JP2022048309A - Optically-transparent film with protective film, and protective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optically-transparent film with a protective film, which can give an optically-transparent film having excellent smoothness, and to provide a protective film.

SOLUTION: The present invention discloses an optically-transparent film 10 with a protective film, which includes a foldable, optically-transparent film 20 at least having a resin substrate 21, and a protective film 30 stuck to a surface 20A of the optically-transparent film 20 in a detachable manner. The protective film 30 has a thickness of 30 μm or more. The protective film 30 has a haze value of 10% or less, in the optically-transparent film 10.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

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

Conventionally, image display devices such as smartphones and tablet terminals have been known, but foldable image display devices are currently being developed. Normally, smartphones and tablet terminals are covered with a cover glass, but when a cover glass is used for the image display device,
Although it has excellent hardness, it is likely to crack when it is folded. Therefore, it has been studied to use a foldable optical film instead of the cover glass for the foldable image display device (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-125063

For the formation of such an optical film, a foldable light-transmitting film composed of only a resin base material or a foldable light composed of a resin base material and a resin layer laminated on at least one surface of the resin base material is used. A permeable film is used. The light-transmitting film is usually wound in a roll shape and pulled out at the time of use, but when the light-transmitting film is wound in a roll shape, the light-transmitting films stick to each other, which makes it difficult to pull out. become. again,
A light transmissive film provided with a resin substrate is easily scratched and expensive. For this reason, the protective film is often attached to at least one side of the light transmissive film. The protective film is releasably attached to the light-transmitting film and is peeled off when the light-transmitting film is processed.

The light-transmitting film is required to have excellent smoothness for the purpose of obtaining high transparency and improving the appearance, but it is wound up with a protective film attached to the light-transmitting film. Since the uneven shape of the surface of the protective film is transferred by applying pressure, there is a problem that unevenness appears on the surface of the resin base material when the protective film is peeled off from the light transmissive film. In particular, when the protective film is directly attached to the resin base material of the light-transmitting film, unevenness appears remarkably on the surface of the resin base material. If the light-transmitting film is treated at a high temperature, the unevenness on the surface of the light-transmitting film can be corrected, but it is inefficient, so 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 transmissive film with a protective film and a protective film capable of obtaining a light transmissive film having excellent smoothness.

According to one aspect of the present invention, light with a protective film comprising a foldable light-transmitting film comprising at least a resin substrate and a protective film detachably attached to at least one side of the light-transmitting film. It is a permeable film, and the thickness of the protective film is
A light transmissive film with a protective film having a haze value of 30 μm or more and a haze value of the protective film of 10% or less is provided.

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

In the light transmissive film with a protective film, the first surface of the resin base material forms the first surface of the light transmissive film, and the protective film is formed on the first surface of the resin base material. It may be attached 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 material.

In the light transmissive 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 light transmissive film side. May be good.

In the light transmissive film with a protective film, the resin base material may be a base material made of a polyimide resin, a polyamide resin, or a mixture thereof.

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

According to another aspect of the present invention, it is a protective film that can be attached to a foldable light transmissive film provided with at least a resin base material, the thickness of the protective film is 30 μm or more, and the haze of the protective film. A protective film having a value of 10% or less is provided.

According to one aspect and the other aspect of the present invention, it is possible to provide a light-transmitting film with a protective film and a protective film capable of obtaining a light-transmitting film having excellent smoothness.

It is a schematic block diagram of the light transmissive film with a protective film which concerns on embodiment. It is a figure which showed the state of the continuous folding test schematically. It is the figure which showed the state of the folding static test schematically. It is a schematic block diagram of the light transmissive film with another protective film which concerns on embodiment. It is a schematic block diagram of the light transmissive film with another 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 device which concerns on embodiment.

Hereinafter, the light transmissive film with a protective film and the protective film according to the embodiment of the present invention will be described with reference to the drawings. In the present specification, "film" and "sheet"
Terms such as are not distinguished from each other based solely on the difference in designation. Therefore, for example, "film" is used to include a member that is also called a sheet. Figure 1
Is a schematic configuration diagram of a light transmissive film with a protective film according to the present embodiment, FIG. 2 is a diagram schematically showing a state of a continuous folding test, and FIG. 3 is a diagram schematically showing a state of a folding static test. 4 and 5 are schematic configuration diagrams of another light transmissive film with a protective film according to the present embodiment.

<<< Light-transmitting film with protective film >>>
The light-transmitting film 10 with a protective film shown in FIG. 1 includes a foldable light-transmitting film 20 having at least a resin base material 21, and a first surface 20 of the light-transmitting film 20.
The first detachably attached to A (hereinafter, may be simply referred to as "surface 20A").
The protective film 30 (hereinafter, may be simply referred to as “protective film 30”) and the second surface 20B (hereinafter, simply “surface 20B” opposite to the first surface 20A of the light transmissive film 20). The second protective film 40 (which may be peelably attached to the protective film 40 (sometimes referred to as)).
Hereinafter, it may be simply referred to as "protective film 40". ) And. That is, in the light transmissive film 10 with a protective film shown in FIG. 1, the light transmissive film 20
Protective films 30 and 40 are provided on both sides of the above. The protective films 30 and 40 are both
As will be described later, the thickness is 30 μm or more and the haze value is 10% or less, which satisfies the requirements of the present invention. The light transmissive film with a protective film may not be provided with a 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 transmissive film. For example, the light transmissive film 10 with a protective film of FIG. 1 does not have to include the protective film 40 as long as it includes the protective film 30. Further, the light transmissive film 10 with a protective film may be wound in a roll shape.

The surface 20A of the light transmissive film 20 is the first surface 21A of the resin base material 21 (hereinafter, may be simply referred to as “surface 21A”). Further, since the light-transmitting film 20 shown in FIG. 1 is composed of only the resin base material 21, as will be described later, the surface 20B of the light-transmitting film 20 is the first surface of the resin base material 21. It is a second surface 21B (hereinafter, may be simply referred to as "surface 21B") on the opposite side of 21A. Therefore, in the light transmissive film 10 with a protective film, the protective film 30 is removably attached to the surface 21A of the resin base material 21, and the protective film 40 is peeled off from the surface 21B of the resin base material 21. It is pasted as possible. If the light-transmitting film is detachably attached to both sides of the light-transmitting film and the protective film is detachably attached to the surface of the resin substrate, at least one protective film is attached to one side of the resin substrate. It suffices as long as it is peelably attached, and it is not always necessary that both protective films are detachably attached to both sides of the resin base material.

<< Light-transmitting film >>
The light-transmitting film 20 is a film having light-transmitting property. As used herein, the "light-transmitting film" may be either an intermediate-stage film used in producing an optical film or an optical film as a finished product, as long as it is a film having light-transmitting property. .. The light transmissive film 20 shown in FIG. 1 is an intermediate stage film used when manufacturing the optical film 100. Further, "light transmittance" means a property of transmitting light, for example, a total light transmittance of 50% or more, preferably 70% or more, more preferably 80.
% Or more, particularly preferably 90% or more. The light transparency does not necessarily have to be transparent, but may be translucent.

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

The light-transmitting film 20 is foldable. Specifically, even when the light-transmitting film 20 is subjected to the folding test (continuous folding test) described below 100,000 times. It is preferable that the light transmissive film 20 does not crack or break, and it is more preferable that the light transmissive film 20 does not crack or break even when the continuous folding test is repeated 200,000 times. Even if you repeat it 1 million times
It is more preferable that the light transmissive film 20 does not crack or break. When the continuous folding test is repeated 100,000 times on the light-transmitting film 20, the light-transmitting film 2
If cracks or the like occur in 0, the foldability of the light transmissive film 20 becomes insufficient.

The continuous folding test is performed as follows. The continuous folding test of the light transmissive film 20 shall be performed with the protective films 30 and 40 peeled off. FIG. 2 (A)
As shown in the above, in the continuous folding test, first, the side portion 20C of the light transmissive film 20 and the side portion 20D facing the side portion 20C are fixed by the fixing portions 50 arranged in parallel. The light-transmitting film 20 may have any shape, but the light-transmitting film 20 in the continuous folding test is preferably a rectangle (for example, a rectangle of 30 mm × 100 mm). Further, as shown in FIG. 2A, the fixed portion 50 can be slidably moved in the horizontal direction.

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

By moving the fixing portion 50 as shown in FIGS. 2 (A) to 2 (C), the light transmissive film 2
0 can be folded 180 °. Further, a continuous folding test is performed so that the bent portion 20E of the light transmissive film 20 does not protrude from the lower end of the fixed portion 50, and the distance when the fixed portions 50 are closest to each other is controlled to 30 mm to transmit light. The distance between the two opposing sides of the sex film 20 can be 30 mm. In this case, the outer diameter of the bent portion 20E is regarded as 30 mm. Since the thickness of the light-transmitting film 20 is sufficiently smaller than the distance between the fixed portions 50 (30 mm), the result of the continuous folding test of the light-transmitting film 20 is that of the light-transmitting film 20. It can be considered that it is not affected by the difference in thickness. In the light transmissive film 20, the distance between the facing sides of the light transmissive film 20 is 180 ° so as to be 30 mm.
It is preferable that cracking or breakage does not occur when the folding test is repeated 100,000 times, but the distance between the opposite sides of the light transmissive film 20 is 20 mm, 15 mm, 10 mm, and 6 m.
It is more preferable that cracking or breaking does not occur when the continuous folding test of folding 180 ° so as to be m, 3 mm, or 2 mm is repeated 100,000 times (the smaller the distance between the sides, the more preferable).

In the light transmissive film 20, as shown in FIG. 3A, the light transmissive film 2
The side portion 20C of 0 and the side portion 20D facing the side portion 20C are fixed by fixed portions 55 arranged in parallel so that the distance between the side portion 20C and the side portion 20D is 30 mm, respectively, and light is transmitted. A folding static test was conducted in which the sex film 20 was allowed to stand at 70 ° C. for 240 hours in a folded state.
As shown in FIG. 3 (B), the folded state is released by removing the fixed portion 55 from the side portion 20D after the folding static test, and after 30 minutes at room temperature, the light transmitting film is formed on the light transmitting film 20. When the opening angle θ, which is the angle at which 20 naturally opens, is measured, it is preferable that the opening angle θ of the light transmissive film 20 is 100 ° or more. The larger the opening angle θ, the better the stability, and the maximum is 180 °. The light transmissive film 2
The folding static test of 0 shall be performed with the protective films 30 and 40 peeled off.

The haze value (total haze value) of the light transmissive film 20 is preferably 3% or less. When the haze value of the light transmissive film 20 is 3% or less, the surface 21A and the surface 21B of the resin base material 21 have less unevenness, and thus have better smoothness. The haze value of the light transmissive film 20 is obtained by peeling the protective films 30 and 40 from the light transmissive film 10 with a protective film cut into a size of 50 mm × 100 mm, and the light transmissive film 20.
JIS K713 using a haze meter (product name "HM-150", manufactured by Murakami Color Technology Research Institute Co., Ltd.) in a single state, without curls or wrinkles, and without fingerprints or dust.
It can be measured by a method according to 6: 2000. 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. As used herein, "measuring three times" means measuring three different points rather than measuring the same place three times. If the light transmissive film cannot be cut out to the above size, for example, the HM-150 has an inlet opening of 20 mmφ for measurement, so a sample size having a diameter of 21 mm or more is required. Therefore, 22 mm x 22 m
The light transmissive film may be appropriately cut out to a size of m or more. If the size of the light-transmitting film is small, the measurement points are set to three points by shifting the light source spot little by little or changing the angle within the range where the light source spot does not deviate. The haze value of the light transmissive film 20 is more preferably 2% or less and 1% or less (the smaller the value, the more preferable).

The total light transmittance of the light transmissive film 20 is preferably 85% or more. When the total light transmittance of the light transmissive film 20 is 85% or more, sufficient optical performance can be obtained. The total light transmittance is such that the protective films 30 and 40 are peeled off from the light transmitting film 10 with a protective film cut out to a size of 50 mm × 100 mm, and the light transmitting film 20 is in a single state without curls or wrinkles. And without fingerprints or dust, JIS K7361-1
: According to 1997, it can be measured using a haze meter (product name "HM-150", manufactured by Murakami Color Technology Laboratory Co., Ltd.). The total light transmittance of the light-transmitting film is an arithmetic mean value obtained by measuring three times for one light-transmitting film. If the light transmissive film cannot be cut out to the above size, for example, the HM-150 has an inlet opening of 20 mmφ for measurement, so a sample size having a diameter of 21 mm or more is required. Therefore, the light transmissive film may be appropriately cut into a size of 22 mm × 22 mm or more. If the size of the light-transmitting film is small, the measurement points are set to three points by shifting the light source spot little by little or changing the angle within the range where the light source spot does not deviate. Light transmissive film 2
The total light transmittance of 0 is more preferable in the order of 88% or more and 90% or more (the larger the value, the more preferable).

The light transmissive film 20 preferably has a yellow index (YI) of 15 or less. When the YI of the light-transmitting film 20 is 15 or less, the yellowness of the light-transmitting film 20 can be suppressed, and it can be applied to applications where transparency is required. Yellow Index (YI) is
A protective film from a light transmissive film 10 with a protective film cut into a size of 50 mm x 100 mm using a spectrophotometer (product name "UV-3100PC", manufactured by Shimadzu Corporation, light source: tungsten lamp and deuterium lamp). 30 and 40 are peeled off, and the chromaticity tristimulus values X, Y, and Z are calculated from the values measured in the state of the light transmissive film 20 alone according to the calculation formula described in JIS Z8722: 2009, and the tristimulus values X are calculated. , Y, Z to ASTM D19
It is a value calculated according to the arithmetic expression described in 25:1962. Light transmissive film 20
The upper limit of the yellow index (YI) of is more preferably less than 10 and less than 1.5 (the smaller the value, the more preferable).

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

The blue dye may be either a pigment or a dye, but for example, when the light transmissive film 20 is used in an organic light emitting diode display device, a dye having both light resistance and heat resistance is preferable. As the blue dye, polycyclic organic pigments, metal complex organic pigments, etc. have a lower degree of molecular tearing due to ultraviolet rays than the molecular dispersion of dyes and have significantly excellent light resistance, so that applications requiring light resistance, etc. More specifically, phthalocyanine-based organic pigments and the like are preferably mentioned. However, since the pigment disperses particles with respect to the solvent, transparency is hindered by particle scattering. Therefore, 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 important, it is preferable to use a dye that is molecularly dispersed with respect to the solvent as the blue dye.

The use of the light transmissive film 20 is not particularly limited, but the use of the light transmissive film 20 includes, for example, smartphones, tablet terminals, personal computers (PCs), and the like.
Examples include image display devices such as wearable terminals, digital signage, televisions, and car navigation systems.

The light-transmitting film 20 may be cut to a desired size, but may be in the form of a roll. 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 transmissive film 20 may be, for example, 2.8 inches or more and 500 inches or less. As used herein, the term "inch" means the length of the diagonal line when the optical film is square, the diameter when it is circular, and the minor axis when it is elliptical. It shall mean the average value of the sum of the major axis and the major axis. Here, when the optical film has a rectangular shape, the aspect ratio of the optical film when obtaining the inch is not particularly limited as long as there is no problem as a display screen of the image display device. For example, vertical: horizontal = 1: 1, 4: 3,
Examples include 16:10, 16: 9, 2: 1 and the like. However, the aspect ratio is not limited to this, especially in in-vehicle applications and digital signage, which are rich in design. If the size of the light transmissive film 20 is large, it is A5 size (148 mm × 21) from an arbitrary position.
After cutting out to 0 mm), it shall be cut out to the size of each measurement item.

<Resin base material>
The resin base material 21 is a base material made of resin. The thickness of the resin base material 21 is 10 μm or more and 10
It is preferably 0 μm or less. If the thickness of the resin base material 21 is 10 μm or more,
Curling can be suppressed, sufficient hardness can be obtained, and a light-transmitting film can be made into Rol.
Even in the case of manufacturing with l to Roll, wrinkles are less likely to occur and there is no risk of deterioration of the appearance. On the other hand, when the thickness of the resin base material 21 is 100 μm or less, the folding performance of the light-transmitting film is good, the requirements of the continuous folding test can be satisfied, and the weight of the light-transmitting film is reduced. Is preferable. For the thickness of the resin base material 21, a cross section of the resin base material 21 is photographed using a scanning electron microscope (SEM), and the resin base material 2 is shown in the image of the cross section.
The thickness of 1 is measured at 10 points and used as the arithmetic mean value of the thickness at the 10 points. The lower limit of the resin base material 21 is more preferably 20 μm or more, and the upper limit of the resin base material 21 is more preferably 80 μm or less.

Examples of the resin constituting the resin base material 21 include a polyimide resin, a polyamide-imide resin, a polyamide resin, and a mixture of two or more of these resins. Among these, not only is it less likely to crack or break in the continuous folding test, but it is also less likely to break.
Polyimide-based resin, polyamide-based resin, or these, from the viewpoint of having excellent hardness and transparency, excellent heat resistance, and being able to impart further excellent hardness and transparency by firing. Mixture of is preferred.

The polyimide-based resin is obtained by reacting a tetracarboxylic acid component with a diamine component. It is preferable to obtain polyamic acid by polymerization of a tetracarboxylic acid component and a diamine component and imidize it. The imidization may be performed by thermal imidization or chemical imidization. It can also be produced by a method in which thermal imidization and chemical imidization are used in combination. 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 contains an aromatic ring in at least one of a tetracarboxylic acid component and a diamine component.

As a specific example of the tetracarboxylic acid component, tetracarboxylic acid dianhydride is preferably used, and cyclohexanetetracarboxylic acid dianhydride, cyclopentanetetracarboxylic acid dianhydride, dicyclohexane-3,4,3', 4 '-Tetracarboxylic acid dianhydride, pyromellitic acid dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride, 2,2',
3,3'-Benzophenone tetracarboxylic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracarboxylic acid dianhydride, 2 , 2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2)
, 3-Dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) 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-hexafluoropropanedianhydride, 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-di) Carboxy) phenoxy] phenyl} propane dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4- [3- (1,2-dicarboxy) Phenoxy] phenyl} ketone dianhydride, 4,4'-bis [4- (1,2-dicarboxy) phenoxy] biphenyl dianhydride, 4,4'-bis [3- (1,2-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}
Sulfone dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl}
Sulfide dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfide dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic acid anhydride, 3,4'- (Hexafluoroisopropylidene) diphthalic acid anhydride, 3,3'-(hexafluoroisopropyridene) diphthalate anhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8 -Naphthalenetetracarboxylic acid dianhydride, 1, 2,
5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6 7
-Anthracene tetracarboxylic dianhydride, 1,2,7,8-phenanthrene tetracarboxylic dianhydride and the like can be mentioned. These can be used alone or in combination of two or more.

Specific examples of the diamine component include p-phenylenediamine, m-phenylenediamine, and the like.
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) benzene, 1,3-bis (4-)
Aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4
-Bis (4-aminophenoxy) benzene, 1,3-bis (3-aminobenzoyl) 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-ditrifluoromethylbenzyl) benzene, 2,6-bis (3-aminophenoxy) benzonitrile, 2,6-bis (3-aminophenoxy) pyridine, N, N'-bis (4-aminophenyl) Telephthalamide, 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-aminophenoxy) -3,3,3', 3'-tetramethyl-1 , 1'-Spirovinedan, 6,6'-Bis (4-aminophenoxy)-
3,3,3', 3'-tetramethyl-1,1'-spirobiindan, 1,3-bis (3-
Aminopropyl) tetramethyldisiloxane, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, 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-cyclohexanediamine, trans-1,4-bismethylene Cyclohexanediamine, 2,6-bis (aminomethyl) bicyclo [2,2,1] heptane, 2,5-bis (aminomethyl) bicyclo [2,2,1] heptane, and on the aromatic ring of the above diamine. Diamines in which some or all of the hydrogen atoms are substituted with a substituent selected from a fluoro group, a methyl group, a methoxy group, a trifluoromethyl group, or a trifluoromethoxy group can also be used. These can be used alone or in combination of two or more.

From the viewpoint of improving light transmission and rigidity, the polyimide-based resin contains an aromatic ring, and (i) a fluorine atom, (ii) an aliphatic ring, and (iii) an aromatic ring. A polyimide resin containing at least one selected from the group consisting of linking groups that cleave electron conjugation with each other is preferable. When the polyimide resin contains an aromatic ring, the orientation is increased and the rigidity is improved, but the transmittance tends to decrease depending on the absorption wavelength of the aromatic ring. When the polyimide resin (i) contains a fluorine atom, the light transmittance is improved from the point that it is possible to make it difficult for the electronic state in the polyimide skeleton to transfer charges. Further, when the polyimide resin contains (ii) an aliphatic ring, the light transmission is improved in that the transfer of charges in the skeleton can be inhibited by breaking the conjugation of π electrons in the polyimide skeleton. .. Furthermore, the polyimide resin is (i)
ii) π in the polyimide skeleton when it contains a linking group that cleaves the electron conjugation between aromatic rings.
Light transmission is improved from the point that the transfer of electric charge in the skeleton can be hindered by breaking the electron conjugate. Examples of the linking group for cleaving the electron conjugation between the aromatic rings include an ether bond, a thioether bond, a carbonyl bond, a thiocarbonyl bond, an amide bond, a sulfonyl bond, a sulfinyl bond, and a fluorine-substituted linking group. Examples thereof include a divalent linking group such as an alkylene group which may be used.

Among these, a polyimide-based resin containing an aromatic ring and containing a fluorine atom is preferably used from the viewpoint of improving light transmission and rigidity. The content ratio of fluorine atoms in the polyimide resin containing fluorine atoms is the ratio (F / C) of the number of fluorine atoms (F) and the number of carbon atoms (C) measured on the surface of the polyimide resin by X-ray photoelectron spectroscopy. ,
It 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 original heat resistance of the polyimide resin may decrease. Therefore, the ratio (F / C) of the number of fluorine atoms (F) to the number of carbon atoms (C). Is preferably 1 or less, and more preferably 0.8 or less. Here, the above ratio measured by X-ray photoelectron spectroscopy (XPS) is an X-ray photoelectron spectroscope (for example, Thermo Sc).
It can be obtained from the value of the atomic% of each atom measured using Theta Probe).

Further, the polyimide resin in which 70% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide resin are hydrogen atoms directly bonded to the aromatic ring improves the light transmission property.
Moreover, it is preferably used from the viewpoint of improving the rigidity. The ratio of the hydrogen atoms (number) directly bonded to the aromatic ring to the total hydrogen atoms (number) bonded to the carbon atoms contained in the polyimide resin is further preferably 80% or more, preferably 85% or more. Is more preferable. When 70% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are polyimides, which are hydrogen atoms directly bonded to the aromatic ring, even after undergoing a heating step in the atmosphere, for example, 2
Even if stretching is performed at 00 ° C or higher, the optical characteristics, especially the total light transmittance and the yellow index (Y)
It is preferable because there is little change in I). When 70% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide resin are polyimides, which are hydrogen atoms directly bonded to the aromatic ring, the reactivity with oxygen is low, so that the polyimide resin has a low reactivity. It is presumed that the chemical structure is difficult to change. A base material made of a polyimide resin utilizes its high heat resistance and is often used for devices that require a processing process involving heating, but 70% of hydrogen atoms bonded to carbon atoms contained in the polyimide resin are used. In the case of the polyimide resin which is a hydrogen atom directly bonded to the aromatic ring, it is not necessary to carry out these subsequent steps in an inert atmosphere in order to maintain transparency, so that the equipment cost and atmosphere are not required. There is an advantage that the cost for control can be suppressed. Here, among the total hydrogen atoms (number) bonded to the carbon atoms contained in the polyimide resin,
The ratio of hydrogen atoms (number) directly bonded to the aromatic ring can be determined by using high performance liquid chromatography, gas chromatograph mass spectrometer and NMR for the decomposition product of polyimide. For example, the sample is decomposed with an alkaline aqueous solution or supercritical methanol, the obtained decomposition product is separated by high performance liquid chromatography, and the qualitative analysis of each separated peak is performed by a gas chromatograph mass spectrometer, NMR, etc. The ratio of hydrogen atoms (number) directly bonded to the aromatic ring can be obtained from the total hydrogen atoms (number) contained in the polyimide by performing the test using high performance liquid chromatography and quantifying the amount.

In addition, as a polyimide resin, it is used as a polyimide resin because it improves light transmission and rigidity.
Above all, it is preferable to have at least one structure selected from the group consisting of the structures represented by the following general formula (1) and the following general formula (3).

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、ｔ
ｒａｎｓ－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, and R ² is t.
Lans-cyclohexanediamine residue, trans-1,4-bismethylenecyclohexanediamine residue, 4,4'-diaminodiphenylsulfone residue, 3,4'-diaminodiphenylsulfone residue, and the following general formula (2) Represents at least one divalent group selected from the group consisting of the represented divalent groups. n represents the number of repeating units and is 1 or more. As used herein, the term "tetracarboxylic acid residue" refers to a residue obtained by removing four carboxyl groups from a tetracarboxylic acid, and is a residue obtained by removing an acid dianhydride structure from a tetracarboxylic acid dianhydride. Represents the same structure. Further, the "diamine residue" means a residue obtained by removing two amino groups from a 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 independently represent a hydrogen atom, an alkyl group, or a perfluoroalkyl group, respectively.

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 (hexafluoroisopropyridene) ^diphthalic acid residues, R6 represents a divalent group which is a diamine residue.
n'represents the number of repeating units and is 1 or more.

In the above general formula (1), R ¹ is a tetracarboxylic dianhydride residue, and can be a residue obtained by removing the acid dianhydride structure from the tetracarboxylic dianhydride as exemplified above. The ^R1 in the above general formula (1) includes 4,4'-(hexafluoroisopropylidene) diphthalic acid residues, 3,3', from the viewpoint of improving light transmission and rigidity. 4,
4'-biphenyltetracarboxylic acid residue, pyromellitic acid residue, 2,3', 3,4'-biphenyltetracarboxylic acid residue, 3,3', 4,4'-benzophenone tetracarboxylic acid residue, Selected from the group consisting of 3,3', 4,4'-diphenylsulfone tetracarboxylic acid residues, 4,4'-oxydiphthalic acid residues, cyclohexanetetracarboxylic acid residues, and cyclopentanetetracarboxylic acid residues. It preferably contains at least one, and further
Selected from the group consisting of 4,4'-(hexafluoroisopropyridene) diphthalic acid residues, 4,4'-oxydiphthalic acid residues, and 3,3', 4,4'-diphenylsulfone tetracarboxylic acid residues. It is preferable to contain at least one of these.

In ^R1 , it is preferable to contain 50 mol% or more, more preferably 70 mol% or more, and further preferably 90 mol% or more of these suitable residues in total.

Further, as R ¹ , 3,3', 4,4'-biphenyltetracarboxylic acid residue, 3,3'
, 4,4'-Benzophenone tetracarboxylic acid residues, and tetracarboxylic acid residue groups suitable for improving rigidity such as at least one selected from the group consisting of pyromellitic acid residues (Group A). ) And 4,4'-(hexafluoroisopropyridene) diphthalic acid residue, 2,3', 3,4'-biphenyltetracarboxylic acid residue, 3,3', 4,4'-diphenylsulfone tetracarboxylic Suitable for improving transparency, such as at least one selected from the group consisting of acid residues, 4,4'-oxydiphthalic acid residues, cyclohexanetetracarboxylic acid residues, and cyclopentanetetracarboxylic acid residues. Tetracarboxylic acid residue group (
It is also preferable to use it in combination with Group B).

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
1 mol of tetracarboxylic acid residue group (group B) suitable for improving transparency, 0.05 mol of tetracarboxylic acid residue group (group A) suitable for improving rigidity. It is preferably 9 mol or more, more preferably 0.1 mol or more and 5 mol or less, and further preferably 0.3 mol or more and 4 mol or less.

The R ² in the above general formula (1) includes 4,4'-diaminodiphenyl sulfone residues and 3,4'-diaminodiphenyl sulfone residues from the viewpoint of improving light transmission and rigidity. , And at least one divalent group selected from the group consisting of the divalent group represented by the above general formula (2), and further, 4,4'-diaminodiphenyl sulfone residue, 3 , 4'-Diaminodiphenyl sulfone residue, and at least one divalent selected from the group consisting of a divalent group represented by the above general formula (2) in which R ³ and R ⁴ are perfluoroalkyl groups. It is preferable that it is a group of.

The R5 in the above general formula ( ³ ) includes 4,4'-(hexafluoroisopropylidene) diphthalic acid residues, 3,3', among others, from the viewpoint of improving light transmission and rigidity.
, 4,4'-Diphenyl sulfone tetracarboxylic acid residue, and oxydiphthalic acid residue are preferably contained.

^In R5, these suitable residues are preferably contained in an amount of 50 mol% or more, further 70.
It is preferably contained in an amount of mol% or more, and more preferably 90 mol% or more.

R6 in the above general formula ( ³ ) is a diamine residue, and can be a residue obtained by removing two amino groups from the diamine as exemplified above. Among the ^R6s in the above general formula (3), 2,2'-bis (trifluoromethyl) benzidine residue and bis [4- (4) are used from the viewpoint of improving light transmission and rigidity. -Aminophenoxy) phenyl] sulfone residue, 4,4'-diaminodiphenyl sulfone residue, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane residue, bis [4- (3- (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- (trifluoromethyl) diphenyl ether residue, 4,4'-Diaminobenzanilide residue,
N, N'-bis (4-aminophenyl) terephthalamide residue, and 9,9-bis (4-aminophenyl)
It preferably contains at least one divalent group selected from the group consisting of aminophenyl) fluorene residues, and further contains 2,2'-bis (trifluoromethyl) benzidine residues, bis [4- (4- (4- (4- (4- (4-) 4-). It preferably contains at least one divalent group selected from the group consisting of aminophenoxy) phenyl] sulfone residues and 4,4'-diaminodiphenyl sulfone residues.

^In R6, it is preferable to contain 50 mol% or more, more preferably 70 mol% or more, and further preferably 90 mol% or more of these suitable residues in total.

^In addition, as R6, a bis [4- (4-aminophenoxy) phenyl] sulfone residue, 4
, 4'-diaminobenzanilide residue, N, N'-bis (4-aminophenyl) terephthalamide residue, para-phenylenediamine residue, meta-phenylenediamine residue, and 4,
A group of diamine residues (Group C) suitable for improving rigidity, such as at least one selected from the group consisting of 4'-diaminodiphenylmethane residues, and 2,2'-bis (trifluoromethyl). Benzidine 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- (trifluoromethyl) diphenyl ether residue, and 9,9-bis (
It is also preferable to use a mixture with a group of diamine residues (Group D) suitable for improving transparency, such as at least one selected from the group consisting of 4-aminophenyl) fluorene residues.

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. The amount of the diamine residue group (group C) suitable for improving the rigidity is 0.05 mol or more and 9 mol or less with respect to 1 mol of the diamine residue group (group D) suitable for the preparation. It is preferable, more preferably 0.1 mol or more and 5 mol or less, and more preferably 0.3 mol or more and 4 mol or less.

In the structures represented by the general formula (1) and the general formula (3), n and n'independently represent the number of repeating units and are 1 or more. The number of repeating units n in the polyimide may be appropriately selected depending on 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 2000, and an additional 15
It is preferably ~ 1000.

Further, the polyimide-based resin may contain a polyamide structure as a part thereof. Examples of the polyamide structure that may be contained include a polyamide-imide structure containing a tricarboxylic acid residue such as trimellitic acid 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, from the viewpoint of ease of stretching and reduction of baking temperature, the glass transition temperature is preferably 400 ° C. or lower, and more preferably 380 ° C. or lower.

Specifically, examples of the polyimide-based resin include compounds having a structure represented by the following formula. In the following formula, n is a repeating unit and represents an integer of 2 or more.

Polyamide-based resin is a concept including not only aliphatic polyamide but also aromatic polyamide (aramid). Examples of the polyamide-based resin include compounds having a skeleton represented by the following formulas (21) to (23). In the following formula, n is a repeating unit and 2
Represents the above integers.

As the substrate made of the polyimide resin or the polyamide resin represented by the above formulas (4) to (20) and (23), commercially available ones may be used. Examples of commercially available products of the base material made of the polyimide resin include Neoprim manufactured by Mitsubishi Gas Chemical Company, Inc., and examples of the commercially available product of the base material made of the above-mentioned polyamide resin include those manufactured by Toray Industries, Inc. Examples include Mictron.

Further, as the polyimide-based resin or the polyamide-based resin represented by the above formulas (4) to (20) and (23), those synthesized by a known method may be used. For example, the above equation (4)
The method for synthesizing the polyimide resin represented by the above is described in JP-A-2009-132091, and specifically, 4,4'-hexafluoropropyridenebis phthalic acid dianhydride represented by the following formula (24). It can be obtained by reacting anhydrate (FPA) with 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (TFDB).

The weight average molecular weight of the polyimide resin or the polyamide resin is 3000 or more and 50.
It is preferably in the range of 10,000 or less, more preferably in the range of 5,000 to 300,000, and even more preferably in the range of 10,000 or more and 200,000 or less. If the weight average molecular weight is less than 3000, sufficient strength may not be obtained, and if it exceeds 500,000, the viscosity increases and the solubility decreases, so that a substrate having a smooth surface and a uniform film thickness is used. It may not be obtained. In the present specification, the "weight average molecular weight" is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

Among the above-mentioned polyimide-based resins and polyamide-based resins, polyimide-based resins or polyamide-based resins having a structure in which charge transfer within or between molecules is unlikely to occur are preferable because they have excellent transparency. Fluorinated polyimide-based resins such as the above formulas (4) to (11), polyimide-based resins having an alicyclic structure such as the above formulas (13) to (16), and polyamide-based resins having a halogen group such as the above formula (23). Resin is mentioned.

Further, the fluorinated polyimide resins of the above formulas (4) to (11) have high heat resistance because they have a fluorinated structure, and the heat at the time of manufacturing the base material made of the polyimide resin is high. It has excellent transparency because it is not colored by.

The resin base material 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) from the viewpoint of being able to improve the hardness. It is preferable to use a base material made of. Above all, from the viewpoint of further improving the hardness, it is more preferable to use a base material made of a polyimide resin represented by the above formula (4).

<< First protective film >>
The protective film 30 is attached to the surface 21A of the resin base material 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 material 21. When the light transmissive film 10 with a protective film is shipped, the curl of the light transmissive film 10 with a protective film is suppressed.
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 handleability at the time of peeling and ease of cutting.

The haze value (total haze value) of the protective film 30 is 10% or less. When the haze value of the protective film 30 is 10% or less, the 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 transmissive film 10 with a protective film cut into a size of 50 mm × 100 mm, and the protective film 30 is in a single state without curls or wrinkles. Haze meter (product name "HM") without fingerprints or dust
-150 ”, manufactured by Murakami Color Technology Laboratory Co., Ltd.) can be measured from the base film 31 side of the protective film 30 by a method conforming to JIS K7136: 2000. The haze value of the protective film 30 is an arithmetic mean value obtained by measuring the protective film 30 three times. If the protective film cannot be cut out to the above size, for example, H
Since the inlet opening of M-150 at the time of measurement is 20 mmφ, a sample size having a diameter of 21 mm or more is required. Therefore, the protective film may be appropriately cut out to a size of 22 mm × 22 mm or more. If the size of the protective film is small, shift the light source spot little by little or change the angle so that the measurement points are set to three points. The haze value of the protective film 30 is more preferably 5% or less, in the order of 3% or less (the smaller the value, the more preferable). In the present specification, the mere "haze value" means the total haze value, 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 of the protective film 30 in contact with the surface 21A of the resin base material 21 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 obtained using a haze meter (product name "HM-150", manufactured by Murakami Color Technology Laboratory Co., Ltd.). Specifically, first, the haze value (total haze value) of the protective film 30 is obtained according to the above-mentioned method for measuring the total haze value. after that,
The film thickness is 25 μm on the surface of the protective film 30 that was in contact with the surface 21A of the resin base material 21.
A triacetyl cellulose substrate (product name "TD60UL", manufactured by FUJIFILM Corporation) having a thickness of 60 μm is attached via a transparent optical adhesive layer (product name "Panaclean PD-S1", manufactured by PANAC Co., Ltd.). .. As a result, the uneven 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 obtained by measuring the haze value by the same method as the above-mentioned method for measuring the total haze value, and the external haze value is obtained by subtracting the internal haze from the total haze value. The external haze value of the protective film 30 is more preferably 5% or less, in the order of 3% or less (the smaller the 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 side of the resin base material 21. The protective film 30 shown in FIG. 1 includes an adhesive layer 32, but depending on the protective film, it may not be provided with the adhesive layer.

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

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 material 21. When the light transmissive film 10 with a protective film is transported or shipped, the thickness of the base film 31 is preferably 50 μm or more in order to suppress curl of the light transmissive 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 handleability at the time of peeling and ease of cutting.

<Adhesive layer>
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 32 is not particularly limited as long as it has a desired adhesiveness, and a general pressure-sensitive adhesive used for a protective film can be used. Examples of such a pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, and a mixture thereof. Among these, an acrylic pressure-sensitive adhesive is preferable because it is easy to adjust an appropriate adhesion.

The film thickness of the adhesive layer 32 is preferably 1 μm or more and 50 μm or less. Adhesive layer 3
If the film thickness of 2 is 1 μm or more, the protective film 30 can be reliably attached to the resin base material 21, and if the film thickness of the adhesive layer 32 is 50 μm or less, the surface of the adhesive layer 32 is smoothed. This makes it possible to suppress the so-called crying separation 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 material 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
It is more preferably 30 μm or less.

<< Second protective film >>
The protective film 40 is attached to the surface 21B of the resin base material 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 material 21. When the light transmissive film 10 with a protective film is transported or shipped, the thickness of the protective film 40 is preferably 50 μm or more in order to suppress curl of the light transmissive film 10 with a protective film. The upper limit of the thickness of the protective film 40 is preferably 250 μm or less from the viewpoint of handleability at the time of peeling and ease of cutting.

The thickness of the protective film 40 may be different from the thickness of the protective film 30. The curl can be adjusted by changing the thickness of the protective film 30 and the protective film 40.

The haze value (total haze value) of the protective film 40 is 10% or less. When the haze value of the protective film 40 is 10% or less, the unevenness on the surface 20B of the light transmissive film 20 is reduced, and the light transmissive film 20 having more excellent smoothness can be obtained. The haze value of the protective film 40 is such that the protective film 40 is peeled off from the light transmissive film 10 with the protective film cut out to a size of 50 mm × 100 mm, and the haze meter (product name “HM-150”) is used as the protective film 40 alone. , Manufactured by Murakami Color Technology Laboratory Co., Ltd.), and can be measured by a method compliant with JIS K7136: 2000. The haze value of the protective film 40 is an arithmetic mean value obtained by measuring the protective film 40 three times. If the protective film cannot be cut out to the above size, for example, HM-15.
Since 0 has an inlet opening of 20 mmφ for measurement, a sample size having a diameter of 21 mm or more is required. Therefore, the protective film may be appropriately cut out to a size of 22 mm × 22 mm or more. If the size of the protective film is small, shift the light source spot little by little or change the angle so that the measurement points are set to three points. The haze value of the protective film 40 is more preferably 5% or less, in the order of 3% or less (the smaller the value, the more preferable).

Since the total haze value of the protective film 40 is 10% or less, the external haze on the surface of the protective film 40 in contact with the surface 20B of the light transmissive film 20 is also 10%.
It is as follows. The external haze value of the protective film 40 can be obtained by the same method as the external haze value of the protective film 30. The external haze value of the protective film 40 is 5%.
Hereinafter, it is more preferable in the order of 3% or less (the smaller the 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 side of the resin base material 21.

<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 thereof will be omitted here.

<<< Light-transmitting film with other protective film >>>
The light transmissive film 10 with a protective film shown in FIG. 1 includes a protective film 30 attached to the surface 21A of the resin base material 21 and a 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 transmissive film.

The light transmissive film 60 with a protective film shown in FIG. 4 has a resin base material 21 and a resin layer 71.
A foldable light-transmitting film 70 comprising the And have. In FIG. 4, the protective film is not provided on the second surface 70B side of the light transmissive film 70, but the protective film is removably attached to the first surface 70A of the light transmissive film 70. In addition to 30, the second light-transmitting film 70
A protective film similar to the protective film 40 may be detachably attached to the surface 70B of the surface 70B. In FIG. 4, the members having the same reference numerals as those in FIG. 1 are the same as the members shown in FIG. 1, so the description thereof will be omitted except for the following.

The surface 70A of the light transmissive film 70 is the first surface 21A of the resin base material 21. Therefore, in the light transmissive film 60 with a protective film, the protective film 30 is removably attached to the surface 21A of the resin base material 21. Further, since the light transmissive film 70 shown in FIG. 4 includes the resin layer 71 in addition to the resin base material 21, the second surface 70B of the light transmissive film 70 (hereinafter, simply referred to as “surface 70B”). (Sometimes referred to as) is the surface 71A of the resin layer 71 opposite to the surface of the resin base material 21 side.

Further, in the light transmissive film 10 with a protective film shown in FIG. 1, the protective film 30 is detachably attached to the surface 21A of the resin base material 21, but the protective film is as shown in FIG. It may be detachably attached to the surface of the resin layer.

The light transmissive film 80 with a protective film shown in FIG. 5 has a resin base material 21 and a resin base material 2.
A foldable light-transmitting film 9 having resin layers 91 and 92 provided on both sides of 1.
0 and a protective film 30 detachably attached to the first surface 90A of the light transmissive film 90 (hereinafter, may be simply referred to as “surface 90A”) are provided. In FIG. 5, the protective film is not provided on the second surface 90B side of the light transmissive film 90, but the protective film is removably attached to the first surface 90A of the light transmissive film 90. In addition to 30, a protective film similar to the protective film 40 may be detachably attached to the second surface 90B of the light transmissive film 90. In FIG. 5, the members having the same reference numerals as those in FIG. 1 are the same as the members shown in FIG. 1, so the description thereof will be omitted except for the following.

The surface 90A of the light transmissive film 90 is the surface 91A of the resin layer 91. Therefore, in the light transmissive film 90 with the protective film, the protective film 30 is the resin layer 9.
It is detachably attached to the surface 91A of 1. Further, the surface 9 of the light transmissive film 90
0B is the surface 92A of the resin layer 92.

<< Light-transmitting film >>
The light transmissive films 70 and 90 are foldable. Specifically, even when the folding test (continuous folding test) described above is repeated 100,000 times on the light transmitting films 70 and 90, the light transmitting films 70 and 90 are cracked or broken. It is preferable that it does not occur, and even when the continuous folding test is repeated 300,000 times, it is more preferable that the light transmissive films 70 and 90 do not crack or break, and when the continuous folding test is repeated 1 million times. However, it is more preferable that the light transmissive films 70 and 90 do not crack or break. The continuous folding test may be performed so as to fold the light-transmitting films 70 and 90 so that the resin layers 71 and 92 are on the inside, and the light-transmitting film 70 so 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 transmissive films 70 and 90 do not crack or break.
Since the conditions of the continuous folding test are the same as the conditions of the continuous folding test described in the column of the light transmissive film 20, the description thereof will be omitted.

The light-transmitting films 70 and 90 are also subjected to the folding static test described above, and then the folded state is opened and the opening angle is measured.
, 90 preferably has an opening angle θ of 100 ° or more. The conditions of the folding static test are the same as the conditions of the folding static test described in the column of the light transmissive film 20, and the measurement conditions of the opening angle are also the measurement of the opening angle described in the column of the light transmissive film 20. Since it is the same as the condition, the description will be omitted.

The haze value (total haze value) of the light transmissive films 70 and 90 is preferably 3% or less. When the haze value of the light-transmitting film 20 is 3% or less, the surfaces 70A and 90A of the light-transmitting films 70 and 90 have less unevenness and have excellent smoothness. Since the measurement conditions for the haze value are the same as the measurement conditions for the haze value described in the column of the light transmissive film 20, the description thereof will be omitted here. The haze value of the light transmissive films 70 and 90 is 2% or less, 1
It is more preferable in the order of% or less (the smaller the value, the more preferable).

The total light transmittance of the light-transmitting films 70 and 90 is preferably 85% or more. When 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 for the total light transmittance are the same as the measurement conditions for the total light transmittance described in the column of the light transmittance film 20, the description thereof will be omitted here. Light transmissive film 70
The total light transmittance of is more preferable in the order of 88% or more and 90% or more (the larger the value, the more preferable).

The light transmissive films 70 and 90 preferably have a yellow index (YI) of 15 or less. When the YI of the light-transmitting films 70 and 90 is 15 or less, the yellowness of the light-transmitting film 70 can be suppressed, and the film can be applied to applications requiring transparency. Since the measurement conditions for the yellow index are the same as the measurement conditions for the yellow index described in the column of the light transmissive film 20, the description thereof will be omitted here. The upper limit of the yellow index (YI) of the light transmissive film 70 is more preferably less than 10 and less than 1.5 (smaller numerical values are more preferable).

<< Resin layer >>
The resin layers 71, 91, and 92 are layers made of resin. The resin layers 71 and 92 are
It is laminated on the surface 21B of the resin base material 21, and the resin layer 91 is laminated on the surface 21A of the resin base material 21. When the protective film is attached to the surface of the resin layer as in the resin layer 91, the thinner the film thickness of the resin layer, the more uneven the surface of the resin layer is likely to appear 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, and 200 nm or less (the smaller the value, the more). Especially effective).

The resin layers 71, 91, and 92 may contain particles, additives, and the like in addition to the resin. Resin layer 7
Examples of 1 and 92 include a hard coat layer and a shock absorbing layer. Examples of the resin layer 91 include a base layer and the like. The resin layers 71, 91, and 92 may be a single layer or may have a multi-layer structure.

<Hard coat layer>
The hard coat layer means a layer having light transmittance and having a martensity hardness higher than that of the resin substrate. In the present specification, "Martens hardness" means
It is the hardness when the indenter is pushed in by 500 nm by the hardness measurement by the nanoindentation method. The measurement of Martens hardness by the above nanoindentation method is performed by HYSITRO.
It shall be performed using "TI950 TriboIndenter" manufactured by N (Heiditron). Specifically, first, all the protective films are peeled off from the light-transmitting film with a protective film cut into 1 mm × 10 mm to obtain a light-transmitting film alone. Then, a block in which this light-transmitting film is embedded with an embedding resin is prepared, and a uniform section having a thickness of 70 nm or more and 100 nm or less without holes or the like is cut out from this block by a general section preparation method. "Ultra Microtome EM UC7" (Leica Microsystems, Inc.) or the like can be used for preparing the sections. Then, the remaining block from which a uniform section having no holes or the like is cut out is used as a measurement sample. Then, in the cross section obtained by cutting out the above-mentioned section in such a measurement sample, under the following measurement conditions,
As the indenter, a Berkovich indenter (triangular pyramid) is placed in the center of the cross section of the hardcourt layer, 50.
After pushing in 0 nm and holding for a certain period of time to relax the residual stress, the load is unloaded, the maximum load after relaxation is measured, and the maximum load P _max (μN) and the recess area A (nm ² ) with a depth of 500 nm are measured.
) And P _max / A to calculate the Martens hardness. Martens hardness is 10
It shall be the arithmetic mean value of the value obtained by measuring the location. The Martens hardness of the resin base material 21 shall also be measured by the same method as described above.
(Measurement condition)
・ Load speed: 10 nm / sec ・ Holding time: 5 seconds ・ Load unloading speed: 10 nm / sec ・ Measurement temperature: 25 ° C

The film 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 decrease, and if it exceeds 20 μm, the workability may deteriorate due to the excessive thickness. In the present specification, the "thickness of the hard coat layer" means the total film thickness (total thickness) of the hard coat layers when the hard coat layer has a multi-layer structure. do. The upper limit of the hard coat layer is more preferably 15 μm or less, further preferably 10 μm or less.

For the film thickness of the hard coat layer, a 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 is measured in the image of the cross section. Measure at 10 points and use the arithmetic average value of the film thickness at those 10 points. A specific method for taking a cross-sectional photograph is described below. First, all the protective films are peeled off from the light-transmitting film with a protective film cut into 1 mm × 10 mm to obtain a single light-transmitting film. Then, a block in which this light-transmitting film is embedded with an embedding resin is produced, and a uniform thickness of 70 nm or more and 100 n without holes or the like is produced from this block by a general section forming method.
Cut out a section of m or less. For preparation of sections, "Ultra Microtome EM UC7" (
Leica Microsystems, Inc.) and the like can be used. Then, a uniform section having no holes or the like is used as a measurement sample. Then, 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). When taking this cross-sectional photograph, the detector is "TE" and the acceleration voltage is 30k.
Cross-section observation is performed with V and emission set to "10 μA". Regarding the magnification, adjust the focus and observe whether each layer can distinguish the contrast and brightness from 5000 times to 20 times.
Adjust appropriately at 10,000 times. The preferred magnification is 10,000 to 100,000 times, and the more preferable magnification is 10,000 to 100,000.
It is 50,000 times, and the most preferable magnification is 25,000 to 50,000 times. When taking a cross-sectional photograph, the aperture was set to the beam monitor aperture 3, the objective lens aperture was set to 3, and W. D. May be 8 mm. When measuring the film thickness of the hard coat layer, it is important that the interfacial contrast between the hard coat layer and another layer (for example, a resin base material) can be observed as clearly as possible when observing the cross section. If this interface is difficult to see due to insufficient contrast, dyeing treatment such as osmium tetroxide, ruthenium tetroxide, and phosphotungstic acid makes it easier to see the interface between the organic layers, and the dyeing treatment may be performed. In addition, the contrast at the interface may be difficult to understand when the magnification is high. In that case, observe the low magnification at the same time. For example, observe at two magnifications, high and low, such as 25,000 times and 50,000 times, and 50,000 times and 100,000 times, obtain the above-mentioned arithmetic mean value at both magnifications, and further calculate the average value for the hardcourt layer. The value of the film thickness of.

The hardcourt layer may have a single-layer structure, but is preferably a multi-layer structure having two or more layers from the viewpoint of improving 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 material than the second hard coat layer.

(First hard coat layer)
The first hard coat layer is mainly a layer for imparting hardness to the light-transmitting film. The first hardcoat layer has a Martens hardness of 50 at the center of the cross section of the first hardcoat layer.
It is preferably 0 MPa or more and 2000 MPa or less. If it is less than 500 MPa, the hardness of the hard coat layer may be insufficient, and if it exceeds 2000 MPa, the folding performance of the light transmissive 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 1500 M.
It is preferably Pa or less.

It is preferable that the maltens hardness of the first hard coat layer is larger than the maltens hardness of the second hard coat layer. By having such a relationship of Martens hardness, the light-transmitting film has a 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 pushed into the light-transmitting film, the deformation of the light-transmitting film is suppressed and the deformation of scratches and dents is reduced. Because. As a method of making the maltens hardness of the first hard coat layer larger than the maltens hardness of the second hard coat layer,
For example, a method of controlling the content of the inorganic particles described later to be contained more on the first hard coat layer side can be mentioned. When the hard coat layer has a single layer structure, the inorganic particles are unevenly distributed on the base film side in the hard coat layer, that is, the abundance ratio of the inorganic particles in the hard coat layer is on the resin base material side. It is preferable that the resin substrate is larger and is inclined so as to be smaller toward the surface side of the resin substrate.

The first hardcoat layer contains a resin. The first hardcoat layer preferably further contains inorganic particles dispersed in the resin.

The resin contains a polymer (cured product) of a polymerizable compound (curable compound). The polymerizable compound is
It has at least one polymerizable functional group in the molecule. Examples of the polymerizable functional group include ethylenically unsaturated groups such as (meth) acryloyl group, vinyl group and allylic group. The "(meth) acryloyl group" means to include both "acryloyl group" and "methacryloyl group".

As the polymerizable compound, polyfunctional (meth) acrylate is preferable. The above polysensitivity (meta)
Examples of the acrylate include trimethyl propanetri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol. Tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylol propanetri (meth) acrylate, ditrimethylol propanetetra ( Meta) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tetrapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate Meta) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, diglycerin tetra (meth) acrylate, adamantyldi (meth)
Examples include acrylates, isoboronyldi (meth) acrylates, dicyclopentanedi (meth) acrylates, tricyclodecandi (meth) acrylates, ditrimethylolpropane tetra (meth) acrylates, and those modified with PO, EO, caprolactone, etc. Be done.

Among these, those having 3 to 6 functionalities are preferable because they can preferably satisfy the above-mentioned Martens hardness, and for example, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and pentaerythritol tetraacrylate (PETTA) are preferable. , Dipentaerythritol pentaacrylate (DPPA), trimethylolpropane tri (meth) acrylate, tripentaerythritol octa (meth)
Acrylate, tetrapentaerythritol deca (meth) acrylate and the like are preferable. In addition, in this specification, (meth) acrylate means acrylate and methacrylate.

In addition, a monofunctional (meth) acrylate monomer may be further contained in order to adjust the hardness and the viscosity of the composition, improve the adhesion, and the like. Examples of the monofunctional (meth) acrylate monomer include hydroxyethyl acrylate (HEA), glycidyl methacrylate, methoxypolyethylene glycol (meth) acrylate, isostearyl (meth) acrylate, 2-acryloyloxyethyl succinate, acryloyl morpholine, and N. -Acryloyloxyethyl hexahydrophthalimide, cyclohexyl acrylate, tetrahydrofuryl acrylate, isobornyl acrylate, phenoxyethyl acrylate,
And adamantane acrylate and the like.

The weight average molecular weight of the monomer is preferably less than 1000, more preferably 200 or more and 800 or less, from the viewpoint of improving the hardness of the resin layer. The weight average molecular weight of the polymerizable oligomer is preferably 1000 or more and 20,000 or less, more preferably 1000 or more and 10,000 or less, and further preferably 2000 or more and 7,000 or less.

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

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

The reactive silica particles are not particularly limited, and conventionally known particles can be used.
For example, reactive silica particles described in JP-A-2008-165040 and the like can be mentioned. As a commercially available product of the above-mentioned reactive silica particles, for example, a MIB manufactured by Nissan Chemical Industries, Ltd.
Examples thereof include K-SD, MIBK-SDMS, MIBK-SDL, MIBK-SDZL, V8802 and V8803 manufactured by JGC Catalysts and Chemicals Co., Ltd.

Further, the silica particles may be spherical silica particles, but are preferably irregularly shaped silica particles. Spherical silica particles and irregularly shaped silica particles may be mixed. The term "spherical silica particles" as used herein means, for example, silica particles such as a true sphere and an elliptical sphere.
Further, the "deformed silica particles" mean silica particles having a potato-like shape (aspect ratio of 1.2 or more and 40 or less at the time of cross-sectional observation) having random irregularities on the surface. Since the surface area of the deformed silica particles is larger than that of the spherical silica particles, the inclusion of such deformed silica particles increases the contact area with the polyfunctional (meth) acrylate and the like, and the hard coat. The hardness of the layer can be improved. Whether or not the silica particles contained in the hard coat layer are irregular silica particles is determined by examining the cross section of the hard coat layer with a transmission electron microscope (T).
It can be confirmed by observing with an EM) or a scanning transmission electron microscope (STEM).

The average particle size of the silica particles is preferably 5 nm or more and 200 nm or less. 5
If it is less than nm, it becomes difficult to manufacture the particles themselves, the particles may agglomerate with each other, and it may be extremely difficult to make the particles into irregular shapes. At the stage, the dispersibility of the irregularly shaped silica particles may be poor and aggregated. On the other hand, if the average particle size of the deformed silica particles exceeds 200 nm, large irregularities may be formed on the hard coat layer, or 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 size of 20 particles is measured and used as the arithmetic average value of the particle size of 20 particles. When the silica particles are irregularly shaped silica particles, the average particle size of the silica particles is an image of a cross section of the hard coat layer taken with 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 circumference of the particle are measured from, and the particle size is calculated by averaging.
It is the arithmetic mean value of the particle size of each particle.

By controlling the size and blending amount of the inorganic particles, the hardness (martence hardness) of the first hard coat layer can be controlled. For example, when forming the first hard coat layer, the silica particles have a diameter of 5 nm or more and 200 nm or less, preferably 25 to 60 parts by mass with respect to 100 parts by mass of the polymerizable compound.

(Second hard coat layer)
The second hardcourt layer is a layer for satisfying the above-mentioned continuous folding test. The second hardcoat layer has a Martens hardness of 37 at the center of the cross section of the second hardcoat layer.
It is preferably 5 MPa or more and 1500 MPa or less. If it is less than 375 MPa, the scratch resistance of the hard coat layer may be insufficient, and if it exceeds 1500 MPa, the folding resistance of the resin base material may be insufficient and the above-mentioned continuous folding test may not be satisfied. be. 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 hardcoat layer contains a resin. The second hardcoat layer may further contain inorganic particles dispersed in the resin.

The resin contains a polymer (cured product) of a polymerizable compound (curable compound). As the polymerizable compound, polyfunctional (meth) acrylate is preferable. Examples of the polyfunctional (meth) acrylate include the same as the polyfunctional (meth) acrylate in the column of the first hard coat layer. Further, the second hard coat layer may contain a polyfunctional urethane (meth) acrylate and / or a polyfunctional epoxy (meth) acrylate in addition to the above-mentioned polyfunctional (meth) acrylate.

Examples of the inorganic particles include those similar to the inorganic particles in the column of the first hard coat layer.
The content of the inorganic particles in the second hard coat layer is not particularly limited, but is preferably 0 to 50% by mass with respect to the second hard coat layer, for example.

At least one of the first hard coat layer and the second hard coat layer may contain a material other than the above-mentioned material as long as the above-mentioned Martens hardness is satisfied, and for example, as a material of the resin component, as a material of the resin component. It may contain a polymerizable monomer, a polymerizable oligomer, or the like that forms a cured product by irradiation with ionizing radiation. Examples of the polymerizable monomer or the polymerizable oligomer include a (meth) acrylate monomer having a radically polymerizable unsaturated group in the molecule.
Alternatively, a (meth) acrylate oligomer having a radically polymerizable unsaturated group in the molecule can be mentioned. A (meth) acrylate monomer having a radically polymerizable unsaturated group in the molecule,
Alternatively, examples of the (meth) acrylate oligomer having a radically polymerizable unsaturated group in the molecule include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, and polyfluoroalkyl. Examples thereof include monomers or oligomers such as (meth) acrylate and silicone (meth) acrylate. These polymerizable monomers or polymerizable oligomers may be used alone or in combination of two or more. Of these, urethane (meth) acrylates that are polyfunctional (six or more functional) and have a weight average molecular weight of 1,000 to 10,000 are preferable.

The hardcoat layer (at least one of the first hardcoat layer and the second hardcoat layer) may further contain an ultraviolet absorber, a spectral transmittance adjuster, and / or an antifouling agent.

(UV absorber)
The resin base material is particularly preferably used for mobile terminals such as foldable smartphones and tablet terminals, but such mobile terminals are often used outdoors, and therefore, the resin base material is closer to the display element side than the resin base material. There is a problem that the arranged polarizing elements are easily deteriorated by being exposed to ultraviolet rays. However, since the resin layer is arranged on the display screen side of the polarizing element, if the resin layer contains an ultraviolet absorber, deterioration due to exposure of the polarizing element to ultraviolet rays can be suitably prevented. The ultraviolet absorber (UVA) may be contained in the resin base material 21. In this case, the ultraviolet absorber (UVA) may not be contained in the hardcoat layer.

Examples of the ultraviolet absorber include a triazine-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, and the like.

Examples of the triazine-based ultraviolet absorber include 2- (2-hydroxy-4- [1-].
Octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine, 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-tridecyloxypropyl) 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 and the like can be mentioned. .. As a commercially available triazine-based ultraviolet absorber, for example, TINUVIN46
0, TINUVIN477 (all manufactured by BASF), LA-46 (manufactured by ADEKA)
And so on.

Examples of the benzophenone-based ultraviolet absorber include 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2', 4,4'-tetrahydroxy. Examples thereof include benzophenone, 2-hydroxy-4-methoxybenzophenone, hydroxymethoxybenzophenone sulfonic acid and its trihydrate, sodium hydroxymethoxybenzophenone sulfonate and the like.
Examples of commercially available benzophenone-based ultraviolet absorbers include CHMASSORB8.
1 / FL (manufactured by BASF) and the like can be mentioned.

Examples of the benzotriazole-based ultraviolet absorber include 2-ethylhexyl-3-.
[3-tert-Butyl-4-hydroxy-5- (5-chloro-2H-benzotriazole-2-yl) phenyl] propionate, 2- (2H-benzotriazole-2-yl) -6- (straight chain and Side chain dodecyl) -4-methylphenol, 2- [5-chloro (2H)
-Benzotriazole-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- (2H-benzotriazole-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''-Tetrahydrophthalimidemethyl) -5'-Methylphenyl) Benzotriazole, 2,2-Methylenebis (4- (1,1,3,3-Tetramethylbutyl) -6- (
2H-benzotriazole-2-yl) phenol) and 2- (2'-hydroxy-
Examples thereof include 3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole. Examples of commercially available benzotriazole-based ultraviolet absorbers include KE.
MISORB71D, KEMISORB79 (all manufactured by Chemipro Kasei Co., Ltd.), J
F-80, JAST-500 (all manufactured by Johoku Chemical Industry Co., Ltd.), ULS-1933
Examples thereof include D (manufactured by Yushi Kogyo Co., Ltd.) and RUVA-93 (manufactured by Otsuka Chemical Co., Ltd.).

As the ultraviolet absorber, a triazine-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber are preferably used. The ultraviolet absorber preferably has high solubility in the resin component constituting the hard coat layer, and preferably has less bleed-out after the above-mentioned continuous folding test. The UV absorber is preferably polymerized or oligomerized. The ultraviolet absorber is preferably a polymer or oligomer having a benzotriazole, triazine, or benzophenone skeleton, and specifically, a (meth) acrylate having a benzotriazole or benzophenone skeleton and methyl methacrylate (MMA) in an arbitrary ratio. It is preferably heat-copolymerized. An organic light emitting diode (OLED)
) When applying a resin substrate to the display device, the UV absorber can also serve to protect the OLED from UV light.

The content of the ultraviolet absorber is not particularly limited, but is preferably 1 part by mass or more and 6 parts by mass or less with respect to 100 parts by mass of the solid content of the composition for the hard coat layer. If it is less than 1 part by mass, the effect of containing the above-mentioned ultraviolet absorber in the hard coat layer may not be sufficiently obtained, and if it exceeds 6 parts by mass, the hard coat layer is significantly colored or its strength is lowered. 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。 (Spectrotransmittance adjuster)
The spectral transmittance adjusting agent adjusts the spectral transmittance of the light-transmitting film. When the hardcoat layer contains, for example, a sesamol-type benzotriazole-based monomer represented by the following general formula (25), the 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 sesamol-type benzotriazole-based monomer is not particularly limited, but specific substance names include 2- [2- (6-hydroxybenzo [1,3] dioxotol-5-yl) -2H-benzo. Triazole-5-yl] ethyl methacrylate, 2- [2- (6- (6-)
Hydroxybenzo [1,3] dioxotol-5-yl) -2H-benzotriazole-5
-Il] ethyl acrylate, 3- [2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazole-5-yl] propylmethacrylate, 3-
[2- (6-Hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazole-5-yl] propyl acrylate, 4- [2- (6-hydroxybenzo [1,3]
3] Dioxol-5-yl) -2H-Benzotriazole-5-yl] Butyl methacrylate, 4- [2- (6-Hydroxybenzo [1,3] dioxol-5-yl) -2H
-Benzotriazole-5-yl] butyl acrylate, 2- [2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazole-5-yloxy] ethyl methacrylate, 2- [2- [2-] (6-Hydroxybenzo [1,3] dioxotri-
5-yl) -2H-benzotriazole-5-yloxy] ethyl acrylate, 2- [
3- {2- (6-Hydroxybenzo [1,3] dioxotol-5-yl) -2H-benzotriazole-5-yl} propanoyloxy] ethyl methacrylate, 2- [3- {2-
(6-Hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazole-5-yl} propanoyloxy] ethyl acrylate, 4- [3- {2- (6-hydroxybenzo [1,3] ] Dioxol-5-yl) -2H-benzotriazole-5-yl
} Propanoyloxy] Butyl methacrylate, 4- [3- {2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H-benzotriazole-5-yl} propanoyloxy] butyl acrylate, 2 -[3- {2- (6-Hydroxybenzo [1,3]
] Dioxol-5-yl) -2H-benzotriazole-5-yl} propanoyloxy] ethyl methacrylate, 2- [3- {2- (6-hydroxybenzo [1,3] dioxol-5-yl) -2H -Benzotriazole-5-yl} propanoyloxy] ethyl acrylate, 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] dioxotol-5-yl) -2H
-Benzotriazole-5-carboxylate, 4- (acryloyloxy) butyl 2-
(6-Hydroxybenzo [1,3] dioxotol-5-yl) -2H-benzotriazole-5-carboxylate and the like can be mentioned. Further, these sesamol-type benzotriazole-based monomers may be used alone or in combination of two or more.

When the resin layer has a multilayer structure of two or more, the sesamol-type benzotriazole-based monomer may be contained in the two or more resin layers to satisfy a desired spectral transmittance. for example,
The sesamol-type benzotriazole-based monomer is contained in one of the resin layers so that only the spectral transmittance at a wavelength of 380 nm can be achieved, and the other resin layers have a wavelength of 410 nm and a wavelength of 440.
Examples thereof include a configuration containing the sesamol-type benzotriazole-based monomer so that the condition of spectral transmittance at nm can be achieved. Further, the resin layer may be composed of three or more layers, and each resin layer may contain the sesamol-type benzotriazole-based monomer so as to satisfy a desired spectral transmittance.

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 the hard coat layer from 15 to 15.
It is preferably contained in an amount of 30% by mass. By containing the sesamol-type benzotriazole-based monomer in such a range, the desired spectral transmittance can be satisfied. The sesamol-type benzotriazole-based monomer may be integrally contained in the hardcoat layer by reacting with the resin component constituting the hardcoat layer, and may react with the resin component constituting the hardcoat layer. It may be contained alone without any problem.

(Anti-fouling agent)
As the 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 amount of addition and suppressing a decrease in the strength of the hard coat layer, the hard coat layer It is preferable that it is unevenly distributed on the surface side of the. When 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, when the hard coat layer is formed, the coating film formed by using the composition for the hard coat layer is used. Dry the membrane,
Before curing, the coating film is heated to reduce the viscosity of the resin component contained in the coating film to increase the fluidity, and the antifouling agent is unevenly distributed on the surface side of the hard coat layer. By selecting and using a low antifouling agent, the antifouling agent is floated on the surface of the coating film without applying heat when the coating film is dried, and then the coating film is cured, the above-mentioned antifouling agent is applied to the hard coat layer. Examples thereof include a method of uneven distribution on the surface side. Further, when the hard coat layer has a multi-layer 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 a silicone-based antifouling agent, a fluorine-based antifouling agent, and a silicone-based and fluorine-based antifouling agent. You may. Further, the antifouling agent may be an acrylic antifouling agent.

The content of the antifouling agent is 0.01 to 3.0 with respect to 100 parts by mass of the resin component described above.
It is preferably parts by mass. If it 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 decrease.

The antifouling agent is preferably a compound having a weight average molecular weight of 5000 or less, and preferably has 1 or more, more preferably 2 or more reactive functional groups in order to improve the durability of the antifouling performance. Above all, 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, whether the resin base material is in the form of a roll or in the form of a sheet, the antifouling agent is transferred to the back surface of the resin base material when stacked, and the resin Attempting to attach or apply another layer to the back surface of the substrate may cause the other layer to peel off, and further.
It may be easily peeled off by performing multiple continuous folding tests.

Further, the antifouling agent having the above-mentioned reactive functional group has good durability (durability) of the antifouling performance, and among them, the hard coat layer containing the above-mentioned fluorine-based antifouling agent is hard to be fingerprinted. ((
It is inconspicuous) and has good wipeability. Further, since the surface tension of the composition for the hard coat layer at the time of coating can be lowered, the leveling property is good and the appearance of the hard coat layer to be formed is good.

The hard coat layer containing a silicone-based antifouling agent has good slipperiness and steel wool resistance. A touch sensor on which a resin base material containing such a silicone-based antifouling agent is mounted on a hard coat layer has a better slipperiness when touched with a finger, a pen, or the like, and thus has a better tactile sensation. In addition, fingerprints are less likely to be attached to the hard coat layer (less conspicuous), and the wiping property is also good. Further, since the surface tension of the composition for the hard coat layer at the time of coating can be lowered, the leveling property is good and the appearance of the hard coat layer to be formed is good.

Examples of commercially available silicone-based antifouling agents include SUA1900L10 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), SUA1900L6 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), and Ebecryl1.
360 (manufactured by Daicel Cytec Co., Ltd.), UT3971 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), BYKUV3500 (manufactured by Big Chemie), BYKUV3510 (manufactured by Big Chemie), BYKUV3570 (manufactured by Big Chemie), X22-164E, X22-174BX
, X22-2426, KBM503, KBM5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), TE
GO-RAD2250, TEGO-RAD2300, TEGO-RAD2200N, TE
GO-RAD2010, TEGO-RAD2500, TEGO-RAD2600, TEG
O-RAD2700 (manufactured by Evonik Japan Co., Ltd.), Megafuck RS854 (DI)
C Co., Ltd.) and the like.

Commercially available fluorine-based antifouling agents include, for example, Optool DAC, Optool DSX (manufactured by Daikin Industries, Ltd.), Megafuck RS71, Megafuck RS74 (manufactured by DIC Corporation), LINK152EPA, LINK151EPA, LINK182UA (Kyoeisha Chemical Co., Ltd.). ), Footergent 650A, Footergent 601AD, Footergent 602 and the like.

Examples of commercially available products of fluorine-based and silicone-based antifouling agents having a reactive functional group include, for example.
Megafuck RS851, Megafuck RS852, Megafuck RS853, Megafuck RS854 (manufactured by DIC Corporation), Opstar TU2225, Opstar TU222
4 (manufactured by JSR Corporation), X71-1203M (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be mentioned.

<Impact absorption layer>
The shock absorbing layer is a layer having shock absorbing properties. The shock absorbing layer may have a multi-layered structure of two or more layers.

The film thickness of the shock 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 decrease in hardness of the shock absorbing layer can be suppressed, and 500.
If it is μm or less, the film thickness is not too thick, so that it is suitable for thinning and deterioration of workability can be suppressed. To determine the film thickness of the shock absorbing layer, use a scanning electron microscope (SEM) to photograph the cross section of the shock absorbing layer, measure the film thickness of the shock absorbing layer at 20 points in the image of the cross section, and measure the film thickness at 20 points. The arithmetic average value of the film thickness. The lower limit of the shock absorbing layer is more preferably 50 μm or more, the upper limit of the shock absorbing layer is more preferably 150 μm or less, and further preferably 100 μm or less.

In the shock absorbing layer, it is preferable that the shear storage elastic modulus G'in the 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. When the shear storage elastic modulus G'of the shock absorbing layer is 1 MP or more, when an impact is applied to the surface of the resin base material, not only the deformation of the resin base material itself but also the inside of the image display device is more than the resin base material. Even when the adhesive layer is arranged on the surface, the plastic deformation of the adhesive layer can be further suppressed. Further, when the shear storage elastic modulus G'of the impact absorbing layer is 1500 MPa or less, cracking of the resin base material at the time of folding can be further suppressed. The lower limit of the shear storage elastic modulus G'of the impact absorbing layer is more preferably 100 MPa or more, and the upper limit of the shear storage elastic modulus G'of the impact absorbing layer is 1200 MP.
It is more preferable that it is a or less. With such an upper limit, good resilience can be obtained when the product is folded, allowed to stand, and reopened.

In the shock absorbing layer, it is preferable that the shear loss elastic modulus G ″ in the frequency range of 25 ° C. and 500 Hz or more and 1000 Hz or less is 0.1 MPa or more and 200 MPa or less.
When 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. Further, if 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 will decrease. The lower limit of the shear loss elastic modulus G ″ of the impact absorbing layer is preferably 1 MPa or more, and the shear loss elastic modulus G ″ of the impact absorbing layer ″.
The upper limit of is more preferably 150 MPa or less from the viewpoint of thinning the shock absorbing layer.

The shear storage elastic modulus G ′ and the shear loss elastic 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 the dynamic viscoelasticity measuring device (DMA), first, all the protective films are selected from the light transmissive film with the protective film. Is peeled off to obtain a single light-transmitting film containing a shock absorbing layer. Next, this light-transmitting film is punched into a rectangular shape of 10 mm × 5 mm to obtain a sample. Then, two samples are prepared and attached to an optional solid shearing jig of a dynamic viscoelasticity measuring device (product name "Rheogel-E4000", manufactured by UBM Co., Ltd.). Specifically, the solid shearing jig includes a single metal solid shearing plate having a thickness of 1 mm and two L-shaped metal fittings arranged on both sides of the solid shearing plate. One sample is sandwiched between the and one L-shaped metal fitting, and the other sample is sandwiched between the solid shear plate and the other L-shaped metal fitting. In this case, the sample is sandwiched so that the shock absorbing layer is on the solid shear plate side and the resin base material is on the L-shaped metal fitting side. Then, tighten the space between the L-shaped metal fittings with screws to fix the sample. 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", manufactured by UBM Co., Ltd.), a solid is formed between the upper chuck and the lower chuck. Attach the shearing jig with a chuck distance of 20 mm. 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 and applying longitudinal vibration with a strain amount of 1% and a frequency of 500 Hz to 1000 Hz to the two L-shaped metal fittings, the dynamic viscoelasticity of the solid was measured at 25 ° C. The shear storage elastic modulus G ′ and the shear loss elastic modulus G ″ of the shock absorbing layer are measured. Here, the sample contains a resin base material in addition to the shock absorbing layer, but since the resin base material is harder than the shock absorbing layer, the influence of the resin base material can be ignored. Therefore, even if the sample contains a resin base material in addition to the shock absorbing layer, the shear storage elastic modulus G ′ and the shear loss elastic modulus G ″ measured from the sample.
Can be regarded as the shear storage elastic modulus G ′ and the shear loss elastic modulus G ′ ′ of the impact absorbing layer. Shear storage elastic modulus G in the frequency range of 500 Hz or more and 1000 Hz or less in the shock absorbing layer
The shear modulus G ′ and the shear loss elastic modulus G ″ are applied to the outer plate with longitudinal vibrations having frequencies of 500 Hz, 750 Hz, and 950 Hz, respectively, and the shear storage elastic modulus G ′ and the shear loss elastic modulus G ″ of the shock absorbing layer at each frequency. Was measured, and the arithmetic average values of these shear storage elastic modulus G ′ and shear loss elastic modulus G ″ were obtained. Further, this measurement was repeated three times, and the three arithmetic average values obtained respectively were further arithmetically averaged. Use as a value. In the above, 500 Hz or more and 100
The frequency range of 0 Hz or less is defined as the frequency in which the surface of the light transmissive film is deformed by several microns to several tens of microns when an object is freely dropped from a height of several cm. This is because the frequency is such that the light transmissive film damages the display panel or the like existing inside the image display device.

The resin constituting the shock absorbing layer is 100 at 25 ° C. and 500 Hz Hz or higher in the shock absorbing layer.
The resin is not particularly limited as long as the resin has a shear storage elastic modulus G ′ and a shear loss elastic modulus G ″ in the frequency range of 0 Hz or less within the above ranges. Examples of such a resin include acrylic gel, urethane gel, silicone gel, urethane resin, epoxy resin and the like. Among these, acrylic gel is preferable. "Gel" generally refers to a dispersion system with high viscosity and loss of fluidity. The shock absorbing layer includes acrylic gel, urethane resin, etc., as well as
It may contain rubber or a thermoplastic elastomer. Further, since the acrylic gel has adhesiveness, when the shock absorbing layer is made of the acrylic gel, the shock absorbing layer and the resin do not need to be provided with the adhesive layer between the shock absorbing layer and the resin base material. The base material can be directly attached.

(Acrylic gel)
As the acrylic gel, various polymers used for adhesives and the like, which are obtained by polymerizing a monomer containing an acrylic acid ester, can be used. Specifically, examples of the acrylic gel include ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, and 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, tridecylic (meth) acrylate, stearyl (meth) acrylate, i-stearyl ( Meta)
Acrylic monomers such as acrylate polymerized or copolymerized can be used. As used herein, the term "(meth) acrylate" is meant to include both "acrylate" and "methacrylate". The acrylic acid ester used for the above (co) polymerization may be used alone or in combination of two or more.

(Urethane resin)
The urethane-based resin is a resin having a urethane bond. Examples of the urethane-based resin include a cured product of an ionizing radiation-curable urethane-based resin composition and a cured product of a thermosetting urethane-based resin composition. Among these, a cured product of an ionizing radiation curable urethane resin composition is preferable from the viewpoint of obtaining high hardness, fast curing speed, and excellent mass productivity.

The ionizing radiation curable urethane resin composition contains a 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 a monomer, an oligomer, and a prepolymer.

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 decrease, and if it exceeds 4, the curing shrinkage increases and the resin substrate curls. In addition, there is a risk that the resin layer will crack during 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. If the weight average molecular weight of the urethane (meth) acrylate is less than 1500, the impact resistance may decrease, and if it exceeds 20000, the viscosity of the ionizing radiation curable urethane resin composition increases, and coating is performed. Sex may worsen. 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 15,000 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
。 Examples of the repeating unit having a structure derived from urethane (meth) acrylate include structures represented by the following general formulas (26), (27), (28) or (29).

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 or a methyl group. , Hydrogen atom, methyl group or ethyl group, m indicates an integer of 0 or more, and x indicates 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 or a methyl group. , Hydrogen atom, methyl group or 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 or a methyl group. , Hydrogen atom, methyl group or ethyl group, m indicates an integer of 0 or more, and x indicates 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 or a methyl group. , Hydrogen atom, methyl group or 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) in which the resin constituting the shock absorbing layer is formed can be determined by, for example, analyzing the shock absorbing layer by thermal decomposition GC-MS and FT-IR. It is possible to judge. In particular, pyrolysis GC-MS is useful because it can detect the monomer unit contained in the shock absorbing layer as a monomer component.

The shock absorbing layer may contain an ultraviolet absorber, a spectral transmittance adjusting agent, an antifouling agent, inorganic particles and / or organic particles and the like. As the ultraviolet absorber or the like, the same ultraviolet absorber or the like described in the column of the hard coat layer can be used, so the description thereof will be omitted here.

<Underground layer>
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 a shock absorbing layer) provided on the resin base material. By providing the base layer on the surface of the resin base material, the adhesion can be improved as compared with the case where the surface of the resin base material is in direct contact with another functional layer.

The film thickness of the base layer is preferably 30 nm or more and 200 nm or less. When the film thickness of the base layer is 30 nm or more, sufficient adhesion between the resin base material and other functional layers can be ensured, and when it is 200 nm or less, the occurrence of interference fringes can be suppressed. The film thickness of the base layer shall be determined by the same method as the film thickness of the hard coat layer. The lower limit of the film thickness of the base layer is more preferably 50 nm or more, and the upper limit is more preferably 150 nm or less.

The base layer contains a resin. The resin of the base layer is selected from the group consisting of (meth) acrylic resin, cellulose resin, urethane resin, vinyl chloride resin, polyester resin, polyolefin resin, polycarbonate, nylon, polystyrene, and ABS resin. It is preferably at least one kind of resin.

<< Manufacturing method of light transmissive film with protective film >>
The light transmissive 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 transmissive film 20 (the surface 21A of the resin base material 21) so that the adhesive layer 32 side is the surface 20A side. And the light transmissive film 20
The protective film 40 is attached to the surface 20B (the surface 21B of the resin base material 21) so that the adhesive layer 42 side is the surface 20B side. As a result, the light transmissive film 10 with a protective film is obtained.

Further, 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 material 21 so that the adhesive layer 32 side is the surface 21A side. Then, a resin layer 71 (for example, a hard coat layer or a shock absorbing layer) is formed on the surface 21B of the resin base material 21, and a light transmissive film 70 composed of the resin base material 21 and the resin layer 71 is formed. As a result, the light transmissive film 60 with a protective film is obtained.
When the processing process for forming the resin layer 71 or the like reaches a temperature equal to or higher than the softening point of the protective film 30, the protective film 30 is once peeled off from the resin base material 21 and then the processing process is performed. The protective film 30 may be attached to the surface 20A of the light transmissive film 20 again.

When the resin layer 71 is formed as a hard coat layer composed of a first hard coat layer and a second hard coat layer laminated on the first hard coat layer, the surface 21B of the resin base material 21 is formed. First, the composition for the first hard coat layer for forming the first hard coat layer is applied, and the coating film for the composition for the first hard coat layer is formed.

<Composition for the first hard coat layer>
The composition for the first hardcourt layer contains a polymerizable compound for forming the first hardcourt layer. The composition for the first hard coat layer may also contain an ultraviolet absorber, a spectral transmittance adjusting agent, an antifouling agent, inorganic particles, a leveling agent, a solvent, and a polymerization initiator, if necessary.

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

(Polymer initiator)
The polymerization initiator is a component that is decomposed by ionizing radiation irradiation to generate radicals to initiate or proceed with the 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 irradiation with ionizing radiation. The polymerization initiator is not particularly limited, and known ones can be used. Specific examples thereof include acetophenones, benzophenones, Michler benzoylbenzoates, α-amyloxime esters, thioxanthones, and propiophenones. Classes, benzyls, benzoins, acylphosphine oxides and the like. again,
It is preferable to use a photosensitizer in combination, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine and the like.

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

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

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

<Composition for second hard coat layer>
The composition for the second hardcourt layer contains a polymerizable compound for forming the second hardcourt layer. The composition for the second hard coat layer may also contain an ultraviolet absorber, a solvent, and a polymerization initiator, if necessary. 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. Since the solvent and the polymerization initiator are the same as the solvent and the polymerization initiator described in the composition for the first hard coat layer, the description thereof will be omitted here.

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

After the coating film is dried, the coating film of the composition for the second hard coat layer is irradiated with ionizing radiation such as ultraviolet rays to irradiate the coating film of the composition for the first hard coat layer and the second hard coat layer. The coating film of the composition for use is completely cured (fully cured) to obtain a hard coat layer composed of a first hard coat layer and a second hard coat layer.

Further, when the shock absorbing layer is formed as the resin layer 71, the surface 21B of the resin base material 21 is formed.
Is coated with a shock absorbing layer composition for forming a shock absorbing layer to form a coating film of the shock absorbing layer composition. After forming the coating film of the composition for the shock absorbing layer, the coating film is dried by heating at a temperature of, for example, 30 ° C. or higher and 120 ° C. or lower for 10 seconds to 120 seconds by various known methods, and the solvent is evaporated. After the coating film is dried, the coating film of the resin layer composition is irradiated with ionizing radiation such as ultraviolet rays to cure the coating film of the shock absorbing layer to form a shock absorbing layer.

Further, the light transmissive film 80 with a protective film can be obtained as follows. First, a resin layer 91 (for example, a base layer) is formed on the surface 21A of the resin base material 21, and the resin layer 9 is formed.
The protective film 30 is attached to the surface 91A of No. 1 so that the adhesive layer 32 side is the resin layer 91 side. Then, a resin layer 92 (for example, a hard coat layer or a shock absorbing layer) is formed on the surface 21B of the resin base material 21. As a result, the light transmissive film 80 with a protective film is obtained. When the processing process for forming the resin layers 91, 92, etc. reaches a temperature equal to or higher than the softening point of the protective film 30, the protective film 30 is once peeled off from the resin layer 91, and then the processing process is performed. After that, 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, unevenness appears on the surface of the light-transmitting film because the unevenness on 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 a light-transmitting film in a rolled state because pressure is applied from the protective film to the light-transmitting film by winding the light-transmitting film in a roll shape. Is considered to be. On the other hand, JIS K713
6: 2000 specifies that haze is a percentage of the transmitted light passing through the test piece that is more than 0.044 rad (2.5 °) deviated from the incident light due to forward scattering. .. 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, if the surface of the protective film has irregularities, the light transmitted through the protective film is diffused by the irregularities, so that the haze value becomes large. Therefore, a small haze value of the protective film means that there are few irregularities existing on the surface of the protective film and the smoothness is excellent. In the present embodiment, the protective films 30 and 40 having a haze value of 10% or less
Therefore, there are few irregularities existing on the surfaces of the protective films 30 and 40. For this reason,
It is possible to obtain the surfaces 20A and 20B of the light transmissive film 20 having less unevenness. This makes it possible to obtain a light transmissive film 20 having excellent smoothness. Further, for the same reason, the light transmissive films 70 and 90 having excellent smoothness can be obtained.

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

The optical film 100 shown in FIG. 6 is provided on a light transmissive film 20 made of a resin base material 21, a resin layer 101 provided on the surface 21A of the resin base material 21, and a surface 21B of the resin base material 21. It includes 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 a shock absorbing layer. For example, when the resin layer 101 is a hard coat layer, the resin layer 102 can be a shock 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 thereof is omitted here. And.

When forming the optical film 100, first, the light transmissive film 1 with a protective film 1 is formed.
At 0, the resin layer 71 is in a state where the protective film 30 is peeled off from the light transmissive film 20.
The resin layer 101 is formed on the surface 21A of the resin base material 21 in the same manner as the formation of the above. Next, in the state where the protective film 40 is peeled off from the light transmissive film 20, the resin layer 102 is formed on the surface 21B of the resin base material 21 in the same manner as the formation of the resin layer 71.

<<< Image display device >>>
The optical film 100 can be used by incorporating it into a foldable image display device. 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 faces the observer side and is mainly a housing 111 in which a battery or the like is housed.
, The protective film 112, the display panel 113, the circularly polarizing plate 114, the touch sensor 115, and the optical film 100 are laminated in this order. A light-transmitting adhesive layer 116 is arranged between the display panel 113 and the circular polarizing plate 114, between the circular 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 arranged between the display panel 113 and the circular polarizing plate 114, between the circular 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 a shock absorbing layer, the optical film 100 is arranged so that the resin layer 101 is closer to the observer than the resin layer 102. There is. In the image display device 110, the optical film 100
The surface of the resin layer 101 of the above 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. Although the touch sensor 115 is arranged on the observer side of the circular polarizing plate 115, it may be arranged between the display panel 113 and the circular polarizing plate 114. Further, 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 impact resistance and preventing damage to the display panel 113, the adhesive layer made of the acrylic gel is used. Is preferable. When the adhesive layer made of the acrylic gel is used for the adhesive layer 116, the circular polarizing plate 11 is located between the display panel 113 and the circular polarizing plate 114.
An adhesive layer made of the acrylic gel may be arranged at least between the touch sensor 115 and the touch sensor 115, and between the touch sensor 115 and the optical film 100.

In the above embodiment, the optical film 100 is used as a cover film constituting the surface of the image display device 110, but the optical film 100 may be used as a film existing inside the image display device. good.

In order to explain the present invention in detail, examples will be given below, but the present invention is not limited to these descriptions. The "100% solid content conversion value" below is a value when the solid content in the solvent-diluted product is 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 a hard coat layer.

(Composition 1 for hard coat layer)
-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, irregularly shaped silica particles (average particle diameter 25 nm, manufactured by JGC Catalysts and Chemicals Co., Ltd.): 50 parts by mass (100% solid content conversion value)
-Photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacu"
re (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 (100% solid content conversion value)
-Methyl isobutyl ketone (MIBK): 150 parts by mass

(Composition 2 for hard coat layer)
-Urethane acrylate (product name "UX5000", manufactured by Nippon Kayaku Co., Ltd.): 25 parts by mass-Mixed mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (product name "M403", manufactured by Toa Synthetic Co., Ltd.): 50 By mass, polyfunctional acrylate polymer (product name "Acryt 8KX-012C", manufactured by Taisei Fine Chemical Co., Ltd.): 25 parts by mass (100% solid content conversion value)
-Antifouling agent (product name "BYKUV3500", manufactured by Big Chemie): 1.5 parts by mass (100% solid content conversion value)
-Photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacu"
re (registered trademark) 184 ", manufactured by BASF Japan Ltd.): 4 parts by mass, methyl isobutyl ketone (MIBK): 150 parts by mass

<Preparation of composition for base layer>
Each component was blended so as to have 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 (100% solid content conversion value)
-Methyl isobutyl ketone (MIBK): 170 parts by mass

<Example 1>
As a resin base material, a polyethylene terephthalate film having a thickness of 38 μm as a base film is formed on a first surface, which is one surface of a polyimide base material (product name “Neoprim”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a thickness of 50 μm. (PET film) and a first protective film (product name "SAT-4") having a total thickness of 63 μm composed of an adhesive layer provided on one surface of the PET film.
2J ”, manufactured by Sanei Kaken Co., Ltd.) is attached so that the adhesive layer is on the polyimide base material side, and as a base film on the second surface opposite to the first surface of the polyimide base material. A second protective film with a total thickness of 63 μm (product name “SAT-42J”, Sanei Kaken Co., Ltd.) consisting of a polyethylene terephthalate film (PET film) with a thickness of 38 μm and an adhesive layer provided on one surface of the PET film. (Made), and the first protective film,
A light-transmitting film with a protective film including a light-transmitting film made of a polyimide base material and a second protective film was obtained.

<Example 2>
In Example 2, the first protective film and the second protective film (product name "SAT").
-42J ", manufactured by Sun A. Kaken Co., Ltd.), with a thickness of 38 μm as a base film
First protective film and second protective film (product name "TP200", manufactured by Nitto Denko Co., Ltd.) having a total thickness of 60 μm composed of a polyethylene terephthalate film (PET film) and an adhesive layer provided on one surface of the PET film. ) Was used, and a light-transmitting film with a protective film was obtained in the same manner as in Example 1.

<Example 3>
In Example 3, a polyamide base material (product name “Mictron”, manufactured by Toray Industries, Inc.) was used instead of the polyimide base material (product name “Neoprim”, manufactured by Mitsubishi Gas Chemical Company, Inc.). A light transmissive film with a protective film was obtained in the same manner as in 1.

<Example 4>
In Example 4, the first protective film and the second protective film (product name "SAT").
-42J ", manufactured by Sun A. Kaken Co., Ltd.), with a thickness of 125μ as a base film
First protective film and second protective film with a total thickness of 135 μm consisting of a polyethylene terephthalate film (PET film) of m and an adhesive layer provided on one surface of the PET film (product name “SAT TM30125”, Sanei Kaken). A light-transmitting film with a protective film was obtained in the same manner as in Example 1 except that (manufactured by the same company) was used.

<Example 5>
As a resin base material, a polyethylene terephthalate film having a thickness of 38 μm as a base film is formed on a first surface, which is one surface of a polyimide base material (product name “Neoprim”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a thickness of 50 μm. (PET film) and a first protective film (product name "SAT-4") having a total thickness of 63 μm composed of an adhesive layer provided on one surface of the PET film.
2J ”, manufactured by Sun A. Kaken Co., Ltd.) was attached so that the adhesive layer was on the polyimide substrate side. Then, the composition 1 for the hard coat layer was applied to the second surface of the polyimide base material opposite to the first surface with a bar coater to form a coating film. Then, the formed coating film is heated at 70 ° C. for 1 minute to evaporate the solvent in the coating film, and ultraviolet rays are emitted using an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source H bulb). Semi-curing the coating film by irradiating it in the air so that the integrated light amount is 100 mJ / cm ² (half cure).
I let you. Next, the composition 2 for the hard coat layer was applied to the surface of the coating film of the semi-cured hard coat layer composition 1 with a bar coater to form a coating film. 70 ° C. for the formed coating film
Evaporate the solvent in the coating film by heating for 1 minute, and use an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source H bulb) to generate ultraviolet light with an oxygen concentration of 200.
The coating film is completely cured (fully cured) by irradiating it so that the integrated light amount becomes 200 mJ / cm ² under the condition of ppm or less, and the first hard coat layer having a film thickness of 10 μm and the first hard coat A hard coat layer composed of a second hard coat layer having a film thickness of 5 μm laminated on the layer was formed. As a result, a light-transmitting film with a protective film including a light-transmitting film composed of a polyimide base material and a hard coat layer and a first protective film removably attached to the first surface of the polyimide base material can be obtained. Obtained.

The film thickness of the hard coat layer is a scanning transmission electron microscope (STEM) (product name "S-48").
00 ”, manufactured by Hitachi High-Technologies Corporation), the cross section of the hard coat layer was photographed, the film thickness of the hard coat layer was measured at 10 points in the image of the cross section, and the arithmetic average value of the film thickness at the 10 points was measured. And said. A cross-sectional photograph of the hardcourt layer was taken as follows. first,
A block in which an optical film cut out to 1 mm × 10 mm was embedded with an embedding resin was prepared, and a uniform section having a thickness of 70 nm or more and 100 nm or less without holes was cut out from this block by a general section preparation method. To prepare the section, "Ultra Microtome EM"
UC7 ”(Leica Microsystems, Inc.) and the like were used. Then, a uniform section having no holes or the like was used as a measurement sample. Then, a cross-sectional photograph of the measurement sample was taken using a scanning transmission electron microscope (STEM). When taking this cross-section photograph, the detector is "TE"
, STEM observation was performed with an acceleration voltage of 30 kV and an emission of "10 μA". The magnification was adjusted appropriately at 5000 to 200,000 times while adjusting the focus and observing whether each layer could be distinguished. When taking a cross-sectional photograph, the aperture was set to the beam monitor aperture 3, the objective lens aperture was set to 3, and W. D. 8
It was set to mm.

<Example 6>
As a resin base material, the base layer composition 1 is applied to the first surface, which is one surface of a polyimide base material (product name "Neoprim", manufactured by Mitsubishi Gas Chemical Company Limited) having a thickness of 50 μm, to form a coating film. Formed. Then, the formed coating film was heated at 90 ° C. for 1 minute to evaporate the solvent in the coating film to form a base layer having a film thickness of 100 nm. Next, on the surface of the base layer, a polyethylene terephthalate film (PET film) having a thickness of 38 μm as a base film was used.
A first protective film (product name "SAT-42J", manufactured by Sun A. Kaken Co., Ltd.) having a total thickness of 63 μm, which is composed of an adhesive layer provided on one surface of the PET film, has an adhesive layer on the base layer side. I pasted it like this. Then, the second surface of the polyimide substrate opposite to the first surface.
The composition 1 for the hard coat layer was applied to the surface of the hard coat layer with a bar coater to form a coating film. Then, the formed coating film is heated at 70 ° C. for 1 minute to evaporate the solvent in the coating film, and ultraviolet rays are emitted using an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source H bulb). The coating film was semi-cured (half-cured) by irradiating in air so that the integrated light amount was 100 mJ / cm ² . Next, the composition 2 for the hard coat layer was applied to the surface of the coating film of the semi-cured hard coat layer composition 1 with a bar coater to form a coating film. The formed coating film is heated at 70 ° C. for 1 minute to evaporate the solvent in the coating film, and the ultraviolet rays are converted into oxygen concentration using an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source H valve). The coating film is completely cured (fully cured) by irradiating it so that the integrated light amount becomes 200 mJ / cm ² under the condition of 200 ppm or less, and the first hard coat layer having a film thickness of 10 μm and the first hard A hard coat layer composed of a second hard coat layer having a film thickness of 5 μm laminated on the coat layer was formed. As a result, a light-transmitting film with a protective film including a light-transmitting film composed of a base layer, a polyimide base material, and a hard coat layer and a first protective film removably attached to the surface of the base layer is obtained. rice field. The film thicknesses of the base layer and the hard coat layer were measured by the same method as the method for measuring the film thickness of the hard coat layer described in the column of Example 5.

<Comparative Example 1>
In Comparative Example 1, the first protective film and the second protective film (product name “SAT”).
-42J ", manufactured by Sun A. Kaken Co., Ltd.), made of polyethylene with a thickness of 60 μm
Self-adhesive first protective film and second protective film (product name "PAC3-50"
A light transmissive film with a protective film was obtained in the same manner as in Example 1 except that "THK" (manufactured by Sun A. Kaken Co., Ltd.) was used.

<Comparative Example 2>
In Comparative Example 2, the first protective film and the second protective film (product name “SAT”).
-42J ", manufactured by Sun A. Kaken Co., Ltd.), made of polyethylene with a thickness of 60 μm
Self-adhesive type first protective film and second protective film (product name "PAC4K-6"
0 ”, manufactured by Sun A. Kaken Co., Ltd.), a light-transmitting film with a protective film was obtained in the same manner as in Example 1.

<Comparative Example 3>
In Comparative Example 3, the first protective film and the second protective film (product name “SAT”).
-42J ", manufactured by Sanei Kaken Co., Ltd.), a polypropylene film (PP film) as a base film, and a first protective film having a total thickness of 30 μm composed of an adhesive layer provided on one surface of the PP film. A light transmissive film with a protective film was obtained in the same manner as in Example 1 except that the second protective film (product name "KD23", manufactured by Sanei Kaken Co., Ltd.) was used.

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

<Comparative Example 5>
In Comparative Example 5, instead of the first protective film (product name "SAT-42J", manufactured by Sun A. Kaken Co., Ltd.), a self-adhesive first protective film (product name) made of polyethylene and having a thickness of 60 μm. Other than using "PAC4K-60", manufactured by Sun A. Kaken Co., Ltd.)
A light transmissive film with a protective film was obtained in the same manner as in Example 5.

<Comparative Example 6>
In Comparative Example 6, instead of the first protective film (product name "SAT-42J", manufactured by Sun A. Kaken Co., Ltd.), a self-adhesive first protective film (product name) made of polyethylene and having a thickness of 60 μm. Other than using "PAC4K-60", manufactured by Sun A. Kaken Co., Ltd.)
A light transmissive film with a protective film was obtained in the same manner as in Example 6.

<Continuous folding test>
In the light-transmitting film with a protective film according to Examples and Comparative Examples, the foldability of the light-transmitting film was evaluated in a state where all the protective films were peeled off from the light-transmitting film. Specifically, each light-transmitting film with a protective film is cut into a size of 30 mm × 100 mm, and in the cut-out light-transmitting film with a protective film, all the protective films are peeled off from the light-transmitting film. A light transmissive film was obtained. Then, the obtained light-transmitting film is fixed to a durability tester (product name "DLDMLLH-FS", manufactured by Yuasa System Equipment Co., Ltd.) with the short side (30 mm) side of the light-transmitting film fixed at a fixing portion. , As shown in FIG. 2C, attach the two opposing sides so that the minimum distance is 30 mm, and perform a continuous folding test of folding the light transmissive film by 180 ° 100,000 times to the bent part. It was examined whether cracks or breaks occurred. In the light transmissive film obtained from the light transmissive film with the protective film according to Examples 5 and 6 and Comparative Examples 4 to 6, the light transmissive so that the surface on the hard coat layer side is folded inward by 180 °. The film was attached to the durability tester. The results of the continuous folding test were evaluated according to the following criteria.
◯: In the continuous folding test, no crack or break occurred in the bent portion.
X: In the continuous folding test, the bent portion was cracked or broken.

<Haze measurement>
The haze value (total haze value) of the protective film used in the light transmissive film with the protective film according to the examples and the comparative examples was measured. First, 50 light-transmitting films with each protective film
It was cut out to a size of mm × 100 mm, and in the cut-out light-transmitting film with a protective film, all the protective films were peeled off from the light-transmitting film. Specifically, in Examples 1 to 4 and Comparative Examples 1 to 3, the first protective film and the second protective film were peeled off from the light-transmitting film, and Examples 5 and 6 and Comparative Examples 4 to 4 to 20 were peeled off. In No. 6, the first protective film was peeled off from the light-transmitting film. Then, the haze values of the first protective film and the second protective film that have been peeled off are measured by a haze meter (product name "HM-150", Murakami Co., Ltd.) with no curls or wrinkles and no fingerprints or dust. It was measured by a method compliant with JIS K7136: 2000 using (manufactured by Color Technology Laboratory). The haze value of the first protective film and the second protective film was an arithmetic mean value obtained by measuring three times for each protective film.

<Total light transmittance>
In the light-transmitting film with a protective film according to Examples and Comparative Examples, the total light transmittance of the light-transmitting film was measured as follows in a state where all the protective films were peeled off from the light-transmitting film. First, the light-transmitting film with each protective film is 50 mm x 10
It was cut out to a size of 0 mm, and in the cut-out light-transmitting film with a protective film, all the protective films were peeled off from the light-transmitting film to obtain a light-transmitting film. Then, the total light transmittance of the light transmissive film is measured using a haze meter (product name "HM-150", manufactured by Murakami Color Technology Laboratory Co., Ltd.) with no curls or wrinkles and no fingerprints or dust. The measurement was performed by a method according to JIS K7361-1: 1997. The total light transmittance was taken as an arithmetic mean value obtained by measuring three times for one light-transmitting film.

<Yellow Index (YI)>
In the light-transmitting film with a protective film according to Examples and Comparative Examples, the yellow index of the light-transmitting film was measured as follows in a state where all the protective films were peeled off from the resin base material such as the polyimide base material. And evaluated. First, each light-transmitting film with a protective film is cut into a size of 50 mm × 100 mm, and in the cut-out light-transmitting film with a protective film, all the protective films are peeled off from the light-transmitting film.
A light transmissive film was obtained. 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 surface side of the light transmissive film. The yellow index was measured from light having a wavelength of 200 nm to 780 nm transmitted through the light transmissive film. The yellow index calculates the chromaticity tristimulus values X, Y, Z from the measured values according to the arithmetic expression described in JIS Z8722: 2009, and from the tristimulus values X, Y, Z, ASTM D1925:
It was calculated according to the arithmetic expression described in 1962, and was used as the arithmetic mean value of the values obtained by measuring three times. The evaluation criteria were as follows.
⊚: YI was less than 1.5.
◯: YI was 1.5 or more and less than 10.0.
Δ: YI was 10.0 or more and 15.0 or less.
X: YI exceeded 15.0.

<Appearance evaluation>
In the light-transmitting film with a protective film according to Examples and Comparative Examples, irregularities are formed on the first surface and the second surface of the light-transmitting film in a state where all the protective films are peeled off from the light-transmitting film. It was visually evaluated. Specifically, each light-transmitting film with a protective film is cut into a size of 100 mm × 100 mm, and in the cut-out light-transmitting film with a protective film, all the protective films are peeled off from the light-transmitting film. A light transmissive film was obtained. Then, the first surface of the light-transmitting film (Example 1).
Whether or not unevenness is formed on the first surface of the resin base material in 5 and Comparative Examples 1 to 5, and the surface of the base layer in Examples 6 and 6), and the light transmissive film No. Whether or not the surface of No. 2 (the second surface of the resin base material in Examples 1 to 4 and Comparative Examples 1 and 2) had irregularities was visually evaluated under a three-wavelength fluorescent lamp.
(Examples 1 to 4 and Comparative Examples 1 to 3)
◯: No unevenness was confirmed on either the first surface or the second surface of the light transmissive film, or some unevenness was confirmed, but the level was not practically problematic.
X: Concavities and convexities 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 confirmed on the first surface of the light transmissive film, or some unevenness was confirmed, but the level was not practically problematic.
X: Unevenness was clearly confirmed on the first surface of the light transmissive film.

The results are shown in Table 1 below.

The results will be described below. In the light-transmitting film with a protective film according to Comparative Examples 1 to 3, the haze value of the first protective film and the haze value of the second protective film each exceeded 10%, so that the light-transmitting property with the protective film was used. The first surface and the second surface of the light transmissive film obtained by peeling the first protective film and the second protective film from the film.
Unevenness was clearly confirmed on any of the surfaces of. On the other hand, in the light transmissive film with the protective film according to Examples 1 to 4, the haze value of the first protective film and the haze value of the second protective film were 10% or less, respectively, so that the light transmissive. No unevenness was confirmed on either the first surface or the second surface of the sex film, or some unevenness was confirmed, but the level was not a problem in practical use.

Further, in the light transmissive film with the protective film according to Comparative Examples 4 to 6, the haze value of the first protective film exceeded 10%, so that the light transmissive film with the protective film was replaced with 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 transmissive film with the protective film according to Examples 5 and 6, since the haze value of the first protective film was 10% or less, the first protection from the light transmissive film with the protective film. No unevenness was confirmed on the first surface of the light transmissive film obtained by peeling the film, or some unevenness was confirmed, but the level was not practically problematic.

Further, in the light transmissive films according to Examples 5 and 6, when the maltens hardness of the resin base material, the first hard coat layer and the second hard coat layer were measured, the maltens hardness of the polyimide base material was 300 MPa. The first hard coat layer had a maltens hardness of 830 MPa, and the second hard coat layer had a maltens hardness of 500 MPa.
Martens hardness is "TI950 Tribo" manufactured by HYSITRON.
It was measured using "Indenter". Specifically, first, all the protective films were peeled off from the light-transmitting film with the protective film cut into 1 mm × 10 mm to obtain a light-transmitting film alone. Then, a block in which this light-transmitting film is embedded with an embedding resin is produced, and a uniform thickness of 70 nm without holes or the like is produced from this block by a general section forming method.
Sections of 100 nm or less were cut out. To prepare the section, "Ultra Microtome E"
MUC7 ”(Leica Microsystems, Inc.) was used. Then, the remaining block from which a uniform section having no holes or the like was cut out was used as a measurement sample. Next, in the cross section obtained by cutting out the above section in such a measurement sample, a Berkovich indenter (triangular pyramid) was used as an indenter, and under the following measurement conditions, a Berkovich indenter was used at the center of the cross section of each hardcourt layer. Push in (triangular pyramid) 500 nm,
After holding for a certain period of time to relax the residual stress, unload it, measure the maximum load after relaxation, and measure it.
Using the maximum load P _max (μN) and the recessed area A (nm ² ) at a depth of 500 nm, P _m .
Calculated by _ax / A. The Martens hardness was taken as the arithmetic mean value of the values obtained by measuring at 10 points. The Martens hardness of the resin base material was also measured in the same manner as the Martens hardness of the polyimide base material.
(Measurement condition)
・ Load speed: 10 nm / sec ・ Holding time: 5 seconds ・ Load unloading speed: 10 nm / sec ・ Measurement temperature: 25 ° C

10, 60, 80 ... Light-transmitting film with protective film 20, 70, 90 ... Light-transmitting 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 (1)

A light transmissive film with a protective film comprising a foldable light transmissive film having at least a resin substrate and a protective film detachably attached to at least one side of the light transmissive film.
The thickness of the protective film is 30 μm or more, and the thickness is 30 μm or more.
A light transmissive film with a protective film, wherein the haze value of the protective film is 10% or less.

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