Method for producing optical member

Abstract

To provide a method for manufacturing an optical member excellent in productivity and capable of controlling a refractive index with high accuracy.SOLUTION: A method for manufacturing an optical member includes a print pattern forming step of forming a print pattern in a direction crossing a thickness direction of a substrate by discharging droplets of at least two kinds of liquid compositions having different refractive indices on the substrate, and an optical function film forming step of forming an optical function film by curing the print pattern. In the print pattern forming step, the liquid compositions are discharged so that a droplet of one liquid composition and a droplet of another liquid composition having a refractive index different from that of the one liquid composition are adjacent to each other in a direction intersecting a thickness direction of the substrate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an optical member. [Background technology]

[0002] Conventionally, anti-reflection coatings have been widely used in a variety of fields, including those that cancel out phase shifts by stacking multiple layers of film, and those that reduce the amount of change in refractive index by using a moth-eye structure (a fine uneven structure).

[0003] For example, Patent Document 1 discloses a method for producing an anti-reflection film having a gradient refractive index film on a substrate, in which the refractive index in the visible light region increases continuously in the range of 1.0 to 2.5 from the side farthest from the substrate in the thickness direction to the side closest to the substrate, and the transmittance in the visible light region is 70% or more, with the aim of producing an anti-reflection film having a gradient refractive index film that is highly productive, can be manufactured in large areas, and is excellent in light transmittance, anti-reflection properties, and adhesion (see, for example, Patent Document 1).The method comprises discharging at least two organic materials with different refractive indices onto the substrate by an inkjet method to form the gradient refractive index film. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a method for manufacturing an optical member that is excellent in productivity and that allows for highly accurate control of the refractive index. [Means for solving the problem]

[0005] The method for manufacturing an optical element of the present invention as a means for solving the problem is a method for manufacturing an optical element, comprising: a printing pattern forming step of ejecting droplets of at least two liquid compositions having different refractive indices onto a substrate to form a printing pattern in a direction intersecting the thickness direction of the substrate; and an optically functional film forming step of curing the printing pattern to form an optically functional film, wherein the printing pattern forming step is characterized in that the liquid compositions are ejected so that droplets of one of the liquid compositions are adjacent to droplets of another liquid composition having a refractive index different from that of the one of the liquid compositions in the direction intersecting the thickness direction of the substrate. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a method for manufacturing an optical member that is excellent in productivity and allows for highly accurate control of the refractive index. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic side view showing the state of a print pattern 90 immediately after a print pattern formation step in a method for manufacturing an optical member according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic top view showing the state of a print pattern 90 immediately after the print pattern formation step in a method for manufacturing an optical member according to another embodiment of the present invention. [Figure 3A] FIG. 3A is a schematic side view showing a process of ejecting droplets of low refractive index liquid composition 21 from head 41 onto droplets of high refractive index liquid composition 22 in a 100% cured state ejected from head 42 and curing them. [Figure 3B] FIG. 3B is a schematic side view showing a process of ejecting droplets of low refractive index liquid composition 21 from head 41 onto droplets of high refractive index liquid composition 22 in a 50% cured state ejected from head 42 and curing them. [Figure 4A] FIG. 4A is a schematic side view showing a process of ejecting and curing droplets of a second layer of low refractive index liquid composition 21 onto an optically functional film made of droplets of a first layer of high refractive index liquid composition 22 in a 100% cured state. [Figure 4B] FIG. 4B is a schematic side view showing the process of ejecting and curing droplets of a second layer of low refractive index liquid composition 21 onto an optically functional film made of droplets of a first layer of high refractive index liquid composition 22 in a 50% cured state. [Figure 5] FIG. 5 is a schematic top view of an optical member obtained by a method for producing an optical member according to another embodiment of the present invention. [Figure 6] FIG. 6 is a schematic top view of an optical member obtained by a method for producing an optical member according to another embodiment of the present invention. [Figure 7] Figure 7 is a schematic perspective view (a) showing the state of an optical element after the laminate formation process in a method for manufacturing an optical element according to one embodiment of the present invention, and a schematic top view (b) showing the printing patterns for forming each layer. [Figure 8] FIG. 8 is a schematic cross-sectional view showing the state of an optical member after a laminate formation step in a method for producing an optical member according to another embodiment of the present invention. [Figure 9] FIG. 9 is a schematic perspective view showing an inkjet drawing apparatus for carrying out a method for manufacturing an optical member according to one embodiment of the present invention. [Figure 10A] FIG. 10A is a schematic cross-sectional view showing a method for producing an optical member according to one embodiment of the present invention. [Figure 10B] FIG. 10B is a schematic cross-sectional view showing a method for producing an optical member according to one embodiment of the present invention. [Figure 10C] FIG. 10C is a schematic cross-sectional view showing a method for manufacturing an optical member according to one embodiment of the present invention. [Figure 11A] FIG. 11A is a schematic diagram showing discharge data in Example 1. FIG. [Figure 11B] FIG. 11B is a schematic top view (a) of the optical member obtained in Example 1, and a schematic side view (b) of the optical member obtained in Example 1. [Figure 12A] FIG. 12A is a schematic diagram showing the discharge data in Example 2. FIG. [Figure 12B]Figure 12B is a schematic top view (a) of the optical element obtained in Example 2 (upper row: first scan, lower row: second scan), and a schematic side view (b) of the optical element obtained in Example 2 (upper row: first scan, lower row: second scan). [Figure 13] FIG. 13 is a schematic top view of the optical member obtained in Example 3. [Figure 14] FIG. 14 is a schematic top view of the optical member obtained in Example 4. [Figure 15] FIG. 15 is a schematic top view of the optical member obtained in Example 5. [Figure 16] FIG. 16 is a schematic perspective view (a) of the optical member obtained in Example 6, and a schematic top view (b) showing the printing patterns for forming each layer. [Figure 17] FIG. 17 is a schematic perspective view (a) of the optical member obtained in Example 7, and a schematic top view (b) showing the printing patterns for forming each layer. [Figure 18] FIG. 18 is a schematic top view showing the ejection data and ejection state for one scan in Example 8. [Figure 19] FIG. 19 is a schematic top view showing the ejection data and ejection state for one scan in Example 9. [Figure 20] FIG. 20 is a schematic top view showing the ejection data and ejection state for one scan in Comparative Example 1. In FIG. [Figure 21A] Figure 21A is a schematic top view (a) showing an example of the state when droplets of a liquid composition for one scan land in a printing pattern formation process in a method for manufacturing an optical element according to one embodiment of the present invention, and a schematic top view (b) showing another example of the state when droplets of a liquid composition for one scan land in a printing pattern formation process in a method for manufacturing an optical element according to one embodiment of the present invention. [Figure 21B]Figure 21B is a schematic top view (a) showing an example of the state when droplets of liquid composition for one scan land in the printing pattern formation process in the method for manufacturing an optical element according to the comparative embodiment, a schematic top view (b) showing another example of the state when droplets of liquid composition for one scan land in the printing pattern formation process in the method for manufacturing an optical element according to the comparative embodiment, and a schematic top view (c) showing yet another example of the state when droplets of liquid composition for one scan land in the printing pattern formation process in the method for manufacturing an optical element according to the comparative embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The invention described in Patent Document 1 is a method for producing an anti-reflection coating by an ink mixing method in which at least two organic materials (inks) with different refractive indices are discharged onto a substrate in layers. However, it is not possible to form a refractive index distribution in a direction intersecting the thickness direction of the substrate, which limits the uses and configurations of the anti-reflection coating. Furthermore, forming a desired refractive index distribution requires delicate control of the drying state of previously discharged droplets, the discharged liquid volume, and the landing position, which raises concerns about restrictions on the device and usage environment. Furthermore, the ink mixing method involves discharging and mixing at least two organic materials (inks) with different refractive indices onto a substrate, which requires time for diffusion and mixing, resulting in poor productivity.

[0009] The method for manufacturing an optical member of the present invention can fully resolve various concerns in the prior art. More specifically, it can realize a method for manufacturing an optical member that is excellent in productivity and allows for highly accurate control of the refractive index.

[0010] The present invention will be described in detail below.

[0011] (Method of manufacturing optical members) The method for producing an optical member of the present invention includes a print pattern forming step and an optically functional film forming step, and may also include a laminate forming step, a semi-curing step, and other steps as necessary.

[0012] The method for producing an optical member of the present invention is a method in which at least two liquid compositions having different refractive indices are applied to a substrate, respectively, and can eliminate the time required for diffusion and mixing in the conventional two-liquid mixing method. In other words, the method for producing an optical member of the present invention is superior in productivity to the conventional two-liquid mixing method.

[0013] Furthermore, with the method for manufacturing an optical element of the present invention, it is possible to control the printing resolution in a direction intersecting the thickness direction of the substrate, and also to control the refractive index at the level of one printing scan (also referred to as one scan or one dot) in the thickness direction of the substrate and in a direction intersecting the thickness direction of the substrate.

[0014] <Printing pattern formation process> The print pattern forming step is a step of ejecting droplets of at least two liquid compositions having different refractive indices onto a substrate to form a print pattern in a direction intersecting the thickness direction of the substrate. In the print pattern forming step, the liquid compositions are ejected so that one liquid composition is adjacent to another liquid composition having a refractive index different from that of the one liquid composition in the direction intersecting the thickness direction of the substrate.

[0015] When one liquid composition is adjacent to another liquid composition having a different refractive index from that of the one liquid composition, it is preferable that droplets of the one liquid composition are adjacent to droplets of the other liquid composition having a different refractive index from that of the one liquid composition.

[0016] In this specification, the "direction intersecting the thickness direction of the substrate" preferably means a direction perpendicular to the thickness direction of the substrate, that is, a planar direction of the surface of the substrate.

[0017] In this specification, "droplets of one liquid composition are adjacent to droplets of another liquid composition having a refractive index different from that of the one liquid composition in a direction intersecting the thickness direction of the substrate" means that part of the ejected droplets of one liquid composition comes into contact with part of the droplets of the other liquid composition. When part of the ejected droplets of one liquid composition comes into contact with part of the droplets of the other liquid composition, the liquid compositions may be partially mixed to the extent that the refractive index of each liquid composition does not change.

[0018] More specifically, the print pattern formation process involves ejecting droplets of one liquid composition onto a substrate, and then ejecting droplets of another liquid composition having a refractive index different from that of the first liquid composition so that they come into contact with a portion of the first liquid composition.By ejecting the droplets of the other liquid composition so that the center of the droplet of the other liquid composition is outside the outer edge of the droplet of the first liquid composition, droplets of at least two liquid compositions with different refractive indices can be arranged adjacent to each other.

[0019] Figure 21A is a schematic top view (a) showing an example of the state when droplets of a liquid composition for one scan land in a printing pattern formation process in a method for manufacturing an optical element according to one embodiment of the present invention, and a schematic top view (b) showing another example of the state when droplets of a liquid composition for one scan land in a printing pattern formation process.

[0020] (a) of Figure 21A shows a state in which the outer edge of a droplet of one liquid composition 22 is in contact with the outer edge of a droplet of another liquid composition 21 adjacent to the droplet of the one liquid composition 22, and the center X2 of the droplet of the other liquid composition 21 is outside the outer edge of the droplet of the one liquid composition 22.

[0021] (b) of Figure 21A shows a state in which the outer edge of a droplet of one liquid composition 22 intersects with the outer edge of a droplet of another liquid composition 21 adjacent to the droplet of the one liquid composition 22, and the center X2 of the droplet of the other liquid composition 21 is outside the outer edge of the droplet of the one liquid composition 22.

[0022] Figure 21B is a schematic top view (a) showing an example of the state when droplets of a liquid composition for one scan land in the printing pattern formation process in the method for manufacturing an optical element according to a comparative embodiment, a schematic top view (b) showing another example of the state when droplets of a liquid composition for one scan land in the printing pattern formation process in the method for manufacturing an optical element according to a comparative embodiment, and a schematic top view (c) showing another example of the state when droplets of a liquid composition for one scan land in the printing pattern formation process in the method for manufacturing an optical element according to a comparative embodiment.

[0023] (a) of Figure 21B shows a state in which the outer edge of a droplet of one liquid composition 22 intersects with the outer edge of a droplet of another liquid composition 21 adjacent to the droplet of the one liquid composition 22, and the center X2 of the droplet of the other liquid composition 21 is on the outer edge of the droplet of the one liquid composition 22.

[0024] (b) of Figure 21B shows a state in which the outer edge of a droplet of one liquid composition 22 intersects with the outer edge of a droplet of another liquid composition 21 adjacent to the droplet of the one liquid composition 22, and the center X2 of the droplet of the other liquid composition 21 is inside the outer edge of the droplet of the one liquid composition 22.

[0025] 21B(c) shows a state in which the outer edge of a droplet of one liquid composition 21 is present inside the outer edge of a droplet of another liquid composition 22, and the center X1 of the droplet of the one liquid composition 22 and the center X2 of the droplet of the other liquid composition 21 are aligned. That is, in FIG. 21B(c), the droplets of the liquid compositions are arranged so as to completely overlap. Note that, although an example is shown here in which the droplets of the other liquid composition 21 are smaller than the droplets of the one liquid composition 22, even if the droplet sizes of the one liquid composition 22 and the other liquid composition 21 are equal to or larger than the size of the droplets of the one liquid composition 22, the case in which the center X1 of the droplet of the one liquid composition 22 and the center X2 of the droplet of the other liquid composition 21 are aligned is included in the printing pattern formation step in the manufacturing method of an optical member according to the comparative embodiment.

[0026] Thus, in the printing pattern formation process, a method of ejecting droplets of liquid composition in which the state of droplets of liquid composition for one scan when they land takes the form shown in Figure 21B is not included in the printing pattern formation process of the present invention.

[0027] In this specification, the center of a droplet of a liquid composition can be identified by the following method. After the print pattern formation process, a top-view image of the droplet of the liquid composition is taken, and the outer edge of the droplet of the liquid composition is identified by image analysis. Next, if the identified outer edge is an ellipse, the major axis and the minor axis of the ellipse are identified. The intersection of these major and minor axes is defined as the center of the droplet of the liquid composition. Furthermore, if the identified outer edge is a perfect circle, the point where the perpendicular bisectors of three arbitrarily selected points on the outer edge intersect is defined as the center of the droplet of the liquid composition. Furthermore, if the identified outer edge is irregular, the center of gravity of the droplet is considered to be the center of the droplet. The center of gravity of a droplet with an irregular outer edge is the intersection point of two vertical lines drawn when the droplet is rotated around an arbitrary axis of rotation.

[0028] 21A(b), in the case where the outer edge of a droplet of one liquid composition 22 intersects with the outer edge of a droplet of another liquid composition 21 adjacent to the droplet of the one liquid composition 22 and the center X2 of the droplet of the other liquid composition 21 is outside the outer edge of the droplet of the one liquid composition 22, when the total area of ​​either the droplet of the one liquid composition 22 or the droplet of the other liquid composition 21 in a top view is taken as 100%, the area of ​​the overlapping portion between the droplet of the one liquid composition 22 and the droplet of the other liquid composition 21 is not particularly limited, but is preferably less than 50%. Note that when the size of the droplet of the one liquid composition 22 and the size of the droplet of the other liquid composition 21 are different, the droplet with the smaller size is taken as the droplet with the total area of ​​100%.

[0029] In the print pattern forming step, it is preferable to eject at least two liquid compositions having different refractive indices so that the refractive index changes in at least one direction intersecting the thickness direction of the substrate, thereby obtaining an optical function film whose refractive index changes in at least one direction perpendicular to the thickness direction of the optical function film formed in the optical function film forming step, i.e., in at least one direction along the surface of the optical function film.

[0030] "At least one direction intersecting the thickness direction of the substrate" or "at least one direction in the plane direction of the optical function film" is not particularly limited and can be appropriately selected depending on the purpose, and examples include a direction from one end of the optical function film to the opposite end, a direction from any position on the optical function film to another any position, etc. Therefore, the start point and end point in "at least one direction intersecting the thickness direction of the substrate" or "at least one direction in the plane direction of the optical function film" can be appropriately selected depending on the purpose.

[0031] An example of a method for ejecting at least two liquid compositions having different refractive indices in at least one direction intersecting the thickness direction of the substrate so that the refractive index changes is a method for alternately ejecting droplets of one liquid composition and droplets of another liquid composition having a refractive index different from that of the one liquid composition.

[0032] By using at least two liquid compositions with different refractive indices in the print pattern formation process, the optically functional film cured in the optically functional film formation process has a cured product with at least two different refractive indices. Two liquid compositions with different refractive indices may be used in the print pattern formation process. Herein, when two liquid compositions are used, a liquid composition capable of forming a cured product with a lower refractive index than the cured product of one of the liquid compositions is referred to as a "low refractive index liquid composition." When two liquid compositions are used, a liquid composition capable of forming a cured product with a higher refractive index than the cured product of one of the liquid compositions is referred to as a "high refractive index liquid composition." When three or more liquid compositions are used in the print pattern formation process, a liquid composition capable of forming a cured product with the highest refractive index is referred to as a "high refractive index liquid composition," and a liquid composition capable of forming a cured product with the lowest refractive index is referred to as a "low refractive index liquid composition." The low refractive index liquid composition may contain particles, preferably containing a resin and particles with a refractive index lower than that of the resin.

[0033] In this specification, when there is no need to distinguish between the "high refractive index liquid composition" and the "low refractive index liquid composition", they may be simply referred to as the "liquid composition".

[0034] Here, an embodiment of an optical member obtained by the method for producing an optical member of the present invention will be described with reference to the drawings, although the present invention is not limited to these embodiments.

[0035] In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0036] [Figure 1] 1 is a schematic cross-sectional view showing the state of a printed pattern 90 immediately after the print pattern formation step in a method for producing an optical member according to one embodiment of the present invention. The printed pattern 90 formed on a substrate 1 has a low-refractive index liquid composition 21 and a high-refractive index liquid composition 22 that have been ejected so that the droplets of each are adjacent to each other.

[0037] In this case, it is sufficient that there is at least one region in one scan where droplets of the low-refractive-index liquid composition 21 and droplets of the high-refractive-index liquid composition 22 are ejected adjacent to each other in a direction intersecting the thickness direction of the substrate. Therefore, there may be a region in one scan where droplets of the high-refractive-index liquid composition 22 are ejected adjacent to each other, or there may be a region where droplets of the low-refractive-index liquid composition 21 are ejected adjacent to each other. This causes the refractive index of the optically functional film obtained in the optically functional film forming step to change in at least one direction along the surface.

[0038] Although FIG. 1 illustrates a configuration in which the low refractive index liquid composition 21 and the high refractive index liquid composition 22 are applied to one side of the substrate 1, the low refractive index liquid composition 21 and the high refractive index liquid composition 22 may be applied to both opposing sides of the substrate 1.

[0039] <<Base>> The substrate 1 is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a transparent dielectric. Specific examples include cellulose acylate films (e.g., cellulose triacetate films, cellulose diacetate films, cellulose acetate butyrate films, and cellulose acetate propionate films), polyethylene terephthalate films, polyethersulfone films, polyacrylic resin films, polyurethane resin films, polyester films, polycarbonate films, polysulfone films, polyether films, polymethylpentene films, polyether ketone films, (meth)acrylonitrile films, polyolefins, polymers having an alicyclic structure (cycloolefin polymers (e.g., norbornene resins), and the like), and transparent glass.

[0040] The refractive index of the substrate is not particularly limited, but is preferably 1.40 to 1.75, more preferably 1.45 to 1.70. By setting the refractive index of the substrate to 1.40 to 1.75, the difference in refractive index between the substrate and the optical functional layer can be set within a preferred range.

[0041] The method for measuring the refractive index of the substrate is not particularly limited and can be appropriately selected depending on the purpose. For example, the measurement can be performed using a spectroscopic ellipsometer M-2000 (manufactured by JA Woollam Japan) or a spectrophotometer (V-770, manufactured by JASCO Corporation).

[0042] The average thickness of the substrate 1 is not particularly limited and can be set appropriately depending on the purpose, but from the viewpoint of suppressing scattering within the optically functional film, it is preferably 25 μm or more and 1,000 μm or less, more preferably 25 μm or more and 250 μm or less, and even more preferably 30 μm or more and 90 μm or less.

[0043] The method for measuring the thickness of the substrate 1 is not particularly limited and can be appropriately selected depending on the purpose, and can be measured using physical or optical techniques such as a stylus-type step film thickness meter (Alpha-Step D-500, manufactured by ULVAC, Inc.) or an optical interference film thickness meter (heliInspect, manufactured by Heliotis, Inc.) In this specification, the average value of thicknesses at three arbitrarily selected points on the substrate 1 is defined as the average thickness of the substrate.

[0044] The width, size, and shape of the substrate 1 are not particularly limited and can be set appropriately depending on the application of the optical member to be manufactured.

[0045] <<Liquid composition>> The liquid composition is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a curable liquid composition.

[0046] Here, an optical member having an optically functional film formed by curing a liquid composition will be described with reference to the drawings, although the present invention is not limited to these embodiments.

[0047] [Figure 2] 2 is a schematic top view showing the state of a printed pattern 90 immediately after the print pattern formation step in a method for producing an optical member according to another embodiment of the present invention. The printed pattern 90 formed on the substrate 1 has a low-refractive index liquid composition 21 and a high-refractive index liquid composition 22 applied in different proportions so that the refractive index changes in at least one direction intersecting the thickness direction of the substrate 1.

[0048] The proportion of the low refractive index liquid composition 21 is applied so as to increase on the left end side of the printed pattern 90 in Fig. 2. Furthermore, the proportion of the high refractive index liquid composition 22 is applied so as to gradually increase from the left end side to the right end side of the printed pattern 90 in Fig. 2. Furthermore, the proportion of the high refractive index liquid composition 22 is applied so as to increase on the right end side of the printed pattern 90 in Fig. 2. As a result, the optical function film obtained in the optical function film forming step has a relatively low refractive index on the left end side compared to the right end side, and the refractive index gradually increases from the left end side to the right end side.

[0049] The print pattern 90 shown in Fig. 2 has an area containing only the low-refractive-index liquid composition 21 and an area containing only the high-refractive-index liquid composition 22. By applying and curing the low-refractive-index liquid composition 21 and the high-refractive-index liquid composition 22 onto the substrate 1 in different proportions, the refractive index of the optical functional film changes in at least one direction intersecting the thickness direction of the substrate, i.e., in at least one direction along the surface of the optical functional film. This makes it possible to obtain an optical element 100 having an optical functional film with a refractive index distribution in which one region has a different refractive index from another region.

[0050] The method for measuring the refractive index of the liquid composition after curing is not particularly limited and can be appropriately selected depending on the purpose, and for example, a desired region in the optically functional film can be measured using a spectroscopic ellipsometer M-2000 (manufactured by JA Woollam Japan), a spectrophotometer (V-770, manufactured by JASCO Corporation), etc. The refractive index of the liquid composition before curing can also be measured in a similar manner.

[0051] The method (means) for curing the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. Examples include heat curing, infrared curing, ultraviolet curing, electron beam curing, two-component curing, and solid-liquid separation curing.

[0052] The liquid composition may contain a resin, and may also contain a solvent, particles, and other components as necessary. Among these, the liquid composition preferably contains a resin, or a resin and particles, and from the viewpoint of ejecting droplets, more preferably contains a resin and a solvent, or a resin, particles, and a solvent.

[0053] <<<Resin>>> The resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoints of having a wide variety of derivatives and having good physical and chemical properties such as heat resistance, corrosion resistance, insulation, and hardness, epoxy resins, phenolic resins, melamine resins, alkyd resins, cyanate resins, (meth)acrylic resins, polyester resins, urethane resins, siloxane resins, and norbornene resins are preferred. Specifically, polystyrene, polyvinyl naphthalene, polyvinyl toluene, polyvinyl biphenyl, polymethyl methacrylate, polyethyl methacrylate, polybenzyl methacrylate, and polynorbornene are preferred. These may be used alone or in combination of two or more.

[0054] From the viewpoint of reducing the refractive index, the film may contain a fluorine-containing resin. The fluorine-containing resin is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include tetrafluoroethylene-perfluorodioxole copolymer (refractive index: 1.35), tetrafluoroethylene-hexafluoropropylene copolymer (refractive index: 1.34), polytrifluoroethyl methacrylate (refractive index: 1.42), and polytetrafluoroethylene (refractive index: 1.35 to 1.38).

[0055] The molecular weight of the resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5,000 or more and less than 500,000 from the viewpoint of achieving good viscosity, mechanical strength, and flowability. When the molecular weight of the resin is 5,000 or more, the viscosity is good, making it easy to control the behavior of the liquid composition to ensure sufficient coating thickness and uniformity. In addition, a decrease in the glass transition temperature is suppressed, and the mechanical strength and environmental resistance of the coating film are good. When the molecular weight of the resin is less than 500,000, the inkjet ejection properties of the liquid composition are good.

[0056] The method for measuring the molecular weight of the resin in the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, the molecular weight can be measured by gel permeation chromatography (GPC), MALS (static light scattering using a multi-angle light scattering detector), etc.

[0057] The structure of the resin is not particularly limited and can be appropriately selected depending on the purpose, and may have, for example, a hollow structure or a porous structure. From the viewpoint of reducing the refractive index, it is preferable that a resin having a hollow structure is dispersed in the liquid composition, and it is more preferable that acrylic resin particles having a hollow structure are dispersed in the liquid composition.

[0058] The refractive index of the optically functional film and the liquid composition of the present invention can be adjusted by the content of the resin contained in the liquid composition. More specifically, the refractive index increases when the content of the resin in the liquid composition increases, and decreases when the content of the resin in the liquid composition decreases.

[0059] For example, when preparing a high-refractive index liquid composition, the resin content can be 1% by mass to 99% by mass, and preferably 50% by mass to 99% by mass, relative to the total amount of the high-refractive index liquid composition. When preparing a low-refractive index liquid composition, the resin content may be less than the resin content in the high-refractive index liquid composition, and can be 1% by mass to 99% by mass, and preferably 1% by mass to less than 50% by mass, relative to the total amount of the low-refractive index liquid composition.

[0060] The liquid composition may be formulated to foam during the film curing step, resulting in voids in the resulting film.

[0061] <<<Solvent>>> The solvent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alcohol-based solvents, ketone-based solvents, etc. Specific examples thereof include acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexane, 2-heptanone, 4-heptanone, methyl isopropyl ketone, ethyl isopropyl ketone, diisopropyl ketone, methyl isobutyl ketone, methyl t-butyl ketone, diacetyl, acetylacetone, acetonylacetone, diacetone alcohol, mesityl oxide, chloroacetone, cyclopentanone, cyclohexanone, acetophenone, n-methylpyrrolidone, propylene glycol monomethyl ether, ester-based solvents (e.g., propylene glycol monomethyl ether acetate, etc.), and fluorine-based solvents (e.g., fluorine-based alcohols, etc.). Among these, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, n-methylpyrrolidone, and propylene glycol monomethyl ether are preferred as the solvent, and PGME (propylene glycol monomethyl ether) is more preferred from the viewpoints of solubility of the polymer resin and ease of ejection. These solvents may be used alone or in combination of two or more.

[0062] The solvent content is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoints of ease of inkjet ejection, coating efficiency, ease of waste disposal, and low drying energy, it is preferably 5% by mass or more and 95% by mass or less of the total amount of the liquid composition. When the solvent content is 5% by mass or more, the liquid composition can be made to have an appropriate viscosity for inkjet ejection, allowing for stable ejection. When the solvent content is 95% by mass or less, it is possible to eliminate the problems of a decrease in the solids concentration of the liquid composition, resulting in reduced productivity, an increase in the amount of solvent released into the atmosphere during drying, and unstable inkjet ejection due to increased viscosity of the liquid composition.

[0063] <<<particles>>> The liquid composition may contain particles. The particles preferably have a lower refractive index than the resin, and more preferably have a relatively lower refractive index than the resin after curing. The refractive index may be reduced by adding particles to the liquid composition to form a low-refractive-index liquid composition. That is, the low-refractive-index liquid composition may have the same composition as the high-refractive-index liquid composition, except that it contains particles.

[0064] The particles are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include organic particles, inorganic particles such as silica, etc. Fluorine-containing materials can also be used.

[0065] The shape of the particles is not particularly limited and can be appropriately selected depending on the purpose, and may be, for example, regular or irregular. Examples of regular shaped particles include spherical, plate-like, flaky, rod-like, columnar, needle-like, dendritic, spongy, angular, and elliptical shapes.

[0066] The particle structure is not particularly limited and can be appropriately selected depending on the purpose. For example, the particle may have a hollow structure or a porous structure. The porosity of particles having a hollow structure or a porous structure is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of lowering the refractive index of the resulting optically functional film and increasing the durability of the particles themselves, it is preferably 40% or more and 80% or less.

[0067] The method for measuring the porosity of particles is not particularly limited and can be appropriately selected depending on the purpose. For example, the porosity can be measured or estimated using a mercury intrusion method with a Poremaster (Anton Paar), a gas adsorption specific surface area / pore size distribution analyzer (manufactured by Seika Digital Image Co., Ltd.), or the relationship between the apparent density D1 and true density D0 of the particles.

[0068] An example of how to estimate the porosity of a particle based on the relationship between the apparent density D1 and the true density D0 of the particle is described below. First, let us consider a volume of 100 cm 3 Approximately 30 cm 3 The particles are packed into the volumetric flask, and the mass of the packed particles is accurately weighed. Next, the volumetric flask filled with the particles is accurately filled up to the marked line with isopropanol, taking care not to introduce air bubbles. The mass of the isopropanol added to the volumetric flask is accurately weighed, and the apparent density D1 (g / cm) of the particles is calculated based on the following formula (I): 3 ) is calculated.

[0069] (Number 1) Apparent density D1 (g / cm 3 ) = [mass of particle] / (100 - [mass of isopropanol] ÷ [specific gravity of isopropanol at the measurement temperature]) Equation (I)

[0070] Next, a capacity of 100 cm 3 Approximately 10 g of crushed particles are filled into a measuring flask, and the mass of the crushed pieces is accurately weighed. In the same manner as in the measurement of apparent density D1, isopropanol is added to the measuring flask, and the mass of the isopropanol is accurately weighed. The true density D0 (g / cm) of the particles is calculated based on the following formula (II). 3 ) is calculated. Note that when calculating the true density D0, voids are not considered to be part of the particle.

[0071] (Number 2) True density D0(g / cm 3 ) = [mass of crushed particles] / (100 - [mass of isopropanol] ÷ [specific gravity of isopropanol at the measurement temperature]) Equation (II)

[0072] The porosity (%) of a particle is calculated from the apparent density D1 and true density D0 of the particle by the following formula (III).

[0073] (Number 3) Porosity (%) = 100 - (apparent density D1 / true density D0) × 100 Equation (III)

[0074] The particle size is not particularly limited and can be appropriately selected depending on the purpose, but the volume average primary particle diameter is preferably 1 nm or more and 200 nm or less, and more preferably 50 nm or more and 100 nm or less. For example, from the viewpoint of excellent haze reduction effect, the particle size is preferably 100 nm or less in terms of average primary particle diameter. Note that the particle size may be appropriately adjusted depending on the application.

[0075] The method for measuring the volume-average primary particle diameter of the particles is not particularly limited and can be appropriately selected depending on the purpose. For example, the volume-average primary particle diameter can be measured using a particle size distribution analyzer using a dynamic light scattering method (VASCO, manufactured by CORDUAN), a laser diffraction particle size distribution analyzer (Partica LA-960V2, manufactured by HORIBA, Ltd.), or by cross-sectional observation using a heated cathode field-scanning electron microscope (Schottky FE-SEM).

[0076] The particle content is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of improving particle dispersibility in the liquid composition, it is preferably 1% by mass or more and 15% by mass or less relative to the total amount of the liquid composition.

[0077] The particles may be appropriately synthesized or commercially available. There are no particular limitations on the commercially available particles, and they can be appropriately selected depending on the purpose. For example, the product name is Techpolymer (manufactured by Sekisui Plastics Co., Ltd.).

[0078] <<<Other ingredients>>> The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include photopolymerization initiators, photosensitizers, surfactants, rheology control agents, antioxidants, antifungal agents, and pigments.

[0079] -Photopolymerization initiator- The photopolymerization initiator is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfonium compounds, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins, etc. These may be used alone or in combination of two or more.

[0080] The content of the photopolymerization initiator is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoints of improving the curing rate, improving the reaction rate, and minimizing the amount of residual initiator, it is preferably 1% by mass or more and 30% by mass or less based on the total amount of the monomer, oligomer, and polymer.

[0081] The photopolymerization initiator may be appropriately synthesized or may be commercially available.The commercially available photopolymerization initiator may be, for example, under the trade name, Irgacure 651, Irgacure 184, Irgacure 819, Irgacure 907, Irgacure 1870 (CGI-403 / Irg184=7 / 3 mixed initiator), Irgacure 500, Irgacure 369, Irgacure 1173, Irgacure 2959, Irgacure 4265, Irgacure 4263, Irgacure 127, OXE01, Lucirin TPO (all manufactured by BASF), Kayacure DETX- S, Kayacure BP-100, Kayacure BDMK, Kayacure CTX, Kayacure BMS, Kayacure 2-EAQ, Kayacure ABQ, Kayacure CPTX, Kayacure EPD, Kayacure ITX, Kayacure QTX, Kayacure BTC, Kayacure MCA (all manufactured by Nippon Kayaku Co., Ltd.), Esacure (KIP100F, KB1, EB3, BP, X33, KTO46, KT37, KIP150, TZT) (manufactured by Sartomer Corporation), and the like.

[0082] -Photosensitizer- The photosensitizer is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone, thioxanthone, etc. Furthermore, one or more auxiliary agents such as azide compounds, thiourea compounds, mercapto compounds, etc. may be used in combination.

[0083] The photosensitizer may be a synthesized one or a commercially available one, such as Kayacure (DMBI, EPA) (manufactured by Nippon Kayaku Co., Ltd.).

[0084] -Surfactants- The surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include fluorine surfactants and silicone surfactants.

[0085] -Rheology control agent- The rheology control agent is not particularly limited and can be appropriately selected depending on the purpose.

[0086] -Antioxidants- The antioxidant is not particularly limited and can be appropriately selected depending on the purpose.

[0087] - Antifungal agent - The antifungal agent is not particularly limited and can be appropriately selected depending on the purpose.

[0088] -Pigments- The pigment is not particularly limited and can be appropriately selected depending on the purpose.

[0089] [Physical properties of liquid composition] The viscosity of the liquid composition at 25°C is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 3 mPa·s or more and 1,000 mPa·s or less, and more preferably 5 mPa·s or more and 20 mPa·s or less. When the viscosity of the liquid composition at 25°C is 3 mPa·s or more, the problem of mist generation from the liquid composition can be eliminated. When the viscosity of the liquid composition is 1,000 mPa·s or less, it becomes possible to eject the liquid composition using an inkjet head, and the process temperature in the optically functional film formation step can be reduced, making leveling easier and achieving a uniform coating film.

[0090] The method for measuring the viscosity of the liquid composition is not particularly limited and can be selected appropriately depending on the purpose. For example, the viscosity can be measured at 25°C using a rotational viscometer (viscometer TVE-25L, manufactured by Tokyo Glass Instruments Co., Ltd.).

[0091] The surface tension of the liquid composition is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoints of uniformity during film formation, inkjet ejection stability of the liquid composition, and storage stability of the liquid composition, it is preferably 10 mN / m or more, more preferably 20 mN / m or more, and preferably 40 mN / m or less, more preferably 30 mN / m or less. If the surface tension of the liquid composition is 10 mN / m or more, the problem of ejected droplets breaking up can be eliminated. If the surface tension of the liquid composition is 40 mN / m or less, the problem of droplets becoming difficult to level, impairing the uniformity of the coating film, can be eliminated.

[0092] The method for measuring the surface tension of the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, the surface tension can be measured using a surface tensiometer (DY-300, manufactured by Kyowa Interface Science Co., Ltd.).

[0093] The ejection means for ejecting the liquid composition is not particularly limited and can be appropriately selected depending on the purpose, but an inkjet method is preferred from the viewpoint of being able to control the landing position of droplets, the amount of ejected liquid, etc. with high precision.

[0094] Examples of inkjet methods include a charge control method that uses electrostatic attraction to eject a liquid composition, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the liquid composition, thereby ejecting it using radiation pressure, and a thermal inkjet (Bubble Jet (registered trademark)) method that heats the liquid composition to form bubbles and uses the resulting pressure.

[0095] Control of droplets of the liquid composition is primarily achieved by the printhead.

[0096] With thermal inkjet printing, it is possible to control the droplet volume by adjusting the print head structure. That is, by changing the sizes of the ink chamber, heating unit, and nozzle, it is possible to eject droplets of a desired size. Furthermore, even with thermal inkjet printing, it is possible to eject droplets of a variety of sizes by providing multiple print heads with different sizes of heating unit and nozzle.

[0097] In the case of the drop-on-demand method using piezoelectric elements, it is possible to change the droplet volume due to the structure of the print head, just as with the thermal inkjet method, but it is also possible to eject droplets of multiple sizes using a print head with the same structure by controlling the waveform of the drive signal that drives the piezoelectric element.

[0098] When the liquid composition is ejected by inkjet, the amount of the liquid to be ejected is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of resolution and productivity, it is preferably 1 pL or more and 100 pL or less.

[0099] When the liquid composition is ejected by inkjet, at least two liquid compositions having different refractive indices may be ejected at different ejection rates in the print pattern formation step, thereby enabling the production of optical members with a wider variety of structures.

[0100] The amount of each liquid composition ejected in one go is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoints of resolution and productivity, it is preferably from 0.1 pL to 100 pL, and more preferably from 1 pL to 30 pL. Here, when the liquid composition is ejected by inkjet, the amount ejected in one go refers to the total amount ejected from multiple holes in the inkjet head in one ejection.

[0101] For example, the amount of high refractive index liquid composition ejected at one time may be set to be large (e.g., 5 pL) and the amount of low refractive index liquid composition ejected at one time may be set to be small (e.g., 2 pL), or the amount of high refractive index liquid composition ejected at one time may be set to be small (e.g., 2 pL) and the amount of low refractive index liquid composition ejected at one time may be set to be large (e.g., 5 pL).

[0102] When the liquid composition is ejected by inkjet, the resolution is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of imparting a refractive index distribution in a direction intersecting the thickness direction of the substrate, it is preferably 20 dpi or more.

[0103] <Semi-curing process> The method for producing an optical member of the present invention may include a step of curing the liquid composition to a desired degree after the print pattern formation step and before the optically functional film formation step. For convenience, the "step of curing the liquid composition to a desired degree" may be referred to as a "semi-curing step."

[0104] When a liquid composition is ejected by inkjet, the semi-curing process can control the curing state of droplets of one liquid composition adjacent to droplets of another liquid composition being ejected, thereby obtaining an optically functional film with a more gradual change in refractive index.

[0105] Curing is a chemical film formation process in which resins and the like are primarily fused and solidified, while drying is a physical film formation process in which a solid solid is primarily solidified by volatilizing a solvent. Drying and curing may proceed simultaneously depending on the composition of the liquid composition. When drying and curing proceed simultaneously, the cured state of the liquid composition can also be evaluated by the amount of evaporation of the solvent in the liquid composition.

[0106] The semi-curing method (means) for realizing the semi-curing step is not particularly limited and can be appropriately selected depending on the purpose. Examples include heat curing, infrared curing, ultraviolet curing, electron beam curing, two-component curing, and solid-liquid separation curing.

[0107] In this specification, a state in which the liquid composition is 100% cured is referred to as a "100% cured state." In other words, a 100% cured state is a state in which the solvent in the liquid composition has completely evaporated (i.e., 100% by mass), or a state in which the energy required for complete curing has been applied. Therefore, for example, a "50% cured state" is a state in which 50% by mass of the solvent in the liquid composition has evaporated, or a state in which the energy required for 50% curing has been applied. On the other hand, a state in which the liquid composition is not cured (a 0% cured state) is referred to as a "0% cured state."

[0108] The method for identifying the cured state of droplets of the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, the cured state can be identified by using a laser displacement meter to measure changes in height, weight, refractive index, hardness, etc.

[0109] [Figures 3A to 4B] The semi-curing step will now be described in detail with reference to Figures 3A to 4B. Figure 3A is a schematic side view showing a step of ejecting droplets of low-refractive-index liquid composition 21 from head 41 onto an optically functional film formed from droplets of high-refractive-index liquid composition 22 in a 100% cured state ejected from head 42 and curing the droplets. Figure 3B is a schematic side view showing a step of ejecting droplets of low-refractive-index liquid composition 21 from head 41 onto an optically functional film formed from droplets of high-refractive-index liquid composition 22 in a 50% cured state ejected from head 42 and curing the droplets.

[0110] Here, we assume that an optical element having a single-layer optically functional film is manufactured using two liquid compositions: a high-refractive index liquid composition 22 that has a relatively high refractive index after curing, and a low-refractive index liquid composition 21 that has a relatively low refractive index after curing. First, the high-refractive index liquid composition 22 is dispensed onto a substrate 1 and subjected to an optically functional film formation process to reach a 100% cured state. The cured product of the high-refractive index liquid composition 22 is designated as a cured product 22a. Next, a low-refractive index liquid composition 21 is dispensed onto the cured product 22a, and droplets of the low-refractive index liquid composition 21 are disposed on the substrate 1. The cured product of the low-refractive index liquid composition 21 obtained by curing the low-refractive index liquid composition 21 to a 100% cured state is designated as a cured product 21a. After curing, an interface 24 is formed between the cured product 22a and the cured product 21a (see FIG. 3A).

[0111] Meanwhile, the high-refractive index liquid composition 22 dispensed onto the substrate 1 is subjected to a semi-curing process, for example, until it is 50% cured. The semi-cured product of the high-refractive index liquid composition 22 is formed into a cured product 22b. Next, the low-refractive index liquid composition 21 is dispensed onto the semi-cured product 22b, and droplets of the low-refractive index liquid composition 21 are placed on the substrate 1 between the semi-cured product 22b. At this time, the interface between the semi-cured product 22b and the droplets of the low-refractive index liquid composition 21 is corroded. This is further cured to make the semi-cured product 22b and the low-refractive index liquid composition 21 100% cured. As a result, the semi-cured product 22b becomes a cured product 22a. Furthermore, the 100% cured cured product of the low-refractive index liquid composition 21 is formed into a cured product 21a. As a result, an interface 24 is not formed, and the refractive index changes gradually between the cured product 21a and the cured product 22a. As a result, the refractive index in the plane direction of the optically functional film changes (see FIG. 3B).

[0112] In this way, when forming the printing pattern 90 so that the refractive index changes in a direction intersecting the thickness direction of the substrate 1, an optically functional film in which the refractive index in the surface direction changes more gradually can be obtained by controlling the curing state of droplets of at least two liquid compositions with different refractive indices that are adjacent in a direction intersecting the thickness direction of the substrate 1 to an arbitrary degree.

[0113] Fig. 4A is a schematic side view showing a process of discharging and curing droplets of a low-refractive-index liquid composition 21 for a second layer onto a first optically functional film layer that is 100% cured. Fig. 4B is a schematic side view showing a process of discharging and curing droplets of a low-refractive-index liquid composition 21 for a second layer onto a first optically functional film layer that is 50% cured.

[0114] Here, we assume that an optical element having a two-layer optically functional film is manufactured using two liquid compositions: a high-refractive index liquid composition 22 that has a relatively high refractive index after curing, and a low-refractive index liquid composition 21 that has a relatively low refractive index after curing. First, the high-refractive index liquid composition 22 is dispensed onto a substrate 1 and subjected to an optically functional film formation process to reach a 100% cured state. The cured product of the high-refractive index liquid composition 22 is designated as a cured product 22a. Next, a low-refractive index liquid composition 21 is dispensed onto the cured product 22a, and droplets of the low-refractive index liquid composition 21 are placed on the cured product 22a. The cured product of the low-refractive index liquid composition 21 obtained by curing the low-refractive index liquid composition 21 to a 100% cured state is designated as a cured product 21a. After curing, an interface 24 is formed between the first layer of cured product 22a and the second layer of cured product 21a (see FIG. 4A).

[0115] Meanwhile, the high-refractive index liquid composition 22 dispensed onto the substrate 1 is subjected to a semi-curing process, for example, until it is 50% cured. The semi-cured product of the high-refractive index liquid composition 22 is formed into a cured product 22b. Next, the low-refractive index liquid composition 21 is dispensed onto the semi-cured product 22b, and droplets of the low-refractive index liquid composition 21 are disposed on the semi-cured product 22b. At this time, the interface between the semi-cured product 22b and the droplets of the low-refractive index liquid composition 21 is corroded. This is further cured to make the semi-cured product 22b and the low-refractive index liquid composition 21 into a 100% cured state. As a result, the semi-cured product 22b becomes a cured product 22a. Furthermore, the 100% cured cured product of the low-refractive index liquid composition 21 is formed into a cured product 21a. As a result, an interface 24 is not formed, and the refractive index changes gradually between the cured products 21a and 22a. As a result, the refractive index in the stacking direction of the optically functional film changes (see FIG. 4B).

[0116] In this way, when forming the printing pattern 90 so that the refractive index changes in the thickness direction of the substrate 1, an optically functional film in which the refractive index changes more gradually in the thickness direction can be obtained by controlling the curing state of droplets of at least two liquid compositions with different refractive indices that are adjacent in the thickness direction of the substrate 1 to an arbitrary degree.

[0117] The optical member 100 having an optically functional film whose refractive index changes in the thickness direction of the substrate 1 can be suitably used as an anti-reflection film.

[0118] The "any degree" in the semi-curing step is not particularly limited and can be selected appropriately depending on the application of the optical component. For example, the cured state of the droplets can be 30% or more but less than 100%, preferably 30% or more but 95%. When it is desired to suppress the refractive index difference between optically functional films stacked in two or more layers, the cured state of the droplets adjacent to the ejected droplets may be 30% or more but 70%.

[0119] The curing state of the droplets can be controlled by measuring in advance the relationship between the curing state of the liquid composition used and the amount of energy applied using the above-mentioned measurement method. For example, when drying and curing proceed simultaneously, the curing state of the droplets can be controlled by measuring in advance the relationship between the curing state of the liquid composition used and the amount of evaporation.

[0120] <Optical functional film formation process> The optically functional film forming step is a step of forming an optically functional film by curing the print pattern obtained in the print pattern forming step. Curing the print pattern means curing the ejected liquid composition. As described above, the optically functional film has a change in refractive index at least in the plane direction. Furthermore, when the laminate forming step described below is included, the optically functional film further has a change in refractive index in the stacking direction.

[0121] The curing method for curing the printed pattern is not particularly limited and can be appropriately selected depending on the purpose, and examples include heat curing, infrared curing, ultraviolet curing, electron beam curing, two-component curing, solid-liquid separation curing, etc. For example, in the case of heat curing, it is desirable to heat at 40°C for 10 minutes using a heating device.

[0122] The refractive index distribution range due to changes in the refractive index in the surface direction or lamination method of the optically functional film is not particularly limited and can be selected appropriately depending on the purpose, but due to the physical limitations of each material, it is preferably 1.0 or more and 2.5 or less.

[0123] The method for measuring the refractive index of the optically functional film is not particularly limited and can be selected appropriately depending on the purpose. For example, the refractive index can be measured while moving a spectroscopic ellipsometer M-2000 (manufactured by JA Woollam Japan) appropriately.

[0124] The average thickness of the optically functional film is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 nm or more and 5,000 nm or less. When the average thickness of the optically functional film is 10 nm or more, the problem of not being able to obtain the desired optical function can be resolved. When the average thickness of the optically functional film is 5,000 nm or less, the problems of the optically functional film being easily broken, the problem of reduced adhesion to adjacent films, the problem of reduced productivity due to a long curing time, and the problem of reduced light transmittance can be resolved. Note that the average thickness of the optically functional film here refers to the average thickness of a single-layer optically functional film.

[0125] The method for measuring the thickness of the optically functional film is not particularly limited and can be appropriately selected depending on the purpose, and can be measured using, for example, a stylus-type step film thickness meter (Alpha-Step D-500, manufactured by ULVAC, Inc.) or an optical interference film thickness meter (heliInspect, manufactured by Heliotis, Inc.) In this specification, the average value of thicknesses at three arbitrarily selected points in the optically functional film or its laminate is defined as the average thickness of the optically functional film.

[0126] The transmittance of the optically functional film is not particularly limited and can be appropriately selected depending on the purpose. When the optical component of the present invention is used as an anti-reflection film or a high-transmittance film, the transmittance of the optically functional film is preferably 92% or more and 100% or less. When the transmittance of the optically functional film is within this range, the problem of not being able to obtain the desired optical function can be resolved.

[0127] The method for measuring the transmittance of the optically functional film is not particularly limited and can be selected appropriately depending on the purpose. For example, it can be measured using a spectrophotometer (V-770, manufactured by JASCO Corporation) or a haze meter (NDH 5000, manufactured by Nippon Denshoku Industries Co., Ltd.).

[0128] In the method for manufacturing optical elements of the present invention, various types of optical elements can be obtained by changing the direction in which the refractive index of the optical functional film is changed in the surface direction or by imparting periodicity to the change in the refractive index of the optical functional film in the surface direction.

[0129] Other embodiments of the optical member obtained by the method for producing an optical member of the present invention will now be described with reference to the drawings, although the present invention is not limited to these embodiments.

[0130] [Figure 5] FIG. 5 is a schematic top view of an optical element obtained by a method for producing an optical element according to another embodiment of the present invention. The optical element 101 comprises a substrate and, on the substrate, an optically functional film 30 having a periodic refractive index distribution formed by a low-refractive index liquid composition and a high-refractive index liquid composition. In FIG. 5, the outer edges of the droplets derived from the low-refractive index liquid composition and the high-refractive index liquid composition are omitted, and the refractive index distribution in the optically functional film 30 is indicated by shading. An optical element 101 having such a structure can be suitably employed as an optical filter that reflects or refracts specific wavelengths.

[0131] [Figure 6] FIG. 6 is a schematic top view of an optical element obtained by a method for manufacturing an optical element according to another embodiment of the present invention. The optical element 102 comprises a substrate and an optically functional film 30 formed on the substrate, in which the refractive index distribution changes continuously from the center to the periphery due to the low-refractive-index liquid composition and the high-refractive-index liquid composition. In FIG. 6, the outer edges of the droplets derived from the low-refractive-index liquid composition and the high-refractive-index liquid composition are omitted, and the refractive index distribution is indicated by shading. An optical element 102 having such a structure achieves a visual effect in which the color and transparency gradually change from the center to the periphery.

[0132] <Laminate formation process> The laminate formation step is a step of repeating the print pattern formation step and the optical function film formation step to form a laminate of optical function films that are stacked in the thickness direction of the base. By including the laminate formation step in the method for manufacturing an optical member of the present invention, the refractive index of the optical function film in the stacking direction can be further controlled, and the refractive index of the obtained optical member can be controlled with higher precision, thereby increasing the range of uses for the optical member. Note that the laminate formation step may also be a step of repeating the print pattern formation step, the semi-curing step, and the optical function film formation step to form a laminate.

[0133] In the laminate formation process, it is preferable to form the laminate so that the refractive index of one layer of optical functional film and the refractive index of another layer of optical functional film arranged in the stacking direction of the one layer of optical functional film change in at least a portion of the region in a direction intersecting the stacking direction of the laminate.

[0134] Note that an optical function film of one layer and an optical function film of another layer arranged in the stacking direction of the optical function film of the one layer do not have to be in contact with each other. That is, in at least a part of the region in the direction intersecting the stacking direction of the three or more layer stack, the refractive index of the optical function film of one layer (assumed to be the first optical function film here) and an optical function film of another layer (assumed to be the second optical function film here) arranged in the stacking direction of the first optical function film and in contact with the first optical function film may not change, but the refractive index of the optical function film of the first layer and an optical function film of a further layer (assumed to be the third optical function film here) arranged so as to face the first optical function film in the stacking direction via the second optical function film may change. Although the description has been given here using an example of a three-layer optical function film, the same applies to the case of four or more layers, and in at least a part of the region in the direction intersecting the stacking direction of the laminate, any number of optical function films having the same refractive index as the optical function film of the one layer or the optical function film of the other layer may be arranged between the optical function film of the one layer and the optical function film of the other layer arranged in the stacking direction of the optical function film of the one layer. Here, this embodiment will be described in more detail with reference to the drawings.

[0135] [Figure 7] Figure 7 is a schematic perspective view (a) showing the state of an optical element after the laminate formation process in a method for manufacturing an optical element according to one embodiment of the present invention, and a schematic top view (b) showing the printing patterns for forming each layer.

[0136] 7(a), the optical member 100 has a base 1, a first optical function film 31 provided on the base 1, a second optical function film 32 provided on the first optical function film 31, and a third optical function film 33 provided on the second optical function film 32. In this specification, the "first optical function film 31," the "second optical function film 32," and the "third optical function film 33" may be collectively referred to as a "laminate." In addition, optical function films formed after the third optical function film 33 are also included in the laminate.

[0137] As shown in Figure 7(b), the printing patterns for forming the first optical functional film 31 and the third optical functional film 33 are formed by applying each liquid composition to the substrate so as to create a refractive index distribution in at least one direction intersecting the thickness direction of the substrate.

[0138] Specifically, the proportion of the high-refractive-index liquid composition 22 is applied so that it is greater on the left side of the printing pattern for forming the first optical function film 31 in Fig. 7(b). Furthermore, the proportion of the low-refractive-index liquid composition 21 is applied so that it gradually increases from the left side to the right side of the printing pattern for forming the first optical function film 31 in Fig. 7(b). Furthermore, the proportion of the low-refractive-index liquid composition 21 is applied so that it is greater on the right side of the printing pattern for forming the first optical function film 31 in Fig. 7(b). As a result, the refractive index of the first optical function film 31 is relatively lower on the right side than on the left side, and the refractive index of the first optical function film 31 gradually decreases from the right side to the left side.

[0139] In the printing pattern for forming the third optical function film 33 in Fig. 7(b), the proportion of the low refractive index liquid composition 21 is applied so that it is larger at the left end side. Furthermore, the proportion of the high refractive index liquid composition 22 is applied so that it gradually increases from the left end side to the right end side of the printing pattern for forming the third optical function film 33 in Fig. 7(b). Furthermore, the proportion of the high refractive index liquid composition 22 is applied so that it is larger at the right end side of the third optical function film 33 in Fig. 7(b). Accordingly, the refractive index of the third optical function film 33 is relatively lower at the left end side than at the right end side, and the refractive index of the third optical function film 33 gradually increases from the left end side to the right end side.

[0140] In the printing pattern for forming the second optical function film 32 in Fig. 7(b), droplets of the low-refractive index liquid composition 21 and droplets of the high-refractive index liquid composition 22 are applied so as to be in contact with each other in a staggered manner (in a checkerboard pattern). As a result, the refractive index of the entire second optical function film 32 is approximately uniform and medium. Here, "medium" means that the refractive index is approximately the same as the refractive index of the central portion between the right and left end sides of the first optical function film 31 or the refractive index of the central portion between the right and left end sides of the third optical function film 33.

[0141] The checkered second optically functional film 32 is obtained by alternately ejecting droplets of the low-refractive-index liquid composition 21 and the high-refractive-index liquid composition 22. The second optically functional film 32 may also be provided with each liquid composition so that the refractive index varies, similar to the first optically functional film 31 and the third optically functional film 33. An optical element having such a structure can be suitably employed, for example, as an optical filter that reflects a specific wavelength.

[0142] In the present invention, the optically functional film may be formed by randomly discharging droplets of each liquid composition onto a substrate.

[0143] When the method for manufacturing an optical member of the present invention includes a laminate formation step, it is preferable to expose particles on the surface of the outermost layer of the laminate to be formed, i.e., on the exposed surface of the optical function film, from the viewpoint of further reducing the refractive index of the surface of the optical member. Here, "the surface of the outermost layer of the laminate" refers to the upper surface of the third optical function film 33 in Figure 7(a).

[0144] The method for exposing particles on the surface of the outermost film of the laminate is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method of applying particles to the surface of the outermost film of the laminate, a method of using a liquid composition containing particles as a liquid composition for forming the outermost film of the laminate, and a method of abrading a part of the outermost film that has already been formed and contains particles to expose the particles.

[0145] When the method for producing an optical member of the present invention includes a laminate formation step, the number of optically functional films to be laminated is not particularly limited and can be appropriately set depending on the application and productivity of the resulting optical member. In this case, the average thickness of each laminated optically functional film is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 nm or more and 5,000 nm or less. When the average thickness of each laminated optically functional film is 10 nm or more, the problem of not being able to obtain the desired optical function can be resolved. When the average thickness of each laminated optically functional film is 5,000 nm or less, the problems of the optically functional film being easily broken, the problem of reduced adhesion between adjacent optically functional films, the problem of reduced productivity due to a long curing time, and the problem of reduced light transmittance can be resolved.

[0146] When the method for manufacturing an optical element of the present invention includes a laminate formation step, various optical elements can be obtained by changing the direction in which the refractive index of the optical functional film is changed in the stacking direction or by imparting periodicity to the change in the refractive index of the optical functional film in the stacking direction.

[0147] Other embodiments of the optical member obtained by the method for producing an optical member of the present invention will now be described with reference to the drawings, although the present invention is not limited to these embodiments.

[0148] [Figure 8] FIG. 8 is a schematic cross-sectional view showing a state after a laminate formation step in a manufacturing method for an optical element according to another embodiment of the present invention. The optical element 103 includes a substrate 1, a first optically functional film 31 provided on the substrate 1, a second optically functional film 32 provided on the first optically functional film 31, and a third optically functional film 33 provided on the second optically functional film 32. As in FIG. 7, the first optically functional film 31, the second optically functional film 32, and the third optically functional film 33 are coated with respective liquid compositions so that their refractive indices change in at least one direction intersecting the thickness direction of the substrate. Note that in FIG. 8, the outer edges of the droplets derived from the low-refractive-index liquid composition and the high-refractive-index liquid composition are omitted, and the refractive index distribution is indicated by shading.

[0149] The optical member 103 having such a structure can provide a visual effect such as a change in color when viewed from a specific angle, or an effect such as reflecting only specific wavelengths.

[0150] Here, the method for producing an optical member of the present invention will be described with reference to the drawings, although the present invention is not limited to these embodiments.

[0151] [Figure 9] 9 is a schematic perspective view showing an inkjet drawing apparatus for carrying out a method for manufacturing an optical member according to one embodiment of the present invention. The inkjet drawing apparatus includes a stage 70, a substrate 1 placed on the stage 70, an inkjet head 41 that ejects a low-refractive-index liquid composition 21 toward the substrate 1, an inkjet head 42 that ejects a high-refractive-index liquid composition 22 toward the substrate 1, an ink tank 51 that supplies the low-refractive-index liquid composition 21 to the inkjet head 41 via a tube 60, and an ink tank 52 that supplies the high-refractive-index liquid composition 22 to the inkjet head 42 via the tube 60.

[0152] The stage 70 is wider than the base 1 and is configured to be freely movable in the horizontal direction by a movement mechanism. Examples of the movement mechanism include a rack and pinion mechanism and a ball screw mechanism. The stage 70 also includes a heater, which can heat the base 1 on the stage 70.

[0153] [Figures 10A to 10C] 10A to 10C are schematic cross-sectional views illustrating a method for manufacturing an optical member according to one embodiment of the present invention. First, a substrate 1 is placed on a stage. The substrate 1 is placed so that its back surface is in contact with the stage. The substrate 1 is then heated by a heater provided on the stage. The surface temperature of the substrate 1 can be, for example, 40°C. Next, a low-refractive-index liquid composition 21 and a high-refractive-index liquid composition 22 are ejected onto the substrate 1 from inkjet heads 41 and 42, respectively. As shown in FIG. 10A, the ejection is performed while the stage is moved by a movement mechanism. In this case, the substrate 1 placed on the stage moves as the stage moves. Alternatively, the inkjet heads may move instead of the stage. Each liquid composition may be ejected in multiple batches until a desired thickness is achieved, as shown in FIG. 10B.

[0154] The liquid composition films thus formed are cured by, for example, UV irradiation to form the first optically functional film. The curing conditions are not particularly limited, but the illuminance is preferably 1,500 mW / cm. 2 More than 5,000mW / cm 2 and the cumulative light intensity is 1,000 mJ / cm 2 More than 5,000mmJ / cm 2 It is preferable that:

[0155] 10C, a low refractive index liquid composition 21 and a high refractive index liquid composition 22 are ejected onto the first optically functional film from inkjet head 41 and inkjet head 42, respectively, to form a second optically functional film in the same manner. Subsequent optically functional films are also formed in the same manner.

[0156] The method for producing an optical member of the present invention is preferably carried out in an environment at room temperature (25° C.) and a humidity of 20% to 30%, although this depends on the physical properties of the liquid composition used.

[0157] The structures of the optical components obtained by the method for producing optical components of the present invention can be confirmed, for example, by cooling them using an ion milling device IM4000 (manufactured by Hitachi High-Technologies Corporation) and observing the surface and cross section of the optical component using a Gemini300 heated cathode field-effect scanning electron microscope (Schottky FE-SEM).

[0158] [Application] The optical member obtained by the method for producing an optical member of the present invention can be suitably used as an anti-reflection film, an optical filter, a high transmittance film, and the like.

[0159] (Optical components) The optical member of the present invention includes a substrate and an optically functional film disposed on the substrate, the optically functional film having regions with different refractive indices in a planar direction of the optically functional film. The optical member of the present invention may further include other layers or members as necessary.

[0160] The optical member of the present invention is preferably produced by the method for producing an optical member of the present invention. Accordingly, the substrate and the optical functional film in the optical member of the present invention are as described above in the section (Method for producing an optical member).

[0161] Specifically, the optically functional film preferably contains a resin, or a resin and particles, and more preferably contains a resin, or a resin and particles having a refractive index lower than that of the resin.

[0162] The optical member of the present invention is, for example, the optical member shown in Fig. 5, Fig. 6, Fig. 7, or Fig. 8. Among these, the optical member of the present invention is preferably a laminate in which two or more optically functional films are laminated in the thickness direction of a substrate, as shown in Fig. 7, and in which, in at least a partial region in a direction intersecting the lamination direction of the laminate, the refractive index of one optically functional film changes from that of another optically functional film arranged in the lamination direction of the one optically functional film, and from the optically functional film on the substrate side toward the outermost film of the laminate.

[0163] The transmittance of the optical member is not particularly limited and can be appropriately selected depending on the purpose. When the optical member of the present invention is used as an anti-reflection film or a high-transmittance film, the transmittance of the optical member is preferably 92% or more and 100% or less. When the transmittance of the optical member is within this range, the problem of not being able to obtain the desired optical function can be resolved. The transmittance of the optical member can be measured using the same method as that for measuring the transmittance of an optically functional film. [Example]

[0164] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples and comparative examples, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0165] Example 1 <Preparation of High Refractive Index Liquid Composition A> The following materials were stirred at 60° C. for 2 hours, and then stirred at 25° C. for 8 hours. Thereafter, the mixture was filtered through a 2 μm filter to prepare a high refractive index liquid composition A. PMMA (polymethyl methacrylate, Sigma-Aldrich): 2.0 g PGME (propylene glycol monomethyl ether, manufactured by Kanto Chemical Co., Ltd.): 98.0 g

[0166] <Preparation of Low Refractive Index Liquid Composition A> The following materials were stirred at 60° C. for 2 hours, and then stirred at 25° C. for 8 hours. Thereafter, the mixture was filtered through a 2 μm filter to prepare a low refractive index liquid composition A. PNB (Polynorbornene, manufactured by Sumitomo Bakelite Co., Ltd.): 2.0g PGME (propylene glycol monomethyl ether, manufactured by Kanto Chemical Co., Ltd.): 98.0 g

[0167] <Cleaning of the substrate> A 4 cm x 4 cm glass plate (Eagle XG, Technoprint Co., Ltd.) was prepared and cleaned with acetone in an ultrasonic cleaner. After that, it was cleaned with a low-pressure mercury lamp (UV wavelengths 254 nm, 185 nm) at a distance of 30 mm and irradiated with 2 mW / cm using a UV-ozone cleaner. 2 The glass substrate was then treated by UV irradiation at 4000 kJ / min for 10 minutes to obtain a glass substrate.

[0168] <Printing conditions> An optical element was produced on the above-mentioned cleaned glass substrate by the following method using a printing device (manufactured by Genesis Co., Ltd.) equipped with an inkjet head ("MH5420" manufactured by Ricoh Co., Ltd.) corresponding to the inkjet drawing device shown in Figure 9. Ink tank 52 was filled with high refractive index liquid composition A as high refractive index liquid composition 22, and ink tank 51 was filled with low refractive index liquid composition A as low refractive index liquid composition 21. An inkjet head 42 (hereinafter sometimes referred to as "head 42") was connected to ink tank 52 via a tube 60, and an inkjet head 41 (hereinafter sometimes referred to as "head 41") was connected to ink tank 51 via a tube 60. Head 42 and head 41 are arranged side by side in the scanning direction of each inkjet head, and head 41 follows the location scanned by head 42. In this specification, continuous scanning of the inkjet heads is defined as one scan.

[0169] -Drawing conditions- The inkjet printing conditions were adjusted by adjusting the applied voltage to set the droplet volume to 3 pL, the resolution to 600 dpi x 600 dpi, and the table transport speed to 45 mm / s. The temperature of the printing device's stage 70 was set to 60°C, and the device was configured so that it could be heated on the stage 70.

[0170] -Discharge data- Data to be ejected in one scan was prepared for each head. The ejection data will now be described with reference to FIG. 11A. FIG. 11A is a schematic diagram showing the ejection data in Example 1. As shown in FIG. 11A, the ejection data is formed by two-dimensional numerical data (0 to 255), with each pixel being a unit formed by droplets ejected from one nozzle. In FIG. 11A, one pixel is represented by a square, and the numbers within the square indicate the numerical data of the two-dimensional data. The direction from left to right in the figure indicates the scanning direction. In the following Examples and Comparative Examples, one pixel and numerical data are represented in the same manner. The numerical data can be set as appropriate, but in this Example, "0" represents no ejection and "255" represents ejection. The ejection amount is adjusted by the applied voltage or pressure. Note that head 42 and head 41 do not eject to the same pixel. For example, for a pixel where the numerical value 255 is input in the ejection data for head 42, "0" is input in the ejection data for head 41.

[0171] <Manufacturing of optical components> Based on the discharge data shown in Figure 11A, droplets were discharged onto all pixels in one scan. The discharged droplets were heated and cured on stage 70 to form an optically functional film. This resulted in an optical element having an optically functional film on a glass substrate. Figure 11B shows a schematic top view (a) of the obtained optical element, and a schematic side view (b) of the obtained optical element.

[0172] Example 2 FIG. 12A is a schematic diagram showing the ejection data in Example 2. Based on the ejection data shown in FIG. 12A, droplets were ejected onto all pixels in a total of two scans. In the first scan, high-refractive-index liquid composition A was ejected from head 42 as high-refractive-index liquid composition 22, and in the second scan, low-refractive-index liquid composition A was ejected from head 41 as low-refractive-index liquid composition 21. Except for this, an optically functional film and an optical element having an optically functional film on a glass substrate were obtained in the same manner as in Example 1. FIG. 12B is a schematic top view (a) of the obtained optical element (upper row: first scan, lower row: second scan) and a schematic side view (b) of the obtained optical element (upper row: first scan, lower row: second scan).

[0173] Example 3 As shown in Figure 13, droplets were ejected onto all pixels in one scan. Specifically, the droplets were ejected so as to achieve a distribution in which the density of droplets made of high-refractive-index liquid composition A (high-refractive-index liquid composition 22) increased in one direction, and the density of droplets made of low-refractive-index liquid composition A (low-refractive-index liquid composition 21) increased in the opposite direction. Except for this, an optically functional film and an optical element having an optically functional film on a glass substrate were obtained in the same manner as in Example 1. Note that Figure 13 is a schematic top view of the optical element obtained in Example 3.

[0174] Example 4 As shown in Figure 14, droplets were ejected onto all pixels in one scan. Specifically, droplets were ejected so as to form a distribution including a region formed solely of high-refractive-index liquid composition A at the end in the direction in which the density of high-refractive-index liquid composition A serving as high-refractive-index liquid composition 22 increases, and a region formed solely of low-refractive-index liquid composition A at the end in the direction in which the density of low-refractive-index liquid composition A serving as low-refractive-index liquid composition 21 increases. Except for this, an optically functional film and an optical element having an optically functional film on a glass substrate were obtained in the same manner as in Example 1. Figure 14 is a schematic top view of the optical element obtained in Example 4.

[0175] Example 5 <Preparation of Low Refractive Index Liquid Composition B> The following materials were stirred at 60° C. for 2 hours, and then stirred at 25° C. for 8 hours. Thereafter, the mixture was filtered through a 2 μm filter to prepare a low refractive index liquid composition B. ·Hollow silica particles (particle size: 80nm, manufactured by Sekisui Plastics Co., Ltd.): 0.2g PMMA (polymethyl methacrylate, Sigma-Aldrich): 2.0 g PGME (propylene glycol monomethyl ether, manufactured by Kanto Chemical Co., Ltd.): 97.8g

[0176] An optically functional film and an optical element having an optically functional film on a glass substrate were obtained in the same manner as in Example 4, except that low-refractive-index liquid composition A as low-refractive-index liquid composition 21 was replaced with low-refractive-index liquid composition B as low-refractive-index liquid composition 23 containing hollow silica particles as particles 211. Fig. 15 is a schematic top view of the optical element obtained in Example 5.

[0177] Example 6 16, the optical function film obtained in Example 4 was used as the first optical function film 31 of the first layer, and the second optical function film 32 of the second layer was produced on the first optical function film 31 of the first layer using the same discharge data as used in Example 4 in the same manner as in Example 4. Similarly, the third optical function film 33 of the third layer was produced on the second optical function film 32 of the second layer using the same discharge data as used in Example 4 in the same manner as in Example 4. FIG. 16 is a schematic perspective view (a) of the optical member obtained in Example 6, and a schematic top view (b) showing the printing patterns for forming each layer.

[0178] Example 7 As shown in FIG. 17 , the optical function film obtained in Example 4 was used as the first optical function film 31, and a second optical function film 32 was produced on the first optical function film 31 by the same method as in Example 4, using different discharge data from that used in Example 4. The different discharge data was set to alternately discharge high-refractive index liquid composition A and low-refractive index liquid composition A. Next, a third optical function film 33 was produced on the second optical function film 32 by the same method as in Example 4, using data that was a horizontal inversion of the discharge data used for the first layer. The resulting three-layer optical function film had a refractive index distribution in the direction intersecting the thickness direction of the substrate, due to the presence ratio of high-refractive index liquid composition A or low-refractive index liquid composition A varying in the same direction. FIG. 17 is a schematic perspective view (a) of the optical member obtained in Example 7, and a schematic top view (b) showing the printing patterns for forming each layer.

[0179] Example 8 18, an optical element was manufactured in the same manner as in Example 1, except that droplets of the high-refractive-index liquid composition A serving as the high-refractive-index liquid composition 22 and droplets of the low-refractive-index liquid composition A serving as the low-refractive-index liquid composition 21 were discharged so as to be adjacent to each other alternately. Here, "alternately adjacent" refers to a state in which, for example, the low-refractive-index liquid composition A is disposed adjacent to the discharged high-refractive-index liquid composition A in the thickness direction of the substrate, and the low-refractive-index liquid composition A is disposed adjacent to the discharged high-refractive-index liquid composition A in a direction intersecting the thickness direction of the substrate. FIG. 18 is a schematic top view showing the ejection data and ejection state for one scan.

[0180] Example 9 An optically functional film and an optical member having an optically functional film on a glass substrate were manufactured in the same manner as in Example 1, except that the discharge data was changed to the following discharge data.

[0181] -Discharge data- Droplets were ejected from each head based on the ejection data shown in Fig. 19. Specifically, the droplets ejected from head 42 were set to be large droplets, with the two-dimensional numerical data set to "1." Additionally, the droplets ejected from head 41 were set to be small droplets, with the two-dimensional numerical data set to "0.5." FIG. 19 is a schematic top view showing the ejection data and ejection state for one scan.

[0182] Example 10 Using the same technique as in Example 1, droplets of high-refractive-index liquid composition A were ejected from head 42 as high-refractive-index liquid composition 22 in one scan. After the ejected droplets of high-refractive-index liquid composition A were brought to a 50% cured state, droplets of low-refractive-index liquid composition A were ejected from head 41 as low-refractive-index liquid composition 21 in the second scan (see FIG. 3B ). Otherwise, an optically functional film and an optical element having an optically functional film on a glass substrate were manufactured in the same manner as in Example 1. The resulting optically functional film exhibited a more gradual change in refractive index due to the controlled degree of curing of adjacent droplets.

[0183] Example 11 Using the same method as in Example 1, droplets of high-refractive-index liquid composition A serving as high-refractive-index liquid composition 22 were ejected from head 42 onto all pixels. The ejected droplets of high-refractive-index liquid composition A were brought to a 50% cured state to form a first layer, and then droplets of low-refractive-index liquid composition A serving as low-refractive-index liquid composition 21 were ejected from head 41 to form a second layer (see FIG. 4B). Except for this, an optically functional film and an optical element were manufactured in the same manner as in Example 1. The obtained optically functional film exhibited a more gradual change in refractive index because the degree of curing of adjacent droplets was controlled.

[0184] (Comparative Example 1) An optical functional film and an optical element having an optical functional film on a glass substrate were manufactured in the same manner as in Example 1, except that the discharge data was changed to the following discharge data and the manufacturing of the optical element was changed as follows:

[0185] -Discharge data- Droplets were ejected from each head based on the ejection data shown in Fig. 20. Specifically, the droplets ejected from head 42 were defined as "127" in two-dimensional numerical data. Also, the droplets ejected from head 41 were defined as "127" in two-dimensional numerical data.

[0186] Fig. 20 is a schematic top view showing the ejection data and ejection state for one scan. Note that in Fig. 20, the droplets ejected from head 42 are shown as larger droplets than the droplets ejected from head 41, but this is merely for the sake of convenience in illustrating the overlap of these droplets, and in reality, the droplets ejected from head 41 and the droplets ejected from head 42 are droplets of the same size based on two-dimensional numerical data.

[0187] <Method of manufacturing optical members> Using the same technique as in Example 1, droplets of high-refractive-index liquid composition A serving as high-refractive-index liquid composition 22 were ejected from head 42 in one scan. Before the ejected droplets of high-refractive-index liquid composition A hardened, droplets of low-refractive-index liquid composition A serving as low-refractive-index liquid composition 21 were ejected from head 41 in the second scan so as to overlap with the high-refractive-index liquid composition A ( FIG. 20 ). Further, time was then allowed for the two liquid compositions to mix. Except for this, an optically functional film and an optical element having an optically functional film on a glass substrate were manufactured in the same manner as in Example 1. In Comparative Example 1, ejecting droplets of low-refractive-index liquid composition A so as to overlap with the high-refractive-index liquid composition A means that at least one of the droplet volume and ejection volume of low-refractive-index liquid composition A was made smaller than that of high-refractive-index liquid composition A. This method was found to have lower productivity than the methods shown in the examples.

[0188] The optical members obtained in Examples 1 to 11 were evaluated by the following methods.

[0189] <Evaluation of refractive index of optical components> The refractive index of the obtained optical component was evaluated using a spectroscopic ellipsometer M-2000 (manufactured by JA Woollam Japan). Scotch tape was attached to the back surface of the substrate to suppress back reflection. The measurement conditions were a D2 lamp and a QTH lamp as light sources, a wavelength range of 190 nm to 1680 nm, an integration time of 10 s, and incident angles of 50°, 60°, 70°, and 80°, and the refractive index distribution of the film thickness and refractive index was calculated. When measurements were taken at three random points, the error from the target refractive index was within 0.05, and it was found that all of them could be used as an anti-reflection film.

[0190] The present invention includes, for example, the following aspects. <1> a print pattern forming step of ejecting droplets of at least two liquid compositions having different refractive indices onto a substrate to form a print pattern in a direction intersecting the thickness direction of the substrate; an optical function film forming step of curing the printed pattern to form an optical function film, The printing pattern formation process is a method for manufacturing an optical element, characterized in that the liquid composition is ejected so that droplets of one of the liquid compositions are adjacent to droplets of another liquid composition having a refractive index different from that of the one liquid composition in the surface direction of the optical functional film. <2> The liquid composition includes a resin or a resin and particles. <1> 1. A method for producing the optical member according to claim 1. <3> The print pattern forming step comprises discharging the at least two liquid compositions having different refractive indices so that the refractive index changes in at least one direction intersecting with the thickness direction of the substrate. <1> or the above <2> 1. A method for producing the optical member according to claim 1. <4> The liquid composition having the lowest refractive index among the at least two liquid compositions having different refractive indices contains a resin and particles having a refractive index lower than that of the resin. <1> From the above <3> 10. The method for producing an optical member according to claim 9, wherein the optical member is a <5> a laminate forming step of repeating the print pattern forming step and the optical function film forming step to form a laminate of the optical function films laminated in the thickness direction of the base, <1> From the above <4> 10. A method for producing an optical member according to any one of the above items. <6> The laminate forming step forms the laminate so that the refractive index of the optical function film of one layer and the refractive index of the optical function film of another layer arranged in the stacking direction of the optical function film of the one layer change in at least a partial region in a direction intersecting the stacking direction of the laminate. <5> 1. A method for producing the optical member according to claim 1. <7> the print pattern forming step includes alternately discharging droplets of one of the liquid compositions and droplets of another of the liquid compositions having a refractive index different from that of the one of the liquid compositions; <1> From the above <6> 10. A method for producing an optical member according to any one of the above items. <8> the step of curing the liquid composition to a desired degree after the step of forming a print pattern and before the step of forming an optically functional film, <1> From the above <4> 10. A method for producing an optical member according to any one of the above items. <9> the print pattern forming step comprises discharging the at least two liquid compositions having different refractive indices while changing the discharge amounts of each of the liquid compositions; <1> From the above <4> 10. A method for producing an optical member according to any one of the above items. <10> a substrate; an optically functional film disposed on the substrate, The optical function film is an optical member characterized by having regions with different refractive indices in the surface direction of the optical function film. <11> The optically functional film includes a resin or a resin and particles. <10> 1. The optical member according to claim 1. <12> the optical function film is a laminate in which two or more layers of the optical function film are laminated in the thickness direction of the base, In at least a part of the region in the direction intersecting the stacking direction of the laminate, the refractive index of the optical function film of one layer and the refractive index of the optical function film of another layer arranged in the stacking direction of the optical function of the one layer change. <10> or the above <11> 1. The optical member according to claim 1.

[0191] The aforementioned <1> From the above <9> A method for manufacturing an optical member and <10> from <12> According to the optical member described in any one of the above, the various problems in the prior art can be solved and the object of the present invention can be achieved. [Explanation of symbols]

[0192] 1 Base 21 Low refractive index liquid composition 21a Cured product 22 High refractive index liquid composition 22a Cured product 22b Semi-cured product 23 Low refractive index liquid composition 24 Interface 30 Optical functional film 31 First Optical Functional Film 32 Second optical functional film 33 Third Optical Functional Film 41 Inkjet head 42 Inkjet head 51 Ink Tank 52 Ink Tank 60 tubes 70 stages 100 Optical Components 101 Optical components 102 Optical components 211 Low refractive index particles X1 center X2 center [Prior art documents] [Patent documents]

[0193] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-181290

Claims

1. a print pattern forming step of ejecting at least two liquid compositions having different refractive indices onto a substrate to form a print pattern in a direction intersecting the thickness direction of the substrate; an optical function film forming step of curing the printed pattern to form an optical function film, The method for manufacturing an optical element is characterized in that the printing pattern formation step comprises ejecting the liquid compositions so that one liquid composition and another liquid composition having a refractive index different from that of the one liquid composition are adjacent to each other in a direction intersecting the thickness direction of the substrate.

2. The method for producing an optical member according to claim 1 , wherein the liquid composition contains a resin or a resin and particles.

3. 2. The method for producing an optical member according to claim 1, wherein the print pattern forming step ejects the at least two liquid compositions having different refractive indices so that the refractive index changes in at least one direction intersecting with the thickness direction of the substrate.

4. The method for manufacturing an optical member according to claim 1 , wherein the liquid composition having the lowest refractive index among the at least two liquid compositions having different refractive indices contains a resin and particles having a refractive index lower than that of the resin.

5. 5. The method for manufacturing an optical member according to claim 1, further comprising a laminate formation step of repeating the printing pattern formation step and the optical function film formation step to form a laminate of the optical function films stacked in the thickness direction of the base.

6. 6. The method for manufacturing an optical element according to claim 5, wherein the laminate formation process forms the laminate so that the refractive index of the optical functional film of one layer and the refractive index of the optical functional film of another layer arranged in the stacking direction of the optical functional film of the one layer change in at least a portion of the region in a direction intersecting the stacking direction of the laminate.

7. The method for manufacturing an optical member according to claim 1 , wherein the print pattern forming step alternately ejects one of the liquid compositions and another of the liquid compositions having a refractive index different from that of the one of the liquid compositions.

8. The method for producing an optical member according to claim 1 , further comprising a step of curing the liquid composition to a desired degree after the print pattern forming step and before the optically functional film forming step.

9. The method for manufacturing an optical member according to claim 1 , wherein the print pattern forming step comprises discharging the at least two liquid compositions having different refractive indices while changing the discharge amounts of each of the liquid compositions.

10. a substrate; an optically functional film disposed on the substrate, The optical member is characterized in that the optical function film has regions with different refractive indices in a surface direction of the optical function film.

11. The optical member according to claim 10 , wherein the optical functional film contains a resin or a resin and particles.

12. the optical function film is a laminate in which two or more layers of the optical function film are laminated in the thickness direction of the base, The optical element according to claim 10, wherein the refractive index of the optical functional film of one layer and the refractive index of the optical functional film of another layer arranged in the stacking direction of the optical functional film of the one layer change in at least a portion of the region in a direction intersecting the stacking direction of the laminate.

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