JP2014174468A - Circularly polarizing layer, laminate of circularly polarizing layer, spectacles, and 3d image appreciation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circularly polarizing layer which has a cholesteric liquid crystal layer obtained by immobilizing a cholesteric liquid crystal phase and is capable of sufficiently reducing crosstalk when being used in spectacles for a circular polarization type 3D image appreciation system.SOLUTION: A circularly polarizing layer 21 includes a cholesteric liquid crystal layer 1 obtained by immobilizing a cholesteric liquid crystal phase and a retardation layer 11 arranged on a cholesteric liquid crystal layer 1 directly or via an isotropic layer and satisfies formula (2.5/64)+n≤Re/λmax≤(6/64)+n where Re represents a retardation (nm) in an in-plane direction of the retardation layer at a wavelength λmax, λmax represents a selective reflection wavelength (nm) of the cholesteric liquid crystal layer, and n is an integer equal to or larger than 0.

Description

  The present invention relates to a circularly polarizing layer, a laminate of circularly polarizing layers, glasses, and a 3D image viewing system. More specifically, a circularly polarizing layer, a laminated body of circularly polarizing layers in which two or more circularly polarizing layers are laminated, glasses having the circularly polarizing layer or the laminated body of circularly polarizing layers, and a 3D image viewing system having the glasses About.

  The 3D TV and 3D movie system are systems that make a viewer feel the 3D feeling by showing different images for the left eye and the right eye, respectively, to the left and right eyes of the viewer. There are various known display methods such as a shutter glasses method, a lenticular lens method, and a parallax barrier method, and one of them is a circular polarization method. In the circularly polarized light system, the display emits images for the left and right eyes with different circularly polarized light. The viewer wears glasses with different left and right circular polarizing plates for the left and right eyes, and views the image, so that only the left eye image is incident on the left eye and the right eye is incident on the right eye. Only the image is incident.

  As such a circular polarizing plate for 3D glasses, a circular polarizing plate using a laminate in which a λ / 4 plate is bonded to a linear polarizing plate, and a circular polarizing plate using a cholesteric liquid crystal are known. The circularly polarizing plate of the 3D glasses utilizes the property that the cholesteric liquid crystal can reflect only one circularly polarized light and transmit the circularly polarized light in the opposite direction only in the vicinity of the selective reflection wavelength. For example, a circularly polarizing plate in which only a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase is used as a single layer or a laminate is used (see, for example, Patent Documents 1 and 2).

KR20100133063 JP-A-2-48634 JP 2010-221585 A JP 2005-049586 A JP 2003-279740 A JP 2001-249225 A JP 2009-223189 A

  Under such circumstances, the inventors have tested the performance of 3D glasses as a circularly polarizing plate. As a result, a circularly polarizing plate using a laminate in which a λ / 4 plate is bonded to a linearly polarizing plate is a 3D image. Although it shows good performance for viewing, it has been found that there is a drawback that the field of view is dark. When the present inventor examined, the cause of the defect that the field of view is dark is that the circularly polarizing plate using a laminate in which a λ / 4 plate is bonded to a conventional linear polarizing plate is not only the absorption axis side of the linear polarizing plate. It has been found that this is because there is some light absorption on the transmission axis side. It is also known that a circularly polarizing plate using a laminate in which a λ / 4 plate is bonded to a linearly polarizing plate has a problem of color shift at the time of neck tilt.

  On the other hand, when the present inventors tested the circularly polarizing plates described in Patent Documents 1 and 2 using only a cholesteric liquid crystal layer in a single layer or a laminate, the above-mentioned linear line is used due to the mechanism in order to use the cholesteric liquid crystal. Circular polarizing plate using a laminate in which a λ / 4 plate is bonded to a linear polarizing plate without causing a dark field of view peculiar to a circular polarizing plate using a laminate in which a λ / 4 plate is bonded to a polarizing plate It has been found that there is an advantage that the field of view is brighter than. Further, a circularly polarizing plate using a laminate in which a λ / 4 plate is bonded to a linearly polarizing plate can greatly suppress the problem of color shift when the neck is inclined. However, when the present inventors tested a circularly polarizing plate using only a cholesteric liquid crystal layer as a single layer, it was crossed compared to a circularly polarizing plate using a laminate in which a λ / 4 plate was bonded to a conventional linear polarizing plate. It became clear that there was a new problem that was not known in the past that the talk characteristics were inferior. Here, the crosstalk characteristic is a property that an image for the eye opposite to the eyes of the observer is mixed due to imperfection of the system. In the 3D image viewing system, it is ideal for obtaining a three-dimensional effect that only the image for the left eye is incident on the left eye and only the image for the right eye is incident on the right eye.

Here, when a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase is used as a circularly polarizing plate, a phase difference layer such as a λ / 4 plate and a cholesteric liquid crystal layer are laminated in a field other than the 3D image viewing system. Examples are known (see Patent Documents 3 to 7). In Patent Document 3, a phase difference layer having a wavelength of about {(2n + 1) / 2} times the selective reflection wavelength of the cholesteric liquid crystal layer is laminated on the cholesteric liquid crystal layer, so that only a desired wavelength can be efficiently obtained even in a large area. It is described that an electromagnetic wave reflecting member capable of reflecting light can be provided. Patent Document 4 discloses that a retardation layer having a front phase difference of almost zero and an incident light incident at an angle of 30 ° or more with respect to the normal direction is at least 1/8 times the selective reflection wavelength of a cholesteric liquid crystal layer. It is described that an optical element that can suppress the transmission of light incident at a large angle with respect to the normal direction and can improve the front luminance and reduce coloring can be provided by laminating the cholesteric liquid crystal layer. Has been. In Patent Document 5, retardation Re in the in-plane direction of 90 to 200 nm, that is, a retardation layer having a phase difference with a certain degree of proportion to the selective reflection wavelength of the cholesteric liquid crystal layer is laminated on the cholesteric liquid crystal layer. Thus, it is described that an optical film having good visibility can be provided not only in the front direction but also when viewed from an oblique direction. Patent Document 6 describes that a polarization separation element having excellent optical characteristics and heat resistance characteristics can be provided by using a quarter-wave retardation layer on a cholesteric liquid crystal layer. In Patent Document 7, a retardation layer having a retardation Re in the front direction of approximately ¼ wavelength of transmitted light of 400 to 700 nm is used by being laminated on a cholesteric liquid crystal layer, thereby being exposed to a high temperature environment for a long time. However, it is described that it is possible to provide a brightness enhancement film which hardly causes a transmission spectrum shift.
However, Patent Documents 3 to 7 did not disclose or suggest that a circularly polarizing plate using a retardation layer laminated on a cholesteric liquid crystal layer is used as a circularly polarizing plate for glasses of a 3D image viewing system.

  The problem to be solved by the present invention is a circularly polarizing layer having a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase and capable of sufficiently reducing crosstalk when used in glasses for a circularly polarizing 3D image viewing system. Is to provide.

  As a result of diligent studies to solve the above-mentioned object, the present inventors have focused on the fact that the cholesteric liquid crystal layer formed by fixing the cholesteric liquid crystal phase reflects light that is slightly elliptically polarized, not completely circularly polarized. By laminating a retardation layer having a very slight phase difference in a specific range compared to a λ / 4 plate, the circularly polarized light transmittance at the selective reflection wavelength of the cholesteric liquid crystal layer can be reduced, and the circularly polarized light system The present inventors have found that it is possible to provide a circularly polarizing layer that can sufficiently reduce crosstalk when used in the glasses of the 3D image appreciation system.

The present invention, which is a specific means for solving the above problems, is as follows.
[1] It has a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase, and a retardation layer arranged directly or via an isotropic layer with the cholesteric liquid crystal layer, and satisfies the following formula (1) A characteristic circularly polarizing layer.
Formula (1)
(2.5 / 64) + n ≦ Re / λmax ≦ (6/64) + n
(In the formula (1), Re represents retardation in the in-plane direction of the retardation layer at a wavelength λmax (unit: nm), λmax represents a selective reflection wavelength (unit: nm) of the cholesteric liquid crystal layer, and n Represents an integer of 0 or more.)
[2] In the circularly polarizing layer according to [1], n in the formula (1) is preferably 0.
[3] In the circularly polarizing layer according to [1] or [2], the selective reflection wavelength λmax of the cholesteric liquid crystal layer is preferably 300 nm to 2500 nm.
[4] In the circularly polarizing layer according to any one of [1] to [3], the number of spiral turns of the cholesteric alignment structure of the cholesteric liquid crystal layer is preferably 8 or more.
[5] In the circularly polarizing layer according to any one of [1] to [4], the retardation layer preferably has a tilt angle of 0 ° to 50 ° (provided that the retardation layer has a tilt angle). Is the angle between the maximum direction of the refractive index of the retardation layer and the surface of the retardation layer).
[6] The circularly polarizing layer according to any one of [1] to [5] preferably has a twist angle of the retardation layer of −100 ° to 100 ° (however, the twist of the retardation layer) The angle is a value obtained by subtracting the in-plane angle at the surface of the portion of the retardation layer in contact with the cholesteric liquid crystal layer from the in-plane angle at the surface of the portion opposite to the portion in contact with the cholesteric liquid crystal layer. The in-plane angle of the surface of the retardation layer means that the direction of the liquid crystal director on the surface of the cholesteric liquid crystal layer on the retardation layer side and the maximum refractive index direction of the retardation layer are aligned with the surface of the retardation layer. (An angle between the projected direction and the rotation direction of the cholesteric liquid crystal layer as seen from the retardation layer side is the same as the helical rotation direction as the positive rotation direction of the in-plane angle of the retardation layer.)
[7] In the circularly polarizing layer according to any one of [1] to [6], the retardation layer is preferably disposed closer to the incident light side than the cholesteric liquid crystal layer.
[8] In the circularly polarizing layer according to any one of [1] to [7], it is preferable that two or more cholesteric liquid crystal layers are laminated.
[9] The circularly polarizing layer according to any one of [1] to [8] is preferably a liquid crystal film in which the retardation layer has a fixed alignment of liquid crystal molecules.
[10] A laminated body of circularly polarizing layers, wherein two or more circularly polarizing layers according to any one of [1] to [9] are laminated.
[11] A left eye polarizing layer and a right eye polarizing layer, wherein at least one of the left eye polarizing layer and the right eye polarizing layer reflects right circularly polarized light and transmits left circularly polarized light. The other of the left eye polarizing layer and the right eye polarizing layer reflects left circularly polarized light and transmits right circularly polarized light, and the left eye polarizing layer and the right eye polarizing layer At least one of them has the circularly polarizing layer according to any one of [1] to [9] or the laminate of the circularly polarizing layer according to [10].
[12] In the glasses according to [11], it is preferable that the cholesteric liquid crystal layer has a cholesteric alignment structure having a leftward twist or a rightward twist.
[13] In the glasses according to [11] or [12], the left-eye polarizing layer and the right-eye polarizing layer are both the circularly polarizing layer according to any one of [1] to [9] or It is preferable to have the laminated body of the circularly-polarizing layer as described in [10].
[14] In the glasses according to any one of [11] to [13], at least one of the left-eye polarizing layer and the right-eye polarizing layer is any one of [1] to [9]. Or a laminate of the circularly polarizing layer according to [10];
The other one of the circularly polarizing layer according to any one of [1] to [9] or the laminated body of the circularly polarizing layer according to [10] and the circularly polarizing layer or the laminated body of the circularly polarizing layers. It is preferable to have a λ / 2 layer disposed on the incident light side.
[15] The glasses according to any one of [11] to [14], and a video driving unit that outputs a left-eye circular polarization signal and a right-eye circular polarization signal, and the left of the glasses An ophthalmic polarizing layer transmits the left-eye circularly polarized signal output from the image driving unit, reflects the right-eye circularly polarized signal, and the right-eye polarizing layer of the eyeglasses from the image driving unit. 3. A 3D image appreciation system, wherein the output circular polarization signal for the right eye is transmitted and the circular polarization signal for the left eye is reflected.

  According to the present invention, there is provided a circularly polarizing layer having a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase and capable of sufficiently reducing crosstalk when used in glasses for a circularly polarizing 3D image viewing system. Can do.

It is a schematic diagram which shows an example of the circularly-polarizing layer of this invention. It is a schematic diagram which shows another example of the circularly-polarizing layer of this invention. It is a schematic diagram which shows another example of the circularly-polarizing layer of this invention. It is a schematic diagram for description of the definition of one turn of cholesteric liquid crystal. FIG. 6 is a schematic diagram for explaining definitions of an in-plane angle and a tilt angle of a retardation layer. It is a schematic diagram for description of the definition of the in-plane angle and twist angle of the phase difference layer with a twist. It is a schematic diagram which shows an example of the laminated body of the circularly-polarizing layer of this invention.

Hereinafter, preferred embodiments of the circularly polarizing layer, the laminate of the circularly polarizing layer, the glasses, and the 3D image viewing system of the present invention will be described.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Circularly polarizing layer]
The circularly polarizing layer of the present invention has a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase, and a retardation layer arranged directly or via an isotropic layer with the cholesteric liquid crystal layer. ) Is satisfied.
Formula (1)
(2.5 / 64) + n ≦ Re / λmax ≦ (6/64) + n
(In the formula (1), Re represents retardation in the in-plane direction of the retardation layer at a wavelength λmax (unit: nm), λmax represents a selective reflection wavelength (unit: nm) of the cholesteric liquid crystal layer, and n Represents an integer of 0 or more.)
With such a configuration, the circularly polarizing layer of the present invention has a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase, and sufficiently reduces crosstalk when used in glasses for a circularly polarizing 3D image viewing system. it can. Although not bound by any theory, the present inventors have examined the cause of the deterioration of the crosstalk characteristics of 3D glasses using a circularly polarizing plate using only a cholesteric liquid crystal layer as a single layer. It turns out that. Cholesteric liquid crystals generally reflect circularly polarized light whose rotational direction and pitch coincide with the cholesteric helix, but in reality, it does not reflect completely circularly polarized light, but reflects slightly elliptical circularly polarized light (Handbook) of liquid crystals, Hans Kelker, Rolf Hatz, Verlag Chemie (1980), p295, lines 5-7, p296, lines 28, 29, etc.). Therefore, even if perfect circularly polarized light is incident from the 3D display side, the circularly polarized light is not completely reflected and shielded by the cholesteric liquid crystal layer, but slightly reversely polarized light is also transmitted through the cholesteric liquid crystal layer. As a result, circularly polarized light in the rotation direction that should be shielded by the eyes of the observer is incident, resulting in deterioration of the crosstalk characteristics.
As a countermeasure, when the circularly polarizing layer of the present invention in which a retardation layer capable of correcting circularly polarized light into elliptically polarized light is installed in front of the cholesteric liquid crystal layer, elliptically polarized light that is more easily reflected by the cholesteric liquid crystal layer. Can be reflected. That is, the entire circularly polarizing layer reflects not circularly polarized circularly polarized light but circularly polarized light that is not ellipticalized. Therefore, when the circularly polarizing layer of the present invention is used for a circularly polarizing plate of glasses (3D image glasses) of a circularly polarized 3D image viewing system, crosstalk characteristics are improved.
Hereinafter, a more preferable aspect of the circularly polarizing layer of the present invention will be specifically described.

<Characteristics of circularly polarizing layer>
The circularly polarizing layer of the present invention has a transmittance of circularly polarized light in the rotational direction to be originally shielded at the selective reflection wavelength of the cholesteric liquid crystal layer included in the circularly polarizing layer (hereinafter also referred to as selective reflection wavelength transmittance). ) Is 2.5% or less regardless of the selective reflection wavelength of the cholesteric liquid crystal layer, it is possible to sufficiently reduce crosstalk when used for a circularly polarizing plate of glasses of a circularly polarizing 3D image viewing system. From the viewpoint, it is preferably 2.0% or less, and particularly preferably 1.5% or less. The circularly polarizing layer of the present invention preferably has the above-mentioned range when the selective reflection wavelength transmittance is at least a wavelength of 550 nm. Further, the circularly polarizing layer of the present invention preferably has the above-mentioned range even when the selective reflection wavelength transmittance is 450 nm and / or 630 nm.
The selective reflection wavelength transmittance (crosstalk) of conventional 3D glasses for movies (manufactured by Master Image) is 3.0% when the wavelength is 450 nm, and 2.5% when the wavelength is 550 nm. Yes, it was 2.0% when the wavelength was 630 nm.

<Configuration of circularly polarizing layer>
An example of the configuration of the circularly polarizing layer of the present invention will be described with reference to the drawings. However, the present invention is not limited to the drawings.
In each of the following drawings, a configuration having no base material is described, but the circularly polarizing layer of the present invention may further have a base material and is limited to a configuration having no base material. It is not a thing.
FIG. 1 is a schematic view showing an example of a circularly polarizing layer of the present invention. An embodiment of a circularly polarizing layer 21 in which a cholesteric liquid crystal layer 1 formed by fixing a cholesteric liquid crystal phase is laminated on a retardation layer 11. Indicates. The retardation layer is arranged directly or via an isotropic layer with the cholesteric liquid crystal layer. For example, as shown in FIG. 1, the cholesteric liquid crystal layer 1 and the retardation layer 11 may be disposed directly (synonymous with and adjacent to each other). As shown in FIG. 2, the cholesteric liquid crystal layer 1 and the retardation layer 11 may be disposed via an isotropic layer 41.
The circularly polarizing layer of the present invention shown in FIG. 1 can be used as a polarizing film for at least one eye of glasses of a 3D image viewing system. When the circularly polarizing layer of the present invention and the laminate of the circularly polarizing layer of the present invention are described, the description only refers to the polarizing layer for one eye unless otherwise specified. For example, in the glasses of the present invention to be described later, when the polarizing layer for one eye uses a laminate of a plurality of cholesteric liquid crystal layers on the circular polarizing layer of the present invention, each cholesteric liquid crystal layer contains the same kind of chiral agent. However, such an explanation is meant only for the circularly polarizing layer for one eye (for the other circularly polarizing layer of the present invention for the other eye). It is not always preferred to include the same kind of chiral agent). In this case, as will be described later, it is naturally preferable to use another chiral agent having a different turning property (chirality) in the other circularly polarizing layer of the present invention used for the polarizing film for the other eye.
When the circularly polarizing layer of the present invention shown in FIG. 1 is used as glasses for a 3D image viewing system, it is preferable that the retardation layer is disposed on the incident light side with respect to the cholesteric liquid crystal layer. With such an arrangement, the phase difference layer on the side of the incident light (perpendicular to the surface of the phase difference layer and the cholesteric liquid crystal layer) 31 that is the circular polarization signal for the left eye or the circular polarization signal for the right eye 11, the circularly polarized signal for the left eye or the circularly polarized signal for the right eye enters the cholesteric liquid crystal layer 1 after passing through the retardation layer, and the transmitted light 32 not reflected by the cholesteric liquid crystal layer is transmitted to the right eye of the observer Or it will inject into the left eye.

  The circularly polarizing layer of the present invention may have only one cholesteric liquid crystal layer or two or more layers. FIG. 3 shows an embodiment in which the circularly polarizing layer of the present invention has two cholesteric liquid crystal layers. FIG. 3 shows an embodiment of a circularly polarizing layer 21 in which a cholesteric liquid crystal layer 1 a and a cholesteric liquid crystal layer 1 b are laminated on a retardation layer 11. As shown in FIG. 3, it is preferable that the retardation layer 11 and the cholesteric liquid crystal layer 1a are disposed in contact with each other, and the cholesteric liquid crystal layer 1a and the cholesteric liquid crystal layer 1b are disposed in contact with each other. At this time, the retardation of the retardation layer 11 is obtained by taking λmax in the formula (1) as the λmax value of the cholesteric liquid crystal layer 1a. There is no restriction | limiting in particular in the number of lamination | stacking of the light reflection layer formed by fixing the said cholesteric liquid crystal phase, For example, it can be set as 1-10 layers, 1-5 layers are preferable, and 1-3 layers are more preferable.

The circularly polarizing layer of the present invention may further have a substrate (not shown). Although there is no restriction | limiting in particular as said base material, The base material used preferably when manufacturing the said cholesteric liquid crystal layer, the base material used preferably when manufacturing the said phase difference layer, etc. can be mentioned. The arrangement position of the base material is not particularly limited as long as it does not contradict the gist of the present invention, and may be on the surface opposite to the phase difference layer side of the cholesteric liquid crystal layer (back side with respect to incident light). it can. Moreover, when the said base material is an isotropic layer, you may arrange | position the said base material to the phase difference layer side of the said cholesteric liquid crystal layer.
The substrate may also serve as a retardation layer. For example, the base material of the cholesteric liquid crystal layer may also serve as the retardation layer. At this time, the base material becomes the incident side. Further, another base material that is a retardation layer may be disposed on the incident light side of the cholesteric liquid crystal layer.
The circularly polarizing layer of the present invention may be used by peeling off the substrate used when producing the cholesteric liquid crystal layer or the substrate preferably used when producing the retardation layer. Only the material may be peeled off. For example, an embodiment in which the circularly polarizing layer of the present invention has the base material used when the cholesteric liquid crystal layer is manufactured, and the base material preferably used when the retardation layer is manufactured is preferably used.

  The circularly polarizing layer of the present invention may have a λ / 2 retardation layer on the opposite side of the retardation layer from the cholesteric liquid crystal layer. Since the λ / 2 phase difference layer reverses the rotation direction of the circularly polarized light, such a configuration makes it possible to use the circularly polarized layer as a reversely rotated circularly polarizing layer.

<Cholesteric liquid crystal layer>
The circularly polarizing layer of the present invention has a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase.
The cholesteric liquid crystal layer is not particularly limited. For example, a cholesteric liquid crystal layer having a constant cholesteric alignment structure pitch can be used. A cholesteric liquid crystal layer that is changed accordingly can also be used. At this time, the retardation layer (11) can take λmax in the formula (1) anywhere in the selective reflection band broadened by the pitch gradient, but is preferably set to the center wavelength of the selective reflection band. Examples of the cholesteric liquid crystal layer having a wide reflection band by the pitch gradient technique include Japanese Patent Application Laid-Open Nos. 2003-13953, 2004-233987, 2008-250187, and 2011-133591. can give.
A cholesteric liquid crystal layer having a constant helical pitch in the cholesteric alignment structure, which is an embodiment preferably used in the present invention, will be described below.

(Number of spiral winding)
The number of spiral turns of the cholesteric alignment structure of the cholesteric liquid crystal layer is preferably 8 or more, more preferably 9 or more, particularly preferably 10 or more, from the viewpoint of reducing crosstalk. More particularly preferred. The upper limit of the number of spiral turns of the cholesteric alignment structure of the cholesteric liquid crystal layer is not particularly limited, but can be, for example, 30 or less and more preferably 20 or less from the viewpoint of film formation. FIG. 4 shows the range of 1 roll 2 of cholesteric liquid crystal. One turn of the cholesteric liquid crystal means that the maximum in-plane direction of the refractive index of the alignment structure of the cholesteric liquid crystal rotates 360 ° with respect to an arbitrary reference direction, as shown in FIG.
In FIG. 4 and FIGS. 5 and 6 to be described later, the disk represents an arbitrary cross section parallel to the surface of the cholesteric liquid crystal layer or the retardation layer, and many elliptical members described in each disk are Represents the maximum direction of refractive index (for example, the director direction of rod-like liquid crystal molecules).

  A cholesteric liquid crystal layer having a desired number of spiral turns and a helical pitch can be formed by adjusting the type and concentration of materials (mainly liquid crystal material and chiral agent) used for forming the cholesteric liquid crystal layer.

(optical properties)
The selective reflection wavelength λmax of the cholesteric liquid crystal layer is preferably 300 nm to 2500 nm from the viewpoint of covering the visible light region and cutting unnecessary ultraviolet rays and infrared rays to reduce eye fatigue. More preferably, it is 360 nm to 900 nm, particularly preferably 380 nm to 780 nm.
The selective reflection wavelength of the cholesteric liquid crystal layer is a half-value transmittance represented by the following formula: T _1/2 (%), where Tmin (%) is the minimum value of transmittance in the cholesteric liquid crystal layer. The average value of two wavelengths.
Formula for obtaining the half-value transmittance: T _1/2 = 100− (100−Tmin) ÷ 2
More specifically, for each cholesteric liquid crystal layer, there are two wavelengths having the above-mentioned half-value transmittance on the long wave side (λ1) and the short wave side (λ2), and the values of the selective reflection wavelengths are λ1 and λ2. Expressed as an average value,

(Lamination of cholesteric liquid crystal)
The circularly polarizing layer of the present invention can have two or more cholesteric liquid crystal layers. At this time, the retardation of the retardation layer in the circularly polarizing layer takes the range of the formula (1). However, as the selective reflection wavelength λmax of the cholesteric liquid crystal layer in the formula (1), The selective reflection wavelength λmax of the arranged cholesteric liquid crystal layer is used.

  When the circularly polarizing layer of the present invention has two or more cholesteric liquid crystal layers, it is preferable that the chiral agents of all the cholesteric liquid crystal layers are the same from the viewpoint of cost effectiveness due to the common use of members. In the glasses of the present invention, when the circularly polarizing layer of the present invention is used as the polarizing film for one eye, it is preferable that the chiral agents of all the cholesteric liquid crystal layers included in the circularly polarizing layer are the same. In addition, it is preferable to use another circular polarizing layer of the present invention using another chiral agent having a different rotational property of the cholesteric liquid crystal layer as the other polarizing film for the eye.

When there are a plurality of the cholesteric liquid crystal layers included in the circularly polarizing layer of the present invention, the selective reflection wavelengths of the cholesteric liquid crystal layers are different from each other, and the reflection when the plurality of cholesteric liquid crystal layers having the same selective reflection wavelength are provided. This is preferable from the viewpoint of a balance between economic factors such as efficiency and manufacturing cost. Here, that the selective reflection wavelengths of the two cholesteric liquid crystal layers are different from each other means that the difference between the selective reflection wavelengths of the cholesteric liquid crystal layers exceeds 20 nm. When there are a plurality of the cholesteric liquid crystal layers, the difference in selective reflection wavelength between the cholesteric liquid crystal layers is preferably more than 20 nm, more preferably 30 nm or more, and particularly preferably 40 nm or more.
The rotation direction of each cholesteric liquid crystal layer is preferably the same direction.

  The cholesteric liquid crystal layer preferably has a reflectance of non-polarized light at a selective reflection wavelength of 40% or more, and more preferably 45% or more.

  The cholesteric liquid crystal layer preferably has a non-polarized light transmittance at a selective reflection wavelength of 60% or less, and more preferably 55% or less. Further, the transmittance of non-polarized light outside the selective reflection region is preferably 80% or more, and more preferably 90% or more.

In the case where there are a plurality of the cholesteric liquid crystal layers included in the circularly polarizing layer of the present invention, the selective reflection wavelength of each cholesteric liquid crystal layer is, for example, a wavelength corresponding to or tuned to each color of R, G, B (630 nm and 550 nm, respectively) , 450 nm) is a wavelength corresponding to R, G, and B of the left-eye circular polarization signal and the right-eye circular polarization signal output from the video drive unit of the 3D image viewing system Are preferably reflected from the viewpoint of reducing crosstalk and suppressing color shift. When the peak wavelengths of the left-eye circular polarization signal and the right-eye circular polarization signal output from the video drive unit of the 3D image viewing system are shifted from R, G, and B, the selective reflection wavelength of each cholesteric liquid crystal layer Needless to say, can be tuned appropriately.
When the cholesteric liquid crystal layer included in the circularly polarizing layer of the present invention is a single layer, the selective reflection wavelength of the cholesteric liquid crystal layer is preferably a wavelength corresponding to G (550 nm).
In this specification, the selective reflection wavelength of the cholesteric liquid crystal layer is the circular polarization signal for the left eye and the circular polarization for the right eye output from the video driving unit of the 3D image viewing system within a range that is optically allowed as an error. There may be a deviation from the signal wavelength (for example, the wavelength corresponding to the above-mentioned R, G, B), and the deviation is preferably ± 20 nm or less, more preferably ± 15 nm or less, and ± 10 nm or less. It is particularly preferred.

  Each cholesteric liquid crystal layer having desired optical characteristics can be formed by adjusting the type and concentration of materials (mainly liquid crystal material and chiral agent) used for forming the cholesteric liquid crystal layer.

(Thickness)
The thickness of each cholesteric liquid crystal layer is preferably about 1 μm to 15 μm (preferably about 2 to 10 μm). However, it is not limited to these ranges.
The thickness of the cholesteric liquid crystal layer can be set to a desired range by adjusting the coating amount of the material for forming the cholesteric liquid crystal layer.

(Cholesteric liquid crystal layer forming material)
The circularly polarizing layer of the present invention is not particularly limited as a material for forming the cholesteric liquid crystal layer of the cholesteric liquid crystal layer, but a cholesteric liquid crystal-containing polymerization containing a polymerizable liquid crystal as described in the method for producing a cholesteric liquid crystal layer described below. It is preferable that the liquid crystal composition is fixed by photopolymerization after being applied and oriented.

In the circularly polarizing layer of the present invention, a polymerizable liquid crystal composition is preferably used for forming the cholesteric liquid crystal layer. As an example of the polymerizable liquid crystal composition, an embodiment containing at least a rod-like liquid crystal compound, a chiral agent (preferably having an HTP of 30 μm ⁻¹ or more), and a polymerization initiator is preferable. Two or more of each component may be included. For example, a polymerizable rod-like liquid crystal compound and a non-polymerizable rod-like liquid crystal compound can be used in combination. Also, a combination of a low-molecular liquid crystal compound and a high-molecular liquid crystal compound is possible. Further, at least one selected from various additives such as an alignment control agent (horizontal alignment agent), a non-uniformity inhibitor, a repellency inhibitor, and a polymerizable monomer in order to improve alignment uniformity, applicability, and film strength. It may contain seeds. Further, in the liquid crystal composition, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, metal oxide fine particles, and the like are added in a range that does not deteriorate the optical performance, if necessary. Can be added.

1. Rod-like liquid crystal compounds As rod-like liquid crystal compounds, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenyl Pyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. In addition to the above low-molecular liquid crystalline molecules, high-molecular liquid crystalline molecules can also be used.

  It is more preferable to fix the orientation of the rod-like liquid crystal compound by polymerization, and examples of the polymerizable rod-like liquid crystal compound include those described in Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. Nos. 4,683,327, 5,622,648, 5,770,107, WO 95/22586, 95/24455, 97/97. No. 0600, No. 98/23580, No. 98/52905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and Japanese Patent Application No. 2001-64627 These compounds can be used. The polymerizable rod-like liquid crystal compound is preferably a polymerizable rod-like liquid crystal compound represented by the following general formula (X).

Formula ^{(X) Q 1 -L 1 -Cy} 1 -L 2 - (Cy 2 -L 3) n -Cy 3 -L 4 -Q 2
(In General Formula (X), Q ¹ and Q ² are each independently a polymerizable group, L ¹ and L ⁴ are each independently a divalent linking group, and L ² and L ³ are each independently a single group. A bond or a divalent linking group, Cy ¹ , Cy ² and Cy ³ are divalent cyclic groups, and n is 0, 1, 2 or 3.)
The polymerizable rod-like liquid crystal compound represented by the general formula (X) will be described below.
In general formula (X), Q ¹ and Q ² are each independently a polymerizable group. The polymerization reaction of the polymerizable group is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. In other words, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

In general formula (X), L ¹ and L ⁴ are each independently a divalent linking group. L ¹ and L ⁴ each independently include —O—, —S—, —CO—, —NR—, —C═N—, a divalent chain group, a divalent cyclic group, and combinations thereof. A divalent linking group selected from the group is preferred. R is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. R is preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, and most preferably a hydrogen atom.

The example of the bivalent coupling group which consists of a combination is shown below. Here, the left side is coupled to Q (Q ¹ or Q ² ), and the right side is coupled to Cy (Cy ¹ or Cy ³ ).

L-1: —CO—O—divalent chain group —O—
L-2: -CO-O-divalent chain group -O-CO-
L-3: —CO—O—divalent chain group —O—CO—O—
L-4: -CO-O-divalent chain group -O-divalent cyclic group-
L-5: -CO-O-divalent chain group -O-divalent cyclic group -CO-O-
L-6: -CO-O-divalent chain group -O-divalent cyclic group -O-CO-
L-7: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-
L-8: -CO-O-divalent chain group -O-divalent cyclic group -divalent chain group -CO-O-
L-9: -CO-O-divalent chain group -O-divalent cyclic group -divalent chain group -O-CO-
L-10: —CO—O—divalent chain group—O—CO—divalent cyclic group—
L-11: -CO-O-divalent chain group -O-CO-divalent cyclic group -CO-O-
L-12: -CO-O-divalent chain group -O-CO-divalent cyclic group -O-CO-
L-13: —CO—O—Divalent chain group—O—CO—Divalent cyclic group—Divalent chain group—
L-14: -CO-O-divalent chain group -O-CO-divalent cyclic group -divalent chain group -CO-O-
L-15: -CO-O-divalent chain group-O-CO-divalent cyclic group-divalent chain group-O-CO-
L-16: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—
L-17: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -CO-O-
L-18: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -O-CO-
L-19: —CO—O—Divalent chain group—O—CO—O—Divalent cyclic group—Divalent chain group—
L-20: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -divalent chain group -CO-O-
L-21: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -divalent chain group -O-CO-

The divalent chain group means an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, or a substituted alkynylene group. An alkylene group, a substituted alkylene group, an alkenylene group and a substituted alkenylene group are preferred, and an alkylene group and an alkenylene group are more preferred.
The alkylene group may have a branch. The alkylene group preferably has 1 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include a halogen atom.
The alkenylene group may have a branch. The alkenylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include a halogen atom.
The alkynylene group may have a branch. The alkynylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkynylene part of the substituted alkynylene group is the same as the above alkynylene group. Examples of the substituent include a halogen atom.
Specific examples of the divalent chain group include ethylene, trimethylene, propylene, tetramethylene, 2-methyl-tetramethylene, pentamethylene, hexamethylene, octamethylene, 2-butenylene, 2-butynylene and the like.

The definition and examples of the divalent cyclic group are the same as those of Cy ¹ , Cy ² and Cy ³ described later.

In general formula (X), L ² or L ³ each independently represents a single bond or a divalent linking group. L ² and L ³ each independently include —O—, —S—, —CO—, —NR—, —C═N—, a divalent chain group, a divalent cyclic group, and combinations thereof. It is preferably a divalent linking group or a single bond selected from the group. R is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom. Preferably, it is a hydrogen atom. The divalent chain group and the divalent cyclic group have the same definitions as L ¹ and L ⁴ .
Preferred divalent linking groups as L ² or L ³ include —COO—, —OCO—, —OCOO—, —OCONR—, —COS—, —SCO—, —CONR—, —NRCO—, —CH _2. CH _2- , -C = C-COO-, -C = N-, -C = N-N = C-, and the like.

In general formula (X), n is 0, 1, 2, or 3. When n is 2 or 3, two L ³ may be the same or different, and two Cy ² may be the same or different. n is preferably 1 or 2, and more preferably 1.

In the general formula (X), Cy ¹ , Cy ² and Cy ³ are each independently a divalent cyclic group.
The ring contained in the cyclic group is preferably a 5-membered ring, 6-membered ring, or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring.
The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring.
The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring and a naphthalene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.
As the cyclic group having a benzene ring, 1,4-phenylene is preferable. As the cyclic group having a naphthalene ring, naphthalene-1,5-diyl and naphthalene-2,6-diyl are preferable. The cyclic group having a cyclohexane ring is preferably 1,4-cyclohexylene. As the cyclic group having a pyridine ring, pyridine-2,5-diyl is preferable. As the cyclic group having a pyrimidine ring, pyrimidine-2,5-diyl is preferable.
The cyclic group may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. An alkylthio group having 1 to 5 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and an alkyl-substituted carbamoyl group having 2 to 6 carbon atoms And an acylamino group having 2 to 6 carbon atoms.

  Examples of the polymerizable rod-like liquid crystal compound represented by the general formula (X) are shown below. The present invention is not limited to these.

  In addition to the polymerizable rod-shaped liquid crystal compound represented by the general formula (X), it is preferable to use at least one compound represented by the following general formula (V) as the rod-shaped liquid crystal compound.

General formula (V)
^{M 1 - (L 1) p} -Cy 1 -L 2 - (Cy 2 -L 3) n -Cy 3 - (L 4) q-M 2
(In the general formula (V), M ¹ and M ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a heterocyclic group, a cyano group, a halogen, -SCN,- CF ₃ , a nitro group, or Q ¹ is represented, but at least one of M ¹ and M ² represents a group other than Q ¹ .
^{However, Q 1, L 1, L} 2, L 3, L 4, Cy 1, Cy 2, Cy 3 and n have the same meanings as the group represented by the general formula (X). P and q are 0 or 1. )

When M ¹ and M ² do not represent Q ¹ , M ¹ and M ² are preferably a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a cyano group, more preferably , An alkyl group having 1 to 4 carbon atoms, or a phenyl group, and p and q are preferably 0.

  Moreover, as a preferable mixing ratio of the compound represented by the general formula (V) in the mixture of the polymerizable liquid crystal compound represented by the general formula (X) and the compound represented by the general formula (V), It is 0.1% -40%, More preferably, it is 1% -30%, More preferably, it is 5% -20%.

  Although the preferable example of a compound represented by general formula (V) below is shown, this invention is not limited to these.

2. Chiral agent:
The circularly polarizing layer of the present invention is not particularly limited as a chiral agent used for the cholesteric liquid crystal layer.
The chiral agent may be any of various known chiral agents (for example, Liquid Crystal Device Handbook, Chapter 3-4-3, TN, chiral agent for STN, page 199, edited by Japan Society for the Promotion of Science, 42nd Committee, 1989). ) Can be selected. A chiral agent generally contains an asymmetric carbon atom, but an axially asymmetric compound or a planar asymmetric compound containing no asymmetric carbon atom can also be used as the chiral agent. Examples of the axial asymmetric compound or the planar asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof. The chiral agent may have a polymerizable group. When the chiral agent has a polymerizable group and the rod-shaped liquid crystal compound used in combination also has a polymerizable group, it is derived from the rod-shaped liquid crystal compound by a polymerization reaction between the chiral agent having a polymerizable group and the polymerizable rod-shaped liquid crystal compound. And a polymer having a repeating unit derived from a chiral agent. In this embodiment, the polymerizable group possessed by the chiral agent having a polymerizable group is preferably the same group as the polymerizable group possessed by the polymerizable rod-like liquid crystal compound. Therefore, the polymerizable group of the chiral agent is also preferably an unsaturated polymerizable group, an epoxy group or an aziridinyl group, more preferably an unsaturated polymerizable group, and an ethylenically unsaturated polymerizable group. Particularly preferred.
The chiral agent may be a liquid crystal compound.

The chiral agent is preferably 1 to 30 mol% with respect to the rod-shaped liquid crystal compound used in combination. A smaller amount of the chiral agent is preferred because it often does not affect liquid crystallinity. Therefore, the optically active compound used as the chiral agent is preferably a compound having a strong twisting force so that a twisted orientation with a desired helical pitch can be achieved even with a small amount.
Circular polarization layer of the present invention, that the cholesteric liquid crystal layer HTP right turning of the chiral agent or at 30 [mu] m ^-1 or more, HTP contains a left turn of the chiral agent is 30 [mu] m ^-1 or more, This is preferable from the viewpoint of easily setting the selective reflection wavelength of the cholesteric liquid crystal layer to 380 to 780 nm (visible light region). By using a chiral agent having high HTP, it is easy to obtain a cholesteric liquid crystal layer having a good surface shape, high transparency, selective reflection characteristics in the visible light region, and high reflection performance. Note that HTP is generally used as an index representing the performance of a chiral agent. HTP is an abbreviation for Helical Twisting Power, and is a factor indicating the helical orientation ability represented by the following formula. For details, see Non-Patent Document 1 “Development of photoreactive chiral agent for cholesteric liquid crystal for color filter for liquid crystal display” (Yoshitomo Yumoto, Mitsuyoshi Ichihashi).
formula:
HTP = 1 / (mass% concentration of chiral agent in solid content of liquid crystal composition × helical pitch length)
However, the helical pitch length = selective reflection wavelength / average refractive index of the solid content of the liquid crystal composition Examples of such chiral agents exhibiting a strong twisting force include JP 2010-181852 A and JP 2003-287623 A. The chiral agents described in JP-A No. 2002-80851, JP-A No. 2002-80478, and JP-A No. 2002-302487 can be mentioned and can be preferably used in the present invention. Furthermore, isosorbide compounds having a corresponding structure can be used for the isosorbide compounds described in these publications, and isosorbide compounds having a corresponding structure can be used for the isomannide compounds described in these publications. It can also be used.

Here, as the right-turning chiral agent, a strong twisting force is provided to the market more than the left-turning chiral agent. For example, as a right-turning chiral agent having an HTP of 30 μm ⁻¹ or more, LC756 (manufactured by BASF) can be preferably used in the present invention.

On the other hand, the left-turning chiral agent having an HTP of 30 μm ⁻¹ or more is not particularly limited, and the chiral agent represented by the following general formulas (1) and (2) can be used even if known ones are used. It may be used.
In addition, although only R form or only S form of a chiral agent may be illustrated below, the corresponding S form and R form can also be used for this invention. The chiral agent exemplified below is preferably left-turning, but it may be used as a right-turning chiral agent because it exhibits high HTP regardless of whether it is R or S.

（一般式（１）中、Ｍはそれぞれ独立に水素原子または置換基を表し、Ｒ¹は以下に示す連結基のいずれかを表す。

ただし＊はそれぞれ一般式（１）中の酸素原子との結合部位を表す。Ｒ³はそれぞれ独立に炭素数１から３のアルキル基または炭素数６から１０のアリール基を表す。）

（一般式（２）中、Ｒ²は以下に示す置換基のいずれかを表し、２つのＲ²は互いに同じでも異なっていてもよい。

ただし＊はそれぞれ一般式（２）中の酸素原子との結合部位を表す。Ｙ¹はそれぞれ独立に単結合、−Ｏ−、−Ｃ（＝Ｏ）Ｏ−、−ＯＣ（＝Ｏ）−、−ＯＣ（＝Ｏ）Ｏ−のいずれかを表し、Ｓｐ¹はそれぞれ独立に単結合または炭素数１から８のアルキレン基を表し、Ｚ¹はそれぞれ独立に水素原子または（メタ）アクリル基を表し、ｎは１以上の整数を表す。）

(In General Formula (1), M represents a hydrogen atom or a substituent each independently, and R < ¹ > represents either of the coupling groups shown below.

However, * represents the coupling | bond part with the oxygen atom in General formula (1), respectively. R ³ each independently represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms. )

(In General Formula (2), R ² represents any of the substituents shown below, and two R ^{2 s} may be the same as or different from each other.

However, * represents the coupling | bond part with the oxygen atom in General formula (2), respectively. Y ¹ represents each independently a single bond, —O—, —C (═O) O—, —OC (═O) —, —OC (═O) O—, and Sp ¹ represents each independently single bond or an alkylene group having a carbon number of 1 to 8, Z ¹ each independently represent a hydrogen atom or a (meth) acryl group, n represents an integer of 1 or more. )

The chiral agent represented by the general formula (1) will be described.
In the general formula (1), each M independently represents a hydrogen atom or a substituent, and preferably represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkynyl group, an alkenyl group, or an alkyloxy group. The CH ₂ group in each group may be independently substituted with an O, S, OCO, COO, OCOO, CO or phenylene group.

The chiral agent represented by the general formula (1) can be synthesized by a method described in known literature or in the same manner. For example, Heteroatom Chemistry, 2011 vol. 22, p. It is preferable to synthesize by the method described in 562.
The R and S isomers of the chiral agent represented by the general formula (1) can be synthesized by synthesizing only the R isomer or the S isomer as the raw materials. In addition, the racemate may be optically resolved by a known method.

  Specific examples of the chiral agent represented by the general formula (2) are shown below, but the present invention is not limited to the following specific examples.

3. Alignment control agent The circularly polarizing layer of the present invention preferably contains an alignment control agent in the cholesteric liquid crystal layer.
Preferable examples of the alignment control agent that can be used in the present invention include a fluorine-based alignment control agent. Two or more kinds of alignment control agents may be contained. The fluorine-based alignment control agent can reduce the tilt angle of the molecules of the liquid crystal compound or substantially horizontally align it at the air interface of the layer.
In this specification, “horizontal alignment” means that the major axis of the liquid crystal molecule is parallel to the film surface, but it is not required to be strictly parallel. An orientation with an inclination angle of less than 20 degrees is meant. When the liquid crystal compound is horizontally aligned in the vicinity of the air interface, alignment defects are less likely to occur, so that transparency in the visible light region is increased and reflectance in the infrared region is increased. On the other hand, when the molecules of the liquid crystal compound are aligned at a large tilt angle, the spiral axis of the cholesteric liquid crystal phase is shifted from the normal to the film surface, which decreases the reflectivity, generates a fingerprint pattern, increases haze and increases diffraction. It is not preferable because it shows sex.
Examples of the alignment control agent include compounds exemplified in [0092] to [0096] of JP-A-2005-99248, [0076] to [0078] and [0082] of JP-A-2002-129162. ] To [0085], and compounds exemplified in [0022] to [0029] of JP-A-2012-211306.

  In the cholesteric liquid crystal layer used in the circularly polarizing layer of the present invention, the addition amount of the fluorine-based horizontal alignment agent is preferably 0.01 to 10% by mass with respect to the polymerizable liquid crystal compound, and 0.01 to It is more preferably 5% by mass, particularly preferably 0.01 to 1% by mass, more particularly preferably 0.01 to 0.09% by mass, and 0.01 to 0.06% by mass. It is even more particularly preferable that

  Further, in the cholesteric liquid crystal layer used in the circularly polarizing layer of the present invention, it is more preferable that the fluorine-based horizontal alignment agent contains a perfluoroalkyl group from the viewpoint of suppressing the addition amount of the fluorine-based horizontal alignment agent in the above range. In particular, it preferably contains a C 3-10 perfluoroalkyl group.

4). Polymerization initiator The cholesteric liquid crystal layer used in the circularly polarizing layer of the present invention preferably contains a polymerization initiator. For example, in an embodiment in which a curing reaction is caused to proceed by ultraviolet irradiation to form a cured film, the polymerization initiator used is preferably a photopolymerization initiator that can initiate a polymerization reaction by ultraviolet irradiation. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatics. Group acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketone (US patents) No. 3549367), acridine and phenazine compounds (JP-A-60-105667, US Pat. No. 4,239,850) and oxadiazole compounds (US Pat. No. 4,221,970), acylphosphine Oxide compounds (Japanese Patent Publication No. 63-40 No. 799, JP-B-5-29234, JP-A-10-95788, JP-A-10-29997) and the like.
The amount of the photopolymerization initiator used is preferably 0.1 to 20% by mass, more preferably 1 to 8% by mass, based on the composition (solid content in the case of a coating solution).

5. Other components The cholesteric liquid crystal layer used in the circularly polarizing layer of the present invention may be added to the rod-like liquid crystal compound, chiral agent, horizontal alignment controller, and polymerization initiator, and, if necessary, a solvent and other additives ( Cellulose ester).

  As a solvent for the composition for forming the cholesteric liquid crystal layer used in the circularly polarizing layer of the present invention, an organic solvent is preferably used. Examples of organic solvents include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone, cyclohexanone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.

(Method for producing cholesteric liquid crystal layer)
The method for producing the cholesteric liquid crystal layer is not particularly limited and can be appropriately selected depending on the purpose. For example, the coating liquid for forming the cholesteric liquid crystal layer is formed on the surface of the lower layer such as the base material. , A dip coater, a die coater, a slit coater, a bar coater, a gravure coater, a spin coater, a method of applying by an ink jet or the like, a method of surface orientation by a method such as an LB film method, a self-organization method, or a spray coating method. Among them, a method of applying with a bar coater or a spin coater is preferable.

  In the case of forming the cholesteric liquid crystal layer of the circularly polarizing layer of the present invention by coating, it is preferable to form the cholesteric liquid crystal layer by applying the coating liquid and then drying and solidifying by a known method. As a drying method, drying by heating is preferable.

An example of a method for producing the cholesteric liquid crystal layer is as follows:
(1) Applying a polymerizable liquid crystal composition to the surface of a substrate or the like to make a cholesteric liquid crystal phase;
(2) irradiating the polymerizable liquid crystal composition with ultraviolet rays to advance a curing reaction, fixing a cholesteric liquid crystal phase to form a cholesteric liquid crystal layer;
Is a production method comprising at least
By repeating the steps (1) and (2) twice on one surface of the substrate, two or more cholesteric liquid crystal layers can be laminated.
Note that the direction of rotation of the cholesteric liquid crystal phase can be adjusted by the type of liquid crystal used or the type of chiral agent added, and the helical pitch (ie, selective reflection wavelength) can be arbitrarily adjusted by the concentration of these materials. In addition, it is known that the wavelength of a specific region reflected by the cholesteric liquid crystal layer can be shifted depending on various factors of the manufacturing method. It can be shifted depending on conditions such as temperature, illuminance, and irradiation time.

In the step (1), first, the polymerizable liquid crystal composition is applied to the surface of the base material or the lower cholesteric liquid crystal layer. The polymerizable liquid crystal composition is preferably prepared as a coating solution in which a material is dissolved and / or dispersed in a solvent.
An alignment layer can also be provided on the surface of the substrate or the lower cholesteric liquid crystal layer.

  Next, the polymerizable liquid crystal composition applied on the surface to form a coating film is brought into a cholesteric liquid crystal phase. In the aspect in which the polymerizable liquid crystal composition is prepared as a coating solution containing a solvent, the coating film may be dried and the solvent may be removed to obtain a cholesteric liquid crystal phase. Moreover, in order to set it as the transition temperature to a cholesteric liquid crystal phase, you may heat the said coating film if desired. For example, the cholesteric liquid crystal phase can be stably formed by heating to the temperature of the isotropic phase and then cooling to the cholesteric liquid crystal phase transition temperature. The liquid crystal phase transition temperature of the polymerizable liquid crystal composition is preferably in the range of 10 to 250 ° C., more preferably in the range of 10 to 150 ° C. from the viewpoint of production suitability and the like. When the temperature is lower than 10 ° C., a cooling step or the like may be required to lower the temperature to a temperature range exhibiting a liquid crystal phase. When the temperature exceeds 150 ° C., a high temperature is required to make the isotropic liquid state higher than the temperature range once exhibiting the liquid crystal phase, which is disadvantageous from waste of thermal energy, deformation of the substrate, and alteration.

Next, in the step (2), the coating film in the cholesteric liquid crystal phase is irradiated with ultraviolet rays to advance the curing reaction. For ultraviolet irradiation, a light source such as an ultraviolet lamp is used. In this step, by irradiating with ultraviolet rays, the curing reaction of the polymerizable liquid crystal composition proceeds, the cholesteric liquid crystal phase is fixed, and a cholesteric liquid crystal layer is formed.
No particular limitation is imposed on the amount of irradiation energy of ultraviolet rays, in ^{general, 100mJ / cm 2 ~800mJ / cm} 2 is preferably about. Moreover, there is no restriction | limiting in particular about the time which irradiates an ultraviolet-ray to the said coating film, but it will be determined from the viewpoint of both sufficient intensity | strength and productivity of a cured film.

  In order to accelerate the curing reaction, ultraviolet irradiation may be performed under heating conditions. Moreover, it is preferable to maintain the temperature at the time of ultraviolet irradiation in the temperature range which exhibits a cholesteric liquid crystal phase, or the temperature range below it so that a cholesteric liquid crystal phase may not be disturbed. Also, since the oxygen concentration in the atmosphere is related to the degree of polymerization, if the desired degree of polymerization is not reached in the air and the film strength is insufficient, the oxygen concentration in the atmosphere is reduced by a method such as nitrogen substitution. It is preferable. A preferable oxygen concentration is preferably 10% or less, more preferably 7% or less, and most preferably 3% or less. The reaction rate of the curing reaction (for example, polymerization reaction) that proceeds by irradiation with ultraviolet rays is 70% or more from the viewpoint of maintaining the mechanical strength of the layer and suppressing unreacted substances from flowing out of the layer. Preferably, it is 80% or more, more preferably 90% or more. In order to improve the reaction rate, a method of increasing the irradiation amount of ultraviolet rays to be irradiated and polymerization under a nitrogen atmosphere or heating conditions are effective. In addition, after polymerization, a method of further promoting the reaction by a thermal polymerization reaction by maintaining the polymer at a temperature higher than the polymerization temperature, or a method of irradiating ultraviolet rays again (however, irradiation is performed under conditions satisfying the conditions of the present invention). Can also be used. The reaction rate can be measured by comparing the absorption intensity of the infrared vibration spectrum of a reactive group (for example, a polymerizable group) before and after the reaction proceeds.

In the above step, the cholesteric liquid crystal phase is fixed and the cholesteric liquid crystal layer is formed. Here, the state in which the liquid crystal phase is “fixed” is the most typical and preferred mode in which the orientation of the rod-like liquid crystal compound that is a cholesteric liquid crystal phase is maintained. However, it is not limited to this, and specifically, it is usually 0 ° C. to 50 ° C., and under severer conditions, in the temperature range of −30 ° C. to 70 ° C., the layer has no fluidity, and is oriented by an external field or an external force. It shall mean a state in which the fixed orientation form can be kept stable without causing a change in form. In the present invention, the alignment state of the cholesteric liquid crystal phase is preferably fixed by a curing reaction that proceeds by ultraviolet irradiation.
In the present invention, it is sufficient that the optical properties of the cholesteric liquid crystal phase are maintained in the cholesteric liquid crystal layer, and the liquid crystal composition in the cholesteric liquid crystal layer no longer needs to exhibit liquid crystal properties. Absent. For example, the liquid crystal composition may have a high molecular weight due to a curing reaction and may no longer have liquid crystallinity.

<Phase difference layer>
(Phase difference of retardation layer)
The circularly polarizing layer of the present invention has a retardation layer arranged directly or via an isotropic layer with the cholesteric liquid crystal layer, and satisfies the following formula (1).
Formula (1)
(2.5 / 64) + n ≦ Re / λmax ≦ (6/64) + n
(In the formula (1), Re represents retardation in the in-plane direction of the retardation layer at a wavelength λmax (unit: nm), λmax represents a selective reflection wavelength (unit: nm) of the cholesteric liquid crystal layer, and n Represents an integer of 0 or more.)

Re in the formula (1) represents retardation in the in-plane direction of the retardation layer at the wavelength λmax. Here, Re is represented by the following formula (I).
Formula (I) Re = (nx−ny) × d
In the above formula (I), nx is the refractive index in the slow axis direction in the film plane of the retardation layer, ny is the refractive index in the fast axis direction in the film plane of the retardation layer, and d Is the thickness (nm) of the retardation layer.
The “slow axis direction” of the retardation layer means a direction in which the refractive index is maximum within the film plane of the retardation layer. The “fast axis direction” means a direction perpendicular to the slow axis in the film plane of the retardation layer.
In this specification, “spiral” may be used when the cholesteric liquid crystal structure reaches one turn, and “twist” may be used when the cholesteric liquid crystal structure may not reach one turn. However, the present invention is not limited by the difference between the terms “helix” and “twist”. For example, “the direction of spiral rotation” and “twist direction” may be considered synonymous.

Re at wavelength λnm can be measured as follows.
Re is measured with KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) by making light of wavelength λ nm incident in the normal direction of the film.
Said Re can be adjusted with the liquid crystal molecule or resin material used for a phase difference layer, addition of various additives, the film thickness of a phase difference layer, the extending | stretching direction and stretch rate of a phase difference layer, etc.

  In the formula (1), λmax is determined from the light source when the circularly polarizing layer of the present invention has two or more cholesteric liquid crystal layers when the circularly polarizing layer of the present invention is used as glasses for a circularly polarizing 3D image viewing system. It refers to λmax of a cholesteric liquid crystal layer arranged directly or via an isotropic layer on the far side.

In the formula (1), n represents an integer of 0 or more, preferably 0 or 1, and more preferably 0 from the viewpoint of easily controlling Re / λmax within the above range during production.
It is known that the influence of the phase difference of the retardation layer on the polarization state of polarized light having a specific light wavelength is equivalent when the phase difference is changed by an integral multiple of the specific light wavelength. Therefore, even if n is changed by an integral multiple in the formula (1), the crosstalk reduction effect is equivalent.

  When the circularly polarizing layer of the present invention has Re / λmax of (2.5 / 64) + n to (5/64) + n, the cross-polarization is more effective when used for glasses of a circularly polarizing 3D image viewing system. It is preferable from a viewpoint which can reduce, and it is more preferable that they are (3/64) + n-(5/64) + n.

(Tilt angle of retardation layer)
The tilt angle of the retardation layer is preferably 0 ° to 50 °, and the angle of 0 ° or more and less than 45 ° can further reduce crosstalk when used in glasses for a circularly polarized 3D image viewing system. From the viewpoint, it is more preferably 0 ° to 40 °, and particularly preferably 0 ° to 35 °.
In this specification, the tilt angle of the retardation layer refers to an angle formed by the maximum direction of the refractive index of the retardation layer and the surface of the retardation layer. The tilt angle of the retardation layer will be described with reference to FIG. In FIG. 5, the tilt angle 17 of the retardation layer is such that the maximum direction of the refractive index of the retardation layer and the surface of the portion 13 opposite to the portion (member 12) in contact with the cholesteric liquid crystal layer. It is shown as an angle 17 formed by
Here, the tilt angle 17 of the retardation layer may be an angle formed by the maximum direction of the refractive index of the retardation layer and the surface of the portion 12 in contact with the cholesteric liquid crystal layer of the retardation layer. The refractive index of the retardation layer is measured on each surface of the portion 12 of the retardation layer that is in contact with the cholesteric liquid crystal layer and the portion 13 of the retardation layer that is opposite to the portion of the retardation layer that is in contact with the cholesteric liquid crystal layer (member 12) When the maximum directions are different, the tilt angle of the retardation layer means the maximum value of both.
For example, when the retardation layer is a liquid crystal film in which the alignment of liquid crystal molecules is fixed, the tilt angle of the retardation layer can be adjusted by the type and amount of the alignment control agent added to the retardation layer. it can.

(In-plane angle of retardation layer)
The in-plane angle of the retardation layer is not particularly limited, and the circularly polarized light transmittance to be shielded at the selective reflection wavelength of the cholesteric liquid crystal layer is as small as possible, and as much as possible when used in glasses for a circularly polarized 3D image viewing system. Adjustments can be made as appropriate so that crosstalk can be reduced.
In this specification, the in-plane angle of the retardation layer refers to the liquid crystal director direction (reference direction) on the surface of the cholesteric liquid crystal layer on the retardation layer side, and the maximum direction of the refractive index of the retardation layer. This is the angle formed by the orthogonal projection direction. The in-plane angle of the retardation layer will be described with reference to FIG. In FIG. 5, the in-plane angle of the retardation layer is the liquid crystal director direction (reference direction) 14 on the surface of the cholesteric liquid crystal layer on the retardation layer side, and the maximum direction of the refractive index of the retardation layer is the cholesteric liquid crystal of the retardation layer. It is shown as an angle 16 formed by an angle 15 formed with the direction orthogonally projected onto the surface of the portion 12 in contact with the layer. At this time, the rotation direction of the cholesteric liquid crystal viewed from the retardation layer side is the same as the helical rotation direction, which is the positive rotation direction of the in-plane angle of the retardation layer.
Here, the in-plane angle 16 of the retardation layer is defined by the liquid crystal director direction (reference direction) 14 on the surface of the cholesteric liquid crystal layer on the retardation layer side, and the maximum direction of the refractive index of the retardation layer. An angle formed by an angle 15 formed with a direction orthogonally projected onto the surface of the portion 13 on the side opposite to the portion (member 12) in contact with the layer may be used. The in-plane angle of the retardation layer is in each surface of the portion 12 in contact with the cholesteric liquid crystal layer of the retardation layer and the portion 13 on the opposite side of the portion of the retardation layer in contact with the cholesteric liquid crystal layer (member 12). In the case where they are different, the in-plane angle of the retardation layer in the present specification means the in-plane angle 16 in the thickness direction central portion 20 of the retardation layer, unless otherwise specified.
The in-plane angle of the retardation layer can be adjusted by, for example, a method of bonding when the retardation layer and the cholesteric liquid crystal layer are bonded.

(Twist angle of retardation layer)
In this specification, the twist angle of the retardation layer refers to the portion of the retardation layer that is in contact with the cholesteric liquid crystal layer when the in-plane angles of the retardation layer are different on both surfaces (the retardation layer is twisted). Means a value obtained by subtracting the in-plane angle at the surface of the portion of the retardation layer in contact with the cholesteric liquid crystal layer from the in-plane angle at the surface of the opposite portion. The twist angle of the retardation layer will be described with reference to FIG. In FIG. 6, the twist angle of the retardation layer is such that the in-plane angle 19 on the surface of the portion 13 opposite to the portion (member 12) in contact with the cholesteric liquid crystal layer of the retardation layer and the cholesteric liquid crystal layer of the retardation layer It is shown as the difference from the in-plane angle 18 at the surface of the contacting portion 12. That is, it is defined as the following formula.
(Twist angle of retardation layer) = {In-plane angle 19 on the surface of the portion 13 opposite to the portion (member 12) in contact with the cholesteric liquid crystal layer of the retardation layer} − (the cholesteric liquid crystal layer of the retardation layer In-plane angle 18 on the surface of the contacting portion 12)
The twist angle of the retardation layer is preferably −100 ° to 100 ° from the viewpoint of further reducing crosstalk when used for glasses of a circularly polarized 3D image viewing system, and is −70 ° to 70 °. More preferably, it is −70 ° to 20 ° or 45 ° to 70 °.
For example, when the retardation layer is a liquid crystal film in which the orientation of liquid crystal molecules is fixed, the twist angle of the retardation layer can be adjusted by the presence or absence of the addition of the chiral agent, the kind of the chiral agent, the addition amount, and the like. it can.

(Configuration and composition of retardation layer)
The circularly polarizing layer of the present invention preferably has only one retardation layer that satisfies the above formula (1).
There is no restriction | limiting in particular as a composition of the said phase difference layer. As the retardation layer, a liquid crystal film in which the orientation of liquid crystal molecules is fixed, a resin film stretched so as to express a desired retardation, etc. can be used, and a liquid crystal in which the orientation of liquid crystal molecules is fixed. A membrane is preferred.
Examples of the liquid crystal film in which the orientation of the liquid crystal molecules is fixed include a liquid crystal film produced without adding a chiral agent in the cholesteric liquid crystal layer.
Examples of the stretched resin film include polycarbonate resins, poly (meth) acrylate resins such as polymethyl methacrylate, polystyrene resins such as polystyrene and styrene copolymers obtained by copolymerizing styrene and other monomers, and polyacrylonitrile resins. Polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide resins such as nylon 6, nylon 6, 6, polyolefin resins such as polyethylene and polypropylene, cyclic polyolefin resins, norbornene resins, polyvinyl alcohol resins, Ethylene vinyl alcohol copolymer resin, polyvinyl butyral resin, epoxy resin, polyimide resin, fluorine resin, polyvinylidene chloride resin, triacetyl cellulose resin, Acrylic resins, urethane resins, and a stretched film made of a silicone resin.

(Manufacturing method of retardation layer)
There is no restriction | limiting in particular as a manufacturing method of the said phase difference layer, It can manufacture by a well-known method.
In the case where the retardation layer is a liquid crystal film in which the orientation of liquid crystal molecules is fixed, it is preferably produced by the same method as the production method of the cholesteric liquid crystal layer.
When the retardation layer is a stretched resin film, it may be an optical uniaxial film or an optical biaxial film. When an optical uniaxial film is produced, a normal uniaxial stretching process or biaxial stretching process may be performed. When manufacturing an optical biaxial film, it is preferable to implement an unbalanced biaxial stretching process. In unbalanced biaxial stretching, a polymer film is stretched in a certain direction (for example, 3 to 100%, preferably 5 to 30%) in a certain direction, and further in a direction perpendicular thereto (for example, 6 to 200%, preferably 10 to 90%). The bi-directional stretching process may be performed simultaneously. It is preferable that the stretching direction (the direction in which the stretching ratio is high in unbalanced biaxial stretching) and the slow axis in the plane of the stretched film are substantially the same direction.

<Isotropic layer>
The circularly polarizing layer of the present invention preferably has an isotropic layer.
There is no restriction | limiting in particular as a composition of the said isotropic layer. In the circularly polarizing layer of the present invention, the isotropic layer is preferably a base material, a pressure-sensitive adhesive layer (hereinafter also referred to as a pressure-sensitive adhesive layer) or an adhesive layer, and more preferably the pressure-sensitive adhesive layer or the adhesive layer. An adhesive layer is preferable, and it is particularly preferable. An adhesive sheet may be used as the adhesive layer. As the adhesive layer, a two-component mixed type, one-component heat curable adhesive or photocurable adhesive may be used, and a colorless and transparent adhesive is preferably used. In addition, the pressure-sensitive adhesive layer and the adhesive layer may be used one by one or two or more. Further, a pressure-sensitive adhesive layer and an adhesive layer may be used in combination.
There is no restriction | limiting in particular as a material which can be utilized for formation of the said isotropic layer, According to the objective, it can select suitably, For example, polyvinyl butyral (PVB) resin, an acrylic resin, a styrene / acrylic resin, a urethane resin, Examples include polyester resin, silicone resin, epoxy resin, polyvinyl alcohol resin, gelatin, ethylene vinyl alcohol resin, polyimide resin, and the like. These may be used individually by 1 type and may use 2 or more types together. An adhesive layer made of these materials can be formed by coating.
Furthermore, you may add a ultraviolet absorber, an antistatic agent, a lubricant, an antiblocking agent, etc. to the said isotropic layer.
The thickness of the isotropic layer is preferably 0.1 μm to 10 μm.

<Base material>
The circularly polarizing layer of the present invention preferably has a substrate.
There is no restriction | limiting in particular as said base material, A well-known base material can be used, and it is preferable that it is a transparent base material.
The transparent substrate is not particularly limited as long as it is an optically transparent transparent substrate, and can be appropriately selected according to the purpose. For example, the material having a visible light transmittance of 70% or more, preferably 80 % Or more.
There is no restriction | limiting in particular about the shape, a structure, a magnitude | size, material, etc. as said base material, According to the objective, it can select suitably. Examples of the shape include a flat plate shape, and the structure may be a single layer structure or a laminated structure, and the size may be a circularly polarized 3D image viewing. It can be appropriately selected according to the size of the glasses of the system.
There is no restriction | limiting in particular as a material of the said base material, According to the objective, it can select suitably, For example, as a material of a transparent base material, polyethylene, a polypropylene, poly 4-methylpentene-1, polybutene-1, etc. Polyolefin resins; Polyester resins such as polyethylene terephthalate and polyethylene naphthalate; Polycarbonate resins, polyvinyl chloride resins, polyphenylene sulfide resins, polyether sulfone resins, polyethylene sulfide resins, polyphenylene ether resins, styrene resins Examples thereof include a film made of a resin, an acrylic resin, a polyamide resin, a polyimide resin, a cellulose resin such as cellulose acetate, or a laminated film thereof. Among these, a polyethylene terephthalate film is particularly preferable.
It is also possible to use materials used for eyeglass lenses such as glass, episulfide resin, thiourethane resin, polyester methacrylate, urethane methacrylate, epoxy methacrylate, diallyl carbonate, dialiphthalate, allyl diglycol carbonate, polymethyl methacrylate, etc. Is possible.
The thickness of the base material is not particularly limited and can be appropriately selected depending on the purpose of use of the circularly polarizing layer. Usually, the thickness is about 10 μm to 500 μm, but the thinner one is preferable from the viewpoint of thinning. preferable. The thickness of the substrate is preferably 10 μm to 100 μm, more preferably 20 to 75 μm, and particularly preferably 35 to 75 μm. When the thickness of the base material is sufficiently thick, adhesion failure tends to hardly occur. Also, if the thickness of the base material is sufficiently thin, when used for glasses of a circularly polarized 3D image viewing system, the material is not too strong, and tends to follow the curved surface of the eyeglass lens and be easily attached. is there. Furthermore, since the base material is sufficiently thin, raw material costs tend to be suppressed.

<Other layers>
The circularly polarizing layer of the present invention may further include at least one of an undercoat layer, an alignment layer, an easy adhesion layer, a hard coat layer, an ultraviolet absorption layer, a λ / 2 layer, and a surface protective layer.

-Undercoat layer-
The circularly polarizing layer of the present invention may have an undercoat layer between the cholesteric liquid crystal layer and the substrate. If the adhesion between the cholesteric liquid crystal layer and the substrate is strong, a peeling failure is unlikely to occur in the process of stacking and manufacturing the cholesteric liquid crystal layer. Therefore, a layer that can improve the adhesion between the cholesteric liquid crystal layer and the substrate can be used as the undercoat layer. On the other hand, when the base material is peeled and used as a circularly polarizing layer, the interface between the base material and the undercoat layer or between the undercoat layer and the cholesteric liquid crystal layer needs to have an adhesive strength that is peelable. It is. The interface to be peeled may be any interface.
The same applies to the space between the retardation layer and the substrate.
Examples of materials that can be used to form the undercoat layer include acrylate copolymer, polyvinylidene chloride, styrene butadiene rubber (SBR), aqueous polyester, and the like. In addition, the undercoat layer appropriately uses a dialdehyde such as glutaraldehyde, 2,3-dihydroxy-1,4-dioxane, or a hardener such as boric acid, as described above, when the adhesive force is appropriately adjusted. It is preferable to harden. The addition amount of the hardener is preferably 0.2 to 3.0% by mass of the dry mass of the undercoat layer.
The thickness of the undercoat layer is preferably 0.05 to 0.5 μm.

-Orientation layer-
The circularly polarizing layer of the present invention may have an alignment layer between the cholesteric liquid crystal layer and the substrate. The alignment layer has a function of more precisely defining the alignment direction of the liquid crystal compound in the cholesteric liquid crystal layer. The alignment layer can be provided by means such as a rubbing treatment of an organic compound (preferably a polymer), oblique vapor deposition of an inorganic compound, or formation of a layer having a microgroove. Furthermore, an alignment layer in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known. The alignment layer is preferably formed on the surface of the polymer film by rubbing treatment. From the viewpoint of uniformity of alignment, a photo-alignment film formed by light irradiation is preferable.
Since the alignment layer is preferably adjacent to the cholesteric liquid crystal layer, it is preferably provided between the cholesteric liquid crystal layer and the base material or the undercoat layer. However, the undercoat layer may have a function of an alignment layer. Further, an alignment layer may be provided between the cholesteric liquid crystal layers.
An alignment film may be similarly provided between the retardation layer and the base material or between the retardation layer and the cholesteric liquid crystal layer.

  The alignment layer preferably has a certain degree of adhesion to any of the adjacent cholesteric liquid crystal layer and the undercoat layer or substrate. However, when the substrate is peeled from the cholesteric liquid crystal layer, it is necessary to have a weakness that can be peeled off at any interface of the cholesteric liquid crystal layer / alignment layer / undercoat layer / substrate. The interface to be peeled may be any interface.

As a material used for the alignment layer, a polymer of an organic compound is preferable, and a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent is often used. Of course, polymers having both functions are also used. Examples of the polymer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleimide copolymer, polyvinyl alcohol and modified polyvinyl alcohol, and poly (N-methylol acrylamide). , Styrene / vinyl toluene copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, carboxymethyl cellulose And polymers such as silica, gelatin, polyethylene, polypropylene and polycarbonate, and compounds such as silane coupling agents. Examples of preferred polymers are water-soluble polymers such as poly (N-methylacrylamide), carboxymethyl cellulose, gelatin, polyville alcohol, and modified polyvinyl alcohol, and gelatin, polyville alcohol, and modified polyvinyl alcohol. Are preferable, and in particular, polyvinyl alcohol and modified polyvinyl alcohol can be mentioned.
The thickness of the alignment layer is preferably 0.1 to 2.0 μm.

The rubbing treatment can be generally carried out by rubbing the surface of the polymer layer several times with paper or cloth in a certain direction. In particular, in the present invention, “Liquid Crystal Handbook” (published by Maruzensha, October 30, 2000). It is preferable to carry out by the method described in (1).
As a method for changing the rubbing density, a method described in “Liquid Crystal Handbook” (published by Maruzen) can be used. The rubbing density (L) is quantified by the following formula (A).
Formula (A) L = Nl (1 + 2πrn / 60v)
In the formula (A), N is the number of rubbing, l is the contact length of the rubbing roller, r is the radius of the roller, n is the number of rotations (rpm) of the roller, and v is the stage moving speed (second speed).
In order to increase the rubbing density, the rubbing frequency should be increased, the contact length of the rubbing roller should be increased, the radius of the roller should be increased, the rotation speed of the roller should be increased, and the stage moving speed should be decreased, while the rubbing density should be decreased. To do this, you can reverse this.
Between the rubbing density and the pretilt angle of the alignment film, there is a relationship in which the pretilt angle decreases as the rubbing density increases and the pretilt angle increases as the rubbing density decreases.

Examples of the material used for the alignment layer include materials capable of photo-alignment.
As a photo-alignment material used for an alignment film formed by light irradiation, there are many literatures and the like. In the alignment film of the present invention, for example, JP 2006-285197 A, JP 2007-76839 A, JP 2007-138138 A, JP 2007-94071 A, JP 2007-121721 A, The azo compounds described in JP 2007-140465 A, JP 2007-156439 A, JP 2007-133184 A, JP 2009-109831 A, Patent No. 3888848, and Japanese Patent No. 4151746, No. 229039, a maleimide and / or alkenyl-substituted nadiimide compound having a photoalignment unit described in JP-A No. 2002-265541 and JP-A No. 2002-317013, Japanese Patent No. 4205195, Patent Photocrosslinking property described in No. 4205198 Run derivatives, Kohyo 2003-520878, JP-T-2004-529220 and JP-mentioned as examples photocrosslinkable polyimide, polyamide, or an ester are preferred according to Patent No. 4,162,850. Particularly preferred are azo compounds, photocrosslinkable polyimides, polyamides, or esters.

The photo-alignment film formed from the above material is irradiated with linearly polarized light or non-polarized light to produce a photo-alignment film.
In this specification, “linearly polarized light irradiation” is an operation for causing a photoreaction in the photo-alignment material. The wavelength of light used varies depending on the photo-alignment material used, and is not particularly limited as long as it is a wavelength necessary for the photoreaction. Preferably, the peak wavelength of light used for light irradiation is 200 nm to 700 nm, more preferably ultraviolet light having a peak wavelength of light of 400 nm or less.

  The light source used for light irradiation is a commonly used light source such as a tungsten lamp, a halogen lamp, a xenon lamp, a xenon flash lamp, a mercury lamp, a mercury xenon lamp, a carbon arc lamp, or various lasers (eg, semiconductor laser, helium). Neon laser, argon ion laser, helium cadmium laser, YAG laser), light emitting diode, cathode ray tube, and the like.

  As means for obtaining linearly polarized light, a method using a polarizing plate (eg, iodine polarizing plate, dichroic dye polarizing plate, wire grid polarizing plate), reflection using a prism-based element (eg, Glan-Thompson prism) or Brewster angle A method using a type polarizer or a method using light emitted from a laser light source having polarization can be employed. Moreover, you may selectively irradiate only the light of the required wavelength using a filter, a wavelength conversion element, etc.

In the case of linearly polarized light, a method of irradiating light from the top surface or the back surface to the alignment film surface perpendicularly or obliquely to the alignment film is employed. The incident angle of the light varies depending on the photo-alignment material, but is, for example, 0 to 90 ° (vertical), preferably 40 to 90.
When non-polarized light is used, the non-polarized light is irradiated obliquely. The incident angle is 10 to 80 °, preferably 20 to 60, and particularly preferably 30 to 50 °.
The irradiation time is preferably 1 minute to 60 minutes, more preferably 1 minute to 10 minutes.

  The thickness of the alignment layer is preferably 0.1 to 2.0 μm.

-Λ / 2 layer-
The circularly polarizing layer of the present invention may have a λ / 2 layer between the light source side of the retardation layer or between the cholesteric liquid crystal layer and the retardation layer. Since the λ / 2 layer has a function of converting circularly polarized light into reversely rotated circularly polarized light, the cholesteric liquid crystal layer has a function of converting the property of reflecting circularly polarized light into the property of reflecting reversely rotated circularly polarized light.
As for the λ / 2 layer, it is preferable to use a liquid crystal or a stretched polymer similarly to the retardation layer. The manufacturing method is the same as that of the retardation layer.

<Method for producing circularly polarizing layer>
There is no restriction | limiting in particular as a method of manufacturing the circularly-polarizing layer of this invention, According to the objective, it can select suitably.
For example, a member in which the cholesteric liquid crystal layer is formed on a base material by applying the coating liquid for forming the cholesteric liquid crystal layer or the coating liquid for forming the retardation layer on the surface of the base material, etc. And a method including a step of forming a member having the retardation layer formed thereon, a member having the cholesteric liquid crystal layer formed thereon, and a step of bonding the member having the retardation layer formed on a substrate. .

  A member in which the cholesteric liquid crystal layer is formed on a base material by applying the coating liquid for forming the cholesteric liquid crystal layer or the coating liquid for forming the retardation layer, and a member in which the retardation layer is formed on the base material A preferred embodiment of the step of forming is the same as the preferred embodiment of the method for producing the cholesteric liquid crystal layer and the method for producing the retardation layer.

  In the step of bonding the member formed with the cholesteric liquid crystal layer and the member formed with the retardation layer on the substrate, the retardation layer is formed on the member formed with the cholesteric liquid crystal layer and the substrate. It is preferable that the members are bonded together using an adhesive material that is an isotropic layer.

  Further, after the step of bonding the member having the cholesteric liquid crystal layer formed thereon and the member having the retardation layer formed on the substrate, the member having the retardation layer formed on the substrate was included. It is preferable to include a step of peeling the substrate from the retardation layer.

  As another example of the method for producing the circularly polarizing layer of the present invention, a step of rubbing on the surface of the substrate or the like, and a coating liquid for forming the cholesteric liquid crystal layer is applied on the rubbed substrate. Forming the cholesteric liquid crystal layer, rubbing the cholesteric liquid crystal layer, and applying the coating liquid for forming the retardation layer on the rubbed cholesteric liquid crystal layer. And a method including a step of forming a layer.

  As another example of the method for producing the circularly polarizing layer of the present invention, a step of rubbing on the surface of the substrate or the like, and a coating liquid for forming the cholesteric liquid crystal layer is applied on the rubbed substrate. Forming a cholesteric liquid crystal layer, applying a photo-alignment layer on the cholesteric liquid crystal layer and performing polarized UV irradiation, and forming a coating solution for forming the retardation layer on the photo-alignment layer. Examples thereof include a method including a step of forming the retardation layer by coating.

  As another example of the method for producing the circularly polarizing layer of the present invention, the cholesteric liquid crystal layer was formed on the substrate by applying the coating liquid for forming the cholesteric liquid crystal layer on the surface of the substrate or the like. Examples of the method include a step of forming a member in which the member is formed, and a step of bonding the member in which the cholesteric liquid crystal layer is formed and the stretched film in which the retardation layer is formed on a substrate.

<Application of circularly polarizing layer>
The circularly polarizing layer of the present invention can be used for a circularly polarizing plate of glasses of a circularly polarizing 3D image viewing system.
Other examples of the use of the circularly polarizing layer of the present invention include brightness enhancement films, heat ray shielding films, security materials, color filters, optical disk optical pickup devices, ellipsometers and other polarization measuring devices, privacy films, circularly polarizing 3D projectors , Retardation films, retardation plates, reflection sheets, decorative sheets, magnetic sensors using optical pumping, laser vehicle detection systems, and the like.

[Laminated body of circularly polarizing layers]
The laminate of the circularly polarizing layer of the present invention is characterized in that two or more circularly polarizing layers of the present invention are laminated.
Since the laminate of the circularly polarizing layer of the present invention has the circularly polarizing layer of the present invention, the crosstalk can be sufficiently reduced when used in the glasses of the circularly polarizing 3D image viewing system.

<Composition of a laminate of circularly polarizing layers>
An example of the configuration of the laminate of the circularly polarizing layers of the present invention will be described with reference to the drawings. However, the present invention is not limited to the drawings.
FIG. 7 is a schematic view showing an example of a laminated body of circularly polarizing layers of the present invention, and shows a laminated body 22 of circularly polarizing layers having three circularly polarizing layers 21. In FIG. 7, the laminated body 22 of circularly polarizing layers includes a circularly polarizing layer 21 in which a cholesteric liquid crystal layer 1a obtained by fixing a cholesteric liquid crystal phase is stacked on a retardation layer 11a, and a cholesteric layer on the retardation layer 11b. A circularly polarizing layer 21 in which a cholesteric liquid crystal layer 1b formed by fixing a liquid crystal phase is stacked, and a circularly polarizing layer 21 in which a cholesteric liquid crystal layer 1c formed by fixing a cholesteric liquid crystal phase is stacked on the retardation layer 11c. Have. In the configuration of FIG. 7, the selective reflection wavelengths of the circularly polarizing layers 21 are preferably different from each other, that is, the selective reflection wavelengths of the cholesteric liquid crystal layer 1a, the cholesteric liquid crystal layer 1b, and the cholesteric liquid crystal layer 1c are preferably different from each other.

  As shown in FIG. 7, each circularly polarizing layer 21 may be disposed directly (synonymous with and adjacent to each other), and each circularly polarizing layer 21 is disposed via an isotropic layer (not shown). It may be. The laminated body of circularly polarizing layers of the present invention preferably has at least one of an adhesive layer and an adhesive layer between the circularly polarizing layers. A preferable aspect of the isotropic layer that may be disposed between the circularly polarizing layers 21 is the same as the preferable aspect of the isotropic layer that may be disposed between the retardation layer and the cholesteric liquid crystal layer. It is.

Although the circularly polarizing layer of the present invention contained in the laminate of the circularly polarizing layer of the present invention may or may not contain the substrate, the above mentioned that is included in the laminated body of the circularly polarizing layer of the present invention. The substrate preferably has a small number of layers from the viewpoint of thinning, and more preferably one layer.
The laminate of the circularly polarizing layer of the present invention may have a λ / 2 retardation layer on the incident side of the circularly polarizing layer. Since the λ / 2 retardation layer reverses the direction of rotation of the circularly polarized light, it is used as a laminated body of the reversely rotated circularly polarizing layer when such a structure is used alone. It becomes possible to do.

<Optical characteristics of a laminate of circularly polarizing layers>
The preferable aspect of the optical characteristics of the laminate of the circularly polarizing layer of the present invention is the same as the preferable aspect of the optical characteristics of the circularly polarizing layer of the present invention.
The plurality of circularly polarizing layers of the present invention contained in the laminate of the circularly polarizing layer of the present invention preferably have mutually different selective reflection wavelengths. That the selective reflection wavelengths of the circularly polarizing layers are different from each other means that the difference of the selective reflection wavelengths of the circularly polarizing layers exceeds 20 nm. However, when there are a plurality of selective reflection wavelengths of the circular polarizing layer, it means that all the selective reflection wavelengths of one circular polarizing layer are different from any of the selective reflection wavelengths of the other circular polarizing layer by more than 20 nm. .
The number of the plurality of circularly polarizing layers of the present invention having different selective reflection wavelengths contained in the laminate of the circularly polarizing layer of the present invention is not particularly limited and can be appropriately determined. For example, the selective reflection wavelength of the laminate of the circularly polarizing layer of the present invention is two or more selected from wavelengths corresponding to R, G, and B (630 nm, 550 nm, and 450 nm, respectively). By laminating a plurality of circular polarization layers, the wavelengths corresponding to R, G, and B of the left-eye circular polarization signal and the right-eye circular polarization signal output from the video drive unit of the 3D image viewing system are selectively selected. It is preferable from the viewpoint of reflection.
The difference in the selective reflection wavelength (peak wavelength) between the circularly polarizing layers of the present invention is not particularly limited, and can be appropriately changed according to the band of the selective reflection wavelength. It is particularly preferred.

<Method for producing laminate of circularly polarizing layer>
The method for producing the laminate of the circularly polarizing layer of the present invention is not particularly limited. For example, when producing a laminate of the circularly polarizing layer having two circularly polarizing layers of the present invention, the first cholesteric liquid crystal layer and the After manufacturing the first circularly polarizing layer of the present invention having one retardation layer by the above method, the second cholesteric liquid crystal layer for forming the circularly polarizing layer of the second present invention, A second retardation layer for forming the circularly polarizing layer of the present invention is prepared by the above-described method, an adhesive is applied to the surface of the retardation layer in the circularly polarizing layer of the first invention, A second cholesteric liquid crystal layer for forming the circularly polarizing layer of the second aspect of the present invention is bonded onto the adhesive material, an adhesive material is applied to the surface of the second cholesteric liquid crystal layer, and the adhesive material is formed on the adhesive material. The second retardation layer for forming the circularly polarizing layer of the second aspect of the present invention is bonded and manufactured. Door can be.
Further, in the case of producing a circularly polarizing layer laminate having a single substrate, after the second cholesteric liquid crystal layer and the second retardation layer are bonded together by the above procedure, the second cholesteric liquid crystal layer It can be manufactured by peeling off the substrate used when manufacturing the second retardation layer and then applying the adhesive material.
Further, as another method for producing the laminate of the circularly polarizing layer of the present invention, rubbing is performed on a substrate, a first cholesteric liquid crystal layer is formed thereon, and then rubbing is performed thereon. A first retardation layer is formed on the substrate, rubbing is performed thereon, a second cholesteric liquid crystal layer is formed thereon, rubbing is performed thereon, and a second retardation layer is formed thereon. The method of manufacturing the laminated body of a circularly-polarizing layer by repeating such a process is also mention | raise | lifted.
Further, as another method of manufacturing the laminate of the circularly polarizing layer of the present invention, rubbing is performed on a substrate, a first cholesteric liquid crystal layer is formed thereon, and a photo-alignment layer is applied thereon. Formed by polarized UV irradiation, a first retardation layer is formed thereon, a second cholesteric liquid crystal layer is formed thereon, and a photo-alignment layer is formed thereon by coating and polarized UV irradiation, There is also a method for producing a laminated body of circularly polarizing layers by repeatedly performing a process of forming a second retardation layer thereon.

[Glasses]
The glasses of the present invention have a left eye polarizing layer and a right eye polarizing layer, and at least one of the left eye polarizing layer and the right eye polarizing layer reflects right circularly polarized light, and Transmits polarized light, and one of the left-eye polarizing layer and the right-eye polarizing layer reflects left-circular polarized light and transmits right-circularly-polarized light, and the left-eye polarizing layer and the right-eye polarizing layer. At least one of the polarizing layers has the circularly polarizing layer of the present invention or the laminate of the circularly polarizing layers of the present invention.
With such a configuration, crosstalk can be sufficiently reduced when used as glasses for a circularly polarized 3D image viewing system. In addition, the glasses of the 3D image viewing system using the circularly polarized light display the left-eye and right-eye polarized images (the left-eye circularly-polarized signal and the right-eye circularly-polarized signal), respectively, and the left and right eyes of the observer. Used to make each incident on the eye. For example, when the left-eye circular polarization signal output from the video driver of the 3D image viewing system is left-circular polarization and the right-eye circular polarization signal is right-circular polarization, the glasses for the left eye of the present invention The polarizing layer reflects right circularly polarized light and transmits left circularly polarized light, and the right eye polarizing layer reflects left circularly polarized light and transmits right circularly polarized light. A 3D image is obtained.

In the glasses of the present invention, it is preferable that both the left-eye polarizing layer and the right-eye polarizing layer have the circularly polarizing layer of the present invention or the laminate of the circularly polarizing layers of the present invention.
Further, the polarizing layer for one eye of the glasses of the present invention is a cholesteric alignment in which the cholesteric liquid crystal layer of the circularly polarizing layer of the present invention or the laminate of the circularly polarizing layer of the present invention is twisted in the left direction or twisted in the right direction. More preferably, it has a structure.
When the eyeglasses of the present invention are configured not to use the λ / 2 layer, the eyeglasses of the present invention have another circular polarizing layer of the present invention in which the twist direction of the cholesteric alignment structure is different from the polarizing layer for the other eye. It is particularly preferable to use the circularly polarizing layer laminate of the present invention.
On the other hand, when the glasses of the present invention are configured to use a λ / 2 layer, the glasses of the present invention are different from the circles of the present invention in which the twist direction of the cholesteric alignment structure is the same in the polarizing layer for the other eye. It is preferable to use a polarizing layer or a laminate of the circularly polarizing layers of the present invention. Here, when the glasses of the present invention are configured to use a λ / 2 layer, at least one of the left-eye polarizing layer and the right-eye polarizing layer is the circularly polarizing layer of the present invention or the circularly polarized light of the present invention. The other is arranged on the incident light side of the circularly polarizing layer of the invention or the laminated body of the circularly polarizing layer of the invention and the circularly polarizing layer or the laminated body of the circularly polarizing layers. A structure having a λ / 2 layer is preferable.

The glasses of the present invention can have a configuration in which the left-eye polarizing layer and the right-eye polarizing layer are fixed to an arbitrary frame. Further, the glasses of the present invention are obtained by laminating a left-eye polarizing layer and a right-eye polarizing layer on the left-eye and right-eye lenses other than the glasses of the circularly polarized 3D image viewing system. It is good also as the structure which attached. Specific examples of the glasses other than the glasses of the circularly polarized 3D image viewing system include normal glasses for nearsightedness, farsightedness, astigmatism, and presbyopia. Also, it has a lens with no degree (may be a transparent lens, or a lens that can shield non-polarized light or polarized light, such as sunglasses), or it has only a frame without a lens. The so-called Date glasses can also be mentioned.
In addition, for example, the configuration of the glasses described in JP 2012-32527 A and JP 2-48634 A can be applied to the glasses of the present invention as long as it does not contradict the gist of the present invention.

(Use)
The glasses of the present invention are preferably used as glasses for a circularly polarized 3D image viewing system. For example, the glasses can be used in the 3D image viewing system of the present invention described later.

[3D image appreciation system]
The 3D image viewing system of the present invention includes the glasses of the present invention and an image driving unit that outputs a circularly polarized signal for left eye and a circularly polarized signal for right eye, and the polarizing layer for the left eye of the glasses is the Transmitting the left-eye circular polarization signal output from the video driver, reflecting the right-eye circular polarization signal, and reflecting the right-eye polarization layer of the glasses from the video driver The circularly polarized signal for the left eye is transmitted and the circularly polarized signal for the left eye is reflected.
With such a configuration, crosstalk can be sufficiently reduced.
In a 3D image viewing system that uses glasses of a circularly polarized 3D image viewing system, a left-eye image and a right-eye image (a left-eye circular polarization signal and a right-eye circular polarization) that are provided with a parallax in advance. Signal) is displayed on the display or alternately projected by the projector, and the left and right eyes can see only the image for the left eye and the image for the right eye, respectively, by viewing the display through each polarizing layer of the glasses of the present invention. And a stereoscopic effect can be obtained.
There is no restriction | limiting in particular as an image drive part which outputs the said circular polarization signal for left eyes, and the circular polarization signal for right eyes, A well-known apparatus can be used. For example, the configuration of the display device described in Japanese Patent No. 4508280, Japanese Patent Application Laid-Open No. 2012-256028, Japanese Patent Application Laid-Open No. 2-48634, the projectors of Special Tables 2010-509629 and Special Tables 2010-528323 is included in the spirit of the present invention. As long as it is not contrary, it can be applied to the video drive unit of the 3D image viewing system of the present invention.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Evaluation method]
(1) Measuring method of selective reflection wavelength of cholesteric liquid crystal layer On an optical surface plate, Xe lamp light source LAX-102 manufactured by Asahi Spectroscopic Co., Ltd., pinhole, convex lens, sample holder, Hamamatsu Photonics Co., Ltd. Multi-channel spectrometer PMA-12 manufactured by the company was arranged in order, and a transmittance measuring optical system using a parallel light source was assembled. The sample was set in the sample holder and the transmission spectrum was measured.
The average value of the two wavelengths on the long-wave side and the short-wave side of the half-value transmittance T1 / 2 (%) by selective reflection of the cholesteric liquid crystal layer represented by the following formula was used as the selective reflection wavelength of the cholesteric liquid crystal layer.
Formula for calculating half-value transmittance: T1 / 2 = 100- (100-Tmin) / 2
Tmin (%): Minimum value of transmittance

(2) Measuring method of retardation of retardation layer A retardation layer sample is set on an automatic birefringence meter (KOBRA-21ADH: manufactured by Oji Scientific Instruments) with the base material removed, and the position at a desired wavelength is set. The phase difference was measured.

(3) Measurement method of crosstalk value On an optical surface plate, Xe lamp light source LAX-102 manufactured by Asahi Spectroscopy Co., Ltd., pinhole, convex lens, and circular polarization conversion manufactured by Biei Imaging Co., Ltd. The circularly polarizing plate (right circularly polarizing plate TCPR or left circularly polarizing plate TCPL), a sample holder, and a multi-channel spectrometer PMA-12 manufactured by Hamamatsu Photonics Co., Ltd. are arranged in order, and transmittance measurement using circularly polarized light is performed. The optical system was assembled. The circularly polarizing layer samples of the examples and comparative examples were set in the sample holder and subjected to spectroscopic measurement, and the transmission spectrum at the time of circularly polarized light irradiation was measured. As a circularly polarizing plate for circularly polarizing conversion, a circularly polarizing plate (right circularly polarizing plate TCPR or left circularly polarizing plate TCPL) in which the obtained circularly polarized light is shielded in combination with the cholesteric liquid crystal layer in the circularly polarizing layers of the examples and comparative examples. Any of the above was used. The circularly polarized light transmittance at the selective reflection wavelength of the cholesteric liquid crystal layer in the circularly polarizing layer of each of the examples and the comparative examples when the light-shielding combination was used in this way was defined as a crosstalk value.
When the circularly polarizing layer sample has a retardation layer, the retardation layer is positioned on the incident light side (light source side) of the cholesteric liquid crystal layer, and the base film is positioned on the side far from the light source. . On the other hand, when the circularly polarizing layer sample did not have a retardation layer, the cholesteric liquid crystal layer was positioned on the incident light side (light source side) and the base film was positioned on the side far from the light source.

[Example 1]
<Manufacture of base film>
A PET film (no undercoat layer, manufactured by Fuji Film Co., Ltd., thickness: 75 μm) is prepared, and rubbing treatment (rayon cloth, pressure: 0.1 kgf, rotation speed: 1000 rpm, conveyance speed: 10 m / min, number of times: 1 reciprocation) )

<Preparation of right-handed cholesteric liquid crystalline mixture>
Methyl ethyl ketone was mixed as the following compound A, compound B, fluorine-based horizontal alignment agent, chiral agent, polymerization initiator and solvent to prepare a coating solution having the following composition. The obtained coating liquid was designated as a right-handed cholesteric liquid crystalline mixture (R1).
-80 mass parts of the following compound A-20 mass parts of the following compound B-0.04 mass parts of the following fluorine-based horizontal alignment agent-Chiral agent LC756 (manufactured by BASF)
The amount of the mixture is appropriately adjusted according to the desired selective reflection wavelength described in Table 1 below. Polymerization initiator IRGACURE 819 (manufactured by Ciba Japan) 3 parts by mass Solvent (methyl ethyl ketone) Amount that the solute concentration is 25% by mass

Fluorine-based horizontal alignment agent: Compound described in JP-A-2005-99248

<Preparation of right-handed cholesteric liquid crystal layer>
A cholesteric liquid crystal layer formed by fixing the cholesteric liquid crystal phase on the base film using the right-handed cholesteric liquid crystal mixture (R1) by the following procedure was produced.
(1) The right-handed cholesteric liquid crystalline mixture (R1) is made of the above-mentioned base so as to have a predetermined film thickness after drying using a wire bar (thickness to obtain the number of windings shown in Table 1 below). It apply | coated on the material film at room temperature.
(2) After drying at room temperature for 30 seconds to remove the solvent, the liquid crystal was aligned by heating at 90 ° C. for 2 minutes. Next, UV irradiation was performed for 6 to 12 seconds at an output of 60% under a nitrogen purge with an electrodeless lamp “D bulb” (90 mW / cm) manufactured by Fusion UV Systems Co., Ltd. to fix the cholesteric liquid crystal phase. A right-handed cholesteric liquid crystal layer having a selective reflection wavelength λmax shown in Table 1 below and a film thickness of 3.40 μm fixed on the film was prepared.
Based on the following formula, the number of spiral turns of the obtained cholesteric liquid crystal layer was converted from the film thickness of the cholesteric liquid crystal layer and the selective reflection wavelength of the cholesteric liquid crystal layer with an average refractive index = 1.575.
Number of spiral turns in cholesteric liquid crystal layer = film thickness x average refractive index / selective reflection wavelength

<Preparation of retardation layer liquid crystalline mixture>
A retardation layer was prepared in the same manner as in the preparation of the right-handed cholesteric liquid crystalline mixture, except that the chiral agent LC756 of the right-handed cholesteric liquid crystalline mixture (R1) was removed and the solute concentration was lowered by increasing the amount of solvent according to the film thickness. A liquid crystal mixture (P1) was prepared.

<Preparation of retardation layer>
Table 1 below shows the same as the right-handed cholesteric liquid crystal mixture (R1) except that the cholesteric liquid crystalline mixture (R1) was changed to the retardation layer liquid crystalline mixture (P1) in the production of the right-handed cholesteric liquid crystal layer. The film thickness was adjusted to 0.22 μm so as to achieve the predetermined retardation described, and a retardation layer was produced on the base film. The obtained retardation layer had a twist angle of 0 °.

<Production of a circularly polarizing layer having a single cholesteric liquid crystal layer>
An adhesive sheet was attached to the upper surface of the cholesteric liquid crystal layer provided on the base film.
On the pressure-sensitive adhesive sheet, the retardation layer provided on the base film produced as described above was attached with the predetermined in-plane angle shown in Table 1 below, with the retardation layer facing the pressure-sensitive adhesive sheet. It was. The base film of the retardation layer was removed, and a circularly polarizing layer in which the base film, the right-handed cholesteric liquid crystal layer, and the retardation layer were laminated in this order and the cholesteric liquid crystal layer was a single layer was produced. The obtained circularly polarizing layer was used as the circularly polarizing layer of Example 1.

<Crosstalk measurement of a circular polarizing layer with a single layer configuration>
Using the circularly polarizing layer of Example 1 as a sample, crosstalk was measured by placing the base film surface on the side far from the light source according to the measurement method described above. The obtained results are shown in Table 1 below.

[Examples 2 and 3]
In Example 1, a cholesteric liquid crystal layer was prepared by changing the addition amount of the chiral agent according to the desired selective reflection wavelength described in Table 1 below, and the film thickness was adjusted so as to satisfy the retardation described in Table 1 below. The circularly polarizing layers of Examples 2 and 3 were produced in the same manner as in Example 1 except that the retardation layer was produced by changing. Using the circularly polarizing layers of Examples 2 and 3 as samples, crosstalk was measured according to the measurement method described above. The obtained results are shown in Table 1 below.

[Example 4]
<Preparation of left-handed cholesteric liquid crystalline mixture>
Example except that the chiral agent LC756 of the right-handed cholesteric liquid crystalline mixture (R1) is changed to the left-turning chiral agent (A) having the following structure, and the amount of the mixture is appropriately adjusted according to the desired selective reflection wavelength The left-handed cholesteric liquid crystalline mixture (L1) was prepared in the same manner as the preparation of the right-handed cholesteric liquid crystalline mixture in No. 1.

<Production of circularly polarizing layer>
The left-handed cholesteric liquid crystalline mixture (R1) was used instead of the right-handed cholesteric liquid crystalline mixture (R1), and the addition amount of the chiral agent was changed in accordance with the desired selective reflection wavelength described in Table 1 below in Example 1. Then, a cholesteric liquid crystal layer was produced, and the circularly polarizing layer of Example 4 was prepared in the same manner as in Example 1 except that the retardation layer was produced by changing the film thickness so as to satisfy the retardation described in Table 1 below. Was made. Using the circularly polarizing layer of Example 4 as a sample, crosstalk was measured according to the measurement method described above. The obtained results are shown in Table 1 below.

[Comparative Examples 1-4]
In Examples 1 to 4, circularly polarizing layers of Comparative Examples 1 to 4 were produced in the same manner as Examples 1 to 4 except that no retardation layer was provided. Using the circularly polarizing layers of Comparative Examples 1 to 4 as samples, crosstalk was measured according to the measurement method described above. The obtained results are shown in Table 1 below.

[Examples 5 to 8, Examples 9-1 to 9-3 and Comparative Examples 5 to 8]
<Calculation of crosstalk by simulation>
The cholesteric liquid crystal layers having the selective reflection wavelength, the winding direction, and the number of turns described in Table 1 below and the positions described in Table 1 below were approximated to the cholesteric liquid crystal layers prepared in Examples 1 to 4 and Comparative Examples 1 to 4. For the circularly polarizing layers of Examples 5 to 8, Examples 9-1 to 9-3 and Comparative Examples 5 to 8 having phase differences and in-plane angles, the BERREMANN 4 × 4 method is used using an optical simulator LCDMaster manufactured by Shintech. I had a simulation. Specifically, when light of various wavelengths of R light, G light, and B light is incident on the circularly polarizing layers of Examples 5 to 8, Examples 9-1 to 9-3, and Comparative Examples 5 to 8 The transmittance was calculated, and the value was defined as crosstalk (the in-plane angle of the retardation layer was adjusted so that the circularly polarized light transmittance at the selective reflection wavelength was minimized. The results are shown in Table 1 below). In addition, Example 5 and Examples 9-1 to 9-3 correspond to the cases of n = 0, 1, 2, and 3 in Formula (1), respectively.
The results of Examples 5 to 8, Examples 9-1 to 9-3 and Comparative Examples 5 to 8 are shown in the “Calculation” column of Table 1 below.

[Reference Example 1]
<Measured value of crosstalk of conventional circular polarizing plate for 3D glasses>
Crosstalk of a known conventional circular polarizing plate for 3D glasses comprising a linear polarizing plate and a λ / 4 layer was measured by the same method as described above. The results are shown in Table 2 below.

From Table 1, it was found that the cross-talk was sufficiently improved in the circularly polarizing layer of the present invention.
On the other hand, from Comparative Examples 1 to 8, it was found that the crosstalk was not sufficiently improved when no retardation layer was provided.
In addition, in the circularly polarizing layers of Examples 1 to 8 and Examples 9-1 to 9-3, the twist angle and the tilt angle of the retardation layer were both 0 °.
Further, Re of the base film and the pressure-sensitive adhesive sheet is almost 0, and there is almost no influence on the optical characteristics.

[Example 11]
<Production level and crosstalk measurement value of cholesteric liquid crystal layer laminated circularly polarizing layer (retardation layer + multiple cholesteric liquid crystal layer laminated circularly polarizing layer)>
(Production of laminated cholesteric liquid crystal layer)
A cholesteric liquid crystal layer (R1) is used to laminate and fix a cholesteric liquid crystal phase by the following procedure, and a cholesteric liquid crystal layer in which two cholesteric liquid crystal layers are fixed on a base film. A liquid crystal layer was produced.
(1) A right-handed cholesteric liquid crystalline mixture (R1) in which the amount of chiral agent is adjusted to show the selective reflection wavelength of the second cholesteric liquid crystal layer from the incident light side in Table 3 below using a wire bar. And it apply | coated on the said base film at room temperature so that it might become the thickness (number of winding of Table 3 below) of the film | membrane after predetermined drying.
(2) After drying at room temperature for 30 seconds to remove the solvent, the liquid crystal was aligned by heating at 90 ° C. for 2 minutes. Next, UV irradiation was performed for 6 to 12 seconds at an output of 60% under a nitrogen purge with an electrodeless lamp “D bulb” (90 mW / cm) manufactured by Fusion UV Systems Co., Ltd. to fix the cholesteric liquid crystal phase. A liquid crystal layer (second cholesteric liquid crystal layer counted from the incident light side) formed by fixing a cholesteric liquid crystal phase having a selective reflection wavelength λmax shown in Table 3 below and a film thickness of 4.07 μm on the film Produced.
(3) In the same procedure as steps (1) and (2) above, on the second cholesteric liquid crystal layer counted from the retardation layer side instead of the base film, 1 from the incident light side in Table 3 below The right-handed cholesteric liquid crystal mixture (R1), in which the amount of the chiral agent is adjusted so as to show the selective reflection wavelength of the first cholesteric liquid crystal layer, is obtained from the incident light side shown in Table 3 below. The resulting cholesteric liquid crystal layer was applied so as to have a thickness of the number of turns, and the first cholesteric liquid crystal layer counted from the incident light side was provided to produce a laminated cholesteric liquid crystal layer.

(Production of retardation layer)
A retardation layer was produced in the same manner as in Example 1 except that the retardation layer was produced by changing the amount of film thickness so that the retardation described in Table 3 below was satisfied in Example 1.

(Production of single-layered cholesteric liquid crystal layer laminated circularly polarizing layer (retardation layer + multiple cholesteric liquid crystal layer laminated circularly polarizing layer))
An adhesive sheet was attached to the upper surface of the cholesteric liquid crystal layer (first cholesteric liquid crystal layer counted from the incident light side) of the laminated cholesteric liquid crystal layer.
On the pressure-sensitive adhesive sheet, the retardation layer provided on the base film produced above was pasted with the predetermined in-plane angles shown in Table 3 below, with the retardation layer facing the pressure-sensitive adhesive sheet. . Remove the base film of the retardation layer, base film, right-handed cholesteric liquid crystal layer (second cholesteric liquid crystal layer counted from the incident light side), right-handed cholesteric liquid crystal layer (first layer counted from the incident light side) The cholesteric liquid crystal layer) and the retardation layer were laminated in this order to produce a single-layered cholesteric liquid crystal layer laminated circularly polarizing layer. The obtained circularly polarizing layer was used as the circularly polarizing layer of Example 11.

(Crosstalk measurement)
The circularly polarizing layer of Example 11 was used as a sample, and the crosstalk was measured by arranging the base film so as to be positioned on the side far from the light source in accordance with the measurement method described above. The obtained results are shown in Table 3 below.
In Table 3 below, the crosstalk “first layer” data is the selective reflection wavelength λmax (447 nm) of the first cholesteric liquid crystal layer from the first retardation layer side to the circularly polarizing layer of Example 11. The data of the second layer of crosstalk is the selective reflection wavelength λmax of the second cholesteric liquid crystal layer from the first retardation layer side with respect to the circularly polarizing layer of Example 11. It represents the transmittance when measured at (634 nm).

[Comparative Example 11]
In Example 11, a circularly polarizing layer of Comparative Example 11 was produced in the same manner as in Example 11 except that the retardation layer was not provided. Using the circularly polarizing layer of Comparative Example 11 as a sample, crosstalk was measured in the same manner as in Example 11 according to the measurement method described above. The obtained results are shown in Table 3 below.

In Table 3 above, λmax used in the calculation of Re / λmax for retardation retardation of the first retardation layer indicates the selective reflection wavelength λmax of the first cholesteric liquid crystal layer counted from the incident light side.
From Table 3 above, it was found that the circularly polarizing layer of Example 11 in which the correction retardation layer was provided on the light source side was sufficient to reduce crosstalk with respect to the sample in which the cholesteric liquid crystal layer was laminated.
In the circularly polarizing layer of Example 11, the twist angle and tilt angle of the first retardation layer were both 0 °.
Further, Re of the base film and the pressure-sensitive adhesive sheet is almost 0, and there is almost no influence on the optical characteristics.

[Example 21]
<Preparation of a laminate of circularly polarizing layers>
A single-layer film of each retardation layer and cholesteric liquid crystal layer having the characteristics described in Table 4 below was prepared according to the same method as in each of the above examples, and in the predetermined stacking order described in Table 4 below through an adhesive sheet. Each of the retardation layers and the cholesteric liquid crystal layer was stuck at a predetermined in-plane angle shown in Table 4 below, and then the base film was removed, thereby producing a laminated film body of circularly polarizing layers. The obtained laminate of circularly polarizing layers was used as the laminate of circularly polarizing layers of Example 21.

[Comparative Example 21]
<Preparation of a laminate of circularly polarizing layers>
In Example 21, a circularly polarizing layer laminate of Comparative Example 21 was produced in the same manner as Example 21 except that no retardation layer was provided. Using the laminate of the circularly polarizing layers of Comparative Example 21 as a sample, crosstalk was measured in the same manner as in Example 21 according to the measurement method described above. The obtained results are shown in Table 4 below.

<Measured value of crosstalk>
The circularly polarizing layer of Example 21 was used as a sample, and the crosstalk was measured by arranging the base film so as to be positioned on the side far from the light source according to the measurement method described above. The obtained results are shown in Table 4 below.
In Table 4 below, the data of “first layer” of crosstalk is the selective reflection wavelength λmax (550 nm) of the first cholesteric liquid crystal layer from the first retardation layer side to the circularly polarizing layer of Example 21. The crosstalk “second layer” data represents the measured transmittance and the selective reflection wavelength λmax of the second cholesteric liquid crystal layer from the first retardation layer side with respect to the circularly polarizing layer of Example 21. This represents the transmittance when measured at (634 nm), and the data of the “third layer” of crosstalk is that of the third cholesteric liquid crystal layer from the first retardation layer side with respect to the circularly polarizing layer of Example 21. It represents the transmittance when measured at a selective reflection wavelength λmax (447 nm).

In Table 4, λmax used for calculating Re / λmax of retardation of each retardation layer indicates λmax of the cholesteric liquid crystal layer adjacent to the side farther from the light source.
From Table 4 above, the circularly polarizing layer of Example 21 in which the correction retardation layer is provided on the light source side for each cholesteric liquid crystal layer with respect to the sample in which the cholesteric liquid crystal layer is laminated, has sufficient crosstalk reduction. I understood.
In addition, in the circularly polarizing layer of Example 21, the twist angle and tilt angle of the first, second, and third retardation layers were both 0 °.
Further, Re of the base film and the pressure-sensitive adhesive sheet is almost 0, and there is almost no influence on the optical characteristics.

[Examples 101 to 111, Comparative Examples 101 and 102]
Examples 101 to 111 having the selective reflection wavelength, the winding direction and the number of turns described in Table 5 below, the phase difference, the in-plane angle at the center and the twist angle described in Table 5 below, and Comparative Example 101 and About 102 circularly polarizing layers, crosstalk was calculated | required according to the above-mentioned measuring method by the simulation using BERREMANN 4 * 4 method using the optical simulator LCDMaster made from Shintec, and the phase difference dependence of the phase difference layer was examined. . The obtained results are shown in Table 5 below.
The in-plane angle of the retardation layer was adjusted so that the selective reflection wavelength circularly polarized light transmittance was minimized.

From Table 5 above, it was found that the circularly polarizing layers of Examples 101 to 111 had a crosstalk (circularly polarized light transmittance) of 2.5% or less at 550 nm in Reference Example 1 and could sufficiently reduce the crosstalk.
On the other hand, the circularly polarizing layer of Comparative Example 101 provided with the retardation layer having a retardation value with Re / λmax lower than the range of the present invention had a large crosstalk. The circularly polarizing layer of Comparative Example 102 provided with a retardation layer having a retardation value with Re / λmax exceeding the range of the present invention had large crosstalk.
In the circularly polarizing layers of Examples 101 to 111 and Comparative Examples 101 and 102, the tilt angle of the retardation layer was all 0 °.

[Examples 201 to 207]
<Twist angle dependency of retardation layer>
Regarding the cholesteric liquid crystal layer having the selective reflection wavelength, the winding direction, and the number of turns described in Table 6 below, and the circularly polarizing layer of Examples 201 to 207 having the phase difference, the in-plane angle at the center, and the twist angle described in Table 6 below The crosstalk was obtained according to the above measurement method by simulation using the BERREMANN 4 × 4 method using an optical simulator LCDMaster manufactured by Shintech Co., Ltd., and the twist angle dependence of the retardation layer was examined. The obtained results are shown in Table 6 below. For manufacturing convenience, a twist angle may be generated by twisting the refractive index of the retardation layer.
The in-plane angle of the retardation layer was adjusted so that the selective reflection wavelength circularly polarized light transmittance was minimized.

From Table 6 above, the circularly polarizing layer of Examples 201 to 207 within the twist angle ± 90 ° of the retardation layer has a crosstalk (circularly polarized light transmittance) at 550 nm in Reference Example 1 of 2.5% or less, and is sufficiently It was found that crosstalk can be reduced.
In the circularly polarizing layers of Examples 201 to 207, the tilt angle of the retardation layer was 0 °.

[Examples 301 to 306]
<Tilt angle dependency>
Regarding the cholesteric liquid crystal layer having the selective reflection wavelength, winding direction, and number of windings described in Table 7 below, and the circularly polarizing layer of Examples 301 to 306 having the phase difference, the in-plane angle at the central portion, and the tilt angle described in Table 7 below. Using the optical simulator LCDMaster manufactured by Shintech Co., Ltd., the crosstalk was obtained according to the above-mentioned measurement method by simulation using the BERREMANN 4 × 4 method, and the tilt angle dependency of the retardation layer was examined. The obtained results are shown in Table 7 below. For manufacturing convenience, a tilt angle may occur in the maximum direction of the refractive index of the retardation layer.
The in-plane angle of the retardation layer was adjusted so that the selective reflection wavelength circularly polarized light transmittance was minimized.

From Table 7 above, the circularly polarizing layers of Examples 301 to 306 in which the tilt angle of the retardation layer is 40 ° or less have a crosstalk (circularly polarized light transmittance) of 2.5% or less at 550 nm in Reference Example 1, and are sufficiently crossed. It was found that talk can be reduced.
In the circularly polarizing layers of Examples 301 to 306, the twist angle of the retardation layer was all 0 °.

[Examples 401 to 425]
<Number of turns dependency>
Regarding the cholesteric liquid crystal layer having the selective reflection wavelength, the winding direction, and the number of turns described in Table 8 below, and the circularly polarizing layer of Examples 401 to 425 having the phase difference, the in-plane angle at the center, and the twist angle described in Table 8 below The crosstalk was obtained according to the above measurement method by simulation using the BERREMANN 4 × 4 method using an optical simulator LCDMaster manufactured by Shintech Co., Ltd., and the twist angle dependence of the retardation layer was examined. The obtained results are shown in Table 8 below.
The in-plane angle of the retardation layer was adjusted so that the selective reflection wavelength circularly polarized light transmittance was minimized.

From Table 8 above, the circularly polarizing layer of Examples 401 to 425 in which the number of spiral turns of the retardation layer is 9 or more is less than 2.5% of the crosstalk (circularly polarized light transmittance) at 550 nm in Reference Example 1 and is sufficient. It was found that crosstalk can be reduced.
Furthermore, from Table 8 above, when the number of turns of the retardation layer and the twist angle dependency are estimated, when the twist angle is set to 30 degrees, the crosstalk may be slightly deteriorated when the number of turns of the retardation layer is the same. all right.
In the circularly polarizing layers of Examples 401 to 425, the tilt angle of the retardation layer was 0 °.

1, 1a, 1b, 1c Cholesteric liquid crystal layer 2 1 turn of cholesteric liquid crystal 3 Part in contact with phase difference layer 4 Liquid crystal director direction 11, 11 a, 11 b, 11 c in phase difference layer in part in contact with phase difference layer A portion 13 of the retardation layer in contact with the cholesteric liquid crystal layer 13 A portion of the retardation layer opposite to the portion 12 in contact with the cholesteric liquid crystal layer 14 A reference direction 15 of the retardation layer In contact with the cholesteric liquid crystal layer of the retardation layer The in-plane maximum direction 16 of the refractive index in the portion where the phase difference is present. The in-plane angle 17 of the retardation layer. The tilt angle 18 of the retardation layer. The in-plane angle 19 in the portion 12 in contact with the cholesteric liquid crystal layer of the retardation layer. In-plane angle 20 in the portion 13 on the opposite side of the contacted portion 20 Thickness direction central portion 21 of the retardation layer 21 Circularly polarizing layer 22 Stacking of circularly polarizing layers Body 31 Direction of incident light (perpendicular to the surface of retardation layer and cholesteric liquid crystal layer)
32 Transmitted light 41 Isotropic layer

Claims (15)

A cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase;
The cholesteric liquid crystal layer and a retardation layer disposed directly or via an isotropic layer,
A circularly polarizing layer satisfying the following formula (1).
Formula (1)
(2.5 / 64) + n ≦ Re / λmax ≦ (6/64) + n
(In the formula (1), Re represents retardation in the in-plane direction of the retardation layer at a wavelength λmax (unit: nm), λmax represents a selective reflection wavelength (unit: nm) of the cholesteric liquid crystal layer, and n Represents an integer of 0 or more.)   The circularly polarizing layer according to claim 1, wherein n in the formula (1) is 0.   3. The circularly polarizing layer according to claim 1, wherein the cholesteric liquid crystal layer has a selective reflection wavelength λmax of 300 nm to 2500 nm.   The circularly polarizing layer according to any one of claims 1 to 3, wherein the number of helical turns of the cholesteric alignment structure of the cholesteric liquid crystal layer is 8 or more.   5. The circularly polarizing layer according to claim 1, wherein the retardation layer has a tilt angle of 0 ° to 50 ° (provided that the tilt angle of the retardation layer is a retardation). This is the angle between the maximum refractive index direction of the layer and the surface of the retardation layer).   The circularly polarizing layer according to any one of claims 1 to 5, wherein the twist angle of the retardation layer (wherein the twist angle of the retardation layer is a position) A value obtained by subtracting the in-plane angle at the surface of the portion of the retardation layer in contact with the cholesteric liquid crystal layer from the in-plane angle at the surface of the portion opposite to the portion in contact with the cholesteric liquid crystal layer. The in-plane angle of the surface of the retardation layer is the direction of the liquid crystal director on the surface of the cholesteric liquid crystal layer on the phase difference layer side and the direction in which the maximum direction of the refractive index of the retardation layer is orthogonally projected onto the surface of the retardation layer. (The rotation direction of the cholesteric liquid crystal layer viewed from the retardation layer side is the same as the helical rotation direction as the positive rotation direction of the in-plane angle of the retardation layer.)   The circularly polarizing layer according to claim 1, wherein the retardation layer is disposed closer to the incident light side than the cholesteric liquid crystal layer.   The circularly polarizing layer according to any one of claims 1 to 7, wherein two or more cholesteric liquid crystal layers are laminated.   The circularly polarizing layer according to any one of claims 1 to 8, wherein the retardation layer is a liquid crystal film in which alignment of liquid crystal molecules is fixed.   A laminate of circularly polarizing layers, wherein two or more circularly polarizing layers according to any one of claims 1 to 9 are laminated. A left eye polarizing layer and a right eye polarizing layer;
At least one of the left eye polarizing layer and the right eye polarizing layer reflects right circularly polarized light and transmits left circularly polarized light,
The other one of the left eye polarizing layer and the right eye polarizing layer reflects left circularly polarized light and transmits right circularly polarized light,
At least one of the polarizing layer for the left eye and the polarizing layer for the right eye has the circularly polarizing layer according to any one of claims 1 to 9 or the laminate of the circularly polarizing layers according to claim 10. Glasses characterized by.   The glasses according to claim 11, wherein the cholesteric liquid crystal layer has a cholesteric alignment structure having a leftward twist or a rightward twist.   The left-eye polarizing layer and the right-eye polarizing layer both have the circularly polarizing layer according to any one of claims 1 to 9 or the laminate of the circularly polarizing layers according to claim 10. The glasses according to claim 11 or 12. At least one of the polarizing layer for left eye and the polarizing layer for right eye has the circularly polarizing layer according to any one of claims 1 to 9 or the laminate of the circularly polarizing layers according to claim 10. ;
The other one is incident light of the circularly polarizing layer according to any one of claims 1 to 9, or the laminate of the circularly polarizing layer according to claim 10 and the circularly polarizing layer or the laminate of the circularly polarizing layer. The glasses according to claim 11, further comprising a λ / 2 layer disposed on the side. Glasses according to any one of claims 11 to 14,
An image drive unit that outputs a circular polarization signal for the left eye and a circular polarization signal for the right eye,
The left-eye polarization layer of the glasses transmits the left-eye circular polarization signal output from the video driver, and the right-eye circular polarization signal is reflected.
The 3D image appreciation system, wherein the right-eye polarizing layer of the glasses transmits the right-eye circular polarization signal output from the video driving unit and reflects the left-eye circular polarization signal.

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