WO2018012339A1

WO2018012339A1 - Method for manufacturing optical member

Info

Publication number: WO2018012339A1
Application number: PCT/JP2017/024367
Authority: WO
Inventors: 賢厚母; 芝井　康博; 健一郎中松
Original assignee: シャープ株式会社
Priority date: 2016-07-12
Filing date: 2017-07-03
Publication date: 2018-01-18
Also published as: CN109476073B; CN109476073A; JPWO2018012339A1; JP6616901B2

Abstract

The present invention provides a method for manufacturing an optical member, whereby antifouling properties and abrasion resistance are increased without compromising transparency. This method for manufacturing an optical member is a method for manufacturing an optical member provided with a substrate and a polymer layer having an uneven structure on a surface thereof in which a plurality of projections are provided at a pitch equal to or less than the wavelength of visible light, wherein the method includes a process (1) for dissolving a photocurable resin and a release agent in a solvent and preparing a resin solution, a process (2) for applying the resin solution to the surface of the substrate, a process (3) for performing a heat treatment for removing the solvent from the applied resin solution and forming a resin layer, a process (4) for pressing the substrate against a die in a state in which the resin layer is sandwiched between the die and the substrate and forming the uneven structure on the surface of the resin layer, and a process (5) for curing the resin layer by photoirradiation and forming the polymer layer, the photocurable resin and the release agent being a combination exhibiting a predetermined turbidity when mixed with each other, and the optical member having a haze of less than 1.0%.

Description

Manufacturing method of optical member

The present invention relates to a method for manufacturing an optical member. More specifically, the present invention relates to a method for manufacturing an optical member having a nanometer-size uneven structure.

Optical members are being studied for application in various fields (see, for example, Patent Documents 1 to 5). In particular, it is known that an optical member having a nanometer-size uneven structure (nanostructure) has excellent antireflection properties. According to such a concavo-convex structure, since the refractive index continuously changes from the air layer to the substrate, the reflected light can be dramatically reduced.

JP 2007-178724 A JP 2005-97371 A International Publication No. 2015/060458 International Publication No. 2013/187506 International Publication No. 2011/125970

As such an optical member, the structure by which the polymer layer which has an uneven structure on the surface is arrange | positioned on the surface of a base material is mentioned, for example. However, since the conventional optical member has a concavo-convex structure on the surface, there is a problem that fingerprints are difficult to wipe off, that is, the antifouling property is low.

On the other hand, the present inventors tried to improve the antifouling property (fingerprint wiping property) by forming a polymer layer using a photocurable resin and a release agent and by the effect of the release agent. However, since the surface area of the concavo-convex structure is large, it has been found that the effective component of the release agent is difficult to orient on the surface of the concavo-convex structure simply by blending the photocurable resin and the release agent. As a result, it was found that not only antifouling property but also slipperiness could not be obtained sufficiently. Insufficient slipperiness increases the load (friction resistance) when rubbing the surface of the polymer layer, resulting in a decrease in abrasion resistance. Further, it was found that when the optical member is left in a high temperature / high humidity environment, the orientation of the active ingredient of the mold release agent changes, so that the antifouling property and abrasion resistance are remarkably reduced.

On the other hand, the present inventors tried to increase the content (concentration) of the active ingredient of the release agent to increase the amount of orientation on the surface of the concavo-convex structure. However, it has been found that simply increasing the content of the active ingredient in the release agent lowers the compatibility with the photocurable resin, so that the release agent becomes insoluble. As a result, it was found that the haze of the optical member increases, that is, the transparency decreases.

As described above, the conventional optical member has room for improvement in terms of enhancing the antifouling property and the abrasion resistance without impairing the transparency.

Patent Document 1 describes a method of forming a concavo-convex structure using a photocurable resin composition containing a fluorine compound. However, simply blending a fluorine compound is insufficient in antifouling properties and abrasion resistance, and there is room for improvement.

Patent Document 2 describes an optical article in which a concavo-convex structure is formed using a fluorine-containing resin composition containing a fluorine-containing compound. However, since the fluorine-containing compound is dissolved in the polyfunctional curing agent used in the examples, the antifouling property and abrasion resistance are insufficient, and there is room for improvement.

Patent Document 3 describes a hard coat film formed using a polymerizable composition (fluororesin). However, simply utilizing the orientation of fluorine atoms is insufficient in antifouling properties and abrasion resistance, and there is room for improvement.

Patent Document 4 describes a laminate in which a surface treatment layer containing fluorine atoms is formed on the surface of an uneven structure. However, since the surface treatment layer is easily peeled off, the abrasion resistance is insufficient and there is room for improvement.

Patent Document 5 discloses a nano unevenness formed by using an active energy ray-curable resin composition containing a polyfunctional monomer having a high surface free energy and a fluorine-based (meth) acrylate compatible with the polyfunctional monomer. A structure is described. However, the effect of orienting fluorine atoms on the surface is insufficient only by utilizing the difference in surface free energy between the two components. Moreover, there is a limit to the amount of the fluorine-based (meth) acrylate that is compatible, and the effect of orienting fluorine atoms on the surface is insufficient. As described above, the antifouling property and abrasion resistance are insufficient, and there is room for improvement.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a method for producing an optical member that improves antifouling properties and abrasion resistance without impairing transparency.

The inventors of the present invention have studied various methods for producing an optical member that enhances antifouling properties and abrasion resistance without impairing transparency. As a result, polymers using a photocurable resin and a release agent that are incompatible with each other are used. We focused on the method of forming the layer. And after (1) dissolving a photocurable resin and a release agent in a solvent, and then removing the solvent, and (2) after applying the photocurable resin and the release agent in two layers And found a method of integrating both layers. As a result, the inventors have conceived that the above problems can be solved brilliantly and have reached the present invention.

That is, according to one embodiment of the present invention, there is provided a base material, and a polymer layer that is provided on the surface of the base material and has a concavo-convex structure provided on the surface with a plurality of convex portions provided at a pitch equal to or less than the wavelength of visible light. A process for producing an optical member comprising: a process (1) for preparing a resin solution by dissolving a photocurable resin and a release agent in a solvent; and a process for applying the resin solution on the surface of the substrate ( 2), a heat treatment for removing the solvent from the coated resin solution, and a resin layer is formed (3), and the substrate is pressed against the mold with the resin layer sandwiched therebetween. A process (4) for forming the concavo-convex structure on the surface of the resin layer, and a process (5) for curing the resin layer by light irradiation to form the polymer layer. And the mold release agent, when mixed with each other, 5 degrees ( Olin) is a combination showing turbidity of 25 degrees (kaolin) or less, and the haze of the optical member is less than 1.0% (hereinafter referred to as the first optical member of the present invention). It may also be called a manufacturing method.

Another embodiment of the present invention includes a base material and a polymer layer that is disposed on the surface of the base material and has a concavo-convex structure provided on the surface with a plurality of convex portions provided at a pitch equal to or less than the wavelength of visible light. A process (1) for applying a first resin and a second resin, and a substrate in a state where the first resin and the second resin are sandwiched therebetween, A process (2) of pressing the mold from the first resin side to form a resin layer having the concavo-convex structure on the surface, and a process of curing the resin layer by light irradiation to form the polymer layer ( 3), the first resin contains a photocurable resin, the second resin contains a release agent, and the first resin and the second resin are mixed with each other. Combination of turbidity of 15 degrees (kaolin) or more and 35 degrees (kaolin) or less There, the haze of the optical member, the method of manufacturing the optical member is less than 1.0% may be (hereinafter, also the manufacturing method of the second optical member of the present invention refers.).

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the optical member which improves antifouling property and abrasion resistance can be provided, without impairing transparency.

FIG. 5 is a schematic cross-sectional view for explaining the method for manufacturing the optical member according to the first embodiment. 6 is a schematic cross-sectional view for explaining a method for manufacturing an optical member according to Embodiment 2. FIG. FIG. 10 is a schematic cross-sectional view for explaining the method for manufacturing the optical member according to the third embodiment.

Embodiments will be described below, and the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited only to these embodiments. In addition, the configurations of the respective embodiments may be appropriately combined or changed within a range not departing from the gist of the present invention.

[Embodiment 1]
The manufacturing method of the optical member of Embodiment 1 is related with the manufacturing method of the 1st optical member of this invention. The manufacturing method of the optical member of Embodiment 1 is demonstrated below with reference to FIG. FIG. 1 is a schematic cross-sectional view for explaining the method of manufacturing the optical member of the first embodiment.

(Process (1): Preparation of resin solution)
A photocurable resin and a release agent are dissolved in a solvent to prepare a resin solution 3.

The resin solution 3 is prepared, for example, by the following procedure.
(I) Various monomers, a photopolymerization initiator, and the like are appropriately mixed to prepare a photocurable resin (transparent state).
(Ii) A mixture (white turbid state) of a photocurable resin and a release agent is prepared.
(Iii) A mixture of a photocurable resin and a release agent is dissolved in a solvent to prepare a resin solution 3 (transparent state or slightly cloudy state).

As a method for preparing the resin solution 3, in the above procedure, the solvent was added after mixing the photocurable resin and the mold release agent. For example, the mold release agent was mixed after mixing the photocurable resin and the solvent. May be added.

(Process (2): Application of resin solution)
As shown in FIG. 1A, the resin solution 3 is applied on the surface of the substrate 2.

Examples of the coating method of the resin solution 3 include a coating method using a spray method, a gravure method, a slot die method, a bar coating method, and the like. From the viewpoint of easily adjusting the film thickness and reducing the cost of the apparatus, a method of applying by a spray method is preferable. Among these, application using a swirl nozzle, electrostatic nozzle, or ultrasonic nozzle is particularly preferable.

(Process (3): Formation of resin layer)
A heat treatment for removing the solvent from the coated material of the resin solution 3 is performed. As a result, the resin layer 4 is formed as shown in FIG.

As a heat treatment method, for example, a method in which a coated product of the resin solution 3 is disposed on the surface of the substrate 2 (the state shown in FIG. 1A) is heated in an oven. The heat treatment is preferably performed at a temperature equal to or higher than the boiling point of the solvent. A part of the solvent may be removed by heat treatment or may be completely removed.

(Process (4): Formation of uneven structure)
As shown in FIG. 1C, the substrate 2 is pressed against the mold 5 with the resin layer 4 sandwiched therebetween. As a result, a concavo-convex structure is formed on the surface of the resin layer 4 (surface opposite to the base material 2).

(Process (5): Curing of resin layer)
The resin layer 4 is cured by light irradiation. As a result, a polymer layer 6 is formed as shown in FIG.

Although hardening of the resin layer 4 is performed by light irradiation, it is preferable to be performed by irradiation of active energy rays. Active energy rays refer to ultraviolet rays, visible rays, infrared rays, plasma, and the like. It is preferable that the resin layer 4 is hardened | cured with an ultraviolet-ray. The light irradiation on the resin layer 4 may be performed from the substrate 2 side of the resin layer 4 or from the mold 5 side of the resin layer 4. Moreover, the light irradiation number with respect to the resin layer 4 may be only once, and may be multiple times. The curing of the resin layer 4 (the above process (5)) may be performed at the same timing as the formation of the concavo-convex structure on the resin layer 4 (the above process (4)).

(Process (6): Mold peeling)
As shown in FIG. 1 (e), the mold 5 is peeled from the polymer layer 6. As a result, the optical member 1 is completed. The concavo-convex structure formed on the surface of the polymer layer 6 (surface opposite to the substrate 2) has a plurality of convex portions (protrusions) 7 having a pitch less than the wavelength of visible light (between the apexes of adjacent convex portions 7). This corresponds to a structure provided at a distance P), that is, a moth-eye structure (an eye-like structure). Therefore, the optical member 1 can exhibit excellent antireflection properties (low reflectivity) due to the moth-eye structure.

In the manufacturing process described above, for example, if the substrate 2 is formed into a roll, the above processes (2) to (6) can be performed continuously and efficiently.

As mentioned above, according to the manufacturing method of the optical member of Embodiment 1, after the photocurable resin and release agent which are mutually incompatible are dissolved in the solvent (the above process (1)), the solvent is removed (the above Since the release agent is insolubilized by the process (3)), the active component of the release agent is easily oriented on the surface of the resin layer 4 (surface opposite to the base material 2). Therefore, the effective component of the release agent can be efficiently oriented on the surface of the polymer layer 6 (the surface opposite to the substrate 2) without greatly increasing the content of the active component of the release agent. . That is, according to the manufacturing method of the optical member of Embodiment 1, antifouling property and abrasion resistance can be improved without impairing transparency (without increasing haze). Furthermore, according to the manufacturing method of the optical member of Embodiment 1, since the antifouling property and the abrasion resistance can be improved even with a small amount of the release agent, the material cost can be reduced.

Then, each member used when manufacturing the optical member 1 is demonstrated below.

Examples of the material of the substrate 2 include resins such as triacetyl cellulose (TAC), polyethylene terephthalate (PET), and methyl methacrylate (MMA). The base material 2 may appropriately contain additives such as a plasticizer in addition to the above materials. The surface of the base material 2 (the surface on the polymer layer 6 side) may be subjected to easy adhesion treatment, and for example, a triacetyl cellulose film subjected to easy adhesion treatment can be used. Further, the surface of the substrate 2 (the surface on the polymer layer 6 side) may be subjected to saponification treatment, and for example, a triacetyl cellulose film subjected to saponification treatment can be used.

Examples of the shape of the substrate 2 include a film shape and a sheet shape. When the film-like optical member 1 is manufactured, the film-like substrate 2 may be used. Moreover, the form in which the base material 2 comprises a part of polarizing plate is preferable.

The thickness of the substrate 2 is preferably 50 μm or more and 100 μm or less from the viewpoint of ensuring transparency and workability.

The haze of the substrate 2 is preferably less than 1% from the viewpoint of ensuring transparency.

The photocurable resin and the release agent are a combination that exhibits a turbidity of 5 degrees (kaolin) or more and 25 degrees (kaolin) or less when mixed with each other. This indicates that the photocurable resin and the release agent are not compatible. In the present specification, the phrase “compatible” means that the turbidity when these materials are mixed is less than 5 degrees (kaolin) (transparent state). On the other hand, “not compatible” with a plurality of materials means that the turbidity when these materials are mixed is 5 degrees (kaolin) or more (white turbid state). When the turbidity when the photocurable resin and the release agent are mixed is less than 5 degrees (kaolin), the active ingredient of the release agent is heavy when the solvent is removed (the above process (3)). Since it becomes difficult to orient on the surface of the combined layer 6 (surface opposite to the base material 2), the antifouling property and the abrasion resistance are lowered. When the turbidity when the photocurable resin and the release agent are mixed is higher than 25 degrees (kaolin), the photocurable resin and the release agent are easily separated. The antifouling property (for example, fingerprint wiping property) in the environment of the above will decrease. The photocurable resin and the release agent are preferably a combination that exhibits a turbidity of 7 degrees (kaolin) or more and 15 degrees (kaolin) or less when mixed with each other. In this specification, turbidity is determined based on a kaolin standard solution. For example, in an integrating sphere turbidimeter “PT-200” manufactured by Mitsubishi Chemical Analytech, turbidity can be measured by placing a sample in a 10 mm cell and using a preset kaolin calibration curve. .

The release agent is preferably a fluororesin having a photoreactive group (hereinafter also simply referred to as a fluororesin), that is, a fluorine-based release agent. According to such a configuration, bleed out in a high temperature / high humidity environment is reduced, and the reliability of the optical member 1 is increased. Further, since the fluororesin has a low surface free energy, it is preferably used for improving the antifouling property (for example, fingerprint wiping property).

The fluororesin contains a fluorine-containing monomer having a photoreactive group (hereinafter also simply referred to as a fluorine-containing monomer) as an active ingredient. According to such a structure, the surface free energy of the polymer layer 6 becomes low, and antifouling property increases. Furthermore, since the fluorine atoms are oriented on the surface of the polymer layer 6 (the surface on the side opposite to the base material 2), the slipperiness is enhanced. As a result, the abrasion resistance is increased. In the present specification, the photoreactive group refers to a functional group that reacts with other components by light. Examples of such photoreactive groups include alkoxysilyl groups, silyl ether groups, hydrolyzed silanol groups, carboxyl groups, hydroxyl groups, epoxy groups, vinyl groups, allyl groups, acryloyl groups, methacryloyl groups. Etc. As the photoreactive group, from the viewpoint of photoreactivity and handling, an alkoxysilyl group, a silyl ether group, a silanol group, an epoxy group, a vinyl group, an allyl group, an acryloyl group, or a methacryloyl group are preferable, a vinyl group, An allyl group, an acryloyl group, or a methacryloyl group is more preferable, and an acryloyl group or a methacryloyl group is still more preferable.

The fluorine-containing monomer includes at least one selected from the group consisting of a fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group in addition to the photoreactive group. It is preferable to have a site. A fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group are respectively an alkyl group, an oxyalkyl group, an alkenyl group, an alkanediyl group, and an oxyalkanediyl group. It is a substituent in which at least part of the hydrogen atoms it has are substituted with fluorine atoms. A fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group are all substituents mainly composed of fluorine atoms and carbon atoms, and are branched in the structure. Part may be present, and a plurality of these substituents may be linked.

An example of the fluorine-containing monomer is represented by the following general formula (A).
R ^f1 -R ² -D ¹ (A)
In the general formula (A), R ^f1 is a moiety containing at least one selected from the group consisting of a fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group. Represents. R ² represents an alkanediyl group, an alkanetriyl group, or an ester structure, urethane structure, ether structure, or triazine structure derived therefrom. D ¹ represents a photoreactive group.

Examples of the fluorine-containing monomer represented by the general formula (A) include 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, and 2-perfluorobutyl. Ethyl acrylate, 3-perfluorobutyl-2-hydroxypropyl acrylate, 2-perfluorohexylethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 2-perfluorooctylethyl acrylate, 3-perfluorooctyl-2 -Hydroxypropyl acrylate, 2-perfluorodecylethyl acrylate, 2-perfluoro-3-methylbutylethyl acrylate, 3-perfluoro-3-methoxybutyl-2-hydroxypropyl acrylate, 2-perfluoro-5 Methylhexylethyl acrylate, 3-perfluoro-5-methylhexyl-2-hydroxypropyl acrylate, 2-perfluoro-7-methyloctyl-2-hydroxypropyl acrylate, tetrafluoropropyl acrylate, octafluoropentyl acrylate, dodecafluoroheptyl Acrylate, hexadecafluorononyl acrylate, hexafluorobutyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2-perfluorobutylethyl methacrylate, 3-par Fluorobutyl-2-hydroxypropyl methacrylate, 2-perfluorooctylethyl methacrylate, 3-perfluorooctyl-2-hydroxypropy Methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluoro-3-methylbutylethyl methacrylate, 3-perfluoro-3-methylbutyl-2-hydroxypropyl methacrylate, 2-perfluoro-5-methylhexylethyl methacrylate, 3 -Perfluoro-5-methylhexyl-2-hydroxypropyl methacrylate, 2-perfluoro-7-methyloctylethyl methacrylate, 3-perfluoro-7-methyloctylethyl methacrylate, tetrafluoropropyl methacrylate, octafluoropentyl methacrylate, dodeca Fluoroheptyl methacrylate, hexadecafluorononyl methacrylate, 1-trifluoromethyl trifluoroethyl methacrylate, hexafluorobut Examples include til methacrylate, triacryloyl-heptadecafluorononenyl-pentaerythritol, and the like.

As a preferable material of the fluorine-containing monomer, for example, a material having a fluoropolyether moiety can be mentioned. The fluoropolyether moiety is a moiety composed of a fluoroalkyl group, an oxyfluoroalkyl group, an oxyfluoroalkyldiyl group, etc., and has a structure represented by the following general formula (B) or (C).
CF _n1 H _(3-n1) -(CF _n2 H _(2-n2) ) _k O- (CF _n3 H _(2-n3) ) _m O- (B)
-(CF _n4 H _(2-n4) ) _p O- (CF _n5 H _(2-n5) ) _s O- (C)
In the above general formulas (B) and (C), n1 is an integer of 1 to 3, n2 to n5 are 1 or 2, and k, m, p, and s are integers of 0 or more. A preferable combination of n1 to n5 is a combination in which n1 is 2 or 3, and n2 to n5 is 1 or 2, and a more preferable combination is n1 is 3, n2 and n4 are 2, and n3 and n5 are 1 or 2. 2 is a combination.

The number of carbon atoms contained in the fluoropolyether moiety is preferably 4 or more and 12 or less, more preferably 4 or more and 10 or less, and still more preferably 6 or more and 8 or less. When the number of carbon atoms is less than 4, there is a concern that the surface free energy decreases. When the number of carbon atoms is more than 12, there is a concern that the solubility in a solvent is lowered. In addition, the fluorine-containing monomer may have a plurality of fluoropolyether sites per molecule.

Known fluorine-containing monomers include “OPTOOL (registered trademark) DAC-HP” manufactured by Daikin Industries, Ltd., “CHEMINOX (registered trademark) FAAC-6” manufactured by Unimatec, “Afluid” manufactured by Asahi Glass Co., Ltd., DIC's "MegaFac (registered trademark) RS-76-NS", DIC's "MegaFac RS-75", Yushi Fats Company's "C10GACRY", Yushi Yushi Products'"C8HGOL", etc. It is done. The fluorine-containing monomer is preferably one that is cured (polymerized) by ultraviolet rays. The fluorine-containing monomer preferably contains at least one of a —OCF ₂ — chain and a ═NCO— chain. The mold release agent may contain one type of fluorine-containing monomer or may contain a plurality of types.

In addition to the fluorine-containing monomer, the fluororesin may appropriately contain a fluorine-based surfactant, a reactive monomer, and the like.

Known fluorine-based surfactants include, for example, “Surflon (registered trademark)” manufactured by AGC Seimi Chemical Co., “Futgent (registered trademark) 650A” manufactured by Neos, and “FC-” manufactured by 3M. 4430 "," FC-4432 "manufactured by 3M Corporation," F Top "manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd., and the like. The fluorine-based surfactant is preferably one that is cured (polymerized) by ultraviolet rays. The fluorosurfactant preferably contains at least one of a —OCF ₂ — chain and a ═NCO— chain. The mold release agent may contain one type of fluorosurfactant or a plurality of types.

Examples of the reactive monomer include amide group-containing monomers such as N-acryloylmorpholine, N- (2-hydroxyethyl) acrylamide, N, N-diethylacrylamide; 1,4-cyclohexanedimethanol monoacrylate, 4-hydroxybutyl Examples thereof include hydroxyl group-containing monomers such as acrylate; acetoacetoxy group-containing monomers such as 2-acetoacetoxyethyl methacrylate. Known examples of N-acryloylmorpholine include “ACMO (registered trademark)” manufactured by KJ Chemicals. Known examples of N- (2-hydroxyethyl) acrylamide include “HEAA (registered trademark)” manufactured by KJ Chemicals. Known examples of N, N-diethylacrylamide include “DEAA (registered trademark)” manufactured by KJ Chemicals. Known examples of 1,4-cyclohexanedimethanol monoacrylate include “CHDMMA” manufactured by Nippon Kasei Co., Ltd. Known examples of 4-hydroxybutyl acrylate include “4HBA” manufactured by Nippon Kasei Co., Ltd. Known examples of 2-acetoacetoxyethyl methacrylate include “AAEM” manufactured by Nippon Synthetic Chemical Co., Ltd. The mold release agent may contain one kind of these reactive monomers or may contain a plurality of kinds. These reactive monomers preferably contain an acid amide bond in the molecule.

As a mold release agent, a silicon type mold release agent, a phosphate ester type mold release agent, etc. other than the fluorine-type mold release agent (fluororesin) mentioned above are mentioned, for example.

Examples of the silicon-based mold release agent include silicon diacrylate and the like, among which known examples include “EBECRYL (registered trademark) 350” manufactured by Daicel Ornex Co., Ltd.

Examples of the phosphoric acid ester release agent include (poly) oxyethylene alkyl phosphate esters. Among them, known ones include, for example, “NIKKOL (registered trademark) TDP-2” manufactured by Nikko Chemicals. Etc.

The content of the active ingredient of the release agent in the resin layer 4 is preferably 0.1 wt% or more and 10 wt% or less, more preferably 0.5 wt% or more and 9 wt% or less. More preferably, it is 1 to 5% by weight. When the content of the active ingredient of the release agent in the resin layer 4 is less than 0.1% by weight, the active ingredient of the release agent on the surface of the polymer layer 6 (the surface opposite to the substrate 2) There is a concern that the amount becomes too small and the antifouling property and abrasion resistance are lowered. When the content rate of the active ingredient of the release agent in the resin layer 4 is higher than 10% by weight, the amount of the active ingredient of the release agent on the surface of the polymer layer 6 (surface opposite to the substrate 2) is Since the polymer layer 6 (convex part 7) is insufficiently elastic because it increases too much, when the surface of the polymer layer 6 (surface opposite to the substrate 2) is rubbed, the collapsed convex part 7 rises. There is no concern (does not restore). As a result, there is a concern that the abrasion resistance is lowered.

The photocurable resin may contain various monomers, photopolymerization initiators and the like as long as the turbidity when mixed with a release agent is 5 degrees (kaolin) or more and 25 degrees (kaolin) or less. Good.

Examples of the various monomers include urethane acrylate, ethoxylated polyglycerin polyacrylate, ethoxylated pentaerythritol tetraacrylate, and the like. Known examples of urethane acrylate include “U-10HA” manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of known ethoxylated polyglycerin polyacrylates include “NK ECONOMER (registered trademark) A-PG5027E” manufactured by Shin-Nakamura Chemical Co., Ltd. Known examples of ethoxylated pentaerythritol tetraacrylate include “ATM-35E” manufactured by Shin-Nakamura Chemical Co., Ltd. The photocurable resin may contain one kind of these various monomers or may contain a plurality of kinds.

The photopolymerization initiator is active with respect to light (active energy rays) and is added to start a polymerization reaction for polymerizing the monomer. As the photopolymerization initiator, for example, a radical polymerization initiator, an anionic polymerization initiator, a cationic polymerization initiator and the like can be used. Examples of such photopolymerization initiators include acetophenones such as p-tert-butyltrichloroacetophenone, 2,2′-diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one; Ketones such as benzophenone, 4,4′-bisdimethylaminobenzophenone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone; benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. Benzoin ethers; benzyl ketals such as benzyl dimethyl ketal and hydroxycyclohexyl phenyl ketone; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide; Scan (2,4,6-trimethylbenzoyl) - acylphosphine oxides such as triphenylphosphine oxide; 1-hydroxy - cyclohexyl - phenyl - phenones such as ketones, and the like. Known examples of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide include, for example, “IRGACURE (registered trademark) TPO” manufactured by BASF. Known examples of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide include “IRGACURE 819” manufactured by BASF. Known examples of 1-hydroxy-cyclohexyl-phenyl-ketone include “IRGACURE 184” manufactured by BASF. The photocurable resin may contain one type of photopolymerization initiator or a plurality of types.

The photocurable resin preferably contains a compatible monomer that is compatible with the release agent. According to such a structure, since the active ingredient of a mold release agent is uniformly distributed on the surface of the polymer layer 6 (the surface opposite to the substrate 2), the antifouling property is improved. Furthermore, according to the compatible monomer, the adhesiveness between the photocurable resin and the release agent is increased, so that the abrasion resistance is increased. When the photocurable resin contains a compatible monomer, the compatible monomer alone is compatible with the release agent, but the photocurable resin as a whole is not compatible with the release agent.

Examples of the compatible monomer include N-acryloylmorpholine (for example, “ACMO” manufactured by KJ Chemicals), N, N-diethylacrylamide (for example, “DEAA (registered trademark)” manufactured by KJ Chemicals), N, N-dimethylacrylamide (for example, “DMAA (registered trademark)” manufactured by KJ Chemicals), tetrahydrofuran acrylate (for example, “Biscoat # 150” manufactured by Osaka Organic Chemical Industries, Ltd.), cyclic trimethylolpropane formal acrylate (for example, Osaka “Biscoat # 200” manufactured by Organic Chemical Industries, Ltd.), 4-hydroxybutyl acrylate (for example, “4HBA” manufactured by Nippon Kasei Co., Ltd.), and the like. The compatible monomer is preferably a monofunctional monomer having a polar group such as an amide group, an ether group or a hydroxyl group. The photocurable resin may contain one type of compatible monomer or a plurality of types.

The content of the compatible monomer in the photocurable resin is preferably 5% by weight or more and 30% by weight or less, more preferably 10% by weight or more and 25% by weight or less, 15% by weight or more, More preferably, it is 25% by weight or less. When the content of the compatible monomer in the photocurable resin is less than 5% by weight, there is a concern that the antifouling property and the abrasion resistance are deteriorated particularly in a high temperature / high humidity environment. When the content of the compatible monomer in the photocurable resin is higher than 30% by weight, the crosslink density of the polymer layer 6 is decreased and the cohesive force between the bonds is increased. Therefore, the hardness of the polymer layer 6 is increased. In particular, there is a concern that the rubbing resistance in a high temperature / high humidity environment is lowered.

Any solvent may be used as long as it dissolves the photocurable resin and the release agent. For example, alcohol (carbon number: 1 to 10: for example, methanol, ethanol, n- or i-propanol, n-, sec-, Or t-butanol, benzyl alcohol, octanol, etc.), ketone (3 to 8 carbon atoms: for example, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, diisobutyl ketone, dibutyl ketone, cyclohexanone, etc.), ester or ether ester (carbon) Number 4 to 10: For example, ethyl acetate, butyl acetate, ethyl lactate, etc., γ-butyrolactone, ethylene glycol monomethyl acetate, propylene glycol monomethyl acetate, ether (carbon number 4 to 10: for example, EG monomethyl ether (methyl cellosorb), EG Noethyl ether (ethyl cellosorb), diethylene glycol monobutyl ether (butyl cellosorb), propylene glycol monomethyl ether, etc.), aromatic hydrocarbons (carbon number 6-10: for example, benzene, toluene, xylene, etc.), amides (carbon number 3-10: For example, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.), halogenated hydrocarbon (C1-2: for example, methylene dichloride, ethylene dichloride, etc.), petroleum solvent (for example, petroleum ether, petroleum naphtha, etc.), etc. Is mentioned. The resin solution may contain one type of solvent or a plurality of types.

The thickness T of the polymer layer 6 is preferably thin from the viewpoint of orienting the active ingredient of the release agent at a high concentration on the surface of the polymer layer 6 (the surface opposite to the substrate 2). Specifically, the thickness T of the polymer layer 6 is preferably 5.0 μm or more and 20.0 μm or less. The thickness T of the polymer layer 6 indicates the distance from the surface on the base 2 side to the apex of the convex portion 7 as shown in FIG.

As a shape of the convex part 7, for example, a shape (bell shape) constituted by a columnar lower portion and a hemispherical upper portion, a cone shape (cone shape, conical shape), or the like that narrows toward the tip ( Taper shape). Further, the convex portion 7 may have a shape having a branch protrusion. The branch protrusion indicates a convex portion corresponding to a portion having irregular intervals, which has been formed in the process of anodizing and etching for producing a mold. In FIG. 1 (e), the bottom of the gap between adjacent convex portions 7 has an inclined shape, but it may have a horizontal shape without being inclined.

The pitch P between the adjacent convex portions 7 is not particularly limited as long as it is less than or equal to the wavelength of visible light (780 nm). However, from the viewpoint of sufficiently preventing the occurrence of optical phenomena such as moire and rainbow unevenness, it is 100 nm or more and 400 nm. Or less, more preferably 100 nm or more and 200 nm or less.

The height of the convex portion 7 is preferably 50 nm or more and 600 nm or less, and more preferably 100 nm or more and 300 nm or less, from the viewpoint of making it compatible with a preferable aspect ratio of the convex portion 7 described later.

The aspect ratio of the convex portion 7 is preferably 0.8 or more and 1.5 or less. When the aspect ratio of the convex portion 7 is less than 0.8, the occurrence of optical phenomena such as moire and rainbow unevenness cannot be sufficiently prevented, and there is a concern that good reflection characteristics cannot be obtained. When the aspect ratio of the convex portion 7 is larger than 1.5, the processability of the moth-eye structure is reduced, sticking occurs, or the transfer condition when forming the moth-eye structure is deteriorated (the mold 5 is clogged). There are concerns. In this specification, the aspect ratio of a convex part refers to the ratio (height / pitch) between the pitch between adjacent convex parts and the height of the convex part.

The convex portions 7 may be arranged randomly or regularly. From the viewpoint of sufficiently preventing the occurrence of moiré, it is preferable that the convex portions 7 are randomly arranged.

The haze of the optical member 1 is less than 1.0%. When the haze of the optical member 1 is 1.0% or more, the transparency is lowered, and as a result, the antireflection property (low reflectivity) by the moth-eye structure is lowered. The haze of the optical member 1 is preferably less than 0.8%, and more preferably less than 0.5%. Unlike the method for producing the optical member of Embodiment 1, when the photocurable resin and the release agent that are incompatible with each other are not dissolved in a solvent and cured in a cloudy state, the haze of the optical member 1 increases (for example, 1.0% or more), transparency is impaired.

As the mold 5, for example, one produced by the following method can be used. First, aluminum used as the material of the mold 5 is formed on the surface of the support base by sputtering. Next, a female mold (mold 5) having a moth-eye structure can be produced by alternately repeating anodic oxidation and etching on the formed aluminum layer. At this time, the concavo-convex structure of the mold 5 can be changed by adjusting the time for performing anodic oxidation and the time for performing etching.

Examples of the material for the supporting substrate include glass; metal materials such as stainless steel and nickel; polypropylene, polymethylpentene, and cyclic olefin polymers (typically, norbornene resins, etc., manufactured by Nippon Zeon Co., Ltd.). Polyolefin resins such as “ZEONOR (registered trademark)” and “ARTON (registered trademark)” manufactured by JSR); polycarbonate resins; resin materials such as polyethylene terephthalate, polyethylene naphthalate, and triacetyl cellulose. Moreover, you may use the base material made from aluminum instead of what formed the aluminum film on the surface of a support base material.

Examples of the shape of the mold 5 include a flat plate shape and a roll shape.

The surface of the mold 5 is preferably subjected to a mold release treatment. Thereby, the metal mold | die 5 can be easily peeled from the polymer layer 6. FIG. Further, since the surface free energy of the mold 5 becomes low, when the base material 2 is pressed against the mold 5 in the process (4), the active ingredient of the release agent is added to the surface of the resin layer 4 (base material 2). Can be efficiently oriented on the opposite surface). Furthermore, before the resin layer 4 is cured, it is possible to prevent the active ingredient of the release agent from separating from the surface of the resin layer 4 (the surface opposite to the substrate 2). As a result, in the optical member 1, the active component of the release agent can be efficiently oriented on the surface of the polymer layer 6 (the surface opposite to the substrate 2).

Examples of the coating material used for the mold release treatment of the mold 5 include a fluorine-based material, a silicon-based material, and a phosphate ester-based material. Examples of known fluorine-based materials include “OPTOOL DSX” manufactured by Daikin Industries, Ltd., “OPTOOL AES4” manufactured by Daikin Industries, Ltd., and the like.

[Embodiment 2]
The manufacturing method of the optical member of Embodiment 2 is related with the manufacturing method of the 2nd optical member of this invention. The manufacturing method of the optical member of Embodiment 2 is demonstrated below with reference to FIG. FIG. 2 is a schematic cross-sectional view for explaining the method of manufacturing the optical member according to the second embodiment. The manufacturing method of the optical member of Embodiment 2 is the same as the manufacturing method of the optical member of Embodiment 1 except that the photocurable resin and the release agent are applied in two layers and then both layers are integrated. Therefore, description of overlapping points will be omitted as appropriate.

(Process (1): Application of first resin and second resin)
As shown in FIG. 2A, a first resin 8 containing a photocurable resin is applied on the surface of the substrate 2. Next, the 2nd resin 9 containing a mold release agent is apply | coated on the surface (surface on the opposite side to the base material 2) of the apply | coated 1st resin 8. FIG.

Examples of the coating method of the first resin 8 and the second resin 9 include a method of coating by a spray method, a gravure method, a slot die method, a bar coating method, or the like. From the viewpoint of easily adjusting the film thickness and reducing the cost of the apparatus, a method of applying by a spray method is preferable. Among these, application using a swirl nozzle, electrostatic nozzle, or ultrasonic nozzle is particularly preferable.

The application of the first resin 8 and the application of the second resin 9 may be performed at different timings or may be performed at the same timing. As a method of applying the first resin 8 and the second resin 9 at the same timing, for example, a method of applying by a coextrusion method can be mentioned.

(Process (2): Formation of resin layer)
As shown in FIG. 2B, the substrate 2 is pressed against the mold 5 from the first resin 8 side with the first resin 8 and the second resin 9 sandwiched therebetween. As a result, the resin layer 4 having a concavo-convex structure on the surface (the surface opposite to the substrate 2) is formed. In the resin layer 4, the first resin 8 and the second resin 9 are integrated, and there is no interface between the two resins.

(Process (3): Curing of resin layer)
Next, the resin layer 4 is cured by light irradiation. As a result, a polymer layer 6 is formed as shown in FIG.

(Process (4): Mold peeling)
As shown in FIG. 2 (d), the mold 5 is peeled from the polymer layer 6. As a result, the optical member 1 is completed.

As mentioned above, according to the manufacturing method of the optical member of Embodiment 2, after applying the 1st resin 8 and the 2nd resin 9 which are mutually incompatible in 2 layers (the above-mentioned process (1)), By integrating both layers (the above process (2)), the release agent in the second resin 9 is insolubilized, so that the active ingredient of the release agent is the surface of the resin layer 4 (opposite of the base material 2). It becomes easy to orient to the surface on the side. Moreover, since the release agent is contained in the second resin 9 that mainly constitutes the surface of the resin layer 4 (surface opposite to the substrate 2), the active ingredient of the release agent is the resin layer 4. It becomes easy to orient on the surface (surface opposite to the base material 2). Therefore, the effective component of the release agent can be efficiently oriented on the surface of the polymer layer 6 (the surface opposite to the substrate 2) without greatly increasing the content of the active component of the release agent. . That is, according to the manufacturing method of the optical member of Embodiment 2, antifouling property and abrasion resistance can be improved without impairing transparency (without increasing haze). Furthermore, according to the manufacturing method of the optical member of Embodiment 2, since the antifouling property and the abrasion resistance can be improved even with a small amount of the release agent, the material cost can be reduced.

The first resin 8 and the second resin 9 are combinations that exhibit turbidity of 15 degrees (kaolin) or more and 35 degrees (kaolin) or less when mixed with each other. This indicates that the first resin 8 and the second resin 9 are not compatible. When the turbidity when the first resin 8 and the second resin 9 are mixed is less than 15 degrees (kaolin), the second resin is integrated (the above process (2)). Since the active ingredient of the release agent in the resin 9 is difficult to be oriented on the surface of the polymer layer 6 (the surface opposite to the base material 2), the antifouling property and the abrasion resistance are lowered. When the turbidity when the first resin 8 and the second resin 9 are mixed is higher than 35 degrees (kaolin), the photocurable resin in the first resin 8 and the second resin 9 Since the release agent is easily separated, the antifouling property (for example, fingerprint wiping property) particularly in a high temperature / high humidity environment is deteriorated. The first resin 8 and the second resin 9 are preferably a combination that exhibits a turbidity of 20 degrees (kaolin) or more and 30 degrees (kaolin) or less when mixed with each other.

The second resin 9 contains a release agent. As in Embodiment 1, the release agent in the second resin 9 is preferably a fluororesin having a photoreactive group, that is, a fluorine-based release agent. According to such a configuration, bleed out in a high temperature / high humidity environment is reduced, and the reliability of the optical member 1 is increased. Further, since the fluororesin has a low surface free energy, it is preferably used for improving the antifouling property (for example, fingerprint wiping property). The second resin 9 may appropriately contain various monomers in addition to the release agent.

The content of the active ingredient of the release agent in the resin layer 4 is preferably 0.1 wt% or more and 10 wt% or less, more preferably 0.5 wt% or more and 9 wt% or less. More preferably, it is 1 to 5% by weight. When the content of the active ingredient of the release agent in the resin layer 4 is less than 0.1% by weight, the surface of the polymer layer 6 (second resin 9) (the surface opposite to the base material 2) There is a concern that the amount of the active ingredient of the release agent becomes too small, and the antifouling property and abrasion resistance are lowered. When the content of the active ingredient of the release agent in the resin layer 4 is higher than 10% by weight, the release on the surface of the polymer layer 6 (second resin 9) (surface opposite to the substrate 2) Since the amount of the active ingredient of the agent becomes excessive, the elasticity of the polymer layer 6 (convex portion 7) is insufficient, and when the surface of the polymer layer 6 (the surface opposite to the substrate 2) is rubbed, There is a concern that the collapsed convex portion 7 will not rise (do not restore). As a result, there is a concern that the abrasion resistance is lowered.

The first resin 8 contains a photocurable resin. The photo-curing resin in the first resin 8 has a turbidity of 15 degrees (kaolin) or more and 35 degrees (kaolin) or less when the first resin 8 and the second resin 9 are mixed. Similarly to Embodiment 1, various monomers, photopolymerization initiators, and the like may be appropriately contained.

The photocurable resin in the first resin 8 preferably contains a compatible monomer that is compatible with the release agent in the second resin 9 as in the first embodiment. According to such a configuration, the active ingredient of the release agent is uniformly distributed on the surface of the polymer layer 6 (second resin 9) (the surface opposite to the substrate 2), so that the antifouling property is achieved. Will increase. Furthermore, according to the compatible monomer, the adhesiveness between the photocurable resin and the release agent is increased, so that the abrasion resistance is increased. When the photocurable resin contains a compatible monomer, the compatible monomer alone is compatible with the release agent, but the first resin 8 as a whole is not compatible with the second resin 9.

It is preferable that the first resin 8 and the second resin 9 do not contain a solvent. That is, the first resin 8 and the second resin 9 are preferably solventless. According to such a configuration, it is possible to reduce the cost related to the use of the solvent and the environmental load (odor or the like during use). Furthermore, an apparatus for removing the solvent is unnecessary, and the apparatus cost can be reduced.

The thickness T1 of the first resin 8 is preferably 3 μm or more and 30 μm or less, and preferably 5 μm or more and 7 μm or less.

The thickness T2 of the second resin 9 is preferably 0.1 μm or more and 15 μm or less, more preferably 1 μm or more and 10 μm or less, further preferably 2 μm or more and 8 μm or less, more preferably 5 μm or more, Particularly preferably, it is 8 μm or less.

The haze of the optical member 1 is less than 1.0%. When the haze of the optical member 1 is 1.0% or more, the transparency is lowered, and as a result, the antireflection property (low reflectivity) by the moth-eye structure is lowered. The haze of the optical member 1 is preferably less than 0.8%, and more preferably less than 0.5%. Unlike the optical member manufacturing method of Embodiment 2, when the turbidity when the first resin 8 and the second resin 9 are mixed is higher than 35 degrees (kaolin), the haze of the optical member 1 is high. It becomes high (for example, 1.0% or more), and transparency is impaired.

[Embodiment 3]
The manufacturing method of the optical member of Embodiment 3 is related with the manufacturing method of the 2nd optical member of this invention. The manufacturing method of the optical member of Embodiment 3 is demonstrated below with reference to FIG. FIG. 3 is a schematic cross-sectional view for explaining the method for manufacturing the optical member of the third embodiment. The manufacturing method of the optical member of Embodiment 3 is the same as the manufacturing method of the optical member of Embodiment 2 except that the second resin is applied on the surface of the mold. Omitted.

(Process (1): Application of first resin and second resin)
As shown in FIG. 3A, a first resin 8 containing a photocurable resin is applied on the surface of the substrate 2. Next, the second resin 9 containing a release agent is applied on the surface (uneven surface) of the mold 5.

The application of the first resin 8 and the application of the second resin 9 may be performed at different timings or may be performed at the same timing.

(Process (2): Formation of resin layer)
As shown in FIG. 3B, the base material 2 is pressed against the mold 5 from the first resin 8 side with the first resin 8 and the second resin 9 sandwiched therebetween. As a result, the resin layer 4 having a concavo-convex structure on the surface (the surface opposite to the substrate 2) is formed.

(Process (4): Mold peeling)
As shown in FIG. 3 (d), the mold 5 is peeled from the polymer layer 6. As a result, the optical member 1 is completed.

Regarding the process (1), in the second and third embodiments, the first resin 8 is applied on the surface of the substrate 2, and the second resin 9 is applied to the surface of the first resin 8 or the mold 5. Although the process of applying above is shown, the second resin 9 may be applied on both the surfaces of the first resin 8 and the mold 5. That is, in the process (1), the first resin 8 is applied on the surface of the base 2, and the second resin 9 is applied to the surface of at least one of the first resin 8 and the mold 5. It may be done by applying on top. In the process (1), the second resin 9 is applied onto the surface (uneven surface) of the mold 5, and the first resin 8 is applied to the surface of the second resin 9 (the side opposite to the mold 5). It may be carried out by applying on the surface).

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

[Evaluation 1: Production Method of First Optical Member of the Present Invention]
In the examples and comparative examples, the materials used for manufacturing the optical member are as follows.

(Base material)
“TAC-TD80U” manufactured by FUJIFILM Corporation was used, and its thickness was 80 μm and haze was 0.1%.

(Photo-curing resin)
Photocurable resins A1 to A4 having the compositions shown in Table 1 were used. Abbreviations for each material name are as follows. The numerical value in Table 1 shows the content rate of each material in each photocurable resin.
<Compatible monomer>
"DM": "DMAA" manufactured by KJ Chemicals
<Various monomers>
・ "U": "U-10HA" manufactured by Shin-Nakamura Chemical Co., Ltd.
・ "DPH": "A-DPH" manufactured by Shin-Nakamura Chemical Co., Ltd.
・ "TMM": "A-TMM-3LM-N" manufactured by Shin-Nakamura Chemical Co., Ltd.
"ATM": "ATM-35E" manufactured by Shin-Nakamura Chemical Co., Ltd.
"PG": "NK ECONOMER A-PG5027E" manufactured by Shin-Nakamura Chemical Co., Ltd.
<Photopolymerization initiator>
・ "TPO": "IRGACURE TPO" manufactured by BASF

(Release agent)
Release agents B1 to B3 having the compositions shown in Table 2 were used. Abbreviations for each material name are as follows. The numerical value in Table 2 shows the content rate of each material in each mold release agent. The content of the active ingredient in the release agent B1 was 20% by weight. The content of the active ingredient in the release agent B2 was 40% by weight.
<Fluorine-containing monomer>
"DAC": "OPTOOL DAC-HP" manufactured by Daikin Industries
・ "FAAC": "CHEMINOX FAAC-6" manufactured by Unimatec
<Reactive monomer>
・ "AC": "ACMO" manufactured by KJ Chemicals

(solvent)
Methyl ethyl ketone (MEK, boiling point: 79.6 ° C.) was used.

(Mold)
What was produced by the following method was used. First, aluminum as a mold material was formed on a 10 cm square glass substrate by a sputtering method. The thickness of the formed aluminum layer was 1.0 μm. Next, by repeating the anodic oxidation and etching alternately on the formed aluminum layer, a large number of minute holes (the distance between the bottom points of adjacent holes is less than the wavelength of visible light) are provided. An anodized layer was formed. Specifically, anodization, etching, anodization, etching, anodization, etching, anodization, etching, and anodization are sequentially performed (anodization: 5 times, etching: 4 times), thereby forming the inside of aluminum. A large number of minute holes (concave portions) having a shape (tapered shape) narrowing toward the surface were formed, and as a result, a mold having an uneven structure was obtained. Anodization was performed using oxalic acid (concentration: 0.03% by weight) under conditions of a liquid temperature of 5 ° C. and an applied voltage of 80V. The time for one anodic oxidation was 25 seconds. Etching was performed using phosphoric acid (concentration: 1 mol / l) at a liquid temperature of 30 ° C. The time for performing one etching was set to 25 minutes. When the mold was observed with a scanning electron microscope, the depth of the recess was 290 nm. In addition, the mold surface was subjected to a mold release treatment in advance by “OPTOOL AES4” manufactured by Daikin Industries, Ltd.

Example 1-1
The optical member of Example 1-1 was produced by the optical member manufacturing method of Embodiment 1.

(Process (1): Preparation of resin solution)
After mixing photocurable resin A1 and mold release agent B1, the mixture was dissolved in the solvent and the resin solution 3 was prepared. In the resin solution 3, the content of the photocurable resin A1 was 80% by weight, the content of the release agent B1 was 10% by weight, and the content of the solvent was 10% by weight. That is, the content of the active ingredient of the release agent B1 in the resin solution 3 was 2% by weight.

(Process (2): Application of resin solution)
The resin solution 3 was dropped (applied) on the surface of the substrate 2 in a band shape. Thereafter, the resin solution 3 was spread over the entire surface of the substrate 2 using a bar coater.

(Process (3): Formation of resin layer)
The thing in which the coating material of the resin solution 3 was arrange | positioned on the surface of the base material 2 was put into oven, and it heat-processed for 1 minute at the temperature of 80 degreeC, and volatilized the solvent from the coating material of the resin solution 3. As a result, the resin layer 4 was formed.

(Process (4): Formation of uneven structure)
The base material 2 was pressed against the mold 5 with a hand roller with the resin layer 4 sandwiched therebetween. As a result, a concavo-convex structure was formed on the surface of the resin layer 4 (surface opposite to the base material 2).

(Process (5): Curing of resin layer)
The resin layer 4 having a concavo-convex structure on the surface was cured by irradiation with ultraviolet rays (irradiation amount: 200 mJ / cm ² ) from the base material 2 side. As a result, the polymer layer 6 was formed.

(Process (6): Mold peeling)
The mold 5 was peeled from the polymer layer 6. As a result, the optical member 1 was completed. The thickness T of the polymer layer 6 was 9.8 μm.

The surface specification of the optical member 1 was as follows.
Shape of convex portion 7: Pitch 200 between bell-shaped adjacent convex portions 7: 200 nm
Height of convex part 7: 200 nm
Aspect ratio of convex part 1: 1

The surface specification of the optical member 1 was evaluated using a scanning electron microscope “S-4700” manufactured by Hitachi High-Technologies Corporation. At the time of evaluation, an osmium coater “Neoc-ST” manufactured by Meiwa Forsys was used on the surface of the optical member 1 (the surface opposite to the base material 2 of the polymer layer 6) manufactured by Wako Pure Chemical Industries, Ltd. Of osmium oxide VIII (thickness: 5 nm) was applied. Specifically, the pitch P between the adjacent convex portions 7 is the average of the distances between all the adjacent convex portions excluding the branch projections in the 1 μm square region of the planar photograph taken with the scanning electron microscope. Value. The height of the convex portion 7 was defined as the average value of the heights of ten convex portions arranged in a row, excluding branch protrusions, in the cross-sectional photograph taken with the scanning electron microscope. However, when 10 convex portions were selected, the convex portions having a defect or a deformed portion (a portion that was deformed when preparing a measurement sample, etc.) were excluded.

(Examples 1-2 to 1-9 and Comparative Examples 1-1 to 1-8)
Optical members of respective examples were produced in the same manner as in Example 1-1 except that the compositions were changed as shown in Tables 3 to 6.

Tables 3 to 6 also show the turbidity (simply referred to as “turbidity”) when the photocurable resin and the release agent are mixed in a ratio in the resin solution of each example. The turbidity was measured by placing a sample in a 10 mm cell in an integrating sphere turbidimeter “PT-200” manufactured by Mitsubishi Chemical Analytech Co., Ltd. and using a preset kaolin calibration curve.

(Evaluation contents and evaluation results)
The optical members of Examples 1-1 to 1-9 and Comparative Examples 1-1 to 1-8 were evaluated for transparency, antifouling property, and abrasion resistance. The results are shown in Tables 3-6.

<Transparency>
As transparency, the haze of the optical member of each example was evaluated. Specifically, the haze of the optical member in each example was measured using a haze meter “NDH7000” manufactured by Nippon Denshoku Industries Co., Ltd. Judgment criteria were as follows.
A: Haze was 0.5% or less.
○: Haze was higher than 0.5% and 0.8% or lower.
Δ: Haze was higher than 0.8% and lower than 1.0%.
X: Haze was 1.0% or more.
Here, the case where the determination was ◎, ○, or Δ was determined to be an acceptable level (excellent transparency).

<Anti-fouling property>
As antifouling property, the fingerprint wiping property of the optical member of each example was evaluated. Specifically, first, a black acrylic plate was attached to the surface of the optical member of each example on the surface opposite to the polymer layer of the base material via the optical adhesive layer. Next, the optical member of each example was left for 101 days in an environment of a temperature of 60 ° C. and a humidity of 95%, and further left for 1 day in an environment of a temperature of 23 ° C. and a humidity of 50%. Then, after attaching a fingerprint to the surface of the optical member of each example (the surface opposite to the base material of the polymer layer), it was rubbed 10 times with “Bencot (registered trademark) S-2” manufactured by Asahi Kasei Corporation. Whether or not the fingerprint was wiped off was visually observed in an environment with an illuminance of 100 lx. Judgment criteria were as follows.
○: The fingerprint was completely wiped off, and the remaining wipe was not visible.
Δ: Fingerprints are inconspicuous, but a slight amount of wiping residue was visible when a fluorescent lamp was reflected.
X: The fingerprint was not wiped off at all.
Here, the case where the determination was ○ or Δ was determined to be an acceptable level (excellent antifouling property).

<Abrasion resistance>
As the abrasion resistance, the change rate of the reflectance before and after rubbing the surface with a nonwoven fabric was evaluated for the optical members of each example. Specifically, first, a black acrylic plate was attached to the surface of the optical member of each example opposite to the polymer layer of the base material. Then, in an environment of a temperature of 23 ° C. and a humidity of 50%, a light source is irradiated from an orientation with a polar angle of 5 ° with respect to the surface of the optical member of each example (the surface opposite to the base material of the polymer layer), The specular reflection spectral reflectance at an incident angle of 5 ° was measured. The reflectance was measured using “UV-3100PC” manufactured by Shimadzu Corporation in the wavelength region of 380 to 780 nm. Then, the average reflectance in the wavelength region of 450 to 650 nm was calculated from the measurement result, and the value was defined as reflectance A (unit:%).

Next, the optical member of each example was left for 101 days in an environment of a temperature of 60 ° C. and a humidity of 95%, and further returned to an environment of a temperature of 23 ° C. and a humidity of 50% and left for one day. Then, using “Bencot Lab (registered trademark)” manufactured by Asahi Kasei Fibers Corporation, the surface of the optical member of each example (the surface opposite to the base material of the polymer layer) was rubbed 10 times. Thereafter, the specular reflection spectral reflectance at 5 ° incident light was measured for the optical members of the respective examples in the same manner as described above. Then, the average reflectance in the wavelength region of 450 to 650 nm was calculated from the measurement result, and the value was defined as reflectance B (unit:%).

As an evaluation index of rubbing resistance, “change rate of reflectance before and after rubbing (unit:%) = 100 × (reflectance B−reflectance A) / reflectance A” is used, and the criterion is as follows: It was.
A: The change rate of the reflectance was 15% or less.
A: The rate of change in reflectance was higher than 15% and lower than 25%.
(Triangle | delta): The change rate of the reflectance was 25% or more and 30% or less.
X: The rate of change in reflectance was higher than 30% and lower than 50%.
XX: Change rate of reflectance was 50% or more.
Here, a case where the determination was ◎, ○, or Δ was determined to be an acceptable level (excellent rub resistance).

As shown in Tables 3 and 4, all of Examples 1-1 to 1-9 were excellent in transparency, antifouling property, and abrasion resistance. Among them, Example 1-1, Example 1-4, Example 1-6, and Example 1-8 were particularly excellent in overall transparency, antifouling property, and abrasion resistance. On the other hand, as shown in Table 5 and Table 6, in Comparative Examples 1-1 to 1-8, at least one of transparency, antifouling property, and abrasion resistance was low.

[Evaluation 2: Manufacturing Method of Second Optical Member of the Present Invention]
In the examples and comparative examples, the materials used for manufacturing the optical member are as follows. The base material and the mold were the same as those used in Evaluation 1.

(First resin)
The first resins C1 to C3 having the composition shown in Table 7 were used. Abbreviations for each material name are the same as in Evaluation 1. The numerical value in Table 7 shows the content rate of each material in each 1st resin.

(Second resin)
Second resins D1 to D4 having a composition as shown in Table 8 were used. Abbreviations for each material name are the same as in Evaluation 1. The numerical value in Table 8 shows the content rate of each material in each 2nd resin. For example, the second resin D1 was prepared by the following method. First, for “OPTOOL DAC-HP” manufactured by Daikin Industries, Ltd., to N-acryloylmorpholine (“ACMO” manufactured by KJ Chemicals) using a rotary evaporator “N-1110 type” manufactured by Tokyo Rika Kikai Co., Ltd. The solvent was replaced. Thereafter, heat treatment was performed at a temperature of 180 ° C. for 5 hours using a mini jet oven “MD-92” manufactured by Toyama Sangyo Co., Ltd. After the heat treatment, the content of the active ingredient was adjusted to 10% by weight by adding “ACMO”.

Example 2-1
The optical member of Example 2-1 was produced by the optical member manufacturing method of Embodiment 2.

(Process (1): Application of first resin and second resin)
The first resin C1 was applied on the surface of the substrate 2 with a bar coater. Next, the 2nd resin D1 was apply | coated with the bar coater on the surface (surface on the opposite side to the base material 2) of the apply | coated 1st resin C1.

(Process (2): Formation of resin layer)
With the first resin C1 and the second resin D1 sandwiched therebetween, the substrate 2 was pressed against the mold 5 from the first resin C1 side with a hand roller. As a result, a resin layer 4 having a concavo-convex structure on the surface (the surface opposite to the substrate 2) was formed.

(Process (3): Curing of resin layer)
The resin layer 4 having a concavo-convex structure on the surface was cured by irradiation with ultraviolet rays (irradiation amount: 200 mJ / cm ² ) from the base material 2 side. As a result, the polymer layer 6 was formed.

(Process (4): Mold peeling)
The mold 5 was peeled from the polymer layer 6. As a result, the optical member 1 was completed. The thickness T of the polymer layer 6 was 10.5 μm. The surface specification of the optical member 1 was as follows.
Shape of convex portion 7: pitch P between adjacent convex portions 7 in a bell shape: 220 nm
Height of convex part 7: 200 nm
Aspect ratio of convex portion 7: about 0.9

(Example 2-2 and Comparative Examples 2-1 to 2-5)
Optical members of the respective examples were produced in the same manner as in Example 2-1, except that the compositions were changed as shown in Table 9 and Table 10. Tables 9 and 10 also show the turbidity (simply referred to as “turbidity”) when the first resin and the second resin are mixed at a ratio in the resin layer of each example. .

(Evaluation contents and evaluation results)
The optical members of Example 2-1, Example 2-2, and Comparative Examples 2-1 to 2-5 were evaluated for transparency, antifouling properties, and abrasion resistance in the same manner as in Evaluation 1. . The results are shown in Table 9 and Table 10.

As shown in Table 9, Example 2-1 and Example 2-2 were excellent in transparency, antifouling property, and abrasion resistance. On the other hand, as shown in Table 10, all of Comparative Examples 2-1 to 2-5 had low at least one of transparency, antifouling property, and abrasion resistance.

[Appendix]
One embodiment of the present invention is an optical device including a base material and a polymer layer that is provided on the surface of the base material and has a concavo-convex structure on the surface, in which a plurality of convex portions are provided at a pitch equal to or less than the wavelength of visible light. A method for producing a member, which is a process (1) for preparing a resin solution by dissolving a photocurable resin and a release agent in a solvent, and a process (2) for applying the resin solution on the surface of the substrate. And a heat treatment for removing the solvent from the coated resin solution, a process (3) for forming a resin layer, and pressing the substrate against the mold with the resin layer sandwiched between them, A process (4) for forming the concavo-convex structure on the surface of the resin layer; and a process (5) for curing the resin layer by light irradiation to form the polymer layer. Release agent is 5 degrees (kaolin) when mixed with each other In addition, the optical member is a combination showing turbidity of 25 degrees (kaolin) or less, and the haze of the optical member is less than 1.0% (the first optical member manufacturing method of the present invention). There may be. According to this aspect, it is possible to realize an optical member manufacturing method that improves antifouling property and abrasion resistance without impairing transparency.

Another embodiment of the present invention includes a base material and a polymer layer that is disposed on the surface of the base material and has a concavo-convex structure provided on the surface with a plurality of convex portions provided at a pitch equal to or less than the wavelength of visible light. A process (1) for applying a first resin and a second resin, and a substrate in a state where the first resin and the second resin are sandwiched therebetween, A process (2) of pressing the mold from the first resin side to form a resin layer having the concavo-convex structure on the surface, and a process of curing the resin layer by light irradiation to form the polymer layer ( 3), the first resin contains a photocurable resin, the second resin contains a release agent, and the first resin and the second resin are mixed with each other. Combination of turbidity of 15 degrees (kaolin) or more and 35 degrees (kaolin) or less There, the haze of the optical member may be a method of producing an optical member is less than 1.0% (production method of the second optical member of the present invention). According to this aspect, it is possible to realize an optical member manufacturing method that improves antifouling property and abrasion resistance without impairing transparency.

In the second method for producing an optical member of the present invention, the first resin and the second resin may not contain a solvent. According to such a configuration, it is possible to reduce costs related to the use of the solvent and environmental loads (such as odor during use). Furthermore, an apparatus for removing the solvent is unnecessary, and the apparatus cost can be reduced.

In the method for producing the first optical member of the present invention and the method for producing the second optical member of the present invention, the content of the active ingredient of the release agent in the resin layer is 0.1% by weight or more. It may be 10% by weight or less. According to such a structure, antifouling property and abrasion resistance can be preferably increased.

In the method for producing the first optical member of the present invention and the method for producing the second optical member of the present invention, the releasing agent may be a fluororesin having a photoreactive group. According to such a configuration, bleed out in a high temperature / high humidity environment is reduced, and the reliability of the optical member is increased. Moreover, since the said fluororesin has low surface free energy, it is preferably used in order to improve antifouling property (for example, fingerprint wiping property).

In the method for producing the first optical member of the present invention and the method for producing the second optical member of the present invention, the photocurable resin contains a compatible monomer compatible with the release agent, and The content of the compatible monomer in the photocurable resin may be 5% by weight or more and 30% by weight or less. According to such a structure, antifouling property and abrasion resistance can be preferably increased.

In the manufacturing method of the first optical member of the present invention and the manufacturing method of the second optical member of the present invention, the thickness of the polymer layer may be 5.0 μm or more and 20.0 μm or less. According to such a configuration, the active ingredient of the release agent can be oriented at a high concentration on the surface of the polymer layer (the surface opposite to the substrate).

In the method for manufacturing the first optical member of the present invention and the method for manufacturing the second optical member of the present invention, the pitch may be not less than 100 nm and not more than 400 nm. According to such a configuration, it is possible to sufficiently prevent the occurrence of optical phenomena such as moire and rainbow unevenness.

In the method for manufacturing the first optical member of the present invention and the method for manufacturing the second optical member of the present invention, the heights of the plurality of convex portions may be 50 nm or more and 600 nm or less, respectively. According to such a configuration, it is possible to achieve a favorable aspect ratio of the plurality of convex portions.

In the first optical member manufacturing method and the second optical member manufacturing method of the present invention, the aspect ratios of the plurality of convex portions are 0.8 or more and 1.5 or less, respectively. May be. According to such a configuration, it is possible to sufficiently prevent the occurrence of optical phenomena such as moire and rainbow unevenness, and to realize good reflection characteristics. Furthermore, it is possible to prevent deterioration in processability of the moth-eye structure, occurrence of sticking, and deterioration of the transfer condition when forming the moth-eye structure.

1: Optical member 2: Base material 3: Resin solution 4: Resin layer 5: Mold 6: Polymer layer 7: Convex part 8: First resin 9: Second resin P: Pitch T: Polymer layer Thickness T1: First resin thickness T2: Second resin thickness

Claims

A method for producing an optical member, comprising: a base material; and a polymer layer having a concavo-convex structure on the surface, wherein the convex portions are provided on the surface of the base material at a pitch equal to or less than a wavelength of visible light. ,
A process (1) for preparing a resin solution by dissolving a photocurable resin and a release agent in a solvent;
A process (2) of applying the resin solution on the surface of the substrate;
A process (3) for performing a heat treatment to remove the solvent from the resin solution coating and forming a resin layer;
A process (4) of pressing the substrate against a mold with the resin layer sandwiched therebetween, and forming the uneven structure on the surface of the resin layer;
The resin layer is cured by light irradiation, and the polymer layer is formed (5),
When the photocurable resin and the release agent are mixed with each other, the photocurable resin and the release agent have a turbidity of 5 degrees (kaolin) or more and 25 degrees (kaolin) or less,
The haze of the said optical member is less than 1.0%, The manufacturing method of the optical member characterized by the above-mentioned.
A method for producing an optical member, comprising: a base material; and a polymer layer having a concavo-convex structure on the surface, wherein the convex portions are provided on the surface of the base material at a pitch equal to or less than a wavelength of visible light. ,
A process (1) for applying a first resin and a second resin;
Process of forming a resin layer having the concavo-convex structure on the surface by pressing the base material against the mold from the first resin side with the first resin and the second resin sandwiched therebetween (2 )When,
The resin layer is cured by light irradiation, and the polymer layer is formed (3),
The first resin contains a photocurable resin,
The second resin contains a release agent,
When the first resin and the second resin are mixed with each other, the first resin and the second resin have a turbidity of 15 degrees (kaolin) or more and 35 degrees (kaolin) or less,
The haze of the said optical member is less than 1.0%, The manufacturing method of the optical member characterized by the above-mentioned.
The method for producing an optical member according to claim 2, wherein the first resin and the second resin do not contain a solvent.
The production of the optical member according to any one of claims 1 to 3, wherein the content of the active ingredient of the release agent in the resin layer is 0.1 wt% or more and 10 wt% or less. Method.
The method for producing an optical member according to any one of claims 1 to 4, wherein the release agent is a fluororesin having a photoreactive group.
The photocurable resin contains a compatible monomer that is compatible with the release agent,
6. The method for producing an optical member according to claim 1, wherein the content of the compatible monomer in the photocurable resin is 5% by weight or more and 30% by weight or less.
7. The method for producing an optical member according to claim 1, wherein the polymer layer has a thickness of 5.0 μm or more and 20.0 μm or less.
The method for manufacturing an optical member according to any one of claims 1 to 7, wherein the pitch is 100 nm or more and 400 nm or less.
The method for manufacturing an optical member according to any one of claims 1 to 8, wherein the heights of the plurality of convex portions are 50 nm or more and 600 nm or less, respectively.
10. The method for manufacturing an optical member according to claim 1, wherein the aspect ratio of the plurality of convex portions is 0.8 or more and 1.5 or less, respectively.