TW201418784A - Peak-valley pattern formed sheet and method for producing the same - Google Patents

Abstract

A peak-valley pattern formed sheet having a resin substrate; a resin rigid layer formed on one side of the resin substrate; and a peak-valley pattern formed on a surface of the rigid layer, wherein the difference (T2-T1 ) between the glass transformation temperature T2 of a resin forming the rigid layer and the glass transformation temperature T1 of a resin forming the substrate is 10 DEG C or more; and the average depth of a valley portion of the peak-valley pattern is 10% or more to the most frequent pitch of the peak-valley pattern as 100%, and the method for producing the same are provided.

Description

Concave-convex pattern forming sheet and method of manufacturing same

The present invention relates to a concave-convex pattern forming sheet provided in a light diffusing body and a method of manufacturing the same. Further, the present invention relates to a light diffusing body using a concave-convex pattern forming sheet. Further, the present invention relates to an engineering sheet original for optical diffuser production which is used as a mold for producing a light diffuser having a concave-convex pattern formed on its surface. Further, the present invention relates to a method of producing a light diffuser.

The present invention relates to an optical sheet and a light diffusing sheet which are used as a light diffusion sheet or the like.

The present invention relates to a diffusing light guide that diffuses light from a light source. Moreover, the present invention relates to a backlight unit provided in a liquid crystal display device.

The present invention relates to a concave-convex pattern forming sheet provided in an optical element such as an antireflection body or a phase difference plate, and a method of manufacturing the same. Moreover, the present invention relates to an antireflection body and a phase difference plate using a concave-convex pattern forming sheet. Moreover, the present invention relates to an engineering sheet for optical element manufacturing which is used as a mold for manufacturing an optical element having a concave-convex pattern.

The present application is based on Japanese Patent Application No. 2007-040694, filed on Feb. 21, 2007, and Japanese Patent Application No. 2007-151676, filed on Jun. 7, 2007, and on June 7, 2007. Japanese Patent Application No. 2007-151677, filed in Japan, Japanese Patent Application No. 2007-151795, filed on June 7, 2007, and Japanese Patent Application No. Priority is claimed on 2007-261176, the contents of which are incorporated herein by reference.

In general, a concavo-convex pattern forming sheet having a corrugated concavo-convex pattern formed on a surface thereof is used as a light diffusing body.

For example, Patent Document 1 discloses a light diffuser as a light diffuser in which a concave-convex pattern is formed, that is, a plurality of protrusions are formed on at least one surface of a light-transmitting substrate, and the height of the protrusions is 2 ~20 μm, the interval between the apexes of the protrusions is 1 to 10 μm, and the aspect ratio of the protrusions is 1 or more. Further, Patent Document 1 discloses a method of forming a protrusion, that is, a surface of a light-transmitting substrate by irradiation with an energy beam such as a KrF excimer laser.

Patent Document 2 discloses a light diffusing body in which an anisotropic diffusion pattern composed of corrugated irregularities is formed on one surface. Further, Patent Document 2 discloses a method of forming an anisotropic diffusion pattern in which a film of a photosensitive resin is irradiated with laser light to be exposed and developed to form a main surface on which irregularities are formed. A hologram, the master hologram is transferred onto a metal mold, and the metal mold is used to shape the resin.

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-123307

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-261064

As an optical sheet having light diffusibility or the like, a sheet having irregularities formed on its surface is known. For example, Patent Document 3 discloses a light diffusion sheet in which a large number of dot-like convex portions are formed on a surface of a substrate. In the optical sheet disclosed in Patent Document 3, ink is ejected onto a substrate by an inkjet method and fixed to form a dot-like convex portion.

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-157430

It is known that a concavo-convex pattern composed of fine wavy irregularities is formed on the surface, and the concavo-convex pattern forming sheet having the most frequent pitch of the concave-convex pattern at a wavelength equal to or less than the wavelength of visible light can be used as an optical element such as an antireflection body or a phase difference plate (refer to Patent Document 1).

The reason why the concave-convex pattern forming sheet can be used as an anti-reflection body is as follows: when the concave-convex pattern is not provided on the surface of the sheet, the fold at the interface between the sheet and the air is obtained. The sudden change in the rate of incidence produces a reflection. However, when a wavy concave-convex pattern is provided on the surface of the sheet, that is, at the interface between the sheet and the air, the refractive index value is between the refractive index of the air and the refractive index of the concave-convex pattern forming sheet in the portion of the concave-convex pattern. The value (hereinafter referred to as an intermediate refractive index), and the intermediate refractive index continuously changes in the depth direction of the concave-convex pattern. Specifically, the deeper the position, the closer to the refractive index of the uneven pattern forming sheet. Since the intermediate refractive index changes continuously as described above, the sharp change in the refractive index at the interface as described above is not caused, and the reflection of light can be suppressed. Further, when the distance between the concave-convex patterns is equal to or less than the wavelength of visible light, it is difficult to cause coloring due to interference of visible light, that is, visible light, in the concave-convex pattern portion.

Moreover, the reason why the uneven pattern forming sheet can be used as the phase difference plate is that the air having the refractive indices different from each other is alternately arranged in the concave-convex pattern, and as a result, the optical anisotropy is exhibited to the light. Further, when the distance between the concave-convex patterns is the same as the wavelength of visible light or below the wavelength of visible light, the phenomenon of displaying the same phase difference in a wide visible light wavelength region appears.

As a specific example of the uneven pattern forming sheet, for example, Non-Patent Document 2 proposes a sheet in which a metal layer is formed by vapor-depositing a surface of a piece of heated polydimethyl siloxane to be cooled, and then cooled. Thereby, the sheet composed of polydimethyl siloxane is shrunk to form a wavy concave-convex pattern on the surface of the metal layer.

Further, Patent Document 4 proposes a sheet in which a base layer and a metal layer are sequentially formed on the surface of a heat-shrinkable synthetic resin film, and then the heat-shrinkable synthetic resin film is heat-shrinked to form on the surface of the metal layer. Wavy embossed pattern.

Patent Document 5 proposes a sheet in which a layer composed of a material which is volume-contracted by exposure processing is formed, and the layer is subjected to exposure treatment to form irregularities on the surface.

However, none of the uneven pattern forming sheets disclosed in Patent Documents 4 and 5 and Non-Patent Document 2 shows excellent performance as an optical element. Specifically, when used as an antireflection body, the reflectance cannot be sufficiently lowered, and when used as a phase difference plate, it cannot be made. The phase difference is sufficiently large and cannot produce the same phase difference over a wide range of wavelengths.

Further, as a method of producing a concave-convex pattern forming sheet, a visible light photolithography method using a pattern mask is known. However, this method cannot produce a concavo-convex pattern forming sheet which can be used as an optical element and has a distance between wavelengths below the wavelength of light. Therefore, it is necessary to apply an ultraviolet laser interference method or an electron ray lithography method which can perform finer processing. In these methods, the photoresist layer formed on the substrate is exposed and developed by ultraviolet laser interference light or electron ray to form a photoresist pattern layer, and the photoresist pattern layer is used as a mask, and dry etching is used. A concave and convex shape is formed. However, when the ultraviolet laser interference method or the electron beam lithography method is applied, there is a problem that it is difficult to perform processing in a wide area of more than 10 cm, and thus it is not suitable for mass production.

Further, in Patent Document 6, a method is proposed in which a particle layer is placed on a substrate, and the particle layer is used as an etching mask to dry-etch the surface of the substrate. However, in this case, there is also a problem that it is difficult to perform processing in a wide area of more than 30 cm, and thus it is not suitable for mass production.

[Patent Document 4] Japanese Patent Laid-Open Publication No. SHO 63-301988

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2003-187503

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2005-279807

[Non-Patent Document 1] Kikuda Kyuo and Iwata Tatsuh, "Optics", Japan Optical Society, Vol. 27, No. 1, 1998, p. 12-17

[Non-Patent Document 2] Ned. Ned Bowden waits for Nature, No. 393, 1998, p.146

The light diffusion system disclosed in Patent Documents 1 and 2 has sufficient light diffusibility. However, there is a problem in the method of processing energy beam irradiation disclosed in Patent Document 1, and the method of exposing and developing a photosensitive resin film by laser using the laser disclosed in Patent Document 2. More complicated. Further, it cannot be said that the diffusion of the light diffusing bodies of Patent Documents 1 and 2 is sufficient.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a concave-convex pattern forming sheet which can be used as a light diffusing body and which can be easily manufactured. Moreover, an object of the present invention is to provide a method for producing a concave-convex pattern forming sheet which can easily produce a concave-convex pattern forming sheet used as a light diffusing body. Further, an object of the present invention is to provide a light diffuser excellent in diffusion anisotropy. Further, an object of the present invention is to provide an engineering sheet for manufacturing a light-diffusing body and a method for producing a light-diffusing body, which can be manufactured in a simple and large-scale manner, and which has a maximum pitch and a pitch between the concave-convex pattern-forming sheet and A light diffuser having a concave-convex pattern having the same average depth.

When it is desired to control the diffusion and reflection of light by the concavities and convexities, if the distance between the concavo-convex portions is about the wavelength of light, coloring problems due to interference may occur, and if the interval exceeds several tens of μm, there is a possibility that Since it is recognized as a bright line or the like, it is required to set the interval between the uneven portions to 20 μm or less. However, in the optical sheet disclosed in Patent Document 3, when the distance between the uneven portions is several tens of micrometers to several hundreds of micrometers, the interval can be stably formed. However, when the distance between the uneven portions is 20 μm or less, it is difficult to obtain the space. The interval between needs.

Further, in the optical sheet, optical characteristics such as light diffusibility are not uniform, and optical characteristics are not uniform, and may be high or low at a specific position. For example, in the light guide plate used in the backlight unit of the liquid crystal display, in order to prevent the image of the linear light source disposed on the side end surface thereof from being reflected on the surface of the light guide plate, it is sometimes necessary to increase the light exit side near the linear light source. The light diffusibility of the surface. Further, when a direct type backlight unit including a plurality of linear light sources or point light sources is used in a liquid crystal display, light diffusing property may be required as the linear light source or the point light source is placed directly above the linear light source.

In order to adjust the optical characteristics in which the unevenness is formed on the surface to make the optical characteristics uneven, it is considered that the distance between the uneven portions varies depending on the position. However, in the optical sheet disclosed in Patent Document 3, the uneven portions are spaced apart from each other. After setting it to 20 μm or less, it is difficult to make The interval changes. Thus, the optical sheet disclosed in Patent Document 3 is difficult to make the optical characteristics uneven or uneven at a specific position.

Therefore, an object of the present invention is to provide an optical sheet which is excellent in target optical characteristics (light diffusibility, etc.) and which can easily make optical characteristics uneven. Moreover, an object of the present invention is to provide a light-diffusing sheet which is excellent in target light diffusibility and which is easy to make light diffusibility uneven.

In the diffused light guide disclosed in Patent Documents 1 and 2, since the anisotropy of light diffusion is insufficient, the backlight unit including the diffused light guides cannot sufficiently diffuse the light from the light source. Therefore, the brightness of the light emitted from the diffused light guide differs depending on the location, resulting in unevenness in the image brightness of the liquid crystal display device.

It is an object of the present invention to provide a diffused light guide and a backlight unit that can sufficiently diffuse light from a light source.

An object of the present invention is to provide a concavo-convex pattern forming sheet which exhibits excellent performance when used as an optical element such as an antireflection body or a phase difference plate. Moreover, an object of the present invention is to provide a method for producing a concave-convex pattern forming sheet which can easily and widely produce a large number of large and large-area patterns. Further, an object of the present invention is to provide an antireflection body having a low reflectance and a phase difference plate which generates the same phase difference over a wide wavelength region. Further, an object of the present invention is to provide an optical element for producing an optical element, which is capable of easily and in large quantities producing an optical element having a concave-convex pattern having the same pitch width and average depth as that of the uneven pattern forming sheet.

The invention includes the following aspects:

[1] A concave-convex pattern forming sheet comprising a resin substrate and a resin hard layer provided on one surface of the substrate, and a bump along one direction is formed on a surface of the hard layer The pattern, the difference between the glass transition temperature Tg ₂ of the resin constituting the hard layer and the glass transition temperature Tg ₁ of the resin constituting the substrate (Tg ₂ -Tg ₁ ) is 10° C. or more, and the most frequent pitch of the concave-convex pattern is more than 1 μm and 20 μm. Hereinafter, the average depth of the bottom of the concave-convex pattern is 10% or more when the above-described maximum frequency spacing is 100%.

[2] A method for producing a concave-convex pattern forming sheet, comprising the step of providing a resin hard layer having a smooth surface and a thickness of more than 0.05 μm and 5.0 μm or less on one surface of a resin substrate; And forming the laminated sheet; and deforming at least the hard layer of the laminated sheet by folding; and the hard layer is formed by a resin having a glass transition temperature higher than 10° C. of the resin constituting the substrate.

[3] The method for producing a concave-convex pattern forming sheet according to [2], wherein a uniaxial direction heat shrinkable film is used as a resin substrate, and in the step of deforming the hard layer in a folded manner, the laminated sheet is subjected to a step of deforming the hard layer in a folded manner. Heating to shrink the heat shrinkable film in the uniaxial direction.

[4] A light diffusing body comprising the uneven pattern forming sheet of [1], wherein the base material and the hard layer of the uneven pattern forming sheet are transparent.

[5] A concave-convex pattern forming sheet comprising a resin base material and a resin hard layer provided on one surface of the base material, and a concave-convex pattern along one direction is formed on a surface of the hard layer The hard layer is made of a metal or a metal compound, and the most frequent pitch of the concave-convex pattern is more than 1 μm and 20 μm or less, and the average depth of the bottom of the concave-convex pattern is 10% or more when the above-mentioned maximum frequency pitch is 100%.

[6] The uneven pattern forming sheet of [5], wherein the hard layer is composed of metal.

[7] The uneven pattern forming sheet according to [5], wherein the metal is selected from the group consisting of gold, aluminum, silver, carbon, copper, bismuth, indium, magnesium, bismuth, palladium, lead, platinum, rhodium, tin, titanium, vanadium, At least one metal of the group consisting of zinc and strontium.

[8] A concave-convex pattern-forming sheet comprising a step of providing a metal or a metal compound having a smooth surface and having a thickness of more than 0.01 μm and a thickness of 0.2 μm or less on one surface of a resin substrate. a layer to form a laminated sheet; and deforming at least the hard layer of the laminated sheet by folding; and the hard layer is composed of a metal or a metal compound.

[9] The method for producing a concave-convex pattern forming sheet according to [8], wherein uniaxial heating is used The shrinkable film is a resin substrate, and in the step of deforming the hard layer in a folded manner, the laminated sheet is heated to shrink the heat shrinkable film in the uniaxial direction.

[10] An engineering sheet precursor for producing a light diffuser, comprising the concave-convex pattern forming sheet of [1], [5] or [8], which is formed on the surface and formed with the concave-convex pattern. The mold of the light diffuser having the same pitch and the same depth and the same average depth is used.

[11] A method for producing a light-diffusing body, comprising: coating an unhardened curable resin on a surface on which a concave-convex pattern is formed on an original sheet for producing a light-diffusing body of [10]; The curable resin is cured, and then the cured coating film is peeled off from the original sheet of the engineering sheet.

[12] A method of producing a light-diffusing body, comprising: bringing a sheet-shaped thermoplastic resin into contact with a surface on which a concave-convex pattern is formed on an original sheet for producing a light-diffusing body of [10]; The thermoplastic resin is pressed against the original sheet of the engineering sheet, heated in this state to soften it, and then cooled, and the cooled sheet-shaped thermoplastic resin is peeled off from the original sheet of the engineering sheet.

[13] A method for producing a light-diffusing body, comprising the step of: laminating a concave-convex pattern-transferring material on a surface on which a concave-convex pattern is formed on an original sheet for producing a light-diffusing body of [10]; The original pattern is obtained by peeling off the uneven pattern transfer material laminated on the uneven pattern to produce a secondary engineering molded product; and the surface of the secondary engineering molded article is in contact with the concave-convex pattern of the original sheet of the engineering sheet The uncured curable resin is applied; and after the curable resin is cured, the cured coating film is peeled off from the secondary engineering molded article.

[14] A method for producing a light-diffusing body, comprising the steps of: laminating a concave-convex pattern-transferring material on a surface on which a concave-convex pattern is formed on an original sheet for producing a light-diffusing body according to [10]; The sheet original plate is peeled off from the concave-convex pattern transfer material laminated on the concave-convex pattern to produce a secondary engineering molded product; and the sheet-shaped thermoplastic resin is brought into contact with the secondary engineering molded article and the above-mentioned engineering sheet original Concave-convex pattern contact one side The sheet-shaped thermoplastic resin is pressed against the molded article for secondary engineering, and heated in this state to be softened, and then cooled; and the cooled product is peeled off from the molded article for secondary engineering. A sheet of thermoplastic resin.

[15] An optical sheet characterized in that a concave-convex region having irregularities is dispersedly disposed on one surface or both surfaces of a flat surface.

[16] The optical sheet of [15], wherein the uneven regions are unevenly arranged.

[17] A light diffusing sheet comprising the optical sheet of [15].

[18] The light-diffusing sheet according to [17], wherein the most frequent pitch A of the unevenness in the uneven region exceeds 1 μm and is 20 μm or less, and the ratio (B/A) of the average depth B of the unevenness to the most frequent pitch A is 0.1. ~3.0.

[19] The light-diffusing sheet of [18], wherein the uneven portion is dispersed in a dot shape.

[20] A diffusing light guide comprising a transparent resin layer in which a meandering corrugated pattern is formed on one surface, and a pitch of a concave-convex pattern is more than 1.0 μm and 20 μm or less. The ratio of the average depth B to the most frequent spacing A (B/A) is 0.1 to 3.0.

[21] A backlight unit comprising: the diffusing light guide of [20]; and a reflecting plate disposed opposite to a surface of the diffusing light guide opposite to a surface on which the uneven pattern is formed; And a light source disposed between the diffusion light guide and the reflector.

[22] A backlight unit comprising: the diffusing light guide of [20]; and a reflecting plate disposed to face a surface of the diffusing light guide opposite to a surface on which the uneven pattern is formed; And a light source adjacent to either side of the diffused light guide.

[23] A concave-convex pattern forming sheet comprising: a resin base material; and a resin hard layer provided on at least a part of an outer surface of the base material, wherein the hard layer has a corrugated concave-convex pattern to constitute a hard material The difference between the glass transition temperature Tg ₂ of the resin of the layer and the glass transition temperature Tg ₁ of the resin constituting the substrate (Tg ₂ -Tg ₁ ) is 10° C. or more, and the pitch of the concave-convex pattern is 1 μm or less, and the bottom of the concave-convex pattern is The average depth is 10% or more when the above-described maximum frequency spacing is set to 100%.

[24] A method for producing a concave-convex pattern forming sheet, comprising: providing a resin-made hard layer having a smooth surface on at least a part of an outer surface of a resin substrate to form a laminated sheet; At least the hard layer of the laminated sheet is serpentinely deformed; and the hard layer is composed of a resin having a glass transition temperature higher than that of the resin constituting the substrate by 10 ° C or more.

[25] An antireflection body comprising the concavo-convex pattern forming sheet of [23].

[26] A phase difference plate comprising the concavo-convex pattern forming sheet of [23].

[27] An engineering sheet for producing an optical element, comprising the feature of the concavo-convex pattern forming sheet of [23], and the optical material for producing a concavo-convex pattern having the same frequency-to-frequency spacing and average depth as the concavo-convex pattern forming sheet. Use the mold of the component.

The uneven pattern forming sheet of the present invention can be used as a light diffuser and can be easily produced.

According to the method for producing a concave-convex pattern forming sheet of the present invention, the concave-convex pattern forming sheet used as the light diffusing body can be easily produced.

The light diffuser of the present invention is excellent in the anisotropy of diffusion.

According to the method for producing a light-diffusing body and the method for producing a light-diffusing body of the present invention, a light-diffusing body in which a concave-convex pattern having the same maximum pitch and average depth as that of the uneven pattern-forming sheet can be easily and largely produced.

The optical sheet of the present invention is excellent in the target optical characteristics, and can make the optical characteristics easy to be uneven.

The light-diffusing sheet of the present invention is excellent in target light diffusibility, and is easy to be uneven in light diffusibility.

According to the diffusing light guide and the backlight unit of the present invention, light from the light source can be sufficiently anisotropically diffused.

The uneven pattern forming sheet of the present invention can be preferably used as an optical element such as an antireflection body or a phase difference plate. Moreover, the uneven pattern forming sheet of the present invention can also be preferably used as an engineering sheet for producing an optical element, and the engineering sheet for producing an optical element is used as a mold for producing an optical element having a corrugated concave-convex pattern.

In the method for producing a concave-convex pattern-forming sheet of the present invention, the fine uneven pattern can be easily formed on a large surface. Therefore, the uneven pattern-forming sheet which can be preferably used for an optical element or the like can be easily and widely produced.

The antireflection system of the present invention has low reflectance and excellent performance.

The phase difference plate of the present invention can produce the same phase difference over a wide wavelength region and has excellent performance.

By using the engineering sheet for producing an optical element of the present invention, an optical element having a concave-convex pattern having the same pitch and average depth as the groove pattern forming sheet can be easily and in a large amount.

10‧‧‧ concave pattern forming sheet

10a‧‧‧Layered film

11‧‧‧Substrate (transparent resin layer)

11a‧‧‧heat shrinkable film

12‧‧‧ Hard layer

12a‧‧‧ concave pattern

12b‧‧‧ bottom

13‧‧‧Smooth layer made of smooth resin (smooth hard surface)

210a, 210b, 210c, 210d‧‧‧ optical sheets

211‧‧‧flat one side

212, 215, 216, 217‧‧ ‧ concave and convex areas

213‧‧‧heat shrinkable film

214‧‧‧ convex parts for forming concave and convex areas

100, 200‧‧‧ backlight unit

310‧‧‧Diffuse Light Guide

315‧‧‧ surface

316‧‧‧ back

320‧‧‧reflector

330‧‧‧Light source

340‧‧‧Diffuser film

350‧‧‧ Picture

360‧‧‧Brightness rising film

Fig. 1 is an enlarged perspective view showing a part of an embodiment of a concave-convex pattern forming sheet of the present invention in an enlarged manner.

2 is a cross-sectional view showing the concavo-convex pattern forming sheet of FIG. 1 cut in a direction orthogonal to the direction in which the concavo-convex pattern is formed.

Fig. 3 is a gradation conversion image of an image obtained by photographing the surface of the concave-convex pattern by a surface optical microscope.

Fig. 4 is an image obtained by performing Fourier transform on the image of Fig. 3.

Figure 5 is a graph depicting the brightness over the distance from the center of the circle in the image of Figure 4.

Figure 6 is a graph depicting the brightness on the auxiliary line L3 in the image of Figure 4.

Fig. 7 is a cross-sectional view showing a laminated sheet according to an embodiment of the method for producing a concave-convex pattern forming sheet of the present invention.

Fig. 8 is an explanatory view showing an example of a method of producing a light diffuser having the uneven pattern forming sheet of the present invention.

Fig. 9 is a gradation conversion image of an image obtained by photographing the surface of the concave-convex pattern in Comparative Example 4 by a surface optical microscope.

Fig. 10 is an image obtained by performing Fourier transform on the image of Fig. 9.

Figure 11 is a graph depicting the brightness over the distance from the center of the circle in the image of Figure 10.

Figure 12 is a graph depicting the brightness on the auxiliary line L ₅ in the image of Figure 10.

Fig. 13 is a perspective view showing a first embodiment of the optical sheet of the present invention.

Fig. 14 is a cross-sectional view showing a printing sheet used in the production of the optical sheet shown in Fig. 13.

Figure 15 is a transmission electron micrograph of the surface of the printed sheet.

Figure 16 is a transmission electron micrograph of the surface of the optical sheet.

Fig. 17 is a perspective view showing a second embodiment of the optical sheet of the present invention.

Fig. 18 is a perspective view showing a third embodiment of the optical sheet of the present invention.

Fig. 19 is a perspective view showing a fourth embodiment of the optical sheet of the present invention.

Fig. 20 is a cross-sectional view showing another embodiment of the diffused light guide of the present invention.

Figure 21 is a cross-sectional view showing a first embodiment of a backlight unit of the present invention.

Figure 22 is a cross-sectional view showing a second embodiment of the backlight unit of the present invention.

Fig. 23 is an enlarged perspective view showing an enlarged view of an embodiment of the concave-convex pattern forming sheet of the present invention.

Fig. 24 is a gradation conversion image of an image obtained by photographing a surface of a concave-convex pattern which is not along a specific direction by an atomic force microscope.

Fig. 25 is an image obtained by performing Fourier transform on the image of Fig. 24.

Figure 26 is a graph depicting the brightness over the distance from the center of the circle in the image of Figure 25.

Concave-convex pattern forming sheet (concave pattern forming sheet-1)

Hereinafter, an embodiment of the uneven pattern forming sheet of the present invention will be described.

Fig. 1 and Fig. 2 show a concave-convex pattern forming sheet of this embodiment. The uneven pattern forming sheet 10 of the present embodiment includes a base material 11 and a hard layer 12 provided on one surface of the base material 11, and the hard layer 12 has a concave-convex pattern 12a.

The concavo-convex pattern 12a on the concavo-convex pattern forming sheet 10 has corrugated irregularities along substantially one direction, and the corrugated irregularities are meandering. Further, the tip end of the convex portion of the uneven pattern 12a of the present embodiment has a curvature.

Glass transition temperature of the resin constituting the hard layer 12 (hereinafter referred to as the second resin) with a Tg ₂ is the glass transition temperature of the resin constituting the base material 11 (hereinafter referred to as the first resin) of _a difference between the Tg (Tg ₂ -Tg ₁ ) is 10 ° C or more, preferably 20 ° C or more, more preferably 30 ° C or more. Since the difference between (Tg ₂ - Tg ₁ ) is 10 ° C or more, it can be easily processed at a temperature between Tg ₂ and Tg ₁ . If the temperature between Tg ₂ and Tg ₁ is taken as the processing temperature, the Young's modulus of the substrate 11 can be processed under the condition that the Young's modulus of the hard layer 12 is higher, and the result can be applied to the hard layer 12. It is easy to form the uneven pattern 12a.

Further, from the viewpoint of economy, the necessity of using a resin having a Tg _{2 of} more than 400 ° C is not required, and a resin having a Tg _{1 of} less than -150 ° C is not present, so (Tg ₂ - Tg ₁ ) is preferably 550 ° C or less. More preferably, it is below 200 °C.

The difference between the Young's modulus of the substrate 11 and the hard layer 12 in the processing temperature at the time of manufacturing the uneven pattern forming sheet 10 is preferably 0.01 to 300 GPa, more preferably from the viewpoint that the uneven pattern 12a can be easily formed. 0.1~10GPa.

The processing temperature as used herein means, for example, the heating temperature at the time of heat shrinkage in the production method of the uneven pattern forming sheet described below. Further, the Young's modulus is a value measured in accordance with JIS K 7113-1995.

The glass transition temperature Tg _{1 of the} first resin is preferably -150 to 300 ° C, more preferably -120 to 200 ° C. The reason for this is that there is no resin having a glass transition temperature Tg _{1 of} less than -150 ° C. When the glass transition temperature Tg ₁ of the first resin is 300 ° C or less, it can be easily heated to the processing for producing the uneven pattern forming sheet 10 . Temperature (temperature between Tg ₂ and Tg ₁ ).

The Young's modulus of the first resin in the processing temperature at the time of producing the uneven pattern forming sheet 10 is preferably 0.01 to 100 MPa, more preferably 0.1 to 10 MPa. When the Young's modulus of the first resin is 0.01 MPa or more, the hardness of the first resin 11 can be used. When the Young resin modulus of the first resin is 100 MPa or less, the hardness of the hard layer 12 can be simultaneously changed. The softness of the deformation.

Examples of the first resin include polyesters such as polyethylene terephthalate; polyolefins such as polyethylene and polypropylene; and polystyrene resins such as styrene-butadiene block copolymer; and polyvinyl chloride. Polyoxymethylene resin such as polyvinylidene chloride or polydimethyl siloxane; fluororesin, ABS resin, polyamine, acrylic resin, polycarbonate, polycycloolefin and the like.

The glass transition temperature Tg _{2 of} the second resin is preferably from 40 to 400 ° C, more preferably from 80 to 250 ° C. When the glass transition temperature Tg ₂ of the second resin is 40° C. or higher, the processing temperature at the time of producing the uneven pattern forming sheet 10 can be useful at room temperature or above, and economically, There is a lack of the use of a resin having a glass transition temperature Tg ₂ exceeding 400 ° C as the second resin.

The Young's modulus of the second resin in the processing temperature at the time of producing the uneven pattern forming sheet 10 is preferably from 0.01 to 300 GPa, more preferably from 0.1 to 10 GPa. The reason for this is that when the Young's modulus of the second resin is 0.01 GPa or more, a hardness more than the Young's modulus in the processing temperature of the first resin can be obtained, and the hardness is after the uneven pattern 12a is formed. It is possible to maintain sufficient hardness of the uneven pattern, and from the viewpoint of economy, it is not necessary to use a resin having a Young's modulus of more than 300 GPa as the second resin.

The above is the type of the first resin, and as the second resin, for example, polyvinyl alcohol can be used. Polystyrene, acrylic resin, styrene-acrylic acid copolymer, styrene-acrylonitrile copolymer, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate , polycarbonate, polyether oxime, fluororesin, etc. Among these, a fluorine resin is particularly preferable in terms of having an antifouling function.

The thickness of the substrate 11 is preferably from 0.3 to 500 μm. When the thickness of the base material 11 is 0.3 μm or more, the uneven pattern forming sheet 10 is less likely to be broken, and when the thickness of the base material 11 is 500 μm or less, the uneven pattern forming sheet 10 can be easily reduced in thickness.

Further, in order to support the substrate 11, a resin support having a thickness of 5 to 500 μm may be provided. Further, when the substrate 11 is used as a light diffuser, a film containing fine bubbles may be attached to the substrate 11 in order to further improve light diffusibility.

When the uneven pattern forming sheet 10 is used as a light diffusing body, in order to further enhance the light diffusing effect, the substrate 11 may be made of an inorganic compound in a range that does not cause a large damage to optical characteristics such as light transmittance. A light diffusing agent or an organic light diffusing agent composed of an organic compound.

Examples of the inorganic light diffusing agent include cerium oxide, white carbon, talc, magnesium oxide, zinc oxide, titanium oxide, calcium carbonate, aluminum hydroxide, barium sulfate, glass, and mica.

Examples of the organic light diffusing agent include styrene polymer particles, acrylic polymer particles, and siloxane polymer particles. These light diffusing agents may be used singly or in combination of two or more.

The content of the light diffusing agent is preferably 10 parts by mass or less based on 100 parts by mass of the first resin, from the viewpoint of being less likely to impair the light transmittance.

Further, when the uneven pattern forming sheet 10 is used as a light diffusing body, in order to further improve the diffusion effect, the substrate 11 may contain fine bubbles in a range that does not greatly impair the optical characteristics such as light transmittance. The fine bubbles absorb less light and it is difficult to lower the light transmittance.

As a method of forming fine bubbles, a method of mixing a foaming agent into the substrate 11 can be applied. (methods disclosed in Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. The method disclosed in Japanese Laid-Open Patent Publication No. 2004-2812, and the like. Further, in order to achieve more uniform surface irradiation, the method of forming the fine bubbles is preferably a method of uniformly foaming a specific position (for example, the method disclosed in Japanese Laid-Open Patent Publication No. 2006-124499) .

Further, the above light diffusing agent may be used in combination with fine foaming.

The thickness of the hard layer 12 is preferably more than 0.05 μm and 5 μm or less, more preferably 0.1 to 2 μm. When the thickness of the hard layer exceeds 0.05 μm and is 5 μm or less, the uneven pattern forming sheet can be easily produced as follows.

Further, in order to improve adhesion and form a finer structure, an undercoat layer may be formed between the substrate 11 and the hard layer 12.

The most frequent pitch A of the uneven pattern 12a of the uneven pattern forming sheet 10 is more than 1 μm and is 20 μm or less, preferably more than 1 μm and not more than 10 μm. When the most frequent pitch A is less than 1 μm, light is transmitted, and if the most frequent pitch A exceeds 20 μm, the light diffusibility is lowered.

The average depth B of the bottom portion 12b of the uneven pattern 12a is 10% or more (i.e., an aspect ratio of 0.1 or more) when the most frequent pitch A is 100%, and preferably 30% or more (that is, an aspect ratio of 0.3 or more). . When the average depth B is less than 10% of the case where the most frequent pitch A is 100%, it is difficult to obtain a light-diffusing body having high light diffusibility even when the concave-convex pattern forming sheet 10 is used as an original for producing a light-diffusing body.

Further, from the viewpoint that the uneven pattern 12a can be easily formed, the average depth B is preferably 300% or less when the most frequent pitch A is 100% (that is, the aspect ratio is 3.0 or less), and more preferably 200. % or less (that is, an aspect ratio of 2.0 or less).

Here, the bottom portion 12b refers to a minimum value of the concave portion of the concave-convex pattern 12a, and the average depth B refers to a cross-section (see FIG. 2) obtained by cutting the concave-convex pattern forming sheet 10 in the longitudinal direction, and is formed from the entire concave-convex pattern. , to the bottom surface direction of the sheet 10 parallel to the reference line L ₁ until the top of each protrusion length _{B 1, B 2, B 3} ... the average value (B _AV) from the reference line L ₁ and the concave portion of each of The difference (b _AV -B _AV ) between the averages (b _AV ) of the lengths b ₁ , b ₂ , and b ₃ .

The top of the convex portion and the bottom of the concave portion are adjacent to the surface of the hard layer 12 opposite to the side of the substrate 11.

As a method of measuring the average depth B, a method of measuring the depth of each bottom portion in the image of the cross section of the concave-convex pattern captured by the atomic force microscope and measuring the average value of the bottom portions can be employed.

In order to obtain a light diffuser having a high anisotropy of light diffusion, it is preferable that the uneven pattern 12a is meandered to some extent, and the adjacent convex portions are not uniform with each other in the direction along the concave-convex pattern 12a. Here, the unevenness of the alignment of the concavo-convex pattern 12a is referred to as an alignment degree. The greater the degree of alignment, the more uneven the alignment. This degree of alignment was determined by the following method.

First, the surface above the concave-convex pattern is photographed by a surface optical microscope, and the image is converted into a grayscale document (for example, a tiff format or the like). In the image of the grayscale document (refer to FIG. 3), the lower the whiteness, the deeper the bottom of the concave portion (the higher the whiteness, the higher the top of the convex portion). Then, Fourier transform is performed on the image of the grayscale document. The Fourier transformed image is shown in FIG. The white portion extending from the center of the image of Fig. 4 to the sides includes information on the distance between the concave and convex patterns 12a and the orientation.

Next, the auxiliary line L ₂ is drawn in the horizontal direction from the center of the image of Fig. 4, and the brightness on the auxiliary line is drawn (refer to Fig. 5). In the depiction of Fig. 5, the horizontal axis represents the reciprocal of the pitch, the vertical axis represents the frequency, and the frequency is the maximum value X. The reciprocal 1/X represents the most frequent pitch of the concavo-convex pattern 12a.

Next, in Fig. 4, the auxiliary line L _{3 is} orthogonal to the auxiliary line L ₂ at the portion of the value X, and the luminance on the auxiliary line L ₃ is drawn (see Fig. 6). In order to compare with various concavo-convex structures, the horizontal axis of Fig. 6 is a value obtained by dividing the X value. The horizontal axis of Fig. 6 indicates an index (orientation) indicating the degree of inclination with respect to the direction in which the unevenness is formed (the vertical direction in Fig. 3), and the vertical axis indicates the frequency. The half value width W ₁ of the peak in the depiction of Fig. 6 (the width of the peak at a height of one half of the maximum value) indicates the degree of alignment of the concave and convex pattern. The larger the half value width W ₁ , the more random the pitch is.

The above alignment is preferably from 0.3 to 1.0. When the degree of alignment is 0.3 to 1.0, the unevenness between the uneven patterns 12a is large. Therefore, the uneven pattern forming sheet and the light diffusing body obtained by using the concave-convex pattern forming sheet as the original sheet of the engineering sheet have higher light diffusibility. . When the degree of alignment exceeds 1.0, the direction of the concavo-convex pattern becomes random to some extent, and thus the light diffusibility becomes high, but the anisotropy becomes low.

In order to adjust the degree of alignment to 0.3 to 1.0, the target of the compressive stress necessary for the production of the uneven pattern forming sheet can be appropriately selected.

The uneven pattern forming sheet of the present invention having a difference between the glass transition temperature Tg ₂ of the second resin constituting the hard layer 12 and the glass transition temperature Tg ₁ of the first resin constituting the substrate 11 (Tg ₂ -Tg ₁ ) of 10 ° C or more 10. Since it can be obtained by the following manufacturing method of the uneven pattern forming sheet, it can be easily manufactured.

Further, as a result of investigation by the inventors, it has been found that when both the substrate 11 and the hard layer 12 are transparent, the most frequent pitch A of the uneven pattern 12a is more than 1 μm and 20 μm or less, and the average depth B of the bottom portion 12b of the uneven pattern 12a is When the above-mentioned maximum frequency spacing A is 10% or more, that is, the concave-convex pattern forming sheet 10 of the present invention has sufficient light diffusibility, it can be used as a light diffusing body.

Further, the uneven pattern forming sheet of the present invention is not limited to the above embodiment. For example, the tip end of the convex portion of the concave-convex pattern of the concave-convex pattern forming sheet of the present invention may be a pointed top. However, in terms of further improving the anisotropy of diffusion, the convex portion of the concave-convex pattern is preferably a shape having a curvature at the tip end.

(concave pattern forming sheet-2)

Further, as a result of investigation by the inventors, it has been found that the most frequent pitch A of the uneven pattern 12a is 1 μm or less, particularly 0.04 μm or less, and the average depth B of the bottom portion 12b of the uneven pattern 12a is set to 100. 10% or more of %, especially 100% or more, borrowed This can serve as an excellent performance as an optical component. Specifically, when the concave-convex pattern forming sheet 10 is used as an antireflection body, the reflectance can be lowered, and when the concave-convex pattern forming sheet 10 is used as a phase difference plate, the same can be generated over a wide wavelength region. Phase difference.

This is because when the pitch A of the concave-convex pattern 12a is short and 1 μm or less, the average depth B is deep, and is 10% or more when the most frequent pitch A is 100%. That is, the minimum frequency spacing A is short, the same as the wavelength of visible light or below the wavelength of visible light, so that visible light is less likely to be diffracted or scattered by the unevenness. Further, since the average depth B is deep, the portion in which the intermediate refractive index continuously changes becomes longer in the thickness direction, so that the effect of suppressing light reflection can be remarkably exhibited. Further, since the most frequent pitch A is short and the average depth B is deep, the portion in which the air having different refractive indices and the concave-convex pattern forming sheet are alternately arranged becomes longer in the thickness direction, and the portion exhibiting optical anisotropy becomes longer. Therefore, a phase difference can be generated. Further, the phase difference generated by the uneven pattern 12a is substantially the same over a wide wavelength region.

At this time, the hard layer 12 has a relatively low refractive index with respect to the substrate 11, but is excellent in antireflection characteristics.

Further, the thickness of the hard layer 12 is preferably from 1 to 100 nm. When the thickness of the hard layer 12 is 1 nm or more, the hard layer 12 is less likely to cause defects, and when the thickness of the hard layer 12 is 100 nm or less, the hard layer 12 can sufficiently ensure light transmittance.

Further, the thickness of the hard layer 12 is more preferably 50 nm or less, and particularly preferably 20 nm or less. When the thickness of the hard layer 12 is 50 nm or less, the uneven pattern forming sheet can be easily produced as follows.

Further, in order to improve adhesion and form a finer structure, an undercoat layer may be formed between the substrate 11 and the hard layer 12.

Further, a resin layer may be provided on the hard layer 12.

The most frequent pitch A of the uneven pattern 12a of the uneven pattern forming sheet 10 is 1 μm or less, preferably 0.4 μm or less. Moreover, from the viewpoint that the uneven pattern 12a can be easily formed, the most The frequency spacing A is preferably 0.05 μm or more.

It is preferable that the pitches A ₁ , A ₂ , and A _{3 of the} uneven pattern 12a are within ±60% of the most frequent pitch A, and more preferably within ±30%. When the pitch is within ±60% of the most frequent pitch A, the pitch is uniform and the performance as an optical element can be exhibited.

Further, after satisfying the most frequent pitch A of 1 μm or less, each of the pitches A ₁ , A ₂ , and A ₃ ... may be continuously changed.

It is preferable that each of the depths B ₁ , B ₂ , B ₃ ... of the concavo-convex pattern 12a is within ±60% of the average depth B, and more preferably within ±30%. When each depth is within ±60% of the average depth B, the depth is uniform and the performance as an optical element can be exhibited.

Further, when the average depth B is satisfied to be 10% or more when the most frequent pitch A is 100%, each of the depths B ₁ , B ₂ , and B ₃ can be continuously changed.

As described below, the concave-convex pattern forming sheet 10 can be applied to an optical element such as an antireflection body or a retardation film and an engineering sheet for optical element production, and can be used for an ultra-water-repellent sheet or a super-hydrophilic sheet.

Further, the uneven pattern forming sheet is not limited to the above embodiment. For example, in the above embodiment, the hard layer has a periodic corrugated concavo-convex pattern along the width direction of the concavo-convex pattern forming sheet. However, in addition to the concavo-convex pattern, the hard layer may have a longitudinal direction along the concavo-convex pattern forming sheet. Periodic undulating pattern. Further, the hard layer may have a large number of undulating concave and convex patterns along a specific direction. In such a case, the pitch of the concave-convex pattern is 1 μm or less, and the average depth of the bottom of the concave-convex pattern is 10% or more when the above-mentioned worst-frequency pitch is 100%, thereby exhibiting excellent as an optical element. Performance.

From the viewpoint of the refractive index, the shape of the convex portion is preferably that the tip is a apex, but the tip may also have a curvature.

When the concave-convex pattern is not in a specific direction, the most frequent pitch can be obtained in the following manner. First, the upper surface of the concave-convex pattern is photographed by an atomic force microscope, and the image is converted into a grayscale document (for example, a tiff format or the like). In the image of the grayscale document (refer to FIG. 24), the lower the whiteness, the deeper the bottom of the concave portion (the higher the whiteness, the higher the top of the convex portion). Then, Fourier transform is performed on the image of the grayscale document. The Fourier transformed image is shown in FIG. In the Fourier-transformed image, the direction observed from the center of the white portion indicates the directionality of the gradation, and the reciprocal of the distance from the center to the white portion indicates the period of the gradation image. When the concave-convex pattern is not along a specific direction, it becomes an image in which a ring is displayed as shown in FIG. Next, the center of the circle in the image after the Fourier transform is directed to the linear auxiliary line L ₂ on the outer side, and the brightness (Y axis) on the distance from the center (X axis) is drawn (refer to FIG. 24). . Then, the value r of the X-axis indicating the maximum value in the depiction is read. The reciprocal of the r value (1/r) is the most frequent spacing.

(concave pattern forming sheet-3)

When the hard layer 12 is composed of a metal or a metal compound, the uneven pattern forming sheet 10 is easily obtained, and therefore the metal is preferable.

As the metal, the Young's modulus is not too high, and the uneven pattern 12a can be formed more easily, so it is preferably selected from the group consisting of gold, aluminum, silver, carbon, copper, bismuth, indium, magnesium, bismuth, palladium, lead, and platinum. At least one metal selected from the group consisting of bismuth, tin, titanium, vanadium, zinc, and antimony. The metal referred to herein also contains a semimetal.

The metal compound is preferably selected from the group consisting of titanium oxide, aluminum oxide, zinc oxide, magnesium oxide, tin oxide, copper oxide, indium oxide, cadmium oxide, lead oxide, antimony oxide, antimony fluoride, and the like. At least one metal compound of the group consisting of potassium fluoride, magnesium fluoride, zinc sulfide, and gallium arsenide.

Further, when the hard layer 12 is made of a metal, the surface of the layer may be oxidized by air to form an air oxide film. However, in the present invention, the layer of such a metal layer which is oxidized by air is also regarded as composed of metal. Layer.

The thickness of the hard layer 12 is preferably more than 0.01 μm and less than 0.2 μm, more preferably It is 0.02~0.1μm. When the thickness of the hard layer exceeds 0.01 μm and is 0.2 μm or less, the uneven pattern forming sheet can be easily produced as follows.

Further, in order to improve adhesion and form a finer structure, an undercoat layer may be formed between the substrate 11 and the hard layer 12.

The most frequent pitch A of the uneven pattern 12a of the uneven pattern forming sheet 10 is more than 1 μm and is 20 μm or less, preferably more than 1 μm and not more than 10 μm. When the most frequent pitch A is less than 1 μm and exceeds 20 μm, even if the uneven pattern forming sheet 10 is used as an original for producing a light diffusing body, it is difficult to obtain a light diffusing body having high light diffusibility.

2. Method for manufacturing concave-convex pattern forming sheet

Hereinafter, an embodiment of a method for producing a concave-convex pattern forming sheet of the present invention will be described.

As shown in Fig. 7, the method for producing a concave-convex pattern forming sheet according to the present embodiment includes a step of providing a hard layer 13 having a smooth surface (hereinafter referred to as a surface) on one surface of a heat shrinkable film 11a as a resin substrate. The hard layer 13) is smoothed to form a laminated sheet 10a (hereinafter referred to as a first step); and the heat shrinkable film 11a is heated and shrunk, and at least the surface smoothing layer 13 of the laminated sheet 10a is deformed by folding ( Hereinafter, it is called a 2nd step).

Here, the surface smooth hard layer 13 is a layer having a center line average roughness of 0.1 μm or less described in JIS B0601.

. Step 1 -1

In the first step, a method of forming the smooth surface layer 13 made of resin on one surface of the heat shrinkable film 11a to form the laminated sheet 10a is exemplified by spin coating on one surface of the heat shrinkable film 11a. A method of applying a solution or dispersion of the second resin by a machine or a bar coater to dry the solvent, and a method of laminating a surface smoothing hard layer 13 prepared in advance on one surface of the heat shrinkable film 11a.

As the heat shrinkable film 11a, for example, polyethylene terephthalate can be used. A shrink film, a polystyrene shrink film, a polyolefin shrink film, a polyvinyl chloride shrink film, or the like.

Among the shrink films, it is particularly preferred to shrink the shrink film of 50 to 70%. When a shrink film having a shrinkage of 50 to 70% is used, the deformation ratio can be 50% or more, and the most frequent pitch A of the uneven pattern 12a can be easily made more than 1 μm and 20 μm or less, and the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily obtained. The sheet 10 is formed in a concave-convex pattern of 10% or more when the most frequent pitch A is 100%. Further, the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily produced as the uneven pattern forming sheet 10 having 100% or more when the most frequent pitch A is 100%.

Here, the deformation rate means (length before deformation - length after deformation) / (length before deformation) × 100 (%), or means (length after deformation) / (length before deformation) × 100 ( %).

Further, the average depth B of the uneven pattern 12a can be made 300% when the most frequent pitch A is set to 100% by the following procedure.

On the heat-shrinkable film 11a, a primer resin layer having a glass transition temperature lower than that of the heat shrinkable film 11a is applied, and a laminate sheet provided with the surface hard smooth layer 13 is formed on the primer resin layer. The laminated sheet is heat-shrinked, whereby a concave-convex pattern forming sheet is formed.

The heat shrinkable film 11a after heat shrinkage is peeled off from the laminated sheet, and another heat shrinkable film is bonded to form a laminated sheet. The laminated sheet is heated and shrunk, whereby the average depth B can be made larger than the case where one sheet of the heat shrinkable film is heated and shrunk. After repeating this step a plurality of times, the average depth B of the uneven pattern 12a can be set to 300% when the most frequent pitch A is set to 100%.

In the present invention, the thickness of the surface smoothing hard layer 13 is more than 0.05 μm and 5.0 μm or less, preferably 0.1 to 1.0 μm. By setting the thickness of the surface smoothing hard layer 13 to the above range, the most frequent pitch A of the uneven pattern 12a can be reliably more than 1 μm and 20 μm or less.

However, if the thickness of the surface smooth hard layer 13 is 0.05 μm or less, the most frequent pitch A may be 1 μm or less, and if the thickness of the surface smooth hard layer 13 exceeds 5.0 μm, the most The frequency spacing A sometimes exceeds 20 μm.

In the present invention, the surface smoothing hard layer 13 is composed of a resin (second resin) having a glass transition temperature higher than that of the resin (first resin) constituting the heat shrinkable film by 10 ° C or more. Since the glass transition temperature of the first resin and the glass transition temperature of the second resin satisfy the above relationship, the most frequent pitch A of the uneven pattern 12a can be reliably more than 1 μm and 20 μm or less.

The thickness of the surface smooth hard layer 13 may also vary continuously. When the thickness of the surface smooth hard layer 13 is continuously changed, the distance and depth between the concavo-convex patterns 12a formed after compression are continuously changed.

In the manufacturing method, from the viewpoint that the uneven pattern 12a can be more easily formed, it is preferable to set the Young's modulus of the surface smooth hard layer 13 to 0.01 to 300 GPa, and more preferably to 0.1 to 10 GPa. .

When the laminated sheet 10a is deformed, it is preferred that the surface smoothing hard layer 13 is deformed at a deformation ratio of 5% or more. When the surface smooth hard layer 13 is deformed by a deformation ratio of 5% or more, the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily made 10% or more when the most frequent pitch A is 100%.

Further, it is more preferable to deform the surface smooth hard layer 13 by a deformation ratio of 50% or more. When the surface smooth hard layer 13 is deformed by a deformation ratio of 50% or more, the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily made 100% or more when the most frequent pitch A is 100%.

. Step 1 - 2

Further, when the hard layer 12 is made of a metal or a metal compound, as a method of forming the laminated sheet 10a, for example, a method of vapor-depositing a metal or a metal compound on one side of the heat shrinkable film 11a; and a heat shrinkable film may be mentioned. On one of the faces of 11a, a method of laminating a pre-made surface smoothing hard layer 13 or the like.

In the manufacturing method, from the viewpoint that the uneven pattern 12a can be more easily formed, Preferably, the Young's modulus of the surface smooth hard layer 13 is set to 0.1 to 500 GPa, and more preferably 1 to 150 GPa.

In order to set the Young's modulus of the surface smooth hard layer 13 to the above range, it is preferred that the surface smooth hard layer 13 is selected from the group consisting of gold, aluminum, silver, carbon, copper, bismuth, indium, magnesium, bismuth, palladium. And at least one metal selected from the group consisting of lead, platinum, rhodium, tin, titanium, vanadium, zinc, and antimony. Alternatively, it is preferred that the surface smoothing hard layer 13 is selected from the group consisting of titanium oxide, aluminum oxide, zinc oxide, magnesium oxide, tin oxide, copper oxide, indium oxide, cadmium oxide, lead oxide, antimony oxide, antimony fluoride, It is composed of at least one metal compound of a group consisting of calcium fluoride, magnesium fluoride, zinc sulfide, and gallium arsenide.

Here, the Young's modulus is a value measured by changing the temperature to 23 ° C according to "Test Method for High Temperature Young's Modulus of Metallic Materials" of JIS Z 2280-1993. The same is true when the hard layer is composed of a metal compound.

The thickness of the surface smooth hard layer 13 is more than 0.01 μm and is 0.2 μm or less, preferably 0.02 to 0.1 μm. By setting the thickness of the surface smoothing hard layer 13 to the above range, the most frequent pitch A of the uneven pattern 12a can be reliably more than 1 μm and 20 μm or less. However, when the thickness of the surface smooth hard layer 13 is less than 0.01 μm, the most frequent pitch A may be 1 μm or less, and when the thickness of the surface smooth hard layer 13 exceeds 0.2 μm, the most frequent pitch A may exceed 20 μm.

Further, the thickness of the surface smooth hard layer 13 may be continuously changed. When the thickness of the surface smooth hard layer 13 is continuously changed, the distance and depth between the concavo-convex patterns 12a formed after compression are continuously changed.

When the laminated sheet 10a is deformed, it is preferred that the surface smoothing hard layer 13 is deformed at a deformation ratio of 5% or more. When the surface smooth hard layer 13 is deformed by a deformation ratio of 5% or more, the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily made 10% or more when the most frequent pitch A is 100%.

Further, it is more preferable to make the surface smooth hard layer 13 change at a deformation rate of 50% or more. shape. When the surface smooth hard layer 13 is deformed by a deformation ratio of 50% or more, the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily made 100% or more when the most frequent pitch A is 100%.

. Step 2 -1

In the second step, the heat shrinkable film 11a is heat-shrinked, whereby the corrugated concave-convex pattern 12a is formed on the surface smooth hard layer 13 in the vertical direction with respect to the contraction direction, whereby the hard layer 12 is obtained.

The heating method for heating and shrinking the heat-shrinkable film 11a is, for example, a method of passing through hot air, steam or hot water, and the like, which is particularly preferable from the viewpoint of uniformly shrinking the heat-shrinkable film 11a. It is a method of passing in hot water.

The heating temperature at the time of thermally shrinking the heat shrinkable film 11a is preferably selected depending on the type of the heat shrinkable film to be used and the distance between the target uneven pattern 12a and the depth of the bottom portion 12b.

In the manufacturing method, if the thickness of the surface smooth hard layer 13 is thinner and the Young's modulus of the surface smooth hard layer 13 is lower, the smaller the frequency spacing A of the concave-convex pattern 12a is, the higher the deformation rate of the substrate is. , the deeper the average depth B is. Therefore, in order to set the concave-convex pattern 12a to the specific frequency spacing A and the average depth B, it is necessary to appropriately select the above conditions.

In the method for producing a concavo-convex pattern forming sheet, the glass transition temperature is higher than 10 ° C or higher in the second resin constituting the surface smooth hard layer 13 compared to the first resin constituting the heat shrinkable film 11 a. Therefore, when the temperature between the glass transition temperature of the first resin and the glass transition temperature of the second resin is higher, the Young's modulus of the surface smooth hard layer 13 is higher than that of the heat shrinkable film 11a. Further, since the thickness of the surface smoothing hard layer 13 is more than 0.05 μm and 5.0 μm or less, the surface is smooth and hard when processed at a temperature between the glass transition temperature of the first resin and the glass transition temperature of the second resin. The layer 13 is said to be thicker as it is said to be folded. Further, since the surface smooth hard layer 13 is laminated on the heat shrinkable film 11a, the stress caused by shrinkage of the heat shrinkable film 11a is integrated. Evenly on the body. Therefore, according to the present invention, the surface smoothing hard layer 13 is deformed by folding, and the uneven pattern forming sheet 10 excellent in the performance of the light diffusing body can be easily and widely produced.

According to this manufacturing method, the most frequent pitch A of the uneven pattern 12a can be easily more than 1 μm and 20 μm or less, and the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily made to be 100% when the most frequent pitch A is set to 100%. More than 10%.

Moreover, as a manufacturing method of the uneven pattern forming sheet, the following methods (1) to (4) can also be applied:

method 1)

On the entire surface of the substrate 11, a smooth surface hard layer 13 is provided to form the laminated sheet 10a, and the entire laminated sheet 10a is compressed in one direction along the surface.

When the glass transition temperature of the substrate 11 is lower than room temperature, the compression of the laminated sheet 10a is performed at room temperature, and when the glass transition temperature of the substrate 11 is above room temperature, the compression of the laminated sheet 10a is applied to the substrate 11 It is carried out at a temperature above the glass transition temperature and below the glass transition temperature of the surface smooth hard layer 13.

Method (2)

On the entire surface of the substrate 11, a smooth surface hard layer 13 is provided to form the laminated sheet 10a, the laminated sheet 10a is extended in one direction, and the direction orthogonal to the extending direction is contracted, and in the direction along one of the surfaces The surface smoothing hard layer 13 is compressed.

When the glass transition temperature of the substrate 11 is lower than room temperature, the extension of the laminated sheet 10a is performed at room temperature, and when the glass transition temperature of the substrate 11 is above room temperature, the extension of the laminated sheet 10a is applied to the substrate 11 It is carried out at a temperature above the glass transition temperature and below the glass transition temperature of the surface smooth hard layer 13.

Method (3)

On the substrate 11 formed of the uncured ionizing radiation curable resin, the hard surface layer 13 is smoothed to form the laminated sheet 10a, and the ionizing radiation is irradiated to make the substrate 11 hard. Thereby, it shrinks and compresses the surface smooth hard layer 13 laminated on the substrate 11 in at least one direction along the surface.

Method (4)

On the substrate 11 which swells and expands the solvent, the hard surface layer 13 is smoothed to form a laminated sheet 10a, and the solvent in the substrate 11 is dried and removed, thereby shrinking and at least one direction along the surface. The surface smooth hard layer 13 laminated on the substrate 11 is compressed.

In the method (1), as a method of forming the laminated sheet 10a, for example, a solution or dispersion of a resin is applied to one surface of the substrate 11 by a spin coater or a bar coater. A method of drying the solvent; a method of laminating a previously prepared surface smoothing hard layer 13 on one side of the substrate 11.

As a method of compressing the entire laminated sheet 10a in one direction along the surface, for example, a method of compressing the end portion of one end portion of the laminated sheet 10a and the opposite side thereof by a vise or the like is performed.

In the method (2), as a method of extending the laminated sheet 10a in one direction, for example, a method of stretching one end portion of the laminated sheet 10a and an end portion on the opposite side thereof to extend it may be mentioned.

In the method (3), examples of the ionizing radiation curable resin include an ultraviolet curable resin or an electron beam curable resin.

In the method (4), the solvent can be appropriately selected depending on the type of the first resin. The drying temperature of the solvent can be appropriately selected depending on the kind of the solvent.

For the surface smooth hard layer 13 in the methods (2) to (4), the same components as in the method (1) can be used, and the same thickness can be used. Further, in the method of forming the laminated sheet 10a, similarly to the method (1), a method of applying a solution or dispersion of a resin onto one surface of the substrate 11 and drying the solvent may be applied to one side of the substrate 11. A method of laminating a pre-made surface smoothing hard layer 13.

. Step 2-2

When the mode gap A of the uneven pattern 12a is 1 μm or less, in the method (1), the thickness of the surface smooth hard layer 13 is preferably 50 nm or less, more preferably 20 nm or less. When the thickness of the surface smooth hard layer 13 is 50 nm or less, the most frequent pitch A of the uneven pattern 12a can be reliably made 1 μm or less.

Further, the surface smooth hard layer 13 is preferably 1 nm or more from the viewpoint that the hard layer 12 after compression is less likely to cause defects.

In this case, the surface smoothing hard layer 13 is formed by a second resin having a glass transition temperature higher than the first resin by 10 ° C or more. When the surface smoothing hard layer 13 is composed of a second resin having a glass transition temperature higher than 10 ° C or higher than the first resin, the surface smoothing layer 13 can be waved in a state where the substrate 11 is deformed during compression. The shape is curved and the meandering is deformed, whereby the uneven pattern 12a can be easily formed.

In the method for producing a concave-convex pattern forming sheet described above, the second resin phase constituting the smooth surface of the hard layer 13 has a glass transition temperature higher than 10 ° C or higher than the first resin constituting the substrate 11 . When the temperature between the glass transition temperature of the first resin and the glass transition temperature of the second resin is higher, the Young's modulus of the surface smooth hard layer 13 is higher than that of the substrate 11. Therefore, when the temperature is between the glass transition temperature of the first resin and the glass transition temperature of the second resin, the surface smooth hard layer 13 is not so thick as it is folded. Further, since the surface smooth hard layer 13 is laminated on the substrate 11, the stress generated by compression or contraction is uniform as a whole. Therefore, according to the present invention, the surface smoothing hard layer 13 can be easily deformed to produce the uneven pattern forming sheet 10, and the uneven pattern forming sheet 10 excellent in performance can be easily produced and printed as an optical element.

Further, according to this manufacturing method, the most frequent pitch A of the uneven pattern 12a can be easily shortened, so that the average depth B can be made deeper. Specifically, the most frequent pitch A of the uneven pattern 12a can be easily made 1 μm or less, and the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily made 10% or more when the maximum pitch A is 100%.

Further, according to this manufacturing method, it is possible to easily make the pitches A ₁ , A ₂ , A ₃ ... and the respective depths B ₁ , B ₂ , B ₃ ... in the uneven pattern 12a uniform.

Step 2 - 3

When a metal or a metal compound is used as the surface smooth hard layer for production, in the second step, the heat shrinkable film 11a is thermally contracted, whereby the surface smoothing hard layer 13 is formed in a direction perpendicular to the shrinking direction. The corrugated concave-convex pattern 12a becomes the hard layer 12.

The heating method for heating and shrinking the heat-shrinkable film 11a is, for example, a method of passing through hot air, steam or hot water, and the like, which is particularly preferable from the viewpoint of uniformly shrinking the heat-shrinkable film 11a. It is a method of passing in hot water.

The heating temperature at the time of thermally shrinking the heat shrinkable film 11a is preferably selected depending on the type of the heat shrinkable film to be used and the distance between the target uneven pattern 12a and the depth of the bottom portion 12b.

In the manufacturing method, if the thickness of the surface smooth hard layer 13 is thinner and the Young's modulus of the surface smooth hard layer 13 is lower, the smaller the frequency spacing A of the concave-convex pattern 12a is, the higher the deformation rate of the substrate is. , the deeper the average depth B is. Therefore, in order to set the concave-convex pattern 12a to the specific frequency spacing A and the average depth B, it is necessary to appropriately select the above conditions.

In the manufacturing method of the uneven pattern forming sheet described above, the Young's modulus of the surface smooth hard layer 13 composed of a metal or a metal compound is much larger than the Young's modulus of the heat shrinkable film 11a, and therefore When the surface of the heat-shrinkable film 11a is harder and the hard layer 13 is thermally compressed, the surface smoothing hard layer 13 is not so thick as it is folded. Further, since the surface smooth hard layer 13 is laminated on the heat shrinkable film 11a, the stress generated by the shrinkage of the heat shrinkable film 11a is uniform as a whole. Therefore, according to the present invention, the surface smoothing hard layer 13 is deformed by folding, and the uneven pattern forming sheet 10 excellent in performance can be easily produced in a large area as a light diffusing body.

Moreover, according to the manufacturing method, the maximum frequency spacing A of the concave-convex pattern 12a can be easily exceeded. It is 1 μm or less and 20 μm or less, and the average depth B of the bottom portion 12b of the uneven pattern 12a can be easily made 10% or more when the most frequent pitch A is 100%.

However, as a method of producing a sheet for forming a concave-convex pattern, a hot nano-imprint method is known, and a concave-convex pattern of a mold for nanoimprinting is pressed against a sheet-shaped thermoplastic resin which is softened by heating and then cooled. And a photon imprint method in which an uncured ionizing radiation curable resin composition is coated on a concave-convex pattern of a nanoimprint mold, and then irradiated with ionizing radiation to be hardened.

In the hot nanoimprint method, a uniform pressure must be applied to the entire mold to press the mold having the concave-convex pattern on the thermoplastic resin, but in the method, if the area of the mold is large, it is applied to the mold. The pressure is easily uneven, and as a result, the transfer of the uneven pattern becomes uneven. Therefore, it cannot be said that it is suitable for the production of a large-area concavo-convex pattern forming sheet used in a display of a liquid crystal television or the like.

Further, in the photon imprint method, since the mold release property between the mold and the cured resin is insufficient, the transfer of the uneven pattern may be incomplete. Moreover, the more the number of times the mold is repeatedly used, the more significant this tendency is.

With respect to these nanoimprint methods, the method for producing the concavo-convex pattern forming sheet can omit the transfer of the concavo-convex pattern, so that the above problems in the nanoimprint method can be eliminated.

Furthermore, in the above embodiment, the hard layer is provided on the entire surface of the substrate, but a hard layer may be provided on one of the surfaces of the substrate, or a hard layer may be provided on both sides of the substrate, or A hard layer may be provided on one of the two sides of the substrate.

3. Light diffuser

The light diffuser of the present invention includes the uneven pattern forming sheet 10 having a most frequent pitch A of more than 1 μm and 20 μm or less.

In the light diffuser of the present invention, other layers may be provided on one surface or both surfaces of the uneven pattern forming sheet 10. For example, in the surface of the concave-convex pattern forming sheet 10 on which one side of the uneven pattern 12a is formed, in order to prevent contamination of the surface, a fluororesin or a polyoxygen tree may be provided. The lipid as a main component has an antifouling layer having a thickness of about 1 to 5 nm.

Further, a support made of a transparent resin or a glass may be provided on the surface of the light-diffusing body on the side of the base material 11 side.

Further, an adhesive layer may be formed on the surface of the substrate 11 side, or may contain a dye to have appropriate functionality.

The light diffusing body of the present invention having the above-described uneven pattern forming sheet 10 having a concave-convex pattern formed on its surface has sufficient light diffusibility.

4. Engineering sheet original for manufacturing light diffusing body and method for producing light diffusing body

The original sheet for producing a light-diffusing body of the present invention (hereinafter referred to as an original sheet) is provided with the uneven pattern forming sheet 10, and is used to transfer the uneven pattern 12a to another material by the method described below. A mold for producing a concave-convex pattern forming sheet in a large area and in a large amount, the concave-convex pattern forming sheet can be used as a light-diffusing body in which a concave-convex pattern having the same frequency-to-frequency pitch and average depth as the original sheet of the engineering sheet is formed on the surface.

On the original sheet of the engineering sheet, a resin or metal support for supporting the uneven pattern forming sheet 10 may be further provided.

Specific examples of the method for producing a light diffuser using the original sheet of the engineering sheet include, for example, the following methods (a) to (c):

Method (a)

The method includes the steps of: coating an uncured ionizing radiation curable resin on a surface on which a concave-convex pattern is formed on an original sheet of an engineering sheet; and irradiating the ionizing radiation to harden the curable resin, and then peeling off the original sheet from the engineering sheet Hardened coating film. Here, the ionizing radiation generally means ultraviolet rays or electron rays, and the present invention also includes visible light rays, X-rays, ion rays, and the like.

Method (b)

The method comprises the steps of: coating an unhardened liquid thermosetting resin on a surface of the original sheet on which the concave-convex pattern is formed; and heating to cause the liquid heat hardening The resin is hardened, and then the hardened coating film is peeled off from the original sheet of the engineering sheet.

Method (c)

The method comprises the steps of: contacting a sheet-shaped thermoplastic resin to a surface of the original sheet of the engineering sheet on which the concave-convex pattern is formed; pressing the sheet-shaped thermoplastic resin on the original sheet of the engineering sheet, and heating in the state of the sheet It is softened and then cooled; and the cooled sheet-like thermoplastic resin is peeled off from the original sheet.

Moreover, it is also possible to produce a molded article for secondary engineering using the original sheet of the engineering sheet, and to manufacture a light diffuser using the molded article for secondary engineering. Examples of the molded article for secondary engineering include secondary engineering sheets. In addition, as a molded article for secondary engineering, a plating roll is used in which the original sheet of the engineering sheet is rounded and attached to the inside of the cylinder, and the sheet is inserted into the inside of the cylinder to be plated, and then rounded. The roll was taken out of the cylinder, and the plating roll thus obtained was obtained.

Specific methods of using the molded article for secondary engineering include the following methods (d) to (f):

Method (d)

The method includes the steps of: performing metal plating such as nickel on a surface on which the concave-convex pattern is formed on the original sheet of the engineering sheet, and depositing a plating layer (material for concave-convex pattern transfer); and peeling the plating layer from the original sheet of the engineering sheet to a metal-made secondary engineering molded article is produced; and then, an unhardened ionizing radiation curable resin is applied to a surface of the second engineering molded article in contact with the concave-convex pattern; and the ionizing radiation is irradiated The curable resin is cured, and then the cured coating film is peeled off from the secondary engineering molded article.

Method (e)

The method comprises the steps of: laminating a plating layer (a material for concave-convex pattern transfer) on a surface on which a concave-convex pattern is formed on an original sheet of an engineering sheet; and peeling the plating layer from the original sheet of the engineering sheet to prepare a second metal for engineering a molded article; a non-hardened liquid thermosetting resin is applied to one surface of the molded article for secondary engineering in contact with the uneven pattern; and the resin is cured by heating, and then used for secondary engineering. Peeling hardened coating on the formed article membrane.

Method (f)

The method comprises the steps of: laminating a plating layer (a material for concave-convex pattern transfer) on a surface on which a concave-convex pattern is formed on an original sheet of an engineering sheet; and peeling the plating layer from the original sheet of the engineering sheet to prepare a second metal for engineering a molded article; a sheet-shaped thermoplastic resin is brought into contact with a surface of the secondary engineering molded article in contact with the concave-convex pattern; and the sheet-shaped thermoplastic resin is pressed against the secondary engineering molded article, and In this state, heating is performed to soften it, and then cooling is performed; and the cooled sheet-shaped thermoplastic resin is peeled off from the secondary engineering molded article.

Specific examples of the method (a) will be described below. As shown in FIG. 8, first, the unhardened liquid ionizing radiation curable resin 112c is applied onto the surface of the mesh-shaped engineering sheet master 110 on which the uneven pattern 112a is formed. Then, the engineering sheet precursor 110 coated with the curable resin is pressed by the roll 130, and the curable resin is filled in the inside of the uneven pattern 112a of the original sheet 110. Thereafter, the ionizing radiation is irradiated by the ionizing radiation irradiation device 140 to crosslink the curable resin. hardening. Then, the hardened ionizing radiation curable resin is peeled off from the original sheet 110, whereby the web-shaped light diffusing body 150 can be produced.

In the method (a), in order to impart releasability, before the application of the uncured ionizing radiation curable resin, a layer having a thickness of about 1 to 10 nm may be provided on the surface on which the concave-convex pattern is formed on the original sheet of the engineering sheet. A layer composed of a silicone resin, a fluororesin, or the like.

A coater for applying an uncured ionizing radiation curable resin to a surface on which a concave-convex pattern is formed on an original sheet of an engineering sheet includes a T-die coater, a roll coater, a bar coater, and the like.

Examples of the uncured ionizing radiation curable resin include one or more selected from the group consisting of epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, and polyester. Acrylate, polyether acrylate, ethylene / Prepolymers of acrylates, polyenes/acrylates, fluorenone acrylates, polybutadienes, polystyrene methyl methacrylates, etc., aliphatic acrylates, alicyclic acrylates, aromatic acrylates, A monomer such as a hydroxyl group acrylate, an allyl group-containing acrylate, a glycidyl group-containing acrylate, a carboxyl group-containing acrylate, or a halogen group-containing acrylate. The uncured ionizing radiation curable resin is preferably diluted with a solvent or the like.

Further, a fluororesin, a polyoxymethylene resin or the like may be added to the uncured ionizing radiation curable resin.

When the uncured ionizing radiation curable resin is cured by ultraviolet rays, it is preferred to add a photopolymerization initiator such as acetophenone or benzophenone to the uncured ionizing radiation curable resin. .

After coating the uncured liquid ionizing radiation-curable resin, a substrate made of resin, glass, or the like may be bonded and irradiated with ionizing radiation. The irradiation of the ionizing radiation may be performed by either the substrate or the original sheet having the ionizing radiation permeability.

The thickness of the ionized radiation curable resin sheet after hardening is preferably about 0.1 to 100 μm. When the thickness of the ionizing radiation-curable resin sheet after hardening is 0.1 μm or more, sufficient strength can be secured, and when it is 100 μm or more, sufficient flexibility can be ensured.

In the method shown in FIG. 8 above, the original piece of the engineering piece is a mesh shape, but may also be a single blade. When a single-blade work piece is used, a single-blade work piece can be used as a flat-plate mold marking method, and a single-blade work piece can be wound on a roll to be used as a roll-shaped embossing method for a cylindrical mold. Wait. Further, the original blade of the single blade may be disposed inside the mold of the injection molding machine.

However, in such a method of using a single-blade engineering sheet, in order to mass-produce a light-diffusing body, it is necessary to repeatedly perform the step of forming a concave-convex pattern. When the release property of the ionizing radiation curable resin and the original sheet of the engineering sheet is low, the uneven pattern is clogged after repeated times, and thus the transfer of the uneven pattern tends to be incomplete.

On the other hand, in the method shown in FIG. 8, since the original piece of the engineering piece is a mesh shape, it can be Since the uneven pattern is formed over a large area and continuously, even if the number of times of use of the uneven pattern forming sheet is small, a desired number of light diffusers can be produced in a short time.

In the methods (b) and (e), examples of the liquid thermosetting resin include uncured melamine resin, urethane resin, and epoxy resin.

Further, the hardening temperature in the method (b) is preferably lower than the glass transition temperature of the original sheet of the engineering sheet. If the hardening temperature is higher than the glass transition temperature of the original sheet of the engineering sheet, the concave-convex pattern of the original sheet of the engineering sheet may be deformed at the time of hardening.

In the methods (c) and (f), examples of the thermoplastic resin include an acrylic resin, a polyolefin, and a polyester.

The pressure at which the sheet-like thermoplastic resin is pressed against the secondary engineering molded article is preferably from 1 to 100 MPa. When the pressure at the time of pressing is 1 MPa or more, the uneven pattern can be transferred with high precision, and when the pressure at the time of pressing is 100 MPa or less, excessive pressurization can be prevented.

Further, the heating temperature of the thermoplastic resin in the method (c) is preferably lower than the glass transition temperature of the original sheet of the engineering sheet. The reason for this is that if the heating temperature is equal to or higher than the glass transition temperature of the original sheet of the engineering sheet, the uneven pattern of the original sheet of the engineering sheet may be deformed during heating.

The cooling temperature after heating is preferably smaller than the glass transition temperature of the thermoplastic resin from the viewpoint of accurately transferring the uneven pattern.

In the methods (a) to (c), the heating step may be omitted, and from the viewpoint of preventing deformation of the concave-convex pattern of the original sheet of the engineering sheet, the method (a) of ionizing radiation curable resin is preferably used.

In the methods (d) to (f), it is preferred that the thickness of the molded article for secondary engineering made of metal is about 50 to 500 μm. When the thickness of the molded article for secondary engineering made of metal is 50 μm or more, the molded article for secondary engineering has sufficient strength, and when the thickness is 500 μm or less, sufficient flexibility can be ensured.

In the methods (d) to (f), since a metal sheet having a small deformation due to heat is used as an engineering sheet, the ionizing radiation curable resin, the thermosetting resin, and the thermoplastic resin are used. Either one can be used as a material for a concave-convex pattern forming sheet.

When the uneven pattern forming sheet produced by the methods (a) to (f) is used as a light diffusing body, in order to further enhance the light diffusing effect, the uneven pattern forming sheet may contain a light diffusing agent composed of the above inorganic compound, and may be organic. An organic light diffusing agent or fine bubbles composed of a compound.

Further, in the methods (d) to (f), the concave-convex pattern of the original sheet of the engineering sheet is transferred onto a metal to obtain a molded article for secondary engineering, but may be transferred onto a resin to obtain a secondary engineering molding. Things. Examples of the resin that can be used at this time include polycarbonate, polyacetal, polyfluorene, and ionizing radiation curable resin used in the method (a). When the ionizing radiation-curable resin is used, the coating, hardening, and peeling of the ionizing radiation-curable resin are sequentially performed in the same manner as in the method (a), whereby a molded article for secondary engineering is obtained.

In the light diffuser obtained as described above, an adhesive layer may be provided on the surface opposite to the surface on which the uneven pattern is formed. Further, a concave-convex pattern may be further formed on the surface opposite to the surface on which the uneven pattern is formed.

Moreover, it is also possible to use it as a protective layer without peeling off the uneven pattern forming sheet used for the original sheet of the engineering sheet or the molded article for secondary engineering, and peeling off the protective layer immediately before using the light diffusing body.

In the light-diffusing body manufactured by the above-described production method, the same concave-convex pattern as that of the uneven pattern-forming sheet 10 is formed. Therefore, the alignment of the unevenness is uneven, and the diffusion is excellent in the anisotropy.

In the light diffusing body, other layers may be provided on one or both sides of the uneven pattern forming sheet. For example, in the surface on which the concave-convex pattern forming sheet is formed on one side of the uneven pattern, in order to prevent contamination of the surface, an anti-fouling layer having a thickness of about 1 to 5 nm containing a fluororesin or a polyoxynoxy resin as a main component may be provided. .

Moreover, a support made of a transparent resin or a glass may be provided on the surface of the light diffuser on the side where the concave-convex pattern is not formed.

5. Optical sheet 5-1. First embodiment

Hereinafter, a first embodiment of the optical sheet of the present invention will be described.

Fig. 13 shows an optical sheet of this embodiment. Further, in Fig. 13, for the sake of convenience of explanation, the uneven portion 212 is enlarged, and the arrangement thereof is displayed in a scattered manner.

The optical sheet 210a of the present embodiment is used as a light diffusing sheet in which the light source 330 is disposed at one end α of the longitudinal direction, and is attached to the flat one surface 11, and the outer shape is dispersed in a dot shape by the following pattern. The concave-convex region 212 of the shape, that is, the pattern gradually densified as the one end α from the longitudinal direction of the optical sheet 210a faces the other end β. In the present invention, the flatness means that the center line average roughness described in JIS B0601 is 0.1 μm or less. Further, the uneven region means that the center line average roughness described in JIS B0601 exceeds 0.1 μm, particularly 0.5 μm or more.

. Concave area

The uneven region 12 is a region having a concave-convex pattern. In the present embodiment, as shown in FIG. 1, a meandering corrugated pattern 12a is formed on the surface of the uneven portion 12.

In the optical sheet 210a of the present embodiment used for the light-diffusing sheet, it is preferable that the pitch A of the uneven pattern 12a exceeds 1 μm and is 20 μm or less, more preferably more than 1 μm and 10 μm or less. When the most frequent pitch A is less than 1 μm, the most frequent pitch A is equal to or less than the wavelength of visible light, so that visible light is not refracted by the concave-convex pattern 12a, but light is transmitted. If the maximum-frequency spacing A exceeds the upper limit, diffusion occurs. The anisotropy becomes lower, and thus the brightness tends to be uneven.

The ratio (B/A, hereinafter referred to as the aspect ratio) of the average depth B of the unevenness of the uneven pattern 12a to the most frequent pitch A of the uneven pattern 12a is preferably 0.1 to 3.0. If the aspect ratio is less than 0.1, the target optical characteristics may not be obtained. On the other hand, when the aspect ratio is more than 3.0, it tends to be difficult to form the uneven pattern 12a when the optical sheet 210a is produced.

Here, the average depth B refers to the average depth of the bottom portion 12b of the concave-convex pattern 12a. degree.

Further, the bottom portion 12b refers to the minimum point of the concave portion of the concave-convex pattern 12a, and the average depth B refers to the surface of the entire optical sheet 10a when the cross section obtained by cutting the uneven portion 12 in the short-diameter direction (see Fig. 2) is observed. The average value (B _AV ) of the lengths B ₁ , B ₂ , B ₃ ... from the reference line L ₁ parallel to the direction to the top of each convex portion, and the length b from the reference line L ₁ to the bottom of each concave portion The difference between the average value (b _AV ) of ₁ , b ₂ , b ₃ ... (b _AV -B _AV ).

As a method of measuring the average depth B, a method of measuring the depth of each of the bottom portions 12b in the image of the cross section of the concave-convex pattern 12a taken by the atomic force microscope, and determining the average value thereof may be employed.

As described in the present embodiment, the meandering of the uneven pattern 12a in one direction means that the degree of alignment of the uneven pattern obtained by the following method is 0.3 or more. The alignment degree is an index of uneven alignment of the concave-convex pattern, and the larger the value, the more uneven the alignment.

When the degree of alignment is less than 0.3, the unevenness of the alignment of the concavo-convex pattern 12a is small, and therefore the diffusibility of light is small.

Further, the degree of alignment is preferably 1.0 or less. When the degree of alignment exceeds 1.0, the direction of the uneven pattern 12a becomes random to some extent, and thus the light diffusibility becomes high, but the anisotropy tends to be low.

In order to achieve an alignment degree of 0.3 or more, for example, in the following production, the heat shrinkable film and the uneven portion forming convex portion can be appropriately selected.

Further, a method may be employed in which a transparent resin is molded by using a metal mold having a concave-convex pattern having an orientation of 0.3 or more on one surface.

The area ratio of the area of the uneven portion 212 to the area of one surface of the optical sheet 210a depends on the target light diffusibility, but is preferably 30 to 100%. When the area ratio of the uneven region 212 is 30% or more, sufficient light diffusibility can be exhibited.

. Optical sheet constituent material

The optical sheet 210a has a high transmittance from visible light (specifically, the full light of visible light) A transparent resin having a linear transmittance of 85% or more.

Moreover, in order to improve heat resistance and light resistance, an additive can be contained in the optical sheet 10a within the range which does not impair optical characteristics, such as a light transmittance. Examples of the additive include a light stabilizer, an ultraviolet absorber, an antioxidant, a lubricant, and a light diffusing agent. Among them, it is particularly preferable to add a light stabilizer in an amount of preferably 0.03 to 2.0 parts by mass based on 100 parts by mass of the transparent resin. When the amount of the light stabilizer added is 0.03 parts by mass or more, the effect of the addition can be sufficiently exhibited. However, when the amount of the light stabilizer added exceeds 2.0 parts by mass, the amount of the light stabilizer is excessive, and the unnecessary cost rises. tendency.

Further, in order to further enhance the light-diffusing effect, the optical sheet 210a may contain an inorganic light diffusing agent composed of an inorganic compound and organic light composed of an organic compound in a range that does not greatly impair optical characteristics such as light transmittance. Agent.

Examples of the inorganic light diffusing agent include cerium oxide, white carbon, talc, magnesium oxide, zinc oxide, titanium oxide, calcium carbonate, aluminum hydroxide, barium sulfate, calcium citrate, magnesium citrate, aluminum citrate, and citric acid. Sodium aluminide, zinc antimonate, glass, mica, and the like.

Examples of the organic light-diffusing agent include styrene-based polymer particles, acrylic polymer particles, siloxane-based polymer particles, and polyamid-based polymer particles. These light diffusing agents may be used singly or in combination of two or more.

Further, in order to obtain excellent light scattering characteristics, the light diffusing agents may be formed into a porous structure such as a petal shape or a spherical crystal.

The content of the light diffusing agent is preferably 10 parts by mass or less based on 100 parts by mass of the transparent resin, from the viewpoint of being difficult to impair the light transmittance.

Further, in order to further enhance the light diffusion effect, the optical sheet 210a may contain fine bubbles in a range that does not greatly impair optical characteristics such as light transmittance. The fine bubbles absorb less light and it is difficult to lower the light transmittance.

As a method of forming the fine bubbles, a method of mixing a foaming agent into the optical sheet 210a can be applied (for example, Japanese Patent Laid-Open No. Hei 5-212811, Japanese Patent Laid-Open No. Hei 6-- The method disclosed in the publication No. 107842), the method of foaming the acrylic foamed resin to contain fine bubbles (for example, the method disclosed in Japanese Laid-Open Patent Publication No. 2004-2812), and the like. Further, in order to achieve more uniform surface irradiation, the method of forming fine bubbles is preferably a method of uniformly foaming a specific position (for example, the method disclosed in Japanese Laid-Open Patent Publication No. 2006-124499).

Further, the above light diffusing agent may be used in combination with fine foaming.

. Optical sheet thickness

The thickness of the optical sheet 10a is preferably 0.02 to 3.0 mm, more preferably 0.05 to 2.5 mm, and particularly preferably 0.1 to 2.0 mm. If the thickness of the optical sheet 10a is less than 0.02 mm, the thickness thereof is less than the depth of the concave-convex pattern 12a. If the thickness is thicker than 3.0 mm, the optical sheet 10a may be difficult to handle because of its large mass.

The optical sheet 210a may also be composed of two or more resin layers. Even when the optical sheet 10a is composed of two or more layers, the thickness of the optical sheet 210a is preferably 0.02 to 3.0 mm.

. Instructions

The above optical sheet 210a is used as a light diffusion sheet. Specifically, the optical sheet 210a is used such that the light source 330 is adjacent to one end α of the optical sheet 210a. The light source 330 is disposed at one end α of the optical sheet 210a, whereby light can be propagated in the optical sheet 210a. Further, the light propagating in the optical sheet 210a is diffused in the uneven portion 212, whereby light can be emitted from the surface on which one side of the uneven portion 212 is formed. Further, since the uneven region 212 is disposed by being gradually densified from the one end α toward the other end β, the amount of light emitted can be increased toward the other end β. In general, the intensity of the light propagating in the optical sheet 210a becomes weaker as it goes away from the light source 330, but since the amount of light emitted increases toward the other end β, the light emitted from the optical sheet 210a can be made. The intensity is even.

When the optical sheet 210a is used, in order to improve the light use efficiency of the light source 330, it is preferable to provide a reflecting plate on the surface having no uneven portion 212.

In the optical sheet 210a of the first embodiment described above, the light diffusing property is exhibited by the uneven pattern 12a formed on the surface of the uneven region 212. In addition, the uneven region 212 is disposed in a pattern in which the other end β side of the longitudinal direction of the optical sheet 210a is dense, so that the light diffusibility becomes higher on the other end β side in the longitudinal direction. As described above, since the light diffusibility can be adjusted by the unevenness of the uneven regions 212, the optical sheet 210a can easily obtain the desired light diffusibility at a desired position.

. Production method

An example of a method of manufacturing the optical sheet 210a will be described below.

(first manufacturing method)

The first production method is a method of producing the optical sheet 210a using a heat shrinkable film.

In other words, the first manufacturing method has a method of manufacturing the concave-convex pattern forming sheet of the optical sheet 210a by the following manufacturing steps, and the manufacturing step refers to forming a concave-convex region of a resin having a smooth printing surface on one surface of the heat-shrinkable film. The convex portion is formed to form a printed sheet (hereinafter referred to as a first step); and the heat shrinkable film is heated and shrunk so that at least the concave-convex region forming convex portion of the printed sheet is deformed by folding (hereinafter referred to as second step).

. Step 1

In the first step, as shown in FIG. 14 and FIG. 15 , as a method of printing the uneven portion 14 on one surface of the heat shrinkable film 13 , for example, screen printing, gravure printing, lithography, or the like can be applied. And inkjet printing.

As the heat shrinkable film 13, for example, a polyethylene terephthalate type shrink film, a polystyrene type shrink film, a polyolefin type shrink film, a polyvinyl chloride type shrink film, or the like can be used.

Among the heat shrinkable films 213, a shrink film of 50 to 70% shrinkage is particularly preferable. When a shrink film having a shrinkage of 50 to 70% is used, the deformation ratio can be 50% or more, and the groove width A of the uneven pattern 12a can be easily manufactured to be more than 1 μm and 20 μm or less. The uneven pattern is formed into a sheet having a ratio of 0.1 or more.

Here, the deformation rate means (length before deformation - length after deformation) / (length before deformation) × 100 (%), or means (length after deformation) / (length before deformation) × 100 ( %).

The uneven portion forming convex portion 214 is a resin having a glass transition temperature higher than a resin (first resin) constituting the heat shrinkable film 213 by 10 ° C or more from the viewpoint of the formation of the meandering corrugated concave-convex pattern 12a. (Second resin).

As the second resin, for example, polyvinyl alcohol, polystyrene, acrylic resin, styrene-acrylic copolymer, styrene-acrylonitrile copolymer, polyethylene terephthalate, polybutylene terephthalate can be used. Glycol ester, polyethylene naphthalate, polycarbonate, polyether oxime, fluororesin, and the like.

The surface of the uneven portion forming convex portion 214 is referred to as a center line average roughness of JIS B0601 of 0.1 μm or less from the viewpoint of easily forming the desired uneven pattern 12a.

Further, the thickness of the uneven portion forming convex portion 214 is preferably 0.05 to 5.0 μm, more preferably 0.1 to 1.0 μm. When the thickness of the uneven portion forming convex portion 214 is in the above range, the most frequent pitch A of the uneven pattern 12a can be reliably more than 1 μm and 20 μm or less. However, when the thickness of the uneven portion forming convex portion 214 is less than 0.05 μm, the most frequent pitch A may be 1 μm or less, and when the thickness of the uneven portion forming convex portion 214 exceeds 5.0 μm, the worst-frequency pitch A may be More than 20μm.

Further, the thickness of the uneven portion forming convex portion 214 may not be constant, and for example, it may be continuously thickened in one direction or continuously thinned in one direction.

Moreover, the Young's modulus of the uneven portion forming convex portion 214 is preferably from 0.01 to 300 GPa, more preferably from 0.1 to 10 GPa, from the viewpoint that the meandering corrugated concave-convex pattern 12a can be more easily formed.

. Step 2

In the second step, the heat shrinkable film 213 is heat-shrinked, thereby being used in the uneven region. On the convex portion 214 for forming, a corrugated concave-convex pattern 12a is formed in a direction perpendicular to the contraction direction to obtain a concave-convex region 212 (see FIG. 16).

The heating method for heating and shrinking the heat shrinkable film 213 is exemplified by a method of passing through hot air, steam, or hot water, and the like, which is particularly preferable from the viewpoint of uniformly shrinking the heat shrinkable film 213. It is a method of passing in hot water.

In the manufacturing method, the thinner the thickness of the uneven portion forming convex portion 214 and the lower the Young's modulus of the uneven portion forming convex portion 214, the smaller the minimum pitch A of the uneven pattern 12a, and the heat shrinkage property. The higher the deformation rate of the film, the deeper the average depth B.

In the first manufacturing method, in the case of the temperature between the glass transition temperature of the first resin and the glass transition temperature of the second resin, the Young's modulus of the uneven portion forming convex portion 214 is higher than that of the heat shrinkable film 213. Young's modulus. Therefore, when the temperature is processed between the glass transition temperature of the first resin and the glass transition temperature of the second resin, the uneven portion forming convex portion 214 is not so thick as to be folded. Further, since the uneven portion forming convex portion 214 is laminated on the heat shrinkable film 213, the stress generated by the shrinkage of the heat shrinkable film 213 is uniform as a whole. Therefore, the heat shrinkable film 213 is shrunk, so that the uneven portion forming convex portion 214 is deformed in a folded manner, whereby the uneven portion 212 can be formed. Therefore, according to the above manufacturing method, the uneven pattern forming sheet which becomes the optical sheet 210a can be obtained.

The uneven pattern forming sheet obtained in the above manner can be directly used as the optical sheet 210a. In this case, the optical sheet 210a is formed by heating the shrinkable film 213 and the uneven portion forming convex portion 214.

(Second manufacturing method)

The second manufacturing method is a method of manufacturing the optical sheet 210a by using the uneven pattern forming sheet obtained by the first manufacturing method as the original sheet of the engineering sheet.

The original piece of the engineering piece may be a single blade shape, or may be a continuous sheet shape or a mesh shape.

Specific examples of the second production method include the following methods (a) to (c):

Method (a)

The method includes the steps of: applying an uncured ionizing radiation curable resin on a surface on which the concave-convex pattern is formed on the original sheet of the engineering sheet; and irradiating the ionizing radiation to harden the curable resin, and then peeling off from the original sheet of the engineering sheet Hardened coating film. Here, the ionizing radiation generally means ultraviolet rays or electron rays, and the present invention also includes visible light rays, X-rays, ion rays, and the like.

Method (b)

The method includes the steps of: coating an uncured liquid thermosetting resin on a surface on which a concave-convex pattern is formed on an original sheet of an engineering sheet; and heating the liquid thermosetting resin to be cured, and then on the original sheet of the engineering sheet The hardened coating film is peeled off.

Method (c)

The method comprises the steps of: contacting a sheet-shaped thermoplastic resin to a surface of the original sheet of the engineering sheet on which the concave-convex pattern is formed; pressing the sheet-shaped thermoplastic resin on the original sheet of the engineering sheet, and heating in the state of the sheet It is softened and then cooled; and the cooled sheet-like thermoplastic resin is peeled off from the original sheet.

Moreover, the molded article for secondary engineering can be produced using the original sheet of the engineering sheet, and the optical sheet 10a can be produced using the molded article for secondary engineering. Specific methods of using the molded article for secondary engineering include the following methods (d) to (f):

Method (d)

The method comprises the steps of: performing metal plating on nickel on a surface on which the concave-convex pattern is formed on the original sheet of the engineering sheet, and laminating the plating layer; peeling the plating layer from the original sheet of the engineering sheet to prepare a metal for secondary engineering a molded article; then, applying an uncured ionizing radiation curable resin to a surface of the second engineering molded article in contact with the concave-convex pattern; and irradiating the ionizing radiation to cure the curable resin, and thereafter The hardened coating film is peeled off from the molded article for secondary engineering.

Method (e)

The method comprises the steps of: laminating a plating layer on a surface of the original sheet on which the concave-convex pattern is formed; peeling the plating layer from the original sheet of the engineering sheet to prepare a metal-made secondary engineering forming product; Applying an unhardened liquid thermosetting resin to the surface on one side of the molded article in contact with the concave-convex pattern; and curing the resin by heating, and then peeling off the hardened coating from the secondary engineering molded article membrane.

Method (f)

The method comprises the steps of: laminating a plating layer on a surface of the original sheet on which the concave-convex pattern is formed; peeling the plating layer from the original sheet of the engineering sheet to prepare a metal-made secondary engineering forming product; and making the sheet-like heat The plastic resin is in contact with the surface on the side in contact with the concave-convex pattern of the secondary engineering molded article; the sheet-shaped thermoplastic resin is pressed against the secondary engineering molded article, and heated in this state. It is softened and then cooled; and the cooled sheet-like thermoplastic resin is peeled off from the secondary engineering molded article.

Specific examples of the method (a) will be described below. As shown in FIG. 8, first, the unhardened liquid ionizing radiation curable resin 112c is applied onto the surface of the mesh-shaped engineering sheet master 110 on which the uneven pattern 112a is formed. Then, the engineering sheet precursor 110 coated with the curable resin is pressed by the roll 130, and the curable resin is filled in the inside of the uneven pattern 112a of the original sheet 110. Thereafter, the ionizing radiation is irradiated by the ionizing radiation irradiation device 140 to crosslink the curable resin. hardening. Then, the hardened ionizing radiation curable resin is peeled off from the original sheet 110, whereby the web-shaped optical sheet 210a can be produced.

In the method (a), in order to impart releasability, before the application of the uncured ionizing radiation curable resin, a layer having a thickness of about 1 to 10 nm may be provided on the surface on which the concave-convex pattern is formed on the original sheet of the engineering sheet. A layer composed of a silicone resin, a fluororesin, or the like.

A coater for applying an uncured ionizing radiation curable resin to a surface on which a concave-convex pattern is formed on an original sheet of an engineering sheet includes a T-die coater, a roll coater, and a bar coating. Cloth machine, etc.

Examples of the uncured ionizing radiation curable resin include one or more selected from the group consisting of epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, and polyester. Prepolymers of acrylate, polyether acrylate, ethylene/acrylate, polyene/acrylate, fluorenone acrylate, polybutadiene, polystyrene methyl methacrylate, etc., aliphatic acrylate, alicyclic Monomers such as acrylates, aromatic acrylates, hydroxy-containing acrylates, allyl-containing acrylates, glycidyl-containing acrylates, carboxyl-containing acrylates, and halogen-containing acrylates. The uncured ionizing radiation curable resin is preferably diluted with a solvent or the like.

Further, a fluororesin, a polyoxymethylene resin or the like may be added to the uncured ionizing radiation curable resin.

When the uncured ionizing radiation curable resin is cured by ultraviolet rays, it is preferred to add a photopolymerization initiator such as acetophenone or benzophenone to the uncured ionizing radiation curable resin. .

The method (d) is specifically the same as the above method (a) except that the original sheet of the method (a) is changed to a molded article for secondary engineering produced using the original sheet of the sheet.

In the methods (b) and (e), examples of the liquid thermosetting resin include uncured melamine resin, urethane resin, and epoxy resin.

Further, the hardening temperature in the method (b) is preferably lower than the glass transition temperature of the original sheet of the engineering sheet. If the hardening temperature is higher than the glass transition temperature of the original sheet of the engineering sheet, the concave-convex pattern of the original sheet of the engineering sheet may be deformed at the time of hardening.

Examples of the transparent thermoplastic resin in the methods (c) and (f) include styrene-methyl methacrylate copolymer (MS), polymethyl methacrylate (PMMA), and polystyrene (PS). Cycloolefin polymer (COP), polycarbonate (PC), polypropylene (PP), polyethylene terephthalate (PET), PET-G, polyether oxime (PES), polyvinyl chloride (PVC) , resin such as polyethylene terephthalate (PET). Among these, from the viewpoint of forming processing, It is preferably MS, PMMA, PS, COP, and PC. From the viewpoint of hygroscopicity and cost, it is more preferable that the styrene content in MS is 30 to 90% by mass.

These transparent thermoplastic resins can be configured in a single layer or a multilayer structure. For example, a transparent thermoplastic resin or the like having a three-layer structure in which PMMA layers are provided on both sides of the PS layer can be used.

Further, a resin having a high refractive index provided on the surface of the above transparent thermoplastic resin may be used. Examples of the resin having a high refractive index include a fluorene-based epoxy compound, a fluorene-based acrylate compound, an anthracene-based polyester (OKP), polymethylphenylnonane (PMPS), and polydiphenyl decane (PDPS).

In the method (c), the pressure at which the sheet-like thermoplastic resin is pressed against the original sheet of the engineering sheet and the pressure at which the sheet-shaped thermoplastic resin is pressed against the molded article for secondary engineering in the method (f) are good. It is 1~100MPa. When the pressure at the time of pressing is 1 MPa or more, the uneven pattern can be transferred with high precision, and when the pressure at the time of pressing is 100 MPa or less, excessive pressurization can be prevented.

Further, the heating temperature of the thermoplastic resin in the method (c) is preferably lower than the glass transition temperature of the original sheet of the engineering sheet. The reason for this is that if the heating temperature is equal to or higher than the glass transition temperature of the original sheet of the engineering sheet, the uneven pattern of the original sheet of the engineering sheet may be deformed during heating.

From the viewpoint of allowing the uneven pattern to be transferred with high precision, the cooling temperature after heating is preferably smaller than the glass transition temperature of the thermoplastic resin.

(third manufacturing method)

In the third manufacturing method, a method of manufacturing the optical sheet 210a by forming a concave-convex pattern forming sheet of a concave-convex region made of a metal or a metal compound on the surface of a resin layer is used.

The concave-convex pattern forming sheet provided with the uneven portion made of a metal or a metal compound can be obtained by replacing the convex portion for forming a concave-convex region made of a resin with a convex portion for forming a concave-convex region made of a metal or a metal compound. In the same manner as the first manufacturing method, the convex portion for forming the uneven portion is formed by vapor deposition instead of printing. Got it.

In other words, the method for producing a concave-convex pattern forming sheet provided with a concave-convex region made of a metal or a metal compound includes the steps of vacuum-depositing a convex portion for forming a concave-convex region made of a metal or a metal compound on one surface of the heat-shrinkable film. To form a vapor-deposited sheet; and to heat-shrink the heat-shrinkable film so that at least the uneven portion forming convex portion of the vapor-deposited sheet is deformed by folding.

In the method for producing a concave-convex pattern forming sheet, the Young's modulus of the convex portion for forming a concave-convex region made of a metal or a metal compound is much larger than the Young's modulus of the heat-shrinkable film, so that the uneven portion is formed during thermal compression. The convex portion is not so thick as it is folded. As a result, a concave-convex pattern forming sheet provided with uneven portions can be obtained. Further, the uneven portion of the uneven pattern forming sheet is the same as the uneven portion of the optical sheet 210a.

The metal constituting the convex portion for forming an uneven portion in the third manufacturing method is preferably selected from the group consisting of gold, aluminum, silver, carbon, copper, bismuth, and indium from the viewpoint that the uneven pattern 12a can be more easily formed. At least one metal selected from the group consisting of magnesium, strontium, palladium, lead, platinum, rhodium, tin, titanium, vanadium, zinc, and antimony. The metal referred to herein also contains a semimetal.

The metal compound is preferably selected from the group consisting of titanium oxide, aluminum oxide, zinc oxide, magnesium oxide, tin oxide, copper oxide, indium oxide, cadmium oxide, lead oxide, antimony oxide, antimony fluoride, and the like. At least one metal compound of the group consisting of potassium fluoride, magnesium fluoride, zinc sulfide, and gallium arsenide.

The surface of the uneven portion forming convex portion means that the center line average roughness described in JIS B0601 is 0.1 μm or less from the viewpoint of easily forming the desired uneven pattern 12a.

The thickness of the convex portion for forming the uneven portion made of a metal or a metal compound is preferably 0.01 to 0.2 μm, more preferably 0.05 to 0.1 μm. When the thickness of the uneven portion forming convex portion is within the above range, the most frequent pitch A of the uneven pattern 12a can be reliably more than 1 μm and 20 μm or less. However, when the thickness of the uneven portion forming convex portion is less than 0.01 μm, the most frequent pitch A may be 1 μm or less, and if it exceeds 0.2 μm, the worst pitch A may be Will exceed 20μm.

Further, the thickness of the uneven portion forming convex portion may not be constant, and for example, it may be continuously thickened in one direction or continuously thinned in one direction.

When a convex portion for forming a concave-convex region made of a metal or a metal compound is deposited on the heat shrinkable film, the same pattern as the convex portion for forming the uneven region to be formed is placed on the surface of the heat shrinkable film. The mask of the opening.

The heating method for heating and shrinking the heat shrinkable film may be, for example, a method of passing through hot air, steam or hot water, and the like, in particular, from the viewpoint of uniformly shrinking the heat shrinkable film, The method of passing through hot water.

Specifically, in the method (a) to (f) in the second production method, a concave-convex pattern forming sheet provided with a concave-convex region made of a metal or a metal compound is used as the third method. The original sheet of the engineering sheet is formed into a sheet instead of the uneven pattern provided with the uneven portion of the second resin.

(fourth manufacturing method)

The fourth manufacturing method is a method of manufacturing an optical sheet 10a from an unformed transparent thermoplastic resin using a molding apparatus, the molding apparatus including a metal mold, a heating and cooling mechanism for heating and cooling the metal mold, and the metal mold Pressurized pressurizing mechanism. The transparent thermoplastic resin used in the fourth production method is the same as the transparent thermoplastic resin used in the second production method.

Specifically, in the fourth manufacturing method, first, a pellet or a powder of a transparent thermoplastic resin is filled in a metal mold, the metal mold is heated by a heating and cooling mechanism, and the metal mold is pressed by a pressurizing mechanism. Pressurize. Next, the inside of the mold is cooled by a heating and cooling mechanism, and the pressurization is stopped to obtain an optical sheet 210a.

In the manufacturing method, a wavy concave-convex pattern in which a meandering is formed on a surface in contact with the exit surface of the optical sheet 210a is used as the metal mold. For example, as a metal mold, a concave-convex pattern forming sheet in the first to third manufacturing methods can be mounted on one surface, A wavy concave-convex pattern of a meandering is formed on one surface by laser irradiation or the like.

As a molding method in the fourth production method, for example, a press molding method or an injection molding method can be applied.

The optical sheet 210a obtained by the above-described first to fourth manufacturing methods can be used as it is, or can be bonded to a reinforcing substrate made of a transparent resin or glass via an adhesive to form a final optical sheet.

In the method of manufacturing the optical sheet 210a described above, it is easy to arrange the uneven region 212 on the flat surface, and to form a pattern in which the other end β side in the longitudinal direction of the optical sheet 210a is dense. Therefore, the optical sheet 210a having high light diffusibility on the other side of the β side in the longitudinal direction can be easily obtained.

5-2. Second embodiment

Next, a second embodiment of the optical sheet of the present invention will be described.

Fig. 17 shows an optical sheet of this embodiment. Further, in Fig. 17, for the sake of convenience of explanation, the uneven portion 215 is enlarged, and the arrangement thereof is displayed in a scattered manner.

The optical sheet 210b of the present embodiment is used as a light diffusing sheet in which the light source 330 is disposed at one end α of the longitudinal direction, and is attached to the flat one surface 211, and is disposed along the optical sheet 210b by the following pattern. The strip-shaped uneven region 215 formed in the width direction, that is, a pattern which gradually becomes denser as one end α from the longitudinal direction of the optical sheet 210b faces the other end β.

When the uneven portion 215 is disposed as described above, the light diffusibility can be improved on the other end β side of the optical sheet 210b in the same manner as the optical sheet 210a of the first embodiment.

The uneven pattern of the uneven portion 215 of the second embodiment is the same as the uneven pattern 12a of the uneven portion 212 of the first embodiment. The area ratio of the area of the uneven portion 215 to the area of one surface of the optical sheet 210b is also the same as the area ratio in the first embodiment.

The optical sheet 210b of the second embodiment can be produced by the same manufacturing method as the method of manufacturing the optical sheet 210a of the first embodiment.

5-3. Third embodiment

Next, a third embodiment of the optical sheet of the present invention will be described.

Fig. 18 shows an optical sheet of this embodiment. Further, in Fig. 18, for the sake of convenience of explanation, the uneven portion 216 is enlarged, and the arrangement thereof is displayed in a scattered manner.

The optical sheet 210c of the present embodiment is used as a light diffusing sheet in which the light source 330 is disposed at one end α of the longitudinal direction, and is attached to the flat one surface 211, and is disposed in a strip shape along the longitudinal direction of the optical sheet 210c. The portion 216a and the mesh-like uneven portion 216 formed along the strip portion 16b in the width direction. The portion 216b of the uneven portion 216 along the width direction of the optical sheet 210c is disposed to be gradually densified as the one end α from the longitudinal direction of the optical sheet 210c faces the other end β.

The uneven pattern of the uneven portion 216 of the third embodiment is the same as the uneven pattern 12a of the uneven portion 212 of the first embodiment. The area ratio of the area of the uneven portion 216 to the area of one surface of the optical sheet 210c is also the same as the area ratio in the first embodiment.

The optical sheet 210c of the third embodiment can be produced by the same manufacturing method as the method of manufacturing the optical sheet 210a of the first embodiment.

5-4. Fourth embodiment

Next, a fourth embodiment of the optical sheet of the present invention will be described.

Fig. 19 shows an optical sheet of this embodiment. Further, in Fig. 19, for the sake of convenience of explanation, the uneven portion 217 is enlarged, and the arrangement thereof is displayed in a scattered manner.

The optical sheet 210d of the present embodiment is used as a light diffuser in which a linear light source 330 is disposed on a surface C on which one side of the uneven portion 217 is not formed. Further, in the optical sheet 210d, an elliptical concave-convex region 217 is disposed on the flat surface 211, and the concave-convex region 217 is denser as it is closer to the light source 330.

In the present embodiment, the light from the light source 330 is unevenly incident on the optical sheet 210d. However, since the portion where the stronger the light reaches, the arrangement of the uneven portion 217 becomes denser, so that the light can be emitted in a diffused state. . Therefore, the light emitted from the optical sheet 210d can be made The intensity is uniformized.

The uneven pattern of the uneven portion 217 of the fourth embodiment is the same as the uneven pattern 12a of the uneven portion 212 of the first embodiment. The area ratio of the area of the uneven portion 217 to the area of one surface of the optical sheet 210d is also the same as the area ratio in the first embodiment.

The optical sheet 210d of the fourth embodiment can be produced by the same manufacturing method as the method of manufacturing the optical sheet 210a of the first embodiment.

5-5. Other embodiments

Furthermore, the optical sheet of the present invention is not limited to the above embodiment.

For example, in the first embodiment and the fourth embodiment, the concave and convex regions are formed in an elliptical shape, but may be circular, rectangular or the like.

Further, in the optical sheet of the present invention, the uneven regions may be formed at random.

Further, the concave-convex pattern of the uneven portion may not be meandering but may be linear.

Further, the uneven regions may be formed on both surfaces of the optical sheet.

Further, the optical sheet can also be reinforced by the reinforcing substrate.

6. Diffusion light guide

Hereinafter, an embodiment of the diffused light guide of the present invention will be described.

Fig. 1 shows a diffused light guide of this embodiment. The diffused light guide 10 of the present embodiment is composed of a transparent resin layer 11 in which a meandering corrugated pattern 12a is formed on one of the surfaces. The other surface (back surface) of the transparent resin layer 11 in the present embodiment is not formed with a smooth surface of the uneven pattern.

The most frequent pitch A of the uneven pattern 12a is more than 1 μm and is 20 μm or less, preferably more than 1 μm and not more than 10 μm. When the most frequent pitch A is less than 1 μm, the most frequent pitch A is equal to or less than the wavelength of visible light, so that visible light is not refracted by irregularities, but light is transmitted. If the most frequent spacing A exceeds 20 μm, the diffusion anisotropy is It becomes low, which tends to cause uneven brightness.

The average depth B of the unevenness of the concave-convex pattern 12a with respect to the most frequent pitch of the concave-convex pattern 12a The ratio A (B/A, hereinafter referred to as the aspect ratio) is preferably 0.1 to 3.0. When the aspect ratio is less than 0.1, the anisotropy of diffusion becomes low, and uneven brightness is likely to occur. On the other hand, when the aspect ratio is more than 3.0, it is difficult to form the uneven pattern 12a when the diffusing light guide 10 is manufactured.

Here, the average depth B refers to the average depth of the bottom portion 12b of the concavo-convex pattern 12a. Further, the bottom portion 12b refers to the minimum value of the concave portion of the concave-convex pattern 12a, and the average depth B refers to the entire diffused light guide body when the cross-section obtained by cutting the diffusion light guide 10 in the longitudinal direction (see FIG. 2) is observed. a direction parallel to the surface 10 of the reference line L ₁ until the top of each protrusion length B up, the bottom _1, B _2, B ₃ ... average value _{(the AV} B) and L ₁ from the reference line to each of the recessed portions The difference between the average values (b _AV ) of the lengths b ₁ , b ₂ , b ₃ ... (b _AV -B _AV ).

As a method of measuring the average depth B, a method of measuring the depth of each of the bottom portions 12b in the image of the cross section of the concave-convex pattern 12a taken by the atomic force microscope, and determining the average value thereof may be employed.

The meandering in the present invention means that the degree of alignment of the irregularities obtained by the following method is 0.3 or more. The alignment degree is an index of the unevenness of the alignment of the unevenness, and the larger the value, the more uneven the alignment.

In order to determine the degree of alignment, first, the surface of the concave-convex pattern is photographed by a surface optical microscope, and the image is converted into a grayscale document (for example, a tiff format or the like). In the image of the grayscale document (refer to FIG. 3), the lower the whiteness, the deeper the bottom of the concave portion (the higher the whiteness, the higher the top of the convex portion). Then, Fourier transform is performed on the image of the grayscale document. The Fourier transformed image is shown in FIG. The white portion extending from the center of the image of Fig. 4 to the sides includes information on the distance between the concave and convex patterns 12a and the orientation.

Next, the auxiliary line L ₂ is drawn in the horizontal direction from the center of the image of Fig. 4, and the brightness on the auxiliary line is drawn (refer to Fig. 5). In the drawing of Fig. 5, the horizontal axis represents the pitch, the vertical axis represents the frequency, and the frequency is the maximum value X represents the most frequent pitch of the concave-convex pattern 12a.

Next, in Fig. 4, the auxiliary line L _{3 is} orthogonal to the auxiliary line L ₂ at the portion of the value X, and the luminance on the auxiliary line L ₃ is drawn (see Fig. 6). In order to compare with various concavo-convex structures, the horizontal axis of Fig. 6 is a value obtained by dividing the X value. The horizontal axis of Fig. 6 indicates an index (orientation) indicating the degree of inclination with respect to the direction in which the unevenness is formed (the vertical direction in Fig. 3), and the vertical axis indicates the frequency. The half value width W ₁ of the peak in the depiction of Fig. 6 (the width of the peak at a height of one half of the maximum value) indicates the degree of alignment of the concave and convex pattern. The larger the half value width W ₁ , the more random the pitch is.

When the degree of alignment is less than 0.3, the unevenness of the alignment of the uneven pattern 12a is small, and the anisotropy of diffusion of light is small.

Further, the degree of alignment is preferably 1.0 or less. When the degree of alignment exceeds 1.0, the direction of the concavo-convex pattern becomes random to some extent, and thus the light diffusibility becomes high, but the anisotropy tends to be low.

In order to make the degree of alignment 0.3 or more, for example, in the following production, a heat shrinkable film and a hard layer having a smooth surface can be appropriately selected. For example, the higher the shrinkage ratio of the heat shrinkable film or the smaller the Young's modulus of the hard layer having a smooth surface, the greater the alignment. The diffusing light guiding body 10 obtained by the manufacturing method is composed of two resin layers.

Further, a method may be employed in which a transparent resin is formed by using a metal mold having a concave-convex pattern having an orientation of 0.3 or more on one surface. The diffusing light guiding body 10 obtained by the manufacturing method is composed of a resin layer.

Further, the most frequent pitch of the concave-convex pattern obtained by Fourier transform in the above manner is the same as the average pitch.

The transparent resin layer 11 is composed of a transparent resin having a high transmittance of visible light (specifically, a total light transmittance of visible light of 85%).

Moreover, in order to improve heat resistance and light resistance, an additive may be contained in the transparent resin layer 11 in the range which does not impair optical characteristics, such as a light transmittance. Examples of the additive include a light stabilizer, an ultraviolet absorber, an antioxidant, a lubricant, and a light diffusing agent. Among them, it is particularly preferable to add a light stabilizer in an amount of preferably 0.03 to 2.0 parts by mass based on 100 parts by mass of the transparent resin. If the amount of the light stabilizer added is 0.03 parts by mass or more, When the addition amount of the light stabilizer exceeds 2.0 parts by mass, the amount of the light stabilizer is excessive, and there is a tendency that unnecessary cost rises.

Further, in order to further improve the light-diffusing effect, the transparent resin layer 11 may contain an inorganic light-diffusing agent composed of an inorganic compound and an organic compound composed of an organic compound in a range that does not greatly impair optical characteristics such as light transmittance. Light diffusing agent.

Examples of the inorganic light diffusing agent include cerium oxide, white carbon, talc, magnesium oxide, zinc oxide, titanium oxide, calcium carbonate, aluminum hydroxide, barium sulfate, calcium citrate, magnesium citrate, aluminum citrate, and citric acid. Sodium aluminide, zinc antimonate, glass, mica, and the like.

Examples of the organic light-diffusing agent include styrene-based polymer particles, acrylic polymer particles, siloxane-based polymer particles, and polyamid-based polymer particles. These light diffusing agents may be used singly or in combination of two or more.

Further, in order to obtain excellent light scattering characteristics, the light diffusing agents may be formed into a porous structure such as a petal shape or a spherical crystal.

The content of the light diffusing agent is preferably 10 parts by mass or less based on 100 parts by mass of the transparent resin, from the viewpoint of being difficult to impair the light transmittance.

Further, in order to further enhance the light diffusion effect, the transparent resin layer 11 may contain fine bubbles in a range that does not greatly impair optical characteristics such as light transmittance. The fine bubbles absorb less light and it is difficult to lower the light transmittance.

As a method of forming the fine bubbles, a method of mixing a foaming agent into the transparent resin layer 11 can be applied (for example, the method disclosed in Japanese Laid-Open Patent Publication No. Hei 5-212811, No. Hei. A method in which an acrylic foamed resin is subjected to a foaming treatment to contain fine air bubbles (for example, a method disclosed in Japanese Laid-Open Patent Publication No. 2004-2812). Further, in order to achieve more uniform surface irradiation, the method of forming fine bubbles is preferably a method of uniformly foaming a specific position (for example, the method disclosed in Japanese Laid-Open Patent Publication No. 2006-124499).

Further, the above light diffusing agent may be used in combination with fine foaming.

The thickness of the transparent resin layer 11 is preferably 0.02 to 3.0 mm, more preferably 0.05 to 2.5 mm, and particularly preferably 0.1 to 2.0 mm. When the thickness of the transparent resin layer 11 is less than 0.02 mm, the thickness thereof is less than the depth of the uneven pattern, and if the thickness is thicker than 3.0 mm, the quality of the diffused light guide 10 may be difficult to handle due to the large mass.

The transparent resin layer 11 may also be composed of two or more resin layers. Even when the transparent resin layer 11 is composed of two or more layers, the thickness of the transparent resin layer 11 is preferably from 0.02 to 3.0 mm.

. Production method

It can be manufactured by the manufacturing method similar to the manufacturing method of the above-mentioned optical sheet.

. Features

The diffused light guide 10 has an anisotropic diffusibility of light. Specifically, when a light source is provided on the side (back surface) side of the diffusing light guide 10 on the side where the concave-convex pattern 12a is not formed, light emitted from the light source is incident from the back surface to the diffusion light guide 10, and passes through The inside of the light guide 10 is diffused to reach the uneven surface. Here, the light having an incident angle of 0 or more and reaching at an angle less than the critical angle is emitted to the outside of the diffused light guide 10 in a state of being refracted. Since the direction of the light passing through the diffused light guide 10 is not one direction, the angle between the uneven surface of the diffused light guide 10 and the light is not fixed, so the light is refracted at a wide angle. Further, since the irregularities are meandering and the alignment is uneven, the anisotropy of diffusion is high.

Further, the light reaching the concave-convex surface at an angle equal to or higher than the critical angle is totally reflected and then travels again in the diffused light guide body, but then exits when reaching the concave-convex surface at an angle less than the critical angle. Further, the light that arrives at an angle of incidence of 0 degrees is not refracted, but is directly emitted outside the diffused light guide.

Further, when a light source is provided on one side surface side of the diffused light guide body 10, as in the case described above, the light incident in the light guide body 10 after the incident angle is 0 degrees or more and reaches the angle of the critical angle is refraction. Out of the diffused light guide. Here, since the unevenness is meandering and the alignment is uneven, the anisotropy of diffusion is high.

Furthermore, the diffusing light guide of the present invention is not limited to the above embodiment. For example, when a light source is disposed on the back side of the transparent resin layer, in order to improve the light incident efficiency, it is preferable to form fine undulations having an antireflection function on the back surface of the transparent resin layer. Here, it is preferable that the fine pitch of the fine undulations is 1 μm or less and the aspect ratio is 0.1 or more. The reason for this is that if the most frequent pitch exceeds 1 μm, or if the aspect ratio exceeds 0.1, the antireflection function cannot be obtained.

The fine wavy irregularities may be formed on the back surface of the transparent resin layer together with the uneven pattern for light diffusion. For example, when the diffusion light guide is manufactured by press molding or injection molding, the following method can be applied, that is, as a metal mold, which is formed on the surface adjacent to the exit surface (surface) side of the transparent resin layer. The light-diffusing concave-convex pattern is formed on the surface adjacent to the incident surface (back surface) side of the transparent resin layer, and a fine wavy concave-convex pattern is formed.

Further, the fine wavy irregularities may be formed separately on the back surface of the transparent resin layer unlike the uneven pattern for light diffusion. For example, a film on which a fine wavy concave-convex pattern is formed may be attached to the back side of the transparent resin layer via an adhesive.

Moreover, in order to further improve the anisotropy of light diffusion, a film containing fine bubbles may be attached to the incident surface side or the emission surface side. As shown in Fig. 20, when the film 317 containing fine bubbles is attached to the incident surface side, in order to effectively utilize the light from the light source 330, it is preferable that the portion 317a of the light of the light source 330 is strongly irradiated. The content of the fine bubbles in the middle is large, and the content of the fine bubbles in the other portion 317b is small or not.

The diffusing light guiding body of the present invention may also have a wedge shape in which the thickness is gradually thinned from one end toward the other end. The light source is disposed on the thicker side of the wedge-shaped diffused light guide.

In the diffused light guiding system of the present invention, it is necessary to form a meandering corrugated pattern on one surface, but it is not limited to those in which a concave-convex pattern is formed only on one surface. That is, a meandering corrugated pattern may be formed on the other surface of the transparent resin layer.

7. Backlight unit 7-1. First embodiment

Hereinafter, a first embodiment of the backlight unit of the present invention will be described.

Fig. 21 shows a backlight unit of this embodiment. The backlight unit 100 of the present embodiment is a so-called direct type backlight unit including a diffusing light guide 310 and a reflecting plate 320 opposite to the surface (surface 315) of the diffusing light guide 310 on which the uneven pattern is formed. The surface (back surface 316) is disposed opposite to each other; and a plurality of light sources 330, 330, ... are disposed between the diffusion light guide 310 and the reflection plate 320. Further, on the surface 315 side of the diffusion light guide 310, a diffusion film 340, a ruthenium sheet 350, and a brightness rising film 360 are laminated in this order.

Examples of the light source 330 include a cold cathode tube, a light emitting diode, and the like.

The reflector 320 may be, for example, a metal plate having a mirror surface or a laminate having such a metal plate.

The diffusion film 340 may, for example, be a resin film containing transparent particles. The diffusion film 340 is configured to further diffuse light emitted from the diffusion light guide.

For example, a resin sheet having a large number of conical or pyramidal protrusions on one surface (for example, trade name Vikuiti BEF III manufactured by Sumitomo 3M Limited) or the like can be cited. The cymbal sheet 350 is used to make the traveling direction of the light emitted from the diffusion film 340 coincide with the direction perpendicular to the surface.

The brightness rising film 360 may be, for example, a sheet in which only the main wave (P wave) of light passes through and the second wave (S wave) is reflected (for example, the product name Vikuiti DBEF-D400 manufactured by Sumitomo 3M Limited).

7-2. Second embodiment

Next, a second embodiment of the backlight unit of the present invention will be described.

Fig. 22 shows a backlight unit of this embodiment. The backlight unit 200 of the present embodiment is a so-called end face illumination type backlight unit, and includes a diffusion light guide 310 and a reflection plate 320 opposite to the surface (surface 315) of the diffusion light guide 310 on which the uneven pattern is formed. Face 316) is disposed opposite to each other; and a plurality of light sources 330 are disposed on one side of the diffusion light guide 310. Further, on the surface 315 side of the diffusion light guide 310, a diffusion film 340, a ruthenium sheet 350, and a brightness rising film 360 are laminated in this order.

The diffusing light guide 310, the reflecting plate 320, the light source 330, the diffusing film 340, the cymbal 350, and the brightness increasing film 360 used in the present embodiment are the same as those in the first embodiment.

In the backlight unit 100 of the above-described embodiment including the diffusing light guide 310 in which the meandering wave-like concave-convex pattern is formed, the light emitted from the light source 330 is diffused on the uneven surface of the diffused light guide 310 by a high anisotropy. . Therefore, in the liquid crystal display device including the backlight units 100 and 200, unevenness in image brightness is less likely to occur.

8. Anti-reflection body

In the anti-reflection system of the present invention, the concave-convex pattern forming sheet 10 is provided, and the uneven pattern, that is, the concave-convex pattern 12a having the most frequent pitch A of 1 μm or less.

In the antireflection body of the present invention, other layers may be provided on one surface or both surfaces of the uneven pattern forming sheet 10. For example, in the surface of the concave-convex pattern forming sheet 10 on which one side of the uneven pattern 12a is formed, in order to prevent contamination of the surface, a thickness of 1 to 5 nm including a fluororesin or a polyoxymethylene resin as a main component may be provided. Stained layer.

In the antireflection body of the present invention, the portion of the corrugated concavo-convex pattern 12a of the concavo-convex pattern forming sheet 10 exhibits an intermediate between the refractive index of the air and the refractive index of the concavo-convex pattern forming sheet 10 (the refractive index of the substrate 11). The refractive index, which varies continuously. Further, the most frequent pitch A of the uneven pattern 12a is 1 μm or less, and the average depth B of the bottom portion 12b of the uneven pattern 12a is 10% or more when the maximum pitch A is 100%. Thereby, the reflectance of light can be made particularly low, and specifically, the reflectance can be made approximately 0%. The reason is that, as described above, when the most frequent pitch A of the concave-convex pattern 12a of the concave-convex pattern forming sheet 10 is short, when the thickness is 1 μm or less, the average depth B is deep, and 10 is when the maximum-frequency spacing A is 100%. When the amount is more than %, the portion in which the intermediate refractive index continuously changes becomes longer in the thickness direction, so that the effect of suppressing light reflection can be remarkably exhibited.

The antireflection body can be attached to, for example, an image display device such as a liquid crystal display panel or a plasma display, a light emitting portion tip of a light emitting diode, and a surface of a solar cell panel.

When the antireflection body is mounted on the image display device, since the illumination light can be prevented from being reflected, the visibility of the image can be improved. When the antireflection body is attached to the tip end of the light emitting portion of the light emitting diode, the light extraction efficiency can be improved. When the above-mentioned antireflection body is mounted on the surface of the solar cell panel, since the amount of light extraction can be increased, the power generation efficiency of the solar cell can be improved.

9. Phase difference plate

The retardation film of the present invention includes the concave-convex pattern forming sheet 10, and the uneven pattern, that is, the concave-convex pattern 12a having the most frequent pitch A of 1 μm or less. Among them, the direction of the concave and convex is not random, but along one direction.

In the retardation film of the present invention, similarly to the above-described antireflection film, another layer may be provided on one surface or both surfaces of the uneven pattern forming sheet 10. For example, the uneven pattern 12a may be formed on the concave-convex pattern forming sheet 10. An anti-fouling layer is provided on one of the sides.

The phase difference plate of the present invention can remarkably exert the effect of generating a phase difference. The reason is that, as described above, when the most frequent pitch A of the concave-convex pattern 12a of the concave-convex pattern forming sheet 10 is short, when the thickness is 1 μm or less, the average depth B is deep, and 10 is when the maximum-frequency spacing A is 100%. When the amount of the air having the refractive indices different from each other and the uneven pattern forming sheet 10 are alternately arranged in the thickness direction, the portion exhibiting the optical anisotropy becomes longer. Further, when the distance between the concave-convex patterns is equal to or lower than the wavelength of visible light or the wavelength of visible light, the same phase difference can be generated over a wide range of visible light wavelengths.

(Engineering sheet for optical component manufacturing)

In the optical element manufacturing sheet (hereinafter, simply referred to as an engineering sheet) of the present invention, the concave-convex pattern forming sheet 10 is provided, and the concave-convex pattern, that is, the concave-convex pattern 12a having the most frequent pitch A of 1 μm or less, and the optical element of the present invention The engineering sheet for manufacturing is used as a large-area and large-scale manufacturing by transferring the uneven pattern 12a to other materials by the method shown below. The concave-convex pattern is used to form a mold for a sheet having a concave-convex pattern having the same frequency-to-average pitch and average depth as the engineered sheet, and can be used as an optical element such as an antireflection body or a phase difference plate.

The specific method of manufacturing an optical component using an engineering sheet is the same as the method of the above optical sheet.

[Example 1]

The Young's modulus in the following examples was a value measured by a tensile tester (TE-7001, manufactured by Tester Industries, Ltd.) in accordance with JIS K 7113-1995. When the temperature is not specifically described, it is a value at 23 °C.

(Example 1)

A heat shrinkable film made of polyethylene terephthalate having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-60S manufactured by Mitsubishi Plastics Co., Ltd., glass transition temperature: 70 ° C) On one surface, polymethyl methacrylate (P4831-MMA, manufactured by POLYMER SOURCE Co., Ltd., glass transition temperature: 100 ° C) diluted in toluene was applied by a bar coater to have a thickness of 200 nm. A laminate is obtained by forming a hard layer.

Then, the laminated sheet was heated at 80 ° C for 1 minute, whereby it was heat-shrinked to 40% of the length before heating (that is, it was deformed at a deformation rate of 60%) to obtain a hard layer having a wavy shape. The concavo-convex pattern of the concavo-convex pattern forms a sheet (light diffuser) having a period along a direction orthogonal to the contraction direction.

Further, the heat shrinkable film made of polyethylene terephthalate and the Young's modulus of the polymethyl methacrylate at 80 ° C were 50 MPa and 1 GPa, respectively.

(Example 2)

A concavo-convex pattern-forming sheet (light diffuser) was obtained in the same manner as in Example 1 except that polystyrene (PS manufactured by POLYMER SOURCE Co., Ltd., glass transition temperature: 100 ° C) diluted with toluene was applied. .

Further, the heat shrinkable film made of polyethylene terephthalate and the Young's modulus of the polystyrene at 80 ° C were 50 MPa and 1 GPa, respectively.

(Example 3)

A concave-convex pattern forming sheet (light diffusing body) was obtained in the same manner as in Example 2 except that the coating thickness of the polystyrene was changed to 1 μm.

(Example 4)

The laminated sheet was heated at 70 ° C for 1 minute, whereby it was heat-shrinked to 90% of the length before heating (that is, it was deformed at a deformation rate of 10%), in addition to the examples. 2 A concavo-convex pattern forming sheet (light diffuser) was obtained in the same manner.

(Example 5)

The concave-convex pattern forming sheet (light diffusing body) obtained in Example 1 was used as an original for an engineering sheet, and a light diffusing body was obtained in the following manner.

That is, the epoxy acrylate-based prepolymer, the 2-ethylhexyl acrylate, and the benzophenone-based prepolymer were coated on the surface of the original sheet of the engineering sheet obtained in Example 1 on which the uneven pattern was formed. An uncured ultraviolet curable resin composition of a photopolymerization initiator.

Then, on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the original sheet of the engineering sheet, a triacetonitrile cellulose film having a thickness of 50 μm was superposed and pressed.

Next, ultraviolet rays are irradiated from the top of the triacetone cellulose film to harden the uncured ultraviolet curable resin composition, and the cured product is peeled off from the original sheet of the engineering sheet, thereby obtaining a light diffuser.

(Example 6)

The concave-convex pattern forming sheet (light diffusing body) obtained in Example 1 was used as an original sheet of an engineering sheet, and an optical element was obtained in the following manner.

That is, the surface on which the uneven pattern was formed on the original sheet obtained in Example 1 was subjected to nickel plating treatment, and thereafter the nickel plating was peeled off, thereby obtaining a thickness of 200 μm. Engineering film. Applying an epoxidized acrylate-based prepolymer, a 2-ethylhexyl acrylate, and a benzophenone-based photopolymerization initiator to the surface on which the uneven pattern is formed on the secondary work piece An ultraviolet curable resin composition.

Then, on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the secondary work piece, a triacetonitrile cellulose film having a thickness of 50 μm was superposed and pressed.

Thereafter, the uncured ultraviolet curable resin composition is cured by irradiating ultraviolet rays from the top of the triacetone cellulose film, and the cured product is peeled off from the secondary work piece, thereby obtaining a light diffuser.

(Example 7)

A light diffuser was obtained in the same manner as in Example 6 except that the thermosetting epoxy resin was used instead of the ultraviolet curable resin composition, and the thermosetting resin was cured by heating instead of ultraviolet irradiation.

(Example 8)

In the same manner as in Example 6, a secondary work piece having a thickness of 200 μm was obtained. On the surface on which the uneven pattern was formed on the secondary work piece, a polymethyl methacrylate film having a thickness of 50 μm was superposed and heated. Pressing the heated and softened polymethyl methacrylate film and secondary engineering sheet from both sides, and then cooling it. It is cured and peeled off from the secondary work piece, whereby a light diffuser is obtained.

(Comparative Example 1)

A concave-convex pattern forming sheet (light diffusing body) was obtained in the same manner as in Example 2 except that the coating thickness of the polystyrene was changed to 6 μm.

(Comparative Example 2)

A concave-convex pattern forming sheet (light diffusing body) was obtained in the same manner as in Example 2 except that the coating thickness of the polystyrene was changed to 40 nm.

(Comparative Example 3)

HISHIPET LX-10S (3 mils) was used to replace HISHIPET LX-60S manufactured by Mitsubishi Plastics Co., Ltd., and the laminated sheet was heated at 70 ° C for 1 minute to thermally shrink to A concave-convex pattern forming sheet (light diffusing body) was obtained in the same manner as in Example 1 except that 97% of the length before heating (that is, it was deformed by a deformation ratio of 3%).

(Comparative Example 4)

The uneven pattern forming sheet is obtained by the method for producing an anisotropic diffusion pattern disclosed in Patent Document 2.

In other words, two plates are provided: a shielding plate having a diffusion plate such as frosted glass that diffuses and transmits laser light and having a slit having a width of 1 mm and a length of 10 cm, and a commercially available photosensitive resin coated with a thickness of 100 μm. The photosensitive film sheet was such that the two sheets were spaced apart from each other by 1 m, and the two sheets were made parallel to each other.

Then, after irradiating the argon laser having a wavelength of 514 nm from the side of the shielding plate, the argon laser light diffused through the slit through the frosted glass exposes the photosensitive resin on the photosensitive film.

The exposure as described above is repeated to expose the photosensitive resin on the entire surface of the photosensitive film sheet. Further, the exposed photosensitive film is developed to obtain a concavo-convex pattern forming sheet (light diffusing body).

Further, the grayscale document converted image of Comparative Example 4 is displayed in Fig. 9, and the Fourier transform image of the grayscale document image is displayed in Fig. 10. Further, the guide line L ₄ is drawn in the horizontal direction from the center of the image of Fig. 10, and the graph obtained by drawing the brightness on the auxiliary line is shown in Fig. 11. Further, in Fig. 10, the auxiliary line L _{5 is} orthogonal to the auxiliary line L _{4 at} the portion of the value Y, and the graph obtained by drawing the brightness on the auxiliary line L ₅ is shown in Fig. 12 .

(Comparative Example 5)

Try to use a biaxially oriented polyethylene terephthalate film (G2 made by Teijin Co., Ltd.) with a thickness of 50 μm and a Young's modulus of 5 GPa instead of the heat shrinkable film. Further, a concavo-convex pattern forming sheet (light diffusing body) was obtained in the same manner as in Example 1. However, since the wavy concave-convex pattern was not formed, the uneven pattern forming sheet (light diffusing body) was not obtained.

(Comparative Example 6)

Heat shrinkable shrink film made of polyethylene terephthalate having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-10S manufactured by Mitsubishi Plastics Co., Ltd., glass transition temperature of 70 ° C On one side, a polydimethyl methoxyoxane having a Young's modulus of 2 MPa (Shin-Etsu Chemical Co., Ltd. KS847T, glass transition temperature of -120 ° C) and a platinum touch were coated by a bar coating method. The medium (Shin-Etsu Chemical Co., Ltd. CAT-PL-50T) was diluted in toluene to have a thickness of 200 nm to form a hard layer to obtain a laminated sheet.

Next, the laminated sheet was heated at 100 ° C for 1 minute to be heat-shrinked, whereby the uneven pattern forming sheet was obtained, but the hard layer could not be deformed by folding, so that the wavy concave-convex pattern was not formed.

The upper surface of the light diffusing body of the concave-convex pattern forming sheets of Examples 1 to 8 and Comparative Examples 1 to 6 was imaged by an atomic force microscope (NanoScope III manufactured by Veeco Co., Ltd., Japan).

With respect to the concavo-convex pattern forming sheets of Examples 1 to 8 and Comparative Examples 1 to 4, the depths of the ten concavo-convex patterns were measured in an image of an atomic force microscope, and the depths were averaged to obtain an average depth.

Further, the degree of alignment of the concavo-convex pattern was obtained as follows.

First, the upper surface of the concave-convex pattern is photographed by a surface optical microscope, and the image is converted into a grayscale document (refer to FIG. 3). Then, Fourier transform is performed on the image of the grayscale document. Figure 4 shows the image after Fourier transform. Next, the auxiliary line L ₂ is drawn in the horizontal direction from the center of the image of Fig. 4, and the brightness on the auxiliary line is drawn (refer to Fig. 5). Thereafter, in FIG. 5, the auxiliary line L _{3 is introduced} , and the portion of the value X (reciprocal of the most frequent pitch) is orthogonal to the auxiliary line L ₂ , and the brightness on the auxiliary line L ₃ is drawn (refer to the figure). 6). Then, the degree of alignment of the concavo-convex pattern is obtained from the half value width W ₁ of the peak in the drawing of FIG. The values are shown in Table 1.

Further, the suitability as a light diffuser was evaluated based on the following pitches based on the most frequent pitch of the uneven pattern and the average depth of the bottom. The evaluation results are shown in Table 1.

○: The most frequent pitch of the uneven pattern is more than 1 μm and 20 μm or less, and the average depth is 10% or more when the most frequent pitch is 100%, and the degree of alignment is 0.3 to 1.0, which is suitable as a light diffuser.

△: The most frequent pitch of the concave-convex pattern is 1 μm or less or more than 20 μm, or the average depth is less than 10% when the most frequent pitch is 100%, or the degree of alignment is less than 0.3, which is not necessarily suitable as a light diffuser.

×: The uneven pattern could not be formed.

In Examples 1 to 8 in which the surface of the laminated sheet was smooth and the hard layer was deformed by folding, the uneven pattern forming sheet can be easily produced.

Further, the groove spacing of the concave-convex pattern forming sheets of Examples 1 to 8 is more than the most frequent pitch 1 μm and 20 μm or less, and the average depth of the bottom is 10% or more when the above-mentioned mode spacing is 100%, and therefore it is suitable as a light diffuser. In Examples 1 to 4, the above-mentioned maximum frequency pitch and average depth were obtained because the thickness of the surface smooth hard layer exceeded 0.05 μm and was 5 μm or less, and the deformation ratio was 10% or more.

Moreover, according to the manufacturing method of Examples 5 to 8 in which the uneven pattern forming sheet (light diffusing body) obtained in Example 1 is used as an engineering sheet, it is possible to easily produce the most formed sheet (light diffusing body) with the uneven pattern. A light diffuser having a concave-convex pattern having the same frequency pitch and average depth.

On the other hand, in Comparative Examples 1 and 2, since the thickness of the surface hard smoothing layer is 0.05 μm or less or more than 5 μm, the groove width of the concave-convex pattern forming sheet (light diffusing body) obtained is 1 μm or less. Or more than 20μm.

Further, in Comparative Example 3, since the deformation ratio was 3%, the average depth of the bottom portion of the uneven pattern of the obtained concave-convex pattern forming sheet was less than 10% when the most frequent pitch was 100%. Further, in Comparative Example 4, the degree of alignment was less than 0.3. These Comparative Examples 1 to 4 are not necessarily suitable as a light diffuser.

Further, in Comparative Example 5 in which a biaxially stretched polyethylene terephthalate film was used as a resin layer, and a production method in Comparative Example 6 in which a laminated sheet using a second resin having a glass transition temperature lower than that of the first resin was used In the case, since the smooth surface of the hard layer cannot be deformed by folding, the concave-convex pattern is not formed.

The Young's modulus in the following examples is a tensile tester (TENSILON RTC-1210 manufactured by Orientec Co., Ltd.), and the temperature is measured according to JIS Z 2280-1993 "High Temperature Young's Modulus Test Method for Metallic Materials". Changed to 23 ° C and measured. The same applies to the case where the hard layer is composed of a metal compound.

(Example 9)

Vacuum-evaporation on one side of a heat shrinkable film made of polyethylene terephthalate having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-10S manufactured by Mitsubishi Plastics Co., Ltd.) Young's modulus is 70GPa of aluminum, making it thicker 0.05 μm to form a smooth hard layer on the surface to obtain a laminated sheet.

Next, the laminated sheet was heated at 100 ° C for 1 minute, whereby it was heat-shrinked to 40% of the length before heating (that is, it was deformed at a deformation rate of 60%), thereby obtaining a hard layer having a wave. The uneven pattern of the uneven pattern forms a sheet having a period along a direction orthogonal to the contraction direction.

Then, the uneven pattern forming sheet was used as an original sheet of the engineering sheet, and a light diffuser was obtained in the following manner.

That is, the unhardened coating containing the epoxy acrylate prepolymer, the 2-ethylhexyl acrylate, and the benzophenone photopolymerization initiator is applied to the surface on which the concave-convex pattern is formed on the original sheet of the engineering sheet. The ultraviolet curable resin composition.

Thereafter, a film of a thickness of 50 μm of triacetyl cellulose film was superposed and pressed on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the original sheet of the engineering sheet.

Then, ultraviolet rays are irradiated from the upper surface of the triacetone cellulose film to harden the uncured ultraviolet curable resin, and the cured product is peeled off from the original sheet of the engineering sheet, thereby obtaining a light diffuser.

(Embodiment 10)

The concave-convex pattern forming sheet obtained by the method of Example 9 was used as an original for an engineering sheet, and a light diffusing body was obtained in the following manner.

That is, the surface on which the uneven pattern was formed on the original sheet obtained in Example 9 was subjected to nickel plating treatment, and thereafter the nickel plating was peeled off, whereby a secondary work sheet having a thickness of 200 μm was obtained. Applying an epoxidized acrylate-based prepolymer, a 2-ethylhexyl acrylate, and a benzophenone-based photopolymerization initiator to the surface on which the uneven pattern is formed on the secondary work piece An ultraviolet curable resin composition.

Next, on the surface of the coating film of the uncured ultraviolet curable resin composition which is not in contact with the secondary engineering sheet, a film of a thickness of 50 μm is laminated and pressed. Pressure.

Then, ultraviolet rays are irradiated from the upper surface of the triacetone cellulose film to harden the uncured curable resin, and the cured product is peeled off from the secondary work piece, thereby obtaining a light diffuser.

(Example 11)

A light diffuser was obtained in the same manner as in Example 10 except that the thermosetting epoxy resin was used in place of the ultraviolet curable resin composition, and the thermosetting epoxy resin was cured by heating instead of ultraviolet irradiation. .

(Embodiment 12)

In the same manner as in Example 10, a secondary work piece having a thickness of 200 μm was obtained. On the surface on which the uneven pattern was formed on the secondary work piece, a polymethyl methacrylate film having a thickness of 50 μm was superposed and heated. The heated and softened polymethyl methacrylate film and the secondary engineering sheet are pressed from both sides thereof, and then cooled. The film was cured, and the cured polymethyl methacrylate film was peeled off from the secondary work piece, whereby a light diffuser was obtained.

(Comparative Example 7)

A light diffuser was obtained in the same manner as in Example 9 except that aluminum was vacuum-deposited to have a thickness of 0.3 μm.

(Comparative Example 8)

A light diffuser was obtained in the same manner as in Example 9 except that aluminum was vacuum-deposited to have a thickness of 0.01 μm.

(Comparative Example 9)

One side of a heat shrinkable film of a polyethylene terephthalate having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-10S manufactured by Mitsubishi Plastics Co., Ltd.), vacuum evaporation The Young's modulus is 70 GPa of aluminum to a thickness of 0.05 μm to form a smooth hard surface layer to obtain a laminated sheet.

Then, the laminated sheet was heated at 70 ° C for 1 minute to shrink to 97% of the length before heating (that is, deformed at a deformation rate of 3%), and in addition, 9 A light diffuser is obtained in the same manner.

The upper surface of the light diffusing body of the uneven pattern forming sheets of Examples 9 to 12 and Comparative Examples 7 to 9 was imaged by an atomic force microscope (NanoScope III manufactured by Veeco Co., Ltd., Japan).

With respect to the concavo-convex pattern forming sheets of Examples 9 to 12 and Comparative Examples 7 to 9, the depths of the ten concavo-convex patterns were measured in an image of an atomic force microscope, and the depths were averaged to obtain an average depth.

Further, the degree of alignment of the concavo-convex pattern was obtained as follows.

First, the upper surface of the concave-convex pattern is photographed by a surface optical microscope, and the image is converted into a grayscale document (refer to FIG. 3). Then, Fourier transform is performed on the image of the grayscale document. Figure 4 shows the image after Fourier transform. Next, the auxiliary line L ₂ is drawn in the horizontal direction from the center of the image of Fig. 4, and the brightness on the auxiliary line is drawn (refer to Fig. 5). Thereafter, in FIG. 5, the auxiliary line L _{3 is introduced} , and the portion of the value X (reciprocal of the most frequent pitch) is orthogonal to the auxiliary line L ₂ , and the brightness on the auxiliary line L ₃ is drawn (refer to the figure). 6). Then, the degree of alignment of the concavo-convex pattern is obtained from the half value width W ₁ of the peak in the drawing of FIG.

The values are shown in Table 2.

Further, the adaptability of the light diffuser was evaluated based on the following criteria based on the most frequent pitch of the concave-convex pattern and the average depth of the bottom. The evaluation results are shown in Table 2.

○: The most frequent pitch of the uneven pattern is more than 1 μm and 20 μm or less, and the average depth is 10% or more when the most frequent pitch is 100%, and the degree of alignment is 0.3 to 1.0, which is suitable as a light diffuser.

△: The most frequent pitch of the concave-convex pattern is 1 μm or less or more than 20 μm, or the average depth is less than 10% when the most frequent pitch is 100%, or the degree of alignment is less than 0.3, which is not necessarily suitable as a light diffuser.

×: The uneven pattern could not be formed.

In the examples 9 to 12 in which the uneven pattern forming sheet obtained by deforming the surface of the laminated sheet by the folding of the hard layer in a folded manner is used as the original sheet of the engineering sheet, the light diffusing body having the uneven pattern can be easily produced. In particular, in the light-diffusing bodies obtained in Examples 9 to 12, the most frequent pitch of the uneven pattern is more than 1 μm and 20 μm or less, and the average depth of the bottom is 10% or more when the above-mentioned worst-frequency pitch is 100%. Suitable as a light diffuser. In Examples 9 to 12, the above-mentioned maximum frequency pitch and average depth were obtained because the thickness of the surface smooth hard layer exceeded 0.01 μm and was 0.2 μm or less, and the deformation ratio was 10% or more.

On the other hand, in Comparative Examples 7 and 8, since the thickness of the surface hard smoothing layer was 0.01 μm or less or more than 0.2 μm, the pitch of the concave-convex pattern of the obtained light-diffusing body was 1 μm or less or more than 20 μm. Further, in Comparative Example 9, since the deformation ratio was 3%, the average depth of the bottom portion of the uneven pattern of the obtained light diffuser was less than 10% when the most frequent pitch was 100%. Further, in Comparative Example 10, the degree of alignment was less than 0.3. These comparative examples are not necessarily suitable as light diffusers.

(Example 13)

Heat shrinkable film made of polyethylene terephthalate having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET manufactured by Mitsubishi Plastics Co., Ltd.) Polystyrene (Polymer SOURCE Co., Ltd.) diluted in toluene by a gravure printing machine (K Printing Proofer manufactured by Matsuo Co., Ltd.) on one side of LX-60S, a glass transition temperature of 70 ° C) The glass transition temperature was 100 ° C) and printed into dots having a diameter of 50 μm and a thickness of 500 nm to obtain a printed sheet.

The pattern of the dots is a gray scale pattern as described below, that is, in the range of 5 cm in width × 10 cm in length, from one end to the other end in the length direction, the dot area ratio is increased from 10 to 100% per 1 cm. %. Furthermore, a dot area ratio of 0% indicates complete printing, and 100% indicates full printing.

Then, the printed sheet was heated at 80 ° C for 1 minute, whereby it was heat-shrinked to 40% of the length before heating (that is, it was deformed at a deformation rate of 60%). At 80 ° C, the Young's modulus (1 GPa) of polystyrene is higher than the Young's modulus (50 MPa) of the heat shrinkable film made of polyethylene terephthalate. Therefore, at the time of heat shrinkage, the dots are deformed in a folded manner to form a corrugated concave-convex pattern having a period along a direction orthogonal to the contraction direction. Thereby, the uneven pattern forming sheet in which the uneven surface is formed on one surface of the flat surface is obtained.

The concave-convex pattern of the uneven pattern of the uneven pattern forming sheet had a mode-to-average pitch of 5 μm, an aspect ratio of 1, and an alignment degree of 0.3.

When the light diffusing property of the obtained concave-convex pattern forming sheet was examined, it was found that the direction perpendicular to the shrinking direction has a stronger anisotropic diffusing property for diffusing light in a direction parallel to the shrinking direction. Further, the light diffusibility gradually increases along the direction in which the area ratio of the uneven region becomes large. The concave-convex pattern forming sheet of Example 13 as such can be used as a light diffusing sheet.

(Example 14)

A polyethylene terephthalate shrink film (HISHIPET PX-40S manufactured by Mitsubishi Plastics Co., Ltd.) having a thickness of 25 μm and a Young's modulus of 3 GPa in a biaxial direction was used to replace Mitsubishi Resin Co., Ltd. A concave-convex pattern forming sheet was obtained in the same manner as in Example 13 except that HISHIPET LX-60S was produced. A corrugated concavo-convex pattern that does not follow a specific direction is formed on one surface of the concavo-convex pattern forming sheet.

The concave-convex pattern of the uneven pattern of the uneven pattern forming sheet had a pitch of 5 μm and an aspect ratio of 1.

The optical characteristics of the uneven pattern forming sheet of Example 14 were examined, and it was found that it had an isotropic light diffusibility. Therefore, the uneven pattern forming sheet of Example 14 can be used as a light diffusing sheet.

(Example 15)

A concave-convex pattern forming sheet was obtained in the same manner as in Example 13 except that dots were printed by an ink jet printer (FUJI FILM Co., Ltd. Dimatix Materials Printer DMP-2831). The concave-convex pattern of the uneven pattern of the uneven pattern forming sheet had a mode-to-average pitch of 5 μm, an aspect ratio of 1, and an alignment degree of 0.3.

The optical characteristics of the obtained concavo-convex pattern forming sheet were examined, and it was found to have the same anisotropic diffusing property as in Example 13. Therefore, the uneven pattern forming sheet of Example 15 can be used as a light diffusing sheet.

(Embodiment 16)

The concave-convex pattern forming sheet obtained by the method of Example 13 was used as an original for an engineering sheet, and a light-diffusing sheet was obtained in the following manner.

That is, the epoxy acrylate-based prepolymer, the 2-ethylhexyl acrylate and the benzophenone were coated on the surface of the original sheet of the engineering sheet obtained in Example 13 on which the uneven pattern was formed. An uncured ultraviolet curable resin composition of a photopolymerization initiator.

Then, on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the original sheet of the engineering sheet, a triacetonitrile cellulose film having a thickness of 50 μm was superposed and pressed.

Next, ultraviolet rays are irradiated from the upper surface of the triacetone cellulose film to harden the uncured ultraviolet curable resin, and the cured product is peeled off from the original sheet of the engineering sheet, thereby obtaining a light-diffusing sheet.

The obtained light-diffusing sheet has the same unevenness as that of the light-diffusing sheet of Example 13. Domains have the same light diffusivity.

(Example 17)

The concave-convex pattern forming sheet obtained by the method of Example 13 was used as an original for an engineering sheet, and a light-diffusing sheet was obtained in the following manner.

That is, the surface on which the uneven pattern was formed on the original sheet obtained in Example 13 was subjected to nickel plating treatment, and thereafter the nickel plating was peeled off, whereby a secondary work sheet having a thickness of 200 μm was obtained. Applying an epoxidized acrylate-based prepolymer, a 2-ethylhexyl acrylate, and a benzophenone-based photopolymerization initiator to the surface on which the uneven pattern is formed on the secondary work piece An ultraviolet curable resin composition.

Then, on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the secondary engineering sheet, a triacetonitrile cellulose film having a thickness of 50 μm was superposed and pressed.

Then, ultraviolet rays were irradiated from the upper surface of the triacetone cellulose film to harden the uncured curable resin, and the cured product was peeled off from the secondary work piece, thereby obtaining a light-diffusing sheet.

The obtained light-diffusing sheet had the same unevenness as that of the light-diffusing sheet of Example 13, and had the same light diffusibility.

(Embodiment 18)

A light-diffusing sheet was obtained in the same manner as in Example 17 except that the thermosetting epoxy resin was used in place of the ultraviolet curable resin composition, and the thermosetting epoxy resin was cured by heating instead of ultraviolet irradiation. .

The obtained light-diffusing sheet had the same unevenness as that of the light-diffusing sheet of Example 13, and had the same light diffusibility.

(Embodiment 19)

In the same manner as in Example 17, a secondary work piece having a thickness of 200 μm was obtained. On the surface of the secondary work piece on which the concave-convex pattern is formed, a polymethyl group having a thickness of 50 μm is used. The methyl acrylate film is overlapped and heated. The heated and softened polymethyl methacrylate film and the secondary engineering sheet are pressed from both sides, and then cooled. The film was cured, and the cured polymethyl methacrylate film was peeled off from the secondary work piece, thereby obtaining a light-diffusing sheet.

The obtained light-diffusing sheet had the same unevenness as that of the light-diffusing sheet of Example 13, and had the same light diffusibility.

(Embodiment 20)

Heat shrinkable film made of polyethylene terephthalate having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-10S manufactured by Mitsubishi Plastics Co., Ltd., glass transition temperature: 70 ° C) On one of the faces, a mask having a large number of dot-shaped openings (aperture 50 μm) was placed.

The pattern of the opening portion of the mask is a gray scale pattern as follows, that is, in a range of a width of 5 cm × a length of 10 cm, from one end of the length direction to the other end, the area ratio of the opening portion is in the range of 0 to 100%. 10% increase per 1cm. Further, the opening area ratio of 0% means no opening, and 100% means full opening.

Then, aluminum was placed in a state of one surface of the heat-shrinkable film, and aluminum having a Young's modulus of 70 GPa was vacuum-deposited to have a thickness of 0.05 μm to obtain a vapor-deposited sheet.

At this time, an aluminum dot is formed on one surface of the heat shrinkable film. The pattern of the point is a gray scale pattern as described below, that is, in the range of 5 cm in width × 10 cm in length, from one end in the longitudinal direction toward the other end, the ratio of the area of the opening portion increases from 1 to 100% per 1 cm. 10%. Further, a dot area ratio of 0% means that it is not completely vapor-deposited, and 100% means that it is fully vapor-deposited.

Then, the vapor-deposited sheet was heated at 100 ° C for 1 minute, whereby it was heat-shrinked to 40% of the length before heating (that is, it was deformed at a deformation rate of 60%). At the time of heat shrinkage, the dots are deformed in a folded manner to form a corrugated concave-convex pattern having a period along a direction orthogonal to the contraction direction. Thereby, the concave-convex pattern formed on one side of the concave-convex region is formed sheet.

The concave-convex pattern of the uneven pattern of the concave-convex pattern forming sheet had a mode-to-average pitch of 3 μm, an aspect ratio of 1, and an alignment degree of 0.3.

Then, the obtained concave-convex pattern forming sheet was used as an original sheet of the engineering sheet, and a light-diffusing sheet was obtained in the following manner.

That is, an unhardened layer containing an epoxy acrylate-based prepolymer, a 2-ethylhexyl acrylate, and a benzophenone-based photopolymerization initiator is applied to the surface on which the concave-convex pattern is formed on the original sheet of the engineering sheet. An ultraviolet curable resin composition.

Then, a film of a triacetyl cellulose film having a thickness of 50 μm was placed on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the original sheet of the engineering sheet, and pressed.

Then, ultraviolet rays are irradiated from the upper surface of the triacetone cellulose film to harden the uncured ultraviolet curable resin, and the cured product is peeled off from the original sheet of the engineering sheet, thereby obtaining a light-diffusing sheet.

The optical characteristics of the light-diffusing sheet obtained by the inspection were found to have the same anisotropy as that of Example 13.

(Example 21)

A polyethylene terephthalate shrink film (HISHIPET PX-40S manufactured by Mitsubishi Plastics Co., Ltd.) having a thickness of 25 μm and a Young's modulus of 3 GPa in a biaxial direction was used to replace Mitsubishi Resin Co., Ltd. A concave-convex pattern forming sheet was obtained in the same manner as in Example 20 except that HISHIPET LX-60S was produced. The concave-convex pattern of the uneven pattern of the concave-convex pattern forming sheet has a mode width of 3 μm and an aspect ratio of 1.

Then, using this concave-convex pattern to form a sheet, a light-diffusing sheet was obtained in the same manner as in Example 20. The optical characteristics of the light-diffusing sheet of Example 21 were examined and found to have an isotropic light diffusibility.

(Example 22)

The concave-convex pattern forming sheet obtained by the method of Example 20 was used as an original for an engineering sheet, and a light-diffusing sheet was obtained in the following manner.

Namely, the surface on which the uneven pattern was formed on the original sheet obtained in Example 20 was subjected to a nickel plating treatment, and thereafter the nickel plating was peeled off, whereby a secondary work sheet having a thickness of 200 μm was obtained. Applying an epoxidized acrylate-based prepolymer, a 2-ethylhexyl acrylate, and a benzophenone-based photopolymerization initiator to the surface on which the uneven pattern is formed on the secondary work piece An ultraviolet curable resin composition.

Then, a film of a triacetyl cellulose film having a thickness of 50 μm was placed on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the secondary work piece, and pressed.

Then, ultraviolet rays were irradiated from the upper surface of the triacetone cellulose film to harden the uncured curable resin, and the cured product was peeled off from the secondary work piece, thereby obtaining a light-diffusing sheet.

The obtained light-diffusing sheet had the same unevenness as that of the light-diffusing sheet of Example 20, and had the same light diffusibility.

(Example 23)

A light-diffusing sheet was obtained in the same manner as in Example 22 except that the thermosetting epoxy resin was used in place of the ultraviolet curable resin composition, and the thermosetting epoxy resin was cured by heating instead of ultraviolet irradiation. .

The obtained light-diffusing sheet had the same unevenness as that of the light-diffusing sheet of Example 20, and had the same light diffusibility.

(Example 24)

In the same manner as in Example 22, a secondary work piece having a thickness of 200 μm was obtained. On the surface of the secondary work piece on which the uneven pattern was formed, a polymethyl methacrylate film having a thickness of 50 μm was laminated and heated. The heated and softened polymethyl methacrylate film and the secondary engineering sheet are pressed from both sides to be cooled. After curing, the cured polymethyl methacrylate film was peeled off from the secondary work piece, thereby obtaining a light-diffusing sheet.

The obtained light-diffusing sheet had the same unevenness as that of the light-diffusing sheet of Example 20, and had the same light diffusibility.

In the optical sheets of Examples 13 to 24 in which the uneven portions were mixed on one surface, light was diffused by the uneven pattern of the uneven portions, and thus the light diffusibility was excellent. Further, in the optical sheet, since the uneven portion is disposed densely on the other end side in the longitudinal direction, the light diffusing property is higher at the other end side in the longitudinal direction.

The Young's modulus in the following examples was measured using a tensile tester (TE-7001, manufactured by Tester Industries, Inc.) in accordance with JIS K 7113-1995. When the temperature is not specifically described, it is a value at 23 °C.

(Embodiment 25)

A polyethylene terephthalate shrink film having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-60S manufactured by Mitsubishi Plastics Co., Ltd., glass transition temperature: 70 ° C) The polymethyl methacrylate (P4831-MMA, manufactured by POLYMER SOURCE Co., Ltd., glass transition temperature: 100 ° C) diluted with toluene was applied by a spin coating method to have a thickness of 12 nm to form a hard layer. And get a layer of film.

Then, the laminated sheet was heated at 80 ° C for 1 minute, whereby the heat was shrunk to 40% of the length before heating (that is, it was deformed at a deformation rate of 60%), thereby obtaining a hard layer having a wave. The uneven pattern of the uneven pattern forms a sheet, and the corrugated pattern has a period along a direction orthogonal to the contraction direction.

Further, the polyethylene terephthalate shrink film and the polymethyl methacrylate have a Young's modulus at 80 ° C of 50 MPa and 1 GPa, respectively.

(Example 26)

On the side of a polyethylene terephthalate shrink film having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-61S manufactured by Mitsubishi Plastics Co., Ltd., glass transition temperature: 70 ° C) , coated with polyvinyl alcohol diluted in water (PVA105 manufactured by KURARAY Co., Ltd., glass transition temperature: 85 ° C), and having a thickness of 12 nm to form a hard layer to obtain a laminated sheet.

Then, the laminated sheet was heated at 75 ° C for 1 minute, whereby it was heat-shrinked to 50% of the length before heating (that is, it was deformed at a deformation rate of 50%), thereby obtaining a hard layer having a wave. The concave-convex pattern forming sheet of the uneven pattern has a period in a direction orthogonal to the contraction direction.

Further, the polyethylene terephthalate shrink film and the Young's modulus of the polyvinyl alcohol at 75 ° C were 50 MPa and 1 GPa, respectively.

(Example 27)

On the side of a polyethylene terephthalate shrink film having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-61S manufactured by Mitsubishi Plastics Co., Ltd., glass transition temperature: 70 ° C) A fluororesin (NANOS B manufactured by Tandk Co., Ltd.) was vapor-deposited and cured to have a thickness of 12 μm to form a hard layer to obtain a laminated sheet.

Then, the laminated sheet was heated at 75 ° C for 1 minute, whereby it was heat-shrinked to 50% of the length before heating (that is, it was deformed at a deformation rate of 50%), thereby obtaining a hard layer having a wave. The concave-convex pattern forming sheet of the uneven pattern has a period in which the corrugated concave-convex pattern has a direction orthogonal to the contraction direction.

(Embodiment 28)

A sheet having a thickness of 5 mm composed of polydimethyl siloxane having a Young's modulus of 2 MPa was stretched to twice the length by a stretching device, and fixed in this state. Next, in this state, polymethyl methacrylate (P4831-MMA, manufactured by POLYMER SOURCE Co., Ltd., glass transition temperature: 100 ° C) diluted in toluene was applied to one side of the sheet to have a thickness of 12 nm to form a hard layer to obtain a laminated sheet.

Then, the stretching is stopped, and the laminated sheet is returned to the length before stretching, whereby the hard layer is compressed at a deformation rate of 50% to obtain a concave layer having a wavy concave-convex pattern. The pattern forming sheet has a period along a direction orthogonal to the contraction direction.

(Example 29)

Polymethyl methacrylate diluted in toluene (P4831-MMA manufactured by POLYMER SOURCE Co., Ltd.) on one side of a sheet having a thickness of 5 mm composed of polydimethyl methoxy hydride having a Young's modulus of 2 MPa The glass transition temperature was 100 ° C) to a thickness of 12 nm to form a hard layer to obtain a laminated sheet.

Then, the laminated sheet is stretched to a length of five times by a stretching device, whereby the length of the normal direction of the stretching direction is contracted by 50% (that is, it is deformed by a deformation ratio of 50%), thereby obtaining The hard layer has a concave-convex pattern forming sheet having a corrugated concave-convex pattern, and the corrugated concave-convex pattern has a period along the stretching direction.

(Comparative Example 10)

A concavo-convex pattern-forming sheet was obtained in the same manner as in Example 25 except that polymethyl methacrylate was applied in such a manner that the thickness was 60 nm.

(Comparative Example 11)

An attempt was made to use a biaxially-oriented polyethylene terephthalate film (G2 manufactured by Teijin Co., Ltd.) having a thickness of 50 μm and a Young's modulus of 5 GPa to replace the shrink film, and the same as in Example 25. In a manner, a sheet for concave and convex pattern engineering is obtained. However, since the wavy concave-convex pattern was not formed, the uneven pattern engineering sheet was not obtained.

(Comparative Example 12)

One side of a polyethylene terephthalate shrink film (HISHIPET LX-10S manufactured by Mitsubishi Plastics Co., Ltd.) having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction was diluted with toluene. Polymethyl methacrylate (P4831-MMA, manufactured by POLYMER SOURCE Co., Ltd., glass transition temperature: 100 ° C) was used to have a thickness of 12 nm to form a smooth hard surface layer to obtain a laminated sheet.

Then, the laminated sheet was heated at 70 ° C for 1 minute to shrink it to the length before heating. A concave-convex pattern forming sheet was obtained in the same manner as in Example 27 except that 97% of the degree (that is, it was deformed by a deformation ratio of 3%) to obtain a sheet for uneven patterning.

(Comparative Example 13)

On the surface of a polyethylene terephthalate shrink film having a thickness of 50 μm and a Young's modulus of 3 GPa in a uniaxial direction (HISHIPET LX-10S manufactured by Mitsubishi Plastics Co., Ltd., glass transition temperature: 70 ° C) Coating polydimethyl methoxyoxane with a Young's modulus of 2 MPa (Shin-Etsu Chemical Co., Ltd. KS847T, glass transition temperature -120 °C) and platinum catalyst (Shin-Etsu Chemical Industry Co., Ltd.) by spin coating The dispersion obtained by diluting in toluene of PS-1) was made to have a thickness of 12 nm to form a hard layer to obtain a laminated sheet.

Then, the laminated sheet was heated at 100 ° C for 1 minute to be heat-shrinked, whereby the uneven pattern forming sheet was obtained. However, since the hard layer was not deformed by the meandering, the wavy concave-convex pattern was not formed.

(Embodiment 30)

The concave-convex pattern forming sheet obtained by Example 25 was used as an engineering sheet, and an optical element was obtained in the following manner.

That is, the epoxy acrylate-based prepolymer, 2-ethylhexyl acrylate, and benzophenone-based light were applied to the surface of the engineering sheet obtained in Example 25 on which the uneven pattern was formed. An uncured ultraviolet curable resin composition of a polymerization initiator.

Then, on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the engineering sheet, a triethylene glycol film having a thickness of 50 μm was superposed and pressed.

Next, ultraviolet rays are irradiated from the top of the triacetone cellulose film to harden the uncured ultraviolet curable resin composition, and the cured product is peeled off from the engineering sheet, thereby obtaining an optical element.

(Example 31)

The concave-convex pattern forming sheet obtained by Example 25 was used as an engineering sheet as follows The optical element is obtained in the manner described.

That is, the surface on which the uneven pattern was formed on the engineering sheet obtained in Example 25 was subjected to nickel plating treatment, and thereafter the nickel plating was peeled off, whereby a nickel-plated sheet having a thickness of 200 μm was obtained. Applying an uncured ultraviolet light containing an epoxy acrylate prepolymer, a 2-ethylhexyl acrylate, and a benzophenone photopolymerization initiator to the surface on which the uneven pattern is formed on the nickel-plated sheet A curable resin composition.

Then, on the surface of the coating film of the uncured ultraviolet curable resin composition which was not in contact with the nickel-plated sheet, a triacetonitrile cellulose film having a thickness of 50 μm was superposed and pressed.

Next, ultraviolet rays are irradiated from the upper surface of the triacetone cellulose film to harden the uncured ultraviolet curable resin composition, and the cured product is peeled off from the nickel-plated sheet, whereby an optical element is obtained.

(Example 32)

An optical element was obtained in the same manner as in Example 31 except that the thermosetting epoxy resin was used instead of the ultraviolet curable resin composition, and the thermosetting resin was cured by heating instead of ultraviolet irradiation.

(Example 33)

In the same manner as in Example 11, a nickel-plated sheet having a thickness of 200 μm was obtained. On the surface of the nickel-plated sheet on which the uneven pattern was formed, a polymethyl methacrylate film having a thickness of 50 μm was superposed and heated. The heated and softened polymethyl methacrylate film and the nickel-plated sheet are pressed from the two sides, and then cooled. It was cured and peeled off from the nickel-plated sheet, whereby a concave-convex pattern-forming sheet was obtained.

The upper surfaces of the optical elements of the concave-convex pattern forming sheets of Examples 25 to 33 and Comparative Examples 10 to 13 were imaged by an atomic force microscope (NanoScope III manufactured by Veeco Co., Ltd., Japan).

For the optical elements of the concave-convex pattern forming sheets of Examples 25 to 33 and Comparative Examples 10 to 13, the depths of the ten concave-convex patterns were measured in an image of an atomic force microscope, and the depth was the same. The average depth is obtained by averaging.

The values of these are shown in Table 3.

Further, the applicability of the optical element was evaluated on the basis of the following criteria based on the most frequent pitch of the concave-convex pattern and the average depth of the bottom. The evaluation results are shown in Table 3.

○: The most frequent pitch of the uneven pattern is 1 μm or less, and the average depth is 10% or more when the most frequent pitch is 100%, and is suitable as an optical element.

X: The most frequent pitch of the concave-convex pattern is more than 1 μm, or the average depth is less than 10% when the maximum-frequency pitch is 100%, which is not suitable as an optical element.

In Examples 25 to 29 and Comparative Examples 10 and 12, the laminated sheet provided with the hard layer on one surface of the first resin substrate was subjected to serpentine deformation, and the hard layer was transferred from the glass to the glass of the first resin. The second resin having a transition temperature higher than 10 ° C is formed, and in this production method, the uneven pattern forming sheet can be easily produced. Further, in the concave-convex pattern forming sheets obtained in Examples 25 to 29, the groove width of the concave-convex pattern is 1 μm or less, and the average depth of the bottom portion is 10% or more when the above-mentioned maximum frequency pitch is 100%, which is suitable. As an optical component. In Examples 25-29, the most frequent spacing and average are obtained as described above. The depth is such that the thickness of the surface smooth hard layer is 50 μm or less and the deformation ratio is 50% or more.

Further, according to the manufacturing method of Examples 30 to 33 in which the uneven pattern forming sheet obtained in Example 25 is used as an engineering sheet, it is possible to easily produce a concave-convex pattern having the same frequency-to-frequency spacing and average depth as that of the concave-convex pattern forming sheet. Optical element.

Further, in Comparative Example 10, since the thickness of the surface hard smooth layer exceeded 50 nm, the pitch of the concave-convex pattern of the obtained concave-convex pattern forming sheet was more than 1 μm. Further, in Comparative Example 12, since the deformation ratio was 3%, the average depth of the bottom portion of the uneven pattern of the obtained concave-convex pattern forming sheet was less than 10% when the most frequent pitch was 100%. These comparative examples are not necessarily suitable as optical elements.

On the other hand, Comparative Example 11 in which a biaxially-oriented polyethylene terephthalate film was used as a resin layer, and a laminated sheet in which a glass transition temperature of the second resin was lower than a glass transition temperature of the first resin was used. In the manufacturing method of Comparative Example 13, since the smooth surface of the hard layer was not meandered, the uneven pattern was not formed.

[Industrial availability]

The uneven pattern forming sheet of the present invention can be used as a light diffuser, and can be easily produced. According to the method for producing a concave-convex pattern forming sheet of the present invention, the concave-convex pattern forming sheet used as the light diffusing body can be easily produced.

The light diffusing body of the present invention is excellent in the anisotropy of diffusion. According to the method for producing a light-diffusing body and the method for producing a light-diffusing body of the present invention, a light-diffusing body in which a concave-convex pattern having the same maximum pitch and average depth as that of the uneven pattern-forming sheet can be easily and largely produced.

The optical sheet of the present invention is excellent in target optical characteristics and can easily make optical characteristics uneven. The light-diffusing sheet of the present invention is excellent in target light diffusibility, and can easily make the light diffusibility uneven.

According to the diffused light guiding body and the backlight unit of the present invention, the light from the light source can be sufficiently Anisotropic spread.

The uneven pattern forming sheet of the present invention can be preferably used as an optical element such as an antireflection body or a phase difference plate. Moreover, the uneven pattern forming sheet of the present invention can also be preferably used as an engineering sheet for producing an optical element, and the engineering sheet for producing an optical element is used as a mold for producing an optical element having a corrugated concave-convex pattern.

10‧‧‧ concave pattern forming sheet

11‧‧‧Substrate (transparent resin layer)

12‧‧‧ Hard layer

12a‧‧‧ concave pattern

12b‧‧‧ bottom

Claims (3)

A diffusing light guide body comprising a transparent resin layer in which a meandering corrugated pattern is formed on one surface, wherein a pitch of a concave-convex pattern exceeds 1.0 μm and is 20 μm or less, and an average depth B of the unevenness The ratio (B/A) to the most frequent spacing A is 0.1 to 3.0. A backlight unit comprising: a diffusing light guiding body according to claim 1; a reflecting plate disposed opposite to a surface of the diffusing light guiding body opposite to a surface on which the concave-convex pattern is formed; and a light source; It is disposed between the diffusion light guide and the reflector. A backlight unit comprising: a diffusing light guiding body according to claim 1; a reflecting plate disposed opposite to a surface of the diffusing light guiding body opposite to a surface on which the concave-convex pattern is formed; and a light source; It is adjacent to either side of the diffused light guide.