JP5707811B2 - Long λ / 4 plate, circularly polarizing plate, polarizing plate, OLED display device, and stereoscopic image display device - Google Patents

Description

  The present invention relates to a long λ / 4 plate, a circularly polarizing plate, a polarizing plate, an OLED display device, and a stereoscopic image display device.

  In a display device using organic EL, a circle is placed on the viewing side of the organic EL element in order to prevent external light from being reflected inside the element and causing deterioration in display performance such as reflection of external scenery and a decrease in contrast. A polarizing plate is used. The circularly polarizing plate is laminated with an angle of 45 ° between the slow axis of the λ / 4 plate and the absorption axis of the polarizer. If the λ / 4 plate is produced by oblique stretching, the bonding process with the polarizer can be produced by roll-to-roll, and the extra step of cutting the λ / 4 plate obliquely can be omitted, so that productivity is good. Since an extra film such as a polarizing plate protective film can be omitted, the polarizing plate can be thinned, and thus a method for producing a λ / 4 plate by oblique stretching has been developed.

  However, when the film is obliquely stretched, there is a problem that it is difficult to obtain optical uniformity in the width direction of the film, and various improvements have been attempted. For example, in Patent Document 1, aiming at improving the optical uniformity in the width direction, an outlet for warm air during oblique stretching is installed obliquely. In Patent Document 2, the optical uniformity in the width direction is also the same. A technique for oblique stretching with a temperature distribution in the width direction is disclosed. Patent Document 3 discloses a technique that aims at improving uniformity by designing the angle of the boundary line between the preheating zone and the stretching zone of the tenter and the stretching zone and the fixed zone. Both of these technologies attempt to improve uniformity by changing the process conditions such as the heating method of stretching and zone regulation from conventional ones using a single layer film. Although the above effect was obtained, there was a rare problem that the film was distorted or warped, and there was a problem in stably producing a film having flatness and optical uniformity.

  Further, studies have been made to reduce the load on the film during oblique stretching from the viewpoint of material. For example, Patent Document 4 discloses that a λ / 4 plate is obliquely stretched using a cellulose acetate propionate resin having high stretchability. Although a desired phase difference is likely to develop even at low magnification, it is still possible to apply it to a large screen display device or a stereoscopic image display device. There were problems with uniformity and flatness in the hand direction.

Japanese Patent No. 473823 JP 2006-224618 A JP 2009-78474 A JP 2008-083307 A

The present invention has been made to solve the above problems, and an object thereof is to provide a thin film elongate lambda / 4 plate having both flatness and optical uniformity width hand. Furthermore, a circularly polarizing plate and a polarizing plate using the λ / 4 plate can reduce OLED display devices (organic EL display devices) with good visibility even under external light, and reduction in luminance when the neck is tilted. It is to provide a stereoscopic (3D) image display device.

The above-described problems of the present invention are solved by the following means .

1. A long λ / 4 plate having an in-plane retardation Ro (590) at a wavelength of 590 nm satisfying Ro (590) = 120 to 160 nm, and the long λ / 4 plate satisfying the following formula (1) a layer a consisting acylate, seen including a layer B of cellulose acetate to satisfy the following equation (2), a laminated film which is adjacent to the order of layer B / layer a / layer B,
The thickness of the layer B is equal to or less than the thickness of the layer A;
The slow axis of the laminated film has an angle of 20 to 70 ° with respect to the longitudinal direction, and only the layer B includes an aliphatic polyester, an acrylic polymer, and a styrene polymer as a retardation adjusting agent. A long λ / 4 plate comprising at least one selected from high molecular weight compounds.
Formula (1) 2.0 <Z1 <2.7
(In the formula, Z1 represents the total acyl substitution degree of the cellulose acylate of layer A.)
Formula (2) 2.7 <= X2
(In the formula, X2 represents the total degree of acetyl substitution of the cellulose acetate of layer B.)

2 . 2. The long λ / 4 plate as described in 1 above, wherein the total film thickness is 80 μm or less.

3 . 3. The long λ / 4 plate according to 1 or 2 above, wherein the layer B contains a retardation developing agent having a rod-like structure, and the layer A contains a retardation developing agent having a disk-like structure.

4 . The amount WB of the rod-shaped compound contained in the layer B, the amount WA of the discotic compound contained in the layer A, according to the 3 and satisfies the WB / WA = 1.3 to 1.6 Long λ / 4 plate.
(WB represents the mass part of the rod-shaped compound with respect to 100 parts by mass of the cellulose acetate contained in the layer B, and WA represents the mass part of the discotic compound with respect to 100 parts by mass of the cellulose acylate contained in the layer A.)

5 . The long λ / 4 plate according to any one of 1 to 4 and a polarizer are disposed adjacent to each other, and an absorption axis of the polarizer and a slow axis of the λ / 4 plate are substantially 45 °. A circularly polarizing plate, which is arranged so as to be oriented.

6 . 6. An OLED display device using the circularly polarizing plate as described in 5 above.

7 . 5. The long λ / 4 plate according to any one of 1 to 4 and a polarizer are arranged adjacent to each other in the order of (λ / 4 plate) / polarizer / (λ / 4 plate). The absorption axis of the child and the slow axis of the λ / 4 plate are each arranged so as to be substantially oriented at 45 °, and the slow axes of the two λ / 4 plates are arranged so as to be orthogonal to each other. A polarizing plate characterized by that.

8 . 5. The long λ / 4 plate according to any one of 1 to 4 and a polarizer are arranged adjacent to each other in the order of (λ / 4 plate) / polarizer / (λ / 4 plate). Arranged so that the absorption axis of the child and the slow axis of the λ / 4 plate are each substantially oriented at 45 °, and the slow axes of the two λ / 4 plates are parallel. A polarizing plate characterized by being made.

9 . A stereoscopic image display device using the polarizing plate described in 7 or 8 above.

  ADVANTAGE OF THE INVENTION According to this invention, the thin film elongate (lambda) / 4 board which has width flatness and optical uniformity can be provided. Furthermore, a circularly polarizing plate and a polarizing plate using the λ / 4 plate, an OLED display device that has good visibility even under external light, and a stereoscopic (3D) image display that can reduce a decrease in luminance when the neck is tilted. An apparatus can be provided.

It is a schematic diagram which shows the diagonal stretch by a tenter. It is the figure showing the place which formed the multilayer casting web by casting with a co-casting die.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  The long λ / 4 plate of the present invention (hereinafter simply referred to as λ / 4 plate) is a λ / 4 plate having an in-plane retardation Ro (590) of 120 to 160 nm at a wavelength of 590 nm, 1 is a resin film in which a layer A containing cellulose acylate satisfying 1) and a layer B containing cellulose acetate satisfying the formula (2) are laminated, and the slow axis of the film is 20 to It is characterized by an angle of 70 °.

  In the present specification, the “layer A” is a layer containing cellulose acylate satisfying the above formula (1), and means the thickest layer among the layers of the λ / 4 plate of the present invention, “Layer B” refers to a layer containing cellulose acetate satisfying the above formula (2) and having a thinner film thickness than “Layer A”. In the present invention, it is preferable that “layer B” is further provided on the “layer A” side of the laminated film of “layer A” and “layer B”. In this case, the “layer B” disposed on both sides of the “layer A” may be the same or different in film thickness, but it is important that the “layer A” is the same as or thicker than the “layer A”. It is not preferable from the viewpoint of phase difference expression.

  With such a configuration, it is possible to provide a long thin λ / 4 plate that has both wide planarity and optical uniformity and can be rolled to roll in the polarizing plate forming step. The present inventor, when making a λ / 4 plate whose slow axis of the film is at an angle of 20 to 70 ° with respect to the longitudinal direction, is a conventional method of applying wind and temperature in the width direction during oblique stretching. In the improvement of the process surface such as the provision of the distribution and the design of the stretching zone, the problems of the decrease in the optical value uniformity in the width direction and the deterioration in the flatness occur. The cellulose acylate represented by the formula (1) A resin film obtained by laminating a layer B containing cellulose acetate having a low birefringence expressed by the formula (2) on a layer A containing a slow axis at an angle of 20 to 70 ° with respect to the longitudinal direction. Thus, it has been found that the above problem can be solved by stretching the film obliquely with respect to the longitudinal direction, and the present invention has been achieved.

  Further, the λ / 4 plate of the present invention preferably has a film thickness of 80 μm or less.

  As an embodiment of the present invention, the layer B contains at least one high molecular weight compound selected from an aliphatic polyester, an acrylic polymer, and a styrene polymer from the viewpoint of manifesting the effects of the present invention and reducing the thickness. Is preferred. When such a high molecular weight compound is contained in the layer B, the stretchability of the layer B can be improved, and the wavelength dispersion of the retardation of the λ / 4 plate can be adjusted in a desired direction.

  Furthermore, it is preferable in adjusting the phase difference that the layer A contains a retardation developing agent having a disk-like structure and the layer B contains a retardation developing agent having a rod-like structure.

  In addition, an amount WB of a retardation developer having a rod-like structure contained in the layer B (hereinafter simply referred to as “rod-like compound”) and a retardation developer having a disc-like structure contained in the layer A (hereinafter, simply Stretchability when obliquely stretching so as to achieve a phase difference of λ / 4 that the amount WA of “sometimes called a discotic compound” satisfies WB / WA = 1.3 to 1.6. And from the viewpoint of optical value expression.

  The method for producing a λ / 4 plate of the present invention is a method of co-casting a dope for layer A containing cellulose acylate satisfying the formula (1) and a dope for layer B containing cellulose acetate satisfying the formula (2). It is preferable to produce a λ / 4 plate by stretching 1.3 times or more in the direction of 20 to 70 ° with respect to the longitudinal direction while drying the peeled web after being dried on the support. It is.

  In addition, the λ / 4 plate of the present invention forms a circularly polarizing plate in which the absorption axis of the polarizer and the slow axis of the λ / 4 plate are bonded with an inclination of substantially 45 °. It is preferably used for a liquid crystal display device, an organic EL display, and a stereoscopic image display device that can reduce a decrease in luminance when the head is tilted.

  Further, a polarized light in which a λ / 4 plate is further bonded to the polarizer side of the circularly polarizing plate so that the absorption axis of the polarizer and the slow axis of the λ / 4 plate have an inclination of substantially 45 °. A plate is also preferred. Such a member is preferable in a stereoscopic image display apparatus using an organic EL display because it can reduce a decrease in luminance when the head is tilted.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail.

(Λ / 4 plate)
The λ / 4 plate of the present invention means a plate having a function of converting linearly polarized light having a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light). The λ / 4 plate is designed such that the in-plane retardation value Ro is about 1/4 with respect to a predetermined wavelength of light (usually in the visible light region).

  In the λ / 4 plate of the present invention, Ro (590) measured at a wavelength of 590 nm is in the range of 120 to 160 nm.

  The λ / 4 plate of the present invention is a retardation plate (resin film) having a retardation of approximately ¼ of the wavelength in the visible light wavelength range in order to obtain almost perfect circularly polarized light in the visible light wavelength range. Preferably there is.

  “Retardation of approximately ¼ in the wavelength range of visible light” means a retardation value represented by the following formula (i) measured at a wavelength of 450 nm and Ro ( 450) and Ro (590), which is a retardation value measured at a wavelength of 590 nm, preferably satisfies 1 <Ro (590) / Ro (450) ≦ 1.6. Furthermore, in order to function effectively as a λ / 4 plate, Ro (450) is in the range of 100 to 125 nm, and Ro (550) which is a retardation value measured at a wavelength of 550 nm is in the range of 125 to 142 nm. More preferably, the retardation film is Ro (590) in the range of 130 to 152 nm.

Formula (i): Ro = (nx−ny) × d
Formula (ii): Rt = {(nx + ny) / 2−nz} × d
In the formula, nx and ny are refractive indexes nx (also referred to as the maximum in-plane refractive index and refractive index in the slow axis direction) at 23 ° C./55% RH, 450 nm, 550 nm, and 590 nm, ny. (Refractive index in the direction perpendicular to the slow axis in the film plane), and d is the thickness (nm) of the film.

  Ro and Rt can be measured using an automatic birefringence meter. Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments), Ro is calculated by birefringence measurement at each wavelength in an environment of 23 ° C. and 55% RH.

  A circularly polarizing plate is obtained by laminating so that the angle between the slow axis of the λ / 4 plate and the transmission axis of the polarizer described later is substantially 45 °. “Substantially 45 °” means 40 to 50 °. The angle between the slow axis in the plane of the λ / 4 plate and the transmission axis of the polarizer is preferably 41 to 49 °, more preferably 42 to 48 °, and 43 to 47 °. Is more preferable, and it is most preferable that it is 44-46 degrees.

(Cellulose acylate, cellulose acetate)
The λ / 4 plate of the present invention is a resin film in which a layer A containing cellulose acylate satisfying the following formula (1) and a layer B containing cellulose acetate satisfying the following formula (2) are laminated. To do.

Formula (1) 2.0 <Z1 <2.7
(In the formula, Z1 represents the total acyl substitution degree of the cellulose acylate of layer A.)
Formula (2) 2.7 <= X2
(In the formula, X2 represents the total degree of acetyl substitution of the cellulose acetate of layer B.)
First, the cellulose acylate used for the layer A will be described in detail.

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by acylating part or all of these hydroxyl groups with an acyl group. The degree of acyl substitution means the ratio of acylation of the hydroxyl groups of cellulose located at the 2-position, 3-position and 6-position (100% acylation is substitution degree 1). In addition, the substitution degree of an acyl group is calculated | required by the method prescribed | regulated to ASTM-D817-96.

  Z1 preferably satisfies 2.1 <Z1 <2.6, and more preferably satisfies 2.1 ≦ Z1 ≦ 2.5.

  When the total acyl group substitution degree of cellulose acylate is less than 2.0, deterioration of film surface quality due to increase in dope viscosity, haze-up due to increase in stretching tension, and the like may occur. Further, when the total acyl substitution degree is larger than 2.7, it is difficult to obtain a necessary phase difference.

  The layer A according to the present invention is more preferably a cellulose acetate satisfying the above formula (1), and particularly preferably diacetyl cellulose.

  The acyl group having 2 or more carbon atoms of cellulose acylate in the present invention may be an aliphatic group or an allyl group, and is not particularly limited. These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group. Preferred examples of these include acetyl group, propionyl group, butanoyl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, isobutanoyl group Group, tert-butanoyl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like. Among these, an acetyl group, a propionyl group, a butanoyl group, a dodecanoyl group, an octadecanoyl group, a tert-butanoyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, a cinnamoyl group, and the like are more preferable, and an acetyl group is particularly preferable. A propionyl group and a butanoyl group (when the acyl group has 2 to 4 carbon atoms), more preferably an acetyl group (when the cellulose acylate is cellulose acetate).

  On the other hand, the cellulose acetate used for the layer B according to the present invention is preferably a cellulose triacetate having a total acetyl substitution degree X2 of 2.7 or more. When X2 uses cellulose triacetate within this range, the peelability from the support can be improved, and both lateral flatness and optical uniformity can be achieved. The total degree of acetyl substitution X2 is more preferably 2.8 ≦ X2 <≦ 3.0.

  The degree of acetyl substitution here refers to the average value of the number of hydroxyl groups (hydroxyl groups) that are esterified (acetylated) among the three hydroxyl groups (hydroxyl groups) of each anhydroglucose that constitutes cellulose. A value in the range of 0 to 3 is shown.

  In the present invention, a portion not substituted with an acetyl group is usually present as a hydroxyl group (hydroxyl group). These can be synthesized by known methods.

  The number average molecular weight (Mn) of the cellulose acylate and cellulose acetate according to the present invention is preferred because the mechanical strength of the film from which a range of 30000-300000 is obtained is strong. Furthermore, the thing of 50000-200000 is used preferably.

  The ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of cellulose acylate and cellulose acetate is preferably 1.4 to 3.0.

  The weight average molecular weight Mw and the number average molecular weight Mn of cellulose acylate and cellulose acetate were measured using gel permeation chromatography (GPC).

  The measurement conditions are as follows.

Solvent: Methylene chloride Column: Shodex K806, K805, K803G (Used by connecting three Showa Denko Co., Ltd.)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) Mw = 100000 to 500 calibration curves with 13 samples were used. Thirteen samples are used at approximately equal intervals.

  Furthermore, the λ / 4 plate of the present invention preferably includes a layer B made of cellulose acetate satisfying the formula (2) on a surface different from the layer B of the layer A. The layers B provided on both sides of the layer A may be the same or different in thickness. However, it is not preferable that the layer A is the same as or thicker than the layer A from the viewpoint of the retardation development.

  The cellulose as a raw material for cellulose acylate and cellulose acetate according to the present invention is not particularly limited, and examples thereof include cotton linter, wood pulp, and kenaf. In addition, cellulose acylate and cellulose acetate obtained from them can be mixed and used in an arbitrary ratio.

  In the acylation of cellulose, when an acid anhydride or acid chloride is used as an acylating agent, an organic acid such as acetic acid or methylene chloride is used as an organic solvent as a reaction solvent.

As the catalyst, when the acylating agent is an acid anhydride, a protic catalyst such as sulfuric acid is preferably used, and when the acylating agent is an acid chloride (for example, CH ₃ CH ₂ COCl), Basic compounds are used.

  In addition, a general method for industrially synthesizing mixed fatty acid esters of cellulose is a mixed organic acid containing cellulose containing fatty acids corresponding to acetyl groups and other acyl groups (acetic acid, propionic acid, valeric acid, etc.) or acid anhydrides thereof. This is a method of acylating with components.

  Specifically, it can be synthesized with reference to the method described in JP-A-10-45804.

  The additive will be described below.

  Additives other than cellulose acylate and cellulose acetate include plasticizers, UV absorbers, retardation modifiers, retardation enhancers, antioxidants, deterioration inhibitors, peeling aids, surfactants, dyes, fine particles, etc. . In the present invention, additives other than fine particles may be added when preparing a cellulose acylate or cellulose acetate solution, or may be added when preparing a fine particle dispersion.

(UV absorber)
The λ / 4 plate of the present invention may or may not contain an ultraviolet absorber. More specifically, when an OLED display device is used as a circularly polarizing plate for preventing external light reflection, an ultraviolet absorber is not essential for the λ / 4 plate, but a neck for a stereoscopic image display device is used. When used for preventing color change when tilted, the display device is preferably arranged on the visual recognition side of the polarizer, and therefore preferably contains an ultraviolet absorber.

  Examples of ultraviolet absorbers that can be used include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, triazine compounds, and the like. A benzotriazole-based compound with little coloring is preferable. Further, ultraviolet absorbers described in JP-A-10-182621, JP-A-8-337574, JP-A-2001-72782, JP-A-6-148430, JP-A-2002-31715, JP-A-2002-169020, 2002-2002. Polymer ultraviolet absorbers described in 47357, 2002-363420, and 2003-113317 are also preferably used. As an ultraviolet absorber, from the viewpoint of preventing the deterioration of polarizers and liquid crystals, it is excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less, and from the viewpoint of liquid crystal display properties, the absorption of visible light having a wavelength of 400 nm or more is small. Is preferred.

  Specific examples of UV absorbers useful in the present invention include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) ) Benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl) benzotriazole, 2,2-methylenebis ( 4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy-3'- ert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5 -Chloro-2H-benzotriazol-2-yl) phenyl] propionate and the like can be mentioned, but not limited thereto. As commercially available products, TINUVIN 109, TINUVIN 171, TINUVIN 326, and TINUVIN 928 (all manufactured by BASF Japan) can be preferably used. An example of the polymeric ultraviolet absorber is a reactive ultraviolet absorber RUVA-93 manufactured by Otsuka Chemical Co., Ltd.

  Specific examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis (2-methoxy-4-hydroxy- 5-benzoylphenylmethane) and the like, but is not limited thereto.

  The ultraviolet absorber described above preferably used in the present invention is preferably a benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber, which has high transparency and is excellent in the effect of preventing the deterioration of the polarizing plate and the liquid crystal element, and unnecessary coloring. A benzotriazole-based ultraviolet absorber with a lower content is particularly preferably used.

  The ultraviolet absorber can be added to the dope without limitation as long as it dissolves the ultraviolet absorber in the dope. In the present invention, the ultraviolet absorber is cellulose such as methylene chloride, methyl acetate, dioxolane and the like. Dope by dissolving in a good solvent for the ester, or a mixed solvent of a good solvent and a poor solvent such as a lower aliphatic alcohol (methanol, ethanol, propanol, butanol, etc.) and adding it to the cellulose ester solution as an ultraviolet absorber solution Is preferred. In this case, it is preferable to make the dope solvent composition and the solvent composition of the ultraviolet absorber solution the same or as close as possible.

(Retardation adjuster)
<High molecular weight compound>
The λ / 4 plate of the present invention preferably contains in layer B a high molecular weight compound selected from aliphatic polyester, acrylic polymer, and styrene polymer as a retardation adjusting agent. By including such a high molecular weight compound in the layer B, the mechanical properties are improved as compared with the case where no addition is made, and failures such as craze and whitening are less likely to occur in the stretching process during the production of the λ / 4 plate. In addition, there is an effect of adjusting the wavelength dispersion of the retardation of the λ / 4 plate in a desired direction.

  Here, the number average molecular weight of the high molecular weight additive in the present invention is more preferably a number average molecular weight of 700 to 8000, still more preferably a number average molecular weight of 700 to 5000, and particularly preferably a number average molecular weight of 1000 to 5000. is there.

  The high molecular weight additive is preferably added in an amount of 1 to 35% by mass, more preferably 4 to 30% by mass, and still more preferably 10 to 25% by mass with respect to cellulose acylate. If the added amount is 1% by mass or less, sufficient effects cannot be exhibited. If the added amount is 35% by mass or more, whitening occurs during stretching, and mechanical strength and physical film physical properties deteriorate. It is not preferable. Moreover, when using 2 or more types of retardation regulators, it is preferable that the total amount is in the said range.

  Hereinafter, although the high molecular weight compound used for this invention is demonstrated in detail, giving the specific example, it cannot be overemphasized that the high molecular weight compound used for this invention is not necessarily limited to these.

  The high molecular weight compound is selected from polyester polymers, styrene polymers, acrylic polymers and copolymers thereof, and aliphatic polyesters, acrylic polymers and styrene polymers are preferred. Moreover, it is preferable that at least one polymer having negative intrinsic birefringence, such as a styrene polymer and an acrylic polymer, is included.

  The polyester polymer is a reaction of an aliphatic dicarboxylic acid having 2 to 20 carbon atoms with at least one diol selected from an aliphatic diol having 2 to 12 carbon atoms and an alkyl ether diol having 4 to 20 carbon atoms. The both ends of the reaction product may be left as the reaction product, or a so-called end-capping may be carried out by further reacting monocarboxylic acids, monoalcohols or phenols. It is effective in terms of storage stability that the end capping is performed in particular so as not to contain free carboxylic acids. The dicarboxylic acid used in the polyester polymer is preferably an aliphatic dicarboxylic acid residue having 4 to 20 carbon atoms or an aromatic dicarboxylic acid residue having 8 to 20 carbon atoms.

  Examples of the aliphatic dicarboxylic acid having 2 to 20 carbon atoms preferably used in the present invention include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid. , Sebacic acid, dodecanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.

  Among these, preferable aliphatic dicarboxylic acids are malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, and 1,4-cyclohexanedicarboxylic acid. Particularly preferably, the aliphatic dicarboxylic acid component is succinic acid, glutaric acid, or adipic acid.

  The diol utilized for the high molecular weight compound is selected from, for example, an aliphatic diol having 2 to 20 carbon atoms and an alkyl ether diol having 4 to 20 carbon atoms.

  Examples of the aliphatic diol having 2 to 20 carbon atoms include alkyl diols and alicyclic diols, such as ethane diol, 1,2-propanediol, 1,3-propanediol, and 1,2-butane. Diol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol) ), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3 -Methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl 1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, and the like. Used as a mixture of two or more.

  Preferred aliphatic diols include ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1 , 4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, particularly preferred Is ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6- Hexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol.

  Preferred examples of the alkyl ether diol having 4 to 20 carbon atoms include polytetramethylene ether glycol, polyethylene ether glycol and polypropylene ether glycol, and combinations thereof. The average degree of polymerization is not particularly limited, but is preferably 2 to 20, more preferably 2 to 10, further 2 to 5, and particularly preferably 2 to 4. As examples of these, commercially useful polyether glycols typically include Carbowax, Pluronics and Niax resins.

  In the present invention, a high molecular weight compound having a terminal capped with an alkyl group or an aromatic group is particularly preferable. This is because the terminal is protected with a hydrophobic functional group, which is effective against deterioration with time at high temperature and high humidity, and is due to the role of delaying hydrolysis of the ester group.

  It is preferable to protect with a monoalcohol residue or a monocarboxylic acid residue so that both ends of the polyester additive used in the present invention do not become a carboxylic acid or an OH group.

  In this case, the monoalcohol is preferably a substituted or unsubstituted monoalcohol having 1 to 30 carbon atoms, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, isohexanol, cyclohexyl alcohol. , Octanol, isooctanol, 2-ethylhexyl alcohol, nonyl alcohol, isononyl alcohol, tert-nonyl alcohol, decanol, dodecanol, dodecahexanol, aliphatic alcohol such as dodecaoctanol, allyl alcohol, oleyl alcohol, benzyl alcohol, 3-phenyl Examples thereof include substituted alcohols such as propanol.

  End-capping alcohols that can be preferably used are methanol, ethanol, propanol, isopropanol, butanol, isobutanol, isopentanol, hexanol, isohexanol, cyclohexyl alcohol, isooctanol, 2-ethylhexyl alcohol, isononyl alcohol, oleyl alcohol Benzyl alcohol, in particular methanol, ethanol, propanol, isobutanol, cyclohexyl alcohol, 2-ethylhexyl alcohol, isononyl alcohol, benzyl alcohol.

  Moreover, when sealing with a monocarboxylic acid residue, the monocarboxylic acid used as a monocarboxylic acid residue is preferably a substituted or unsubstituted monocarboxylic acid having 1 to 30 carbon atoms. These may be aliphatic monocarboxylic acids or aromatic ring-containing carboxylic acids. Preferred aliphatic monocarboxylic acids are described, for example, acetic acid, propionic acid, butanoic acid, caprylic acid, caproic acid, decanoic acid, dodecanoic acid, stearic acid, oleic acid, and examples of the aromatic ring-containing monocarboxylic acid include Benzoic acid, p-tert-butylbenzoic acid, p-tert-amylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, normal propylbenzoic acid, aminobenzoic acid, acetoxybenzoic acid, etc. Yes, these can be used alone or in combination of two or more.

  The high molecular weight compound used in the present invention is synthesized by a hot melt condensation method by a polyesterification reaction or a transesterification reaction between the dicarboxylic acid and a diol and / or a monocarboxylic acid or monoalcohol for end-capping by a conventional method. Alternatively, it can be easily synthesized by any of the interfacial condensation methods of acid chlorides of these acids and glycols. These polyester-based additives are described in detail in Koichi Murai, “Additives, Theory and Application” (Kokaibo Co., Ltd., first edition published on March 1, 1973). In addition, Japanese Patent Laid-Open Nos. 05-155809, 05-155810, Japanese Patent Laid-Open Nos. 05-97073, 2006-259494, 07-330670, 2006-342227, 2007-003679. The materials described in each publication can also be used.

  The styrenic polymer is preferably a structural unit obtained from an aromatic vinyl monomer represented by the general formula (1).

In the formula, each of R ^{101 to} R ¹⁰⁴ independently represents a substituted or unsubstituted carbon atom which may have a linking group containing a hydrogen atom, a halogen atom, an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. Represents a hydrocarbon group of 1 to 30 or a polar group, and R104 may be the same atom or group or different atoms or groups, and may be bonded to each other to form a carbocyclic or heterocyclic ring (these These carbocycles and heterocycles may be monocyclic structures, or other rings may be condensed to form a polycyclic structure.

  Specific examples of the aromatic vinyl monomer include styrene; alkyl-substituted styrenes such as α-methylstyrene, β-methylstyrene, and p-methylstyrene; halogen-substituted styrenes such as 4-chlorostyrene and 4-bromostyrene. Hydroxystyrenes such as p-hydroxystyrene, α-methyl-p-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3,4-dihydroxystyrene; vinyl benzyl alcohols; p-methoxystyrene, p-tert Alkoxy-substituted styrenes such as butoxystyrene and m-tert-butoxystyrene; vinyl benzoic acids such as 3-vinylbenzoic acid and 4-vinylbenzoic acid; vinyl such as methyl-4-vinylbenzoate and ethyl-4-vinylbenzoate Benzoic acid esters; 4-vinyl vinyl 4-acetoxystyrene; amidostyrenes such as 2-butylamidostyrene, 4-methylamidostyrene, p-sulfonamidostyrene; 3-aminostyrene, 4-aminostyrene, 2-isopropenylaniline, vinylbenzyldimethyl Aminostyrenes such as amines; nitrostyrenes such as 3-nitrostyrene and 4-nitrostyrene; cyanostyrenes such as 3-cyanostyrene and 4-cyanostyrene; vinylphenylacetonitrile; arylstyrenes such as phenylstyrene, indene The present invention is not limited to these specific examples. Two or more of these monomers may be used as a copolymerization component. Of these, styrene and α-methylstyrene are preferred because they are easily available industrially and are inexpensive.

  The acrylic polymer is preferably a structural unit obtained from an acrylate ester monomer represented by the general formula (2).

In the formula, each of R ^{105 to} R ¹⁰⁸ independently represents a substituted or unsubstituted carbon atom which may have a linking group containing a hydrogen atom, a halogen atom, an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. This represents a hydrocarbon group having 1 to 30 or a polar group.

  Examples of the acrylate monomer include, for example, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, tert-). , Pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), acrylic acid Nonyl (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2- Hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid (2-methoxyethyl) Acrylic acid (2-ethoxyethyl) phenyl acrylate, phenyl methacrylate, acrylic acid (2 or 4-chlorophenyl), methacrylic acid (2 or 4-chlorophenyl), acrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), Methacrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), acrylic acid (o or m or p-tolyl), methacrylic acid (o or m or p-tolyl), benzyl acrylate, benzyl methacrylate, phenethyl acrylate, Phenethyl methacrylate, acrylic acid (2-naphthyl), cyclohexyl acrylate, cyclohexyl methacrylate, acrylic acid (4-methylcyclohexyl), methacrylic acid (4-methylcyclohexyl), acrylic acid (4-ethylcyclohexyl), Examples thereof include tacrylic acid (4-ethylcyclohexyl) and the like, or those obtained by replacing the acrylic ester with a methacrylic ester, but the present invention is not limited to these specific examples. Two or more of these monomers may be used as a copolymerization component. Of these, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, tert-), pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), or those obtained by replacing the acrylate ester with a methacrylate ester are preferred.

  The copolymer contains at least one structural unit obtained from an aromatic vinyl monomer represented by the general formula (1) and an acrylate ester monomer represented by the general formula (2). Is preferred.

In the formula, each of R ^{101 to} R ¹⁰⁴ independently represents a substituted or unsubstituted carbon atom which may have a linking group containing a hydrogen atom, a halogen atom, an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. Represents a hydrocarbon group of 1 to 30 or a polar group, and R104 may be the same atom or group or different atoms or groups, and may be bonded to each other to form a carbocyclic or heterocyclic ring (these These carbocycles and heterocycles may be monocyclic structures, or other rings may be condensed to form a polycyclic structure.

In the formula, R ^{105 to} R ¹⁰⁸ each independently have a linking group containing a hydrogen atom, a halogen atom, an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom, and the number of substituted or unsubstituted carbon atoms 1-30 hydrocarbon groups or a polar group is represented. Further, the structure other than the above constituting the copolymer composition is preferably excellent in copolymerizability with the monomer, and examples thereof include maleic anhydride, citraconic anhydride, cis-1-cyclohexene-1 , 2-dicarboxylic anhydride, 3-methyl-cis-1-cyclohexene-1,2-dicarboxylic anhydride, 4-methyl-cis-1-cyclohexene-1,2-dicarboxylic anhydride and the like, acrylonitrile, Nitrile group-containing radical polymerizable monomers such as methacrylonitrile; amide bond-containing radical polymerizable monomers such as acrylamide, methacrylamide, trifluoromethanesulfonylaminoethyl (meth) acrylate; fatty acid vinyls such as vinyl acetate; Chlorine-containing radical polymerizable monomers such as vinyl and vinylidene chloride; 1,3-butadiene; Isoprene, 1,4-dimethyl butadiene and the like can be mentioned conjugated diolefins but the present invention is not limited thereto. Of these, styrene-acrylic acid copolymers, styrene-maleic anhydride copolymers, and styrene-acrylonitrile copolymers are particularly preferred.

(Low molecular weight compound)
As the retardation adjusting agent useful for the λ / 4 plate of the present invention, it is most preferable to use a high molecular weight compound as described above, but the following low molecular weight compounds can also be used.

  Examples of the low molecular weight compound include the following. These may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of an ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and a mixture of deterioration preventing agents are also possible. Furthermore, infrared absorbing dyes are described, for example, in JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the cellulose acylate solution (dope) preparation step, but it may be added by adding a preparation step to the final preparation step of the dope preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested.

  Although it does not specifically limit as a low molecular weight compound, The compound represented by General formula (3)-(7) described below is mentioned.

(In the formula, R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represents a hydrogen atom, an alkyl group, or an aryl group. The number of carbon atoms of R ¹ , R ^2, and R ³ is The sum is 10 or more.)

(In the formula, R ⁴ and R ⁵ each independently represents an alkyl group or an aryl group. The total number of carbon atoms of R ⁴ and R ⁵ is 10 or more.)
In General Formula (3), R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Moreover, it is especially preferable that the total number of carbon atoms of R ¹ , R ² and R ³ is 10 or more. In the general formula (4), R ⁴ and R ⁵ each independently represents an alkyl group or an aryl group. The total number of carbon atoms of R ⁴ and R ⁵ is 10 or more, and each of the alkyl group and aryl group may have a substituent. As the substituent, a fluorine atom, an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are preferable, and an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are particularly preferable. The alkyl group may be linear, branched, or cyclic, and preferably has 1 to 25 carbon atoms, more preferably 6 to 25, and 6 to 20 ( For example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, amyl group, isoamyl group, tert-amyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, bicyclooctyl Group, nonyl group, adamantyl group, decyl group, tert-octyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, didecyl group). As the aryl group, those having 6 to 30 carbon atoms are preferable, and those having 6 to 24 carbon atoms (for example, phenyl group, biphenyl group, terphenyl group, naphthyl group, binaphthyl group, triphenylphenyl group) are particularly preferable. Although the preferable example of a compound represented by General formula (3) or General formula (4) is shown below, this invention is not limited to these specific examples.

  The compound represented by the general formula (3) or the general formula (4) can be produced by the following method.

  The compound of the general formula (3) can be obtained by a condensation reaction between a sulfonyl chloride derivative and an amine derivative. The compound of the general formula (4) can be obtained by oxidation reaction of sulfide or Friedel-Crafts reaction of aromatic compound and sulfonic acid chloride.

  Next, the compound represented by the general formula (5) will be described in detail.

In the general formula (5), R ¹¹ represents an aryl group. R ¹² and R ¹³ each independently represents an alkyl group or an aryl group, and at least one of them is an aryl group. When R ¹² is an aryl group, R ¹³ may be an alkyl group or an aryl group, but is more preferably an alkyl group. Here, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and 1 to 12 carbon atoms. Is most preferred. The aryl group preferably has 6 to 36 carbon atoms, and more preferably 6 to 24 carbon atoms.

  Next, the compound represented by the general formula (6) will be described in detail.

In the general formula (6), R ²¹ , R ²² and R ²³ each independently represents an alkyl group. Here, the alkyl group may be linear, branched or cyclic. R ²¹ is preferably a cyclic alkyl group, and more preferably at least one of R ²² and R ²³ is a cyclic alkyl group. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 12 carbon atoms. As the cyclic alkyl group, a cyclohexyl group is particularly preferable.

  The alkyl group and aryl group in the general formulas (5) and (6) may each have a substituent. Substituents include halogen atoms (for example, chlorine, bromine, fluorine and iodine), alkyl groups, aryl groups, alkoxy groups, aryloxy groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, acyloxy groups, sulfonylamino groups, A hydroxy group, a cyano group, an amino group and an acylamino group are preferred, more preferably a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a sulfonylamino group and an acylamino group, and particularly preferably an alkyl group and an aryl group. A sulfonylamino group and an acylamino group.

  Next, although the preferable example of a compound represented by General formula (5) and (6) is shown below, this invention is not limited to these specific examples.

  Next, the compound represented by the general formula (7) will be described.

In the general formula (7), R ³¹ , R ³² , R ³³ and R ³⁴ each represent a hydrogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group, and an aliphatic group Is preferred. The aliphatic group may be linear, branched or cyclic, and more preferably cyclic. Examples of the substituent that the aliphatic group and the aromatic group may have include the substituent T described later, but an unsubstituted one is preferable.

X ³¹ , X ³² , X ³³ and X ³⁴ are each a single bond, —CO— and NR ³⁵ — (R ³⁵ represents a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group; It represents a divalent linking group formed from one or more groups selected from the group consisting of unsubstituted and / or aliphatic groups. The combination of X ³¹ , X ³² , X ³³ and X ³⁴ is not particularly limited, but is more preferably selected from —CO— and —NR ³⁵ —. a, b, c and d are integers of 0 or more, preferably 0 or 1, a + b + c + d is 2 or more, preferably 2 to 8, more preferably 2 to 6, still more preferably 2-4. Z ³¹ represents an (a + b + c + d) -valent organic group (excluding a cyclic group). Valence of Z ³¹ is preferably 2 to 8, more preferably 2 to 6, preferably 2 to 4 further 2 or 3 being most preferred. An organic group refers to a group composed of an organic compound.

  The general formula (7) is preferably a compound represented by the following general formula (7-1).

Formula (7-1)
R ³¹¹ -X ³¹¹ -Z ³¹¹ -X ³¹² -R ³¹²
In the general formula (7-1), R ³¹¹ and R ³¹² each represent a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aromatic group, and an aliphatic group is preferable. The aliphatic group may be linear, branched or cyclic, and more preferably cyclic. Examples of the substituent that the aliphatic group and the aromatic group may have include the substituent T described later, but an unsubstituted one is preferable. X ³¹¹ and X ³¹² each independently represent —CONR ³¹³ — or NR ³¹⁴ CO—, and R ³¹³ and R ^{314 each} represents a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. More preferred are unsubstituted and / or aliphatic groups. Z ³¹¹ is —O—, —S—, —SO—, —SO ₂ —, —CO—, —NR ³¹⁵ — (R ³¹⁵ is a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. Represents an unsubstituted group and / or an aliphatic group, and a divalent organic group (excluding a cyclic group) formed from one or more groups selected from an alkylene group and an arylene group. . The combination of Z ³¹¹ is not particularly limited, but is preferably selected from —O—, —S—, —NR ³¹⁵ —, and an alkylene group, and more preferably selected from —O—, —S—, and an alkylene group. Most preferably, it is selected from, -O-, -S- and an alkylene group.

  The general formula (7-1) is preferably a compound represented by the following general formulas (7-2) to (7-4).

In the general formulas (7-2) to (7-4), R ³²¹ , R ³²² , R ³²³ and R ³²⁴ each represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aromatic group. An aliphatic group is preferred. The aliphatic group may be linear, branched or cyclic, and more preferably cyclic. Examples of the substituent that the aliphatic group and the aromatic group may have include the substituent T described later, but an unsubstituted one is preferable. Z ³²¹ is —O—, —S—, —SO—, —SO ₂ —, —CO—, —NR ³²⁵ — (R ³²⁵ is a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. Represents an unsubstituted group and / or an aliphatic group, and a divalent linking group formed from one or more groups selected from an alkylene group and an arylene group. The combination of Z321 is not particularly limited, but is preferably selected from —O—, —S—, —NR ³²⁵ —, and an alkylene group, more preferably selected from —O—, —S—, and an alkylene group, Most preferably, it is selected from —O—, —S— and an alkylene group.

  Hereinafter, the substituted or unsubstituted aliphatic group will be described. The aliphatic group may be linear, branched or cyclic, preferably having 1 to 25 carbon atoms, more preferably having 6 to 25 carbon atoms, particularly preferably having 6 to 20 carbon atoms. preferable. Specific examples of the aliphatic group include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, tert-butyl group, amyl group, isoamyl group, tert- Amyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, bicyclooctyl group, adamantyl group, n-decyl group, tert-octyl group, dodecyl group, hexadecyl group, octadecyl group, didecyl group, etc. Is mentioned.

  Below, said aromatic group is demonstrated.

  The aromatic group may be an aromatic hydrocarbon group or an aromatic heterocyclic group, and more preferably an aromatic hydrocarbon group. The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, and more preferably 6 to 12 carbon atoms. Specific examples of the aromatic hydrocarbon group include benzene, naphthalene, anthracene, biphenyl, terphenyl, and the like. As the aromatic hydrocarbon group, benzene, naphthalene, and biphenyl are particularly preferable. As the aromatic heterocyclic group, those containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom are preferable. Specific examples of the heterocyclic ring include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, Examples include isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. As the aromatic heterocyclic group, pyridine, triazine, and quinoline are particularly preferable.

  Moreover, the said substituent T is demonstrated in detail below.

  Examples of the substituent T include alkyl groups (preferably those having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methyl group, ethyl group, isopropyl group, and tert-butyl group. , N-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2). For example, vinyl group, allyl group, 2-butenyl group, 3-pentenyl group, etc.), alkynyl group (preferably having 2-20 carbon atoms, more preferably 2-12 carbon atoms, particularly preferably 2-8 carbon atoms). Yes, for example, propargyl group, 3-pentynyl group, etc., aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably -12, for example, phenyl group, biphenyl group, naphthyl group, etc., amino group (preferably 0-20 carbon atoms, more preferably 0-10, particularly preferably 0-6, for example amino group, methylamino Group, dimethylamino group, diethylamino group, dibenzylamino group, etc.), alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12, particularly preferably 1 to 8, such as methoxy group, ethoxy group, Butoxy group, etc.), aryloxy group (preferably 6-20, more preferably 6-16, particularly preferably 6-12, such as phenyloxy group, 2-naphthyloxy group, etc.), acyl group (preferably Has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms such as acetyl, benzoyl, Group, pivaloyl group, etc.), alkoxycarbonyl group (preferably having 2-20 carbon atoms, more preferably 2-16, particularly preferably 2-12, such as methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (Preferably 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms such as phenyloxycarbonyl group), acyloxy groups (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms). And particularly preferably 2 to 10, for example, an acetoxy group, a benzoyloxy group, etc.), an acylamino group (preferably 2 to 20, more preferably 2 to 16, particularly preferably 2 to 10, such as acetylamino) Group, benzoylamino group, etc.), alkoxycarbonylamino group (preferably carbon number) 2 to 20, more preferably 2 to 16, particularly preferably 2 to 12, for example, methoxycarbonylamino group, etc., aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16, particularly Preferably it is 7-12, for example, phenyloxycarbonylamino group, etc., sulfonylamino group (preferably 1-20 carbon atoms, more preferably 1-16, particularly preferably 1-12, for example, methanesulfonylamino group , Benzenesulfonylamino group, etc.), sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16, particularly preferably 0 to 12, such as sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group) , Phenylsulfamoyl group, etc.), carbamoyl group (preferably carbon number) -20, more preferably 1-16, particularly preferably 1-12. For example, carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group, etc., alkylthio group (preferably having 1-20 carbon atoms, more preferably Is 1 to 16, particularly preferably 1 to 12, for example, methylthio group, ethylthio group, etc.), arylthio group (preferably 6 to 20, more preferably 6 to 16, particularly preferably 6 to 12, For example, a phenylthio group, etc.), a sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms such as a mesyl group and a tosyl group). ), A sulfinyl group (preferably having a carbon number of 1 to 20, more preferably 1 to 16, particularly preferably 1 to 12, such as a methanesulfinyl group, a benzenesulfinyl group, etc.), a ureido group (preferably having a carbon number of 1 to 20). More preferably, it is 1-16, Most preferably, it is 1-12, for example, a ureido group, a methylureido group, a phenylureido group etc., a phosphoric acid amide group (preferably C1-C20, more preferably 1-16) , Particularly preferably 1 to 12, such as diethyl phosphoric acid amide and phenyl phosphoric acid amide), a hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a cyano group, Sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Rocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom, specifically, for example, an imidazolyl group, a pyridyl group and a quinolyl group. , Furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms). And examples thereof include trimethylsilyl group and triphenylsilyl group. These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

  Preferred examples of the compound represented by the general formula (7) are shown below, but the present invention is not limited to these specific examples.

  Compounds of general formula (5), general formula (6), and general formula (7) are obtained by dehydration condensation reaction of carboxylic acids with amines using a condensing agent (for example, dicyclohexylcarbodiimide (DCC)), or carboxylic acid It can be obtained by a substitution reaction between a chloride derivative and an amine derivative.

  As the retardation adjusting agent used in the present invention, many compounds known as cellulose acylate plasticizers can be usefully used. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred.

  The retardation adjusting agent used in the present invention is more preferably an Rt reducing agent from the viewpoint of realizing a suitable Nz factor. Among the retardation adjusting agents, examples of the Rt reducing agent include aliphatic polyesters, acrylic polymers and styrenic polymers, and low molecular compounds of the general formulas (3) to (7). Preferred are aliphatic polyesters, acrylic polymers and styrene polymers, and more preferred are aliphatic polyesters and acrylic polymers.

(Retardation expression agent)
In the present invention, a retardation developer may be added to the layer A and the layer B in order to obtain a phase difference of λ / 4. Examples of the retardation developer include those composed of rod-like or discotic compounds. As the rod-like or discotic compound, a compound having at least two aromatic rings can be preferably used as a retardation developer.

  In the present invention, it is preferable to add a retardation developing agent having a rod-like structure to layer B and a retardation developing agent having a disk-like structure to layer A.

In addition, an amount WB of a retardation developer having a rod-like structure contained in the layer B (hereinafter simply referred to as “rod-like compound”) and a retardation developer having a disc-like structure contained in the layer A (hereinafter, simply Stretchability when obliquely stretching so as to achieve a phase difference of λ / 4 that the amount WA of “sometimes called a discotic compound” satisfies WB / WA = 1.3 to 1.6. And WB is a mass part of the rod-shaped compound with respect to 100 parts by mass of the cellulose ester contained in the layer B, and WA represents a mass part of the discotic compound with respect to 100 parts by mass of the cellulose ester contained in the layer A. )
The addition amount of the retardation developer composed of the rod-like compound is preferably 0.1 to 30 parts by mass, and more preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymer component containing cellulose acylate. preferable. The disk-shaped retardation developer is preferably used in a range of 0.05 to 20 parts by mass, and in a range of 1.0 to 15 parts by mass with respect to 100 parts by mass of the polymer component containing the cellulose acylate. More preferably, it is more preferably used in the range of 3.0 to 10 parts by mass.

  Since the discotic compound is superior to the rod-shaped compound in Rt retardation expression, it is preferably used when a particularly large Rt retardation is required. Two or more types of retardation developing agents may be used in combination.

  The retardation developer preferably has maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

<Retardation expression agent having a disk-like structure>
The discotic compound will be described. As the discotic compound, a compound having at least two aromatic rings can be used.

  In the present specification, the “aromatic ring” includes an aromatic hetero ring in addition to an aromatic hydrocarbon ring.

  The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).

  The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.

  As the aromatic ring, a benzene ring, a condensed benzene ring, and biphenyls are preferable. In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.

  The number of carbon atoms of the aromatic ring in the retardation enhancer is preferably 2 to 20, more preferably 2 to 12, still more preferably 2 to 8, and most preferably 2 to 6. preferable.

  The bonding relationship between two aromatic rings can be classified into (a) when a condensed ring is formed, (b) when directly linked by a single bond, and (c) when linked via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

  Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiant It includes emissions ring. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.

  The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded with two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.

The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-
The aromatic ring and the linking group may have a substituent.

  Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, carboxyl groups, cyano groups, amino groups, nitro groups, sulfo groups, carbamoyl groups, sulfamoyl groups, ureido groups, alkyl groups, alkenyls. Group, alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group An aliphatic substituted carbamoyl group, an aliphatic substituted sulfamoyl group, an aliphatic substituted ureido group, and a non-aromatic heterocyclic group.

  It is preferable that the alkyl group has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (for example, a hydroxy group, a carboxy group, an alkoxy group, an alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl, and 2- Each group of a diethylaminoethyl group is included.

  The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of the alkenyl group include a vinyl group, an allyl group, and a 1-hexenyl group.

  The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of the alkynyl group include ethynyl group, 1-butynyl group and 1-hexynyl group.

  The number of carbon atoms in the aliphatic acyl group is preferably 1-10. Examples of the aliphatic acyl group include an acetyl group, a propanoyl group, and a butanoyl group.

  The number of carbon atoms in the aliphatic acyloxy group is preferably 1-10. Examples of the aliphatic acyloxy group include an acetoxy group.

  The number of carbon atoms of the alkoxy group is preferably 1-8. The alkoxy group may further have a substituent (for example, an alkoxy group). Examples of the alkoxy group (including a substituted alkoxy group) include a methoxy group, an ethoxy group, a butoxy group, and a methoxyethoxy group.

  The number of carbon atoms of the alkoxycarbonyl group is preferably 2-10. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

  The number of carbon atoms of the alkoxycarbonylamino group is preferably 2-10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

  The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an octylthio group.

  The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group.

  The number of carbon atoms in the aliphatic amide group is preferably 1-10. Examples of the aliphatic amide group include acetamide.

  The number of carbon atoms of the aliphatic sulfonamide group is preferably 1-8. Examples of the aliphatic sulfonamido group include a methanesulfonamido group, a butanesulfonamido group, and an n-octanesulfonamido group.

  The number of carbon atoms of the aliphatic substituted amino group is preferably 1-10. Examples of the aliphatic substituted amino group include a dimethylamino group, a diethylamino group, and a 2-carboxyethylamino group.

  The number of carbon atoms in the aliphatic substituted carbamoyl group is preferably 2-10. Examples of the aliphatic substituted carbamoyl group include a methylcarbamoyl group and a diethylcarbamoyl group.

  The number of carbon atoms in the aliphatic substituted sulfamoyl group is preferably 1-8. Examples of the aliphatic substituted sulfamoyl group include a methylsulfamoyl group and a diethylsulfamoyl group.

  The number of carbon atoms in the aliphatic substituted ureido group is preferably 2-10. Examples of the aliphatic substituted ureido group include a methylureido group.

  Examples of the non-aromatic heterocyclic group include a piperidino group and a morpholino group.

  The molecular weight of the retardation developer is preferably 300 to 800.

  As the discotic compound, a triazine compound represented by the following general formula (I) is preferably used.

In the above general formula (I):
R ²⁰¹ each independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho, meta and para positions.

X ²⁰¹ each independently represents a single bond or —NR ²⁰² —. Here, each R ²⁰² independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, or a heterocyclic group.

The aromatic ring represented by R ²⁰¹ is preferably phenyl or naphthyl, and particularly preferably phenyl. The aromatic ring represented by R ²⁰¹ may have at least one substituent at any substitution position. Examples of the substituent include halogen atom, hydroxyl group, cyano group, nitro group, carboxyl group, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, Alkenyloxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamide group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide Groups, alkylthio groups, alkenylthio groups, arylthio groups and acyl groups.

The heterocyclic group represented by R ²⁰¹ preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.

When X ²⁰¹ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. Further, the heterocyclic group may have a hetero atom other than the nitrogen atom (for example, O, S). Examples of heterocyclic groups having free valences on nitrogen atoms are shown below. Here, _-C 4 _{H 9} n represents a _n-C 4 _{H 9.}

The alkyl group represented by R ²⁰² may be a cyclic alkyl group or a chain alkyl group, but a chain alkyl group is preferable, and a linear alkyl group is more preferable than a branched chain alkyl group. preferable. The number of carbon atoms in the alkyl group is preferably 1-30, more preferably 1-20, further preferably 1-10, still more preferably 1-8, and 1-6. Most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group) and an acyloxy group (for example, acryloyloxy group, methacryloyloxy group).

The alkenyl group represented by R ²⁰² may be a cyclic alkenyl group or a chain alkenyl group, but is preferably a chain alkenyl group, and is a straight chain alkenyl group rather than a branched chain alkenyl group. More preferably it represents a group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, 6 is most preferred. The alkenyl group may have a substituent. Examples of the substituent are the same as those of the alkyl group described above.

The aromatic ring group and heterocyclic group represented by R ²⁰² are the same as the aromatic ring and heterocyclic ring represented by R ²⁰¹ , and the preferred range is also the same. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent are the same as those of the aromatic ring and heterocyclic ring of ^R201 .

  Although the specific example of a compound represented by general formula (I) below is given, it is not limited to this.

  As the discotic compound, a triphenylene compound represented by the following general formula (II) can also be preferably used.

In the general formula (II), R ^{203 to} R ²⁰⁸ each independently represent a hydrogen atom or a substituent.

Examples of the substituent represented by each of R ^{203 to} R ²⁰⁸ include an alkyl group (preferably an alkyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms. Group, ethyl group, isopropyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably carbon An alkenyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 2-butenyl group, and a 3-pentenyl group. An alkynyl group (preferably an alkynyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 to 20 carbon atoms. For example, a propargyl group, 3-pentynyl group, etc.), an aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms). A phenyl group, a p-methylphenyl group, a naphthyl group, etc.), a substituted or unsubstituted amino group (preferably having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms, and particularly preferably carbon number). 0 to 20 amino groups such as an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, and an anilino group)
An alkoxy group (preferably an alkoxy group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). Aryloxy group (preferably an aryloxy group having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, particularly preferably 6 to 20 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably an acyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms, such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. Etc.), an alkoxycarbonyl group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably carbon number) To 20 alkoxy groups such as methoxycarbonyl group and ethoxycarbonyl group), aryloxycarbonyl groups (preferably having 7 to 40 carbon atoms, more preferably having 7 to 30 carbon atoms, and particularly preferably carbon atoms). An aryloxycarbonyl group having 7 to 20 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 carbon atoms). To 20 acyloxy groups, such as an acetoxy group and a benzoyloxy group, and acylamino groups (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 to 20 carbon atoms). Acylamino groups such as acetylamino group, benzoylamino group, etc. And an alkoxycarbonylamino group (preferably an alkoxycarbonylamino group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as a methoxycarbonylamino group) An aryloxycarbonylamino group (preferably 7 to 40 carbon atoms, more preferably 7 to 30 carbon atoms, particularly preferably 7 to 20 carbon atoms, such as phenyloxycarbonylamino group). Group), a sulfonylamino group (preferably a sulfonylamino group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a methanesulfonylamino group, Benzenesulfonylamino group), sulfamoyl A group (preferably a sulfamoyl group having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms, particularly preferably 0 to 20 carbon atoms, such as a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, A phenylsulfamoyl group), a carbamoyl group (preferably a carbamoyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms. Carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group, etc.),
Alkylthio group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group , Heptylthio group, octylthio group and the like), arylthio group (preferably having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example, phenylthio group). ), A sulfonyl group (preferably a sulfonyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, and examples thereof include a mesyl group and a tosyl group), sulfinyl Group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 2 carbon atoms) Sulfinyl group, for example, methanesulfinyl group, benzenesulfinyl group, etc.), ureido group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms). A ureido group, for example, an unsubstituted ureido group, a methylureido group, a phenylureido group, and the like, a phosphoric acid amide group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably Is a phosphoric acid amide group having 1 to 20 carbon atoms, and examples thereof include a diethylphosphoric acid amide group and a phenylphosphoric acid amide group, a hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, bromine). Atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group A hydrazino group, an imino group, a heterocyclic group (preferably a heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12, and having a hetero atom such as a nitrogen atom, an oxygen atom, a sulfur atom, And examples thereof include imidazolyl group, pyridyl group, quinolyl group, furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, 1,3,5-triazyl group). Silyl group (preferably a silyl group having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group) Is included. These substituents may be further substituted with these substituents. Moreover, when it has two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

The substituent represented by each of R ^{203 to} R ²⁰⁸ is preferably an alkyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an alkylthio group, or a halogen atom.

  Although the specific example of a compound represented by general formula (II) below is given, it is not limited to this.

  The compound represented by the general formula (I) is, for example, a method described in JP-A No. 2003-344655, and the compound represented by the general formula (II) is, for example, a method described in JP-A-2005-134484. Can be synthesized by a known method.

<Retardation expression agent having rod-like structure>
In the present invention, rod-like compounds having a linear molecular structure can be preferably used in addition to the above-mentioned discotic compounds. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation is performed using molecular orbital calculation software (for example, WinMOPAC2000, manufactured by Fujitsu Limited), and a molecular structure that minimizes the heat of formation of a compound can be obtained. The molecular structure being linear means that in the thermodynamically most stable structure obtained by calculation as described above, the angle of the main chain constituting the molecular structure is 140 degrees or more.

  As the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (11) is preferable.

Formula (11): Ar ¹ -L ¹ -Ar ²
In the general formula (11), Ar ¹ and Ar ² are each independently an aromatic group.

  In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group.

  An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocyclic ring of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable. As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amino group, an alkylamino group (for example, methyl Amino group, ethylamino group, butylamino group, dimethylamino group), nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group (for example, N-methylcarbamoyl group, N-ethylcarbamoyl group, N, N-) Dimethylcarbamoyl group), sulfamoyl group, alkylsulfamoyl group (eg, N-methylsulfamoyl group, N-ethylsulfamoyl group, N, N-dimethylsulfamoyl group), ureido Group, alkylureido group (for example, N-methylureido group, N, N-dimethylureido group, N, N, N′-tri group) Each group of tilureido group), alkyl group (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, heptyl group, octyl group, isopropyl group, s-butyl group, tert-amyl group, cyclohexyl group, cyclopentyl) Group), alkenyl group (for example, vinyl group, allyl group, hexenyl group), alkynyl group (for example, ethynyl group, butynyl group), acyl group (for example, formyl group, acetyl group, butyryl group, Hexanoyl group, lauryl group), acyloxy group (for example, acetoxy group, butyryloxy group, hexanoyloxy group, lauryloxy group), alkoxy group (for example, methoxy group, ethoxy group, propoxy group, butoxy group) , Pentyloxy group, heptyloxy group, octyloxy group), aryl Xy group (for example, phenoxy group), alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, heptyloxycarbonyl group), aryloxycarbonyl group ( For example, phenoxycarbonyl group), alkoxycarbonylamino group (for example, butoxycarbonylamino group, hexyloxycarbonylamino group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, heptylthio group, octylthio group) Each group), arylthio group (for example, phenylthio group), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfo group) Nyl group, pentylsulfonyl group, heptylsulfonyl group, octylsulfonyl group), amide group (for example, acetamido group, butyramide group, hexylamide group, laurylamide group) and non-aromatic heterocyclic group ( For example, a morpholyl group and a pyrazinyl group) are included.

  Among these, preferred substituents include halogen atoms, cyano groups, carboxyl groups, hydroxyl groups, amino groups, alkylamino groups, acyl groups, acyloxy groups, amide groups, alkoxycarbonyl groups, alkoxy groups, alkylthio groups, and alkyl groups. Can be mentioned.

  The alkyl part and alkyl group of the alkylamino group, alkoxycarbonyl group, alkoxy group and alkylthio group may further have a substituent. Examples of the alkyl moiety and the substituent of the alkyl group include halogen atom, hydroxyl group, carboxyl group, cyano group, amino group, alkylamino group, nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group, sulfamoyl group, alkylsulfur group. Famoyl group, ureido group, alkylureido group, alkenyl group, alkynyl group, acyl group, acyloxy group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, An alkylsulfonyl group, an amide group and a non-aromatic heterocyclic group are included. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, a hydroxyl group, an amino group, an alkylamino group, an acyl group, an acyloxy group, an acylamino group, an alkoxycarbonyl group, and an alkoxy group are preferable.

  In the general formula (11), L1 is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a combination thereof.

  The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group.

  The number of carbon atoms of the alkylene group is preferably 1-20, more preferably 1-15, still more preferably 1-10, still more preferably 1-8, and most preferably 1-6. It is.

  The alkenylene group and the alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure.

  The alkenylene group and the alkynylene group preferably have 2 to 10 carbon atoms, more preferably 2 to 8, more preferably 2 to 6, still more preferably 2 to 4, and most preferably 2. (Vinylene group or ethynylene group).

  The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and still more preferably 6 to 12.

In the molecular structure of the general formula (11), the angle formed by Ar ¹ and Ar ² across L ¹ is preferably 140 degrees or more.

  As the rod-like compound, a compound represented by the following formula (12) is more preferable.

Formula ^{(12): Ar 1 -L 2} -X-L 3 -Ar 2
In the general formula (12), Ar ¹ and Ar ² are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Ar ¹ and Ar ^{2 in} the general formula (12).

In General Formula (12), L ² and L ³ are each independently a divalent linking group selected from an alkylene group, —O—, —CO—, and a group consisting of a combination thereof.

  The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure.

  The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and 1 or 2 (methylene group). Or ethylene group).

  L2 and L3 are particularly preferably —O—CO— or —CO—O—.

  In the general formula (12), X is a 1,4-cyclohexylene group, a vinylene group or an ethynylene group.

  Specific examples of the compound represented by the general formula (11) or (12) include compounds described in [Chemical Formula 1] to [Chemical Formula 11] of JP-A No. 2004-109657.

  Two or more rod-shaped compounds whose maximum absorption wavelength (λmax) is longer than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.

  The rod-like compound can be synthesized with reference to methods described in literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989), J. Am. Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. 40, 420 pages (1975), Tetrahedron, Vol. 48, No. 16, page 3437 (1992).

  Moreover, you may use the rod-shaped aromatic compound of pages 11-14 of Unexamined-Japanese-Patent No. 2004-50516 as said Re expression agent.

  Further, as the retardation developer, one kind of compound can be used alone, or two or more kinds of compounds can be mixed and used. It is preferable to use two or more compounds different from each other as the retardation developer because the adjustment range of the retardation is widened and easily adjusted to a desired range.

  When the cellulose acylate film is produced by a solvent cast method, the retardation developer may be added to the dope. The addition may be performed at any timing. For example, the retardation developer may be dissolved in an organic solvent such as alcohol, methylene chloride, dioxolane, etc., and then added to the cellulose acylate solution (dope) or directly. You may add during dope composition.

  In addition, specific examples of preferable compounds of rod-like compounds other than those described in the above-mentioned publications are shown below.

  The specific examples (1) to (34), (41), and (42) have two asymmetric carbon atoms at the 1-position and the 4-position of the cyclohexane ring. However, since the specific examples (1), (4) to (34), (41), and (42) have a symmetrical meso type molecular structure, there are no optical isomers (optical activity), and geometric isomers (trans Type and cis type). The trans type (1-trans) and cis type (1-cis) of specific example (1) are shown below.

  As described above, the rod-like compound preferably has a linear molecular structure. Therefore, the trans type is preferable to the cis type.

  Specific examples (2) and (3) have optical isomers (a total of four isomers) in addition to geometric isomers. As for geometric isomers, the trans type is similarly preferable to the cis type. The optical isomer is not particularly superior or inferior, and may be D, L, or a racemate.

  In specific examples (43) to (45), the central vinylene bond includes a trans type and a cis type. For the same reason as above, the trans type is preferable to the cis type.

  In the present invention, deterioration inhibitors, peeling accelerators, matting agents, lubricants, the aforementioned plasticizers, and the like can be appropriately used as necessary.

(Deterioration inhibitor)
In the present invention, a known deterioration (oxidation) inhibitor such as 2,6-di-tert-butyl-4-methylphenol, 4,4'-thiobis- (6-tert-butyl-3) is added to the cellulose acylate solution. -Methylphenol), 1,1'-bis (4-hydroxyphenyl) cyclohexane, 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, pentaerythris A phenolic or hydroquinone antioxidant such as lithyl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] can be added. Further, tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert) It is preferable to use a phosphorus-based antioxidant such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite. The addition amount of the deterioration inhibitor is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cellulose resin.

(Peeling accelerator)
It is preferable that the λ / 4 plate of the present invention contains a peeling accelerator from the viewpoint of improving the peelability. The peeling accelerator can be included at a ratio of 0.001 to 1% by mass, for example, and the addition of 0.5% by mass or less is preferable because separation of the release agent from the film hardly occurs. 005% by mass or more is preferable because a desired peeling reduction effect can be obtained. Therefore, it is preferably included at a rate of 0.005 to 0.5% by mass, and at a rate of 0.01 to 0.3% by mass. More preferably. As the peeling accelerator, known ones can be adopted, and organic and inorganic acidic compounds, surfactants, chelating agents and the like can be used. Among them, polyvalent carboxylic acids and esters thereof are effective, and in particular, ethyl esters of citric acid can be used effectively.

  In the λ / 4 plate of the present invention, the layer B preferably contains a peeling accelerator.

(Matting agent)
In particular, the λ / 4 plate of the present invention is generally added with fine particles in order to prevent scratching or deterioration of transportability when handled. They are called matting agents, anti-blocking agents or anti-scratching agents and have been used conventionally. They are not particularly limited as long as they have the above-described functions, and may be an inorganic compound matting agent or an organic compound matting agent.

  Specific examples of the inorganic compound matting agent include silicon-containing inorganic compounds (for example, silicon dioxide, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, etc.), titanium oxide, and zinc oxide. , Aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony, calcium carbonate, talc, clay, calcined kaolin, calcium phosphate, etc., more preferably silicon-containing inorganic compounds and oxides Although it is zirconium, since the turbidity of a cellulose acylate film can be reduced, silicon dioxide is particularly preferably used. As the silicon dioxide fine particles, for example, commercially available products having trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. As the zirconium oxide fine particles, for example, those commercially available under trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

  Preferable specific examples of the organic compound matting agent include, for example, polymers such as silicone resin, fluorine resin and acrylic resin, and among them, silicone resin is preferably used. Among the silicone resins, those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, Tospearl 105, Tospearl 108, Tospearl 120, Tospearl 145, Tospearl 3120 and Tospearl 240 (manufactured by Toshiba Silicone Co., Ltd.) A commercial product having a trade name can be used.

  When these matting agents are added to the cellulose acylate solution, the method is not particularly limited, and there is no problem as long as a desired cellulose acylate solution can be obtained by any method. For example, an additive may be contained at the stage of mixing cellulose acylate and a solvent, or an additive may be added after preparing a mixed solution with cellulose acylate and a solvent. Further, it may be added and mixed immediately before casting the dope, which is a so-called immediately preceding addition method, and the mixing is used by installing screw-type kneading online. Specifically, a static mixer such as an in-line mixer is preferable, and the in-line mixer is, for example, a static mixer SWJ (Toray static type in-pipe mixer Hi-Mixer) (manufactured by Toray Engineering). Is preferred. As for in-line addition, in order to eliminate density unevenness, particle aggregation, etc., Japanese Patent Application Laid-Open No. 2003-053752 adds an additive solution having a different composition to the main raw material dope in a method for producing a cellulose acylate film. There is described an invention in which the distance L between the nozzle tip and the starting end portion of the in-line mixer is 5 times or less of the main raw material pipe inner diameter d, thereby eliminating concentration unevenness, matting particles and the like. As a more preferred embodiment, the distance (L) between the tip opening of the additive liquid supply nozzle having a composition different from that of the main raw material dope and the starting end of the in-line mixer is 10 times or less the inner diameter (d) of the supply nozzle tip opening. And that the in-line mixer is a static unstirred in-tube mixer or a dynamic agitated in-tube mixer. More specifically, it is disclosed that the flow rate ratio of the cellulose acylate film main raw material dope / in-line additive solution is 10/1 to 500/1, preferably 50/1 to 200/1. Furthermore, the additive is also used in Japanese Patent Application Laid-Open No. 2003-014933, which aims at a retardation film with little additive bleed-out, no delamination phenomenon between layers, and excellent slipperiness and excellent transparency. As a method of addition, it may be added in a melting pot, or a solution in which additives or additives are dissolved or dispersed between the melting pot and a co-casting die may be added to the dope being fed. However, in the latter case, it is described that it is preferable to provide a mixing means such as a static mixer in order to improve the mixing property.

  The λ / 4 plate of the present invention contains a matting agent in the layer B, is resistant to scratches by reducing the friction coefficient of the film surface, prevents creaking that occurs when a wide film is wound in a long length, and prevents film folding. It is preferable from the viewpoint of prevention.

  In the λ / 4 plate of the present invention, if the matting agent is not added in a large amount, the haze of the film does not increase, and when actually used in an LCD, inconveniences such as a decrease in contrast and generation of bright spots are unlikely to occur. . If the amount is too small, the above-mentioned creaking and scratch resistance can be realized. From these viewpoints, it is preferably included at a ratio of 0.01 to 5.0 mass%, more preferably included at a ratio of 0.03 to 3.0 mass%, and a ratio of 0.05 to 1.0 mass% It is particularly preferable to include

(Manufacture of λ / 4 plate)
The λ / 4 plate of the present invention may be produced by either a solution casting method or a melt casting method, but is preferably produced by a solution casting method.

  In the production of the λ / 4 plate of the present invention, cellulose acylate or cellulose acetate (hereinafter, both are collectively referred to as cellulose acylate) and additives such as a retardation adjusting agent, a retardation developer, and a matting agent are used as solvents. The step of preparing a dope by dissolving in a metal, the step of casting the dope on a belt-shaped or drum-shaped metal support, the step of drying the cast dope as a web, the step of peeling from the metal support, the step of stretching Further, it is carried out by a step of further drying, a step of further heat-treating the obtained film if necessary, and a step of winding after cooling. The λ / 4 plate of the present invention preferably contains 60 to 95% by mass of cellulose acylate in the solid content.

(Dope preparation)
The process for preparing the dope will be described. The concentration of cellulose acylate in the dope is preferably higher because the drying load after casting on the metal support can be reduced, but if the concentration of cellulose acylate is too high, the load during filtration increases. Filtration accuracy deteriorates. As a density | concentration which makes these compatible, 10-35 mass% is preferable, More preferably, it is 15-25 mass%.

  The solvent used in the dope may be used alone or in combination of two or more, but it is preferable in terms of production efficiency that a good solvent and a poor solvent of cellulose acylate are mixed, and the good solvent is used. A larger amount is preferable from the viewpoint of the solubility of cellulose acylate. The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. With a good solvent and a poor solvent, what dissolve | melts the cellulose acylate to be used independently is defined as a good solvent, and a solvent that swells or does not dissolve alone is defined as a poor solvent. Therefore, depending on the acetyl group substitution degree of cellulose acylate, the good solvent and the poor solvent change. For example, when acetone is used as a solvent, cellulose acetate (acetyl substitution degree 2.4) becomes a good solvent, and cellulose acetate Esters (acetyl group substitution degree 2.8) are poor solvents.

  Although the good solvent used for this invention is not specifically limited, Organic halogen compounds, such as a methylene chloride, dioxolanes, acetone, methyl acetate, methyl acetoacetate, etc. are mentioned. Particularly preferred is methylene chloride or methyl acetate.

  Moreover, although the poor solvent used for this invention is not specifically limited, For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, etc. are used preferably. Moreover, it is preferable that 0.01-2 mass% of water contains in dope.

  As a method for dissolving cellulose acylate when preparing the dope described above, a general method can be used. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure. It is preferable to stir and dissolve while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and that the solvent does not boil under pressure, in order to prevent the generation of massive undissolved materials called gels and mamacos. In addition, a method in which cellulose acylate is mixed with a poor solvent and wetted or swollen, and then a good solvent is added and dissolved is also preferably used.

  The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  A higher heating temperature with the addition of a solvent is preferable from the viewpoint of the solubility of cellulose acylate, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  Alternatively, a cooling dissolution method is also preferably used, whereby cellulose acylate can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose acylate solution is filtered using a suitable filter medium such as filter paper. As the filter medium, it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like. However, if the absolute filtration accuracy is too small, there is a problem that the filter medium is likely to be clogged. For this reason, a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is still more preferable.

  There are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable. It is preferable to remove and reduce impurities, particularly bright spot foreign matter, contained in the raw material cellulose acylate by filtration.

The bright spot foreign material is arranged in a crossed Nicols state with two polarizing plates, a cellulose acylate film is placed between them, light is applied from the side of one polarizing plate, and observation is performed from the side of the other polarizing plate. It is a point (foreign matter) where light from the opposite side sometimes leaks, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm ² or less. More preferably, it is 100 pieces / cm < ² > or less, More preferably, it is 50 pieces / m < ² > or less, More preferably, it is 0-10 pieces / cm < ² > or less. Further, it is preferable that the number of bright spots of 0.01 mm or less is small.

  The dope can be filtered by a normal method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration. The increase in the difference (referred to as differential pressure) is small and preferable. A preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and still more preferably 45 to 55 ° C.

  A smaller filtration pressure is preferred. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.

(Casting)
Here, the dope casting will be described.

  From the cellulose acylate solution (dope) prepared for the layer A and the layer B according to the present invention, a cellulose acylate film having a multilayer structure can be produced by a solvent cast method.

(Co-casting)
In the present invention, the obtained cellulose acylate solution (dope) is preferably formed by casting the two or more kinds of cellulose acylate solutions on a smooth band or drum as a support.

  Two or more kinds of dopes may be cast on the support at the same time or separately on the support. In the case of the sequential casting method in which the casting is performed separately, the dope on the support side can be cast first and dried to some extent on the support, and then overlaid on the support. When three or more kinds of dopes are used, a film having a laminated structure can be produced by appropriately combining simultaneous casting (also called co-casting) and sequential casting. These methods, which are formed by co-casting or sequential casting, differ from the method of coating on a dried film, and the boundary of each layer of the laminated structure becomes unclear, and the laminated structure is clear by observing the cross section. There is a feature that there is a case where there is no separation, there is an effect of improving the adhesion between each layer.

  The production method of the λ / 4 plate of the present invention is preferably carried out by co-casting from the viewpoint of productivity, and a known co-casting method can be used. For example, the film may be produced while casting and laminating a solution containing cellulose acylate from a plurality of casting ports provided at intervals in the traveling direction of the metal support. The methods described in JP-A Nos. 158414, 1-122419, and 11-198285 can be applied. Further, it may be formed into a film by casting a cellulose acylate solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, It can be carried out by the methods described in JP-A Nos. 61-104813, 61-158413, and 6-134933. Further, a cellulose acylate film in which a flow of a high-viscosity cellulose acylate solution described in JP-A-56-162617 is wrapped with a low-viscosity cellulose acylate solution and the high- and low-viscosity cellulose acylate solutions are simultaneously extruded. A casting method may be used. Furthermore, it is also a preferred embodiment that the outer solution described in JP-A-61-94724 and JP-A-61-94725 contains a larger amount of an alcohol component which is a poor solvent than the inner solution.

  Alternatively, by using two casting ports, the film cast on the metal support is peeled off by the first casting port, and the second casting is performed on the side in contact with the metal support surface. Further, a film may be prepared, for example, a method described in Japanese Patent Publication No. 44-20235. The cellulose acylate solutions to be cast may be the same solution or different cellulose acylate solutions, and are not particularly limited. In order to give a function to a plurality of cellulose acylate layers, a cellulose acylate solution corresponding to the function may be extruded from each casting port. Furthermore, the cellulose acylate solution according to the present invention can be simultaneously cast with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorbing layer, a polarizing layer). . As a method for producing the film of the present invention, it is preferable that the film formation is simultaneous or sequential multilayer casting.

  In the case of co-casting, the thickness of each layer is not particularly limited, but preferably the layer B is preferably 0.2 to 50% of the total thickness of the λ / 4 plate, more preferably 2 to 30%. It is preferable. In the case of co-casting with three or more layers, when there are a plurality of layers B made of cellulose acetate satisfying the formula (2), the total thickness of the layers B is 0.2 of the total thickness of the λ / 4 plate. It is preferably ˜50%, more preferably 2 to 30%.

  Moreover, it is also a preferable aspect that a release agent is contained only in the metal support side layer. In order to cool the metal support by the cooling drum method to gel the solution, it is also preferable to add more alcohol as a poor solvent to the layer in contact with the support than the other layer. The viscosity of the solution containing cellulose acylate at the time of casting may be different between the layer A and the layer B, and the viscosity of the layer B is preferably smaller than the viscosity of the layer A. It may be smaller.

  In the method for producing a film of the present invention, as described above, the layer B dope includes a retardation developing agent having a rod-like structure, and the layer A is added with a retardation developing agent having a disk-like structure. A film having a multilayer structure of cellulose acylate with improved expression can be obtained.

  In the present invention, the multi-layer cast dope is dried and peeled from the support.

  The dope is cast on a drum or metal support and the solvent is evaporated to form a film. The concentration of the dope before casting is preferably adjusted so that the solid content is 18 to 35% by mass. The surface of the drum or metal support is preferably finished in a mirror state. As for casting and drying methods in the solvent casting method, U.S. Pat. No. 736892, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, No. 60-203430, and No. 62-1115035.

  The dope is preferably cast on a drum or metal support having a surface temperature of 10 ° C. or less. After casting, it is preferable to dry it by applying air for 2 seconds or more. The obtained film can be peeled off from a drum or a metal support, and further dried by high-temperature air whose temperature is successively changed from 100 ° C. to 160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or metal support during casting.

  The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support. The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is set to −50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferable because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate. The preferable support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing warm air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. . In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

  In order for the λ / 4 plate of the present invention to exhibit good planarity, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60%. It is -130 mass%, Most preferably, it is 20-30 mass% or 70-120 mass%. The temperature at the peeling position on the metal support is preferably −50 to 40 ° C., more preferably 10 to 40 ° C., and most preferably 15 to 30 ° C.

  In the present invention, the amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Note that M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  Moreover, in the drying process of the cellulose acylate film, the web is peeled off from the metal support, further dried, and dried until the residual solvent amount is 0.5% by mass or less.

  In the film drying process, generally, a roll drying method (a method in which a plurality of rolls arranged on the upper and lower sides are alternately passed through and dried) or a method of drying while transporting the web by a tenter method is adopted.

  When peeling from the metal support, the web is stretched in the longitudinal direction due to the peeling tension and the subsequent conveying tension. Therefore, in the present invention, when peeling the web from the casting support, the peeling and conveying tensions are reduced as much as possible. It is preferable to carry out in the state. Specifically, for example, it is effective to set it to 50 to 170 N / m or less. At that time, it is preferable to apply a cold air of 20 ° C. or less to fix the web rapidly.

  The cellulose acylate film is further adjusted by adjusting the refractive index (the refractive index nx in the in-plane slow axis direction, the refractive index ny in the direction perpendicular to the in-plane slow axis and the refractive index nz in the thickness direction). can do. In the λ / 4 plate of the present invention, Ro (590) measured at a wavelength of 590 nm is in the range of 120 to 160 nm.

  Further, the retardation value Rt in the film thickness direction represented by the above-mentioned formula (ii) is influenced by the draw ratio, but is preferably in the range of 0 to 400 nm.

(Stretching process)
The λ / 4 plate of the present invention is characterized in that the slow axis of the film is 20 to 70 ° with respect to the longitudinal direction, more preferably the slow axis of the film is 40 to 50 ° with respect to the longitudinal direction, Furthermore, it is preferable that it is substantially 45 degrees. “Substantially 45 °” means 44 to 46 °. Therefore, the film is continuously obliquely stretched in the direction of an arbitrary angle θ (20 ° <θ <70 °, more preferably 40 to 50 °, and still more preferably substantially 45 °) with respect to the longitudinal direction. Is preferred. By continuously stretching an unstretched film obliquely in the direction of an arbitrary angle θ with respect to the longitudinal direction, a long stretched film having an orientation axis of an angle θ with respect to the longitudinal direction of the film is obtained. Can do.

  The oblique stretching method is not particularly limited as long as it is continuously stretched in an oblique direction with respect to the longitudinal direction and the polymer orientation axis is inclined to a desired angle, and a known method is adopted. Can do.

  In order to stretch the cellulose acylate film obliquely in the direction of an arbitrary angle θ (20 ° <θ <70 °, more preferably 40 to 50 °, and still more preferably substantially 45 °) with respect to the longitudinal direction, It is preferable to use the tenter shown in FIG. FIG. 1 is a schematic diagram showing oblique stretching by a tenter.

  The stretched film according to the present invention is produced using a tenter. This tenter is a device that widens a film fed from a film roll (feeding roll) in an oblique direction with respect to its traveling direction (moving direction of the middle point in the film width direction) in a heating environment by an oven. The tenter includes an oven, a pair of rails on the left and right on which a gripping tool for transporting the film travels, and a number of gripping tools that travel on the rails. Both ends of the film fed out from the film roll and sequentially supplied to the entrance portion of the tenter are gripped by a gripping tool, the film is guided into the oven, and the film is released from the gripping tool at the exit portion of the tenter. The film released from the gripping tool is wound around the core. Each of the pair of rails has an endless continuous track, and the gripping tool which has released the grip of the film at the exit portion of the tenter travels outside and is sequentially returned to the entrance portion.

  The rail shape of the tenter is asymmetrical on the left and right according to the orientation angle, stretch ratio, etc. given to the stretched film to be manufactured, and can be finely adjusted manually or automatically. In the present invention, a long thermoplastic resin film is stretched, and the orientation angle θ can be set to an arbitrary angle within the range of 10 ° to 80 ° with respect to the winding direction after stretching. Yes. In the present invention, the gripping tool of the tenter is configured to travel at a constant speed with a certain distance from the front and rear gripping tools.

  FIG. 1 shows a rail track (rail pattern) of a tenter used for oblique stretching. The feeding direction DR1 of the cellulose acylate film is different from the winding direction (MD direction) DR2 of the stretched film, thereby obtaining a wide and uniform optical characteristic even in a stretched film having a relatively large orientation angle. It is possible. The feeding angle θi is an angle formed by the feeding direction DR1 of the film before stretching and the winding direction DR2 of the film after stretching. In the present invention, in order to produce a film having an orientation angle of 20 ° to 70 ° as described above, the feeding angle θi is set to 10 ° <θi <80 °, preferably 15 ° <θi <50 °. The By setting the feeding angle θi in the above range, the variation in the optical characteristics in the width direction of the obtained film becomes good (becomes small).

  The cellulose acylate film fed from the film roll (feeding roll) is gripped by the right and left gripping tools at the tenter inlet (position a), and then traveled as the gripping tool travels. The The left and right grips CL and CR, which are opposed to the direction of the film traveling direction (feeding direction DR1) at the tenter entrance (position a), run on a rail that is asymmetrical to the left and right, and are in a preheating zone. Through an oven having a stretching zone and a heat setting zone. Here, “substantially perpendicular” indicates that the angle formed by the straight line connecting the aforementioned gripping tools CL and CR and the film feeding direction DR1 is within 90 ± 1 °.

  The preheating zone refers to a section in which the vehicle travels while maintaining a constant interval between the gripping tools gripping both ends at the oven entrance. The stretching zone refers to an interval until the gap between the gripping tools gripping both ends starts to become constant again. In addition, the cooling zone refers to a section in which the temperature in the zone is set to be equal to or lower than the glass transition temperature Tg ° C. of the thermoplastic resin constituting the film during a period in which the interval between the gripping tools after the stretching zone becomes constant again. .

  The temperature of each zone is set to Tg + 5 to Tg + 20 ° C., the temperature of the stretching zone is set to Tg to Tg + 20 ° C., and the temperature of the cooling zone is set to Tg−30 to Tg ° C. with respect to the glass transition temperature Tg of the thermoplastic resin. It is preferable to do.

  The draw ratio R (W / Wo) in the drawing step according to the present invention is preferably 1.3 to 3.0 times, more preferably 1.5 to 2.8 times. When the draw ratio is within this range, thickness unevenness in the width direction is reduced, which is preferable. In the stretching zone of the tenter stretching machine, if the stretching temperature is differentiated in the width direction, the thickness unevenness in the width direction can be further improved. In addition, Wo represents the width of the film before stretching, and W represents the width of the film after stretching.

(Drying process)
The means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web drying step is preferably a glass transition point of the film of −5 ° C. or less, and it is effective to perform a heat treatment at 100 ° C. or more and 10 minutes or more and 60 minutes or less. Drying is performed at a drying temperature of 100 to 200 ° C, more preferably 110 to 160 ° C.

  After the predetermined heat treatment, it is preferable to provide a slitter and cut off the end portion before winding to obtain a good winding shape. Furthermore, it is preferable to knurling both ends of the width.

(Knurling)
The knurling process can be formed by pressing a heated embossing roll. Fine embossing is formed on the embossing roll, and the embossing roll can be pressed to form asperity on the film and make the end bulky.

  The height of the knurling at both ends of the λ / 4 plate of the present invention is preferably 4 to 20 μm and a width of 5 to 20 mm.

  In the present invention, the knurling process is preferably provided after the drying in the film forming process and before winding.

  So far, a method for producing a λ / 4 plate by obliquely stretching by laminating a cellulose acylate film by co-casting has been described, but the λ / 4 plate according to the present invention is formed into a film in advance, formula (1) A film composed of cellulose acylate satisfying the above and a film composed of cellulose acetate satisfying the formula (2) may be produced by stretching in an oblique direction, and each of these films may be known. After saponification by the method, a laminated film bonded with a water-soluble polymer adhesive such as polyvinyl alcohol may be produced by oblique stretching.

(Haze)
The λ / 4 plate of the present invention preferably has a haze of less than 1%, more preferably less than 0.5%. By setting the haze to less than 1%, there is an advantage that the transparency of the film becomes higher and it becomes easier to use as an optical film.

(Average moisture content)
In the λ / 4 plate of the present invention, the equilibrium moisture content at 25 ° C. and a relative humidity of 60% is preferably 4% or less, and more preferably 3% or less. By setting the average moisture content to 4% or less, it is easy to cope with changes in humidity, and the optical characteristics and dimensions are more difficult to change.

(Film thickness)
The total thickness of the λ / 4 plate according to the present invention is preferably 80 μm or less, and more preferably 50 μm or less. A film thicker than 80 μm is not preferable because it tends to cause a change in color and the like, and is not preferable because it does not match the trend of thinning display devices in recent years.

(Film length, width)
The λ / 4 plate of the present invention is preferably long, specifically, preferably has a length of about 100 to 10,000 m, and is wound up in a roll shape. Further, the width of the λ / 4 plate of the present invention is preferably 1 m or more, more preferably 1.4 m or more, and particularly preferably 1.4 to 4 m.

(Hard coat layer)
It is also preferable that a hard coat layer is provided on the λ / 4 plate of the present invention, and the hard coat layer is preferably either a clear hard coat layer or an antiglare hard coat layer.

  The hard coat layer preferably contains an active energy ray-curable resin that is cured by irradiation with active energy rays such as ultraviolet rays.

  The active energy ray-curable resin is a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. Typical examples of the active energy ray curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin that is cured by irradiation with an active energy ray other than an ultraviolet ray or an electron beam may be used.

  Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. be able to.

(Antireflection layer)
It is also preferable to provide an antireflection layer on the hard coat layer of the λ / 4 plate of the present invention.

  The antireflection layer to be used may have a single layer structure consisting of only a low refractive index layer, but it is also preferable to provide a multilayer refractive index layer. A λ / 4 plate has a hard coat layer, and can be laminated on the surface in consideration of the refractive index, film thickness, number of layers, layer order, etc. so that the reflectivity is reduced by optical interference. The antireflection layer is composed of a combination of a high refractive index layer having a higher refractive index than that of the support and a low refractive index layer having a lower refractive index than that of the support, and particularly preferably from three or more refractive index layers. An anti-reflection layer comprising three layers having different refractive indexes from the support side, a medium refractive index layer (having a higher refractive index than the support or anti-glare hard coat layer, and having a higher refractive index than the high refractive index layer). It is preferable that the layers are laminated in the order of (low layer) / high refractive index layer / low refractive index layer.

  Examples of preferred layer structures of the antireflection layer according to the present invention are shown below. Here, / indicates that the layers are arranged in layers.

(Λ / 4 plate) / Clear hard coat layer / Low refractive index layer (λ / 4 plate) / Clear hard coat layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Clear hard coat layer / Medium Refractive index layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Low refractive index layer, medium refractive index layer, and high refractive index layer are known structures In particular, it is preferable that hollow spherical silica-based fine particles are suitably used for the low refractive index layer. (I) A composite comprising porous particles and a coating layer provided on the surface of the porous particles Particles or (II) hollow particles having cavities inside and filled with a solvent, gas or porous substance are used.

  The low refractive index layer, medium refractive index layer, and high refractive index layer are described in detail in JP-A-2005-266051.

<Polarizing plate>
The polarizing plate using the λ / 4 plate of the present invention is preferably a circularly polarizing plate in which the absorption axis of the polarizer and the slow axis of the λ / 4 plate are bonded with an inclination of substantially 45 °. .

  The polarizing plate according to the present invention uses a stretched polyvinyl alcohol doped with iodine or a dichroic dye as a polarizer, and is bonded in a configuration of (λ / 4 plate) / polarizer / optical film. Can be manufactured.

  The optical film is not particularly limited, but is preferably a polymer film, preferably easy to manufacture, optically uniform, and optically transparent. Any of these may be used, for example, cellulose ester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene terephthalate, polyethylene naphthalate. Polyester film, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene resin Film, polymethylpentene film, polyetherketone film, Polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, a cycloolefin polymer film, a polyvinyl acetal resin film, there may be mentioned polymethyl methacrylate film, or an acrylic film or the like, but are not limited to. As these films, films formed by a solution casting method or a melting method are preferably used. Of these, cellulose ester film, polycarbonate film, polysulfone (including polyethersulfone) and cycloolefin polymer film are preferred. In the present invention, cellulose ester film and cycloolefin polymer film are particularly advantageous in terms of production, cost and transparency. From the viewpoints of uniformity, adhesion and the like. For example, commercially available cellulose ester films include Konica Minoltack KC8UX, KC4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC4UY, KC12UR, KC16UR, KC4UE, KC8UE, KC4UE, KC4F Etc.) are preferably used.

  Examples of the polarizer preferably used in the polarizing plate according to the present invention include a polyvinyl alcohol polarizing film, which includes a polyvinyl alcohol film dyed with iodine and a dichroic dye dyed. As the polyvinyl alcohol film, a modified polyvinyl alcohol film modified with ethylene is preferably used. For the polarizer, a polyvinyl alcohol aqueous solution is formed into a film and dyed by uniaxial stretching or dyed or uniaxially stretched and then preferably subjected to a durability treatment with a boron compound. Stretching is preferably performed uniaxially in the film forming direction.

  The film thickness of the polarizer is 5 to 40 μm, preferably 5 to 30 μm, and particularly preferably 5 to 20 μm.

  The polarizing plate can be produced by a general method. The λ / 4 plate of the present invention that has been subjected to alkali saponification treatment can be bonded to at least one surface of a polarizer prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. preferable. It is preferable to saponify and bond the optical film to the other surface in the same manner.

  In the production of the λ / 4 plate of the present invention, in the case of a λ / 4 plate produced by stretching in a direction substantially 45 ° with respect to the longitudinal direction, the absorption axis of the polarizing film is positioned in the longitudinal direction. The polarizer and the longitudinal direction of the polarizer and the slow axis of the λ / 4 plate are 20 ° or more and less than 70 °, more preferably 40 ° or more and less than 50 °, and particularly preferably 44 ° or more and less than 46 °. , Can be bonded continuously by roll-to-roll.

  The polarizing plate can be constructed by further bonding a protective film on one surface of the polarizing plate and a separate film on the opposite surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection.

  In the λ / 4 plate of the present invention, the absorption axis of the polarizer and the slow axis of the λ / 4 plate are bonded with an inclination of substantially 45 °, respectively, and (λ / 4 plate) / polarizer / (λ / It is also preferable that the polarizing plate is laminated in the order of (4 plates). In this case, the λ / 4 plates on both sides of the polarizer may be the same or different as long as they satisfy the scope of the present invention. Further, the two λ / 4 plates may have the slow axes parallel or perpendicular to each other. As will be described later, the polarizing plate having such a configuration is preferably arranged on the viewing side of a stereoscopic image display device using an organic EL display device.

<Liquid crystal display device>
In the liquid crystal display device according to the present invention, it is preferable that the polarizing plate is disposed on the viewing side with respect to the liquid crystal cell, and the liquid crystal cell, the polarizer, and the λ / 4 plate are provided in this order.

  By using the polarizing plate according to the present invention as a liquid crystal display device bonded to the surface on the viewing side of the liquid crystal cell, the display image is difficult to see depending on the direction of the polarization axis even when observed through an optical member having a polarizing action such as polarized sunglasses. Therefore, the liquid crystal display device according to the present invention having higher durability against the use environment can be manufactured. The polarizing plate according to the present invention is a reflective type, transmissive type, transflective type LCD or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, etc. Preferably used.

  The position of the polarizing plate according to the present invention in the liquid crystal display device needs to be arranged on the viewing side with respect to the liquid crystal cell, and the linearly polarized light is obtained by arranging the λ / 4 plate with hard coat of the present invention on the viewing side. Is converted into circularly polarized light, and the visibility when viewed through an optical member having a polarizing action such as polarized sunglasses can be greatly improved.

<Organic EL display device>
The organic EL image display device is not particularly limited, and in the conventionally known organic EL image display device, a circularly polarizing plate comprising the λ / 4 plate of the present invention and a polarizer is used as a plurality of self-luminous elements (organic EL elements). May be provided on the viewing side of the image forming cells arranged in a plane. At this time, the λ / 4 plate is arranged so as to be closer to the element side than the polarizer. With this arrangement, much of the reflected light from the counter electrode is absorbed by the polarizing layer both when the element emits light and when the element does not emit light. Therefore, an organic EL element with high contrast can be provided.

<Stereoscopic image display device>
The λ / 4 plate of the present invention can be used in various modes in a stereoscopic image display device. For example, a stereoscopic image display device including a liquid crystal display device and liquid crystal shutter glasses, wherein the liquid crystal shutter glasses are (1) a λ / 4 plate, a liquid crystal cell, and a polarizer are provided in this order, or ( 2) The λ / 4 plate, the polarizer, the liquid crystal cell, and the liquid crystal shutter glasses in which the polarizer is provided in this order can be used in a stereoscopic image display apparatus.

  In any case, the front polarizing plate of the liquid crystal display device is provided with a λ / 4 plate, a polarizer, and an optical film in this order, and the λ / 4 plate is disposed on the viewing side. It is configured. In the present invention, with the above-described aspect and configuration, crosstalk or luminance reduction and color change when tilting the head when viewing a stereoscopic (3D) image can be reduced, and excellent visibility with respect to the use environment can be maintained. Therefore, a stereoscopic image display device with higher durability against the use environment can be obtained.

<Organic EL stereoscopic image display device>
The λ / 4 plate of the present invention can also be applied to a stereoscopic image display device using an organic EL element. When the λ / 4 plate of the present invention is used in an organic EL stereoscopic image display device, a λ / 4 plate, a polarizer, and a polarizing plate provided with a λ / 4 plate in this order are arranged in an organic EL element in a planar shape. What is necessary is just to arrange | position to the visual recognition side of the made image formation cell. With this arrangement, external light reflection from the counter electrode can be prevented both when the element emits light and when the element does not emit light, and in the stereoscopic image display device using the liquid crystal shutter glasses as described above. Further, it is possible to reduce crosstalk or luminance reduction and color change when tilting the neck, and provide an organic EL stereoscopic image display device with good visibility.

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

(Synthesis of cellulose acylate)
The cellulose acylates shown in Table 1 were synthesized by the methods described in JP-A-10-45804 and 08-231761, and the degree of substitution was measured. Specifically, sulfuric acid (7.8 parts by mass with respect to 100 parts by mass of cellulose) was added as a catalyst, and carvone as a raw material for the acyl substituent was added, and an acylation reaction was performed at 40 ° C. At this time, the kind and substitution degree of the acyl group were adjusted by adjusting the kind and amount of the carboxylic acid. In addition, aging was performed at 40 ° C. after acylation. Further, the low molecular weight component of the cellulose acylate was removed by washing with acetone.

  The degree of substitution was determined by the method specified in ASTM-D817-96.

<Example 101> Note: The example 101 is a reference example.
The following cellulose acylate dope was prepared.

(Preparation of cellulose acylate dope for layer A)
Cellulose acylate resin: DAC1 listed in Table 1 100 parts by mass Dichloromethane 406 parts by mass Methanol 61 parts by mass (Preparation of cellulose acetate dope for layer B)
Cellulose acetate resin: TAC1 described in Table 1 100 parts by weight Matting agent: Compound VI described in Table 2 0.12 parts by weight Dichloromethane 406 parts by weight Methanol 61 parts by weight Peeling accelerator: Compound VII described in Table 2 0.05 Part by mass Each of the cellulose acylate dopes described above is put into a mixing tank and stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm to obtain a cellulose acylate dope. Prepared.

  Next, using the dope for layer A and layer B prepared as described above, a film having a multilayer structure of layer B / layer A / layer B was formed. When casting the dope, as shown in FIG. 2, the above three types of dopes were co-cast from a co-casting die on a traveling casting support.

  FIG. 2 is a diagram showing a co-casting die and a casted multi-layered web.

  In the figure, a co-casting die 10, a base part 11, layer B slits 13 and 15, layer A slit 14, metal support 16, layer B dopes 17 and 19, layer A dope 18, multilayer structure web 20 , Layer B21, Layer A22, and Layer B23, respectively.

  Here, the thickness of the layer A was adjusted to be the largest by adjusting the casting amount of each dope.

  After the multilayer web 20 is peeled off from the casting support 16, the apparatus shown in FIG. 1 is used, and the film is stretched in an oblique direction so that the angle θ formed with the longitudinal direction becomes the angle shown in Table 3. And dried to prepare a long cellulose acylate film 101. The stretching ratio and the stretching temperature were appropriately adjusted so that the in-plane retardation Ro described in Table 3 was obtained.

<Example 102>
It manufactured and evaluated similarly to Example 101 except having changed into dope for the layer B of Example 101, and having formed into the following film.

(Preparation of cellulose acetate dope for layer B)
Cellulose acetate resin: TAC1 described in Table 1 100 parts by mass Retardation adjusting agent: Compound I ₁ described in Table 2 20 parts by weight Matting agent: Compound VI described in Table 2 0.12 parts by weight Dichloromethane 406 parts by weight Methanol 61 parts Part Peeling Accelerator: 0.05 part by mass of Compound VII described in Table 2 <Example 103>
Production and evaluation were conducted in the same manner as in Examples 101 and 102 except that the dope for layer A and layer B of Example 102 was changed to the following, and the film was produced.

(Preparation of cellulose acylate dope for layer A)
Cellulose acylate resin: 100 parts by mass of DAC1 described in Table 1 Retardation developer: Compound III ₁ described in Table 2 7 parts by mass Dichloromethane 406 parts by mass Methanol 61 parts by mass (Preparation of cellulose acetate dope for layer B)
Cellulose acetate resin: TAC1 described in Table 1 100 parts by mass Retardation adjuster: Compound I ₁ 20 parts by mass described in Table 2 Retardation developer: Compound II ₁ described in Table 2 8.4 parts by mass Matting agent: Table 2 Compound VI described in 0.12 parts by mass Dichloromethane 406 parts by mass Methanol 61 parts by mass Peeling accelerator: Compound VII described in Table 2 0.05 parts by mass <Examples 104, 105, 107 to 113>
Except that the conditions of Example 103 were changed as shown in Tables 3 and 4, they were produced and evaluated in the same manner as Example 103.

<Example 106>
The layer A was prepared and evaluated in the same manner as in Example 103 except that the layer A dope of Example 103 was changed to the one prepared below.

(Preparation of cellulose acylate dope for layer A)
Cellulose acylate resin: DAC1 listed in Table 1 100 parts by mass Retardation developer: Compound III ₁ listed in Table 2 7 parts by weight UV absorber: Compound VIII listed in Table 2 3 parts by weight Dichloromethane 406 parts by weight Methanol 61 parts by weight <Comparative Example 101>
The following dopes were prepared.

Cellulose acylate resin: Table 1 CAP1 100 parts by weight plasticizers described in: compounds listed in Table 2 IX and X 5.5 / 5.5 parts by weight retardation developer: compound shown in Table 2 III ₃ 2.0 Mass parts Matting agent: Compound VI described in Table 2 0.12 parts by mass Dichloromethane 300 parts by mass Ethanol 40 parts by mass Using this dope, a monolayer cellulose acylate film was formed. Thereafter, in the same manner as in Examples 101 to 113, the film was stretched in an oblique direction to produce a λ / 4 film. Table 4 shows the results of the same evaluation as in Examples 101 to 113.

<Comparative Example 102>
The following dopes were prepared.

(Preparation of cellulose acylate dope for layer A)
Cellulose acylate resin: 100 parts by mass of TAC1 described in Table 1 Retardation developer: 1 part by mass of Compound III ₁ described in Table 2 Additive: Compounds IV and V described in Table 2 7.8 / 3.9 parts by mass Dichloromethane 450 parts by mass Methanol 39 parts by mass (Preparation of cellulose acetate dope for layer B)
Cellulose acetate resin: TAC1 listed in Table 1 100 parts by mass Retardation developer: Compound III ₁ listed in Table 2 1 part by weight Additive: Compounds IV and V listed in Table 2 7.8 / 3.9 parts by weight Matte Agent: Compound VI described in Table 2 0.12 parts by weight Dichloromethane 450 parts by weight Methanol 39 parts by weight Peeling accelerator: Compound VII described in Table 2 0.05 parts by weight In the same manner as in Example 101, the co-casting method was used. A multilayer film of layer B / layer A / layer B was formed. Then, the longitudinal uniaxial stretching process was performed with the roll stretching machine. The roll of the roll drawing machine was an induction heating jacket roll having a mirror-finished surface, and the temperature of each roll could be adjusted individually. The stretching zone was covered with a casing and set to 130 ° C. The roll before the stretching part was set so that it could be gradually heated to 130 ° C. The distance between the stretches was adjusted so that the L / W ratio was 2.5. After stretching, the film was cooled and wound up. Table 4 shows the results of evaluating the obtained long film by the above method.

<Comparative Example 103>
With reference to JP 2010-58331 A, the following dopes were prepared.

(Preparation of cellulose acylate dope for layer A)
Cellulose acylate resin: 100 parts by mass of DAC1 described in Table 1 Retardation developer: Compound XI described in Table 2 10 parts by mass Dichloromethane 450 parts by mass Methanol 39 parts by mass (Preparation of cellulose acetate dope for layer B)
Cellulose acetate resin: TAC1 described in Table 1 100 parts by mass Retardation developer: Compound III ₁ described in Table 2 4 parts by mass Matting agent: Compound VI described in Table 2 0.12 parts by mass Dichloromethane 450 parts by mass Methanol 39 parts by mass Part Peeling accelerator: 0.05 parts by mass of compound VII described in Table 2 Using this dope, a multilayer film of layer B / layer A / layer B was formed by a co-casting method. Thereafter, similar to Examples 101 to 113, an attempt was made to produce a λ / 4 film by stretching in an oblique direction, but Ro (590) could not satisfy the scope of the present invention. Table 4 shows the results of the same evaluation as in Examples 101 to 113.

<Evaluation>
The retardation values Ro (450) and Ro (590) of the produced cellulose acylate film were measured by the following method.

(Retardation values Ro (450), Ro (590), measurement of in-plane orientation angle)
The average refractive index of the film sample was measured using an Abbe refractometer and a spectral light source. The thickness of the film was measured using a commercially available micrometer.

  Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments Co., Ltd.), the retardation of the film was measured at a wavelength of 450 nm in the same environment for 23 hours at 23 ° C. and 55% RH. The above-described average refractive index and film thickness were input into the following formula, and the in-plane retardation Ro (450) at a wavelength of 450 nm was determined. The measurement was performed on a central part in the width direction and a total of 21 points of 10 points every 50 mm toward both ends, and the average values are shown in Tables 3 and 4. Similarly, retardation measurement was performed at the 21 points in the width direction of the film at a wavelength of 590 nm to determine an in-plane retardation Ro (590) and an in-plane orientation angle, and the average values are shown in Tables 3 and 4. The in-plane orientation angle was defined by defining the angle in the counterclockwise direction with the film transport direction being 0 °. Further, the difference between the maximum value and the minimum value of Ro (590) at the 21 points is defined as the width variation of Ro (590) and is shown in Tables 3 and 4. Similarly, the difference between the maximum value and the minimum value of the in-plane orientation angle at the 21 points is shown in Tables 3 and 4 as variations in the in-plane orientation angle in the width direction.

Ro = (nx−ny) × d
(Where nx, ny are 23 ° C. RH, refractive index nx (also referred to as the maximum refractive index in the plane of the film, refractive index in the slow axis direction) at each wavelength, ny (perpendicular to the slow axis in the film plane) D is the thickness (nm) of the film.)
It can be said that the effect of the present invention is obtained when the width variation of Ro (590) is within 5 nm. Moreover, it can be said that it is a highly uniform film when the width variation of the in-plane orientation angle is within 1 °.

(Calculation of Ro (590) / Ro (450))
Ro (590) / Ro (450) is calculated by dividing Ro (590) by Ro (450) using the average value of Ro (450) and the average value of Ro (590) obtained as described above. did. Ro (590) / Ro (450) is preferably larger than 1 and 1.6 or smaller.

(Measurement of film thickness)
The film thickness was measured using a micrometer for a total of 21 points of 10 points every 50 mm toward the center in the width direction and both ends, and the average values are shown in Tables 3 and 4. Tables 3 and 4 show the difference between the maximum value and the minimum value of the film thickness at the above 21 points as the film thickness variation in the width direction. If the width variation in the width direction is within 2 μm, it can be said that the film has high film thickness uniformity.

(Haze)
Using a haze meter (1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.), the measurement was performed according to JISK-6714. The measurement was performed for each of five points at 100 mm intervals toward the center in the width direction and both ends, and the average values are shown in Tables 3 and 4.

  According to the present invention, it is possible to provide a long thin λ / 4 plate with good width flatness and optical uniformity.

<Example 201>
Using the λ / 4 plate produced in Example 103, a circularly polarizing plate was produced in the following manner.

[Production of circularly polarizing plate]
A 120 μm thick polyvinyl alcohol film was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times) to obtain a long roll film.

  This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a long roll-shaped polarizer.

  Next, according to the following steps 1 to 5, a long roll-shaped polarizer, the λ / 4 plate 103 of the present invention, and a commercially available cellulose acetate film (Konica Minolta Tack KC4UY, manufactured by Konica Minolta Opto Co., Ltd.) ) Were laminated with a roll-to-roll to produce a polarizing plate.

  Step 1: Soaked in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried to obtain a λ / 4 plate 103 ′ and KC4UY ′ saponified on the side to be bonded to the polarizer. .

  Process 2: The said polarizer was immersed in the polyvinyl alcohol adhesive tank of 2 mass% of solid content for 1-2 seconds.

  Step 3: Excess adhesive adhered to the polarizer in Step 2 was lightly wiped off and placed on the λ / 4 plate 103 ′ treated in Step 1.

Step 4: The λ / 4 plate 103 ′, the polarizer, and KC4UY ′ laminated in Step 3 were bonded at a pressure of 20 to 30 N / cm ² and a conveyance speed of about 2 m / min.

  Step 5: A sample obtained by bonding the polarizer prepared in Step 4 with the λ / 4 plate 103 ′ and KC4UY ′ by roll-to-roll in a dryer at 80 ° C. is dried for 2 minutes, and the polarizing plate 201 of the present invention is formed. Produced. In the polarizing plate, the slow axis of the λ / 4 plate and the absorption axis of the polarizer were bonded with an inclination of 45 °.

[Production of organic EL display device]
The circularly polarizing plate was peeled off from the display panel mounted on the mobile phone W56T (manufactured by Toshiba Corporation), and the circularly polarizing plate 201 of the present invention was attached. At that time, the λ / 4 plate was placed on the display element side. Thus, the organic EL display device 201 of the present invention was produced.

<Example 202>
An organic EL display device 202 was produced in the same manner as in Example 201 except that the λ / 4 plate 103 used in Example 201 was changed to the λ / 4 plate 105 of the present invention.

<Comparative Examples 201 and 202>
Comparative organic EL display devices 201 and 202 were produced in the same manner as in Example 201 except that the λ / 4 plate 103 used in Example 201 was changed to the λ / 4 plates 101 and 102 of the comparative example. .

<Evaluation>
The following evaluation was performed using the obtained organic EL display device.

(Evaluation of blackness when no external light voltage is applied)
After storing the above display device in a room at 23 ° C. and 55% RH for 24 hours, applying no voltage and not emitting light, placing it in an environment with an illuminance of about 100 lx, the four corners and the center of the display panel For the five points, the visual evaluation of the blackness level of the reflected color was performed as follows.

◎: There are no problems because the blackness is tightened at all five points. ○: There is a point where light leaks at one or two points and the blackness is insufficient. ×: There is an insufficient blackness at three or more points. Table 5 shows the evaluation results.

  Table 5 shows the evaluation results. According to the present invention, it is possible to provide a display device that does not cause unevenness in the ability to prevent reflection of external light and has no blackness unevenness.

<Example 301, Example 302>
A hard coat layer and an antireflection layer were provided on the λ / 4 plate of Example 106 of the present invention by the following procedure to produce a λ / 4 plate 106 ′ with an antireflection layer.

(Coating of hard coat layer)
On the produced λ / 4 plate 106, the following hard coat layer coating solution 1 is die-coated with a coating width of 1.4 m, dried at 80 ° C., and then cured by irradiating with 120 mJ / cm ² ultraviolet light with a high-pressure mercury lamp. A clear hard coat layer was provided so that the film thickness of the film was 6 μm.

(Coating solution 1 for hard coat layer)
Acetone 45 parts by mass Ethyl acetate 45 parts by mass Propylene glycol monomethyl ether 10 parts by mass Pentaerythritol triacrylate 30 parts by mass Pentaerythritol tetraacrylate 45 parts by mass Urethane acrylate (trade name U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.) 25 parts by mass 1- Hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by BASF Japan) 5 parts by mass 2-methyl-1- [4- (methylthio) phenyl] -2-monoforino-1-one (Irgacure 907, manufactured by BASF Japan) 3 parts by mass BYK-331 (silicone surfactant, manufactured by Big Chemie Japan Co., Ltd.)
<Application of antireflection layer>
(Application of medium refractive index layer)
The following medium refractive index layer coating solution is die-coated on the surface of the hard coat layer, dried at 80 ° C., and then irradiated with 120 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp so that the cured film thickness becomes 110 nm. A medium refractive index layer was provided. The refractive index was 1.60.

(Medium refractive index layer coating solution)
<Preparation of fine particle dispersion 2>
Methanol-dispersed antimony double oxide colloid (solid content 60%, zinc antimonate sol manufactured by Nissan Chemical Industries, Ltd., trade name: Celnax CX-Z610M-F2) 6.0 kg of isopropyl alcohol was gradually stirred with stirring. To prepare a fine particle dispersion 2.

PGME (propylene glycol monomethyl ether) 40 parts by mass Isopropyl alcohol 25 parts by mass Methyl ethyl ketone 25 parts by mass Pentaerythritol triacrylate 0.9 parts by mass Pentaerythritol tetraacrylate 1.0 part by mass Urethane acrylate (trade name: U-4HA Shin-Nakamura Chemical 0.6 parts by mass Fine particle dispersion 2 20 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by BASF Japan Ltd.) 0.4 parts by mass 2-methyl-1- [4- (methylthio) Phenyl] -2-monoforinopropan-1-one (Irgacure 907, manufactured by BASF Japan) 0.2 parts by mass 10% FZ-2207, propylene glycol monomethyl ether solution (manufactured by Nippon Unicar Company) 0.4 mass (Coating of the low refractive index layer)
On the medium refractive index layer, the following low refractive index layer coating solution is die-coated, dried at 80 ° C., and then irradiated with 120 mJ / cm ² of ultraviolet light with a high pressure mercury lamp so that the film thickness becomes 92 nm. A rate layer was provided to prepare an antireflection layer. The refractive index was 1.38.

(Low refractive index layer coating solution)
<Preparation of tetraethoxysilane hydrolyzate 3>
After mixing 230 g of tetraethoxysilane (trade name: KBE04, manufactured by Shin-Etsu Chemical Co., Ltd.) and 440 g of ethanol and adding 120 g of a 2% aqueous acetic acid solution thereto, the mixture is stirred for 26 hours at room temperature (25 ° C.). Silane hydrolyzate 3 was prepared.

Propylene glycol monomethyl ether 430 parts by mass Isopropyl alcohol 430 parts by mass Tetraethoxysilane hydrolyzate 3 120 parts by mass γ-methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) 3.0 parts by mass Isopropyl alcohol dispersion Hollow silica sol (solid content 20%, silica sol manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name: ELCOM V-8209) 40 parts by mass Aluminum ethyl acetoacetate diisopropylate (manufactured by Kawaken Fine Chemicals) 3.0 parts by mass 10% FZ- 2207, propylene glycol monomethyl ether solution (manufactured by Nihon Unicar Co., Ltd.) 3.0 parts by mass The λ / 4 plate 106 ′ with an antireflection layer produced as described above and the λ / 4 plate of Example 105 of the present invention The same procedure as Example 201 And polarization-board processing, to produce a polarizing plate 301 'and the polarizing plate 302' of the present invention. In the polarizing plate 301 ′, a polarizing plate is formed so that the slow axes of the λ / 4 plates disposed on both sides of the polarizer are parallel to each other. In the polarizing plate 302 ′, the λ disposed on both sides of the polarizer. A polarizing plate was formed so that the slow axes of the / 4 plates were orthogonal to each other.

  The polarizing plates 301 ′ and 302 ′ are arranged so as to be on the viewing side of the light emitting element of the organic EL display device that can alternately display the right-eye image and the left-eye image in time series. Stereoscopic image display devices 301 and 302 corresponding to 302 'were produced. When incorporating the polarizing plate of the present invention into a display device, the polarizing plates 301 ′ and 302 ′ were assembled with attention to the direction so that the surface of the λ / 4 plate 106 ′ provided with the antireflection layer was closest to the viewing side. .

  Further, the λ / 4 plate 106 ′ with an antireflection layer of the present invention was bonded to the panel surface side (surface side opposite to the eyes) of the stereoscopic image viewing glasses with a liquid crystal shutter. Switching between opening and closing the liquid crystal shutter was synchronized with switching between the right-eye image and the left-eye image on the display device.

  The produced stereoscopic image display device was visually evaluated for crosstalk when the head was tilted when viewing 3D video, and for blackness when no voltage was applied under external light.

(Evaluation of blackness when no external light voltage is applied)
Visual evaluation was performed according to the same criteria as in Example 201.

(Evaluation of crosstalk when tilting the head when viewing 3D images)
3D glasses were worn in an environment of 23 ° C. and 55% RH, 3D images were viewed with the neck tilted so that the glasses were tilted 25 °, and crosstalk was evaluated according to the following criteria.

A: There is no crosstalk. O: Very weak crosstalk is visible. Δ: Weak crosstalk is visible. X: Crosstalk is clearly visible. The results of evaluation as described above are shown in Table 6.

  It is apparent that the stereoscopic image display devices 301 and 302 equipped with the λ / 4 plate of the present invention are excellent in blackness under external light and crosstalk when tilting the neck when viewing 3D video.

DR1 Feeding direction DR2 Winding direction θi Feeding angle (An angle formed between the feeding direction and the winding direction)
CR, CL Gripping tool Wo Width of the film before stretching W Width of the film after stretching 10 Co-casting die 11 Base part 13, 15 Slit for layer B 14 Slit for layer A 16 Metal support 17, 19 Dope for layer B 18 Dope for layer A 20 Multilayer web 21 Layer B
22 Layer A
23 Layer B

Claims (9)

A long λ / 4 plate having an in-plane retardation Ro (590) at a wavelength of 590 nm satisfying Ro (590) = 120 to 160 nm, and the long λ / 4 plate satisfying the following formula (1) a layer a consisting acylate, seen including a layer B of cellulose acetate to satisfy the following equation (2), a laminated film which is adjacent to the order of layer B / layer a / layer B,
The thickness of the layer B is equal to or less than the thickness of the layer A;
The slow axis of the laminated film has an angle of 20 to 70 ° with respect to the longitudinal direction, and only the layer B includes an aliphatic polyester, an acrylic polymer, and a styrene polymer as a retardation adjusting agent. A long λ / 4 plate comprising at least one selected from high molecular weight compounds.
Formula (1) 2.0 <Z1 <2.7
(In the formula, Z1 represents the total acyl substitution degree of the cellulose acylate of layer A.)
Formula (2) 2.7 <= X2
(In the formula, X2 represents the total degree of acetyl substitution of the cellulose acetate of layer B.) The long λ / 4 plate according to claim 1 , wherein the film thickness is 80 μm or less. Includes a retardation developer having a rod-like structure in the layer B, the elongate lambda / 4 plate according to claim 1 or claim 2, characterized in that it comprises a retardation developer having a disc-like structure on the layer A . The amount WB of the rod-shaped compound contained in the layer B, the amount WA of the discotic compound contained in the layer A is, according to claim 3, characterized in that to satisfy the WB / WA = 1.3 to 1.6 Long λ / 4 plate.
(WB represents the mass part of the rod-shaped compound with respect to 100 parts by mass of the cellulose acetate contained in the layer B, and WA represents the mass part of the discotic compound with respect to 100 parts by mass of the cellulose acylate contained in the layer A). The elongated λ / 4 plate according to any one of claims 1 to 4 and a polarizer are disposed adjacent to each other, and an absorption axis of the polarizer and a slow axis of the λ / 4 plate are substantially 45 °. It arrange | positions so that it may become direction. An OLED display device using the circularly polarizing plate according to claim 5 . The elongated λ / 4 plate according to any one of claims 1 to 4 and a polarizer are arranged adjacent to each other in the order of (λ / 4 plate) / polarizer / (λ / 4 plate), Arranged so that the absorption axis of the polarizer and the slow axis of the λ / 4 plate are each substantially oriented at 45 °, and the slow axes of the two λ / 4 plates are orthogonal to each other. A polarizing plate characterized by that. The elongated λ / 4 plate according to any one of claims 1 to 4 and a polarizer are arranged adjacent to each other in the order of (λ / 4 plate) / polarizer / (λ / 4 plate), The polarizer is arranged so that the absorption axis of the polarizer and the slow axis of the λ / 4 plate are substantially oriented at 45 °, and the slow axes of the two λ / 4 plates are parallel to each other. A polarizing plate characterized by being arranged. A stereoscopic image display device using the polarizing plate according to claim 7 or 8 .

Images