JP2016133728A - Method for manufacturing laminate, laminate, polarizing plate and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminate that includes a first optical anisotropic layer in which a first liquid crystal composition is subjected to homogeneous alignment and a second optical anisotropic layer in which a second liquid crystal composition is subjected to homeotropic alignment and that has excellent viewing angle characteristics, by which a laminate that can be made extremely thin is manufactured without requiring a complicated manufacturing process.SOLUTION: The method for manufacturing a laminate includes: a step of applying a coating liquid containing a first liquid composition on an alignment substrate (A) and subjecting the first liquid crystal composition to homogeneous alignment to form a first optical anisotropic layer on the alignment substrate (A); a step of laminating the first optical anisotropic layer with a polarizer; a step of removing the alignment substrate (A); a step of applying a coating liquid containing a second liquid crystal composition on an alignment substrate (B) and subjecting the second liquid crystal composition to homeotropic alignment to form a second optical anisotropic layer on the alignment substrate (B); a step of laminating the first optical anisotropic layer with the second optical anisotropic layer; and a step of removing the alignment substrate (B).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laminate manufacturing method, a laminate, a polarizing plate, and an image display device.

  An organic electroluminescence element (hereinafter referred to as an organic EL element) used as a light source of an image display device is a self-luminous element that is excellent in terms of thin and light, low power consumption, high contrast, and high-speed response. R & D and practical use are being promoted as a surface light source for devices. There are several forms of such organic EL elements, but as a main form, a transparent electrode as an anode, an organic light emitting layer, and a metal electrode as a cathode are sequentially laminated on a transparent support substrate. Produced and put to practical use. In such an organic EL element, the voltage applied between the transparent electrode and the metal electrode causes the electrons supplied from the cathode and the holes supplied from the anode to recombine in the organic light emitting layer. The principle that electroluminescence is emitted when the excitons generated therewith shift from the excited state to the ground state is used.

  In the organic EL element, in order to extract light emitted from the organic light emitting layer, at least one of the electrodes must be transparent. Usually, a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is used as the anode. It is used as. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material with a small work function for the cathode, and usually metal electrodes made of metals or alloys such as Al, AlLi, MgAg, MgIn are used. . These metal electrodes generally have high light reflectivity and have a mirror surface structure, so that they not only function as electrodes, but also reflect light emitted in the direction of the metal electrodes by the organic light emitting layer and emit it from the transparent support substrate. It also plays a role in increasing the amount of light and improving the brightness.

  However, the high light reflectance and mirror structure of the metal electrode cause external light reflection. That is, the organic EL element has a problem that the reflection of external light is intense in the presence of strong external light such as illumination or sunlight, and the contrast is remarkably reduced when used as an image display device.

  As a method for preventing external light reflection on a mirror surface, it is known to use a circularly polarizing plate. For example, Patent Documents 1 and 2 disclose a circularly polarizing plate including a polarizing plate and a retardation plate (for example, a quarter wavelength plate). Patent Document 3 discloses a quarter-wave plate constituted by a plurality of birefringent plates. Patent Document 4 discloses a retardation film having so-called “negative dispersion” characteristics. However, when these are applied to a circularly polarizing plate, it functions ideally only for external light incident from the vertical direction on the circularly polarizing plate and the metal electrode, and external light incident from an oblique direction. On the other hand, since the optical path length of the light passing through the phase difference plate becomes long, a deviation occurs from the quarter wavelength, so that it does not function as an ideal circularly polarizing plate. That is, when the image display device using the retardation plate is observed from the front, external light reflection is suppressed by the circularly polarizing plate, but when viewed from an oblique direction, the viewing angle dependency of the circularly polarizing plate causes There is a problem that reflection of external light cannot be suppressed and reflected light is visually recognized. For the above reasons, the organic EL element may have a viewing angle dependency in black display due to the characteristics of the circularly polarizing plate used for the purpose of preventing reflection of external light.

  As a method for suppressing such a phenomenon, for example, Patent Document 5 discloses a polarizing plate in which a quarter-wave plate composed of two organic polymer films is laminated, The first retardation layer having a refractive index characteristic of nx> ny ≧ nz and a so-called “negative dispersion” characteristic, and a refractive index characteristic of nz> nx ≧ ny It has been proposed that viewing characteristics due to external light reflection can be improved by laminating a second retardation layer and applying a polarizing plate having an in-plane retardation of both in a predetermined range to an image display device. .

  However, the first retardation layer and the second retardation layer provided in the circularly polarizing plate disclosed in Patent Document 5 are retardation films formed by uniaxially stretching a polymer film, and have a very high birefringence Δn. Therefore, in order to use it as a quarter wavelength plate, it is necessary to increase the thickness to 50 to 200 μm. In recent years, a retardation layer used for a liquid crystal display device or an organic EL display device has been required to be thinned, and a polymer stretched film having a small birefringence Δn is desired to have a thin film thickness.

  In addition, when a phase layer is formed by using a conventional liquid crystal composition, it is necessary to align the liquid crystal composition on an alignment substrate, and the liquid crystal display device takes into account the thickness of the alignment substrate, resulting in a thin display. It was not able to meet the demands of the development.

Japanese Patent Laid-Open No. 8-322138 JP 2005-289980 A Japanese Patent Laid-Open No. 9-127858 JP 2002-48919 A JP 2014-26266 A

  In order to produce a laminate, the present inventors have now bonded a first optically anisotropic layer comprising a first liquid crystal composition formed on an alignment substrate (A) and a polarizer. After the alignment substrate (A) is peeled off and the second optical anisotropic layer made of the second liquid crystal composition and the first optical anisotropic layer are bonded together, the alignment substrate (B) is removed. It was found that by peeling, a remarkable thinned laminate can be realized without requiring a complicated manufacturing process.

  Accordingly, an object of the present invention is to provide a first optically anisotropic layer in which the first liquid crystal composition is homogeneously aligned, and a second optically anisotropic layer in which the second liquid crystal composition is homeotropically aligned. And a method for manufacturing a laminate that can be more significantly thinned without requiring a complicated manufacturing process.

The method for producing a laminate according to the present invention comprises:
A coating liquid containing the first liquid crystal composition is applied on the alignment substrate (A), the first liquid crystal composition is homogeneously aligned, and the first optical anisotropy is formed on the alignment substrate (A). Forming a layer;
Bonding the first optically anisotropic layer and a polarizer;
Peeling the alignment substrate (A);
A coating liquid containing a second liquid crystal composition is applied on the alignment substrate (B), the second liquid crystal composition is homeotropically aligned, and a second optical anisotropic is applied on the alignment substrate (B). Forming a conductive layer;
Bonding the first optically anisotropic layer and the second optically anisotropic layer;
Peeling the alignment substrate (B);
It is characterized by comprising.

  In the embodiment of the present invention, the coating liquid containing the first liquid crystal composition preferably contains a dichroic dye.

  In an aspect of the present invention, the first liquid crystal composition comprises a polymerizable liquid crystal compound, and after the homogeneous alignment on the alignment substrate (A), the polymerizable liquid crystal compound is polymerized. It is preferable that the homogeneous orientation is fixed.

  In an aspect of the present invention, the second liquid crystal composition comprises a polymerizable liquid crystal compound, and after homeotropic alignment on the alignment substrate (B), the polymerizable liquid crystal compound is polymerized. It is preferred that the homeotropic orientation is fixed.

  In the aspect of the present invention, it is preferable that the first liquid crystal composition and the second liquid crystal composition are the same liquid crystal composition.

  In the embodiment of the present invention, the first liquid crystal composition and the second liquid crystal composition are preferably different liquid crystal compositions.

  In an aspect of the present invention, the first optically anisotropic layer and the polarizer are bonded to each other by the homogeneous orientation direction of the first optically anisotropic layer and the absorption axis of the polarizer. It is preferable that the angle is 40 to 50 degrees.

  In an aspect of the present invention, the dichroic dye has a polymerizable group and is polymerized with the first liquid crystal composition, and the alignment of the first liquid crystal composition is performed on the alignment substrate (A). It is preferable to align in substantially the same direction as the direction.

  In the aspect of the present invention, the maximum absorption wavelength of the dichroic dye is preferably 380 to 780 nm.

In the aspect of the present invention, the maximum principal refractive index nx1 and / or birefringence Δn1 of the first optically anisotropic layer becomes larger as the measurement wavelength is longer in at least a part of the wavelength region of the visible light region. Has the characteristics of `` negative dispersion ''
The second optically anisotropic layer preferably has a birefringence characteristic of nz2> nx2 ≧ ny2.
(Where nx2 is the maximum main refractive index in the second optical anisotropic layer surface for light with a wavelength of 550 nm, and ny2 is the direction having the maximum main refractive index in the second optical anisotropic layer surface for light with a wavelength of 550 nm. The main refractive index in the direction orthogonal to nz2 is the main refractive index in the thickness direction of the second optically anisotropic layer for light having a wavelength of 550 nm.)

In an aspect of the present invention, Rth1 of the first optical anisotropic layer and Rth2 of the second optical anisotropic layer are:
40 nm ≧ Rth1 (550) + Rth2 (550) ≧ −40 nm (1)
It is preferable to satisfy.
(Here, the thickness direction retardation Rth1 is represented by Rth1 = {(nx1 + ny1) / 2-nz1} × d1 [nm], where d1 is the thickness of the first optical anisotropic layer, nx1. Is the maximum main refractive index in the first optical anisotropic layer surface for light having a wavelength of 550 nm, and ny1 is a direction orthogonal to the direction having the maximum main refractive index in the first optical anisotropic layer surface for light having a wavelength of 550 nm. The main refractive index, nz1, is the main refractive index in the thickness direction of the first optical anisotropic layer with respect to light having a wavelength of 550 nm, and the thickness direction retardation Rth2 is Rth2 = {(nx2 + ny2) / 2-nz2. } × d2 [nm] where d2 is the thickness of the second optically anisotropic layer, nx2 is the maximum principal refractive index in the plane of the second optically anisotropic layer for light having a wavelength of 550 nm, ny2 For light with a wavelength of 550 nm The main refractive index in the direction orthogonal to the direction having the maximum main refractive index in the plane of the second optical anisotropic layer, nz2 is the main refractive index in the thickness direction of the second optical anisotropic layer with respect to light having a wavelength of 550 nm .)

  According to the other aspect of this invention, the laminated polarizing plate manufactured by the said method is provided.

  According to still another aspect of the present invention, an image display device using the laminate is provided.

  According to the present invention, when the laminate is manufactured, the first optical anisotropic layer is once formed on the alignment substrate (A), and the alignment substrate (A) is bonded to the polarizer. Peeling and further forming a second optically anisotropic layer on the alignment substrate (B), and bonding the first optically anisotropic layer and then peeling the alignment substrate (B) A thin laminate can be obtained.

It is a figure which shows the wavelength dispersion characteristic of the refractive index of a liquid crystal composition, and an absorption coefficient. It is the schematic which shows one Embodiment of the manufacturing method of the laminated body of this invention. It is the figure which compared the wavelength dispersion of the main refractive index ny of the direction orthogonal to the direction with the largest main refractive index nx before and after adding a dichroic dye to a liquid-crystal composition, and a direction with the largest main refractive index. It is a figure of the emission spectrum when the organic EL image display device displays the emission spectrum of three colors of red, blue, and green and the three colors are lit simultaneously. It is a figure which shows the process of bonding a 1st optically anisotropic layer and a polarizer. It is a cross-sectional schematic diagram of the image display apparatus of this invention. FIG. 3 is a graph showing the wavelength dispersion characteristic of birefringence Δn of the first optically anisotropic layer produced in Example 1. It is a figure which shows the wavelength dispersion characteristic of birefringence (DELTA) n of the 1st optically anisotropic layer produced in the comparative example 1. FIG. It is a figure which shows the wavelength dispersion characteristic of birefringence (DELTA) n of the 1st optically anisotropic layer produced in the comparative example 2. FIG.

<Definition>
(1) Birefringence Δn
The birefringence Δn is represented by nx−ny.
(2) Refractive index (nx, ny, nz)
nx is the maximum main refractive index in the plane of the optical anisotropic layer, and ny is the main refractive index in the direction orthogonal to the direction having the maximum main refractive index in the plane of the optical anisotropic layer. nz is the main refractive index in the thickness direction of the optically anisotropic layer.
(3) In-plane retardation value Re
The in-plane retardation value Re is represented by Re = Δn × d = (nx−ny) × d [nm]. Re (550) means an in-plane retardation value of the optically anisotropic layer in light having a wavelength of 550 nm. The temperature at the time of measurement is 23 ± 2 ° C., and the relative humidity is 45 ± 5%.
(4) Thickness direction retardation value Rth
The thickness direction retardation Rth is represented by Rth = {(nx + ny) / 2−nz} × d [nm]. Rth (550) means the thickness direction retardation value of the optically anisotropic layer in light having a wavelength of 550 nm. The temperature at the time of measurement is 23 ± 2 ° C., and the relative humidity is 45 ± 5%.
(5) Negative dispersion characteristics Negative dispersion characteristics are dispersions in which the refractive index n in the wavelength region including intrinsic absorption (regions b1, b2, and b3 in FIG. 1) increases as the measurement wavelength increases. means. The “negative dispersion characteristic” is also referred to as “anomalous dispersion characteristic”. In contrast to the “negative dispersion characteristic”, the “positive dispersion characteristic” is refracted as the measurement wavelength becomes longer in a region away from the intrinsic absorption wavelength (regions a1, a2, and a3 in FIG. 1). It means the dispersion in which the rate n decreases. The “positive dispersion characteristic” is also referred to as “normal dispersion characteristic”.

  In the present invention, the extraordinary refractive index ne and the ordinary refractive index no are, for example, spectroscopic ellipsometry (manufactured by Horiba, Ltd., product name “AUTO-SE”), temperature 23 ° C. ± 2 ° C., relative humidity. It can be obtained by measuring the spectrum in the wavelength region of 440 to 1000 nm under the condition of 45 ± 5%. The in-plane retardation value and the thickness direction retardation value are, for example, a device capable of measuring birefringence Δn (for example, a trade name “Axoscan” manufactured by Axometrics, a trade name “manufactured by Oji Scientific Instruments” KOBRA-WR "etc.).

<Method for producing laminate>
The method for producing a laminate according to the present invention, as shown in FIG.
A coating liquid containing the first liquid crystal composition is applied onto the alignment substrate (A) 20, the first liquid crystal composition is homogeneously aligned, and the first optical anisotropy is formed on the alignment substrate (A) 20. Forming the layer 10 (step 1);
A step of bonding the first optical anisotropic layer 10 and the polarizer 30 (step 2);
A step of peeling the alignment substrate (A) 20 (step 3);
A coating liquid containing the second liquid crystal composition is applied onto the alignment substrate (B), the second liquid crystal composition is homeotropically aligned, and the second optical different composition is formed on the alignment substrate (B) 50. A step of forming the isotropic layer 40 (step 4);
A step of bonding the first optical anisotropic layer 10 and the second optical anisotropic layer 40 (step 5);
And a step of peeling the alignment substrate (B) 50 (step 6).
By passing through such a process, the laminated body provided with the first optically anisotropic layer 10, the second optically anisotropic layer 40, and the polarizer 30 which are not thin and do not have an alignment substrate. 100 can be manufactured.
Hereinafter, each step will be described.

[Step 1: First optical anisotropic layer forming step]
A first liquid anisotropy is formed on the alignment substrate (A) by applying a coating liquid containing the first liquid crystal composition on the alignment substrate (A) and homogeneously aligning the first liquid crystal composition. A layer can be formed. The first liquid crystal composition preferably contains one or more liquid crystal compounds having a polymerizable group (polymerizable liquid crystal compound). That is, it is preferable to polymerize a polymerizable liquid crystal compound and fix the homogeneous alignment of the first liquid crystal composition.

  As a method for fixing the alignment state, a known method can be appropriately employed depending on the type of the first liquid crystal composition and the like. For example, depending on the type of polymerization initiator, which will be described later, by performing light irradiation and / or heat treatment, the polymerizable group (reactive functional group) is reacted to fix the alignment in the homogeneous alignment state. A method may be adopted. The state that “the alignment state is fixed in a homogeneous alignment state” means that the first optical anisotropic layer obtained after polymerizing the first liquid crystal composition to fix the alignment is homogeneous alignment. This means that (the alignment in which the major axis direction of the liquid crystal molecules is aligned in a direction substantially parallel to the alignment substrate (A)) is confirmed, and a component derived from the first liquid crystal composition or the like (preferably Is a component derived from a polymerizable liquid crystal compound: the polymerizable liquid crystal compound itself, a composition formed by decomposing the polymerizable liquid crystal compound, a polymer of the polymerizable liquid crystal compound, or the like). However, what is necessary is just to be fixed in the state of homogeneous orientation.

When the polymerization initiator is such that it exhibits the function of an initiator by light irradiation (for example, in the case of a so-called photo radical initiator or photo cation generator), the homogeneous alignment state is fixed by light irradiation. Is preferable. The light irradiation method is not particularly limited. For example, a light source having a spectrum in the absorption wavelength region of the polymerization initiator used (for example, a metal halide lamp, an intermediate pressure or a high pressure mercury lamp having an illuminance of 10 mW / cm ² or more. (Medium pressure or high pressure mercury ultraviolet lamp), ultra high pressure mercury lamp, low pressure mercury lamp, xenon lamp, arc lamp, LED, laser, etc.) and a method of irradiating light from the light source. In addition, it becomes possible to activate a polymerization initiator by such light irradiation, and to react a polymerizable group efficiently.

Further, in such a light irradiation method, the integrated light irradiation amount is preferably 10 to 2000 mJ / cm ² and more preferably 100 to 1500 mJ / cm ² as the integrated exposure amount at a wavelength of 365 nm. preferable. However, this is not the case when the absorption region of the polymerization initiator and the spectrum of the light source are significantly different, or when the first liquid crystal composition itself has the ability to absorb light of the light source wavelength. In that case, from the viewpoint of fixing (curing) the coating film while maintaining the orientation state more efficiently, an appropriate photosensitizer and two or more polymerization initiators having different absorption wavelengths are mixed. It is also possible to adopt a method such as Further, the temperature condition at the time of such light irradiation is not particularly limited as long as it is in a temperature range in which the first liquid crystal composition can maintain a homogeneous alignment state. Note that a cold mirror or other cooling device may be provided between the substrate and the light source (ultraviolet lamp or the like) so that the surface temperature of the coating film can maintain the liquid crystal temperature range during light irradiation.

  Furthermore, the atmospheric conditions at the time of light irradiation are not particularly limited, and may be an air atmosphere, or may be a nitrogen atmosphere in which oxygen is blocked in order to increase reaction efficiency. Since the oxygen concentration in the atmosphere is related to the degree of polymerization, when the desired degree of polymerization is not reached in the air, it is preferable to perform light irradiation in an atmosphere in which the oxygen concentration is reduced by a method such as nitrogen substitution. In such a case, the oxygen concentration in the atmospheric gas is preferably 10% by volume or less, more preferably 7% by volume or less, and most preferably 3% by volume or less.

  In addition, when the polymerization initiator is such that the function of the initiator is expressed by heat (for example, in the case of a so-called thermal radical initiator or thermal cation generator), it is aligned in a homogeneous alignment state by heat treatment. Is preferably immobilized. The conditions for such heat treatment are not particularly limited, and the temperature conditions may be selected so that the orientation state is sufficiently maintained according to the type of the polymerization initiator, and known conditions are appropriately employed. be able to. When using a substrate with low heat resistance as the alignment substrate (A), use a polymerization initiator that exhibits the function of an initiator by light irradiation, and fix the alignment state of homogeneous alignment by light irradiation. Is preferable.

  Here, the polymerizable liquid crystal compound is preferably a liquid crystal compound having a polymerizable group that reacts with light and / or heat from the viewpoint that the alignment state can be more efficiently fixed. Such a liquid crystal compound having a polymerizable group that reacts with light or heat can be polymerized with components (liquid crystal compound, etc.) present around it by light and / or heat to fix the alignment. The kind is not specifically limited, A liquid crystal compound provided with a well-known polymeric group can be utilized suitably. Such a polymerizable group is preferably a vinyl group, a (meth) acryloyl group, a vinyloxy group, an oxiranyl group, an oxetanyl group, an aziridinyl group, or the like. As such a polymerizable group, other polymerizable groups such as an isocyanate group, a hydroxyl group, an amino group, an acid anhydride group, and a carboxyl group may be used depending on the reaction conditions.

  In addition, from the viewpoint of availability, heat resistance, and ease of handling, a liquid crystal compound having a (meth) acryloyl group as a polymerizable group is preferred, and a (meth) acrylate liquid crystal compound (a liquid crystal compound having a (meth) acrylate group). It is more preferable to use

As such a (meth) acrylate type liquid crystal compound, compounds represented by the following general formulas (10) to (12) are preferable.

In the general formulas (10) to (12), each W independently represents one of H and CH ₃ . Depending on the type of W, a group represented by CH ₂ = CWCOO in the formula is either an acrylate group or a methacrylate group. N is an integer of 1 to 20 (more preferably 2 to 12, more preferably 3 to 6). When the value of n is less than the lower limit, the temperature range in which the compound exhibits liquid crystallinity tends to be small. On the other hand, when the value exceeds the upper limit, the compound is derived from the liquid crystal necessary to realize good homogeneous alignment. As a result of the decrease in the fluidity, it tends to be difficult to realize good homogeneous orientation.

In the general formula (10), R ^a represents any group selected from an alkyl group having 1 to 20 carbon atoms and an alkoxy group having 1 to 20 carbon atoms. Such an alkyl group having 1 to 20 carbon atoms that can be selected as ^Ra is preferably one having 1 to 12 carbon atoms, and more preferably 3 to 6 carbon atoms. If the number of carbons exceeds the upper limit, the fluidity derived from the liquid crystal of the compound required for realizing good homogeneous alignment tends to decrease, and as a result, it becomes difficult to realize good homogeneous alignment. Moreover, when the carbon number is less than the lower limit, the temperature range in which the compound exhibits liquid crystallinity tends to be small. Such an alkyl group may be linear, branched, or cyclic, and is not particularly limited, but it is possible to achieve a good homogeneous orientation. Is more preferably linear.

Moreover, as for the C1-C20 alkoxy group which can be selected as Ra, ^a C1-C12 thing is more preferable, and a C3-C6 thing is still more preferable. If the number of carbons exceeds the upper limit, the fluidity derived from the liquid crystal of the compound required for realizing good homogeneous alignment tends to decrease, and as a result, it becomes difficult to realize good homogeneous alignment. Moreover, when the carbon number is less than the lower limit, the temperature range in which the compound exhibits liquid crystallinity tends to be small. The alkoxy group has a structure in which an alkyl group is bonded to an oxygen atom. The structure of the alkyl group portion may be linear, branched, or cyclic. Although it may be sufficient and it does not restrict | limit, From a viewpoint of implement | achieving favorable homogeneous orientation, it is more preferable that it is a linear thing.

In the general formula (12), Z ¹ and Z ² each independently represent any group of —COO— and —OCO—. Such Z ¹ and Z ² are groups in which ^one of Z ¹ and Z ² is represented by —COO—, and the other group is — A group represented by OCO- is preferable.

Further, in the general formula (12), ^{X 1} and ^{X 2} are each independently, H, and carbon atoms represents any of an alkyl group having 1 to 7. The alkyl group having 1 to 7 carbon atoms that can be selected as X ¹ and X ² is more preferably 1 to 3 carbon atoms, and the alkyl group is 1 (the alkyl group is CH ₃ . Is more preferable. When the number of carbon atoms exceeds the upper limit, it tends to be difficult to achieve good orientation. Thus, it is particularly preferable that X ¹ and X ² are each independently one of H and CH ₃ .

  Examples of the (meth) acrylate liquid crystal compounds represented by the general formulas (10) to (12) include compounds described in the following general formulas (110) to (113). Such (meth) acrylate liquid crystal compounds may be used singly or in combination of two or more.

  The polymerizable liquid crystal compound is preferably used in combination with the compounds represented by the general formulas (10) to (12), and is combined with the compounds represented by the general formulas (110) to (113). It is more preferable to use it.

  As described above, when the compounds represented by the general formulas (10) to (12) are used in combination as the polymerizable liquid crystal compound, the content of the compound represented by the general formula (10) It is preferably 20 to 60 parts by weight, more preferably 30 to 45 parts by weight, based on the total amount of the compounds represented by formulas (10) to (12). If the content of the compound represented by the general formula (10) is out of the numerical range, an orientation defect tends to occur with respect to the homogeneous alignment. If the content is within the above range, the orientation defect has to occur with respect to the homogeneous orientation. It can be suppressed from occurring.

  In the case where the compounds represented by the general formulas (10) to (12) are used in combination, the content of the compound represented by the general formula (11) is represented by the general formulas (10) to (12). It is preferable that it is 10-50 weight part with respect to the total amount of the compound represented, and it is more preferable that it is 20-30 weight part. If the content of the compound represented by the general formula (11) is within the above numerical range, it is possible to suppress the occurrence of alignment defects with respect to homogeneous alignment.

  Further, when the compounds represented by the general formulas (10) to (12) are used in combination, the content of the compound represented by the general formula (12) is represented by the general formulas (10) to (12). The amount is preferably 10 to 70 parts by weight, more preferably 25 to 45 parts by weight, based on the total amount of the compound represented. When the content of the compound represented by the general formula (12) is within the above range, it is possible to suppress the occurrence of alignment defects with respect to homogeneous alignment.

  Furthermore, when the compounds represented by the general formulas (110) to (113) are combined and used as the polymerizable liquid crystal compound, the mass ratio of each compound is ([ Compound Represented by General Formula (110)]: [Compound Represented by General Formula (111)]: [Compound Represented by General Formula (112)]: [Compound Represented by General Formula (113)]) Is preferably 45: 40: 15: 0 to 35: 5: 30: 30, and more preferably 35: 23: 23: 19 to 38: 25: 25: 12.

  Moreover, the manufacturing method in particular of a polymeric liquid crystal compound is not restrict | limited, A well-known method can be utilized suitably. For example, when the compound represented by the above general formula (110) is produced, for example, the method described in British Patent Application Publication No. 2,280,445 may be adopted, and the above general formula ( 111) is produced, for example, D.I. J. et al. The method described on pages 3201 to 3215 of “Makromol. Chem. (Vol. 190, published in 1989)” by Broer et al. May be employed, and is represented by the above general formulas (112) to (113). For example, a method described in International Publication WO 93/22397 may be employed. Thus, the polymerizable liquid crystal compound can be produced by appropriately using a known method according to the type of the compound to be used. Moreover, you may utilize a commercial item as such a polymeric liquid crystal compound. Further, such polymerizable liquid crystal compounds may be used alone or in combination of two or more.

Moreover, it is preferable that a 1st optically anisotropic layer satisfies following formula (1) so that it may mention later.
1.00> Re1a (450) / Re1a (550)> 0.70 (1)
As one of the methods for satisfying the requirement of the above formula (1), the polymerizable liquid crystal compound is a compound having two or more kinds of mesogenic groups, and at least one of the mesogenic groups is used as a slow axis of homogeneous alignment of the liquid crystal layer. On the other hand, it is described in Japanese Patent Application Laid-Open Nos. 2002-267838 and 2010-31223 that the phase difference increases as the wavelength increases by orienting in a substantially orthogonal direction. Here, the mesogen of the mesogen group is also an intermediate phase (= liquid crystal phase) forming molecule ("Liquid Crystal Dictionary", Japan Society for the Promotion of Science, 142nd Committee on Organic Materials for Information Science, edited by Liquid Crystal Division, 1989) And is almost synonymous with the liquid crystalline molecular structure. In the present invention, it is preferable to employ a mesogenic group in the rod-like liquid crystal compound (molecular structure relating to liquid crystallinity of the rod-like liquid crystal compound). The mesogenic group in the rod-shaped liquid crystal compound is described in various documents (for example, Flussige Kristalle in Tabellen, VEB Deutscher Verlag fur Grundstoffindustrie, Leipzig (1984), Volume 2).

  Examples of mesogenic groups include biphenyl, phenylcyclohexyl, cyclohexylphenyl, phenyloxycarbonylphenyl, phenylcarbonyloxyphenyl, phenyloxycarbonylcyclohexyl, cyclohexylcarbonyloxyphenyl, phenylcarbonyloxyphenyloxycarbonylphenyl, phenylcarbonyloxyphenyloxycarbonylphenyl , Phenylcarbonyloxycyclohexyloxycarbonylphenyl, phenyloxycarbonylcyclohexylcarbonyloxyphenyl, phenylcarbonyloxyphenylaminocarbonylphenyl, phenylethenylenephenyl, phenylethynylenephenyl, phenylethynylenephenylethynylenephenyl, phenylethenylenecarbonyloxy Include phenyl and phenyl et tennis alkyleneoxy phenyl ethynylenes phenyl.

  The mesogenic group (a benzene ring or a cyclohexane ring constituting the mesogenic group) may have a substituent. As the substituent, the polymerizable group described above or a derivative thereof is preferable. As a combination of two kinds of mesogenic groups, one mesogenic group is biphenyl, phenylcyclohexyl, cyclohexylphenyl, phenyloxycarbonylphenyl, phenylcarbonyloxyphenyl, phenyloxycarbonylcyclohexyl, cyclohexylcarbonyloxyphenyl, phenylcarbonyloxyphenyloxycarbonyl. Selected from the group consisting of phenyl, phenylcarbonyloxyphenyloxycarbonylphenyl, phenylcarbonyloxycyclohexyloxycarbonylphenyl, phenyloxycarbonylcyclohexylcarbonyloxyphenyl and phenylcarbonyloxyphenylaminocarbonylphenyl, the other mesogenic group is phenylethenylenephenyl Phenylethynylenepheny , Phenyl ethynylene phenyl ethynylene phenyl, particularly preferably selected from the group consisting of phenyl et tennis alkylene carbonyloxy biphenyl and phenyl et tennis alkyleneoxy phenyl ethynylenes phenyl.

  A compound having two or more kinds of mesogenic groups can be synthesized by applying a general synthesis method. For example, 1) a sequential introduction method in which one of two or more kinds of mesogenic groups is first introduced by functional group conversion of the starting material, and then another mesogenic group is continuously introduced by functional group conversion; 2) starting material It is possible to adopt a simultaneous introduction method in which two or more kinds of mesogenic groups are simultaneously introduced by the functional group conversion of 3), or a combined method of 3) sequential introduction method and simultaneous introduction method. Thus, the method for producing a compound having two or more kinds of mesogenic groups is not particularly limited, and a known method can be appropriately used. For example, the method described in JP-A-2002-267838 May be adopted. Thus, the polymerizable liquid crystal compound can be produced by appropriately using a known method according to the type of the compound to be used. As other methods, Japanese translations of PCT publication No. 2010-522892, JP-T 2010-522893, JP-T 2010-537954, JP-T 2010-537955, JP-T 2010-540472, JP-T 2012- No. 532155, JP 2013-509458, JP 2007-2208, JP 2007-2209, JP 2007-2210, JP 2009-173893, JP 2010-30979. Gazette, JP2011-6360, JP2011-6361, JP2011-42606, JP2011-162678, JP2011-207765, JP2013-71956, JP 2005-289980 A, JP 2006-24347 A JP, 2008-273925, JP 2009-62508, JP 2009-179563, JP 2010-84032, JP 2005-208415, JP 2005-208416. WO2012 / 169424 and the like.

  Moreover, you may utilize a commercial item as said polymeric liquid crystal compound. Further, such polymerizable liquid crystal compounds may be used alone or in a mixture of two or more. Moreover, when combining 2 or more types of liquid crystal compounds, it is not necessary for all the liquid crystal compounds to show liquid crystallinity, and the 1st liquid crystal composition which is a mixture should just show liquid crystallinity. For example, a compound having two or more kinds of mesogenic groups may exhibit liquid crystallinity even if it does not exhibit liquid crystallinity itself and a mixture with other liquid crystal compounds. Further, when a mixture of two or more polymerizable liquid crystal compounds is used, it is not necessary that all the liquid crystal compounds have a polymerizable functional group, and at least one liquid crystal compound has a polymerizable functional group. That's fine.

  The 1st liquid crystal composition may contain the other polymerizable compound which does not show liquid crystallinity other than the liquid crystal compound which has a polymeric group. Such a polymerizable compound is not particularly limited as long as it is compatible with a liquid crystal compound having a polymerizable group and does not significantly cause alignment inhibition when the liquid crystal compound is aligned. As such other polymerizable compounds, known polymerizable compounds can be used as appropriate, and by selecting and using a suitable compound from known polymerizable compounds according to the design of the target liquid crystal composition. Good. Examples of such other polymerizable compounds include compounds having a polymerizable functional group such as an ethylenically unsaturated group (for example, vinyl group, vinyloxy group, (meth) acryloyl group). In addition, the addition amount of such other polymerizable compounds is 0.5 to 50 parts by weight with respect to the total amount of the liquid crystal compound having the polymerizable group and the other polymerizable compound not exhibiting liquid crystallinity. Is preferable, and it is preferable to set it as 1-30 weight part. In addition, the number of polymerizable functional groups of such a polymerizable compound is 2 from the viewpoint of sufficiently increasing the polymerization rate and imparting sufficient heat resistance to the obtained first optically anisotropic layer. The above is preferable. Furthermore, the method for producing such a polymerizable compound is not particularly limited, and a known method can be appropriately used. Moreover, you may utilize a commercial item as such a polymeric compound.

  The coating liquid containing the first liquid crystal composition preferably contains a dichroic dye. The dichroic dye as used herein refers to a dye having a property that the absorbance in the major axis direction of the molecule is different from the absorbance in the minor axis direction. As long as it has such properties, the dichroic dye is not particularly limited, and may be a dye used as a dye or a dye used as a pigment. A plurality of dichroic dyes may be used, or a dye used as a dye and a dye used as a pigment may be combined.

  As shown by the thin lines in FIG. 3 (the solid line is nx and the dotted line is ny), when the first optical anisotropic layer is usually formed using the coating liquid containing the first liquid crystal composition, the type of dipole Are different depending on the axial direction, the maximum main refractive index nx and the main refractive index ny in the direction orthogonal to the direction having the maximum main refractive index show different “positive dispersion” curves. For example, when a dichroic dye having an absorption spectrum having a maximum absorption wavelength at 580 nm is added to the coating liquid containing the first liquid crystal composition, the maximum is obtained even in the wavelength region of 550 to 650 nm, which is near the absorption wavelength. A first optically anisotropic layer having a characteristic that the main refractive index nx has “negative dispersion” is obtained.

  The dichroic dye preferably has a polymerizable group. For example, the polymerizable group is preferably an acryl group, a methacryl group, a vinyl group, a vinyloxy group, an epoxy group, or an oxetanyl group. In view of the above, an acrylic group, an epoxy group, and an oxetanyl group are particularly preferable. When the dichroic dye has a polymerizable group, it is polymerized with the first liquid crystal composition, and is aligned on the alignment substrate (A) in substantially the same direction as the alignment direction of the first liquid crystal composition. Therefore, a “negative dispersion” characteristic can be reduced in a high-temperature and high-humidity environment, and the change in the absorbance and dichroic ratio of the dichroic dye can be prevented, and a retardation plate excellent in optical reliability can be realized. Further, the dichroic dye may have liquid crystallinity, and those having a nematic phase and a smectic phase are particularly preferable.

  The dichroic dye preferably has a maximum absorption wavelength (λmax) in the range of 380 to 780 nm, more preferably 400 to 750 nm, particularly preferably 450 to 700 nm, and most preferably 540 to 620 nm. When the retardation film of the present invention is applied to an image display device, a maximum absorption wavelength different from the maximum absorption wavelength of the emission spectrum of the image display device is selected in consideration of the emission spectrum of the light source of the image display device. Is most preferred.

  FIG. 4 shows the emission spectra of three colors of red, blue, and green of the organic EL image display device and the emission spectrum when the three colors are turned on simultaneously to display white. As shown in FIG. 4, the blue light has a maximum value at about 460 nm, the green light has a maximum value at 530 nm, and the red light has a maximum value at 630 nm. When the laminate of the present invention is applied to an organic EL image display device, light absorption by the dichroic dye is inevitable, but in order to minimize the decrease in transmittance due to this absorption, the emission spectrum of the three colors is reduced. It is preferable to select a dichroic dye having a maximum absorption wavelength different from the maximum absorption wavelength. For example, it is preferable to apply a dichroic dye having a maximum absorption wavelength around 580 nm. FIG. 4 shows the emission spectrum of the organic EL image display device, but the same applies to other image display devices. For example, in a liquid crystal image display device, when an LED is used as a light source, a decrease in transmittance can be suppressed by using a dichroic dye having a maximum absorption wavelength different from the maximum absorption wavelength of the LED. The difference between the maximum absorption wavelength of the dichroic dye and the maximum absorption wavelength of the emission spectrum of the image display device is 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more. By setting the difference between the maximum absorption wavelength of the dichroic dye and the maximum absorption wavelength of the emission spectrum of the image display device to be 5 nm or more, a decrease in transmittance can be suppressed.

  The dichroic ratio of the dichroic dye is defined by the ratio of the absorbance at the maximum absorption wavelength in the major axis direction of the dye molecule to the absorbance in the minor axis direction. The dichroic ratio can be determined by measuring the absorbance in the orientation direction of the dye and the absorbance in the direction perpendicular to the orientation direction. The dichroic dye that can be used in the present invention preferably has a dichroic ratio of 2 to 50, preferably 2 to 50, and more preferably 3 to 50. When the dichroic ratio is within the above range, the alignment direction of the dye is aligned in the liquid crystal composition, and loss of transmittance at the absorption wavelength of the dye can be suppressed.

  Such dichroic dyes are not particularly limited. For example, acridine dyes, azine dyes, azomethine dyes, oxazine dyes, cyanine dyes, merocyanine dyes, squarylium dyes, naphthalene dyes, azo dyes, anthraquinone dyes, benzotriazoles Dye, benzophenone dye, pyrazoline dye, diphenyl polyene dye, binaphthyl polyene dye, stilbene dye, benzothiazole dye, thienothiazole dye, benzimidazole dye, coumarin dye, nitrodiphenylamine dye, polymethine dye, naphthoquinone dye, perylene dye, quinophthalone dye, Examples thereof include stilbene dyes and indigo dyes. Among these, the dichroic dye is preferably an anthraquinone dye or an azo dye. Examples of the azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, and preferred examples include bisazo dyes, trisazo dyes, and derivatives of these series of dyes. Any dye that satisfies the above conditions can be used in the present invention. An example of a dye that can be used in the present invention is represented by a dye number described in a dye handbook (Nobu Okawara, Shinjiro Kitao, Tsuneaki Hirashima, Ken Matsuoka, Kodansha Scientific Co., Ltd .: 1986, 1st edition). It is shown in 1.

The dichroic dye is particularly preferably one represented by the following formula (1) (hereinafter sometimes referred to as “azo dye (1)”).

In the formula (1), n is an integer of 1 to 4, and Ar ₁ and Ar ₃ each independently represent a group selected from the following group.

In Formula (1), Ar ₂ represents a group selected from the following group. When n is 2 or more, Ar ₂ may be the same as or different from each other.

In the above groups, A ₁ and A ₂ each independently represent a group selected from the following group.
(In the formula, m is an integer of 0 to 10, and when there are two m's in the same group, these two m's may be the same or different from each other.)

  The positional isomerism of the azobenzene moiety of the azo dye (1) is preferably trans.

Specific examples of the polymerizable dichroic dye having a polymerizable functional group include the following compounds.

As the anthraquinone dye, a compound represented by the formula (1-59) is preferable.
(In the formula, R ^{1 to} R ⁸ each independently represent a hydrogen atom, —Rx, —NH ₂ , —NHRx, —NRx ₂ , —SRx, or a halogen atom. Rx has 1 to 4 carbon atoms. Represents an alkyl group or an aryl group having 6 to 12 carbon atoms.)

Moreover, as an oxazone pigment | dye, the compound represented by Formula (1-60) is preferable.
(In the formula, R ^{9 to} R ¹⁵ each independently represent a hydrogen atom, —Rx, —NH ₂ , —NHRx, —NRx ₂ , —SRx or a halogen atom. Rx has 1 to 4 carbon atoms. Represents an alkyl group or an aryl group having 6 to 12 carbon atoms.)

Moreover, as an acridine pigment | dye, the compound represented by Formula (1-61) is preferable.
(In the formula, R ^{16 to} R ²³ each independently represent a hydrogen atom, —Rx, —NH ₂ , —NHRx, —NRx ₂ , —SRx, or a halogen atom. Rx has 1 to 4 carbon atoms. Represents an alkyl group or an aryl group having 6 to 12 carbon atoms.)

  In the above formula (1-59), formula (1-60) and formula (1-61), the alkyl group having 1 to 6 carbon atoms of Rx is a methyl group, an ethyl group, a propyl group, a butyl group, or pentyl. A aryl group having 6 to 12 carbon atoms, such as a phenyl group, a toluyl group, a xylyl group, and a naphthyl group.

Moreover, as a cyanine pigment | dye, the compound represented by Formula (1-62) and the compound represented by Formula (1-63) are preferable.
(In the formula, D ¹ and D ² each independently represent a group represented by any of the following formulas (1-62a) to (1-62d), and n5 represents an integer of 1 to 3. .)

(In Formula (1-63), D ³ and D ⁴ each independently represent a group represented by any of the following Formulas (1-63a) to (1-63h); Represents an integer of 3.)

  The preferred examples of the dichroic dye have been described above. Among them, the azo dye (1) is preferable as the dichroic dye, and at least two kinds of azo dyes (1) having different maximum absorption wavelengths are preferable. You may contain.

  The addition amount of the dichroic dye can be adjusted as appropriate according to the type of the dichroic dye, but is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the first liquid crystal composition. 03-2.0 weight part is more preferable, and 0.03-1.2 weight part is further more preferable. When the content of the dichroic dye is within this range, the first liquid crystal composition can be formed or polymerized without disturbing the alignment of the first liquid crystal composition. When there is too much content of a dichroic dye, there exists a possibility that the transmittance | permeability of a 1st optical anisotropy layer may fall by inhibiting the orientation of a 1st liquid crystal composition or absorption of a dichroic dye. Therefore, the content of the dichroic dye can be determined within a range in which the first liquid crystal composition can maintain homogeneous alignment. In addition, content of dichroic pigment | dye here means the total amount, when two or more types of dichroic pigment | dye are included.

  The coating liquid containing the first liquid crystal composition preferably contains a polymerization initiator for polymerizing the polymerizable liquid crystal compound as described above. The polymerization initiator is not particularly limited, and a known polymerization initiator can be used as appropriate. From among known polymerization initiators, the polymerization initiator is more efficient depending on the type of the liquid crystal compound in the first liquid crystal composition. It is only necessary to appropriately select and use those capable of initiating polymerization of the polymerizable liquid crystal compound.

  The polymerization initiator may be a thermal polymerization initiator (an initiator when using a thermal polymerization reaction) or a photopolymerization initiator (an initiator when using light or electron beam irradiation). Also good. As such a polymerization initiator, in the case of using a plastic film or the like as the alignment substrate (A), from the viewpoint of preventing the alignment substrate (A) or the like from being deformed or denatured by heat. It is more preferable to use a polymerization initiator. Examples of such photopolymerization initiators include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, triarylimidazole dimers and p-aminophenyl ketones. , Acridine and phenazine compounds and oxadiazole compounds. Examples of such α-carbonyl compounds include α-carbonyl compounds described in US Pat. No. 2,367,661 and US Pat. No. 2,367,670. Examples of the acyloin ether include US Pat. The thing etc. which are described in 2448828 specification are mentioned. Examples of the α-hydrocarbon substituted aromatic acyloin compound include those described in US Pat. No. 2,722,512. Examples of the polynuclear quinone compound include US Pat. No. 3,046,127 and US Pat. No. 2,951,758. And the like described in the specification. Examples of the combination of triarylimidazole dimer and p-aminophenylketone include those described in US Pat. No. 3,549,367, and the acridine and phenazine compounds include, for example, Examples described in JP-A-60-105667 and U.S. Pat. No. 4,239,850 are exemplified. Further, examples of the oxadiazole compound include those described in U.S. Pat. No. 4,212,970. .

  Moreover, as a photoinitiator, you may utilize a commercial item, for example, the photoinitiator made from BASF (brand name "Irgacure 907", brand name "Irgacure 651", brand name "Irgacure 184"). Alternatively, a photopolymerization initiator (trade name “UVI6974”) manufactured by Union Carbide may be used as appropriate. Such photopolymerization initiators include those that generate free radicals and those that generate ions upon irradiation with light or an electron beam. The type of the first liquid crystal composition and the conditions for the polymerization reaction Depending on the above, a photopolymerization initiator that generates free radicals (for example, trade name “Irgacure 651” manufactured by BASF, etc.), a photopolymerization initiator that generates ions (for example, photopolymerization initiator manufactured by Union Carbide, etc.) A suitable agent may be appropriately selected from the agents (trade name “UVI6974”).

  Moreover, as content of a polymerization initiator, it is preferable that it is 0.5-10 weight part with respect to 100 weight part of total amounts of a 1st liquid crystal composition and a dichroic dye, and is 1-5 weight part. It is more preferable. If content of a polymerization initiator is in the said numerical range, it can suppress producing a defect in the orientation of a liquid crystal.

  Further, the coating liquid containing the first liquid crystal composition may appropriately contain a solvent in consideration of applicability. The solvent is not particularly limited as long as it can dissolve the first liquid crystal composition and the dichroic dye and can be distilled off under suitable conditions. Generally, acetone, methyl ethyl ketone, isophorone, cyclohexanone, cyclopentanone, etc. Ketones, isopropyl alcohol, alcohols such as n-butanol, ether alcohols such as butoxyethyl alcohol, hexyloxyethyl alcohol, methoxy-2-propanol, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, 2-methoxyethyl acetate, propylene glycol Glycol ethers such as 1-monomethyl ether 2-acetate, esters such as ethyl acetate and ethyl lactate, phenols such as phenol and chlorophenol, N, N-dimethylformamide, , N-dimethylacetamide, amides such as N-methylpyrrolidone, halogenated hydrocarbons such as chloroform, dichloromethane, trichloroethylene, tetrachloroethane, tetrachloroethane, tetrachloroethylene, chlorobenzene, dichlorobenzene, etc., tetrahydrofuran, γ-butyrolactone, etc. Heterocycles, aromatic hydrocarbons such as benzene, toluene, xylene, methoxybenzene, 1,2-dimethoxybenzene, cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and the like, and mixed systems thereof are preferably used.

  Moreover, as such a solvent, with respect to the first liquid crystal composition, etc., a drying speed suitable for applying the coating liquid so as to obtain a uniform film thickness, ease of handling (harmful to the environment), and the like. From the viewpoint of solubility, propylene glycol 1-monomethyl ether 2-acetate, 2-methoxyethyl acetate, toluene, xylene, methoxybenzene, 1,2-methoxybenzene, cyclohexanone, cyclopentanone, methyl cellosolve, ethyl cellosolve, butyl cellosolve, γ-butyrolactone is preferred, and propylene glycol 1-monomethyl ether 2-acetate, toluene, and γ-butyrolactone are more preferred. In addition, you may utilize 1 type as such a solvent individually or in combination of 2 or more types. In addition, depending on the type of solvent used, corrosion may occur in the alignment substrate (A). Therefore, it is preferable to select and use a suitable solvent according to the type of alignment substrate (A).

  In addition, as the content of the solvent, taking into account the usage method (for example, when using it to form an optically anisotropic layer, the usage method including the design of the thickness and the coating method, etc.) It can be adjusted appropriately. For example, the content of the solvent is preferably 30 to 98 parts by weight, more preferably 50 to 95 parts by weight, with respect to 100 parts by weight of the coating liquid containing the first liquid crystal composition. More preferably, it is 90 parts by weight. If the content of the solvent is 30 parts by weight or more, the amount of the solvent with respect to the first liquid crystal composition and / or the dichroic dye is secured, so that the first liquid crystal composition is precipitated during storage. Suppressing or preventing the coating liquid containing the first liquid crystal composition from increasing in viscosity and lowering the wetting property, and improving the coating during the production of the first optically anisotropic layer It can be carried out. In addition, if the solvent content is 95 parts by weight or less, the solvent removal step (drying step) can be completed in a short time, so that the coating liquid containing the first liquid crystal composition is used as the alignment substrate (A). When applied on the surface, it is possible to suppress a decrease in fluidity of the surface and to produce a uniform optically anisotropic layer. Thus, the content of the first liquid crystal composition and / or dichroic dye of the present invention is 2 to 70 parts by weight with respect to 100 parts by weight of the coating liquid containing the first liquid crystal composition. Is preferably 5 to 50 parts by weight, more preferably 10 to 30 parts by weight. In addition, in the coating liquid containing the first liquid crystal composition, not only the above-described solvent but also a reaction activator, a sensitizer, a surfactant, You may add an antifoamer, a leveling agent, etc.

  Moreover, as an orientation board | substrate (A), what has a smooth plane is preferable, and the film and sheet | seat which consist of organic polymer materials, a glass plate, a metal plate, etc. can be mentioned. From the viewpoint of cost and continuous productivity, it is preferable to use a material made of an organic polymer. Examples of organic polymer materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as diacetyl cellulose and triacetyl cellulose, polycarbonate resins, acrylic resins such as polymethyl methacrylate, epoxy resins, The film which consists of transparent resins, such as a phenol resin, is mentioned. Also, styrene resins such as polystyrene and acrylonitrile / styrene copolymers, olefin resins such as polyethylene, polypropylene, and ethylene / propylene copolymers, cycloolefin resins having a cyclic or norbornene structure, vinyl chloride resins, nylon, aromatic A film made of a transparent resin such as an amide resin such as an aromatic polyamide or polyamideimide may also be used. Furthermore, imide resins such as polyimide, sulfone resins, polyether sulfone resins, polyether ether ketone resins, polyphenylene sulfide resins such as polyphenylene sulfide, vinyl alcohol resins such as polyvinyl alcohol, vinylidene chloride resins, vinyl butyral Examples thereof include a film made of a transparent resin such as a series resin, an arylate series resin, a polyoxymethylene series resin, an epoxy series resin or a blend of the above resins.

  As the cellulose resin, a lower fatty acid ester of cellulose is more preferable. As such a lower fatty acid, a fatty acid having 6 or less carbon atoms is preferable. The number of carbon atoms of such lower fatty acids is more preferably 2-4. Examples of such a cellulose-based resin include cellulose acetate, cellulose propionate, and cellulose butyrate. Among such cellulose resins, cellulose triacetate is particularly preferable. As the cellulose resin, mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate may be used.

  Examples of the cycloolefin resin (COP) include cycloolefin ring-opening polymers such as dicyclopentadiene derivatives, cycloolefin addition polymers, random copolymers of cycloolefin and α-olefins such as ethylene and propylene. Examples thereof include polymers, graft-modified products obtained by modifying these with unsaturated carboxylic acid or derivatives thereof, and hydrides thereof. Moreover, as such a cycloolefin, norbornene, its derivative (s), and dicyclopentadiene are preferable. Commercially available products can also be used as the COP film. For example, ZEONOR (trade name, manufactured by ZEON CORPORATION), ZEONEX (trade name, manufactured by ZEON CORPORATION), Arton (trade name, manufactured by JSR Corporation) ) Etc. can be used.

  Among the films made of the organic polymer materials described above, plastic films such as triacetyl cellulose, polycarbonate, norbornene polyolefin, and polyethylene terephthalate used as an optical film can be preferably used. Moreover, as a metal film, the said film formed from aluminum etc. is mentioned, for example.

  Such a substrate substrate (A) may be uniaxially stretched (so-called uniaxially stretched film) or biaxially stretched (so-called biaxially stretched film). Such an alignment substrate (A) may have biaxial optical anisotropy by stretching it in the vertical and horizontal directions, and may have optical anisotropy.

  Moreover, as such an alignment substrate (A), you may use what gave the Z-axis alignment process. Furthermore, such an alignment substrate (A) may be appropriately subjected to surface treatment such as corona treatment, plasma treatment, UV-ozone treatment, and saponification treatment on one or both sides for the purpose of controlling its adhesion. . The treatment conditions for adopting such a surface treatment may be appropriately set according to the alignment substrate to be used, and are not particularly limited, and known conditions may be appropriately adopted.

  Some alignment substrates (A) exhibit sufficient alignment ability with respect to the first liquid crystal composition without any particular treatment, but in the case where alignment ability is insufficient or does not show alignment ability. If necessary, these alignment substrates (A) are stretched under moderate heating, or the surface of the alignment substrate (A) is rubbed in one direction with a rayon cloth or the like, or the alignment substrate (A) A rubbing treatment is performed by providing an alignment film made of a known alignment agent such as polyimide, polyvinyl alcohol, silane coupling agent on the top, or after applying a photoreactant on the alignment substrate (A) and heating at an appropriate temperature, You may perform the process which expresses alignment ability by irradiating a linearly polarized ultraviolet ray, forming a photo-alignment film | membrane, performing oblique vapor deposition processing, such as a silicon oxide, or combining these means suitably.

  In addition, aluminum, iron, copper, nickel, stainless steel or other metal plates provided with regular fine grooves on the surface, various glass plates, etc., or those as master molds, the surface of the alignment substrate (A) is regular. Those obtained by thermally transferring fine grooves or those obtained by transferring regular fine grooves on the surface of the alignment substrate (A) using an ultraviolet curable resin or the like can also be used. Among these, in the field of liquid crystal, it is common to perform a rubbing process that rubs the alignment substrate (A) with a cloth or the like. An important setting value that defines the rubbing condition is a peripheral speed ratio. This represents the ratio between the movement speed of the cloth and the movement speed of the substrate when the alignment substrate (A) is rubbed while the rubbing cloth is wound around a roll and rotated. In the present invention, the peripheral speed ratio is usually 50 or less, more preferably 25 or less, and particularly preferably 10 or less. When the peripheral speed ratio is 50 or less, since the rubbing effect is sufficient, the first liquid crystal composition can be perfectly aligned, and the deterioration of characteristics can be suppressed.

  Moreover, by providing a guideline in the alignment substrate (A) in a direction parallel to the transport direction of the first optically anisotropic layer, the guideline is detected by an inspection device or the like incorporated in the device. It can be confirmed that the first optically anisotropic layer does not meander. As a result, before the first optical anisotropic layer and the polarizer are bonded together, the apparatus is stopped if the first optical anisotropic layer side having the alignment substrate (A) is not aligned at a predetermined angle. Then, the angle of the film can be readjusted to a predetermined angle, and bonding at an incorrect angle can be prevented in advance. When the alignment substrate (A) is not peeled off, it is difficult to provide an erasable guideline on the first optical anisotropic layer surface, and it is difficult to detect meandering of the first optical anisotropic layer during transportation There is.

  Next, a method for applying a coating liquid containing the first liquid crystal composition to the alignment substrate (A) will be described. The application method is not particularly limited as long as the uniformity of the coating film is ensured, and a known method can be adopted. Examples thereof include spin coating, die coating, curtain coating, dip coating, and roll coating. Such a coating film differs depending on the content of the solvent in the first liquid crystal composition and cannot be generally described, but the thickness of the coating film (wet film thickness) before drying is 3 to 3. It is preferable that it is 50 micrometers, and it is more preferable that it is 5-20 micrometers. When the thickness (wet film thickness) is within the above numerical range, precipitation of solid content in the first liquid crystal composition can be suppressed, and a uniform optically anisotropic layer can be obtained. Moreover, it becomes possible to perform uniform coating and maintain the smoothness of the first optically anisotropic layer. Furthermore, the drying time after application can be shortened.

  Next, the first liquid crystal composition is homogeneously aligned by drying and heat-treating the coating film. This drying condition varies depending on the type of the first liquid crystal composition, the dichroic dye, the solvent, and the like, and is not general and is not particularly limited. For example, depending on the type of solvent, the solvent can be removed from the coating film even at room temperature (25 ° C.). As described above, depending on the type of the solvent and the like, it is possible to produce the homogeneously oriented first optically anisotropic layer without particularly performing a heat treatment. Moreover, as temperature conditions in such a solvent removal process, it is preferable that it is 15-110 degreeC, and it is more preferable that it is 20-80 degreeC. If the temperature in the solvent removal step is within the above numerical range, it is not necessary to use a separate cooling facility for drying, and the substrate is not deformed by heat, so that the first optical device having desired optical characteristics is obtained. An anisotropic layer can be obtained.

  Moreover, it does not restrict | limit especially as a pressure condition in this drying process, However, It is preferable that it is 650-1400 hPa, and it is more preferable that it is 900-1100 hPa. When the pressure condition is within the above numerical range, drying unevenness does not occur and the drying time can be shortened. The time for the solvent removal step (drying time) is not particularly limited, but is preferably 10 seconds to 60 minutes, and more preferably 30 seconds to 30 minutes. When the drying time is within the above numerical range, a decrease in smoothness (drying unevenness) of the first optically anisotropic layer can be suppressed, and high productivity can be maintained. In addition, when using a drying apparatus for such a solvent removal process, it is preferable to control the relative moving speed of the said coating film and a drying apparatus so that a relative wind speed may be 60-1200 m / min. . Any known method can be employed without particular limitation as long as the uniformity of the coating film is maintained. For example, a method such as a heater (furnace) or hot air blowing may be used.

  The film thickness after the drying step of the coating liquid containing the applied first liquid crystal composition is preferably 0.1 to 50 μm, more preferably 0.2 to 20 μm, and further preferably 0.5 to 10 μm. . If the film thickness after drying is within the above numerical range, the optical performance of the obtained first optically anisotropic layer can be sufficiently maintained, and the first liquid crystal composition and / or the dichroic dye can be used. It can be fully oriented.

  By the above drying and / or heat treatment, the liquid crystal compound and / or the dichroic dye is homogeneously aligned. Here, the homogeneous alignment means a state in which the major axis direction of the liquid crystal molecules is aligned in a direction substantially parallel to the substrate. The orientation refers to, for example, Δn · d of 20 nm or more at a measurement wavelength of 550 nm. Here, Δn · d is a product of the birefringence Δn and the film thickness d when the retardation plate is used.

  Here, the following method may be adopted as a confirmation method of the homogeneous alignment. As a method for confirming the homogeneous alignment, a known method can be appropriately employed, and is not particularly limited. However, a pair of orthogonal polarizing plates (the direction in which one deflector deflects and the direction in which the other deflector deflects) A method of sandwiching an optically anisotropic layer (which may be laminated with an alignment substrate) between a pair of vertical polarizing plates) and confirming transmitted light with the naked eye, or a method of observing with a polarizing microscope May be adopted. In addition, the homogeneously oriented optically anisotropic layer has different phase difference characteristics depending on the incident angle of light. Therefore, the phase difference in the direction perpendicular to the surface of the sample (vertical incident angle) A birefringence measuring apparatus capable of measuring a phase difference when the incident angle of light is tilted from a vertical incident angle to a specific angle (for example, trade name “Axoscan” manufactured by Axo-metrix, manufactured by Oji Scientific Instruments) Using a product name of “KOBRA-21ADH”, etc.), and measuring the phase difference while appropriately changing the angle from a viewing angle of 0 ° (perpendicular to the liquid crystal film) to a larger viewing angle, The phase difference of the sample is respectively obtained at a plurality of viewing angles, the phase difference is confirmed in a direction perpendicular to the surface of the sample, and the phase difference values in the minus direction and the plus direction of the incident angle are symmetric. Confirm By, it may be employed a method to confirm the presence or absence of a homogeneous orientation.

  As described above, the first liquid crystal composition and / or dichroism is applied by applying the coating liquid containing the first liquid crystal composition on the alignment substrate (A) and removing the solvent from the coating film as desired. The first optically anisotropic layer in which the alignment state is fixed in a homogeneous alignment state can be formed on the alignment substrate by homogeneously aligning the dye and preferably fixing the alignment state.

  The first optically anisotropic layer produced by the above process is a sufficiently strong film. Specifically, the mesogens are three-dimensionally bonded by the curing reaction, and not only the heat resistance (the upper limit temperature for maintaining the liquid crystal alignment) is improved as compared to before curing, but also scratch resistance, abrasion resistance, crack resistance. The mechanical strength such as property is also greatly improved.

Further, the first optically anisotropic layer obtained as described above has a “negative dispersion” characteristic in which the birefringence Δn becomes larger as the measurement wavelength becomes longer in at least a part of the wavelength region of the visible light region. It is preferable to have.
More specifically, it preferably has retardation characteristics that satisfy the following formulas (2) and (3).
1.00> Re1 (450) / Re1 (550)> 0.70 (2)
1.30> Re1 (650) / Re1 (550)> 1.00 (3)
(Here, Re1 represents the in-plane retardation value of the first optically anisotropic layer, and is represented by the product of birefringence Δn1 and the film thickness d1 of the first optically anisotropic layer, and Re1 ( 450), Re1 (550) and Re1 (650) are in-plane retardation values of the first optical anisotropic layer at wavelengths of 450 nm, 550 nm and 650 nm.)
More preferably, the following formulas (2-1) and (3-1) are satisfied.
0.95> Re1 (450) / Re1 (550)> 0.80 (2-1)
1.20> Re1 (650) / Re1 (550)> 1.02 (3-1)

Moreover, it is preferable to have a retardation characteristic that satisfies the following formulas (4) and (5) in consideration of the specific visibility characteristic.
1.10> Re1 (500) / Re1 (550)> 0.80 (4)
1.15> Re1 (580) / Re1 (550)> 1.00 (5)
More preferably, the following formulas (4-1) and (5-1) are satisfied.
1.05> Re1 (500) / Re1 (550)> 0.85 (4-1)
1.12> Re1 (580) / Re1 (550)> 1.02 (5-1)

  When the retardation of the first optically anisotropic layer is out of the above range, when used as a quarter wavelength plate, when a linearly polarized light of 400 to 700 nm is incident, the obtained polarization state is completely at a specific wavelength. Although circularly polarized light can be obtained, it may deviate greatly from circularly polarized light at other wavelengths.

Further, when the first optical anisotropic layer contains a dichroic dye, the in-plane retardation value is Re1a (= (nx1a−ny1a) × d1),
When the in-plane retardation value of the first optical anisotropic layer obtained by removing the dichroic dye from the first optical anisotropic layer is Re1b (= (nx1b−ny1b) × d1), It is preferable to have a retardation characteristic that satisfies formula (6).
Re1a (580) / Re1a (550) -Re1b (580) / Re1b (550)> 0 (6)
In the present invention, the retardation ratio at the predetermined wavelength of the first optical anisotropic layer containing the dichroic dye is set to be the retardation at the predetermined wavelength of the first optical anisotropic layer not containing the dichroic dye. By making it larger than the foundation ratio, it is possible to realize a first optically anisotropic layer in which the maximum principal refractive index nx and / or birefringence Δn = (nx−ny) has a “negative dispersion” characteristic.

  The first optically anisotropic layer preferably has a “negative dispersion” characteristic in which the maximum principal refractive index nx and / or birefringence Δn is at least in a part of the wavelength range of the visible light region.

  The first optically anisotropic layer may be required to have a specific retardation value as well as a film thickness depending on the application and the like. Here, the in-plane retardation value of the first optical anisotropic layer for light having a wavelength of 550 nm is preferably 20 to 450 nm, and more preferably 50 to 300 nm.

[Step 2: First optically anisotropic layer and polarizer bonding step]
Next, the first optical anisotropic layer formed on the alignment substrate (A) and the polarizer are bonded together.

  As shown in FIG. 5, the first optical anisotropic layer and the polarizer are bonded to each other between the homogeneous orientation direction A of the first optical anisotropic layer 10 and the absorption axis B of the polarizer 30. Bonding is preferably performed so that the angle α is 40 to 50 degrees. Bonding with the polarizer 30 expresses a desired antireflection performance when the homogeneous orientation direction A of the first optically anisotropic layer 10 and the absorption axis B of the polarizer 30 are 40 to 50 degrees. I can do it.

  The polarizer can be attached to the first optically anisotropic layer via an adhesive or an adhesive. In the present specification, “pressure-sensitive adhesive” refers to a material that exhibits a peeling resistance without solidifying, and “adhesive” refers to a material that solidifies and exhibits a resistance to peeling. The pressure-sensitive adhesive or adhesive used is not particularly limited as long as it is optically isotropic and transparent, and generally used materials such as acrylic pressure-sensitive adhesives, epoxy pressure-sensitive adhesives, urethane pressure-sensitive adhesives, etc. are used. be able to. Moreover, you may bond together through an adhesion layer. The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer is not particularly limited. For example, acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive, polyester-based pressure-sensitive adhesive, polyurethane-based pressure-sensitive adhesive, polyamide-based pressure-sensitive adhesive, polyether-based pressure-sensitive adhesive, fluorine-based and rubber Those having a base adhesive or the like as a base adhesive can be appropriately selected and used. In particular, those having excellent optical transparency, such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and being excellent in weather resistance, heat resistance and the like are preferably used.

  The pressure-sensitive adhesive layer can be formed by an appropriate method. As an example, for example, an adhesive solution of about 10 to 40 parts by weight in which a base resin or a composition thereof is dissolved or dispersed in a solvent composed of a single solvent or a mixture of appropriate solvents such as toluene and ethyl acetate is prepared. A method of directly attaching the first optically anisotropic layer to the first optically anisotropic layer by an appropriate development method such as a casting method or a coating method, or forming an adhesive layer on the separator according to the above and And a method of transferring on the optically anisotropic layer 1. In addition, the adhesive layer includes, for example, natural and synthetic resins, in particular, tackifier resins, fillers composed of glass fibers, glass beads, metal powders, other inorganic powders, pigments, colorants, oxidation agents, and the like. You may contain the additive added to adhesion layers, such as an inhibitor. Moreover, the adhesive layer etc. which contain microparticles | fine-particles and show light diffusibility may be sufficient.

  In addition, when bonding a 1st optically anisotropic layer and a polarizer via an adhesive, the 1st optically anisotropic layer surface is processed and adhesiveness with a polarizer is improved. be able to. The surface treatment means is not particularly limited, and a surface treatment method such as corona discharge treatment, sputtering treatment, low-pressure UV irradiation, or plasma treatment that can maintain the transparency of the first optically anisotropic layer can be suitably employed. Among these surface treatment methods, the corona discharge treatment can be particularly preferably employed.

  The thickness of the pressure-sensitive adhesive or adhesive is not particularly limited as long as the member to be bonded can be bonded and sufficient adhesion can be maintained, and is appropriately selected depending on the characteristics of the pressure-sensitive adhesive or the adhesive and the member to be bonded and bonded. be able to. Since the necessity of reducing the thickness of the elliptically polarizing plate is high as the image display device becomes thinner, the adhesive layer or the adhesive layer is preferably thin, usually 2 to 80 μm, more preferably 3 to 50 μm, particularly preferably 5-40 micrometers is preferable. Outside this range, it is not preferable because the adhesive force is insufficient, or the pressure-sensitive adhesive oozes out from the end during lamination or storage of the laminate.

  The polarizer is not particularly limited, and various types can be used. For example, for a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, an ethylene / vinyl acetate copolymer partially saponified film. , Uniaxially stretched by adsorbing dichroic substances such as iodine and dichroic dyes, polyene-based alignment films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride, and alignment films containing lyotropic liquid crystals Etc. Commercially available polarizers can also be used. Among these, a film obtained by stretching a polyvinyl alcohol resin film and adsorbing and orienting a dichroic material (iodine, dye) is preferably used. The thickness of the polarizer is not particularly limited, but is generally about 5 to 80 μm.

  The above-described polarizer may be provided with a protective film on one side or both sides. As the protective film, conventionally known ones can be used. From the viewpoint of transparency, mechanical strength, thermal stability, moisture shielding property, isotropic property, etc., a cellulose resin film such as triacetyl cellulose is used. It can be preferably used.

[Step 3: Alignment substrate (A) peeling step]
Next, the alignment substrate (A) is peeled from the first optical anisotropic layer bonded to the polarizer. In the manufacturing process of the laminate, the alignment substrate (A) is not optically isotropic, or the obtained first optical anisotropic layer is opaque, or the alignment substrate (A) is too thick. If the adhesion between the alignment substrate (A) and the first optical anisotropic layer is poor, peeling between the alignment substrate (A) and the first optical anisotropic layer may occur. There is a possibility that problems such as These problems can be solved by peeling the alignment substrate (A) from the first optically anisotropic layer.

[Step 4: Second optical anisotropic layer forming step]
By applying a coating liquid containing the second liquid crystal composition on the alignment substrate (B) and homeotropically aligning the second liquid crystal composition, the second optical anisotropy is formed on the alignment substrate (B). An adhesive layer can be formed. The second liquid crystal composition preferably contains one or more liquid crystal compounds having a polymerizable group (polymerizable liquid crystal compound). That is, it is preferable to polymerize a polymerizable liquid crystal compound and fix the homeotropic alignment of the second liquid crystal composition. The second optically anisotropic layer is formed by applying a coating liquid containing the second liquid crystal composition on the alignment substrate (B), aligning the second liquid crystal composition homeotropically, and then irradiating with light if necessary. It is preferable to fix the orientation state by cooling after heat treatment.

  As a method for fixing the alignment state, a known polymerizable method can be appropriately employed depending on the type of the second liquid crystal composition and the like. For example, after light irradiation and / or heat treatment, it is cooled and cured to be fixed. The second liquid crystal composition is homeotropically aligned by a method such as heat treatment, and then cooled and fixed in a glass state, or the polymerization that the second liquid crystal composition contains, if necessary, while maintaining the homeotropic alignment state. The fixed value can be obtained by curing by a polymerization reaction of a reactive group such as an oxetanyl group possessed by the conductive liquid crystal compound. Thereby, the 2nd optically anisotropic layer formed can be made stronger.

  When the polymerizable liquid crystal compound has a polymerizable oxetanyl group, it is preferable to use a cationic polymerization initiator (cation generator) for the polymerization (crosslinking) of the polymerizable group. Moreover, as a polymerization initiator, it is preferable to use a photo cation generator rather than a thermal cation generator. When a photo cation generator is used, the liquid crystal compound can be obtained by adding the photo cation generator to the heat treatment for liquid crystal alignment under dark conditions (light blocking conditions that do not cause the photo cation generator to dissociate). The liquid crystal can be aligned with sufficient fluidity without curing until the alignment stage. Thereafter, the second optically anisotropic layer can be obtained by generating and curing a cation by irradiating light from a light source that emits light of an appropriate wavelength.

  As a method of light irradiation, light from a light source such as a metal halide lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, or a laser having a spectrum in the absorption wavelength region of the photocation generator to be used is used. Cleave the generator. The dose per square centimeter is usually in the range of 1 to 2000 mJ, preferably 10 to 1000 mJ as the cumulative dose. However, this is not the case when the absorption region of the photocation generator and the spectrum of the light source are significantly different, or when the second liquid crystal composition itself has the ability to absorb light from the light source. In these cases, an appropriate photosensitizer or two or more photocation generators having different absorption wavelengths may be used in combination. The temperature at the time of light irradiation needs to be in a temperature range in which the second liquid crystal composition takes homeotropic alignment. In order to ensure sufficient strength after curing, it is preferable to perform light irradiation at a temperature equal to or higher than Tg of the liquid crystal compound included in the second liquid crystal composition.

  The second optically anisotropic layer manufactured by the above process is a sufficiently strong film. Specifically, the mesogens are three-dimensionally bonded by the curing reaction, and not only the heat resistance (the upper limit temperature for maintaining the liquid crystal alignment) is improved as compared to before curing, but also scratch resistance, abrasion resistance, crack resistance. The mechanical strength such as property is also greatly improved.

  As the polymerizable liquid crystal compound, a positive uniaxial liquid crystal compound capable of homeotropic alignment of the second liquid crystal composition on the alignment substrate (B) and fixing the alignment is preferable. The compound is not particularly limited as long as it has such properties, and may be a low-molecular liquid crystal compound, a high-molecular liquid crystal compound, or a material composed of a mixture thereof.

  As the low-molecular liquid crystal compound, those having a reactive group that reacts with light or heat are preferable. As the reactive group, a vinyl group, a (meth) acryloyl group, a vinyloxy group, an oxiranyl group, an oxetanyl group, an aziridinyl group and the like are preferable, but other reactive groups such as an isocyanate group, a hydroxyl group, an amino group, and an acid anhydride are preferable. Groups, carboxyl groups and the like can also be used depending on the reaction conditions.

  The polymer liquid crystal compound includes a main chain type liquid crystal compound and a side chain type liquid crystal compound, and any of them can be used. Examples of the main chain type liquid crystal compound include polyester, polyesterimide, polyamide, and polycarbonate. Of these, polyesters are preferable from the viewpoints of ease of synthesis, orientation, glass transition point, and the like, and main-chain liquid crystalline polyesters having a cationic polymerizable group are particularly preferable. Examples of the side chain type liquid crystal compound include polyacrylate, polymethacrylate, polymalonate, polysiloxane and the like. As the side chain type liquid crystal compound, those having the reactive group in the side chain are preferable.

  The main-chain liquid crystal polyester includes an aromatic diol unit (hereinafter referred to as a structural unit (A)), an aromatic dicarboxylic acid unit (hereinafter referred to as a structural unit (B)), and an aromatic hydroxycarboxylic acid unit (hereinafter referred to as a structural unit (B)). , Which is a main-chain liquid crystal polyester containing at least two of the structural units (C) as essential units, and includes a structural unit having a cationic polymerizable group at least at one end of the main chain. It is a main chain type liquid crystal polyester. Hereinafter, the structural units (A), (B), and (C) will be sequentially described.

  The compound for introducing the structural unit (A) is preferably a compound represented by the following general formula (a), specifically, catechol, resorcin, hydroquinone or the like or a substituted product thereof, 4,4′-biphenol 2,2 ′, 6,6′-tetramethyl-4,4′-biphenol, 2,6-naphthalenediol, and the like, and catechol, resorcin, hydroquinone, and the like, or substituted products thereof are particularly preferable.

However, -X in the _{formula, -H, -CH 3, -C 2} H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, -CH 2 CH 2 CH 2 CH 3, -CH _{2 CH (CH 3) CH 3} , -CH (CH 3) CH 2 CH 3, -C (CH 3) 3, -OCH 3, -OC 2 H 5, -OC 6 H 5, -OCH 2 C 6 H ₅ , —F, —Cl, —Br, —NO ₂ , or —CN, particularly preferably a compound represented by the following formula (a ′).

  The compound for introducing the structural unit (B) is preferably a compound represented by the following general formula (b), specifically, terephthalic acid, isophthalic acid, phthalic acid or the like, or a substituted product thereof, 4, 4 Examples include '-stilbene dicarboxylic acid or a substituted product thereof, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and the like, and terephthalic acid, isophthalic acid, phthalic acid, and the like or substituted products thereof are particularly preferable.

However, -X in the _{formula, -H, -CH 3, -C 2} H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, -CH 2 CH 2 CH 2 CH 3, -CH _{2 CH (CH 3) CH 3} , -CH (CH 3) CH 2 CH 3, -C (CH 3) 3, -OCH 3, -OC 2 H 5, -OC 6 H 5, -OCH 2 C 6 H ₅ , -F, -Cl, -Br, -NO ₂ , or -CN.

  As the compound for introducing the structural unit (C), a compound represented by the following general formula (c) is preferable. Specifically, hydroxybenzoic acid or a substituted product thereof, 4′-hydroxy-4-biphenylcarboxylic acid Or a substituted product thereof, 4′-hydroxy-4-stilbenecarboxylic acid or a substituted product thereof, 6-hydroxy-2-naphthoic acid, 4-hydroxycinnamic acid, and the like. Particularly, hydroxybenzoic acid and a substituted product thereof, 4 '-Hydroxy-4-biphenylcarboxylic acid or a substituted product thereof, 4'-hydroxy-4-stilbenecarboxylic acid or a substituted product thereof is preferred.

However, -X in the formula, -X1, -X2 are each _{independently, -H, -CH 3, -C 2} H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, -CH ₂ CH ₂ CH ₂ CH ₃ , —CH ₂ CH (CH ₃ ) CH ₃ , —CH (CH ₃ ) CH ₂ CH ₃ , —C (CH ₃ ) ₃ , —OCH ₃ , —OC ₂ H ₅ , —OC ₆ H _5, represents _{-OCH 2 C 6 H 5, -F} , -Cl, -Br, any group of -NO _2, or -CN,.

  The main chain type liquid crystal polyester has at least two kinds of (A) aromatic diol units, (B) aromatic dicarboxylic acid units, and (C) aromatic hydroxycarboxylic acid units as constituent units, Any structural unit may be used as long as it contains a structural unit having a cationically polymerizable group (hereinafter referred to as structural unit (D)) at at least one of the chain ends and exhibits thermotropic liquid crystallinity, and the other structural units satisfy these conditions. There is no particular limitation.

  The proportion of the structural units (A), (B) and (C) constituting the main chain type liquid crystal polyester in the total structural units is the same as that of the structural units (A), (B) and (C) being diol, dicarboxylic acid or hydroxy. As the carboxylic acid, a range of usually 20 to 99 parts by weight, preferably 30 to 95 parts by weight, and 40 to 90 parts by weight is particularly preferable with respect to 100 parts by weight of all monomers. If it is 20 parts by weight or more, the temperature range that exhibits liquid crystallinity can be suppressed from becoming extremely narrow, and if it is 99 parts by weight or less, the proportion of structural units having a cationic polymerizable group is relatively high. The orientation retention ability and the mechanical strength can be improved without lowering.

  Next, the structural unit (D) having a cationic polymerizable group will be described. As the cationic polymerizable group, a functional group selected from the group consisting of an epoxy group, an oxetanyl group, and a vinyloxy group is preferable, and an oxetanyl group is particularly preferable. The compound for introducing the structural unit (D) is selected from an epoxy group, an oxetanyl group, and a vinyloxy group as an aromatic compound having a phenolic hydroxyl group or a carboxyl group, as shown in the following general formula (d). It is a compound to which a cationically polymerizable group is bonded. A spacer may exist between the aromatic ring and the cationic polymerizable group.

However, _-X in the formula, -X _1, -X 2, -Y, -Z represents any of the following groups independently for each unit each configuration.
_{(1) -X, -X 1,} -X 2: -H, -CH 3, -C 2 H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, -CH 2 CH 2 CH 2 _{CH 3, -CH 2 CH (CH} 3) CH 3, -CH (CH 3) CH 2 CH 3, -C (CH 3) 3, -OCH 3, -OC 2 H 5, -OC 6 H 5, - _{OCH 2 C 6 H 5, -F} , -Cl, -Br, -NO 2 or -CN,
(2) -Y: single _{bond, - (CH 2) n -} , - O -, - O- (CH 2) n -, - (CH 2) n -O -, - O- (CH 2) n - O -, - O-CO - , - CO-O -, - O-CO- (CH 2) n -, - CO-O- (CH 2) n -, - (CH 2) n -O-CO- , — (CH ₂ ) _n —CO—O—, —O— (CH ₂ ) _n —O—CO—, —O— (CH ₂ ) _n —CO—O—, —O—CO— (CH ₂ ) _{n -O -, - CO-O-} (CH 2) n -O -, - O-CO- (CH 2) n -O-CO -, - O-CO- (CH 2) n -CO-O- _{, -CO-O- (CH 2)} n -O-CO- or _{-CO-O- (CH 2) n} -CO-O-, ( where, n is an integer of 1-12.)
(3) Z:

  In the structural unit (D), the bonding position of a cationic polymerizable group or a substituent containing a cationic polymerizable group and a phenolic hydroxyl group or a carboxylic acid group is as follows when the skeleton to which these functional groups are bonded is a benzene ring: From the viewpoint of liquid crystallinity, a 1,4-positional relationship, a 2,6-positional relationship in the case of a naphthalene ring, and a 4,4′-positional relationship in the case of a biphenyl skeleton or a stilbene skeleton are preferable. More specifically, 4-vinyloxybenzoic acid, 4-vinyloxyphenol, 4-vinyloxyethoxybenzoic acid, 4-vinyloxyethoxyphenol, 4-glycidyloxybenzoic acid, 4-glycidyloxyphenol, 4- (oxetanyl) Methoxy) benzoic acid, 4- (oxetanylmethoxy) phenol, 4′-vinyloxy-4-biphenylcarboxylic acid, 4′-vinyloxy-4-hydroxybiphenyl, 4′-vinyloxyethoxy-4-biphenylcarboxylic acid, 4′- Vinyloxyethoxy-4-hydroxybiphenyl, 4′-glycidyloxy-4-biphenylcarboxylic acid, 4′-glycidyloxy-4-hydroxybiphenyl, 4′-oxetanylmethoxy-4-biphenylcarboxylic acid, 4′-oxetanylmethoxy- 4- Droxybiphenyl, 6-vinyloxy-2-naphthalenecarboxylic acid, 6-vinyloxy-2-hydroxynaphthalene, 6-vinyloxyethoxy-2-naphthalenecarboxylic acid, 6-vinyloxyethoxy-2-hydroxynaphthalene, 6-glycidyloxy 2-naphthalenecarboxylic acid, 6-glycidyloxy-2-hydroxynaphthalene, 6-oxetanylmethoxy-2-naphthalenecarboxylic acid, 6-oxetanylmethoxy-2-hydroxynaphthalene, 4-vinyloxycinnamic acid, 4-vinyloxyethoxy cinnamic Acid, 4-glycidyloxycinnamic acid, 4-oxetanylmethoxycinnamic acid, 4'-vinyloxy-4-stilbenecarboxylic acid, 4'-vinyloxy-3'-methoxy-4-stilbenecarboxylic acid, 4'-vinyloxy-4- Hide Xistylben, 4′-vinyloxyethoxy-4-stilbenecarboxylic acid, 4′-vinyloxyethoxy-3′-methoxy-4-stilbenecarboxylic acid, 4′-vinyloxyethoxy-4-hydroxystilbene, 4′-glycidyl Oxy-4-stilbenecarboxylic acid, 4′-glycidyloxy-3′-methoxy-4-stilbenecarboxylic acid, 4′-glycidyloxy-4-hydroxystilbene, 4′-oxetanylmethoxy-4-stilbenecarboxylic acid, 4 ′ -Oxetanylmethoxy-3'-methoxy-4-stilbene carboxylic acid, 4'-oxetanylmethoxy-4-hydroxystilbene and the like are preferable.

  Each structural unit of (A) to (D) has one or two carboxyl groups or phenolic hydroxyl groups, but the carboxyl groups and phenolic hydroxyl groups of (A) to (D) are charged. It is desirable that the total number of equivalents of the respective functional groups be roughly aligned at this stage. That is, when the structural unit (D) is a unit having a free carboxyl group, (number of moles of (A) × 2) = (number of moles of (B) × 2) + number of moles of (D) ), When the structural unit (D) is a unit having a free phenolic hydroxyl group, (number of moles of (A) × 2) + (number of moles of (D)) = (number of moles of (B) × 2) It is desirable to generally satisfy the relationship By satisfying this relational expression, a carboxylic acid or phenol other than the structural unit involved in cationic polymerization, or a derivative thereof becomes a molecular end, and sufficient cationic polymerizability can be obtained, and an acidic functional group remains. Since this can be prevented, polymerization reaction and decomposition reaction in an undesired process can be prevented.

  The main-chain liquid crystal polyester can contain structural units other than (A), (B), (C) and (D). Other structural units that can be contained are not particularly limited, and compounds (monomers) known in the art can be used. For example, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, aliphatic dicarboxylic acid, compounds in which halogen groups or alkyl groups are introduced into these compounds, biphenols, naphthalenediol, aliphatic diols, and compounds in which halogen groups or alkyl groups are introduced into these compounds Etc.

  The molecular weight of the main chain type liquid crystal polyester is preferably such that the logarithmic viscosity η measured at 30 ° C. in a phenol / tetrachloroethane mixed solvent (weight ratio 60/40) is 0.03 to 0.50 dl / g. Is 0.05 to 0.15 dl / g. When η is greater than 0.03 dl / g, the solution viscosity of the main chain type liquid crystal polyester can be maintained, and a uniform coating film can be obtained. Further, when it is smaller than 0.50 dl / g, the alignment treatment temperature required for liquid crystal alignment can be suppressed to a low temperature, so that the simultaneous occurrence of alignment and crosslinking reaction can be suppressed, and high alignment can be maintained.

  In the present invention, the molecular weight of the main-chain liquid crystal polyester is determined solely by the charged composition. Specifically, the main chain obtained by the relative content in the total charge composition of a monofunctional monomer that reacts in a form that seals both ends of the molecule, that is, the compound for introducing the structural unit (D) described above. The average degree of polymerization of the liquid crystal polyester (the average number of bonds of the structural units (A) to (D)) is determined. Therefore, in order to obtain a main-chain liquid crystalline polyester having a desired logarithmic viscosity, it is necessary to adjust the charged composition according to the type of charged monomer.

  The main chain type liquid crystal polyester obtained in this way should be identified by the analytical means such as NMR (nuclear magnetic resonance method) at what ratio each monomer is present in the main chain type liquid crystal polyester. Can do. In particular, the average number of bonds of the main-chain liquid crystal polyester can be calculated from the amount ratio of the cationic polymerizable group.

  It is also possible to mix other compounds with the main-chain liquid crystal polyester containing the cationic polymerizable group as long as the scope of the present invention is not exceeded. For example, you may add the other high molecular compound miscible with the main chain type liquid crystal polyester used for this invention, various low molecular weight compounds, etc. Such a low molecular compound may or may not have liquid crystallinity, and may or may not have a polymerizable group capable of reacting with a crosslinkable main chain liquid crystal polyester. However, it is preferable to use a liquid crystal compound having a polymerizable group. Examples of the main chain type liquid crystal having a polymerizable group include the following.

Here, n represents an integer of 2 to 12, and -V- and -W each represents one of the following groups.
-V-: single _{bond, -O -, - O-C} m H 2m -O- ( although, m is an integer from 2 to 12)
-W:

  Examples of the side chain type liquid crystal compound include poly (meth) acrylate, polymalonate, polysiloxane and the like as mentioned above, and among them, poly (meth) acrylate bonded with a reactive group represented by the following general formula (1). Is preferred.

In Formula (1), each R ³ independently represents hydrogen or a methyl group, and each R ⁴ independently represents hydrogen, methyl group, ethyl group, butyl group, hexyl group, octyl group, nonyl group, decyl group. Group, dodecyl group, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group, cyano group, bromo group, chloro group, fluoro R ⁵ represents a hydrogen group, a methyl group or an ethyl group, R ⁶ represents a hydrocarbon group having 1 to 24 carbon atoms, and L ² each independently represents a group or a carboxyl group. Represents a single bond, —O—, —O—CO—, —CO—O—, —CH═CH— or —C≡C—, p represents an integer of 1 to 10, and q represents Represents an integer of 10 from, a, b, c, d, e and f represent the mole ratio of each unit in the polymer (a + b + c + d + e + f = 1.0, but not the c + d + e = 0).

The molar ratio of each component constituting the side chain type polymer liquid crystal compound represented by the formula (1) is not a + b + c + d + e + f = 1.0, c + d + e = 0, and needs to exhibit liquid crystallinity. The molar ratio of each component may be arbitrary as long as this requirement is satisfied, but is preferably as follows.
a: Preferably 0 to 0.80, more preferably 0.05 to 0.50
b: preferably 0 to 0.90, more preferably 0.10 to 0.70
c: preferably 0 to 0.50, more preferably 0.10 to 0.30
d: preferably 0 to 0.50, more preferably 0.10 to 0.30
e: preferably 0 to 0.50, more preferably 0.10 to 0.30
f: Preferably 0 to 0.30, more preferably 0.01 to 0.10

Each component in these poly (meth) acrylates does not need to be present in all six types as long as the above conditions are satisfied. Moreover, each component of af may consist of a some structure, respectively.
R ⁴ is preferably hydrogen, methyl group, butyl group, methoxy group, cyano group, bromo group or fluoro group, particularly preferably hydrogen, methoxy group or cyano group, and L ² is preferably Is a single bond, —O—, —O—CO— or —CO—O—, and R ⁶ preferably represents a hydrocarbon group having 2, 3, 4, ⁶ , 8 or 18 carbon atoms.
Further, the side chain type polymer liquid crystal compound represented by the general formula (1) changes in birefringence depending on the molar ratio of each component a to f and the orientation form, but the birefringence when nematic orientation is taken is 0. It is preferably 0.001 to 0.300, more preferably 0.05 to 0.25.

  Said side chain type liquid crystal compound is easily synthesized by copolymerizing the (meth) acrylic group of each (meth) acrylic compound obtained by the above method corresponding to each component by radical polymerization or anionic polymerization. Can do. Polymerization conditions are not particularly limited, and normal conditions can be employed.

  As an example of radical polymerization, a (meth) acryl compound corresponding to each component is dissolved in a solvent such as dimethylformamide (DMF) or diethylene glycol dimethyl ether, and 2,2′-azobisisobutyronitrile (AIBN) or benzoyl peroxide is dissolved. The method of making it react for several hours at 60-120 degreeC by using (BPO) etc. as an initiator is mentioned. Moreover, in order to make the liquid crystal phase appear stably, copper bromide (I) / 2,2′-bipyridyl series, 2,2,6,6-tetramethylpiperidinooxy free radical (TEMPO) series, etc. are used. A method of controlling the molecular weight distribution by conducting living radical polymerization as an initiator is also effective. These radical polymerizations need to be performed under deoxygenated conditions.

  An example of anionic polymerization is a method in which a (meth) acrylic compound corresponding to each component is dissolved in a solvent such as tetrahydrofuran (THF) and reacted with a strong base such as an organic lithium compound, an organic sodium compound, or a Grignard reagent as an initiator. Can be mentioned. In addition, the molecular weight distribution can be controlled by optimizing the initiator and the reaction temperature for living anionic polymerization. These anionic polymerizations need to be performed under dehydration and deoxygenation conditions.

  The side chain type liquid crystal compound preferably has a weight average molecular weight of 1,000 to 200,000, particularly preferably 3,000 to 50,000. If it is in the said numerical range, it has sufficient intensity | strength and can implement | achieve favorable orientation.

  The 2nd liquid crystal composition may contain the various compound which can be mixed, without impairing liquid crystallinity other than the said side chain type liquid crystal compound. For example, compounds having cationic polymerizable functional groups such as oxetanyl group, epoxy group, vinyl ether group, various polymer compounds having film forming ability, various low-molecular liquid crystal compounds and polymer liquid crystal compounds exhibiting liquid crystallinity, etc. It is done.

  The content of the side chain type liquid crystal compound is 10 parts by weight or more, preferably 30 parts by weight or more, and more preferably 50 parts by weight or more with respect to 100 parts by weight of the second liquid crystal composition. When the content of the side chain type liquid crystal compound is 10 parts by weight or more, it becomes easy to form a film, the polymerizable group concentration in the composition is kept in a preferable range, and the mechanical strength after polymerization is sufficient. It becomes.

Moreover, it is preferable that the 2nd liquid crystal composition mix | blends the dioxetane compound represented by following General formula (2) with the said side chain type liquid crystal compound.

In the formula (2), each R ⁷ independently represents hydrogen, a methyl group or an ethyl group, and each L ³ independently represents a single bond or — (CH ₂ ) _n — (n is an integer of 1 to 12) X ¹ represents each independently a single bond, —O—, —O—CO— or —CO—O—, and M ¹ is represented by formula (3) or formula (4). P1 in the formulas (3) and (4) each independently represents a group selected from the formula (5), P2 represents a group selected from the formula (6), and L ⁴ represents Each independently represents a single bond, —CH═CH—, —C≡C—, —O—, —O—CO— or —CO—O—.
^{-P1-L 4 -P2-L 4} -P1- (3)
-P1-L ⁴ -P1- (4)

In the formulas (5) and (6), Et represents an ethyl group, i-Pr represents an isopropyl group, n-Bu represents a normal butyl group, and t-Bu represents a tertiary butyl group.
More specifically, the linking groups connecting the left and right oxetanyl groups as viewed from the M ¹ group may be different (asymmetric) or the same (symmetric), particularly when two L ³ are different or other Depending on the structure of the linking group, it may not exhibit liquid crystallinity, but it is not a restriction for use.
The compound represented by the general formula (2) can be exemplified by many compounds from the combination of M ¹ , L ³ and X ¹ , and preferably the following compounds can be mentioned.

  The liquid crystal compound is preferably subjected to alignment treatment, and then the oxetanyl group is cationically polymerized to crosslink to fix the liquid crystal state. For this reason, it is preferable that the coating liquid containing the second liquid crystal composition contains a photocation generator and / or a thermal cation generator that generates cations by an external stimulus such as light or heat. Moreover, you may use various sensitizers together as needed.

The photo cation generator means a compound capable of generating a cation by irradiating with light having an appropriate wavelength, and examples thereof include organic sulfonium salt systems, iodonium salt systems, and phosphonium salt systems. Antimonates, phosphates, borates and the like are preferably used as counter ions of these compounds. Specific examples of the compound include Ar ₃ S + SbF ₆ −, Ar ₃ P + BF ₄ −, Ar ₂ I + PF ₆ − (wherein Ar represents a phenyl group or a substituted phenyl group), and the like. In addition, sulfonic acid esters, triazines, diazomethanes, β-ketosulfone, iminosulfonate, benzoinsulfonate and the like can also be used.

  The thermal cation generator is a compound capable of generating a cation when heated to an appropriate temperature, for example, benzylsulfonium salts, benzylammonium salts, benzylpyridinium salts, benzylphosphonium salts, hydrazinium salts, carboxylic acid esters Examples thereof include sulfonic acid esters, amine imides, antimony pentachloride-acetyl chloride complexes, diaryliodonium salts-dibenzyloxycopper, and boron halide-tertiary amine adducts.

  The amount of these cation generators added in the coating liquid containing the second liquid crystal composition depends on the structure of the mesogenic part or spacer part constituting the side chain type polymer liquid crystal compound used, the oxetanyl group equivalent, the alignment of the liquid crystal. Since it differs depending on conditions and the like, it cannot be generally stated, but is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, more preferably 0.2 to 0.2 parts by weight with respect to 100 parts by weight of the second liquid crystal composition. The range is 7 parts by weight. If it is 0.1 parts by weight or more, the generated polymerization reaction can proceed sufficiently, and if it is 20 parts by weight or less, the decomposition residue of the cation generator in the optically anisotropic layer is reduced. It is possible to suppress deterioration of various physical properties such as light resistance.

  In addition, the coating liquid containing the second liquid crystal composition may appropriately contain a solvent in consideration of applicability. The solvent is not particularly limited as long as it can dissolve the second liquid crystal composition and can be distilled off under appropriate conditions. Generally, ketones such as acetone, methyl ethyl ketone, isophorone, cyclohexanone, butoxyethyl alcohol, hexyl, etc. Ether alcohols such as oxyethyl alcohol and methoxy-2-propanol, glycol ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, esters such as ethyl acetate and ethyl lactate, phenols such as phenol and chlorophenol, N, N- Amides such as dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, halogens such as chloroform, tetrachloroethane, dichlorobenzene, and the like, and mixed systems thereof are preferably used. Moreover, in order to form a uniform coating film on the alignment substrate (B), a surfactant, an antifoaming agent, a leveling agent, a colorant, etc. are added to the coating liquid containing the second liquid crystal composition. Also good.

  A coating film is formed by apply | coating the coating liquid containing the above-mentioned 2nd liquid crystal composition on an orientation board | substrate (B) in a molten state. The alignment substrate (B) may be the same as or different from the alignment substrate (A), and preferably has a smooth flat surface. A film or sheet made of an organic polymer, a glass plate And a metal plate. From the viewpoint of cost and continuous productivity, it is preferable to use an organic polymer. Examples of organic polymers include polyvinyl alcohol resins, polyimide resins, polyphenylene oxide resins, polyphenylene sulfide resins, polysulfone resins, polyether ketone resins, polyether ether ketone resins, polyarylate resins, polyethylene Polyester resins such as terephthalate and polyethylene naphthalate; cellulose resins such as diacetyl cellulose and triacetyl cellulose; polycarbonate resins; acrylic resins such as polymethyl methacrylate; styrene resins such as polystyrene and acrylonitrile / styrene copolymers; Olefin polymers such as polyethylene, polypropylene and ethylene / propylene copolymers, cycloolefin resins, vinyl chloride resins, nylon and aromatic polyamides, etc. Amide resins. These may be a mixture of two or more resins. Further, a photocured resin such as acrylic, epoxy, or oxetane, or a thermosetting resin, or a film cured with light or heat can also be used.

  These alignment substrates (B) may be further provided with an alignment film as necessary from the viewpoints of realizing stable homeotropic alignment and improving the solvent resistance of the alignment substrate (B) and controlling adhesion. . As a material for forming the alignment film, polyvinyl alcohol resin, polyimide resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfone resin, polyether ketone resin, polyether ether ketone resin, polyarylate resin, Polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulosic resins such as diacetyl cellulose and triacetyl cellulose, polycarbonate resins, acrylic resins such as polymethyl methacrylate, and styrene resins such as polystyrene and acrylonitrile / styrene copolymers Olefin resins such as polyethylene, polypropylene, ethylene / propylene copolymers, cycloolefin resins, vinyl chloride resins, nylon and aromatic polymers It includes transparent resin amide resins and the like. These may be a mixture in which the two or more kinds of resins are mixed. In addition, a cured film obtained by curing a photocurable resin or thermosetting resin such as acrylic, epoxy, or oxetane with light or heat can also be used. As a method for forming these alignment films, it is possible to use a direct or solution application method, vapor deposition, sputtering, co-extrusion with an alignment substrate, or the like. In addition, an inorganic material layer may be formed on the alignment substrate (B) by a method such as vapor deposition, sputtering, or coating. Examples of inorganic substances include inorganic metals such as aluminum and silver, and inorganic compounds such as silica, silicon oxide, and aluminum oxide.

  Next, a method for applying a coating liquid containing the second liquid crystal composition to the alignment substrate (B) will be described. Regardless of the method of directly applying the liquid crystal composition or the method of applying a solution, the application method is not particularly limited as long as the uniformity of the coating film is ensured, and a known method is adopted. Can do. Examples thereof include spin coating, die coating, curtain coating, dip coating, and roll coating. In the method of applying the solution of the liquid crystal composition, it is preferable to include a drying step for removing the solvent after the application. As long as the uniformity of a coating film is maintained, this drying process can employ | adopt a well-known method, without being specifically limited. For example, a method such as a heater (furnace) or hot air blowing may be used.

  Subsequently, the second liquid crystal composition is homeotropically aligned on the alignment substrate (B) by a method such as heat treatment. In this heat treatment, the liquid crystal can be aligned by the self-alignment ability inherent in the liquid crystal compound by heating to the liquid crystal phase expression temperature range of the liquid crystal compound in the second liquid crystal composition used. The conditions for the heat treatment cannot be generally specified because the optimum conditions and limit values differ depending on the liquid crystal phase behavior temperature (transition temperature) of the liquid crystal compound to be used, but are usually in the range of 10 to 250 ° C., preferably 30 to 160 ° C. When the liquid crystal compound has a glass transition temperature, it is preferably heat-treated at a temperature not lower than the glass transition point (Tg), more preferably at a temperature higher by 10 ° C. than Tg. If Tg is within the above numerical range, the liquid crystal alignment can be sufficiently advanced, and it is possible to suppress adverse effects on the cationically polymerizable reactive group and the alignment substrate in the second liquid crystal composition. Moreover, about heat processing time, it is 3 seconds-30 minutes normally, Preferably it is the range of 10 seconds-20 minutes. If the heat treatment time is 3 seconds or more, the liquid crystal alignment is sufficiently completed, and if the heat treatment time is 30 minutes or less, good productivity can be maintained.

  Although the thickness of the second optically anisotropic layer depends on the type of the liquid crystal image display device and various optical parameters, it cannot be generally stated, but is usually 0.1 to 100 μm, preferably 0.3 to 50 μm, More preferably, it is 0.5-20 micrometers. If the thickness of the second optically anisotropic layer is within the above numerical range, it becomes easy to express a desired retardation, and the organic EL element can be made thin.

The homeotropically aligned second optically anisotropic layer obtained as described above is evaluated for orientation by measuring the optical phase difference of the optically anisotropic layer at an angle inclined from normal incidence. Can do. When the liquid crystal is homeotropically aligned, this retardation value is symmetric with respect to normal incidence.
Several methods can be used to measure the optical phase difference. For example, an automatic birefringence measuring device KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd., AxoScan manufactured by AXOMETRICS, and a polarizing microscope can be used.

The second optically anisotropic layer obtained as described above preferably has a refractive index characteristic of nz2> nx2 ≧ ny2.
(Where nx2 is the maximum main refractive index in the second optical anisotropic layer surface for light with a wavelength of 550 nm, and ny2 is the direction having the maximum main refractive index in the second optical anisotropic layer surface for light with a wavelength of 550 nm. The main refractive index in the direction orthogonal to nz2 is the main refractive index in the thickness direction of the second optically anisotropic layer for light having a wavelength of 550 nm.)

Moreover, it is preferable that a 2nd optically anisotropic layer has a retardation characteristic which satisfies following formula (7) and (8).
20 nm ≧ Re2 (550) ≧ 0 nm (7)
−30 nm ≧ Rth2 (550) ≧ −500 nm (8)
If it is out of this range, the effect of improving the viewing angle characteristics of the laminate is lowered, and it tends to be difficult to produce a film, which is not desirable.

More preferably, the second optically anisotropic layer has a retardation characteristic that satisfies the following formula (9).
−45 nm ≧ Rth2 ≧ −400 nm (9)
More preferably, it has a retardation characteristic that satisfies the following formula (10).
−40 nm ≧ Rth2 ≧ −300 nm (10)

More preferably, the second optical anisotropic layer has a retardation characteristic that satisfies the following formula (11).
10 nm ≧ Re2 ≧ 0 nm (11)
More preferably, it has a retardation characteristic that satisfies the following formula (12).
5 nm ≧ Re2 ≧ 0 nm (12)

Further, the thickness direction retardation value Rth2 (= {(nx2 + ny2) / 2−nz2} × d) of the second optical anisotropic layer is the thickness direction retardation value of the first optical anisotropic layer. In relation to Rth1 (= {(nx1a + ny1a) / 2−nz1a} × d1), it is preferable that the following expression (13) is satisfied.
40 nm ≧ Rth1 (550) + Rth2 (550) ≧ −40 nm (13)
When the laminated body satisfies the retardation characteristic, the viewing angle characteristic of the laminated body can be remarkably improved.

[Step 5: Bonding of first optically anisotropic layer and second optically anisotropic layer]
Next, the second optical anisotropic layer is bonded to the surface from which the alignment substrate (A) of the first optical anisotropic layer bonded to the polarizer is peeled off. The second optical anisotropic layer can be bonded to the first optical anisotropic layer via the above-mentioned pressure-sensitive adhesive or adhesive. The pressure-sensitive adhesive or adhesive used here may be the same as or different from that used for bonding the first optically anisotropic layer and the polarizer.

[Step 6: Stripping of alignment substrate (B)]
Next, the alignment substrate (B) is peeled from the second optical anisotropic layer bonded to the first optical anisotropic layer. After bonding the first optically anisotropic layer and the second optically anisotropic layer, the alignment substrate (B) is peeled off from the second optically anisotropic layer. The laminated body which does not have can be manufactured. In the present invention, when the first optically anisotropic layer and the second optically anisotropic layer are bonded together via an adhesive or an adhesive, after the adhesive or adhesive is cured, It is preferable to peel the alignment substrate (B).

  When the alignment substrate (B) is peeled from the second optical anisotropic layer, the second optical anisotropic layer is exposed. Therefore, you may coat | cover the exposed 2nd optically anisotropic layer with a transparent protective layer. As the transparent protective layer, a transparent resin film such as polyester or triacetyl cellulose, a photocurable resin such as acrylic or epoxy, and the like can be used.

  The laminated body 100 manufactured by the said method is demonstrated referring FIG. The stacked body 100 includes at least a first optical anisotropic layer 10, a second optical anisotropic layer 40, and a polarizer 30. The linearly polarized light transmitted through the polarizer 30 is converted into circularly polarized light by the first optical anisotropic layer 10. The light (circularly polarized light) emitted from the first optically anisotropic layer 10 is incident on the second optically anisotropic layer 40. The second optically anisotropic layer 40 has a very large front phase difference. Since it is small, it hardly affects the state of circularly polarized light. The light transmitted through the second optical anisotropic layer 40 is specularly reflected by the cathode of the organic EL element as will be described later, the phase is inverted by 180 degrees, and is incident on the second optical anisotropic layer 40 again. However, the polarization state hardly changes. . The light transmitted through the second optical anisotropic layer 40 is incident on the first optical anisotropic layer 10, but is linearly polarized light orthogonal to the transmission axis of the polarizer 30 by the first optical anisotropic layer 10. Is absorbed by the polarizer 30.

  On the other hand, since external light incident from an oblique direction has a long optical path length when passing through the first optical anisotropic layer 10, the first optical anisotropic layer 40 is not present when the second optical anisotropic layer 40 is not present. The optically anisotropic layer 10 alone does not function as a quarter-wave plate, becomes elliptically polarized light, and the reflected light partially transmits when passing through the polarizer 30 and is visually recognized by an observer. That is, the conventional polarizing plate without the second optically anisotropic layer 40 has a problem that the effect of preventing reflection of external light from an oblique direction is significantly reduced compared to the front direction. However, since the laminated body of the present invention has the second optical anisotropic layer 40 in addition to the first optical anisotropic layer 10, it is almost a quarter-wave plate for light from an oblique direction. It becomes possible to function, and reflection of external light can be prevented not only for the front but also for light from an oblique direction. For this reason, the image display apparatus provided with the laminate according to the present invention can be thinned, has little viewing angle dependency, and can display with high contrast even in an oblique direction.

  In one embodiment, the laminate may include a protective film such as a TAC (triacetyl cellulose) film on the polarizer side (not shown). Furthermore, the laminated body of this invention may be equipped with members, such as a light-diffusion layer, a light control film, a light-guide plate, and a prism sheet, as needed.

  Although there will be no restriction | limiting in particular if the total thickness of the laminated body of this invention is a range which can be used as an organic EL element etc., 40-500 micrometers is preferable, More preferably, it is 50-200 micrometers, More preferably, it is 60-150 micrometers.

<Image display device>
An image display apparatus according to an embodiment will be described with reference to the drawings. FIG. 6 is a schematic cross-sectional view illustrating a schematic configuration of the image display device. As shown in FIG. 6, the image display device 200 includes at least the above-described laminate 100, a transparent substrate 90, an anode 91, a light emitting layer 92, and a cathode 93. In the image display device 200 having such a configuration, electrons are injected from the cathode 93 and holes are injected from the anode 91, and both are recombined in the light emitting layer 92, so that the light emission characteristics of the light emitting layer 92 are satisfied. Emits light at a wavelength. The light generated in the light emitting layer 92 is reflected directly or by the cathode 93, and then passes through the anode 91, the transparent substrate 90, and the laminate 100 and is emitted to the outside.

  At least half of the external light incident perpendicularly to the element surface from the outside of the image display device 200 due to sunlight or indoor lighting is absorbed by the polarizer 30, and the rest is transmitted as linearly polarized light. Incident to the isotropic layer 10. Since the first optical anisotropic layer 10 functions as a quarter wavelength plate, it is converted into circularly polarized light when passing through the first optical anisotropic layer 10. The light emitted from the first optically anisotropic layer 10 is incident on the second optically anisotropic layer 40. Since the second optically anisotropic layer 40 has a very small front phase difference, It has little effect on the state of polarization. The circularly polarized light that has passed through the second optically anisotropic layer 40 passes through the transparent substrate 90, the anode 91, and the light emitting layer 92, and is specularly reflected by the cathode 93. However, when reflected, the phase is inverted by 180 degrees. It is reflected as circularly polarized light, which is the reverse of the incident time. The reversely circularly polarized light passes through the light emitting layer 92, the anode 91, the transparent substrate 90, and the second optical anisotropic layer 40 without changing the polarization state, and is incident on the first optical anisotropic layer 10. However, since it is converted into linearly polarized light orthogonal to the transmission axis of the polarizer 30 by the first optical anisotropic layer 10, it is absorbed by the polarizer 30 and is not emitted outside.

  On the other hand, since external light incident from an oblique direction has a long optical path length when passing through the first optical anisotropic layer 10, the first optical anisotropic layer 40 is not present when the second optical anisotropic layer 40 is not present. The optically anisotropic layer 10 alone does not function as a quarter-wave plate, becomes elliptically polarized light, and the reflected light partially transmits when passing through the polarizer 30 and is visually recognized by an observer. That is, the conventional circularly polarizing plate without the second optically anisotropic layer 40 has a problem that the antireflection effect of the external light from the oblique direction is significantly reduced as compared with the front direction. However, since the laminated body of the present invention has the second optical anisotropic layer 40 in addition to the first optical anisotropic layer 10, it is almost a quarter-wave plate for light from an oblique direction. It becomes possible to function, and reflection of external light can be prevented not only for the front but also for light from an oblique direction.

  The image display device can be provided with other constituent members in addition to the constituent members described above. For example, by attaching a color filter, an image display device capable of performing multicolor or full color display with high color purity can be manufactured.

  The image display device according to the present invention may be provided with members (all not shown) such as a light diffusion layer, a light control film, a light guide plate, and a prism sheet as necessary.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

In addition, each analysis method used in the Example is as follows.
(1) Molecular weight The compound was dissolved in tetrahydrofuran and measured with an 8020 GPC system manufactured by Tosoh Corporation. The column was measured by connecting TSK-GEL SuperH1000, SuperH2000, SuperH3000, and SuperH4000 in series and using tetrahydrofuran as an eluent. Polystyrene was used as a standard for calibration of the weight average molecular weight.
(2) Thermal behavior, glass transition temperature (Tg), and phase transition temperature of liquid crystal composition The phase behavior of the liquid crystal composition was observed on a hot stage FP82HT manufactured by METTLER and observed with an Olympus BH2 polarizing microscope. did. The glass transition temperature (Tg) and the phase transition temperature were measured using a differential scanning calorimeter DSC8000 manufactured by Perkin-Elmer at a heating / cooling rate of 20 ° C./min.
(3) Alignment state of liquid crystal composition It confirmed with the Olympus optical company BH2 polarizing microscope.
(4) Film thickness SURFACE TEXTURE ANALYSIS SYSTEM Dektak 3030ST manufactured by SLOAN or DIGIMICRO MFC-101 manufactured by Nikon was used. Moreover, the method of calculating | requiring a film thickness from the data of interference wave measurement (The JASCO Corporation UV / visible / near infrared spectrophotometer V-570) and refractive index data was used together.
(5) Birefringence, in-plane retardation value Re, and retardation value Rth in the film thickness direction,
The birefringence, the in-plane retardation value Re, and the retardation value Rth in the film thickness direction were measured using an automatic birefringence meter KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd., and an AxoScan manufactured by AXOMETRICS.
(6) Absorption spectrum and transmittance of dichroic dye Measured using a spectrum (V-570) manufactured by JASCO Corporation.

<Preparation of coating liquid containing first liquid crystal composition (A) and dichroic dye>
A rod-shaped liquid crystal compound (21) represented by the following formula and a compound (22) having two or more kinds of mesogenic groups were prepared. The rod-like liquid crystal compound (21) and the compound (22) were produced by the method described in JP-A-2002-267838.

  17.6% by weight of the rod-shaped liquid crystal compound (21) and 2.0% by weight of the compound (22) having two or more kinds of mesogenic groups were mixed, and the first mixture (first liquid crystal composition (A) and Obtained). Next, 0.08 wt.% Of the dichroic dye (Nagase Sangyo Trisazo Dye, trade name: G-241, maximum absorption wavelength 560 nm) with respect to the first liquid crystal composition (A) is 100 wt. Further, 3.0 parts by weight of a polymerization initiator (BASF, trade name: Irgacure 651) is added to 100 parts by weight of the total amount of the first liquid crystal composition (A) and the dichroic dye. Thus, a second mixture (solid) obtained by mixing the first liquid crystal composition (A), the dichroic dye and the polymerization initiator was obtained.

  Next, the second mixture obtained as described above is dissolved in methyl ethyl ketone (solvent), and the insoluble matter is filtered with a polytetrafluoroethylene filter having a pore diameter of 0.45 μm, whereby the first liquid crystal composition is obtained. A coating solution containing the product (A) and a dichroic dye was obtained. In the preparation of the coating liquid containing the first liquid crystal composition (A) and the dichroic dye, the content of the solvent in the coating liquid is 80 parts by weight, and the first liquid crystal composition The total amount of (A), dichroic dye and polymerization initiator was adjusted to 20 parts by weight.

<Preparation of coating liquid (B) containing second liquid crystal composition (B)>
With reference to JP 2004-315736 A and JP 2007-277462 A, a side chain type liquid crystal compound represented by the following formula (7) was synthesized by radical polymerization. The number average molecular weight Mn of the obtained side chain type liquid crystal compound was 8,900, and the weight average molecular weight Mw was 19,600. In addition, the number in Formula (7) represents the molar composition ratio of each unit, and does not mean a block copolymer. As a result of DSC measurement, Tg at the time of temperature increase was 59 ° C., and a temperature higher than that showed a nematic liquid crystal phase and an isotropic phase at 175 ° C. or higher.
0.9 g of the side chain type liquid crystal compound represented by the formula (7), 0.05 g of the dioxetane compound represented by the formula (8), and 9 g of the acrylic compound represented by the formula (9) In a dark place, 0.1 g (formula (7), formula (8), 50% propylene carbonate solution (manufactured by Aldrich) of cationic photoinitiator triallylsulfonium hexafluoroantimonate) in the dark. A concentration of 5% by weight based on the total weight of the mixture of the three compounds of formula (9), and 0.002 g of a perfluoroalkyl group-containing surfactant as the surfactant (formula (7), formula (8), After adding 0.2 wt% of the total weight of the liquid crystal material comprising the three compounds of the formula (9), a polytetrafluoroethylene filter having a pore diameter of 0.5 μm (manufactured by Advantech Toyo Co., Ltd., product name) The second liquid crystal composition was filtered (coating solution containing B) (B) was prepared in 5JP050AN). The dioxetane compound of the formula (8) was observed by polarizing microscope and DSC measurement. As a result, the crystal phase changed from the crystal phase to the nematic liquid crystal phase at 74 ° C. at the time of temperature increase, became an isotropic phase at 96 ° C., and 88 ° C. at the time of temperature decrease. After transition from the isotropic phase to the nematic phase, a crystalline phase was exhibited at 54 ° C. Moreover, the acrylic compound of Formula (9) did not show a liquid crystal phase as a result of polarizing microscope observation and DSC measurement, and melted at 30 ° C. when the temperature was raised. A part of the second liquid crystal composition (B) was applied onto a glass substrate by a spin coating method, and heated on a hot plate at 55 ° C. for 60 minutes to remove the solvent. The composition was scraped from the glass substrate and the thermal behavior was confirmed by polarization microscope observation and DSC measurement. The Tg at the time of temperature increase was 50 ° C., showing a liquid crystal phase up to 155 ° C., and a temperature higher than that. It showed an isotropic phase.

<Preparation of Coating Liquid (C) Containing Second Liquid Crystal Composition (C)>
First, second liquid crystal compounds (C) (acrylate-based polymerizable liquid crystal compounds) represented by the following formulas (110) to (113) were prepared.
Each polymerizable liquid crystal compound represented by the general formulas (110) to (113) was produced by a known method. Specifically, the compound represented by the above general formula (110) (hereinafter sometimes simply referred to as “liquid crystal compound (I)”) was described in British Patent Application Publication No. 2,280,445. A compound produced by the method and represented by the above general formula (111) (hereinafter sometimes simply referred to as “liquid crystal compound (II)”) was published in 1989 (DJ Broer et al., “ Makromol. Chem. ", Vol. 190, 1989, pp. 3201 to 3215), and a compound represented by the above general formula (112) (hereinafter sometimes referred to simply as" liquid crystal compound "). III) ") and (113) (hereinafter sometimes simply referred to as" liquid crystal compound (IV) ") are disclosed in WO 93/22397. It was prepared by placing methods. Moreover, all the polymerizable liquid crystal compounds represented by the general formulas (110) to (113) were solid at room temperature (25 ° C.).

  Next, the liquid crystal compounds (I) to (IV) are mixed with the liquid crystal compound (I): 35 parts by weight, the liquid crystal compound (II): 23 parts by weight, the liquid crystal compound (III): 23 parts by weight, and the liquid crystal compound ( IV): Mixed at a ratio of 19 parts by weight to obtain a second liquid crystal composition (C). Next, a polymerization initiator (trade name “Irgacure 907” manufactured by BASF Corporation) was added at a ratio of 4.0 parts by weight with respect to the second liquid crystal composition (C), and then dichlorobenzene (solvent). Then, the insoluble matter was filtered with a polytetrafluoroethylene filter having a pore diameter of 0.45 μm to obtain a coating liquid (C) containing a second liquid crystal composition (C), a polymerization initiator and a solvent. In the preparation of the coating liquid (C) containing the second liquid crystal composition (C), the polymerization initiator and the solvent, the content of the solvent in the coating liquid is 80 parts by weight, and the second liquid crystal The total amount of the composition (C) and the polymerization initiator was adjusted to 20 parts by weight.

<Preparation of PVA (A) Solution and Production of PVA Oriented Substrate (A)>
The alignment substrate (A) was produced as follows. A 38 μm thick polyethylene terephthalate (PET) film (trade name: Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) was cut into a 15 cm square, and alkyl-modified polyvinyl alcohol (PVA: manufactured by Kuraray Co., Ltd., trade name: MP-203). 5% by weight solution (the solvent is a mixed solvent of water and isopropyl alcohol in a weight ratio of 1: 1) (PVA (A) solution) is applied by spin coating and dried on a hot plate at 50 ° C. for 30 minutes. And heated in an oven at 120 ° C. for 10 minutes. Subsequently, it was rubbed with a rayon rubbing cloth to prepare a PVA oriented substrate (A) (PVA (A) layer / PET) comprising a PVA layer and a PET film. The film thickness of the obtained PVA (A) layer was 1.2 μm. The peripheral speed ratio during rubbing (moving speed of rubbing cloth / moving speed of substrate film) was 4.

<Preparation of PVA (B) Solution and Production of PVA Oriented Substrate (B)>
In a 1 L three-necked flask equipped with a reflux condenser and a stirrer, 24.0 g of PVA (product name: JL-18E, saponification degree: 83-86%, average polymerization degree: 1800) manufactured by Nippon Vinegar Poval Co., Ltd. and deionized 460.8 g of water (electric conductivity value: 1 μS / cm or less) was added, heated at 95 ° C. for 3 hours, dissolved by stirring, and then cooled to 70 ° C. 115.2 g of isopropyl alcohol (manufactured by Kanto Chemical Co., Inc., deer grade, purity 99% or more) was gradually added and stirred at 65 ° C. to 70 ° C. for 2 hours to obtain a transparent uniform solution. After cooling to room temperature, the PVA (B) solution was extracted from the tank while filtering. For the filtration, a cartridge filter (ADVANTEC TCP-JX-S1FE (1 μm)) capable of collecting particles having an average particle diameter of 1 μm was used, and 350 g of a PVA (B) solution having a solid content concentration of about 4% by weight was obtained.
Next, a polyethylene terephthalate (PET) film having a thickness of 50 μm (trade name: Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) was cut into a 15 cm square, subjected to corona discharge treatment (100 W · min / m ² ), and then thickened. The sample was fixed on a 1.1 mm, 13 cm square glass substrate and set on a spin coater. The PVA (B) solution is applied by spin coating at 300 rpm for 30 seconds, dried on a hot plate at 50 ° C. for 30 minutes, and then heated in an oven at 120 ° C. for 10 minutes to obtain a PVA oriented substrate (B) (PVA (B) layer / PET) was obtained. The film thickness of the PVA (B) layer of the obtained PVA oriented substrate (B) was 1.2 μm.

<Production of polarizer>
The polyvinyl alcohol film was immersed in warm water to swell, then dyed in an iodine / potassium iodide aqueous solution, and then uniaxially stretched in an aqueous boric acid solution to obtain a polarizer. When the single transmittance, parallel transmittance, and orthogonal transmittance were examined with a spectrophotometer, this polarizer had a thickness of 20 μm, a transmittance of 43.5%, and a polarization degree of 99.9%.

<Production of Polarizer (A1)>
TAC / adhesion is made by adhering a 40 μm thick triacetylcellulose film (product name: T40UZ, hereinafter TAC) as a transparent protective layer to one surface of the polarizer via a 5 μm thick adhesive layer. A polarizer (A1) having a layer / polarizer configuration was prepared.

<Production of Polarizer (B1)>
A polarizer having a structure of TAC / adhesive layer / polarizer / adhesive layer / TAC is obtained by adhering TAC as a transparent protective layer to the polarizer surface side of the polarizer (A1) via an adhesive layer having a thickness of 5 μm. (B1) was produced.

<Production of Polarizer (C1)>
A COP film having a thickness of 40 μm (manufactured by Nippon Zeon Co., Ltd., trade name: ZEONOR) is adhered to the polarizer surface side of the polarizer (A1) as a transparent protective layer via an adhesive layer having a thickness of 5 μm. A polarizer (C1) composed of / adhesive layer / polarizer / adhesive layer / COP was produced.

<Production of Polarizer (D1)>
From the TAC / adhesive layer / polarizer / adhesive layer / acrylic film, an acrylic film having a thickness of 40 μm is adhered as a transparent protective layer to the polarizer surface side of the polarizer (A1) via an adhesive layer having a thickness of 5 μm. A polarizer (D1) was produced.

Example 1
<Preparation of the 1st optically anisotropic layer which consists of a 1st liquid crystal composition (A)>
A coating liquid containing a first liquid crystal composition (A), a dichroic dye, a polymerization initiator, and a solvent is applied (coated) to the PVA alignment substrate (A) by a spin coating method. Film thickness: 12.5 μm) was formed, and a laminate of the coating film and the alignment substrate (A) was obtained.

  Next, the solvent was dried and removed from the coating film by allowing the laminate of the coating film and the alignment substrate (A) to stand for 2 minutes under the conditions of pressure: 1013 hPa and temperature: room temperature (25 ° C.) (solvent removal step) ). In addition, it was confirmed that the solvent was removed from the entire surface of the coating film after 2 minutes from the completion of the coating on the alignment substrate (A).

Next, ultraviolet light (however, light having a wavelength of 365 nm was measured under a condition where the integrated irradiation amount was 200 mJ / cm ² using a high-pressure mercury lamp with an illuminance of 15 mW / cm ² with respect to the dried coating film. The first liquid crystal composition (A) is polymerized (cured) to fix the alignment state, and the laminate (a) (the first liquid crystal composition (A) comprising the first liquid crystal composition (A)) is irradiated. Optically anisotropic layer / PVA (A) / PET) was obtained.

  Since the PET film used as the alignment substrate has a large birefringence and is not preferable as a retardation film, the first optical anisotropic layer of the laminate (a) was transferred to the TAC via an adhesive. That is, the first optically anisotropic layer and TAC are bonded via an adhesive having a thickness of 15 μm, the alignment substrate (A) is peeled off, and the laminate (b) (from the first liquid crystal composition (A)). First optically anisotropic layer / adhesive layer / TAC) was obtained. When the laminate (b) was observed under a polarizing microscope, it was found that there was no disclination (orientation defect) and the monodomain was uniformly oriented.

  The wavelength dispersion characteristic of the retardation (Δnd) in the in-plane direction of the laminate (b) having the first optically anisotropic layer made of TAC and the first liquid crystal composition (A) and TAC alone is shown by Axometrics. The product name “Axoscan” was used, and the birefringence wavelength dispersion characteristic of the first optically anisotropic layer was measured from the subtraction of the two. FIG. 7 shows the birefringence wavelength dispersion characteristics of the first optically anisotropic layer. The in-plane retardation value Re1 (550) at 550 nm was 143 nm, and the retardation value Rth1 (550) in the thickness direction was 72 nm. Re1 (500) / Re1 (550) was 0.973, and Re1 (580) / Re1 (550) was 1.014. Further, Re1a (450) / Re1a (550) = 0.908 and Re1a (650) / Re1a (550) = 1.026. In particular, in the measurement wavelength range of 500 to 600 nm, it was confirmed that the phase difference increases as the measurement wavelength is longer. The thickness of the first optical anisotropic layer was 2.5 μm.

<Preparation of Second Optically Anisotropic Layer Consisting of Second Liquid Crystal Composition (B)>
The coating liquid (B) containing the second liquid crystal composition (B) was applied onto the PVA alignment substrate (B) by a spin coating method. Subsequently, it dried for 10 minutes with a 55 degreeC hotplate, and the 2nd liquid crystal composition (B) was orientated by heat-processing for 3 minutes in 100 degreeC oven. Next, the sample was brought into close contact with an aluminum plate heated to 70 ° C., and 300 mJ / cm ² ultraviolet light (amount of light measured at 365 nm) was irradiated in the air with a high-pressure mercury lamp lamp to cation the oxetanyl group. The second liquid crystal composition (B) is made of the second liquid crystal composition (B) having the alignment state fixed on the PVA alignment substrate (B) by polymerizing (curing) the second liquid crystal composition (B). A laminate (c) of optically anisotropic layers (second optically anisotropic layer / PVA (B) / PET comprising the second liquid crystal composition (B)) was obtained. The thickness of the second optical anisotropic layer was 0.8 μm.

  Since the PET film used as the alignment substrate has a large birefringence and it is difficult to optically measure the second optical anisotropic layer, the second liquid crystal composition (B) of the laminate (c) is used. The optically anisotropic layer was transferred onto an optically isotropic glass substrate having a thickness of 0.5 mm and a 40 mm square through an optically isotropic adhesive. That is, the second optically anisotropic layer of the laminate (c) and the glass substrate are bonded via an adhesive having a thickness of 15 μm, and the alignment substrate (B) is peeled off, thereby the laminate with a glass substrate. (D) (second optically anisotropic layer / adhesive layer / glass substrate comprising the second liquid crystal composition (B)) was obtained.

  When the obtained laminate (d) is observed under a polarizing microscope with crossed Nicols, it is a homeotropic alignment having a positive uniaxial refractive index from a microscopic observation with uniform orientation of monodomains without disclination. I understood. When the laminate (d) was tilted and light was incident from an oblique direction, observation was similarly performed with crossed Nicols, and transmission of light was observed. Moreover, as a result of measuring the phase difference of the laminate (d), the in-plane retardation value Re2 (550) of the second optically anisotropic layer alone was 0 nm, and the retardation value Rth2 (550) in the thickness direction was -81 nm.

<Preparation of laminate (e)>
On the polarizer side of the polarizer (A1), the first optical anisotropic layer of the laminate (a) was transferred using a UV curable acrylic adhesive. That is, an acrylic adhesive is applied on the first optically anisotropic layer of the laminate (a) so as to have a thickness of 5 μm, and the polarizer of the polarizer (A1) (TAC / adhesive layer / polarizer). From the TAC / adhesive layer / polarizer / adhesive layer / first liquid crystal composition (A), the adhesive layer is cured by irradiation with 600 mJ / cm ² ultraviolet rays from the PET film side. After forming a laminate composed of the first optically anisotropic layer / PVA alignment substrate (A), the PVA alignment substrate (A) is peeled off and the laminate (e) (TAC / adhesion layer / polarizer / adhesion) Layer / first optically anisotropic layer comprising the first liquid crystal composition (A)). At this time, the absorption axis of the polarizer and the slow axis of the first optical anisotropic layer of the laminate (a) were bonded at an angle of 45 degrees. The laminating angle of the slow axis of the optically anisotropic layer may be either 45 degrees or 135 degrees, and it may be appropriately selected depending on the method of using the laminate. The thickness of the laminate (e) was 72.5 μm.

<Preparation of laminate (A)>
The laminate (c) is provided on the side of the first optically anisotropic layer comprising the first liquid crystal composition (A) of the laminate (e) via a UV-curable V-curable acrylic adhesive having a thickness of 5 μm. The second optically anisotropic layer comprising the second liquid crystal composition (B) was transferred. That is, a UV curable acrylic adhesive was applied as an adhesive layer on the second optically anisotropic layer made of the second liquid crystal composition (B) of the laminate (c) to a thickness of 5 μm. The first optical anisotropic layer side of the laminate (e) is adhered and laminated, and the adhesive layer is cured by irradiating 600 mJ / cm ² of ultraviolet light from the PET film side, and TAC / adhesive layer / polarizer After forming a laminate composed of / adhesive layer / first optical anisotropic layer / UV curable resin layer / second optical anisotropic layer / PVA alignment substrate (B), the PVA alignment substrate (B) is The laminate (A) (TAC / adhesive layer / polarizer / adhesive layer / first liquid crystal composition (A) first optical anisotropic layer / adhesive layer / second liquid crystal composition ( A second optically anisotropic layer consisting of B) was obtained. The thickness of the laminate (A) was 78.3 μm, and the thickness of the laminate (A) excluding the polarizer (A1) was 13.3 μm. A laminate (A) comprising a first optical anisotropic layer made of the first liquid crystal composition (A) and a second optical anisotropic layer made of the second liquid crystal composition (B). , The value of Rth1 (550) + Rth2 (550) was +9 nm.

(Example 2)
<Preparation of laminate (B)>
The first optically anisotropic layer of the laminate (e) and the second optically anisotropic layer of the laminate (c) are bonded with an optically isotropic adhesive having a thickness of 15 μm and oriented. By peeling off the substrate (B), only the second optical anisotropic layer made of the second liquid crystal composition (B) is transferred to the polarizer (A2), and the laminate (B) (TAC / adhesive layer) / Polarizer / adhesive layer / first optical anisotropic layer comprising the first liquid crystal composition (A) / adhesive layer / second optical anisotropic layer comprising the second liquid crystal composition (B)) Got. The thickness of the laminate (B) was 88.3 μm, and the thickness of the laminate (B) excluding the polarizer (A1) was 23.3 μm.

Example 3
<Preparation of Second Optically Anisotropic Layer Consisting of Second Liquid Crystal Composition (C)>
A laminate composed of the second liquid crystal composition (C) on the PVA alignment substrate (B) in the same manner as in Example 1 except that the coating liquid (C) containing the second liquid crystal compound (C) was used. A product (f) (second optically anisotropic layer / PVA alignment substrate (B) comprising the second liquid crystal composition (C)) was obtained. The thickness of the second optically anisotropic layer made of the second liquid crystal composition (C) was 1.0 μm. In the same manner as in Example 1, the second optically anisotropic layer on the PVA-oriented substrate (B) is optically optically having a thickness of 0.5 mm and a 40 mm square via an optically isotropic adhesive. Was transferred onto an isotropic glass substrate to obtain a laminate (g) (second optically anisotropic layer / adhesive layer / glass substrate comprising the second liquid crystal compound (C)) with a glass substrate. . When this laminate (g) was observed under a polarizing microscope with crossed Nicols, it was found that it had a uniform orientation of monodomains with no disclination, and homeotropic orientation with positive uniaxiality from microscopic observation. . When this film was tilted and light was incident from an oblique direction and observed in the same manner with crossed Nicols, light transmission was observed. Further, as a result of measuring the optical retardation of the laminate (g), the in-plane retardation value Re2 (550) of the second optically anisotropic layer alone was 0 nm, and the retardation value Rth2 in the thickness direction ( 550) was -75 nm.

<Preparation of laminate (C)>
A pressure-sensitive adhesive having a thickness of 15 μm which is optically isotropic of the first optical anisotropic layer comprising the first liquid crystal composition (A) in the laminate (a) and the polarizer side of the polarizer (A1). And the alignment substrate (A) is peeled off, whereby only the first optical anisotropic layer is transferred to the polarizer (A1), and the laminate (h) (TAC / adhesive layer / polarizer / adhesive) Layer / first optically anisotropic layer comprising the first liquid crystal compound (A)). Further, after that, the second optical layer made of the second liquid crystal composition (C) of the laminate (f) is disposed on the first optical anisotropic layer side of the laminate (h) through an adhesive layer having a thickness of 5 μm. The anisotropic layer was transferred. That is, a UV curable acrylic adhesive is applied as an adhesive layer on the second optically anisotropic layer made of the second liquid crystal composition (C) of the laminate (f) so as to have a thickness of 5 μm. The first optically anisotropic layer is bonded and laminated, and the adhesive layer is cured by irradiating with 600 mJ / cm ² ultraviolet rays from the PET film side, and TAC / adhesive layer / polarizer / adhesive layer / first Laminate comprising the first optically anisotropic layer comprising the liquid crystal composition (A) / adhesive layer / second optically anisotropic layer comprising the second liquid crystal composition (C) / PVA alignment substrate (B) After forming PVA, the PVA alignment substrate (B) is peeled off, and the laminate (C) (first optical anisotropy comprising TAC / adhesive layer / polarizer / adhesive layer / first liquid crystal composition (A)) is formed. Layer / adhesive layer / second liquid crystal anisotropic layer (C)) was obtained. The thickness of the laminate (C) was 88.5 μm, and the thickness of the laminate (C) excluding the polarizer (A1) was 23.5 μm. A laminate (C) comprising the first optical anisotropic layer made of the first liquid crystal composition (A) and the second optical anisotropic layer made of the second liquid crystal composition (C). , The value of Rth1 (550) + Rth2 (550) is −3 nm.

Example 4
<Preparation of laminate (D)>
A first optical anisotropic layer composed of the first liquid crystal composition (A) of the laminate (h) and a second optical anisotropy composed of the second liquid crystal compound (C) in the laminate (f). The second optically anisotropic layer made of the second liquid crystal compound (C) is bonded to the optical layer with an optically isotropic adhesive having a thickness of 15 μm and the alignment substrate (B) is peeled off. The first optically anisotropic layer / adhesive layer comprising the laminate (D) (TAC / adhesive layer / polarizer / adhesive layer / first liquid crystal composition (A)) / The 2nd optically anisotropic layer which consists of a 2nd liquid crystal compound (C) was obtained. The thickness of the laminate (D) was 98.5 μm, and the thickness of the laminate (D) excluding the polarizer (A1) was 33.5 μm.

(Example 5)
<Preparation of laminate (E)>
Except having changed the polarizer (A1) used when producing the laminate (e) in Example 1 to the polarizer (B1), the same as the case of producing the laminate (A) in Example 1. A laminate (i) (TAC / adhesive layer / polarizer / adhesive layer / TAC / adhesive layer / first optically anisotropic layer comprising the first liquid crystal composition (A)) was prepared by the procedure. Further, the second liquid crystal of the laminate (f) is disposed on the side of the first optical anisotropic layer made of the first liquid crystal composition (A) of the laminate (i) via an adhesive layer having a thickness of 5 μm. Only the second optical anisotropic layer made of the polymerizable liquid crystal compound (C) is obtained by laminating the second optical anisotropic layer made of the composition (C) and peeling the PVA alignment substrate (B). Was transferred to the laminate (i). That is, a UV curable acrylic adhesive is applied as an adhesive layer on the second optically anisotropic layer made of the second liquid crystal compound (C) of the laminate (i) to a thickness of 5 μm. , Laminate (E) (TAC / adhesive layer / polarizer / adhesive layer / TAC / adhesive layer / first optical anisotropic layer / adhesive layer / second liquid crystal comprising the first liquid crystal composition (A)) A second optically anisotropic layer comprising compound (C) was obtained. The thickness of the laminate (E) was 123.5 μm, and the thickness of the laminate (E) excluding the polarizer (B1) was 13.5 μm.

(Example 6)
<Preparation of laminate (F)>
A first optically anisotropic layer made of the first liquid crystal compound (A) in the laminate (i) and a second optically anisotropic layer made of the polymerizable liquid crystal compound (C) in the laminate (f) Are bonded with an optically isotropic pressure-sensitive adhesive having a thickness of 15 μm, and the PVA alignment substrate (B) is peeled off, whereby only the second optical anisotropic layer made of the polymerizable liquid crystal compound (C) is formed. Transferred to laminate (i), laminate (F) (TAC / adhesive layer / polarizer / adhesive layer / TAC / adhesive layer / first optical anisotropic layer comprising first liquid crystal compound (A) / Adhesive layer / second optically anisotropic layer comprising second liquid crystal compound (C)) was obtained. The thickness of the laminate (F) was 133.5 μm, and the thickness of the laminate (F) excluding the polarizer (B1) was 23.5 μm.

(Example 7)
<Preparation of laminate (G)>
Except for changing the polarizer (A1) used in producing the laminate (h) in Example 3 to the polarizer (B1), the same as in producing the laminate (h) in Example 3. A laminate (j) (TAC / adhesive layer / polarizer / adhesive layer / TAC / adhesive layer / first optical anisotropic layer comprising the first liquid crystal compound (A)) was prepared by the procedure. Further, a second optical layer made of the second liquid crystal composition (C) of the laminate (f) is provided on the first optical anisotropic layer side of the laminate (j) via an adhesive layer having a thickness of 5 μm. The anisotropic layer was transferred. That is, a UV curable acrylic adhesive is applied as an adhesive layer on the second optically anisotropic layer made of the second liquid crystal composition (C) of the laminate (f) so as to have a thickness of 5 μm. , Laminate (G) (TAC / adhesive layer / polarizer / adhesive layer / TAC / adhesive layer / first optical anisotropic layer / adhesive layer / second liquid crystal comprising the first liquid crystal composition (A)) A second optically anisotropic layer comprising the composition (C) was obtained. The thickness of the laminate (G) was 133.5 μm, and the thickness of the laminate (G) excluding the polarizer (B1) was 23.5 μm.

(Example 8)
<Preparation of laminate (H)>
A first optical anisotropic layer composed of the first liquid crystal composition (A) of the laminate (j) and a second optical anisotropy composed of the second liquid crystal compound (C) in the laminate (f). The second optically anisotropic layer made of the second liquid crystal compound (C) is bonded to the optical layer with an optically isotropic adhesive having a thickness of 15 μm and the alignment substrate (B) is peeled off. The first optical anisotropy consisting of the laminate (H) (TAC / adhesive layer / polarizer / adhesive layer / TAC / adhesive layer / first liquid crystal compound (A)) Layer / adhesive layer / second liquid crystal anisotropic layer comprising the second liquid crystal compound (C)). The thickness of the laminate (H) was 143.5 μm, and the thickness of the laminate (H) excluding the polarizer (B1) was 33.5 μm.

Example 9
<Production of Laminate (I)>
In the same procedure as in Example 5, except that the polarizer (B1) used in producing the laminate (E) in Example 5 was changed to the polarizer (C1), the laminate (I) (TAC / Adhesive layer / polarizer / adhesive layer / COP / adhesive layer / first optical anisotropic layer comprising the first liquid crystal composition (A) / adhesive layer / second liquid crystal composition (C) Optically anisotropic layer). The thickness of the laminate (I) was 123.5 μm, and the thickness of the laminate (I) excluding the polarizer (C1) was 13.5 μm.

(Example 10)
<Preparation of laminate (J)>
Except for changing the polarizer (B1) used in the production of the laminate (F) in Example 6 to the polarizer (C1), the laminate (J) (TAC / Adhesive layer / polarizer / adhesive layer / COP / adhesive layer / first optical anisotropic layer composed of first liquid crystal composition (A) / adhesive layer / second liquid crystal composition (C) The thickness of the laminate (J) was 133.5 μm, and the thickness of the laminate (J) excluding the polarizer (C1) was 23.5 μm.

(Example 11)
<Preparation of laminate (K)>
Except for changing the polarizer (B1) used in preparing the laminate (G) in Example 7 to the polarizer (C1), the procedure for producing the laminate (K) (TAC / Adhesive layer / polarizer / adhesive layer / COP / adhesive layer / first optical anisotropic layer comprising the first liquid crystal composition (A) / adhesive layer / second liquid crystal composition (C) Optically anisotropic layer). The thickness of the laminate (K) was 133.5 μm, and the thickness of the laminate (K) excluding the polarizer (C1) was 23.5 μm.

(Example 12)
<Preparation of laminate (L)>
In the same procedure as in Example 8, except that the polarizer (B1) used in preparing the laminate (H) in Example 8 was changed to the polarizer (C1), the laminate (L) (TAC / Adhesive layer / polarizer / adhesive layer / COP / adhesive layer / first optical anisotropy consisting of first liquid crystal composition (A) / adhesive layer / second liquid crystal composition consisting of second liquid crystal composition (C) An optically anisotropic layer) was obtained. The thickness of the laminate (L) was 143.5 μm, and the thickness of the laminate (L) excluding the polarizer (C1) was 33.5 μm.

(Example 13)
<Preparation of laminate (M)>
Except for changing the polarizer (B1) used in producing the laminate (E) in Example 5 to the polarizer (D1), the procedure for producing the laminate (M) (TAC / 1st optical anisotropy / adhesive layer / second liquid crystal composition (C) composed of adhesive layer / polarizer / adhesive layer / acrylic film / adhesive layer / first liquid crystal composition (A) Optically anisotropic layer). The thickness of the laminate (M) was 123.5 μm, and the thickness of the laminate (M) excluding the polarizer (D1) was 13.5 μm.

(Example 14)
<Preparation of laminate (N)>
Except for changing the polarizer (B1) used in producing the laminate (F) in Example 6 to the polarizer (D1), the procedure for producing the laminate (N) (TAC / First optical anisotropic layer / adhesive layer / second liquid crystal composition (C) composed of adhesive layer / polarizer / adhesive layer / acrylic film / adhesive layer / first liquid crystal composition (A) 2 optically anisotropic layer). The thickness of the laminate (N) was 133.5 μm, and the thickness of the laminate (N) excluding the polarizer (D1) was 23.5 μm.

(Example 15)
<Preparation of laminate (O)>
Except for changing the polarizer (B1) used in producing the laminate (G) in Example 7 to the polarizer (D1), the laminate (O) (TAC / The first optical anisotropic layer / adhesive layer / second liquid crystal composition (C) composed of adhesive layer / polarizer / adhesive layer / acrylic film / adhesive layer / first liquid crystal composition (A). Thus, the thickness of the laminate (O) was 133.5 μm, and the thickness of the laminate (O) excluding the polarizer (D1) was 23.5 μm.

(Example 16)
<Preparation of laminate (P)>
In the same procedure as in Example 8, except that the polarizer (B1) used in producing the laminate (H) in Example 8 was changed to the polarizer (D1), the laminate (P) (TAC / 1st optical anisotropy / adhesive layer / second liquid crystal composition (C) composed of adhesive layer / polarizer / adhesive layer / acrylic film / adhesive layer / first liquid crystal composition (A) The thickness of the laminate (P) was 143.5 μm, and the thickness of the laminate (P) excluding the polarizer (D1) was 33.5 μm.

(Example 17)
<Preparation of laminate (Q)>
The same procedure as that for producing the laminate (A) in Example 1 except that the laminate (a) used in producing the laminate (A) in Example 1 was changed to the laminate (c). Thus, a laminate (k) (TAC / adhesive layer / polarizer / adhesive layer / second optically anisotropic layer comprising the second liquid crystal composition (B)) was obtained. Furthermore, the second optically anisotropic layer made of the second liquid crystal composition (B) of the laminate (k) and the first liquid crystal composition (a) of the laminate (a) obtained in Example 1 ( The first optically anisotropic layer made of A) is bonded with an optically isotropic adhesive having a thickness of 15 μm, and the alignment substrate (A) is peeled off, whereby the first liquid crystal composition (A Only the first optically anisotropic layer made of () is transferred to the laminate (k) and made of the laminate (Q) (TAC / adhesive layer / polarizer / adhesive layer / second liquid crystal composition (B). A second optically anisotropic layer comprising a second optically anisotropic layer / adhesive layer / first liquid crystal composition (A) was obtained. The thickness of the laminate (Q) was 88.3 μm, and the thickness of the laminate (Q) excluding the polarizer (A1) was 23.3 μm.

(Comparative Example 1)
<Production of first optically anisotropic layer>
As a first optically anisotropic layer, a polycarbonate film having a fluorene skeleton having a thickness of 50 μm and 200 mm square produced by uniaxial stretching in the vertical direction (trade name: Pure Ace WR, hereinafter referred to as WR film, manufactured by Teijin Chemicals Ltd.) Prepared. The in-plane retardation value Re1 (550) at a measurement wavelength of 550 nm of the WR film was 143 nm, and the retardation value Rth1 (550) in the thickness direction was 72 nm. Re1 (500) / Re1 (550) = 0.963 and Re1 (580) / Re1 (550) = 1.015. In particular, in the measurement wavelength range of 500 nm to 600 nm, it was confirmed that the phase difference increases as the measurement wavelength becomes longer. FIG. 8 shows the birefringence wavelength dispersion characteristics of the WR film as the first optically anisotropic layer.

<Preparation of laminate (l)>
The PVA (B) solution was applied by spin coating at 300 rpm for 30 seconds, dried on a hot plate at 50 ° C. for 30 minutes, and then heated in an oven at 100 ° C. for 10 minutes to form PVA on the polycarbonate film. A layer (B) was provided to obtain a laminate (l). The film thickness of the obtained PVA (B) layer was 1.2 μm. In addition, this PVA (B) layer is optically isotropic.

On the PVA (B) layer formed on the WR film as the first optical anisotropic layer, a coating liquid containing the second liquid crystal composition (B) was applied by a spin coating method. Next, the second liquid crystal composition was aligned by drying for 10 minutes on a hot plate at 55 ° C. and heat treatment for 3 minutes in an oven at 100 ° C. Next, the sample was placed in close contact with an aluminum plate heated to 70 ° C., and then irradiated with 300 mJ / cm ² of ultraviolet light (however, the amount of light measured at 365 nm) with a high-pressure mercury lamp lamp in the air, and oxetanyl group The second optical anisotropy comprising the second liquid crystal composition (B) on the laminate of the WR film / PVA (B) layer, which is the first optical anisotropic layer, by cationically reacting and curing The laminated layer (m) (WR film / PVA (B) / second optically anisotropic layer comprising the second liquid crystal composition (B)) was obtained. The thickness of the second optical anisotropic layer made of the second liquid crystal composition (B) was 0.8 μm, and the thickness of the laminate (m) was 52.0 μm.

  When the obtained laminate (m) was observed under a polarizing microscope with crossed Nicols, there was no disclination and the monodomain was uniformly oriented. Further, a second liquid crystal composition (B) comprising a second liquid crystal composition (B) calculated by measuring the optical retardation of the laminate (m) and subtracting the optical retardation of the WR film as the first optical anisotropic layer. The retardation value Re2 (550) of the optically anisotropic layer was 0 nm, the retardation value Rth2 (550) in the thickness direction was −81 nm, and it was confirmed to be homeotropic alignment. That is, the value of Rth1 (550) + Rth2 (550) of the laminate (m) was +9 nm.

<Preparation of laminate (R)>
The polarizer side of the polarizer (A1) and the WR film of the laminate (m) are bonded with an optically isotropic 15 μm-thick adhesive, and the laminate (R) (TAC / adhesive layer / A polarizer / adhesive layer / WR film (first optical anisotropic layer) / PVA (B) / second optical anisotropic layer comprising the second liquid crystal composition (B) was obtained. The thickness of the laminate (R) was 132.0 μm, and the thickness of the laminate (R) excluding the polarizer (A1) was 67.0 μm.

(Comparative Example 2)
<Preparation of laminate (S)>
After obtaining the first optically anisotropic layer in the same manner as in Example 1 except that the dichroic dye is not mixed, the laminate is produced in the same manner as in the case of producing the laminate (B) in Example 2. (S) (TAC / adhesive layer / polarizer / adhesive layer / first optical anisotropic layer (no dichroic dye) comprising the first liquid crystal composition (A) / adhesive layer / second liquid crystal composition A second optically anisotropic layer comprising the product (B) was obtained. The thickness of the laminate (S) was 88.3 μm, and the thickness of the laminate (S) excluding the polarizer (A1) was 23.3 μm. FIG. 9 shows the birefringence wavelength dispersion characteristics of the first optically anisotropic layer.

(Comparative Example 3)
<Preparation of laminate (T)>
As a form not including the second optically anisotropic layer, a laminate (T) composed only of the first optically anisotropic layer produced in Example 1 (TAC / adhesive layer / polarizer / adhesive layer / first The first optically anisotropic layer comprising the liquid crystal composition (A) was obtained. The thickness of the laminate (T) was 72.5 μm, and the thickness of the laminate (T) excluding the polarizer (A1) was 7.5 μm.

(Comparative Example 4)
<Production of first optically anisotropic layer>
Similar to the case of producing the laminate (a) of Example 1, except that the PET film used in producing the laminate (a) in Example 1 was changed to an unstretched COP film having a thickness of 40 μm. Through the procedure, a laminate (n) (first optical anisotropic layer / PVA (A) / COP made of the first liquid crystal composition (A)) was obtained.

<Preparation of laminate (U)>
The laminate (n) was bonded to the polarizer side of the polarizer (A1) via an acrylic adhesive having a thickness of 5 μm. That is, a UV curable acrylic adhesive is applied as an adhesive layer to the polarizer side of the polarizer (A1) so as to have a thickness of 5 μm, and the first optical anisotropy comprising the first liquid crystal composition (A) is applied. After laminating and laminating with the first optical anisotropic layer of the laminate (n) composed of layer / PVA (A) / COP, the adhesive layer is cured by irradiating with 600 mJ / cm ² ultraviolet rays from the COP side. Then, a laminate (o) (TAC / adhesive layer / polarizer / adhesive layer / first optical anisotropic layer / PVA (A) / COP comprising the first liquid crystal composition (A)) was obtained. The thickness of the laminate (o) was 113.7 μm.

  Furthermore, the COP of the laminate (o) and the second optical anisotropic layer composed of the second liquid crystal composition (B) of the laminate (c) obtained in Example 1 are optically isotropic. By sticking with a 15 μm thick adhesive and peeling off the alignment substrate (B), only the second optical anisotropic layer made of the second liquid crystal composition (B) is formed on the laminate (o). Transfer and laminate (U) (TAC / adhesive layer / polarizer / adhesive layer / first optical anisotropic layer comprising first liquid crystal composition (A) / PVA (A) / COP / adhesive layer / A second optically anisotropic layer comprising the second liquid crystal composition (B) was obtained. The thickness of the laminate (U) was 129.5 μm, and the thickness of the laminate (U) excluding the polarizer (A1) was 64.5 μm.

(Comparative Example 5)
<Preparation of second optically anisotropic layer>
In the same procedure as that for producing the laminate (c) of Example 1, except that the PET film used for producing the laminate (c) in Example 1 was changed to a COP having a thickness of 40 μm, A product (p) (second optically anisotropic layer / PVA (B) / COP comprising the second liquid crystal composition (B)) was obtained.

<Preparation of laminate (V)>
The first optically anisotropic layer (B) of the laminate (e) obtained in Example 1 and the second optically anisotropic layer (B) composed of the second liquid crystal composition of the laminate (p) Is laminated with a pressure-sensitive adhesive having a thickness of 15 μm and is laminated (V) (first optical material comprising TAC / adhesive layer / polarizer / adhesive layer / first liquid crystal composition (A)). A second optically anisotropic layer / PVA (B) / COP comprising an anisotropic layer / adhesive layer / second liquid crystal composition (B) was obtained. The thickness of the laminate (V) was 129.5 μm, and the thickness of the laminate (V) excluding the polarizer (A1) was 64.5 μm.

(Comparative Example 6)
<Preparation of laminate (W)>
A second optically anisotropic layer comprising the COP of the laminate (n) obtained in Comparative Example 4 and the second liquid crystal composition (B) of the laminate (p) obtained in Comparative Example 5 was optically First, the first optical anisotropy comprising a laminate (W) (TAC / adhesive layer / polarizer / adhesive layer / first liquid crystal composition (A)). Layer / PVA (A) / COP / adhesive layer / second liquid crystal composition layer (PVA (B) / COP). The thickness of the laminate (W) was 170.7 μm, and the thickness of the laminate (W) excluding the polarizer (A1) was 105.7 μm.

  The laminates (A) to (W) created in Examples 1 to 17 and Comparative Examples 1 to 6 were attached to a transparent glass substrate of an organic EL element of a commercially available organic EL display via an acrylic adhesive. Thus, an organic EL image display device was produced.

(A) Evaluation of anti-reflection effect of external light during frontal observation In a state where no voltage is applied to the organic EL element, it was placed in an environment with an illuminance of about 100 lux, and the black display of the reflected light of the laminated body was visually evaluated. . It was confirmed whether the black display corresponds to one of the following four levels. The evaluation results are shown in Table 3.
1: There is almost no external light reflection and the color is black.
Although inferior to 2: 1, external light reflection is sufficiently suppressed, and the color is almost black.
3: A little external light reflection is visually recognized.
4: External light reflection is extremely visually recognized.

(A) Evaluation of viewing angle characteristics of external light anti-reflection effect With no voltage applied to the organic EL element, it is placed in an environment with an illuminance of about 100 lux. The black display was visually evaluated. It was confirmed whether the black display corresponds to one of the following four levels. The evaluation results are shown in Table 3.
1: Almost no change in external light reflection is seen between the front and diagonal directions.
Although it is inferior to 2: 1, the difference in external light reflection between the front and the diagonal direction is slight.
3: A difference in external light reflection is recognized between the front and the diagonal direction.
4: There is a considerable difference in external light reflection between the front and diagonal directions

  As shown in Table 2, the laminates of the organic EL elements of Examples 1 to 17 and Comparative Examples 1 and 4 to 6 are excellent in the effect of preventing external light reflection at the time of front observation, and also have good viewing angle characteristics. I understood. On the other hand, it was confirmed that the laminate of Comparative Example 2 that did not contain the dichroic dye was observed to have external light reflection and bluish black display when viewed from the front and oblique directions.

  In addition, the laminate (T) of Comparative Example 3 that does not include the second optically anisotropic layer was found to have an effect of preventing external light reflection during frontal observation, but there was a difference in external light reflection between the front and the diagonal direction. A considerable amount of color was observed, and it was confirmed that the tint was strongly bluish when viewed from an oblique direction.

  Moreover, as shown in Table 3, when the thicknesses of the laminates excluding the polarizer are compared, any form of Examples 1 to 17 is significantly thinner than Comparative Examples 1 and 4 to 6 and is a remarkable thin film. It was confirmed that it was realized.

  In addition, when comparing the interlayer adhesion of the optically anisotropic layer in each Example and Comparative Example, with respect to Examples 1 to 17 and Comparative Examples 1 to 3, the optically anisotropic layer and the retardation layer are made of UV curable resin, Or since it has laminated | stacked directly by the adhesion layer, there is no problem regarding adhesiveness. On the other hand, in the forms of Comparative Examples 4 to 6, since the PVA layer that is the alignment film and the optically anisotropic layer are not subjected to the adhesion improving treatment, the adhesiveness between the PVA layer and the optically anisotropic layer is poor, and It peeled easily at the time of the process which forms a body, and the handling after producing a laminated body. That is, by adopting an embodiment of the present invention that includes a transfer step, the thickness of the laminate can be greatly reduced while maintaining high external light antireflection performance, and the adhesion of the optically anisotropic layer can be greatly increased. It is possible to improve.

(Example 18)
In Example 1, the laminate (A) was incorporated into a polarizing plate reflective liquid crystal image display device, and the color was evaluated. From the observation side, the configuration is laminate (A) / glass substrate / ITO transparent electrode / alignment film / twist nematic liquid crystal / alignment film / metal electrode / reflection film / glass substrate (adhesive layer between each layer is omitted). Bonding was performed at an angle that displayed white when the voltage was turned off, and the color was evaluated visually. In particular, it was confirmed that there was little coloring in black display when a voltage was applied, whereby a clear contrast could be realized and the image visibility was excellent.
<Explanation of symbols>

1 Organic polymer (rod-like molecule)
2 Polymer film 3 Organic polymer (discotic molecule)
10 First optical anisotropic layer 20 Alignment substrate (A)
30 Polarizer 40 Second optical anisotropic layer 50 Alignment substrate (B)
DESCRIPTION OF SYMBOLS 90 Transparent substrate 91 Anode 92 Light emitting layer 93 Cathode 100 Laminated body 200 Image display apparatus A: The homogeneous orientation direction B of a 1st optically anisotropic layer: Absorption axis alpha of a polarizer: The homogeneous of a 1st optically anisotropic layer Angle between orientation direction and absorption axis of polarizer

Claims (15)

A coating liquid containing the first liquid crystal composition is applied on the alignment substrate (A), the first liquid crystal composition is homogeneously aligned, and the first optical anisotropy is formed on the alignment substrate (A). Forming a layer;
Bonding the first optically anisotropic layer and a polarizer;
Peeling the alignment substrate (A);
A coating liquid containing a second liquid crystal composition is applied on the alignment substrate (B), the second liquid crystal composition is homeotropically aligned, and a second optical anisotropic is applied on the alignment substrate (B). Forming a conductive layer;
Bonding the first optically anisotropic layer and the second optically anisotropic layer;
Peeling the alignment substrate (B);
The manufacturing method of a laminated body characterized by including.   The manufacturing method of the laminated body of Claim 1 with which the coating liquid containing a said 1st liquid crystal composition contains a dichroic dye.   The first liquid crystal composition comprises a polymerizable liquid crystal compound, and after the homogeneous alignment on the alignment substrate (A), the homogeneous alignment is fixed by polymerizing the polymerizable liquid crystal compound. Item 3. A method for producing a laminate according to Item 1 or 2.   The second liquid crystal composition comprises a polymerizable liquid crystal compound, and after homeotropic alignment on the alignment substrate (B), the homeotropic alignment is fixed by polymerizing the polymerizable liquid crystal compound. The manufacturing method of the laminated body as described in any one of Claims 1-3.   The manufacturing method of the laminated body as described in any one of Claims 1-4 whose said 1st liquid crystal composition and said 2nd liquid crystal composition are the same liquid crystal compositions.   The manufacturing method of the laminated body as described in any one of Claims 1-4 which is a liquid crystal composition from which a said 1st liquid crystal composition and a said 2nd liquid crystal composition differ.   The bonding angle between the first optically anisotropic layer and the polarizer is such that the homogeneous orientation direction of the first optically anisotropic layer and the absorption axis of the polarizer are 40 to 50 degrees. The manufacturing method of the laminated body as described in any one of Claims 1-6 performed so that it may become.   The dichroic dye has a polymerizable group, is polymerized with the first liquid crystal composition, and is aligned in substantially the same direction as the alignment direction of the first liquid crystal composition on the alignment substrate (A). The manufacturing method of the laminated body as described in any one of Claims 2-7.   The manufacturing method of the laminated body as described in any one of Claims 2-8 whose maximum absorption wavelength of the said dichroic dye is 380-780 nm.   The production of a laminate according to any one of claims 2 to 9, wherein the content of the dichroic dye is 0.01 to 10 parts by weight with respect to 100 parts by weight of the first liquid crystal composition. Method. The maximum principal refractive index nx1 and / or birefringence Δn1 of the first optically anisotropic layer has a “negative dispersion” characteristic that becomes larger as the measurement wavelength is longer in at least a part of the wavelength region of the visible light region. And
The manufacturing method of the laminated body as described in any one of Claims 1-10 with which the said 2nd optically anisotropic layer has a birefringence characteristic of nz2>nx2> = ny2.
(Where nx2 is the maximum main refractive index in the second optical anisotropic layer surface for light with a wavelength of 550 nm, and ny2 is the direction having the maximum main refractive index in the second optical anisotropic layer surface for light with a wavelength of 550 nm. The main refractive index in the direction orthogonal to nz2 is the main refractive index in the thickness direction of the second optically anisotropic layer for light having a wavelength of 550 nm.) The laminate according to any one of claims 1 to 11, wherein Rth1 of the first optically anisotropic layer and Rth2 of the second optically anisotropic layer satisfy the following formula (1). Manufacturing method.
40 nm ≧ Rth1 (550) + Rth2 (550) ≧ −40 nm (1)
(Here, the thickness direction retardation Rth1 is represented by Rth1 = {(nx1 + ny1) / 2-nz1} × d1 [nm], where d1 is the thickness of the first optical anisotropic layer, nx1. Is the maximum main refractive index in the first optical anisotropic layer surface for light having a wavelength of 550 nm, and ny1 is a direction orthogonal to the direction having the maximum main refractive index in the first optical anisotropic layer surface for light having a wavelength of 550 nm. The main refractive index, nz1, is the main refractive index in the thickness direction of the first optically anisotropic layer with respect to light having a wavelength of 550 nm, and the thickness direction retardation Rth2 is Rth2 = {(nx2 + ny2) / 2−nz2. } × d2 [nm] where d2 is the thickness of the second optically anisotropic layer, nx2 is the maximum principal refractive index in the plane of the second optically anisotropic layer for light having a wavelength of 550 nm, ny2 For light with a wavelength of 550 nm The main refractive index in the direction orthogonal to the direction having the maximum main refractive index in the plane of the second optical anisotropic layer, nz2 is the main refractive index in the thickness direction of the second optical anisotropic layer with respect to light having a wavelength of 550 nm .)   A laminate produced by the laminate production method according to any one of claims 1 to 11.   A polarizing plate using the laminate according to claim 13.   An image display device comprising the laminate according to claim 13 or the polarizing plate according to claim 14.