JP2003161833A - Laminated retardation plate and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method or the like of a laminated retardation plate whose production efficiency is superior and which can be produced at a low cost. <P>SOLUTION: In this manufacturing method of a laminated retardation plate, a resin whose intrinsic birefringence value is positive and a resin whose intrinsic birefringence value is negative are coextruded and then drawn, and a laminated retardation film, including a layer which includes a resin whose intrinsic birefringence value is positive and a layer which includes a resin whose intrinsic birefringence is negative, is manufactured. The manufacturing method of a laminated retardation plate is characterized in that a resin whose intrinsic birefringence value is negative is a polycarbonate which includes a repeating unit which is described as formula (1) and a repeating unit which is described as formula (2). In the formula (2), A<SP>1</SP>, to A<SP>8</SP>is at least one kind, which is independently chosen from among hydrogen atom, halogen atom, and hydrocarbon group of carbon number 1 to 3, respectively. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadband quarter-wave plate for a reflective LCD and a method for manufacturing a retardation plate which is preferably used for a broadband half-wave plate such as a PBS for a projector.

[0002]

2. Description of the Related Art Retardation (Re) is 1 / wavelength
The 1/4 wavelength plate of 4 has various uses such as being used for a reflective liquid crystal display device, an optical disc pickup, and an antiglare film. On the other hand, the retardation (R
The half-wave plate whose e) is half the wavelength also has various uses such as being used in a liquid crystal projector.

As the material of the quarter-wave plate and the half-wave plate, generally, polycarbonate, polyvinyl alcohol, polysulfone, polyether sulfone, amorphous polyolefin and the like, as well as polymer liquid crystal and discotic liquid crystal are used. ing.

The quarter-wave plate and the half-wave plate using the above materials generally exhibit a refractive index anisotropy by a uniaxial stretching process, but the anisotropy of the obtained film is also uniaxial. There was a problem of becoming. In order to solve this problem, various techniques for laminating a retardation plate having negative refractive index anisotropy and a retardation plate having positive refractive index anisotropy have been proposed. However, the retardation plate having negative refractive index anisotropy has problems such as low heat resistance and poor moldability.
Further, since it is necessary to independently form each layer into a film, stretch it, apply pressure-sensitive adhesively, and further bond each layer, there are problems that the manufacturing process is complicated and the manufacturing efficiency is poor.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the various problems in the prior art and achieve the following objects. That is, the present invention provides a laminated retardation plate which is excellent in manufacturing efficiency and can be manufactured at low cost, and a laminated retardation plate which is obtained by the manufacturing method of the laminated retardation plate and has good wavelength dispersion. The purpose is to do.

[0006]

Means for solving the above-mentioned problems are as follows. <1> A resin having a positive intrinsic birefringence value and a resin having a negative intrinsic birefringence value are coextruded and then stretched, and a layer containing a resin having a positive intrinsic birefringence value and a negative intrinsic birefringence value. A method for manufacturing a laminated retardation plate, which comprises a layer containing a resin-containing layer, wherein the resin having a negative intrinsic birefringence value is a repeating unit represented by the following formula (1): A method for producing a laminated retardation plate, which is a polycarbonate containing a repeating unit represented by the following formula (2).

[0007]

[Chemical 4]

[0008]

[Chemical 5]

In the formula (2), A ^{1 to} A ⁸ are each independently at least one selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 3 carbon atoms. X is any one represented by the following formula group (3). Formula group (3)

[0010]

[Chemical 6]

In the formula group (3), A ^{9 to} A ¹¹ , A
^{13 to} A ¹⁴ each independently represent a hydrogen atom, a halogen atom,
And at least one selected from a hydrocarbon group having 1 to 22 carbon atoms. A ¹² and A ¹⁵ are each independently at least one selected from a hydrocarbon group having 1 to 20 carbon atoms. Ar _{1 to} Ar ₃ are at least one type independently selected from an aryl group having 6 to 10 carbon atoms.

<2> The method for producing a laminated retardation plate according to <1>, wherein the resin having a positive intrinsic birefringence value is a polycarbonate containing a repeating unit represented by the formula (2). <3> A layer containing a resin having a positive intrinsic birefringence value and a layer containing a resin having a negative intrinsic birefringence value, obtained by the method for producing a laminated retardation plate according to <1> or <2> And a laminated retardation plate. <4> The laminated retardation plate according to <3>, further including an adhesion layer between a layer containing a resin having a positive intrinsic birefringence value and a layer containing a resin having a negative intrinsic birefringence value. <5> Wavelength 450 nm, 550 nm, and 650 nm
Retardation (Re) value in Re (45
0), Re (550), and Re (650), Re (450) <Re (550) <Re (650)
The laminated retardation plate according to <3> or <4>, which satisfies the above condition.

<6> The retardation (Re) / wavelength (λ) value at wavelengths of 450 nm, 550 nm, and 650 nm is 0.2 to 0.3. It is a laminated retardation plate of. <7> The value of retardation (Re) / wavelength (λ) at wavelengths of 450 nm, 550 nm and 650 nm is
The laminated retardation plate according to any one of <3> to <5>, which is 0.4 to 0.6. <8> When the thickness of the laminated retardation plate is d, the refractive index in the in-plane slow axis direction is nx, the refractive index in the in-plane fast axis direction is ny, and the refractive index in the thickness direction is nz, nz ≧ (Nx + ny) /
The laminated retardation plate according to any one of <3> to <7>, which satisfies 2.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. [Method for producing laminated retardation plate] In the method for producing a laminated retardation plate of the present invention, a resin having a positive intrinsic birefringence value and a resin having a negative intrinsic birefringence value are coextruded and then stretched, A laminated retardation plate including a layer containing a resin having a positive intrinsic birefringence value and a layer containing a resin having a negative intrinsic birefringence value is manufactured.

-Resin having a negative intrinsic birefringence value-The resin having a negative intrinsic birefringence value is a resin having a characteristic of exhibiting optically negative uniaxiality when a uniaxial orientation rule is given to a molecule. Is. In the present invention, a polycarbonate containing a repeating unit represented by the following formula (1) (a repeating unit having a fluorene skeleton having a methyl group) and a repeating unit represented by the following formula (2) is required. Is.

[0016]

[Chemical 7]

[0017]

[Chemical 8]

In the formula (2), A ^{1 to} A ⁸ are each independently at least one selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 3 carbon atoms. X is any one represented by the following formula group (3). Formula group (3)

[0019]

[Chemical 9]

In the above formula (2), examples of the halogen atom represented by A ^{1 to} A ⁸ include fluorine, chlorine, bromine and iodine. Examples of the hydrocarbon group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group,
Examples thereof include alkyl groups such as isopropyl group. A ¹ ~
A ⁸ is that all hydrogen atom. In the formula group (3), A ^{9 to} A ¹¹ , A ¹³ and A ¹⁴ each independently represent a hydrogen atom, a halogen atom and a carbon number of 1 to 1.
It is at least one selected from 22 hydrocarbon groups.
As the halogen atom, all the same ones as described above can be mentioned.

Examples of the hydrocarbon group having 1 to 22 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, a pentyl group, and a cyclohexyl group (having 1 to 22 carbon atoms). ) Alkyl groups, phenyl groups, biphenyl groups, terphenyl groups, and aryl groups having 6 to 18 carbon atoms such as naphthyl.

In formula group (3), A ¹² and A
¹⁵ is at least one type independently selected from a hydrocarbon group having 1 to 20 carbon atoms. As the hydrocarbon group,
Examples thereof include a divalent (cyclo) alkylene group having 2 to 20 carbon atoms such as ethylene group, a divalent arylene group having 6 to 18 carbon atoms such as phenyl group, biphenyl group, terphenyl group and naphthyl group.

In the formula group (3), Ar _{1 to} Ar ₃ are
Each independently has 6 to 1 carbon atoms such as phenyl group and naphthyl group.
It is a kind selected from 0 aryl groups.

Polycarbonate, which is a resin having a negative intrinsic birefringence value, has good heat resistance and moldability, and has low viewing angle dependence, and a repeating unit represented by the above formula (1): An embodiment containing a repeating unit represented by the formula (4) is particularly preferable.

[0025]

[Chemical 10]

In the above formula (4), A ¹⁶ and A ¹⁷
Are each independently at least one selected from a hydrogen atom and a methyl group. Y is at least one represented by the following formula group (5).

Formula group (5)

[Chemical 11]

Of the repeating unit represented by the above formula (1),
As content (mol%) in the whole polycarbonate, 71-98 mol% is preferable, 72-96 mol% is more preferable, 73-94 mol% is further more preferable. or,
The content (mol%) of the repeating unit represented by the formula (2) in the entire polycarbonate is 2 to 29.
Mol% is preferable, 4-28 mol% is more preferable, and 6
˜27 mol% is more preferred.

The repeating unit represented by the above formula (1) is
Even when homopolymerized, it has a negative refractive index anisotropy, but this content is 98 mol% of the whole polycarbonate.
When it is more than 71 mol%, the polymerization becomes difficult, resulting in poor productivity and poor moldability. On the other hand, when it is less than 71 mol%, it is difficult to obtain negative refractive index anisotropy. May be.

The polycarbonate includes a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (4) (wherein Y is represented by the following formula (5)). The embodiment is most preferred. Formula (5)

[0031]

[Chemical 12]

In this case, the repeating unit represented by the above formula (1) is 76 to 90 mol% of the whole polycarbonate.
And the repeating unit represented by the formula (2) is 10
The aspect which occupies -24 mol% is preferable.

The polycarbonate is preferably a copolymer of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2). The mode of copolymerization is not particularly limited, and examples thereof include block copolymerization, random copolymerization, alternating copolymerization, and graft copolymerization. The structure of the polycarbonate in the present invention is analyzed and confirmed by 1 H-NMR and the like.

The molecular weight of the polycarbonate is
It is specified by the intrinsic viscosity measurement using methylene chloride as a solvent, and the intrinsic viscosity at 20 ° C. is 0.30 to 2.
It is preferably 0 dl / g.

As a structure similar to the repeating unit represented by the formula (1), the polycarbonate may contain a repeating unit having a structure of the following formula (6) having a fluorene skeleton. When the number of units is large, it becomes more rigid and the glass transition temperature becomes higher than that in the case of using the above formula (1), so that the moldability may be insufficient.

[0036]

[Chemical 13]

-Resin having a positive intrinsic birefringence value-The resin having a positive intrinsic birefringence value is a resin having a characteristic of exhibiting optically positive uniaxiality when a uniaxial orientation rule is given to a molecule. Is, there is no particular limitation as long as the intrinsic birefringence value is positive, in terms of transparency, birefringence value, and wavelength dispersion,
A polycarbonate type is preferable, for example, the above formula (2)
A polycarbonate containing a repeating unit represented by is preferred. The polycarbonate may be a homopolymer of the repeating unit represented by the formula (2), and as long as the intrinsic birefringence value satisfies the above conditions, it may be a copolymer or blend with other repeating units. It may be.

Examples of the polycarbonate having a positive intrinsic birefringence value include polycarbonate containing bisphenol A as a bisphenol component and polycarbonate having a fluorene skeleton. As the polycarbonate having a fluorene skeleton, for example, the following formula (7)
A polycarbonate containing a repeating unit represented by and a repeating unit represented by the formula (2) is preferable.

[0039]

[Chemical 14]

In the above formula (7), A ^{18 to} A ^18
25 is at least one type independently selected from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 6 carbon atoms. Z is a group represented by the following formula (8). Formula (8)

[0041]

[Chemical 15]

The content of the repeating unit represented by the formula (7) in the polycarbonate is 40.
Is preferably 71 to 71 mol%, and the content of the repeating unit represented by the formula (2) is preferably 60 to 29 mol%.

As a method for producing a polycarbonate having a positive intrinsic birefringence value and a polycarbonate having a negative intrinsic birefringence value, interfacial polycondensation of a dihydroxy compound and phosgene, a melt polycondensation method and the like are preferable.

When the above polycarbonates are blended and used, a compatible blend is preferable, but even if they are not completely compatible, by adjusting the refractive index between the components, light scattering between the components can be suppressed and the transparency can be improved. It is possible to improve the sex.

—Coextrusion / Stretching— In the coextrusion / stretching, the resin having a positive intrinsic birefringence value and the resin having a negative intrinsic birefringence value are coextruded and then stretched to give a retardation ( Re)
Is adjusted to manufacture a laminated retardation plate. In the co-extrusion, for example, a resin having a positive intrinsic birefringence value, a resin having a negative intrinsic birefringence value, and optionally a resin for an adhesion layer are introduced into an extrusion die, and the inside of the die or the die. It is possible to form a laminate by bringing the polymers into contact with each other through the openings of and integrating them.

The die is not particularly limited, but T
A die can be preferably used, and the internal shape of the T die is not particularly limited and various shapes can be mentioned. If desired, the extruded molten laminate may be stretched over a plurality of rolls and moved by following the rotation of the rolls to adjust the thickness of the laminate to a desired thickness.

FIG. 1 is a schematic configuration diagram of a coextrusion apparatus preferably used for the coextrusion. The co-extrusion device 20 includes an extrusion die 22, extruders 24 and 26, and a tension roll 2.
It has 8, 30, 32. In the co-extrusion device 20, the resin having a positive intrinsic birefringence value and the resin having a negative intrinsic birefringence value, which are stored in the extruder 24 and the extruder 26, are introduced into the extrusion die 22 and merge at the opening of the extrusion die 22. , The resins are brought into contact with each other to be integrated with each other to form the laminated body 34. When the adhesiveness between the resin having a positive intrinsic birefringence value and the resin having a negative intrinsic birefringence value is poor, an extruder for forming an adhesive layer may be further provided. The formed laminated body 34 is stretched by rotating tensioning rolls 28, 30, 32, moves following the rotation of the tensioning rolls 28, 30, 32, and is adjusted to a desired thickness to form a film or sheet. Then, the laminated retardation plate is manufactured by adjusting the value of the retardation (Re) by appropriately stretching. Suitable examples of the stretching include longitudinal uniaxial stretching for stretching in the mechanical flow direction and lateral uniaxial stretching for stretching in the direction orthogonal to the mechanical flow direction (for example, tenter stretching), but if there is some It may be axial stretching.

As described above, a laminated retardation plate including a layer containing a resin having a positive intrinsic birefringence value and a layer containing a resin having a negative intrinsic birefringence value is manufactured. In the method for producing a laminated retardation plate of the present invention described above, each layer is independently produced without the need for complicated operations such as film forming / stretching, adhesive coating, and further laminating each layer. Since it has few steps and is simple, it is excellent in production efficiency.

[Laminated retardation plate] The laminated retardation plate of the present invention is obtained by the method for producing a laminated retardation plate of the present invention, and has a layer containing a resin having a positive intrinsic birefringence value and an intrinsic birefringence. It has a layer containing a resin having a negative value and optionally other layers.

—Structure of Laminated Phase Difference Plate— The layer containing a resin having a positive intrinsic birefringence value and the layer containing a negative resin are as described above. Between the layer containing the resin having a positive intrinsic birefringence value and the layer containing the resin having a negative intrinsic birefringence value, it is preferable to have an adhesion layer capable of suitably adhering each layer.

Examples of the material of the adhesion layer include epoxy resin, epoxy acrylate, SiO ₂ and Si.
_x O, Al ₂ O ₃ , Si ₃ O ₄ , TiO ₂ , AlN, Z
nO, ZnS, ZrO ₂ , SiC, Si: O: N, S
i: O: H, Si: N: H, Si: O: N: H, and the like. These may be used alone or in combination of two or more.

Examples of the other layers include a hard coat layer, a protective layer, a transparent conductive layer, a color filter and the like in addition to the adhesion layer. Suitable examples of these materials include the same materials as those of the adhesion layer.

The laminated retardation plate may have at least one layer containing a resin having a positive intrinsic birefringence value and at least one layer containing a resin having a negative intrinsic birefringence value. However, there is no particular limitation, but a configuration in which three or more layers are laminated via the adhesion layer or the like may be used.

-Physical Properties of Laminated Phase Difference Plate- In the laminated phase difference plate, wavelengths of 450 nm and 550 are used.
nm and 650 nm have retardation values of Re (450), Re (550) and Re (65), respectively.
0), Re (450) <Re (550) <R
It is preferable that e (650) is satisfied, that is, the retardation value and the wavelength have a positive correlation. Due to the correlation, it is possible to suitably provide a retardation plate which has a constant retardation characteristic with respect to incident light in the visible light region and which can be easily black-and-white and colored.

In the laminated retardation plate, a wavelength of 450
The value of retardation (Re) / wavelength (λ) at nm, 550 nm, and 650 nm is preferably 0.2 to 0.3, more preferably 0.23 to 0.27, and even more preferably 0.1.
24 to 0.26 is more preferable. When the value of the retardation (Re) / wavelength (λ) is within the above numerical range, it is possible to provide a quarter retardation plate having more uniform retardation characteristics with respect to incident light in the entire visible light range. .

In the laminated retardation plate, the wavelength of 4
The values of retardation (Re) / wavelength (λ) at 50 nm, 550 nm and 650 nm are 0.4 to 0.
6 is preferable, 0.46 to 0.54 is more preferable,
0.48 to 0.52 is more preferable. When the value of the retardation (Re) / wavelength (λ) is within the numerical range, it is possible to provide a ½ retardation plate having more uniform retardation characteristics with respect to incident light in the entire visible light range. .

In the laminated retardation plate, the thickness is d, the in-plane slow axis direction refractive index is nx, the in-plane fast axis direction refractive index is ny, and the thickness direction refractive index is nz. When
It is preferable that nz ≧ (nx + ny) / 2 is satisfied. By satisfying such a relationship, the viewing angle dependency is low,
A laminated retardation plate having high visibility is provided.

In the laminated retardation plate, the retardation of light incident on the laminated retardation plate in the normal direction is Re [0], and the retardation of light incident at an angle inclined by θ degrees from the normal direction. When the retardation is Re [θ], the value of Re [0] / Re [θ] at a wavelength of 550 nm is
It is preferably 0.93 to 1.07, and 0.95 to
1.05 is more preferable, and 0.97 to 1.03
Is more preferable. In the laminated retardation plate,
When the value of Re [0] / Re [θ] at a wavelength of 550 nm is 0.93 to 1.07, a laminated retardation plate having low viewing angle dependency and high visibility is provided.

[0059]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1) -Preparation of laminated retardation plate-As a resin having a negative intrinsic birefringence value, a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2). (However, in the formula (2), A ^{1 to} A ⁸ are all hydrogen atoms, and X is a —C (CH ₃ ) ₂ — group.) (Compounding amount: in the formula (1) Blending amount of repeating units represented = 80 in the entire polycarbonate
Mol%, the blending amount of the repeating unit represented by the formula (2) = 20 mol% in the whole polycarbonate) was used.
As a resin having a positive intrinsic birefringence value, a repeating unit represented by the above formula (7) (provided that in the formula (7), A ^{18 to} A ^18
25 are all hydrogen atoms, and Z is a group represented by the above formula (8). ) And the above formula (2) (provided that in the formula (2), A ^{1 to} A ⁸ are all hydrogen atoms, and X is
It is -C _{(CH 3) 2} - a group. ) Polycarbonate containing repeating unit (blending amount: blending amount of repeating unit represented by the formula (7) = 60 in the entire polycarbonate)
Mol%, the blending amount of the repeating unit represented by the formula (2) = 40 mol% in the entire polycarbonate) was used.
These polycarbonates were used after being dried under a nitrogen purge to reduce the water content.

A coextrusion device 20 (manufactured by Toyo Seiki Co., Ltd .; "LABO PLASTOMILI", width of extrusion die 22 of 250 mm) having the structure shown in FIG. 1 was used. In this example,
The extruder 26 has two openings. Inside the extrusion die 22 (the internal structure is shown in FIG. 2), the resin hopper extruded from the two openings of the extruder 26 is extruded from the extruder 24. It has a structure that joins from both sides of the resin hopper. Stretching roll 2 under the extrusion die 22
With 8, 30, and 32, the thickness of the film (laminate) 34 having a three-layer structure extruded from the extrusion die 22 is adjusted.

The extruder 24 stores a polycarbonate hopper which is a resin having a negative intrinsic birefringence value, and the extruder 26 stores a polycarbonate hopper which is a resin having a positive intrinsic birefringence value. To obtain a three-layered melt-molded film (laminate) 34 composed of a positive polycarbonate / a polycarbonate having a negative intrinsic birefringence value / a polycarbonate having a positive intrinsic birefringence value. The thickness of the laminated body 34 is tried to be adjusted by controlling the peripheral speed of the tension rolls 28, 30, and 32, and the peripheral speed of the tension rolls 28, 30, and 32 is determined with the final thickness of 150 μm as a target.
A laminated body having a thickness of 8 μm was obtained. The obtained laminate was subjected to a stretching treatment of 58% in an atmosphere of 130 ° C.
A layered stretched film (laminated retardation film) was obtained. The thickness of each layer in the obtained stretched film (laminated phase difference plate) is as follows: polycarbonate having a positive intrinsic birefringence value / polycarbonate having a negative intrinsic birefringence value / polycarbonate having a positive intrinsic birefringence value = 33 μm / 48 μm / 31 μm Yes, the photoelasticity was 3.4 Brewster.

-Measurement of Retardation- With respect to the obtained laminated retardation plate, the wavelength dispersion of retardation (Re) was measured using a retardation measuring device (manufactured by Oji Scientific Instruments; "KOBRA-21ADH"). The results are shown in Table 1 and FIG.

[0064]

[Table 1]

As shown in Table 1 and FIG. 3, the laminated retardation plate has retardation (Re) values of Re (45) at wavelengths of 450 nm, 550 nm and 650 nm, respectively.
0), Re (550) and Re (650),
It was found that Re (450) <Re (550) <Re (650) was satisfied, and that it had excellent characteristics of a 1/4 retardation plate in a wide band.

-Measurement of Refractive Index- In the laminated retardation plate, the refractive index in the in-plane slow axis direction (n
x), the refractive index in the in-plane fast axis direction (ny), and the refractive index in the thickness direction (nz) were determined by known methods,
The formula (nz ≧ (nx + ny) / 2) was satisfied.

[0067]

EFFECTS OF THE INVENTION According to the present invention, a method for producing a laminated retardation plate which is excellent in production efficiency and can be produced at low cost, and a laminated layer which is obtained by the method for producing the laminated retardation plate and has good wavelength dispersion. A retardation plate can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a co-extrusion device suitably used for co-extrusion.

FIG. 2 is a schematic configuration diagram of an extrusion die of a coextrusion device preferably used for coextrusion.

FIG. 3 is a diagram showing the results of measuring the wavelength dispersion of retardation (Re) of the laminated retardation plate manufactured in Example 1 using a retardation measuring device.

[Explanation of symbols] 20 Coextrusion equipment 22 Extrusion die 24 extruder 26 Extruder 28 tension roll 30 tension roll 32 tension roll 34 laminate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B29K 69:00 B29K 69:00 B29L 9:00 B29L 9:00 11:00 11:00 F term ( reference) 2H049 BA06 BA07 BA42 BB03 BB42 BB52 BC01 BC03 BC22 2H091 FA11X FA11Z FB02 FC07 FC08 FD06 FD17 LA12 LA16 LA20 MA07 4F207 AA28 AG01 AG03 KA01 KA17 KB26 KW26 4F210 AA28 AG01 AG03 AH73 QC01 QC02 QG01 QG15 QG18 4J029 AA09 AB07 AC02 AD01 AD09 AE03 AE04 BB12A BB12B BB12C BB13A BB13B BB13C BB16A BB16B BB16C BD08 BD09A BD09B BD09C BE03 BG06X BG08X BG08Y BG09X BG09Y BH02 BH04 DB07 DB13

Claims (8)

[Claims] 1. A layer containing a resin having a positive intrinsic birefringence value and a resin having a negative intrinsic birefringence value, which is co-extruded and stretched, and a layer containing the resin having a positive intrinsic birefringence value, and an intrinsic birefringence value. Is a method for producing a laminated retardation plate including a layer containing a negative resin, wherein the resin having a negative intrinsic birefringence value is a repeating unit represented by the following formula (1): And a repeating unit represented by the following formula (2), which is a polycarbonate. [Chemical 1] [Chemical 2] In formula (2), A ^{1 to} A ⁸ are each independently at least one selected from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 3 carbon atoms. X is the following formula group (3)
It is one represented by. Formula group (3) In the formula group (3), A ^{9 to} A ¹¹ , A ^{13 to} A
¹⁴ is at least one selected independently from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 22 carbon atoms. A ¹² and A ¹⁵ each independently have 1 to 2 carbon atoms.
It is at least one selected from 0 hydrocarbon groups. A
Each of r _{1 to} Ar ₃ is independently at least one selected from an aryl group having 6 to 10 carbon atoms. 2. The method for producing a laminated retardation plate according to claim 1, wherein the resin having a positive intrinsic birefringence value is a polycarbonate containing a repeating unit represented by the formula (2). 3. A layer containing a resin having a positive intrinsic birefringence value and a layer containing a resin having a negative intrinsic birefringence value, which are obtained by the method for producing a laminated retardation plate according to claim 1 or 2. A laminated retardation plate having. 4. The laminated retardation plate according to claim 3, further comprising an adhesion layer between a layer containing a resin having a positive intrinsic birefringence value and a layer containing a resin having a negative intrinsic birefringence value. 5. Wavelengths of 450 nm, 550 nm, and 65
Retardation (Re) value at 0 nm is expressed as Re
When (450), Re (550), and Re (650), Re (450) <Re (550) <Re (65
0) The laminated retardation plate according to claim 3 or 4, which satisfies 0). 6. Wavelengths of 450 nm, 550 nm, and 65
Retardation (Re) / wavelength (λ) at 0 nm
6. The laminated retardation plate according to claim 3, wherein the value of is 0.2 to 0.3. 7. Wavelengths of 450 nm, 550 nm and 650.
The retardation (Re) / wavelength (λ) value in nm is 0.4 to 0.6, and the laminated retardation plate according to any one of claims 3 to 5. 8. When the thickness of the laminated retardation plate is d, the refractive index in the in-plane slow axis direction is nx, the refractive index in the in-plane fast axis direction is ny, and the refractive index in the thickness direction is nz, nz ≧ (nx + n
The laminated retardation plate according to any one of claims 3 to 7, which satisfies y) / 2.