JP2019191426A - Optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical member capable of suppressing glare and improving visibility without causing optical interference with an image display panel. An optical member arranged on the surface of an image display panel, which has at least a transparent base material and an antireflection layer and a diffusion layer which are arranged so as to be laminated on the transparent base material. The surface of the layer has an irregular roughness structure having an arithmetic average roughness Ra of 0.01 μm or more and 1.00 μm or less and an average roughness period RSm of 1 μm or more and 30 μm or less. The diffusing layer is composed of a binder and light diffusing particles dispersed in the binder, and has a haze value of 15% or more and 60% or less, and the light diffusing particles are refracted with respect to the binder. It is characterized by being composed of materials having different rates. [Selection diagram] Figure 1

Description

  The present invention relates to an optical member having a light diffusion function that can be suitably applied to an image display panel.

  In order to prevent a decrease in visibility due to reflected light on the display surface side of an image display panel such as a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), or a cathode ray tube display (CRT). In many cases, an antireflection film is provided.

  As the antireflection film, for example, a structure in which several layers of interference films having different refractive indexes are laminated on a base material is known, and usually manufactured by a method such as a vacuum deposition method, a sputtering method, or a coating method. Is done. Also known is an antireflection film in which a concavo-convex structure is formed on the surface of the film by dispersing fine particles in the film material or transferring the concavo-convex shape of the mold to the film surface using a mold such as an embossed plate. It has been.

  In recent years, a film in which an antiglare property is imparted to an antireflection film has been proposed. For example, Patent Document 1 discloses a reflection using an embossed plate produced by electrical discharge machining and having an arithmetic average roughness Ra of 0.3 to 1.0 μm and an average unevenness period RSm of 5 to 30 μm. A method for producing an antiglare film by forming an unevenness while heating one side of a polymer film having a prevention layer is disclosed.

JP 2004-333936 A

  However, when the anti-glare film described in Patent Document 1 is used in a high-definition image display panel, the surface may appear to be glaring due to light interference generated between fine pixels. There has been a problem of reducing the visibility of the image display panel.

  The present invention has been made in view of the above problems, and provides an optical member capable of improving visibility by suppressing glare without causing optical interference with an image display panel. Objective.

The optical member of the present invention has the following configuration.
An optical member disposed on the surface of an image display panel, comprising at least a transparent substrate, and an antireflection layer and a diffusion layer disposed on the transparent substrate, wherein the antireflection layer comprises a surface An irregular uneven structure having an arithmetic average roughness Ra of 0.01 μm or more and 1.00 μm or less and an average unevenness period RSm of 1 μm or more and 30 μm or less is transferred and formed as described above. The layer is composed of a binder and light diffusing particles dispersed in the binder, and has a haze value of 15% or more and 60% or less, and the light diffusing particles have a refractive index different from that of the binder. It is comprised from these.

  In the present invention, the light diffusing particles preferably have a particle size in the range of 3 μm to 15 μm.

  Moreover, in this invention, it is preferable that the said diffusion layer consists of an adhesive sheet | seat with which the said light-diffusion particle is disperse | distributed and thickness is 15 micrometers or more and 100 micrometers or less.

  In the present invention, it is preferable that the pressure-sensitive adhesive sheet has a thickness of 20 μm and an adhesive strength to the glass plate of 2.0 N / 25 mm or more.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the optical member which can suppress glare and can improve visibility, without producing optical interference with respect to an image display panel.

It is sectional drawing which shows the optical member of 1st Embodiment of this invention. It is a principal part expanded sectional view which shows the transparent substrate which comprises the optical member of 1st Embodiment of this invention. It is sectional drawing which shows the optical member of 2nd Embodiment of this invention. It is sectional drawing which shows the optical member of 3rd Embodiment of this invention.

  Hereinafter, an optical member according to an embodiment of the present invention will be described with reference to the drawings. Each embodiment described below is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for convenience, and the dimensional ratio of each component is the same as the actual one. Not necessarily.

(First embodiment)
FIG. 1 is a cross-sectional view showing the optical member of the first embodiment.
The optical member 10 of the present embodiment is provided on the surface (display surface) side of the liquid crystal display (image display panel) 1, for example, and suppresses glare of the liquid crystal display 1 by diffusing the emitted light of the liquid crystal display 1. , Improve the visibility of the displayed image.
The optical member 10 includes a transparent substrate 11 and a transparent substrate 13 having an antireflection layer 12 provided on the one surface 11 a side of the transparent substrate 11, and the liquid crystal display 1 on the other surface 11 b side of the transparent substrate 11. And a diffusion layer 14 disposed on the surface.

FIG. 2 is an enlarged cross-sectional view of a main part showing the transparent substrate constituting the optical member in more detail.
The transparent substrate 13 includes a transparent base material 11 having optical transparency, a barrier layer 15 disposed on the one surface 11a side of the transparent base material 11, a buffer layer 16 provided on the barrier layer 15, and a buffer layer. 16 and an antireflection layer 12 provided on the substrate 16.

Among these, the buffer layer 16 is obtained by fully curing a semi-cured material layer formed of a semi-cured material of the ultraviolet curable resin composition formed on the barrier layer 15 at the time of production by ultraviolet irradiation.
Moreover, the barrier layer 15 should just be formed as needed, and the structure which formed the buffer layer 16 without providing the barrier layer 15 in the one surface 11a side of the transparent base material 11 may be sufficient.

  The transparent substrate 13 preferably has an irregular uneven structure on the surface of the antireflection layer 12. By having an irregular concavo-convex structure on the surface of the antireflection layer 12, antiglare properties can be expressed. The irregular concavo-convex structure in the present embodiment means that a plurality of concave portions and convex portions having different shapes, dimensions, and the like are formed in an irregular arrangement pattern (interval).

  The arithmetic average roughness Ra of the surface of the concavo-convex structure of the antireflection layer 12 is 0.01 to 1.00 μm, and preferably 0.03 to 0.50 μm. When the arithmetic average roughness Ra is 0.01 μm or more, sufficient antiglare property can be exhibited. On the other hand, if the arithmetic average roughness Ra is 1.00 μm or less, glare is unlikely to occur.

  Moreover, 0.01-1.25 micrometers is preferable and, as for arithmetic mean height Sa of the surface of the uneven structure of the antireflection layer 12, 0.03-0.60 micrometer is more preferable. If the arithmetic average height Sa is 0.01 μm or more, sufficient antiglare property can be exhibited. On the other hand, if the arithmetic average height Sa is 1.25 μm or less, glare is unlikely to occur.

  Moreover, the average uneven | corrugated period RSm of the surface of the uneven structure of the antireflection layer 12 is 1-30 micrometers, and 5-15 micrometers is preferable. When the average unevenness period RSm is 1 μm or more, sufficient antiglare property can be exhibited. On the other hand, if the average unevenness period RSm is 30 μm or less, glare is unlikely to occur.

  In this embodiment, arithmetic average roughness Ra, arithmetic average height Sa, and average uneven | corrugated period RSm are the values measured by ISO 25178, and can be measured using a commercially available surface texture measuring machine. Examples of the measuring instrument having these shapes include a shape analysis laser microscope.

(Transparent substrate)
The transparent substrate 11 constituting the transparent substrate 13 has translucency, and is made of, for example, a thermoplastic resin having a total light transmittance of 85% or more at a wavelength of 750 to 400 nm. As such a light-transmitting thermoplastic resin, for example, an acrylic resin typified by polymethyl methacrylate, a polycarbonate resin, a polyethylene terephthalate resin, a polyallyl diglycol carbonate resin, a polystyrene resin, and the like are suitable.

  As for the transparent base material 11, it is preferable that the one surface 11a side in which the antireflection layer 12 is formed is formed with acrylic resin, polycarbonate resin, or polyethylene terephthalate resin. Therefore, a laminate of polycarbonate resin and acrylic resin can also be suitably used as the constituent material of the transparent substrate 11.

The transparent substrate 11 may be colored with an oil-soluble dye or the like as long as the translucency is not impaired.
Moreover, the surface 11a side in which the antireflection layer 12 is formed on the transparent substrate 11 may be surface-treated with a known primer for the purpose of improving the adhesion between the transparent substrate 11 and the adjacent layer.

  The thickness of the transparent substrate 11 is not particularly limited as long as the thickness is uneven, but in general, the thickness is preferably moderately thin, for example, about 30 to 1000 μm. Is preferred.

(Barrier layer)
The barrier layer 15 constituting the transparent substrate 13 imparts chemical resistance to the transparent substrate 13, and when the transparent substrate 13 is exposed to chemicals such as brake oil, the transparent base material 11 is swollen by the chemicals. It plays a role to prevent

  The barrier layer 15 contains a tetrafunctional or higher urethane acrylate. A tetrafunctional or higher urethane acrylate forms a hard part by curing. Therefore, the transparent substrate 13 provided with the barrier layer 15 has high chemical resistance.

  The tetrafunctional or higher-functional urethane acrylate is obtained by further reacting a hydroxyl group-containing (meth) acrylate with a terminal isocyanate compound, which is a reaction product of a polyvalent isocyanate compound and a polyol compound having a plurality of hydroxyl groups (terminal isocyanate compound and Among the reaction product with a hydroxyl group-containing (meth) acrylate, it has four or more (meth) acryloyl groups.

  For example, pentaerythritol di (meth) acrylate is reacted with a terminal isocyanate compound, and two (meth) acryloyl groups are introduced into both ends of the isocyanate compound, respectively, and used as a tetrafunctional urethane acrylate. Also, pentaerythritol tri (meth) acrylate is reacted with both terminal isocyanates (for example, trihexadiethylene diisocyanate) to introduce three (meth) acryloyl groups at each molecular chain end. Used as urethane acrylate.

Examples of the polyvalent isocyanate compound constituting the tetra- or higher functional urethane acrylate include aliphatic diisocyanates such as ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate; isophorone diisocyanate, 4,4′-methylenebis (Cyclohexyl isocyanate), alicyclic diisocyanates such as ω, ω'-diisocyanate dimethylcyclohexane; aromatic rings such as tolylene diisocyanate, xylylene diisocyanate, α, α, α ', α'-tetramethylxylylene diisocyanate Aliphatic diisocyanates having the following.
These may be used individually by 1 type and may use 2 or more types together.

Examples of the polyol compound constituting the tetra- or more functional urethane acrylate include glycerin, diglycerin, triglycerin, trimethylolethane, trimethylolpropane, sorbitol, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tripentaerythritol, adamantane. Triol etc. are mentioned.
These may be used individually by 1 type and may use 2 or more types together.

Examples of the hydroxyl group-containing (meth) acrylate constituting the tetrafunctional or higher urethane acrylate include pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and the like.
These may be used individually by 1 type and may use 2 or more types together.

The elongation rate of the barrier layer 15 is preferably the same as the elongation rate of the semi-cured material layer which is a form at the time of manufacturing the buffer layer 16. The elongation percentage of the barrier layer 15 is obtained as follows.
That is, for a test piece having a barrier layer formed on a substrate, the sample is heated to near the Tg of the substrate, and then sandwiched between L-shaped bent male and female molds so that the substrate surface is on the concave side. The female mold is pressed and cooled. After cooling, observe the bent convex surface with a microscope to check for cracks. The same operation is performed by changing the bending radius (bending R), and the elongation to the bending R when no crack is generated is calculated.

  The thickness of the barrier layer 15 is preferably 50 to 200 nm, and more preferably 60 to 150 nm. If the thickness of the barrier layer 15 is 50 nm or more, sufficient hardness and chemical resistance can be obtained. The effects such as chemical resistance by the barrier layer tend to be easily obtained as the barrier layer becomes thicker. From the viewpoint of a balance between the effects such as chemical resistance and the thickness of the entire transparent substrate 13, the thickness of the barrier layer 15 is preferably 200 nm or less.

  Note that the barrier layer 15 having the above-described configuration may be formed as necessary, and may be a configuration in which no barrier layer is provided.

(Buffer layer)
The buffer layer 16 constituting the transparent substrate 13 is obtained by fully curing a semi-cured material layer made of a semi-cured material of the ultraviolet curable resin composition formed on the barrier layer 15 during production by ultraviolet irradiation. Here, the semi-cured material layer that becomes the buffer layer 16 by curing will be described. The semi-cured product layer is an intermediate product when the buffer layer 16 is manufactured, and serves as a buffer material when the surface of the antireflection layer 12 is processed into an uneven shape.

  The uneven shape on the surface of the antireflection layer 12 is formed by forming the unevenness on the surface of the antireflection layer 12 using a transfer mold having an uneven structure on the transfer surface. At this time, even if the surface of the antireflection layer 12 is processed into an uneven shape by the semi-cured material layer, the external force applied to the antireflection layer 12 during the transfer process is absorbed by the semi-cured material layer. Therefore, the antireflection layer 12 can be prevented from being damaged, and the original function (antireflection property) of the antireflection layer 12 can be maintained well.

The semi-cured product layer, which is an intermediate product when the buffer layer 16 is produced, is composed of a semi-cured product of an ultraviolet curable resin composition.
In the present embodiment, semi-curing refers to a state before the ultraviolet curable resin composition is completely cured, and further refers to a state in which the curing reaction can proceed. Specifically, it indicates a state in which the curing reaction of the ultraviolet curable resin composition is completed by 60 to 90%.

The Young's modulus of the semi-cured product layer is 0.1 to 2.5 GPa, preferably 0.3 to 2.0 GPa, and more preferably 0.4 to 1.5 GPa. When the Young's modulus of the semi-cured material layer is 0.1 GPa or more, the antireflection layer 12 can be formed on the semi-cured material layer, and the antireflection property can be maintained. On the other hand, when the Young's modulus of the semi-cured material layer is 2.5 GPa or less, the pressure at the time of processing the surface of the antireflection layer 12 into a concavo-convex shape (during transfer processing) can be sufficiently absorbed.
In this embodiment, the Young's modulus is obtained by performing a bending test under the conditions of a temperature of 23 ° C. and a speed of 1 mm / min in accordance with JIS K 7171 and drawing a strain-stress curve. It is a value represented by the slope of the straight line portion.

  The elongation percentage of the semi-cured product layer, which is an intermediate product when producing the buffer layer 16, is preferably 105 to 200%, more preferably 108 to 180%, and still more preferably 115 to 160%. If the elongation percentage of the semi-cured product layer is 105% or more, the pressure at the time of processing the surface of the antireflection layer 12 into a concavo-convex shape (during transfer processing) can be absorbed more. On the other hand, if the elongation percentage of the semi-cured material layer is 200% or less, the antireflection layer 12 can be formed on the semi-cured material layer, and the antireflection property can be maintained.

In addition, the elongation rate of a semi-hardened | cured material layer is calculated | required as follows.
That is, for a test piece in which a semi-cured material layer is formed on a sample base material, after heating to near the Tg of the base material, the base material surface is on the concave side between the L-shaped bending male and female dies. Hold and cool male and female molds. After cooling, observe the bent convex surface with a microscope to check for cracks.
The same operation is performed by changing the bending radius (bending R), and the elongation to the bending R when no crack is generated is calculated.

The ultraviolet curable resin composition preferably contains a trifunctional or lower functional urethane acrylate, a silane coupling agent, and a metal chelate compound.
Moreover, as for an ultraviolet curable resin composition, it is more preferable that silica particle and tetrafunctional or more urethane acrylate are further included.

  Trifunctional or lower urethane acrylate is obtained by further reacting a hydroxyl group-containing (meth) acrylate with a terminal isocyanate compound which is a reaction product of a polyvalent isocyanate compound and a polyol compound having a plurality of hydroxyl groups (terminal isocyanate compound and Among the reaction product with a hydroxyl group-containing (meth) acrylate, it has 3 or less (meth) acryloyl groups. A urethane acrylate having one (meth) acryloyl group is monofunctional (monofunctional), a urethane acrylate having two (meth) acryloyl groups is bifunctional, and a urethane acrylate having three (meth) acryloyl groups is Trifunctional.

  For example, pentaerythritol mono (meth) acrylate is reacted with a terminal isocyanate compound, and one (meth) acryloyl group is introduced into both ends of the isocyanate compound, respectively, and used as a bifunctional urethane acrylate. In addition, pentaerythritol mono (meth) acrylate and pentaerythritol di (meth) acrylate are reacted with a terminal isocyanate compound, one (meth) acryloyl group is introduced at one end of the isocyanate compound, and the other end is introduced. Those in which two (meth) acryloyl groups are introduced are used as a trifunctional urethane acrylate.

  Examples of the polyvalent isocyanate compound and polyol compound constituting the trifunctional or lower urethane acrylate include the polyvalent isocyanate compound and polyol compound exemplified above in the description of the tetrafunctional or higher functional urethane acrylate.

Examples of the hydroxyl group-containing (meth) acrylate constituting trifunctional or lower urethane acrylate include pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, and phenylglycidyl ether (meth) acrylate.
These may be used individually by 1 type and may use 2 or more types together.

  Examples of the tetrafunctional or higher urethane acrylate include the tetrafunctional or higher urethane acrylates exemplified above in the description of the barrier layer 15.

  A trifunctional or lower urethane acrylate forms a part that is relatively flexible by curing, and a tetrafunctional or higher urethane acrylate forms a hard part by curing. Thus, the buffer layer 16 having a hardness can be formed.

  The content of trifunctional or lower urethane acrylate is preferably 5% by mass or more, and the content of tetrafunctional or higher urethane acrylate is 95% by mass or less, based on the total mass of all urethane acrylates contained in the ultraviolet curable resin composition. Is preferred. If the content of the trifunctional or lower urethane acrylate is 5% by mass or more, the adhesion between the semi-cured product layer and the transparent substrate 11 is increased, and the followability of the semi-cured product layer to the transparent substrate 11 is not easily impaired. Become. As a result, cracks and the like are less likely to occur when the transparent substrate 13 is press-formed.

  Moreover, when the ultraviolet curable resin composition contains silica particles, it is possible to suppress the dropping of the silica particles. On the other hand, if the content of the tetrafunctional or higher urethane acrylate is 95% by mass or less, the hardness of the buffer layer 16 can be maintained well.

  The content of the trifunctional or lower urethane acrylate is preferably 5 to 100 mass%, more preferably 12 to 90 mass%, and the content of the tetrafunctional or higher urethane acrylate is preferably 0 to 95 mass%, and 10 to 88 mass%. % Is more preferable.

The silane coupling agent is a component that enhances adhesion with the transparent substrate 11 and the antireflection layer 12. Moreover, when an ultraviolet curable resin composition contains a silica particle, it is also a component which suppresses the drop-off | omission of a silica particle and is stably disperse | distributed and hold | maintained.
Examples of the silane coupling agent include compounds represented by the following general formula (1).
R ¹ _n —Si (OR ² ) _4-n (1)
In Formula (1), R ¹ is an alkyl group or an alkenyl group, R ² is an alkyl group, an alkoxyalkyl group, an acyloxy group, or a halogen atom, and n is a number of 1 or 2.

Examples of R ¹ include an alkyl group such as a methyl group, an ethyl group, and a propyl group, and an alkenyl group such as a vinyl group. The alkyl group includes a halogen atom such as chlorine, a mercapto group, an amino group, and a (meth) acryloyl group. And may be substituted with a functional group such as an oxirane ring-containing group.
R ² is an alkyl group, an alkoxyalkyl group, an acyloxy group or a halogen atom, and OR ² bonded to the silicon atom is a hydrolyzable group.

Examples of the compound represented by the formula (1) include vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and γ- (meth) acryloxypropyl. Trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ- Aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, γ- (N-styrylmethyl-β-aminoethylamino) propyltrimethoxysilane Hydrochloride, γ-chloro Trimethoxysilane, .gamma.-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltrichlorosilane, dimethyl dichlorosilane, and the like.
These may be used individually by 1 type and may use 2 or more types together.

Such a silane coupling agent undergoes polycondensation simultaneously with hydrolysis to form a polymer connected in a network by Si—O—Si bonds. Therefore, the buffer layer 16 can be made dense by using such a silane coupling agent.
In the semi-cured product layer, which is an intermediate product when the buffer layer 16 is manufactured, and the buffer layer 16, at least a part of the silane coupling agent is present as a hydrolyzate.

  1-30 mass parts is preferable with respect to 100 mass parts of all the urethane acrylates contained in a ultraviolet curable resin composition, and, as for content of a silane coupling agent, 10-15 mass parts is more preferable. If content of a silane coupling agent is 1 mass part or more, adhesiveness with the transparent base material 11 or the antireflection layer 12 will increase, and it can suppress that a semi-hardened material layer and the buffer layer 16 peel. On the other hand, when the content of the silane coupling agent is 30 parts by mass or less, the basic performance of the semi-cured product layer (absorption of external force applied to the antireflection layer 12) can be sufficiently exhibited.

  The metal chelate compound is used to introduce a cross-linked structure into the semi-cured material layer and make the semi-cured material layer and the buffer layer 16 denser. Although the above-described trifunctional or lower urethane acrylate imparts flexibility, it tends to lower the density. The metal chelate compound compensates for a decrease in denseness without impairing the flexibility of the semi-cured product layer. In other words, the metal chelate compound is used to adjust mechanical properties such as hardness which are influenced by the denseness of the film. In particular, when the antireflection layer 12 described later also contains a metal chelate compound, the adhesion between the semi-cured material layer or the buffer layer 16 and the antireflection layer 12 is further improved, and when the transparent substrate 13 is press-formed. Can be effectively prevented.

As the metal chelate compound, compounds of titanium, zirconium, aluminum, tin, niobium, tantalum and lead containing a bidentate ligand are suitable.
A bidentate ligand is a chelating agent having a coordination number of 2, that is, two atoms capable of coordinating to a metal, and generally forms a 5- to 7-membered ring by O, N, and S atoms. Thus, a chelate compound is formed. Examples of these bidentate ligands include acetylacetonate, ethylacetoacetate, diethylmalonate, dibenzoylmethanato, salicylate, glycolato, catecholate, salicylaldehyde, oxyacetophenonate, biphenolato, pyromeconato, oxynaphthoquino Nato, oxyanthraquinonato, tropolonato, vinochilato, glycinato, alaninato, antroninato, picolinato, aminophenolato, ethanolaminato, mercaptoethylaminato, 8-oxyquinolinato, salicylaldiminato, benzoinoxymato, salicylaldoximato, oxy Azobenzenato, phenylazonaphtholate, β-nitroso-α-naphtholate, diazoaminobenzenato, biuretate, diphenylcarbazonate, diphenylthiocarbazonate, biphenyl Examples thereof include guanidate and dimethylglyoximato.

As the metal chelate compound, a compound represented by the following general formula (2) is preferable.
M ¹ (Li) _k (X) _m−k (2)
In the formula (2), M ¹ is titanium, zirconium, aluminum, tin, niobium, tantalum or lead, Li is a bidentate ligand, X is a monovalent group, and m is an atom of M ¹ K is a number of 1 or more within a range not exceeding the valence of M ¹ .

M ¹ is preferably titanium, zirconium, or aluminum.
X is preferably a hydrolyzable group, and among them, an alkoxy group is particularly preferable.

Examples of the metal chelate compound represented by the formula (2) include a Ti chelate compound, a Zr chelate compound, and an Al chelate compound.
Specific examples of the Ti chelate compound include triethoxy mono (acetylacetonato) titanium, tri-n-propoxy mono (acetylacetonato) titanium, tri-i-propoxy mono (acetylacetonato) titanium, tri-n. -Butoxy mono (acetylacetonato) titanium, tri-sec-butoxy mono (acetylacetonato) titanium, tri-t-butoxy mono (acetylacetonato) titanium, diethoxy bis (acetylacetonato) titanium, di -N-propoxy bis (acetylacetonato) titanium, di-i-propoxy bis (acetylacetonato) titanium, di-n-butoxy bis (acetylacetonato) titanium, di-sec-butoxy bis (acetyl) Acetonato) titanium, di-t-butoxy bis (acetylacetonate) Titanium, monoethoxy-tris (acetylacetonato) titanium, mono-n-propoxy-tris (acetylacetonato) titanium, mono-i-propoxy-tris (acetylacetonato) titanium, mono-n-butoxy-tris (acetyl) Acetonato) titanium, mono-sec-butoxy-tris (acetylacetonato) titanium, mono-t-butoxy-tris (acetylacetonato) titanium, tetrakis (acetylacetonato) titanium, triethoxy-mono (ethylacetoacetate) Titanium, tri-n-propoxy mono (ethyl acetoacetate) titanium, tri-i-propoxy mono (ethyl acetoacetate) titanium, tri-n-butoxy mono (ethyl acetoacetate) titanium, tri-sec -Butoxy mono (ethylacetoacetate) tita , Tri-t-butoxy mono (ethyl acetoacetate) titanium, diethoxy bis (ethyl acetoacetate) titanium, di-n-propoxy bis (ethyl acetoacetate) titanium, di-i-propoxy bis ( Ethyl acetoacetate) titanium, di-n-butoxy bis (ethyl acetoacetate) titanium, di-sec-butoxy bis (ethyl acetoacetate) titanium, di-t-butoxy bis (ethyl acetoacetate) Titanium, monoethoxy tris (ethyl acetoacetate) titanium, mono-n-propoxy tris (ethyl acetoacetate) titanium, mono-i-propoxy tris (ethyl acetoacetate) titanium, mono-n-butoxy Tris (ethyl acetoacetate) titanium, mono-sec-butoxy tris (ethyl acetoacetate) ) Titanium, mono-t-butoxy tris (ethylacetoacetato) titanium, tetrakis (ethylacetoacetato) titanium, mono (acetylacetonato) tris (ethylacetoacetato) titanium, bis (acetylacetonato) bis ( Examples include ethyl acetoacetate) titanium and tris (acetylacetonato) mono (ethyl acetoacetate) titanium.
These may be used individually by 1 type and may use 2 or more types together.

Specific examples of the Zr chelate compound include triethoxy mono (acetylacetonato) zirconium, tri-n-propoxy mono (acetylacetonato) zirconium, tri-i-propoxy mono (acetylacetonato) zirconium, tri-n. -Butoxy mono (acetylacetonato) zirconium, tri-sec-butoxy mono (acetylacetonato) zirconium, tri-t-butoxy mono (acetylacetonato) zirconium, diethoxybis (acetylacetonato) zirconium, di -N-propoxy bis (acetylacetonato) zirconium, di-i-propoxy bis (acetylacetonato) zirconium, di-n-butoxy bis (acetylacetonato) zirconium, di-sec-butoxy bis (acetylato) Tonato) zirconium, di-t-butoxy bis (acetylacetonato) zirconium, monoethoxytris (acetylacetonato) zirconium, mono-n-propoxytris (acetylacetonato) zirconium, mono-i-propoxytris (Acetylacetonato) zirconium, mono-n-butoxy-tris (acetylacetonato) zirconium, mono-sec-butoxy-tris (acetylacetonato) zirconium, mono-t-butoxy-tris (acetylacetonato) zirconium, tetrakis (Acetylacetonato) zirconium, triethoxy mono (ethylacetoacetate) zirconium, tri-n-propoxy mono (ethylacetoacetate) zirconium, tri-i-propoxy mono (ethylacetoacetate) G) Zirconium, tri-n-butoxy mono (ethyl acetoacetate) zirconium, tri-sec-butoxy mono (ethyl acetoacetate) zirconium, tri-t-butoxy mono (ethyl acetoacetate) zirconium, diethoxy・ Bis (ethyl acetoacetate) zirconium, di-n-propoxy bis (ethyl acetoacetate) zirconium, di-i-propoxy bis (ethyl acetoacetate) zirconium, di-n-butoxy bis (ethyl aceto) Acetato) zirconium, di-sec-butoxy bis (ethylacetoacetate) zirconium, di-t-butoxy bis (ethylacetoacetate) zirconium, monoethoxy tris (ethylacetoacetate) zirconium, mono-n -Propoxy tris (ethyla Cetoacetato) zirconium, mono-i-propoxy-tris (ethylacetoacetato) zirconium, mono-n-butoxy-tris (ethylacetoacetato) zirconium, mono-sec-butoxy-tris (ethylacetoacetato) zirconium, mono -T-butoxy tris (ethylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium, mono (acetylacetonato) tris (ethylacetoacetate) zirconium, bis (acetylacetonato) bis (ethylacetoacetate) ) Zirconium, tris (acetylacetonato) mono (ethylacetoacetate) zirconium and the like.
These may be used individually by 1 type and may use 2 or more types together.

Specific examples of the Al chelate compound include diethoxy mono (acetylacetonato) aluminum, monoethoxy bis (acetylacetonato) aluminum, di-i-propoxy mono (acetylacetonato) aluminum, mono-i-propoxy Bis (acetylacetonato) aluminum, mono-i-propoxy bis (ethylacetoacetate) aluminum, monoethoxy bis (ethylacetoacetate) aluminum, diethoxy mono (ethylacetoacetate) aluminum, di-i- Examples include propoxy mono (ethyl acetoacetate) aluminum.
These may be used individually by 1 type and may use 2 or more types together.

  The content of the metal chelate compound is preferably 0.1 to 3.0 parts by mass, and 0.5 to 1.5 parts by mass with respect to 100 parts by mass of all urethane acrylates contained in the ultraviolet curable resin composition. More preferred. If content of a metal chelate compound exists in the said range, adhesiveness with the reflection preventing layer 12 will improve.

The silica particles are components that enhance adhesion to the antireflection layer 12 and effectively suppress cracking of the buffer layer 16 and the antireflection layer 12 when the transparent substrate 13 is press-formed.
As the silica particles contained in the ultraviolet curable resin composition, solid colloidal silica (solid silica sol) can be used. Here, “solid” means that the density is 1.9 g / cm ³ or more.

The average particle size of the solid silica sol is preferably 5 to 500 nm. If the average particle diameter of the solid silica sol is within the above range, properties such as hardness can be imparted uniformly throughout the semi-cured product layer.
The refractive index of the solid silica sol is preferably 1.44 to 1.50. When the refractive index of the solid silica sol is within the above range, properties such as hardness can be imparted uniformly throughout the semi-cured product layer.

  The solid silica sol is commercially available, for example, in the form of a sol in which solid silica particles are dispersed in an organic solvent such as isopropanol or methyl isobutyl ketone.

  80 mass parts or less are preferable with respect to 100 mass parts of all the urethane acrylates contained in a ultraviolet curable resin composition, as for content of a silica particle, 10-60 mass parts is more preferable, and 20-50 mass parts is further. preferable. If the content of the silica particles is within the above range, while maintaining the basic properties of the semi-cured product layer, the adhesion with the antireflection layer 12 is improved, and cracks and the like when press-molding the transparent substrate 13 are caused. It can be effectively prevented.

  The thickness of the buffer layer 16 obtained by fully curing the semi-cured product layer is, for example, 1.0 to 10.0 μm, preferably 1.2 to 8.5 μm, more preferably 1.5 to 5.0 μm. More preferably, the thickness is from 5 to 3.0 μm. When the thickness of the buffer layer 16 is 1.0 μm or more, the basic performance of the semi-cured product layer (absorption of external force applied to the antireflection layer 12) can be sufficiently exhibited. On the other hand, if the thickness of the buffer layer 16 is 10.0 μm or less, it is possible to suppress an increase in physical property difference (for example, flexibility and elongation) from the transparent base material 11, and cracks when forming irregularities by transfer. Etc. can be effectively prevented. Further, the uneven structure on the transfer surface of the transfer mold can be sufficiently transferred (that is, the transfer rate is high).

(Antireflection layer)
The antireflection layer 12 includes a low refractive index layer 12a having a refractive index of, for example, 1.47 or less and a thickness of 50 to 200 nm as an outermost layer. Note that the antireflection layer 12 of this embodiment shown in FIG. 2 has a single-layer structure, and is composed of only the low refractive index layer 12a.

  The low refractive index layer 12a preferably contains silica particles, a silane coupling agent or a hydrolyzate thereof, and a metal chelate compound. By setting it as such a structure, a silane coupling agent or its hydrolyzate becomes a binder, and hold | maintains a fine silica particle. Moreover, if the low refractive index layer 12a is formed using the silane coupling agent used for the buffer layer 16 or a hydrolyzate thereof, high adhesiveness is secured between the buffer layer 16 and unevenness is caused by the transfer. It is possible to effectively prevent molding defects when forming.

The silica particles are used for adjusting physical properties with the buffer layer 16.
As the silica particles contained in the low refractive index layer 12a, hollow colloidal silica (hollow silica sol) can be used. Here, “hollow” means a density of 1.5 g / cm ³ or less.

The average particle size of the hollow silica sol is preferably 10 to 150 nm. If the average particle diameter of the hollow silica sol is within the above range, a certain strength and hardness can be ensured and characteristics such as scratch resistance can be imparted without impairing the translucency of the transparent substrate 11.
The refractive index of the hollow silica sol is preferably less than 1.44. If the refractive index of the hollow silica sol is within the above range, it is possible to ensure a certain strength and hardness without impairing the translucency of the transparent substrate 11 and to impart characteristics such as scratch resistance.

  Hollow silica sol is produced by, for example, synthesizing silica in the presence of a surfactant as a template, and finally decomposing and removing the surfactant by baking, and dispersing it in an organic solvent such as isopropanol or methyl isobutyl ketone. It is commercially available in the form of sol.

  As a silane coupling agent and a metal chelate compound, the silane coupling agent and metal chelate compound which were illustrated previously in description of a semi-hardened | cured material layer are mentioned.

  The content of the silica particles is preferably 5 to 50% by mass with respect to the total mass of the total of the silica particles, the silane coupling agent or the hydrolyzate thereof, and the metal chelate compound, and the silane coupling agent or the hydrolysis thereof The content of the product is preferably 15 to 94% by mass, and the content of the metal chelate compound is preferably 1 to 35% by mass.

  The thickness of the low refractive index layer 12a is 50 to 200 nm. If the thickness of the low refractive index layer 12a is within the above range, sufficient antireflection properties can be obtained. In particular, if the thickness of the low refractive index layer 12a is 50 nm or more, properties such as strength can be maintained satisfactorily, and breakage or the like is unlikely to occur when the transparent substrate 13 is press-formed. On the other hand, if the thickness of the low refractive index layer 12a is 200 nm or less, flexibility can be maintained well. Therefore, for example, a difference in physical properties from the transparent substrate 11 is difficult to increase, and molding defects such as cracks when forming irregularities by transfer are less likely to occur.

  Of the transparent substrate 13, the intermediate laminate including the semi-cured material layer in which the ultraviolet curable resin composition for forming the buffer layer 16 is in a semi-cured state has an elongation of, for example, 105 to 150%, 110 to 130% is more preferable. If the elongation percentage of the intermediate laminate is 105% or more, the semi-cured material layer effectively applies the external force applied to the antireflection layer 12 during the transfer process even if irregularities are formed on the surface of the antireflection layer 12 by transfer. Since it absorbs, it can prevent that the antireflection layer 12 damages, and can maintain the original function (antireflection property) of the antireflection layer 12 favorably. On the other hand, if the elongation percentage of the intermediate laminate is 150% or less, it is possible to form a sufficiently uneven shape.

The elongation rate of the intermediate laminate can be adjusted by the elongation rate of the semi-cured product layer, the accumulated light amount of ultraviolet rays when the buffer layer 16 is formed by irradiating the ultraviolet curable resin composition with ultraviolet rays and completely curing it. The elongation percentage of the intermediate laminate is determined as follows.
That is, the intermediate laminate is heated to the vicinity of the glass transition point (Tg) of the base material, and then sandwiched between the L-shaped male and female dies so that the base material surface is on the concave side, and the male and female dies are pressed against each other. Cooling. After cooling, observe the bent convex surface with a microscope to check for cracks. The same operation is performed by changing the bending radius (bending R), and the elongation to the bending R when no crack is generated is calculated.

(Diffusion layer)
In this embodiment, the diffusion layer 14 formed on the other surface 11b side of the transparent base material 11 diffuses image light emitted from the liquid crystal display 1 and includes the transparent substrate 13 and the diffusion layer 14. Serves as an adhesive layer for bonding the liquid crystal display 1 to the liquid crystal display 1.
The diffusion layer 14 is composed of, for example, a functional film in which the light diffusion particles B are dispersed in the binder D. More specifically, as the functional film constituting the diffusion layer 14, light diffusion particles B made of a material having a refractive index different from that of the binder D are uniformly dispersed in the binder D, and the thickness is 15 μm or more and 100 μm or less. It is composed of an adhesive sheet. The pressure-sensitive adhesive sheet preferably has a thickness of 20 μm and an adhesive strength to the glass plate of 2.0 N / 25 mm or more. Thereby, the optical member 10 can be reliably bonded to the surface of the liquid crystal display (image display panel) 1 via the diffusion layer 14.

  The functional film which is the binder D constituting the diffusion layer 14 is, for example, as a monomer having a functional group copolymerizable with at least one alkyl (meth) acrylate monomer having an alkyl group having C1 to C14 carbon atoms. A copolymer comprising a copolymerizable monomer having a hydroxyl group, a vinyl monomer having a nitrogen atom, and at least one selected from the group consisting of monomers having an aromatic group, and a crosslinking agent and a pressure-sensitive adhesive composition Is done.

  Examples of the alkyl (meth) acrylate monomer having a C1-C14 alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and isobutyl. (Meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (Meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate , Cyclopentyl (meth) acrylate, and at least one kind such as cyclohexyl (meth) acrylate. The alkyl group of the alkyl (meth) acrylate monomer may be linear, branched or cyclic. In the alkyl (meth) acrylate monomer having an alkyl group with C1 to C14, the ratio of the main component to 100 parts by weight of the (meth) acrylate monomer is preferably 70 to 95 parts by weight.

  Examples of copolymerizable vinyl monomers having an aromatic group (monomers having an aromatic group) include benzyl (meth) acrylate, naphthyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxybutyl (meth) acrylate, 2- ( 1-naphthyloxy) ethyl (meth) acrylate, 2- (2-naphthyloxy) ethyl (meth) acrylate, 6- (1-naphthyloxy) hexyl (meth) acrylate, 6- (2-naphthyloxy) hexyl (meth) ) Acrylate, 8- (1-naphthyloxy) octyl (meth) acrylate, 8- (2-naphthyloxy) octyl (meth) acrylate, ethylene glycol o-phenyl phenyl ether acrylate, polyethylene glycol o-phenyl phenyl ether acrylate Acrylic monomer having any aromatic group, vinyl monomers having an aromatic group such as styrene.

  By mixing the monomer having these aromatic groups with an alkyl (meth) acrylate monomer having a C1-C14 alkyl group as a main component monomer, the refractive index of the resulting diffusion layer 14 is increased. The total light transmittance can be improved by reducing the difference in refractive index between the optical members and reducing the total reflection. In the diffusion layer 14 according to the present embodiment, when the pressure-sensitive adhesive composition contains a monomer having an aromatic group, for example, a ratio of 5 to 30 parts by weight of 100 parts by weight of the main component (meth) acrylate monomer It is preferable to contain.

  Examples of the vinyl monomer having a nitrogen atom include cyclic nitrogen vinyl compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, (meth) acryloylmorpholine, N-ethyl-N-methyl (meth) acrylamide, N-methyl-N- Propyl (meth) acrylamide, N-methyl-N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, Dialkyl-substituted (meth) acrylamides such as N-diisopropyl (meth) acrylamide and N, N-dibutyl (meth) acrylamide, N-ethyl-N-methylaminoethyl (meth) acrylate, N-methyl-N-propylaminoethyl ( (Meth) acrylate, N- Til-N-isopropylaminoethyl (meth) acrylate, N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, Dialkylamino (meth) acrylates such as N-dimethylaminobutyl (meth) acrylate, N, N-dipropylaminoethyl (meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate, N-ethyl-N-methyl Aminopropyl (meth) acrylamide, N-methyl-N-propylaminopropyl (meth) acrylamide, N-methyl-N-isopropylaminopropyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N -Diethylami Dialkyl-substituted aminoalkyl (meth) such as propyl (meth) acrylamide, N, N-dipropylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide There may be mentioned at least one kind such as acrylamide.

  As the vinyl monomer having a nitrogen atom, one having no hydroxyl group is preferable, and one having no hydroxyl group and carboxyl group is more preferable in order to be distinguishable from a copolymerizable monomer having a hydroxyl group described later. Examples of such monomers include the monomers exemplified above, for example, acrylic monomers having N, N-dialkyl-substituted amino groups and N, N-dialkyl-substituted amide groups; N-vinylpyrrolidone, N-vinylcaprolactam and other N-type monomers. -Vinyl-substituted lactams; N- (meth) acryloyl-substituted cyclic amines such as N- (meth) acryloylmorpholine are preferred.

  In addition, in the diffusion layer 14 according to the present embodiment, as a vinyl monomer having a nitrogen atom to be contained in the acrylic polymer of the pressure-sensitive adhesive composition, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-dibutyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N-vinylcaprolactam and the like are particularly preferably used.

  Examples of the copolymerizable vinyl monomer having a carboxyl group (copolymerizable monomer having a carboxyl group) include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, and 2- (meth) acrylic. Leuoxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meta ) At least one or more of acryloyloxyethylmaleic acid, carboxypolycaprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyltetrahydrophthalic acid and the like.

  In addition, in the diffusion layer 14 according to the present embodiment, the copolymerizable monomer having a carboxyl group to be included in the acrylic polymer of the pressure-sensitive adhesive composition can impart the necessary cohesive force to the diffusion layer 14. . In the diffusion layer 14 according to the present embodiment, the acrylic polymer of the pressure-sensitive adhesive composition may not contain a copolymerizable monomer having a carboxyl group. For example, the ratio is preferably 0 to 5 parts by weight with respect to 100 parts by weight of the main component (meth) acrylate monomer.

  Examples of the copolymerizable vinyl monomer having a hydroxyl group (copolymerizable monomer having a hydroxyl group) include 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. , Hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, and hydroxyl groups such as N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide ( Examples thereof include at least one or more of (meth) acrylamides.

  Moreover, in the diffusion layer 14 according to the present embodiment, the copolymerizable monomer having a hydroxyl group to be contained in the acrylic polymer of the pressure-sensitive adhesive composition is such that the resulting diffusion layer 14 corrodes the ITO surface or the like of the transparent conductive film. It can be used as a copolymerizable monomer for reducing the content of a copolymerizable monomer having a carboxyl group, which is considered to affect the corrosiveness to an adherend which is easily formed. Therefore, the copolymerizable monomer having a hydroxyl group can be used for improving the adhesive strength of the diffusion layer 14 and reducing the corrosivity. In the diffusion layer 14 according to this embodiment, the copolymerizable monomer having a hydroxyl group contained in the acrylic polymer of the pressure-sensitive adhesive composition is 0.1% with respect to 100 parts by weight of the main component (meth) acrylate monomer. It is preferably ˜5 parts by weight.

  The acrylic polymer of the pressure-sensitive adhesive composition used for the diffusion layer 14 according to the present embodiment has a functional group copolymerizable with at least one alkyl (meth) acrylate monomer having a C1-C14 alkyl group. A copolymer having a weight average molecular weight of 20 to 2.5 million, comprising at least one selected from the group consisting of a copolymerizable monomer having a hydroxyl group, a vinyl monomer having a nitrogen atom, and a monomer having an aromatic group Is preferred.

  As the crosslinking agent, for example, a buret modified product of a diisocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, an isocyanurate modified product, trimethylol propane, or a trivalent or higher valent compound such as glycerin. Examples thereof include at least one or more of a polyisocyanate compound such as an adduct with a polyol, a metal chelate compound, and an epoxy compound. Further, the pressure-sensitive adhesive may be crosslinked by photocrosslinking such as ultraviolet rays.

  When the copolymer is cross-linked using a cross-linking agent, the copolymer preferably has a functional group capable of cross-linking reaction with the cross-linking agent (such as a hydroxyl group or a carboxyl group, depending on the type of the cross-linking agent) Moreover, it is preferable to contain the monomer which has these functional groups in a side chain. Moreover, it is preferable that an adhesive composition contains 0.001-5 weight part of isocyanate compounds as a crosslinking agent with respect to 100 weight part of (meth) acrylate monomers of a main component.

  The light diffusing particles B dispersed in the functional film which is the binder D constituting the diffusion layer 14 are selected from materials having a refractive index different from that of the binder D, for example, acrylic, urethane, silica, styrene and the like. Further, two or more kinds of these materials may be included. The light diffusing particles B preferably have a particle size in the range of 3 μm to 15 μm. If the particle size of the light diffusing particles B is less than 3 μm, the light diffusing effect is low, and if the particle size of the light diffusing particles B exceeds 15 μm, the transparency may be lowered and glare may occur.

  The diffusion layer 14 in which such light diffusion particles B are diffused has a haze value in the range of 15% to 60%. Further, the difference in refractive index between the light diffusing particles B and the binder D may be, for example, 0.01 or more, and particularly preferably in the range of 0.01 to 0.05.

  In the present embodiment, silica particles are used as the light diffusing particles B. The silica particles may be, for example, silica melamine core-shell particles, silicone particles, silicate glass particles, etc. in addition to silica particles composed only of silica. Among these, the silica melamine core-shell particles are composite particles having a melamine core and a silica shell. This composite particle has a structure in which fine particles (nanoparticles) of colloidal silica are closely packed on the surface of melamine particles. Examples of the silicone particles include silicone resin particles, silicone rubber particles, and crosslinked silicone particles.

  The content ratio of the light diffusion particles B to the diffusion layer 14 is preferably 0.01 to 20 parts by weight of the light diffusion particles B with respect to 100 parts by weight of the main component (meth) acrylate monomer, for example.

  According to the optical member 10 of one embodiment of the present invention having the above-described configuration, the transparent substrate 13 having the antireflection layer 12 on the one surface 11a side of the transparent substrate 11 is used, and the other surface 11b side of the transparent substrate 11 is used. By forming a diffusion layer 14 in which light diffusing particles containing acrylic, urethane, silica, etc. are dispersed in the binder D, light interference occurs between fine pixels of a high-definition liquid crystal display (image display panel) 1. Can be prevented, and image light can be diffused. Thereby, the glare of the surface of the liquid crystal display 1 can be suppressed and the visibility of the high-definition liquid crystal display 1 can be kept favorable.

(Second Embodiment)
FIG. 3 is a cross-sectional view showing the optical member of the second embodiment. In addition, the same number is attached | subjected to the structure similar to 1st Embodiment, and the detailed description is abbreviate | omitted.
The optical member 20 of the present embodiment includes a transparent substrate 23 having a transparent base material 21 and an antireflection layer 12 provided on the one surface 21 a side of the transparent base material 21.

  The transparent substrate 21 includes a transparent substrate main body 21A and a diffusion layer 21B that forms part of the transparent substrate 21 and is formed on one surface side of the transparent substrate main body 21A.

  In the present embodiment, the transparent base body 21A is made of, for example, polycarbonate (PC), and the diffusion layer 21B is made of the light diffusion particles B diffused in a binder D made of, for example, acrylic resin (PMMA). Even in the configuration in which the diffusion layer 21 </ b> B is formed as a part of the transparent substrate 21 as in the present embodiment, the image light of the high-definition liquid crystal display (image display panel) 1 is diffused and the liquid crystal display 1 The glare on the surface can be suppressed, and the visibility of the high-definition liquid crystal display 1 can be kept good.

(Third embodiment)
FIG. 4 is a cross-sectional view showing the optical member of the third embodiment. In addition, the same number is attached | subjected to the structure similar to 2nd Embodiment, and the detailed description is abbreviate | omitted.
The optical member 30 of the present embodiment includes a transparent substrate 33 having a transparent base 31 and an antireflection layer 12 provided on the one surface 31a side of the transparent base 31.

  The transparent substrate 31 includes a transparent substrate body 31A, and diffusion layers 31B and 31C that are formed on one side and the other surface side of the transparent substrate body 31A and constitute a part of the transparent substrate 31. .

  In this embodiment, the transparent base body 31A is made of, for example, polycarbonate (PC), and the diffusion layers 31B and 31C are made by diffusing the light diffusion particles B in the binder D made of, for example, acrylic resin (PMMA). Become. Even in the configuration in which the diffusion layers 31B and 31C are respectively formed as a part of the transparent substrate 21 as in the present embodiment, the image light of the high-definition liquid crystal display (image display panel) 1 is diffused and the liquid crystal The glare on the surface of the display 1 can be suppressed, and the visibility of the high-definition liquid crystal display 1 can be kept good.

  Further, as compared with the optical member 20 of the second embodiment, by providing the diffusion layers 31B and 31C on both the one surface side and the other surface side of the transparent base body 31A, the image light of the liquid crystal display 1 is more reliably obtained. Can diffuse.

  As mentioned above, although embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

The effect of the present invention was verified. In the verification, the optical characteristics of each sample of the following verification examples 1 to 12 were measured.
As Verification Examples 1 to 12, a transparent substrate (AGAR) formed by forming an antireflection layer on a transparent base material was prepared, and light diffusing particles were diffused only in this transparent substrate and in the adhesive (sheet) on the transparent substrate. The optical characteristics of the optical member on which the diffusion layer was formed were measured.

As the pressure-sensitive adhesive (sheet) of the diffusion layer, acrylic pressure-sensitive adhesives (Verification Examples 1 to 12) having a refractive index of 1.5 with a thickness of 25 μm, 50 μm, 75 μm, and 100 μm were used.
Spherical particles are used as light diffusion particles in the diffusion layer, and acrylic particles (Verification Examples 1 to 4), urethane particles (Verification Examples 5 to 8), and silica particles (Verification Examples 9 to 12) are used as materials. Using. The particle size of each light diffusion particle is 1 μm (Verification Examples 1, 5, 9), 5 μm (Verification Examples 2, 6, 10), 10 μm (Verification Examples 3, 7, 11), 15 μm (Verification Examples 4, 8, 12). The particle size of these particles was measured with a laser microscope (VK-X150 manufactured by Keyence Corporation).

  For these verification examples 1 to 12, the haze value (%) of the diffusion layer, the haze value (%) of the transparent substrate (AGAR) provided with the antireflection layer, and the diffusion layer attached to the transparent substrate (AGAR) A gloss (60 °) value (GU) and a haze value (%) were measured. The results of these verification examples 1 to 12 are shown in Tables 1 to 12. In each table, the item “none” indicates an example in which no diffusion layer is formed.

  According to the results of these verification examples 1-12, the optical member in which the diffusion layer obtained by diffusing the light diffusing particles of any material is attached to the transparent substrate (AGAR), compared with the case of the transparent substrate alone, It was confirmed that the gloss value, that is, the glare is small and the haze value is large. Therefore, according to this invention, it was confirmed that the optical member which suppresses glare and can improve visibility can be implement | achieved.

1. Liquid crystal display (image display panel)
DESCRIPTION OF SYMBOLS 10 ... Optical member 11 ... Transparent base material 12 ... Antireflection layer 13 ... Transparent substrate 14 ... Diffusion layer 15 ... Barrier layer 16 ... Buffer layer B ... Light-diffusion particle D ... Binder

Claims (4)

An optical member disposed on the surface of the image display panel,
Having at least a transparent substrate, and an antireflection layer and a diffusion layer disposed on the transparent substrate,
The antireflection layer has an irregular roughness structure in which the arithmetic average roughness Ra of the surface is in the range of 0.01 μm or more and 1.00 μm or less, and the average unevenness period RSm is in the range of 1 μm or more and 30 μm or less. Formed,
The diffusion layer is composed of a binder and light diffusion particles dispersed in the binder, and has a haze value of 15% or more and 60% or less,
The optical member, wherein the light diffusing particles are made of a material having a refractive index different from that of the binder.   The optical member according to claim 1, wherein the light diffusing particles have a particle size in a range of 3 μm to 15 μm.   The optical member according to claim 1, wherein the diffusion layer is made of an adhesive sheet having a thickness of 15 μm or more and 100 μm or less in which the light diffusion particles are dispersed.   The optical member according to claim 3, wherein the adhesive sheet has a thickness of 20 μm and an adhesive strength to a glass plate of 2.0 N / 25 mm or more.

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