阅读说明：本技术 光学膜 (Optical film ) 是由 梶谷俊一 于 2016-12-16 设计创作，主要内容包括：本发明的光学膜用于通过被透光的光引导装置按压于涂布有光固化性树脂的被粘体的一面,并在被所述光引导装置按压的状态下使光在所述光引导装置传导而使所述光固化性树脂固化,从而在所述被粘体上形成微细结构体,所述光学膜具备：微细凹凸层,形成在基材膜上,并具有凹凸图案；以及微细结构体,形成在所述微细凹凸层上,所述基材膜和所述微细结构体具有光透过性。(An optical film according to the present invention is an optical film for forming a microstructure on an adherend, which is coated with a photocurable resin, by being pressed against one surface of the adherend by a light guide device that transmits light therethrough, and curing the photocurable resin by transmitting the light through the light guide device in a state where the optical film is pressed by the light guide device, the optical film including: a fine uneven layer formed on the base material film and having an uneven pattern; and a microstructure formed on the fine uneven layer, the base film and the microstructure having light transmittance.)

1. An optical film which is pressed against a surface of an adherend coated with a photocurable resin by a light guide device which transmits light therethrough, and which is cured by transmitting light through the light guide device while being pressed by the light guide device, thereby forming a microstructure on the adherend,

the optical film is provided with:

a fine uneven layer formed on the base material film and having an uneven pattern; and

a fine structure formed on the fine uneven layer,

the base material film and the microstructure have light transmittance.

2. An optical film, characterized in that a light guide means which transmits light is pressed against one surface of an adherend, and light is transmitted through the light guide means in a state where the light guide means is pressed, thereby forming a microstructure on the one surface of the adherend,

the optical film is provided with:

a fine uneven layer formed on the base material film and having an uneven pattern;

a microstructure formed on the fine uneven layer; and

a photocurable resin layer formed on the microstructure and composed of a semi-cured photocurable resin,

the base material film and the microstructure have light transmittance.

3. The optical film according to claim 1 or 2, further comprising:

and an inorganic film formed between the fine uneven layer and the fine structure.

4. The optical film according to claim 1 or 2,

the microstructure has a microstructure formed on one surface of the base film and on another surface opposite to the one surface.

5. The optical film according to claim 1 or 2,

the average reflectance of the microstructure is 7% or more in a wavelength range of 350nm to 450 nm.

Technical Field

The invention relates to a method for forming an antireflection optical body, a display panel and an optical film. This application claims 2015-18/12 to priority for japanese patent application laid-open in japanese 2015-247855, and the entire disclosure of this prior application is incorporated herein by reference.

Background

In most electronic devices such as notebook PCs (personal computers), tablet PCs, smartphones, and mobile phones, an image pickup device (first image pickup device) is provided on a surface opposite to a surface on which a display for displaying an image is provided (display surface side). According to such an electronic device, when a user takes a picture of a landscape or the like, the user can take the picture while confirming the picture taken by the first image pickup element on the display.

In recent years, electronic devices in which an imaging element (second imaging element) is also provided on the display surface side have become widespread. According to the electronic apparatus, when the user himself/herself is photographed, for example, the user can photograph the image photographed by the second photographing element while confirming the image on the display, and convenience is improved.

In the electronic apparatus in which the image pickup device is provided on the display surface side as described above, the transmissive area is provided in a part of the display panel, and the image pickup device (second image pickup device) is provided directly below the transmissive area. In this case, a ghost (ghost) may occur due to the light reflected by the mirror of the image pickup device being reflected by the display panel and then incident again on the mirror of the image pickup device. Therefore, in order to suppress the occurrence of ghost images, improve transmittance, and the like, an antireflection process for preventing reflection of light by forming a microstructure (antireflection optical body) in a region on the display panel corresponding to the image pickup device (second image pickup device) is performed.

As a method of the antireflection treatment, there is a method (first method) in which an adherend (a liquid crystal panel or the like) is put into a vacuum chamber, and a dielectric film is formed as an antireflection film (ar (antireflection) film) on the adherend by wet coating such as dip coating.

Another method is a method (second method) in which a film having a fine structure is bonded to an adhesive body by a roll-to-roll method, and the film is bonded to an adherend via the adhesive body.

As another method, patent documents 1 and 2 disclose a method of producing an antireflection transfer film in which a transparent resin layer is formed as a transfer layer on a film having a concavo-convex mold release property, and transferring the transfer layer on the antireflection transfer film onto a substrate (third method). In patent document 1, a microstructure is formed on a substrate made of a cured resin by applying a resin in a fluid state to a mold-releasable film, curing the resin, and then peeling the mold-releasable film. In patent document 2, after the transparent resin layer of the antireflection transfer film is bonded to the substrate by a roll transfer method, a simultaneous injection molding transfer method, or the like, the releasable film is peeled off to form a microstructure on the substrate.

Disclosure of Invention

Technical problem

In consideration of the use of electronic devices, it is required that the antireflection treatment be thin (on the order of 10 μm or less), and that partial treatment be possible not for the entire surface of an adherend (display panel).

In the first method, in order to perform the antireflection treatment only on a part of the adherend, it is also necessary to charge the adherend having a large area into the vacuum chamber. Therefore, it is not realistic to apply the first method to the antireflection treatment for a part of the adherend.

In the second method, since the film having a fine structure is bonded to the adhesive by the roll-to-roll method, the total thickness of the film and the adhesive needs to be 50 μm or more in consideration of handling easiness, strength, and the like. Therefore, in the second method, it is difficult to achieve thinning.

Further, with respect to the third method, neither patent document 1 nor patent document 2 makes any consideration of a specific method of forming an antireflection optical body having a fine structure only in a part on an adherend.

In view of the above-described problems, an object of the present invention is to provide a method for forming an antireflection optical body, a display panel, and an optical film, in which an antireflection optical body is formed only on a part of an adherend while achieving a reduction in thickness.

Technical scheme

In order to solve the above problems, a method for forming an antireflection optical body according to the present invention includes: a coating step of coating a photocurable resin on one surface of an adherend; a pressing step of pressing a base material film having a microstructure on one surface side with a light-transmitting light guide device from the other surface side opposite to the one surface side to the photocurable resin; a curing step of curing the photocurable resin by transmitting light to the light guide device while the base film is pressed by the light guide device; and a separation step of separating the microstructure fixed to the adherend by the cured photocurable resin from the base film while releasing the pressing of the base film and separating the microstructure fixed to the adherend by the cured photocurable resin from the microstructures on the base film except for the position fixed by the photocurable resin, thereby forming the microstructure fixed to the adherend as an antireflection optical body on the adherend.

In order to solve the above problem, a method for forming an antireflection optical body according to the present invention includes: a pressing step of pressing a base material film, which has a microstructure on one surface side and on which a semi-cured photocurable resin layer is formed, against an adherend from the other surface side opposite to the one surface side by a light-transmitting light guide device; a curing step of curing the photocurable resin layer by transmitting light to the light guide device while the base film is pressed by the light guide device; and a separation step of separating the microstructure fixed to the adherend by the cured photocurable resin layer from the base film while releasing the pressing of the base film and separating the microstructure fixed to the adherend by the cured photocurable resin layer from the microstructure other than the position fixed by the photocurable resin layer on the base film, thereby forming the microstructure fixed to the adherend as an antireflection optical body on the adherend.

In the method for forming an antireflection optical body according to the present invention, it is preferable that the microstructure has a microstructure formed on one surface of the base film side and another surface opposite to the one surface.

In the method for forming an antireflection optical body according to the present invention, it is preferable that a fine uneven layer having an uneven pattern is formed on the base film, an inorganic film is formed on the fine uneven layer, and the microstructure is formed on the inorganic film.

In the method for forming an antireflection optical body according to the present invention, it is desirable that the thickness of the microstructure is 10 μm or less and the microstructure has a concave-convex pattern with a pitch equal to or smaller than the wavelength of visible light.

In the method for forming an antireflection optical body according to the present invention, it is desirable that the pressure for pressing the base film against the adherend is 0.5MPa or more.

In the method for forming an antireflection optical body according to the present invention, it is desirable that the antireflection optical body has ultraviolet transparency.

In order to solve the above problem, the display panel of the present invention is configured such that the microstructure is formed only in a part thereof by any of the above methods for forming an antireflection optical body.

In order to solve the above-described problems, an optical film according to the present invention is an optical film for forming a microstructure on an adherend by pressing a surface of the adherend coated with a photocurable resin with a light guide device that transmits light therethrough, and curing the photocurable resin by transmitting light through the light guide device in a state of being pressed by the light guide device, the optical film including: a fine uneven layer formed on the base material film and having an uneven pattern; and a microstructure formed on the fine uneven layer.

In order to solve the above-described problems, an optical film according to the present invention is an optical film for forming a microstructure on one surface of an adherend by pressing the optical film against the one surface of the adherend with a light guide device that transmits light therethrough and transmitting the light through the light guide device in a state where the optical film is pressed by the light guide device, the optical film including: a fine uneven layer formed on the base material film and having an uneven pattern; a microstructure formed on the fine uneven layer; and a photocurable resin layer formed on the microstructure and composed of a semi-cured photocurable resin.

In addition, the optical film of the present invention preferably further comprises: and an inorganic film formed between the fine uneven layer and the fine structure.

In the optical film of the present invention, it is desirable that the microstructure has a microstructure formed on one surface of the substrate film and on another surface opposite to the one surface.

Technical effects

According to the method for forming an antireflection optical body, the display panel, and the optical film of the present invention, the antireflection optical body can be formed only in a part of the adherend while achieving a reduction in thickness.

Drawings

Fig. 1A is a view illustrating a coating step in the method for forming an antireflection optical body according to the first embodiment of the present invention.

Fig. 1B is a diagram illustrating a pressing step in the method for forming an antireflection optical body according to the first embodiment of the present invention.

Fig. 1C is a view showing a curing step in the method for forming an antireflection optical body according to the first embodiment of the present invention.

Fig. 1D is a view illustrating a peeling and separating step in the method for forming an antireflection optical body according to the first embodiment of the present invention.

Fig. 2 is a diagram illustrating an example of the structure of the optical film shown in fig. 1.

Fig. 3A is a view illustrating a method of manufacturing the optical film shown in fig. 2.

Fig. 3B is a view illustrating a method of manufacturing the optical film shown in fig. 2.

Fig. 3C is a view illustrating a method of manufacturing the optical film shown in fig. 2.

Fig. 4 is a diagram illustrating another configuration example of the optical film shown in fig. 1.

Fig. 5A is a view illustrating a method of manufacturing the optical film shown in fig. 4.

Fig. 5B is a view illustrating a method of manufacturing the optical film shown in fig. 4.

Fig. 5C is a view illustrating a method of manufacturing the optical film shown in fig. 4.

Fig. 6 is a diagram illustrating an example of a state of formation of an antireflection optical body on an adherend, which is obtained by the formation method according to the first embodiment of the present invention.

Fig. 7 is a diagram illustrating another example of a state of formation of an antireflection optical body on an adherend, which is obtained by the formation method according to the first embodiment of the present invention.

Fig. 8A is a diagram illustrating a method of forming an antireflection optical body according to a second embodiment of the present invention.

Fig. 8B is a diagram illustrating a pressing step in the method for forming an antireflection optical body according to the second embodiment of the present invention.

Fig. 8C is a view showing a curing step in the method for forming an antireflection optical body according to the second embodiment of the present invention.

Fig. 8D is a view showing a peeling and separating step in the method for forming an antireflection optical body according to the second embodiment of the present invention.

Fig. 9 is a diagram showing an example of the configuration of the optical film shown in fig. 8.

Fig. 10A is a view illustrating a method of manufacturing the optical film shown in fig. 9.

Fig. 10B is a diagram illustrating a method of manufacturing the optical film illustrated in fig. 9.

Fig. 10C is a view illustrating a method of manufacturing the optical film shown in fig. 9.

Fig. 10D is a view illustrating a method of manufacturing the optical film shown in fig. 9.

Fig. 11 is a diagram illustrating an example of a state of formation of an antireflection optical body on an adherend, which is obtained by the formation method according to the second embodiment of the present invention.

Fig. 12A is a graph showing the measurement results of the surface properties of the antireflection optical body of example 1.

Fig. 12B is a graph showing the measurement results of the surface properties of the antireflection optical body of comparative example 1.

Fig. 13A is a top view of the antireflection optical body according to example 1.

Fig. 13B is a top view of the antireflection optical body according to example 2.

Fig. 13C is a top view of the antireflection optical body according to example 3.

Fig. 13D is a top view of the antireflection optical body according to example 4.

Fig. 13E is a top view of the antireflection optical body of comparative example 1.

Fig. 13F is a top view of the antireflection optical body of comparative example 2.

Fig. 14 is a graph showing reflection spectra of the antireflection optical bodies of examples 1 to 4.

Description of the symbols:

10: component, 11: adherend, 12: UV curable resin, 13: light guide device, 14 a: optical film, 15: substrate film, 16: microstructure, 16 a: antireflection optical body, 16 p: UV curable resin layer, 17: adhesive layer, 17 p: UV curable resin layer, 18: a jig, 21: fine uneven layer, 21 p: UV curable resin layer, 22: inorganic film, 23, 25, 26, 28: roller, 24: sputtering target, 27: release film

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. In the following, the same components are denoted by the same reference numerals in the drawings, and descriptions thereof are omitted.

(first embodiment)

Fig. 1A to 1D are views illustrating a method for forming an antireflection optical body according to a first embodiment of the present invention. The method for forming an antireflection optical body according to the present embodiment includes: a coating step, a pressing step, a curing step, and a peeling and separating step.

In the coating step shown in fig. 1A, a UV curable resin 12 as a photocurable resin is coated on the adherend 11. The optical film 14 is held by a light guide 13 that can transmit light (light for curing the UV curable resin 12). The optical film 14 has a microstructure 16 (thin-film optical layer) having Ultraviolet (UV) light transmittance formed on one surface side of a base film 15, and is held so that the one surface side on which the microstructure 16 is formed faces the adherend 11. When the average reflectance in the wavelength range of 350nm to 450nm is measured with a spectrophotometer in a state where the microstructure 16 is formed on the base film 15, the UV-curable resin 12 described later is insufficiently cured, and when the average reflectance is 7%, sufficient curing and close adhesion of the UV-curable resin 12 can be obtained. Therefore, the microstructure 16 having ultraviolet transmittance means that the average reflectance in the wavelength range of 350nm to 450nm is 7% or more.

The structure of the optical film 14 will be described in more detail with reference to fig. 2.

As shown in fig. 2, the optical film 14 includes: a base film 15, a fine uneven layer 21, an inorganic film 22, and a microstructure 16 (thin film optical body layer). In fig. 1A to 1D, the fine uneven layer 21 and the inorganic film 22 are not described for simplification of the drawings.

The base film 15 is provided for protecting the microstructure 16 and the like and improving the handling properties. The kind of the substrate film 15 is not particularly limited, but is preferably a film which is transparent and is hard to break. As the substrate film 15, for example, a PET (polyethylene terephthalate) film, a TAC (triacetylcellulose) film, or the like can be used. The thickness of the base film 15 may be appropriately adjusted according to the handling properties required for the optical film 14, and is, for example, 50 μm to 125 μm.

The fine uneven layer 21 is formed on one surface of the base film 15. An uneven pattern (convex portions that are convex in the film thickness direction of the optical film 14 and concave portions that are concave in the film thickness direction of the optical film 14) is formed on the surface of the fine uneven layer 21. The projections and the recesses may be arranged periodically (for example, in a shape of a thousand-bird lattice, a rectangular lattice), and may be arranged randomly. The shape of the convex portion and the concave portion is not particularly limited, and may be a shell shape, a cone shape, a columnar shape, a needle shape, or the like. The shape of the recess is a shape formed by an inner wall of the recess.

The average period (pitch) of the uneven pattern on the surface of the fine uneven layer 21 is equal to or less than the wavelength of visible light (for example, equal to or less than 830 nm), preferably equal to or more than 100nm and equal to or less than 350nm, and more preferably equal to or more than 150nm and equal to or less than 280 nm. Therefore, the surface of the fine uneven layer 21 has a so-called moth-eye structure. By setting the pitch of the uneven pattern on the surface of the fine uneven layer 21 to a wavelength of visible light or less, the antireflection property can be improved.

The average period of the uneven pattern of the fine uneven layer 21 is an arithmetic average of distances between adjacent convex portions and concave portions. The uneven pattern of the fine uneven layer 21 can be observed by, for example, a Scanning Electron Microscope (SEM) or a cross-sectional transmission electron microscope (cross-sectional TEM). As a method of calculating the average period, for example, there is a method of extracting a combination of a plurality of adjacent convex portions and a combination of adjacent concave portions, measuring the distance between convex portions and the distance between concave portions constituting each combination, and averaging the measured values.

The height of the convex portion (depth of the concave portion) of the fine uneven layer 21 is not particularly limited, but is preferably 150nm or more and 300nm or less, more preferably 190nm or more and 300nm or less, and still more preferably 190nm or more and 230nm or less.

The inorganic film 22 is made of an inorganic substance such as tungsten oxide, silicon, ITO, or the like. The inorganic film 22 is formed on the surface of the fine uneven layer 21 with a film thickness of about 20 nm. The inorganic film 22 is provided as a release layer for facilitating peeling of the microstructure 16 from the optical film 14.

The microstructure 16 as a thin-film optical body layer is formed on the inorganic film 22. An uneven pattern obtained by inverting the uneven pattern of the fine uneven layer 21 is formed on the surface of the fine structure 16 on the inorganic film 22 side. The surface of the microstructure 16 opposite to the inorganic film 22 is flat. The thickness of the microstructure 16 is preferably 10 μm or less. When the thickness of the microstructure 16 exceeds 10 μm, details will be described later, but in this case, it is difficult to separate the microstructure 16 fixed to the adherend 11 from the microstructure 16 other than the fixing position on the base film 15.

A method for manufacturing the optical film 14 shown in fig. 2 will be described with reference to fig. 3A to 3C.

A substrate film 15 is prepared, and as shown in fig. 3A, a UV-curable resin layer 21p made of an uncured UV-curable resin (e.g., a UV-curable acrylic resin) is formed on one surface of the substrate film 15.

Note that the resin used for formation of the UV-curable resin layer 21p is not limited to the UV-curable acrylic resin.

The UV curable resin layer 21p is desirably formed of a curable resin of which cured product has transparency. The curable resin contains, for example, a polymerizable compound and a curing initiator. The polymerizable compound is a resin cured by a curing initiator. Examples of the polymerizable compound include an epoxy polymerizable compound and an acrylic polymerizable compound.

The epoxy polymerizable compound is a monomer, oligomer or prepolymer having one or more epoxy groups in the molecule. Examples of the epoxy polymerizable compound include various bisphenol type epoxy resins (bisphenol a type, F type, etc.), novolac type epoxy resins, various modified epoxy resins such as rubber and polyurethane, naphthalene type epoxy resins, biphenyl type epoxy resins, phenol novolac type epoxy resins, stilbene type epoxy resins, triphenylphenolmethane type epoxy resins, dicyclopentadiene type epoxy resins, triphenylmethane type epoxy resins, and prepolymers thereof.

The acrylic polymerizable compound is a monomer, oligomer or prepolymer having one or more acrylic groups in the molecule. Here, the monomers are also classified into monofunctional monomers having one acrylic group in a molecule, bifunctional monomers having two acrylic groups in a molecule, and polyfunctional monomers having three or more acrylic groups in a molecule.

Examples of the "monofunctional monomer" include carboxylic acids (acrylic acid), hydroxyl groups (2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate), alkyl or alicyclic monomers (isobutyl acrylate, tert-butyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate, isobornyl acrylate, cyclohexyl acrylate), other functional monomers (2-methoxyethyl acrylate, methoxyethyl glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofuryl acrylate, benzyl acrylate, ethylcarbitol acrylate, phenoxyethyl acrylate, N-dimethylaminoethyl acrylate, N-dimethylaminopropyl acrylamide, N-dimethylacrylamide, acryloylmorpholine, N-isopropylacrylamide, N-hydroxybutyl acrylate, and mixtures thereof, N, N-diethylacrylamide, N-vinylpyrrolidone, 2- (perfluorooctyl) ethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 3-perfluorooctyl-2-hydroxypropyl-acrylate, 2- (perfluorodecyl) ethyl-acrylate, 2- (perfluoro-3-methylbutyl) ethyl acrylate), 2,4, 6-tribromophenol acrylate, 2,4, 6-tribromophenol methacrylate, 2- (2,4, 6-tribromophenoxy) ethyl acrylate, 2-ethylhexyl acrylate, and the like.

Examples of the "bifunctional monomer" include tri (propylene glycol) diacrylate, trimethylolpropane-diallyl ether, and urethane acrylate.

Examples of the "polyfunctional monomer" include trimethylolpropane triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ditrimethylolpropane tetraacrylate.

Examples of the acrylic polymerizable compounds other than those listed above include acrylic morpholine, glycerin acrylate, polyether acrylate, N-vinylformamide, N-vinylcaprolactone, ethoxydiglycol acrylate, methoxytriglycol acrylate, polyethylene glycol acrylate, EO-modified trimethylolpropane triacrylate, EO-modified bisphenol a diacrylate, aliphatic urethane oligomer, and polyester oligomer. The polymerizable compound is preferably an acrylic polymerizable compound from the viewpoint of transparency and peelability from the microstructure 16.

The curing initiator is a material for curing a curable resin. Examples of the curing initiator include a thermal curing initiator and a photo curing initiator. The curing initiator may be a material that is cured by heat, any energy ray other than light (e.g., electron beam), or the like. When the curing initiator is a thermal curing initiator, the curable resin becomes a thermosetting resin, and when the curing initiator is a photo-curing initiator, the curable resin becomes a photo-curable resin.

Here, the curing initiator is preferably an ultraviolet curing initiator from the viewpoint of transparency and peelability from the microstructure 16. Therefore, the curable resin is preferably an ultraviolet-curable acrylic resin. The ultraviolet curing initiator is one of the photo-curing initiators. Examples of the ultraviolet curing initiator include 2, 2-dimethoxy-1, 2-diphenylethane-1-one, 1-hydroxy-cyclohexylphenylketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one.

The UV curable resin layer 21p may contain additives according to the application of the optical film 14. Examples of such additives include inorganic fillers, organic fillers, leveling agents, surface control agents, and defoaming agents. It should be noted thatAs the kind of the inorganic filler, for example, SiO is exemplified₂、TiO₂、ZrO₂、SnO₂、Al₂O₃And the like. Further, a release agent or the like may be added to the fine uneven layer 21 in order to easily peel the fine structure 16 from the optical film 14.

As shown in fig. 3A, the roll 23 and the UV curable resin layer 21p are brought into close contact with each other while forming the UV curable resin layer 21 p.

The roller 23 has, for example, a cylindrical shape or a cylindrical shape. An uneven pattern corresponding to the uneven pattern formed on the fine uneven layer 21 is formed on the surface of the roller 23. The roller 23 may be flat. The method of manufacturing the roller 23 having the above-described configuration is well known to those skilled in the art, and since it is not directly related to the present invention, the description thereof will be omitted.

The roller 23 is brought into close contact with the UV curable resin layer 21p made of an uncured UV curable resin, whereby the uneven pattern formed on the surface of the roller 23 is transferred to the surface of the UV curable resin layer 21 p. Although the roller 23 may be a flat plate as described above, the uneven pattern of the roller 23 can be transferred to the UV curable resin layer 21p by a roller-to-roller method by forming the roller 23 in a cylindrical shape or a columnar shape, and thus the transfer efficiency can be improved.

As shown in fig. 3A, the UV-curable resin layer 21p is cured by irradiating UV light from the other surface side of the base film 15 while transferring the uneven pattern of the roller 23 to the UV-curable resin layer 21 p. By doing so, the fine uneven layer 21 can be formed on the base material film 15. The surface of the roller 23 may be subjected to a release treatment using a fluorine material or the like so as to peel the fine uneven layer 21 from the roller 23.

After the fine uneven layer 21 is formed, as shown in fig. 3B, an inorganic film 22 as a release layer is formed on the surface of the fine uneven layer 21 with a film thickness of 5nm to 50nm, more preferably 15nm to 35nm, by a sputtering method using a sputtering target 24 made of tungsten oxide, for example. When the thickness of the inorganic film 22 is smaller than the above range, or when the thickness of the inorganic film 22 is larger than the above range, the effect of peeling the microstructure 16 from the inorganic film 22 is low. As a material constituting the inorganic film 22, silicon oxide, silicon, ITO, or the like can be used.

After the inorganic film 22 is formed, as shown in fig. 3C, a UV-curable resin layer 16p composed of an uncured UV-curable resin (e.g., a UV-curable acrylic resin) is formed on the inorganic film 22 in a thickness of about 2 μm. Since the UV curable resin layer 16p is made of an uncured UV curable resin, the UV curable resin penetrates into the concave portions of the concave-convex pattern of the inorganic film 22 on the surface of the UV curable resin layer 16p on the inorganic film 22 side, thereby forming a concave-convex structure. That is, an uneven pattern in which the uneven pattern on the surface of the fine uneven layer 21 is inverted is formed on the surface of the UV-curable resin layer 16p on the inorganic film 22 side.

Next, as shown in fig. 3C, the roll 25 is brought into close contact with the UV curable resin layer 16 p. The surface of the roller 25 is flat. Therefore, the surface of the UV curable resin layer 16p opposite to the inorganic film 22 becomes a flat surface. The UV-curable resin layer 16p is cured by irradiating UV light to the UV-curable resin layer 16p while closely adhering the roller 25 to the UV-curable resin layer 16p, thereby forming the microstructure 16 (thin film optical body layer).

In fig. 2 and 3A to 3C, the description has been given of an example in which the surface of the microstructure 16 opposite to the inorganic film 22 using the optical film 14 is a flat surface, but as shown in fig. 4, the optical film 14 may be formed with an uneven pattern also on the surface of the microstructure 16 opposite to the inorganic film 22. That is, the uneven pattern can be formed on both surfaces of the microstructure 16.

A method for manufacturing the optical film 14 shown in fig. 4 will be described with reference to fig. 5A to 5C. In fig. 5A to 5C, the same components as those in fig. 3A to 3C are denoted by the same reference numerals, and description thereof is omitted.

The process shown in fig. 5A and 5B is the same as the process shown in fig. 3A and 3B. That is, in the step shown in fig. 5A, the UV-curable resin layer 21p is formed on one surface of the base film 15, and the roller 23 is brought into close contact with the UV-curable resin layer 21p, thereby forming the uneven pattern on the surface of the UV-curable resin layer 21 p. Then, the UV-curable resin layer 21p is cured by irradiating UV light to the UV-curable resin layer 21p, thereby forming the fine uneven layer 21. In the step shown in fig. 5B, the inorganic film 22 is formed on the fine uneven layer 21.

In the step shown in fig. 5C, a UV curable resin layer 16p is formed on the inorganic film 22 in the same manner as in the step shown in fig. 3C. Next, as shown in fig. 5C, the roll 26 is brought into close contact with the UV curable resin layer 16 p. Here, a concave-convex pattern is formed on the surface of the roller 26. Therefore, the uneven pattern is also formed on the surface of the UV curable resin layer 16p opposite to the inorganic film 22. As the roller 26, the same roller as the roller 23 can be used. By irradiating the UV-curable resin layer 16p with UV light while closely adhering the roller 26 to the UV-curable resin layer 16p, the UV-curable resin layer 16p can be cured, and the microstructure 16 (thin film optical body layer) having the uneven pattern formed on both surfaces can be formed.

Referring again to fig. 1, after the application step shown in fig. 1A, in the pressing step shown in fig. 1B, the light guide device 13 is fixed by the jig 18, and the optical film 14 shown in fig. 2 or 4 is pressed by the light guide device 13 through the jig 18 from the surface opposite to the surface on which the microstructure 16 is formed to the UV curable resin 12 applied to the adherend 11. The UV curable resin 12 is pressed by the optical film 14, and thereby pressed between the adherend 11 and the optical film 14. The jig 18 fixes the light guide device 13 so as not to block the light transmitted through the light guide device 13.

In the curing step shown in fig. 1C, UV light is transmitted to the light guide device 13 in a state where the optical film 14 is pressed by the light guide device 13 via the jig 18, and the UV curable resin 12 is cured.

In the peeling and separating step shown in fig. 1D, the optical film 14 is released from the adherend 11 by releasing the pressing of the optical film 14, and the microstructure 16 is peeled from the optical film 14 (peeled with the interface with the inorganic film 22 as a boundary). According to the curing step, in a region where the UV curable resin 12 is present and light transmitted by the light guide device 13 is irradiated in the microstructure 16 (thin film optical body layer) formed in the optical film 14, the microstructure 16 and the adherend 11 are fixed by the cured UV curable resin 12. Then, by releasing the optical film 14, the microstructure 16 fixed by the cured UV-curable resin 12 is peeled from the optical film 14 (substrate film 15) at the interface with the inorganic film 22 as a boundary while separating (dividing) the microstructure 16 fixed by the cured UV-curable resin 12 from the microstructure 16 other than the position fixed by the UV-curable resin 12 on the substrate film 15, and is formed as the antireflection optical body 16a on the adherend 11.

Fig. 6 and 7 are views showing an example of a state in which the antireflection optical body 16a obtained by the forming method of the present embodiment is formed on the adherend 11. Fig. 6 shows an example in which the optical film 14 shown in fig. 2 (the optical film 14 having a flat surface on the opposite side of the microstructure 16 from the inorganic film 22) is used. Fig. 7 shows an example in which the optical film 14 shown in fig. 4 (the optical film 14 in which the uneven pattern is formed on both surfaces of the microstructure 16) is used.

As shown in fig. 6 and 7, according to the present embodiment, it is possible to form a member 10 in which an antireflection optical body 16a is formed only on a part of an adherend 11 via a cured UV curable resin 12, and the member 10 is used, for example, for a display panel or the like, and when the member 10 is used for a display panel of an electronic device such as a mobile phone or a smartphone, the antireflection optical body 16a is formed, for example, in a peripheral region (for example, a region of about several mm × to several mm) of a lens of an imaging element provided on a display surface side of the electronic device in the entire surface of the display panel.

In the case of using the optical film 14 having the uneven pattern formed on both surfaces of the microstructure 16 as shown in fig. 7, the UV curable resin 12 also enters the concave portion on the adherend 11 side surface of the microstructure 16 and is cured. Therefore, the adhesion between the microstructure 16 and the adherend 11 can be improved.

In this way, in the present embodiment, since the UV curable resin 12 is irradiated with the UV light through the light guide device 13, the UV curable resin 12 is cured only in the region where the UV curable resin 12 is present and the light transmitted through the light guide device 13 is irradiated, and the microstructure 16 formed on the optical film 14 is fixed to the adherend 11. Then, the fine structure 16 fixed to the adherend 11 is peeled off from the optical film 14, whereby the antireflection optical body 16a is formed on the adherend 11. Therefore, the antireflection optical body 16a can be easily formed only in a partial region on the adherend 11 by adjusting the region to which the UV curable resin 12 is applied and the shape of the light guide device 13.

(second embodiment)

Next, a method for forming the antireflection optical body 16a according to the second embodiment of the present invention will be described.

Fig. 8A to 8D are views illustrating a method of forming the antireflection optical body 16a according to the present embodiment. The method for forming an antireflection optical body according to the present embodiment includes: a pressing step, a curing step, and a peeling and separating step.

In the first embodiment, the UV curable resin 12 is applied to the adherend 11, and then the optical film 14 is pressed against the adherend 11 and the UV curable resin 12 is cured, whereby the antireflection optical body 16a is formed only in a partial region of the adherend 11. On the other hand, in the present embodiment, as shown in fig. 9, an optical film 14a in which an adhesive layer 17 (photocurable resin layer) made of a semi-cured photocurable resin (UV curable resin) is formed on a microstructure 16 is used. In the optical film 14a, the surface of the microstructure 16 opposite to the inorganic film 22 is a flat surface.

A method for manufacturing the optical film 14a shown in fig. 9 will be described with reference to fig. 10A to 10D.

The process shown in fig. 10A to 10C is the same as the process shown in fig. 3A to 3C. That is, in the step shown in fig. 10A, the UV-curable resin layer 21p is formed on one surface of the base film 15, and the roller 23 is brought into close contact with the UV-curable resin layer 21p, thereby forming the uneven pattern on the surface of the UV-curable resin layer 21 p. Then, the UV-curable resin layer 21p is cured by irradiating UV light to the UV-curable resin layer 21p, thereby forming the fine uneven layer 21. In the step shown in fig. 10B, an inorganic film 22 is formed on the fine uneven layer 21. In the step shown in fig. 10C, an uncured UV-curable resin layer 16p is formed on the inorganic film 22, and the roll 25 is brought into close contact with the UV-curable resin layer 16 p. Then, the UV-curable resin layer 16p is irradiated with UV light while the roll 25 is being brought into close contact with the UV-curable resin layer 16p, whereby the UV-curable resin layer 16p is cured to form the microstructure 16. As shown in fig. 4, a concave-convex pattern (fine structure) may be formed on both surfaces of the fine structure 16 (thin film optical layer).

In the step shown in fig. 10D, a UV-curable resin is poured onto the microstructure 16, and a pressure is applied from above via a release film 27 by a roller 28, thereby forming a UV-curable resin layer 17 p. Then, UV light is irradiated to the UV curable resin layer 17p to semi-cure the UV curable resin layer 17p, thereby forming the adhesive layer 17.

The dose of UV light irradiated to the UV curable resin layer 17p was 2kJ/m²In the case of (2), the UV curable resin layer 17p is not cured and is in a liquid state. Further, the irradiation amount of UV light to the UV curable resin layer 17p was 4kJ/m²In the case of (2), the UV curable resin layer 17p is completely cured. On the other hand, the irradiation amount of UV light to the UV curable resin layer 17p was 3kJ/m²In the case of (3), the UV curable resin layer 17p is semi-cured, and the adherend 11 and the microstructure 16 described later can be fixed to each other.

Referring again to fig. 8, as shown in fig. 8A, the optical film 14a is held by the light guide 13. Here, the optical film 14a is held so that the surface on which the microstructure 16 and the adhesive layer 17 are formed faces the adherend 11. In fig. 8A to 8D, the fine uneven layer 21 and/or the inorganic film 22 are not described for simplification of the drawings.

In the pressing step shown in fig. 8B, the light guide device 13 is fixed by the jig 18, and the optical film 14a is pressed by the light guide device 13 via the jig 18 from the surface opposite to the surface on which the microstructure 16 and the adhesive layer 17 are formed toward the adherend 11.

In the curing step shown in fig. 8C, UV light is transmitted through the light guide device 13 to cure the adhesive layer 17 in a state where the optical film 14a is pressed by the light guide device 13 via the jig 18.

In the peeling and separating step shown in fig. 8D, the pressing of the optical film 14a is released and the optical film 14a is released from the adherend 11, thereby peeling the microstructure 16 from the optical film 14 a. In the curing step, the microstructure 16 formed on the optical film 14a and the adherend 11 are fixed to each other by the cured adhesive layer 17 in the region irradiated with the light transmitted by the light guide device 13. Then, by releasing the optical film 14a, the microstructure 16 fixed by the cured adhesive layer 17 is peeled from the optical film 14a (the base film 15) at the interface with the inorganic film 22 while separating (dividing) the microstructure 16 fixed by the cured adhesive layer 17 from the microstructure 16 other than the position fixed by the adhesive layer 17 on the base film 15, and is formed as the antireflection optical body 16a on the adherend 11.

Fig. 11 is a diagram illustrating an example of a state in which the antireflection optical body 16a obtained by the forming method of the present embodiment is formed on the adherend 11.

As shown in fig. 11, according to the present embodiment, the member 10 in which the antireflection optical body 16a is formed only on a part of the adherend 11 through the cured adhesive layer 17 can be formed.

In this way, in the present embodiment, since UV light is irradiated to the adhesive layer 17 through the light guide device 13, the adhesive layer 17 is cured only in the region irradiated with the light transmitted through the light guide device 13, and the microstructure 16 formed on the optical film 14a is fixed to the adherend 11. Then, the fine structure 16 fixed to the adherend 11 is peeled off from the optical film 14a, whereby the antireflection optical body 16a is formed on the adherend 11. Therefore, the antireflection optical body 16a can be easily formed only in a partial region on the adherend 11 by adjusting the shape of the pressure surface of the light guide device 13.

The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

In the following examples, white plate glass manufactured by Sonbo Nitzson industry, product name "S9112" was used as the adherend 11, quartz material having a size of 10mm × 10mm × 20mm (a size of a contact surface with the optical films 14, 14a is 10mm × 10mm) was used as the light guide 13, and the contact surface with the optical films 14, 14a of the light guide 13 was a flat surface.

(example 1)

In the present embodiment, the optical film 14 shown in fig. 2 is used. First, the conditions for producing the optical film 14 will be described.

As the base film 15, a PET film having a thickness of 125 μm manufactured by Dichen corporation was used. A UV-curable resin layer 21p made of a UV-curable resin is formed on the base film 15, and the UV-curable resin layer 21p is cured by irradiation with UV light while the roller 23 is brought into close contact with it, thereby forming the fine uneven layer 21. In this example, an uneven pattern having an uneven pitch of 150nm to 230nm and a concave depth of about 250nm was formed on the fine uneven layer 21. Then, an inorganic film 22 as a release layer was formed on the surface of the fine uneven layer 21 with a film thickness of 20nm by a sputtering method using a sputtering target made of tungsten oxide. As described above, the thickness of the inorganic film 22 is desirably 5nm to 50nm, and more preferably 15nm to 35 nm. When the thickness of the inorganic film 22 is smaller than the above range and when the thickness of the inorganic film 22 is larger than the above range, the effect of peeling the microstructure 16 from the inorganic film 22 is deteriorated. Therefore, in the present embodiment, the thickness of the inorganic film 22 is set to 20 nm.

On the inorganic film 22, a UV-curable resin layer 16p composed of an uncured UV-curable acrylic resin was formed in a thickness of about 2 μm. Then, the roll 25 was closely attached to the UV curable resin layer 16p at 10kJ/m²The irradiation amount of (3) is an amount of irradiating the UV curable resin layer 16p with UV light to cure the UV curable resin layer 16p, thereby forming the microstructure 16. On the surface of the microstructure 16 on the inorganic film 22 side, an uneven pattern having an uneven pitch of 150nm to 230nm and a depth of a concave portion of about 250nm is formed corresponding to the uneven pattern formed on the fine uneven layer 21. As described above, the thickness of the microstructure 16 is preferably 10 μm or less. When the thickness of the microstructure 16 exceeds 10 μm, details will be described later, but in this case, it is difficult to fix the microstructure 16 fixed to the adherend 11 from the position other than the fixing position on the base film 15The microstructure 16 is separated. Therefore, in the present embodiment, the thickness of the microstructure 16 is set to about 2 μm.

Then, as shown in fig. 1A, 0.3 μ L was dropped on one surface of the adherend 11 using a micropipette, in which the UV curable resin 12 (triple bond (product name "TB 3042") was manufactured by triple bond corporation).

Next, as shown in fig. 1B, the optical film 14 is pressed by the light guide 13 via the jig 18 at a pressure of about 0.5MPa from the surface opposite to the surface on which the microstructure 16 is formed to the UV curable resin 12 applied to the adherend 11.

Next, as shown in fig. 1C, in a state where the optical film 14 is pressed by the light guide device 13 via the jig 18, UV light is transmitted to the light guide device 13 to cure the UV curable resin 12. In the present embodiment, the halogen lamp passes through the light guide 13 at 15kJ/m²The irradiation amount of (3) is UV light.

Next, as shown in fig. 1D, the optical film 14 is released from the adherend 11 by releasing the pressing of the optical film 14, and the microstructure 16 fixed to the adherend 11 by the UV curable resin 12 is peeled off from the optical film 14.

Here, by making the adhesion force between the adherend 11 and the microstructure 16 stronger than the adhesion force between the microstructure 16 and the fine uneven layer 21 by the UV curable resin 12, the microstructure 16 can be peeled off from the optical film 14 and fixed to the adherend 11 as the antireflection optical body 16 a. Further, since the thickness of the microstructure 16 is reduced to about 2 μm, the microstructure 16 can be easily separated from the microstructure 16 other than the fixing position. Since the inorganic film 22 is formed as the release layer between the microstructure 16 and the fine uneven layer 21, the microstructure 16 can be easily peeled from the optical film 14.

(example 2)

In this embodiment, the optical film 14 shown in fig. 4 in which the uneven pattern is formed on both surfaces of the microstructure 16 is used. The method for manufacturing the optical film 14 used in this example is substantially the same as that of example 1. In the present embodiment, after the UV curable resin layer 16p is formed on the inorganic film 22, the roll 26 having the uneven pattern formed on the surface thereof is brought into close contact with the roll 25 having the flat surface, and the UV curable resin layer 16p is cured. The uneven pattern formed on the surface of the microstructure 16 opposite to the inorganic film 22 has an uneven pitch of 150nm to 230nm and a depth of the concave portion of about 250nm, as in the uneven pattern formed on the surface of the microstructure 22. In the present embodiment, the thickness of the microstructure 16 is also set to about 2 μm. This is because, as described above, when the thickness of the microstructure 16 exceeds 10 μm, it is difficult to separate the microstructure 16 fixed to the adherend 11 from the microstructure 16 other than the fixing position on the base film 15.

In the present example, using the optical film 14 (optical film having the uneven pattern formed on both surfaces of the microstructure 16) thus produced, the antireflection optical body 16a was formed on the adherend 11 by the formation method shown in fig. 1A to 1D under the same conditions as in example 1.

(example 3)

In this example, the optical film 14 (the optical film 14 having the uneven pattern formed on both surfaces of the microstructure 16) prepared under the same conditions as in example 2 was used. Then, according to the forming method shown in fig. 1A to 1D, the antireflection optical body 16a is formed on the adherend 11 using the optical film 14. In this example, in the steps shown in fig. 1B and 1C, the pressing pressure for pressing the optical film 14 against the adherend 11 by the light guide device 13 was set to be higher than that in example 2. That is, in example 2, the pressing pressure for pressing the optical film 14 against the adherend 11 by the light guide device 13 was 0.5MPa, but in this example, the pressing pressure for pressing the optical film 14 against the adherend 11 by the light guide device 13 was changed to 3.0 MPa. Other conditions were the same as in example 2.

(example 4)

In this embodiment, the optical film 14a shown in fig. 9 in which the adhesive layer 17 is formed on the microstructure 16 is used. First, the conditions for producing the optical film 14a will be described.

Since the process is the same as in example 1 until the microstructure 16 is formed, the description thereof is omitted. In the shape of microstructure 16After that, a UV curable resin is poured onto the microstructure 16, and pressure is applied from above with a roller 28 through a release film 27, thereby forming a UV curable resin layer 17 p. Then, at 3kJ/m²The UV curable resin layer 17p is irradiated with UV light at the irradiation amount of (2) to semi-cure the UV curable resin, thereby forming the adhesive layer 17 with a film thickness of about 3 μm.

Using the optical film 14a thus produced (the optical film having the adhesive layer 17 formed on the microstructure 16), the antireflection optical body 16a is formed on the adherend 11 according to the forming method shown in fig. 8A to 8D.

That is, as shown in fig. 8A, the optical film 14a is held by the light guide device 13 via the jig 18 from the surface opposite to the surface on which the microstructure 16 and the adhesive layer 17 are formed. Then, as shown in fig. 8B, the pressure is applied to the adherend 11 at a pressure of about 0.5 MPa.

Next, as shown in fig. 8C, in a state where the optical film 14a is pressed by the light guide device 13 via the jig 18, UV light is transmitted to the light guide device 13 to cure the adhesive layer 17. In the present embodiment, the halogen lamp passes through the light guide 13 at 15kJ/m²The irradiation amount of (3) is UV light.

Next, as shown in fig. 8D, the pressing of the optical film 14a is released and the optical film 14a is released from the adherend 11, thereby peeling the microstructure 16 from the optical film 14 a.

Here, by making the adhesive strength between the adherend 11 and the microstructure 16 stronger than the adhesive strength between the microstructure 16 and the fine uneven layer 21 by the adhesive layer 17, the microstructure 16 can be peeled off from the optical film 14a and fixed to the adherend 11 as the antireflection optical body 16 a. Since the inorganic film 22 is formed as the release layer between the microstructure 16 and the fine uneven layer 21, the microstructure 16 can be easily peeled from the optical film 14 a.

Comparative example 1

Next, a method for forming the antireflection optical body into an adherend according to comparative example 1 will be described.

A cyclic olefin film (COC film) having a thickness of 50 μm was used as the base film. A UV-curable resin was applied to one surface of the COC film, and a concave-convex pattern was formed on the UV-curable resin by a roll-to-roll method using a roll having a concave-convex pattern formed on the surface thereof. Then, the UV curable resin is cured to produce an optical film having a microstructure on one surface. The uneven pattern of the microstructure was set to have an uneven pitch of 150nm to 230nm and a depth of the concave portion of about 250nm as in examples 1 to 4. Then, using an adhesive material (an adhesive tape (product name "PDS 1" manufactured by PANAC corporation) which is an acrylic adhesive material having a thickness of 25 μm), a surface opposite to the surface of the optical film on which the microstructure is formed was bonded to the adherend by a roller, and an antireflection optical body was formed on the adherend.

Comparative example 2

Next, a method for forming the antireflection optical body on the adherend of comparative example 2 will be described.

First, a PET film having a thickness of 125 μm manufactured by Dichen corporation was used as a base film. A UV-curable resin was applied to one surface of a PET film, and a concave-convex pattern was formed on the UV-curable resin by a roll-to-roll method using a roll having a concave-convex pattern formed on the surface. Then, the UV curable resin was cured, and a tungsten oxide film having a thickness of 20nm was coated on the cured UV curable resin by a sputtering method. Then, a fluororesin was coated with a release material (product name "Novec 1720" manufactured by 3M) to produce an optical film having a microstructure formed on one surface thereof.

Then, after applying a UV curable resin to the adherend, a surface opposite to the surface of the optical film on which the microstructure is formed is pressed against the adherend by a roller. Thereafter, the pressure applied by the roller is released, and the UV curable resin is cured by irradiation with UV light, whereby the antireflection optical body is formed on the adherend.

The evaluation results of the antireflection optical body formed on the adherend 11 by the above-described examples 1 to 4 and comparative examples 1 and 2 will be described.

First, the evaluation results of the film thickness of the antireflection optical body formed on the adherend 11 by examples 1 to 4 and comparative examples 1 and 2 are shown in table 1.

The film thickness was measured by measuring the film thickness at two positions at the edge and at one position at the center of the antireflection optical body, i.e., at nine positions in total, along the X direction and the Y direction perpendicular to the X direction, respectively, along the formation surface of the antireflection optical body using a film thickness meter (manufactured by sanfeng corporation, L ITEMATIC V L-50S).

[ Table 1]

As shown in table 1, in comparative example 1, the standard deviation of the thickness of the formed body was substantially the same as in examples 1 to 3, but the film thickness was larger than in examples 1 to 4. As described above, when the electronic device application is considered, the thickness of the antireflection optical body is required to be at a level of 10 μm or less. Therefore, in comparative example 1, the film thickness was too large, and the film was not suitable for the above-described application.

In comparative example 2, the film thickness was reduced to a level almost equal to that in examples 1 to 4, but the variation in the thickness was large, and the distortion of the surface was problematic.

On the other hand, in examples 1 to 4, the film thickness was 10 μm or less, and the reduction in thickness was achieved. In examples 1 to 3, the thickness variation was also small, and low distortion was achieved. In addition, if example 2 is compared with example 3, the thickness of the antireflection optical body formed is greatly different. The pressing pressure of the optical film 14 against the adherend 11 is different between the embodiments 2 and 3. Therefore, it is found that the thickness of the antireflection optical body to be formed can be adjusted by adjusting the pressing pressure of the optical film 14 against the adherend 11.

Fig. 12A and 12B show the measurement results of the surface properties of the formed antireflection optical body. As a representative example, fig. 12A shows the measurement result of the surface characteristics of the antireflection optical body formed in example 1, and fig. 12B shows the measurement result of the surface characteristics of the antireflection optical body formed in comparative example 1. Fig. 12A and 12B show measurement results obtained using a three-dimensional surface roughness meter ("VertScan" manufactured by mitsubishi corporation). In fig. 12A and 12B, the horizontal axis represents the distance along one direction on the antireflection optical body to be formed, and the vertical axis represents the difference in film thickness at each position with the thickness at a certain position as a reference.

As shown in fig. 12A and 12B, it is understood that the antireflection optical body formed in example 1 has less variation in film thickness and achieves low distortion compared to the antireflection optical body formed in comparative example 1.

Fig. 13A to 13F are views each showing an image obtained by imaging the antireflection optical body formed on the adherend 11 in examples 1 to 4 and comparative examples 1 and 2 from above. In fig. 13A to 13F, a microstructure is formed with a rectangular (rectangular) region as a target region. When taking a photograph, a black tape is attached to the back surface (the surface opposite to the surface on which the microstructure is formed) of the adherend, and observation is facilitated.

As shown in fig. 13A to 13D, it is understood that in examples 1 to 4, a microstructure is formed in alignment with a rectangular region as a target region, and a microstructure is formed only in a partial region of an adherend with high accuracy.

As shown in fig. 13E, in comparative example 1, a microstructure was formed so as to be substantially aligned with a rectangular region as a target region. However, in comparative example 1, since the adhesive material and the optical film were arranged in alignment with the target area and bonded by a roller, it was difficult to perform bonding if the target area was small. As described above, in comparative example 1, the film thickness of the microstructure was increased, and it was difficult to apply the method of comparative example 1 to the formation of an antireflection optical body for electronic device use.

Further, as shown in fig. 13F, in comparative example 2, since the microstructure cannot be formed in alignment with the rectangular region as the target region, it is difficult to form the antireflection optical body only in a desired region with high accuracy by using the method of comparative example 2.

Next, the results of evaluating the antireflection characteristics of the microstructure on the adherend 11 in examples 1 to 4 will be described.

The apparent reflectance (reflectance of Y value in XYZ color system, measured according to JIS Z8722) obtained from the anti-reflection optical body formed in example 1 to example 4 is shown in table 2. In general, when used as an antireflection member, the apparent reflectance is desirably 1% or less, and preferably 0.6% or less. Fig. 14 shows reflection spectra of the antireflection optical bodies formed in examples 1 to 4. In fig. 14, the horizontal axis represents the wavelength of incident light, and the vertical axis represents the reflectance of incident light.

[ Table 2]

	Perceived reflectance
		Example 1	0.27
Example 2	0.26
		Example 3	0.15
Example 4	0.42

As shown in table 2, the apparent reflectance was 0.6% or less in all of examples 1 to 4. As shown in fig. 14, in examples 1 to 4, the reflectance at each wavelength was 0.8% or less, and the reflection characteristics were good.

As shown in fig. 14, the reflectance spectrum of example 1 fluctuates over the entire wavelength range. On the other hand, in example 2 in which an antireflection optical body was formed under the same conditions except for the structure of the optical film 14 (the microstructure 16), such a fluctuation was not generated. Accordingly, it is considered that the generation of the ripple in example 1 is caused by the structure of the microstructure 16.

In example 1, the interface between the adherend 11 and the UV curable resin 12 and the interface between the UV curable resin 12 and the microstructure 16 are substantially flat, respectively. Therefore, it can be considered that the fluctuation generated in the reflection spectrum of example 1 is caused by the difference in the optical refractive index at the interface between the adherend 11 and the UV curable resin 12, and the optical refractive index at the interface between the UV curable resin 12 and the minute structure 16. That is, it is considered that the light reflected at the interface between the adherend 11 and the UV curable resin 12 interferes with the light reflected at the interface between the UV curable resin 12 and the microstructure 16, and a fluctuation occurs in the reflection spectrum.

On the other hand, in example 2, although the interface between the adherend 11 and the UV curable resin 12 is flat, the interface between the UV curable resin 12 and the microstructure 16 has an uneven structure. Therefore, it is considered that interference of light reflected at both interfaces does not occur, and generation of the ripple is suppressed. Therefore, by providing the uneven patterns on both surfaces of the microstructure 16 as in examples 2 and 3, it is possible to suppress the occurrence of fluctuation in the reflection spectrum and obtain more favorable reflection characteristics.

As described above, the method for forming the antireflection optical body 16a on the adherend 11 according to the first embodiment of the present invention includes: a coating step of coating a surface of an adherend 11 with a UV curable resin 12 (photocurable resin), a pressing step of pressing a base material film 15 having a microstructure 16 formed into a thin film on one surface side thereof with a light-transmitting light guide device 13 from the other surface side opposite to the one surface side toward the UV curable resin 12, and in a state where the base material film 15 is pressed with the light guide device 13, a curing step of curing the UV curable resin 12 by transmitting UV light to the light guide 13, and releasing the pressing of the base film 15, and a peeling and separating step of forming the antireflection optical body 16a on the adherend 11 by peeling the microstructure 16 fixed to the adherend 11 by the cured UV-curable resin 12 from the base film 15 while separating the microstructure 16 fixed to the adherend 11 by the cured UV-curable resin 12 from the microstructure 16 on the base film 15 except for the position fixed by the photocurable resin 12.

Further, a method of forming the antireflection optical body 16a on the adherend 11 according to the second embodiment of the present invention includes: a thin microstructure 16 is formed on one surface side by a light guide device 13 which transmits light, and a pressing step of pressing the base material film 15 having the adhesive layer 17 (photocurable resin layer) of a semi-cured photocurable resin formed on the microstructure 16 against the adherend 11 from the other surface side opposite to the one surface side, in a state where the base material film 15 is pressed by the light guide device 13, a curing step of curing the adhesive layer 17 by transmitting light to the light guide 13, and releasing the pressing of the base film 15, and a peeling and separating step of forming the antireflection optical body 16a on the adherend 11 by peeling the microstructure 16 fixed to the adherend 11 by the cured adhesive layer 17 from the base film 15 while separating the microstructure 16 fixed to the adherend 11 by the cured adhesive layer 17 from the microstructure 16 on the base film 15 except for the position fixed by the adhesive layer 17.

According to the curing step, in the region where the UV curable resin 12 or the adhesive layer 17 is present and the light transmitted by the light guide device 13 is irradiated, the microstructure 16 formed on one surface side of the base film 15 and the adherend 11 are fixed by the cured UV curable resin 12 or the adhesive layer 17. Then, by releasing the optical films 14 and 14a by releasing the pressing of the base film 15, the microstructure 16 fixed to the adherend 11 is peeled off from the optical films 14 and 14a only in the region where the UV curable resin 12 or the adhesive layer 17 is present and the light guided by the light guide device 13 is irradiated, and is formed as the antireflection optical body 16a on the adherend 11. Therefore, in the first embodiment, the microstructure 16 can be easily formed only in a partial region on the adherend 11 by adjusting the shapes of the region to which the UV curable resin 12 is applied and the pressure surface of the light guide device 13, and in the second embodiment, the microstructure 16 can be easily formed only in a partial region on the adherend 11 by adjusting the shape of the pressure surface of the light guide device 13. Further, since it is not necessary to fix the adherend 11 and the microstructure 16 by an adhesive film as in comparative example 1, it is possible to make the film thinner.

The present invention has been described based on the drawings and the embodiments, but it is to be noted that various modifications and corrections are easily made by those skilled in the art based on the present disclosure. Therefore, it is intended that these modifications and variations be included within the scope of the present invention.