the film thickness of the resin layer is, for example, 1 μm or less, 500 nm or less, 200 nm or less (the smaller the value, Especially effective).

  The resin layers 71, 91, 92 may contain particles, additives and the like in addition to the resin. Examples of the resin layers 71 and 92 include a hard coat layer and an impact absorption layer. Examples of the resin layer 91 include an underlayer and the like. The resin layers 71, 91, 92 may be single-layered or multi-layered.

<Hard coat layer>
The hard coat layer is intended to mean a layer having light transmittance and having a Martens hardness higher than the Martens hardness of the resin substrate. In the present specification, “martens hardness” is a hardness when an indenter is indented by 500 nm by hardness measurement by a nanoindentation method. The measurement of Martens hardness by the above-mentioned nanoindentation method shall be performed using "TI950 TriboIndenter" manufactured by HYSITRON (Hyditron). Specifically, first, all protective films are peeled off from the light transmitting film with protective film cut out into 1 mm × 10 mm to obtain a light transmitting film alone. Then, a block in which the light transmitting film is embedded with the embedding resin is prepared, and from this block, a section having a thickness of 70 nm or more and 100 nm or less without a hole or the like is cut out by a general section manufacturing method. For preparation of the section, “Ultra Microtome EM UC7” (Leica Microsystems Inc.) or the like can be used. Then, the remaining block from which the uniform section without the hole etc. is cut out is used as a measurement sample. Next, in the section obtained by cutting out the section in such a measurement sample, a Berkovich indenter (triangular pyramid) is pushed 500 nm into the center of the cross section of the hard coat layer as the above indenter under the following measurement conditions, for a fixed time After holding and relieving residual stress, unloading is performed, and the maximum load after relaxation is measured, and the maximum load P _max (μN) and the depression area A (nm ² ) with a depth of 500 nm are used, Martens hardness is calculated by P _max / A. Martens hardness is taken as the arithmetic mean value of the value obtained by measuring ten places. The Martens hardness of the resin base 21 is also measured by the same method as described above.
(Measurement condition)
Loading speed: 10 nm / sec Holding time: 5 seconds Load unloading speed: 10 nm / sec Measurement temperature: 25 ° C.

  The thickness of the hard coat layer is preferably 1 μm or more and 20 μm or less. If the film thickness of the hard coat layer is less than 1 μm, the hardness of the hard coat layer may be reduced, and if it exceeds 20 μm, the processability may be deteriorated due to the thickness being too large. In the case where the hard coat layer has a multilayer structure, the “film thickness of the hard coat layer” in the present specification means the total film thickness (total thickness) of the respective hard coat layers. Do. The upper limit of the hard coat layer is more preferably 15 μm or less, still more preferably 10 μm or less.

  For the film thickness of the hard coat layer, the cross section of the hard coat layer is photographed using a scanning transmission electron microscope (STEM) or a transmission electron microscope (TEM), and the film thickness of the hard coat layer in the image of the cross section It measures ten places and makes it the arithmetic mean value of the film thickness of ten places. A specific cross-sectional photography method is described below. First, all protective films are peeled off from the light transmitting film with protective film cut out to 1 mm × 10 mm to obtain a light transmitting film alone. Then, a block in which the light transmitting film is embedded with the embedding resin is prepared, and from this block, a section having a thickness of 70 nm or more and 100 nm or less without a hole or the like is cut out by a general section manufacturing method. For preparation of the section, “Ultra Microtome EM UC7” (Leica Microsystems Inc.) or the like can be used. Then, a uniform section without this hole or the like is used as a measurement sample. Thereafter, a cross-sectional photograph of the measurement sample is taken using a scanning transmission electron microscope (STEM) (product name "S-4800", manufactured by Hitachi High-Technologies Corporation). At the time of photographing this cross-sectional photograph, cross-sectional observation is performed with a detector of “TE”, an acceleration voltage of 30 kV and an emission of “10 μA”. As for the magnification, the focus is adjusted, and the contrast and the brightness are appropriately adjusted at 5000 to 200,000 times while observing whether each layer can be distinguished. The magnification is preferably 10,000 times to 100,000, more preferably 10,000 to 50,000, and most preferably 25,000 to 50,000. In addition, when taking a cross-sectional photograph, the aperture is set to the beam monitor stop 3 and the objective lens stop is set to 3, W. D. May be 8 mm. When measuring the film thickness of the hard coat layer, it is important that the contrast of the interface between the hard coat layer and another layer (for example, a resin substrate) can be observed as clearly as possible at the time of cross-sectional observation. If it is difficult to see this interface due to lack of contrast, if the staining process is carried out with osmium tetraoxide, ruthenium tetraoxide, phosphotungstic acid, etc., the interface between the organic layers can be easily seen, so the staining process may be performed. In addition, the contrast of the interface may be difficult to understand when the magnification is high. In that case, low magnification is also observed simultaneously. For example, observation is made at two high and low magnifications, such as 25,000 times and 50,000 times, 50,000 times and 100,000 times, and the above-mentioned arithmetic average value is obtained with both magnifications, and the average value is further determined by the hard coat layer The film thickness of

  The hard coat layer may have a single-layer structure, but preferably has a multilayer structure of two or more layers from the viewpoint of improving the folding performance. The hard coat layer is preferably composed of a first hard coat layer and a second hard coat layer laminated on the first hard coat layer. The first hard coat layer is located closer to the resin base than the second hard coat layer.

(First hard coat layer)
The first hard coat layer is a layer mainly for imparting hardness to the light transmitting film. The first hard coat layer preferably has a Martens hardness of 500 MPa or more and 2000 MPa or less at the center of the cross section of the first hard coat layer. If it is less than 500 MPa, the hardness of the hard coat layer may be insufficient. If it exceeds 2000 MPa, the folding performance of the light transmitting film may be insufficient. The lower limit of the Martens hardness at the center of the cross section of the first hard coat layer is preferably 600 MPa or more, and the upper limit is preferably 1500 MPa or less.

  The Martens hardness of the first hard coat layer is preferably larger than the Martens hardness of the second hard coat layer. By having such a relationship of Martens hardness, the light transmitting film has particularly good pencil hardness. This is because the pencil hardness test is performed while applying a load to the pencil, but even when the pencil is pressed into the light transmitting film, the deformation of the light transmitting film is suppressed and the scratch and the dent deformation are reduced. It is for. As a method of making the Martens hardness of the first hard coat layer larger than the Martens hardness of the second hard coat layer, for example, control is performed such that the content of inorganic particles described later is contained more on the first hard coat layer side. And the like. When the hard coat layer has a single layer structure, the inorganic particles in the hard coat layer are localized on the substrate film side, that is, the ratio of the inorganic particles in the hard coat layer is on the resin base side. It is preferable to incline so as to be larger and to become smaller toward the surface side of the resin substrate.

  The first hard coat layer contains a resin. The first hard coat layer preferably further contains inorganic particles dispersed in a resin.

  The resin includes a polymer (cured product) of a polymerizable compound (curable compound). The polymerizable compound is one having at least one polymerizable functional group in the molecule. Examples of the polymerizable functional group include ethylenic unsaturated groups such as (meth) acryloyl group, vinyl group and allyl group. In addition, "(meth) acryloyl group" is a meaning which includes both "acryloyl group" and "methacryloyl group."

  As a polymeric compound, polyfunctional (meth) acrylate is preferable. Examples of the polyfunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate and pentaerythritol tri ( Meta) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate Salts, tetrapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, di Glycerin tetra (meth) acrylate, adamantyl di (meth) acrylate, isoboronyl di (meth) acrylate, dicyclopentadi (meth) acrylate, tricyclodecane di (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, or the like Those modified with PO, EO, caprolactone and the like can be mentioned.

  Among them, those having 3 to 6 functional groups are preferable because they can suitably satisfy the above-mentioned martens hardness. For example, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), pentaerythritol tetraacrylate (PETTA) Dipentaerythritol pentaacrylate (DPPA), trimethylolpropane tri (meth) acrylate, tripentaerythritol octa (meth) acrylate, tetrapentaerythritol deca (meth) acrylate and the like are preferable. In the present specification, (meth) acrylate means acrylate and methacrylate.

  In addition, the monofunctional (meth) acrylate monomer may be further included for hardness adjustment, viscosity adjustment of a composition, adhesion improvement, etc. Examples of the monofunctional (meth) acrylate monomer include hydroxyethyl acrylate (HEA), glycidyl methacrylate, methoxy polyethylene glycol (meth) acrylate, isostearyl (meth) acrylate, 2-acryloyloxyethyl succinate, acryloyl morpholine, N Acryloyloxyethyl hexahydrophthalimide, cyclohexyl acrylate, tetrahydrofuryl acrylate, isobornyl acrylate, phenoxyethyl acrylate, adamantyl acrylate and the like.

  From the viewpoint of improving the hardness of the resin layer, the weight average molecular weight of the monomer is preferably less than 1000, and more preferably 200 or more and 800 or less. The weight average molecular weight of the polymerizable oligomer is preferably 1,000 or more and 20,000 or less, more preferably 1,000 or more and 10,000 or less, and still more preferably 2,000 or more and 7,000 or less.

  The inorganic particles are not particularly limited as long as they can improve hardness, but silica particles are preferable from the viewpoint of obtaining excellent hardness. Among the silica particles, reactive silica particles are preferable. The above-mentioned reactive silica particles are silica particles which can form a crosslinked structure with the above-mentioned polyfunctional (meth) acrylate, and by containing this reactive silica particle, the first hard coat layer The hardness can be sufficiently increased.

  The reactive silica particles preferably have a reactive functional group on the surface, and as the reactive functional group, for example, the above-mentioned polymerizable functional group is suitably used.

  The reactive silica particles are not particularly limited, and conventionally known ones can be used, and examples thereof include reactive silica particles described in JP-A-2008-165040. Further, as commercial products of the above reactive silica particles, for example, MIBK-SD, MIBK-SDMS, MIBK-SDL, MIBK-SDZL manufactured by Nissan Chemical Industries, Ltd., V8802, V8803 manufactured by JGC Catalysts Chemical Corporation, etc. It can be mentioned.

  The silica particles may be spherical silica particles, but are preferably modified silica particles. Spherical silica particles and irregularly shaped silica particles may be mixed. In the present specification, "spherical silica particles" means, for example, silica particles such as true spherical and elliptical spherical, and "deformed silica particles" are potato-like (with an aspect ratio of 1 in cross-sectional observation). .2 means a silica particle having a shape having random unevenness of 2 to 40) on the surface. The surface area of the irregular silica particles is larger than that of the spherical silica particles, and by containing such irregular silica particles, the contact area with the polyfunctional (meth) acrylate or the like becomes large, and the hard coat is difficult. The hardness of the layer can be improved. Whether or not the silica particles contained in the hard coat layer is a modified silica particle is confirmed by observing the cross section of the hard coat layer with a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) be able to.

  It is preferable that the average particle diameter of the said silica particle is 5 nm or more and 200 nm or less. If it is less than 5 nm, it may be difficult to produce the particles themselves, the particles may be aggregated, and it may be extremely difficult to form an irregular shape. At the stage, the dispersibility of the irregularly shaped silica particles may be poor and may cause aggregation. On the other hand, when the average particle diameter of the modified silica particles exceeds 200 nm, large irregularities may be formed in the hard coat layer, and problems such as an increase in haze may occur. When the silica particles are spherical silica particles, the average particle size of the silica particles is 20 particles from the image of the cross section of the particles taken using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) The particle diameter of the particle diameter is measured and taken as the arithmetic mean value of the particle diameter of 20 particles. When the silica particles are modified silica particles, the average particle size of the silica particles is an image of the cross section of the hard coat layer taken using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) The maximum value (major axis) and the minimum value (minor axis) of the distance between two points on the outer periphery of the particles are measured, and the particle sizes are determined on average to obtain the arithmetic mean value of the particle sizes of the 20 particles.

  The hardness (Martens hardness) of the first hard coat layer can be controlled by controlling the size and the amount of the inorganic particles. For example, when the first hard coat layer is formed, the diameter of the silica particle is preferably 5 nm or more and 200 nm or less, and preferably 25 to 60 parts by mass with respect to 100 parts by mass of the polymerizable compound.

(Second hard coat layer)
The second hard coat layer is a layer for satisfying the above-mentioned continuous folding test. The second hard coat layer preferably has a Martens hardness of 375 MPa or more and 1500 MPa or less at the center of the cross section of the second hard coat layer. If it is less than 375 MPa, the abrasion resistance of the hard coat layer may be insufficient, and if it exceeds 1500 MPa, the folding resistance of the resin substrate may be insufficient to satisfy the above-mentioned continuous folding test. is there. The lower limit of the Martens hardness at the center of the cross section of the second hard coat layer is more preferably 450 MPa or more, and the upper limit is more preferably 575 MPa or less.

  The second hard coat layer contains a resin. The second hard coat layer may further contain inorganic particles dispersed in a resin.

  The resin includes a polymer (cured product) of a polymerizable compound (curable compound). As a polymeric compound, polyfunctional (meth) acrylate is preferable. As said polyfunctional (meth) acrylate, the thing similar to the polyfunctional (meth) acrylate of the column of a 1st hard-coat layer is mentioned. In addition to the above-mentioned polyfunctional (meth) acrylate, the second hard coat layer may contain polyfunctional urethane (meth) acrylate and / or polyfunctional epoxy (meth) acrylate.

  Examples of the inorganic particles include the same as the inorganic particles in the column of the first hard coat layer. Although it does not specifically limit as content of the inorganic particle in a 2nd hard-coat layer, For example, it is preferable that it is 0-50 mass% with respect to a 2nd hard-coat layer.

  At least one of the first hard coat layer and the second hard coat layer may contain materials other than the above-described materials as long as the above-described Martens hardness is satisfied. For example, as the material of the resin component, It may contain a polymerizable monomer, a polymerizable oligomer or the like which forms a cured product by irradiation of ionizing radiation. Examples of the polymerizable monomer or polymerizable oligomer include (meth) acrylate monomers having a radically polymerizable unsaturated group in the molecule, and (meth) acrylate oligomers having a radically polymerizable unsaturated group in the molecule. Be As a (meth) acrylate monomer having a radically polymerizable unsaturated group in the molecule or a (meth) acrylate oligomer having a radically polymerizable unsaturated group in the molecule, for example, urethane (meth) acrylate, polyester (meth) And monomers) or oligomers such as acrylates, epoxy (meth) acrylates, melamine (meth) acrylates, polyfluoroalkyl (meth) acrylates, silicone (meth) acrylates and the like. These polymerizable monomers or polymerizable oligomers may be used alone or in combination of two or more. Among them, urethane (meth) acrylates having a multifunctional (six or more functional) and a weight average molecular weight of 1000 to 10,000 are preferable.

  The hard coat layer (at least one of the first hard coat layer and the second hard coat layer) may further contain a UV absorber, a spectral transmittance modifier, and / or an antifouling agent.

(UV absorber)
Although the resin base material is particularly suitably used for mobile terminals such as foldable smart phones and tablet terminals, such mobile terminals are often used outdoors, and therefore, on the display element side relative to the resin base material There is a problem that the disposed polarizer is easily deteriorated by being exposed to ultraviolet light. However, since the resin layer is disposed on the display screen side of the polarizer, when the ultraviolet absorber is contained in the resin layer, it is possible to preferably prevent the deterioration due to the polarizer being exposed to ultraviolet light. In addition, the said ultraviolet absorber (UVA) may be contained in the resin base material 21. FIG. In this case, the ultraviolet absorber (UVA) may not be contained in the hard coat layer.

  As a ultraviolet absorber, a triazine type ultraviolet absorber, a benzophenone series ultraviolet absorber, a benzotriazole type ultraviolet absorber etc. are mentioned, for example.

  Examples of the triazine-based ultraviolet absorber include 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy) phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine, for example. 2- [4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2 , 4-Bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3-tridecyl) Oxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, and 2- [4-[(2-hydroxy-3- (2) - ethyl) hexyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine. As a triazine type ultraviolet absorber marketed, TINUVIN460, TINUVIN477 (all are BASF Corporation make), LA-46 (ADEKA company make) etc. are mentioned, for example.

  Examples of the benzophenone-based UV absorbers include 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxy Benzophenone, 2-hydroxy-4-methoxybenzophenone, hydroxymethoxybenzophenone sulfonic acid and its trihydrate salt, sodium hydroxymethoxybenzophenone sulfonate and the like can be mentioned. Examples of benzophenone-based ultraviolet absorbers that are commercially available include CHMASSORB 81 / FL (manufactured by BASF).

  Examples of the benzotriazole-based ultraviolet absorber include 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate, and the like. -(2H-benzotriazol-2-yl) -6- (linear and branched dodecyl) -4-methylphenol, 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl- 6- (tert-Butyl) phenol, 2- (2H-benzotriazol-2-yl) -4,6-di-tert-pentylphenol, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′ ′ tert-Butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3) '-(3' ', 4' ', 5' ', 6' '-tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3- Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, etc. Can be mentioned. Examples of commercially available benzotriazole-based ultraviolet absorbers include KEMISORB 71 D, KEMISORB 79 (all are Chemipro Chemical Co., Ltd. made), JF-80, JAST-500 (both made by Johoku Chemical Co., Ltd.), ULS- 1933D (one side oil and fat industry Ltd. make), RUVA-93 (made by Otsuka Chemical Co., Ltd.), etc. are mentioned.

  Among the UV absorbers, triazine-based UV absorbers and benzotriazole-based UV absorbers are preferably used. The ultraviolet absorber preferably has a high solubility with the resin component constituting the hard coat layer, and preferably has a low bleed out after the continuous folding test described above. The UV absorber is preferably polymerized or oligomerized. The UV absorber is preferably a benzotriazole, triazine, a polymer or oligomer having a benzophenone skeleton, and more specifically, a benzotriazole or (meth) acrylate having a benzophenone skeleton and methyl methacrylate (MMA) in any ratio. It is preferable that it is thermally copolymerized. In addition, when applying a resin base material to an organic light emitting diode (OLED) display device, an ultraviolet absorber can also play a role which protects OLED from an ultraviolet-ray.

  Although it does not specifically limit as content of a ultraviolet absorber, It is preferable that they are 1 mass part or more and 6 mass parts or less with respect to 100 mass parts of solid content of the composition for hard-coat layers. When the amount is less than 1 part by mass, the above-mentioned effect of containing the ultraviolet absorber in the hard coat layer may not be sufficiently obtained. When the amount is more than 6 parts by mass, the hard coat layer may be significantly colored or reduced in strength. Sometimes. The more preferable lower limit of the content of the ultraviolet absorber is 2 parts by mass or more, and the more preferable upper limit is 5 parts by mass or less.

式中、Ｒ^７は水素原子又はメチル基を表す。Ｒ^８は炭素数１〜６の直鎖状又は枝分かれ鎖状のアルキレン基又は炭素数１〜６の直鎖状または分岐鎖状のオキシアルキレン基を表す。 (Spectral transmission factor modifier)
A spectral transmission factor adjustment agent adjusts the spectral transmission factor of a light transmissive film. When the hard coat layer contains, for example, a sesamol-type benzotriazole-based monomer represented by the following general formula (25), a desired spectral transmittance can be satisfied.

In the formula, R ⁷ represents a hydrogen atom or a methyl group. R ⁸ represents a linear or branched alkylene group having 1 to 6 carbon atoms or a linear or branched oxyalkylene group having 1 to 6 carbon atoms.

  The above-mentioned sesamol-type benzotriazole-based monomer is not particularly limited, but specific substance names include 2- [2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzo Triazol-5-yl] ethyl methacrylate, 2- [2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl] ethyl acrylate, 3- [2- (6 -Hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl] propyl methacrylate, 3- [2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H -Benzotriazol-5-yl] propyl acrylate, 4- [2- (6-hydroxybenzo [1,3] dioxol-5-yl) 2H-benzotriazol-5-yl] butyl methacrylate, 4- [2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl] butyl acrylate, 2- [2 -(6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yloxy] ethyl methacrylate, 2- [2- (6-hydroxybenzo [1,3] dioxol-5-yl ) -2H-benzotriazol-5-yloxy] ethyl acrylate, 2- [3- {2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl} propanoyl Oxy] ethyl methacrylate, 2- [3- {2- (6-hydroxybenzo [1,3] dioxol-5-yl) 2H-benzotriazol-5-yl} propanoyloxy] ethyl acrylate, 4- [3- {2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl} Propanoyloxy] butyl methacrylate, 4- [3- {2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl} propanoyloxy] butyl acrylate, 2- [3- {2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl} propanoyloxy] ethyl methacrylate, 2- [3- {2- (6- (6-) Hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazol-5-yl} propanoyloxy] ethyl acrelay , 2- (methacryloyloxy) ethyl 2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazole-5 carboxylate, 2- (acryloyloxy) ethyl 2- (6-hydroxybenzo) [1,3] dioxol-5-yl) -2H-benzotriazole-5-carboxylate, 4- (methacryloyloxy) butyl 2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H- Examples include benzotriazole-5-carboxylate, 4- (acryloyloxy) butyl 2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazole-5-carboxylate and the like. Moreover, these sesamol-type benzotriazole monomers may be used alone or in combination of two or more.

  When the resin layer has a multilayer structure of two or more layers, the sesamol-type benzotriazole-based monomer may be contained in two or more resin layers to satisfy a desired spectral transmittance. For example, one of the resin layers contains the above-mentioned sesamol-type benzotriazole-based monomer so that only spectral transmittance at a wavelength of 380 nm can be achieved, and the other resin layers have conditions of spectral transmittance at wavelengths of 410 nm and 440 nm. The composition etc. which contain the above-mentioned sesamol type benzotriazole type monomer so that it can achieve are mentioned. Furthermore, the resin layer may be composed of three or more layers, and the above-mentioned sesamol-type benzotriazole-based monomer may be contained so that the desired spectral transmittance is satisfied in each resin layer.

  When the sesamol-type benzotriazole-based monomer is contained in the hard coat layer, for example, the sesamol-type benzotriazole-based monomer is contained in 15 to 30% by mass in the hard coat layer preferable. By containing the sesamol-type benzotriazole-based monomer in such a range, a desired spectral transmittance can be satisfied. The above-mentioned sesamol-type benzotriazole-based monomer may be integrally contained in the hard coat layer by reacting with the resin component constituting the hard coat layer, and the resin component constituting the hard coat layer may react with the resin component. You may contain independently, without doing.

(Antifouling agent)
The antifouling agent may be uniformly dispersed in the hard coat layer, but from the viewpoint of obtaining sufficient antifouling property with a small addition amount and suppressing the decrease in strength of the hard coat layer, the hard coat layer It is preferable that it is contained unevenly on the surface side of In the case where the hard coat layer has a single layer structure, as a method of unevenly distributing the antifouling agent on the surface side of the hard coat layer, for example, a paint formed using the composition for hard coat layer at the time of forming the hard coat layer. A method of heating the coating film to lower the viscosity of the resin component contained in the coating film before drying and curing the film, thereby increasing the fluidity and causing the antifouling agent to be unevenly distributed on the surface side of the hard coat layer Or, select and use an antifouling agent with low surface tension, float the antifouling agent on the surface of the coating without applying heat when drying the coating, and then cure the coating to obtain the above antifouling agent. The method of making it unevenly distributed in the outermost surface side of a hard-coat layer etc. is mentioned. When the hard coat layer has a multilayer structure, the antifouling agent can be unevenly distributed on the surface side of the hard coat layer by containing the antifouling agent in the hard coat layer on the surface side.

  The antifouling agent is not particularly limited, and examples thereof include silicone antifouling agents, fluorine antifouling agents, silicone and fluorine antifouling agents, which may be used alone or in combination. May be In addition, as the antifouling agent, an acrylic antifouling agent may be used.

  The content of the antifouling agent is preferably 0.01 to 3.0 parts by mass with respect to 100 parts by mass of the above-described resin component. If the amount is less than 0.01 parts by mass, sufficient antifouling performance may not be imparted to the resin layer, and if it exceeds 3.0 parts by mass, the hardness of the hard coat layer may be reduced.

  The antifouling agent preferably has a weight average molecular weight of 5000 or less, and is a compound having preferably 1 or more, more preferably 2 or more reactive functional groups in order to improve the durability of the antifouling performance. Among them, excellent scratch resistance can be imparted by using an antifouling agent having two or more reactive functional groups.

  When the antifouling agent does not have a reactive functional group, the antifouling agent is transferred to the back surface of the resin base when stacked, even when the resin base is roll-like or sheet-like, and the resin When it is attempted to attach or apply another layer to the back surface of the substrate, peeling of the other layer may occur, and further, it may be easily peeled off by performing a plurality of continuous folding tests.

  Furthermore, the antifouling agent having the reactive functional group is excellent in the ability to maintain the antifouling performance (durability), and among them, the hard coat layer containing the above-mentioned fluorine-based antifouling agent is less likely to have a fingerprint. (It is hard to be noticeable) and the wiping property is also good. Furthermore, since the surface tension at the time of application of the composition for hard coat layer can be lowered, the leveling property is good and the appearance of the hard coat layer to be formed becomes good.

  The hard coat layer containing the silicone antifouling agent has good slipperiness and good steel wool resistance. A touch sensor in which a resin base material containing such a silicone-based antifouling agent is mounted on the hard coat layer has a good touch feeling because sliding on contact with a finger or a pen is improved. In addition, it is difficult for fingerprints to be attached to the hard coat layer (not noticeable), and the wiping performance is also improved. Furthermore, since the surface tension at the time of application of the composition for hard coat layer can be lowered, the leveling property is good and the appearance of the hard coat layer to be formed becomes good.

  Commercially available silicone antifouling agents include, for example, SUA1900L10 (manufactured by Shin-Nakamura Chemical Co., Ltd.), SUA1900L6 (manufactured by Shin-Nakamura Chemical Co., Ltd.), Ebecryl 1360 (manufactured by Daicel-Cytech Co., Ltd.), UT3971 (Nippon Synthetic Chemical Industry Co., Ltd.) Inc.), BYKUV 3500 (manufactured by Bick Chemie), BYKUV 3510 (manufactured by Bick Chemie), BYKUV 3570 (manufactured by Bick Chemie), X22-164E, X22-174 BX, X22-2426, KBM 503, KBM 5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), TEGO-RAD 2250, TEGO-RAD 2300, TEGO-RAD 2200 N, TEGO-RAD 2010, TEGO-RAD 2500, TEGO-RAD 2600, TEGO-RAD 2700 (EBONI) Manufactured by Japan Co., Ltd.), such as Mega fuck RS854 (manufactured by DIC Co., Ltd.) and the like.

  Commercially available fluorine antifouling agents include, for example, Optool DAC, Optool DSX (manufactured by Daikin Industries, Ltd.), Megafuck RS71, Megafuck RS74 (manufactured by DIC Inc.), LINC152EPA, LINC151EPA, LINC182UA (Kyoeisha Chemical Co., Ltd.) H.T.), H.T. Agent 650 A, H. T. Agent 601 AD, H. T.

  As a commercial item of the antifouling agent which has a reactive functional group of fluorine type and silicone, for example, Megafac RS851, Megafac RS852, Megafac RS853, Megafac RS854 (made by DIC Corporation), Opstar TU2225, Opstar TU2224 (Made by JSR Corporation), X71-1203M (made by Shin-Etsu Chemical Co., Ltd.), etc. are mentioned.

<Shock absorbing layer>
The shock absorbing layer is a layer having shock absorbing properties. The shock absorbing layer may have a multilayer structure of two or more layers.

  The thickness of the impact absorbing layer is preferably 10 μm or more and 500 μm or less. If the film thickness of the shock absorbing layer is 10 μm or more, the hardness drop of the shock absorbing layer can be suppressed, and if it is 500 μm or less, the film thickness is not too thick, so it is suitable for thinning and processing It can control the deterioration. For the film thickness of the shock absorbing layer, the cross section of the shock absorbing layer is photographed using a scanning electron microscope (SEM), and the film thickness of the shock absorbing layer is measured at 20 points in the image of the cross section. It is an arithmetic mean value of thickness. The lower limit of the impact absorbing layer is more preferably 50 μm or more, the upper limit of the impact absorbing layer is more preferably 150 μm or less, and further preferably 100 μm or less.

  In the impact absorbing layer, it is preferable that the shear storage elastic modulus G ′ in a frequency range of 25 ° C. and 500 Hz or more and 1000 Hz or less is 1 MPa or more and 1500 MPa or less. If the shear storage elastic modulus G 'of the impact absorbing layer is 1 MP or more, not only the deformation of the resin base itself but also the inside of the image display device when the impact is applied to the surface of the resin base Even in the case where the adhesive layer is disposed, plastic deformation of the adhesive layer can be further suppressed. Moreover, if shear storage elastic modulus G 'of an impact-absorbing layer is 1500 Mpa or less, the crack of the resin base material at the time of folding can be suppressed more. The lower limit of the shear storage modulus G ′ of the impact absorbing layer is more preferably 100 MPa or more, and the upper limit of the shear storage modulus G ′ of the impact absorbing layer is more preferably 1200 MPa or less. With such an upper limit, good restorability can be obtained when the sheet is folded, allowed to stand, and reopened.

  In the impact absorbing layer, the shear loss elastic modulus G ′ ′ in a frequency range of 25 ° C., 500 Hz or more and 1000 Hz or less is preferably 0.1 MPa or more and 200 MPa or less. If the shear loss elastic modulus G ′ ′ of the impact absorbing layer is 0.1 MPa or more, the impact absorbing performance can be further obtained. In addition, when the shear loss elastic modulus G ′ ′ of the impact absorbing layer is 200 MPa or less, there is no possibility that the hardness of the impact absorbing layer is lowered. The lower limit of the shear loss elastic modulus G ′ ′ of the impact absorption layer is preferably 1 MPa or more, and the upper limit of the shear loss elastic modulus G ′ ′ of the impact absorption layer is from the viewpoint of thinning the impact absorption layer And 150 MPa or less are more preferable.

  The shear storage modulus G ′ and the shear loss modulus G ′ ′ of the impact absorbing layer can be measured by a dynamic viscoelasticity measuring device (DMA). When measuring the shear storage elastic modulus G ′ and the shear loss elastic modulus G ′ ′ of the impact absorbing layer by a dynamic viscoelasticity measuring apparatus (DMA), first, all the protective films from the light transmitting film with a protective film Is peeled off to obtain a light transmitting film alone comprising an impact absorbing layer. Next, this light transmitting film is punched into a 10 mm × 5 mm rectangular shape to obtain a sample. Then, two pieces of this sample are prepared and attached to a jig for solid shearing, which is an option of a dynamic viscoelasticity measuring apparatus (product name "Rheogel-E4000", manufactured by UBM Co., Ltd.). Specifically, the solid shearing jig is provided with one metal solid shearing plate having a thickness of 1 mm and two L-shaped brackets disposed on both sides of the solid shearing plate, One sample is sandwiched between the two and one L-shaped bracket, and the other sample is sandwiched between the solid shear plate and the other L-shaped bracket. In this case, the sample is sandwiched such that the impact absorbing layer is on the solid shear plate side and the resin base is on the L-shaped metal fitting side. Then, fix the sample by tightening the L-shaped brackets with a screw. Next, after attaching a tensile test chuck consisting of an upper chuck and a lower chuck to a dynamic viscoelasticity measuring device (product name "Rheogel-E4000", UMB Inc. made), a solid between the upper chuck and the lower chuck Attach a shearing jig at a distance of 20 mm between chucks. The distance between chucks is the distance between the upper chuck and the lower chuck. Then, the set temperature is set to 25 ° C. and the temperature is raised at 2 ° C./min. In this state, while fixing the solid shear plate, perform dynamic viscoelasticity measurement of the solid at 25 ° C. while giving longitudinal vibrations in the range of 1% strain and a frequency of 500 Hz to 1000 Hz to the two L-shaped brackets, The shear storage modulus G 'and the shear loss modulus G' 'of the impact absorbing layer are measured. Here, the sample contains a resin base in addition to the shock absorbing layer, but since the resin base is harder than the shock absorbing layer, the influence of the resin base can be ignored. For this reason, even if the sample contains a resin substrate other than the shock absorbing layer, the shear storage elastic modulus G ′ and the shear loss elastic modulus G ′ ′ measured from the sample are the shear storage elastic modulus of the shock absorbing layer. It can be regarded as a modulus G ′ and a shear loss modulus G ′ ′. The shear storage elastic modulus G 'and shear loss elastic modulus G' 'in the shock absorption layer in the frequency range of 500 Hz to 1000 Hz give longitudinal vibrations of 500 Hz, 750 Hz, and 950 Hz to the outer plate, respectively, at each frequency The shear storage elastic modulus G 'and shear loss elastic modulus G' 'of the shock absorbing layer are measured, and the arithmetic mean value of these shear storage elastic modulus G' and shear loss elastic modulus G '' is obtained, and further, this measurement is Repeat three times, and take the three arithmetic average values obtained respectively as the values obtained by further arithmetic average. In the above, the frequency range of 500 Hz to 1000 Hz is that the frequency of this frequency range is several microns to several microns when the object is allowed to freely fall from a height of several cm. This is because it is a frequency that deforms by 10 microns and is a frequency that damages the display panel and the like present inside the image display device from the light transmitting film.

  The resin constituting the shock absorbing layer is a resin such that the shear storage elastic modulus G ′ and the shear loss elastic modulus G ′ ′ of the shock absorbing layer in the frequency range of 25 ° C. and 500 Hz to 1000 Hz are within the above ranges. There is no particular limitation. Examples of such resins include acrylic gels, urethane gels, silicone gels, urethane resins, epoxy resins and the like. Among these, acrylic gels are preferable. "Gel" generally refers to a dispersion with high viscosity and loss of flowability. The impact absorbing layer may contain rubber or thermoplastic elastomer in addition to acrylic gel and urethane resin. In addition, since the above-mentioned acrylic gel is adhesive, when the shock absorbing layer is made of the above acrylic gel, the shock absorbing layer and the resin may be provided without providing an adhesive layer between the shock absorbing layer and the resin substrate. The substrate can be stuck directly.

(Acrylic gel)
As the acrylic gel, various polymers can be used, as long as they are polymers used for pressure-sensitive adhesives and the like and obtained by polymerizing monomers containing an acrylic ester. Specifically, as the acrylic gel, for example, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, n-amyl (meth) acrylate, i-amyl (meth) acrylate, octyl (meth) acrylate, i-octyl (meth) acrylate, i-myristyl (Meth) acrylate, lauryl (meth) acrylate, nonyl (meth) acrylate, i-nonyl (meth) acrylate, i-decyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, i-stearyl (meth) ) Such as acrylate It can be used obtained by polymerizing or copolymerizing acrylic monomers. As used herein, "(meth) acrylate" is meant to include both "acrylate" and "methacrylate". In addition, you may use together 2 or more types of acrylic acid ester used when carrying out the said (co) superposition | polymerization in addition to using independently.

(Urethane resin)
The urethane resin is a resin having a urethane bond. As a urethane type resin, the hardened | cured material of an ionizing radiation curable urethane type resin composition, the hardened | cured material of a thermosetting urethane type resin composition, etc. are mentioned. Among these, a cured product of an ionizing radiation curable urethane resin composition is preferable from the viewpoint of obtaining high hardness and a high curing rate and excellent mass productivity.

  The ionizing radiation curable urethane resin composition contains urethane (meth) acrylate, and the thermosetting urethane resin contains a polyol compound and an isocyanate compound. The urethane (meth) acrylate, the polyol compound and the isocyanate compound may be any of monomers, oligomers and prepolymers.

  The number of (meth) acryloyl groups (number of functional groups) in the urethane (meth) acrylate is preferably 2 or more and 4 or less. If the number of (meth) acryloyl groups in the urethane (meth) acrylate is less than 2, the pencil hardness may be lowered, and if it exceeds 4, the cure shrinkage becomes large, and the resin substrate curls. In addition, the resin layer may be cracked at the time of bending. The upper limit of the number of (meth) acryloyl groups in the urethane (meth) acrylate is more preferably 3 or less.

  The weight average molecular weight of the urethane (meth) acrylate is preferably 1500 or more and 20000 or less. When the weight average molecular weight of the urethane (meth) acrylate is less than 1,500, impact resistance may be decreased, and when it exceeds 20000, the viscosity of the ionizing radiation curable urethane resin composition is increased, and coating is performed. There is a possibility that the sex may deteriorate. The lower limit of the weight average molecular weight of the urethane (meth) acrylate is more preferably 2000 or more, and the upper limit is more preferably 15000 or less.

上記一般式（２６）中、Ｒ^９は分岐鎖状アルキル基を示し、Ｒ^１０は分岐鎖状アルキル基又は飽和環状脂肪族基を示し、Ｒ^１１は水素原子又はメチル基を示し、Ｒ^１２は、水素原子、メチル基又はエチル基を示し、ｍは０以上の整数を示し、ｘは０〜３の整数を示す。 Moreover, as a repeating unit which has a structure derived from urethane (meth) acrylate, the structure etc. which are represented by following General formula (26), (27), (28) or (29) are mentioned, for example.

In the above general formula (26), R ⁹ represents a branched alkyl group, R ¹⁰ represents a branched alkyl group or a saturated cyclic aliphatic group, R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents , A hydrogen atom, a methyl group or an ethyl group, m represents an integer of 0 or more, and x represents an integer of 0 to 3.

上記一般式（２７）中、Ｒ^９は分岐鎖状アルキル基を示し、Ｒ^１０は分岐鎖状アルキル基又は飽和環状脂肪族基を示し、Ｒ^１１は水素原子又はメチル基を示し、Ｒ^１２は、水素原子、メチル基又はエチル基を示し、ｎは１以上の整数を示し、ｘは０〜３の整数を示す。

In the above general formula (27), R ⁹ represents a branched alkyl group, R ¹⁰ represents a branched alkyl group or a saturated cyclic aliphatic group, R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents , A hydrogen atom, a methyl group or an ethyl group, n represents an integer of 1 or more, and x represents an integer of 0 to 3.

上記一般式（２８）中、Ｒ^９は分岐鎖状アルキル基を示し、Ｒ^１０は分岐鎖状アルキル基又は飽和環状脂肪族基を示し、Ｒ^１１は水素原子又はメチル基を示し、Ｒ^１２は、水素原子、メチル基又はエチル基を示し、ｍは０以上の整数を示し、ｘは０〜３の整数を示す。

In the above general formula (28), R ⁹ represents a branched alkyl group, R ¹⁰ represents a branched alkyl group or a saturated cyclic aliphatic group, R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents , A hydrogen atom, a methyl group or an ethyl group, m represents an integer of 0 or more, and x represents an integer of 0 to 3.

上記一般式（２９）中、Ｒ^９は分岐鎖状アルキル基を示し、Ｒ^１０は分岐鎖状アルキル基又は飽和環状脂肪族基を示し、Ｒ^１１は水素原子又はメチル基を示し、Ｒ^１２は、水素原子、メチル基又はエチル基を示し、ｎは１以上の整数を示し、ｘは０〜３の整数を示す。

In the above general formula (29), R ⁹ represents a branched alkyl group, R ¹⁰ represents a branched alkyl group or a saturated cyclic aliphatic group, R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents , A hydrogen atom, a methyl group or an ethyl group, n represents an integer of 1 or more, and x represents an integer of 0 to 3.

  The structure of the polymer chain (repeating unit) of the resin constituting the shock absorbing layer may be formed, for example, by analyzing the shock absorbing layer by thermal decomposition GC-MS and FT-IR. It can be judged. In particular, thermal decomposition GC-MS is useful because it can detect a monomer unit contained in an impact absorption layer as a monomer component.

  The impact absorbing layer may contain an ultraviolet absorber, a spectral transmittance regulator, an antifouling agent, inorganic particles and / or organic particles and the like. As the UV absorber and the like can be used similar to the UV absorber and the like described in the section of the hard coat layer, the description will be omitted here.

<Underlayer>
The base layer is a layer for improving the adhesion between the resin base material and another functional layer (for example, a hard coat layer or an impact absorption layer) provided on the resin base material. By providing the underlayer on the surface of the resin substrate, the adhesion can be improved as compared to the case where the surface of the resin substrate is in direct contact with the other functional layers.

  The thickness of the underlayer is preferably 30 nm or more and 200 nm or less. If the film thickness of the underlayer is 30 nm or more, sufficient adhesion between the resin substrate and the other functional layers can be secured, and if 200 nm or less, the generation of interference fringes can be suppressed. The film thickness of the underlayer is determined by the same method as the film thickness of the hard coat layer. The lower limit of the film thickness of the underlayer is more preferably 50 nm or more, and the upper limit is more preferably 150 nm or less.

  The underlayer contains a resin. The resin of the underlayer is selected from the group consisting of (meth) acrylic resins, cellulose resins, urethane resins, vinyl chloride resins, polyester resins, polyolefin resins, polycarbonates, nylons, polystyrenes, and ABS resins. It is preferable that it is at least one resin.

<< Production method of light transmitting film with protective film >>
The light transmitting film 10 with a protective film can be obtained as follows. First, the protective film 30 is attached to the surface 20A of the light transmitting film 20 (the surface 21A of the resin base 21) such that the adhesive layer 32 side is the surface 20A side. Then, the protective film 40 is attached to the surface 20B of the light transmitting film 20 (the surface 21B of the resin base 21) so that the adhesive layer 42 side is the surface 20B side. Thereby, the light transmitting film 10 with a protective film is obtained.

  Moreover, the light transmissive film 60 with a protective film can be obtained as follows. First, the protective film 30 is attached to the surface 21A of the resin base 21 so that the adhesive layer 32 side is the surface 21A side. Then, the resin layer 71 (for example, a hard coat layer or an impact absorption layer) is formed on the surface 21 B of the resin base 21, and the light transmitting film 70 made of the resin base 21 and the resin layer 71 is formed. Thereby, a light transmitting film 60 with a protective film is obtained. In addition, when the processing process at the time of forming resin layer 71 grade | etc., Becomes the temperature more than the softening point of the protective film 30, after processing the protective film 30 once peeled off from the resin base material 21, a processing process is performed after that The protective film 30 may be attached to the surface 20A of the light transmitting film 20 again.

  In the case of forming a hard coat layer consisting of a first hard coat layer and a second hard coat layer laminated on the first hard coat layer as the resin layer 71, the surface 21B of the resin base 21 is used. First, a first composition for hard coat layer for forming a first hard coat layer is applied to form a coating film of the first composition for hard coat layer.

<Composition for First Hard Coat Layer>
The composition for the first hard coat layer contains a polymerizable compound for forming the first hard coat layer. The composition for the first hard coat layer may further contain, if necessary, an ultraviolet light absorber, a spectral transmittance regulator, an antifouling agent, inorganic particles, a leveling agent, a solvent, and a polymerization initiator.

(solvent)
Examples of the solvent include alcohols (eg, methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol, diacetone alcohol), ketones (eg, acetone, methyl ethyl ketone, Methyl isobutyl ketone, cyclopentanone, cyclohexanone, heptanone, diisobutyl ketone, diethyl ketone, diacetone alcohol, ester (methyl acetate, ethyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, methyl formate, PGMEA), aliphatic Hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic hydrocarbons (eg, benzene, toluene, xylene), (Eg, dimethylformamide, dimethylacetamide, N-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methoxy-2-propanol), carbonate (dimethyl carbonate, diethyl carbonate, Ethyl methyl carbonate) and the like. These solvents may be used alone or in combination of two or more. Among them, methyl isobutyl ketone is preferable because the above-mentioned solvent can dissolve or disperse components such as urethane (meth) acrylate and other additives and can be suitably coated with the first composition for a hard coat layer. And methyl ethyl ketone are preferred.

(Polymerization initiator)
The polymerization initiator is a component that is decomposed by ionizing radiation and generates radicals to initiate or promote polymerization (crosslinking) of the polymerizable compound.

  The polymerization initiator is not particularly limited as long as it can release a substance that initiates radical polymerization by ionizing radiation. The polymerization initiator is not particularly limited, and known ones may be used. Specific examples thereof include, for example, acetophenones, benzophenones, Michler's benzoylbenzoate, α-amyloxime ester, thioxanthones, propiophenone , Benzyls, benzoins, acyl phosphine oxides. Further, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine and the like.

  After forming a coating film of the first composition for a hard coat layer, the coating film is dried by heating at a temperature of 30 ° C. or more and 120 ° C. or less for 10 seconds to 120 seconds by various known methods. Evaporate.

  After the coated film is dried, the coated film is irradiated with ionizing radiation such as ultraviolet light to semi-cure the coated film. The term "semi-hardening" as used herein means that curing further proceeds substantially upon further irradiation with ionizing radiation. However, at this stage, the coating may be completely cured (full cure). The term "complete cure" as used herein means that curing does not substantially proceed even when further irradiated with ionizing radiation.

  After the coating film is semi-cured, a second hard coating composition for forming a second hard coating layer is coated on the coating by a coating apparatus such as a bar coater, A coating film of the composition for hard coat layer is formed.

<Composition for Second Hard Coat Layer>
The composition for the second hard coat layer contains a polymerizable compound for forming the second hard coat layer. The composition for the second hard coat layer may further contain, if necessary, a UV absorber, a solvent, and a polymerization initiator. The composition for the second hard coat layer preferably has a total solid content of 25 to 55%, similarly to the composition for the first hard coat layer. The solvent and the polymerization initiator are the same as the solvent and the polymerization initiator described in the first composition for a hard coat layer, and thus the description thereof is omitted here.

  After forming the coating film of the composition for the second hard coat layer, the coating film is dried by heating for 10 seconds to 120 seconds at a temperature of 30 ° C. or more and 120 ° C. or less by various known methods. Evaporate.

  After the coated film is dried, the coated film of the second hard coat layer composition is irradiated with ionizing radiation such as ultraviolet light, and the coated film of the first hard coat layer composition and the second hard coat layer The coating of the coating composition is fully cured (full cure) to obtain a hard coat layer comprising the first hard coat layer and the second hard coat layer.

  Moreover, when forming an impact absorption layer as the resin layer 71, the composition for impact absorption layers for forming an impact absorption layer is apply | coated to surface 21B of the resin base material 21, and the composition for impact absorption layers Form a coating of the object. After forming a coating film of the composition for an impact absorbing layer, the coating film is dried by heating for 10 seconds to 120 seconds, for example, at a temperature of 30 ° C. or more and 120 ° C. or less by various known methods to evaporate the solvent. After drying the coating film, the coating film of the composition for resin layer is irradiated with ionizing radiation such as ultraviolet light to cure the coating film of the impact absorbing layer, thereby forming an impact absorbing layer.

  Also, the light transmitting film 80 with a protective film can be obtained as follows. First, the resin layer 91 (for example, base layer) is formed on the surface 21A of the resin base material 21, and the protective film 30 is attached to the surface 91A of the resin layer 91 such that the adhesive layer 32 side is the resin layer 91 side. Then, a resin layer 92 (for example, a hard coat layer or an impact absorption layer) is formed on the surface 21 B of the resin base 21. Thereby, a light transmitting film 80 with a protective film is obtained. If the processing process for forming the resin layers 91, 92, etc. is at a temperature above the softening point of the protective film 30, the processing process is performed after the protective film 30 is peeled off from the resin layer 91 once, Thereafter, the protective film 30 may be attached to the surface 90A of the resin layer 91 again.

  When the protective film is peeled off from the light transmitting film, the unevenness appears on the surface of the light transmitting film because the unevenness of the surface of the protective film is transferred to the surface of the light transmitting film. In particular, this phenomenon is likely to occur in the light transmitting film in a state of being wound in a roll because the pressure is applied to the light transmitting film from the protective film by winding the light transmitting film in a roll. It is considered to be. On the other hand, according to JIS K 7136: 2000, the haze is a percentage of the transmitted light which deviates 0.044 rad (2.5 °) or more from the incident light by the forward scattering among the transmitted light passing through the test piece It is prescribed. That is, in the definition of haze, transmitted light deviated by 2.5 ° or more with respect to incident light is measured as haze, but transmitted light less than 2.5 ° with respect to incident light is not measured as haze. Here, when unevenness is present on the surface of the protective film, the light passing through the protective film is diffused by the unevenness, and therefore the haze value becomes large. Therefore, the fact that the haze value of the protective film is small means that there are few irregularities present on the surface of the protective film, and the smoothness is excellent. In the present embodiment, since the protective films 30 and 40 having a haze value of 10% or less are used, the unevenness present on the surfaces of the protective films 30 and 40 is small. For this reason, it is possible to obtain the surfaces 20A and 20B of the light transmitting film 20 with less unevenness. Thereby, the light transmitting film 20 having excellent smoothness can be obtained. In addition, for the same reason, it is possible to obtain the light transmitting films 70 and 90 having excellent smoothness.

<<< Optical film >>>
The light transmissive films 20, 70, 90 can be used to form a foldable optical film. FIG. 6 is a schematic configuration view of an optical film according to the present embodiment.

  The optical film 100 shown in FIG. 6 is provided on the light transmitting film 20 made of the resin base 21, the resin layer 101 provided on the surface 21 A of the resin base 21, and the surface 21 B of the resin base 21. And a resin layer 102.

<< Resin layer >>
The resin layers 101 and 102 are not particularly limited, and examples thereof include a hard coat layer and an impact absorption layer. For example, when the resin layer 101 is a hard coat layer, the resin layer 102 can be an impact absorbing layer. The hard coat layer is the same as the hard coat layer described in the column of the resin layer 71, and the shock absorbing layer is the same as the shock absorbing layer described in the column of the resin layer 71, so the description is omitted here. I assume.

  In the case of forming the optical film 100, first, in the light transmitting film 10 with a protective film, in a state in which the protective film 30 is peeled from the light transmitting film 20, in the same manner as the formation of the resin layer 71, a resin base The resin layer 101 is formed on the surface 21 A of 21. Next, in a state where the protective film 40 is peeled from the light transmitting film 20, the resin layer 102 is formed on the surface 21B of the resin base 21 in the same manner as the formation of the resin layer 71.

<<< image display device >>>
The optical film 100 can be incorporated into a foldable image display and used. FIG. 7 is a schematic configuration diagram of an image display device according to the present embodiment. As shown in FIG. 7, the image display device 110 mainly faces a viewer, and a housing 111 in which a battery or the like is accommodated, a protective film 112, a display panel 113, a circularly polarizing plate 114, and a touch sensor 115. , And the optical film 100 are laminated in this order. A light transmitting adhesive layer 116 is disposed between the display panel 113 and the circularly polarizing plate 114, between the circularly polarizing plate 114 and the touch sensor 115, and between the touch sensor 115 and the optical film 100. These members are fixed to each other by the adhesive layer 116. The adhesive layer 116 is disposed between the display panel 113 and the circularly polarizing plate 114, between the circularly polarizing plate 114 and the touch sensor 115, and between the touch sensor 115 and the optical film 100. The arrangement location is not particularly limited as long as it is between the optical film 100 and the display panel 113.

  In the optical film 100, when the resin layer 101 is a hard coat layer and the resin layer 102 is an impact absorption layer, the optical film 100 is disposed such that the resin layer 101 is closer to the viewer than the resin layer 102 There is. In the image display device 110, the surface of the resin layer 101 of the optical film 100 constitutes the surface of the image display device 110.

  In the image display device 110, the display panel 113 is an organic light emitting diode panel including an organic light emitting diode and the like. The touch sensor 115 is disposed closer to the viewer than the circularly polarizing plate 115, but may be disposed between the display panel 113 and the circularly polarizing plate 114. The touch sensor 115 may be an on-cell system or an in-cell system.

  As the adhesive layer 116, for example, OCA (Optical Clear Adhesive) can be used, but from the viewpoint of improving the impact resistance and preventing damage to the display panel 113, using the adhesive layer made of the above acrylic gel Is preferred. When the adhesive layer made of the above-mentioned acrylic gel is used as the adhesive layer 116, between the display panel 113 and the circularly polarizing plate 114, between the circularly polarizing plate 114 and the touch sensor 115, the touch sensor 115 and the optical film 100. An adhesive layer made of the above-mentioned acrylic gel may be disposed in at least one of the above.

  In the above embodiment, the optical film 100 is used as a cover film constituting the surface of the image display device 110. However, even if the optical film 100 is used as a film present inside the image display device Good.

  EXAMPLES The present invention will be described by way of examples to describe the present invention in detail, but the present invention is not limited to these descriptions. In addition, the following "solid content 100% conversion value" is a value when solid content in solvent dilution goods is made into 100%.

<Preparation of composition for hard coat layer>
First, each component was blended so as to have the composition shown below to obtain a composition for hard coat layer.

(Composition for hard coat layer 1)
-Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (product name "M403", manufactured by Toagosei Co., Ltd.): 25 parts by mass-Dipentaerythritol EO modified hexaacrylate (product name "A-DPH-6E", Shin-Nakamura Chemical Industry Co., Ltd .: 25 parts by mass / atypical silica particles (average particle diameter 25 nm, manufactured by JGC Catalysts & Chemicals Co., Ltd.): 50 parts by mass (solid content 100% conversion value)
-Photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacure (registered trademark) 184, manufactured by BASF Japan Ltd.): 4 parts by mass-fluorine-based leveling agent (product name" F568 ", manufactured by DIC Corporation) 0.2 parts by mass (solid content 100% conversion value)
・ Methyl isobutyl ketone (MIBK): 150 parts by mass

(Composition for hard coat layer 2)
-Urethane acrylate (product name "UX 5000", manufactured by Nippon Kayaku Co., Ltd.): 25 parts by mass-Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (product name "M403", manufactured by Toagosei Co., Ltd.): 50 25 parts by mass (solid content 100% conversion value): Multifunctional acrylate polymer (product name "Akrit 8KX-012C", manufactured by Taisei Fine Chemical Co., Ltd.)
Antifouling agent (product name "BYKUV3500", manufactured by BIC-Chemie): 1.5 parts by mass (solid content 100% conversion value)
Photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacure (registered trademark) 184, manufactured by BASF Japan Ltd.): 4 parts by mass Methylisobutyl ketone (MIBK): 150 parts by mass

<Preparation of composition for base layer>
Each component was blended so as to obtain the composition shown below, to obtain a composition for an underlayer.
(Composition for base layer)
-Urethane-modified polyester resin (product name "UR-3200", manufactured by Toyobo Co., Ltd.): 5 parts by mass (solid content 100% conversion value)
-Methyl isobutyl ketone (MIBK): 170 parts by mass

Example 1
As a resin substrate, a 38 μm-thick polyethylene terephthalate film as a substrate film on a first surface which is one surface of a 50 μm-thick polyimide substrate (product name “Neoprim”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) (PET film) and a first protective film having a total thickness of 63 μm (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.) consisting of an adhesive layer provided on one side of the PET film; It is pasted so as to become the substrate side, and a 38 μm thick polyethylene terephthalate film (PET film) and a PET film as a substrate film are provided on the second surface opposite to the first surface of the polyimide substrate. Second protective film with a total thickness of 63 μm consisting of an adhesive layer provided on one side (product name “SAT-42J” A light transmitting film with a protective film provided with a first protective film, a light transmitting film made of a polyimide substrate, and a second protective film, is attached to the product.

Example 2
In Example 2, instead of the first protective film and the second protective film (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.), a 38 μm-thick polyethylene terephthalate film (base film) Using a first protective film having a total thickness of 60 μm and a second protective film (product name “TP200”, manufactured by Nitto Denko Corporation) consisting of an adhesive layer provided on one side of PET film and PET film) A light transmitting film with a protective film was obtained in the same manner as in Example 1 except for the above.

Example 3
In Example 3, it is an example except using the polyamide substrate (product name "Mikutron", Toray Industries, Inc.) instead of the polyimide substrate (product name "Neoprim", manufactured by Mitsubishi Gas Chemical Co., Ltd.). In the same manner as in 1, a light transmitting film with a protective film was obtained.

Example 4
In Example 4, instead of the first protective film and the second protective film (product name “SAT-42J”, manufactured by Sun Akaken Co., Ltd.), a 125 μm-thick polyethylene terephthalate film (base film) Using a first protective film having a total thickness of 135 μm and a second protective film (product name “SAT TM 30125”, manufactured by Sun Akaken Co., Ltd.) consisting of an adhesive layer provided on one side of PET film and PET film) A light transmitting film with a protective film was obtained in the same manner as Example 1 except for the above.

Example 5
As a resin substrate, a 38 μm-thick polyethylene terephthalate film as a substrate film on a first surface which is one surface of a 50 μm-thick polyimide substrate (product name “Neoprim”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) (PET film) and a first protective film having a total thickness of 63 μm (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.) consisting of an adhesive layer provided on one side of the PET film; It stuck so that it might become a substrate side. Then, the composition 1 for hard-coat layers was apply | coated with the bar coater on the 2nd surface on the opposite side to the 1st surface in a polyimide base material, and the coating film was formed. Thereafter, the formed coating film is heated at 70 ° C. for 1 minute to evaporate the solvent in the coating film, and the ultraviolet light is irradiated using an ultraviolet irradiation apparatus (light source H bulb manufactured by Fusion UV System Japan Co., Ltd.) The coating was half-cured by irradiation in air so that the accumulated light amount would be 100 mJ / cm ² . Subsequently, the composition 2 for hard-coat layers was apply | coated with the bar coater on the surface of the coating film of the composition 1 for semi-hardened layers, and the coating film was formed. The coating film formed is heated at 70 ° C. for 1 minute to evaporate the solvent in the coating film, and the ultraviolet light is irradiated with oxygen using an ultraviolet irradiation device (Fusion UV System Japan Ltd., light source H bulb) Under the condition of 200 ppm or less so that the integrated light quantity is 200 mJ / cm ² and the coating film is completely cured (full cure) to obtain a first hard coat layer having a thickness of 10 μm and a first hard coat layer. A hard coat layer consisting of a second hard coat layer with a thickness of 5 μm laminated on the coat layer was formed. Thus, a light transmitting film with a protective film comprising: a light transmitting film comprising a polyimide substrate and a hard coat layer; and a first protective film releasably attached to the first surface of the polyimide substrate Obtained.

  The thickness of the hard coat layer is obtained by photographing a cross section of the hard coat layer using a scanning transmission electron microscope (STEM) (product name "S-4800", manufactured by Hitachi High-Technologies Corporation) The film thickness of the hard coat layer was measured at 10 points in the above, and the arithmetic average value of the film thickness of the 10 points was taken. The cross-sectional photograph of the hard coat layer was taken as follows. First, a block is prepared by embedding an optical film cut out into 1 mm × 10 mm with an embedding resin, and a uniform section with a thickness of 70 nm or more and 100 nm or less is cut out from this block by a general section preparation method. The For preparation of the section, “Ultra Microtome EM UC7” (Leica Microsystems Inc.) and the like were used. Then, a uniform section without the holes and the like was used as a measurement sample. Thereafter, a cross-sectional photograph of the measurement sample was taken using a scanning transmission electron microscope (STEM). At the time of photographing of this cross-sectional photograph, STEM observation was performed with a detector of “TE”, an acceleration voltage of 30 kV and an emission of “10 μA”. As for the magnification, the focus was adjusted, and the contrast and the brightness were appropriately adjusted at 5000 to 200,000 times while observing whether each layer was distinguishable. In addition, when taking a cross-sectional photograph, the aperture is set to the beam monitor stop 3 and the objective lens stop is set to 3, W. D. To 8 mm.

Example 6
As a resin substrate, the composition 1 for foundation layer is applied to a first surface which is one surface of a polyimide substrate (product name "Neoprim", manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a thickness of 50 μm, and a coating film is provided. It formed. Then, the solvent in the coating film was evaporated by heating the formed coating film at 90 ° C. for 1 minute to form an undercoat layer having a thickness of 100 nm. Next, a first protective film having a total thickness of 63 μm comprising a 38 μm thick polyethylene terephthalate film (PET film) as a base film and an adhesive layer provided on one side of the PET film on the surface of the underlayer The name "SAT-42J" (manufactured by Sun Akaken Co., Ltd.) was attached so that the adhesive layer was on the underlayer side. Then, the composition 1 for hard-coat layers was apply | coated with the bar coater on the 2nd surface on the opposite side to the 1st surface in a polyimide base material, and the coating film was formed. Thereafter, the formed coating film is heated at 70 ° C. for 1 minute to evaporate the solvent in the coating film, and the ultraviolet light is irradiated using an ultraviolet irradiation apparatus (light source H bulb manufactured by Fusion UV System Japan Co., Ltd.) The coating was half-cured by irradiation in air so that the accumulated light amount would be 100 mJ / cm ² . Subsequently, the composition 2 for hard-coat layers was apply | coated with the bar coater on the surface of the coating film of the composition 1 for semi-hardened layers, and the coating film was formed. The coating film formed is heated at 70 ° C. for 1 minute to evaporate the solvent in the coating film, and the ultraviolet light is irradiated with oxygen using an ultraviolet irradiation device (Fusion UV System Japan Ltd., light source H bulb) Under the condition of 200 ppm or less so that the integrated light quantity is 200 mJ / cm ² and the coating film is completely cured (full cure) to obtain a first hard coat layer having a thickness of 10 μm and a first hard coat layer. A hard coat layer consisting of a second hard coat layer with a thickness of 5 μm laminated on the coat layer was formed. Thereby, a light transmitting film with a protective film comprising a light transmitting film comprising the base layer, the polyimide substrate and the hard coat layer, and the first protective film peelably attached to the surface of the base layer is obtained. The The film thicknesses of the above-mentioned underlayer and hard coat layer were measured by the same method as the method of measuring the film thickness of the hard coat layer described in the column of Example 5.

Comparative Example 1
In Comparative Example 1, instead of the first protective film and the second protective film (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.), a 60 μm thick self-adhesive type first film made of polyethylene is used. A light transmitting film with a protective film was obtained in the same manner as in Example 1 except that the second protective film (product name “PAC3-50THK”, manufactured by Sun Aiken Co., Ltd.) was used.

Comparative Example 2
In Comparative Example 2, instead of the first protective film and the second protective film (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.), a 60 μm thick self-adhesive type first film made of polyethylene. A light transmitting film with a protective film was obtained in the same manner as in Example 1 except that the second protective film (product name “PAC4K-60”, manufactured by Sun Aiken Co., Ltd.) was used.

Comparative Example 3
In Comparative Example 3, a polypropylene film (PP film) as a base film and PP instead of the first protective film and the second protective film (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.) Example except using a first protective film having a total thickness of 30 μm consisting of an adhesive layer provided on one side of the film and a second protective film (product name “KD23”, manufactured by Sun Aiken Co., Ltd.) In the same manner as in 1, a light transmitting film with a protective film was obtained.

Comparative Example 4
In Comparative Example 4, instead of the first protective film (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.), a 60 μm thick self-adhesive first protective film and a second protective film made of polyethylene A light transmitting film with a protective film was obtained in the same manner as in Example 5 except that a protective film of the above (product name “PAC3-50THK”, manufactured by Sun Akaken Co., Ltd.) was used.

Comparative Example 5
In Comparative Example 5, a 60 μm-thick self-adhesive first protective film (product name) made of polyethylene instead of the first protective film (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.) A light transmitting film with a protective film was obtained in the same manner as in Example 5 except that “PAC 4 K-60” (manufactured by Sun Akaken Co., Ltd.) was used.

Comparative Example 6
In Comparative Example 6, a self-adhesive first protective film (product name: 60 μm thick) made of polyethylene instead of the first protective film (product name “SAT-42J”, manufactured by Sun Aiken Co., Ltd.) A light transmitting film with a protective film was obtained in the same manner as in Example 6 except that “PAC 4 K-60” (manufactured by Sun Akaken Co., Ltd.) was used.

<Continuous folding test>
In the light transmissive film with a protective film which concerns on an Example and a comparative example, in the state which peeled all the protective films from the light transmissive film, the foldability of the light transmissive film was evaluated. Specifically, each protective film-carrying light transmitting film is cut into a size of 30 mm × 100 mm, and in this cut-out protective film-carrying light transmitting film, all protective films are peeled from the light transmitting film, A light transmitting film was obtained. Then, the obtained light transmitting film is fixed to a durability tester (product name "DLDMLH-FS" manufactured by Yuasa System Instruments Co., Ltd.) with the short side (30 mm) side of the light transmitting film at the fixing portion. As shown in FIG. 2 (C), a continuous folding test is performed 100,000 times so that the minimum distance between two opposing side portions is 30 mm and the light transmitting film is folded 180 °, and the bent portion is It was examined whether or not cracking or breakage occurred. In addition, in the light transmissive film obtained from the light transmissive film with a protective film which concerns on Example 5, 6 and Comparative Examples 4-6, light transmittance is carried out so that the surface by the side of a hard-coat layer may be folded 180 degrees inside. The film was attached to the endurance tester. The results of the continuous folding test were evaluated according to the following criteria.
○: In the continuous folding test, no fracture or breakage occurred in the bent portion.
X: In the continuous folding test, a crack or break occurred in the bent portion.

<Haze measurement>
The haze value (total haze value) of the protective film used in the light transmitting film with the protective film according to the example and the comparative example was measured. First, each protective film-carrying light transmitting film was cut into a size of 50 mm × 100 mm, and all protective films were peeled from the light transmitting film in the cut-out protective film-carrying light transmitting film. Specifically, in Examples 1 to 4 and Comparative Examples 1 to 3, the first protective film and the second protective film are peeled off from the light transmitting film, and Examples 5 and 6 and Comparative Examples 4 to 4 are separated. In 6, the first protective film was peeled off from the light transmitting film. And haze meter (product name "HM-150", Murakami Co., Ltd.) in the state where there is no curl and wrinkles, and there are no fingerprints and dust, etc. for the haze value of the peeled first and second protective films. It measured by the method based on JISK7136: 2000 using the Color Technology Research Institute make). In addition, the haze value of a 1st protective film and a 2nd protective film was made into the arithmetic mean value of the value obtained by measuring 3 times with respect to 1 sheet of each protective film.

<Total ray transmittance>
In the light transmitting film with a protective film according to the examples and comparative examples, the total light transmittance of the light transmitting film was measured as follows, with all the protective films peeled from the light transmitting film. First, a light transmitting film with a protective film is cut out to a size of 50 mm x 100 mm, and in the light transmitting film with a protective film cut out, all protective films are peeled from the light transmitting film, and light transmitting I got a film. Then, using a haze meter (product name “HM-150”, manufactured by Murakami Color Research Laboratory Co., Ltd.) in a state in which the total light transmittance of the light transmitting film is free from curls and wrinkles, and fingerprints and dust, etc. It measured by the method based on JIS K7361-1: 1997. In addition, total light transmittance was taken as the arithmetic mean value of the value obtained by measuring 3 times with respect to one light transmissive film.

<Yellow Index (YI)>
In the light transmitting film with protective film according to the example and the comparative example, the yellow index of the light transmitting film is measured as follows in a state where all the protective films are peeled from the resin base such as the polyimide base And evaluated. First, a light transmitting film with a protective film is cut out to a size of 50 mm x 100 mm, and in the light transmitting film with a protective film cut out, all protective films are peeled from the light transmitting film, and light transmitting I got a film. Then, using a spectrophotometer (product name “UV-3100PC”, manufactured by Shimadzu Corporation, light source: tungsten lamp and deuterium lamp), light with a wavelength of 200 nm to 780 nm is irradiated from the back side of the light transmitting film The yellow index was measured from light with a wavelength of 200 nm to 780 nm that passes through the light transmitting film. The yellow index calculates chromaticity tristimulus values X, Y, Z from measured values according to the arithmetic equation described in JIS Z 8722: 2009, and is described in tristimulus values X, Y, Z to ASTM D1925: 1962. It was calculated according to the equation and was measured three times and used as the arithmetic mean of the values obtained. Evaluation criteria were as follows.
◎: YI was less than 1.5.
○: YI was 1.5 or more and less than 10.0.
Fair: YI was 10.0 or more and 15.0 or less.
X: YI exceeded 15.0.

<Appearance evaluation>
In the light transmitting film with protective film according to the example and the comparative example, in a state where all the protective films are peeled from the light transmitting film, unevenness is formed on the first surface and the second surface of the light transmitting film It was evaluated by visual observation. Specifically, each protective film-carrying light transmitting film is cut into a size of 100 mm × 100 mm, and in this cut-out protective film-carrying light transmitting film, all protective films are peeled from the light transmitting film, A light transmitting film was obtained. Then, asperities on the first surface of the light transmitting film (the first surface of the resin base in Examples 1 to 5 and Comparative Examples 1 to 5; the surface of the underlayer in Example 6 and Comparative Example 6) Whether or not the second surface of the light transmitting film (the second surface of the resin base in Examples 1 to 4 and Comparative Examples 1 and 2) is uneven or not. It evaluated by visual observation under 3 wavelength fluorescent lamp.
(Examples 1 to 4 and Comparative Examples 1 to 3)
Good: No unevenness was found on any of the first surface and the second surface of the light transmitting film, or some unevenness was confirmed, but at a level causing no problem in practical use.
X: Irregularities were clearly confirmed on both the first surface and the second surface of the light transmitting film.
(Examples 5 and 6 and Comparative Examples 4 to 6)
:: No unevenness was observed on the first surface of the light transmitting film, or some unevenness was observed but at a level causing no problem in practical use.
X: Irregularities were clearly confirmed on the first surface of the light transmitting film.

The results are shown in Table 1 below.

  The following describes the results. In the light transmitting film with protective film according to Comparative Examples 1 to 3, since the haze value of the first protective film and the haze value of the second protective film each exceeded 10%, the light transmitting property with the protective film is Irregularities were clearly confirmed on both the first surface and the second surface of the light transmitting film obtained by peeling the first protective film and the second protective film from the film. On the other hand, in the light transmitting film with protective film according to Examples 1 to 4, since the haze value of the first protective film and the haze value of the second protective film were respectively 10% or less, the light transmission was No unevenness was found on any of the first surface and the second surface of the sexing film, or some unevenness was found but at a level that causes no problem in practical use.

  In addition, in the light transmitting films with protective film according to Comparative Examples 4 to 6, since the haze value of the first protective film exceeded 10%, the light transmitting film with the protective film was changed to the first protective film. Unevenness was clearly confirmed on the first surface of the light transmitting film obtained by peeling. On the other hand, in the light transmitting film with protective film according to Examples 5 and 6, since the haze value of the first protective film was 10% or less, the first protective film from the light transmitting film with protective film was Irregularities were not observed on the first surface of the light transmitting film obtained by peeling the film, or some irregularities were observed but at a level at which there is no problem in practical use.

In the light transmitting films according to Examples 5 and 6, when the Martens hardness of the resin base, the first hard coat layer and the second hard coat was measured, the Martens hardness of the polyimide base was 300 MPa. The Martens hardness of the first hard coat layer was 830 MPa, and the Martens hardness of the second hard coat layer was 500 MPa. Martens hardness was measured using "TI950 TriboIndenter" manufactured by HYSITRON (Hyditron). Specifically, first, all protective films were peeled off from the light transmitting film with protective film cut out into 1 mm × 10 mm to obtain a light transmitting film alone. Then, a block in which the light transmitting film was embedded with the embedding resin was prepared, and from this block, a section having a thickness of 70 nm or more and 100 nm or less without a hole or the like was cut out by a general section manufacturing method. "Ultramicrotome EM UC7" (Leica Microsystems Inc.) was used for preparation of sections. And the remaining block from which the uniform section which did not have this hole etc. was cut out was made into the measurement sample. Next, in a cross section obtained by cutting out the above-mentioned section in such a measurement sample, using a Berkovich indenter (triangular pyramid) as an indenter, Berkovich indenter in the center of the cross section of each hard coat layer under the following measurement conditions After pressing (triangular pyramid) 500 nm and holding it for a certain time to relieve the residual stress, it is unloaded, and the maximum load after relaxation is measured, and the maximum load P _max (μN) and the depression 500 nm deep It calculated by _Pmax / A using area A (nm < ² >). Martens hardness was taken as the arithmetic mean value of the value obtained by measuring ten places. Further, the Martens hardness of the resin base was also measured in the same manner as the Martens hardness of the polyimide base.
(Measurement condition)
Loading speed: 10 nm / sec Holding time: 5 seconds Load unloading speed: 10 nm / sec Measurement temperature: 25 ° C.

10, 60, 80 ... Transparent film with protective film 20, 70, 90 ... Transparent film 20A, 70A, 90A ... First surface 20B, 70B, 90B ... Second surface 21 ... Resin base material 21A ... 1st surface 21B ... 2nd surface 30 ... 1st protective film 40 ... 2nd protective film

Claims (8)

A light transmitting film with a protective film, comprising: a foldable light transmitting film comprising at least a resin substrate; and a protective film releasably attached to at least one side of the light transmitting film,
The thickness of the protective film is 30 μm or more,
The light transmissive film with a protective film whose haze value of the said protective film is 10% or less.   The light transmitting film with a protective film according to claim 1, wherein the protective film is peelably attached to both sides of the light transmitting film.   The first surface of the resin substrate constitutes the first surface of the light transmitting film, and the protective film is peelably attached to the first surface of the resin substrate. The light transmissive film with a protective film as described in 1.   The light transmitting film with a protective film according to claim 1, wherein the light transmitting film further comprises a resin layer provided on at least one side of the resin substrate.   The light with a protective film according to claim 1, wherein the protective film comprises a base film made of a polyester resin, and an adhesive layer provided on the surface of the base film on the light transmitting film side. Permeable film.   The light transmitting film with a protective film according to claim 1, wherein the resin base is a base comprising a polyimide resin, a polyamide resin, or a mixture thereof.   The light transmitting film with a protective film according to claim 1, wherein the light transmitting film with a protective film is wound in a roll. It is a protective film which can be stuck on a foldable light transmission film provided with at least a resin base material,
The thickness of the protective film is 30 μm or more,
The protective film whose haze value of the said protective film is 10% or less.

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