JP5662019B2 - Optical body and method for manufacturing the same - Google Patents

Description

  The present invention relates to an optical body and a method for manufacturing the same. In detail, it is related with the optical body which has an uneven | corrugated shaped interface inside.

  In recent years, optical films aimed at giving various effects such as absorption and reflection to incident light have been widely known. This optical film has various configurations depending on the intended function. As one of them, there is one having a concavo-convex shaped interface inside, and a thin film formed on this interface. For example, in Patent Document 1, as an optical film having the above-described configuration, a first base material having a concavo-convex surface in which a plurality of prisms are arranged one-dimensionally, a laminated film formed on the concavo-convex surface, and this laminated film A retroreflective polarizer is disclosed comprising a second substrate formed thereon.

  The optical film having the above-described configuration is manufactured as follows. First, the 1st base material which has an uneven surface is produced. Next, after forming a thin film made of a metal or an oxide thereof on the uneven surface of the first base material, the uneven surface on which the thin film is formed is embedded with a resin to form a second base material. . In recent years, such a manufacturing process is generally performed by roll-to-roll in consideration of improvement in productivity.

JP 2004-78234 A

  However, in the above-described optical film manufacturing process, the uneven shape of the interface may be deformed by heat or heat and pressure. This deformation is considered to occur in the following steps. That is, in the process of embedding an uneven surface on which a thin film is formed with a resin and sealing it to produce an optical film, the optical film may be heated and pressurized. Due to this heating and pressurization, the uneven shape of the interface may be deformed.

  Further, as described above, roll-to-roll manufacturing processes are generally used in recent optical film manufacturing processes. For this reason, it is desired not only to suppress the deformation of the uneven shape of the interface due to heat or heat and pressure, but also not to impair the flexibility of the optical film.

  Accordingly, an object of the present invention is to provide an optical body capable of suppressing deformation of the uneven shape of the interface due to heat or heat and pressure without impairing flexibility, and a method for manufacturing the same. .

In order to solve the above-mentioned problem, the first invention
An optical layer having smooth surfaces on both main surfaces, and having an uneven surface inside,
An intermediate layer that mainly includes an inorganic material provided at the interface and selectively directs and reflects light in a specific wavelength band;
The optical layer is
A first optical layer having a first surface of a concavo-convex shape composed of a plurality of structures arranged one-dimensionally or two-dimensionally ;
A second optical layer having a concave-convex second surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally ,
The interface is formed by the first surface and the second surface arranged to face each other,
At least one of the first optical layer and the second optical layer is
The storage elastic modulus at 100 ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less.

The second invention is
A first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface formed of a plurality of structures arranged one-dimensionally or two-dimensionally on the other surface ;
An intermediate layer mainly composed of an inorganic material formed on the concavo-convex surface of the first optical layer, which selectively reflects light in a specific wavelength band;
To the intermediate layer on the uneven surface formed, are formed uneven surface consisting of one-dimensional or two-dimensional array is a plurality of structures to fill the irregularities, and a surface opposite to the concave convex And a second optical layer having a smooth surface formed thereon,
At least one of the first optical layer and the second optical layer is
The storage elastic modulus at 100 ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less.

The third invention is
An optical layer having smooth surfaces on both main surfaces, and having an uneven surface inside,
An intermediate layer that mainly includes an inorganic material provided at the interface and selectively directs and reflects light in a specific wavelength band;
The optical layer is
A first optical layer having a first surface of a concavo-convex shape composed of a plurality of structures arranged one-dimensionally or two-dimensionally ;
A second optical layer having a concave-convex second surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally ,
The interface is formed by the first surface and the second surface arranged to face each other,
The first optical layer is
When the process temperature at the time of forming the second optical layer is t ° C., the storage elastic modulus at (t−20) ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less.

The fourth invention is:
A first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface formed of a plurality of structures arranged one-dimensionally or two-dimensionally on the other surface ;
An intermediate layer mainly composed of an inorganic material formed on the concavo-convex surface of the first optical layer, which selectively reflects light in a specific wavelength band;
To the intermediate layer on the uneven surface formed, are formed uneven surface consisting of one-dimensional or two-dimensional array is a plurality of structures to fill the irregularities, and a surface opposite to the concave convex a second optical layer smooth surface is formed
With
The first optical layer is
When the process temperature at the time of forming the second optical layer is t ° C., the storage elastic modulus at (t−20) ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less.

The fifth invention is:
An inorganic material is formed on the concavo-convex surface of the first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally is formed on the other surface. Forming an intermediate layer as a main component and selectively direct-reflecting light in a specific wavelength band;
The uneven surface on which the intermediate layer is formed is embedded with a second optical layer to form an uneven surface made of a plurality of structures arranged one-dimensionally or two-dimensionally on the intermediate layer; and A step of forming a smooth surface on the surface opposite to the uneven surface ,
At least one of the first optical layer and the second optical layer is
The storage elastic modulus at 100 ° C. is 3 × 10 ⁷ Pa or more,
This is a method for producing an optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less.

The sixth invention is:
An inorganic material is formed on the concavo-convex surface of the first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally is formed on the other surface. Forming an intermediate layer as a main component and selectively direct-reflecting light in a specific wavelength band;
The uneven surface on which the intermediate layer is formed is embedded with a second optical layer to form an uneven surface made of a plurality of structures arranged one-dimensionally or two-dimensionally on the intermediate layer; and Forming a smooth surface on the surface opposite to the uneven surface ,
The first optical layer is
When the process temperature of the embedding step is t ° C, the storage elastic modulus at (t-20) ° C is 3 × 10 ⁷ Pa or more,
This is a method for producing an optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less.

In the present invention, at least one of the first optical layer and the second optical layer forming the interface inside the optical layer has a storage elastic modulus at 100 ° C. of 3 × 10 ⁷ Pa or more. And pressurization can suppress deformation of the uneven shape of the interface inside the optical layer. Further, since at least one of the first optical layer and the second optical layer has a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less, flexibility can be imparted to the optical body at room temperature. . Therefore, it becomes possible to produce an optical body by a manufacturing process such as roll-to-roll.

In the present invention, the first optical layer forming the interface inside the optical layer has a storage elastic modulus at (t-20) ° C. when the process temperature at the time of forming the second optical layer is t ° C. Since it is 3 × 10 ⁷ Pa or more, it is possible to suppress deformation of the concavo-convex shape of the interface inside the optical layer due to heat or heat and pressure. In addition, since the first optical layer has a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less, flexibility can be imparted to the optical body at room temperature. Therefore, it becomes possible to produce an optical body by a manufacturing process such as roll-to-roll.

  As described above, according to the present invention, it is possible to suppress deformation of the concavo-convex shape of the optical body internal interface due to heat or heat and pressure without impairing flexibility.

FIG. 1A is a cross-sectional view showing a configuration example of an optical film according to the first embodiment of the present invention. FIG. 1B is a cross-sectional view showing an example in which the optical film according to the first embodiment of the present invention is bonded to an adherend. FIG. 2 is a perspective view showing a relationship between incident light incident on the optical film and reflected light reflected by the optical film. 3A to 3C are perspective views showing examples of the shape of the structure formed in the first optical layer. FIG. 4A is a perspective view showing an example of the shape of the structure formed in the first optical layer. FIG. 4B is a cross-sectional view showing a configuration example of an optical film including a first optical layer in which the structure shown in FIG. 4A is formed. 5A and 5B are cross-sectional views for explaining an example of the function of the optical film. 6A and 6B are cross-sectional views for explaining an example of the function of the optical film. FIG. 7A is a cross-sectional view for explaining an example of the function of the optical film. FIG. 7B is a plan view for explaining an example of the function of the optical film. FIG. 8 is a schematic diagram illustrating a configuration example of a manufacturing apparatus for manufacturing the optical film according to the first embodiment of the present invention. 9A to 9C are process diagrams for explaining an example of a method for producing an optical film according to the first embodiment of the present invention. 10A to 10C are process diagrams for explaining an example of a method for producing an optical film according to the first embodiment of the present invention. 11A to 11C are process diagrams for explaining an example of a method for producing an optical film according to the first embodiment of the present invention. FIG. 12A is a plan view showing a first configuration example of the first optical layer in the optical film according to the second embodiment of the present invention. 12B is a cross-sectional view taken along line BB of the first optical layer shown in FIG. 12A. 12C is a cross-sectional view taken along the line CC of the first optical layer shown in FIG. 12A. FIG. 13A is a plan view showing a second configuration example of the first optical layer in the optical film according to the second embodiment of the present invention. FIG. 13B is a cross-sectional view taken along line BB of the first optical layer shown in FIG. 13A. FIG. 13C is a cross-sectional view taken along line CC of the first optical layer shown in FIG. 13A. FIG. 14A is a plan view showing a third configuration example of the first optical layer in the optical film according to the second embodiment of the present invention. FIG. 14B is a cross-sectional view taken along line BB of the first optical layer shown in FIG. 14A. FIG. 15A is a cross-sectional view showing a configuration example of an optical film according to the third embodiment of the present invention. FIG. 15B is a perspective view illustrating a configuration example of the first optical layer included in the optical film according to the third embodiment of the present invention. FIG. 16A is a cross-sectional view showing a first configuration example of an optical film according to the fourth embodiment of the present invention. FIG. 16B is a cross-sectional view showing a second configuration example of the optical film according to the fourth embodiment of the present invention. FIG. 16C is a cross-sectional view showing a third configuration example of the optical film according to the fourth embodiment of the present invention. 17 is a cross-sectional view showing the shape of the molding surface of the Ni-P mold of Comparative Example 1. FIG. FIG. 18 is a schematic diagram showing the configuration of a measuring apparatus for measuring the retroreflectance of an optical film.

Embodiments of the present invention will be described in the following order with reference to the drawings.
1. First embodiment (example in which structures are arranged one-dimensionally)
2. Second embodiment (example in which structures are two-dimensionally arranged)
3. Third Embodiment (Example of louver type wavelength selective reflection layer)
4). Fourth Embodiment (Example in which a light scatterer is provided on an optical film)

<1. First Embodiment>
[Configuration of optical film]
FIG. 1A is a cross-sectional view showing a configuration example of an optical film according to the first embodiment of the present invention. FIG. 1B is a cross-sectional view showing an example in which the optical film according to the first embodiment of the present invention is bonded to an adherend. The optical film 1 as an optical body is an optical film having so-called directional reflection performance. As shown in FIG. 1A, an optical film 1 includes an optical layer 2 having a concavo-convex shaped interface therein, and a wavelength selective reflection layer (an intermediate layer mainly composed of an inorganic material) provided at the interface of the optical layer 2. 3). The optical layer 2 includes a first optical layer 4 having a concavo-convex first surface and a second optical layer 5 having a concavo-convex second surface. The interface inside the optical layer is formed by a first surface and a second surface having a concave and convex shape that are arranged to face each other. The optical film 1 has an incident surface S1 on which light such as sunlight is incident and an output surface S2 from which light transmitted through the optical film 1 is emitted out of the light incident from the incident surface S1.

  The optical film 1 may further include a first substrate 4a on the emission surface S2 of the optical layer 2 as necessary. Further, the optical film 1 may further include a second base material 5a on the incident surface S1 of the optical layer 2 as necessary. In addition, when providing the 1st base material 4a and / or the 2nd base material 5a in the optical film 1 in this way, the 1st base material 4a and / or the 2nd base material 5a are optical films. In the state prepared for 1, it is preferable to satisfy the following optical properties such as transparency and transmitted color.

  The optical film 1 may further include a bonding layer 6 as necessary. The bonding layer 6 is formed on the surface of the incident surface S1 and the emitting surface S2 of the optical film 1 that is bonded to the window material 10. The optical film 1 is bonded to the indoor side or the outdoor side of the window material 10 that is an adherend through the bonding layer 6. As the bonding layer 6, for example, an adhesive layer containing an adhesive as a main component or an adhesive layer containing an adhesive as a main component can be used. When the bonding layer 6 is an adhesive layer, it is preferable to further include a release layer 7 formed on the bonding layer 6. This is because the optical film 1 can be easily bonded to an adherend such as the window material 10 through the bonding layer 6 simply by peeling off the peeling layer 7 with such a configuration.

  From the viewpoint of improving the bondability between the second base material 5a and the bonding layer 6 and / or the second optical layer 5, the optical film 1 has the second base material 5a, the bonding layer 6 and / or the second material. A primer layer (not shown) may be further provided between the optical layer 5 and the optical layer 5. Moreover, it is preferable to perform a known physical pretreatment instead of the primer layer or together with the primer layer from the viewpoint of improving the bondability at the same location. Known physical pretreatments include, for example, plasma treatment and corona treatment.

  The optical film 1 further includes a barrier layer (not shown) on the entrance surface S1 or the exit surface S2 bonded to the adherend such as the window member 10 or between the surface and the wavelength selective reflection layer 3. You may do it. By providing the barrier layer in this way, it is possible to reduce the diffusion of moisture from the incident surface S1 or the output surface S2 to the wavelength selective reflection layer 3, and to suppress the deterioration of the metal contained in the wavelength selective reflection layer 3. . Therefore, the durability of the optical film 1 can be improved.

  The optical film 1 may further include a hard coat layer 8 from the viewpoint of imparting scratch resistance to the surface. The hard coat layer 8 is preferably formed on the opposite surface of the incident surface S1 and the emission surface S2 of the optical film 1 from the surface to be bonded to the adherend such as the window material 10.

  The optical film 1 preferably has flexibility from the viewpoint of allowing the optical film 1 to be easily bonded to an adherend such as the window material 10. Here, the film includes a sheet. That is, the optical film 1 includes an optical sheet.

  The optical film 1 has transparency. As transparency, it is preferable that it has the range of the transmitted image clarity mentioned later. The refractive index difference between the first optical layer 4 and the second optical layer 5 is preferably 0.010 or less, more preferably 0.008 or less, and still more preferably 0.005 or less. If the refractive index difference exceeds 0.010, the transmitted image tends to appear blurred. If it is in the range of more than 0.008 and not more than 0.010, there is no problem in daily life although it depends on the external brightness. If it is in the range of more than 0.005 and less than or equal to 0.008, the diffraction pattern is worrisome only for a very bright object such as a light source, but the outside scenery can be clearly seen. If it is 0.005 or less, the diffraction pattern is hardly a concern. Of the first optical layer 4 and the second optical layer 5, the optical layer to be bonded to the window material 10 or the like may contain an adhesive as a main component. By setting it as such a structure, the optical film 1 can be bonded together to the window material 10 etc. with the 1st optical layer 4 or the 2nd optical layer 5 which has an adhesive material as a main component. In addition, when setting it as such a structure, it is preferable that the refractive index difference of an adhesive is in the said range.

  It is preferable that the first optical layer 4 and the second optical layer 5 have the same optical characteristics such as refractive index. More specifically, the first optical layer 4 and the second optical layer 5 are preferably made of the same material having transparency in the visible region. By configuring the first optical layer 4 and the second optical layer 5 with the same material, the refractive indexes of both are equal, and thus the transparency of visible light can be improved. However, it should be noted that even if the same material is used as a starting source, the refractive index of the finally generated layer may differ depending on the curing conditions in the film forming process. On the other hand, if the first optical layer 4 and the second optical layer 5 are made of different materials, the refractive indexes of the two are different. Therefore, the light is refracted with the wavelength selective reflection layer 3 as a boundary, and a transmitted image is formed. There is a tendency to blur. In particular, when an object close to a point light source such as a distant electric light is observed, the diffraction pattern tends to be observed remarkably. Note that an additive may be mixed in the first optical layer 4 and / or the second optical layer 5 in order to adjust the value of the refractive index.

  It is preferable that the first optical layer 4 and the second optical layer 5 have transparency in the visible region. Here, the definition of transparency has two kinds of meanings: no light absorption and no light scattering. In general, when the term “transparent” is used, only the former may be pointed out, but the optical film 1 according to the first embodiment preferably includes both. The retroreflectors currently used are intended for visually recognizing display reflected light such as road signs and clothes for night workers, so even if they have scattering properties, they are in close contact with the underlying reflector. If so, the reflected light can be visually recognized. For example, even if an anti-glare process having a scattering property is applied to the front surface of the image display device for the purpose of imparting anti-glare properties, the same principle is that an image can be visually recognized. However, the optical film 1 according to the first embodiment is characterized in that it transmits light other than the specific wavelength that is directionally reflected. The optical film 1 is bonded to a transmission body that mainly transmits the transmission wavelength. In order to observe the transmitted light, it is preferable that there is no light scattering. However, depending on the application, the second optical layer 5 can be intentionally provided with scattering properties.

  The optical film 1 is preferably used by being bonded to a rigid body that is mainly transmissive to light having a wavelength other than the specified wavelength, for example, a window material 10 via an adhesive or the like. Examples of the window material 10 include window materials for buildings such as high-rise buildings and houses, and window materials for vehicles. When the optical film 1 is applied to a building window material, it is particularly preferable to apply the optical film 1 to the window material 10 disposed in any direction between the east and south to west directions (for example, the southeast to southwest direction). . It is because a heat ray can be reflected more effectively by applying to the window material 10 in such a position. The optical film 1 can be used not only for a single-layer window glass but also for a special glass such as a multi-layer glass. Moreover, the window material 10 is not limited to what consists of glass, You may use what consists of a polymeric material which has transparency. It is preferable that the optical layer 2 has transparency in the visible region. This is because when the optical film 1 is bonded to the window material 10 such as a window glass, visible light can be transmitted and sunlight can be secured by having transparency in this way. Moreover, as a bonding surface, it can be used not only on the inner surface of the glass but also on the outer surface.

  The optical film 1 can be used in combination with other heat ray cut films. For example, a light-absorbing coating film can be provided on the interface between air and the optical film 1 (that is, the outermost surface of the optical film 1). The optical film 1 can be used in combination with a hard coat layer, an ultraviolet cut layer, a surface antireflection layer, or the like. When these functional layers are used in combination, it is preferable to provide these functional layers at the interface between the optical film 1 and air. However, since it is necessary to arrange | position about an ultraviolet cut layer on the solar side rather than the optical film 1, when using it for an internal application especially to the indoor window glass surface, between this window glass surface and the optical film 1 is used. It is desirable to provide an ultraviolet cut layer. In this case, an ultraviolet absorber may be kneaded into the bonding layer between the window glass surface and the optical film 1.

  Moreover, according to the use of the optical film 1, you may make it color with respect to the optical film 1 and provide designability. Thus, when designability is imparted, it is preferable that the optical layer 2 absorb only light in a specific wavelength band as long as the transparency is not impaired.

FIG. 2 is a perspective view showing a relationship between incident light incident on the optical film 1 and reflected light reflected by the optical film 1. The optical film 1 has an incident surface S1 on which the light L is incident. The optical film 1 selectively reflects light L ₁ in a specific wavelength band in a direction other than regular reflection (−θ, φ + 180 °) among the light L incident on the incident surface S1 at an incident angle (θ, φ). On the other hand, light L ₂ other than the specific wavelength band is transmitted. Moreover, the optical film 1 has transparency with respect to light other than the specific wavelength band. As transparency, it is preferable that it has the range of the transmitted image clarity mentioned later. Where θ is an angle formed between the perpendicular l ₁ to the incident surface S1 and the incident light L or the reflected light L ₁ . φ: An angle formed between a specific straight line l ₂ in the incident surface S1 and a component obtained by projecting the incident light L or the reflected light L ₁ onto the incident surface S1. Here, the specific straight line l ₂ in the incident surface means that when the incident angle (θ, φ) is fixed and the optical film 1 is rotated about the perpendicular l ₁ with respect to the incident surface S ₁ of the optical film 1, This is the axis that maximizes the reflection intensity in the direction (see FIGS. 3 and 4). However, when there are a plurality of axes (directions) at which the reflection intensity is maximum, one of them is selected as the straight line l ₂ . The angle θ rotated clockwise with respect to the perpendicular l ₁ is defined as “+ θ”, and the angle θ rotated counterclockwise is defined as “−θ”. The angle φ rotated clockwise with respect to the straight line l ₂ is defined as “+ φ”, and the angle φ rotated counterclockwise is defined as “−φ”.

  The light of a specific wavelength band that selectively and directionally reflects and the specific light that is transmitted vary depending on the application of the optical film 1. For example, when the optical film 1 is applied to the window material 10, the light in a specific wavelength band that is selectively directionally reflected is near-infrared light, and the light in the specific wavelength band that is transmitted is visible light. Is preferred. Specifically, it is preferable that light in a specific wavelength band that is selectively directionally reflected is mainly near-infrared light having a wavelength band of 780 nm to 2100 nm. By reflecting near infrared rays, when an optical body is bonded to a window material such as a glass window, an increase in temperature in the building can be suppressed. Therefore, the cooling load can be reduced and energy saving can be achieved. Here, the directional reflection means that the reflected light intensity in a specific direction other than the regular reflection is stronger than the regular reflected light intensity and sufficiently stronger than the diffuse reflection intensity having no directivity. Here, “reflecting” means that the reflectance in a specific wavelength band, for example, near infrared region is preferably 30% or more, more preferably 50% or more, and further preferably 80% or more. Transmitting means that the transmittance in a specific wavelength band, for example, in the visible light region is preferably 30% or more, more preferably 50% or more, and further preferably 70% or more.

  In the optical film 1, the direction φo for directional reflection is preferably −90 ° or more and 90 ° or less. This is because, when the optical film 1 is pasted on the window member 10, the light in the specific wavelength band among the light incident from the sky can be returned to the sky direction. When there are no tall buildings around, the optical film 1 in this range is useful. Further, the direction of directional reflection is preferably in the vicinity of (θ, −φ). The vicinity means a deviation within a range of preferably within 5 degrees from (θ, −φ), more preferably within 3 degrees, and even more preferably within 2 degrees. By making this range, when the optical film 1 is pasted on the window material 10, light of a specific wavelength band out of the light incident from above the buildings of the same height is efficiently placed above other buildings. This is because it can be returned. In order to realize such directional reflection, it is preferable to use a three-dimensional structure such as a spherical surface, a part of a hyperboloid, a triangular pyramid, a quadrangular pyramid, or a cone. The light incident from the (θ, φ) direction (−90 ° <φ <90 °) is based on the shape (θo, φo) direction (0 ° <θo <90 °, −90 ° <φo <90 °). ) Can be reflected. Alternatively, a columnar body extending in one direction is preferable. Light incident from the (θ, φ) direction (−90 ° <φ <90 °) is reflected in the (θo, −φ) direction (0 ° <θo <90 °) based on the inclination angle of the columnar body. Can do.

  In the optical film 1, the directional reflection of the light of the specific wavelength body is in the direction near the retroreflection, that is, the reflection direction of the light of the specific wavelength body with respect to the light incident on the incident surface S1 at the incident angle (θ, φ). It is preferably in the vicinity of θ, φ). This is because, when the optical film 1 is attached to the window member 10, light in a specific wavelength band can be returned to the sky among the light incident from the sky. Here, the vicinity is preferably within 5 degrees, more preferably within 3 degrees, and further preferably within 2 degrees. This is because, when the optical film 1 is pasted on the window member 10 within this range, light in a specific wavelength band among the light incident from the sky can be efficiently returned to the sky. In addition, when the infrared light irradiation part and the light receiving part are adjacent to each other as in an infrared sensor or infrared imaging, the retroreflection direction must be equal to the incident direction, but sensing from a specific direction as in the present invention. If it is not necessary to do so, it is not necessary to have the exact same direction.

  In the optical film 1, the value when the optical comb of 0.5 mm is used is preferably 50 or more, more preferably 60 or more, and still more preferably 75 or more, with respect to the transmitted image clarity for a wavelength band having transparency. . If the value of the transmitted image definition is less than 50, the transmitted image tends to appear blurred. If it is 50 or more and less than 60, it depends on the brightness of the outside, but there is no problem in daily life. If it is 60 or more and less than 75, only the very bright object such as a light source is concerned about the diffraction pattern, but the outside scenery can be clearly seen. If it is 75 or more, the diffraction pattern is hardly a concern. Furthermore, the total value of transmitted image sharpness values measured using optical combs of 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm is preferably 230 or more, more preferably 270 or more, and even more preferably 350. That's it. When the total value of the transmitted image definition is less than 230, the transmitted image tends to appear blurred. If it is 230 or more and less than 270, it depends on the external brightness, but there is no problem in daily life. If it is 270 or more and less than 350, the diffraction pattern is worrisome only for a very bright object such as a light source, but the outside scenery can be clearly seen. If it is 350 or more, the diffraction pattern is hardly a concern. Here, the value of transmitted image definition is measured according to JIS K7105 using ICM-1T manufactured by Suga Test Instruments. However, when the wavelength to be transmitted is different from the wavelength of the D65 light source, it is preferable to perform measurement after calibrating with a filter having a wavelength to be transmitted.

In the optical film 1, the haze with respect to the wavelength band having transparency is preferably 6% or less, more preferably 4% or less, and further preferably 2% or less. This is because if the haze exceeds 6%, the transmitted light is scattered and it looks cloudy. Here, haze is measured by a measuring method defined in JIS K7136 using HM-150 made by Murakami Color. However, when the wavelength to be transmitted is different from the wavelength of the D65 light source, it is preferable to perform measurement after calibrating with a filter having a wavelength to be transmitted. The incident surface S1, preferably the incident surface S1 and the exit surface S2 of the optical film 1 have smoothness that does not reduce the transmitted image definition. Specifically, the arithmetic average roughness Ra of the entrance surface S1 and the exit surface S2 is preferably 0.08 μm or less, more preferably 0.06 μm or less, and even more preferably 0.04 μm or less. The arithmetic average roughness Ra is calculated as a roughness parameter by measuring the surface roughness of the incident surface, obtaining a roughness curve from a two-dimensional sectional curve. Measurement conditions are based on JIS B0601: 2001. The measurement apparatus and measurement conditions are shown below.
Measuring device: Fully automatic fine shape measuring machine Surfcoder ET4000A (Kosaka Laboratory Ltd.)
λc = 0.8mm, evaluation length 4mm, cutoff x5 times Data sampling interval 0.5μm

  The transmitted color of the optical film 1 is as close to neutral as possible, and a light color tone such as blue, blue-green, or green that gives a cool impression even if colored is preferable. From the viewpoint of obtaining such a color tone, the chromaticity coordinates x and y of the transmitted light and the reflected light that are incident from the incident surface S1, are transmitted through the optical layer 2 and the wavelength selective reflection layer 3, and are emitted from the output surface S2. For example, for irradiation with a D65 light source, preferably 0.20 <x <0.35 and 0.20 <y <0.40, more preferably 0.25 <x <0.32 and 0.25. It is desirable to satisfy the range of <y <0.37, more preferably 0.30 <x <0.32 and 0.30 <y <0.35. Furthermore, in order for the color tone not to be reddish, it is preferable that y> x−0.02, more preferably y> x. Further, if the reflection color tone changes depending on the incident angle, for example, when applied to a building window, the color tone varies depending on the location or the color appears to change when walking, which is not preferable. From the viewpoint of suppressing such a change in color tone, regular reflection is incident from the incident surface S1 or the exit surface S2 at an incident angle θ of 0 ° or more and 60 ° or less, and is reflected by the optical layer 2 and the wavelength selective reflection layer 3. The absolute value of the difference between the color coordinates x of light and the absolute value of the difference between the color coordinates y are preferably 0.05 or less, more preferably 0.03 or less, in any of both main surfaces of the optical film 1. Preferably it is 0.01 or less. It is desirable that the limitation of the numerical range regarding the color coordinates x and y with respect to the reflected light is satisfied on both the incident surface S1 and the exit surface S2.

  Hereinafter, the 1st optical layer 4, the 2nd optical layer 5, and the wavelength selection reflection layer 3 which comprise the optical film 1 are demonstrated sequentially.

(First optical layer, second optical layer)
The first optical layer 4 is, for example, for supporting and protecting the wavelength selective reflection layer 3. The 1st optical layer 4 consists of a layer which has resin as a main component from a viewpoint which provides the optical film 1 with flexibility, for example. Of the two main surfaces of the first optical layer 4, for example, one surface is a smooth surface and the other surface is an uneven surface (first surface). The wavelength selective reflection layer 3 is formed on the uneven surface.

  The second optical layer 5 is for protecting the wavelength selective reflection layer 3 by embedding the first surface (uneven surface) of the first optical layer 4 on which the wavelength selective reflection layer 3 is formed. It is. The 2nd optical layer 5 consists of a layer which has resin as a main component from a viewpoint which provides the optical film 1 with flexibility, for example. Of the two main surfaces of the second optical layer 5, for example, one surface is a smooth surface and the other surface is an uneven surface (second surface). The concavo-convex surface of the first optical layer 4 and the concavo-convex surface of the second optical layer 5 are in a relationship in which the unevenness is inverted.

  The uneven surface of the first optical layer 4 is formed by, for example, a plurality of structures 4c arranged one-dimensionally. The uneven surface of the second optical layer 5 is formed by, for example, a plurality of structures 5c arranged one-dimensionally (see FIGS. 3 and 4). The structure 4c of the first optical layer 4 is different from the structure 5c of the second optical layer 5 only in that the unevenness is inverted. Therefore, the structure 4c of the first optical layer 4 will be described below. To do.

  In the optical film 1, the pitch P of the structures 4c is, for example, 5 μm or more and 5 mm or less, preferably 30 μm or more and 5 mm or less, more preferably 10 μm or more and less than 250 μm, and still more preferably 20 μm or more and 200 μm or less. If the pitch of the structures 4c is less than 5 μm, it is difficult to make the shape of the structures 4c desirable, and it is generally difficult to make the wavelength selective characteristics of the wavelength selective reflection layer 3 steep. Therefore, part of the transmission wavelength may be reflected. When such reflection occurs, diffraction occurs and even higher-order reflection is visually recognized, so that the transparency tends to be felt poorly. Further, when the pitch of the structures 4c exceeds 5 mm, when considering the shape of the structures 4c necessary for directional reflection, the necessary film thickness increases and flexibility is lost, and the structure 4c is bonded to a rigid body such as the window material 10. It becomes difficult.

  Further, the shape of the structure 4 c formed on the surface of the first optical layer 4 is not limited to one type, and a plurality of types of structures 4 c are formed on the surface of the first optical layer 4. You may do it. When a plurality of types of structures 4c are provided on the surface, a predetermined pattern composed of a plurality of types of structures 4c may be periodically repeated. Further, depending on desired characteristics, a plurality of types of structures 4c may be formed randomly (non-periodically).

  3A to 3C are perspective views showing examples of the shape of the structure formed in the first optical layer. The structure 4c is a columnar recess extending in one direction, and the columnar structures 4c are arranged one-dimensionally in one direction. Since the wavelength selective reflection layer 3 is formed on this structure 4c, the shape of the wavelength selective reflection layer 3 has the same shape as the surface shape of the structure 4c.

  Examples of the shape of the structure 4c include a prism shape shown in FIG. 3A, a shape shown in FIG. 3B in which valleys between the prisms are rounded, a cylindrical shape shown in FIG. 3C, or an inverted shape thereof. it can. The ridge portion may have R, and preferably the ratio R / P of the radius of curvature R and the pitch P of the structures 4c is 7% or less, more preferably 5% or less, and even more preferably 3% or less. . Moreover, the shape of the structure 4c is not limited to the shape shown in FIGS. 3A to 3C or the inverted shape thereof, and may be a toroidal shape, a hyperbolic column shape, an elliptical column shape, a polygonal column shape, or a free-form surface shape. Good. When the structure 4c has a prism shape, the inclination angle θ of the prism-shaped structure 4c is, for example, 45 °. When applied to the window member 10, the structure 4c preferably has a flat surface or a curved surface with an inclination angle of 45 ° or more from the viewpoint of reflecting a large amount of light incident from above and returning it to the sky. By adopting such a shape, the incident light returns to the sky with almost one reflection, so that the incident light can be efficiently reflected in the sky direction even if the reflectance of the wavelength selective reflection layer 3 is not so high. This is because light absorption in the selective reflection layer 3 can be reduced.

Further, as shown in FIG. 4A, the shape of the structure 4c may be asymmetric with respect to the perpendicular l ₁ perpendicular to the incident surface S1 or the outgoing surface S2 of the optical film 1. In this case, the main axis l _m of the structure 4c is inclined in the arrangement direction a of the structures 4c with respect to the perpendicular l ₁ . Here, the main axis l _m of the structure 4c means a straight line passing through the midpoint of the bottom of the structure cross section and the vertex of the structure. When the optical film 1 is pasted on the window material 10 arranged substantially perpendicular to the ground, as shown in FIG. 4B, the main axis l _m of the structure 4 c is the window material 10 with respect to the perpendicular l ₁ . It is preferable to incline downward (on the ground side). In general, the heat inflow through the window is mostly in the time zone around noon, and the altitude of the sun is often higher than 45 °. Therefore, by adopting the above shape, the light incident from these high angles can be efficiently used. This is because it can be reflected upward. 4A and 4B show an example in which the prism-shaped structure 4c has an asymmetric shape with respect to the perpendicular l ₁ . The structure 4c other than the prism shape may be asymmetric with respect to the perpendicular l ₁ . For example, the corner cube body may have an asymmetric shape with respect to the perpendicular l ₁ .

It is preferable that the first optical layer 4 is mainly composed of a resin in which the storage elastic modulus at 100 ° C. is small and the storage elastic modulus at 25 ° C. and 100 ° C. is not significantly different. Specifically, it is preferable to contain a resin having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or lower and a storage elastic modulus at 100 ° C. of 3 × 10 ⁷ Pa or higher. The first optical layer 4 is preferably made of one type of resin, but may contain two or more types of resins. Moreover, the additive may be mixed as needed.

  Thus, when the main component is a resin in which the storage elastic modulus at 100 ° C. is small and the storage elastic modulus at 25 ° C. and 100 ° C. is not significantly different, a process involving heat or heat and pressurization is performed. Even when the uneven surface (first surface) of the first optical layer 4 is present after the formation, the designed interface shape can be substantially maintained. On the other hand, when the storage elastic modulus at 100 ° C. is greatly reduced and the main component is a resin having significantly different storage elastic modulus at 25 ° C. and 100 ° C., the deformation from the designed interface shape becomes large, The optical film 1 may be curled.

  Here, the process involving heat is not limited to a process in which heat is directly applied to the optical film 1 or its constituent members, such as an annealing process, but also during the formation of a thin film and the resin composition. During curing, the temperature of the film formation surface rises locally and heat is indirectly applied to them, or the temperature of the mold rises due to energy ray irradiation, which indirectly heats the optical film. The process of adding is also included. In addition, the effect obtained by limiting the numerical range of the storage elastic modulus described above is not particularly limited to the type of resin, and any of a thermoplastic resin, a thermosetting resin, and an energy beam irradiation type resin can be obtained. it can.

  The storage elastic modulus of the first optical layer 4 can be confirmed as follows, for example. When the surface of the 1st optical layer 4 is exposed, it can confirm by measuring the storage elastic modulus of the exposed surface using a micro hardness meter. Further, when the first substrate 4a or the like is formed on the surface of the first optical layer 4, the first substrate 4a or the like is peeled off to expose the surface of the first optical layer 4. Then, the storage elastic modulus of the exposed surface can be confirmed by measuring using a micro hardness meter.

  Examples of a method for suppressing a decrease in elastic modulus at high temperature include a method for adjusting the length and type of side chains in the case of a thermoplastic resin, a thermosetting resin, and energy beam irradiation. In the case of a mold resin, a method of adjusting the amount of crosslinking points, the molecular structure of the crosslinking material, and the like can be mentioned. However, it is preferable that such a structural change does not impair the characteristics required for the resin material itself. For example, depending on the type of cross-linking agent, the modulus of elasticity near room temperature may be high and become brittle, or shrinkage may increase and the film may be curved or curled. It is preferable to select appropriately according to the characteristics to be performed.

  When the first optical layer 4 contains a crystalline polymer material as a main component, the glass transition point is higher than the maximum temperature during the manufacturing process, and the storage elastic modulus at the maximum temperature during the manufacturing process. It is preferable that the main component is a resin with a small decrease in the temperature. On the other hand, when a resin having a glass transition point in the range of room temperature 25 ° C. or higher and below the maximum temperature during the manufacturing process and a large decrease in storage elastic modulus at the maximum temperature during the manufacturing process is used, It becomes difficult to maintain the designed ideal interface shape during the process.

  In the case where the first optical layer 4 contains an amorphous polymer material as a main component, the melting point is higher than the maximum temperature during the manufacturing process, and the storage elastic modulus at the maximum temperature during the manufacturing process is It is preferable that the main component is a resin with little decrease. On the other hand, if a resin having a melting point within a range of room temperature 25 ° C. or higher and lower than the maximum temperature during the manufacturing process and a large decrease in storage elastic modulus at the maximum temperature during the manufacturing process is used, In addition, it is difficult to maintain the designed ideal interface shape.

  Here, the maximum temperature during the manufacturing process means the maximum temperature of the uneven surface (first surface) of the first optical layer 4 during the manufacturing process. It is preferable that the above-described numerical range of the storage elastic modulus and the temperature range of the glass transition point also satisfy the second optical layer 5.

It is preferable that at least one of the first optical layer 4 and the second optical layer 5 contains a resin having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less. This is because flexibility can be imparted to the optical film 1 at room temperature of 25 ° C., so that the optical film 1 can be manufactured in a roll-to-roll manner.

  The 1st base material 4a and the 2nd base material 5a have transparency, for example. The shape of the substrate 51 is preferably a film shape from the viewpoint of imparting flexibility to the optical film 1, but is not particularly limited to this shape. As a material of the first base material 4a and the second base material 5a, for example, a known polymer material can be used. Known polymer materials include, for example, triacetyl cellulose (TAC), polyester (TPEE), polyethylene terephthalate (PET), polyimide (PI), polyamide (PA), aramid, polyethylene (PE), polyacrylate, polyether Examples include sulfone, polysulfone, polypropylene (PP), diacetyl cellulose, polyvinyl chloride, acrylic resin (PMMA), polycarbonate (PC), epoxy resin, urea resin, urethane resin, melamine resin, etc. It is not limited. Although it is preferable that the thickness of the 1st base material 4a and the 2nd base material 5a is 38-100 micrometers from a viewpoint of productivity, it is not specifically limited to this range. The first base material 4a and the second base material 5a preferably have energy ray permeability. Thereby, as will be described later, the first base 4a or the energy base curable resin interposed between the second base 5a and the wavelength selective reflection layer 3 is used as the first base 4a. This is because the energy ray curable resin can be cured by irradiating energy rays from the second substrate 5a side.

  The first optical layer 4 and the second optical layer 5 have transparency, for example. The first optical layer 4 and the second optical layer 5 are obtained, for example, by curing a resin composition. From the viewpoint of ease of production, the resin composition is preferably an energy beam curable resin that is cured by light or an electron beam, or a thermosetting resin that is cured by heat. As the energy ray curable resin, a photosensitive resin composition curable by light is preferable, and an ultraviolet curable resin composition curable by ultraviolet light is most preferable. From the viewpoint of improving the adhesion between the first optical layer 4 or the second optical layer 5 and the wavelength selective reflection layer 3, the resin composition includes a compound containing phosphoric acid, a compound containing succinic acid, and butyrolactone. It is preferable to further contain a compound containing As the compound containing phosphoric acid, for example, (meth) acrylate containing phosphoric acid, preferably a (meth) acrylic monomer or oligomer having phosphoric acid as a functional group can be used. As the compound containing succinic acid, for example, a (meth) acrylate containing succinic acid, preferably a (meth) acrylic monomer or oligomer having succinic acid as a functional group can be used. As the compound containing butyrolactone, for example, a (meth) acrylate containing butyrolactone, preferably a (meth) acryl monomer or oligomer having butyrolactone as a functional group can be used.

  The ultraviolet curable resin composition contains, for example, (meth) acrylate and a photopolymerization initiator. Moreover, you may make it an ultraviolet curable resin composition further contain a light stabilizer, a flame retardant, a leveling agent, antioxidant, etc. as needed.

  As the acrylate, it is preferable to use a monomer and / or an oligomer having two or more (meth) acryloyl groups. As this monomer and / or oligomer, for example, urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, polyol (meth) acrylate, polyether (meth) acrylate, melamine (meth) acrylate and the like are used. be able to. Here, the (meth) acryloyl group means either an acryloyl group or a methacryloyl group. Here, the oligomer refers to a molecule having a molecular weight of 500 or more and 60000 or less.

  Examples of the polyfunctional monomer include ethanediol diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1 , 14-tetradecanediol diacrylate, 1,15-pentadecanediol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, 2-butyl-2-ethylpropanediol diacrylate, ethylene oxide Modified bisphenol A diacrylate, polyethylene oxide modified bisphenol A diacrylate, polyethylene oxide modified hydrogenated bisphenol Diacrylate, propylene oxide modified bisphenol A diacrylate, polypropylene oxide modified bisphenol A diacrylate, hydroxypivalic acid ester neopentyl glycol ester diacrylate, hydroxypivalic acid ester neopentyl glycol ester caprolactone adduct diacrylate, ethylene oxide modified isocyanuric acid di Acrylate, pentaerythritol diacrylate monostearate, 1,6-hexanediol diglycidyl ether acrylic acid adduct, polyoxyethylene epichlorohydrin modified bisphenol A diacrylate, tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol Dimethacrylate, trimethylolpropane triacrylate, Tylene oxide modified trimethylolpropane triacrylate, polyethylene oxide modified trimethylolpropane triacrylate, propylene oxide modified trimethylolpropane triacrylate, polypropylene oxide modified trimethylolpropane triacrylate, pentaerythritol triacrylate, ethylene oxide modified isocyanuric acid triacrylate, ethylene oxide modified Glycerol triacrylate, polyethylene oxide modified glycerol triacrylate, propylene oxide modified glycerol triacrylate, polypropylene oxide modified glycerol triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol tetraacrylate Examples include acrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, polycaprolactone-modified dipentaerythritol hexaacrylate, dioxane glycol diacrylate, and caprolactone-modified tris (acryloxyethyl) isocyanurate. .

  More specific examples of product names include those manufactured by Osaka Organic Chemical Co., Ltd. such as Biscoat 215, Biscoat 230, Biscoat 195, Biscoat 300, Biscoat 3PA, Biscoat 295, and Biscoat 310. In the company, TMP-A9EGA, NPA, 1.6HX-A, BP-4EA, light ester 1, 3-BG, light ester 2EG, light ester EG, epoxy ester 40EM, light ester 1,6HX, 4EG-A, Epoxy ester 70PA, 3EG-A, epoxy ester 80MFA, light ester TMP, etc., manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester NPG, NK ester A-NPG, NK ester HD, NK ester A-HD, NK ester A-BPE-4, NK ester B E-200, NK ester BPE-500, NK ester BPE-1300, NK ester BG, NK ester 2G, NK ester IG, NK ester 701-A, NK ester 701, NK ester A-TMM-3, NK ester A- TMMT, NK ester, NK ester A-200, NK ester A-400, NK ester A-600, NK ester 4G, NK ester 9G, NK ester 14G, NK ester 23G, NK ester APG-400, NK ester 9PG, NK Ester 3G, NK ester A-TMPT, NK ester TMPT, NK ester APG-200, NK ester A-DCP, NK ester DCP, NK ester A-DOG, NK ester A-9300, NK ester A-9300-1CL, NK Beauty treatment Kayarad R-526, Kayarad R-551, Kayarad R-712, Kayarad R-684, Kayarad DEGDA, Kayarad DPHA, Kayarad D-, manufactured by Nippon Kayaku Co., Ltd., such as A-DPH and NK ester A-GLY 310, Kayarad D-320, Kayarad D-330, Kayarad DPCA-20, Kayarad DPCA-30, Kayarad DPCA-60, Kayarad DPCA-120, Kayarad HDDA, Kayarad R-167, Kayarad NPGDA, Kayarad MANDA, Kayarad HX-220 Kayarad HX-620, Kayarad PET-30, Kayarad PET-40, Kayamar PM-2, Kayamar PM-21, Kayarad PEG400DA, Kayarad R-604, Kayarad TMPTA, Kayalad Dopa TPA-330, Kayarad TPA-310, Kayarad TPA-320, Kayarad TPA-330, Kayarad TPGDA, etc., manufactured by Toagosei Co., Ltd., Aronix M-205, Aronix M-210, Aronix M-215, Aronix M -220, Aronix M-233, Aronix M-240, Aronix M-245, Aronix M-305, Aronix M-309, Aronix M-310, Acronix M-313, Aronix M-315, Aronix M-320, Aronix M-325, Acronix M-327, Aronix M-400, Aronix M-450, TO-458, TO-747, TO-755, THIC, TA2, etc., manufactured by Sartomer, SR-349, SR-34 SR-213, SR-214, SR-212, SR-297, SR-230, SR-231, SR-399, SR-355, SR-238, SR-239, C-2000, C-2100, SR -444, SR-295, SR-367, SR-259, SR-344, SR-210, SR-252, SR-268, SR-209, SR-640, SR-272, SR-205, SR-351 SR-454, SR-350, SR-306, SR-368, SR-290, SR-416, SR-365, etc., manufactured by Tokyo Chemical Industry Co., Ltd. include T2325, etc. It is not what was given.

  As the photopolymerization initiator, those appropriately selected from known materials can be used. As a known material, for example, a benzophenone derivative, an acetophenone derivative, an anthraquinone derivative, or the like can be used alone or in combination. The blending amount of the polymerization initiator is preferably 0.1% by mass or more and 10% by mass or less in the solid content. If it is less than 0.1% by mass, the photocurability is lowered, which is substantially unsuitable for industrial production. On the other hand, when it exceeds 10 mass%, when the amount of irradiation light is small, odor tends to remain in the coating film. Here, solid content means all the components which comprise the hard-coat layer 12 after hardening. Specifically, for example, acrylate, photopolymerization initiator, and the like are referred to as solid content.

  The resin is preferably one that can transfer the structure by irradiation with energy rays or heat, and any type of resin can be used as long as it satisfies the above refractive index requirements, such as vinyl resin, epoxy resin, and thermoplastic resin. May be.

  In order to reduce curing shrinkage, an oligomer may be added. Polyisocyanate and the like may be included as a curing agent. In consideration of adhesion to the first optical layer 4 and the second optical layer 5, monomers having a hydroxyl group, a carboxyl group, and a phosphate group, polyhydric alcohols, carboxylic acid, silane, Coupling agents such as aluminum and titanium and various chelating agents may be added.

  As the vinyl resin, an acrylic (meth) resin is preferable, and as a preferred acrylic (meth) resin, specific examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl ( (Meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) ) Acrylate, di-2-hydroxyethyl fumarate or mono-2-hydroxyethyl-monobutyl fumarate, polyethylene glycol- or polypropylene glycol mono (meth) acrylate or adducts of these with ε-caprolactone, Plastic Cell [manufactured by Daicel Chemical Co., trade name of caprolactone addition monomer] FM or FA Monomer "such as various alpha, such as hydroxyalkyl esters of β- ethylenically unsaturated carboxylic acid.

  Specific examples of the carboxyl group-containing vinyl monomer include various unsaturated mono- or dicarboxylic acids or monoethyl fumarate such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid or citraconic acid. Dicarboxylic acid monoesters such as monobutyl maleate or the above-mentioned hydroxyl group-containing (meth) acrylates and succinic acid, maleic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, benzenetricarboxylic acid, benzenetetracarboxylic Acid, “Himic acid” [product of Hitachi Chemical Co., Ltd .; “Himic acid” is a registered trademark of the company. And adducts of various polycarboxylic acids such as tetrachlorophthalic acid with anhydrides.

  Specific examples of the phosphoric acid group-containing vinyl monomer include dialkyl [(meth) acryloyloxyalkyl] phosphates or (meth) acryloyloxyalkyl acid phosphates, dialkyl [(meth) acryloyloxyalkyl] phosphites or (Meth) acryloyloxyalkyl acid phosphites are mentioned.

  Examples of polyhydric alcohols include ethylene glycol, propylene glycol, glycerin, trimethylol ethane, trimethylol propane, neopentyl glycol, 1,6-hexanediol, 1,2,6-hexanetriol, pentaerythritol or sorbitol, One type or two or more types of various polyhydric alcohols can be used. Further, although not alcohol, various fatty acid glycidyl esters such as “Cardura E” (trade name of glycidyl ester of fatty acid manufactured by Shell of the Netherlands) can be used instead of alcohol.

  Carboxylic acids include benzoic acid, p-tert-butylbenzoic acid, (anhydrous) phthalic acid, hexahydro (anhydrous) phthalic acid, tetrahydro (anhydrous) phthalic acid, tetrachloro (anhydrous) phthalic acid, hexachloro (anhydrous) phthalic acid , Tetrabromo (anhydrous) phthalic acid, trimellitic acid, "hymic acid", (anhydrous) succinic acid, (anhydrous) maleic acid, fumaric acid, (anhydrous) itaconic acid, adipic acid, sebacic acid or oxalic acid etc. Various carboxylic acids can be used. These monomers may be used alone or copolymerized, and examples of the copolymerizable monomers are shown below.

  Styrene monomers such as styrene, vinyl toluene, p-methyl styrene, ethyl styrene, propyl styrene, isopropyl styrene or p-tert-butyl styrene.

  Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, iso (i) -propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meta ) Acrylate, sec-butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate or lauryl (meth) acrylate, “Acryester SL” [C12- / C13 methacrylate, manufactured by Mitsubishi Rayon Co., Ltd. Trade name of the mixture], alkyl (meth) acrylates such as stearyl (meth) acrylate; cyclohexyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate or isobornyl (meth) acrylate (Meth) acrylates that do not contain a functional group in the side chain such as H, adamantyl (meth) acrylate, and benzyl (meth) acrylate; and bifunctional vinyl monomers such as ethylene-di- (meth) acrylate.

  Various alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate or methoxybutyl (meth) acrylate.

  Various dicarboxylic acids represented by maleic acid, fumaric acid or itaconic acid, such as dimethyl maleate, diethyl maleate, diethyl fumarate, di (n-butyl) fumarate, di (i-butyl) fumarate or dibutyl itaconate And diesters of monohydric alcohols.

  Various vinyl esters such as vinyl acetate, vinyl benzoate, or “Beoba” (trade name of vinyl esters of branched (branched) aliphatic monocarboxylic acids, manufactured by Shell of the Netherlands), (meth) acrylonitrile, etc. .

N, N-alkylaminoalkyl (meth) acrylates such as N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate; and (meth) acrylamide, N-methylol (meth) Nitrogen-containing vinyl monomers such as amide bond-containing vinyl monomers such as butyl ether of acrylamide and dimethylaminopropyl acrylamide.
The content of the prepolymer or the like described above can be arbitrarily adjusted according to the properties of the dielectric layer or the metal layer included in the wavelength selective reflection layer 3.

  It is preferable that the resin composition further contains a crosslinking agent. As this crosslinking agent, it is particularly preferable to use a cyclic crosslinking agent. This is because the use of the cross-linking agent makes it possible to heat the resin without greatly changing the storage elastic modulus at room temperature. In addition, when the storage elastic modulus at room temperature changes greatly, the optical film 1 becomes brittle, and it becomes difficult to produce the optical film 1 by a roll-to-roll process or the like. Examples of the cyclic crosslinking agent include dioxane glycol diacrylate, tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate, ethylene oxide modified isocyanuric acid diacrylate, ethylene oxide modified isocyanuric acid triacrylate, caprolactone modified tris (acryloxy). And ethyl) isocyanurate.

The first base material 4a or the second base material 5a preferably has a lower water vapor transmission rate than the first optical layer 4 or the second optical layer 5. For example, when the first optical layer 4 is formed of an energy ray curable resin such as urethane acrylate, the first substrate 4a has a water vapor transmission rate lower than that of the first optical layer 4, and energy rays. It is preferably formed of a resin such as polyethylene terephthalate (PET) having transparency. Thereby, the diffusion of moisture from the incident surface S1 or the exit surface S2 to the wavelength selective reflection layer 3 can be reduced, and deterioration of the metal or the like contained in the wavelength selective reflection layer 3 can be suppressed. Therefore, the durability of the optical film 1 can be improved. The water vapor transmission rate of PET having a thickness of 75 μm is about 10 g / m ² / day (40 ° C., 90% RH).

  It is preferable that at least one of the first optical layer 4 and the second optical layer 5 includes a highly polar functional group, and the content thereof is different between the first optical layer 4 and the second optical layer 5. Both the 1st optical layer 4 and the 2nd optical layer 5 contain a phosphoric acid compound (for example, phosphate ester), The said phosphoric acid compound in the 1st optical layer 4 and the 2nd optical layer 5 It is preferable that the contents of are different. The content of the phosphoric acid compound in the first optical layer 4 and the second optical layer 5 is preferably 2 times or more, more preferably 5 times or more, and further preferably 10 times or more.

  When at least one of the first optical layer 4 and the second optical layer 5 contains a phosphoric acid compound, the wavelength selective reflection layer 3 is the first optical layer 4 or the second optical layer containing a phosphoric acid compound. The surface in contact with 5 preferably contains an oxide, nitride, or oxynitride. The wavelength selective reflection layer 3 particularly preferably has a layer containing zinc oxide or niobium oxide on the surface in contact with the first optical layer 4 or the second optical layer 5 containing a phosphate compound. This is because the anti-corrosion effect is high when the wavelength selective reflection layer 3 contains a metal such as Ag. Moreover, this layer may contain dopants, such as Al and Ga. This is because the film quality and smoothness are improved when the metal oxide layer is formed by sputtering or the like.

From the viewpoint that at least one of the first optical layer 4 and the second optical layer 5 imparts design properties to the optical film 1, the window material 10, and the like, it has a characteristic of absorbing light of a specific wavelength in the visible region. It is preferable to have. The pigment dispersed in the resin may be either an organic pigment or an inorganic pigment, but it is particularly preferable to use an inorganic pigment having high weather resistance. Specifically, zircon gray (Co, Ni-doped ZrSiO ₄ ), praseodymium yellow (Pr-doped ZrSiO ₄ ), chrome titanium yellow (Cr, Sb-doped TiO ₂ or Cr, W-doped TiO ₂ ), chrome green (Cr ₂ O ₃ ), peacock blue ((CoZn) O (AlCr) ₂ O ₃ ), Victoria Green ((Al, Cr) ₂ O ₃ ), bitumen (CoO · Al ₂ O ₃ · SiO ₂ ), vanadium zirconium blue (V Inorganic pigments such as doped ZrSiO ₄ ), chrome tin pink (Cr doped CaO · SnO ₂ · SiO ₂ ), porcelain red (Mn doped Al ₂ O ₃ ), salmon pink (Fe doped ZrSiO ₄ ), azo pigments and phthalocyanine series Examples thereof include organic pigments such as pigments.

(Wavelength selective reflection layer)
The wavelength selective reflection layer 3 is, for example, a laminated film, a transparent conductive layer, a functional layer, or a semi-transmissive layer. Moreover, it is good also as a wavelength selective reflection layer combining 2 or more of laminated films, a transparent conductive layer, a functional layer, and a semi-transmissive layer. The average film thickness of the wavelength selective reflection layer 3 is preferably 20 μm, more preferably 5 μm or less, and even more preferably 1 μm or less. When the average film thickness of the wavelength selective reflection layer 3 exceeds 20 μm, the optical path through which the transmitted light is refracted becomes long and the transmitted image tends to appear distorted. As a method for forming the wavelength selective reflection layer, for example, a sputtering method, a vapor deposition method, a dip coating method, a die coating method, or the like can be used.

Hereinafter, the laminated film, the transparent conductive layer, the functional layer, or the semi-transmissive layer will be sequentially described.
(Laminated film)
The laminated film is, for example, a laminated film obtained by alternately laminating low refractive index layers and high refractive index layers having different refractive indexes. Alternatively, the laminated film is, for example, a laminated layer in which a metal layer having a high reflectance in the infrared region and an optical transparent layer having a high refractive index in the visible region and functioning as an antireflection layer, or a transparent conductive layer are alternately laminated. It is a membrane.

  The metal layer having high reflectivity in the infrared region may be, for example, a simple substance such as Au, Ag, Cu, Al, Ni, Cr, Ti, Pd, Co, Si, Ta, W, Mo, Ge, or a simple substance thereof. The main component is an alloy containing two or more kinds. Of these, Ag-based, Cu-based, Al-based, Si-based, or Ge-based materials are preferred among these. When an alloy is used as the material of the metal layer, the metal layer is mainly composed of AlCu, AlTi, AlCr, AlCo, AlNdCu, AlMgSi, AgPdCu, AgPdTi, AgCuTi, AgPdCa, AgPdMg, AgPdFe, Ag, or SiB. It is preferable to do. In order to suppress corrosion of the metal layer, it is preferable to add materials such as Ti and Nd to the metal layer. In particular, when Ag is used as the material of the metal layer, it is preferable to add the above material.

  The optical transparent layer is an optical transparent layer that has a high refractive index in the visible region and functions as an antireflection layer. The optical transparent layer contains, as a main component, a high dielectric material such as niobium oxide, tantalum oxide, or titanium oxide. The transparent conductive layer includes, for example, main components such as zinc oxide and indium tin oxide (ITO).

  Note that the laminated film is not limited to a thin film containing an inorganic material as a main component, and a thin film made of a polymer material or a layer in which fine particles are dispersed in a polymer may be laminated. For the purpose of preventing oxidative deterioration of the lower layer metal during the formation of the optical transparent layer, a thin buffer layer such as Ti of about several nm may be provided at the interface of the optical transparent layer to be formed. Here, the buffer layer is a layer for suppressing oxidation of a metal layer or the like as a lower layer by oxidizing itself when forming the upper layer.

(Transparent conductive layer)
The transparent conductive layer is a transparent conductive layer mainly composed of a conductive material having transparency in the visible region. The transparent conductive layer is mainly composed of a transparent conductive material such as tin oxide, zinc oxide, indium tin oxide (ITO), indium zinc oxide (IZO), antimony-doped tin oxide, or a carbon nanotube-containing body. Alternatively, a layer in which nanoparticles, nanorods, and nanowires of conductive materials such as nanoparticles and metals are dispersed in a resin at a high concentration may be used.

(Functional layer)
The functional layer is mainly composed of a chromic material whose reflection performance is reversibly changed by an external stimulus. The chromic material is a material that reversibly changes its structure by an external stimulus such as heat, light, or an intruding molecule. As the chromic material, for example, a photochromic material, a thermochromic material, a gas chromic material, or an electrochromic material can be used.

A photochromic material is a material that reversibly changes its structure by the action of light. The photochromic material can reversibly change various physical properties such as reflectance and color by irradiation with light such as ultraviolet rays. As the photochromic material, for example, transition metal oxides such as TiO ₂ , WO ₃ , MoO ₃ , and Nb ₂ O ₅ doped with Cr, Fe, Ni, or the like can be used. Moreover, wavelength selectivity can also be improved by laminating | stacking the layer from which these layers and refractive indexes differ.

A thermochromic material is a material that reversibly changes its structure by the action of heat. The photochromic material can reversibly change various physical properties such as reflectance and color by heating. For example, VO ₂ can be used as the thermochromic material. Further, for the purpose of controlling the transition temperature and the transition curve, elements such as W, Mo, and F can be added. Further, a laminated structure in which a thin film mainly composed of a thermochromic material such as VO ₂ is sandwiched between antireflection layers mainly composed of a high refractive index body such as TiO ₂ or ITO may be employed.

  Alternatively, a photonic lattice such as cholesteric liquid crystal can be used. Cholesteric liquid crystals can selectively reflect light with a wavelength according to the layer spacing, and this layer spacing changes with temperature, so that physical properties such as reflectance and color can be reversibly changed by heating. . At this time, it is possible to widen the reflection band by using several cholesteric liquid crystal layers having different layer intervals.

An electrochromic material is a material that can reversibly change various physical properties such as reflectance and color by electricity. As the electrochromic material, for example, a material that reversibly changes its structure by applying a voltage can be used. More specifically, as the electrochromic material, for example, a reflection-type light control material whose reflection characteristics are changed by doping or dedoping such as proton can be used. Specifically, the reflective dimming material is a material that can control its optical properties to a transparent state, a mirror state, and / or an intermediate state thereof by an external stimulus. Examples of such reflective light-modulating materials include magnesium and nickel alloy materials, alloy materials mainly composed of magnesium and titanium alloy materials, WO ₃ and acicular crystals having selective reflectivity in microcapsules. A confined material or the like can be used.

As a specific functional layer configuration, for example, the above alloy layer, a catalyst layer containing Pd, a thin buffer layer such as Al, an electrolyte layer such as Ta ₂ O ₅ , and a proton are included on the second optical layer. A structure in which an ion storage layer such as WO ₃ and a transparent conductive layer are laminated can be used. Alternatively, a configuration in which a transparent conductive layer, an electrolyte layer, an electrochromic layer such as WO _3, and a transparent conductive layer are stacked on the second optical layer can be used. In these configurations, by applying a voltage between the transparent conductive layer and the counter electrode, protons contained in the electrolyte layer are doped or dedoped in the alloy layer. Thereby, the transmittance | permeability of an alloy layer changes. In order to improve wavelength selectivity, it is desirable to laminate an electrochromic material with a high refractive index material such as TiO ₂ or ITO. As another configuration, a configuration in which a transparent conductive layer, an optical transparent layer in which microcapsules are dispersed, and a transparent electrode are stacked on the second optical layer can be used. In this configuration, by applying a voltage between both transparent electrodes, the acicular crystal in the microcapsule is in a transmission state in which it is oriented, or by removing the voltage, the acicular crystal is directed in all directions to be in a wavelength selective reflection state. can do.

(Semi-transmissive layer)
The semi-transmissive layer is made of, for example, a single layer or a plurality of metal layers, and has a semi-permeable property. As a material of the metal layer, for example, the same material as that of the above-described laminated film can be used.

(Function of optical film)
5A and 5B are cross-sectional views for explaining an example of the function of the optical film. Here, as an example, the case where the shape of the structure is a prism shape with an inclination angle of 45 ° will be described as an example. As shown in FIG. 5A, a part of the near-infrared ray L ₁ in the sunlight incident on the optical film 1 is directed and reflected in the sky direction as much as the incident direction, whereas the visible light L ₂ is The light passes through the optical film 1.

Further, as shown in FIG. 5B, incident on the optical film 1, the light reflected by the reflective layer surface of the wavelength-selective reflective layer 3, at a rate corresponding to the incident angle, the component L _A of the sky reflected, not reflected toward the sky It is separated into a component L _B. The component L _B not reflected toward the sky is totally reflected at the interface between the second optical layer 4 and the air is reflected in a direction different from the final incident direction.

The incident angle of light alpha, the refractive index of the first optical layer 4 n, the reflectance of the wavelength-selective reflective layer 3 is R, the ratio x of the sky reflection component L _A to the total incident component the following equation (1 ).
x = (sin (45−α ′) + cos (45−α ′) / tan (45 + α ′)) / (sin (45−α ′) + cos (45−α ′)) × R ² (1)
However, α ′ = sin ⁻¹ (sin α / n)

If the proportion of the component L _B not reflected toward the sky increases, the percentage of incident light is reflected over is reduced. In order to improve the ratio of the sky reflection, it is effective to devise the shape of the wavelength selective reflection layer 3, that is, the shape of the structure 4c of the first optical layer 4. For example, in order to improve the ratio of the sky reflection, the shape of the structure 4c is preferably a cylindrical shape shown in FIG. 3C or an asymmetric shape shown in FIG. By making such a shape, even if it is not possible to reflect the light in exactly the same direction as the incident light, increase the proportion of the light that is incident from the upper direction, such as architectural window material, reflected upward. Is possible. As shown in FIGS. 6A and 6B, the two shapes shown in FIGS. 3C and 4 require only one reflection of incident light by the wavelength selective reflection layer 3, so that the two shapes shown in FIG. It is possible to increase the final reflection component more than the shape to be reflected (three times or more). For example, when two-time reflection is used, if the reflectance of the wavelength selective reflection layer 3 with respect to a certain wavelength is 80%, the sky reflectance is theoretically 64%. Is 80%.

FIG. 7 shows the relationship between the ridge line l ₃ of the columnar structure 4c and the incident light L and reflected light L ₁ . The optical film 1 selectively selects light L ₁ in a specific wavelength band (θo, −φ) in the direction (0 ° <θo <90) among the light L incident on the incident surface S1 at an incident angle (θ, φ). It is preferable to transmit light L ₂ other than the specific wavelength band. It is because the light of a specific wavelength band can be reflected in the sky direction by satisfying such a relationship. Where θ is an angle formed between the perpendicular l ₁ to the incident surface S1 and the incident light L or the reflected light L ₁ . φ: An angle formed by a straight line l ₂ orthogonal to the ridge line l ₃ of the columnar structure 4c in the incident surface S1 and a component obtained by projecting the incident light L or the reflected light L ₁ onto the incident surface S1. The angle θ rotated clockwise with respect to the perpendicular l ₁ is defined as “+ θ”, and the angle θ rotated counterclockwise is defined as “−θ”. The angle φ rotated clockwise with respect to the straight line l ₂ is defined as “+ φ”, and the angle φ rotated counterclockwise is defined as “−φ”.

[Optical film manufacturing equipment]
FIG. 8 is a schematic diagram illustrating a configuration example of a manufacturing apparatus for manufacturing the optical film according to the first embodiment of the present invention. As shown in FIG. 8, the manufacturing apparatus includes laminate rolls 41 and 42, a guide roll 43, a coating device 45, and an irradiation device 46.

  The laminate rolls 41 and 42 are arranged so that the optical layer 9 with a reflective layer and the second substrate 5a can be nipped. Here, the optical layer 9 with a reflective layer is obtained by forming the wavelength selective reflection layer 3 on one main surface of the first optical layer 4. In addition, as the optical layer 9 with a reflective layer, the 1st base material 4a may be formed on the other main surface on the opposite side to the surface in which the wavelength selection reflection layer 3 of the 1st optical layer 4 was formed into a film. . In this example, the wavelength selective reflection layer 3 is formed on one main surface of the first optical layer 4 and the first base material 4a is formed on the other main surface. The guide roll 43 is disposed on a conveyance path in the manufacturing apparatus so that the belt-shaped optical film 1 can be conveyed. The material of the laminate rolls 41 and 42 and the guide roll 43 is not particularly limited, and a metal such as stainless steel, rubber, silicone, or the like can be appropriately selected and used according to desired roll characteristics.

  As the coating device 45, for example, a device including coating means such as a coater can be used. As the coater, for example, a coater such as a gravure, a wire bar, and a die can be appropriately used in consideration of physical properties of the resin composition to be applied. The irradiation device 46 is an irradiation device that irradiates an ionizing ray such as an electron beam, an ultraviolet ray, a visible ray, or a gamma ray. In this example, a case where a UV lamp that irradiates ultraviolet rays is used as the irradiation device 46 is illustrated.

[Method for producing optical film]
Hereinafter, an example of a method for producing an optical film according to the first embodiment of the present invention will be described with reference to FIGS. Note that part or all of the manufacturing process shown below is preferably performed by roll-to-roll as shown in FIG. 8 in consideration of productivity. However, the mold manufacturing process is excluded.

  First, as shown in FIG. 9A, a mold having the same concavo-convex shape as the structure 4c or a mold (replica) having an inverted shape of the mold is formed by, for example, cutting or laser processing. Next, as shown in FIG. 9B, the uneven shape of the mold is transferred to a film-like resin material by using, for example, a melt extrusion method or a transfer method. As a transfer method, an energy ray curable resin is poured into a mold and cured by irradiating energy rays, a method of transferring heat and pressure to the resin to transfer a shape, or a resin film is supplied from a roll and heat is applied. In addition, a method of transferring the shape of the mold (laminate transfer method) and the like can be mentioned. Thereby, as shown in FIG. 9C, the first optical layer 4 having the structure 4c on one main surface is formed.

  Further, as shown in FIG. 9C, the first optical layer 4 may be formed on the first substrate 4a. In this case, for example, the first substrate 4a in the form of a film is supplied from a roll, applied with an energy ray curable resin on the substrate, and then pressed against the die to transfer the shape of the die. Is used to cure the resin. The resin preferably further contains a cross-linking agent. This is because the resin can be heat resistant without greatly changing the storage elastic modulus at room temperature.

  Next, as shown in FIG. 10A, the wavelength selective reflection layer 3 is formed on one main surface of the first optical layer 4. Examples of the method for forming the wavelength selective reflection layer 3 include sputtering, vapor deposition, CVD (Chemical Vapor Deposition), dip coating, die coating, wet coating, and spray coating. It is preferable that the film forming method is appropriately selected according to the shape of the structure 4c. Next, as shown in FIG. 10B, annealing treatment 31 is performed on the wavelength selective reflection layer 3 as necessary. The annealing temperature is, for example, in the range of 100 ° C. or higher and 250 ° C. or lower.

  Next, as shown in FIG. 10C, an uncured resin 22 is applied on the wavelength selective reflection layer 3. As the resin 22, for example, an energy beam curable resin, a thermosetting resin, or the like can be used. As the energy ray curable resin, an ultraviolet curable resin is preferable. Next, as shown in FIG. 11A, the second base material 5a is covered on the resin 21, thereby forming a laminate. Next, as shown in FIG. 11B, for example, the resin 22 is cured by the energy beam 32 or the heating 32, and a pressure 33 is applied to the laminate. As the energy beam, for example, an electron beam, an ultraviolet ray, a visible ray, a gamma ray, an electron beam or the like can be used, and an ultraviolet ray is preferable from the viewpoint of production equipment. The integrated irradiation dose is preferably selected as appropriate in consideration of the curing characteristics of the resin, suppression of yellowing of the resin and the substrate 11, and the like. The pressure applied to the laminate is preferably in the range of 0.01 MPa to 1 MPa. If the pressure is less than 0.01 MPa, a problem occurs in the runnability of the film. On the other hand, when it exceeds 1 MPa, it is necessary to use a metal roll as a nip roll, and pressure unevenness is likely to occur, which is not preferable. Thus, as shown in FIG. 11C, the second optical layer 5 is formed on the wavelength selective reflection layer 3, and the optical film 1 is obtained.

  Here, the formation method of the optical film 1 is demonstrated concretely using the manufacturing apparatus shown in FIG. First, the second base material 5 a is sent from a base material supply roll (not shown), and the sent second base material 5 a passes under the coating device 45. Next, the ionizing radiation curable resin 44 is applied by the coating device 45 to the second base material 5 a passing under the coating device 45. Next, the 2nd base material 5a with which ionizing ray hardening resin 44 was applied is conveyed toward a lamination roll. On the other hand, the optical layer 9 with a reflective layer is sent out from an optical layer supply roll (not shown) and conveyed toward the laminate rolls 41 and 42.

  Next, the carried-in 2nd base material 5a and the optical layer 9 with a reflection layer are laminated rolls 41 and 42 so that a bubble may not enter between the 2nd base material 5a and the optical layer 9 with a reflection layer. The optical layer 9 with a reflective layer is laminated on the second substrate 5a. Next, while conveying the 2nd base material 5a laminated | stacked by the optical layer 9 with a reflecting layer along the outer peripheral surface of the lamination roll 41, ionizing-ray hardening from the 2nd base material 5a side by the irradiation apparatus 46 is carried out. The resin 44 is irradiated with ionizing radiation, and the ionizing radiation curable resin 44 is cured. Thereby, the 2nd base material 5a and the optical layer 9 with a reflection layer are bonded together through the ionizing-curing resin 44, and the target elongate optical film 1 is produced. Next, the produced belt-like optical film 1 is wound up by a winding roll (not shown). Thereby, the original fabric by which the strip | belt-shaped optical film 1 was wound is obtained.

The cured first optical layer 4 has a storage elastic modulus at (t-20) ° C. of 3 × 10 ⁷ Pa or more when the process temperature at the time of forming the second optical layer is t ° C. Is preferred. Here, the process temperature t is, for example, the heating temperature of the laminate roll 41. For example, the first optical layer 4 is provided on the first base material 4a and is conveyed along the laminating roll 41 via the first base material 4a. It has been empirically found that the temperature applied to is about (t-20) ° C. Accordingly, by setting the storage elastic modulus at (t-20) ° C. of the first optical layer 4 to 3 × 10 ⁷ Pa or more, the uneven shape of the interface inside the optical layer is deformed by heat or heat and pressure. Can be suppressed.

The first optical layer 4 preferably has a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less. Thereby, flexibility can be imparted to the optical film at room temperature. Therefore, the optical film 1 can be produced by a production process such as roll-to-roll.

  The process temperature t is preferably 200 ° C. or lower in consideration of the heat resistance of the resin used for the optical layer or the base material. However, the process temperature t can be set to 200 ° C. or higher by using a resin having high heat resistance.

As described above, according to the optical film 1 according to the first embodiment, at least one of the first optical layer 4 and the second optical layer 5 has a storage elastic modulus at 100 ° C. of 3 × 10 ⁷ Pa. That's it. Therefore, minute deformation of the optical layer interface can be suppressed by heat or heat and pressure.

In addition, since at least one of the first optical layer 4 and the second optical layer 5 arranged to face each other has a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less, the optical film 1 has flexibility. Can be granted. Therefore, the optical film 1 can be produced by a roll-to-roll process, and the productivity of the optical film 1 can be improved.

<2. Second Embodiment>
FIGS. 12-14 is sectional drawing which shows the structural example of the structure of the optical film which concerns on the 2nd Embodiment of this invention. In the second embodiment, portions corresponding to those in the first embodiment are denoted by the same reference numerals. The second embodiment is different from the first embodiment in that the structures 4 c are two-dimensionally arranged on one main surface of the first optical layer 4.

  On one main surface of the first optical layer 4, the structures 4c are two-dimensionally arranged. This arrangement is preferably the arrangement in the closest packed state. For example, a dense array such as a square dense array, a delta dense array, and a hexagonal dense array is formed on one main surface of the first optical layer 4 by two-dimensionally arranging the structures 4c in the most densely packed state. . For example, as shown in FIGS. 12A to 12C, the square dense array is a structure in which structures 4 c having a rectangular (for example, square) bottom surface are arranged in a square dense form. The hexagonal close-packed array is, for example, as shown in FIGS. 13A to 13C, in which structures 4c having hexagonal bottom surfaces are arranged in a hexagonal close-packed shape. For example, as shown in FIGS. 14A to 14B, the delta dense array is a structure in which structures 4c (for example, triangular pyramids) having a triangular bottom surface are arranged in a close-packed state.

  The structure 4c is, for example, a convex or concave portion such as a corner cube shape, a hemispherical shape, a semi-elliptical spherical shape, a prism shape, a free-form surface shape, a polygonal shape, a conical shape, a polygonal pyramid shape, a truncated cone shape, or a parabolic shape. is there. The bottom surface of the structure 4c has, for example, a circular shape, an elliptical shape, or a polygonal shape such as a triangular shape, a quadrangular shape, a hexagonal shape, or an octagonal shape. In addition, the pitches P1 and P2 of the structures 4c are preferably selected as appropriate according to desired optical characteristics. Further, when the main axis of the structure 4c is tilted with respect to a perpendicular perpendicular to the incident surface of the optical film 1, the main axis of the structure 4c is tilted in at least one arrangement direction of the two-dimensional arrangement of the structures 4c. It is preferable to do so. When the optical film 1 is pasted on a window material arranged substantially perpendicular to the ground, it is preferable that the main axis of the structure 4c is inclined downward (on the ground side) with respect to the vertical line.

  When the structure 4c is a corner cube shape, when the ridge line R is large, it is better to incline toward the sky. For the purpose of suppressing downward reflection, it is preferable to incline toward the ground side. Since sunlight is incident on the film from an oblique direction, it is difficult for light to enter the back of the structure, and the shape on the incident side is important. That is, when the ridge portion R is large, the retroreflected light decreases, and this phenomenon can be suppressed by tilting toward the sky. In the corner cube body, retroreflection is realized by reflecting the reflection surface three times, but part of light leaks in a direction other than the retroreflection due to reflection twice. By tilting the corner cube toward the ground side, a large amount of this leaked light can be returned to the sky. Thus, it may be tilted in either direction depending on the shape and purpose.

<3. Third Embodiment>
FIG. 15A is a cross-sectional view showing a configuration example of an optical film according to the third embodiment of the present invention. In 3rd Embodiment, the same code | symbol is attached | subjected to the location same as 1st Embodiment, and description is abbreviate | omitted. In the third embodiment, the optical layer 2 includes a plurality of wavelength selective reflection layers 3 inclined with respect to the light incident surface, and the wavelength selective reflection layers 3 are arranged in parallel to each other. This is different from the first embodiment.

  FIG. 15B is a perspective view showing an example of the structure of the optical film structure according to the third embodiment of the present invention. The structure 4c is a triangular prism-shaped convex portion extending in one direction, and the columnar structures 4c are arranged one-dimensionally in one direction. The cross section perpendicular to the extending direction of the structure 4c has, for example, a right triangle shape. On the inclined surface on the acute angle side of the structure 4c, the wavelength selective reflection layer 3 is formed by a directional thin film forming method such as vapor deposition or sputtering.

  According to the third embodiment, the plurality of wavelength selective reflection layers 3 are arranged in parallel in the optical layer 5. Thereby, the frequency | count of reflection by the wavelength selection reflection layer 3 can be reduced compared with the case where the structure 4c of a corner cube shape or a prism shape is formed. Therefore, the reflectance can be increased and the absorption of light by the wavelength selective reflection layer 3 can be reduced.

<4. Fourth Embodiment>
The fourth embodiment is different from the first embodiment in that light having a specific wavelength is directionally reflected while light other than the specific wavelength is scattered. The optical film 1 includes a light scatterer that scatters incident light. This scatterer is provided, for example, at least one place among the surface of the optical layer 2, the inside of the optical layer 2, and between the wavelength selective reflection layer 3 and the optical layer 2. The light scatterer is preferably provided between at least one of the wavelength selective reflection layer 3 and the first optical layer 4, the inside of the first optical layer 4, and the surface of the first optical layer 4. It has been. When the optical film 1 is bonded to a support such as a window material, it can be applied to both the indoor side and the outdoor side. When the optical film 1 is bonded to the outdoor side, it is preferable to provide a light scatterer that scatters light other than the specific wavelength only between the wavelength selective reflection layer 3 and a support such as a window material. This is because if a light scatterer is present between the wavelength selective reflection layer 3 and the incident surface, the directional reflection characteristics are lost. In addition, when the optical film 1 is bonded to the indoor side, it is preferable to provide a light scatterer between the emission surface opposite to the bonding surface and the wavelength selective reflection layer 3.

  FIG. 16A is a cross-sectional view showing a first configuration example of an optical film 1 according to the fourth embodiment of the present invention. As shown in FIG. 16A, the first optical layer 4 includes a resin and fine particles 11. The fine particles 11 have a refractive index different from that of the resin that is the main constituent material of the first optical layer 4. As the fine particles 11, for example, at least one of organic fine particles and inorganic fine particles can be used. Further, as the fine particles 11, hollow fine particles may be used. Examples of the fine particles 11 include inorganic fine particles such as silica and alumina, or organic fine particles such as styrene, acrylic and copolymers thereof, and silica fine particles are particularly preferable.

  FIG. 16B is a cross-sectional view showing a second configuration example of the optical film 1 according to the fourth embodiment of the present invention. As shown in FIG. 16B, the optical film 1 further includes a light diffusion layer 12 on the surface of the first optical layer 4. The light diffusion layer 12 includes, for example, a resin and fine particles. As the fine particles, the same fine particles as in the first example can be used.

  FIG. 16C is a cross-sectional view showing a third configuration example of the optical film 1 according to the fourth embodiment of the present invention. As shown in FIG. 16C, the optical film 1 further includes a light diffusion layer 12 between the wavelength selective reflection layer 3 and the first optical layer 4. The light diffusion layer 12 includes, for example, a resin and fine particles. As the fine particles, the same fine particles as in the first example can be used.

  According to the fourth embodiment, light in a specific wavelength band such as infrared rays can be directed and reflected, and light other than the specific wavelength pair such as visible light can be scattered. Therefore, the optical film 1 can be fogged to impart design properties to the optical film 1.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited only to these Examples.

In the present invention, the storage elastic modulus Pa is measured as follows.
The resin cured to have a film thickness of 100 μm was punched out to a width of 5 mm and a length of about 20 mm, the temperature was increased from −50 ° C. to 150 ° C. by 5 ° C. per minute, and dynamic viscoelasticity measurement was performed at 1 Hz. . For the measurement, a dynamic viscoelasticity measuring device DVA-220 (manufactured by IT Measurement Control Co., Ltd.) was used.

Example 1
First, as shown in FIG. 17, a prism shape was applied to a Ni-P mold by cutting with a cutting tool. Next, a resin composition having the following composition was applied to this Ni-P mold, and a PET film having a thickness of 75 μm (product name: A4300, manufactured by Toyobo Co., Ltd.) was placed thereon. Next, the resin composition was irradiated with UV light from the PET (polyethylene terephthalate) film side and cured to obtain a laminate composed of the first optical layer and the PET film.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 70 parts by weight dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: A-DPH) 30 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd.) Name: Irgacure 184) 3 parts by weight

Next, the first optical layer was peeled from the Ni-P mold to obtain a first optical layer having a prism-shaped molding surface. Next, an alternating multilayer film (intermediate layer) of a niobium pentoxide layer and a silver layer was formed by vacuum sputtering on the molding surface on which the prism shape was molded by a mold. Next, a resin composition having the following composition is applied onto an alternating multilayer film, and after extruding bubbles, a PET film is placed, pressurized with a nip roll at 0.5 MPa, and irradiated with UV light. Was cured to form a second optical layer on the alternating multilayer film. In the process of curing the resin composition, the temperature of the mold was increased by irradiation with UV light, and the optical film was heated. Thus, the target optical film was obtained.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 70 parts by weight dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: A-DPH) 30 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd.) Name: Irgacure 184) 3 parts by weight (meth) acrylic monomer (adhesive) having phosphoric acid as a functional group (manufactured by Kyoeisha Chemical Co., Ltd., trade name: P-2M) 0.3 parts by weight

(Example 2)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 70 parts by weight trimethylolpropane triacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayarad TMPTA) 30 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 184) 3 parts by weight However, 0.3 parts by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

Example 3
As the resin composition for forming the first optical layer and the second optical layer, a resin composition having the following composition is used, and the pressure applied when producing the resin composition is 0.01 MPa, An optical film was obtained in the same manner as in Example 1.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 85 parts by weight ethylene oxide-modified glycerol triacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: T2325) 15 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure) 184) 3 parts by weight However, 0.3 part by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

Example 4
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 85 parts by weight ethylene oxide-modified glycerol triacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: T2325) 15 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure) 184) 3 parts by weight However, 0.3 part by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Example 5)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 80 parts by weight ethylene oxide-modified glycerol triacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: T2325) 20 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure) 184) 3 parts by weight However, 0.3 part by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Example 6)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 70 parts by weight ethylene oxide modified glycerol triacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: T2325) 30 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure) 184) 3 parts by weight However, 0.3 part by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Example 7)
Except that a semi-transmissive Al film (film pressure 11 nm) was used as an intermediate layer mainly composed of an inorganic material formed at the interface between the first optical layer and the second optical layer, the same as in Example 4. To obtain an optical film.

(Comparative Example 1)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: UF8001G) 100 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 184) 3 parts by weight However, resin composition for forming the second optical layer To the product, 0.3 part by weight of the same adhesive as in Example 1 was added.

(Comparative Example 2)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: UF8001G) 70 parts by weight dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: A-DPH) 30 parts by weight initiator (manufactured by Ciba Specialty Chemicals, Product name: Irgacure 184) 3 parts by weight However, 0.3 parts by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Comparative Example 3)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (Kyoeisha Chemical Co., Ltd., trade name: UF8001G) 60 parts by weight Trimethylolpropane triacrylate (Nippon Kayaku Co., Ltd., trade name: Kayarad TMPTA) 40 parts by weight initiator (Ciba Specialty Chemicals, trade name) : Irgacure 184) 3 parts by weight However, 0.3 parts by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Comparative Example 4)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: UF8001G) 60 parts by weight ethylene oxide-modified glycerol triacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: T2325) 40 parts by weight initiator (manufactured by Ciba Specialty Chemicals, trade name: Irgacure 184) 3 parts by weight However, 0.3 parts by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Comparative Example 5)
Use urethane acrylate (trade name: Aronix, manufactured by Toagosei Co., Ltd.) as the acrylate forming the first optical layer and the second optical layer, and the pressure applied when producing the resin composition is 0.01 MPa. An optical film was obtained in the same manner as in Example 1 except that.

(Comparative Example 6)
An optical film was obtained in the same manner as in Example 1 except that urethane acrylate (trade name: Aronix, manufactured by Toagosei Co., Ltd.) was used as the acrylate forming the first optical layer and the second optical layer.

(Comparative Example 7)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix) 95 parts by weight ethylene oxide modified glycerol triacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: T2325) 5 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure) 184) 3 parts by weight However, 0.3 part by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Comparative Example 8)
As a resin composition for forming the first optical layer and the second optical layer, an optical film was obtained in the same manner as in Example 1 except that a resin composition having the following composition was used.
<Resin formulation>
Urethane acrylate (product of Toagosei Co., Ltd., trade name: Aronix) 90 parts by weight ethylene oxide modified glycerol triacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: T2325) 10 parts by weight initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure) 184) 3 parts by weight However, 0.3 part by weight of the same adhesive as in Example 1 was added to the resin composition for forming the second optical layer.

(Shape evaluation)
The shape of the molding surface of the optical film of Examples 1-7 and Comparative Examples 1-8 was evaluated as follows. The optical film was cut with a microtome and observed with a scanning confocal laser microscope (manufactured by Olympus Corporation, trade name: OLS3000) to obtain an image. The obtained image was compared with the ideal shape of the molding surface and evaluated according to the following criteria.
Y: The angle between the apex angle and the bottom surface is within ± 1 degree from the ideal shape angle. N: The angle between the apex angle and the bottom surface exceeds ± 1 degree from the ideal shape angle.

(Evaluation of directional reflectance)
The directional reflectances of the optical films of Examples 1 to 7 and Comparative Examples 1 to 8 were evaluated as follows.
FIG. 18 shows the configuration of a measuring apparatus for measuring the retroreflectance of the optical film. First, the linear light emitted from the halogen lamp light source 101 and collimated by the lens is incident on the half mirror 102 installed at an angle of 45 ° with respect to the light traveling direction. Half of the incident light is reflected by the half mirror 102 and its traveling direction is rotated by 90 °, while the other half of the incident light is transmitted through the half mirror 102. Next, the reflected light is retroreflected by the sample 103 and enters the half mirror 102 again. Half of this incident light passes through the half mirror 102 and enters the detector 104. The intensity of this incident light is measured by the detector 104 as the reflection intensity.

Using the measuring apparatus having the above-described configuration, the retroreflectance at wavelengths of 900 nm and 1100 nm was determined by the following method. First, a mirror was installed in the sample folder of this measuring apparatus at an incident angle θ = 0 °, and the light intensity of each wavelength was measured by the detector 104. Next, an optical film was installed in the sample folder of this measuring apparatus, and the light intensity was measured at an incident angle θ = 0 ° and 20 ° (φ = 0 ° in this measurement). Thereafter, the retroreflectance of the optical film was determined with the light intensity of the mirror as 90% retroreflectance. Next, the obtained retroreflectance was evaluated according to the following criteria.
Y: 0 degree reflectivity of 60 nm or more at a wavelength of 900 nm and 1100 nm, and 20 degree reflectivity satisfying the relationship of 20% or less N: Reflectance of 0 degree at a wavelength of 900 nm and 1100 nm is 60% or more And the reflectance of 20 degrees does not satisfy the relationship of 20% or less

Table 1 shows the structure of the optical film of Examples 1-7 and Comparative Examples 1-8.

Table 2 shows the evaluation results of the optical films of Examples 1 to 7 and Comparative Examples 1 to 8.

Table 1 and Table 2 show the following.
In Examples 1 to 7, the first optical layer is formed using a resin having a storage elastic modulus at 100 ° C. of 3 × 10 ⁷ Pa or more and a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less. Since the second optical layer is formed, distortion of the irregular shape at the interface can be suppressed. Accordingly, excellent retroreflection performance can be obtained.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, The various deformation | transformation based on the technical idea of this invention is possible.

  For example, the configurations, methods, shapes, materials, numerical values, and the like given in the above-described embodiments are merely examples, and different configurations, methods, shapes, materials, numerical values, and the like may be used as necessary.

  The configurations of the above-described embodiments can be combined with each other without departing from the gist of the present invention.

  Moreover, in the above-described embodiment, an example in which the present invention is applied to an optical film having directional reflection performance has been described, but the present invention is not limited to this example, and has an uneven surface, The present invention is applicable to any optical film produced by a process involving heat or pressure. Examples of such an optical film include a window film, a display film, a projector screen, an optical filter, and a solar cell.

  Further, in the above-described embodiment, the numerical range of the pitch of the uneven shape of the interface has been described by taking the optical film having directional reflection performance as an example, but the numerical range of the pitch of the uneven shape of the interface is limited to this example. Yes. For example, the present invention can be applied to uneven shapes ranging from a pitch of about several tens of nm to 1 μm transferred by so-called nanoimprint to a pitch of about several tens of μm.

  In the above-described embodiment, the film-shaped optical body has been described as an example. However, the present invention is not limited to this, and the present invention can be applied to optical bodies having other shapes such as a plate shape.

  Moreover, although the above-mentioned embodiment demonstrated as an example the case where the optical body (directional reflector) which concerns on this invention is applied to a window material etc., the optical body which concerns on this invention is a building, a vehicle, etc., for example. As an exterior member and an interior member, it can apply to all uses.

  For example, it can be applied to blinds and roll curtains. Examples of the blind or roll curtain to which the optical body is applied include a blind or roll curtain constituted by the optical body itself, a blind or roll curtain constituted by a transparent base material on which the optical body is bonded, and the like. By installing such a blind or a roll curtain near the indoor window, for example, only infrared rays can be directionally reflected outdoors and visible light can be taken into the room. Therefore, the need for room lighting is reduced even when blinds or roll curtains are installed. Moreover, since there is no scattering reflection by a blind or a roll curtain, the surrounding temperature rise can also be suppressed. Further, when the necessity for heat ray reflection is low such as in winter, there is an advantage that the heat ray reflection function can be easily used properly depending on the situation by raising the blinds or the roll curtain. On the other hand, conventional blinds and roll curtains for shielding infrared rays are coated with infrared reflecting paints and have a white, gray, or cream appearance, so try to block the infrared rays. Then, visible light is also cut off at the same time, and indoor lighting is required.

  Similarly, it is possible to adopt a form like a shoji. Further, the optical body of the present invention may be used by being attached to a wall.

  Although not shown, a laminated glass in which an optical body is sandwiched between two opposing glasses can be used. In this case, an intermediate layer is provided between each glass and the optical body. By applying thermocompression bonding or the like, the intermediate layer functions as an adhesive layer, and the laminated glass can be manufactured. As such an intermediate layer, for example, polyvinyl butyral (PVB) can be used. It is preferable that the intermediate layer also has a scattering prevention function in case the laminated glass is broken. By using this laminated glass as a vehicle-mounted window, heat rays can be reflected by the optical body, so that the interior of the vehicle can be prevented from becoming hot. This laminated glass can be widely used for all transportation means such as vehicles, trains, aircraft, ships, vehicles in theme parks, etc., and the two glasses may be curved depending on the application. In this case, it is preferable that the optical body has a follow-up property with respect to the curvature of the glass and has a certain directional reflection property and transparency even when it is curved. Since the laminated glass needs to have a certain degree of transparency as a whole, the material (for example, resin) used for the intermediate layer and the resin contained in the optical body preferably have the same or similar refractive index. . On the other hand, the intermediate layer may be omitted, and the resin contained in the optical body may also serve as an adhesive layer with glass. In this case, it is preferable to use a resin that does not collapse the shape of the resin as much as possible in the thermocompression bonding step or the like during bonding. The two opposing substrates are not limited to glass, and one or both may be a resin film, a sheet, a plate, or the like. For example, a lightweight, strong, flexible engineering plastic or reinforced plastic can be used. In addition, the use of laminated glass is not limited to in-vehicle use.

DESCRIPTION OF SYMBOLS 1 Optical film 2 Optical layer 3 Wavelength selective reflection layer 4 1st optical layer 4a 1st base material 5 2nd optical layer 5a 2nd base material 6 Bonding layer 7 Peeling layer 8 Hard coat layer 9 Optics with a reflection layer Layer S1 entrance surface S2 exit surface

Claims (17)

An optical layer having smooth surfaces on both main surfaces, and having an uneven surface inside,
An intermediate layer that mainly includes an inorganic material provided at the interface and selectively directs and reflects light in a specific wavelength band;
The optical layer is
A first optical layer having a first surface of a concavo-convex shape composed of a plurality of structures arranged one-dimensionally or two-dimensionally ;
A second optical layer having a concave-convex second surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally ,
The interface is formed by the first surface and the second surface arranged to face each other,
At least one of the first optical layer and the second optical layer is
The storage elastic modulus at 100 ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less. A first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface formed of a plurality of structures arranged one-dimensionally or two-dimensionally on the other surface ;
An intermediate layer mainly composed of an inorganic material formed on the concavo-convex surface of the first optical layer, which selectively reflects light in a specific wavelength band;
To the intermediate layer on the uneven surface formed, are formed uneven surface consisting of one-dimensional or two-dimensional array is a plurality of structures to fill the irregularities, and a surface opposite to the concave convex And a second optical layer having a smooth surface formed thereon,
At least one of the first optical layer and the second optical layer is
The storage elastic modulus at 100 ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less. An optical layer having smooth surfaces on both main surfaces, and having an uneven surface inside,
An intermediate layer that mainly includes an inorganic material provided at the interface and selectively directs and reflects light in a specific wavelength band;
The optical layer is
A first optical layer having a first surface of a concavo-convex shape composed of a plurality of structures arranged one-dimensionally or two-dimensionally ;
A second optical layer having a concave-convex second surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally ,
The interface is formed by the first surface and the second surface arranged to face each other,
The first optical layer is
When the process temperature at the time of forming the second optical layer is t ° C., the storage elastic modulus at (t−20) ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less. A first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface formed of a plurality of structures arranged one-dimensionally or two-dimensionally on the other surface ;
An intermediate layer mainly composed of an inorganic material formed on the concavo-convex surface of the first optical layer, which selectively reflects light in a specific wavelength band;
To the intermediate layer on the uneven surface formed, are formed uneven surface consisting of one-dimensional or two-dimensional array is a plurality of structures to fill the irregularities, and a surface opposite to the concave convex a second optical layer smooth surface is formed
With
The first optical layer is
When the process temperature at the time of forming the second optical layer is t ° C., the storage elastic modulus at (t−20) ° C. is 3 × 10 ⁷ Pa or more,
An optical body having a storage elastic modulus at 25 ° C. of 3 × 10 ⁹ Pa or less.   The optical body according to claim 1, wherein the intermediate layer is a wavelength selective reflection layer that transmits light other than the specific wavelength band.   The wavelength selective reflection layer is a transparent conductive layer whose main component is a conductive material having transparency in the visible light region, or a functional layer whose main component is a chromic material whose reflection performance is reversibly changed by an external stimulus. The optical body according to claim 5.   The optical body according to claim 5, wherein the wavelength selective reflection layer is made of a single layer or a plurality of metal layers and is semi-transmissive.   The optical body according to any one of claims 1 to 4, further comprising a base material formed on at least one of both main surfaces of the optical layer.   5. The method according to claim 1, wherein at least one of the first optical layer and the second optical layer includes an energy ray curable resin or a thermosetting resin and a crosslinking agent. The optical body described.   The optical body according to claim 9, wherein the crosslinking agent is a crosslinking agent having a cyclic structure. The optical body according to any one of claims 1 to 4, wherein the structure has a prism shape, a cylindrical shape, a hemispherical shape, or a corner cube shape. An inorganic material is formed on the concavo-convex surface of the first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally is formed on the other surface. Forming an intermediate layer as a main component and selectively direct-reflecting light in a specific wavelength band;
The uneven surface on which the intermediate layer is formed is embedded with a second optical layer to form an uneven surface made of a plurality of structures arranged one-dimensionally or two-dimensionally on the intermediate layer; and Forming a smooth surface on the surface opposite to the uneven surface ,
At least one of the first optical layer and the second optical layer is
The storage elastic modulus at 100 ° C. is 3 × 10 ⁷ Pa or more,
The manufacturing method of the optical body whose storage elastic modulus in 25 degreeC is 3 * 10 < ⁹ > Pa or less. An inorganic material is formed on the concavo-convex surface of the first optical layer in which a smooth surface is formed on one surface and a concavo-convex surface composed of a plurality of structures arranged one-dimensionally or two-dimensionally is formed on the other surface. Forming an intermediate layer as a main component and selectively direct-reflecting light in a specific wavelength band;
The uneven surface on which the intermediate layer is formed is embedded with a second optical layer to form an uneven surface made of a plurality of structures arranged one-dimensionally or two-dimensionally on the intermediate layer; and Forming a smooth surface on the surface opposite to the uneven surface ,
The first optical layer is
When the process temperature of the embedding step is t ° C, the storage elastic modulus at (t-20) ° C is 3 × 10 ⁷ Pa or more,
The manufacturing method of the optical body whose storage elastic modulus in 25 degreeC is 3 * 10 < ⁹ > Pa or less. The method for manufacturing an optical body according to claim 13 , wherein an upper limit of the process temperature t in the embedding step is 200 ° C. or less. The method for manufacturing an optical body according to claim 12 or 13 , further comprising a step of applying heat and pressure to the first optical layer and / or the second optical layer. The optical body according to claim 12 or 13 , wherein at least one of the first optical layer and the second optical layer contains an energy ray curable resin or a thermosetting resin and a crosslinking agent. Production method. The method for producing an optical body according to claim 16 , wherein the crosslinking agent is a crosslinking agent having a cyclic structure.

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