Resin film, method for producing resin film, and display device

Abstract

To provide a resin film capable of improving visual field angle characteristics and antireflection characteristics, for example, when applied to a display.SOLUTION: A resin film includes a low refractive index layer 17, and an anisotropic diffusion layer 16. The low refractive index layer 17 has a refractive index of 1.40 or less. The anisotropic diffusion layer 16 anisotropically diffuses light. The anisotropic diffusion layer 16 includes anisotropic particles 162, and a resin part 161. The anisotropic particles 162 have an anisotropic shape, and its major axis direction is arrayed in one direction. The resin part 161 diffuses the anisotropic particles 162, and is made of a resin. A reflectance excluding a positively reflected light component of the resin film is 1.0% or less.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a resin film and the like. More specifically, it relates to a resin film and the like provided on the surface of a display means of a display device.

Background Art

[0002] Display devices such as liquid crystal displays (LCDs: Liquid Crystal Displays) and plasma display panels (PDPs: Plasma Display Panels) are known. Also, display devices such as electroluminescence displays (ELDs: Electroluminescence Displays) and field emission displays (FEDs: Field Emission Displays) are known. On the image display surface of these display devices, an antireflection film or an antiglare film having a low refractive index layer is usually provided. And, the low refractive index layer suppresses the reflection of the observer and the background of the observer and the like. The low refractive index layer is usually provided on the outermost surface of the antireflection film. Then, the reflected light from the low refractive index layer and the interface between the low refractive index layer and the lower layer cancel each other out, thereby reducing the reflected light and suppressing the reflection. Due to its image display principle, a liquid crystal display tends to have inferior image quality (viewing angle characteristics) when observed from an oblique direction compared to other image display devices. Specifically, the luminance and contrast ratio when observed from an oblique direction are significantly reduced compared to when observed from the front. On the other hand, in recent years, a method of improving the viewing angle characteristics of a liquid crystal display by applying a diffusion layer that diffuses image light has attracted attention.

[0003] Patent Document 1 describes an antireflection film. This antireflection film has at least one light diffusion layer on a transparent substrate. And in the antireflection film having at least one low refractive index layer thereon, the light diffusion layer has a haze value of 40% or more. And the low refractive index layer is made of a cured product of a fluorine-containing resin of a thermosetting type or an ionizing radiation curable type. Also, the average value in the wavelength range from 450 nm to 650 nm of the specular reflectance at 5-degree incidence is 2.5% or less.

[0004] Patent Document 2 describes an optical structure. This optical structure is disposed below the antireflection film. This optical structure includes a low refractive index layer and a high refractive index layer. The interface between the low refractive index layer and the high refractive index layer has an uneven shape. The concave portion of the uneven shape is recessed toward the low refractive index layer side. The convex portion protrudes toward the high refractive index layer side. Each of the concave portion and the convex portion has a flat portion extending along the plane direction of the low refractive index layer and the high refractive index layer. On the side surface of the uneven shape, two adjacent side surfaces sandwiching the flat portion of the concave portion form a tapered shape toward the low refractive index layer side. Two adjacent side surfaces sandwiching the flat portion of the convex portion form a tapered shape toward the high refractive index layer side. And the high refractive index layer is disposed so as to face the display surface side of the display device. By utilizing refraction and diffraction at the uneven structure interface having a refractive index difference, image light is diffused in a specific direction.

[0005] Patent Document 3 describes an anisotropic light diffusing adhesive laminate. This anisotropic light diffusing adhesive laminate is an adhesive laminate having two or more adhesive layers containing an adhesive. At least one of the adhesive layers contains a needle-shaped filler having a different refractive index from the adhesive. And the needle-shaped fillers are dispersed with substantially the same orientation. Also, in this anisotropic light diffusing adhesive laminate, it may have two adhesive layers in which the orientation directions of the needle-shaped fillers are different from each other.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] The method of applying the light diffusion layer significantly reduces the luminance and contrast ratio during front view observation in order to diffusely emit image light isotropically. The method of making the interface between the low refractive index layer and the high refractive index layer have an uneven shape requires the use of an expensive film with a fine structure transferred thereon. In addition, since it is necessary to adhere the film having the uneven shape into the display, the number of necessary members increases and the manufacturing process becomes complicated. Furthermore, when external light such as illumination is incident, color bleeding occurs due to diffraction by the uneven shape, and rainbow-colored unevenness is visually recognized on the display. Also, the method of using the anisotropic light diffusion adhesive laminate enables light diffusion biased in a specific direction by blending needle-shaped fillers in the adhesive resin. By applying these into the display, it becomes possible to expand the viewing angle. However, it is necessary to newly provide an adhesive layer having a large light diffusibility in the display. Therefore, it is likely to cause a decrease in the luminance and contrast in the front direction of the display. In addition, an increase in the number of necessary members and complication of the manufacturing process result in an increase in the manufacturing cost. Furthermore, the influence of light scattering from the adhesive layer when external light is incident is large. And even if an antireflection film is provided, the reflectance of the display surface does not decrease and the display looks whitish. An object of the present invention is to provide a resin film that can improve viewing angle characteristics and antireflection characteristics when applied to, for example, a display.

Means for Solving the Problems

[0008] The resin film of the present invention includes a low refractive index layer and an anisotropic diffusion layer. The low refractive index layer has a refractive index of 1.40 or less. The anisotropic diffusion layer anisotropically diffuses light. Further, the anisotropic diffusion layer includes anisotropic particles and a resin portion. The anisotropic particles have an anisotropic shape and are arranged along one direction in the major axis direction. The resin portion disperses the anisotropic particles and is made of a resin. The reflectance of the resin film excluding the specular reflection light component is 1.0% or less.

[0009] Here, the anisotropic particles can have different refractive indices in the major axis direction and the minor axis direction. Also, let the refractive index of the resin portion be n b Let the refractive index of the anisotropic particles in the major axis direction be n ax Let the refractive index of the anisotropic particles in the minor axis direction be n ay At this time, at least one of the following relationships (I) and (II) holds. (I) |n b - n ax | < 0.04 and 0.04 < |n b - n ay | < 0.50 (II) |n b - n ay | < 0.04 and 0.04 < |n b - n ax | < 0.50

[0010] Furthermore, the anisotropic particles can have a length in the major axis direction of 1 μm or more and 200 μm or less. Furthermore, the anisotropic particles can have a length in the minor axis direction of 0.1 μm or more and 10 μm or less. Moreover, the aspect ratio, which is the ratio of the length in the major axis direction to the length in the minor axis direction of the anisotropic particles, can be 10 or more. And the interface between the anisotropic particles and the resin portion can be made compatible.

[0011] Also, the refractive index of the resin portion can be 1.45 or more and 1.65 or less. Furthermore, the anisotropic particles can include at least one of metal oxides, carbonate compounds, hydroxide compounds, and phosphate compounds. Furthermore, the difference in refractive index between the resin portion and the low refractive index layer can be 0.1 or more. And the anisotropic diffusion layer can have a haze value of 20% or more and 80% or less. Also, the anisotropic diffusion layer can have an anisotropic diffusion degree of 3 or more.

[0012] And it can be further provided with a high refractive index layer having a refractive index of 1.60 or more. Also, it can be further provided with a hard coat layer having a refractive index of 1.54 or more. And it can be further provided with a substrate that supports the low refractive index layer and the anisotropic diffusion layer. This substrate is provided between the low refractive index layer and the anisotropic diffusion layer. Also, the anisotropic diffusion layer can function as a substrate that supports the low refractive index layer.

[0013] Moreover, the method for producing the resin film of the present invention includes a low refractive index layer forming step and an anisotropic diffusion layer forming step. The low refractive index layer forming step forms a low refractive index layer having a refractive index of 1.40 or less. The anisotropic diffusion layer forming step forms an anisotropic diffusion layer that anisotropically diffuses light. The anisotropic diffusion layer includes anisotropic particles and a resin portion. The anisotropic particles have an anisotropic shape and are arranged along one direction in the major axis direction. The resin portion disperses the anisotropic particles and is made of resin. The reflectance of the resin film excluding the specular reflection light component is 1.0% or less.

[0014] And the anisotropic diffusion layer can be a substrate that supports the low refractive index layer. In this case, the low refractive index layer forming step forms the low refractive index layer on the substrate. Also, the anisotropic diffusion layer can be formed by stretching.

[0015] And the display device of the present invention includes display means for displaying an image and the above resin film provided on the surface of the display means. Also, the optical member of the present invention includes a substrate and the above resin film provided on the substrate. Furthermore, the polarizing member of the present invention includes a polarizing means for polarizing light and the resin film provided on the polarizing means.

Advantages of the Invention

[0016] According to the present invention, for example, when applied to a display, it is possible to provide a resin film or the like that can improve viewing angle characteristics and antireflection characteristics.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof. Furthermore, the drawings used are for explaining the present embodiment and do not represent the actual size.

[0019] <Description of the Display Device> FIG. 1(a) is a diagram for explaining a display device 1 to which the present embodiment is applied. The illustrated display device 1 is, for example, a liquid crystal display for a PC (Personal Computer) or a liquid crystal television. The display device 1 displays an image on a liquid crystal panel 1a.

[0020] <Explanation of the liquid crystal panel 1a> FIG. 1(b) is a cross-sectional view taken along the line Ib-Ib of FIG. 1(a), and shows an example of the configuration of the liquid crystal panel 1a to which the present embodiment is applied. The liquid crystal panel 1a is an example of display means for displaying an image. The liquid crystal panel 1a of the present embodiment is, for example, a VA type liquid crystal panel. The illustrated liquid crystal panel 1a has a backlight 11 and a polarizing film 12a. The liquid crystal panel 1a also has a retardation film 13a, a liquid crystal 14, a retardation film 13b, and a polarizing film 12b. Further, the liquid crystal panel 1a has a substrate 15, an anisotropic diffusion layer 16, and a low refractive index layer 17. And these have a structure laminated in this order from the inner side to the surface side. Hereinafter, when the polarizing film 12a and the polarizing film 12b are not distinguished, they may be simply referred to as the polarizing film 12. In the present embodiment, the laminate of the anisotropic diffusion layer 16 and the low refractive index layer 17 is an example of a resin film. Also, the laminate of the substrate 15, the anisotropic diffusion layer 16, and the low refractive index layer 17 is an example of a resin film.

[0021] The backlight 11 irradiates light to the liquid crystal 14. The backlight 11 is, for example, a cold cathode fluorescent lamp or a white LED (Light Emitting Diode). The polarizing films 12a and 12b are an example of a polarizing means for polarizing light. The polarizing film 12a and the polarizing film 12b are arranged such that their polarization directions are orthogonal to each other. The polarizing films 12a and 12b include, for example, a resin film in which iodine compound molecules are contained in polyvinyl alcohol (PVA). Then, this is sandwiched and adhered with a resin film made of triacetyl cellulose (TAC). By including iodine compound molecules, light is polarized.

[0022] The retardation films 13a and 13b compensate for the viewing angle dependence of the liquid crystal panel 1a. The light transmitted through the liquid crystal 14 changes its polarization state from linearly polarized light to elliptically polarized light. For example, when a black display is made, when the liquid crystal panel 1a is viewed from the vertical direction, it appears black. On the other hand, when the liquid crystal panel 1a is viewed from an oblique direction, retardation of the liquid crystal 14 occurs. Also, the axis of the polarizing film 12 is not 90°. Therefore, there is a problem that light leakage occurs and the contrast decreases. That is, the liquid crystal panel 1a has viewing angle dependence. The retardation films 13a and 13b have a function of returning this elliptically polarized light to linearly polarized light. Thereby, the retardation films 13a and 13b can compensate for the viewing angle dependence of the liquid crystal panel 1a.

[0023] A power source (not shown) is connected to the liquid crystal 14, and when a voltage is applied by this power source, the alignment direction of the liquid crystal 14 changes. Then, the liquid crystal 14 controls the light transmission state accordingly. In the case of a VA type liquid crystal panel, when no voltage is applied to the liquid crystal 14 (voltage OFF), the liquid crystal molecules are aligned in the vertical direction in the figure. Then, when light is irradiated from the backlight 11, first, the light passes through the polarizing film 12a and becomes polarized. Then, the polarized light passes through the liquid crystal 14 as it is. Further, since the polarization direction of the polarizing film 12b is different, this polarized light is blocked. In this case, a user viewing the liquid crystal panel 1a cannot visually recognize this light. That is, in a state where no voltage is applied to the liquid crystal 14, the color of the liquid crystal becomes "black".

[0024] On the other hand, when the maximum voltage is applied to the liquid crystal 14, the liquid crystal molecules are arranged in the horizontal direction in the figure. Then, the polarization that has passed through the polarizing film 12a has its polarization direction rotated by 90 degrees due to the action of the liquid crystal 14. Therefore, the polarizing film 12b does not block this polarization but transmits it. In this case, a user viewing the liquid crystal panel 1a can visually recognize this light. That is, when the maximum voltage is applied to the liquid crystal 14, the color of the liquid crystal becomes "white". Also, the voltage can be between the OFF voltage and the maximum voltage. In this case, the liquid crystal 14 is in a state between the vertical direction in the figure and the direction perpendicular to the vertical direction in the figure. That is, the liquid crystal 14 is arranged in an oblique direction that is a direction intersecting both the vertical direction and the perpendicular direction. In this state, the color of the liquid crystal becomes "gray". Therefore, by adjusting the voltage applied to the liquid crystal 14 between the OFF state and the maximum voltage, in addition to black and white, intermediate gradations can be expressed. And an image is displayed thereby. Although not shown in the figure, a color image can also be displayed by using a color filter.

[0025] Figure 2 is a view showing the base material 15, the anisotropic diffusion layer 16, and the low refractive index layer 17. Here, in the figure, the upper side is the front side of the liquid crystal panel 1a, and the lower side is the inner side of the liquid crystal panel 1a.

[0026] The base material 15 is a support for forming the anisotropic diffusion layer 16 and the low refractive index layer 17. The base material 15 is preferably a transparent base material with a total light transmittance of 85% or more. The base material 15 is, for example, the above-mentioned triacetyl cellulose (TAC: triacetylcellulose) is used. Also, it is not limited to this, and polyethylene terephthalate (PET: polyethylene terephthalate) etc. can also be used. However, in this embodiment, triacetyl cellulose (TAC) can be more preferably used. The base material 15 has a thickness of, for example, 20 μm or more and 200 μm or less.

[0027] The anisotropic diffusion layer 16 diffuses light anisotropically. Here, "anisotropic diffusion" refers to the property of having strong light diffusibility in a specific direction. And the "anisotropic diffusion layer" is a diffusion layer having strong light diffusibility in a specific direction. When an isotropic light (circular) such as a laser beam is irradiated on a member having an anisotropic diffusion layer, the transmitted light becomes linear or elliptical.

[0028] Figs. 3(a) to (c) are diagrams for explaining the anisotropic diffusion layer 16. Among these, Fig. 3(a) is a view of the anisotropic diffusion layer 16 as seen from the III direction in Fig. 2. As shown in Figs. 2 and 3(a), the anisotropic diffusion layer 16 includes at least a resin part 161 and anisotropic particles 162. The resin part 161 disperses the anisotropic particles 162 and is made of resin. Therefore, it can also be said that the resin part 161 is a dispersion layer that fixes the anisotropic particles 162 so that the major axis directions are arranged along one direction. The anisotropic particles 162 have an anisotropic shape and are arranged in the resin part 161 with their major axis directions along one direction. In this case, as shown in Fig. 2, the major axis directions of the anisotropic particles 162 are arranged along the in-plane direction of the anisotropic diffusion layer 16. Also in this case, as shown in Fig. 3(a), they are arranged along the vertical direction in the figure.

[0029] The resin part 161 is made of resin as described above. It is preferable that the refractive index of the resin part 161 is 1.45 or more and 1.65 or less. The SCE (Specular Component Exclude), which is the reflectance excluding the specular reflection light component of the anisotropic diffusion layer 16, needs to be 1.0% or less. By setting the refractive index of the resin part 161 within this range, the SCE is likely to be 1.0% or less. On the contrary, if it is outside this range, the SCE is likely to exceed 1.0%. Also, it is preferable that the difference in refractive index between the resin part 161 and the low refractive index layer 17 is 0.1 or more. By making the difference in refractive index between the resin part 161 and the low refractive index layer 17 larger, the reflectance can be further reduced.

[0030] As the resin constituting the resin part 161, for example, (meth)acrylic resin, polyethylene resin, or polypropylene resin can be used. Further, for example, polystyrene resin, polyurethane resin, polycarbonate resin, polyester resin, or silicone resin can be used.

[0031] The anisotropic particles 162 have an anisotropic shape and form an ellipsoidal sphere shape in this embodiment. And due to this shape, the refractive index in the major axis direction and the refractive index in the minor axis direction of the anisotropic particles 162 are different. Thereby, anisotropic diffusivity is exhibited in the anisotropic diffusion layer 16. Further, the refractive index of the anisotropic particles 162 and the refractive index of the resin part 161 are different. Note that the shape of the anisotropic particles 162 is not particularly limited as long as it is an anisotropic shape. For example, it may be a spindle shape, a needle shape, a fibrous shape, a cylindrical shape, a disk shape, or the like.

[0032] FIGS. 3(b) and (c) are diagrams showing the refractive index of the anisotropic particles 162. Here, the refractive index in the major axis direction of the anisotropic particles 162 is n ax , the refractive index in the minor axis direction is n ay , and the refractive index of the resin part 161 is n b . In this case, when the anisotropic diffusion direction is the horizontal direction in the figure, in the case of FIG. 3(b), the difference between the refractive index n ax and the refractive index n b is preferably small. Also, in the case of FIG. 3(c), the difference between the refractive index n ay and the refractive index n b is preferably small. That is, the difference between the refractive indices n ax , n ay of the anisotropic particles 162 in the direction perpendicular to the anisotropic diffusion direction and the refractive index n b of the resin part 161 is preferably small. More specifically, it is preferable that at least one of the following relationships (I) and (II) holds. By setting the refractive indices of the anisotropic particles 162 and the resin part 161 within the following ranges, backscattering in the direction perpendicular to the anisotropic diffusion direction is suppressed. And it becomes possible to lower the SCE of the anisotropic diffusion layer 16.

[0033] (I)|n b-n ax |Less than 0.04 and less than 0.04|n b -n ay |Less than 0.50 (II)|n b -n ay |Less than 0.04 and less than 0.04|n b -n ax |Less than 0.50

[0034] In addition, in order to make the SCE of the anisotropic diffusion layer 16 1.0% or less, it is preferable that the length and aspect ratio of the anisotropic diffusion layer 16 be in the following ranges. If it is outside this range, the SCE is likely to exceed 1.0%. That is, the length of the anisotropic particles 162 in the major axis direction is preferably 0.5 μm or more and 500 μm or less. Further, the length of the anisotropic particles 162 in the major axis direction is more preferably 1 μm or more and 200 μm or less. And the length of the anisotropic particles 162 in the minor axis direction is preferably 0.05 μm or more and 30 μm or less. Further, the length of the anisotropic particles 162 in the minor axis direction is more preferably 0.1 μm or more and 10 μm or less. By making the anisotropic particles 162 such a size, while ensuring good anisotropic diffusivity, backscattering at the interface between the anisotropic particles 162 and the resin portion 161 is suppressed, and the SCE of the anisotropic diffusion layer is easily reduced.

[0035] Furthermore, the aspect ratio, which is the ratio of the length in the major axis direction to the length in the minor axis direction of the anisotropic particles 162, is preferably 10 or more. Further, the aspect ratio is more preferably 20 or more. By setting the aspect ratio of the anisotropic particles 162 within this range, it becomes easier to ensure anisotropic diffusivity capable of improving the viewing angle characteristics of the display.

[0036] From the same perspective, it is preferable that the interface between the anisotropic particles 162 and the resin portion 161 is compatible. Thereby, the refractive index at the interface between the two changes continuously, and it becomes possible to reduce backscattering. And it becomes easier to further reduce the SCE. In this case, since the boundary between the anisotropic particles 162 and the resin portion 161 is compatible, it is ambiguous. However, even in this case, it is clear that the anisotropic particles 162 exist as particles in the resin portion 161. As a method for compatibilizing the interface, a method of blending a compatibilizer can be mentioned. Also, although it will be described in detail later, a method of blending a solvent that dissolves the components of the anisotropic particles 162 during the application (coating) of the coating solution for forming the anisotropic diffusion layer 16 can be mentioned. The compatibility of the interface can be confirmed by a scanning electron microscope (SEM) for the cross-section of the anisotropic diffusion layer 16.

[0037] The anisotropic particles 162 contain, for example, at least one of metal oxides, carbonate compounds, hydroxide compounds, and phosphate compounds. The metal oxides are, for example, silica, titanium oxide, aluminum oxide, zinc oxide, etc. Also, the anisotropic particles 162 are, for example, compounds such as calcium carbonate, silicon carbide, carbon nitride, and basic magnesium sulfate. Also, the anisotropic particles 162 are glass fibers, (meth)acrylic resins, polystyrene resins, melamine resins, etc.

[0038] The anisotropic diffusion layer 16 preferably has a haze value of 20% or more and 80% or less. More preferably, the haze value is 30% or more and 65% or less. Thereby, when the anisotropic diffusion layer 16 is mounted on a display, it becomes possible to ensure a sharp image quality with less flicker.

[0039] Note that the anisotropic diffusivity of the anisotropic diffusion layer 16 can be measured with a goniophotometer. The transmitted light when the light beam is irradiated onto the anisotropic diffusion layer 16 at an incident angle of 0° (vertical direction) is acquired while changing the light receiving angle. Then, the intensity distribution state of the transmitted scattered light is measured. By acquiring this in the anisotropic diffusion direction and the direction perpendicular to the anisotropic diffusion direction, the anisotropic diffusivity can be quantitatively evaluated. In the present embodiment, the anisotropic diffusivity is evaluated by the anisotropic diffusion degree (ADV). The anisotropic diffusion degree can be calculated by the following mathematical formula. And the anisotropic diffusion layer 16 preferably has an anisotropic diffusion degree (ADV) of 3 or more. Further, the ADV is more preferably 15 or more, and even more preferably 25 or more.

[0040] ADV = (the amount of 5° transmitted light in the anisotropic diffusion direction measured with a goniophotometer) / (the amount of 5° transmitted light in the direction perpendicular to the anisotropic diffusion direction measured with a goniophotometer)

[0041] The low refractive index layer 17 is a functional layer for reducing the reflectivity of the liquid crystal panel 1a. The low refractive index layer 17 has a small refractive index. Specifically, the low refractive index layer 17 needs to have a refractive index of 1.40 or less. Further, it is preferably 1.20 or more and 1.35 or less. Thereby, a liquid crystal panel 1a with a small reflectivity can be realized. The low refractive index layer 17 may be formed as a single layer or a multi-layer, but it is preferably formed with as few layers as possible from the viewpoint of manufacturing cost. The low refractive index layer 17 preferably has a thickness of 50 nm or more and 500 nm or less.

[0042] And the low refractive index layer 17 includes a binder 171 and hollow silica particles 172 distributed in the binder 171. Further, the low refractive index layer 17 further includes a surface modifier 173 mainly distributed on the surface side of the binder 171.

[0043] The binder 171 has a network structure and connects the hollow silica particles 172 to each other. The binder 171 contains a resin as a main component. The resin may contain a fluorine-containing resin. In this case, all of the resins may be fluorine-containing resins, or some of them may be fluorine-containing resins. The fluorine-containing resin is a resin containing fluorine, for example, polytetrafluoroethylene (PTFE). Also, for example, it is perfluoroalkoxyalkane (PFA). Further, for example, it is a perfluoroethylene propene copolymer (FEP) or an ethylene tetrafluoroethylene copolymer (ETFE). The fluorine-containing resin has a low refractive index. Therefore, by using the fluorine-containing resin, the low refractive index layer 17 is more likely to have a lower refractive index, and the reflectance can be further reduced.

[0044] Further, the fluorine-containing resin is more preferably a photocurable fluorine-containing resin. The photocurable fluorine-containing resin is a product of photopolymerization of a photopolymerizable fluorine-containing monomer represented by the following general formulas (1) to (2). And it contains 0.1 mol% or more and 100 mol% or less of the structural unit M. Also, it contains more than 0 mol% and 99.9 mol% or less of the structural unit A. Further, the number average molecular weight is 30,000 or more and 1,000,000 or less.

[0045]

Chemical formula

[0046] In the general formula (1), the structural unit M is a structural unit derived from a fluorine-containing ethylenic monomer represented by the general formula (2). Also, the structural unit A is a structural unit derived from a monomer copolymerizable with the fluorine-containing ethylenic monomer represented by the general formula (2). In the general formula (2), X 1 and X 2 are H or F. Also, X 3 is H, F, CH3 or CF3. X 4 and X 5 are H, F or CF3. Rf is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having an ether bond with 2 to 100 carbon atoms, Y 1It is an organic group in which one or more and three or less are bonded. Note that Y 1 is a monovalent organic group having 2 to 10 carbon atoms with an ethylenic carbon-carbon double bond at the terminal. Also, a is 0, 1, 2, or 3, and b and c are 0 or 1. Examples of the photopolymerizable fluorine-containing resin include, for example, OPTOOL AR-110 manufactured by Daikin Industries, Ltd. Also, EBECRYL8110 manufactured by Daicel Ornex, the LINC series manufactured by Kyoeisha Chemical Co., Ltd., and the like can be exemplified. Specific examples of the binder containing no fluorine atom include Light Acrylate POB-A, NP-A, DCP-A, TMP-A, UA-306I, and UA-306H manufactured by Kyoeisha Chemical Co., Ltd. Further, NK Ester A-DOD-N, A-200, and A-BPE-4 manufactured by Shin-Nakamura Chemical Co., Ltd. can be mentioned. Furthermore, Aronix M-315, M-306, and M-408 manufactured by Toagosei Co., Ltd. can be mentioned. Furthermore, KAYARAD DPHA, DPEA-12, etc. manufactured by Nippon Kayaku Co., Ltd. can be mentioned. These binders are effective in improving the film strength.

[0047] The hollow silica particles 172 have an outer shell layer, and the inside of the outer shell layer is hollow or a porous body. The outer shell layer and the porous body are mainly composed of silicon oxide (SiO2). Also, a large number of photopolymerizable groups and hydroxyl groups are bonded to the surface side of the outer shell layer. The photopolymerizable group and the outer shell layer are bonded via at least one of the Si-O-Si bond and the hydrogen bond. Examples of the photopolymerizable group include an acryloyl group and a methacryloyl group. That is, the hollow silica particles 172 contain at least one of an acryloyl group and a methacryloyl group as the photopolymerizable group. The photopolymerizable group is also referred to as an ionizing radiation curable group. The hollow silica particles 172 only need to have at least a photopolymerizable group, and the number and type of these functional groups are not particularly limited.

[0048] The average primary particle diameter of the hollow silica particles 172 is preferably 35 nm or more and 120 nm or less. More preferably, the average primary particle diameter of the hollow silica particles 172 is 50 nm or more and 100 nm or less. When the average primary particle diameter is less than 35 nm, the porosity of the hollow silica particles 172 tends to be small. Therefore, it becomes difficult to obtain the effect of lowering the refractive index of the low refractive index layer 17. Further, when the median diameter exceeds 120 nm, the surface irregularities of the low refractive index layer 17 tend to become prominent. Therefore, the antifouling property and the scratch resistance tend to deteriorate.

[0049] The average primary particle diameter of the hollow silica particles 172 can be measured by observation images using SEM, TEM, and STEM of the dry film of the particle dispersion liquid.

[0050] The blending amount of the hollow silica particles 172 is preferably 30% by mass or more and 65% by mass or less in the low refractive index layer 17. When the blending amount of the hollow silica particles 172 is less than 30% by mass, the reflectance of the low refractive index layer 17 tends to be high. Further, when the blending amount of the hollow silica particles 172 exceeds 65% by mass, the film strength tends to decrease. Furthermore, deposits tend to be conspicuous and it becomes difficult to wipe them off.

[0051] Also, the hollow silica particles 172 can have a plurality of maxima in the frequency curve (particle size distribution curve) with respect to the particle diameter of the hollow silica particles 172. That is, in this case, the hollow silica particles 172 are composed of a plurality of particles having different particle size distributions. For example, a plurality are selected from those having an average primary particle diameter of 30 nm, 60 nm, and 75 nm for the hollow silica particles 172 and used after mixing.

[0052] The surface modifier 173 is mainly distributed on the surface side of the binder 171 and modifies the surface of the low refractive index layer 17. That is, the surface modifier 173 is segregated on the surface side of the low refractive index layer 17. Even if it is present inside the binder 171, it does not impair the function of the low refractive index layer 17. In the present embodiment, the surface modifier 173 includes an oil-repellent surface modifier and a lipophilic surface modifier.

[0053] The oil-repellent surface modifier plays a role in improving the oil repellency of the film surface by being blended into a binder such as 171 and segregating on the surface. The effect of the oil-repellent surface modifier can be confirmed by measuring the contact angle of oleic acid or the like. In this case, the effect can be confirmed by the difference in the contact angle of the film surface between when the oil-repellent surface modifier is added and when it is not added (contact angle when added - contact angle when not added). In this case, when the oil-repellent surface modifier is added, the contact angle becomes larger. And it is preferable that the difference in the contact angle is 10° or more. Further, it is more preferable that the difference in the contact angle is 20° or more, and even more preferable that the difference in the contact angle is 30° or more.

[0054] The oil-repellent surface modifier is preferably a fluorine-based compound having a photopolymerizable group. Specific examples of the oil-repellent surface modifier include, for example, KY-1203 and KY-1207 manufactured by Shin-Etsu Chemical Co., Ltd. Also, for example, Optool DAC-HP manufactured by Daikin Industries, Ltd. Further, for example, Megafac F-477, F-554, F-556, F-570, RS-56, RS-58, RS-75, RS-78, RS-90 manufactured by DIC Corporation. Still further, for example, FS-7024, FS-7025, FS-7026, FS-7031, FS-7032 manufactured by Fluoro Technology Co., Ltd. Still further, for example, H-3593 and H-3594 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Further, for example, SURECO AF Series manufactured by AGC Inc. And, for example, Phthalgent F-222F, M-250, 601AD, 601ADH2 manufactured by Neos Co., Ltd.

[0055] The lipophilic surface modifier is blended with a binder such as 171 and segregates on the surface, playing a role in improving the lipophilicity of the film surface. The effect of the lipophilic surface modifier can be confirmed by measuring the contact angle of oleic acid or the like. In this case, the effect can be confirmed by the difference in the contact angle of the film surface between when the lipophilic surface modifier is not added and when it is added (contact angle when not added - contact angle when added). In this case, when the lipophilic surface modifier is added, the contact angle becomes smaller. And it is preferable that the difference in the contact angle is 3° or more. Further, it is more preferable that the difference in the contact angle is 5° or more, and even more preferable that the difference in the contact angle is 7° or more.

[0056] Specific lipophilic surface modifiers include, for example, Merclear 350L manufactured by Sanyo Chemical Industries, Ltd. Further, for example, Furgent 730LM, 602A, 650A, 650AC manufactured by Neos Co., Ltd. are included.

[0057] Even when deposits such as sebum adhere to the low refractive index layer 17, the deposits are not easily noticeable. Also, it is easy to wipe off and remove the deposits. The same applies even when a large amount of hollow silica particles 172 are contained.

[0058] Also, the configuration of the resin film of the present embodiment is not limited to the form shown in FIG. 2. FIGS. 4(a) to (e) are diagrams showing examples of the configuration of the resin film. Among these, FIG. 4(a) is the same as in the case of FIG. 2, and the base material 15, the anisotropic diffusion layer 16, and the low refractive index layer 17 are laminated in this order. FIG. 4(b) is a diagram showing an example in which the base material 15, the anisotropic diffusion layer 16, the hard coat layer 18, and the low refractive index layer 17 are laminated in this order. That is, compared with the case of FIG. 4(a), a hard coat layer 18 is formed between the anisotropic diffusion layer 16 and the low refractive index layer 17. In this case, the strength of the resin film can be improved. The refractive index of the hard coat layer 18 is preferably 1.54 or more. Thereby, the reflectance can be reduced compared to the case of only the low refractive index layer 17. And it is possible to impart more excellent anti-glare property.

[0059] FIG. 4(c) is a diagram showing an example in which a base material 15, an anisotropic diffusion layer 16, a hard coat layer 18, a high refractive index layer 19, and a low refractive index layer 17 are laminated in this order. That is, compared with the case of FIG. 4(b), a high refractive index layer 19 is formed between the hard coat layer 18 and the low refractive index layer 17. The high refractive index layer 19 is a layer having a refractive index higher than that of the low refractive index layer 17. The refractive index of the high refractive index layer 19 is preferably 1.60 or more. Thereby, the reflectance can be reduced compared with the case of only the low refractive index layer 17. And it is possible to impart more excellent anti-reflection property.

[0060] FIG. 4(d) is a diagram showing an example in which an anisotropic diffusion layer 16, a base material 15, a hard coat layer 18, a high refractive index layer 19, and a low refractive index layer 17 are laminated in this order. That is, compared with FIG. 4(a), it shows the case where the anisotropic diffusion layer 16 has moved to the inner side with respect to the base material 15. In this case, it can also be said that the base material 15 is provided between the low refractive index layer 17 and the anisotropic diffusion layer 16.

[0061] FIG. 4(e) shows the case where the base material 15 has the function of the anisotropic diffusion layer 16. That is, it shows the case where anisotropic particles 162 are dispersed in the resin constituting the base material 15. In this case, it can also be said that the anisotropic diffusion layer 16 functions as a base material 15 that supports the low refractive index layer 17.

[0062] The hard coat layer 18 is a functional layer for making it difficult to cause scratches on the liquid crystal panel 1a. The hard coat layer 18 is composed of, for example, a binder as a base material mainly composed of a resin. As the binder, the same ones as those exemplified in the low refractive index layer 17 can be used. In addition to the binder, metal oxide particles can also be included. As the metal oxide particles, for example, zirconium oxide, tin oxide, titanium oxide, cerium oxide, etc. can be used. Thereby, the hard coat property of the hard coat layer 18 is improved. Furthermore, a conductive substance may be added. The conductive substance is, for example, metal fine particles or a conductive polymer. More specifically, the conductive substance is, for example, tin oxide doped with antimony (Sb), phosphorus (P), indium (In), an ionic liquid containing a fluorine-based anion or an ammonium salt, a conductive polymer such as PEDOT / PSS, carbon nanotubes, and the like. Also, the conductive substance is not limited to one type, and two or more types may be added. This can lower the surface resistance value of the hard coat layer 18 and impart an antistatic function to the hard coat layer 18.

[0063] In order to reduce the reflectivity of the liquid crystal panel 1a, the refractive index of the hard coat layer 18 is preferably 1.48 or more and 1.65 or less. More preferably, it is 1.50 or more and 1.60 or less, and even more preferably, it is 1.54 or more and 1.56 or less. By increasing the refractive index of the hard coat layer 18, it is possible to reduce the reflectivity. On the other hand, if the refractive index of the hard coat layer 18 is too high, it becomes difficult to adjust the angle dependence of the reflectivity and the color tone. Also, the thickness of the hard coat layer 18 is preferably 0.5 μm or more and 20 μm or less. More preferably, the thickness of the hard coat layer 18 is 3 μm or more and 10 μm or less.

[0064] The high refractive index layer 19 is provided as a functional layer below the low refractive index layer 17 to further reduce the reflectivity. The high refractive index layer 19 contains a binder and high refractive index particles. The high refractive index layer 19 can be formed, for example, from a coating solution containing a binder and high refractive index particles. The high refractive index layer 19 may be formed as a single layer or multiple layers, but it is preferably formed with as few layers as possible from the perspective of manufacturing cost.

[0065] In order to reduce the reflectivity of the liquid crystal panel 1a, it is preferable to increase the refractive index of the high refractive index layer 19. As a specific refractive index, it is preferably 1.55 or more and 1.80 or less, and more preferably 1.60 or more and 1.75 or less. Further, as the upper limit of the thickness of the high refractive index layer 19, 500 nm or less is preferable. Further, 350 nm or less is more preferable, and 200 nm or less is even more preferable. And as the lower limit of the thickness of the high refractive index layer 19, 50 nm or more is preferable. Further, 80 nm or more is more preferable, and 100 nm or more is even more preferable.

[0066] Examples of the high refractive index particles include zirconium oxide, hafnium oxide, tantalum oxide, titanium oxide, zinc oxide, aluminum oxide, magnesium oxide, tin oxide, yttrium oxide, barium titanate, antimony-doped tin oxide (ATO), phosphorus-doped tin oxide (PTO), indium-doped tin oxide (ITO), zinc sulfide, and the like. From the viewpoint of durability and stability, zirconium oxide, barium titanate, antimony-doped tin oxide (ATO), phosphorus-doped tin oxide (PTO), and indium-doped tin oxide (ITO) are particularly preferable.

[0067] The average particle diameter (average primary particle diameter) of the primary particles of the high refractive index particles is preferably 1 nm or more and 200 nm or less. Further, 3 nm or more and 100 nm or less is more preferable, and 5 nm or more and 50 nm or less is even more preferable. The average primary particle diameter of the high refractive index particles can be measured from the observation images obtained by using SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), and STEM (Scanning Transmission Electron Microscope) of the dry film of the particle dispersion liquid.

[0068] It is preferable that the above high refractive index particles are subjected to dispersion stabilization treatment from the viewpoint of suppressing aggregation. Examples of the means for dispersion stabilization include using particles subjected to surface treatment and adding a dispersant. Further, a means of adding another particle having a smaller surface charge amount than the high refractive index particles is also included.

[0069] The content of the high refractive index particles is preferably 20 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the binder. More preferably, it is 50 parts by mass or more and 400 parts by mass or less, and even more preferably, it is 100 parts by mass or more and 300 parts by mass or less.

[0070] As the binder, the same ones as those exemplified in the low refractive index layer 17 can be used. However, in order to reduce the content of the high refractive index particles, the refractive index of the binder is preferably about 1.50 or more and 1.70 or less. The high refractive index layer 19 may contain other components in addition to the binder and the high refractive index particles, if necessary. For example, it may contain additives such as a polymerization initiator, an ultraviolet absorber, a leveling agent, a surfactant, etc. and a diluting solvent. By adding additives such as a leveling agent and a surfactant, the surface state of the high refractive index layer 19 can be controlled, and as a result, the performance of the upper layer can be improved. In this case, the upper layer is, for example, the low refractive index layer 17.

[0071] Further, the film having the resin film of the present embodiment can be used as a surface film of a polarizing plate. Figs. 5(a) to (b) are diagrams showing an example of the configuration of a polarizing plate to which the present embodiment is applied. The polarizing plate shown in Fig. 5(a) has a substrate 15a, an adhesive layer 21a, and a polarizing film 12 laminated thereon. Then, further thereon, an adhesive layer 21b, a substrate 15b, an anisotropic diffusion layer 16, and a low refractive index layer 17 are laminated. In this case, although two layers of the substrate and the adhesive layer are formed respectively, they may be composed of the same material or different materials. In this case, the polarizing film 12 is bonded to the base material 15a with the adhesive layer 21a. Then, further thereon, a resin film composed of the base material 15b, the anisotropic diffusion layer 16, and the low refractive index layer 17 is bonded with the adhesive layer 21b. The adhesive layers 21a and 21b are, for example, layers made of a UV (ultraviolet) adhesive. Also, the adhesive layers 21a and 21b may be a PSA (Pressure Sensitive Adhesive). Furthermore, the adhesive layers 21a and 21b may be an OCA (Optical Clear Adhesive). Even further, the adhesive layers 21a and 21b may be an OCR (Optical Clear Resin). And among these, a UV adhesive can be preferably used.

[0072] Also, in the polarizing plate shown in FIG. 5(b), the base material 15a, the adhesive layer 21a, and the polarizing film 12 are laminated. And thereon, the adhesive layer 21b and the base material 15c are laminated. Further thereon, the adhesive layer 21c, the base material 15b, the anisotropic diffusion layer 16, and the low refractive index layer 17 are laminated. That is, the polarizing plate shown in FIG. 5(b) is different in that the base material 15c and the adhesive layer 21c are added compared to the polarizing plate of FIG. 5(a). In this case, for example, the adhesive layers 21a and 21b can be layers made of a UV adhesive, and the adhesive layer 21c can be a layer made of PSA.

[0073] <Explanation of the method for manufacturing the resin film> Next, an explanation will be given of the method for manufacturing a resin film having the layer structure shown in FIG. 2. FIG. 6(a) is a flowchart showing the method for manufacturing a resin film having the layer structure shown in FIG. 2. First, the anisotropic diffusion layer 16 is created (step 101: anisotropic diffusion layer creation step). The anisotropic diffusion layer 16 may be coated on the base material 15, or an anisotropic diffusion film may be formed by melt extrusion or the like. Also, if necessary, the anisotropic diffusion layer 16 is stretched (Step 102: stretching step). By stretching the anisotropic diffusion layer 16, the orientation of the anisotropic particles 162 can be improved, and the anisotropic diffusivity can be enhanced. Further, by stretching the anisotropic diffusion layer 16 containing organic particles such as (meth)acrylic resin, polystyrene resin, and melamine resin near the glass transition point of the resin, the organic particles become anisotropic in shape and the anisotropic diffusivity is significantly improved. That is, before stretching, it is an isotropic diffusion film containing isotropic particles. By stretching this, the isotropic particles change into anisotropic particles 162. As a result, it becomes an anisotropic diffusion film containing anisotropic particles 162.

[0074] Furthermore, a low refractive index layer 17 is formed on the anisotropic diffusion layer 16 (Step 103: low refractive index layer forming step).

[0075] Also, each of the anisotropic diffusion layer 16 and the low refractive index layer 17 can be formed by the following method. FIG. 6(b) is a flowchart explaining a method for forming the anisotropic diffusion layer 16 and the low refractive index layer 17. First, a coating solution for forming each layer is prepared (Step 201: preparation step). Here, "preparation" includes not only the case of preparing by creating the coating solution but also the case of purchasing and preparing the coating solution.

[0076] The coating solution consists of a solid content and a solvent. When forming the anisotropic diffusion layer 16, the solid content includes monomers, oligomers, and polymers that are the basis of the resin part 161. Also, the solid content includes anisotropic particles 162. The monomers and / or oligomers polymerize to become the resin contained in the resin part 161. In this embodiment, the polymerization is photopolymerization, thermal polymerization, or the like. Hereinafter, this monomer and / or oligomer may sometimes be referred to as a "binder component". When forming the low refractive index layer 17, the solid content includes a binder component that is the basis of the binder 171. Also, the solid content includes hollow silica particles 172 and a surface modifier 173. Each layer contains a photoinitiator as a solid content. Additionally, as solid contents, a dispersant, an antifoaming agent, an ultraviolet absorber, a leveling agent, etc. may be included. Then, by putting each solid content into a solvent and stirring, a coating solution for each layer can be prepared.

[0077] The solvent disperses the solid content. As the solvent, for example, methylene chloride, toluene, xylene, ethyl acetate, butyl acetate, and acetone can be used. Also, MEK (methyl ethyl ketone), MIBK (methyl isobutyl ketone), ethanol, methanol, and normal propyl alcohol can be used. Furthermore, isopropyl alcohol, Tert-butyl alcohol, 1-butanol, mineral spirit, oleic acid, and cyclohexanone can be used. Additionally, NMP (N-methyl-2-pyrrolidone), DMP (dimethyl phthalate), dimethyl carbonate, and dioxolane can be used. The solid content concentration of the coating solution can be, for example, 2 wt% or more and 80 wt% or less. The anisotropic diffusion layer 16 is coated in a high-viscosity state by increasing the solid content concentration. Thereby, a strong shear force is applied during coating, and the orientation of the anisotropic particles 162 can be improved. Also, when forming an ultra-thin film on the order of nm such as the low refractive index layer 17, it is desirable to lower the solid content concentration to ensure the film thickness uniformity during coating.

[0078] Returning to FIG. 6(b), next, the coating solution is applied (coated) to form a coating film (step 202: coating process). The method of applying is not particularly limited, but it can be performed by a die coating method or a microgravure coating method. Also, a method of dropping the coating solution, rotating it, and creating a film-like body with a uniform thickness by centrifugal force can be adopted. The coating solution may be applied in a heated state. At this time, the surface modifier of the low refractive index layer 17 segregates on the surface side of the coating film.

[0079] Further, the applied coating film is dried (Step 203: Drying step). Drying can be performed by leaving it at room temperature to volatilize the solvent, or by forcibly removing the solvent by heating or evacuation.

[0080] Then, light energy such as ultraviolet rays or heat is irradiated to polymerize the binder component in the coating film. As a result, the binder component in the coating film is cured to become the resin part 161 and the binder 171 (Step 204: Polymerization step). By the above steps, each layer of the anisotropic diffusion layer 16 and the low refractive index layer 17 can be formed. Note that the drying step and the polymerization step can be regarded as a curing step for curing the applied coating solution.

[0081] According to the resin film described in detail above, the anisotropic diffusion layer 16 is provided. Thereby, the incident light is scattered in a specific direction. And while maintaining excellent antireflection characteristics, surface brightness, and contrast, the viewing angle of the display is enlarged. Also, according to the resin film described in detail above, the refractive indices of the anisotropic particles 162 and the resin part 161 are optimized as in the formulas (I) and (II) above. Thereby, backward scattering in the anisotropic diffusion layer 16 can be suppressed, and SCE can be reduced. And excellent antireflection characteristics are exhibited even when the low refractive index layer 17 is provided. Also, when the hard coat layer 18 and the high refractive index layer 19 are provided, the refractive index can be optimized as described above for reducing the reflectance. That is, the reflectance can be reduced more than in the case of only the low refractive index layer 17. And it is possible to impart more excellent anti-reflection property. Also, as shown in FIG. 5, the resin film and the polarizing film 12 can be bonded using the adhesive layer 21. Thereby, the number of laminated layers can be significantly reduced compared to the anisotropic diffusion film of the uneven structure type. And it contributes to the improvement of the brightness of the display and the reduction of the manufacturing cost. And since no uneven structure is used, no rainbow unevenness due to diffraction by the structure occurs even when external light such as illumination is incident, and an excellent anti-reflection effect is exhibited.

[0082] Note that in the above example, the display device 1 shows the case where the anisotropic diffusion layer 16 and the low refractive index layer 17 are formed on the liquid crystal panel. However, the present invention is not limited to this. For example, it may be formed on an organic EL or a cathode ray tube. Also, these layers may be formed on the surface of a lens or the like made of a material such as glass or plastic. In this case, the lens or the like is an example of a base material. Further, the lens or the like on which the anisotropic diffusion layer 16 and the low refractive index layer 17 are formed is an example of an optical member. Also, as the base material, a film made of TAC or the like can be used. And these layers may be formed on this film. This can be used as a low refractive index film or an antireflection film. This is also an example of an optical member.

[0083] Furthermore, in the above example, the case where the binder component is polymerized by photopolymerization is shown, but the binder component may be polymerized by thermal polymerization. Also, as shown in FIG. 4(e), the anisotropic diffusion layer 16 may be used as the base material 15.

Example

[0084] Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited by these examples as long as the gist thereof is not exceeded.

[0085] 〔Formation of anisotropic diffusion layer 16〕 First, a method for creating the anisotropic diffusion layer 16 will be described. Here, the anisotropic diffusion layers AD-1 to AD-10 were created as the anisotropic diffusion layer 16 by the method shown below. Also, the isotropic diffusion layers ID-1 to ID-2 were created. The isotropic diffusion layers ID-1 to ID-2 are diffusion layers having isotropic light diffusibility. The anisotropic diffusion layers AD-1 to AD-10 contain anisotropic particles 162. On the other hand, the isotropic diffusion layers ID-1 to ID-2 contain isotropic particles.

[0086] (Anisotropic diffusion layer AD-1) The anisotropic diffusion layer AD-1 was created as follows. An acrylic oligomer having an acryloyl group with a refractive index of 1.51 was dissolved in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone. Needle-shaped calcium carbonate particles were added as anisotropic particles 162 to this mixed solution in an amount of 65 parts by mass with respect to 100 parts by mass of the acrylic oligomer. The average length of the major axis of these needle-shaped calcium carbonate particles is 20 μm, and the average length of the minor axis is 0.6 μm. The refractive index is 1.66 in the major axis direction and 1.50 in the minor axis direction. Further, 4 parts by mass of a photopolymerization initiator (Irgacure 127 manufactured by IGM Resin) was added. Then, methyl ethyl ketone and dimethyl carbonate were added and adjusted so that the solid content concentration became 80% by mass. This composition was coated on a TAC film as the substrate 15 using a bar coater. The TAC film has a film thickness of 60 μm. Next, after drying at 80°C for 2 minutes, it was irradiated with a high-pressure mercury lamp with an illuminance of 200 mW / cm 2 for 3 seconds to be cured. Thereby, an anisotropic diffusion layer AD-1 was obtained on the film-shaped substrate 15. The film thickness of the anisotropic diffusion layer AD-1 was 10 μm.

[0087] (Anisotropic diffusion layer AD-2) An anisotropic diffusion layer AD-2 was prepared in the same manner as the anisotropic diffusion layer AD-1, except that the anisotropic particles 162 were changed. These anisotropic particles 162 are needle-shaped calcium carbonate particles, but the average length of the major axis is 160 μm, and the average length of the minor axis is 8 μm. That is, those larger than the anisotropic diffusion layer AD-1 were used. The refractive index is 1.66 in the major axis direction and 1.50 in the minor axis direction. The film thickness of the anisotropic diffusion layer AD-2 was 10 μm.

[0088] (Anisotropic diffusion layer AD-3) The anisotropic diffusion layer AD-3 was prepared in the same manner as the anisotropic diffusion layer AD-1, except that the anisotropic particles 162 were changed. These anisotropic particles 162 are acicular calcium carbonate particles, with an average major axis length of 3 μm and an average minor axis length of 0.2 μm. That is, those smaller than the anisotropic diffusion layer AD-1 were used. Also, the refractive index is 1.66 in the major axis direction and 1.50 in the minor axis direction. The film thickness of the anisotropic diffusion layer AD-3 was 10 μm.

[0089] (Anisotropic diffusion layer AD-4) The anisotropic diffusion layer AD-4 was prepared as follows. The anisotropic particles 162 were changed with respect to the anisotropic diffusion layer AD-1 and prepared as follows. An acrylic oligomer having an acryloyl group with a refractive index of 1.49 was dissolved in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone. To this mixed solution, basic magnesium sulfate fiber was added as the anisotropic particles 162 in an amount of 80 parts by mass with respect to 100 parts by mass of the acrylic oligomer. The average length of the major axis of this basic magnesium sulfate fiber is 30 μm, and the average length of the minor axis is 0.8 μm. Also, the refractive index is 1.55 in the major axis direction and 1.50 in the minor axis direction. Further, 4 parts by mass of a photoinitiator (Irgacure 127 manufactured by IGM Resin) was added. Then, methyl ethyl ketone and dimethyl carbonate were added and adjusted so that the solid content concentration became 70% by mass. This composition was coated on a TAC film as the substrate 15 using a bar coater. The thickness of this TAC film is 60 μm. Next, after drying at 80°C for 2 minutes, it was irradiated with a high-pressure mercury lamp with an illuminance of 200 mW / cm 2 for 3 seconds to be cured. Thereby, an anisotropic diffusion layer AD-4 was obtained on the film-like substrate 15. The film thickness of the anisotropic diffusion layer AD-4 was 10 μm.

[0090] (Anisotropic diffusion layer AD-5) The anisotropic diffusion layer AD-5 was prepared by changing the anisotropic particles 162 with respect to the anisotropic diffusion layer AD-1 and prepared as follows. An acrylic oligomer having an acryloyl group with a refractive index of 1.49 was dissolved in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone. Needle-shaped titanium oxide particles were added as anisotropic particles 162 to this mixed solution in an amount of 30 parts by mass based on 100 parts by mass of the acrylic oligomer. The average length of the long axis of these needle-shaped titanium oxide particles is 20 μm, and the average length of the short axis is 0.2 μm. The refractive index is 2.27 in the long axis direction and 2.10 in the short axis direction. Further, 4 parts by mass of a photopolymerization initiator (Irgacure 127 manufactured by IGM Resin) was added. Thereafter, methyl ethyl ketone and dimethyl carbonate were added and adjusted so that the solid content concentration became 75% by mass. This composition was coated on a TAC film as the base material 15 using a bar coater. The TAC film has a film thickness of 60 μm. Next, after drying at 80 °C for 2 minutes, it was irradiated with a high-pressure mercury lamp with an illuminance of 200 mW / cm 2 for 3 seconds to be cured. Thereby, an anisotropic diffusion layer AD-5 was obtained on the film-shaped base material 15. The film thickness of the anisotropic diffusion layer AD-5 was 10 μm.

[0091] (Anisotropic diffusion layer AD-6) The anisotropic diffusion layer AD-6 was prepared by changing the anisotropic particles 162 with respect to the anisotropic diffusion layer AD-1 as follows. An acrylic oligomer having an acryloyl group with a refractive index of 1.49 was dissolved in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone. Glass long fibers were added as anisotropic particles 162 to this mixed solution in an amount of 40 parts by mass based on 100 parts by mass of the acrylic oligomer. The average length of the long axis of these glass long fibers is 120 μm, and the average length of the short axis is 4 μm. The refractive index is 1.55. Further, 4 parts by mass of a photopolymerization initiator (Irgacure 127 manufactured by IGM Resin) was added. Thereafter, methyl ethyl ketone and dimethyl carbonate were added and adjusted so that the solid content concentration became 65% by mass.

[0092] This composition was applied to a TAC film serving as the base material 15 using a bar coater. The TAC film had a film thickness of 60 μm. Next, after drying at 80°C for 2 minutes, it was cured by irradiating with a high-pressure mercury lamp with an illuminance of 200 mW / cm 2 for 3 seconds. Thereby, an anisotropic diffusion layer AD-6 was obtained on the film-shaped base material 15. The film thickness of the anisotropic diffusion layer AD-6 was 10 μm.

[0093] (Anisotropic diffusion layer AD-7) An anisotropic diffusion layer AD-7 was prepared in the same manner as the anisotropic diffusion layer AD-1, except that the anisotropic particles 162 were changed. These anisotropic particles 162 are acicular calcium carbonate particles, with an average major axis length of 0.8 μm and an average minor axis length of 0.1 μm. That is, those smaller than the anisotropic diffusion layer AD-3 were used. Also, the refractive index was 1.66 in the major axis direction and 1.50 in the minor axis direction. The film thickness of the anisotropic diffusion layer AD-7 was 10 μm.

[0094] (Anisotropic diffusion layer AD-8) An anisotropic diffusion layer AD-8 was prepared in the same manner as the anisotropic diffusion layer AD-1, except that the anisotropic particles 162 were changed. These anisotropic particles 162 are acicular calcium carbonate particles, with an average major axis length of 250 μm and an average minor axis length of 12 μm. That is, those larger than the anisotropic diffusion layer AD-2 were used. Also, the refractive index was 1.66 in the major axis direction and 1.50 in the minor axis direction. The film thickness of the anisotropic diffusion layer AD-8 was 10 μm.

[0095] (Anisotropic diffusion layer AD-9) Polymethyl methacrylate resin with a refractive index of 1.50 was dissolved in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone. To this mixed solution, polystyrene particles were added as anisotropic particles 162 at a ratio of 70 parts by mass per 100 parts by mass of the polymethyl methacrylate resin. The average particle size of these polystyrene particles was 5 μm. Also, the refractive index was 1.60. Thereafter, methyl ethyl ketone was added to adjust the solid content concentration to 70% by mass. This composition was applied to a release-treated PET film using a bar coater. Next, after drying at 80°C for 5 minutes, it was peeled off from the PET film to obtain a resin film with a thickness of 600 μm. This resin film was stretched 3.5 times in an atmosphere near the glass transition point of polystyrene (90°C or higher and 120°C or lower) to obtain an anisotropic diffusion layer AD-9. The thickness of the anisotropic diffusion layer AD-9 was 60 μm.

[0096] (Anisotropic diffusion layer AD-10) An anisotropic diffusion layer AD-10 was prepared in the same manner as the anisotropic diffusion layer AD-1, except that the anisotropic particles 162 were changed. These anisotropic particles 162 are needle-shaped calcium carbonate particles, with an average length in the major axis direction of 220 μm and an average length in the minor axis direction of 12 μm. That is, those larger than the anisotropic diffusion layer AD-8 were used. Also, the refractive index is 1.66 in the major axis direction and 1.50 in the minor axis direction. The thickness of the anisotropic diffusion layer AD-10 was 10 μm.

[0097] (Isotropic diffusion layer ID-1) The isotropic diffusion layer ID-1 was prepared as follows. An acrylic oligomer having an acryloyl group with a refractive index of 1.51 was dissolved in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone. Calcium carbonate particles were added to this mixed solution as anisotropic particles 162 in a proportion of 65 parts by mass per 100 parts by mass of the acrylic oligomer. The average particle size of these calcium carbonate particles is 3 μm. Also, the refractive index is 1.65. Further, 4 parts by mass of a photopolymerization initiator (Irgacure 127 manufactured by IGM Resin) was added. Thereafter, methyl ethyl ketone and dimethyl carbonate were added and adjusted so that the solid content concentration became 65% by mass. This composition was applied to a TAC film as the substrate 15 using a bar coater. This TAC film has a film thickness of 60 μm. Next, after drying at 80°C for 2 minutes, it was irradiated with a high-pressure mercury lamp with an illuminance of 200 mW / cm 2 for 3 seconds to be cured. Thereby, an isotropic diffusion layer ID-1 was obtained on the film-shaped substrate 15. The thickness of the isotropic diffusion layer ID-1 was 10 μm.

[0098] (Isotropic Diffusion Layer ID-2) Isotropic Diffusion Layer ID-2 was created as follows. Methyl polymethacrylate resin with a refractive index of 1.50 was dissolved in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone. To this mixed solution, 70 parts by mass of polystyrene particles were added per 100 parts by mass of the resin. The average particle size of these polystyrene particles is 5 μm. Also, the refractive index is 1.60. Then, methyl ethyl ketone was added and adjusted so that the solid content concentration became 70% by mass. This composition was coated on a release-treated PET film using a bar coater. Next, it was dried at 80 °C for 5 minutes. After drying, it was peeled off from the PET film to obtain a resin film with a thickness of 60 μm.

[0099] 〔Formation of Hard Coat Layer 18〕 Here, coating solutions HC-1 to HC-3 of Hard Coat Layer 18 were prepared with the compositions shown in Table 1.

[0100] (Coating Solution HC-1) Coating Solution HC-1 contains monomers and / or oligomers as binder components. Also, Coating Solution HC-1 contains a photoinitiator, an antifoaming agent, and a solvent. As the binder component, UA-306T manufactured by Kyoeisha Chemical Co., Ltd. was used. As the binder component, Biscoat #300 manufactured by Osaka Organic Chemical Industry Co., Ltd. and KAYARAD PET-30 manufactured by Nippon Kayaku Co., Ltd. were also used. Furthermore, as the photoinitiator, IRGACURE184 manufactured by BASF Japan Ltd. was used. Additionally, as the antifoaming agent, NR-121X-9IPA manufactured by Cork Coat Co., Ltd. was used. And, as the antifoaming agent, BYK-066N manufactured by ALTANA was used. These are solid components, and the mixing ratios are as shown in Table 1. Then, these solid components were put into a solvent and stirred so that they became 50% by mass. As the solvent, propylene glycol monomethyl ether and ethyl acetate were used.

[0101] (Coating Solution HC-2) Coating solution HC-2 was added with metal oxide particles compared to coating solution HC-1. As the metal oxide particles, zirconium oxide which is nanoparticles with an average primary particle size of 30 nm was used. Also, NR-121X-9IPA manufactured by Corcoat Co., Ltd., which is an antistatic agent, was not used. These mixing ratios are as shown in Table 1.

[0102] (Coating solution HC-3) Coating solution HC-3 had its solvent changed compared to coating solution HC-1. That is, as the solvent, dimethyl carbonate was used in addition to propylene glycol monomethyl ether and ethyl acetate. These mixing ratios are as shown in Table 1. Thereby, coating solution HC-3 was prepared.

[0103] Coating solutions HC-1 to HC-3 were applied with a wire bar to form a coating film. Further, after leaving the coating film at room temperature for 1 minute, it was dried by heating at 80°C for 1 minute. Then, it was irradiated with an ultraviolet lamp (metal halide lamp, illuminance 300 mW / cm 2 ) for 1 second. Thereby, the coating film could be cured. Through the above steps, the hard coat layer 18 could be formed.

[0104]

Table 1

[0105] 〔Formation of the high refractive index layer 19〕 Next, the method for preparing the high refractive index layer 19 will be described. Here, a coating solution HR-1 for the high refractive index layer 19 was prepared with the composition shown in Table 2.

[0106] (Coating solution HR-1) Coating solution HR-1 contains a monomer and / or oligomer as a binder component, high refractive index particles, and a photoinitiator. Further, coating solution HR-1 contains a surface modifier and a solvent. As the binder component, KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd. was used. As the high refractive index particles, zirconium oxide which is nanoparticles with an average primary particle diameter of 10 nm was used. Further, as the photoinitiator, IRGACURE184 manufactured by BASF Japan Ltd. was used. And as the surface modifier, Megafac F-568 manufactured by DIC Corporation was used. These are solid components, and the blending ratios are as shown in Table 2. Then, these solid components were put into methyl isobutyl ketone which is a solvent so as to be 10% by mass, and stirred. Thereby, coating solution HR-1 for the high refractive index layer 19 was prepared.

[0107] Coating solution HR-1 was applied with a wire bar to form a coating film. Further, after leaving the coating film at room temperature for 1 minute, it was dried by heating at 80°C for 2 minutes. And it was irradiated with an ultraviolet lamp (metal halide lamp, illuminance 300 mW / cm 2 ) for 1 second. Thereby, the coating film can be cured. Through the above steps, the high refractive index layer 19 could be formed.

[0108]

Table 2

[0109] 〔Formation of low refractive index layer 17〕 Next, a method for preparing the low refractive index layer 17 will be described. Here, a coating solution for the low refractive index layer 17 was prepared with the composition shown in Table 3.

[0110] (Coating solution LR-1) Coating solution LR-1 contains monomers and / or oligomers as binder components, and hollow silica particles 172. Also, coating solution LR-1 contains a photoinitiator, an oil-repellent surface modifier 173, and a lipophilic surface modifier 173. Furthermore, the coating solution contains an antifoaming agent and a solvent. As the binder component, Optool AR-100 manufactured by Daikin Industries, Ltd. was used. Furthermore, KAYARAD PET-30 manufactured by Nippon Kayaku Co., Ltd. was used as the binder component. Also, as the hollow silica particles 172, those with an average primary particle diameter of 75 nm were used. And in addition to the hollow silica particles 172, as solid silica particles, those with an average primary particle diameter of 10 nm were used. Solid silica particles are silica particles with a solid interior rather than a hollow one. Furthermore, as the photoinitiator, IRGACURE 184 manufactured by BASF Japan Ltd. was used. And as the oil-repellent surface modifier 173, KY-1203 manufactured by Shin-Etsu Chemical Co., Ltd. was used. Furthermore, as the lipophilic surface modifier 173, Megafac RS-58 manufactured by DIC Corporation was used. Additionally, as the lipophilic surface modifier 173, Fujent 650A manufactured by Neos Co., Ltd. was used. And as the antifoaming agent, BYK-066N manufactured by ALTANA was used. These are solid components, and the mass mixing ratios are as shown in Table 3.

[0111] Then, these solid components were put into a mixed solution of methyl isobutyl ketone and n-butyl alcohol, which is the solvent, and stirred. At this time, the solid components were adjusted to be 5% by mass. Thereby, the coating solution LR-1 for the low refractive index layer 17 was prepared. The mass mixing ratio of the solvent is as shown in Table 3.

[0112] (Coating solution LR-2) For the coating solution LR-2, as the binder component, KAYARAD PET-30 manufactured by Nippon Kayaku Co., Ltd. was used. Also, as the binder component, NK Ester A-200 manufactured by Shin-Nakamura Chemical Co., Ltd. was used. And for the hollow silica particles 172, those with an average primary particle diameter of 60 nm were used. In addition to the hollow silica particles 172, as the solid silica particles, those with an average primary particle diameter of 10 nm were used. Furthermore, as the photoinitiator, IRGACURE 127 manufactured by BASF Japan Ltd. was used. And as the oil-repellent surface modifier 173, KY-1203 manufactured by Shin-Etsu Chemical Co., Ltd. was used. Additionally, as the lipophilic surface modifier 173, Megafac RS-90 manufactured by DIC Corporation was used. And as the defoamer, BYK-066N manufactured by ALTANA was used. These are the solid components, and the mass mixing ratio is as shown in Table 3.

[0113] Then, these solid components were put into a mixed solution of methyl isobutyl ketone and Tert-butyl alcohol, which are solvents, and stirred. At this time, the solid content was adjusted to 5% by mass. Thereby, the coating solution LR-2 for the low refractive index layer 17 was prepared. The mass mixing ratio of the solvents is as shown in Table 3.

[0114] The coating solutions LR-1 to LR-2 were applied with a wire bar to form a coating film. Further, after leaving the coating film at room temperature for 1 minute, it was dried by heating at 60°C for 3 minutes. Then, it was irradiated with an ultraviolet lamp (metal halide lamp, illuminance 300 mW / cm 2 ) for 1 second under a nitrogen gas replacement atmosphere. Thereby, the coating film can be cured. Through the above steps, the low refractive index layer 17 could be formed.

[0115]

Table 3

[0116] 〔Composition of the resin film〕 Next, the combination of the anisotropic diffusion layer 16, hard coat layer 18, high refractive index layer 19, and low refractive index layer 17 described above will be explained. Here, these layers were formed on the substrate 15 in this order in the combinations shown in Tables 4 to 6. However, as shown in Tables 4 to 6, there were cases where at least one of the layers was not formed.

[0117] (Example 1) In Example 1, as shown in Table 4, the anisotropic diffusion layer AD-1 was formed as the anisotropic diffusion layer 16 on the substrate 15. Further, using the coating solution HC-1, the hard coat layer 18 was formed on the anisotropic diffusion layer 16. Furthermore, using the coating solution LR-1, the low refractive index layer 17 was formed on the hard coat layer 18. In Example 1, the high refractive index layer 19 was not formed.

[0118] (Examples 2 to 12) As Examples 2 to 12, each layer constituting the resin film was formed with the combinations of the anisotropic diffusion layers and coating solutions shown in Tables 4 to 5. Among these, Example 2 is the case where the anisotropic diffusion layer AD-2 was used instead of the anisotropic diffusion layer AD-1 compared to Example 1. Example 2 is the case where, as the anisotropic particles 162, those having a size close to the upper limit within a more preferable range were used. Also, Example 3 is the case where the anisotropic diffusion layer AD-3 was used instead of the anisotropic diffusion layer AD-1 compared to Example 1. Example 3 is the case where, as the anisotropic particles 162, those having a size close to the lower limit within a more preferable range were used. Furthermore, Example 3 is the case where, as the anisotropic particles 162, those having an aspect ratio close to the lower limit within a preferable range were used. Furthermore, Example 4 is the case where the coating solution HR-1 was used to form the high refractive index layer 19 compared to Example 1. Moreover, Example 5 is the case where the hard coat layer 18 was not formed compared to Example 1. And Example 6 is the case where the coating solution HC-2 was used to form the hard coat layer 18 compared to Example 1. Examples 7 to 11 are cases where anisotropic diffusion layers AD-4 to AD-8 are used respectively for Example 1. Among these, in Examples 7 to 9, the type of anisotropic particles 162 is changed compared to Example 1. Also, in Examples 10 to 11, at least one of the size and aspect ratio of the anisotropic particles 162 is outside the more preferable range. Furthermore, Example 12 is a case where the anisotropic diffusion layer AD-9 also functions as the base material 15. Also, it is a case where the anisotropic particles 162 and the resin part 161 are compatible.

[0119] (Comparative Examples 1 to 5) As Comparative Examples 1 to 5, each layer was created with the combinations of anisotropic diffusion layers, isotropic diffusion layers, and coating solutions shown in Table 6. Among these, Comparative Example 1 is a case where it does not contain anisotropic particles 162 compared to Example 1. Comparative Examples 2 and 3 are cases where an isotropic diffusion layer is formed instead of an anisotropic diffusion layer for Example 1. That is, Comparative Examples 2 and 3 form isotropic diffusion layer ID-1 and isotropic diffusion layer ID-2 respectively. Comparative Example 4 is a case where the reflectance excluding the specular reflection light component of the anisotropic diffusion layer AD-10 does not become 1.0% or less and exceeds it compared to Example 1. Comparative Example 5 is a case where the low refractive index layer 17 was not created compared to Example 1.

[0120]

Table 4

[0121]

Table 5

[0122]

Table 6

[0123] 〔Evaluation Method〕 For Examples 1 to 12 and Comparative Examples 1 to 5, the following items were evaluated.

[0124] (Film thickness, refractive index) The film thickness of each layer constituting the resin film was measured. Also, the refractive indices of the hard coat layer 18, the high refractive index layer 19, and the low refractive index layer 17 constituting the resin film were measured. The film thickness and refractive index were measured using a spectroscopic ellipsometer (VUV-VASE) manufactured by J.A. Woollam Co., Ltd. At this time, measurements were taken at n = 3 points within the same sample, and the average value was adopted.

[0125] (SCI reflectance, SCE reflectance) The SCI reflectance (reflectance of regular reflected light) of the resin film and the SCE reflectance (reflectance excluding the regular reflected light component) of the anisotropic diffusion layer 16 were measured. The SCI reflectance and SCE reflectance were measured using a CM-2600d manufactured by Konica Minolta, Inc. The measurement was performed after attaching a black PET film to the back surface of the measurement film. A smaller SCI reflectance results in better performance. The SCI reflectance needs to be 1.0% or less.

[0126] (Haze value) The haze value of the anisotropic diffusion layer 16 was measured. The haze value was measured using a haze meter NDH5000W manufactured by Nippon Denshoku Industries Co., Ltd. At this time, measurements were taken at n = 3 points within the same sample, and the average value was adopted.

[0127] (ADV) The ADV (anisotropic diffusion degree) of the anisotropic diffusion layer 16 was measured. The ADV was measured using a variable-angle photometer GP-200 manufactured by Murakami Color Research Laboratory. The sample was placed so that the incident light was perpendicular to the sample surface, and the luminance distributions in the anisotropic diffusion direction and the perpendicular direction of the transmitted light were measured. The luminance distribution was measured in the range of -50° or more and +50° or less. Then, the ratio of the transmitted light amount of 5° in the anisotropic diffusion direction to the transmitted light amount of 5° in the direction perpendicular to the anisotropic diffusion direction was defined as the ADV.

[0128] (Viewing angle characteristics) As viewing angle characteristics, the front luminance, front contrast, and 60° luminance were measured. These were measured using a ConoScope manufactured by Autronic Melchers GmbH. After mounting the created sample on the VA panel so that the diffusion direction was in the horizontal direction of the display, the luminance distribution in the horizontal direction of the display during black display (gray level 0) and white display (gray level 255) was measured. The luminance distribution was measured in the range of -80° or more and +80° or less. The 60° luminance adopted the average value of the luminance at -60° and +60°. Also, the luminance at the front (0°) during white display was measured as the front luminance. Further, the ratio of the luminance at the front during white display to the luminance at the front during black display was defined as the front contrast.

[0129] The evaluation at this time was performed as follows. When the front luminance was 400 cd / m 2 or more, it was rated as "A". Also, when the front luminance was 350 cd / m 2 or more and less than 400 cd / m 2 , it was rated as "B". Furthermore, when the front luminance was 300 cd / m 2 or more and less than 350 cd / m 2 , it was rated as "C". Additionally, when the front luminance was less than 300 cd / m 2 , it was rated as "D".

[0130] Also, when the front contrast was 3000 or more, it was rated as "A". When the front contrast was 2300 or more and less than 3000, it was rated as "B". Furthermore, when the front contrast was 1800 or more and less than 2300, it was rated as "C". Additionally, when the front contrast was less than 1800, it was rated as "D".

[0131] And when the 60° luminance was 30% or more, it was rated as "A". When the 60° luminance was 23% or more and less than 30%, it was rated as "B". Furthermore, when the 60° luminance was 18% or more and less than 23%, it was rated as "C". Additionally, when the 60° luminance was less than 18%, it was rated as "D". And when the evaluation was A or B, it was considered a pass, and when the evaluation was C or D, it was considered a fail.

[0132] (Reflection onto the display) After the sample was attached to the display using an adhesive film, the state of external light reflection onto the screen when the display was lit was visually determined.

[0133] The evaluation at this time was conducted as follows. When the external light reflection was very little and the visibility of the image was excellent, it was rated as "A". Also, when some external light reflection could be confirmed but the influence on the visibility of the image was minor, it was rated as "B". Furthermore, when the external light reflection was often prominent and a decrease in the visibility of the image could be confirmed, it was rated as "C". Moreover, when the external light reflection was intense and the visibility of the image was poor, it was rated as "D". And, when the evaluation was A or B, it was considered a pass, and when the evaluation was C or D, it was considered a fail.

[0134] 〔Evaluation results〕 The evaluation results are shown in Tables 4 - 6. Note that the refractive indices of the hard coat layer 18, the high refractive index layer 19, and the low refractive index layer 17 are shown in Tables 1 - 3. As shown in Table 3, the refractive index of the low refractive index layer 17 was 1.40 or less, and good results were obtained. And, as shown in Tables 4 - 5, in Examples 1 - 12, the SCE reflectance was 1.0% or less, and good results were obtained. Examples 1 - 7 are cases where acicular calcium carbonate particles or basic magnesium sulfate fibers were used as the anisotropic particles 162. Also, both the size and aspect ratio of the anisotropic particles 162 were in a more preferable range. That is, the length of the short axis direction of the anisotropic particles 162 was 0.1 μm or more and 10 μm or less. Further, the aspect ratio, which is the ratio of the length in the long axis direction to the length in the short axis direction of the anisotropic particles 162, was 10 or more. In the case of Examples 1 - 7, for the viewing angle characteristics, the front luminance, front contrast, and 60° luminance, all the evaluations were A. Also, for the reflection onto the display, all the evaluations were A.

[0135] Example 8 is the case where acicular titanium oxide particles are used as the anisotropic particles 162. Further, Example 9 is the case where glass long fibers are used as the anisotropic particles 162. In this case, the evaluations of the viewing angle characteristics and the reflection on the display were A or B, falling within the acceptable range.

[0136] In Examples 10 and 11, at least one of the size and aspect ratio of the anisotropic particles 162 is outside the more preferable range. In this case, all the evaluations of the viewing angle characteristics and the reflection on the display were B, falling within the acceptable range. Example 12 is the case where the anisotropic particles 162 and the resin part 161 are compatible. In this case, all the evaluations of the viewing angle characteristics and the reflection on the display were A.

[0137] Comparative Example 1 is the case where the anisotropic particles 162 are not included. In this case, the luminance at 60° was D, which was unacceptable. Comparative Examples 2 and 3 are the cases where an isotropic diffusion layer is used without using an anisotropic diffusion layer. In this case, the front luminance, front contrast, and luminance at 60° were C or D, which was unacceptable. Comparative Example 4 is the case where the reflectance excluding the specular reflection light component does not become 1.0% or less but exceeds it. In this case, the front luminance, front contrast, and reflection on the display were C or D, which was unacceptable. Comparative Example 5 is the case where the low refractive index layer 17 is not provided. In this case, the reflection on the display was D, which was unacceptable. Regarding Example 1, a film was prepared by changing the position of the anisotropic diffusion layer 16 to the back surface of the substrate 15 (TAC), and the same evaluation was performed. As a result, it was confirmed that the same performance as in Example 1 could be ensured.

[0138] From the above results, it can be seen that the resin film requires the anisotropic diffusion layer 16 and the low refractive index layer 17 having a refractive index of 1.40 or less. It can also be seen that the reflectance excluding the specular reflection light component needs to be 1.0% or less.

Explanation of Reference Numerals

[0139] 1… denotes a device, 1a… a liquid crystal panel, 11… a backlight, 12, 12a, 12b… polarizing films, 13, 13a, 13b… retardation films, 14… liquid crystal, 15… a substrate, 16… an anisotropic diffusion layer, 17… a low refractive index layer, 18… a hard coat layer, 19… a high refractive index layer, 161… a resin part, 162… anisotropic particles

Claims

1. 1. A low refractive index layer having a refractive index of 40 or less, an anisotropic diffusion layer that anisotropically diffuses light, comprising: wherein the anisotropic diffusion layer has an anisotropic shape and includes anisotropic particles arranged along one direction in the major axis direction, and a resin portion that disperses the anisotropic particles and is made of a resin, has a reflectance of 1.0% or less excluding the specular reflection light component, the anisotropic particles have different refractive indices in the major axis direction and the minor axis direction, a resin film in which when the refractive index of the resin portion is n b, the refractive index in the major axis direction of the anisotropic particles is n ax, and the refractive index in the minor axis direction of the anisotropic particles is n ay, at least one of the following relationships (I) and (II) holds. (I) |n b - n ax| < 0.04 and 0.04 < |n b - n ay| < 0.50 (II) |n b - n ay| < 0.04 and 0.04 < |n b - n ax| < 0.50

2. The resin film according to claim 1, wherein the anisotropic particles have a length in the major axis direction of 1 μm or more and 200 μm or less, and a length in the minor axis direction of 0.1 μm or more and 10 μm or less.

3. The resin film according to claim 2, wherein the aspect ratio, which is the ratio of the length in the major axis direction to the length in the minor axis direction of the anisotropic particles, is 10 or more.

4. The resin film according to claim 1, wherein the interface between the anisotropic particles and the resin portion is compatible.

5. The resin film according to claim 1, wherein the refractive index of the resin portion is 1.45 or more and 1.65 or less.

6. The resin film according to claim 1, wherein the anisotropic particles contain at least one of a metal oxide, a carbonate compound, a hydroxide compound, and a phosphate compound.

7. The resin film according to claim 1, wherein the difference in refractive index between the resin portion and the low refractive index layer is 0.1 or more.

8. The resin film according to claim 1, wherein the anisotropic diffusion layer has a haze value of 20% or more and 80% or less.

9. The resin film according to claim 1, wherein the anisotropic diffusion layer has an anisotropic diffusion degree of 3 or more.

10. The resin film according to claim 1, further comprising a high refractive index layer having a refractive index of 1.60 or more.

11. The resin film according to claim 1, further comprising a hard coat layer having a refractive index of 1.54 or more.

12. further comprising a substrate that supports the low refractive index layer and the anisotropic diffusion layer, The resin film according to claim 1, wherein the substrate is provided between the low refractive index layer and the anisotropic diffusion layer.

13. The resin film according to claim 1, wherein the anisotropic diffusion layer functions as a substrate that supports the low refractive index layer.

14. A low refractive index layer forming step of forming a low refractive index layer having a refractive index of 1.40 or less; An anisotropic diffusion layer forming step of forming an anisotropic diffusion layer that includes anisotropic particles having an anisotropic shape and arranged along a major axis direction in one direction, and a resin portion that disperses the anisotropic particles and is made of a resin, and has a reflectance excluding a specular reflection light component of 1.0% or less and anisotropically diffuses light. A method for producing a resin film including the above.

15. The anisotropic diffusion layer is a base material that supports the low refractive index layer. The method for producing a resin film according to claim 14, wherein the low refractive index layer forming step forms the low refractive index layer on the base material.

16. The method for producing a resin film according to claim 14, wherein the anisotropic diffusion layer is formed by stretching.

17. Display means for displaying an image; The resin film according to any one of claims 1 to 13, provided on the surface of the display means. A display device including the above.

18. A base material; The resin film according to any one of claims 1 to 13, provided on the base material. An optical member having the above.

19. Polarizing means for polarizing light; The resin film according to any one of claims 1 to 13, provided on the polarizing means. A polarizing member having the above.

Images