JP2001290009A - Light diffusion layer, light diffusive sheet and optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusion layer having glare shielding property and good surface hardness and to provide a light diffusive sheet with the light diffusion layer and an optical element with the light diffusive sheet. SOLUTION: The light diffusion layer is formed by overlaying a resin coating layer (b) whose surface has a fine rugged structure on a resin coating layer (a) not containing fine particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light diffusion layer (anti-glare layer) used for suppressing a decrease in visibility of a screen in a liquid crystal display (LCD), an EL, a plasma display (PDP), and the like. The present invention relates to a light diffusing sheet having the light diffusing layer, and an optical element provided with the light diffusing sheet.

[0002]

2. Description of the Related Art Conventionally, in an image display device such as an LCD, the visibility of an image is hindered by room lighting such as a fluorescent lamp on the surface of the display device, sunlight incident from a window, and a shadow of an operator. Can be Therefore, on the display surface, in order to improve the visibility of the image, the surface reflected light is diffused, the specular reflection of external light can be suppressed, and reflection of the external environment can be prevented (having anti-glare properties). A light diffusion layer having an uneven structure is provided. As a method of forming the light diffusion layer, a method of forming a resin film layer by coating an ultraviolet-curable resin solution in which fine particles are dispersed has been mainly used because the structure can be easily miniaturized and the productivity is good. I have.

[0003] However, when the surface of the fine uneven structure is formed with an ultraviolet-curable resin solution in which fine particles are dispersed, the thickness of the coating film itself tends to be thin, and the hardness of the cured film on the surface of the fine uneven structure decreases, and the damage resistance is increased. Sex becomes weak.

[0004] In addition, the recent miniaturization of the pixel size has resulted in high definition (for example, 100 ppi or more) images,
In the case of a high-quality LCD such as a flat panel LCD, when the light diffusion layer is attached to the LCD, glare (a difference in brightness) caused by a fine uneven structure formed by particles protruding from the surface of the light diffusion layer is considered. Portion) occurs on the LCD surface and deteriorates visibility (the image is coarse and loses sharpness). However, in order to improve the glare phenomenon, for example, fine particles dispersed in an ultraviolet-curable resin solution include: When organic fine particles such as styrene beads are used, or when a thixotropic agent is contained to cause particles to protrude from the surface of the fine uneven structure, the surface hardness of the fine uneven structure tends to be particularly weak.

[0005]

SUMMARY OF THE INVENTION The present invention provides a high definition L
An object is to provide a light diffusion layer having antiglare properties and good surface hardness even when applied to a CD.
It is still another object of the present invention to provide a light diffusing sheet having the light diffusing layer and an optical element provided with the light diffusing sheet.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, have found that the above object can be achieved by a light diffusion layer having the following structure. It has arrived.

That is, the present invention provides a light diffusion layer characterized in that a resin coating layer (b) having a fine uneven structure is superposed on a resin coating layer (a) containing no fine particles. About.

The light diffusion layer of the present invention has a resin film layer (a) forming a back layer in addition to a resin film layer (b) forming a surface layer of the light diffusion layer. Layer (a)
Thereby, the adhesion to a transparent substrate or the like supporting the light diffusion layer is improved, and a high surface hardness is realized. Fine particles are not contained in the resin film layer (a) in order to improve the adhesiveness and to impart the damage resistance by improving the surface hardness.

It is preferable that the resin film layer (b) of the light diffusion layer contains fine particles, and the fine surface uneven structure of the resin film layer (b) is formed by the fine particles. Further, it is preferable that the resin film layer (a) and the resin film layer (b) are formed of an ultraviolet curable resin.

By using fine particles for forming the resin film layer (b), a resin film layer having a fine uneven surface structure can be easily and reliably realized. Further, the light diffusion layer composed of the resin coating layer (a) and the resin coating layer (b) can be efficiently formed by a simple processing operation by a curing treatment by irradiation of the ultraviolet ray-curable resin. .

In the light diffusion layer, the fine particles contained in the resin film layer (b) are preferably organic fine particles. Further, it is preferable that the resin film layer (b) contains a thixotropic agent.

When the light diffusion layer contains organic fine particles and a thixotropic agent, the surface hardness of the light diffusion layer having fine irregularities on the surface tends to be weak. According to this, a decrease in surface hardness can be suppressed.

Further, the light diffusion layer is a resin film layer (b)
When the thickness of the resin film layer is 1 μm or less, it is one of preferred embodiments that the thickness of the resin film layer (b) is set to 1/6 or less of the thickness of the resin film layer (a).

By setting the thickness of the resin film layer (b) within the above range, the sharpness can be effectively prevented without deteriorating the sharpness of a high-definition image due to downsizing of the pixel size and the like. In addition, a light diffusion layer having excellent film strength and good damage resistance can be obtained.

[0015] The present invention also relates to a light diffusing sheet, wherein the light diffusing layer is provided on at least one surface of a transparent substrate.

Further, the present invention relates to an optical element, wherein the light diffusion layer or the light diffusion sheet is provided on one side or both sides of the optical element.

The light diffusion layer of the present invention can be used for various applications as a light diffusion sheet provided on a transparent substrate.
For example, it is used for an optical element and is used for a liquid crystal display device having excellent display quality such as visibility.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a transparent substrate 1
Above, as a light diffusion layer 4, a lower resin coating layer 2 (a)
And a light diffusing sheet in which a resin film layer 2 (b) having a fine uneven structure on the surface is superimposed on the upper layer. The fine uneven structure of the resin film layer 2 (b) is formed by the fine particles 3. Although FIG. 1 shows the case where each of the resin film layers 2 (a) and 2 (b) is a single layer, these may be formed by a plurality of layers.

Examples of the transparent substrate 1 include transparent polymers such as polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate polymers; and acrylic polymers such as polymethyl methacrylate. Film. Styrene polymers such as polystyrene and acrylonitrile-styrene copolymer; polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure; olefin polymers such as ethylene-propylene copolymer; vinyl chloride polymers; nylon and aromatic polyamides And a film made of a transparent polymer such as an amide-based polymer. Furthermore, imide-based polymers, sulfone-based polymers, polyethersulfone-based polymers, polyetheretherketone-based polymers, polyphenylene sulfide-based polymers, vinyl alcohol-based polymers, vinylidene chloride-based polymers, vinyl butyral-based polymers, arylate-based polymers, and polyoxymethylene-based polymers A film made of a transparent polymer such as a polymer, an epoxy-based polymer, or a blend of the above polymers may also be used. One or more transparent polymers can be used as appropriate, and a resin having excellent mechanical strength, thermal stability and water resistance is preferable. In particular, those having low optical birefringence are preferably used.

The thickness of the transparent substrate 1 can be determined as appropriate, but is generally about 10 to 500 μm from the viewpoints of workability such as strength and handleability, thin layer properties, light transmittance and the like. Especially 2
It is preferably from 0 to 300 μm, more preferably from 30 to 200 μm. The surface of the transparent substrate 1 can be appropriately subjected to a corona treatment, an ultraviolet irradiation treatment, a plasma treatment, a sputter etching treatment, an undercoat treatment, etc. for the purpose of improving the adhesion of a layer attached thereto.

The resin film layer 2 (a), the resin film layer 2
As the resin forming (b), a resin having sufficient strength as a film after forming the resin film layer and having transparency can be used without particular limitation. Resin film layer 2 (a), resin film layer 2
The resin forming (b) may be the same or different, but the same resin is preferable from the viewpoint of preventing adhesion and preventing reflection on the sea surface.

Examples of the resin include a thermosetting resin, a thermoplastic resin, an ultraviolet-curable resin, an electron beam-curable resin, and a two-component mixed type resin. The light diffusion layer can be efficiently formed by a simple processing operation, and from the viewpoint of damage resistance such as hard coat property for the purpose of preventing surface damage, etc.
Curable resins, particularly UV-curable resins, are preferred.

Examples of the UV-curable resin include various resins such as polyester, acrylic, urethane, amide, silicone, and epoxy resins, and include UV-curable monomers, oligomers, and polymers. It is. The UV-curable resin preferably used is, for example, a resin having a UV-polymerizable functional group, particularly a resin containing an acrylic monomer or oligomer having two or more, especially 3 to 6 functional groups. Further, an ultraviolet polymerization initiator is blended with the ultraviolet curing resin.

The resin film layer 2 (b) may contain additives such as a leveling agent, a thixotropic agent, and an antistatic agent. In forming a resin film layer, by including a thixotropic agent (silica, mica, etc. of 0.1 μm or less), a fine uneven structure can be easily formed by projecting particles on the surface of the resin film layer (light diffusion layer). Can be. The content of these additives is
Usually, 1 to 1 with respect to 100 parts by weight of the ultraviolet curable resin.
It is preferable to use about 5 parts by weight.

The formation of the superposed layer composed of the resin film layer 2 (a) and the resin film layer 2 (b) is performed by forming the film by an appropriate method such as the coextrusion molding method of the resin, A method of sequentially forming a film by repeatedly applying a resin, a method of sequentially forming a cured film in the case of a curable resin, and the like can be employed. The curable resin (for example, ultraviolet curable resin: coating liquid) applied on the transparent substrate 1 is cured after drying. The coating liquid is applied by an appropriate method according to the resin type such as fountain, die coater, casting, spin coating, fountain metalling, and gravure.

The method for forming the surface of the fine uneven structure of the resin film layer 2 (b) is not particularly limited, and an appropriate method can be adopted. For example, the surface of the film used for forming the resin film layer 2 (b) is roughened in advance by a suitable method such as sand blasting, embossing roll, chemical etching, or buffing to form a fine uneven structure on the film surface. And the like, a method of forming the surface of the material itself for forming the resin film layer 2 (b) into a fine uneven structure. Further, there is a method in which a resin coating layer is separately applied on the resin coating layer 2 (b), and a fine uneven structure is provided on the surface of the resin coating layer by a transfer method using a mold or the like. Further, as shown in FIG. 1, there is a method in which fine particles 3 are dispersed and contained in the resin film layer 2 (b) to give a fine uneven structure. As a method for forming the fine uneven structure, two or more methods may be combined to form a layer in which the surfaces of the fine uneven structure in different states are combined.

Among the methods for forming the resin film layer 2 (b), the resin film layer containing the fine particles 3 dispersed therein from the viewpoints of the formability of the surface of the fine uneven structure, the prevention of deterioration of image clarity, the light diffusion effect and the like. The method of providing 2 (b) is preferable.

As the fine particles 3, those which are insoluble in the resin for forming the resin film layer 2 (b) and have transparency, such as various metal oxides, glass, and plastics, can be used without any particular limitation. For example, silica and alumina, titania and zirconia, calcium oxide and tin oxide, inorganic fine particles that may be conductive such as indium oxide and cadmium oxide, antimony oxide, polymethyl methacrylate, polystyrene, polyurethane, acrylic-styrene copolymer,
Examples include crosslinked or uncrosslinked organic fine particles and silicone fine particles made of various polymers such as benzoguanamine, melamine, and polycarbonate, with organic fine particles being preferred. One or more of these fine particles 3 can be appropriately selected and used.

The average particle diameter of the fine particles 3 is preferably 10 μm or less, in order to effectively prevent the appearance of an external scene having a fine uneven structure on the surface which does not reduce the sharpness of a high-definition image due to a reduction in pixel size or the like. Is from 0.1 to 5 μm, more preferably from 0.5 to 3 μm. The proportion of the fine particles 3 is not particularly limited, but is 50 parts by weight or less, preferably 2 to 40 parts by weight, based on 100 parts by weight of the resin for forming the resin film layer 2 (b) from the viewpoint of preventing the appearance of the outside scene from being reflected. More preferably, it is 5 to 30 parts by weight.

The thickness of the resin coating layer 2 (a) and the resin coating layer 2 (b) forming the light diffusion layer of the superposed layer is not particularly limited, but the thickness of the resin coating layer 2 (a) is not harmful. 2-30 μm, preferably 3-20 μm, from the viewpoint of properties and thinning
m, more preferably 5 to 10 μm.

The thickness of the resin film layer 2 (b) is not particularly limited, but is 0.1 to 10 μm, preferably 1 to 7 μm.
m, more preferably 3 to 5 μm.

When the thickness of the resin coating layer 2 (b) is set to 1 μm or less and a thin and light diffusing effect is exhibited, the thickness of the resin coating layer 2 (b) is maintained when the fine particles 3 are used. From the viewpoint of force and surface protrusion, preferably 0.1 to 0.9 μm
m, more preferably 0.2 to 0.8 μm. In this case, the thickness of the resin film layer 2 (a) is 1/6 or less of the resin film layer 2 (b) from the viewpoint of damage resistance. It is preferable that

When the resin coating layer 2 (b) is formed using fine particles, the light diffusing layer is a resin coating layer 2 forming a surface layer.
Fine particles are unevenly distributed only in (b). As described above, since the fine particles 3 are not uniformly dispersed in the light diffusion layer, the sharpness of the transmitted image does not decrease due to irregular reflection at the interface of the resin coating layer 2 (a) of the back layer, and the quality of the clear image is reduced. Good. Further, since the resin film layer 2 (a) of the back layer does not have the fine particles 3, the surface hardness is not reduced and the damage resistance is excellent. From these points, it is preferable that the light diffusing layer is such that the fine particles 3 are localized on the surface of the resin coating layer 2 (b) in a single layer arrangement as much as possible.

An antireflection layer can be further provided on the uneven surface of the resin film layer (b), which is the outermost surface of the light diffusion layer, for the purpose of suppressing surface reflection of external light. The anti-reflection layer has a lower refractive index than the resin film layer (b). For example, the anti-reflection layer may be a multilayer coating film of an inorganic oxide or an interference film made of a coating film of a low refractive index material such as a fluorine compound. Can be formed. Although the thickness of the antireflection layer is not particularly limited, it is preferably about 0.05 to 0.3 μm, particularly preferably 0.1 to 0.3 μm. The low refractive index layer can be formed on the surface of the resin film layer 2 by an appropriate method. As a forming method, an appropriate coating method such as an evaporation method such as an ion plating method or a sputtering method, a plating method or a sol-gel method, or a method similar to the method of forming the resin film layer 2 can be employed.

An optical element can be bonded to the transparent substrate 1 of the light diffusing sheet shown in FIG. 1 (not shown). Examples of the optical element include a polarizing plate, a retardation plate, an elliptically polarizing plate, a polarizing plate with optical compensation, and the like, and these can be used as a laminate. In addition, the light diffusion layer can be provided directly on an optical element or an optical element on a display device.

As the polarizing plate, iodine or a dye is adsorbed on a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, an ethylene / vinyl acetate copolymer partially saponified film and stretched. And polarizing films such as dehydration products of polyvinyl alcohol and dehydrochlorination products of polyvinyl chloride. Examples of the retardation plate include a uniaxially or biaxially stretched film of a polymer film exemplified as the transparent substrate and a liquid crystal polymer film. The retardation plate may be formed as a superimposed body of two or more stretched films. Elliptical polarizing plates and polarizing plates with optical compensation
It can be formed by laminating a polarizing plate and a retardation plate. The elliptically polarizing plate and the polarizing plate with optical compensation have a light diffusion layer formed on the surface on the polarizing plate side.

The adhesion of the optical element may be performed, if necessary, using an acrylic, rubber, silicone, polyester, polyurethane, or polyether adhesive or a hot melt adhesive, such as transparency or weather resistance. And an appropriate adhesive layer having excellent adhesiveness. Among these, acrylic adhesives have excellent optical transparency, moderate wettability, cohesiveness,
It shows adhesive properties such as adhesiveness and is preferable. In addition, those having excellent heat resistance and weather resistance are more preferable.

As the acrylic pressure-sensitive adhesive, for example, one or more alkyl (meth) acrylates having an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, a butyl group, and an ethylhexyl group are mainly used. The base polymer is an acrylic polymer used as a component, or a copolymer of one or more appropriate monomer components other than an alkyl acrylate for the purpose of modifying the adhesive properties as required. Things.

The adhesive layer may be attached to the transparent substrate 1 or the optical element, for example, by directly applying an adhesive liquid by an appropriate developing method such as a casting method or a coating method, or by applying an adhesive on the separator in the same manner as described above. It can be performed by an appropriate method such as a method of forming a layer and transferring it. The thickness of the pressure-sensitive adhesive layer can be appropriately determined according to the adhesive strength and the like, and is generally 1 to 500 μm.

The adhesive layer may contain natural or synthetic resins, if necessary, for example, appropriate additives such as tackifiers, fillers, pigments, coloring agents and antioxidants. It can also be blended to form an adhesive layer exhibiting light diffusion.
The adhesive layer can also be provided as a superimposed layer of different compositions or types. When the adhesive layer is exposed on the surface, it is preferable to cover and protect the surface with a separator or the like before practical use.

The light diffusing sheet and the optical element may be provided with a transparent conductive layer for the purpose of preventing electrification and blocking electromagnetic waves. One or two or more transparent conductive layers can be provided on the surface of the transparent substrate, or inside the optical element or at an appropriate position on the surface. The formation of the transparent copper transmission, for example, a coating method of a transparent conductive paint, a vacuum deposition method or a sputtering method of a conductive material, an ion plating method or a chemical vapor deposition method,
It can be performed by an appropriate method such as a spray pyrolysis method, an electroplating method, or a combination thereof.

Examples of the conductive material include indium oxide, tin oxide, mixed oxides of indium and tin, cadmium oxide, titanium oxide, indium, tin, gold, silver, and the like.
Appropriate materials such as platinum, palladium, copper, aluminum, nickel, chromium, iron, cobalt, copper iodide, and alloys thereof can be used alone or in combination of two or more, and there is no particular limitation, and any of known materials can be used. .

Further, a fluorine-based surface treatment coat may be provided on the surface of the resin film layer 2 (b) for the purpose of making it difficult for stains such as fingerprints to adhere and for facilitating wiping of the adhered stains. it can. In forming the coat, for example, an appropriate fluorine-based compound capable of forming a film having a small surface energy such as a fluorine-based resin or a fluorine-based silane coupling agent can be used. Furthermore, a light diffusion layer,
The transparent substrate and the optical element are provided with an ultraviolet absorbing ability by, for example, a method of treating with a UV absorbent such as a salicylic acid ester compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt compound, or the like. Can also.

[0044]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 UV-curable resin (urethane acrylate monomer)
A composition comprising 100 parts by weight and 3 parts by weight of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) is applied onto triacetyl cellulose, and then cured by irradiation with ultraviolet light to form a surface having a thickness of 5 μm.
Was formed (resin film layer (a)).

Next, 5 parts by weight of acrylic (polymethyl methacrylate) beads having an average particle diameter of 2 μm as fine particles, 100 parts by weight of an ultraviolet curable resin (urethane acrylate monomer), and a photopolymerization initiator (manufactured by Ciba Specialty Chemicals, Inc.) Irgacure 184) A resin solution obtained by mixing 3 parts by weight and a solvent (toluene) measured to have a solid content of 50% by weight was applied on the resin film layer (a), After drying for 5 minutes,
A light diffusing sheet having a resin coating layer (b) on the surface of the fine uneven structure having a thickness of 3 to 5 μm which was cured by irradiation with ultraviolet light was produced.

Example 2 In Example 1, 5 parts by weight of polystyrene beads having an average particle diameter of 2 μm were used as the fine particles used for forming the resin film layer (b), and a thixotropic agent (Corp Chemical Co., Ltd.) was added to the resin solution. (Trade name: Lucentite) was prepared in the same manner as in Example 1 except that 3 parts by weight was added.

Comparative Example 1 The light diffusing property was the same as in Example 1 except that the resin film layer (b) was formed on the triacetyl cellulose without forming the resin film layer (a). A sheet was prepared.

Comparative Example 2 The light diffusing property was the same as in Example 2 except that the resin film layer (b) was formed on the triacetyl cellulose without forming the resin film layer (a). A sheet was prepared.

(Measurement of Surface Hardness) The light-diffusing sheets obtained in Examples and Comparative Examples were measured according to JIS K5400.
The pencil hardness on the surface of the light diffusion layer was measured according to the method described in Example 1. Table 1 shows the results.

[0051]

[Table 1] As shown in Table 1, the light-diffusing sheet obtained in the example has a pencil hardness of 3H that can withstand a practical level, and has a light-diffusing layer excellent in damage resistance.

The light diffusing sheets obtained in the above Examples and Comparative Examples, to which a polarizing plate (185 μm) was adhered, were adhered to a glass substrate, and a mask pattern (opening ratio: 25 %), And glare under the fluorescent lamp (anti-glare property) was visually evaluated, and all were good.

Example 3 10 parts by weight of a crosslinking agent (trimethylolpropane trimethacrylate) and 100 parts by weight of a UV-curable acrylic urethane oligomer and a photopolymerization initiator (trade name Irgacure 907, manufactured by Ciba Specialty Chemicals)
A composition consisting of 3 parts by weight was applied to one surface of a 50 μm-thick triacetylcellulose film and cured by irradiation with ultraviolet light from a high-pressure mercury lamp to form a 6 μm-thick resin film layer (a).

Further, 10 parts by weight of transparent fine silica particles having an average particle diameter of 2 μm, 10 parts by weight of the crosslinking agent, 3 parts by weight of the photopolymerization initiator, and 100 parts by weight of the polyfunctional oligomer, and an organic solvent (toluene) Is mixed with a homogenizer, and a dispersion having a solid content of 15% by weight is applied with a bar coater, dried at 120 ° C. for 5 minutes, and then cured by ultraviolet irradiation with a high-pressure mercury lamp to retain transparent fine particles. A light diffusing sheet having a 0.8 μm-thick resin film layer (b) formed thereon was prepared.

When the cross section of the light diffusing sheet was observed with a scanning electron microscope, the fine particles were unevenly distributed in a single layer at the interface of the resin film layer (b). A fine uneven structure was formed.

The light diffusing sheet is made of color TF of high definition
When the resin film layer (b) was applied to the T liquid crystal display device as the surface side, no decrease was observed in the sharpness of the image, the outside scene was not reflected, the antiglare effect was excellent, and the surface was resistant to damage. It was excellent. The pencil hardness was 3H.

[Brief description of the drawings]

FIG. 1 is an example of a sectional view of a light diffusing sheet of the present invention.

[Explanation of symbols]

 1: transparent substrate 2: resin film layer 3: fine particles 4: light diffusion layer

[Procedure amendment]

[Submission date] May 23, 2001 (2001.5.2)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 3

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 8

[Correction method] Change

[Correction contents]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/30 349 G09F 9/30 349Z (72) Inventor Takuya Matsunaga 1-1-1 Shimohozumi, Ibaraki-shi, Osaka No. 2 Inside Nitto Denko Corporation (72) Shimohozumi, Inventor 1-1-2, Shimohozumi, Ibaraki City, Osaka Prefecture Inside Nitto Denko Corporation (72) Takayuki Shigematsu 1-1-2, Shimohozumi, Ibaraki City, Osaka Prefecture No. Nitto Denko Corporation (72) Inventor Shigeo Kobayashi 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation F-term (reference) 2H042 BA02 BA03 BA12 BA15 BA20 2H091 FA31X FA31Z FA37X FA37Z FB02 FB12 FC23 FC25 LA03 4F100 AH00B AH00E AH00H AK01A AK01B AK01D AK01E AK25 AK25B AK25E AK25H AK51 AL06 AR00C BA02 BA05 BA06 BA10B BA10E BA25 CA13B CA13E CA23B CA23E CA30 DD07 B DD07E DE01B DE01E DE01H GB41 JB14A JB14B JB14D JB14E JK12 JN01C JN30 YY00B YY00E 5C094 AA31 BA27 BA31 BA43 EB02 ED13 JA08 5G435 AA01 BB06 BB12 FF06 HH04

Claims (8)

[Claims] 1. A light diffusion layer in which a resin film layer (b) having a fine uneven structure on the surface is superimposed on a resin film layer (a) containing no fine particles. 2. The light diffusion layer according to claim 1, wherein the resin coating layer (b) contains fine particles, and the fine surface unevenness structure of the resin coating layer (b) is formed by the fine particles. 3. The light diffusing sheet according to claim 1, wherein the resin film layer (a) and the resin film layer (b) are formed of an ultraviolet curable resin. 4. The light diffusion layer according to claim 1, wherein the fine particles are organic fine particles. 5. The light diffusion layer according to claim 1, wherein the resin film layer (b) contains a thixotropic agent. 6. The method according to claim 1, wherein the thickness of the resin film layer (b) is 1 μm or less, and 1/6 or less of the thickness of the resin film layer (a). 3. The light diffusion layer according to 1. 7. A light diffusion sheet, wherein the light diffusion layer according to claim 1 is provided on at least one surface of a transparent substrate. 8. An optical element, wherein the light diffusing layer according to claim 1 or the light diffusing sheet according to claim 6 is provided on one side or both sides of the optical element.