Optical film

Abstract

To provide an optical film which excels in low moisture permeability and excoriation resistance and is suitable for polarizing plate projective films.SOLUTION: This optical film 10 has a laminate structure with a resin layer 1 laminated on one surface of a light permeable substrate 2. The resin layer 1 is formed from a cured substance of a curable composition that contains at least one polymerizable compound selected from the group consisting of a monomer having a polymerizable function group and an oligomer having a polymerizable function group. A change rate of moisture vapor permeability [g / m2 24h] of the optical film 10 under a temperature 40°C and relative humidity 92% environment before and after an excoriation resistance test is 20 or less. Excoriation resistance test: Reciprocated 10 rounds on the surface of the resin layer using a steel wool under the conditions of a load 3.92 N and movement speed 100 mm / second.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical film, and more particularly to an optical film suitable for use as a polarizing plate protective film. [Background technology]

[0002] In many image display devices (e.g., liquid crystal display devices, organic EL display devices, etc.), a polarizing plate is arranged on at least one side of the display cell due to the image formation method used. The polarizing plate plays a role in transmitting only light polarized in a certain direction, and the performance of the image display device is greatly influenced by the performance of the polarizing plate. A polarizing plate is generally composed of a polarizer made of a polyvinyl alcohol film or the like on which iodine or a dye has been adsorbed and aligned, and a transparent protective film (polarizer protective film) attached to at least one side of the polarizer (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-338329 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the market for mobile applications such as smartphones and tablet terminals has expanded, and the need for thinner image display devices has further increased, which has led to a demand for thinner components constituting polarizing plates, such as polarizing plate protective films. However, as the thickness of polarizing plate protective films decreases, there is a problem in that their protective function for polarizers decreases.

[0005] For example, when the polarizing plate protective film becomes thinner, its moisture permeability (moisture permeability) increases, and the polarizing performance of the polarizer may be lost in a humid environment, resulting in a phenomenon known as "color loss."

[0006] Furthermore, when the polarizing plate protective film becomes thin, there are problems such as a decrease in surface hardness and scratch resistance, making the film more susceptible to scratches during the manufacturing process, a decrease in moisture permeability, and other deterioration in the performance of the polarizing plate. Therefore, the optical film used in the polarizing plate protective film is also required to have excellent scratch resistance.

[0007] The present invention has been devised in light of the above circumstances, and an object of the present invention is to provide an optical film that has low moisture permeability and excellent scratch resistance even when made thin, and is suitable as a polarizing plate protective film. [Means for solving the problem]

[0008] That is, a first aspect of the present invention provides an optical film having a resin layer laminated on one surface of a light-transmitting substrate. The resin layer imparts excellent low moisture permeability to the optical film of the first aspect of the present invention. The resin layer also imparts excellent scratch resistance to the optical film of the first aspect of the present invention. Therefore, the optical film of the first aspect of the present invention having the resin layer in a laminate structure is suitable as a polarizing plate protective film.

[0009] In the optical film of the first aspect of the present invention, the resin layer is formed from a cured product of a curable composition containing at least one polymerizable compound selected from the group consisting of a monomer having a polymerizable functional group and an oligomer having a polymerizable functional group. This configuration is suitable for imparting excellent low moisture permeability to the optical film of the first aspect of the present invention. It is also suitable for imparting excellent scratch resistance to the optical film of the first aspect of the present invention.

[0010] The optical film according to the first aspect of the present invention has a moisture permeability [g / m 2 ] of the optical film in an environment of a temperature of 40°C and a relative humidity of 92% before and after the following scratch resistance test. 2 The change in [24h] is 20 or less. ·Scratch resistance test The surface of the resin layer is reciprocated 10 times using steel wool under the conditions of a load of 3.92 N and a moving speed of 100 mm / sec.

[0011] The configuration in which the change amount is 20 or less is preferable in that, when the optical film of the first aspect of the present invention is used as a polarizing plate protective film, even if the resin layer is thin, the surface hardness and scratch resistance are less likely to decrease, a decrease in low moisture permeability due to scratches is prevented, and the occurrence of "color bleeding" of the polarizer can be suppressed. From the viewpoint of achieving a higher level of both suppression of color bleeding of the polarizer and the scratch resistance of the resin layer, the change amount is preferably 18 or less, more preferably 15 or less, and may be 12 or less, or 10 or less.

[0012] In the optical film according to the first aspect of the present invention, it is preferable that the surface of the resin layer is not scratched when subjected to a scratch resistance test using steel wool under the conditions of a load of 0.98 N, a moving speed of 100 mm / sec, and 10 round trips. As described above, the resin layer imparts excellent scratch resistance to the optical film according to the first aspect of the present invention. Therefore, when the optical film according to the first aspect of the present invention is used as a polarizing plate protective film, the resin layer has excellent scratch resistance, making it less likely to be scratched during the manufacturing process and preventing deterioration in polarizing plate performance, such as a decrease in low moisture permeability.

[0013] In the optical film according to the first aspect of the present invention, the resin layer preferably has a thickness of 0.1 to 10 μm. As described above, even if the resin layer is thin, it can impart excellent low moisture permeability and scratch resistance to the optical film according to the first aspect of the present invention. From the viewpoint of enabling a thinner polarizing plate when the optical film according to the first aspect of the present invention is used as a polarizing plate protective film, the resin layer preferably has a thickness of 7 μm or less, more preferably 5 μm or less, and may be 3.2 μm or less, or 3 μm or less. From the viewpoint of achieving both low moisture permeability and scratch resistance at a higher level, the lower limit of the resin layer thickness is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 1.8 μm or more, and may be 2 μm or more.

[0014] In the optical film according to the first aspect of the present invention, the light-transmitting substrate preferably contains at least one resin selected from the group consisting of cellulose-based resins, polyester-based resins, acrylic-based resins, and cyclic olefin-based polymers. These resins can be suitably used as the substrate for polarizing plate protective films.

[0015] A second aspect of the present invention provides a polarizing plate, in which a polarizer is disposed on the side of the optical film according to the first aspect of the present invention opposite to the resin layer. Furthermore, a third aspect of the present invention provides an image display device having the polarizing plate of the second aspect of the present invention. In the image display device of the third aspect of the present invention, it is preferable that a pressure-sensitive adhesive layer and an optical member are laminated in this order on the resin layer.

[0016] The polarizing plate according to the second aspect of the present invention uses the optical film according to the first aspect of the present invention as a polarizing plate protective film, and therefore has excellent low moisture permeability and scratch resistance even when the resin layer is thin. Therefore, the image display device according to the third aspect of the present invention, which includes the polarizing plate according to the second aspect of the present invention, is less likely to suffer from color fading or the like in the polarizing plate in a humid environment, even when it is thin, and has excellent durability. [Effects of the Invention]

[0017] A polarizing plate obtained by using the optical film of the present invention as a polarizing plate protective film has low moisture permeability and excellent scratch resistance even when thin, is less susceptible to discoloration of the polarizer, and is excellent in durability. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram (cross-sectional view) showing one embodiment of the optical film of the present invention. [Figure 2] FIG. 2 is a schematic diagram (cross-sectional view) showing one embodiment of a polarizing plate having the optical film of FIG. [Figure 3] FIG. 3 is a schematic diagram (cross-sectional view) showing one embodiment of an image display device having the polarizing plate of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] A first aspect of the present invention provides an optical film in which a resin layer is laminated on one surface of a light-transmitting substrate. The optical film of the first aspect of the present invention may be referred to herein as the "optical film of the present invention." The light-transmitting substrate and resin layer constituting the optical film of the present invention may be referred to herein as the "light-transmitting substrate of the present invention" and the "resin layer of the present invention," respectively. The term "film" also includes the meanings of "sheet" and "tape." That is, the optical film of the present invention may be in the form of a sheet or tape.

[0020] A second aspect of the present invention provides a polarizing plate, in which a polarizer is disposed on the opposite side of the optical film of the present invention from the resin layer. The polarizing plate of the second aspect of the present invention may be referred to as the "polarizing plate of the present invention" in this specification. A third aspect of the present invention provides an image display device having the polarizing plate of the present invention. The image display device of the third aspect of the present invention may be referred to as the "image display device of the present invention" in this specification.

[0021] Hereinafter, embodiments of the optical film of the present invention will be described with reference to the drawings, but the present invention is not limited thereto and is merely an example.

[0022] FIG. 1 is a schematic diagram (cross-sectional view) showing one embodiment of the optical film of the present invention. In FIG. 1, the optical film 10 has a laminated structure in which a resin layer 1 is laminated on one surface of a light-transmitting substrate 2 .

[0023] FIG. 2 is a schematic diagram (cross-sectional view) showing one embodiment of the polarizing plate of the present invention. 2, the polarizing plate 20 has a laminated structure in which a polarizer 3 is disposed on the side of an optical film 10 opposite to a resin layer 1. In this embodiment, a second light-transmitting substrate 4 and a pressure-sensitive adhesive layer 5 are further laminated in this order on the side of the polarizer 3 opposite to the optical film 10.

[0024] FIG. 3 is a schematic diagram (cross-sectional view) showing one embodiment of an image display device having the polarizing plate of FIG. 3, an image display device 30 has an image display panel 6 laminated on an adhesive layer 5 of a polarizing plate 20. In this embodiment, an adhesive layer 7 and an optical member 8 are laminated on a resin layer 1 in this order. Each component will be described below.

[0025] <Optical film> The term "optical" in the optical film of the present invention means that the film is used for optical purposes, and more specifically, means that the film is used in the manufacture of products (optical products) that use optical components. Examples of optical products include image displays and input devices such as touch panels, and the film can be suitably used in the manufacture of liquid crystal image displays and self-luminous image displays (e.g., organic EL (electroluminescence) image displays and LED image displays). More specifically, the film can be suitably used as a protective film for polarizing plates that constitute image displays.

[0026] The optical film of the present invention is not particularly limited in its form as long as a resin layer is laminated on one side of a light-transmitting substrate. For example, the optical film of the present invention may have a resin layer on only one side, or may have a resin layer on both sides. When the optical film of the present invention has a resin layer on both sides, the optical film of the present invention may have a form in which both resin layers are provided by the resin layer of the present invention, or one resin layer is provided by the resin layer of the present invention, and the other resin layer is provided by a resin layer other than the resin layer of the present invention (another resin layer). When the optical film of the present invention is used as a polarizing plate protective film, an optical film having a resin layer on only one side is preferred.

[0027] In addition to the light-transmitting substrate of the present invention and the resin layer of the present invention, the optical film of the present invention may have other layers, such as a substrate other than the light-transmitting substrate of the present invention, a resin layer other than the resin layer of the present invention, an intermediate layer, an undercoat layer, an antistatic layer, a separator, a surface protective film, etc., on the surface or between any layers, as long as the effects of the present invention are not impaired.

[0028] The optical film of the present invention was tested for moisture permeability [g / m 2 ] of the optical film under an environment of a temperature of 40°C and a relative humidity of 92% before and after the following scratch resistance test. 2 The change in [24h] is 20 or less. ·Scratch resistance test The surface of the resin layer is reciprocated 10 times using steel wool under the conditions of a load of 3.92 N and a moving speed of 100 mm / sec. In general, the moisture permeability after the scratch resistance test tends to increase compared to the moisture permeability before the test, but this also includes the amount of change when the moisture permeability after the scratch resistance test decreases compared to the moisture permeability before the test. Therefore, the amount of change is, for example, the absolute value of the moisture permeability after the scratch resistance test minus the moisture permeability before the test.

[0029] The resin layer of the present invention imparts excellent low moisture permeability to the optical film of the present invention, and generally, the thicker the film thickness, the higher the moisture permeability, and the thinner the film thickness, the lower the moisture permeability. The resin layer of the present invention also imparts excellent scratch resistance to the optical film of the present invention, and generally, the thicker the film thickness, the higher the scratch resistance, and the thinner the film thickness, the lower the scratch resistance. Therefore, the optical film of the present invention, which has a laminate structure including the resin layer of the present invention so that the rate of change is 20 or less, is endowed with excellent low moisture permeability and scratch resistance even when the resin layer of the present invention is thin, and thus combines thinness with excellent low moisture permeability and durability.

[0030] The configuration in which the rate of change is 20 or less is preferable because, when the optical film of the present invention is used as a polarizing plate protective film, even if the resin layer of the present invention is thin, the surface hardness and scratch resistance are less likely to decrease, and a decrease in low moisture permeability due to scratches is prevented, thereby suppressing the occurrence of "color bleeding" in the polarizer. From the viewpoint of achieving a high level of both suppression of color bleeding in the polarizer and scratch resistance of the resin layer of the present invention, the rate of change is preferably 18 or less, more preferably 15 or less, and may be 12 or less, or 10 or less. The lower limit of the rate of change is not particularly limited, and 0, i.e., no change, is most preferable. However, from the viewpoint of suppressing the occurrence of "color bleeding" in the polarizer, the rate of change may be, for example, about 0.1 or more to 0.5 or more.

[0031] The moisture permeability M of the optical film of the present invention in an environment of a temperature of 40°C and a relative humidity of 92% before the scratch resistance test 1 [g / m 2 24h is 700g / m 2 It is preferable that the moisture permeability M 1 is 700g / m 2 The moisture permeability M is preferably 24 hours or less, since when the optical film of the present invention is used as a polarizing plate protective film, the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed. 1 is 600g / m 2 24 hours or less is preferable, 550g / m 2 The moisture permeability M may be 24 hours or less. 1 The lower limit of the value is not particularly limited, but from the viewpoint of preventing the occurrence of "color bleeding" of the polarizer by allowing moisture in the polarizing plate to escape to the outside, it is set to 100 g / m 2 24 hours or more is preferable, 200g / m 2 24 hours or more is preferable, 300g / m 2 It may be more than 24 hours.

[0032] The moisture permeability [g / m 2 ] of the optical film of the present invention after the scratch resistance test under an environment of a temperature of 40°C and a relative humidity of 92% 2·24h] is a moisture permeability M of the optical film of the present invention in an environment of a temperature of 40°C and a relative humidity of 92% before the scratch resistance test, in that it can suppress the occurrence of "color fading" of the polarizer in a humid environment. 1 [g / m 2 ·24h] may be in the range of 20 or less, preferably 18 or less, more preferably 15 or less, 12 or less, or 10 or less.

[0033] The moisture permeability M of the optical film of the present invention in an environment of a temperature of 60°C and a relative humidity of 90% 2 [g / m 2 24h is 1,500g / m 2 It is preferable that the moisture permeability M 2 is 1,500g / m 2 The moisture permeability M is preferably 24 hours or less, since when the optical film of the present invention is used as a polarizing plate protective film, the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed. 2 is 1,400g / m 2 24 hours or less is preferable, 1,300 g / m 2 24 hours or less is preferable, 1,200g / m 2 The moisture permeability M may be 24 hours or less. 2 The lower limit of the thickness is not particularly limited, but from the viewpoint of preventing the occurrence of "color loss" of the polarizer by allowing moisture in the polarizing plate to escape to the outside, it is preferable that the lower limit be 300 g / m 2 24 hours or more is preferable, 500g / m 2 24 hours or more is preferable, 800g / m 2 It may be more than 24 hours.

[0034] The moisture permeability M of the optical film of the present invention in an environment of a temperature of 65°C and a relative humidity of 90% 3 [g / m 2 24h is 2,000g / m 2 It is preferable that the moisture permeability M 3 is 2,000g / m 2The moisture permeability M is preferably 24 hours or less, since when the optical film of the present invention is used as a polarizing plate protective film, the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed. 3 is 1,800g / m 2 24 hours or less is preferable, 1,600 g / m 2 24 hours or less is preferable, 1,400g / m 2 The moisture permeability M may be 24 hours or less. 3 The lower limit of the value is not particularly limited, but from the viewpoint of preventing the occurrence of "color loss" of the polarizer by allowing moisture in the polarizing plate to escape to the outside, it is set to 500 g / m 2 24 hours or more is preferable, 750g / m 2 24 hours or more is preferable, 1,000g / m 2 It may be more than 24 hours.

[0035] In the optical film of the present invention, the thickness T [μm] of the resin layer of the present invention and the moisture permeability M of the optical film of the present invention under an environment of a temperature of 40° C. and a relative humidity of 92% are 1 [g / m 2 24h] product (T×M 1 ) is preferably 1,500 or less. The resin layer of the present invention imparts excellent low moisture permeability to the optical film of the present invention, and generally, the thicker the film thickness, the higher the moisture permeability, and the thinner the film thickness, the lower the moisture permeability, which are in an inversely proportional relationship. For this reason, the thickness T [μm] of the resin layer of the present invention and the moisture permeability M 1 The product of (T×M 1 ) can be an index of the moisture permeability of the resin layer itself of the present invention, and it can be said that the lower the value, the better the low moisture permeability. 1 The optical film of the present invention having a laminate structure including the resin layer of the present invention in which the moisture permeability (moisture permeability) is 1,500 or less is imparted with excellent low moisture permeability even when the resin layer of the present invention is thin, and thus has both a thin profile and excellent low moisture permeability.

[0036] The product (T × M 1The structure in which the product (T×M) is 1,500 or less is preferable in that, when the optical film of the present invention is used as a polarizing plate protective film, excellent low moisture permeability can be imparted even when the resin layer of the present invention is thin, and the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed. From the viewpoint of achieving both the suppression of color bleeding of the polarizer and the thinning of the resin layer of the present invention at a higher level, 1 ) is preferably 1,400 or less, more preferably 1,300 or less, and may be 1,200 or less. 1 The lower limit of ) is not particularly limited, but from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer, it is preferably 500 or more, more preferably 600 or more, and may be 700 or more.

[0037] In the optical film of the present invention, the thickness T [μm] of the resin layer of the present invention and the moisture permeability M of the optical film of the present invention under an environment of a temperature of 60° C. and a relative humidity of 90% 2 [g / m 2 24h] product (T×M 2 ) is preferably 3,000 or less. 2 ) is also the above product (T×M 1 ), it can be said that the lower the value, the better the low moisture permeability. 2 The optical film of the present invention having a laminate structure including the resin layer of the present invention in which the value of [Delta] is 3,000 or less is preferably provided with excellent low moisture permeability even when the resin layer of the present invention is thin, and thus has both a thin profile and excellent low moisture permeability.

[0038] The product (T × M 2 The structure in which the product (T×M) is 3,000 or less is preferred in that when the optical film of the present invention is used as a polarizing plate protective film, the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed even if the resin layer of the present invention is thin. From the viewpoint of achieving both the suppression of color bleeding of the polarizer and the thinning of the resin layer of the present invention at a higher level, 2) is preferably 2,900 or less, more preferably 2,800 or less, and may be 2,700 or less. 2 The lower limit of ) is not particularly limited, but from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer, it is preferably 500 or more, more preferably 1,000 or more, and may be 1,500 or more.

[0039] In the optical film of the present invention, the product (T×M 1 ) and the product (T × M 2 ) and the product ((T×M 1 )×(T×M 2 It is preferable that the product ((T×M 1 )×(T×M 2 )) is also the product (T × M 1 ), the product (T × M 2 ), it can be said that the lower the value, the better the low moisture permeability. 1 )×(T×M 2 The optical film of the present invention having a laminate structure including the resin layer of the present invention having a molecular weight of 4,500,000 or less is provided with excellent low moisture permeability even when the resin layer of the present invention is thin, and is therefore preferred because it combines both thinness and excellent low moisture permeability.

[0040] The product ((T × M 1 )×(T×M 2 The structure in which the product ((T×M )) is 4,500,000 or less is preferred in that when the optical film of the present invention is used as a polarizing plate protective film, the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed even if the resin layer of the present invention is thin. From the viewpoint of achieving both the suppression of color bleeding of the polarizer and the thinning of the resin layer of the present invention at a higher level, 1 )×(T×M 2 The product ((T×M)) is preferably 4,000,000 or less, and more preferably 3,500,000 or less. 1 )×(T×M 2The lower limit of the modulus of elasticity is not particularly limited, but is preferably 50,000 or more, more preferably 100,000 or more, and may be 150,000 or more, from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer.

[0041] In the optical film of the present invention, the thickness T [μm] of the resin layer of the present invention and the moisture permeability M of the optical film of the present invention under an environment of a temperature of 65° C. and a relative humidity of 90% 3 [g / m 2 24h] product (T×M 3 ) is preferably 4,000 or less. 3 ) is also the above product (T×M 1 ), product (T×M 2 ), it can be said that the lower the value, the better the low moisture permeability. 3 The optical film of the present invention having a laminate structure including the resin layer of the present invention in which the value of [theta] is 4,000 or less is preferably provided with excellent low moisture permeability even when the resin layer of the present invention is thin, and thus has both a thin profile and excellent low moisture permeability.

[0042] The product (T × M 3 The structure in which the product (T×M) is 4,000 or less is preferred in that, when the optical film of the present invention is used as a polarizing plate protective film, the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed even if the resin layer of the present invention is thin. From the viewpoint of achieving both the suppression of color bleeding of the polarizer and the thinning of the resin layer of the present invention at a higher level, 3 ) is preferably 3,800 or less, more preferably 3,600 or less, and may be 3,400 or less. 3 The lower limit of ) is not particularly limited, but from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer, it is preferably 1,000 or more, more preferably 1,500 or more, and may be 2,000 or more.

[0043] In the optical film of the present invention, the moisture permeability M of the optical film under an environment of a temperature of 40° C. and a relative humidity of 92% is1 [g / m 2 24h] is subtracted from the value obtained by dividing the value by the thickness T [μm] of the resin layer ((1,000-M 1 ) / T) is preferably 100 or more. The resin layer of the present invention imparts excellent low moisture permeability to the optical film of the present invention, and generally, the thicker the film thickness, the higher the moisture permeability, and the thinner the film thickness, the lower the moisture permeability. The above numerical value "1,000" is an approximate value of the moisture permeability of the light-transmitting substrate of the present invention itself (light-transmitting substrate having no resin layer) at a temperature of 40°C and a relative humidity of 92%, and is calculated by multiplying the moisture permeability M by 1,000. 1 [g / m 2 The value obtained by subtracting [1,000-M] from [24h] is an approximate value of the moisture permeability reduced by providing a resin layer on the light-transmitting substrate of the present invention. 1 ) / T) can be an index of the moisture permeability that is reduced per 1 μm of thickness of the resin layer of the present invention in an environment of a temperature of 40° C. and a relative humidity of 92%, and it can be said that the higher the value, the better the low moisture permeability. Therefore, the above value ((1,000-M 1 An optical film having a laminate structure of the resin layer of the present invention in which the ratio (R / T) is 100 or more is imparted with excellent low moisture permeability even when the resin layer is thin, and thus has both a thin profile and excellent low moisture permeability.

[0044] The value ((1,000-M 1 The configuration in which the value ((1,000-M 1 ) / T) is preferably 105 or more, more preferably 110 or more, and may be 115 or more. 1 The upper limit of ) / T)) is not particularly limited, but from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer, it is preferably 500 or less, more preferably 400 or less, and may be 300 or less.

[0045] In the optical film of the present invention, the moisture permeability M of the optical film in an environment of 2,000 to 60°C and a relative humidity of 90% is 2 [g / m 2 24h] is subtracted from the value obtained by dividing the value by the thickness T [μm] of the resin layer ((2,000-M 2 ) / T) is preferably 200 or more. The value "2,000" is an approximate value of the moisture permeability of the light-transmitting substrate of the present invention itself (light-transmitting substrate having no resin layer) under an environment of a temperature of 60°C and a relative humidity of 90%, and the moisture permeability M 2 [g / m 2 The value obtained by subtracting [2,000 - M] is an approximate value of the moisture permeability reduced by providing a resin layer on the light-transmitting substrate of the present invention. 2 ) / T) can be an index of the moisture permeability that is reduced per 1 μm of thickness of the resin layer of the present invention in an environment of a temperature of 60° C. and a relative humidity of 90%, and it can be said that the higher the value, the better the low moisture permeability. Therefore, the above value ((2,000-M 2 An optical film having a laminate structure of the resin layer of the present invention in which the ratio (R / T) is 200 or more is imparted with excellent low moisture permeability even when the resin layer is thin, and thus has both a thin profile and excellent low moisture permeability.

[0046] The value ((2,000-M 2 The structure in which the product value ((2,000-M 2 ) / T) is preferably 210 or more, more preferably 220 or more, and may be 230 or more. 2 The upper limit of ) / T)) is not particularly limited, but from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer, it is preferably 1,000 or less, more preferably 800 or less, and may be 500 or less.

[0047] In the optical film of the present invention, the value ((1,000-M 1 ) / T) and the value ((2,000-M 2 ) / T) and the product [((1,000-M 1 ) / T)×((2,000-M 2 ) / T)] is preferably 20,000 or more. 1 ) / T)×((2,000-M 2 ) / T)] is also the value ((1,000-M 1 ) / T), the value ((2,000-M 2 ) / T), it can be said that the higher the product, the better the low moisture permeability. 1 ) / T)×((2,000-M 2 The optical film of the present invention having a laminate structure including the resin layer of the present invention in which the ratio (%) of (x, y) / T) is 20,000 or more is imparted with excellent low moisture permeability even when the resin layer of the present invention is thin, and is therefore preferred because it combines both thinness and excellent low moisture permeability.

[0048] The product [((1,000-M 1 ) / T)×((2,000-M 2 The structure in which the product [((1,000-M 1 ) / T)×((2,000-M 2 ) / T)] is preferably 21,000 or more, more preferably 22,000 or more. 1 ) / T)×((2,000-M 2 The upper limit of the ratio (%) / T) is not particularly limited, but from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer, it is preferably 200,000 or less, more preferably 150,000 or less, and may be 120,000 or less.

[0049] In the optical film of the present invention, the moisture permeability M of the optical film in an environment of 2,700 to 65°C and a relative humidity of 90% is 3 [g / m 2 24h] is subtracted and divided by the thickness T [μm] of the resin layer ((2,700-M 3 ) / T) is preferably 250 or more. The value "2,700" is an approximate value of the moisture permeability of the light-transmitting substrate of the present invention itself (light-transmitting substrate having no resin layer) under an environment of a temperature of 65°C and a relative humidity of 90%, and the moisture permeability M 3 [g / m 2 The value obtained by subtracting [2,700 - M] is an approximate value of the moisture permeability reduced by providing a resin layer on the light-transmitting substrate of the present invention. 3 ) / T) can be an index of the moisture permeability that is reduced per 1 μm of thickness of the resin layer of the present invention in an environment of a temperature of 65° C. and a relative humidity of 90%, and it can be said that the higher the value, the better the low moisture permeability. Therefore, the above value ((2,700-M 3 An optical film having a laminate structure of the resin layer of the present invention in which the ratio (R / T) is 250 or more is imparted with excellent low moisture permeability even when the resin layer is thin, and thus has both a thin profile and excellent low moisture permeability.

[0050] The value ((2,700-M 3 The configuration in which the value ((2,700-M ) / T) is 250 or more is preferred in that when the optical film of the present invention is used as a polarizing plate protective film, excellent low moisture permeability can be imparted even when the resin layer of the present invention is thin, and the occurrence of "color bleeding" of the polarizer in a humid environment can be suppressed. From the viewpoint of achieving both the suppression of color bleeding of the polarizer and the thinning of the resin layer of the present invention at a higher level, the value ((2,700-M 3 ) / T) is preferably 270 or more, more preferably 280 or more, and may be 300 or more. 3 The upper limit of ) / T)) is not particularly limited, but from the viewpoint of allowing moisture in the polarizing plate to escape to the outside and preventing the occurrence of "color bleeding" of the polarizer, it is preferably 1,000 or less, more preferably 800 or less, and may be 600 or less.

[0051] The moisture permeability M 1 , M 2 , M 3 , the change in moisture permeability before and after the scratch resistance test, the thickness T of the resin layer and the moisture permeability M 1 , M 2 , or M 3 The product of (1,000-M 1 ) / T), value((2,000-M 2 ) / T), as well as the value ((2,700-M 3 ) / T), and the product thereof can be specifically measured by the method described in the Examples below. 1 , M 2 , M 3 , ,Change in moisture permeability before and after scratch resistance test, resin layer thickness T and moisture permeability M 1 , M 2 , or M 3 The product of (1,000-M 1 ) / T), value((2,000-M 2 ) / T), as well as the value ((2,700-M 3 ) / T), their product, etc. can be adjusted by adjusting the type and thickness of the resin constituting the light-transmitting substrate of the present invention, the type, composition, degree of crosslinking, etc. of the resin constituting the resin layer of the present invention.

[0052] The haze of the optical film of the present invention is not particularly limited, but from the viewpoint of obtaining good transparency, it is preferably 1.0% or less, more preferably 0.8% or less. The haze can be determined in accordance with JIS K 7136 (2000). The haze of the optical film of the present invention can be adjusted by the type and thickness of the resin constituting the light-transmitting substrate of the present invention, the type and thickness of the resin constituting the resin layer of the present invention, etc.

[0053] The total light transmittance in the visible light wavelength region of the optical film of the present invention is not particularly limited, but is preferably 85% or more, more preferably 88% or more. The visible light wavelength region can be determined in accordance with JIS K 7361-1. The total light transmittance of the optical film of the present invention can be adjusted by the type and thickness of the resin constituting the light-transmitting substrate of the present invention, the type and thickness of the resin constituting the resin layer of the present invention, etc.

[0054] The thickness of the optical film of the present invention is not particularly limited, but in consideration of, for example, thinness, strength, ease of handling, and other workability, the thickness is preferably in the range of 1 to 500 μm, more preferably in the range of 10 to 300 μm, and most preferably in the range of 20 to 200 μm.

[0055] <Light transparent base material> Examples of materials constituting the light-transmitting substrate of the present invention include glass and plastic films. Examples of the plastic film include cellulose-based resins such as triacetyl cellulose (TAC), acrylic resins such as polymethyl methacrylate (PMMA), polyester-based resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), cyclic olefin polymers (COP) (e.g., trade name "Arton" (manufactured by JSR Corporation) and trade name "Zeonor" (manufactured by Zeon Corporation)), polycarbonate-based resins, polysulfone-based resins, polyarylate-based resins, polyimide-based resins, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, and ethylene-propylene copolymers. From the viewpoints of optical uniformity, surface smoothness, and good secondary processability in producing polarizing plates, cellulose-based resins, acrylic resins, polyester-based resins, and cyclic olefin polymers (COP) are preferred, with cellulose-based resins being particularly preferred. These plastic materials can be used alone or in combination of two or more.

[0056] The haze of the light-transmitting substrate of the present invention is not particularly limited, but from the viewpoint of obtaining good transparency, it is preferably 1.0% or less, more preferably 0.8% or less. The haze can be determined in accordance with JIS K 7136 (2000). The haze of the light-transmitting substrate of the present invention can be adjusted by the type and thickness of the resin constituting the light-transmitting substrate of the present invention.

[0057] The total light transmittance in the visible light wavelength region of the light-transmitting substrate of the present invention is not particularly limited, but is preferably 85% or more, more preferably 88% or more. The visible light wavelength region can be determined in accordance with JIS K 7361-1. The total light transmittance of the light-transmitting substrate of the present invention can be adjusted by the type and thickness of the resin constituting the light-transmitting substrate of the present invention.

[0058] The thickness of the light-transmitting substrate of the present invention is not particularly limited, but taking into consideration workability such as thinness, strength, and handleability, and thinness, the thickness is preferably in the range of 1 to 500 μm, more preferably in the range of 10 to 300 μm, and most preferably in the range of 20 to 200 μm.

[0059] The refractive index of the light-transmitting substrate of the present invention is not particularly limited, but is, for example, in the range of 1.30 to 1.80, preferably 1.40 to 1.70. The surface of the light-transmitting substrate of the present invention (the surface on which the resin layer is formed and / or the surface opposite thereto) may be appropriately subjected to a known and commonly used surface treatment, for example, a physical treatment such as corona discharge treatment or plasma treatment, or a chemical treatment such as an undercoat treatment.

[0060] <Resin layer> The resin layer of the present invention is laminated on one side of the light-transmitting substrate of the present invention and imparts excellent low moisture permeability to the optical film of the present invention. The resin layer of the present invention also imparts excellent scratch resistance to the optical film of the present invention. Therefore, the optical film of the present invention having a laminate structure including the resin layer of the present invention can be suitably used as a polarizing plate protective film.

[0061] The resin layer of the present invention preferably does not scratch its surface when subjected to a scratch resistance test using steel wool under the conditions of a load of 0.98 N, a moving speed of 100 mm / sec, and 10 round trips. That is, since the optical film of the present invention is coated with the resin layer of the present invention, which has excellent scratch resistance, it is less likely to be scratched during the manufacturing process even when made thin, and when used as a polarizing plate protective film, it can provide a polarizing plate with excellent durability. The excellent scratch resistance of the resin layer of the present invention can be imparted by adjusting the composition and thickness of the resin layer, which will be described later.

[0062] The resin layer of the present invention is formed from a cured product of a curable composition containing at least one polymerizable compound selected from the group consisting of a monomer having a polymerizable functional group and an oligomer having a polymerizable functional group. In this specification, the polymerizable compound constituting the resin layer of the present invention may be referred to as the "polymerizable compound of the present invention," and the curable composition containing the polymerizable compound of the present invention may be referred to as the "curable composition of the present invention." The configuration in which the resin layer of the present invention is formed from a cured product of the curable composition of the present invention containing the polymerizable compound of the present invention is preferred in that it can impart excellent low moisture permeability and scratch resistance to the optical film of the present invention.

[0063] The "polymerizable functional group" possessed by the polymerizable compound of the present invention is not particularly limited, and examples thereof include an unsaturated double bond group, an epoxy group, and an oxetanyl group. From the viewpoint of excellent low moisture permeability and scratch resistance, an unsaturated double bond group is preferred. Examples of the unsaturated double bond group include a (meth)acryloyl group, a vinyl group, a styryl group, and an allyl group. Among these, a (meth)acryloyl group is preferred. In this specification, "(meth)acryloyl" refers to either or both of "acryloyl" and "methacryloyl," and "(meth)acrylic" refers to either or both of "acrylic" and "methacrylic."

[0064] The number of "polymerizable functional groups" contained in the polymerizable compound of the present invention is not particularly limited as long as it is 1 or more, but in terms of being able to impart excellent low moisture permeability and scratch resistance to the optical film of the present invention, it is preferable that the curable composition of the present invention contains at least a polymerizable compound having preferably 2 or more, more preferably 3 or more, even more preferably 4 or more, or 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, or 10 or more polymerizable functional groups. The upper limit of the number of "polymerizable functional groups" is not particularly limited, but may be 30 or less, 25 or less, or 20 or less.

[0065] In order to impart excellent low moisture permeability to the optical film of the present invention, the curable composition of the present invention preferably contains, as the polymerizable compound of the present invention, a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule (hereinafter, sometimes referred to as "polymerizable compound A"). It is believed that the cyclic aliphatic hydrocarbon group in the molecule of polymerizable compound A hydrophobicizes the resin layer of the present invention and reduces the moisture permeability. The curable composition of the present invention may contain one type of polymerizable compound A, or may contain two or more types of polymerizable compound A.

[0066] The polymerizable functional group of the polymerizable compound A is preferably an unsaturated double bond group such as a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group, and among these, a (meth)acryloyl group is preferred. Particularly preferred are the following compounds containing two or more (meth)acryloyl groups in one molecule:

[0067] The number of "polymerizable functional groups" that the polymerizable compound A has in its molecule is not particularly limited as long as it is 1 or more, but in terms of being able to impart excellent low moisture permeability and scratch resistance to the optical film of the present invention, it is preferable that the polymerizable functional groups be 2 or more, more preferably 3 or more, and even more preferably 4 or more. The upper limit of the number of "polymerizable functional groups" that the polymerizable compound A has is not particularly limited, but may be 10 or less, 9 or less, or 8 or less.

[0068] The "alicyclic hydrocarbon group" contained in the molecule of polymerizable compound A is preferably a group derived from an alicyclic compound having 7 or more carbon atoms, more preferably a group derived from an alicyclic compound having 10 or more carbon atoms, and even more preferably a group derived from an alicyclic compound having 12 or more carbon atoms. Particularly preferred alicyclic hydrocarbon groups are groups derived from polycyclic compounds such as bicyclic and tricyclic compounds.

[0069] The cyclic aliphatic hydrocarbon group (including a linking group) is preferably a group represented by any one of the following general formulas (I) to (V), more preferably a group represented by the following general formula (I), (II), or (IV), and even more preferably a group represented by the following general formula (I). [ka]

[0070] In formula (I), L and L' each independently represent a divalent or higher valent linking group, and n represents an integer of 1 to 3. [ka]

[0071] In formula (II), L and L' each independently represent a divalent or higher valent linking group, and n represents an integer of 1 or 2. [ka]

[0072] In formula (III), L and L' each independently represent a divalent or higher valent linking group, and n represents an integer of 1 or 2. [ka]

[0073] In formula (IV), L and L' each independently represent a divalent or higher valent linking group, and L'' represents a hydrogen atom or a divalent or higher valent linking group. [ka]

[0074] In formula (V), L and L' each independently represent a divalent or higher valent linking group.

[0075] Specific examples of the cyclic aliphatic hydrocarbon group include monovalent to trivalent groups derived from norbornane, tricyclodecane, tetracyclododecane, pentacyclopentadecane, adamantane, diamantane, and the like.

[0076] The polymerizable compound A containing a group represented by any one of the above general formulae (I) to (V) as a cyclic aliphatic hydrocarbon group has a polymerizable functional group via a linking group represented by L, L', and L". Examples of the linking group include a single bond, an alkylene group having 1 to 6 carbon atoms which may be substituted, an amide group which may be di-substituted at the N-position, a carbamoyl group which may be substituted at the N-position, an ester group, an oxycarbonyl group, an ether group, and the like, as well as groups obtained by combining these.

[0077] The polymerizable compound A can be easily synthesized, for example, by a one- or two-step reaction between a polyol such as a diol or triol having a cyclic aliphatic hydrocarbon group and a carboxylic acid, carboxylic acid derivative, epoxy derivative, or isocyanate derivative of a compound having a (meth)acryloyl group, a vinyl group, a styryl group, an allyl group, etc. Preferably, the polymerizable compound A can be synthesized by reacting a polyol having a cyclic aliphatic hydrocarbon group with (meth)acrylic acid, (meth)acryloyl chloride, (meth)acrylic anhydride, glycidyl (meth)acrylate, 1,1-bis(acryloxymethyl)ethyl isocyanate, or the like.

[0078] Preferred specific examples of the polymerizable compound A are shown below, but the present invention is not limited to these. [ka] [ka] [ka] [ka] [ka] [ka]

[0079] The content of polymerizable compound A in the curable composition of the present invention is not particularly limited, but from the viewpoint of imparting excellent low moisture permeability to the resin layer of the present invention, it is preferably 10% by weight or more, more preferably 15% by weight or more, or may be 15% by weight or more, 20% by weight or more, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 45% by weight or more, 50% by weight or more, 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, 80% by weight or more, 85% by weight or more, or 90% by weight or more, relative to 100% by weight of the non-volatile solids content of the curable composition of the present invention. On the other hand, from the viewpoint of achieving a higher level of both low moisture permeability and scratch resistance in the resin layer of the present invention, the content may be 95% by weight or less, 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, 65% by weight or less, 60% by weight or less, 55% by weight or less, 50% by weight or less, 45% by weight or less, 40% by weight or less, 35% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, 15% by weight or less, or 10% by weight or less.

[0080] In order to impart excellent abrasion resistance to the optical film of the present invention in addition to excellent low moisture permeability, the curable composition of the present invention preferably further contains, in addition to polymerizable compound A, a polymerizable compound other than polymerizable compound A, i.e., a compound having a polymerizable functional group but not a cyclic aliphatic hydrocarbon group in the molecule (hereinafter, sometimes referred to as "polymerizable compound B"). Polymerizable compound A tends to have a low crosslink density due to the three-dimensional structure of the cyclic aliphatic hydrocarbon group in the molecule. It is believed that the curable composition of the present invention, which contains polymerizable compound B in addition to polymerizable compound A, increases the crosslink density and improves the abrasion resistance.

[0081] The polymerizable functional group of the polymerizable compound B is preferably an unsaturated double bond group such as a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group, and among these, a (meth)acryloyl group is preferred. Particularly preferred are the following compounds containing two or more (meth)acryloyl groups in one molecule:

[0082] The number of "polymerizable functional groups" possessed by the polymerizable compound B is not particularly limited as long as it is 1 or more, but from the viewpoint of imparting excellent scratch resistance to the optical film of the present invention, it is preferable that the polymerizable compound B has 2 or more, more preferably 3 or more, even more preferably 4 or more, or 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, or 10 or more. The upper limit of the number of "polymerizable functional groups" possessed by the polymerizable compound B is not particularly limited, but may be 30 or less, 25 or less, or 20 or less.

[0083] Examples of the polymerizable compound B include a monomer having a polymerizable functional group but not having a cyclic aliphatic hydrocarbon group in the molecule (hereinafter, this may be referred to as "polymerizable monomer B"), and an oligomer having a polymerizable functional group but not having a cyclic aliphatic hydrocarbon group in the molecule (hereinafter, this may be referred to as "polymerizable oligomer B"). The curable composition of the present invention may contain only a polymerizable monomer as the polymerizable compound B, only a polymerizable oligomer B, or both a polymerizable monomer B and a polymerizable oligomer B. From the viewpoint of forming a high crosslink density, it is preferable to contain at least a polymerizable oligomer B.

[0084] Examples of polymerizable monomer B include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol (meth)hexaacrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, and propoxylated trimethylolpropane tri(meth)acrylate. The curable composition of the present invention may contain one type of polymerizable monomer B, or may contain two or more types of polymerizable monomer B.

[0085] The polymerizable oligomer B is a compound containing two or more repeating units and having a polymerizable functional group. That is, the polymerizable oligomer B is a polymer having a polymerizable functional group in the molecule. Examples of the polymerizable oligomer B include urethane (meth)acrylate in which two or more (meth)acryloyl groups are added as functional groups to a urethane skeleton, polyester (meth)acrylate in which two or more (meth)acryloyl groups are added as functional groups to a polyester skeleton, and epoxy (meth)acrylate in which two or more (meth)acryloyl groups are added as functional groups to an epoxy skeleton. From the viewpoint of forming a high crosslink density, it is preferable to contain at least a urethane (meth)acrylate. The curable composition of the present invention may contain one type of polymerizable oligomer B or may contain two or more types of polymerizable oligomer B.

[0086] Urethane (meth)acrylates can be obtained, for example, by reacting polyols, isocyanates, and hydroxy (meth)acrylates. As the polyol constituting the urethane (meth)acrylate, any known polyol can be used without limitation, but from the viewpoint of improving the crosslink density, a polyol having three or more hydroxyl groups (preferably four or more, more preferably five or more, and even more preferably six or more) is preferred, and examples thereof include trimethylolpropane, ethoxylated isocyanuric acid, pentaerythritol, dipentaerythritol, tripentaerythritol, tetrapentaerythritol, etc. These polyols may be used alone or in combination of two or more.

[0087] As the isocyanate constituting the urethane (meth)acrylate, polyisocyanates composed of chain saturated hydrocarbons, cyclic saturated hydrocarbons, and aromatic hydrocarbons can be used. Examples of such polyisocyanates include linear saturated hydrocarbon isocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate; cyclic saturated hydrocarbon isocyanates such as isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylenebis(4-cyclohexylisocyanate), hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, and hydrogenated toluene diisocyanate; and aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 1,3-xylylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate, 6-isopropyl-1,3-phenyl diisocyanate, and 1,5-naphthalene diisocyanate. Preferred examples include isophorone diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate. These polyisocyanates may be used alone or in combination of two or more.

[0088] Examples of hydroxy(meth)acrylates constituting urethane(meth)acrylate include 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, 6-hydroxyhexyl(meth)acrylate, etc. These hydroxy(meth)acrylates may be used alone or in combination of two or more.

[0089] Examples of urethane (meth)acrylates include the Art Resin UN series manufactured by Negami Chemical Industrial Co., Ltd., the NK Oligo U series manufactured by Shin-Nakamura Chemical Co., Ltd., and the Shikou UV series manufactured by Mitsubishi Chemical Corporation.

[0090] Polyester (meth)acrylates can be obtained, for example, by reacting (meth)acrylic acid with the terminal hydroxyl groups of polyesters obtained by polymerizing polyols and polycarboxylic acids. Specific examples of polyester (meth)acrylates include Aronix M-6000, Aronix M-7000, Aronix M-8000, and Aronix M-9000, all manufactured by Toagosei Co., Ltd.

[0091] Epoxy (meth)acrylates can be obtained, for example, by reacting epoxy resins with (meth)acrylic acid. Specific examples of epoxy (meth)acrylates include Lipoxy SP and Lipoxy VR manufactured by Showa Polymer Co., Ltd., and the Epoxy Ester series manufactured by Kyoeisha Chemical Co., Ltd.

[0092] The weight-average molecular weight of the polymerizable oligomer B is not particularly limited, but from the viewpoint of improving the scratch resistance of the resin layer of the present invention, it is preferably 400 or more, more preferably 500 or more, even more preferably 600 or more, and particularly preferably 700 or more. Furthermore, from the viewpoint of the coatability of the curable composition of the present invention, the weight-average molecular weight of the polymerizable oligomer B is preferably 10,000 or less, more preferably 7,000 or less, and even more preferably 5,000 or less. The weight-average molecular weight of the polymerizable oligomer B can be determined, for example, by high-performance liquid chromatography (HPLC). For example, the weight-average molecular weight can be measured using an HPLC8020 manufactured by Tosoh Corporation as the apparatus, two TSKgel GMH-H(20) columns connected in series as the column, tetrahydrofuran as the solvent, and a flow rate of 0.5 mL / min.

[0093] The content of polymerizable compound B in the curable composition of the present invention is not particularly limited, but from the viewpoint of imparting excellent scratch resistance to the resin layer of the present invention, it is preferably 5% by weight or more, more preferably 10% by weight or more, and even more preferably 15% by weight or more, or alternatively 20% by weight or more, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 45% by weight or more, 50% by weight or more, 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, 80% by weight or more, 85% by weight or more, or 90% by weight or more, relative to 100% by weight of the non-volatile solids content of the curable composition of the present invention. On the other hand, from the viewpoint of achieving a higher level of both low moisture permeability and scratch resistance in the resin layer of the present invention, the content may be 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, 65% by weight or less, 60% by weight or less, 55% by weight or less, 50% by weight or less, 45% by weight or less, 40% by weight or less, 35% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, 15% by weight or less, 10% by weight or less, or 5% by weight or less.

[0094] When the curable composition of the present invention contains polymerizable compound A and polymerizable compound B, the ratio thereof (polymerizable compound A / polymerizable compound B) is preferably 10 / 90 or more, more preferably 15 / 85 or more, or may be 20 / 80 or more, 25 / 75 or more, 30 / 70 or more, 35 / 65 or more, 40 / 60 or more, 45 / 55 or more, 50 / 50 or more, 55 / 45 or more, 60 / 40 or more, 65 / 35 or more, 70 / 30 or more, 75 / 25 or more, 80 / 20 or more, 85 / 15 or more, or 90 / 10 or more, from the viewpoint of imparting excellent low moisture permeability to the resin layer of the present invention. On the other hand, from the viewpoint of achieving a higher level of both low moisture permeability and scratch resistance in the resin layer of the present invention, the ratio may be 95 / 5 or less, 90 / 10 or less, 85 / 15 or less, 80 / 20 or less, 75 / 25 or less, 70 / 30 or less, 65 / 35 or less, 60 / 40 or less, 55 / 45 or less, 50 / 50 or less, 45 / 55 or less, 40 / 60 or less, 35 / 65 or less, 30 / 70 or less, 25 / 75 or less, 15 / 85 or less, or 10 / 90 or less.

[0095] The curable composition of the present invention preferably contains a polymerization initiator, and the polymerization initiator is preferably a photopolymerization initiator. Examples of the photopolymerization initiator include benzophenone-based compounds such as benzil, benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; aromatic ketone compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and α-hydroxycyclohexylphenyl ketone; acetophenone-based compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin. Examples of polymerization initiators include benzoin alkyl ether compounds such as benzoin butyl ether and anisoin methyl ether; aromatic ketal compounds such as benzil dimethyl ketal; aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone; camphorquinone; halogenated ketones; acylphosphinoxides; and acylphosphonates. These polymerization initiators may be used alone or in combination.

[0096] The content of the photopolymerization initiator in the curable composition of the present invention is not particularly limited, but from the viewpoint of ensuring that the resin layer of the present invention has sufficient low moisture permeability and scratch resistance, it is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, and even more preferably 0.2 parts by weight or more, relative to 100 parts by weight of the polymerizable compounds (total of polymerizable compounds A and B). Furthermore, from the viewpoint of preventing the problem of insufficient curing of the curable composition of the present invention due to excessive radiation absorption by the photopolymerization initiator, the content of the photopolymerization initiator in the curable composition of the present invention is preferably 10 parts by weight or less, more preferably 8 parts by weight or less, relative to 100 parts by weight of the polymerizable compounds (total of polymerizable compounds A and B).

[0097] Various leveling agents can be added to the curable composition of the present invention. As the leveling agent, for example, a fluorine-based or silicone-based leveling agent can be used for the purpose of preventing coating unevenness (uniformity of the coated surface). When antifouling properties are required on the surface of the resin layer of the present invention, a leveling agent can be appropriately blended. The amount of the leveling agent added is, for example, 5 parts by weight or less, preferably in the range of 0.01 to 5 parts by weight, relative to 100 parts by weight of the polymerizable compounds (total of polymerizable compounds A and B).

[0098] The curable composition of the present invention may contain a solvent. As the solvent, various solvents can be used taking into consideration the solubility of the polymerizable compounds (polymerizable compound A and / or polymerizable compound B), drying properties at the time of coating, etc. Examples of such organic solvents include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole, phenetole, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-methoxyethanol, 2-propoxyethanol, 2-methylpropionate ... 1,2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, xylene, and the like can be used alone or in combination of two or more.

[0099] The curable composition of the present invention may further contain any appropriate additive, such as a plasticizer, a surfactant, an antioxidant, an ultraviolet absorber, a thixotropic agent, or an antistatic agent, as needed, within a range that does not impair the effects of the present invention.

[0100] The resin layer of the present invention preferably has a thickness of 0.1 to 10 μm. As described above, even if the resin layer is thin, it can impart excellent low moisture permeability to the optical film of the present invention. From the viewpoint of enabling a thinner polarizing plate when the optical film of the present invention is used as a polarizing plate protective film, the thickness of the resin layer is preferably 7 μm or less, more preferably 5 μm or less, and may be 3.2 μm or less, or 3 μm or less. From the viewpoint of achieving both low moisture permeability and scratch resistance at a higher level, the lower limit of the thickness of the resin layer is preferably 0.5 μm or more, preferably 1 μm or more, preferably 1.8 μm or more, and may be 2 μm or more. The resin layer of the present invention may be a single layer or may have multiple layers. When the resin layer of the present invention is composed of multiple layers, the thickness of the resin layer of the present invention is the total thickness of each of the layers constituting the multiple layers.

[0101] The resin layer of the present invention can be formed by mixing the polymerizable compound of the present invention (polymerizable compound A and / or polymerizable compound B) with a photopolymerization initiator, a leveling agent, a solvent, other additives, etc., as necessary, to prepare a coating liquid (the curable composition of the present invention), applying the coating liquid to one surface of a light-transmitting substrate, drying, and curing the coating film.

[0102] The solid content concentration of the coating liquid is preferably 1 to 70% by weight, more preferably 2 to 50% by weight, and even more preferably 5 to 40% by weight.

[0103] Examples of methods for applying the coating liquid include dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, die coating, extrusion coating, and bar coating.

[0104] The method for curing the coating film is appropriately selected depending on the type of curable composition, etc. When the curable composition is photocurable, it can be cured by irradiating it with light using a light source that emits light of the required wavelength. For example, the light to be irradiated may have an exposure dose of 150 mJ / cm. 2 More than 200mJ / cm 2~1000mJ / cm 2 Heating may be carried out during the photo-curing treatment. Examples of light include ionizing radiation such as α-rays, β-rays, γ-rays, neutron beams, and electron beams, as well as ultraviolet light, with ultraviolet light being particularly preferred. The irradiation time, irradiation method, and the like are not particularly limited as long as they can activate the photopolymerization initiator and cause a reaction of the polymerizable compound.

[0105] <Polarizing plate> The polarizing plate of the present invention has a laminated structure in which a polarizer is disposed on the side of the optical film of the present invention opposite the resin layer. In FIG. 2, polarizing plate 20 has a laminated structure in which polarizer 3 is disposed on the side of optical film 10 opposite the resin layer 1. Because optical film 10 is used as a polarizing plate protective film, polarizing plate 20 has excellent low moisture permeability and scratch resistance even though resin layer 1 is thin, and quality deterioration such as discoloration of polarizer 3 is unlikely to occur. In this embodiment, a second light-transmitting substrate 4 and a pressure-sensitive adhesive layer 5 are further laminated in this order on the side of polarizer 3 opposite optical film 10.

[0106] The polarizer 3 is an element that transmits only light polarized in a certain direction, and any known polarizer can be used without limitation, such as a polyvinyl alcohol polarizing film. The polyvinyl alcohol polarizing film may be a polyvinyl alcohol film dyed with iodine or a dichroic dye.

[0107] The polyvinyl alcohol polarizing film may be a polyvinyl alcohol film that has been uniaxially stretched and then dyed with iodine or a dichroic dye (preferably further treated with a boron compound for durability), or a polyvinyl alcohol film that has been dyed with iodine or a dichroic dye and then uniaxially stretched (preferably further treated with a boron compound for durability). The absorption axis of the polarizer is parallel to the stretching direction of the film.

[0108] The thickness of the polarizer 3 is preferably 5 to 25 μm, and from the viewpoint of making the polarizing plate 20 thinner, it is more preferably 10 to 15 μm.

[0109] The second light-transmitting substrate 4 protects the polarizer 3 on the side opposite to the optical film 10 (polarizing plate protective film). The second light-transmitting substrate 4 can be made of glass, plastic film, or the like similar to the light-transmitting substrate of the present invention. Cellulose-based resins, cyclic olefin polymers (COP), and polycarbonate-based resins are preferred, with cyclic olefin polymers (COP) and polycarbonate-based resins being more preferred. The light-transmitting substrate 4 may be made of the same material as the light-transmitting substrate 2, or a different material. The light-transmitting substrate 4 may be laminated with the resin layer 1, or may not have the resin layer 1. The light-transmitting substrate 4 may be composed of a single layer, or may have a laminate structure of two or more layers, the same or different.

[0110] The light-transmitting substrate 4 is also preferably an optical compensation film (retardation film) having an optical compensation layer including an optically anisotropic layer. The optical compensation film can improve the viewing angle characteristics of a liquid crystal display screen, for example. Any known optical compensation film can be used without limitation, and for example, a retardation film described in JP 2014-194484 A or the like may be used.

[0111] The thickness of the light-transmitting substrate 4 is preferably 5 to 25 μm, and from the viewpoint of making the polarizing plate 20 thinner, it is more preferably 10 to 15 μm.

[0112] The pressure-sensitive adhesive layer 5 is formed from any appropriate pressure-sensitive adhesive. Examples of materials constituting the pressure-sensitive adhesive layer 5 include materials whose base polymer is an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based polymer, a rubber-based polymer, an isocyanate-based polymer, a polyvinyl alcohol-based polymer, a gelatin-based polymer, a vinyl-based polymer, a latex-based polymer, or a water-based polyester. Among these, materials whose base polymer is an acrylic polymer and / or a rubber-based polymer are preferred from the viewpoint of low moisture permeability. The pressure-sensitive adhesive layer 5 may contain a single base polymer or may contain two or more base polymers.

[0113] The thickness of the pressure-sensitive adhesive layer 5 is preferably 5 to 25 μm, and from the viewpoint of making the polarizing plate 20 thinner, it is more preferably 10 to 20 μm.

[0114] The polarizing plate 20 can be obtained by bonding the polarizer 1 and the optical film 10 together via an adhesive. The polarizer 1 and the light-transmitting substrate 4 can also be bonded together via an adhesive. The adhesive used for bonding may be a fully saponified polyvinyl alcohol aqueous solution (water glue), or an active energy ray-curable adhesive.

[0115] The pressure-sensitive adhesive layer 5 can be formed by applying a pressure-sensitive adhesive composition containing a base polymer constituting the pressure-sensitive adhesive to the light-transmitting substrate 4, drying it, and then curing it as necessary. Alternatively, the pressure-sensitive adhesive layer 5 may be formed on a separator in the same manner, and then attached and transferred to the light-transmitting substrate 4.

[0116] The polarizing plate 20, the optical film 10, the polarizing plate 3, the light-transmitting substrate 4, and the pressure-sensitive adhesive layer 5 may have a layer (e.g., a surface protective film, a separator, etc.) on the surface or between any of the layers. For example, the surface of the pressure-sensitive adhesive layer 5 may be protected by a separator, and the surface of the resin layer 1 of the optical film 10 may be protected by a surface protective film.

[0117] The thickness of the polarizing plate 20 (total thickness including the light-transmitting substrate 4 and the pressure-sensitive adhesive layer 5) is preferably 50 to 100 μm, and from the viewpoint of making the polarizing plate 20 thinner, more preferably 60 to 75 μm.

[0118] <Image display device> The image display device of the present invention includes the polarizing plate of the present invention. Since the image display device of the present invention has the polarizing plate of the present invention in a laminated structure, it has excellent low moisture permeability and scratch resistance even when the resin layer 1 is thin, and is less susceptible to quality deterioration such as discoloration of the polarizer 3. Therefore, even though the image display device of the present invention is thin, discoloration of the polarizing plate and the like are less likely to occur in a humid environment, and it has excellent durability. 3, an image display device 30 has an image display panel 6 laminated on an adhesive layer 5 of a polarizing plate 20. In this embodiment, an adhesive layer 7 and an optical member 8 are laminated on a resin layer 1 in this order.

[0119] The image display panel 6 is not particularly limited, but examples thereof include a liquid crystal image display panel and a self-luminous image display panel (for example, an organic EL (electroluminescence) image display panel, an LED image display panel).

[0120] The image display panel 6 is formed by arranging RGB elements alternately, and in order to improve contrast, it is preferable that the spaces between the RGB elements are filled with a black matrix (BM).

[0121] The adhesive layer 7 can be made of a material containing a base polymer similar to those exemplified for the adhesive layer 5. Among these, materials containing an acrylic polymer and / or a rubber polymer as the base polymer are preferred from the viewpoint of low moisture permeability. The adhesive layer 7 may contain a single base polymer or may contain two or more types of base polymers. The adhesive layer 7 may be made of the same material as the adhesive layer 5, or may be made of a different material.

[0122] The optical member 8 can be made of glass, plastic film, or the like similar to the light-transmitting substrate of the present invention, and is preferably made of acrylic resin, polyester resin, or cyclic olefin polymer (COP), with polyester resin being particularly preferred. When the optical member 8 is located on the outermost surface of the viewing side of the image display device 30, it functions as a cover member.

[0123] The image display device 30 may include optical members other than the optical film 10, polarizing plate 3, light-transmitting substrate 4, adhesive layer 5, image display panel 6, adhesive layer 7, and optical member 8 on the surface or between any layers. Examples of the optical members include, but are not limited to, polarizing plates other than the polarizing plate 3, retardation plates, anti-reflection films, viewing angle adjusting films, and optical compensation films. The optical members also include members that play a role in decorating or protecting the image display device or input device while maintaining its visibility (such as design films, decorative films, and surface protection plates).

[0124] The image display device 30 can be produced by laminating together an image display panel 6, a polarizing plate 20, and an optical film in which an optical member 8 and a pressure-sensitive adhesive layer 7 are laminated together. Specifically, lamination can be carried out under heat and / or pressure. After lamination under heat and / or pressure, active energy rays may be irradiated to cure the laminate. Irradiation of active energy rays can be carried out in the same manner as in the formation of the resin layer of the present invention. [Example]

[0125] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0126] Example 1 (Preparation of Coating Solution for Forming Resin Layer) The resins contained in the resin layer were prepared as follows: 50 parts by weight (solids equivalent) of a UV-curable acrylate resin (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "A-DCP," 100% solids content) and 50 parts by weight (solids equivalent) of a UV-curable acrylate resin (manufactured by Mitsubishi Chemical Corporation, product name "UV-1700TL," 80% solids content). Five parts by weight of a photopolymerization initiator (manufactured by BASF, product name "OMNIRAD907") and 0.2 parts by weight of a leveling agent (manufactured by Kyoeisha Chemical Co., Ltd., product name "LE-303," 40% solids content) were mixed per 100 parts by weight of the resin solids content. This mixture was diluted with a mixed solvent of MIBK and cyclopentanone (60 / 40 by weight) to a solids concentration of 30%, to prepare a coating solution for forming the resin layer.

[0127] (Preparation of Optical Film) A transparent plastic film substrate (TAC, manufactured by Fujifilm Corporation, product name "TJ25UL") was prepared as a light-transmitting substrate. The resin layer-forming coating liquid prepared above was used to form a coating film on one side of the transparent plastic film substrate using a bar coater #7. The transparent plastic film substrate on which this coating film was formed was then transported to a drying process. In the drying process, the coating film was dried by heating at 60°C for 1 minute. Thereafter, the coating film was dried using a high-pressure mercury lamp with an integrated light intensity of 220 mJ / cm. 2 The coating film was cured by irradiating it with ultraviolet light of 1000 kJ / cm to form a resin layer having a thickness of 2.5 μm, and an optical film 1 of Example 1 was obtained. Details of the resin used in Example 1 are as follows: A-DCP: Tricyclodecane dimethanol dimethacrylate UV-1700TL: 10-functional urethane acrylate

[0128] Example 2 Optical film 2 of Example 2 was obtained in the same manner as in Example 1, except that 70 parts by weight (solid content equivalent) of A-DCP and 30 parts by weight (solid content equivalent) of UV-1700TL were blended as the resin contained in the resin layer.

[0129] Example 3 The resin layer contains 0.1 parts by weight of leveling agent, and the cumulative light intensity is 260 mJ / cm 2 An optical film 3 of Example 3 was obtained in the same manner as in Example 1, except that the above conditions were changed.

[0130] Example 4 The resin contained in the resin layer was 100 parts by weight (solids content equivalent) of Unidic 17-806 (manufactured by DIC Corporation, product name "Unidic 17-806", solid content 80%), mixed with 3 parts by weight of OMNIRAD 907 and 0.01 parts by weight of a leveling agent (manufactured by DIC Corporation, product name "PC4100", solid content 40%). This mixture was diluted with a PGM / cyclopentanone mixed solvent (weight ratio 63 / 37) to a solids concentration of 36%, to prepare a coating liquid for forming the resin layer. An optical film 4 of Example 4 was obtained in the same manner as in Example 1, except that the resin layer-forming coating liquid prepared above was applied to form a coating film using bar coater #14.

[0131] (evaluation) The optical films obtained in the above examples were evaluated as follows. The evaluation methods are shown below. The results are shown in Table 1.

[0132] (1) Film thickness measurement The thickness of the optical films of the Examples and Comparative Examples was measured at five points across the width using a digital linear gauge (product name "MODELD-10HS", manufactured by Ozaki Seisakusho Co., Ltd.), and the average value of the thicknesses at the five points was taken as the total thickness. The thickness of the light-transmitting substrate used in the examples was measured using the same measurement method, and the average value of the thicknesses at the five points was taken as the substrate thickness. The difference between the total thickness and the substrate thickness was taken as the thickness of the resin layer.

[0133] (2) Measurement of change in moisture permeability before and after scratch resistance test The moisture permeability of the optical films of the examples was measured at 40° C. and a relative humidity of 92% in accordance with JIS Z0208. Next, the optical film of the example was cut into a size of 5 cm x 15 cm, and a 2.5 cm diameter and 6.25 x π cm contact area was applied to the surface of the resin layer. 2A load of 400 gf (3.92 N) was applied to the steel wool, which was rubbed back and forth across the surface of the resin layer 10 times at a moving speed of 100 mm / s in the long side direction of the film, and then the moisture permeability was measured in the same manner at a temperature of 40°C and a relative humidity of 92%.

[0134] (3) Moisture permeability measurement The moisture permeability of the optical films of the examples was measured at a temperature of 60° C. and a relative humidity of 90% in accordance with JIS Z0208. The temperature and humidity conditions for the test were a temperature of 65°C and a relative humidity of 90%, and the moisture permeability of the optical film of the example was measured in the same manner as under the temperature and humidity conditions of 60°C and 90%.

[0135] (4) Evaluation of polarizer color fading The optical film of each example was stored for 120 hours in an environment with a temperature of 60°C and a relative humidity of 90%, and then the film was observed in a dark room with the backlight illuminance set to 8000 candela. If color loss such as unevenness or streaks was visible, it was determined that color loss had occurred in the polarizer.

[0136] (5) Scratch resistance measurement The optical film of the example was cut into a size of 5 cm x 15 cm, and a 2.5 cm diameter and 6.25 x π cm contact area was applied to the surface of the resin layer. 2 A load of 100 gf (0.98 N) was applied to the steel wool, and the surface of the resin layer was rubbed back and forth 10 times in the long side direction of the film at a moving speed of 100 mm / s. After the test under fluorescent light and LED light source conditions, the presence or absence of scratches was visually inspected in a central 5cm x 5cm area of ​​the film.

[0137] [Table 1]

[0138] Variations of the present invention are listed below. [Appendix 1] An optical film in which a resin layer is laminated on one surface of a light-transmitting substrate, the resin layer is formed from a cured product of a curable composition containing at least one polymerizable compound selected from the group consisting of a monomer having a polymerizable functional group and an oligomer having a polymerizable functional group; Before and after the following scratch resistance test, the moisture permeability [g / m ] of the optical film under an environment of a temperature of 40°C and a relative humidity of 92% was measured. 2 An optical film in which the change in [temperature / temperature characteristics] over 24 hours is 20 or less. ·Scratch resistance test The surface of the resin layer is reciprocated 10 times using steel wool under the conditions of a load of 3.92 N and a moving speed of 100 mm / sec. [Appendix 2] An optical film according to Appendix 1, wherein the surface of the resin layer is not scratched when subjected to a scratch resistance test using steel wool under the conditions of a load of 0.98 N, a moving speed of 100 mm / sec, and 10 round trips. [Appendix 3] The optical film according to appendix 1 or 2, wherein the resin layer has a thickness of 0.1 to 10 μm. [Appendix 4] The optical film according to any one of Appendices 1 to 3, wherein the light-transmitting substrate comprises at least one selected from the group consisting of a cellulose-based resin, a polyester-based resin, an acrylic-based resin, and a cyclic olefin-based polymer. [Appendix 5] A polarizing plate comprising the optical film according to any one of Appendices 1 to 4, and a polarizer disposed on the side opposite to the resin layer. [Appendix 6] An image display device having the polarizing plate according to appendix 5. [Appendix 7] The image display device according to appendix 6, wherein a pressure-sensitive adhesive layer and an optical member are laminated in this order on the resin layer. [Explanation of symbols]

[0139] 10 Optical Film 1 resin layer 2 Light-transparent base material 20 Polarizing plate 3 Polarizer 4. Light-transmitting substrate (optical compensation film) 5. Adhesive layer 30 Image display device 6 Image display panel 7 Adhesive layer 8 Optical Components

Claims

1. An optical film having a resin layer laminated on one surface of a light-transmitting substrate, the material constituting the light-transmitting substrate is at least one selected from the group consisting of cellulose-based resins and polyester resins, the resin layer is formed from a cured product of a curable composition containing at least one polymerizable compound selected from the group consisting of a monomer having a polymerizable functional group and an oligomer having a polymerizable functional group, the polymerizable compound includes a compound having, in the molecule, a cyclic aliphatic hydrocarbon group derived from a polycyclic compound and two or more polymerizable functional groups; Before and after the following scratch resistance test, the moisture permeability [g / m] of the optical film in an environment of a temperature of 40°C and a relative humidity of 92% was measured. 2 - An optical film in which the change in [24h] is 20 or less. ・Scratch resistance test The surface of the resin layer is reciprocated 10 times using steel wool under the conditions of a load of 3.92 N and a moving speed of 100 mm / sec.

2. 2. The optical film according to claim 1, wherein the surface of the resin layer is not scratched when subjected to an abrasion resistance test using steel wool under the conditions of a load of 0.98 N, a moving speed of 100 mm / sec, and 10 reciprocations.

3. 3. The optical film according to claim 1, wherein the resin layer has a thickness of 0.1 to 10 μm.

4. A polarizing plate comprising the optical film according to any one of claims 1 to 3, and a polarizer disposed on the opposite side of the resin layer.

5. An image display device comprising the polarizing plate according to claim 4 .

6. The image display device according to claim 5 , wherein a pressure-sensitive adhesive layer and an optical member are laminated in this order on the resin layer.

Images