Optical film and image display device

Abstract

To provide an optical film with excellent scratch resistance, and an image display device including the same.SOLUTION: An optical film 10 comprises an optical transparency substrate 11, a hard coat layer 12, and an inorganic layer 13 in this order. In the optical film 10, the hard coat layer 12 is in contact with the inorganic layer 13, and the hard coat layer 12 includes binder resin 12A and inorganic particles 12B. A film thickness of the hard coat layer 12 is 1 μm or more, and an indentation hardness of the hard coat layer 12 is 200 MPa or more.SELECTED DRAWING: Figure 1

Description

REFERENCE TO RELATED APPLICATIONS

[0001] This application is a direct sequel to the prior Japanese application No. 2017-191319 (filing date: 2017 This application claims the benefit of priority from US Pat. No. 6,313,639, filed Sep. 29, 2003, the entire disclosure of which is incorporated herein by reference. No. 60 / 633,333 filed on Nov. 23, 2005, and is hereby incorporated by reference in its entirety. [Technical field]

[0002] The present invention relates to an optical film and an image display device. [Background technology]

[0003] Optical films have traditionally been used in image display devices such as smartphones and tablet terminals. The optical film is made up of a light-transmitting substrate, a hard coat layer, and an inorganic layer. In some cases, an optical film having the above-mentioned structures in this order is used (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-128927 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in such an optical film having an inorganic layer, the surface of the inorganic layer is 1kg / cm with #0000 steel wool 2 The steel is rubbed back and forth 10 times while applying a load of When the fluorine test is performed, the inorganic layer may be scratched or may become damaged. The hard coat layer may be scraped off.

[0006] The present invention has been made to solve the above problems. and an image display device including the optical film. [Means for solving the problem]

[0007] The present invention includes the following inventions. [1] An optical film having a hard coat layer and an inorganic layer in this order, A coating layer is in contact with the inorganic layer, and the hard coating layer contains a binder resin and inorganic particles. The hard coat layer has a thickness of 1 μm or more, and the hard coat layer is made of indium. An optical film having a thermal expansion hardness of 200 MPa or more.

[0008] [2] In a cross section of the hard coat layer in the thickness direction, the hard coat layer and the inorganic layer The area of ​​the inorganic particles in the region from the interface to a depth of 500 nm of the hard coat layer The optical film according to the above [1], wherein the ratio is 5% or more and 75% or less.

[0009] [3] The optical filter according to the above [1] or [2], wherein the inorganic particles are silica particles. Hmm.

[0010] [4] An optical film comprising a light-transmitting substrate, a hard coat layer, and an inorganic layer in this order. The hard coat layer is in contact with the inorganic layer, and the hard coat layer contains a metal element and The hard coat layer contains at least one of semi-metallic elements, and the thickness of the hard coat layer is 1 μm or more. The hard coat layer has an indentation hardness of 200 MPa or more. Film.

[0011] [5] The inorganic layer according to any one of the above [1] to [4], wherein the inorganic layer is an inorganic oxide layer. Optical film used.

[0012] [6] The photoresist according to any one of the above [1] to [4], wherein the inorganic layer contains silicon. School film.

[0013] [7] The thickness of the inorganic layer is 10 nm or more and 300 nm or less, [1] to [6] above. ] The optical film described in any one of the above.

[0014] [8] The hard coat layer contains a metalloid element, and the metalloid element is silicon. [4] The optical film according to any one of [4] to [7].

[0015] [9] The gold contained in the hard coat layer and measured by X-ray photoelectron spectroscopy the total atomic ratio of the group element and the metalloid element is 1.5% or more and 30% or less. [4] The optical film according to any one of [8] to [9].

[0016]

[10] The hard coat layer is a polymerizable layer comprising a silsesquioxane having a polymerizable functional group. The optical film according to any one of the above [1] to [9], which contains a polymer of a compound.

[0017]

[11] Fold the optical film 180° so that the distance between the opposing sides is 6 mm. An optical film according to any one of [1] to

[0010] above, which does not crack or break when the test is repeated 100,000 times.

[0018]

[12] The inorganic layer is on the inside, and the distance between the opposing sides of the optical film is 2 mm When the test was repeated 100,000 times to fold the material 180 degrees, no cracks or breaks occurred. The optical film according to any one of the above [1] to

[11] .

[0019]

[13] The light-transmitting substrate is made of a polyimide resin, a polyamide resin, or a mixture thereof. The optical filter according to any one of the above [1] to

[12] , wherein the substrate is a composite material. Hmm.

[0020]

[14] A display panel and the optical film according to any one of [1] to

[0013] , which is disposed on a viewer side of the display panel, The image display device, wherein the coating layer is located closer to a viewer than the light-transmitting substrate.

[0021]

[15] The display panel according to

[14] , wherein the display panel is an organic light-emitting diode panel. Image display device. Effect of the Invention

[0022] According to one and other aspects of the present invention, an optical film having excellent scratch resistance is provided. According to another aspect of the present invention, an image display device including such an optical film can be provided. The device can be provided. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic diagram of an optical film according to a first embodiment. [Diagram 2] 2 is an enlarged view of a portion of the optical film shown in FIG. 1. [Diagram 3] FIG. 13 is a schematic diagram showing a folding test. [Figure 4] 1 is a schematic configuration diagram of an image display device according to a first embodiment. [Diagram 5] FIG. 4 is a schematic diagram of an optical film according to a second embodiment. [Figure 6] FIG. 11 is a schematic configuration diagram of an image display device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [First embodiment] Hereinafter, the optical film and the image display device according to the first embodiment of the present invention will be described with reference to the drawings. In this specification, the terms "film", "sheet" and the like are used interchangeably. They are not distinguished from each other solely on the basis of the difference in title. The term "film" is used to include members also called sheets. FIG. 2 is a schematic diagram of the optical film, and FIG. 3 is an enlarged view of a part of the optical film shown in FIG. FIG. 3 is a schematic diagram showing the state of the folding test.

[0025] The optical film 10 shown in FIG. 1 includes a light-transmitting substrate 11, a hard coat layer 12, and The hard coat layer 12 is in contact with the inorganic layer 13. The optical film 10 further includes a functional layer 14 between the light-transmitting substrate 11 and the hard coat layer 12. The optical film 10 shown in FIG. 1 includes a functional layer 14. The system may not have a functional layer.

[0026] In FIG. 1, the surface 10A of the optical film 10 is the surface 13A of the inorganic layer 13. In this specification, the surface of the optical film means one surface of the optical film. Since it is used as a taste, the side opposite to the optical film surface is The rear surface 10B of the optical film 10 is a light-transmitting surface. This is the surface of the hard substrate 11 opposite to the surface on which the hard coat layer 12 is formed.

[0027] The haze value (total haze value) of the optical film 10 is preferably 2.5% or less. If the haze value of the optical film 10 is 2.5% or less, excellent transparency can be obtained. The haze value is more preferably 1.5% or less, and more preferably 1.0% or less (the smaller the value, the better). preferable).

[0028] The above haze values ​​were measured using a haze meter (product name "HM-150", manufactured by Murakami Color Research Laboratory). It can be measured by a method conforming to JIS K7136:2000 using the above. The haze value was measured after cutting into a piece of 50 mm x 100 mm without curling or wrinkles. In a state free of fingerprints and dust, place the inorganic layer side facing away from the light source. The measurement is performed three times, and the arithmetic mean value of the three measurements is used. "Measure" means to measure three different places, not the same place three times. In the optical film 10, the surface 10A when viewed from the outside is flat and In addition, the layers to be laminated, such as the hard coat layer 12, are also flat, and the variation in thickness is within the range of ±10%. Therefore, the haze value was measured at three different points on the cut optical film. It is believed that this gives an approximate average haze value for the entire surface of the optical film. The variation in haze value is 1m x 3000m even when the measurement target is a 5 inch Even for a smartphone size, the error is within ±10%. If it is not possible to cut it to the above size, for example, the entrance opening of the HM-150 is 20 Since the diameter is mm, a sample size of 21 mm or more is required. Therefore, the optical film may be cut to a size of 22 mm x 22 mm or more. If the size of the room is small, move it little by little as long as the light spot does not shift, or If the optical film is in roll form, The film is the effective part that is used in the product (e.g., image display device) and the part that is used in the product. The optical film has a non-effective portion that is not used for measurement of the haze value, etc. When cutting out the optical film, it is necessary to cut out the effective portion of the optical film. The areas up to 5 cm from each end in the width direction may be non-usable.

[0029] In addition, another film such as a polarizing plate is attached to one side of the optical film 10 via an adhesive layer or a bonding layer. If a film is attached to the surface, peel off the other film together with the adhesive layer and then apply the light. The haze value of the optical film is to be obtained. The peeling of other films is, for example, as follows: First, another film is attached to the optical film via a pressure-sensitive adhesive layer or a bonding layer. The laminate was heated with a dryer, and the area that seemed to be the interface between the optical film and other films was Insert the tip of a cutter into the mold and slowly peel it off. This process of heating and peeling is repeated. This allows the adhesive layer, the bonding layer and other films to be peeled off. Even if a peeling process is performed, it does not have a significant effect on the measurement of the haze value.

[0030] The total light transmittance of the optical film 10 is preferably 80% or more. If the total light transmittance of the optical fiber 10 is 80% or more, sufficient light transmittance can be obtained. The total light transmittance of the film 10 is preferably 85% or more, and more preferably 90% or more (the larger the value, the more preferable the light transmittance). (The higher the better).

[0031] The total light transmittance was measured using a haze meter (product name "HM-150", Murakami Color Research Institute) The measurement can be performed using a method conforming to JIS K7361-1:1997 using a fluorine-containing ... The total light transmittance is measured after cutting into a size of 50 mm x 100 mm and removing any curls or wrinkles. The optical filter was placed so that the inorganic layer side was facing away from the light source in a state where there was no dirt, fingerprints, dust, etc. The measurement is carried out three times for each film, and the arithmetic average value obtained from the three measurements is used. In the case of the mold 10, the surface 10A when viewed from the outside is flat, and the laminated layer such as the hard coat layer 12 is not formed. The layer that is cut is also flat, and the variation in film thickness is within the range of ±10%. By measuring the total light transmittance at three different points on the optical film, an approximate optical transmittance can be obtained. It is believed that the average value of the total light transmittance over the entire surface of the film can be obtained. Even if the measurement target is as long as 1m x 3000m, the deviation is about the same as a 5-inch smartphone. The deviation in the degree of the optical film is within ±10%. If this is not possible, you may cut the optical film to a size of 22 mm x 22 mm or more. If the size of the optical film is small, move it little by little as long as the light source spot does not shift. Or change the angle to have three measurement points.

[0032] In addition, another film such as a polarizing plate is attached to one side of the optical film 10 via an adhesive layer or a bonding layer. If a film is provided, the film may be removed by the same method as above together with the adhesive layer and the other film. After peeling off the film, the total light transmittance of the optical film is measured. Even if there is any, it does not significantly affect the total light transmittance measurement.

[0033] The yellow index (YI) of the optical film 10 is preferably 15 or less. If the yellow index YI of the optical film 10 is 15 or less, the yellowness of the optical film The color is not conspicuous, so it can be used in applications where transparency is required. The upper limit of the low index (YI) is more preferably 10 or less. The index (YI) is a spectrophotometer (product name "UV-3100PC", manufactured by Shimadzu Corporation, Light source: tungsten lamp and deuterium lamp) was used, and a 50mm x 100mm The measured values ​​for the optical film cut out from the film were used to determine the Calculate the chromaticity tristimulus values ​​X, Y, and Z according to the formula described, and convert A from the tristimulus values ​​X, Y, and Z. The value is calculated according to the formula described in STM D1925:1962. The Yellow Index (YI) was measured three times for each optical film. The arithmetic mean of the values ​​obtained shall be taken as the average.

[0034] In addition, another film such as a polarizing plate is attached to one side of the optical film 10 via an adhesive layer or a bonding layer. If a film is provided, the adhesive layer and other layers are also attached in the same manner as above. The film is then peeled off and the yellow index (YI) is measured. However, even if such a peeling process is performed, it has no significant effect on the measurement of the yellow index (YI). There is no significant impact.

[0035] In order to adjust the yellow index (YI) of the optical film 10, for example, the light transmittance The hard substrate 11 and the hard coat layer 12 may contain a blue dye, which is the complementary color of yellow. By using a substrate made of polyimide resin as the light-transmitting substrate 11, the problem of yellowing is eliminated. Even in such a case, the light-transmitting substrate 11 and the hard coat layer 12 may have a blue color. By incorporating the dye, the yellow index (YI) of the optical film 10 can be reduced. This can be done.

[0036] The blue coloring matter may be either a pigment or a dye. For example, an optical filter may be used. When the film 10 is used in an organic light-emitting diode display device, it is necessary to use a film having both light resistance and heat resistance. As the blue coloring matter, polycyclic organic pigments and metal complex organic pigments are preferably used as dyes. Compared to molecular dispersion, the degree of molecular cleavage caused by ultraviolet rays is less and the light resistance is significantly superior, so it is It is preferable for applications requiring light resistance, and more specifically, phthalocyanine organic pigments are preferable. However, since the pigment is dispersed in the solvent, the transparency may be affected by particle scattering. Since there is a possibility of photoinduced retardation, it is preferable to set the particle size of the pigment dispersion within the Rayleigh scattering region. On the other hand, when the transparency of the optical film is important, the blue dye should be resistant to solvents. It is preferable to use a dye that undergoes molecular dispersion.

[0037] The optical film 10 preferably has a transmittance of 8% or less for light having a wavelength of 380 nm. If the transmittance of the optical film is 8% or less, when the optical film is used in a mobile device, In this case, the polarizer can be prevented from being exposed to ultraviolet rays and from being deteriorated. The upper limit of the transmittance is more preferably 5%. 100PC, Shimadzu Corporation, Light source: Tungsten lamp and Deuterium lamp) The transmittance can be measured by cutting the sample into a size of 50 mm x 100 mm. The optical film is measured three times, and the arithmetic average value obtained from the three measurements is used. The transmittance of the optical film 10 is determined by the amount of the ultraviolet absorbing agent in the hard coat layer 12, which will be described later. This can be achieved by adjusting the amount of addition, etc.

[0038] From the viewpoint of foldability, the optical film 10 is folded in the following manner. Even after 100,000 repeated folding tests, the optical film did not crack or break. It is preferable that no such phenomenon occurs, and even when a folding test is repeated 200,000 times, It is more preferable that the film 10 does not crack or break. Even if the optical film is heated, it is more preferable that the optical film does not crack or break. When the optical film 10 was repeatedly folded 100,000 times, If cracks or the like occur, the foldability of the optical film 10 will be insufficient.

[0039] Another film such as a polarizing plate is provided on one side of the optical film via an adhesive layer or bonding layer. If the optical film is folded, the folding test shall be performed on the optical film in the same manner as above. This is done after peeling off the adhesive layer and other films from the film. A folding test was conducted on a laminate in which another film was attached to an adhesive layer or a bonding layer on an optical film. When the folding test was conducted, the optical film showed no signs of deterioration even after 10,000 repeated folding tests. Preferably, no cracks or breaks occur.

[0040] The folding test is carried out as follows. As shown in FIG. 3(A), In the process, first, a side portion 1 of the optical film 10 cut to a size of 20 mm×100 mm is 0C and a side portion 10D opposite to the side portion 10C are fixed to each other by the fixing portion 20 arranged in parallel. If the optical film cannot be cut to the above size, a 20mm x 40m cut is used. The optical film may be cut into a size of at least m. The fixed portion 20 is slidable in the horizontal direction.

[0041] Next, as shown in FIG. 3B, the fixing parts 20 are moved closer to each other. Then, the optical film 10 is deformed so as to be folded, and then, as shown in FIG. The distance between the two opposing side portions 10C and 10D of the film 10 fixed by the fixing portion 20 is 6 mm. After moving the fixing part 20 to the position where the optical filter 10 is located, the fixing part 20 is moved in the opposite direction to the position where the optical filter 10 is located. Eliminate the deformation of M10.

[0042] As shown in FIG. 3(A) to (C), the optical film 10 is fixed by moving the fixing portion 20. The optical film 10 can be folded by 180°. A folding test was performed so that the bottom end did not protrude, and the fixing part 20 was closest to the By controlling the distance by a spacer or the like, the distance between the two opposing sides of the optical film 10 is In this case, the outer diameter of the bent portion 10E is considered to be 6 mm.

[0043] In addition, the inorganic layer 13 is on the inside, and the opposing sides 10C and 10D of the optical film 10 are When the test was repeated 100,000 times to fold the material 180 degrees so that the gap between the edges was 2 mm, no cracks were found. In this case, the optical film 10 is fixed at the fixing portion 20. The fixing portion 20 is moved to a position where the distance between the two opposing side portions 10C and 10D is set to 2 mm. After the movement, the fixing portion 20 is moved in the opposite direction to eliminate the deformation of the optical film 10. The folding test is carried out in the same manner as above, except that the folding test is carried out.

[0044] In addition, another film such as a polarizing plate is attached to one side of the optical film 10 via an adhesive layer or a bonding layer. If a film is provided, the film may be removed by the same method as above together with the adhesive layer and the other film. The film is peeled off and then the folding test is carried out. Even if it does, it will not have a significant effect on the folding test.

[0045] The surface 10A of the optical film 10 is defined in JIS K5600-5-4:1999. It is preferable that the hardness (pencil hardness) measured by a pencil hardness test is 2H or more. The pencil hardness test was carried out by applying a pencil to the surface of an optical film cut to a size of 50 mm x 100 mm. Pencil hardness tester (product name: "Pencil scratch coating hardness tester (electric type)" manufactured by Toyo Co., Ltd. A pencil (product name "Uni", manufactured by Mitsubishi Pencil Co., Ltd.) was placed on the This is done by moving the pencil at a speed of 1 mm / sec while applying a weight. The pen hardness is the highest hardness that does not scratch the surface of the optical film in the pencil hardness test. When measuring the pencil hardness, several pencils with different hardness are used. A pencil hardness test was carried out five times for each book, and the optical film surface was not scratched in more than four out of five tests. In this case, it was determined that the surface of the optical film was not scratched by the pencil of this hardness. The above scratches were observed by observing the surface of the optical film after the pencil hardness test under a fluorescent lamp. The pencil hardness of the surface 10A of the optical film 10 is 3H or more. More preferably, it is 5H, and most preferably, it is 6H or more. I wish.

[0046] In recent years, the backlight of image display devices such as personal computers and tablet terminals has become Light emitting diodes (LEDs) are actively used as a light source. However, this light-emitting diode emits a strong light called blue light. Blue light has a wavelength of 380 to 495 nm and is similar to ultraviolet light, making it a strong Because it has high energy, it can reach the retina without being absorbed by the cornea or lens, and it It is said that this can cause damage to the eyes, eye fatigue, and adverse effects on sleep. When this system is applied to an image display device, it is possible to obtain a blue-ray image without affecting the color of the display screen. It is preferable that the light shielding property is excellent. From this viewpoint, the optical film 10 has a spectral transmittance of less than 1% at a wavelength of 380 nm. The spectral transmittance at a wavelength of 410 nm is less than 10%, and the spectral transmittance at a wavelength of 440 nm is It is preferable that the spectral transmittance at a wavelength of 380 nm is 1% or less. If the spectral transmittance at a wavelength of 410 nm is 10% or more, The problem of light cannot be solved, and the spectral transmittance at a wavelength of 440 nm is 7 If it is less than 0%, it will affect the color of the display screen of the image display device using the optical film. The optical film 10 has a wavelength of 100 nm, which is the wavelength of blue light. While it sufficiently absorbs light in the wavelength range below 410 nm, it also fully absorbs light with wavelengths above 440 nm. It allows the majority of the light to pass through, providing excellent blue light blocking without affecting the color of the display screen. In addition, the optical film 1 having such excellent blue light shielding properties can be obtained. When OLED display devices are used as image display devices, It is also effective in suppressing the deterioration of light-emitting diode elements.

[0047] The optical transmittance of the optical film 10 is almost 0% up to a wavelength of 380 nm. The light transmission gradually increases from 400 nm, and the light transmission increases sharply at a wavelength of 440 nm. Specifically, for example, the wavelength is preferably between 410 nm and 440 nm. It is preferable that the light transmittance changes in a sigmoid curve. The spectral transmittance at m is more preferably less than 0.5%, and even more preferably less than 0.2%. The spectral transmittance at a wavelength of 410 nm is preferably less than 7%, more preferably less than 5%. %, and the spectral transmittance at a wavelength of 440 nm is more preferably 75% or more, and even more preferably The optical film 10 has a spectral transmittance of 80% or more at a wavelength of 420 nm. It is preferable that the spectral transmittance is less than 50%. The optical film 10 exhibits a sharp increase in transmittance at a wavelength of about 440 nm. It is possible to obtain extremely excellent blue light blocking properties without affecting the color tone of the surface.

[0048] The optical film 10 has a spectral transmittance of less than 0.1% at a wavelength of 380 nm. More preferably, the spectral transmittance at a wavelength of 410 nm is less than 7%. It is preferable that the spectral transmittance at a wavelength of 440 nm is 80% or more.

[0049] The optical film 10 has a transmittance in the wavelength range of 415 to 435 nm obtained by using the least squares method. It is preferable that the slope of the overspectrum is greater than 2.0. When the slope is 2.0 or less, , and is sufficient in the light wavelength region of blue light, for example, the wavelength region of 415 to 435 nm. The blue light blocking effect may be weakened if the light cannot be blocked. It is possible that the light wavelength range (415-435 nm) is being cut too much. In this case, the backlight of the image display device or the emission wavelength region (for example, the wavelength of OLED is 430 nm) This can cause problems such as poor color reproduction due to interference with the light emitted from the The above slope can be measured, for example, using a spectrophotometer (manufactured by Sigma) that can measure in 0.5 nm increments. Using a UV-3100PC (manufactured by Shimadzu Corporation), a minimum of 5 nm was measured within 1 nm of the It can be calculated by measuring the transmittance data for each point between 415 and 435 nm. Cut.

[0050] The optical film 10 preferably has a blue light blocking rate of 40% or more. If the blue light blocking rate is less than 40%, the problems caused by blue light mentioned above will not be fully resolved. The above blue light blocking rate is, for example, JIS T7333: This is a value calculated by the 2005 standard. Note that such a blue light blocking rate is calculated, for example, as follows: When the hard coat layer 12 contains a sesamol-type benzotriazole monomer described later, can be achieved.

[0051] The use of the optical film 10 is not particularly limited, but examples of the use of the optical film 10 include: For example, smartphones, tablet devices, personal computers (PCs), wearables Image display devices such as mobile terminals, digital signage, televisions, and car navigation systems The optical film 10 is also suitable for use in vehicles. The form of the product is that it is used in applications that require flexibility, such as foldable and rollable. Also preferred.

[0052] The optical film 10 may be cut to a desired size, or may be in a roll. When the optical film 10 is cut to a desired size, the size of the optical film is not particularly limited and is appropriately determined depending on the size of the display surface of the image display device. The size of the optical film 10 is, for example, 2.8 inches or more and 500 inches or less. In this specification, "inch" means that when the optical film has a rectangular shape, It means the length of the diagonal, in the case of a circle, it means the diameter, in the case of an ellipse, The average value of the sum of the minor axis and the major axis is used here. In this case, the aspect ratio of the optical film when calculating the above inches is the display screen of the image display device. There is no particular limitation as long as there is no problem. For example, vertical:horizontal=1:1, 4:3, 16:10, 16 However, especially for in-vehicle applications and digital signage, The aspect ratio of the optical film 10 is not limited to this. If the size is large, cut it out from any position to A5 size (148mm x 210mm). Then, cut out to the size of each measurement item.

[0053] The optical film 10 may be disposed inside the image display device. It is preferable that the surface of the image display device is used near the surface of the image display device. When used in a liquid crystal display, the optical film 10 acts as a cover film in place of a cover glass. It functions as such.

[0054] <<Light transparent base material>> The light-transmitting substrate 11 is a substrate having light-transmitting properties. means the property of transmitting light, for example, a total light transmittance of 50% or more, preferably 70 % or more, more preferably 80% or more, and particularly preferably 90% or more. The term "transparent" does not necessarily mean transparent, but may be semi-transparent.

[0055] The thickness of the light-transmitting substrate 11 is preferably 10 μm or more and 100 μm or less. When the thickness of the light-transmitting substrate is 10 μm or more, curling of the optical film 10 can be suppressed. In addition, the hardness is sufficient, and the pencil hardness can be increased to 3H or more. When manufacturing by roll, wrinkles can be suppressed, so there is no risk of the appearance being deteriorated. On the other hand, if the thickness of the light-transmitting substrate 11 is 100 μm or less, the optical film can be folded without any problems. The thickness of the light-transmitting substrate is measured by scanning electron microscopy. A cross section of the light-transmitting substrate is photographed using a scanning electron microscope (SEM), and the light-transmitting The thickness of the optically transparent substrate is measured at 10 points, and the arithmetic average value of the thicknesses at the 10 points is used. The lower limit of the thickness of the light-transmitting substrate 11 is more preferably 25 μm or more, and the upper limit of the thickness of the light-transmitting substrate 11 is more preferably 80 μm or more. It is more preferable that the length is equal to or less than m.

[0056] The light-transmitting substrate 11 may be made of, for example, a polyimide resin or a polyamide-imide. resins, polyamide resins, polyester resins (e.g., polyethylene terephthalate Among these, the most popular resins for the folding test are Not only is it difficult for cracks or breaks to occur in the coating, but it also has excellent hardness and transparency, It also has excellent heat resistance, and by firing it can be given even greater hardness and transparency. From this viewpoint, polyimide resins, polyamide resins, or mixtures thereof are preferred.

[0057] Polyimide resins are obtained by reacting a tetracarboxylic acid component with a diamine component. The polyimide resin is not particularly limited, but may be, for example, a polyimide resin having excellent light transmittance and From the viewpoint of having excellent rigidity, the following general formula (1) and the following general formula (3) are preferred: It is preferable that the polycyclic aromatic hydrocarbon has at least one structure selected from the group consisting of the following structures:

[0058] [ka]

[0059] In the above general formula (1), R 1 is a tetravalent group which is a tetracarboxylic acid residue, R 2 t trans-Cyclohexanediamine residue, trans-1,4-bismethylenecyclohexane Sandiamine residue, 4,4'-diaminodiphenyl sulfone residue, 3,4'-diaminodiphenyl A divalent group selected from the group consisting of a phenylsulfone residue and a divalent group represented by the following general formula (2): n represents the number of repeating units and is 1 or more. In the details, "tetracarboxylic acid residue" means a residue obtained by isolating four carboxylates from a tetracarboxylic acid. This refers to the residue obtained by removing the silyl group, and is the residue obtained by removing the acid dianhydride structure from a tetracarboxylic dianhydride. The term "diamine residue" refers to a diamine with two amino groups removed. This refers to a residue.

[0060] [ka] In the above general formula (2), R 3 and R 4each independently represents a hydrogen atom, an alkyl group, or a perfluoroalkyl group.

[0061] [ka]

[0062] In the above general formula (3), R 5 is the residue of cyclohexanetetracarboxylic acid, Tantalumtetracarboxylic acid residue, dicyclohexane-3,4,3',4'-tetracarboxylic acid residues, and 4,4'-(hexafluoroisopropylidene)diphthalic acid residues At least one tetravalent group selected from R 6 represents a divalent group which is a diamine residue. n' represents the number of repeating units and is 1 or more.

[0063] In the above general formula (1), R 1 is a tetracarboxylic acid residue, as exemplified above. The above-mentioned tetracarboxylic dianhydride can be a residue obtained by removing the acid dianhydride structure from the above-mentioned tetracarboxylic dianhydride. R in general formula (1) 1 Among other things, the objective is to improve light transmittance and rigidity. From 4,4'-(hexafluoroisopropylidene)diphthalic acid residue, 3,3',4, 4'-biphenyltetracarboxylic acid residue, pyromellitic acid residue, 2,3',3,4'-biphenyltetracarboxylic acid residue Phenyltetracarboxylic acid residue, 3,3',4,4'-benzophenonetetracarboxylic acid Residue, 3,3',4,4'-diphenylsulfonetetracarboxylic acid residue, 4,4'-oxy Diphthalic acid residue, cyclohexanetetracarboxylic acid residue, and cyclopentanetetracarboxylic acid residue It is preferable that the carboxylic acid residue contains at least one selected from the group consisting of carboxylic acid residues, and further contains 4,4'-(Hexafluoroisopropylidene)diphthalic acid residue, 4,4'-oxydiphthalic acid residue from tetracarboxylic acid residues and 3,3',4,4'-diphenylsulfonetetracarboxylic acid residues It is preferable that the compound contains at least one selected from the group consisting of:

[0064] R 1 In the above, it is preferable that the total amount of these suitable residues is 50 mol % or more, and It is preferable that the content is 70 mol % or more, and more preferably 90 mol % or more.

[0065] Also, R 1 3,3',4,4'-biphenyltetracarboxylic acid residue, 3,3' , 4,4'-benzophenonetetracarboxylic acid residues, and pyromellitic acid residues. Tetracarboxylic acids suitable for improving stiffness, such as at least one selected from the group Group A and 4,4'-(hexafluoroisopropylidene)diphthalic acid residues group, 2,3',3,4'-biphenyltetracarboxylic acid residue, 3,3',4,4'-diphenyl Phenylsulfonetetracarboxylic acid residue, 4,4'-oxydiphthalic acid residue, cyclohexa cyclopentanetetracarboxylic acid residues, and cyclopentanetetracarboxylic acid residues. At least one of the tetracarboxylic acid residues suitable for improving transparency is selected from the group consisting of It is also preferable to use a mixture of these with group B).

[0066] In this case, the tetracarboxylic acid residue group (group A) suitable for improving the rigidity and The content ratio of the tetracarboxylic acid residue group (Group B) suitable for improving transparency is as follows: For every 1 mole of tetracarboxylic acid residue group (Group B) suitable for improving transparency, The tetracarboxylic acid residue group (group A) suitable for improving the rigidity is 0.05 mol or less. It is preferably from 0.1 to 5 mol, more preferably from 0.1 to 5 mol. The amount is preferably 0.3 mol or more and more preferably 4 mol or less.

[0067] R in the above general formula (1) 2 Among other things, the objective is to improve light transmittance and rigidity. From the viewpoint of a divalent group represented by the general formula (2) At least one kind of divalent group is preferred, and further, 4,4'-diaminodiphenylsulfonyl is preferably used. a sulfone residue, a 3,4'-diaminodiphenylsulfone residue, and R3 and R4 are A divalent group represented by the above general formula (2), which is a perfluoroalkyl group, is selected from the group consisting of the divalent group represented by the above general formula (2). It is preferable that the aryl group is at least one divalent group.

[0068] R in the above general formula (3) 5 Among other things, the objective is to improve light transmittance and rigidity. From this viewpoint, 4,4'-(hexafluoroisopropylidene)diphthalic acid residue, 3,3' ,4,4'-diphenylsulfonetetracarboxylic acid residue, and oxydiphthalic acid residue It is preferable to do so.

[0069] R 5 In the above, it is preferable that the content of these suitable residues is 50 mol % or more, and more preferably 70 It is preferable that the content is 90 mol % or more, and more preferably 90 mol % or more.

[0070] R in the above general formula (3) 6 is a diamine residue, and the diamines exemplified above are The residue can be obtained by removing two amino groups from R6 in the above general formula (3). Among them, 2,2'-bis(trimethylsilyl)phenylene oxide is preferred from the viewpoint of improving light transmittance and rigidity. Fluoromethyl)benzidine residue, bis[4-(4-aminophenoxy)phenyl]sulf 4,4'-diaminodiphenylsulfone residue, 2,2-bis[4-(4-amino hexafluoropropane residue, bis[4-(3-aminophenoxy)phenyl]hexafluoropropane residue 4,4'-diamino-2,2'-bis(trifluoromethoxy)phenyl]sulfone residue ethyl)diphenyl ether residue, 1,4-bis[4-amino-2-(trifluoromethyl )phenoxy]benzene residue, 2,2-bis[4-(4-amino-2-trifluoromethyl 4,4'-diamino-2-(trifluorophenyl)hexafluoropropane residue, (trifluoromethyl)diphenyl ether residue, 4,4'-diaminobenzanilide residue, N,N'-bis(4-aminophenyl)terephthalamide residue, and 9,9-bis(4- At least one divalent group selected from the group consisting of aminophenyl)fluorene residues It is preferable that the aryl group contains 2,2'-bis(trifluoromethyl)benzidine residue, bis [4-(4-aminophenoxy)phenyl]sulfone residue, and 4,4'-diaminodiphenyl It is preferred that the alkyl group contains at least one divalent group selected from the group consisting of phenyl sulfone residues. It is.

[0071] R 6 In the above, it is preferable that the total amount of these suitable residues is 50 mol % or more, and It is preferable that the content is 70 mol % or more, and more preferably 90 mol % or more.

[0072] Also, R 6As the bis[4-(4-aminophenoxy)phenyl]sulfone residue, 4 ,4'-Diaminobenzanilide residue, N,N'-bis(4-aminophenyl)terephthalic acid amide residue, paraphenylenediamine residue, metaphenylenediamine residue, and 4, At least one selected from the group consisting of 4'-diaminodiphenylmethane residues The diamine residue group (Group C) is suitable for improving rigidity, and the 2,2'-bis(trifluoromethyl) (fluoromethyl)benzidine residue, 4,4'-diaminodiphenylsulfone 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( At least one selected from the group consisting of 4-aminophenyl)fluorene residues It is also preferable to use it in combination with a diamine residue group (group D) suitable for improving transparency. I wish.

[0073] In this case, the diamine residue group (group C) suitable for improving the rigidity and the transparency The content ratio of the diamine residue group (group D) suitable for improving transparency is For 1 mole of the diamine residue group (group D) suitable for improving the rigidity, The amount of the diamine residue group (group C) is preferably 0.05 moles or more and 9 moles or less. The amount is preferably 0.1 mol or more and 5 mol or less, and more preferably 0.3 mol or more and 4 mol or less. It is more preferable to do so.

[0074] In the structures represented by the above general formula (1) and the above general formula (3), n and n' are Each independently represents the number of repeating units, which is 1 or more. The number n may be appropriately selected depending on the structure so as to exhibit a preferred glass transition temperature, which will be described later. The average number of repeating units is usually 10 to 2000, and more preferably 15 It is preferable that the ratio is 1 to 1000.

[0075] The polyimide resin may partially contain a polyamide structure. Examples of polyamide structures that may be used include tricarboxylic acids such as trimellitic anhydride. Polyamide-imide structures containing acid residues and polyamides containing dicarboxylic acid residues such as terephthalic acid are also available. An example of such a structure is a triamide structure.

[0076] From the viewpoint of heat resistance, it is preferable that the polyimide resin has a glass transition temperature of 250° C. or higher. On the other hand, it is preferable that the temperature is 270° C. or higher in view of ease of stretching and low bake temperature. From the viewpoint of reducing the amount of the resin, the glass transition temperature is preferably 400° C. or less, and more preferably 380° C. or less. It is preferable that:

[0077] Specifically, the polyimide resin may be, for example, a compound 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.

[0078] [ka]

[0079]

change

[0080]

change

[0081]

change

[0082]

change

[0083]

change

[0084]

change

[0085]

change

[0086]

change

[0087]

change

[0088]

change

[0089]

change

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] Among the above polyimide resins, the polyimide resin has excellent transparency and is therefore suitable for intramolecular or intermolecular polymerization. Polyimide resins or polyamide resins having a structure in which charge transfer is unlikely to occur are preferred. Specifically, fluorinated polyimide resins such as those represented by the above formulas (4) to (11) and those represented by the above formula (1 Examples of the polyimide resins include those having an alicyclic structure such as 3) to (16).

[0096] In addition, in the fluorinated polyimide resins of the above formulas (4) to (11), etc., the fluorinated structure It has high heat resistance due to its structure, and is a polyimide film made of polyimide resin. It has excellent transparency because it is not discolored by the heat during the manufacturing process.

[0097] Polyamide resins include not only aliphatic polyamides but also aromatic polyamides (aramids). Polyamide resins are generally represented by the following formulas (21) and (22): The polyamide resin has a skeleton represented by the following formula ( 23) In the following formula, n is a repeating unit, and Represents an integer greater than or equal to 1.

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] Polyimide resins or polyamides represented by the above formulas (4) to (20) and (23) The substrate made of the polyimide-based resin may be a commercially available one. Examples of commercially available products of the above include Neoprim manufactured by Mitsubishi Gas Chemical Co., Ltd. Commercially available products of substrates made of polyamide resins include, for example, Miktron manufactured by Toray Industries, Inc. Examples include:

[0102] The polyimide resin or polyimide resin represented by the above formulas (4) to (20) and (23) is also The substrate made of an amide resin may be synthesized by a known method. For example, The method for synthesizing the polyimide resin represented by the above formula (4) is described in JP 2009-132091 A. Specifically, the compound is a 4,4'-hexafluoropropane compound represented by the following formula (24): Pyridenebisphthalic dianhydride (FPA) and 2,2'-bis(trifluoromethyl)-4 ,4'-diaminobiphenyl (TFDB) can be obtained by reacting with [ka]

[0103] The weight average molecular weight of the polyimide resin or polyamide resin is 3000 or more and 50 It is preferable that the range is 5,000 to 300,000, and more preferable that the range is 5,000 to 300,000. More preferably, the weight average molecular weight is in the range of 10,000 to 200,000. If it is more than 500,000, the viscosity increases and the solubility decreases. As a result, it may not be possible to obtain a substrate with a smooth surface and a uniform film thickness. In this document, "weight average molecular weight" is measured by gel permeation chromatography (GPC). This is a polystyrene equivalent value determined.

[0104] Among the above polyimide-based resins and polyamide-based resins, the resin has excellent transparency. A polyimide resin having a structure in which intramolecular or intermolecular charge transfer is unlikely to occur, Polyamide resins are preferred, and specifically, fluorinated polyamides such as those represented by the above formulas (4) to (11) are preferred. polyimide resins having an alicyclic structure such as those represented by the above formulas (13) to (16); (23) and other halogen-containing polyamide resins.

[0105] In addition, in the fluorinated polyimide resins of the above formulas (4) to (11), etc., the fluorinated structure Due to its structure, it has high heat resistance and is able to withstand the heat generated during the production of the polyimide resin base material. Since it is not colored by, it has excellent transparency.

[0106] The light-transmitting substrate 11 has a surface 13A of the inorganic layer 13 that satisfies JIS K5600-5-4: The test was performed under the conditions of the pencil hardness test (load: 1 kg, speed: 1 mm / sec) specified in the 1999 standard. From the viewpoint that the hardness can be increased to 3H or more, Fluorinated polyimide resins or halogen-containing polyamides such as those represented by the above formula (23) It is preferable to use a substrate made of a resin having a pencil hardness of 3H or more. Since excellent hardness can be imparted to the polyimide-based resin represented by the above formula (4), It is more preferable to use a substrate.

[0107] Examples of polyester resins include polyethylene terephthalate and polypropylene. terephthalate, polybutylene terephthalate, polyethylene naphthalate Examples of resins that contain one type of component include:

[0108] <<Hard coat layer>> The hard coat layer 12 has an indentation hardness (H IT ) In this specification, the term "indentation hardness" refers to the hardness measured by the nanoindentation method. The value obtained from the load-displacement curve from loading to unloading of the indenter obtained by hardness measurement using The indentation hardness (H IT ) has a lower limit of 200MP a or more, 500 MPa or more, and 800 MPa or more are preferable in that order (the larger the value, the more preferable). The upper limit of the indentation hardness of the hard coat layer 12 is In order to suppress the occurrence of breakage or cracks in the hard coat layer 12 when the sheet is folded, The order of preference is 00MPa or less, 1300MPa or less, and 1100MPa or less (the smaller the value, the the more the better).

[0109] The indentation hardness (H IT ) Measurement of the measurement sample HYSITR This is done using the "TI950 TriboIndenter" manufactured by ON (Hygitron). Specifically, first, an optical film cut to 1 mm x 10 mm is embedded in resin. The embedded block was prepared by the above method, and the hole was cut from the block by a general sectioning method. Cut out uniform sections with a thickness of 70 nm to 100 nm. "Ultramicrotome EM UC7" (Leica Microsystems, Inc.) etc. Then, the remaining block from which the uniform slices without holes were cut is The measurement sample is then cut out from the above-mentioned section of the measurement sample. In the cross section obtained by the above, a Berkovich ( Berkovich) indenter (triangular pyramid, BRUKER TI-0039) was placed on the hard coat The cross section of the layer is pressed vertically with a maximum pressing load of 500 μN for 25 seconds. In order to avoid the influence of the light-transmitting substrate and the inorganic layer, the Berkovich indenter was used. In order to avoid the influence of the side edge of the hard coat layer, 500 nm away from the interface between the hard coat layer and the inorganic layer toward the center of the hard coat layer. The hard coat layer was then placed 500 nm apart from each other, and 50 nm from each end of the hard coat layer toward the center of the hard coat layer. The hard coat layer is pressed into the light-transmitting substrate and the hard coat layer. When a functional layer is present between the hard coat layer and the functional layer, the hard coat layer is The hard coat layer is 500 nm away from the interface between the hard coat layer and the inorganic layer. The hard coat layer is then placed at a distance of 500 nm from the center of the hard coat layer. The sample is then pushed into the hard coat layer at a distance of 500 nm from the sample side. After the residual stress was relieved, the load was removed for 25 seconds and the maximum load after the relaxation was measured. The maximum load P max (μN) and contact projection area A p (nm 2 ) and P max / A p To Therefore, the indentation hardness (H IT The contact projected area is calculated as The Oliver-Pharr method was used to press the fused quartz (BRUKER 5-0098). The contact projected area is the area corrected for the tip curvature. IT ) is 10 The arithmetic mean value is taken from the values ​​measured at each point. Note that the measured values ​​may vary by ±20 from the arithmetic mean value. If any measurement value is out of range by more than 10%, that measurement value shall be excluded and remeasured. Whether any of the measured values ​​deviate from the arithmetic mean by ±20% or more is determined by comparing the measured values. If A is the average value and B is the arithmetic mean value, the value (%) calculated by (AB) / B×100 The indentation hardness (H I T ) can be adjusted by the type of binder resin 12A and the content of inorganic particles 12B, which will be described later. Cut. (Measurement conditions) ·Loading speed: 20μN / sec ·Holding time: 5 seconds ·Loading and unloading speed: 20μN / sec ·Measurement temperature: 25℃

[0110] The thickness of the hard coat layer 12 is 1 μm or more. If the thickness is 1 μm or more, the degree of penetration of steel wool during steel wool testing is small. This can prevent the surface of the hard coat layer from being scratched. The lower limit of 12 is more preferably 2 μm or more, 3 μm or more, and 4 μm or more in that order (the larger the value, the more preferable the The upper limit of the hard coat layer 12 is 100% from the viewpoint of obtaining sufficient folding performance. The more preferable values ​​are 0 μm or less, 9 μm or less, 8 μm or less, and 7 μm or less (the smaller the value, the more preferable the value). is more preferable).

[0111] The thickness of the hard coat layer was measured using a scanning transmission electron microscope (STEM) or a transmission electron microscope. A cross section of the hard coat layer was photographed using a transmission electron microscope (TEM), and the hard coat layer was The thickness of the coating layer is measured at 10 points, and the arithmetic average value of the thicknesses at the 10 points is used. The method for taking surface photographs is described below. First, cut the optical film to a size of 1 mm x 10 mm. A block was prepared by embedding the specimen in resin, and then sections were prepared from the block using the general sectioning method. The slices are cut out with a thickness of 70 nm to 100 nm and are uniform and free of holes. The preparation was performed using an ultramicrotome EM UC7 (Leica Microsystems, Inc.). The uniform slice without holes is used as the measurement sample. After that, a scanning transmission electron microscope (STEM) (product name: S-4800, Hitachi Ltd. The cross-sectional photograph of the measurement sample is taken using the S-480 (manufactured by High Technologies). When taking cross-sectional photographs using 0, the detector is set to "TE", the accelerating voltage to "30kV", The cross-section is observed with the transmission current set to "10μA". The magnification is adjusted by adjusting the focus. Observe the contrast and brightness of each layer at 5,000 to 200,000 magnifications. The magnification is preferably 10,000 to 100,000 times, and more preferably 10,000 to 50,000 times. The most preferable magnification is 25,000 to 50,000. When taking cross-sectional photographs, the aperture is set to "Beam monitor aperture 3" and The objective lens aperture may be set to "3" and the WD may be set to "8 mm." Hard coat layer When measuring the thickness of the hard coat layer, the hard coat layer and other layers (e.g., functional layer) were observed during cross-sectional observation. It is important to be able to observe the interface contrast between the two as clearly as possible. If the interface is difficult to see due to lack of last, use osmium tetroxide, ruthenium tetroxide, phosphorus The interface between the organic layers can be easily seen by staining with tungstic acid, so we performed the staining process. Also, the contrast of the interface may be difficult to see at higher magnifications. In that case, observe at lower magnifications at the same time. For example, 25,000x and 50,000x, or 50,000x and 10 Observe at two magnifications, high and low, such as 10,000 times, and calculate the arithmetic mean value at both magnifications. The average value is regarded as the thickness of the hard coat layer.

[0112] The hard coat layer 12 contains a binder resin 12A and inorganic particles 12B. The hard coat layer 12 contains a binder resin 12A and inorganic particles 12B, as well as an ultraviolet absorbing agent, a spectrophotometer, and the like. Additives such as transmittance adjusters may also be included.

[0113] In the cross section of the hard coat layer 12 in the thickness direction shown in FIG. A region IR (hereinafter, This region is sometimes referred to as the "near-interface region." The surface area of ​​the inorganic particles in the interface vicinity region IF is preferably 5% or more and 75% or less. If the volume ratio is 5% or more, the hard coat layer 12 contains a large amount of inorganic particles 12B. Therefore, the hard coat layer 12 can be made harder and the adhesion to the inorganic layer 13 can be improved. In addition, the steel wool test applies a load to the surface of the inorganic layer. However, the surface of the inorganic layer is rubbed with steel wool, so the inorganic layer is rubbed only in the thickness direction. The load is also applied in the shear direction. If the volume ratio is 75% or less, the steel wool test applies a load in the shear direction. Even in this case, the binder resin 12A is present to a certain extent in the hard coat layer 12. In addition, the hard coat layer 12 is not easily scratched or scraped. The presence of A to a certain extent can further improve adhesion to the functional layer 14. Here, the area ratio of the inorganic region in the region near the interface is calculated because When conducting a water wool test, the area near the interface is particularly susceptible to scratches and chipping. The lower limit of the area ratio of the inorganic particles 12B in the interface vicinity region IF is 23% or more. More preferably, the range is 33% or more, and 44% or more (the larger the value, the more preferable). The upper limit of the area ratio of the inorganic particles 12B in the surface vicinity region IF is 71% or less, 67% or less, It is more preferable if the value is 60% or less (the smaller the value, the more preferable).

[0114] The area ratio of the inorganic particles in the region near the interface is calculated as follows. First, the optical film cut to 1 mm × 10 mm was embedded in embedding resin. A block was prepared, and a uniform thickness of 7 mm was cut from the block using a general sectioning method. Cut out 10 sections with a thickness of 100 nm or more and 100 nm or less. "Tom EM UC7" (Leica Microsystems, Inc.) can be used. Then, these 10 uniform pieces without holes were used as the measurement samples. A cross-section of each measurement sample was taken using a microscope (TEM) or a scanning transmission electron microscope (STEM). Take a photograph. Note that a cross-sectional photograph should be taken at one location per measurement sample. Scanning transmission electron microscope (STEM) (product name: S-4800, Hitachi High-Tech Corporation) When taking cross-sectional photographs of each measurement sample using a measuring instrument (manufactured by Epson), In the case of shadowing, the detector was set to "TE", the acceleration voltage to "30 kV", and the emission current to "10 μ For magnification, adjust the focus and contrast and brightness so that each layer is clearly visible. While observing whether the specimen can be separated, adjust the magnification appropriately from 5,000 to 200,000. The preferred magnification is 10,000. 10,000 to 100,000 times, more preferably 10,000 to 50,000 times, and most preferably 25,000 times In addition, when taking cross-sectional photographs, the aperture is set to "Beam Monitor". You can also set the objective lens aperture to "3" and the WD to "8 mm." In the 10 cross-sectional photographs obtained, the area of ​​the region near the interface was set as 100%, and the area of ​​the region near the interface was set as 100%. The ratio of the area of ​​the inorganic particles to the area of ​​the interface vicinity region (area ratio) is calculated. The area ratio of inorganic particles in the region was calculated from 10 cross-sectional photographs of the region near the interface. The arithmetic average value of the area ratio of the inorganic particles 12B is used. For example, the inorganic particles 12B are mixed with a polymerizable compound that becomes the binder resin 12A after curing. The content (weight ratio) is 10% or more and 300% or less, preferably 10% or more and 200% or less. It is preferable that

[0115] The surface of the hard coat layer 12 on the inorganic layer 13 side is selectively etched to remove the binder resin 12A. The inorganic particles 12B may be exposed by a process such as coating. By carrying out such a treatment, the adhesion between the hard coat layer 12 and the inorganic layer 13 is further improved. However, if this treatment is carried out excessively, the surface of the hard coat layer may become rough. The surface of the inorganic layer becomes rough and the inorganic layer is thin, so the surface shape of the hard coat layer is irregular. When the steel wool test is performed, the surface of the inorganic layer is affected by the surface shape of the inorganic layer. There is a risk that the steel wool will get caught in the unevenness present, reducing scratch resistance. Methods for selectively etching the binder resin include, for example, glow discharge treatment, plasma etching, etc. Examples of the treatment include a fluorine treatment, an ion etching treatment, and an alkali treatment.

[0116] <Binder resin> The binder resin 12A is a polymer (hardened product) of a polymerizable compound (hardening compound) and a thermoplastic resin. The polymerizable compound includes at least one of a radical polymerizable functional group and a plastic resin. and has at least one cationic polymerizable functional group. A polymerizable compound having a functional group is called a radical polymerizable compound, and a polymerizable compound having a cationic polymerizable functional group is called a cationic polymerizable compound. The polymerizable compound that polymerizes in this way is called a cationic polymerizable compound. Examples of radical polymerizable functional groups include Examples of such ethylenically unsaturated groups include (meth)acryloyl groups, vinyl groups, and allyl groups. In addition, the term "(meth)acryloyl group" refers to both "acryloyl group" and "methacryloyl group." The cationic polymerizable functional group includes a hydroxyl group, a carboxyl group, and a carboxyl group. groups, isocyanate groups, amino groups, cyclic ether groups, mercapto groups, etc.

[0117] The binder resin 12A has a polymerizable functional group equivalent (weight average molecular weight / number of polymerizable functional groups) of 13. It is preferable that the polymerizable compound does not contain more than 10% by mass of such a polymerizable compound. By not including the substance in an amount of 10 mass % or more, hardness can be imparted to the hard coat layer 12, Even when a steel wool test was performed on the surface 10A of the optical film 10, no scratches were observed. In addition, the adhesion between the hard coat layer 12 and the functional layer 14 is improved. It can be raised.

[0118] As the radical polymerizable compound, a polyfunctional (meth)acrylate is preferable. Examples of (meth)acrylates include trimethylolpropane tri(meth)acrylate. acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate acrylate, dipropylene glycol di(meth)acrylate, pentaerythritol Pentaerythritol tri(meth)acrylate, Pentaerythritol tetra(meth)acrylate, Di Pentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate ) acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane Panthylene tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate , dipentaerythritol penta(meth)acrylate, tripentaerythritol octyl Tetrapentaerythritol deca(meth)acrylate, isopropyl alcohol Cyanuric acid tri(meth)acrylate, isocyanuric acid di(meth)acrylate, polyethylene Steltri(meth)acrylate, polyester di(meth)acrylate, bisphenol Diglycerol tetra(meth)acrylate, adamantyl diacrylate (Meth)acrylate, Isobornyl di(meth)acrylate, Dicyclopentane di(meth)acrylate meth)acrylate, tricyclodecane di(meth)acrylate, ditrimethylolpropane Tetra(meth)acrylate and those modified with PO, EO, caprolactone, etc. The following are some of the reasons.

[0119] Among these, 3 to 6 is preferable because it can satisfactorily satisfy the above-mentioned indentation hardness. Functional ones are preferred, for example, pentaerythritol triacrylate (PETA), Dipentaerythritol hexaacrylate (DPHA), Pentaerythritol tetraacrylate Acrylate (PETTA), Dipentaerythritol Pentaacrylate (DPPA) , Trimethylolpropane tri(meth)acrylate, Tripentaerythritol octadecyl (meth)acrylate, tetrapentaerythritol deca(meth)acrylate, etc. are preferred. In this specification, (meth)acrylate means acrylate and methacrylate. This means the rate.

[0120] In order to adjust the hardness and viscosity of the composition, improve adhesion, etc., a monofunctional (meth)acrylic acid may be further added. The monofunctional (meth)acrylate monomer may include a methacrylate monomer. For example, hydroxyethyl acrylate (HEA), glycidyl methacrylate, Polyethylene glycol (meth)acrylate, isostearyl (meth)acrylate , 2-Acryloyloxyethyl succinate, acryloylmorpholine, N-Acryloyl Triethyloxyethylhexahydrophthalimide, Cyclohexyl acrylate, Tetrahydantoyl Drofulyl acrylate, isobornyl acrylate, phenoxyethyl acrylate, and adamantyl acrylate.

[0121] From the viewpoint of improving the hardness of the hard coat layer 12, the weight average molecular weight of the monomer is It is preferably less than 1000, and more preferably 200 to 800. The weight average molecular weight of the copolymer is preferably 1,000 or more and 20,000 or less, and more preferably 1,000 or more. It is more preferable that the number is 10,000 or less, and further more preferable that the number is 2,000 or more and 7,000 or less. stomach.

[0122] The cationic polymerizable compound is not particularly limited, and examples thereof include epoxy compounds, polyols, and the like. compounds, isocyanate compounds, melamine compounds, urea compounds, phenol compounds, etc. Examples include:

[0123] Examples of the thermoplastic resin include styrene-based resin, (meth)acrylic resin, vinyl acetate resin, etc. vinyl ether resin, halogen-containing resin, alicyclic olefin resin, polycarbonate Carbonate resins, polyester resins, polyamide resins, cellulose derivatives, silicones Examples of the resin include carbon-based resins and rubber or elastomers.

[0124] <Inorganic particles> The inorganic particles 12B are particles mainly composed of inorganic matter. However, it is preferable that the inorganic particles 12B are composed only of inorganic substances. The inorganic particles 12B may be surface-treated with an organic component. As long as the hardness can be improved, there is no particular limitation, but from the viewpoint of obtaining excellent hardness, silica Particles are preferred.

[0125] Among the silica particles, reactive silica particles are preferred. The silica particles are capable of forming a crosslinked structure with a functional (meth)acrylate, By including these reactive silica particles, the hardness of the hard coat layer can be sufficiently increased. Cut.

[0126] The reactive silica particles preferably have a reactive functional group on the surface thereof. As the functional group, for example, the above-mentioned polymerizable functional groups are preferably used.

[0127] The reactive silica particles are not particularly limited, and any conventionally known reactive silica particles may be used. For example, reactive silica particles described in JP-A-2008-165040 can be mentioned. In addition, examples of commercially available reactive silica particles include MIB K-SD, MIBK-SDMS, MIBK-SDL, MIBK-SDZL, JGC Catalysts & Chemicals Examples include V8802 and V8803 manufactured by Co., Ltd.

[0128] The silica particles may be spherical silica particles, but are preferably irregular shaped silica particles. In addition, the term "spherical silica particles" as used herein refers to, for example, spherical, elliptical, or the like. The term "irregularly shaped silica particles" refers to randomly shaped silica particles such as potato-shaped particles. The irregular shaped silica particles have a surface area of ​​100 to 200 nm. Since the irregular silica particles are larger than spherical silica particles, the inclusion of such irregular silica particles improves the above The contact area with the polyfunctional (meth)acrylate increases, and the hardness of the hard coat layer increases. The irregular shaped silica particles can be determined by a transmission electron microscope (TEM). Alternatively, this can be confirmed by observing the cross section of the functional layer using a scanning transmission electron microscope (STEM). can.

[0129] The average particle size of the silica particles is preferably 8 nm or more and 100 nm or less. If the average particle size of the inorganic particles is 8 nm or more, sufficient adhesion to the inorganic layer 13 can be obtained. If the average particle size of the silica particles is 100 nm or less, whitening can be suppressed. The order of the thickness is more preferably 65 nm or less, 40 nm or less, and 25 nm or less (the smaller the value, the more preferable the thickness). In the case where the silica particles are spherical, the average particle size of the silica particles is preferably From images taken with a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) The value is measured using image processing software. In the case of a silica particle, the average particle size of the silica particles can be determined by transmission electron microscopy (TEM) or scanning electron microscopy (SEM). The distance between two points on the periphery of an irregularly shaped silica particle shown in an image taken with a transmission electron microscope (STEM) The distance is the average of the maximum distance (longer diameter) and the minimum distance (shorter diameter).

[0130] It is preferable to use a mixture of two or more types of silica particles. For example, the silica particles may be a mixture of the reactive silica particles and non-reactive silica particles, or A mixture of first silica particles and second silica particles having a particle size smaller than that of the first silica particles. In the case where a mixture of the reactive silica particles and the non-reactive silica particles is used, In addition, curling can be suppressed while maintaining adhesion to the inorganic layer 13 and scratch resistance. When a mixture of the first silica particles and the second silica particles is used, the hard coat layer The hardness can be further improved, and thus the scratch resistance can be further improved. .

[0131] <Ultraviolet absorbing agent> Optical films are used in mobile devices such as bendable smartphones and tablet computers. However, such mobile terminals are often used outdoors, and Therefore, the polarizer placed closer to the display element than the optical film is easily exposed to ultraviolet light and deteriorates. In response to this problem, the hard coat layer is disposed on the display screen side of the polarizer. Therefore, if the hard coat layer contains an ultraviolet absorbing agent, the polarizer will be exposed to ultraviolet light. This makes it possible to effectively prevent deterioration due to heat.

[0132] Examples of the ultraviolet absorbing agent include triazine-based ultraviolet absorbing agents and benzophenone-based ultraviolet absorbing agents. absorbents and benzotriazole-based ultraviolet absorbents.

[0133] 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-dodecyloxypropionyl) Pyr)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

[0036] -4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, etc. Commercially available triazine-based UV absorbers include, for example, TINUVIN 46 0, TINUVIN477 (both manufactured by BASF), LA-46 (ADEK Corporation) A) and others.

[0134] The benzophenone-based ultraviolet absorber may, for example, be 2-hydroxybenzophenone. , 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethox Dibenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy Hydroxy-4-methoxybenzophenone, Hydroxymethoxybenzophenone sulfonic acid and Examples thereof include its trihydrate and sodium hydroxymethoxybenzophenone sulfonate. Commercially available benzophenone-based UV absorbers include, for example, CHMASSORB8. 1 / FL (manufactured by BASF) and the like.

[0135] The benzotriazole-based ultraviolet absorber is, for example, 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol- 2-(2H-benzotriazol-2-yl)phenyl]propionate )-6-(linear and branched chain dodecyl)-4-methylphenol, 2-[5-chloro(2H) -Benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol , 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenyl 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-( 2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)benzotriazole Azole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5 -Chlorobenzotriazole, 2-(2'-hydroxy-3'-(3'',4'',5' ',6''-Tetrahydrophthalimidomethyl)-5'-methylphenyl)benzotriazole 2,2-methylenebis(4-(1,1,3,3-tetramethylbutyl)-6-( 2H-benzotriazol-2-yl)phenol) and 2-(2'-hydroxy- 3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, etc. Examples of commercially available benzotriazole-based ultraviolet absorbers include KE MISORB71D, KEMISORB79 (both manufactured by Chemipro Chemical Co., Ltd.), J F-80, JAST-500 (both manufactured by Johoku Chemical Industry Co., Ltd.), ULS-1933 D (Lion Specialty Chemicals Co., Ltd.), RUVA-93 (Otsuka Chemical Co., Ltd.), (manufactured by the Company)

[0136] Among the ultraviolet absorbents, triazine-based ultraviolet absorbents and benzotriazole-based ultraviolet The ultraviolet absorbing agent is preferably used. The ultraviolet absorbing agent has high solubility in the resin component constituting the functional layer. It is preferable that the bleed-out after the folding test described above is small. The ultraviolet absorbing agent is preferably polymerized or oligomerized. The absorbent is a polymer with a benzotriazole, triazine, or benzophenone skeleton. Preferably, the compound has a benzotriazole or benzophenone skeleton. (Meth)acrylate having the above structure and methyl methacrylate (MMA) are mixed in an arbitrary ratio and then heated. It is preferable that the polymer is polymerized. When applying optical films, UV absorbers also play a role in protecting OLEDs from UV rays. It can be achieved.

[0137] The content of the ultraviolet absorbing agent is not particularly limited, but is preferably 100% by weight of the solid content of the functional layer composition. It is preferable that the amount of the hydroxypropyl ether is 1 part by mass or more and 6 parts by mass or less. The effect of including the ultraviolet absorbing agent in the functional layer may not be fully obtained. If the amount exceeds 6 parts by mass, the functional layer may be significantly discolored or have a reduced strength. The more preferable lower limit of the content of the absorbent is 2 parts by mass or more, and the more preferable upper limit is 5 parts by mass or less. be.

[0138] <Spectral transmittance adjuster> The spectral transmittance adjusting agent adjusts the spectral transmittance of the optical film. The layer 12 is, for example, a sesamol-type benzotriazole-based monomer represented by the following general formula (21): When the monomer is contained, the above-mentioned spectral transmittance can be satisfactorily satisfied.

[0139] [ka]

[0140] In the formula, R 7 R represents a hydrogen atom or a methyl group. 8 is a straight or branched chain with 1 to 6 carbon atoms represents a chain alkylene group or a linear or branched oxyalkylene group having 1 to 6 carbon atoms. vinegar.

[0141] The sesamol-type benzotriazole monomer is not particularly limited, but specifically The name of the substance is 2-[2-(6-hydroxybenzo[1,3]dioxole-5-yl] 2-[2-(6- Hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazole-5 -yl]ethyl acrylate, 3-[2-(6-hydroxybenzo[1,3]dioxo 2H-benzotriazol-5-yl]propyl methacrylate, 3- [2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazole Azol-5-yl]propyl acrylate, 4-[2-(6-hydroxybenzo[1, 3]Dioxol-5-yl)-2H-benzotriazol-5-yl]butyl methacrylate Late, 4-[2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H -benzotriazol-5-yl]butyl acrylate, 2-[2-(6-hydroxybenzoyl) Benzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yloxy ]ethyl methacrylate, 2-[2-(6-hydroxybenzo[1,3]dioxole- 5-yl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[ 3-{2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-benzo Triazol-5-yl}propanoyloxy]ethyl methacrylate, 2-[3-{2- (6-Hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol 4-[3-{2-(6-hydroxy-5-yl}propanoyloxy]ethyl acrylate (xybenzo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl }propanoyloxy]butyl methacrylate, 4-[3-{ 2 -(6-hydroxybenzoyl {zo[1,3]dioxol-5-yl)-2H-benzotriazol-5-yl}propan noyloxy]butyl acrylate, 2-[3-{2-(6-hydroxybenzo[1,3 ]dioxol-5-yl)-2H-benzotriazol-5-yl}propanoyloxy 2-[3-{2-(6-hydroxybenzo[1,3]dioxa]ethyl methacrylate 2H-benzotriazol-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]dioxole- 5-yl)-2H-benzotriazole-5-carboxylate, 4-(methacryloyl 2-(6-hydroxybenzo[1,3]dioxol-5-yl)-2H-oxybutyl -Benzotriazole-5-carboxylate, 4-(acryloyloxy)butyl 2- (6-Hydroxybenzo[1,3]dioxol-5-yl)-2H-benzotriazol In addition, these sesamol-type benzotriesters can be used as benzotriesters. The riazole monomer may be used alone or in combination of two or more.

[0142] The sesamol-type benzotriazole monomer is contained in the hard coat layer 12. In this case, for example, the sesamol-type benzotriazole monomer is It is preferable that the content is 15 to 30 mass %. The inclusion of azotriazole monomer makes it possible to satisfy the above-mentioned spectral transmittance. In addition, the sesamol-type benzotriazole monomer can be used in the hard coat layer 12. In addition, it may react with the resin component constituting the hard coat layer 12 and be contained therein integrally. However, it may be contained alone without reacting with the resin component constituting the hard coat layer 12. stomach.

[0143] <<Inorganic layer>> The inorganic layer 13 is a layer mainly made of an inorganic material. For example, the inorganic material in the inorganic layer is If the inorganic layer 13 contains an organic component, the inorganic layer 13 is considered to be an inorganic layer. However, it is preferable that the hard coat layer 12 is made of only inorganic materials. Whether the layer corresponds to an inorganic layer or not can be determined by X-ray photoelectron spectroscopy (X-Ray Photoelectron Spectroscopy). electron spectroscopy: XPS or Electron Spectroscopy Electroscopy for Chemical Analysis (ESCA) This can be confirmed.

[0144] The inorganic layer 13 may be made of a metal such as Ti, Al, Mg, or Zr, or may be made of silicon oxide. (SiO x (x=1~2)), aluminum oxide, silicon oxynitride, aluminum oxynitride Inorganic oxides such as aluminum, magnesium oxide, zinc oxide, indium oxide, tin oxide, and yttrium oxide Examples of the oxides include inorganic oxides, inorganic nitrides, and diamond-like carbon. From the viewpoint of improving transmittance and scratch resistance, silicon oxide is preferred.

[0145] The inorganic layer 13 preferably contains silicon. When the inorganic layer 13 contains silicon, Whether or not the inorganic layer contains silicon can be determined by X-ray photoelectron spectroscopy. Analysis method (X-Ray Photoelectron Spectroscopy:XPS or Electron Spectroscopy for Chemical An This can be confirmed by ESCA.

[0146] The thickness of the inorganic layer 13 is preferably 10 nm or more and 300 nm or less. If the thickness of the layer 13 is 10 nm or more, excellent scratch resistance can be imparted. If the thickness is 00 nm or less, the adhesiveness to other layers is good without affecting the flexibility or optical properties. The lower limit of the film thickness of the organic layer 13 is more preferably 30 nm or more, 50 nm or more, and 80 nm or more, in that order. The upper limit is 250 nm or less, 200 nm or less, and 150 nm or less. The thickness of the inorganic layer 13 is preferably in the range of 100 to 2000 nm (the smaller the value, the more preferable). The thickness of the hard coat layer 12 is determined in the same manner as that of the hard coat layer 12.

[0147] In the inorganic layer 13, the water vapor transmission rate (WVTR) at 40° C. and a relative humidity of 90% Vapor Transmission Rate: 100g / (m 2 -24 hours or less is preferred. The higher the temperature and the higher the relative humidity, the worse the folding resistance. This is because 3 allows moisture to permeate, and the moisture causes hydrolysis of the hard coat layer. It is considered that the water vapor transmission rate of the inorganic layer 13 is 100 g / (m 2 24 hours or less This reduces the amount of moisture that permeates the inorganic layer 13, making it possible to improve the hard coat. The hydrolysis of the layer can be suppressed. The water vapor permeability is JIS K7129:2008 The water vapor transmission rate is a value obtained by a method that conforms to the standards. The measurement can be performed using a PERMATRAN-W3 / 31 (manufactured by MOCON). The water vapor transmission rate is the average value obtained by measuring three times.

[0148] The inorganic layer 13 can be formed by using a deposition method such as a PVD method or a CVD method. Examples of the PVD method include vacuum deposition, sputtering, and ion plating. Examples of the vacuum deposition method include the electron beam (EB) heating method. Examples of the method include a vacuum deposition method using a high-frequency dielectric heating system, and a vacuum deposition method using a high-frequency dielectric heating system.

[0149] <<Functional Layer>> The functional layer 14 is a layer that exerts some function in the optical film 10. Examples of the functional layer 14 include an optical adjustment layer, an antistatic layer, and the like. For example, the functional layer 14 may have an optical adjustment function and an antistatic function. Alternatively, the layer may have both functions.

[0150] The thickness of the functional layer 14 is preferably 30 nm or more and 200 nm or less. If the thickness of the layer 14 is 30 nm or more, the hard coat layer 12 and the optical adjustment layer 14 can be sufficiently bonded to each other. Adhesion can be ensured, and if the thickness is 200 nm or less, interference fringes can be further suppressed. The lower limit of the functional layer 14 is more preferably 50 nm or more, 70 nm or more, and 90 nm or more in that order. The larger the value, the better), the upper limit is 150nm or less, 140nm or less, 130nm or less The thickness of the functional layer 14 is preferably in the order of 100 to 200 mm (the smaller the value, the more preferable). The thickness of the insulating layer 12 is determined in the same manner as that of the insulating layer 12.

[0151] <Optical adjustment layer> Generally, the resin that makes up a bendable light-transmitting substrate has a high refractive index, so The refractive index difference between the light-transmitting substrate and the hard coat layer becomes large. Due to the difference in refractive index, there is a risk of occurrence of interference fringes, which are rainbow-like irregularities. The optical adjustment layer is a layer for suppressing the occurrence of interference fringes. From this viewpoint, the refractive index of the hard coat layer 12 is set to be lower than that of the light-transmitting substrate 11 and The refractive index of the optical adjustment layer is preferably higher than 0.01. When the refractive index of the optical adjustment layer is measured by the Becke method, the defect of the optical adjustment layer can be Ten pieces were cut out, and the refractive index was measured using a standard liquid. The refractive index of each piece was measured by the method, and the average value of the 10 measured refractive indexes was used as the optical adjustment layer. The refractive index of the light-transmitting substrate 11 and the hard coat layer 12 is also set to be equal to the refractive index of the optical adjustment layer. It can be measured by the same method as above.

[0152] The difference in refractive index between the optical adjustment layer and the hard coat layer 12 (refractive index of the optical adjustment layer - hard coat layer The refractive index difference is preferably 0.005 or more and 0.100 or less. If it is 0.005 or more, the interface reflection occurs between the optical adjustment layer and the hard coat layer 12. The interference fringes can be made invisible, and if it is less than 0.100, the interference fringes will be Although some difference in refractive index is observed, it can be reduced to a level that does not cause any problems in practical use. The upper limit is preferably 0.007 or more, and more preferably 0.090 or less. The refractive index of the optical adjustment layer may be not less than 0.010 and not more than 0.080.

[0153] The optical adjustment layer may be made of only resin, but it is also preferable to use a binder resin and a material for adjusting the refractive index. It is preferable that the optical control particles are contained. In addition to the optical control function, the optical control particles also have an antistatic function. In order to achieve the above-mentioned effect, the optical adjustment layer may further contain an antistatic agent. The binder resins are (meth)acrylic resins, cellulose resins, urethane resins, and chloride resins. Vinyl resin, polyester resin, polyolefin resin, polycarbonate, nylon At least one resin selected from the group consisting of styrene, polystyrene, and ABS resin. The particles of the optical adjustment layer 14 are preferably made of a material with a low refractive index such as silica or magnesium fluoride. Metal oxide particles such as titanium oxide and zirconium oxide, inorganic pigment particles such as cobalt blue It is preferable that the material is at least one selected from the group consisting of: From the viewpoint of adhesion and refractive index difference adjustment, polyester resin and titanium oxide or zirconium oxide are used. A combination with metal oxide particles such as titanium dioxide is more preferable.

[0154] <Antistatic layer> The antistatic layer contains an antistatic agent. The antistatic agent is an ion-conductive antistatic agent. From the viewpoint of compatibility with binder resin, ion-conductive band antistatic agents are used. Antistatic agents are preferred.

[0155] Examples of the ion-conducting antistatic agent include quaternary ammonium salts and pyridinium salts. cationic antistatic agents, alkali metal salts of sulfonic acid, phosphoric acid, carboxylic acid, etc. (e.g. Anionic antistatic agents such as lithium salts, sodium salts, potassium salts, etc., amino acid-based Amphoteric antistatic agents such as amino acid sulfate esters, amino alcohols, glycerin, poly Examples of the antistatic agents include nonionic antistatic agents such as polyethylene glycol. Quaternary ammonium salts and lithium salts are used because they have excellent compatibility with Indium resins. preferable.

[0156] Examples of the electron conductive antistatic agent include polyacetylene-based and polythiophene-based agents. Examples of the conductive particles include conductive polymers, metal particles, and metal oxide particles. However, by combining conductive polymers such as polyacetylene and polythiophene with dopants, Antistatic agents, metal particles, and metal oxide particles are preferred. Particles may also be included.

[0157] Specific examples of the antistatic agent made of the conductive polymer include polyacetylene, poly Aniline, polythiophene, polypyrrole, polyphenylene sulfide, poly(1,6 -heptadiyne), polybiphenylene (polyparaphenylene), polyparaphenylene phenylacetylene, poly(2,5-thienylene), or derivatives thereof and the like. Preferably, polythiophene-based conductive organic polymers (e.g. For example, 3,4-ethylenedioxythiophene (PEDOT) can be mentioned.

[0158] By using the antistatic agent made of the conductive organic polymer, it has less humidity dependency and can be used for a long time. It maintains antistatic properties for a long period of time, and also achieves high transparency and low haze value. The hard coat properties, especially pencil hardness and scratch resistance against steel wool, can be significantly improved. do.

[0159] The metal constituting the metal particles is not particularly limited, and examples thereof include Au, Ag, Cu, and A. Examples of the metals include I, Fe, Ni, Pd, Pt, etc., or alloys of these metals. The metal oxide constituting the metal oxide particles is not particularly limited, and examples thereof include tin oxide (S nO2), antimony oxide (Sb2O5), antimony doped tin oxide (ATO), tin Doped indium oxide (ITO), aluminum doped zinc oxide (AZO), fluorine doped Examples include tin oxide (FTO) and zinc oxide (ZnO).

[0160] The content of the antistatic agent is not particularly limited, but may be any of the polymerizable compounds in the composition for the antistatic layer. It is preferable that the amount is 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the product. If the amount is 50 parts by mass or less, the antistatic properties described above can be sufficiently obtained. The antistatic agent can provide a highly transparent film having a small slip value and a good total light transmittance. The lower limit of the content is more preferably 10 parts by mass or more, and the upper limit is 40 parts by mass or less. It is more preferable to do so.

[0161] <<Optical film manufacturing method>> The optical film 10 can be produced, for example, as follows. A functional layer 14 is formed on one surface of the functional substrate 11 by a coating device such as a bar coater. The composition for the functional layer is applied to form a coating film of the composition for the functional layer. The composition for the functional layer is a composition for an optical adjustment layer, but it may be a composition for an antistatic layer. stomach.

[0162] <Composition for functional layer> The composition for the functional layer contains a binder resin precursor, particles of a metal oxide or the like, and a solvent. The composition for the functional layer may further contain, as necessary, a low refractive index material such as silica or magnesium fluoride. At least one of the following: particles, inorganic pigments such as cobalt blue, leveling agents, and polymerization initiators. The binder resin precursor may contain a polyester resin. In this case, the composition for the functional layer may further contain, as necessary, a (meth)acrylic resin, a cell Polyurethane resin, polyvinyl chloride resin, polyolefin resin, polycarbonate One or more resins selected from the group consisting of acrylate, nylon, polystyrene, and ABS resin may also include

[0163] After forming a coating film of the composition for the functional layer, the coating film is heated at 40° C. or higher for 2 hours by various known methods. Dry the product by heating it at a temperature below 00°C for 10 to 120 seconds to evaporate the solvent. If necessary, the coating film is exposed to ionizing radiation such as ultraviolet light to improve its functionality. Layer 14 is formed.

[0164] After the functional layer 14 is formed, a hard coat is applied to the functional layer 14 by a coating device such as a bar coater. A composition for forming a hard coat layer 12 is applied to the substrate 10. A coating of the composition is formed.

[0165] <Hard Coat Layer Composition> The composition for the hard coat layer is made up of a polymerizable compound that becomes the binder resin 12A after curing and an inorganic compound. The composition for the hard coat layer may further include, if necessary, a UV ray ... The ink may contain an absorber, a spectral transmittance adjuster, a leveling agent, a solvent, and a polymerization initiator.

[0166] (solvent) The solvent may be alcohol (e.g., methanol, ethanol, propanol, isopropanol, etc.). propyl alcohol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol, diacetone alcohol), ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, Tanone, diisobutyl ketone, diethyl ketone, diacetone alcohol), esters (acetic acid Methyl acetate, ethyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, methyl formate , PGMEA), aliphatic hydrocarbons (e.g., hexane, cyclohexane), halogenated hydrocarbons Hydrocarbons (e.g., methylene chloride, chloroform, carbon tetrachloride), aromatic hydrocarbons (e.g., benzene benzene, toluene, xylene), amides (e.g., dimethylformamide, dimethylacetamide ether (e.g., diethyl ether, dioxane, tetrahydrofuran, Ether alcohol (e.g., 1-methoxy-2-propanol), carbonyl alcohol (e.g., 1-methoxy-2-propanol), These solvents include dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. The solvent may be used alone or in combination of two or more kinds. In this case, components such as urethane (meth)acrylate and other additives are dissolved or dispersed. In addition, methyl isobutyl ketone and methyl ethyl ketone are preferred because they can be suitably applied with the resin layer composition. Ketones are preferred.

[0167] (Polymerization initiator) The polymerization initiator is decomposed by exposure to ionizing radiation or heat to generate radicals and polymerize. A component that initiates or advances the polymerization (crosslinking) of a compound.

[0168] A polymerization initiator is a compound that releases a substance that starts radical polymerization when exposed to ionizing radiation or heat. The polymerization initiator is not particularly limited as long as it can be used. Specific examples of the compounds that can be used include acetophenones, benzophenones, Michler's benzoyl benzoate, α-amyloxime ester, thioxanthones, pro Pyophenones, benzils, benzoins, and acylphosphine oxides. It is also preferable to use a mixture of photosensitizers, and specific examples thereof include n- butylamine, triethylamine, poly-n-butylphosphine, and the like.

[0169] After forming a coating film of the composition for a hard coat layer, the coating film is dried for, for example, 30 minutes by various known methods. Dry the film by heating it at a temperature of 10 to 120°C for 10 to 120 seconds to remove the solvent. Allow to evaporate.

[0170] After drying the coating, the coating is irradiated with ionizing radiation such as ultraviolet light to harden the coating. A hard coat layer 12 is formed.

[0171] After the hard coat layer 12 is formed, the hard coat layer 12 is formed by a deposition method such as a sputtering method. An inorganic layer 13 is formed in contact with the hard coat layer 12. As a result, the optical film shown in FIG. 10 academic films are obtained.

[0172] <<<Image display devices>>> The optical film 10 can be incorporated into a foldable image display device. FIG. 4 is a schematic diagram of an image display device according to this embodiment. As shown in FIG. The image display device 40 is mainly made up of a housing 41 that houses a battery and a protective film, and is arranged to face the observer. A film 42, a display panel 43, a touch sensor 44, a circular polarizing plate 45, and an optical film 10 are laminated in this order. Between the display panel 43 and the touch sensor 44, Between the circular polarizer 44 and the circular polarizer 45, and between the circular polarizer 45 and the optical film 10, for example, O A light-transmitting adhesive layer 46 such as CA (Optical Clear Adhesive) is disposed on the substrate 40. They are secured together by a light-transmitting adhesive layer 46 .

[0173] The optical film 10 is arranged so that the hard coat layer 12 is closer to the viewer than the light-transmitting substrate 11. In the image display device 40, the surface 10A of the optical film 10 is It constitutes the surface 40A of the image display device 40.

[0174] In the image display device 40, the display panel 43 is made of organic light-emitting diodes or the like. The touch sensor 44 is a light-emitting diode panel. 43 side, but may be disposed between the circular polarizing plate 45 and the optical film 10. The touch sensor 44 may be of an on-cell type or an in-cell type.

[0175] The present inventors have investigated the scratch resistance of an optical film having an inorganic layer formed on a hard coat layer. As a result of intensive research, we found that the hard coat layer contains inorganic particles, and the hard coat layer The thickness is 1 μm or more, and the indentation hardness of the hard coat layer is 200 MPa or more. It has been found that the scratch resistance can be improved by adjusting the By blending suitable inorganic particles in the hard coat layer, adhesion with the inorganic layer is ensured, and This is believed to be because the hard coat layer has a high hardness. The thickness of the hard coat layer 12 containing the binder resin 12A and the inorganic particles 12B is set to 1 μm or more. and the indentation hardness of the hard coat layer 12 is set to 200 MPa or more. Therefore, it is possible to provide an optical film 10 having excellent scratch resistance.

[0176] When a steel wool test is performed on the surface of the hard coat layer, the inorganic particles tend to fall off. For this reason, from the viewpoint of improving scratch resistance, the hard coat layer does not contain inorganic particles. However, in this embodiment, an inorganic layer is formed on the hard coat layer 12. Since the inorganic particles 113 are formed, the inorganic particles 113 in the hard coat layer 12 are not easily observed during the steel wool test. As a result, the inorganic particles 12 are contained in the hard layer 2B, and the hard layer 2B is prevented from falling off. The hardness of the coating layer 12 can be increased, and the scratch resistance can be improved.

[0177] [Second embodiment] Hereinafter, the optical film and the image display device according to the second embodiment of the present invention will be described with reference to the drawings. The description will be given with reference to FIG. 5, which is a schematic diagram of the optical film according to this embodiment. In FIG. 5, the same reference numerals as in FIG. 1 denote the same members as those in FIG. 1. Therefore, the description will be omitted.

[0178] <<<Optical films>>> The optical film 50 shown in FIG. 5 includes a light-transmitting substrate 11, a The optical filter includes a hard coat layer 51 and an inorganic layer 13 in this order. The surface 50A of the film 50 is the surface 13A of the inorganic layer 13, and the back surface 50B is a light-transmitting This is the surface of the substrate 11 opposite to the surface on which the hard coat layer 51 is disposed. The physical properties of the film 50 are similar to those of the optical film 10, so a detailed description is omitted here. It shall be so.

[0179] <<Hard coat layer>> For the same reason as explained in the section on the hard coat layer 12, the hard coat layer 51 is The indentation hardness is 200MPa or more, and the film thickness is 1μm or more. The preferred upper and lower limits of the indentation hardness and film thickness of the hard coat layer 51 are as follows: are the same as the preferred upper and lower limits of the indentation hardness and film thickness of the hard coat layer 12. Other physical properties of the hard coat layer 51 are the same as those of the hard coat layer 12. Since the physical properties are similar, the description will be omitted here.

[0180] The hard coat layer 51 contains at least one of a metal element and a metalloid element. The hard coat layer 51 contains at least one of a metal element and a metalloid element. This improves adhesion to the inorganic layer 13, thereby improving scratch resistance. Examples of the metal elements include typical metal elements such as aluminum and tin, and zirconium. The metalloid elements may be any of the transition metal elements such as nium and titanium. For example, boron, silicon, germanium, arsenic, antimony, tellurium, and the like can be mentioned. Whether or not the hard coat layer contains the above elements can be confirmed by the following method. First, in an optical film cut to a size of 1 mm x 6 mm, The microtome (product name "Ultramicrotome EM UC7, Leica) was used at an angle of 0.5° or less. The hard coat layer was exposed by cutting the inorganic layer to a thickness greater than that of the inorganic layer using a cutting tool (manufactured by Microsystems Co., Ltd.). Then, an X-ray photoelectron spectrometer (ESCA, product name "KRATOS Nova ", manufactured by Shimadzu Corporation) was used to remove elements from the surface obtained by the above cutting. As a result, it was found that the hard coat layer contains at least one of metal elements and semi-metal elements. It is possible to check whether the document contains any of the following:

[0181] Metal elements contained in the hard coat layer 51 and measured by X-ray photoelectron spectroscopy The total atomic ratio of the metalloid elements is preferably 1.5% or more and 30% or less. When the total atomic ratio of the metal element and the metalloid element is 1.5% or more, the inorganic layer 13 and If the difference is 30% or less, the flexibility can be maintained. The total atomic ratio of the metal elements and metalloid elements can be calculated by the above-mentioned elemental analysis. The surface was cut to obtain a roughness of 1.0 mm, and the roughness was measured by X-ray photoelectron spectroscopy (ESCA). The product to be measured is "KRATOS Nova" (manufactured by Shimadzu Corporation). The lower limit of the atomic ratio of the total amount of the metal elements and the metalloid elements in the hard coat layer 51 is It is preferable that the value is 2% or more, and more preferably 5% or more (the larger the value, the better). The limit is 25% or less, and preferably 20% or less (the smaller the number, the better). .

[0182] The hard coat layer 51 is made of a silicone resin 51A and a fluorine-containing polymer film 51B. However, it is preferable that the hard coat layer 51 contains a metal element and an inorganic particle 51B. and semi-metallic elements, the silicone resin 51A and the inorganic For example, the hard coat layer may not include both the silicone resin and the organic particles 51B. In the case where the inorganic particles 51 are contained, the hard coat layer contains silicon derived from the silicone resin. B may not be contained. In addition, when the hard coat layer contains silica particles as inorganic particles, In the hard coat layer, silicon derived from silica particles is contained, so it does not contain silicone resin. The term "silicone resin" as used herein refers to a resin having a siloxane bond (a bond between silicon and oxygen). The hard coat layer 51 is a polymer compound having a main skeleton formed by the bond of In addition to the silicone resin 51A and the inorganic particles 51B, the material may contain other additives such as an ultraviolet absorbing agent and a spectral transmittance adjusting agent. The composition may contain such additives.

[0183] <Silicone resin> The silicone resin 51A is a silicone resin having a polymerizable functional group represented by the general formula (R 9 SiO 1.5 ) n It is preferable that the polymerizable compound containing silsesquioxane represented by the formula: In the above formula, R 9 The polymerizable functional group may be a radical polymerizable functional group or a cationic polymerizable functional group. group, and n is an integer of 1 or more. The polymerizable compound may be any of the above-mentioned silsesquioxanes and other compounds. The polymerizable compound may contain the above-mentioned silsesquioxane, or may be composed solely of the above-mentioned silsesquioxane. The silicone resin 51A contains a polymer of a polymerizable compound containing such silsesquioxane. By including the radical polymerizable functional group, adhesion to the inorganic layer can be further ensured. For example, an ethylenically unsaturated group such as a (meth)acryloyl group, a vinyl group, or an allyl group may be used. Examples of the cationic polymerizable functional group include an epoxy group and an oxetanyl group. By including such radical polymerizable functional groups or cationic polymerizable functional groups, In this way, silsesquioxanes can be linked to each other to obtain a polymer.

[0184] The structure of silsesquioxane is not particularly limited, and may be, for example, a complete cage type or an incomplete cage type. Examples of the structure include a cage structure, a ladder structure, and a random structure. Commercially available silsesquioxanes include those available from Constell Chemical Co., Ltd. Glycidyl polysilsesquioxane cage mix Examples include ure and the light-curing SQ series manufactured by Toagosei Co., Ltd.

[0185] The polymerizable compound forming the silicone resin 51A is a compound other than the silsesquioxane. , dimethylpolysiloxane having a radical polymerizable functional group such as a (meth)acryloyl group, Silicone oligomer and / or silicone polymer having an alkoxysilyl group The silicone oligomer and silicone polymer may be used as a hard coat. From the viewpoint of further increasing the hardness of the adhesive layer, the radical polymerizable functional group or the cationic polymerizable functional group may be used. It is preferred that the compound has a polymerizable functional group such as a polymerizable functional group.

[0186] Commercially available dimethylpolysiloxanes with radical polymerizable functional groups include Shin-Etsu Chemical Co., Ltd. KR series manufactured by K.K. Co., Ltd., such as KP-410, KP-411, KP-412, P-413, KP-414, KP-415, KP-423 (all double-terminated), KP- The following are listed: KP-416, KP-418, KP-422 (all single-terminus type), and KP-420 (side chain type). Can be obtained.

[0187] Commercially available silicone oligomers having alkoxysilyl groups include, for example, Shin-Etsu Chemical Co., Ltd. KR-500, KR-515, KC-895, X-40-9225, etc. manufactured by Gakushu Kogyo Co., Ltd. Examples of ultra-high molecular weight silicone resins include those manufactured by Shin-Etsu Chemical Co., Ltd. Examples include KR-251 manufactured by

[0188] <Inorganic particles> The inorganic particles 51B are similar to the inorganic particles 12B described in the first embodiment. The explanation of will be omitted.

[0189] The present inventors have investigated the scratch resistance of an optical film having an inorganic layer formed on a hard coat layer. As a result of intensive research, it was found that the hard coat layer contains at least one metal element and / or metalloid element. The hard coat layer is made to have a thickness of 1 μm or more, and the index of the hard coat layer is By increasing the axial hardness to 200 MPa or more, it is possible to improve scratch resistance. This is because at least one of a metal element and a metalloid element can be hardened. By incorporating it into the hard coat layer, adhesion with the inorganic layer is ensured and the hard coat layer has high hardness. According to the present embodiment, the metal element and the metalloid element are The hard coat layer 51 containing at least one of the elements has a thickness of 1 μm or more, and The indentation hardness of the coating layer 51 is set to 200 MPa or more, so that the coating layer 51 has excellent abrasion resistance. It is possible to provide an optical film 50 that is scratch resistant.

[0190] When a steel wool test is performed on the surface of the hard coat layer, the inorganic particles tend to fall off. For this reason, from the viewpoint of improving scratch resistance, the hard coat layer does not contain inorganic particles. However, in this embodiment, an inorganic layer is formed on the hard coat layer 51. Since the inorganic particles 513 are formed, the inorganic particles 51 in the hard coat layer 51 are not easily observed during the steel wool test. As a result, the inorganic particles 51B can be prevented from falling off. This can increase the hardness of the hard coat layer 51 and improve the scratch resistance.

[0191] <<<Image display devices>>> The optical film 50 can be incorporated into a foldable image display device. FIG. 6 is a schematic diagram of an image display device according to this embodiment. The display device 60 includes an optical film 50. The image display device 60 includes an optical film 1 The image display device is the same as the image display device 40 except that the optical film 50 is used as the optical film 50. The explanation will be omitted. EXAMPLES

[0192] In order to explain the present invention in detail, the following examples are given. The "solid content equivalent to 100%" below refers to the solid content in the solvent-diluted product. This is the value when minutes is 100%.

[0193] <Preparation of composition for hard coat layer> First, the components were mixed so as to obtain the composition shown below, thereby obtaining a composition for an optical adjustment layer. (Hard Coat Layer Composition 1) Polyester acrylate (product name "M-9050", manufactured by Toagosei Co., Ltd.): 50% Quantity Silica particles (product name "MIBK-SD", manufactured by Nissan Chemical Industries, Ltd.): 50 parts by weight Polymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacur e(registered trademark) 184" manufactured by BASF Japan Ltd.): 5 parts by weight Methyl isobutyl ketone: 100 parts by weight

[0194] (Hardcoat layer composition 2) Polyester acrylate (product name "M-9050", manufactured by Toagosei Co., Ltd.): 67% Quantity Silica particles (product name "MIBK-SD", manufactured by Nissan Chemical Industries, Ltd.): 33 parts by weight Polymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacur e(registered trademark) 184" manufactured by BASF Japan Ltd.): 5 parts by weight Methyl isobutyl ketone: 100 parts by weight

[0195] (Hardcoat layer composition 3) Polyester acrylate (product name "M-9050", manufactured by Toagosei Co., Ltd.): 90% Quantity Silica particles (product name "MIBK-SD", manufactured by Nissan Chemical Industries, Ltd.): 10 parts by weight Polymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacur e(registered trademark) 184" manufactured by BASF Japan Ltd.): 5 parts by weight Methyl isobutyl ketone: 100 parts by weight

[0196] (Hardcoat layer composition 4) Alkoxylated dipentaerythritol acrylate (product name: A-DPH-12E, Shin-Nakamura Chemical Co., Ltd.): 50 parts by weight Silica particles (product name "MIBK-SD", manufactured by Nissan Chemical Industries, Ltd.): 50 parts by weight Polymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacur e(registered trademark) 184" manufactured by BASF Japan Ltd.): 5 parts by weight Methyl isobutyl ketone: 100 parts by weight

[0197] (Hardcoat layer composition 5) Glycidyl polysilsesquioxane (product name: Glycidyl polysilsesquioxane) "Squioxane Cage Mixture" manufactured by Constur Chemical Co., Ltd. ):100 parts by mass Polymerization initiator (tri-p-tolylsulfonium hexafluorophosphate, Tokyo Chemical Industry Co., Ltd. Manufactured by: 5 parts by weight 1-Methoxy-2-propanol: 100 parts by weight

[0198] (Hard Coat Layer Composition 6) Polyester acrylate (product name "M-9050", manufactured by Toagosei Co., Ltd.): 100 Mass part Polymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacur e(registered trademark) 184" manufactured by BASF Japan Ltd.): 5 parts by weight Methyl isobutyl ketone: 100 parts by weight

[0199] (Hardcoat layer composition 7) Polypropylene glycol diacrylate (product name "M-220", Toagosei Co., Ltd. ): 90 parts by mass Silica particles (product name "MIBK-SD", manufactured by Nissan Chemical Industries, Ltd.): 10 parts by weight Polymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacur e(registered trademark) 184" manufactured by BASF Japan Ltd.): 5 parts by weight Methyl isobutyl ketone: 100 parts by weight

[0200] <Preparation of composition for optical adjustment layer> The components were mixed so as to obtain the composition shown below, thereby obtaining a composition for an optical adjustment layer. (Composition 1 for optical adjustment layer) - Urethane-modified polyester resin (product name "UR-3200", manufactured by Toyobo Co., Ltd.): 85 parts by weight (100% solid content) Zirconium oxide (average particle size 20 nm, manufactured by CIK Nanotech Co., Ltd.): 15 parts by weight (100% solid content) Methyl isobutyl ketone (MIBK): 170 parts by weight

[0201] <Preparation of polyimide substrate> In a 500 ml separable flask, add 278.0 g of dehydrated dimethylacetamide and and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (AprTMOS) The temperature of the solution containing 8.1 g (33 mmol) of 4,4'- (Hexafluoroisopropylidene)diphthalic anhydride (6FDA) 18.1g (41m mol) was gradually added so that the temperature rise was 2°C or less, and the mixture was stirred for 1 The mixture was stirred for 2 hours. 2,2'-bis(trifluoromethyl)benzidine (TFMB) was added to the mixture. Add 46.1 g (131 mmol) of 4,4'-(hexafluoropropanediol) and confirm that it is completely dissolved. 6-fluoroisopropylidene diphthalic anhydride (6FDA) 51.8g (122mm ol) was gradually added in several portions so that the temperature rise was kept below 2°C, and the polyimide precursor A polyimide precursor solution (1) (solid content 30 wt %) in which 1 was dissolved was synthesized.

[0202] The polyimide precursor solution (1) was cooled to room temperature, and dehydrated dimethylacetamide was added. 196.8g was added and stirred until homogenous. Next, 128.9g (1. 63 mol) and 167.7 g (1.63 mol) of acetic anhydride were added and stirred at room temperature for 24 hours. A polyimide solution was synthesized. 400.0 g of the obtained polyimide solution was placed in a 5 L separable flask. The mixture was transferred to a LASCO, 119.2 g of butyl acetate was added, and the mixture was stirred until it was homogenous. 688.0 g was gradually added to obtain a slightly cloudy solution. 2.064 kg of ethanol was added at once to obtain a white slurry. The slurry was filtered and filtered five times. After washing with methanol, 65.0 g of polyimide resin (1) was obtained.

[0203] 10.0 g of the polyimide resin (1) was added to 42.2 g of butyl acetate and stirred at room temperature for 1 hour. The polyimide solution was obtained by stirring the mixture in a tabletop ultrasonic cleaner (product name: UT-10 The container was degassed for 10 minutes using a vacuum degasser (Sharp Corporation, No. 4), removed, and then allowed to stand at room temperature for 1 hour. The polyimide solution was left to stand and then applied to a polyethylene terephthalate (PET) film with a thickness of 250 μm. The solution was applied to a film (product name: Lumirror T60, manufactured by Toray Industries, Inc.) and circulated at 40°C. After drying for 10 minutes in a vacuum oven and 10 minutes at 150°C, the film was peeled off from the PET film and Dry at 150℃ for 1 hour and cut into pieces of A5 size (148mm x 210mm) and 5mm thick. The thickness of the polyimide-based substrate was measured by scanning electron microscopy. A cross-section of the polyimide-based substrate was photographed using a scanning electron microscope (SEM), and the polyimide was The thickness of the mid-based substrate was measured at 10 points, and the arithmetic average value of the film thicknesses at the 10 points was calculated.

[0204] <Example 1> The light-transmitting substrate is a polyimide substrate with a refractive index of 1.630 and a thickness of 50 μm (product A polyimide substrate (manufactured by Mitsubishi Gas Chemical Co., Ltd.) was attached to one side of the polyimide substrate. Then, the composition 1 for hard coat layer was applied with a bar coater to form a coating film. The coating film was heated at 70℃ for 1 minute to evaporate the solvent in the coating film, and then exposed to ultraviolet light. Using an irradiation device (Fusion UV Systems Japan, Inc., light source H bulb), The cumulative light intensity of the ultraviolet rays in a nitrogen atmosphere is 200 mJ / cm 2 The coating is hardened by irradiating it so that A hard coat layer having a refractive index of 1.521 and a thickness of 4 μm was formed. On the surface of the coated layer, a 100 nm thick SiO x (x=1~2 An inorganic layer consisting of 100% ethylenediaminetetraacetate was formed on the inorganic layer, and an optical film was obtained.

[0205] The thickness of the polyimide substrate was measured using a scanning electron microscope (SEM). The cross section of the substrate was photographed, and the thickness of the polyimide substrate was measured at 10 points on the cross section image. The thickness of the hard coat layer was measured at 10 points and the arithmetic average value was used. Scanning Transmission Electron Microscope (STEM) (product name: S-4800, Hitachi High-Technologies Corporation) A cross section of the hard coat layer was photographed using a microscope (manufactured by Gies). The thickness of the hard coat layer was measured at 10 points, and the arithmetic average value of the thicknesses at the 10 points was used. The cross-sectional photographs of the layers were taken as follows. First, an optical The film was embedded in resin to create a block, from which standard sections were then cut. Depending on the manufacturing method, a uniform section with a thickness of 70 nm to 100 nm is cut out without holes. Sections were prepared using an ultramicrotome EM UC7 (Leica Microsystems). The uniform slices without holes were used as the measurement samples. Then, a cross-sectional photograph of the measurement sample was taken using a scanning transmission electron microscope (STEM). When taking this cross-sectional photograph, the detector was set to "TE", the acceleration voltage was set to "30 kV", and the emitter was set to "100 V". The current was set to 10 μA for STEM observation. Adjust the contrast and brightness and observe whether each layer can be distinguished by magnification from 5000 to 200. The magnification was adjusted appropriately. When taking cross-sectional photographs, the aperture was set to "Beam The monitor aperture was set to "3", the objective lens aperture to "3", and the WD to "8mm". The thickness of the inorganic layer was measured in the same manner as the thickness of the hard coat layer. The refractive index of the hard coat layer and the base material is based on JIS K7142:2008 B method. The refractive index of polyimide substrates was determined using the Becke method. In this case, 10 pieces of polyimide substrate are cut out, and the 10 pieces are The refractive index of the fragment was measured using the sodium D line of 589 nm and a refractive index standard solution. The refractive index of the polyimide substrate was determined by averaging the refractive indexes of the ten pieces. When the refractive index of the coated layer is determined by the Becke method, the polyimide The refractive index of the base material was determined in the same manner as in Examples 2 to 7 and Comparative Examples 1 to 4. In this example, the thickness and refractive index of the polyimide-based substrate were measured in the same manner as in Example 1. It was determined.

[0206] <Example 2> In Example 2, composition 2 for hard coat layer was used instead of composition 1 for hard coat layer. An optical film was obtained in the same manner as in Example 1, except that the above was used.

[0207] <Example 3> In Example 3, composition 3 for hard coat layer was used instead of composition 1 for hard coat layer. An optical film was obtained in the same manner as in Example 1, except that the above was used.

[0208] <Example 4> In Example 4, composition 4 for hard coat layer was used instead of composition 1 for hard coat layer. An optical film was obtained in the same manner as in Example 1, except that the above was used.

[0209] <Example 5> In Example 5, the film thickness of the hard coat layer was set to 2 μm, but the film thickness was the same as in Example 1. In this manner, an optical film was obtained.

[0210] <Example 6> In Example 6, the same procedure as in Example 1 was followed except that the thickness of the hard coat layer was 10 μm. Similarly, an optical film was obtained.

[0211] <Example 7> In Example 7, the same procedure as in Example 1 was followed except that the thickness of the hard coat layer was 20 μm. Similarly, an optical film was obtained.

[0212] <Example 8> The light-transmitting substrate is a polyimide substrate with a refractive index of 1.630 and a thickness of 50 μm (product A polyimide substrate (manufactured by Mitsubishi Gas Chemical Co., Ltd.) was attached to one side of the polyimide substrate. The composition 1 for optical adjustment layer was applied with a bar coater to form a coating film. The film was heated at 90°C for 1 minute to evaporate the solvent in the film, resulting in a refractive index of 1 After the optical adjustment layer was formed, the optical Composition 1 for hard coat layer was applied to the surface of the adjustment layer with a bar coater to form a coating film. After that, the formed coating film was heated at 70°C for 1 minute to evaporate the solvent in the coating film. The ultraviolet ray irradiation device (Fusion UV System Japan Co., Ltd., light source H bulb) ) was used, and the integrated dose of ultraviolet light was 200 mJ / cm in a nitrogen atmosphere. 2 Irradiation so that The coating was cured to form a hard coat layer with a refractive index of 1.521 and a thickness of 4 μm. Finally, a 100 nm thick SiO film was deposited on the surface of the hard coat layer by sputtering. x (x=1 to less than 2) was formed to obtain an optical film. , Scanning Transmission Electron Microscope (STEM) (Product name: S-4800, Hitachi High-Tech Corporation A cross section of the optical adjustment layer was photographed using a microscope (manufactured by Nology), and the optical adjustment layer was measured in the cross-sectional image. The thickness of each layer was measured at 10 points, and the arithmetic average value of the thicknesses at the 10 points was determined. The thickness of the optical adjustment layer was measured in the same manner as for the thickness of the hard coat layer. The refractive index is measured based on the B method of JIS K7142:2008, similar to polyimide-based substrates. It was determined by the Kecke method.

[0213] <Example 9> In Example 9, a polyimide-based substrate (product name "Neoplum", Mitsubishi Gas Chemical Company, Inc.) was used. The same procedure as in Example 1 was repeated except that the polyimide-based substrate 1 prepared above was used. Thus, an optical film was obtained.

[0214] <Example 10> In Example 10, the composition for hard coat layer was used instead of the composition for hard coat layer 1. An optical film was obtained in the same manner as in Example 1, except that No. 5 was used.

[0215] <Comparative Example 1> In Comparative Example 1, composition 6 for hard coat layer was used instead of composition 1 for hard coat layer. An optical film was obtained in the same manner as in Example 1, except that the above was used.

[0216] <Comparative Example 2> In Comparative Example 2, composition 7 for hard coat layer was used instead of composition 1 for hard coat layer. An optical film was obtained in the same manner as in Example 1, except that the above was used.

[0217] <Comparative Example 3> In Comparative Example 3, the film thickness of the hard coat layer was set to 0.8 μm, but the film thickness was the same as that of Example 1. In the same manner as above, an optical film was obtained.

[0218] <Indentation hardness measurement> The indentation hardness of the hard coat layer of the optical film according to the examples and the comparative examples is Specifically, the optical film was cut into 1 mm × 10 mm pieces and embedded in a resin. A block was prepared by embedding the specimen in the endothelial cell, and holes were cut from the block using a general sectioning method. The sections were cut into uniform thicknesses of 70 nm to 100 nm. Ultramicrotome EM UC7 (Leica Microsystems) was used. The remaining block from which the uniform slices without holes were cut was used as the measurement sample. Then, the above-mentioned slice was cut out from the measurement sample. In the cross section, a Berkovich indenter (triangular pyramid, BR The cross section of the hard coat layer was subjected to a 25-second test using a TI-0039 (UKER) under the following measurement conditions: The specimen was pressed vertically until the maximum pressing load reached 500 μN. In the optical films according to Examples 1 to 7, 9, and 10 and Comparative Examples 1 to 3, To avoid the influence of the polyimide base material and inorganic layer, and to avoid the influence of the side edge of the hard coat layer In order to achieve this, a thickness of 50 mm was measured from the interface between the polyimide substrate and the hard coat layer toward the center of the hard coat layer. 0 nm away from the interface between the hard coat layer and the inorganic layer, and 500 nm away from the center of the hard coat layer The hard coat layer was then coated with a hard coat layer 500 nm away from each end of the hard coat layer toward the center of the hard coat layer. For the same reason, the optical filter according to Example 8 was pressed into the hard coat layer. In the case of the hard coat layer, the thickness of the hard coat layer is 500 mm from the interface between the optical adjustment layer and the hard coat layer toward the center of the hard coat layer. nm away from the interface between the hard coat layer and the inorganic layer, and 500 nm away from the center of the hard coat layer The hard coat layer was then cut at a distance of 500 nm from each of the two ends of the hard coat layer toward the center of the hard coat layer. After that, it was held for a certain period of time to relieve the residual stress. The load was removed over 25 seconds, and the maximum load after relaxation was measured. max Contact with (μN) Projected area A p (nm 2 ) and P max / A p The indentation hardness was calculated by The above contact projection area was measured using a standard sample of fused quartz (BRUKER 5-0098). The contact projected area was corrected for the indenter tip curvature by the Oliver-Pharr method using Indentation hardness (H IT ) was the arithmetic mean value obtained by measuring at 10 points. If any of the measured values ​​deviate from the arithmetic mean by ±20% or more, The measured values ​​shall be excluded and remeasured. (Measurement conditions) ·Loading speed: 20μN / sec ·Holding time: 5 seconds ·Loading and unloading speed: 20μN / sec ·Measurement temperature: 25℃

[0219] <Confirmation of the presence of metallic elements and semi-metallic elements and measurement of the atomic ratio of the total amount of these elements> The hard coat layer of the optical film according to the examples and comparative examples does not contain a metal element or a semi-metal element. We confirmed whether at least one of the following existed. Specifically, first, The optical film was cut to size and then cut parallel to the in-plane direction using a microtome (product name "Ultramicrotome EM UC7 (Leica Microsystems)" The hard coat layer was exposed by cutting about 0.00 nm. (ESCA, product name "KRATOS Nova", manufactured by Shimadzu Corporation) An elemental analysis was performed on the surface obtained by cutting, and metal elements and semi-metal elements were In addition, it was confirmed whether the cutting process included at least one of the above elements. The surface obtained by the above procedure was analyzed using an X-ray photoelectron spectroscopy (ESCA, product name "KRAT The total amount of metallic and semi-metallic elements was measured using "OS Nova" (manufactured by Shimadzu Corporation). The atomic ratio (%) of was measured. (Measurement conditions) Measurement method: Wide / Narrow X-ray source: Monochrome AlKα X-ray power: 150W Emission current: 10mA Acceleration voltage: 15kV Charge neutralization mechanism: ON ·Measurement area: 300×700μm Pass Energy (Survey): 160eV Pass Energy (Narrow): 40eV

[0220] <Area ratio of silica particles> In the cross section in the thickness direction of the hard coat layer of the optical film according to the examples and the comparative examples, The region near the interface from the interface between the hard coat layer and the inorganic layer to a depth of 500 nm in the hard coat layer The area ratio of the inorganic particles in the region near the interface was calculated. The optical film was cut into a size of 1 mm x 10 mm and embedded in a resin. A block was prepared by embedding the specimen in fat, and the specimen was then sectioned by standard sectioning methods. Ten uniform sections with a thickness of 70 nm to 100 nm were cut out without holes. The preparation was performed using an ultramicrotome EM UC7 (Leica Microsystems, Inc.). Ten of these uniform pieces without holes were used as the measurement samples. , Scanning Transmission Electron Microscope (STEM) (Product name: S-4800, Hitachi High-Tech Corporation Cross-sectional photographs of each measurement sample were taken using a microscope (manufactured by Nology). A cross-sectional photograph was taken at one location per time. The observation was performed with the TE setting, the acceleration voltage set to 30 kV, and the emission current set to 10 μA. For magnification, adjust the focus and contrast and brightness to distinguish each layer. The magnification was adjusted appropriately from 5,000 to 200,000 while observing the specimen. In addition, set the aperture to "Beam monitor aperture 3" and the objective lens aperture to "3". The WD was set to 8 mm. In the 10 cross-sectional images obtained, The area of ​​the region is taken as 100%, and the ratio of the area of ​​the inorganic particles to the area of ​​the region near the interface (area ratio The area ratio of the inorganic particles in the region near the interface was calculated as 1 / 100 of the area near the interface. The area ratio of inorganic particles was calculated from 0 cross-sectional photographs and the arithmetic average value was used.

[0221] <Scratch resistance> The surface of the optical film according to the examples and the comparative examples (the surface of the inorganic layer) was subjected to a steel Specifically, a 50mm x 100mm-sized optical fiber was cut out and evaluated. Place the optical film on the glass plate using cellophane tape (registered trademark) manufactured by Nichiban Co., Ltd. The inorganic layer was fixed with a 0.000-grit steel wool ( Product name: "BON STAR" (manufactured by Nippon Steel Wool Co., Ltd.) was used, and the density was 1 kg / cm 2 A steel wool test was performed by rubbing the material back and forth 10 times at a speed of 50 mm / sec. The surface of the optical film was then visually inspected for scratches. The evaluation criteria were as follows: Ta. ○: No scratches or scrapes were found, or some scratches or scrapes were found but no practical problem was found. It was at a high level. ×: Scratches or scratches were clearly observed.

[0222] <Haze measurement> The haze values ​​(total haze values) of the optical films according to the examples and comparative examples were measured. The haze value was measured using a haze meter (product name "HM-150", manufactured by Murakami Color Research Laboratory). The haze value was measured by a method conforming to JIS K7136:2000. After cutting into a size of 0mm x 100mm, there should be no curls or wrinkles, and no fingerprints or dust. The optical film was placed in such a state that the inorganic layer side was the side not exposed to the light source, and measurements were taken three times for each optical film. The arithmetic mean value was calculated from three measurements.

[0223] <Total light transmittance> The total light transmittance of the optical films according to the examples and the comparative examples was measured. The transmittance was measured using a haze meter (product name "HM-150", manufactured by Murakami Color Research Laboratory). The total light transmittance was measured according to a method in accordance with IS K7361-1:1997. The total light transmittance above was measured after cutting into a piece measuring 50mm x 100mm without curling or wrinkles. The optical film 1 was placed on the substrate 1 in a state free of fingerprints, dust, etc., with the inorganic layer side facing away from the light source. The measurement was performed three times for each sheet, and the arithmetic mean value obtained from the three measurements was used.

[0224] <Foldability> A folding test was carried out on the optical films according to the examples and comparative examples to evaluate the folding properties. Specifically, first, the optical film was cut to a size of 30 mm x 100 mm. A durability test machine (product name "DLDMLH-FS", manufactured by Yuasa System Co., Ltd.) was used. The short sides of the optical film are fixed at the fixing parts, and the two opposing The optical film is attached so that the minimum distance between the sides is 6 mm. Folding test: fold the film 100,000 times to 90° (with the inorganic layer on the inside and the polyimide substrate on the outside) A test was conducted in which the product was folded so that the outermost part was facing outward, and the bent part was checked for cracks or breaks. Similarly, a new optical film was cut into a size of 30 mm x 100 mm. A durability test machine (product name "DLDMLH-FS", manufactured by Yuasa System Devices Co., Ltd.) was used. The short sides of the film are fixed with fixing parts, and the minimum distance between the two opposing sides is 2 mm. Then, fold the front side of the optical film 100,000 times to make a 180° angle. Folding test (fold so that the inorganic layer is on the inside and the polyimide base material is on the outside. The bending test was carried out to check whether cracks or breaks occurred in the bent parts. The evaluation criteria are as follows: It was decided. (Foldability) ◯: No cracks or breaks were observed at the bent portion during the folding test. ×: Cracks or breaks occurred at the bent portion during the folding test.

[0225] <Interference fringe evaluation> In the optical films according to the examples and the comparative examples, an evaluation was performed to see whether interference fringes were observed. Specifically, a 25μ thick film is attached to the back of an optical film cut to a size of 50mm x 100mm. m transparent adhesive (product name: Highly transparent double-sided tape 8146-1, manufactured by 3M) A black acrylic plate was attached to prevent backside reflection, and each light was projected from the front side of the optical film. The optical film was irradiated with light, and the interference fringes were visually observed. A fluorescent tube was used. The occurrence of interference fringes was evaluated according to the following criteria. ○: No interference fringes were observed. △: A small amount of interference fringes was observed. ×: interference fringes were clearly observed.

[0226] [Table 1]

[0227] [Table 2]

[0228] The results are described below. As shown in Table 1, in the optical film according to Comparative Example 1, In the case of the hard coat layer, the hard coat layer is made of inorganic particles or at least one of a metal element and a semi-metal element. Since the inorganic layer did not contain any of the above, the scratch resistance of the surface of the inorganic layer was poor. The optical film had an indentation hardness of less than 200 MPa, so the inorganic layer The optical film according to Comparative Example 3 had poor scratch resistance on the surface. Since the film thickness was small, the scratch resistance of the surface of the inorganic layer was poor. The optical films according to Examples 1 to 10 each have a hard coat layer made of inorganic particles or metal elements and semi-metallic particles. It contains at least one of the group elements and has an indentation hardness of 200 MPa or more. Since the thickness of the hard coat layer was 2 μm or more, the scratch resistance of the surface of the inorganic layer was high. In the optical films of Examples 1 to 6 and 8 to 10, the folding test After the test, a steel wool test was performed under the same conditions as above, and the surface of the optical film was then examined for scratches. When visually inspected for scratches or scrapes, no scratches or scrapes were found on any of the optical films. There was no damage, or slight scratches or scrapes were found, but they were not of a level that would cause any practical problems.

[0229] In the optical films according to Examples 1 to 6 and 8 to 10, the thickness of the hard coat layer is 10 μm or less. Therefore, compared with the optical film according to Example 7 in which the thickness of the hard coat layer is 20 μm, It also had excellent foldability.

[0230] The optical film according to Example 7 has a considerably thick hard coat layer, so that the optical film according to Example 8 The optical film according to Example 9 had an optical adjustment layer formed thereon. Due to the low refractive index of the polyimide-based substrate, no interference fringes were observed.

[0231] In the optical film according to the embodiment, the presence of silicon in the inorganic layer was determined by X-ray photoelectron spectroscopy. The results were confirmed using a device (product name "KRATOS Nova", manufactured by Shimadzu Corporation). In addition, it was confirmed that silicon was present in the inorganic layer in all of the optical films. When checking whether silicon is present in the layer, a sample was cut into pieces of 1 mm x 6 mm. On the surface of the inorganic layer of the optical film, an X-ray photoelectron spectroscopy (ESCA, product name "K The metal elements and Elemental analysis was performed under the same measurement conditions as for the presence or absence of metalloid elements. [Explanation of symbols]

[0232] 10, 50...Optical film 11...Light-transmitting base material 12, 51...Hard coat layer 12A…Binder resin 12B…Inorganic particles 13...Inorganic layer 40, 60...Image display device 43...Display panel 51A…Silicone resin 51B…Inorganic particles

Claims

1. An optical film comprising a light-transmitting substrate, a hard coat layer, and an inorganic layer in this order, the hard coat layer is in contact with the inorganic layer, the hard coat layer contains a binder resin and inorganic particles, the thickness of the hard coat layer is 1 μm or more and 10 μm or less, The hard coat layer has an indentation hardness of 200 MPa or more, The optical film, wherein the inorganic layer has a water vapor transmission rate of 100 g / (m 2 ·24 h) or less at 40° C. and a relative humidity of 90%.

2. The optical film according to claim 1 , wherein the inorganic particles are silica particles.

3. An optical film comprising a light-transmitting substrate, a hard coat layer, and an inorganic layer in this order, the hard coat layer is in contact with the inorganic layer, the hard coat layer contains at least one of a metal element and a metalloid element, the thickness of the hard coat layer is 1 μm or more and 10 μm or less, The hard coat layer has an indentation hardness of 200 MPa or more, The optical film, wherein the inorganic layer has a water vapor transmission rate of 100 g / (m 2 ·24 h) or less at 40° C. and a relative humidity of 90%.

4. The optical film according to claim 1 , wherein the inorganic layer is an inorganic oxide layer.

5. The optical film according to claim 1 , wherein the inorganic layer comprises silicon.

6. The optical film according to claim 1 , wherein the inorganic layer has a thickness of 10 nm or more and 300 nm or less.

7. The optical film according to claim 3 , wherein the hard coat layer contains a metalloid element, and the metalloid element is silicon.

8. 4. The optical film according to claim 3, wherein the total atomic ratio of the metal element and the metalloid element contained in the hard coat layer, as measured by X-ray photoelectron spectroscopy, is 1.5% or more and 30% or less.

9. The optical film according to claim 1 , wherein the hard coat layer comprises a polymer of a polymerizable compound containing silsesquioxane having a polymerizable functional group.

10. 10. The optical film according to claim 1, which does not crack or break when a test in which the optical film is folded 180° so that the distance between opposing sides of the optical film is 6 mm is repeated 100,000 times.

11. 11. The optical film according to claim 1, wherein the optical film does not crack or break when a test of folding the optical film 180° with the inorganic layer facing inward and with the distance between opposing sides of the optical film being 2 mm is repeated 100,000 times.

12. 12. The optical film according to claim 1, wherein the light-transmitting substrate is a substrate made of a polyimide-based resin, a polyamide-based resin, or a mixture thereof.

13. A display panel; the optical film according to claim 1 , which is disposed closer to a viewer than the display panel; The image display device, wherein the hard coat layer of the optical film is located closer to a viewer than the light-transmitting substrate.

14. The image display device according to claim 13, wherein the display panel is an organic light-emitting diode panel.

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