JP2023147946A - Optical sheet and optical component - Google Patents

Abstract

To provide an optical sheet including a half mirror layer that selectively reflects light of a specific wavelength region (visible light) and lets light of other wavelength regions pass through, and a polarization layer that is composed of a polarizer having polarizability, the optical sheet being capable of exhibiting excellent processability, and high productivity during manufacture, and an optical component that includes said optical sheet and excels in reliability.SOLUTION: An optical sheet 15 according to the present invention comprises a polarization layer 13, a first substrate 11, and a second substrate 12. The first substrate 11 has a retardation of 2000 nm to 7000 nm inclusive, and includes a first base material 111, a half mirror layer 113 composed of a laminate in which a high refractive index layer and a low refractive index layer are alternately and repeatedly laminated, and a second base material 112. The half mirror layer 113 is constructed such that an interface between the first base material 111 and the half mirror layer 113 forms a continuous layer, and an interface between the second base material 112 and the half mirror layer 113 forms a continuous layer.SELECTED DRAWING: Figure 3

Description

The present invention relates to an optical sheet and an optical component.

In recent years, lenses in eyewear such as glasses and sunglasses have been used to selectively reflect light in a specific wavelength range (visible light) and reflect light in other wavelength ranges, with the aim of improving their design. An optical sheet having an optical sheet provided with a half mirror layer that transmits light on its surface has been proposed.

In addition, when considering that this lens should further have polarizing properties, it is necessary to replace the optical sheet with a substrate mainly made of a resin material on both sides of a laminate in which a half mirror layer and a polarizer are laminated. In this optical sheet, the half mirror layer, polarizer, and substrate are bonded by interposing an adhesive layer between them. It is possible that

For example, a lens having such an optical sheet on its surface is prepared by preparing an optical sheet having the above-mentioned structure and having a flat plate shape in plan view, and attaching protective films to both sides of the optical sheet. The optical sheet is punched out into a predetermined shape such as a circular shape. Thereafter, this optical sheet is subjected to a thermal bending process under heating to obtain a curved optical sheet having a curved convex surface and a curved concave surface, which are formed into a curved shape by thermal bending. After the protective film is peeled off from the curved optical sheet, the curved optical sheet is placed in a mold having a curved recess so that the recess of the mold and the convex part of the curved optical sheet come into contact with each other. It is manufactured by forming a resin layer (molded layer) mainly composed of a resin material on the concave surface of this curved optical sheet using an insert injection molding method in the adsorbed state (for example, Patent Document 1 reference).

As mentioned above, in the manufacturing method of such a lens, by subjecting an optical sheet to a thermal bending process, one surface of the optical sheet is made into a curved convex surface and the other surface is made into a curved concave surface. Although a sheet is obtained, the optical sheet is required to have excellent workability in this heat bending process.

Furthermore, as mentioned above, the optical sheet may have a structure in which the half mirror layer, the polarizer, and the substrate are bonded by adhesive layers interposed between them. , from the viewpoint of improving productivity, a simpler configuration is required.

Therefore, there has been a need to develop an optical sheet including a half mirror layer and a polarizer that has excellent processability and productivity.

JP2009-294445A

An object of the present invention is to provide a polarizing layer composed of a half mirror layer that selectively reflects light in a specific wavelength range (visible light) and transmits light in other wavelength ranges, and a polarizer having polarization properties. An object of the present invention is to provide an optical sheet that can exhibit excellent workability and high productivity during manufacturing, and an optical component that is equipped with such an optical sheet and has excellent reliability.

Such objects are achieved by the present invention described in (1) to (8) below.
(1) An optical sheet comprising a polarizing layer made of a polarizer, and a first substrate and a second substrate provided on one side and the other side of the polarizing layer, respectively,
The first substrate has a retardation of 2000 nm or more and 7000 nm or less,
a first base material mainly composed of a resin material having light transmittance;
a half mirror layer bonded to one surface of the first base material and consisting of a laminate in which high refractive index layers and low refractive index layers are alternately and repeatedly laminated;
a second base material made of the resin material as a main material and bonded to a surface of the half mirror layer opposite to the first base material;
In the half mirror layer, the refractive index of the high refractive index layer is higher than the refractive index of the low refractive index layer,
The interface between the first base material and the half mirror layer forms a continuous layer between the first base material and the half mirror layer, and the interface between the second base material and the half mirror layer forms a continuous layer between the first base material and the half mirror layer. An optical sheet comprising two base materials and the half mirror layer forming a continuous layer.

(2) The above, where Tg1, Tg2≧105°C, where the glass transition point of the main material constituting the high refractive index layer is Tg1, and the glass transition point of the main material constituting the low refractive index layer is Tg2. The optical sheet according to (1).

(3) The optical sheet according to (2) above, wherein the glass transition point Tg1 and the glass transition point Tg2 satisfy the following relationship: 0°C≦|Tg1−Tg2|≦60°C.

(4) The optical sheet according to (2) or (3) above, wherein the lower glass transition point of the glass transition point Tg1 and the glass transition point Tg2 is 110°C or more and 250°C or less.

(5) When the refractive index of the high refractive index layer at a wavelength of 589 nm is N1 and the refractive index of the low refractive index layer at a wavelength of 589 nm is N2, the refractive index difference (N1-N2) is 0.05. The optical sheet according to any one of (1) to (4) above, which has a particle diameter of 0.25 or less.

(6) The optical sheet according to any one of (1) to (5) above, wherein the high refractive index layer and the low refractive index layer each have an average thickness of 50 nm or more and 300 nm or less.

(7) In the half mirror layer, the number of repetitions in which the high refractive index layer and the low refractive index layer are alternately stacked is 50 or more and 750 or less. The optical sheet described in any of the above.

(8) An optical component comprising the optical sheet according to any one of (1) to (7) above.

According to the present invention, there is provided a half mirror layer having a repeating portion constituted by a laminate in which high refractive index layers and low refractive index layers are alternately and repeatedly stacked, and a half mirror layer bonded to the half mirror layer. The first base material and the second base material form a continuous layer of the first base material and the half mirror layer at the interface between the first base material and the half mirror layer, and the second base material and the half mirror layer form a continuous layer of the first base material and the half mirror layer. At the interface, a continuous layer of the second base material and the half mirror layer is formed. Therefore, even if the optical sheet is subjected to a thermal bending process to obtain a curved optical sheet with one surface of the optical sheet as a curved convex surface and the other surface as a curved concave surface, the interface between the first base material and the half mirror layer, Moreover, it is possible to accurately suppress or prevent peeling between the second base material and the half mirror layer at the interface between them. Further, the retardation of the first substrate including the half mirror layer is set within the range of 2000 nm or more and 7000 nm or less, and the first substrate side is the curved convex side and heat bending is performed, so that the heat bending process is performed. When the optical sheet is viewed from the concave side of the curved surface, that is, from the human eye side, coloring of the transmitted image caused by optical distortion of the first substrate can be accurately suppressed or prevented. Further, as described above, at the interface between the first base material and the half mirror layer, a continuous layer of the first base material and the half mirror layer is formed, and at the interface between the second base material and the half mirror layer, a continuous layer is formed at the interface between the first base material and the half mirror layer. Forming a continuous layer of the base material and the half mirror layer, and forming an adhesive layer for joining each base material and the half mirror layer is omitted. Therefore, it is possible to improve productivity during manufacturing of optical sheets. Therefore, it can be said that the optical sheet has excellent processability and high productivity during manufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of sunglasses including a lens having a curved optical sheet according to the present invention. FIG. 2 is a schematic diagram for explaining a method for manufacturing a lens having a curved optical sheet according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows 1st Embodiment of the optical sheet of this invention. FIG. 4 is an enlarged cross-sectional view of a part of the half mirror layer included in the optical sheet located in the region [B] surrounded by the dashed line in FIG. 3. FIG. It is a longitudinal cross-sectional view showing a second embodiment of the optical sheet of the present invention.

Hereinafter, the optical sheet and optical component of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

The optical sheet of the present invention is provided with a first substrate and a second substrate provided on one side and the other side of the polarizing layer, respectively, and the first substrate has a particle diameter of 2000 nm or more and 7000 nm or less. a first base material mainly composed of a resin material having retardation and light transmittance; a high refractive index layer and a low refractive index layer bonded to one surface of the first base material; a half-mirror layer consisting of a laminate formed by alternately and repeatedly laminating the above, and a second half-mirror layer formed mainly of the resin material and bonded to the surface of the half-mirror layer opposite to the first base material. a base material, in the half mirror layer, the refractive index of the high refractive index layer is higher than the refractive index of the low refractive index layer, and the interface between the first base material and the half mirror layer is , a continuous layer is formed between the first base material and the half mirror layer, and an interface between the second base material and the half mirror layer forms a continuous layer between the second base material and the half mirror layer. are doing.

Thus, in the present invention, the half mirror layer, the first base material, and the second base material form a continuous layer of the first base material and the half mirror layer at the interface between the first base material and the half mirror layer. A continuous layer of the second base material and the half mirror layer is formed at the interface between the second base material and the half mirror layer. Therefore, even if the optical sheet is subjected to a thermal bending process to obtain a curved optical sheet with one surface of the optical sheet as a curved convex surface and the other surface as a curved concave surface, the interface between the first base material and the half mirror layer, Moreover, it is possible to accurately suppress or prevent peeling between the second base material and the half mirror layer at the interface between them. Further, the retardation of the first substrate including the half mirror layer is set within the range of 2000 nm or more and 7000 nm or less, and the first substrate side is the curved convex side and heat bending is performed, so that the heat bending process is performed. When the optical sheet is viewed from the concave side of the curved surface, that is, from the human eye side, coloring of the transmitted image caused by optical distortion of the first substrate can be accurately suppressed or prevented. Further, when the retardation of the first substrate is lower than 2000 nm, blurring of the transmitted image occurs significantly. Furthermore, if it is higher than 7000 nm, a problem occurs during thermal bending to curve the optical sheet, and the desired radius of curvature cannot be obtained. Therefore, it can be said that the optical sheet has excellent processability.

Further, as described above, at the interface between the first base material and the half mirror layer, a continuous layer of the first base material and the half mirror layer is formed, and at the interface between the second base material and the half mirror layer, a continuous layer is formed at the interface between the first base material and the half mirror layer. By forming a continuous layer between the base material and the half-mirror layer, the formation of an adhesive layer for bonding each base material and the half-mirror layer is omitted, improving productivity when manufacturing optical sheets. can be achieved.

Therefore, it can be said that the optical sheet has excellent processability and high productivity during manufacturing.

A curved optical sheet having a curved shape including a curved convex surface and a curved concave surface obtained by thermally bending the optical sheet of the present invention under heating can be used, for example, as a lens for sunglasses, which is a type of eyeglasses. The resin substrate having a curved shape (curved resin substrate) is used to impart half-mirror properties to this lens. Therefore, in the following, first, prior to explaining the optical sheet of the present invention, the sunglasses will be explained.

<Sunglasses>
FIG. 1 is a perspective view showing an embodiment of sunglasses including a lens having a curved optical sheet according to the present invention. In FIG. 1, when the sunglasses are worn on the user's head, the surface of the lenses facing the user's eyes is called the back surface, and the surface on the opposite side is called the front surface.

As shown in FIG. 1, sunglasses 100 include a frame 20 and lenses 30 (lenses for spectacles).

Note that in this specification, the term "lens (lens for spectacles)" includes both those that have a light condensing function and those that do not have a light condensing function.

The frame 20 is attached to the user's head and allows the lens 30 to be placed near the front of the user's eyes.

This frame 20 has a rim part 21, a bridge part 22, a temple part 23, and a nose pad part 24.

The rim part 21 has a ring shape, and one rim part 21 is provided for each of the right eye and the left eye, and a lens 30 is attached to the inside thereof. Thereby, the user can visually recognize external information through the lens 30.

Further, the bridge portion 22 has a rod shape, and when worn on the user's head, is located in front of the upper part of the user's nose and connects the pair of rim portions 21.

The temple portion 23 has a temple shape and is connected to an edge of each rim portion 21 on the opposite side of the position where the bridge portion 22 is connected. The temple portion 23 is hung over the user's ear when worn on the user's head.

The nose pad section 24 is provided at the edge of each rim section 21 corresponding to the user's nose when the sunglasses 100 are worn on the user's head, and comes into contact with the user's nose. It has a shape that corresponds to the contact part of the nose. Thereby, the attached state can be stably maintained.

The constituent materials of each part constituting the frame 20 are not particularly limited, and for example, various metal materials, various resin materials, etc. can be used. Note that the shape of the frame 20 is not limited to that shown in the drawings, as long as it can be mounted on the user's head.

Lenses 30 (optical components of the present invention) are attached to each rim portion 21, respectively. The lens 30 is a member having a light transmitting property and having a plate shape whose overall shape is curved outward, and includes a resin layer 35 (molding layer) and a curved optical sheet 10.

The resin layer 35 has light transmittance and is located on the back side of the lens, and when imparting a light condensing function to the lens 30, this resin layer 35 has a light condensing function.

The constituent material of the resin layer 35 is not particularly limited as long as it is a resin material having light transmittance, but for example, various thermoplastic resins, thermosetting resins, various curable resins such as photocurable resins, etc. One type or a combination of two or more types of these can be used.

Examples of resin materials include polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyvinyl chloride, polystyrene, polyamide, polyimide, polycarbonate, poly(4-methylpentene-1), ionomers, acrylic resins, Polyesters such as polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc. , polyether, polyetherketone (PEK), polyetheretherketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer) ), polytetrafluoroethylene, polyvinylidene fluoride, other fluororesins, epoxy resins, phenol resins, urea resins, melamine resins, silicone resins, polyurethanes, etc., or copolymers, blends, polymer alloys, etc. mainly based on these Among them, it is preferable that the resin material is the same kind or the same as the resin material that mainly constitutes the second substrate 12 of the curved optical sheet 10, which will be described later. Thereby, it is possible to improve the adhesion between the resin layer 35 and the curved optical sheet 10. Furthermore, since the refractive index difference between the resin layer 35 and the curved optical sheet 10 (second substrate 12) can be set low, light is diffusely reflected between the resin layer 35 and the curved optical sheet 10. Since this can be accurately suppressed or prevented, light can be transmitted between the resin layer 35 and the curved optical sheet 10 with excellent light transmittance. Note that the refractive index difference between the resin layer 35 and the curved optical sheet 10 (second substrate 12) is preferably 0.1 or less, more preferably 0.05 or less. Thereby, the effect obtained by setting the refractive index difference to a low value can be more clearly exhibited.

The thickness of the resin layer 35 is not particularly limited, and is preferably, for example, 0.5 mm or more and 5.0 mm or less, and more preferably 1.0 mm or more and 3.0 mm or less. Thereby, the lens 30 can achieve both relatively high strength and weight reduction.

The curved optical sheet 10 has a curved shape having a curved convex surface and a curved concave surface corresponding to the shape on the outer surface of the resin layer 35, that is, the curved convex surface of the resin layer 35. The curved concave surface of the resin layer 35 is a curved resin substrate that is bonded with the curved concave surface as the curved convex surface side of the resin layer 35, and by providing the lens 30 with this curved optical sheet 10, the sunglasses 100 are given half mirror properties and polarizing properties. . As a result, the sunglasses 100 function as sunglasses having both half-mirror properties and polarization properties. This curved optical sheet 10 is made of the optical sheet of the present invention in a curved shape, and its detailed explanation will be given later.

Note that, as described above, the lenses 30 included in the sunglasses 100 may or may not have a light collecting function.

In addition to having the frame 20 as described above, the sunglasses 100 may have a frameless structure from the viewpoint of fashionability, lightness, etc.

Further, in the present embodiment, the glasses including the lenses 30 are applied to the sunglasses 100, but the glasses are not limited to this, and can be used, for example, to prevent prescription glasses, fancy glasses, wind and rain, dust, chemicals, etc. It may also be goggles or the like to protect the eyes.

In the sunglasses 100 (glasses) having the above configuration, the lenses 30 included in the sunglasses 100 are manufactured by, for example, a method for manufacturing the lenses 30 as shown below.

<Lens manufacturing method>
FIG. 2 is a schematic diagram for explaining a method of manufacturing a lens having a curved optical sheet according to the present invention. Note that, hereinafter, for convenience of explanation, the upper side of FIG. 2 will be referred to as "upper" and the lower side will be referred to as "lower".

Hereinafter, each step of the method for manufacturing a lens 30 including a curved optical sheet 10 in which the optical sheet 15 of the present invention is curved will be described in detail.
[1] First, an optical sheet 15 (optical sheet of the present invention) having a flat overall shape is prepared, which includes a first substrate 11, a polarizing film 13, and a second substrate 12, which are laminated in this order. do. Then, by pasting protective films 50 (masking tape) on both sides of this optical sheet 15, a multilayer laminate 150 in which protective films 50 are pasted on both sides of the optical sheet 15 is obtained (see FIG. 2(a)). .

[2] Next, as shown in FIG. 2(b), the prepared multilayer laminate 150, that is, the optical sheet 15 with the protective film 50 attached to both sides of the optical sheet 15, is heated in the thickness direction. By punching, the multilayer laminate 150 has a circular shape in plan view.

[3] Next, as shown in FIG. 2(c), the multilayer laminate 150 having a circular shape is subjected to thermal bending under heating, so that the multilayer laminate 150 is shaped like the first substrate 11. The curved multilayer laminate 200 has a curved shape in which the side (one surface side) is a curved convex surface and the second substrate 12 side (the other surface side) is a curved convex surface. Thereby, the flat optical sheet 15 can be made into the curved optical sheet 10 having a curved shape with the protective film 50 attached to both sides.

This heat bending process is usually performed by press molding or vacuum forming.
At this time, the heating temperature (molding temperature) of the multilayer laminate 150 (optical sheet 15) is as described above. In consideration of the melting or softening temperature of 12 and the base materials 111 and 112, the temperature is preferably set to about 180°C or more and 320°C or less, more preferably about 230°C or more and 300°C or less. By setting the heating temperature within this range, the optical sheet 15 is softened or melted while preventing deterioration or deterioration of the optical sheet 15, and the optical sheet 15 is reliably thermally bent to form a curved shape. It can be an optical sheet 10.

[4] Next, the protective film 50 is peeled off from the curved optical sheet 10 that has been thermally bent. Thereafter, as shown in FIG. 2(d), the curved concave surface of the mold 40 and the curved convex surface of the curved optical sheet 10 are brought into contact with a mold 40 having a curved concave surface. With the sheet 10 adsorbed, a resin layer 35 mainly made of a resin material is injection molded onto the curved concave surface of the curved optical sheet 10 using, for example, an insert injection molding method. That is, by cooling and solidifying the molten material of the resin layer 35 in contact with the curved concave surface of the curved optical sheet 10, an adhesive layer or the like is formed on the curved concave surface of the curved optical sheet 10. The resin layer 35 is molded in direct contact with the resin layer 35 without intervening. As a result, a lens 30 (optical component of the present invention) including the thermally bent curved optical sheet 10 and the resin layer 35 is manufactured.

When injection molding this resin layer 35, the heating temperature (molding temperature) of the constituent material of the resin layer 35 to bring it into a molten state is set as appropriate depending on the type of constituent material of the resin layer 35. When the constituent material of the layer 35 is the same kind or the same as the constituent material of the first substrate 11 included in the curved optical sheet 10 described later, the temperature is preferably 180°C or more and 320°C or less, more preferably 230°C or more and 300°C or less. Set. By setting the heating temperature within this range, the constituent material of the resin layer 35 in a molten state can be reliably supplied to the curved concave surface of the curved optical sheet 10.

Moreover, among the insert injection molding methods, the injection compression molding method is preferably used. In the injection compression molding method, a resin material for forming the resin layer 35 is injected into the mold 40 at low pressure, and then the mold 40 is closed at high pressure to apply compressive force to the resin material. This is preferably used because optical anisotropy due to molding distortion or local orientation of resin molecules during molding is less likely to occur in the resin layer 35 as a molded body, and thus in the lens 30. Further, by controlling the mold compression force uniformly applied to the resin material, the resin material can be cooled at a constant specific volume, so it is possible to obtain the resin layer 35 with high dimensional accuracy.

The optical sheet 15 of the present invention having a curved shape is used as the curved optical sheet 10 included in the lens 30 manufactured by the lens manufacturing method described above. Hereinafter, each embodiment of this optical sheet 15 will be described in detail.
<<First embodiment>>
FIG. 3 is a longitudinal cross-sectional view showing the first embodiment of the optical sheet of the present invention, and FIG. 4 shows a half mirror layer included in the optical sheet located in the region [B] surrounded by the dashed line in FIG. FIG. 3 is an enlarged cross-sectional view of a portion thereof.

Note that, hereinafter, for convenience of explanation, the upper side of FIG. 3 will be referred to as "upper" and the lower side will be referred to as "lower". In addition, the x direction in Figures 3 and 4 is referred to as the "left-right direction" or "flow direction (MD)," the y direction is referred to as the "back-and-forth direction" or "vertical direction (TD)," and the z direction is referred to as the "up-down direction." . Further, in FIGS. 3 and 4, the thickness direction of the optical sheet is exaggerated, so the dimensions differ greatly from the actual dimensions.

In this embodiment, as shown in FIG. 3, the optical sheet 15 (optical substrate) includes a first substrate 11 having a light transmittance and a light transmittance provided on one side of the first substrate 11. It includes a second substrate 12 and a polarizing film 13 provided between the first substrate 11 and the second substrate 12.

Further, the first substrate 11 includes a first base material 111 having a light transmittance, a second base material 112 having a light transmittance provided on one side of the first base material 111, and a first base material 111 having a light transmittance. 111 and a half mirror layer 113 provided between the second base material 112.

By setting the positional relationship in which each layer is arranged in the optical sheet 15 as described above, the polarizing film 13 and the half mirror layer 113 are located between the first substrate 11 and the second substrate 12, It is not exposed on the surface of the optical sheet 15. That is, the polarizing film 13 and the half mirror layer 113 do not constitute the outermost layer exposed on the top or bottom surface of the optical sheet 15. Therefore, as in the case where the outermost layer is configured, the polarizing film 13 and the half mirror layer 113 are prevented from colliding with dust, rain, etc., and the polarizing film 13 and the half mirror layer 113 are abraded by other members, etc. can be reliably prevented. Therefore, it is possible to reliably prevent the polarizing film 13 and the half mirror layer 113 from being damaged by this collision or friction. Therefore, the optical sheet 15 can maintain its design and optical properties over a long period of time.

Furthermore, in the optical sheet 15 having such a configuration, the half mirror layer 113 is composed of a laminate in which high refractive index layers 31 and low refractive index layers 32 are alternately and repeatedly laminated. As a result, the half mirror layer 113 selectively reflects light in a specific wavelength range among the incident light and transmits the remaining part, so that when a person is located on the back side of the optical sheet 15, When a person wears the sunglasses 100, the person (wearer) can visually recognize the front side of the optical sheet 15 through the optical sheet 15. In addition, since the light in a specific wavelength range reflected on the front side of the optical sheet 15 will be visible to a person located on the opposite side of the wearer via the optical sheet 15, the optical sheet 15 may be It can be considered as having gender.

The optical sheet 15 also has a polarizing film 13 that has a function of extracting linearly polarized light having a plane of polarization in one predetermined direction from incident light (unpolarized natural light). Therefore, the light passing through the optical sheet 15 can be polarized.
Each layer constituting this optical sheet 15 will be explained below.

In the present invention, in the optical sheet 15, the first substrate 11 has a retardation of 2000 nm or more and 7000 nm or less, and is provided on one surface side of the first base material 111 that has light transmittance. The first base material 111 is composed of a laminate including a second base material 112 having light transmittance, and a half mirror layer 113 provided between the first base material 111 and the second base material 112. The interface between the first base material 111 and the half mirror layer 113 forms a continuous layer, and the interface between the second base material 112 and the half mirror layer 113 forms a continuous layer between the second base material 112 and the half mirror layer 113. It forms a continuous layer with the mirror layer 113.

The first base material 111 supports a half-mirror layer 113 (laminate), and is an optical device in which the half-mirror layer 113 and the polarizing film 13 are disposed between the first base material 111 and a second substrate 12, which will be described later. It constitutes the outermost layer of the sheet 15 and has a function as a protective layer that protects the half mirror layer 113 and the polarizing film 13.

This first base material 111 is not particularly limited as long as it is mainly composed of a transparent resin material, but it may contain a thermoplastic transparent resin (base resin) as its main material. It is preferable.

Note that, in this specification, the term "main material" refers to a constituent material containing 50% by weight or more of the constituent materials constituting the layer (base material) containing this material.

Examples of the transparent resin include, but are not limited to, acrylic resins, polystyrene resins, polyethylene resins, polypropylene resins, polyester resins such as polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), and polycarbonate resins. , polyamide resins, cycloolefin resins, vinyl chloride resins, polyacetal resins, and other transparent resins, and one type or a combination of two or more of these can be used. Among these, polycarbonate resins or polyamide resins are preferred, and polycarbonate resins are particularly preferred. Polycarbonate-based resin has high mechanical strength such as transparency (translucency) and rigidity, and also has high heat resistance. Therefore, by using polycarbonate-based resin as the transparent resin, the transparency and The impact resistance and heat resistance of the base material 111 can be improved.

Although various resins can be used as the polycarbonate resin, aromatic polycarbonate resins are particularly preferred. The aromatic polycarbonate resin has an aromatic ring in its main chain, and as a result, the first base material 111 having superior strength can be obtained.

This aromatic polycarbonate resin is synthesized, for example, by interfacial polycondensation reaction between bisphenol and phosgene, transesterification reaction between bisphenol and diphenyl carbonate, and the like.

Examples of bisphenol include bisphenol A and bisphenol (modified bisphenol) which is the origin of the repeating unit of polycarbonate shown in the following formula (1A).

(In formula (1A), X is an alkyl group having 1 to 18 carbon atoms, an aromatic group, or a cycloaliphatic group, and Ra and Rb are each independently an alkyl group having 1 to 12 carbon atoms. , m and n are each integers from 0 to 4, and p is the number of repeating units.)

In addition, specific examples of the bisphenol that is the origin of the repeating unit of the polycarbonate shown in the formula (1A) include 4,4'-(pentane-2,2-diyl)diphenol, 4,4'-( Pentane-3,3-diyl)diphenol, 4,4'-(butane-2,2-diyl)diphenol, 1,1'-(cyclohexanediyl)diphenol, 2-cyclohexyl-1,4-bis( 4-hydroxyphenyl)benzene, 2,3-biscyclohexyl-1,4-bis(4-hydroxyphenyl)benzene, 1,1'-bis(4-hydroxy-3-methylphenyl)cyclohexane, 2,2'- Examples include bis(4-hydroxy-3-methylphenyl)propane, and one or more of these may be used in combination.

In particular, as the polycarbonate resin, it is preferable to use a bisphenol type polycarbonate resin having a skeleton derived from bisphenol as a main component. By using such a bisphenol type polycarbonate resin, the first base material 111 exhibits even better strength.

The glass transition temperature (Tg) of the resin material contained as the main material in the first base material 111 is preferably 100°C or more and 190°C or less, more preferably 105°C or more and 155°C or less. Thereby, the formation of the curved optical sheet 10 by thermal bending of the optical sheet 15 in the step [3] can be performed relatively easily. Moreover, when causing the first substrate 11 to develop retardation, stretching for developing this retardation can be suitably performed. Furthermore, the durability and reliability of the optical sheet 15 can be improved.

Further, the first base material 111 may be colorless, or may have any color such as red, blue, yellow, etc., as long as it has light transmittance.

Selection of these colors is made possible by containing dye or pigment in the first base material 111. Examples of the dye include acid dyes, direct dyes, reactive dyes, and basic dyes, and one type or a combination of two or more types selected from these can be used.

Specific examples of dyes include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C. I. Acid Red 52, 80, 82, 249, 254, 289, C. I. Acid Blue 9,45,249, C. I. Acid Black 1, 2, 24, 94, C. I. Food black 1, 2, C. I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, C. I. Direct Red 1, 4, 9, 80, 81, 225, 227, C. I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C. I. Direct black 19, 38, 51, 71, 154, 168, 171, 195, C. I. Reactive Red 14, 32, 55, 79, 249, C. I. Examples include Reactive Black 3, 4, and 35.

The first base material 111 may optionally contain, in addition to the above-mentioned transparent resin, dye, or pigment, an antioxidant, a filler, a plasticizer, a light stabilizer, an ultraviolet absorber, a heat ray absorber, and a flame retardant. It may contain various additives such as.

In this case, the content of the resin material in the first substrate 11 is not particularly limited, but is preferably 75% by weight or more, more preferably 85% by weight or more. By setting the content of the resin material within the above range, the optical sheet 15 can exhibit excellent strength.

Further, the refractive index of the first base material 111 at a wavelength of 589 nm is preferably 1.3 or more and 1.8 or less, and more preferably 1.4 or more and 1.65 or less. By setting the refractive index of the first base material 111 within the above numerical range, it is possible to accurately suppress or prevent the functions of the polarizing film 13 and the half mirror layer 113 from being inhibited.

The average thickness of the first base material 111 is preferably set to 0.1 mm or more and 1.5 mm or less, more preferably 0.2 mm or more and 0.8 mm or less. By setting the average thickness of the first base material 111 within this range, it is possible to reduce the thickness of the optical sheet 15 while accurately suppressing or preventing the optical sheet 15 from being bent. Therefore, the color of the light in the specific wavelength range that is selectively reflected by the half mirror layer 113 can be more uniformly viewed over the entire optical sheet 15.

The second base material 112 has a function of supporting the half mirror layer 113 (optical multilayer film) and the polarizing film 13.

The second base material 112 can be made of the same materials as those mentioned for the first base material 111. Note that the constituent material of the second base material 112 and the constituent material of the first base material 111 may be the same (same type) or may be different.

Further, the refractive index of the second base material 112 at a wavelength of 589 nm may be the same or different from the refractive index of the first base material 111, but is 1.3 or more and 1.8 or less. It is preferably 1.4 or more and 1.65 or less. By setting the refractive index of the second base material 112 within the above numerical range, it is possible to accurately suppress or prevent the functions of the polarizing film 13 and the half mirror layer 113 from being inhibited.

Further, the average thickness of the second base material 112 may be the same or different from that of the first base material 111, but for example, the average thickness is 0.2 mm or more and 1.5 mm or less. It is preferably 0.2 mm or more and 0.8 mm or less. By setting the average thickness of the second base material 112 within this range, it is possible to reduce the thickness of the optical sheet 15 while accurately suppressing or preventing the optical sheet 15 from being bent. Therefore, the color of the light in the specific wavelength range that is selectively reflected by the half mirror layer 113 can be more uniformly viewed over the entire optical sheet 15.

The half mirror layer 113 is an intermediate layer located at the center of the first substrate 11 in the thickness direction, and in the present invention, it selectively reflects light having a specific wavelength range (specific wavelength range), and by this reflection, The remainder, which is the light that is not reflected, is transmitted.

As shown in FIG. 4, the half mirror layer 113 is formed by alternately and repeatedly stacking a high refractive index layer 31 having a high refractive index and a low refractive index layer 32 having a low refractive index for light in the visible light region. It is provided with a repeating portion 33 made of a laminate. In other words, the half mirror layer 113 is constructed of a multilayer laminate in which the repeating portions 33 are stacked multiple times, so that the structure in which one high refractive index layer 31 is sandwiched between two low refractive index layers 32 is repeated. It is something that you have.

In this half mirror layer 113, the high refractive index layer 31 contains a resin material that has a high refractive index for light in the visible light region, and the low refractive index layer 32 contains a resin material that has a high refractive index for light in the visible light region. By having a structure containing a low resin material, between the high refractive index layer 31 and the low refractive index layer 32, the refractive index difference for light in the visible light region is increased and the refractive index difference for unreflected light is decreased. be able to. This allows the half mirror layer 113 to function as a multilayer laminate, that is, a multilayer laminate reflector that selectively reflects light in a specific wavelength region of the visible light region and transmits the remaining light that is not reflected as transmitted light. can be granted. In other words, when light in the visible light region enters the half mirror layer 113 as incident light, the half mirror layer 113 blocks (reflects) the reflected light (reflected light) of the incident light to the maximum extent possible. On the other hand, when light that is not reflected (transmitted light) enters the half mirror layer 113 as incident light, the multilayer laminated reflecting plate blocks the transmitted light with a minimum amount, that is, transmits it with a maximum amount. Demonstrate function.

Here, in order to selectively reflect light in a specific wavelength region of the visible light region and transmit the remaining light that is not reflected as transmitted light, specifically, in the half mirror layer 113, the high refractive index layer 31 When the refractive index at a wavelength of 589 nm is N1, and the refractive index at a wavelength of 589 nm of the low refractive index layer 32 is N2, the refractive index difference (N1-N2) is preferably 0.05 or more and 0.25 or less, more preferably Preferably, it is set to 0.08 or more and 0.25 or less. By setting the refractive index difference (N1-N2) at a wavelength of 589 nm within the above range, the refractive index difference for light in the visible light region is set to be large between the high refractive index layer 31 and the low refractive index layer 32. It can be said that the light in the visible light range can be blocked (reflected) to the maximum extent possible.

Note that a specific wavelength region of visible light that blocks (reflects) light in the visible light region to the maximum extent and blocks unreflected light to the minimum, and furthermore, the intensity of the light in that wavelength region is determined by the high refractive index layer 31. and the type of resin material contained in the low refractive index layer 32, the number of repetitions of the high refractive index layer 31 and the low refractive index layer 32 in the half mirror layer 113 (repetitive portion 33), and the The desired size (within a range) can be adjusted by appropriately setting the thicknesses of the index layer 31 and the low refractive index layer 32).

Therefore, by providing the lens 30 with the curved optical sheet 10 in which the optical sheet 15 has a curved shape, it is possible to prevent external light irradiated from the outside of the sunglasses 100, that is, direct sunlight and its reflected light. When transmitted through the optical sheet 15, light in a specific wavelength region in the visible light region is reflected by the optical sheet 15, and the remaining light, that is, attenuated light that is not reflected, reaches the eyes of the wearer of the sunglasses 100. It will be reached. This prevents light in a specific wavelength range from entering the eyes of visible light included in direct sunlight and reflected light, thereby improving the wearer's ability to recognize objects. can. On the other hand, light in a specific wavelength range (reflected light) reflected from the optical sheet 15 is visible to a person located on the opposite side of the wearer through the lens 30 (optical sheet 15). , the design of the sunglasses 100 can be improved. In this manner, the optical sheet 15 functions as a reflector that selectively reflects light having a specific wavelength range among visible light and selectively transmits the remainder.

Further, in the above-described lens manufacturing method, the optical sheet 15 is subjected to heat bending in the step [3] and injection molding in the step [4], so it undergoes a thermal history. In addition, as mentioned above, the heating temperature during these processes is preferably set to about 120° C. or more and 250° C. or less in the step [3], and preferably about 180° C. or more and 320° C. or less in the step [4]. Therefore, it is preferable that the half mirror layer 113 included in the optical sheet 15 has excellent heat resistance.

As described above, the half mirror layer 113 exhibits the characteristic of reflecting light in a specific wavelength region in the visible light region to the maximum extent, and transmitting the remaining light that is not reflected to the maximum extent. Therefore, it can be said that the half mirror layer 113 exhibits excellent heat resistance because the characteristics of the half mirror layer 113 are suitably maintained even when exposed to severe conditions.

Therefore, as the main material of the high refractive index layer 31 and the main material of the low refractive index layer 32 constituting the half mirror layer 113, a high refractive index that has a high refractive index with respect to light in the visible light region contained in each of them is used. When the glass transition point of the resin material included in the layer 31 is Tg1, and the glass transition point of the resin material included in the low refractive index layer 32, which has a low refractive index for light in the visible light region, is Tg2, Tg1, Tg2 It is preferable to satisfy the relationship ≧105°C. In this way, by preferably selecting a layer in which both Tg1 and Tg2 are 105° C. or higher, both the high refractive index layer 31 and the low refractive index layer 32 can have excellent heat resistance. Therefore, it is possible to accurately suppress or prevent a change in the film thickness of the refractive index layer having a lower glass transition point among the low refractive index layer 32 and the high refractive index layer 31. Therefore, the half mirror layer 113 included in the optical sheet 15 is excellent because it accurately suppresses or prevents deterioration of its function as a reflector that selectively reflects light in a specific wavelength range (visible light). Demonstrates excellent heat resistance. Note that the resin material with a low refractive index in the low refractive index layer 32 is generally selected to have a lower glass transition point than the resin material with a high refractive index included as the main material of the high refractive index layer 31. The tendency is high. Therefore, by using a resin material with a low refractive index whose glass transition point Tg2 is 105° C. or higher, the above effect can be reliably exhibited.

The optical sheet 15 including this half mirror layer 113 has a glass transition point Tg1 of the main material constituting the high refractive index layer 31 and a glass transition point Tg2 of the main material constituting the low refractive index layer 32, whichever is higher. Light with a wavelength of 589 nm from the curved optical sheet 10 when the optical sheet 15 is made into a curved shape with a radius of curvature of 60 mm by pressing it against a metal mold at a temperature 10° C. higher than the glass transition point. Let the reflectance of the curved optical sheet 10 be R1 [%], and after storing this curved optical sheet 10 in a thermal circulation oven at a temperature of 105°C for 1000 hours, the reflectance of the curved optical sheet 10 for light with a wavelength of 589 nm is R2 When expressed as [%], the reflectance retention determined by R2/R1 x 100 [%] is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. preferable.

As mentioned above, even if the curved optical sheet 10 having a curved shape with a radius of curvature of 60 mm is exposed to the severe condition of being stored for 1000 hours in a temperature environment of 105° C., the reflectance retention will not exceed the lower limit. Maintains a value greater than or equal to the value. As described above, since the reflectance retention is maintained at a ratio equal to or higher than the lower limit value, it can be said that this half mirror layer 113 exhibits excellent heat resistance. Further, the reflectance R1 of the curved optical sheet 10 for light having a wavelength of 589 nm is preferably 40% or more, and more preferably 45% or more and 70% or less. It can be said that such a curved optical sheet 10 reflects light in the visible light region with excellent reflectance.

In addition, as described above, the repeating portion 33 (laminate) blocks (reflects) light in the visible light region to the maximum extent and blocks unreflected light to the minimum in a specific wavelength region of visible light. The intensity of light in the wavelength region depends on the type of resin material contained in the high refractive index layer 31 and the low refractive index layer 32, and the high refractive index layer 31 and the low refractive index layer 32 in the half mirror layer 113 (repetitive portion 33). By appropriately setting the number of repetitions, the thickness of the half mirror layer 113 (high refractive index layer 31, low refractive index layer 32), etc., the desired size (within range) can be adjusted.

In such a half mirror layer 113 (repetitive part 33), specifically, using the sodium D line (589 nm), which is generally used as a reference wavelength of visible light, as a representative value, a high refractive index layer at a wavelength of 589 nm is used. The half mirror layer 113 (Repeat portion 33) That is, the reflecting plate may be configured to reflect light in a visible light region, specifically, light in a specific wavelength range of visible light in a wavelength range of 400 nm to 780 nm to the maximum.

Furthermore, as the main material of the high refractive index layer 31 and the main material of the low refractive index layer 32, a glass transition point Tg1 of a resin material that has a high refractive index for light in the visible light region and is included in the high refractive index layer 31; By selecting a resin material that is included in the low refractive index layer 32 and has a low refractive index for light in the visible light region, the glass transition point Tg2 preferably satisfies the relationship Tg1, Tg2≧105°C. The half mirror layer 113 (repetitive portion 33), that is, the reflective plate (multilayer laminated reflective plate) can exhibit excellent heat resistance.

As described above, the high refractive index layer 31 has a refractive index difference (N1-N2) of preferably 0.05 or more and 0.25 or less, and further preferably satisfies Tg1, Tg2≧105°C. The main material, that is, the resin material that has a high refractive index for light in the visible light region, and the main material of the low refractive index layer 32, that is, the resin material that has a low refractive index for light in the visible light region, are amorphous. It is preferably at least one of polycarbonate resins, polystyrene resins, polyether resins, styrene resins, polyester resins, and acrylic resins, and polycarbonate resins, polyether resins, and polyester resins. More preferably, it is at least one of the resins. By appropriately selecting the main materials of the high refractive index layer 31 and the low refractive index layer 32 from these materials, the half mirror layer 113 including the high refractive index layer 31 and the low refractive index layer 32 can be formed relatively easily. It is possible to satisfy both that the rate difference (N1-N2) is 0.05 or more and 0.25 or less, and that Tg1, Tg2≧105°C.

Considering the above points, the main materials for the high refractive index layer 31 include polyester resins such as polycarbonate (PC), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), polyether sulfone ( At least one of PES) and polyarylate (PAR) is preferably selected.

The main materials of the low refractive index layer 32 include polyester resins such as polycarbonate (PC), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), and acrylic resins such as polymethyl methacrylate (PMMA). , polystyrene (PS), styrenic resin such as acrylonitrile-styrene copolymer (AS), and polyarylate (PAR).

When using such a resin material, the combination of main materials contained in the high refractive index layer 31 and the low refractive index layer 32 is specifically polycarbonate (PC) and polymethyl methacrylate (PMMA). combination, combination of polyarylate (PAR) and polymethyl methacrylate (PMMA), combination of polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA), combination of polyethersulfone (PES) and polyarylate (PAR). ), a combination of polyethylene naphthalate (PEN) and acrylonitrile-styrene copolymer (AS), a combination of polyethylene naphthalate (PEN) and polymethyl methacrylate (PMMA), etc. According to such a combination, both the refractive index difference (N1-N2) of 0.05 or more and 0.25 or less and Tg1, Tg2≧105°C can be more easily satisfied. It can be done.

Note that the high refractive index layer 31 and the low refractive index layer 32 may each contain an additive such as a filler in addition to the main material. Thereby, the half mirror layer 113 including the high refractive index layer 31 and the low refractive index layer 32 has a refractive index difference (N1-N2) of 0.05 or more and 0.25 or less, and Tg1, Tg2≧105°C. This makes it easier to satisfy both the

Examples of fillers include, but are not limited to, inorganic fillers such as silica, alumina, calcium carbonate, strontium carbonate, calcium phosphate, kaolin, talc, and smectite, crosslinked polystyrene, and styrene-divinylbenzene copolymers. Among them, organic fillers such as strontium carbonate and smectite are preferred, and at least one of strontium carbonate and smectite is preferred. It is more preferable that there be.

Further, the filler may have any shape such as spherical or flat particulate, granule, pellet, or scale, but it is preferably contained in particulate form.

In the high refractive index layer 31 and the low refractive index layer 32 obtained by the combination of resin materials as described above, the glass transition point Tg1 of the resin material having a high refractive index for light in the visible light region and the light in the visible light region The glass transition point Tg2 of a resin material having a low refractive index preferably satisfies the relationship Tg1, Tg2≧105°C. It is preferable that the lower temperature of Tg1 and Tg2 satisfies the relationship that the lower temperature is 110°C or more and 250°C or less, and the relationship that the lower temperature of Tg1 and Tg2 is 110°C or more and 200°C or less is satisfied. It is better to be satisfied. Further, it is preferable to satisfy the relationship 0°C≦|Tg1−Tg2|≦60°C, and more preferably to satisfy the relationship 25°C≦|Tg1−Tg2|≦60°C. In this way, both Tg1 and Tg2 are within the above range, and by selecting a layer in which the difference between the two is equal to or less than the upper limit value, both the high refractive index layer 31 and the low refractive index layer 32 can be Since the half mirror layer 113 can be made to have excellent heat resistance, it is possible to ensure that the half mirror layer 113 exhibits excellent heat resistance.

Further, the refractive index difference (N1-N2), which is a relational expression between the refractive index N1 of the high refractive index layer 31 at a wavelength of 589 nm and the refractive index N2 of the low refractive index layer 32 at a wavelength of 589 nm, is 0.05 or more. The refractive index N1 of the high refractive index layer 31 is preferably 1.57 or more and 1.85 or less at a wavelength of 589 nm. It is preferable that the refractive index N2 is 1.49 or more and 1.67 or less. Thereby, light in a specific wavelength region in the visible light region can be more reliably reflected.

Furthermore, the average thickness of the high refractive index layer 31 and the low refractive index layer 32 is preferably 50 nm or more and 300 nm or less, and more preferably 50 nm or more and 200 nm or less. In the average thickness within this range, the optical thickness (average thickness of the layer x refractive index of the layer) of the high refractive index layer 31 and the low refractive index layer 32 is determined by the wavelength of light in the visible light region to be selectively reflected. Set the size to 1/4 of the original size. Thereby, the light reflected at the interface can be strengthened, so that the half mirror layer 113 can selectively reflect light in a specific wavelength region in the visible light region.

Further, in the repeating portion 33 in which the high refractive index layer 31 and the low refractive index layer 32 are laminated, the number of laminations is preferably 50 or more and 750 or less, and 100 or more and 600 or less. is more preferable.

Visible The specific wavelength (wavelength region) of light that is blocked to the maximum in the optical region can be adjusted to a desired size (within a range).

The first substrate 11 as described above is composed of a laminate in which the first base material 111, the half mirror layer 113, and the second base material 112 are bonded to each other and stacked in this order. , the optical sheet 15 including the first substrate 11 is subjected to the heat bending process in step [3] in the above-described lens manufacturing method, so that the optical sheet 15 includes the first substrate 11 (first base material 111) side ( The optical sheet 10 is thermally bent into a curved optical sheet 10 having a curved convex surface on the upper side and a concave curved surface on the second substrate 12 side (lower side). Therefore, the first substrate 11 formed of a laminate is required to have excellent workability in the optical sheet 15.

The first base material 111 and the second base material 112 contain a resin material as their main material. Further, as described above, in the present invention, the half mirror layer 113 is made of materials having a glass transition point of Tg1 as the main material of the high refractive index layer 31 and the main material of the low refractive index layer 32 that constitute the half mirror layer 113. It contains a resin material whose glass transition temperature is Tg2.

In this way, the main materials of the first base material 111 and the second base material 112 and the main materials of the high refractive index layer 31 and the low refractive index layer 32 that constitute the half mirror layer 113 are both made of resin materials. By doing so, excellent workability can be imparted to the first substrate 11 composed of these laminates. Therefore, when the optical sheet 15 including the first substrate 11 is thermally bent into a curved shape, for example, the high refractive index layer 31 and the low refractive index layer 32 are made of a metal-based (inorganic) material. It is possible to accurately suppress or prevent the occurrence of cracks in the high refractive index layer 31 and the low refractive index layer 32, as in the case of

In the present invention, in such a first substrate 11, the interface between the first base material 111 and the half mirror layer 113 forms a continuous layer of the first base material 111 and the half mirror layer 113, and the second base material 111 and the half mirror layer 113 form a continuous layer. The interface between the base material 112 and the half mirror layer 113 forms a continuous layer of the second base material 112 and the half mirror layer 113. In this way, in the first substrate 11, at the interface where the layers constituting the substrate are bonded to each other, a continuous layer is formed in which the constituent materials contained in the bonded layers are mixed with each other. Therefore, the adhesion between the first base material 111 and the half mirror layer 113 and the adhesion between the second base material 112 and the half mirror layer 113 are improved. Therefore, in the step [3], the curved optical sheet is formed into a curved shape in which the first substrate 11 (first base material 111) side (upper side) is a curved convex surface and the second substrate 12 side (lower side) is a curved concave surface. 10, even if the optical sheet 15 including the first substrate 11 is thermally bent, the interface between the first base material 111 and the half mirror layer 113 and the interface between the second base material 112 and the half mirror At the interface with layer 113, it is possible to accurately suppress or prevent separation between these layers. Therefore, better workability can be imparted to the optical sheet 15.

In addition, in this way, a continuous layer of the first base material 111 and the half mirror layer 113 is formed at the interface between the first base material 111 and the half mirror layer 113, and a continuous layer of the first base material 111 and the half mirror layer 113 is formed. At the interface, a continuous layer of the second base material 112 and the half mirror layer 113 is formed, and the formation of an adhesive layer for joining the base materials 111, 112 and the half mirror layer 113 is omitted. Therefore, it is possible to improve productivity when manufacturing the optical sheet 15.

Note that this continuous layer refers to a state in which the constituent materials contained in the first base material 111 and the half mirror layer 113 are mixed with each other at the interface between the first base material 111 and the half mirror layer 113, More specifically, at the interface between the first base material 111 and the half mirror layer 113, the constituent material of the first base material 111 is dispersed on the half mirror layer 113 side, and furthermore, the constituent material of the half mirror layer 113 is dispersed on the half mirror layer 113 side. This refers to a state in which the particles are dispersed on the 1 base material 111 side. Further, at the interface between the second base material 112 and the half mirror layer 113, the constituent materials contained in the second base material 112 and the half mirror layer 113 are mixed with each other. At the interface between the base material 112 and the half mirror layer 113, the constituent material of the second base material 112 is dispersed on the half mirror layer 113 side, and the constituent material of the half mirror layer 113 is further dispersed on the second base material 112 side. Refers to a dispersed state.

Further, in the present invention, the first substrate 11 constituted by a laminate including the first base material 111, the half mirror layer 113, and the second base material 112 as described above has a retardation (birefringence x thickness) is set within a range of 2000 nm or more and 7000 nm or less. Thereby, polarization can be imparted to the first substrate 11.

The first substrate 11 is arranged such that its slow axis (or fast axis) is parallel to the absorption axis of the polarizing film 13.

The first substrate 11 whose retardation size is set within the above range is coated with the first adhesive so that its slow axis (or fast axis) is parallel to the absorption axis of the polarizing film 13. By bonding to the polarizing film 13 via the layer 14, the optical sheet 15 is thermally bent so that the first substrate 11 side is the curved convex side to form a curved optical sheet 10. When viewed from the curved concave side, that is, from the second substrate 12 side, it is possible to accurately suppress or prevent coloring of the transmitted image caused by optical distortion of the first substrate 11, thereby ensuring a clear field of view. Further, when the retardation of the first substrate 11 is lower than 2000 nm, blurring of the transmitted image occurs significantly. Further, if it is higher than 7000 nm, a problem occurs during thermal bending of the optical sheet 15 to form the curved optical sheet 10, and the desired radius of curvature cannot be obtained.

The retardation of the first substrate 11 may be set within a range of 2000 nm or more and 7000 nm or less, preferably 2500 nm or more and 6000 nm or less, and more preferably 3000 nm or more and 5000 nm or less. Thereby, when viewed from the second substrate 12 side, coloring of the transmitted image can be more accurately suppressed or prevented, and a clear field of view can be ensured.

Further, it is particularly preferable that the slow axis (or fast axis) of the first substrate 11 and the absorption axis of the polarizing film 13 are parallel to each other, preferably about ±3°, more preferably ±1 It is permissible for a deviation to occur within a range of about . Even if such a shift occurs, it is possible to reliably prevent the transmitted image from being colored due to optical distortion of the first substrate 11 when viewed from the concave side of the curved surface. In addition, the "slow axis" refers to the direction in which the speed of light passing through the first substrate 11 is slow (the phase is delayed), and on the contrary, the direction in which the light travels is fast (the phase is advanced). The direction is called the "fast axis" of the retarder.

Note that the difference in retardation of the first substrate 11 can be achieved by varying the constituent materials contained in the layers, the thickness, and the stretching ratio.

Further, the optical sheet 15 including the first substrate 11 has a higher glass transition point Tg1 of the main material forming the high refractive index layer 31 and a glass transition point Tg2 of the main material forming the low refractive index layer 32. By pressing the optical sheet 15 against a metal mold at a temperature 10° C. higher than the glass transition point of the other side, the optical sheet 15 is made into a curved optical sheet 10 having a curved shape with a radius of curvature of 60 mm, and this curved optical sheet 10 is heated through thermal circulation. Out of 50 curved optical sheets 10, the number of curved optical sheets 10 that maintained a shape with a radius of curvature of 60 ± 5 mm after being stored in a 105° C. temperature environment for 1000 hours in an oven was 48. The number is preferably at least 50, more preferably 50.

As mentioned above, even if the curved optical sheet 10, which has a curved shape with a radius of curvature of 60 mm, is exposed to the harsh conditions of being stored in a temperature environment of 105° C. for 1000 hours, the shape of the curved optical sheet 10 is maintained. The property is maintained to be equal to or higher than the lower limit value. In this way, since the shape retention is maintained at a rate equal to or higher than the lower limit value, it can be said that this curved optical sheet 10 exhibits excellent workability.

Further, as described above, after the curved optical sheet 10 is stored in a thermal circulation oven in a temperature environment of 105° C. for 1000 hours, the space between the first base material 111 and the half mirror layer 113 or the second base material It is preferable that the number of sheets in which peeling occurs between the material 112 and the half mirror layer 113 is 2 or less out of the 50 curved optical sheets, and more preferably 0.

As mentioned above, even if the curved optical sheet 10, which has a curved shape with a radius of curvature of 60 mm, is exposed to the harsh conditions of being stored in a temperature environment of 105° C. for 1000 hours, peeling occurs in the curved optical sheet 10. is maintained below the upper limit value. In this way, since the occurrence of peeling is suppressed to a rate below the upper limit value, this curved optical sheet 10 can be used to suppress the occurrence of peeling between the base materials 111, 112 and the half mirror layer 113. Therefore, it can be said that it exhibits excellent workability.

The first substrate 11 having such a configuration includes a first base material 111 and a half mirror layer 113 in which a plurality of repeating parts 33 are formed in which a high refractive index layer 31 and a low refractive index layer 32 are alternately and repeatedly laminated. and the second base material 112 are bonded and laminated together in this order to integrally form a film, and then this product is stretched in the machine direction (MD). Specifically, for example, it can be manufactured as follows.

That is, first, as resin compositions for forming the high refractive index layer 31 and the low refractive index layer 32, a resin material having a high refractive index with respect to light in the visible light region and a resin material with a high refractive index with respect to light in the visible light region are used, respectively. On the other hand, by preparing a material containing a resin material with a low refractive index as the main material and laminating these layers alternately, a repeating section in which the high refractive index layer 31 and the low refractive index layer 32 are alternately and repeatedly laminated. After obtaining a plurality of laminates in which a plurality of 33 (laminates) were laminated, resin compositions mainly composed of resin materials for forming the first base material 111 and the second base material 112 were obtained. By laminating the upper and lower surfaces of the multiple laminate, an integrated body in which the first base material 111, the multiple laminate, and the second base material 112 are laminated in this order is obtained (lamination step). In other words, an integrated product is obtained in which the upper and lower surfaces of the multiple laminate are covered with the first base material 111 and the second base material 112 as coating layers (skin layers), respectively.

In this way, the method for obtaining an integrated product in which the first base material 111, a plurality of laminates, and the second base material 112 are laminated in this order is not particularly limited, but for example, each layer may be obtained by using several extruders. Feedblock method, coextrusion T-die method such as multi-manifold method, and air-cooled or water-cooled coextrusion inflation method include melt-extrusion of resin compositions containing resin materials as raw materials, respectively. In particular, coextrusion T-die method is preferred. The coextrusion T-die method is preferably used because it is excellent in controlling the thickness of each layer formed so as to overlap each other in the thickness direction.

Next, the obtained integrated product is cooled, dried and solidified (cooling step). Thereby, a laminate in which the first base material 111, the half mirror layer 113, and the second base material 112 are bonded to each other and stacked in this order can be integrally obtained.

Then, by stretching the obtained laminate in the machine direction (MD), it is possible to obtain the first substrate 11 whose retardation is set within a range of 2000 nm or more and 7000 nm or less.

Note that the stretching ratio of the laminate when stretching the laminate in the MD is preferably 1.2 or more, more preferably 1.5 or more and 3.0 or less. Thereby, the retardation of the first substrate 11 can be set within the above range relatively easily.

The polarizing film 13 constitutes a polarizer that has a function of extracting linearly polarized light having a plane of polarization in one predetermined direction from incident light (unpolarized natural light). Thereby, the light passing through the optical sheet 15 becomes polarized.

The degree of polarization of the polarizing film 13 is not particularly limited, but is preferably, for example, 50% or more and 100% or less, more preferably 80% or more and 100% or less. Further, the visible light transmittance of the polarizing film 13 is not particularly limited, but is preferably, for example, 10% or more and 80% or less, and more preferably 20% or more and 50% or less.

The constituent material of the polarizing film 13 is not particularly limited as long as it has the above-mentioned functions, but examples thereof include polyvinyl alcohol (PVA), partially formalized polyvinyl alcohol, polyethylene vinyl alcohol, polyvinyl butyral, polycarbonate, and ethylene-vinyl alcohol. A polymer film composed of partially saponified vinyl acetate copolymer, etc., is dyed by adsorbing a dichroic substance such as iodine or a dichroic dye, and then uniaxially stretched, a dehydrated product of polyvinyl alcohol, or a polyvinyl alcohol film. Examples include polyene-based oriented films such as vinyl chloride treated with dehydrochloric acid.

Among these, the polarizing film 13 is preferably a polymer film mainly made of polyvinyl alcohol (PVA), which is dyed by adsorbing iodine or a dichroic dye, and then uniaxially stretched. Polyvinyl alcohol (PVA) is a material that is excellent in transparency, heat resistance, affinity with iodine or dichroic dyes as dyeing agents, and orientation during stretching. Therefore, the polarizing film 13 mainly made of PVA has excellent heat resistance and polarizing ability.

The dichroic dyes include, for example, chloratin fast red, Congo red, brilliant blue 6B, benzopurpurin, chlorazole black BH, direct blue 2B, diamine green, chrysophenone, sirius yellow, direct fast red, and acid black. Examples include.

The refractive index of the polarizing film 13 at a wavelength of 589 nm is not particularly limited, but is preferably, for example, 1.45 or more and 1.55 or less, and preferably 1.47 or more and 1.53 or less.

Further, the thickness of the polarizing film 13 is not particularly limited, and is preferably, for example, 5 μm or more and 60 μm or less, and more preferably 10 μm or more and 40 μm or less.

The second substrate 12 supports the polarizing film 13 and has a half mirror layer 113 and the polarizing film 13 disposed between the second substrate 12 and the above-mentioned first base material 111, and the outermost layer of the optical sheet 15. It has a function as a protective layer that protects the half mirror layer 113 and the polarizing film 13.

Like the first base material 111, the second substrate 12 is not particularly limited as long as it is mainly composed of a transparent resin material, but is made of a thermoplastic transparent resin (base resin). It is preferable that it is contained as a main material.

As this transparent resin, the same ones as those mentioned for the first base material 111 described above can be used, but among them, it is preferable that the transparent resin is mainly composed of polyamide resin or polycarbonate resin.

Since the polycarbonate resin is rich in mechanical strength such as transparency (translucency) and rigidity, it can improve the transparency and impact resistance of the optical sheet 15. Further, since polycarbonate resin has a specific gravity of about 1.2 and is classified as one of the lightest resin materials, the weight of the optical sheet 15 can be reduced. In addition, polyamide resins can improve not only transparency and impact resistance but also chemical resistance, stress resistance, and the like.

The polyamide resin is not particularly limited, and various resins can be used, such as alicyclic polyamide, semi-aromatic polyamide, and the like. Alicyclic polyamide is a material with excellent impact resistance. Therefore, the optical sheet 15 can exhibit excellent impact resistance. Moreover, semi-aromatic polyamide is a material with high elastic modulus. Therefore, the optical sheet 15 can have excellent resistance to stress such as bending.

In addition, in this specification, semi-aromatic polyamide refers to a polyamide in which one of dicarboxylic acid and diamine as monomers constituting the polyamide is an aromatic compound and the other is an aliphatic compound, Specifically, it can be represented by the following formula (1B).

(However, in formula (1B), one of R ¹ and R ² is a divalent aromatic substituent and the other is a divalent aliphatic substituent, and n is an integer of 2 or more.)

Note that the polyamide may be a copolymer (random copolymer, block copolymer, etc.) containing two or more types of monomers for at least one of dicarboxylic acid and diamine.

Furthermore, the aromatic substituent among R ¹ and R ² in the above formula (1B) is preferably one represented by the following formula (2B).

(However, in formula (2B), l and m are each independently an integer of 0 or more and 2 or less.)

Thereby, the polarizing film 13 can be more suitably protected, and the processability of the optical sheet 15 can be made more excellent. Moreover, when providing retardation to the second substrate 12, the retardation can be more easily controlled by stretching the second substrate 12.

The aliphatic substituent among R ¹ and R ² in the above formula (1B) preferably has 4 to 18 carbon atoms, and is preferably a hydrocarbon group having 4 to 18 carbon atoms. is more preferable, and even more preferably a saturated hydrocarbon group having 4 or more and 18 or less carbon atoms.
Thereby, the processability of the optical sheet 15 can be improved.

Further, the semi-aromatic polyamide preferably contains an aromatic dicarboxylic acid and an aliphatic diamine as constituent monomers. Thereby, the half mirror layer 113 and the polarizing film 13 can be better protected, and the processability of the optical sheet 15 can be improved. Furthermore, retardation due to stretching of the second substrate 12 can be more easily controlled.

Alicyclic polyamide has an alicyclic chemical structure in its molecule, and may have an alicyclic chemical structure in its main chain structure, or an alicyclic chemical structure in its side chain structure. It may have the chemical structure.

Examples of the alicyclic polyamide include compounds in which at least one of dicarboxylic acid and diamine as monomers constituting the polyamide has an alicyclic chemical structure, and specifically, for example, the following formula: (3B).

(However, in formula (3B), R ³ and R ⁴ are each independently a hydrogen atom or a hydrocarbon group having 4 or less carbon atoms, o is an integer of 2 or more and 14 or less, and p is 0 or more and 6 or less n is an integer of 2 or more.)

The polycarbonate resin is not particularly limited and various types can be used, but aromatic polycarbonate resins are preferred among them, and the same resins as those mentioned for the first base material 111 described above are preferred. can be used.

The glass transition temperature (Tg) of the resin material contained as the main material in the second substrate 12 is preferably 100°C or more and 190°C or less, more preferably 105°C or more and 155°C or less. Thereby, the formation of the curved optical sheet 10 by thermal bending of the optical sheet 15 in the step [3] can be performed relatively easily. Moreover, when causing the first substrate 11 to develop retardation, stretching for developing this retardation can be suitably performed. Furthermore, the durability and reliability of the optical sheet 15 can be improved.

Further, the second substrate 12 may contain other components in addition to the resin material contained as the main material. Such components are not particularly limited, but include, for example, resin materials other than the main material, colorants such as dyes, fillers, alignment aids, stabilizers (thermal stabilizers, ultraviolet absorbers, antioxidants, etc.) ), plasticizers, colorants, flame retardants, antistatic agents, and viscosity modifiers.

In this case, the content of the resin material in the second substrate 12 is not particularly limited, but it is preferably 75% by weight or more, more preferably 85% by weight or more based on 100% by weight of the second substrate 12. preferable. By setting the content of the resin material within the above range, the optical sheet 15 can exhibit excellent strength.

Further, when the second substrate 12 is made to exhibit retardation, it is preferable that the retardation of the first substrate 11 and the retardation of the second substrate 12 are different, and the retardation of the second substrate 12 is the retardation of the first substrate 11. It is more preferable that it is lower than .

Thereby, the first substrate 11 is easily deformed in a direction in which the curvature becomes smaller due to thermal contraction, but the second substrate 12 can be made difficult to deform due to thermal contraction. Therefore, as shown in FIG. 2, by applying it to the curved optical sheet 10 included in the lens 30, it is used in a curved state, but at this time, the second substrate 12 is positioned on the curved concave side. However, it is preferable to have a curved shape so that the first substrate 11 is located on the side of the curved convex surface. In this case, the first substrate 11 has a relatively high thermal shrinkage rate and is therefore relatively easily deformed by heat. However, in the curved optical sheet 10, the second substrate 12 has a function of suppressing thermal deformation of the first substrate 11. Demonstrate. Therefore, the curved optical sheet 10 as a whole can be prevented from being excessively deformed due to heat. As a result, it is possible to accurately suppress or prevent the shape of the lens 30 itself from deforming due to thermal deformation of the curved optical sheet 10.

The retardation of the second substrate 12 is preferably 0 nm or more and 6000 nm or less, more preferably 0 nm or more and 4000 nm or less. Thereby, the retardation of the second substrate 12 can be made sufficiently low. Therefore, the effect obtained by making the retardation of the second substrate 12 lower than the retardation of the first substrate 11 can be more clearly exhibited.

Note that the difference in retardation of the second substrate 12 can be achieved by varying the constituent materials contained in the layers, the thickness, and the stretching ratio.

The stretching ratio of the second substrate 12 is not particularly limited, but is preferably, for example, 0.95 or more and 1.1 or less so as to be set to the size of the retardation.

Further, the refractive index of the second substrate 12 at a wavelength of 589 nm is preferably 1.3 or more and 1.8 or less, and more preferably 1.4 or more and 1.65 or less. By setting the refractive index of the second substrate 12 within the above numerical range, it is possible to accurately suppress or prevent the functions of the polarizing film 13 and the half mirror layer 113 from being inhibited.

The second substrate 12 preferably has an average thickness of 0.1 mm or more and 1.5 mm or less, more preferably 0.2 mm or more and 0.8 mm or less. By setting the average thickness of the second substrate 12 within this range, it is possible to reduce the thickness of the optical sheet 15 while accurately suppressing or preventing the optical sheet 15 from being bent. Therefore, the color of the light in the specific wavelength range that is selectively reflected by the half mirror layer 113 can be more uniformly viewed over the entire optical sheet 15.

The first adhesive layer 14 is provided between the first substrate 11 (one substrate) and the polarizing film 13 and has a function of bonding the first substrate 11 and the polarizing film 13 together. Thereby, excellent adhesion can be provided between the first substrate 11 and the polarizing film 13 via the first adhesive layer 14.

Further, the second adhesive layer 16 is provided between the second substrate 12 (the other substrate) and the polarizing film 13 and has a function of bonding the second substrate 12 and the polarizing film 13 together. Thereby, excellent adhesion can be provided between the second substrate 12 and the polarizing film 13 via the second adhesive layer 16.

The first adhesive layer 14 and the second adhesive layer 16 are each made of a light-transmitting adhesive. Examples of this adhesive include, but are not limited to, silicone-based, silylated urethane resin-based, urethane resin-based, epoxy-based, polyolefin-based, chlorinated polyolefin-based, acrylic-based, cyanoacrylate-based, rubber-based, polyester-based, Examples include polyimide adhesives, phenolic adhesives, and the like.

Among these, it is preferable that the first adhesive layer 14 and the second adhesive layer 16 are made of a urethane resin adhesive. Thereby, when heat bending the optical sheet 15 to the curved optical sheet 10 having a curved shape, it is possible to impart heat resistance necessary for the heat bending process. Furthermore, it is also preferable that the adhesive is made of silicone adhesive. Thereby, gas generation during curing of the adhesive can be accurately suppressed or prevented. Therefore, it is possible to accurately suppress or prevent air bubbles from remaining in the adhesive layers 14 and 16.

Note that the first adhesive layer 14 and the second adhesive layer 16 may be the same or the same type, or may be different from the same or the same type.

Further, the refractive index of the first adhesive layer 14 and the second adhesive layer 16 at a wavelength of 589 nm is preferably 1.3 or more and 1.7 or less, and 1.4 or more and 1.65. The following is more preferable.

The thickness of the first adhesive layer 14 and the second adhesive layer 16 is preferably, for example, 2 μm or more and 100 μm or less, and more preferably 5 μm or more and 35 μm or less, each independently. The first adhesive layer 14 and the second adhesive layer 16 can reliably bond the first adhesive layer 14 and the second adhesive layer 16 to the polarizing film 13, respectively.

Further, the total thickness of the optical sheet 15 is not particularly limited, but is preferably about 0.2 mm or more and 3.0 mm or less, and more preferably about 0.4 mm or more and 1.6 mm or less. Thereby, it is possible to impart excellent strength to the optical sheet 15 and also impart excellent thermoformability to the optical sheet 15 when forming the optical sheet 15 into the curved optical sheet 10 having a curved shape. .

Further, the optical sheet 15 includes an adhesive layer as an intermediate layer between the first adhesive layer 14 and the polarizing film 13 and at least one between the second adhesive layer 16 and the polarizing film 13. There may be. Thereby, it is possible to improve the adhesion between the adhesive layers 14 and 16 and the polarizing film 13.

This adhesive layer is not particularly limited, but includes, for example, a layer mainly composed of at least one of SiO ₂ and Al ₂ O ₃ .

<Second embodiment>
Further, the optical sheet 15 may have the structure described below in addition to the structure described in the first embodiment.
FIG. 5 is a longitudinal sectional view showing a second embodiment of the optical sheet of the present invention.

Note that, hereinafter, for convenience of explanation, the upper side of FIG. 5 will be referred to as "upper" and the lower side will be referred to as "lower". In addition, the x direction in FIG. 5 is referred to as the "left-right direction," the y direction is referred to as the "front-back direction," and the z direction is referred to as the "up-down direction." Furthermore, in FIG. 5, the thickness direction of the optical sheet is exaggerated, so the dimensions are significantly different from the actual dimensions.

Hereinafter, a second embodiment of the optical sheet of the present invention will be described with reference to this figure, but the explanation will focus on the differences from the embodiments described above, and the explanation of similar matters will be omitted.

The optical sheet 15 of this embodiment is the same as the optical sheet 15 of the first embodiment except that it further includes a coating layer 17 (hard coat layer) that covers the first substrate 11 and the second substrate 12 as the outermost layer. The same is true.

That is, as shown in FIG. 5, in the present embodiment, the optical sheet 15 further includes a coating layer 17 on one surface side (upper surface side) of the first substrate 11 as an outermost layer that covers the first substrate 11. are doing. Further, on the other surface side (lower surface side) of the second substrate 12, a coating layer 17 that covers the second substrate 12 is further provided as an outermost layer. In other words, in the optical sheet 15 of this embodiment, the coating layer 17, the second substrate 12, the second adhesive layer 16, the polarizing film 13, the first adhesive layer 14, the first substrate 11, and the coating layer 17, The optical sheet 15 is composed of a laminate stacked in this order from the bottom side to the top side.

By providing the coating layer 17 that covers the first substrate 11 and the second substrate 12 as in this embodiment, it is possible to reliably prevent the first substrate 11 and the second substrate 12 from being damaged. can.

This coating layer 17 (coat layer) is a so-called hard coat layer formed using a resin composition, and as this resin composition, for example, one containing a silicone-modified (meth)acrylic resin is preferably used. . Therefore, a resin composition containing this silicon-modified (meth)acrylic resin will be explained below.

(Silicon-modified (meth)acrylic resin)
Silicon-modified (meth)acrylic resin (siloxane-modified (meth)acrylate) has a main chain in which constituent units derived from a (meth)acrylic monomer having a (meth)acryloyl group are repeated, and a siloxane It is a polymer (prepolymer) having repeating units (side chains) in which structural units having bonds are repeated.

That is, it is a polymer (prepolymer) in which a (meth)acrylic compound as a main chain and a compound having a siloxane bond (-Si-O-Si-) as a side chain are linked.

The silicone-modified (meth)acrylic resin has the main chain, thereby imparting excellent transparency to the coating layer 17, and also has repeating units having the siloxane bond, so that the silicone-modified (meth)acrylic resin can provide excellent transparency to the coating layer 17. The layer 17 can be provided with excellent scratch resistance and weather resistance, that is, the function as the covering layer 17 can be reliably provided.

Specifically, the main chain of the silicon-modified (meth)acrylic resin is composed of repeating structural units derived from a monomer having at least one (meth)acryloyl group of the following formula (1) and formula (2). Examples include those having the chemical formula shown in the following formula (12) as those having repeating structural units derived from both of these monomers.

(In formula (1), n represents an integer of 1 or more, R1 independently represents a hydrocarbon group, an organic group, or a hydrogen atom, and R0 independently represents a hydrocarbon group or a hydrogen atom. .)

(In formula (2), m represents an integer of 1 or more, R2 independently represents a hydrocarbon group, an organic group, or a hydrogen atom, and R0 independently represents a hydrocarbon group or a hydrogen atom. .)

(In formula (12), m and n represent an integer of 1 or more, R1, R2, and R3 each independently represent a hydrocarbon group, an organic group, or a hydrogen atom, and R0 independently represents a carbonized (Indicates a hydrogen group or hydrogen atom.)

Further, a repeating body (side chain) in which structural units having a siloxane bond are repeated is bonded to at least one end or side chain of the main chain having such a structure.

Since siloxane bonds have high bonding strength, the silicone-modified (meth)acrylic resin has repeating bodies in which constituent units having siloxane bonds are repeated, thereby obtaining a coating layer 17 with better heat resistance and weather resistance. be able to. Further, since the bonding strength of the siloxane bonds is high, it is possible to obtain a hard coating layer 17, so that the scratch resistance of the optical sheet 15 can be further increased.

Specific examples of repeating bodies in which structural units having siloxane bonds are repeated include those constituted by repeating structural units having at least one of the siloxane bonds of the following formula (3) and formula (4). It will be done.

(In formula (3), X ₁ represents a hydrocarbon group or a hydroxyl group.)

(In formula (4), X ₂ represents a hydrocarbon group or a hydroxyl group, and X ₃ represents a divalent group in which hydrogen is removed from a hydrocarbon group or a hydroxyl group.)

Specific examples of repeating bodies in which the structural units having siloxane bonds are repeated include those having polyorganosiloxane and those having silsesquioxane. Note that the structure of silsesquioxane may be any structure such as a random structure, a cage structure, a ladder structure (ladder structure), etc.

Examples of the hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, and isopropyl group, cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group, phenyl group, naphthyl group, etc. Examples include aryl groups such as -methylphenyl, aralkyl groups such as benzyl, diphenylmethyl, and naphthylmethyl, and biphenyl.

Moreover, it is preferable that an unsaturated double bond is introduced into the terminal or side chain of a repeating product in which structural units having a siloxane bond are repeated. As a result, when the resin composition contains urethane (meth)acrylate, which will be described later, the urethane (meth)acrylate is bonded to the (meth)acryloyl group that this urethane (meth)acrylate has, and the silicone-modified (meth)acrylic resin and urethane (meth)acrylate are bonded together. Can form a network with acrylate. Therefore, in the coating layer 17, the silicone-modified (meth)acrylic resin and the urethane (meth)acrylate are more uniformly dispersed, and as a result, the coating layer 17 can exhibit the above-mentioned properties more uniformly over its entirety. can.

The content of the silicon-modified (meth)acrylic resin in the resin composition is not particularly limited, but is preferably 5 parts by mass or more and 45 parts by mass or less, and 11 parts by mass or more, based on 100 parts by mass of the resin composition. More preferably, it is 28 parts by mass or less. If the content of the silicon-modified (meth)acrylic resin in the resin composition is less than the lower limit, the hardness of the coating layer 17 obtained from the resin composition may decrease. Furthermore, when the content of the silicon-modified (meth)acrylic resin in the resin composition exceeds the upper limit, the content of materials other than the silicon-modified (meth)acrylic resin in the resin composition decreases relatively. As a result, the flexibility of the coating layer 17 formed using the resin composition may be reduced.

Examples of the silicon-modified (meth)acrylic resin having the above structure include compounds represented by the following formulas (5) and (6).

(In formula (5), Me represents a methyl group, and m, n, and p each represent an integer of 1 or more.)

(In formula (6), Me represents a methyl group, m, n, and p each represent an integer of 1 or more; R1, R2, R3, and R4 each independently represent a hydrocarbon group, an organic group, or hydrogen atom)

(Urethane (meth)acrylate)
Moreover, it is preferable that the resin composition further contains urethane (meth)acrylate.

If an unsaturated double bond is introduced at the terminal or side chain of a repeating unit consisting of repeated structural units having a siloxane bond, which is included in a silicone-modified (meth)acrylic resin, urethane (meth)acrylate is present in the resin composition. By containing, the (meth)acryloyl group of this urethane (meth)acrylate and the unsaturated double bond bond together, forming a network between the silicone-modified (meth)acrylic resin and the urethane (meth)acrylate. Ru. As a result, the resin composition is cured and a cured product is obtained, thereby forming the coating layer 17 made of this cured product. The curing of the resin composition due to the bonding between the (meth)acryloyl group and the unsaturated double bond is carried out by photocuring, which is curing the resin composition by irradiating it with energy rays such as ultraviolet rays.

By containing urethane (meth)acrylate in the coating layer 17 formed as described above, the flexibility of the coating layer 17 can be improved, and the optical sheet 15 can be partially or completely curved. Since the optical sheet 15 is applied to objects having a shape, it is possible to accurately suppress the occurrence of cracks on the surface of the coating layer 17 when the optical sheet 15 is thermally bent, thereby imparting excellent thermoformability to the optical sheet 15. I can do it.

Furthermore, by combining the above-mentioned silicone-modified (meth)acrylic resin and this urethane (meth)acrylate, it is possible to obtain an optical sheet 15 that has both excellent scratch resistance and thermoformability. .

This urethane (meth)acrylate refers to a compound having a main chain having a urethane bond (-OCONH-) and a (meth)acryloyl group connected to this main chain. Moreover, urethane (meth)acrylate is a monomer or an oligomer.

Urethane (meth)acrylate having such a structure is a compound with excellent flexibility because it has a urethane bond. Therefore, by including the urethane (meth)acrylate in the coating layer 17, further flexibility (softness) can be imparted to the coating layer 17. Therefore, when the optical sheet 15 is formed into the curved optical sheet 10 having a curved shape, it is possible to accurately suppress the occurrence of cracks at the bent portions.

Note that this urethane (meth)acrylate can be obtained, for example, as a reaction product of an isocyanate compound obtained by reacting a polyol and a diisocyanate and a (meth)acrylate monomer having a hydroxyl group.

Further, examples of the polyol include polyether polyol, polyester polyol, and polycarbonate diol.

Further, polyester polyols can be obtained, for example, by polycondensation reaction of a diol and a dicarboxylic acid or dicarboxylic acid chloride, or by esterification of a diol or dicarboxylic acid and a transesterification reaction. Examples of dicarboxylic acids include adipic acid, succinic acid, glutaric acid, pimelic acid, sebacic acid, azelaic acid, maleic acid, terephthalic acid, isophthalic acid, and phthalic acid. Examples of diols include ethylene glycol, Examples include 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, and tetrapropylene glycol.

Further, examples of polycarbonate diols include reaction products of diols and carbonic esters, and examples of diols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, propylene glycol, diethylene glycol, and tricarbonate diol. Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 2-ethyl-1,3-hexanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanediol, polyoxyethylene glycol, etc. are used, and one type or a combination of two or more types can be used.

Examples of (meth)acrylate monomers having a hydroxyl group include trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, -Hydroxybutyl acrylate, polyethylene glycol monoacrylate, etc.

Further, the content of urethane (meth)acrylate in the resin composition is not particularly limited, but it is preferably 10 parts by mass or more and 75 parts by mass or less, and 17 parts by mass or more and 50 parts by mass, based on 100 parts by mass of the resin composition. More preferably, it is less than parts by mass. If the content of urethane (meth)acrylate in the resin composition is less than the lower limit, depending on the type of urethane (meth)acrylate, the flexibility of the coating layer 17 may become poor. Additionally, if the content of urethane (meth)acrylate in the resin composition exceeds the above upper limit, depending on the type of urethane (meth)acrylate, the content of materials other than urethane (meth)acrylate in the resin composition may increase. There is a possibility that the scratch resistance of the optical sheet 15 may decrease relatively.

((meth)acrylate monomer)
Moreover, it is preferable that the resin composition further contains a (meth)acrylate monomer.

If an unsaturated double bond is introduced at the end or side chain of a repeating unit consisting of repeated structural units having a siloxane bond, which is included in a silicone-modified (meth)acrylic resin, the (meth)acrylate monomer is present in the resin composition. By containing, the (meth)acryloyl group of this (meth)acrylate monomer and the unsaturated double bond bond to form a network between the silicone-modified (meth)acrylic resin and the (meth)acrylate monomer. As a result, the coating layer 17 is formed by curing the resin composition.

Examples of (meth)acrylate monomers include, but are not limited to, pentaerythritol tetraacrylate, ditrimethylolpropane triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, and ethoxylated trimethylolpropane triacrylate. , ethoxylated pentaerythritol triacrylate, ethoxylated pentaerythritol tetraacrylate, polyethylene glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated hydrogenated bisphenol A diacrylate, ethoxylated cyclohexanedimethanol diacrylate, tricyclodecane dimethanol diacrylate Acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, isobornyl acrylate, etc., and use one type or a combination of two or more of these. I can do it. Among these, from the viewpoint of improving the weather resistance of the optical sheet 15, a resin that does not contain aromatics is preferable.

The content of the (meth)acrylate monomer in the resin composition is not particularly limited, but it is preferably 15 parts by mass or more and 55 parts by mass or less, and 27 parts by mass or more and 55 parts by mass, based on 100 parts by mass of the resin composition. It is more preferable that it is below.

(Isocyanate)
Moreover, it is preferable that the resin composition further contains an isocyanate.
Thereby, in the resin composition, the isocyanate functions as a crosslinking agent that bonds (crosslinks) the silicon-modified (meth)acrylic resin intermolecularly. That is, the inclusion of isocyanate as a crosslinking agent strengthens the hydroxyl group in the main chain of the silicon-modified (meth)acrylic resin, which is a repeating structural unit derived from a (meth)acrylic monomer having a (meth)acryloyl group. The isocyanate reacts with the isocyanate group possessed by the isocyanate to form a crosslinked structure composed of urethane bonds, and as a result, a coating layer 17 composed of a cured product of the resin composition is formed. The resin composition is cured by bonding the hydroxyl group and the isocyanate group by thermosetting, which is performed by heating the resin composition.

In the coating layer 17 formed as described above, a network formed by bonding hydroxyl groups and isocyanate groups can be constructed, so that the scratch resistance and weather resistance of the coating layer 17 can be further improved. I can do it.

The content of isocyanate in the resin composition is not particularly limited, but it is preferably 3 parts by mass or more and 40 parts by mass or less, and 10 parts by mass or more and 25 parts by mass or less, based on 100 parts by mass of the resin composition. is more preferable.

(Other materials)
Furthermore, the resin composition may contain other materials in addition to the various materials mentioned above.
Other materials include, but are not particularly limited to, resin materials other than the silicone-modified (meth)acrylic resin, photopolymerization initiators, ultraviolet absorbers, colorants, sensitizers, stabilizers, surfactants, oxidation Examples include inhibitors, reduction inhibitors, antistatic agents, surface conditioners, hydrophilic additives, fillers, and solvents, and one or more of these may be used in combination.

The average thickness of the coating layer 17 composed of the cured product of the resin composition as described above is not particularly limited, but is preferably 1 μm or more and 40 μm or less, more preferably 2 μm or more and 30 μm or less, and 5 μm or more. More preferably, the thickness is not less than 20 μm. If the thickness of the coating layer 17 is less than the lower limit, the weather resistance of the optical sheet 15 may deteriorate. On the other hand, if the thickness of the coating layer 17 exceeds the upper limit, cracks may occur in the curved optical sheet 10 when the optical sheet 15 is formed into a curved optical sheet 10 having a curved shape.

The optical sheet 15 of the second embodiment also provides the same effects as the first embodiment.

Although the optical sheet and optical component of the present invention have been described above, the present invention is not limited thereto, and the present invention is not limited thereto. Each layer constituting 15 can be replaced with any structure that can perform the same function.

Furthermore, in the embodiment, when the optical sheet 15 of the present invention is applied to the lens 30 provided with the curved optical sheet 10 having a curved shape as a curved resin substrate, that is, the optical component of the present invention is applied to the lens 30. For example, cover films for display devices such as liquid crystal displays and head-up displays, transportation means such as motorcycles, cars, airplanes, and trains, machine tools, and windows for buildings. The optical sheet 15 is used by attaching it to components, cover members of headlights and fog lamps, brightness enhancement films and cold mirrors provided in light sources of head-up displays, reflective plates of in-vehicle sensors such as infrared sensors, etc. You can also. In addition, in these cases, an optical component is constituted by a cover film, a window member, a cover member, a brightness enhancement film, a cold mirror, or a reflecting plate, and the curved optical sheet 10 attached thereto.

Hereinafter, the present invention will be explained more specifically based on Examples. Note that the present invention is not limited in any way by these Examples.

1. Preparation of raw materials <Polycarbonate (PC1)>
Iupilon E2000 (manufactured by Mitsubishi Engineering Plastics) was prepared as polycarbonate (PC1).

<Polymethyl methacrylate (heat-resistant PMMA1)>
Delpet PM120N (manufactured by Asahi Kasei Corporation) was prepared as polymethyl methacrylate (heat-resistant PMMA1).

<Polyethylene terephthalate (heat-resistant PETG1)>
Tritan TX2001 (manufactured by Eastman Chemical Company, glycol-modified polyethylene terephthalate) was prepared as heat-resistant amorphous polyethylene terephthalate (heat-resistant PETG1).

<Polyethylene terephthalate (PETG2)>
Sky Green K2012 (manufactured by SK Chemicals) was prepared as an amorphous polyethylene terephthalate copolymer (PETG2).

<Polyarylate (PAR1)>
U polymer P-5001 (manufactured by Unitika) was prepared as polyarylate (PAR1).

<Polyether sulfone (PES)>
Sumika Excel 3600G (manufactured by Sumitomo Chemical Co., Ltd.) was prepared as polyether sulfone (PES).

<Polyethylene naphthalate (PEN1)>
Teonex TN8065S (manufactured by Teijin) was prepared as polyethylene naphthalate (PEN1).

<Polyethylene terephthalate (APET1)>
Novapex GM700Z (manufactured by Mitsubishi Chemical Corporation, crystalline polyethylene terephthalate) was prepared as polyethylene terephthalate (APET1).

<Acrylonitrile-styrene copolymer (AS1)>
Denka AS-XGS (manufactured by Denka Corporation) was prepared as an acrylonitrile-styrene copolymer (AS1).

<Styrene-N-phenylmaleimide-maleic anhydride copolymer (IP1)>
Denka IP-ND (manufactured by Denka Corporation) was prepared as the styrene-N-phenylmaleimide-maleic anhydride copolymer (IP1).

<Silicone adhesive>
As the silicone adhesive, a liquid heat-curable silicone adhesive (manufactured by Shin-Etsu Chemical Co., Ltd., "KER-2937A, B") was prepared.

2. Production of optical sheet (Example 1)
[1] First, polycarbonate (PC1) was used as a resin material for forming the base materials 111 and 112 and the high refractive index layer 31, and polymethyl methacrylate (heat-resistant PMMA1) was used as a resin material for forming the low refractive index layer 32. ) were prepared respectively.

[2] Next, polycarbonate (PC1, Tg 150°C) and polymethyl methacrylate (heat-resistant PMMA1, Tg 123°C) were heated at 270°C using an extruder (SNT40-28, manufactured by Sun NT Co., Ltd.). The high refractive index layer 31 and the low refractive index layer 32 were alternately and repeatedly laminated by forming a film by coextruding it using a feed block and die and cooling it. , a laminate in which the upper and lower surfaces of a half mirror layer 113 composed of a laminate (multilayer laminate) with a total of 1023 layers (repetition number 511 times) are covered with a first base material 111 and a second base material 112, respectively. After obtaining the body, the first substrate 11 was obtained by stretching this laminate along the MD at a stretching ratio of 2 times. Here, the ejection amount was adjusted so that the laminated thickness ratio was high refractive index layer 31:low refractive index layer 32=1:1.

In addition, in the obtained half mirror layer 113, the refractive index of the low refractive index layer 32 at a wavelength of 589 nm was measured using an Appe refractometer (manufactured by ATAGO, "NA-1T SOLID") and found to be 1.510. there were. Further, the refractive index of the high refractive index layer 31 at a wavelength of 589 nm was measured using an Appe refractometer (manufactured by ATAGO, "NA-1T SOLID") and found to be 1.585. Further, the average thickness of the half mirror layer 113 was 100 μm, and the average thicknesses of the first base material 111 and the second base material 112 were both 0.3 mm.

Further, the retardation of the first substrate 11 was measured using a phase difference measuring device (manufactured by Oji Scientific Instruments, "KOBRA-21ADH") and found to be 3100 nm.

[3] Next, polycarbonate (PC1) is prepared as a resin material for forming the second substrate 12, and then 100 parts by mass of polycarbonate (PC1) is extruded to form a resin material with a thickness of 0.3 mm. A second substrate 12 was obtained.

Further, the retardation of the second substrate 12 was measured using a phase difference measuring device (manufactured by Oji Scientific Instruments, "KOBRA-21ADH") and found to be 3100 nm.

[4] Next, the polyvinyl alcohol film was dyed with an aqueous solution containing a dye while being stretched in a water bath, and treated with boric acid. Thereafter, the treated polyvinyl alcohol film was washed with water and dried to obtain a polarizing film 13 with a thickness of 35 μm.

[5] Next, on both surfaces of the polarizing film 13, a coating film made of silicone adhesive is applied so that the thickness of the adhesive layers 14 and 16 formed after curing is 50 μm. Coated.

The first substrate 11 and the second substrate 12 were bonded together so as to be in contact with the coating films formed on both surfaces of the polarizing film 13, and then heated at a temperature of 100° C. for a period of 1.0 hr. After primary heating under the following conditions, the coating film was cured by secondary heating at a temperature of 120°C and a time of 2.0 hr, and then cured for 7 days at a temperature of 25°C and a humidity of 50% RH. By doing so, the first adhesive layer 14 and the second adhesive layer 16 were formed between the first substrate 11 and the polarizing film 13 and between the second substrate 12 and the polarizing film 13, respectively.
The optical sheet 15 of Example 1 was obtained through the steps [1] to [5] as described above.

(Examples 2 to 6, Reference Examples 1 and 2, Comparative Examples 1 and 2)
In the step [1], resin materials for forming the first base material 111, the second base material 112, the high refractive index layer 31, the low refractive index layer 32, and the second substrate 12 are shown in Table 1, respectively. In the same manner as in Example 1, except that in step [2], the stretching ratio for stretching the laminate to obtain the first substrate 11 was changed as necessary, Optical sheets 15 of Examples 2 to 6, Reference Examples 1 and 2, and Comparative Examples 1 and 2 were obtained.

3. Evaluation The optical sheet 15 of each Example, each Reference Example, and each Comparative Example was evaluated by the following method.

<1A> Measurement of reflectance R1 (%) of curved optical sheet 10 before heating First, optical sheets 15 of each example, each reference example, and each comparative example were measured as the main material constituting the high refractive index layer 31. The optical sheet is pressed against a metal mold at a temperature 10° C. higher than the glass transition point Tg1 of the main material constituting the low refractive index layer 32 and the glass transition point Tg2 of the main material constituting the low refractive index layer 32. 15 (laminate) was used as a curved optical sheet 10 (curved laminate) having a curved shape with a radius of curvature of 60 mm.

Next, the curved optical sheet 10 is placed between the light source that emits light of 589 nm and the light receiving section so that the angle between the top surface of the curved optical sheet and the straight line connecting the light source and the light receiving section is 90°. did.

Next, the light emitted from the light source (transmitted light) that has passed through the curved optical sheet 10 is received by the light receiving section, and the transmittance (%) of this transmitted light is measured to determine the initial (before heating) state. The reflectance R1 (%) was determined.

<2A> Measurement of reflectance R2 (%) of curved optical sheet 10 after heating First, optical sheets 15 of each example, each reference example, and each comparative example were measured as the main material constituting the high refractive index layer 31. The optical sheet is pressed against a metal mold at a temperature 10° C. higher than the glass transition point Tg1 of the main material constituting the low refractive index layer 32 and the glass transition point Tg2 of the main material constituting the low refractive index layer 32. 15 (laminate) was used as a curved optical sheet 10 (curved laminate) having a curved shape with a radius of curvature of 60 mm.

Next, the curved optical sheet 10 is stored in a thermal circulation oven at a temperature of 105° C. for 1000 hours, and then the upper surface of the curved optical sheet 10 is placed between the light source that emits light of 589 nm and the light receiving section. It was arranged so that the angle formed between the light receiving part and the straight line connecting the light receiving part was 90°.

Next, the light emitted from the light source (transmitted light) that has passed through the curved optical sheet 10 is received by the light receiving section, and the transmittance (%) of this transmitted light is measured to determine the reflectance R2 after heating. (%) was calculated.

Then, using the reflectance R2 (%) after heating obtained here and the initial (before heating) reflectance R1 (%) obtained in <1A> above, reflectance retention ( R2/R1×100 [%]) was calculated.

<3A> Confirmation of heat resistance of optical sheet in visible light region First, the reflectance at a wavelength of 590 nm was measured for the optical sheet 15 of each Example, each Reference Example, and each Comparative Example. Thereafter, a durability test (105°C x 1000 hr) was conducted, and the reflectance of the sample (optical sheet) after the test was similarly measured.

Then, assuming that the reflectances before and after the durability test were R3 and R4, respectively, the rate of change in reflectance was determined based on these as shown below.

Rate of change in reflectance: R4/R3×100 (%)
Thereafter, the rate of change in the obtained reflectance was evaluated based on the evaluation criteria shown below.

[Evaluation criteria]
◎: R4/R3×100 is 85% or more ○: R4/R3×100 is 80% or more and less than 85% ×: R4/R3×100 is less than 80%

<4A> Confirmation of thermal bendability of optical sheet First, for the optical sheet 15 of each example, each reference example, and each comparative example, the glass transition point is the higher of the glass transition point Tg1 and the glass transition point Tg2. The material was heated to a temperature 10° C. higher than the original temperature and was pressed against a metal mold with a radius of curvature of 60 mm to perform thermal bending.
Then, the thermally bent curved optical sheet 10 was stored in a thermal circulation oven at a temperature of 105° C. for 1000 hours, and the radius of curvature was then measured and evaluated based on the evaluation criteria shown below.

[Evaluation criteria]
After being stored in a heat circulation oven at a temperature of 105°C for 1000 hours, the number of items that maintain a radius of curvature of 60 ± 5 mm is
◎: 50 out of 50 curved optical sheets ○: 48 or more but less than 50 out of 50 curved optical sheets ×: Less than 48 out of 50 curved optical sheets

In addition, after being stored in a thermal circulation oven for 1000 hours in a temperature environment of 105°C, the presence or absence of peeling between the base materials 111 and 112 of the curved optical sheet 10 and the half mirror layer 113 was visually confirmed. The results were evaluated based on the evaluation criteria shown below.

[Evaluation criteria]
After being stored in a thermal circulation oven for 1000 hours in a temperature environment of 105° C., the number of peeling observed between the base materials 111 and 112 and the half mirror layer 113 is as follows:
◎: 0 out of 50 curved optical sheets ○: 1 or more but less than 3 out of 50 curved optical sheets ×: 3 or more out of 50 curved optical sheets

<5A> Evaluation of visibility of transparent images of optical sheets First, regarding the optical sheets 15 of each Example, each Reference Example, and each Comparative Example, each glass has a glass transition point Tg1 or a glass transition point Tg2, whichever is higher. Heat bending was performed by pressing the sample against a metal mold with a radius of curvature of 60 mm while heating the sample to a temperature 10° C. higher than the transition point.

Then, when the thermally bent curved optical sheet 10 was visually viewed from the second substrate 12 side, the presence or absence of coloring in the visually recognized transmitted image was checked, and evaluated based on the evaluation criteria shown below.

[Evaluation criteria]
In the curved optical sheet 10, the number of sheets in which coloring is recognized in the transmitted image is
◎: 0 out of 50 curved optical sheets ○: 1 or more but less than 3 out of 50 curved optical sheets ×: 3 or more out of 50 curved optical sheets

The evaluation results for the optical sheet 15 of each Example, each Reference Example, and each Comparative Example obtained as described above are shown in Table 1 below.

As shown in Table 1, in the optical sheet in each example, the retardation of the first substrate 11 is 2000 nm or more and 7000 nm or less, and the interface between the first base material 111 and the half mirror layer 113 and the second base material A continuous layer was formed at the interface between 112 and the half mirror layer 113, and this resulted in excellent heat bending workability.

On the other hand, in the optical sheets in each comparative example, continuous layers were formed at the interface between the first base material 111 and the half mirror layer 113 and at the interface between the second base material 112 and the half mirror layer 113. However, the retardation of the first substrate 11 was not satisfied as being 2000 nm or more and 7000 nm or less, and as a result, the results showed that it could not be said that it had excellent hot bending workability.

10 Curved optical sheet 11 First substrate 12 Second substrate 13 Polarizing film 14 First adhesive layer 15 Optical sheet 16 Second adhesive layer 17 Covering layer 20 Frame 21 Rim portion 22 Bridge portion 23 Temple portion 24 Nose pad portion 30 Lens 31 High refractive index layer 32 Low refractive index layer 33 Repeating portion 35 Resin layer 40 Mold 50 Protective film 100 Sunglasses 111 First base material 112 Second base material 113 Half mirror layer 150 Multilayer laminate 200 Curved multilayer laminate

Claims (8)

An optical sheet comprising a polarizing layer made of a polarizer, and a first substrate and a second substrate provided on one side and the other side of the polarizing layer, respectively,
The first substrate has a retardation of 2000 nm or more and 7000 nm or less,
a first base material mainly composed of a resin material having light transmittance;
a half mirror layer bonded to one surface of the first base material and consisting of a laminate in which high refractive index layers and low refractive index layers are alternately and repeatedly laminated;
a second base material made of the resin material as a main material and bonded to a surface of the half mirror layer opposite to the first base material;
In the half mirror layer, the refractive index of the high refractive index layer is higher than the refractive index of the low refractive index layer,
The interface between the first base material and the half mirror layer forms a continuous layer between the first base material and the half mirror layer, and the interface between the second base material and the half mirror layer forms a continuous layer between the first base material and the half mirror layer. An optical sheet characterized in that two base materials and the half mirror layer form a continuous layer. Claim 1, wherein Tg1, Tg2≧105°C, where the glass transition point of the main material constituting the high refractive index layer is Tg1, and the glass transition point of the main material constituting the low refractive index layer is Tg2. Optical sheet as described. The optical sheet according to claim 2, wherein the glass transition point Tg1 and the glass transition point Tg2 satisfy the following relationship: 0°C≦|Tg1−Tg2|≦60°C. The optical sheet according to claim 2 or 3, wherein the lower glass transition point of the glass transition point Tg1 and the glass transition point Tg2 is 110°C or more and 250°C or less. The refractive index difference (N1-N2), where the refractive index of the high refractive index layer at a wavelength of 589 nm is N1 and the refractive index of the low refractive index layer at a wavelength of 589 nm is N2, is 0.05 or more. The optical sheet according to any one of claims 1 to 4, which has a particle size of 25 or less. The optical sheet according to any one of claims 1 to 5, wherein the high refractive index layer and the low refractive index layer each have an average thickness of 50 nm or more and 300 nm or less. In the half mirror layer, the number of repetitions in which the high refractive index layer and the low refractive index layer are alternately stacked is 50 to 750 times, according to any one of claims 1 to 6. optical sheet. An optical component comprising the optical sheet according to any one of claims 1 to 7.

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