JP6564714B2 - Optical retardation member, composite optical member including optical retardation member, and method of manufacturing optical retardation member - Google Patents

Description

  The present invention relates to an optical phase difference member, a composite optical member including the optical phase difference member, and a method for manufacturing the optical phase difference member.

  Optical phase difference plates have a great variety of applications, such as reflective liquid crystal display devices, transflective liquid crystal display devices, optical disk pickups, PS conversion elements, projectors (projection display devices), and various other applications. Is used.

  The optical phase difference plate should be provided with a natural birefringent crystal such as calcite, mica and quartz, a birefringent polymer, and a periodical structure artificially shorter than the wavelength used. And so on.

  As an optical phase difference plate formed by artificially providing a periodic structure, there is one in which an uneven structure is provided on a transparent substrate. The concavo-convex structure used for the optical retardation plate has a period shorter than the wavelength used, and has, for example, a stripe pattern as shown in FIG. Such a concavo-convex structure has refractive index anisotropy, and when light enters perpendicularly to the substrate 420 of the optical phase difference plate 400 in FIG. Since the component and the polarization component perpendicular to the periodic direction of the concavo-convex structure propagate at different speeds, a phase difference occurs between both polarization components. This phase difference can be controlled by adjusting the height (depth) of the concavo-convex structure, the refractive index difference between the material constituting the convex portion and the material (air) between the convex portions, and the like. The optical retardation plate used for the display device or the like needs to generate a phase difference of λ / 4 or λ / 2 with respect to the wavelength λ to be used. However, such a sufficient phase difference should be generated. In order to form an optical retardation plate that can be used, the difference between the refractive index of the material constituting the convex part and the refractive index of the material (air) between the convex parts and the height (depth) of the concave-convex structure are sufficiently large. There is a need to. As such an optical phase difference plate, Patent Documents 1 and 2 propose that the surface of the concavo-convex structure is coated with a high refractive index material.

Japanese Patent Publication No. 7-99402 Japanese Patent Laying-Open No. 2005-10377

  As a result of intensive studies by the present inventors, it has been found that the optical retardation plate as described above has the following drawbacks. When used in a device such as the above display device, the optical retardation plate is used by being attached to another member. For example, when an optical retardation plate is used in an organic EL display device, it is necessary to attach (bond) a polarizing plate to one surface of the optical retardation plate and attach an organic EL panel to the other surface. Usually, an adhesive is used to attach the optical retardation plate to another member. However, as illustrated in FIG. 10A, when the optical retardation plate 400 is attached to another member 320 using an adhesive, the adhesive 340 is interposed between the convex portions of the concavo-convex structure of the optical retardation plate 400. Get in. Since the adhesive has a higher refractive index than air, the difference between the refractive index of the material constituting the convex portion and the refractive index of the adhesive that has entered between the convex portions is the difference between the refractive index of the material constituting the convex portion and the air. Smaller than the difference in refractive index. Therefore, the optical phase difference plate 400 in which the adhesive enters between the convex portions is sufficient because the refractive index difference between the material constituting the convex portions and the material between the convex portions is small and the refractive index anisotropy is small. A phase difference cannot be generated.

  In addition, in order for the optical retardation plate to produce a desired retardation, the uneven structure of the optical retardation plate needs to have a sufficient uneven height (depth) while having a periodic structure shorter than the wavelength used. is there. That is, the concavo-convex structure needs to have a high aspect ratio. However, when a load is applied to such an optical retardation plate, the uneven structure of the optical retardation plate 400 is deformed, for example, as shown in FIG. May not occur.

  Furthermore, the optical phase difference plate is required to generate a phase difference corresponding to its application. The phase difference generated by the optical phase difference plate can be usually adjusted by the shape of the concavo-convex structure such as the aspect ratio of the convex portion of the optical phase difference plate. When forming the concavo-convex structure of the optical phase difference plate by the nanoimprint method, in order to adjust the shape of the concavo-convex structure, it is necessary to prepare a master having a concavo-convex structure corresponding to the shape of the concavo-convex structure of the optical phase difference plate. . However, the original mold is expensive and requires a long time. Therefore, for each application of the optical phase difference plate, it is not desirable from the economical viewpoint and the temporal viewpoint to produce a master having a concavo-convex structure corresponding thereto.

  Therefore, the object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and can produce a desired phase difference even when bonded to another member or applying a load using an adhesive. An object of the present invention is to provide an optical phase difference member that can be manufactured at a low cost and in a short time, and a manufacturing method thereof.

According to the first aspect of the present invention, a transparent substrate having a concavo-convex pattern;
A phase difference adjusting layer formed on the surface of the concave and convex portions of the concave-convex pattern;
A coating layer for coating the retardation adjustment layer;
A gap section defined between the projections of the concavo-convex pattern in which the retardation adjustment layer and the coating layer are formed;
A sealing layer provided on the top of the concavo-convex pattern so as to connect the tops of the convex portions of the concavo-convex pattern and seal the gap portion;
An optical retardation member, wherein the refractive index n _{1 of} the convex portion, the refractive index n ₂ of the retardation adjusting layer, and the refractive index n _{3 of the} covering layer satisfy n ₁ <n ₂ <n _3. Provided.

In the optical phase difference member, the refractive index n _{1 of} the convex portion, the refractive index n ₂ of the retardation adjustment layer, and the refractive index n _{3 of the} coating layer are 0.8√ (n ₁ · n ₃ ) ≦ n ₂ ≦ 1.05√ (n ₁ · n ₃ ) may be satisfied.

  In the optical retardation member, the thickness of the retardation adjustment layer may be in a range of 10 to 200 nm.

  In the optical phase difference member, a cross section of the convex portion of the concave / convex pattern may be substantially trapezoidal.

  The said optical phase difference member WHEREIN: The said gap | interval part may have height more than the height of the said convex part of the said uneven | corrugated pattern.

In the optical retardation member, the retardation adjustment layer may be made of ZnO, BaO, MgO, TiO ₂ , Nb ₂ O ₅ , or a mixture thereof.

  In the optical retardation member, the coating layer and the sealing layer may be made of metal, metal oxide, metal nitride, metal sulfide, metal oxynitride, or metal halide.

  In the optical phase difference member, the material constituting the concavo-convex pattern may be a photocurable resin or a thermosetting resin. Or the material which comprises the said uneven | corrugated pattern may be a sol-gel material.

  In the optical phase difference member, air may exist in the gap portion.

According to the second aspect of the present invention, the optical retardation member of the first aspect;
There is provided a composite optical member comprising a surface of the transparent substrate opposite to the surface on which the concave / convex pattern is formed or a polarizing plate attached to the sealing layer.

According to the third aspect of the present invention, the composite optical member of the second aspect;
A display device is provided, comprising: a display element attached to a surface opposite to the surface on which the concave / convex pattern of the transparent substrate is formed or the sealing layer.

According to the fourth aspect of the present invention, a step of preparing a transparent substrate having a concavo-convex pattern;
Forming a phase difference adjusting layer that covers the surface of the concave and convex portions of the concave and convex pattern; and
Forming a coating layer for coating the retardation adjustment layer;
A sealing layer is formed on the concavo-convex pattern so that adjacent convex portions of the concavo-convex pattern on which the phase difference adjusting layer and the coating layer are formed are connected and a gap section between the convex portions is sealed. And a process of
The refractive index n _{1 of} the convex portion, the refractive index n ₂ of the retardation adjusting layer, and the refractive index n _{3 of the} covering layer satisfy n ₁ <n ₂ <n ₃ . A manufacturing method is provided.

  In the phase difference adjusting layer forming step, the coating layer forming step, and the sealing layer forming step of the method for producing the optical phase difference member, the phase difference adjusting layer, the coating layer, and the sealing layer are formed by sputtering, CVD, or vapor deposition. It may be formed.

  In the optical phase difference member of the present invention, the gap portion existing between adjacent convex portions of the concavo-convex pattern (concavo-convex structure) of the substrate is sealed by the sealing layer and the concavo-convex pattern. In this case, the refractive index anisotropy of the optical phase difference member is impaired by reducing the refractive index difference between the material forming the convex portion and the material between the convex portion due to the adhesive entering between the convex portions of the concave and convex pattern. There is nothing. Therefore, the optical retardation member of the present invention can exhibit excellent retardation characteristics even when incorporated in a device. In addition, since the sealing layer is formed on the convex and concave portions of the concave and convex pattern so as to connect (bridge) adjacent convex portions, the convex and concave portions of the concave and convex pattern are not easily deformed even when a load is applied. This prevents the desired phase difference from being obtained. In addition, since the optical retardation member of the present invention can adjust the phase difference depending on the thickness of the retardation adjustment layer, etc., an optical retardation member that produces a different phase difference from the original mold of one kind of uneven pattern is manufactured. can do. Therefore, an optical phase difference member that generates various phase differences can be manufactured at a low cost and in a short time. Therefore, the optical retardation member of the present invention can be suitably used for various applications such as a display device.

Drawing 1 (a)-(c) is a schematic diagram showing the example of the section structure of the optical phase contrast member of an embodiment. It is the schematic of the manufacturing apparatus used for the manufacturing method of the optical phase difference member of embodiment. It is a flowchart which shows the manufacturing method of the optical phase difference member of embodiment. It is a schematic sectional drawing of a display apparatus provided with the optical phase difference member of an embodiment. FIG. 5 shows a graph in which the phase difference obtained by simulation in Example 1 is plotted against the film thickness of the medium refractive index material. FIG. 6 is a graph in which the amount of change in phase difference due to the phase difference adjusting layer obtained by simulation in Example 2 is plotted against the refractive index of the medium refractive index material. FIG. 7 shows the optimum values of the refractive index of the medium refractive index material obtained by simulation in Examples 2 to 5, and the refractive index of the medium refractive index material because the phase difference adjusting layer has a sufficient phase difference adjusting function. It is a table | surface which shows a minimum and an upper limit. FIG. 8 shows a graph in which the phase difference obtained by simulation in the comparative example is plotted against the film thickness of the high refractive index material. It is a figure which shows notionally an example of the optical phase difference member of a prior art. Fig.10 (a) is a schematic sectional drawing of the optical phase difference member of the prior art affixed on the other member with the adhesive. FIG.10 (b) is a schematic sectional drawing of the optical phase difference member of the prior art which applied the load.

  Hereinafter, embodiments of an optical phase difference member, a method for producing the optical phase difference member, and a composite optical member including the optical phase difference member of the present invention will be described with reference to the drawings.

[Optical phase difference member]
As shown in FIG. 1A, the optical phase difference member 100 according to the embodiment includes a transparent substrate 40 having a concavo-convex pattern 80, and a gap portion 90 defined between adjacent convex portions 60 of the concavo-convex pattern 80, The sealing layer 20 provided above the convex part 60 and the gap | interval part 90 (above an uneven | corrugated pattern) is provided so that the adjacent convex part 60 may be connected and the convex part 60 and the gap | interval part 90 may be covered. The gap portion 90 is surrounded and sealed by the uneven pattern 80 and the sealing layer 20. The retardation adjustment layer 35 is formed on the concave and convex surfaces of the concave-convex pattern 80 of the transparent substrate 40, and the retardation adjustment layer 35 is covered with the coating layer 30.

<Transparent substrate>
In the optical phase difference member 100 of the embodiment shown in FIG. 1A, the transparent substrate 40 is composed of a flat substrate 42 and an uneven structure layer 50 formed on the substrate 42.

  The substrate 42 is not particularly limited, and a known substrate that transmits visible light can be appropriately used. For example, a substrate made of a transparent inorganic material such as glass; polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyarylate, etc.), acrylic resin (polymethyl methacrylate, etc.), polycarbonate, polyvinyl chloride, styrene resin (ABS resin or the like), cellulose resin (triacetyl cellulose or the like), polyimide resin (polyimide resin, polyimide amide resin or the like), a substrate made of a resin such as cycloolefin polymer, or the like can be used. Further, it is desirable that the front phase difference of the base material 42 be as small as possible. When the optical phase difference member 100 is used for an antireflection film of an organic EL display, the base material 42 may be a flexible base material. In this respect, the base material 42 may be a base material made of resin. A surface treatment or an easy adhesion layer may be provided on the base material 42 in order to improve the adhesion. Further, a smoothing layer may be provided in order to fill the protrusions on the surface of the substrate 42. The thickness of the base material 42 may be in the range of 1 μm to 20 mm.

The concavo-convex structure layer 50 has a plurality of convex portions 60 and concave portions, and thereby the surface of the concavo-convex structure layer 50 defines the concavo-convex pattern 80. The concavo-convex structure layer 50 may be made of a material having a refractive index in the range of 1.1 to 2.0, preferably in the range of 1.3 to 1.8. Examples of the material constituting the concavo-convex structure layer 50 include Si-based materials such as silica, SiN, and SiON, Ti-based materials such as TiO ₂ , ITO (indium tin oxide) -based materials, ZnO, ZnS, Inorganic materials such as ZrO ₂ , Al ₂ O ₃ , BaTiO ₃ , Cu ₂ O, MgS, AgBr, CuBr, BaO, Nb ₂ O ₅ , and SrTiO ₂ can be used. These inorganic materials may be materials (sol-gel materials) formed by a sol-gel method or the like. In addition to the above inorganic materials, polyethylene, polypropylene, polyvinyl alcohol, polyvinylidene chloride, polyethylene terephthalate, polyvinyl chloride, polystyrene, AS resin, acrylic resin, polyamide, polyacetal, polybutylene terephthalate, glass reinforced polyethylene terephthalate, polycarbonate, modified polyphenylene ether , Polyphenylene sulfide, polyether ether ketone, fluororesin, polyarate, polysulfone, polyethersulfone, polyamideimide, polyetherimide, thermoplastic polyimide, etc .; phenol resin, melamine resin, urea resin, epoxy resin, unsaturated Thermosetting resins such as polyester resin, alkyd resin, silicone resin, diallyl phthalate resin; UV curable type UV curable resins such as (meth) acrylate resins, UV curable acrylic urethane resins, UV curable polyester acrylate resins, UV curable epoxy acrylate resins, UV curable polyol acrylate resins, UV curable epoxy resins; Resin materials such as materials blended in two or more types can also be used. Furthermore, a material obtained by compositing the inorganic material with the resin material may be used. Further, both the inorganic material and the resin material may contain known fine particles and fillers in order to obtain hard coat properties and the like. Further, a material obtained by adding an ultraviolet absorbing material to the above material may be used. The ultraviolet absorbing material has an action of suppressing deterioration of the concavo-convex structure layer 50 by absorbing ultraviolet rays and converting light energy into a harmless form such as heat. As the ultraviolet absorber, conventionally known ones can be used. For example, a benzotriazole-based absorbent, a triazine-based absorbent, a salicylic acid derivative-based absorbent, a benzophenone-based absorbent, or the like can be used.

  Each convex part 60 of the concavo-convex structure layer 50 extends in the Y direction (depth direction) of FIG. 1A, and the plurality of convex parts 60 generate a phase difference by the design wavelength (the optical phase difference member 100). Are arranged with a shorter period than the wavelength of the light to be generated. The cross section in the ZX plane orthogonal to the extending direction of each convex part 60 may be substantially trapezoidal. In the present application, the “substantially trapezoidal shape” means a pair of opposite sides that are substantially parallel to the surface of the base material 42, and the side (lower base) close to the surface of the base material 42 is the other side (upper base). ) And an angle formed by the lower base and the two hypotenuses is an acute rectangle. Each side of the substantially rectangular shape may be curved. That is, each convex portion 60 has a width (a length in a direction perpendicular to the extending direction of the convex portion 60), that is, a length in a direction perpendicular to the extending direction of the convex portion 60, that is, FIG. The length in the X direction) is only required to be small. Each vertex may be rounded. Further, the length of the upper base may be zero. That is, in the present application, “substantially trapezoidal shape” is a concept including “substantially triangular shape”. When the cross section of the convex portion 60 has a substantially triangular shape with the length of the upper base being zero, the height of the convex portion 60 necessary for generating a desired phase difference exceeds the length of the upper base. Since it is smaller than the case, there is an advantage that it is easy to form an uneven pattern. Note that the length of the upper base of the cross section of the convex portion 60 may exceed zero. A convex portion having a substantially trapezoidal cross section with an upper base larger than 0 has the following advantages over a convex portion having a substantially triangular cross section. That is, it is necessary for the formation of the mold used for forming the convex portion by the imprint method, the mechanical strength such as the surface pressing resistance of the convex portion is high, and the formation of the sealing layer 20 described later. The film formation time is short. The cross-sectional shape of the convex portion 60 may be various shapes such as a rectangular shape and a polygonal shape in addition to a substantially trapezoidal shape. As will be described later, from the viewpoint of easy formation of the sealing layer 20, the top portion 60 t of the convex portion 60 may be flat, that is, a flat shape parallel to the surface of the base material 42. The concave portion 70 is partitioned by the convex portion 60 and extends in the Y direction (depth direction) along the convex portion 60.

  The height (convex height) Hc of the convex portion 60 is desirably in the range of 100 to 2000 nm. When the height Hc of the convex portion 60 is less than 100 nm, it becomes difficult to generate a desired phase difference when visible light is incident on the optical phase difference substrate 100. When the height Hc of the convex portion 60 exceeds 2000 nm, it is difficult to form the concave / convex pattern because the aspect ratio of the convex portion 60 (ratio of the convex portion height to the convex portion width) is large. The width W of the convex portion 60 may be in the range of 10 to 500 nm. When the width W of the convex portion 60 is less than 10 nm, it is difficult to form the concave / convex pattern because the aspect ratio of the convex portion 60 (the ratio of the convex portion height to the convex portion width) is large. When the width W of the convex portion 60 exceeds 500 nm, the transmitted light is colored, and it is difficult to ensure sufficient colorless transparency as an optical phase difference member, and it is difficult to generate a desired phase difference. . Furthermore, since the space | interval of the upper part of the adjacent convex part 60 becomes wide, it becomes difficult to form the sealing layer 20 with high intensity | strength. In addition, the width W of the convex part 60 here means the value which averaged the width | variety of the convex part 60 in each Z direction position (height direction position). The uneven pitch of the uneven pattern 80 may be in the range of 100 to 1000 nm. When the pitch is less than 100 nm, it becomes difficult to generate a desired phase difference when visible light is incident on the optical phase difference substrate 100. When the pitch exceeds 1000 nm, it becomes difficult to ensure sufficient colorless transparency as an optical retardation member. Moreover, since the space | interval of the upper part of the adjacent convex part 60 becomes wide, it becomes difficult to form the sealing layer 20 with high intensity | strength.

<Phase difference adjusting layer>
The phase difference adjusting layer 35 covers the transparent substrate 40 along the uneven pattern 80. That is, the phase difference adjusting layer 35 covers the surfaces of the convex portions 60 and the concave portions 70 of the concave / convex pattern 80. The thickness Tp of the phase difference adjusting layer 35 may be in the range of 10 to 200 nm. The thickness Tp of the phase difference adjusting layer 35 is set so that the phase difference generated by the optical phase difference member 100 becomes a desired value. When the thickness Tp of the phase difference adjusting layer 35 is less than 10 nm or exceeds 200 nm, the effect of adjusting the phase difference generated by the optical phase difference member 100 becomes small, as shown in examples described later. In the present application, the “thickness Tp of the phase difference adjusting layer 35” is a direction perpendicular to the surface of the base material 42 of the phase difference adjusting layer 35 at the top of the convex portion 60 (that is, the Z direction in FIG. 1A). Means the thickness. The thickness of the phase difference adjusting layer formed on the side surface of the convex portion 60 (particularly at a height of Hc / 2 from the bottom surface of the convex portion 60) depends on the shape of the convex portion 60, the film formation method, and the like. It is about 0.05 Tp to 0.2 Tp.

The phase difference adjusting layer 35 is larger than the refractive index _{n 1} of the protrusion 60, having a refractive index _{n 3} smaller than the refractive index _{n 2} of the cover layer 30. That is, n ₁ <n ₂ <n ₃ is satisfied. If n ₂ ≦ n ₁ or n ₂ ≧ n ₃ , the effect of adjusting the phase difference generated by the optical phase difference member 100 cannot be obtained. Further, the refractive index n ₂ of the phase difference adjusting layer 35 may satisfy 0.8√ (n ₁ · n ₃ ) ≦ n ₂ ≦ 1.05√ (n ₁ · n ₃ ), and 0.82√ ( n ₁ · n ₃ ) ≦ n ₂ ≦ 1.01√ (n ₁ · n ₃ ) may be satisfied. As a material constituting the phase difference adjusting layer 35, for example, an oxide of Ti, Nb, Zn, Ba or Mg, or a mixture thereof can be used.

<Coating layer>
The covering layer 30 covers the retardation adjustment layer 35 along the uneven pattern 80. That is, the phase difference adjusting layer 35 is sandwiched between the covering layer 30 and the protrusions 60 and the recesses 70 of the uneven pattern 80. The thickness of the covering layer 30 is set to a thickness at which the sealing layer 20 covering the convex portion 60 and the gap portion 90 described later can be formed. In this case, the covering layer 30 is formed on the convex portion 60 adjacent to the gap portion 90 described later. It has a thickness that can be formed between them. If the coating layer 30 is too thick and the gap 90 is not formed between the coating layer 30 and the sealing layer 20, the refractive index difference between the coating layer 30 and the air or the like existing in the gap 90 cannot be used. It becomes difficult for the phase difference member 100 to produce a desired phase difference. The thickness Tc of the coating layer 30 may be 10 nm or more. In the present application, the “thickness Tc of the covering layer 30” means that the height of the convex portion 60 is Hc, and the phase difference adjusting layer 35 is covered at a position Hc / 2 from the bottom surface of the convex portion 60. It means the thickness of the covering layer 30 formed on the side surface of the convex portion 60.

  The covering layer 30 may be made of a material having a refractive index in the range of 1.8 to 2.6. By coating the phase difference adjusting layer 35 and the convex portion 60 with the coating layer 30 having a refractive index of 1.8 or more, the phase difference caused by the periodic arrangement of the convex portion 60 and the gap portion 90 described later is increased. Therefore, the height of the convex portion 60 can be reduced, that is, the aspect ratio of the convex portion 60 can be reduced, and the concave / convex pattern 80 can be easily formed. Moreover, it is difficult to obtain a substance having a refractive index exceeding 2.6, or it is difficult to form a film at a temperature at which the base material 42 does not deform. Examples of the material constituting the coating layer 30 include metals such as Ti, In, Zr, Ta, Nb, and Zn, and inorganic materials such as oxides, nitrides, sulfides, oxynitrides, and halides of these metals. Can be used. A member containing these materials may be used as the covering layer 30.

<Gap>
The gap 90 is partitioned between the adjacent protrusions 60. The gap 90 is enclosed and sealed by the covering layer 30 and a sealing layer 20 described later. The gap portion 90 may be filled with air, or may be seen with an inert gas such as N ₂ , Ar, or He, or other low refractive index medium. Further, a vacuum may be used without a medium. The height Ha of the gap 90 is preferably equal to or higher than the height Hc of the protrusion 60. In the optical phase difference member 100, the gap 90 and the coating layer 30 are periodically arranged, so that a phase difference can be generated in the light transmitted through the optical phase difference member 100. When the height Ha is smaller than the height Hc of the convex portion 60, the height of the periodic arrangement structure of the gap portion 90 and the coating layer 30 is small, so that the phase difference generated by the optical phase difference substrate 100 is small.

<Sealing layer>
The sealing layer 20 is formed on the upper portions of the convex portion 60 and the gap portion 90 so as to cover them. The sealing layer 20 surrounds the gap 90 together with the coating layer 30 and seals it. Accordingly, when the optical phase difference member 100 of the present embodiment is joined to another member using an adhesive in order to incorporate it into the device, the adhesive enters between the adjacent convex portions 60 (gap portion 90). There is no. Therefore, it is prevented that the phase difference generated by the optical phase difference member 100 is reduced due to the adhesive entering between the convex portions. Therefore, even when the optical retardation member 100 of the embodiment is used while being joined to another member, the optical retardation member 100 can generate a desired retardation.

  Therefore, the sealing layer 20 is supported by the adjacent protrusions via the sealing layer 20 when a load is applied from the upper part (sealing layer 20 side) of the optical phase difference member 100. Moreover, since the applied force is disperse | distributed because each convex part is joined via the sealing layer 20, the load added to each convex part 60 becomes small. Therefore, even if a load is applied to the optical phase difference member 100 of the embodiment, the convex portion 60 of the concave / convex pattern 80 is not easily deformed. Therefore, it is possible to prevent a desired phase difference from being generated by applying a load to the optical phase difference member 100.

  The sealing layer 20 may be formed of the same material as the covering layer 30. When the sealing layer 20 and the covering layer 30 are formed of different materials, a layer made of a material constituting the sealing layer 20 is further formed on the covering layer 30 formed on the side surface of the protruding portion 60, so that the protruding portion In some cases, the phase difference caused by the periodic arrangement of 60 and the gap 90 may be reduced or the control of the phase difference may be difficult. The sealing layer 20 may be light transmissive, for example, the transmittance at a wavelength of 550 nm may be 90% or more. The thickness T of the sealing layer 20 may be in the range of 10 to 1000 nm. Here, the thickness T of the sealing layer 20 means the distance from the upper end of the gap 90 to the surface of the sealing layer 20 (see FIG. 1A). In addition, when joining another member to the contact | adherence layer 20 side of the optical phase difference member 100, the sealing layer 20 and another member are joined via an adhesive. That is, the adhesion layer 20 is different from the pressure-sensitive adhesive used for joining with other members.

  In general, an optical phase difference member can cause a phase difference in transmitted light by forming an interface between materials having a difference in refractive index substantially parallel to the traveling direction of the transmitted light. Unlike the optical phase difference member 100 of the present embodiment, the optical phase difference member that does not have a phase difference adjustment layer, that is, the coating layer directly covers the transparent substrate along the concavo-convex pattern is the traveling direction of transmitted light. The interface between the gap portion and the coating layer and the interface between the coating layer and the convex portion cause a phase difference in the transmitted light. Here, since it is necessary to form the coating layer under film forming conditions that form a sealing layer that connects (bridges) the tops of the convex portions, it is difficult to control the shape of these interfaces. For this reason, it is difficult to control the phase difference generated by the optical phase difference member in the transmitted light by the film forming conditions such as the coating layer. In order to change or adjust the phase difference, the uneven pattern of the transparent substrate 40 80 needs to be changed. In order to change the concavo-convex pattern 80, as will be described later, it is necessary to prepare a new master of the concavo-convex pattern 80. However, a high cost and a long time are required to newly manufacture the master.

On the other hand, optical retardation member 100 of the present embodiment, as described above, larger than the refractive index n ₁ of the convex portion 60, the phase difference adjusting layer having a refractive index n ₃ smaller than the refractive index n ₂ of the cover layer 30 35 Is provided between the covering layer 30 and the convex portion 60. Thereby, the effective refractive index difference of the interface between the coating layer 30 and the convex portion 60 can be reduced. For example, by changing the thickness of the phase difference adjusting layer 35, the coating layer 30 and the convex portion 60 It is possible to adjust the effective refractive index difference between the interfaces. Therefore, as shown in the examples described later, the phase difference generated by the optical phase difference member can be controlled by changing the thickness of the phase difference adjusting layer 35. According to the present embodiment, since the optical retardation member 100 that generates different phase differences can be obtained using the transparent substrate 40 having the same uneven pattern 80, the original pattern of the uneven pattern 80 can be obtained without newly forming the original pattern. The phase difference can be changed and adjusted. Therefore, the optical phase difference member 100 of this embodiment is advantageous in terms of manufacturing cost and manufacturing time.

  Further, even when the transparent substrate 40 having the uneven pattern 80 different from the design shape is formed due to variations in the original shape of the uneven pattern 80 and the formation process of the transparent substrate 40, the film thickness and the like of the retardation adjustment layer 35 are controlled. Thereby, the phase difference produced by the optical phase difference member 100 can be controlled, and the optical phase difference member 100 producing a desired phase difference can be manufactured.

  In addition, instead of the transparent substrate 40 in which the concavo-convex structure layer 50 is formed on the base material 42, a structure having a convex portion 60a on the base material 42a, such as an optical retardation member 100a shown in FIG. A transparent substrate 40a in which a plurality of layers are formed may be used. In the transparent substrate 40a, a concave portion (region where the surface of the base material 42a is exposed) 70a is defined between the convex portions 60a, and a concave / convex pattern 80a including the convex portions 60a and the concave portions 70a is formed. As the base material 42a, a base material similar to the base material 42 of the optical phase difference member 100 shown in FIG. The convex part 60a may be comprised with the material similar to the material which comprises the uneven | corrugated structure layer 50 of the optical phase difference member 100 shown to Fig.1 (a).

  Further, like the optical phase difference member 100b shown in FIG. 1 (c), the transparent substrate 40b is formed of a base material that is shaped so that the surface of the base material itself forms a concave / convex pattern 80b composed of convex portions 60b and concave portions 70b. May be configured. In this case, the transparent substrate 40b can be manufactured by molding the base material so as to have the uneven pattern 80b as shown in FIG.

  The optical retardation members 100, 100a, 100b are further bonded with a protective member such as a protective sheet on the surface opposite to the surface on which the concave / convex pattern 80 of the transparent bases 40, 40a, 40b is formed and / or the sealing layer. It may be. Thereby, it is possible to prevent the optical retardation members 100, 100a, 100b from being damaged such as scratches when the optical retardation members 100, 100a, 100b are transported, transported, or the like.

[Optical retardation member manufacturing apparatus]
As an example of an apparatus for manufacturing an optical retardation member, a roll process apparatus 200 is shown in FIG. Below, the structure of the roll process apparatus 200 is demonstrated.

  The roll process apparatus 200 mainly includes a transport system 120 that transports the film-like base material 42, a coating unit 140 that applies a UV curable resin to the base material 42 being transported, and an uneven pattern on the UV curable resin. The transfer part 160 to transfer and the film-forming part 180 which forms a phase difference adjustment layer, a coating layer, and a sealing layer on an uneven | corrugated pattern are included.

  The conveyance system 120 is disposed on the upstream side and the downstream side of the feeding roll 172 that feeds the film-like base material 42 and the transfer roll 70 provided in the transfer unit 160, and biases the base material 42 toward the transfer roll 170. It has a nip roll 174 and a peeling roll 176 and a take-up roll 178 that winds up the obtained optical retardation member 100. Further, the transport system 120 includes a guide roll 175 for transporting the base material 42 to each of the above parts. The application unit 140 includes a die coater 182 for applying the UV curable resin 50 a to the base material 42. The transfer unit 160 is located on the downstream side of the coating unit 140 in the substrate transport direction, and a transfer roll 170 having a concavo-convex pattern, which will be described later, and an irradiation light source 185 provided to face the transfer roll 170 across the substrate 42. With. The film forming unit 180 includes a film forming apparatus such as the sputtering apparatus 10. The sputtering apparatus 10 includes a vacuum chamber 11. The vacuum chamber 11 is not particularly limited in shape, and is usually a rectangular parallelepiped shape or a cylindrical shape. Inside the vacuum chamber 11, sputtering targets 16 and 18 are arranged so as to face the surface on which the concave / convex pattern of the transparent substrate 40 being transported is formed. When a retardation adjusting layer made of a metal oxide such as Ti, Nb, Zn, Ba, or Mg is formed on the concavo-convex pattern, a target made of these metals or metal oxides can be used as the sputtering target 16. . Further, when forming a coating layer and a sealing layer made of an inorganic material such as metal, metal oxide, metal nitride, metal sulfide, metal oxynitride, metal halide, etc. on the phase difference adjusting layer, as the sputtering target 18 A target made of an inorganic material such as metal, metal oxide, metal nitride, metal sulfide, metal oxynitride, or metal halide can be used.

  The transfer roll 170 is a roll-shaped (columnar or cylindrical) mold having an uneven pattern on the outer peripheral surface. The transfer roll 170 can be manufactured as follows. First, a concavo-convex pattern is formed on a substrate made of silicon, metal, quartz, resin, or the like by a fine processing method such as a photolithography method, a cutting method, an electron beam direct writing method, a particle beam processing method, or an operation probe processing method. A matrix is produced by The matrix has a concavo-convex pattern composed of convex portions and concave portions extending linearly in a uniform direction.

  After forming the mother mold, a mold on which the concave / convex pattern of the mother mold is transferred can be formed by electroforming or the like as follows. First, a seed layer that becomes a conductive layer for electroforming can be formed on a matrix having a concavo-convex pattern by electroless plating, sputtering, vapor deposition, or the like. The seed layer may be 10 nm or more in order to make the current density uniform in the subsequent electroforming process and make the thickness of the metal layer deposited by the subsequent electroforming process constant. Examples of seed layer materials include nickel, copper, gold, silver, platinum, titanium, cobalt, tin, zinc, chromium, gold / cobalt alloy, gold / nickel alloy, boron / nickel alloy, solder, copper / nickel / chromium An alloy, a tin-nickel alloy, a nickel-palladium alloy, a nickel-cobalt-phosphorus alloy, or an alloy thereof can be used. Next, a metal layer is deposited on the seed layer by electroforming (electroplating). The thickness of the metal layer can be, for example, 10 to 30000 μm in total including the thickness of the seed layer. Any of the above metal species that can be used as a seed layer can be used as a material for the metal layer deposited by electroforming. The formed metal layer desirably has an appropriate hardness and thickness from the viewpoint of ease of processing such as pressing, peeling and cleaning of the resin layer for forming a subsequent mold.

  The metal layer including the seed layer obtained as described above is peeled off from the matrix having the concavo-convex structure to obtain a metal substrate. The peeling method may be physically peeled, or may be peeled by dissolving and removing the material for forming the concave / convex pattern of the matrix using an organic solvent, acid, alkali or the like that dissolves them. When the metal substrate is peeled from the mother die, the remaining material components can be removed by washing. As a cleaning method, wet cleaning using a surfactant or the like, or dry cleaning using ultraviolet rays or plasma can be used. Further, for example, remaining material components may be adhered and removed using an adhesive or an adhesive. The metal substrate (metal mold) on which the pattern is transferred from the mother die thus obtained can be used as a concavo-convex pattern transfer mold used for manufacturing the optical phase difference member of this embodiment.

  Furthermore, by using the obtained metal substrate, the concavo-convex structure (pattern) of the metal substrate is transferred to a film-like support substrate, whereby a flexible mold like a film-like mold can be produced. For example, after the curable resin is applied to the support substrate, the resin layer is cured while pressing the uneven structure of the metal substrate against the resin layer. As a support substrate, for example, a base material made of an inorganic material such as glass, quartz, silicon, etc .; silicone resin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), cycloolefin polymer (COP), polymethyl Examples thereof include base materials made of organic materials such as methacrylate (PMMA), polystyrene (PS), polyimide (PI), and polyarylate, and metal materials such as nickel, copper, and aluminum. The thickness of the support substrate can be in the range of 1 to 500 μm.

  Examples of the curable resin include epoxy, acrylic, methacrylic, vinyl ether, oxetane, urethane, melamine, urea, polyester, polyolefin, phenol, cross-linked liquid crystal, fluorine, and silicone. And various resins such as monomers, oligomers, polymers, and the like. The thickness of the curable resin may be in the range of 0.5 to 500 μm. If the thickness is less than the lower limit, the height of the irregularities formed on the surface of the cured resin layer tends to be insufficient, and if the thickness exceeds the upper limit, the influence of the volume change of the resin that occurs during curing increases and the irregular shape is well formed. It may not be possible.

Examples of the method for applying the curable resin include spin coating, spray coating, dip coating, dropping, gravure printing, screen printing, letterpress printing, die coating, curtain coating, ink jet, and sputtering. Various coating methods such as a method can be employed. Furthermore, although the conditions for curing the curable resin vary depending on the type of resin used, for example, the curing temperature is in the range of room temperature to 250 ° C., and the curing time is in the range of 0.5 minutes to 24 hours. It may be. It is also possible by a method of curing by irradiation of energy rays such as ultraviolet rays or electron beams, in which case the dose may be in the range of ^{20mJ / cm 2 ~10J / cm 2} .

  Next, the metal substrate is removed from the cured resin layer after curing. The method for removing the metal substrate is not limited to the mechanical peeling method, and a known method can be adopted. The film-like resin mold having a cured resin layer in which unevenness is formed on a support substrate that can be obtained in this way can be used as a mold for transferring an uneven pattern used for manufacturing the optical phase difference member of this embodiment.

  In addition, by applying a rubber-based resin material on the concavo-convex structure (pattern) of the metal substrate obtained by the above-described method, curing the applied resin material, and peeling from the metal substrate, the concavo-convex pattern of the metal substrate can be obtained. A transferred rubber mold can be produced. The obtained rubber mold can be used as a concavo-convex pattern transfer mold used in the production of the optical retardation member of the present embodiment. Natural rubber and synthetic rubber can be used as the rubber-based resin material. In particular, silicone rubber, or a mixture or copolymer of silicone rubber and other materials can be used. Examples of the silicone rubber include polyorganosiloxane, cross-linked polyorganosiloxane, polyorganosiloxane / polycarbonate copolymer, polyorganosiloxane / polyphenylene copolymer, polyorganosiloxane / polystyrene copolymer, polytrimethylsilylpropyne, poly 4-methylpentene or the like is used. Silicone rubber is cheaper than other resin materials, has excellent heat resistance, high thermal conductivity, elasticity, and is not easily deformed even under high temperature conditions. Is suitable. Furthermore, since the silicone rubber-based material has high gas and water vapor permeability, the solvent and water vapor of the transfer material can be easily transmitted. Therefore, when a rubber mold is used for the purpose of transferring a concavo-convex pattern to a film of a resin material or inorganic material precursor solution as described later, a silicone rubber-based material is preferable. The surface free energy of the rubber material may be 25 mN / m or less. Thereby, the releasability when transferring the concave / convex pattern of the rubber mold to the coating film on the substrate becomes good, and transfer defects can be prevented. For example, the rubber mold can have a length of 50 to 1000 mm, a width of 50 to 3000 mm, and a thickness of 1 to 50 mm. Moreover, you may perform a mold release process on the uneven | corrugated pattern surface of a rubber mold as needed.

  The transfer roll 170 can be obtained by winding and fixing the metal mold, film mold, or rubber mold obtained as described above around the outer peripheral surface of the cylindrical substrate roll. In addition to the above-described method, the transfer roll 170 forms, for example, a concave / convex pattern directly on the surface of a roll such as a metal roll by an electron beam drawing method or a cutting process, or a cylindrical substrate having a concave / convex pattern. It can also be formed by inserting and fixing to a roll.

[Method for producing optical retardation member]
A method for manufacturing the optical retardation member 100 shown in FIG. 1A using the roll process apparatus 200 as described above will be described. As shown in FIG. 3, the manufacturing method of the optical phase difference member mainly includes a step S1 of preparing a transparent substrate having a concavo-convex pattern, and a step of forming a phase difference adjusting layer on the concave and convex surfaces of the concavo-convex pattern S2, a step S3 of forming a coating layer that covers the retardation adjustment layer, and a step S4 of forming a sealing layer on the concave-convex pattern of the transparent substrate.

<Process for preparing transparent substrate>
In the method for producing an optical retardation member of the embodiment, a transparent substrate on which a concavo-convex pattern is formed is prepared as follows (step S1 in FIG. 3). In the roll process apparatus 200 shown in FIG. 2, the film-like base material 42 wound around the film feeding roll 172 is fed downstream by the rotation of the film feeding roll 172. The film-like base material 42 is conveyed to the application unit 140, and the UV curable resin 50 a is applied on the film-like base material 42 with a predetermined thickness by the die coater 182.

  As a method for applying the UV curable resin 50a to the base material 42, a bar coating method, a spin coating method, a spray coating method, a dip coating method, a dripping method, a gravure printing method, a screen printing, instead of the above-described die coating method. Various coating methods such as a printing method, a relief printing method, a die coating method, a curtain coating method, an ink jet method, and a sputtering method can be employed. If the UV curable resin 50a can be uniformly applied to a substrate having a relatively large area, a bar coating method, a die coating method, a gravure printing method, and a spin coating method can be employed.

Further, in order to improve the adhesion between the base material 42 and the UV curable resin 50a, a surface modification layer may be formed on the base material 42 before the UV curable resin 50a is applied on the base material 42. Good. Examples of the material for the surface modification layer include silane monomers such as n-octyltriethoxysilane, methyltriethoxysilane, and methyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltris (2-methoxyethoxy) silane. , Vinyl silane such as vinylmethyldimethoxysilane, methacryl silane such as 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycid Epoxy silanes such as xylpropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, mercaptosilanes such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3- Sulfur silane such as kutanoylthio-1-propyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2 -Aminoethyl) -3-aminopropylmethyldimethoxysilane, aminosilanes such as 3- (N-phenyl) aminopropyltrimethoxysilane, and polymers obtained by polymerizing these monomers. In addition to these silane coupling agents, titanium coupling agents may be used. The plasma treatment to the surface of the substrate 42, a corona treatment, excimer irradiation treatment may be provided with surface modification layer by performing the processing by energy rays such as UV / O ₃ treatment.

  The film-like base material 42 on which the UV curable resin 50 a is applied in the application unit 140 as described above is conveyed toward the transfer unit 160. In the transfer unit 160, the film-like substrate 42 is pressed (biased) against the transfer roll 170 by the nip roll 174, and the uneven pattern of the transfer roll 170 is transferred to the UV curable resin 50a. At the same time or immediately after that, the UV curable resin 50a is irradiated with UV light from an irradiation light source 185 provided facing the transfer roll 170 with the film-like substrate 42 interposed therebetween, and the UV curable resin 50a is cured. . The cured UV curable resin and the film-like substrate 42 are separated from the transfer roll 170 by the peeling roll 176. Thus, the transparent substrate 40 including the concavo-convex structure layer 50 (see FIG. 1A) to which the concavo-convex pattern of the transfer roll 170 is transferred is obtained.

  The transparent substrate on which the concave / convex pattern is formed may be manufactured by an apparatus other than the roll process apparatus shown in FIG. 2, or may not be manufactured by itself, but should be obtained through a manufacturer such as the market or a film manufacturer. May be prepared.

<Phase difference adjusting layer forming step>
Next, the transparent substrate 40 on which the concavo-convex pattern is formed is conveyed to the film forming unit 180, and the phase difference adjusting layer 35 (see FIG. 1A) is formed on the concave and convex surfaces of the concavo-convex pattern of the transparent substrate 40. (Step S2 in FIG. 3). In the roll process apparatus 200 shown in FIG. 2, the transparent substrate 40 peeled from the transfer roll 170 is conveyed directly into the sputtering apparatus 10 via the guide roll 175, but after the transparent substrate 40 is peeled from the transfer roll 170. The roll-shaped transparent substrate 40 wound up on a roll may be conveyed into the sputtering apparatus 10.

  A method of forming a retardation adjustment layer 35 (see FIG. 1A) made of, for example, a metal oxide, using the sputtering apparatus 10 shown in FIG. 2 will be described. First, the inside of the vacuum chamber 11 is depressurized to a high vacuum. Next, while introducing a rare gas such as Ar and oxygen gas into the vacuum chamber 11, metal atoms (and oxygen atoms) of the sputtering target 16 are knocked out by DC plasma or high-frequency plasma. While the transparent substrate 40 is being transported in the vacuum chamber 11, metal atoms knocked out of the sputtering target 16 on the surface of the transparent substrate 40 and oxygen react to deposit metal oxide. Thereby, the phase difference adjusting layer 35 (see FIG. 1A) is formed on the surface of the convex portion 60 and the concave portion 70 of the concave / convex pattern 80 of the transparent base 40 along the concave / convex pattern 80.

<Coating layer forming step>
Next, a coating layer 30 (see FIG. 1A) that covers the retardation adjustment layer 35 is formed (step S3 in FIG. 3). The coating layer 30 can be formed following the formation of the phase difference adjusting layer 35 by using the sputtering apparatus 10 used in the phase difference adjusting layer forming step S2. For example, a method for forming the coating layer 30 made of a metal oxide will be described. After the phase difference adjusting layer is formed, the transparent substrate 40 is conveyed to a position facing the sputtering target 18 while introducing a rare gas such as Ar and oxygen gas into the vacuum chamber 11, and the sputtering target 18 is subjected to DC plasma or high frequency plasma. Knock out metal atoms (and oxygen atoms). While the transparent substrate 40 is being transported in the vacuum chamber 11, the metal atoms knocked out of the sputtering target 18 on the phase difference adjusting layer 35 and oxygen react to deposit metal oxide. Thereby, the coating layer 30 (see FIG. 1A) that covers the retardation adjustment layer 35 is formed along the uneven pattern 80.

<Sealing layer forming step>
Next, the sealing layer 20 (see FIG. 1A) is formed on the transparent substrate 40 (step S4 in FIG. 3). The sealing layer 20 can be formed following the formation of the coating layer 30 by using the sputtering apparatus 10 used in the coating layer forming step S3. When the sealing layer 20 is formed of the same metal oxide as that of the coating layer 30, the metal oxide is further deposited on the transparent substrate 40 by continuously sputtering the target 18 after the formation of the coating layer 30. At this time, among the sputtered metal atoms, it reaches between the adjacent convex portions 60 (see FIG. 1A) of the concave-convex pattern 80 of the transparent substrate 40, in particular, the side surface of the lower portion (base material 42 side) of the convex portion 60. There are few things to do, and most of the metal atoms adhere to the upper surface 60 t and the upper side surface of the convex portion 60. Therefore, the deposition amount of the metal oxide is larger on the upper portion of the convex portion 60 (on the upper surface 60 t and the upper side surface) than on the concave portion 70 and the lower side surface of the convex portion 60. Therefore, by continuing the sputtering, before the space between the adjacent convex portions 60 is filled with the metal oxide deposit, the metal oxide deposited on the upper portions of the adjacent convex portions 60 is connected to form a sealed layer, A gap 90 is formed between the adjacent protrusions 60. The gap 90 is sealed by the coating layer 30 and the sealing layer 20. In particular, when the top (upper surface) 60t of each projection 60 is a plane parallel to the base material 42, that is, a plane parallel to the sputtering target 18 (for example, a cross section in a plane orthogonal to the extending direction of each projection 60). When the structure is trapezoidal), the metal oxide is particularly preferentially deposited on the upper surface 60t of the convex portion 60. Therefore, the metal oxide deposited on the upper portion of the adjacent convex portion 60 is connected to form the sealing layer 20. Therefore, it is possible to shorten the film formation time required for the production, and to suppress the consumption of the material (target).

  In the case where the sealing layer 20 and the covering layer 30 are formed of the same material, the covering layer is formed simultaneously with the formation of the sealing layer 30 until the metal oxide deposited on the adjacent convex portions 60 is connected in the sealing layer forming step. The formation of 30 also proceeds. That is, in this case, the covering layer forming step S3 and the sealing layer forming step S4 are not separate independent steps but are partially overlapping steps.

  The phase difference adjusting layer 35, the coating layer 30, and the sealing layer 20 are formed by a known dry process such as physical vapor deposition (PVD) method such as vapor deposition or chemical vapor deposition (CVD) method instead of the above sputtering. can do. For example, when forming a metal oxide as the phase difference adjusting layer 35, the coating layer 30, and the sealing layer 20 on the transparent substrate 40 by the electron beam heating vapor deposition method, for example, a metal for forming the phase difference adjusting layer 35 Or a crucible containing a metal oxide, a crucible containing a metal or metal oxide for forming the coating layer 30 and the sealing layer 20, and evaporating the metal or metal oxide by irradiating each crucible with an electron beam It is possible to use an electron beam heating vapor deposition apparatus in which an electron gun for the purpose is provided in a vacuum chamber. Each crucible is installed so as to face the conveyance path of the transparent substrate 40, and the crucible for forming the coating layer 30 and the sealing layer 20 is in the conveyance direction of the transparent substrate 40 with respect to the crucible for forming the phase difference adjusting layer 35. Provided on the downstream side. In this case, the metal or metal oxide in each crucible is heated and evaporated by an electron beam while transporting the transparent substrate 40, and the metal oxide is deposited on the transparent substrate 40 being transported, so that the position on the transparent substrate 40 is increased. The phase difference adjusting layer 35, the coating layer 30, and the sealing layer 20 can be formed. Further, oxygen gas may or may not flow depending on the degree of oxidation of the material put in the crucible and the degree of oxidation of the target phase difference adjusting layer 35, the coating layer and the sealing layer.

  In the case where a metal oxide is formed as the retardation adjustment layer 35, the coating layer 30, and the sealing layer 20 on the transparent substrate 40 by atmospheric pressure plasma CVD, for example, Japanese Patent Application Laid-Open Nos. 2004-52028 and 2004-198902. Can be used. An organic metal compound may be used as the raw material compound, and the raw material compound may be in a gas, liquid, or solid state at normal temperature and pressure. In the case of gas, it can be introduced into the discharge space as it is, but in the case of liquid or solid, it is used after being vaporized by means such as heating, bubbling, decompression, ultrasonic irradiation and the like. From such a situation, for example, a metal alkoxide having a boiling point of 200 ° C. or lower is suitable as the organometallic compound.

  Examples of such metal alkoxides include silicon compounds such as silane, tetramethoxysilane, tetraethoxysilane (TEOS), and tetra-n-propoxysilane; titanium methoxide, titanium ethoxide, titanium isopropoxide, and titanium tetraisopoloxide. Titanium compounds such as poxide; zirconium compounds such as zirconium-n-propoxide; aluminum compounds such as aluminum ethoxide, aluminum triisopropoxide, aluminum isopropoxide; antimony ethoxide; arsenic triethoxide; zinc acetylacetonate; Zinc etc. are mentioned.

  Moreover, in order to decompose | disassemble these with the raw material gas containing these organometallic compounds, and to obtain an inorganic compound, decomposition gas is used together and a reactive gas is comprised. As this cracked gas, hydrogen gas, methane gas, acetylene gas, carbon monoxide gas, carbon dioxide gas, nitrogen gas, ammonia gas, nitrous oxide gas, nitrogen oxide gas, nitrogen dioxide gas, oxygen gas, water vapor, fluorine gas, Examples thereof include hydrogen fluoride, trifluoroalcohol, trifluorotoluene, hydrogen sulfide, sulfur dioxide, carbon disulfide, and chlorine gas. For example, a metal oxide can be formed by using oxygen gas, a metal nitride can be formed by using ammonia gas, and a metal oxynitride can be formed by using ammonia gas and nitrous oxide gas. Can be formed.

  In the plasma CVD method, these reactive gases are mainly mixed with a discharge gas that tends to be in a plasma state. As the discharge gas, nitrogen gas, Group 18 atom of the periodic table, specifically, a rare gas such as helium, neon, or argon is used. In particular, nitrogen gas may be used from the viewpoint of manufacturing cost.

  The discharge gas and the reactive gas are mixed, and a film is formed by supplying the mixed gas as a mixed gas to a plasma discharge generator (plasma generator). The ratio of the discharge gas and the reactive gas varies depending on the properties of the target film, but the reactive gas is supplied with the ratio of the discharge gas being 50% or more with respect to the entire mixed gas.

  For example, silicon alkoxide (tetraalkoxysilane (TEOS)), which is a metal alkoxide having a boiling point of 200 ° C. or less, is used as a raw material compound, oxygen is used as a decomposition gas, and an inert gas such as a rare gas or nitrogen is used as a discharge gas. By performing plasma discharge, a silicon oxide film can be formed as the first film.

  A film obtained by such a CVD method can be obtained by selecting metal carbide, metal nitride, metal oxide, metal sulfide, metal halogen, etc. by selecting conditions such as a metal compound, decomposition gas, decomposition temperature, and input power as raw materials. Further, it is preferable in that a compound or a mixture thereof (metal oxynitride, metal oxyhalide, metal nitride carbide, etc.) can be formed separately.

  The optical phase difference member 100 as shown to Fig.1 (a) is obtained as mentioned above. The obtained optical retardation member 100 may be wound up by a winding roll 178. The optical phase difference member 100 may pass through a guide roll 175 or the like as appropriate. Moreover, you may affix a protective member on the surface and / or sealing layer on the opposite side to the surface in which the uneven | corrugated pattern 80 of the transparent base | substrate 40 was formed. Thereby, when the obtained optical phase difference member 100 is conveyed, transported, etc., it is possible to prevent the optical phase difference member 100 from being damaged such as scratches.

  In the above embodiment, a transfer roll is used as a mold used to transfer the concavo-convex pattern to the UV curable resin. However, a UV curable resin in which a long film mold, a plate mold, or the like is applied on the substrate. The uneven pattern may be formed by pressing against the resin.

  In the above embodiment, the concavo-convex structure layer 50 is formed using a UV curable resin. However, the concavo-convex structure layer 50 may be formed using a thermoplastic resin, a thermosetting resin, an inorganic material, or the like. When forming the concavo-convex structure layer 50 with an inorganic material, a method in which a precursor of an inorganic material is applied on the mold and then cured, a method in which a fine particle dispersion is applied on the mold and the dispersion medium is dried, and a resin material is molded The transparent substrate 40 can be prepared by a method of coating and curing on the top, a liquid phase deposition (LPD) method, or the like.

  An alkoxide such as silicon or titanium may be used as a precursor of the inorganic material (sol-gel method). For example, when the concavo-convex structure layer 50 made of silica is formed on a base material, tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), tetra-i-propoxysilane, tetra-n- are used as the silica precursor. Tetraalkoxide monomers typified by tetraalkoxysilanes such as propoxysilane, tetra-i-butoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-t-butoxysilane, methyltrimethoxysilane, ethyl Trimethoxysilane, propyltrimethoxysilane, isopropyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane (MTES), ethyltriethoxysilane, propyltriethoxysilane, isopropyltriethoxysilane, phenyl Riethoxysilane, methyltripropoxysilane, ethyltripropoxysilane, propyltripropoxysilane, isopropyltripropoxysilane, phenyltripropoxysilane, methyltriisopropoxysilane, ethyltriisopropoxysilane, propyltriisopropoxysilane, isopropyltriiso Trialkoxide monomers represented by trialkoxysilanes such as propoxysilane, phenyltriisopropoxysilane, tolyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldiisopropoxysilane, dimethyldi-n- Butoxysilane, dimethyldi-i-butoxysilane, dimethyldi-sec-butoxysilane, dimethyldi-t-butoxysilane Diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldiisopropoxysilane, diethyldi-n-butoxysilane, diethyldi-i-butoxysilane, diethyldi-sec-butoxysilane, diethyldi-t-butoxysilane, di Propyldimethoxysilane, dipropyldiethoxysilane, dipropyldipropoxysilane, dipropyldiisopropoxysilane, dipropyldi-n-butoxysilane, dipropyldi-i-butoxysilane, dipropyldi-sec-butoxysilane, dipropyldi-t-butoxysilane , Diisopropyldimethoxysilane, diisopropyldiethoxysilane, diisopropyldipropoxysilane, diisopropyldiisopropoxysilane, diisopropyldi-n-butyl Toxisilane, diisopropyldi-i-butoxysilane, diisopropyldi-sec-butoxysilane, diisopropyldi-t-butoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldipropoxysilane, diphenyldiisopropoxysilane, diphenyldi-n Dialkoxide monomers typified by dialkoxysilanes such as -butoxysilane, diphenyldi-i-butoxysilane, diphenyldi-sec-butoxysilane, and diphenyldi-t-butoxysilane can be used. Furthermore, alkyltrialkoxysilane or dialkyl dialkoxysilane whose alkyl group has C4-C18 carbon atoms can also be used. Monomers having a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxy Monomers having an epoxy group such as silane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, monomers having a styryl group such as p-styryltrimethoxysilane, 3-methacryloxypropylmethyl Monomers having a methacrylic group such as dimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropiyl Monomers having an acrylic group such as trimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltri Monomers having amino groups, such as methoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, Monomers having a ureido group such as 3-ureidopropyltriethoxysilane, monomers having a mercapto group such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane, sulfs such as bis (triethoxysilylpropyl) tetrasulfide A monomer having an alkyl group, a monomer having an isocyanate group such as 3-isocyanatopropyltriethoxysilane, a polymer obtained by polymerizing a small amount of these monomers, a composite material characterized by introducing a functional group or a polymer into a part of the material, etc. The metal alkoxides may be used. In addition, some or all of the alkyl group and phenyl group of these compounds may be substituted with fluorine. Furthermore, metal acetylacetonate, metal carboxylate, oxychloride, chloride, a mixture thereof and the like can be mentioned, but not limited thereto. Examples of the metal species include, but are not limited to, Ti, Sn, Al, Zn, Zr, In, and a mixture thereof in addition to Si. What mixed suitably the precursor of the said metal oxide can also be used. Further, a mesoporous concavo-convex structure layer may be formed by adding a surfactant to these materials. Furthermore, a silane coupling agent having a hydrolyzable group having affinity and reactivity with silica and an organic functional group having water repellency can be used as a precursor of silica. For example, silane monomers such as n-octyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane, vinylsilane such as vinylmethyldimethoxysilane, Methacrylic silane such as 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycyl Epoxy silanes such as Sidoxypropyltriethoxysilane, 3-Mercaptopropyltrimethoxysilane, Mercaptosilanes such as 3-Mercaptopropyltriethoxysilane, 3-Octanoylthio-1-pro Sulfur silane such as rutriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl)- Examples include aminosilanes such as 3-aminopropylmethyldimethoxysilane and 3- (N-phenyl) aminopropyltrimethoxysilane, and polymers obtained by polymerizing these monomers.

  When a mixture of TEOS and MTES is used as the precursor of the inorganic material, the mixing ratio can be 1: 1, for example, in a molar ratio. This precursor produces amorphous silica by performing hydrolysis and polycondensation reactions. In order to adjust the pH of the solution as a synthesis condition, an acid such as hydrochloric acid or an alkali such as ammonia is added. The pH may be 4 or less or 10 or more. Moreover, you may add water in order to perform a hydrolysis. The amount of water to be added can be 1.5 times or more in molar ratio with respect to the metal alkoxide species.

  Examples of the solvent for the precursor solution used in the sol-gel method include alcohols such as methanol, ethanol, isopropyl alcohol (IPA) and butanol, aliphatic hydrocarbons such as hexane, heptane, octane, decane and cyclohexane, benzene, toluene, Aromatic hydrocarbons such as xylene and mesitylene, ethers such as diethyl ether, tetrahydrofuran and dioxane, ketones such as acetone, methyl ethyl ketone, isophorone and cyclohexanone, butoxyethyl ether, hexyloxyethyl alcohol, methoxy-2-propanol and benzyl Ether alcohols such as oxyethanol, glycols such as ethylene glycol and propylene glycol, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether Ter, glycol ethers such as propylene glycol monomethyl ether acetate, esters such as ethyl acetate, ethyl lactate and γ-butyrolactone, phenols such as phenol and chlorophenol, N, N-dimethylformamide, N, N-dimethylacetamide, Amides such as N-methylpyrrolidone, halogen-based solvents such as chloroform, methylene chloride, tetrachloroethane, monochlorobenzene and dichlorobenzene, hetero-containing compounds such as carbon disulfide, water, and mixed solvents thereof can be mentioned. In particular, it may be ethanol and isopropyl alcohol, or a mixture of these with water.

  Additives for the precursor solution used in the sol-gel method include polyethylene glycol, polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol for viscosity adjustment, alkanolamines such as triethanolamine, which are solution stabilizers, and β-diketones such as acetylacetone , Β-ketoester, formamide, dimethylformamide, dioxane and the like can be used. Further, as an additive for the precursor solution, a material that generates an acid or an alkali by irradiating light such as energy rays typified by ultraviolet rays such as excimer UV light can be used. By adding such a material, the precursor solution can be cured (gelled) by irradiation with light, whereby an inorganic material can be formed.

Further, polysilazane may be used as a precursor of the inorganic material. Polysilazane is oxidized and ceramicized (silica modification) by heating or irradiation with energy rays such as excimer to form silica, SiN or SiON. “Polysilazane” is a polymer having a silicon-nitrogen bond, such as SiO ₂ , Si ₃ N _{4 made of} Si—N, Si—H, N—H, etc., and ceramics such as both intermediate solid solutions SiO _X N _Y. It is a precursor inorganic polymer. It may be a compound that is converted to ceramics and modified to silica or the like at a relatively low temperature as represented by the following general formula (1) described in JP-A-8-112879.

General formula (1):
-Si (R1) (R2) -N (R3)-
In the formula, R1, R2, and R3 each represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group, or an alkoxy group.

  Among the compounds represented by the general formula (1), perhydropolysilazane (also referred to as PHPS) in which all of R 1, R 2 and R 3 are hydrogen atoms, and the hydrogen part bonded to Si is partially an alkyl group or the like. Substituted organopolysilazanes may be used.

  As another example of polysilazane which is ceramicized at low temperature, silicon alkoxide-added polysilazane obtained by reacting polysilazane with silicon alkoxide (for example, JP-A No. 5-23827), glycidol-added polysilazane obtained by reacting glycidol ( For example, JP-A-6-122852), alcohol-added polysilazane obtained by reacting alcohol (for example, JP-A-6-240208), metal carboxylate-added polysilazane obtained by reacting metal carboxylate ( For example, JP-A-6-299118), an acetylacetonate complex-added polysilazane obtained by reacting a metal-containing acetylacetonate complex (for example, JP-A-6-306329), and metal fine particles are added. Metal fine particle Polysilazane (e.g., JP-A-7-196986) and the like can also be used.

  As the solvent for the polysilazane solution, hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ethers such as halogenated hydrocarbon solvents, aliphatic ethers, and alicyclic ethers can be used. In order to promote the modification to a silicon oxide compound, an amine or metal catalyst may be added.

  After applying the precursor solution of the inorganic material such as the metal alkoxide or polysilazane to the base material, the precursor coating film is heated while pressing the mold having the concavo-convex pattern against the precursor coating film. By irradiating the coating film with energy rays, it is possible to form a concavo-convex structure layer made of an inorganic material in which the coating film gels and the concavo-convex pattern of the mold is transferred.

  In addition, the structure which makes the convex part 60a as shown in FIG.1 (b) is formed on the base material 42a, and the area | region (concave part 70a) which the surface of the base material 42a exposed between the convex parts 60a is divided. The transparent substrate 40a can be manufactured as follows, for example. In the manufacturing method described above, instead of applying the UV curable resin 50a on the base material 42, the UV curable resin is applied only to the concave portions or only the convex portions of the concave / convex pattern transfer mold. The UV curable resin applied to the mold is brought into close contact with the substrate 42a, and the UV curable resin is transferred to the substrate 42a. Thereby, the convex part 60a which has a shape corresponding to the shape of the concave part or convex part of a mold is formed on the base material 42a. Between the convex portions 60a thus formed, a concave portion (region where the surface of the base material 42a is exposed) 70a is defined.

  As shown in FIG. 1C, the transparent substrate 40b formed of a base material shaped so that the surface of the base material itself forms a concavo-convex pattern composed of convex portions 60b and concave portions 70b is, for example, In this way, it can be manufactured. A resist layer having a concavo-convex pattern is formed on a substrate by a known technique such as nanoimprinting or photolithography. After the recess of the resist layer is etched to expose the substrate surface, the substrate is etched using the remaining resist layer as a mask. After etching, the remaining mask (resist) is removed with a chemical solution. By the above operation, the uneven pattern 80b can be formed on the surface of the substrate itself.

  By forming the retardation adjustment layer 35, the coating layer 30 and the sealing layer 20 on the transparent bases 40a and 40b manufactured as described above by the same method as in the above embodiment, FIG. The optical phase difference members 100a and 100b shown in FIG.

[Composite optical member]
A composite optical member formed using the optical retardation members 100, 100a, 100b will be described. As shown in FIG. 4, the composite optical member 300 includes the optical phase difference member 100 according to the above embodiment and optical members 320 a and 320 b joined to the optical phase difference member 100. In the composite optical member 300, the optical member 320a is bonded (bonded) to the sealing layer 20 of the optical retardation member 100, and the optical member 320b is bonded to the surface of the transparent substrate 40 opposite to the surface on which the concavo-convex pattern is formed. ing. The composite optical member according to the present invention may not include both of the optical members 320a and 320b, and may include only one of them. For example, a composite optical member in which a polarizing plate is bonded as the optical member 320a or 320b to the optical retardation member 100 can be used as an antireflection film. In addition, by attaching the optical retardation member side of such an antireflection film to a display element such as an organic EL element or a liquid crystal element, a display device in which reflection of wiring electrodes of the display element is prevented (for example, an organic EL display, A liquid crystal display or the like).

  An adhesive is used to bond the optical retardation member to an optical member such as a polarizing plate or a display element. As the adhesive, known ones such as acrylic and silicone can be used. In the optical phase difference member of the embodiment, since the gap between the convex portions is sealed by the sealing layer, the adhesive does not enter between the convex portions. Therefore, even after the optical phase difference member is bonded to the optical member, the phase difference generated by the optical phase difference member does not change, and a sufficient phase difference can be generated.

  EXAMPLES Hereinafter, the optical retardation member of the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1
On a transparent substrate in which the period of the concavo-convex pattern is 240 nm, the width of the top surface of the convex part is 0 nm, the distance between the bottom surfaces of adjacent convex parts is 48 nm, the convex part height is 350 nm, and the refractive index n ₁ of the convex part is 1.68 A material having a refractive index n ₂ of 1.93 (medium refractive index material) is deposited with a film thickness within a range of 0 to 290 nm, and a material having a refractive index n ₃ of 2.37 (high The structure of the optical phase difference member when the refractive index material was deposited with a film thickness of 600 nm was calculated by simulation. Here, the “film formation thickness” means the thickness of the film formed on the top (upper surface) of the convex portion in the direction perpendicular to the surface of the transparent substrate (uneven pattern surface). This “film thickness” is the maximum value of the thickness of the film formed on the transparent substrate surface in the direction perpendicular to the transparent substrate surface. Further, the “film thickness” is substantially equal to the thickness of a film formed when each material is deposited on a flat substrate under the same conditions. The optical phase difference member is composed of a medium refractive index material and a phase difference adjusting layer that covers the uneven pattern, a high refractive index material that covers the phase difference adjusting layer, and a high refractive index material that is adjacent to the convex portion. It had a sealing layer connecting the top (top).

  The optical retardation member having the structure obtained by the above calculation calculated the retardation produced in the transmitted light having a wavelength of 400 to 700 nm. FIG. 5 shows the calculation result of the phase difference generated in the transmitted light having a wavelength of 550 nm. In FIG. 5, the horizontal axis represents the film thickness of the medium refractive index material (that is, the thickness of the phase difference adjusting layer), and the vertical axis represents the value obtained by dividing the phase difference by the wavelength of light (550 nm). When the thickness of the retardation adjustment layer is in the range of 200 nm or less, the rate of change of the retardation relative to the thickness of the retardation adjustment layer is large, and the retardation can be controlled by the thickness of the retardation adjustment layer. I understood. It has been found that when the thickness of the phase difference adjusting layer exceeds 200 nm, the rate of change of the phase difference with respect to the change in the thickness of the phase difference adjusting layer is small, and the effect of adjusting the phase difference is small. Further, when the thickness of the phase difference adjusting layer is less than 10 nm, the phase difference is hardly different from that when there is no phase difference adjusting layer, and therefore the thickness of the phase difference adjusting layer may be 10 nm or more.

Example 2
On a transparent substrate having a concavo-convex pattern similar to that of Example 1 and having a refractive index n _{1 of a} convex portion of 1.68, a refractive index n ₂ as a medium refractive index material is within a range of 1.5 to 2.3. The structure of the optical phase difference member is calculated by simulation when a certain material is deposited with a film thickness of 50 nm and the high refractive index material similar to that of Example 1 is deposited with the same film thickness as that of Example 1. did. The optical phase difference member is composed of a medium refractive index material and a phase difference adjusting layer that covers the uneven pattern, a high refractive index material that covers the phase difference adjusting layer, and a high refractive index material that is adjacent to the convex portion. It had a sealing layer connecting the top (top). In this example, the geometric mean n _ave of the refractive index n ₁ of the convex portion and the refractive index n ₃ of the high refractive index material was 1.99.

  Furthermore, the structure of the optical retardation member produced in the same manner as the above-described optical retardation member except that no medium refractive index material was formed was calculated by simulation. This optical phase difference member does not have a phase difference adjustment layer, but is made of a high refractive index material, a coating layer covering the phase difference adjustment layer, and an upper surface (top) of an adjacent convex portion made of a high refractive index material. It had the sealing layer which connects.

For each of the optical phase difference member having the phase difference adjustment layer and the optical phase difference member not having the phase difference adjustment layer, a phase difference generated in transmitted light having a wavelength of 550 nm is calculated, and the difference (that is, phase difference adjustment) is calculated. The amount of change in retardation by layer) was determined. FIG. 6 shows the calculation result of the change amount of the phase difference. As shown in the table of FIG. 7, the refractive index (that is, the optimum value of the refractive index) n _2opt of the medium refractive index material that maximizes the amount of change in phase difference was 1.80. Further, the amount of change in the phase difference is 0.9 times or more the maximum value of the amount of change in the phase difference (that is, the amount of change in the phase difference when the refractive index n ₂ of the medium refractive index material is n _2opt ). lower _{n 2min} refractive index _{n 2} is 1.65, the upper limit _{n 2max} was 1.95. _{Further, n 2opt, n 2min, n} 2max , _{respectively,} 0.90 times the _{n ave,} 0.83 times, 0.98 times. Therefore, it has been found that if the refractive index n ₂ of the medium refractive index material satisfies 0.83 n _ave ≦ n ₂ ≦ 0.98 n _ave , the amount of change in phase difference due to the phase difference adjusting layer can be sufficiently increased.

Example 3
The refractive index n ₁ of the convex portion except for using 1.52 in the same manner as in Example 2, was determined the change of the phase difference by the phase difference adjusting layer. In this example, the geometric mean n _ave of the refractive index n ₁ of the convex portion and the refractive index n ₃ of the high refractive index material was 1.90.

As shown in the table of FIG. 7, the refractive index n _2opt of the medium refractive index material that maximizes the amount of change in phase difference was 1.70. Further, the refraction of the medium refractive index material in which the amount of change in the phase difference is 0.9 times or more of the maximum value (that is, the amount of change in the phase difference when the refractive index n ₂ of the medium refractive index material is n _2opt ). lower _{n 2min} rate _{n 2} is 1.55, the upper limit _{n 2max} was 1.90. _{n 2opt,} n 2min, n _{2max, respectively,} 0.90 times the _{n ave,} 0.82-fold, was 1.00 times. Therefore, if the refractive index n ₂ of the medium refractive index material satisfies 0.82 n _ave ≦ n ₂ ≦ 1.00 n _ave , the amount of change in the phase difference due to the phase difference adjusting layer can be sufficiently increased, It was found that the phase difference adjusting layer has a sufficient phase difference adjusting effect.

Example 4
Except that the refractive index n ₃ of the high refractive index material and 2.47 in the same manner as in Example 2, was determined the change of the phase difference by the phase difference adjusting layer. In this example, the geometric mean n _ave of the refractive index n ₁ of the convex portion and the refractive index n ₃ of the high refractive index material was 2.04.

As shown in the table of FIG. 7, the refractive index n _2opt of the medium refractive index material that maximizes the amount of change in phase difference was 1.85. Further, the refraction of the medium refractive index material in which the amount of change in the phase difference is 0.9 times or more of the maximum value (that is, the amount of change in the phase difference when the refractive index n ₂ of the medium refractive index material is n _2opt ). lower _{n 2min} rate _{n 2} is 1.70, the upper limit _{n 2max} was 2.05. _{n 2opt,} n 2min, n _{2max, respectively,} 0.91 times the _{n ave,} 0.84-fold, was 1.01 times. Therefore, it has been found that if the refractive index n ₂ of the medium refractive index material satisfies 0.84 n _ave ≦ n ₂ ≦ 1.01 n _ave , the amount of change in the phase difference due to the phase difference adjusting layer can be sufficiently increased.

Example 5
Except that the refractive index n ₃ of the high refractive index material and 2.47 in the same manner as in Example 3, was determined the change of the phase difference by the phase difference adjusting layer. In this example, the geometric mean n _ave of the refractive index n ₁ of the convex portion and the refractive index n ₃ of the high refractive index material was 1.93.

As shown in the table of FIG. 7, the refractive index n _2opt of the medium refractive index material that maximizes the amount of change in phase difference was 1.75. Further, the refraction of the medium refractive index material in which the amount of change in the phase difference is 0.9 times or more of the maximum value (that is, the amount of change in the phase difference when the refractive index n ₂ of the medium refractive index material is n _2opt ). lower _{n 2min} rate _{n 2} is 1.60, the upper limit _{n 2max} was 1.95. _{n 2opt,} n 2min, n _{2max, respectively,} 0.90 times the _{n ave,} 0.83-fold, was 1.01 times. Therefore, it has been found that if the refractive index n ₂ of the medium refractive index material satisfies 0.83 n _ave ≦ n ₂ ≦ 1.01 n _ave , the amount of change in the phase difference due to the phase difference adjusting layer can be sufficiently increased.

From Examples 2-5, the refractive index _{n 2} of the phase difference adjusting layer may satisfy the _{0.8n ave ≦ n 2 ≦ 1.05n ave} , satisfies _{0.82n ave} ≦ _{n 2} ≦ _{1.01n ave} It was found that 0.84 n _ave ≦ n ₂ ≦ 1.00 n _ave may be satisfied, and thereby a sufficiently large phase difference adjusting effect can be obtained.

Comparative Example On a transparent substrate having the same structure as that of Example 1, a high refractive index material similar to that of Example 1 was deposited with a film thickness in the range of 100 to 1000 nm without depositing a medium refractive index layer. The structure of the optical phase difference member was calculated by simulation. When the film thickness of the high refractive index material was less than 600 nm, the coating layer covering the concavo-convex pattern was formed, but the sealing layer connecting the upper surfaces (tops) of the adjacent convex portions was not formed. On the other hand, the sealing layer was formed when the film thickness of the high refractive index material was 600 nm or more.

  The optical retardation member having the structure obtained by the above calculation calculated the retardation produced in the transmitted light having a wavelength of 400 to 700 nm. FIG. 8 shows the calculation result of the phase difference generated in the transmitted light having a wavelength of 550 nm. In FIG. 8, the horizontal axis represents the film thickness of the high refractive index material, and the vertical axis represents the value obtained by dividing the phase difference by the wavelength of light (550 nm). When the film thickness of the high refractive index material was less than 600 nm, that is, when the sealing layer was not formed, the phase difference increased as the film thickness of the high refractive index material increased. On the other hand, when the film thickness of the high refractive index material is 600 nm or more, that is, when the sealing layer is formed, the phase difference hardly changes even when the film thickness of the high refractive index material increases. It was. Therefore, when the high refractive index material is formed directly on the concavo-convex pattern as in this comparative example (that is, when the phase difference adjusting layer is not formed), it is difficult to control the phase difference while forming the sealing layer. I found out.

  As mentioned above, although this invention was demonstrated by embodiment, the optical phase difference member manufactured by the manufacturing method of this invention is not limited to the said embodiment, It is suitably in the range of the technical idea described in the claim. Can be modified.

  The optical retardation member of the present invention can maintain excellent retardation characteristics even when incorporated in a device. Further, it is possible to prevent the concavo-convex structure from being deformed by applying a load and a desired phase difference from being obtained. Therefore, the optical retardation member of the present invention includes various functional members such as an antireflection film, a display device such as a reflective or transflective liquid crystal display device, a touch panel, and an organic EL display device, a pickup device for an optical disc, a polarizing device. It can use suitably for various devices, such as a conversion element.

20 sealing layer, 30 coating layer, 35 phase difference adjusting layer, 40 transparent substrate 42 base material, 50 concavo-convex structure layer, 60 convex portion, 70 concave portion 90 gap portion, 100 optical phase difference member, 120 transport system, 140 coating portion 160 Transfer unit, 170 Transfer roll, 180 Film formation unit 200 Roll process device, 320 Optical member, 340 Adhesive 300 Composite optical member

Claims (13)

A transparent substrate having a concavo-convex pattern;
A phase difference adjusting layer formed on the surface of the concave and convex portions of the concave-convex pattern;
A coating layer for coating the retardation adjustment layer;
A gap section defined between the projections of the concavo-convex pattern in which the retardation adjustment layer and the coating layer are formed;
A sealing layer provided on the top of the concavo-convex pattern so as to connect the tops of the convex portions of the concavo-convex pattern and seal the gap portion;
Refractive index _{n 1} of the convex portion, the refractive index _{n 2} of the phase difference adjusting layer, the refractive index _{n 3} of the coating _layer, meets the n _{1 <n} 2 _{<n 3,}
The optical retardation member , wherein the gap portion has a height that exceeds a height of the convex portion of the concavo-convex pattern . The refractive index n _{1 of} the convex portion, the refractive index n ₂ of the retardation adjusting layer, and the refractive index n _{3 of the} covering layer are 0.8√ (n ₁ · n ₃ ) ≦ n ₂ ≦ 1.05√ ( optical retardation member according to claim 1, characterized in that satisfy n 1 _· n _3).   The optical phase difference member according to claim 1 or 2, wherein the thickness of the phase difference adjusting layer is within a range of 10 to 200 nm.   The optical phase difference member according to any one of claims 1 to 3, wherein a cross section of the convex portion of the concavo-convex pattern is substantially trapezoidal. The phase difference adjusting layer, ZnO, BaO, MgO, optical according to TiO _2, or _Nb 2 _{O 5} or any one of claims 1 to 4, characterized in that it is composed of a mixture thereof, Phase difference member. The said coating layer and the said sealing layer are comprised from the metal, the metal oxide, the metal nitride, the metal sulfide, the metal oxynitride, or the metal halide, The any one of Claims 1-5 characterized by the above-mentioned. Item 4. An optical retardation member according to Item. Optical retardation member according to any one of claims 1 to 6, the material constituting the concavo-convex pattern is characterized in that the photo-curable resin or a thermosetting resin. Optical retardation member according to any one of claims 1 to 6, the material constituting the concavo-convex pattern is characterized in that it is a sol-gel material.   The optical phase difference member according to claim 1, wherein air exists in the gap portion. The optical phase difference member according to any one of claims 1 to 9 ,
A composite optical member, comprising: a surface of the transparent substrate opposite to a surface on which the concave / convex pattern is formed, or a polarizing plate attached to the sealing layer. The composite optical member according to claim 10 ,
A display device comprising: a surface of the transparent substrate opposite to the surface on which the concave / convex pattern is formed or a display element attached to the sealing layer. It is a manufacturing method of the optical phase contrast member according to any one of claims 1 to 11,
Preparing a transparent substrate having a concavo-convex pattern;
Forming a phase difference adjusting layer that covers the surface of the concave and convex portions of the concave and convex pattern; and
Forming a coating layer for coating the retardation adjustment layer;
A sealing layer is formed on the concavo-convex pattern so that adjacent convex portions of the concavo-convex pattern on which the phase difference adjusting layer and the coating layer are formed are connected and a gap section between the convex portions is sealed. And a process of
The refractive index n _{1 of} the convex portion, the refractive index n ₂ of the retardation adjusting layer, and the refractive index n _{3 of the} covering layer satisfy n ₁ <n ₂ <n ₃ . Production method. The phase difference adjusting layer, the coating layer, and the sealing layer are formed by sputtering, CVD, or vapor deposition in the phase difference adjusting layer forming step, the coating layer forming step, and the sealing layer forming step. 12. A method for producing an optical retardation member according to 12 .

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