WO2008050525A1 - Retardation film - Google Patents

Abstract

Disclosed is a retardation film for use in a liquid crystal display device, particularly a retardation film which enables to improve the unevenness in a corner part of a big-screen VA-type liquid crystal panel. In the retardation film, the elastic modulus (E23) as measured in the film-stretching direction under the conditions of a temperature of 23˚C and a humidity of 55% RH is 3.4 to 4.4 GPa, and the difference (E23-50) between the elastic modulus (E50) as measured in the film-stretching direction under the conditions of a temperature of 50˚C and a humidity of 55% RH and the above-mentioned elastic modulus (E23) satisfies the requierment shown by the formula (1). When the amount of an additive present on a surface of the retardation film to be bounded to a polarizer is defined as 100 by mass, the amount of the additive present on a surface of the retardation film to be adhered to a glass surface is 20 to 70 by mass. Formula (1): 0.30 ≤ E23-50 ≤ 0.80 [wherein, E23-50 = E23 - E50.]

Description

 Specification

 Retardation film

 Technical field

 [0001] The present invention relates to a retardation film used in various display devices such as a liquid crystal display device (LCD) or an organic EL (electric mouth luminescence) display, and in particular, a protective film for a polarizing plate used in these display devices, In addition, the present invention relates to a retardation film having birefringence that can be used as a retardation film.

 Background art

 In general, the basic configuration of a liquid crystal display device is one in which polarizing plates are provided on both sides of a liquid crystal cell. Since a polarizing plate allows only light with a polarization plane in a certain direction to pass, it plays an important role in visualizing changes in the orientation of liquid crystal due to an electric field in a liquid crystal display device. The performance of a liquid crystal display device depends on the performance of the polarizing plate. Is greatly affected.

 [0003] In recent years, the demand for display quality of thin-film liquid crystal display devices has increased, and various liquid crystal display methods such as VA (vertical alignment mode), OCB, and IPS have been proposed. A liquid crystal display device with a wide viewing angle generally uses a retardation correction film. The quality required for retardation films has become stricter due to the larger screen and higher definition, and the uniformity of the film retardation value in the lateral and longitudinal directions is required.

 [0004] Conventionally, a polarizing plate used in a VA mode liquid crystal panel is bonded to a liquid crystal cell so as to have a polarization axis in the vertical and horizontal directions of the screen. The polarizer of the elements constituting the polarizing plate used here is manufactured by greatly stretching a PVA film. As a result of trying to shrink due to temperature and humidity, cellulose protecting the polarizer is used. There may be a problem of so-called “corner unevenness”, in which shrinkage stress is applied to the esthetic film or the retardation film that is laminated, and the four corners appear white when the screen is displayed in black.

[0005] Conventionally, various proposals have been made on the elastic modulus ratio of a retardation film used in a liquid crystal display device, and the following patent documents are available.

[0006] Patent Document 1 discloses a cellulose ester film, an optical compensation sheet (retardation plate), and an elliptically polarizing plate. Tensile elasticity in the machine direction of a cell mouth ester film is disclosed. And the tensile modulus in the direction perpendicular to the machine direction, and by adjusting the ratio of tensile modulus in the machine direction / tensile modulus in the direction perpendicular to the machine direction, the thickness direction of the cellulose ester film It is described that the relationship between the letter decision value (Rth) and the in-plane letter decision value (Re) is adjusted.

 Patent Document 1: Japanese Patent Laid-Open No. 2001-100039

 Disclosure of the invention

 Problems to be solved by the invention

However, the technique described in Patent Document 1 has a problem that “corner unevenness” in the large-screen VA liquid crystal panel is insufficient to improve the problem.

[0008] An object of the present invention is to provide a retardation film capable of solving the above-described problems of the prior art and improving corner unevenness in a large-screen VA liquid crystal panel.

Means for solving the problem

The present inventor has conducted extensive research to solve the above-described problems of the prior art, and as a result, in order to improve corner unevenness in a large-screen VA-type liquid crystal panel, a protective film according to the contraction force of the polarizer Alternatively the retardation film itself may force ^s it is preferable to deform revealed.

 [0010] In particular, the temperature of the retardation film may reach nearly 50 ° C due to lighting of the panel backlight, and in this state, the elastic modulus power of the protective film or retardation film alone will be reduced to the elastic modulus at a temperature of 23 ° C. The present inventors have found that the effect is remarkable when the temperature is 0.3 to 0.8 GPa lower than that, and have completed the present invention.

 [0011] On the other hand, in the normal temperature region such as 23 ° C, the protective film or retardation film itself has a low elastic modulus, especially for polarizing plates for large-screen liquid crystal panels! Since it becomes impossible to counter the contraction force, the protective film or the retardation film is apt to be distorted, resulting in a decrease in front contrast.

 [0012] The inventor has an elastic modulus (E) measured under measurement conditions at a temperature of 23 ° C and a humidity of 55% RH.

 twenty three

3. 4 to 4.4 GPa, and the difference (Δ Ε) from the elastic modulus (E) under the measurement conditions at a temperature of 50 ° C and a humidity of 55% is 0 · 30-0.80GPa Retardation film It came to invent.

 [0013] In addition, the present invention can significantly suppress the occurrence of corner unevenness by reducing the amount of plasticizer on the surface in contact with the polarizer of the retardation film to be less than the amount of plasticizer on the surface in contact with the glass side. It is.

 [0014] Estimated force By using a high plasticizer amount on the surface of the phase difference film on the polarizer side, the bonding force between the phase difference film and PVA (polarizer) increases, while the surface of the phase difference film on the glass side This is because, since the amount of plasticizer is small, the stress generated by the PVA shrinkage due to temperature change is transmitted to the retardation film, and the force is relatively weakened. It is thought that there is.

 [0015] In order to achieve the above object, the invention of claim 1 is characterized in that means for holding the end of the film and stretching in a direction perpendicular to the conveying direction is part of the film forming process. A retardation film produced in the production process provided, wherein the elastic modulus (E) in the film stretching direction measured under measurement conditions at a temperature of 23 ° C. and a humidity of 55% RH is 3.4 to 4. 4

 twenty three

 The difference (E) between the elastic modulus (E) in the film stretching direction measured under the measurement conditions of GPa, temperature 50 ° C, and humidity 55% RH, and the above elastic modulus (E) is Satisfies the following formula (1)

 50 23 23-50

 If the amount of additive present on the surface of the retardation film bonded to the polarizer is 100, the amount of additive present on the surface of the retardation film adhered to the glass surface is The mass ratio is 20 to 70.

 [0016] Equation (1) 0. 30≤E ≤0. 80

 23-50

 However, E = E -E.

 23 -50 23 50

 [0017] The invention of claim 2 is the retardation film of claim 1, characterized in that the film thickness force of the film contained in the film is 35-60 111.

[0018] The invention of claim 3 is the phase difference according to claim 1 or 2: lum, wherein the intrinsic viscosity (IV) of the resin contained in the film is 1.3. ~; 1. It is characterized by 7.

[0019] The invention of claim 4 is the retardation film according to any one of claims 1 to 3, wherein the main component of the resin contained in the film is cellulose. S And the cellulose ester contains at least one selected from cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate! /.

[0020] The invention according to claim 5 is the retardation film according to claim 4, comprising:

 Ester group substitution degree power: 2.42-2.60

 The invention's effect

 [0021] The invention of the retardation film of claim 1 is a production film in which means for gripping an end portion of the film and stretching in a direction perpendicular to the conveying direction is provided in a part of the film forming process. A retardation film produced at a temperature of 23 ° C. and a humidity of 55% RH, and the elastic modulus (E) in the direction of stretching of the film measured under the measurement conditions is 3.4 to 4.4 GPa, Power,

 twenty three

 The difference (E) between the elastic modulus in the film stretching direction measured under the measurement conditions at a temperature of 50 ° C and a humidity of 55% RH satisfies the following formula (1): Is,

50 23 23-50

 When the amount of additive present on the surface of the retardation film to be bonded to the polarizer is 100 in terms of mass ratio, the amount of additive present on the surface of the phase difference film to be adhered to the glass surface is 20 in terms of mass ratio. ~ 70.

[0022] Equation (1) 0. 30≤E ≤0. 80

 23-50

 However, E = E -E.

 23 -50 23 50

 [0023] According to the retardation film of the present invention, the elastic modulus (E) in the film stretching direction measured under the measurement conditions at a temperature of 23 ° C and a humidity of 55% RH, a temperature of 50 ° C and a humidity of 55% Measurement conditions at RH

 twenty three

 The difference (E) from the elastic modulus (E) in the film stretching direction measured below satisfies the above equation (1).

 50 23 -50

 In other words, for example, when the backlight of a large-screen VA liquid crystal panel is turned on, the temperature of the retardation film may reach nearly 50 ° C, and the retardation film itself in that state has an elastic modulus (E) force temperature Compared to the elastic modulus (E) at 23 ° C, the range of 0.3 to 0.8 GPa

 50 23

 When the surrounding area is low, the protective film or retardation film itself can be deformed according to the contraction force of the polarizer, and the power to improve corner unevenness in the large-screen VA liquid crystal panel can be improved! If the effect is remarkable, it will produce the effect!

In particular, according to the retardation film of the present invention, the contraction of the polarizer caused by environmental fluctuations. It is possible to prevent the dimensional change of the polarizing film itself without losing the retardation film, and to prevent the so-called curling of the polarizing film, so that the liquid crystal panel can be manufactured with high productivity. There is an effect that can be done.

 [0025] In addition, the invention of claim 1 is characterized in that corner unevenness is generated by making the amount of plasticizer on the surface in contact with the polarizer of the retardation film smaller than the amount of plasticizer on the surface in contact with the glass side. This has the effect of significantly reducing

 [0026] This is because, by increasing the amount of surface plasticizer on the polarizer side of the retardation film, the bonding force between the retardation film and PVA (polarizer) increases, while the surface of the retardation film on the glass side increases. This is because the stress caused by PVA shrinkage due to temperature change is transmitted to the phase difference film due to the small amount of plasticizer, so that the force is relatively weakened and the birefringence is not easily disturbed. Think of it as something.

 [0027] The invention of claim 2 is the retardation film of claim 1, wherein the film thickness force of the film contained in the film is 35-60111. According to the present invention, it is possible to satisfactorily meet the demand for thinning of a retardation film used for thin displays in recent years, particularly thin displays such as large size TVs.

 [0028] The invention of claim 3 is the retardation film of claim 1 or 2, wherein the intrinsic viscosity (IV) of the resin contained in the film is 1.3. According to the present invention, it is possible to prevent the film from tearing and to avoid the risk of breakage in the film stretching process according to the present invention. It has the effect of being able to.

[0029] The invention of claim 4 is the retardation film according to any one of claims 1 to 3, wherein the main component of the resin contained in the film is cellulose. It is an ester, and the cellulose ester contains at least one selected from cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. According to the present invention, as the resin constituting the film, When a cellulose ester as described above is used, a retardation film capable of improving corner unevenness in a large-screen VA-type liquid crystal panel while maintaining the transparency of the film is obtained. There is an effect.

 [0030] The invention of claim 5 is the retardation film of claim 4, which has a degree of ester group substitution degree of cellulose ester of 2.42-2.60. According to the invention, when a cellulose ester having an ester group substitution degree as defined above is used, a retardation film having good adhesion to the polarizing film while maintaining the transparency of the film can be obtained! / , Has an effect.

 Brief Description of Drawings

 [0031] FIG. 1 is an explanatory diagram for explaining a stretching angle in a film stretching step.

 FIG. 2 is a schematic plan view showing an example of a stretching process used in the method of the present invention.

 FIG. 3 is a schematic plan view schematically showing an example of a tenter stretching apparatus used in the method of the present invention.

 Explanation of symbols

[0032] la: Left-side chain (rotary drive)

 lb: Right wheel chain (rotary drive)

 2a: Left clip

 2b: Right side clip

 3a: Left clip closer

 3b: Right clip closer

 4a: Left clip opener

 4b: Right clip opener

 10a: Tenter stretching device

 BEST MODE FOR CARRYING OUT THE INVENTION

Next, embodiments of the present invention will be described, but the present invention is not limited to these.

 [0034] The retardation film according to the present invention has an elastic modulus (E) in the film stretching direction of 3.4 measured under measurement conditions of a temperature of 23 ° C and a humidity of 55% RH.

 The elastic modulus (E) in the film stretching direction measured under the measurement conditions of 23 to 4.4 GPa and a temperature of 50 ° C. and a humidity of 55% RH,

The difference (E) from the elastic modulus (E) described in 50 satisfies the following formula (1). [0035] Equation (1) 0. 30≤E ≤0. 80

 23-50

 However, E = E -E.

 23 -50 23 50

 In the present invention, in order to improve corner unevenness in a large screen VA type liquid crystal panel, it is important that the protective film or the retardation film itself is deformed according to the contraction force of the polarizer. The temperature of the retardation film may reach nearly 50 ° C due to the backlighting of the VA-type LCD panel, and the elastic modulus (E) force of the retardation film alone in that state Elasticity at a temperature of 23 ° C ( E) in the range of 0.3 to 0.8 GPa

 50 23

 The effect is remarkable when the surrounding area is low, and according to the present invention, it is possible to improve corner unevenness in a large-screen VA liquid crystal panel.

 [0037] These will be described in detail below.

 [0038] The retardation film according to the present invention includes preferable requirements such as easy manufacture, good adhesion to the polarizing film, optical transparency, and the like. Rum is preferred.

[0039] The term "transparent" as used in the present invention means a visible light transmittance of 60% or more, preferably 80

% Or more, particularly preferably 90% or more.

[0040] The polymer film is not particularly limited as long as it has the above-mentioned properties. For example, a cellulose diacetate film, a cellulose triacetate film, a cellulose acetate butyrate vinylome, a cenorelose acetate propionate vinylome. Such as polyester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyester film such as polyethylene terephthalate, polyethylene naphthalate, polyethylene film, polypropylene film, Cellophane, Polyvinylidene Chloride Film, Polybula Norecore Renoinolem, Ethylene Vinylenorenoreno Reino Inolem, Shinji Tactics Polystyrene film, polycarbonate film, cycloolefin polymer film (Arton (manufactured by JSR), ZEONEX, ZENOA (manufactured by ZEON CORPORATION), polymethylpentene film, polyetherketone film, polyetherketoneimide film, polyamide Examples include phenol, fluororesin film, nylon film, polymethyl methacrylate film, talyl film, glass plate, etc. Among them, cellulose ester film In the present invention where a nolem, a cycloolefin polymer film, a polycarbonate film, or a polysulfone (including polyethersulfone) film is preferred, in particular, a cellulose esterolino vinyl, a cycloolefin polymer vinyl, or a polycarbonate film is preferred. From the viewpoint of production, cost, transparency, adhesiveness, etc., Finorem is preferably used. These films may be films produced by melt casting or film produced by solution casting! /.

 [0041] Further, the retardation film of the present invention is formed as a polymer layer on the film described in JP-A-2000-190385, JP-A-2004-4474, JP-A-2005-195811, and the like. A polymer film provided with an optically anisotropic layer such as polyamide or polyimide is also preferred.

 [Senorelose Estenolefinolem]

 Preferred as the main component of the retardation film according to the present invention, the cellulose ester is preferably cellulose acetate, cenololose propionate, cenololose butyrate, cenololose acetate butyrate, or cellulose acetate propionate. Suacetate, cellulose acetate butyrate, and cellulose acetate propionate are preferably used.

[0042] In particular, the main component of the resin contained in the film is a cellulose ester, and the cellulose ester has at least one selected from the group consisting of cenorelose acetate, cenorelose acetate propiate, and cenorelose acetate petite. The force _{S is} preferred.

[0043] As described above, in the present invention, by using the cellulose ester as described above as the resin constituting the film, the corner unevenness in the large screen VA liquid crystal panel is improved while maintaining the transparency of the film. can do.

 [0044] Here, the ester group substitution degree of the cellulose ester is preferably 2.42-2.60. By using a cellulose ester whose ester group substitution degree is defined in this way, a retardation film having good adhesion to the polarizing film while maintaining the transparency of the film can be obtained. These cellulose esters can be synthesized by known methods.

[0045] In the present invention, the intrinsic viscosity (IV) of the resin contained in the film is 1.3 to 1.7; According to the present invention, which is preferred, it is possible to prevent the film from being avoided in the phase difference film manufacturing stage, and to avoid the risk of breakage in the film stretching process with the force S.

 Here, the intrinsic viscosity (IV) of the resin contained in the film can be measured using an Ubbelohde viscometer. Specifically, tetrahydrofuran was used as the solvent, and the cell mouth ester resin was dissolved in the solvent. Prepare. Using the Ubbelohde viscometer, the specific viscosity (η sp) at each concentration (C) is obtained.

 [0047] [Equation 1]

Intrinsic viscosity = lim ^ "

 c → 0 C

[0048] The external viscosity is zeroed to obtain the intrinsic viscosity [7].

 [0049] When a cellulose ester is used as the retardation film according to the present invention, the cellulose used as a raw material for the cellulose ester is not particularly limited. Can be mentioned. Moreover, the cellulose ester obtained from them can be mixed and used at an arbitrary ratio. When the acylating agent is an acid anhydride (acetic anhydride, propionic anhydride, or anhydrous butyric acid), these cellulose esters use an organic solvent such as acetic acid, such as acetic acid methylene chloride, and sulfuric acid. It can be obtained by reacting with cellulose raw material using such a protic catalyst

[0050] When the acylating agent is an acid chloride (CH C 0 C1, C H C 0 C1, C H C 0 C1),

 3 2 5 3 7

The reaction is carried out using a basic compound such as amine as a medium. Specifically, it can be synthesized with reference to the method described in JP-A-10-45804. In addition, the cellulose ester used in the present invention is obtained by mixing and reacting the above amount of the acylating agent in accordance with the degree of substitution. In the cellulose ester, these acylating agents react with hydroxyl groups of cellulose molecules. Cellulose molecules are composed of many glucose units connected, and the glucose unit has three hydroxyl groups. These three hydroxyl groups have an acyl group Is the number of substitutions (mol%). For example, cellulose triacetate has a acetyl group bonded to all three hydroxyl groups of a dulose unit (actually 2.6 · 3.0).

 [0051] The cellulose ester used in the present invention includes, as described above, a propionate group or a butyrate in addition to a acetyl group such as cellulose acetate propionate, cenorelose acetate butyrate, or cenorelose acetate propionate butyrate. A mixed fatty acid ester of cellulose to which a group is bonded is particularly preferably used. Cellulose acetate propionate containing a propionate group as a substituent is excellent in water resistance and is useful as a film for liquid crystal image display devices.

 [0052] The method for measuring the degree of substitution of the acyl group can be measured according to ASTM-D817-96.

[0053] The number average molecular weight of the cellulose ester is preferably 40,000 to 200,000, and has a high mechanical strength when it is molded, and an appropriate dope viscosity in the case of a solution casting method. 150000. The mass average molecular weight (Mw) / number average molecular weight (Mn) is preferably in the range of 1.4 to 4.5.

 [0054] Here, since the average molecular weight of the cellulose ester can be measured using gel permeation chromatography, the number average molecular weight (Mn) and the mass average molecular weight (Mw) can be calculated using this. Can do.

[0055] The mass average molecular weight (Mw) and number average molecular weight (Mn) of the cellulose ester were measured by gel permeation chromatography using the apparatus and materials shown below. The measurement conditions for the average molecular weight are as follows.

 Solvent (eluent): dichloromethane

 Column name: Showa Denko GPCk806-GPCk805-GPCk803 (3 pieces)

 Sample concentration: 0.1 (mass%)

 Flow rate: 1 · 0 (ml / min)

 Sample injection volume: 100 (1)

Standard sample: Polystyrene (Mw: 5 million to 6.7 million) Temperature: 25 ° C

 Detection: RI (Suggested Refractometer)

 These cellulose esters apply a cellulose ester solution (dope) generally called a solution casting film forming method onto, for example, an endless metal belt for infinite transport or a support for casting of a rotating metal drum. Preferably, the dope is cast from a pressure die and cast to form a film.

 [0057] As the organic solvent used for the preparation of these dopes, it is preferable that the cellulose ester can be dissolved and has an appropriate boiling point. For example, methylene chloride, methyl acetate, ethyl acetate, amyl acetate, acetoacetic acid. Methyl, acetone, tetrahydrofuran, 1,3-dioxolan, 1,4 dioxane, cyclohexanone, ethyl formate, 2, 2,2 trifluoroethanol, 2, 2, 3, 3 tetrafluoro-1 propanol, 1, 3 Difluoro-2-propanol, 1,1,1,1,3,3,3-Hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-Hexafnoroleo 2-prononorole, 2, 2, 3, 3, 3-Pentafluoro 1 Power to cite propanol, nitroethane, 1, 3 dimethyl 2 imidazolidinone, etc. Power to be able to S Organic halogen such as methylene chloride Compounds, Jiokisoran induction body, methyl acetate, Echiru, acetone, Aseto such as methyl acetate are preferred organic solvents (immediate Chi, good solvent), and as.

 [0058] Further, as shown in the following film forming process, when the solvent is dried from the web (dope film) formed on the casting support in the solvent evaporation process, the concept of preventing foaming in the web is prevented. From the point of view, the boiling point of the organic solvent used is preferably 30 to 80 ° C. For example, the boiling point of the above-mentioned good solvent is methylene chloride (boiling point 40.4 ° C), methyl acetate (boiling point 56. 32 ° C), acetone (boiling point 56.3 ° C), ethyl acetate (boiling point 76 · 82 ° C), and the like.

 [0059] Among the good solvents described above, methylene chloride or methyl acetate having excellent solubility is preferably used.

[0060] In addition to the organic solvent, it is preferable to contain 0.1% by mass to 40% by mass of an alcohol having 1 to 4 carbon atoms. It is particularly preferable that the alcohol is contained at 5 to 30% by mass. After casting the above-mentioned dope on a casting support, the web (dope film) gels when the solvent starts to evaporate and the proportion of alcohol increases. It is used as a gelling solvent that makes it easy to peel off from the casting support, and when these ratios are small, it has the role of promoting the dissolution of cellulose esters of non-chlorine organic solvents. .

 [0061] Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol and the like.

 [0062] Of these solvents, ethanol is preferred because the dope has a good boiling point, a relatively low boiling point, and a good drying property. It is preferable to use a solvent containing 5% by mass to 30% by mass of ethanol with respect to 70% by mass to 95% by mass of methylene chloride. Methyl acetate can be used in place of methylene chloride. At this time, the dope may be prepared by a cooling dissolution method.

 [0063] As the plasticizer used in the present invention, phosphate ester plasticizers and non-phosphate ester plasticizers are preferably used.

 [0064] Examples of the phosphoric acid ester plasticizer include triphenyl phosphate, tricresyl phosphate, credinole resin phenolino phosphate, otachinino resin phenolino phosphate, diphenolino biphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like. Is mentioned.

 [0065] Non-phosphate ester plasticizers include phthalate ester plasticizers, trimellitic acid ester plasticizers, pyromellitic acid plasticizers, polyhydric alcohol plasticizers, glycolate plasticizers, Ability to preferably use a citrate ester plasticizer, a fatty acid ester plasticizer, a polyester plasticizer, a polycarboxylic acid ester plasticizer, etc. In particular, in order to obtain the effect of the present invention, a polyhydric alcohol is preferable. It is preferable to use a plasticizer, a polyester plasticizer, and a polycarboxylic acid plasticizer.

 [0066] The polyhydric alcohol ester is composed of an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule.

 [0067] The polyhydric alcohol used in the present invention is represented by the following general formula (1).

 [0068] General formula (1) R — (OH) n

 (However, R represents an n-valent organic group, and n represents a positive integer of 2 or more.)

Preferable! / Examples of polyhydric alcohols include the following: The present invention is not limited to these. Aditol, arabitol, ethylen glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2 butanediol 1,3 butanediol, 1,4 butanediol, dibutylene glycol, 1,2,4 butanetriol, 1,5 pentanediol, 1,6-hexanediol, hexanetriol, galactitanol, mannitol, 3-methylpentane 1, 3,5-trio-monore, pinaconole, sonorebitolone, trimethylolpronone, trimethylololethane, xylitolonere, pentaerythritol, dipentaerythritol, etc. Of these, trimethylolpropane and pentaerythritol are preferred.

 [0069] As the monocarboxylic acid used in the polyhydric alcohol ester of the present invention, known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid and the like without particular limitation can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferable in terms of improving moisture permeability and retention. Examples of preferred monocarboxylic acids include the following force S, and the present invention is not limited thereto.

 [0070] As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. It is particularly preferable that the number of carbons is more preferably 1 to 20; When acetic acid is used, compatibility with the cellulose ester is increased, so that it is also preferable to use a mixture of acetic acid and other monocarboxylic acid.

[0071] Preferable aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, strength prillic acid, pelargonic acid, strength purine acid, 2-ethyl-hexane strength rubonic acid, undecyl Acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, araquinic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, ratacel Examples thereof include saturated fatty acids such as acids, and unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid. Preferred examples of the alicyclic monocarboxylic acid include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane strength rubonic acid, and derivatives thereof. Preferred aromatic monocarboxylic Examples of acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and aromatic monocarboxylic acids having two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. The ability to list carboxylic acids or their derivatives. In particular, benzoic acid is preferred.

[0072] The molecular weight of the polyhydric alcohol ester is preferably in the range of 300 to 1500, more preferably in the range of 350 to 750. Since the one where molecular weight is larger becomes difficult to volatilize, the smaller one is preferable from the viewpoint of preferable moisture permeability and compatibility with cellulose ester. The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. In addition, all OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are. The specific compounds of polyhydric alcohol esters are shown below.

 [0073] The content of the polyhydric alcohol ester according to the present invention is preferably contained in the cellulose ester film; from! To 15% by mass, particularly preferably from 3 to 10% by mass.

Yes

[0074] [Chemical 1]

C ₄ H ₃ -C-0- (CH ₂ ) ₂ -0- (CH

II ₂ ) ₂ -0- (CH ₂ ) ₂ -0-C- 'C ₄ H ₉

C ₄ H ₉ -O CH ₂ CH "C4H9

cocll,

 o One-

H

 27

(Polyester plasticizer)

The polyester plasticizer is not particularly limited, but a polyester plasticizer having an aromatic ring or a cycloalkyl ring in the molecule can be preferably used. A preferable polyester plasticizer is not particularly limited, but, for example, an aromatic terminal ester plasticizer represented by the following general formula (2) is preferable. [0079] General formula (2) B- (GA) nGB

 (Wherein B is a benzene monocarboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms or 6 to carbon atoms; 12 aryl glycol residues or carbon number powers; and 12 oxyalkylene glycol residues) Group, A represents an alkylenedicarboxylic acid residue having 4 to 12 carbon atoms, or an aryldicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.) In the general formula (2) Benzene monocarboxylic acid residue represented by B and alkylene glycol residue or oxyalkylene glycol residue or arylene glycol residue represented by G, alkylene dicarboxylic acid residue or arylene dicarboxylic acid residue represented by A And can be obtained by the same reaction as a normal polyester plasticizer.

 [0080] The benzene monocarboxylic acid component of the polyester plasticizer used in the present invention includes, for example, benzoic acid, paratertiarybutylbenzoic acid, orthotoluic acid, metatolulic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid. Normalpropyl benzoic acid, amino benzoic acid, acetooxy benzoic acid and the like, and these can be used as one kind or a mixture of two or more kinds, respectively.

 [0081] The alkylene glycol component having 2 to 12 carbon atoms of the polyester plasticizer used in the present invention includes ethylene glycol, 1,2 propylene glycol, 1,3 propylene glycolone, 1,2 butanediol, 1,3 Butanediol, 1,2 propanediol, 2-Methylanol 1,3-propanediol, 1,4 Butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl) Glycol), 2, 2— jetyl 1,3 propanediol (3,3 dimethylolpentane), 2-n butyl-2-ethynole 1,3 propanediol (3,3 dimethylolheptane), 3 methyl-1,5-pentanediol 1, 6-hexanediol, 2, 2, 4-trimethyl 1, 3-pentanediol, 2 ethinole 1, 3, hexanediol, 2 methino 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc. These glycols are used as one or a mixture of two or more. In particular, alkylene glycols having 2 to 12 carbon atoms are particularly preferred because of excellent compatibility with cellulose esters.

[0082] The aromatic terminal ester used in the present invention has 4 to 12 carbon atoms; Examples of the glycol component include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol and the like, and these glycols can be used as one kind or a mixture of two or more kinds.

 [0083] Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the aromatic terminal ester used in the present invention include succinic acid, maleic acid, fumaric acid, dartaric acid, adipic acid, azelaic acid, and sebacic acid. , Dodecanedicarboxylic acid and the like, and these are used as a mixture of one or two or more. Examples of the arylenedicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5 naphthalenedicarboxylic acid, and 1,4 naphthalenedicarboxylic acid.

 [0084] The polyester plasticizer used in the present invention preferably has a number average molecular weight of 300 to 1500, more preferably (from 400 to; 1000), and its acid value (0 5 mg KOH / g or less, a hydroxyl value of 25 mg KOH / g or less, more preferably an acid value of 0.3 mg KOH / g or less and a hydroxyl value of 15 mg KOH / g or less are suitable.

 [0085] Synthesis examples of aromatic terminal ester plasticizers preferable for the present invention are shown below.

 [0086] <Sample No. 1 (Aromatic terminal ester sample)>

 Charge 410 parts of phthalic acid, 610 parts of benzoic acid, 737 parts of dipropylene glycol, and 0.40 part of tetraisopropyl titanate as a catalyst in a reaction vessel. While the monohydric alcohol was refluxed, heating was continued at 130 to 250 ° C. until the acid value became 2 or less, and water produced was continuously removed. Subsequently, the distillate was removed at 200 to 230 ° C. under a reduced pressure of 100 to finally 4 × 102 Pa or less, and then filtered to obtain an aromatic terminal ester plasticizer having the following properties.

 [0087] Viscosity (25 ° C, mPa-s); 43400

 Acid value; 0.2

 <Sample No. 2 (Aromatic terminal ester sample)>

 Aromatic ends having the following properties exactly as in Sample No. 1 except that 410 parts of phthalic acid, 610 parts of benzoic acid, 341 parts of ethylene glycol and 0.335 part of tetraisopropyl titanate as the catalyst were used in the reaction vessel. An ester was obtained.

[0088] Viscosity (25. C, mPa's); 31000 Acid value; 0.1

 <Sample No. 3 (Aromatic terminal ester sample)>

 The following properties were obtained in exactly the same manner as Sample No. 1, except that 410 parts of phthalic acid, 610 parts of benzoic acid, 418 parts of 1,2-propanediol, and 0.335 part of tetraisopropyl titanate as a catalyst were used in the reaction vessel. An aromatic terminal ester having was obtained.

[0089] Viscosity (25 ° C, mPa-s); 38000

 Acid value; 0.05

 <Sample No.4 (Aromatic terminal ester sample)>

 Exactly the same as sample No. 1 except that 410 parts of phthalic acid, 610 parts of benzoic acid, 418 parts of 1,3-propanediol, and 0.335 part of tetraisopropyl titanate as the catalyst were used in the reaction vessel. An aromatic terminal ester having was obtained.

[0090] Viscosity (25 ° C, mPa-s); 37000

 Acid value; 0.05

 In the following, the ability to show specific compounds of the aromatic terminal ester plasticizer used in the present invention is not limited to this.

[0091] [Chemical 5]

Blasphemy

[0093] The polyvalent carboxylic acid plasticizer useful in the present invention comprises an ester of a divalent or higher, preferably divalent to 20valent polyvalent carboxylic acid and an alcohol. In addition, it is preferable that the aliphatic polyvalent carboxylic acid is 20 to 20 valent aromatic polycarboxylic acid, and the alicyclic polyvalent carboxylic acid is preferably 3 to 20 valent! /.

 [0094] The polyvalent carboxylic acid used in the present invention is represented by the following general formula (3).

 [0095] Formula (3) R (COOH) m (OH) n

 Five

(Where R is an (m + n) -valent organic group, m is a positive integer greater than or equal to 2, n is an integer greater than or equal to 0, CO OH group represents a carboxyl group, and OH group represents an alcoholic or phenolic hydroxyl group.) Preferred examples of polyvalent carboxylic acids include the following: It is not limited. Trivalent or higher aromatic polyvalent carboxylic acids such as trimellitic acid, trimesic acid, pyromellitic acid or derivatives thereof, succinic acid, adipic acid, azelaic acid, sebacic acid, oxalic acid, fumaric acid, maleic acid, tetrahydro An aliphatic polyvalent carboxylic acid such as phthalic acid, an oxypolyvalent carboxylic acid such as tartaric acid, tartronic acid, malic acid, and citrate can be preferably used. In particular, it is preferable to use oxypolycarboxylic acid from the viewpoint of improving the retention.

 [0096] The alcohol used in the polyvalent carboxylic acid ester compound used in the present invention is not particularly limited, and known alcohols and phenols can be used. For example, an aliphatic saturated alcohol or aliphatic unsaturated alcohol having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. It is more preferable that the number of carbon atoms is 1-20. It is particularly preferable that the number of carbon atoms is 1-10. In addition, alicyclic alcohols such as cyclopentanol and cyclohexanol or derivatives thereof, aromatic alcohols such as benzyl alcohol and cinnamyl alcohol, or derivatives thereof can also be preferably used.

 [0097] When an oxypolycarboxylic acid is used as the polycarboxylic acid, the alcoholic or phenolic hydroxyl group of the oxypolycarboxylic acid may be esterified with a monocarboxylic acid! /. Preferable! / Examples of monocarboxylic acids include the following: The present invention is not limited to this.

 [0098] As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. It is particularly preferable that the number of carbons is more preferably 1 to 20;

[0099] Preferable! / As the aliphatic monocarboxylic acid, acetic acid, propionic acid, butyric acid, valeric acid, strong proacid, enanthate, strong prillic acid, pelargonic acid, strong purine acid, 2-ethylhexanecarborane Acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melisin Saturated fatty acids such as acid, latacetic acid, undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachid Examples thereof include unsaturated fatty acids such as acid.

[0100] Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.

 [0101] Examples of preferable aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, benzene such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. Mention may be made of aromatic monocarboxylic acids having two or more rings or derivatives thereof. Particularly preferred are acetic acid, propionic acid and benzoic acid.

 [0102] The molecular weight of the polyvalent carboxylic acid ester compound is not particularly limited, but the molecular weight is preferably in the range of 300 to 1000, and more preferably in the range of 350 to 750. The larger one is preferable in terms of improving retention, and the smaller one is preferable in terms of compatibility with cellulose ester.

 [0103] The alcohols used in the polyvalent carboxylic acid ester used in the present invention may be one kind or a mixture of two or more kinds.

[0104] The acid value of the polyvalent carboxylic acid ester compound used in the present invention is preferably 1 mgKOH / g or less, more preferably 0.2 mgKOH / g or less.

Examples of particularly preferred polyvalent carboxylic acid ester compounds are as follows: The present invention is not limited thereto. For example, triethyl citrate, tributyl citrate, acetyl tributyl citrate (HATEC), acetil tributyl citrate (HATBC), benzoyl tributino recitrate, acetinole triphenyleno recitrate, acetinore tripenzino resi Examples thereof include trays, dibutyl tartrate, diacetyl dibutyl tartrate, tributyl trimellitic acid, and tetrabutyl pyromellitic acid.

[0106] These plasticizers can be used alone or in combination of two or more. If the amount of the plasticizer used is less than 1% by mass relative to the cellulose derivative, the effect of reducing the moisture permeability of the film is small. If it exceeds 20% by mass, the plasticizer bleeds out from the film and the physical properties of the film to degrade, preferably 1 to 20 mass _^0/0. 6; 16 mass _^0/0 force S More preferably, particularly preferably 8-13 wt%. [0107] For the retardation film of the present invention, an ultraviolet absorber is preferably used.

 [0108] As the ultraviolet absorber, those having excellent absorption ability of ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties.

 [0109] Specific examples of ultraviolet absorbers preferably used in the present invention include, for example, oxybenzozophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds Force S, etc. are not limited to these.

 [0110] As the benzotriazole-based ultraviolet absorber, for example, the power S mentioned below as a specific example of the following ultraviolet absorber, the present invention is not limited thereto.

 [0111] UV—l: 2— (2 ′ —Hydroxy 5 ′ methylphenol) benzotriazole

 UV-2: 2-2'-hydroxy 3 ', 5'-tert butyl phenenole) benzotriazonole

 UV-3: 2- 2 '—Hydroxy 1 3' —tert Butyl 5 '—Methylphenole) Benzotriazolene

 UV-4: 2-2'-hydroxy 3 ', 5'-tert butyl butenoleveneol)

 UV— 5: 2— (2 ′ —Hydroxy 1 3 ′ — “,“, 5 ”, et al — Tetrahydrophthalenoylimidomethyl) 5 ′ — Methylphenenole) benzotriazole

 UV-6: 2, 2 Methylenebis (4- (1, 1, 3, 3 tetramethylbutyl) -6- (2H-benzotriazole-2-ynole) phenol)

 UV—7: 2— (2 ′ —Hydroxy 3 ′ —tert Butyl 5 ′ —Metinolefénole) 5 Black mouth benzotriazole

 UV— 8: 2— (2H benzotriazole—2 yl) —6— (straight and side chain dodecyl) — 4-methylphenol (TINUVIN171, Ciba)

UV—9: Octyl-3 -— [3-tert-butyl 4-hydroxy-5- (black mouth 2H benzotriazole- 2-yl) phenyl] propionate and 2-ethylhexyl 3 -— [3-—tert-butyl 4-hydroxy 1-5— (5 black 2H benzotriazole 2 Nole) phenyl] propionate mixture (TINUVIN109, Ciba)

 Further, the following specific examples of the benzophenone-based ultraviolet absorber are shown, but the present invention is not limited thereto.

 [0112] UV-10: 2, 4-Dihydroxybenzophenone

 UV-11: 2, 2'-dihydroxy-4-methoxybenzophenone

 UV—12: 2 Hydroxy 4-methoxy 4-sulfobenzophenone

 UV-13: Bis (2 methoxy-1,4 hydroxy-1,5 benzoyl methane) As an ultraviolet absorber preferably used in the present invention, Benzo excellent in the effect of preventing the deterioration of polarizing plate and liquid crystal having high transparency. Triazole-based UV absorbers and benzophenone-based UV absorbers are preferred because of less unwanted coloring! /, And benzotriazole-based UV absorbers are particularly preferably used.

 [0113] Further, the ultraviolet absorber having a distribution coefficient of 9.2 or more described in JP-A-2001-187825 improves the surface quality of a long film and is excellent in coating properties. It is particularly preferable to use an ultraviolet absorber having a distribution coefficient of 10.1 or more.

 [0114] Further, the polymer ultraviolet ray described in the general formula (1) or general formula (2) described in JP-A-6-148430, or the general formulas (3), (6), or (7) described in JP-A-2002-47357 Absorbers and UV-absorbing polymers) or UV-absorbing copolymer polymers described in JP-A-2002-169020, paragraphs [0027 to [0055] are also preferably used. PUV A-30M (manufactured by Otsuka Chemical Co., Ltd.) is commercially available as a polymer UV absorber!

 [0115] An antioxidant may be used in the retardation film of the present invention. When a liquid crystal image display device or the like is placed in a high humidity and high temperature state, the polarizing plate protective film may be deteriorated. The antioxidant has a role of delaying or preventing the polarizing plate protective film from being decomposed by, for example, phosphoric acid of a halogenated phosphoric acid plasticizer of the residual solvent amount in the polarizing plate protective film. It is preferable to be contained in the polarizing plate protective film.

[0116] As such an antioxidant, a hindered phenol-based compound is preferably used. For example, 2,6-di-tert-butyl-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t] -Butyl-4-hydroxyphenyl) propionate], triethylene Glycol bis [3- (3-tert-butyl 5-methyl 4-hydroxyphenol) propionate], 1,6-hexanediol bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4 Bis (n-octylthio) -6- (4-hydroxy-3,5 di-tert-butylanilino) -1,3,5 triazine, 2,2 thiodiethylene bis [3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionate], Octadecinole 1- (3,5-Di-tert-Butyl 4-hydroxyphenyl) propionate, N, N'-Hexamethylenebis (3,5-di-tert-butyl- 4-hydroxy-hydrocinnamamide), 1, 3, 5 trimethylolene 2, 4, 6 tris (3,5 di-tert-butyl 4-hydroxybenzyl) benzene, tris-su (3,5-di-tert-butyl-4-hydroxybenzyl) Iso Leave by force S include Anurei Bok and the like.

 [0117] In particular, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3-

 (3,5-di-tert-butyl-4-hydroxyphenol) propionate] and triethyleneglycol rubis [3- (3-tert-butyl 5-methyl 4-hydroxyphenyl) propionate] are preferred. Also, for example, hydrazine-based metal deactivators such as N, N'-bis [3- (3,5-di-tert-butynole 4-hydroxyphenyl) propionyl] hydrazine, tris (2,4-di-tert Phosphorus processing stabilizers such as butylphenyl) phosphite may be used in combination.

 [0118] The amount of these compounds added is preferably from 1 ppm by mass to 1.0%, more preferably from 10%;

 [0119] In addition, it is preferable to use fine particles for imparting slipperiness to the retardation film according to the present invention.

 [0120] The primary average particle diameter of the fine particles added to the retardation film according to the present invention is preferably 20ηm or less, more preferably 5 to 16nm, and particularly preferably 5 to 12nm. . These fine particles preferably form secondary particles having a particle size of 0.1 to 5 m and are preferably contained in the retardation film. The preferable average particle size is 0.1 to 2 111, more preferably 0. 2—0. 6〃m. As a result, irregularities having a height of approximately 0 ········ O ^ m are formed on the surface of the finolem, thereby providing appropriate slipperiness to the film surface.

 [0121] The primary average particle diameter of the fine particles used in the present invention is measured by a transmission electron microscope (magnification

(500,000 to 2,000,000 times), observe the particles, observe 100 particles, and measure the particle size. Was the primary average particle size.

[0122] The apparent specific gravity of the fine particles is preferably 70 g / liter or more, more preferably 90 to 200 g / liter, and particularly preferably 100 to 200 g / liter. A higher apparent specific gravity makes it possible to produce a high-concentration dispersion, which improves the haze and agglomerates, and is preferred when preparing a dope having a high solid content concentration as in the present invention. Is particularly preferably used.

 [0123] Silicon dioxide fine particles having an average primary particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more are, for example, 1000-; 1200 ° C obtained by mixing vaporized silicon tetrachloride and hydrogen Can be obtained by burning in air. In addition, for example, Aerosil 200V, Aerosil R972V (above, Nippon Aerosil Co., Ltd.) are commercially available, and they can be used.

 [0124] The apparent specific gravity described above is calculated by the following equation by measuring a weight of a predetermined amount of silicon dioxide fine particles in a graduated cylinder and measuring the weight.

 [0125] Apparent specific gravity (g / liter) = mass of silicon dioxide (g) / volume of silicon dioxide (liter) There are three methods for preparing the dispersion of fine particles used in the present invention, for example, as shown below. Is mentioned.

 << Preparation Method A >>

 After stirring and mixing the solvent and the fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. The fine particle dispersion is added to the dope solution and stirred.

 << Preparation Method B >>

 After stirring and mixing the solvent and the fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. Separately, a small amount of cellulose triacetate is added to the solvent and dissolved by stirring. The fine particle dispersion is added to this and stirred. This is a fine particle addition solution. Thoroughly mix the additive solution with the dope solution using an in-line mixer.

 << Preparation Method C >>

Add a small amount of cellulose triacetate to the solvent and dissolve with stirring. Fine particles are added to this and dispersed with a disperser. This is a fine particle addition solution. Thoroughly mix the additive solution with the dope solution using an in-line mixer. [0126] Preparation method A is excellent in dispersibility of the silicon dioxide fine particles, and preparation method C is excellent in that the silicon dioxide fine particles are difficult to re-aggregate. Among them, the preparation method B described above is a preferable preparation method that is excellent in both dispersibility of the silicon dioxide fine particles and difficulty in reaggregation of the silicon dioxide fine particles.

 《Distribution method》

 The concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent or the like is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and most preferably 15 to 20% by mass. . A higher dispersion concentration is preferred because the turbidity with respect to the added amount tends to be low, and haze and aggregates are improved.

[0127] Solvents to be used are preferably lower alcohols such as methyl alcohol, ethyl alcoholone, propino alcoholo, isopropino alcoholo, butyno alcoholo and the like. The solvent other than the lower alcohol is not particularly limited, but it is preferable to use a solvent used for forming a cellulose ester film.

[0128] The addition amount of silicon dioxide fine particles to cellulose ester is preferably 0.01 parts by mass to 5.0 parts by mass with respect to 100 parts by mass of cellulose ester, and 0.05 parts by mass to 1. parts by mass. 0 parts by mass is more preferable 0.1 parts by mass to 0.5 parts by mass is most preferable. The larger the added amount, the better the coefficient of dynamic friction and the smaller the added amount.

[0129] As the disperser, a normal disperser can be used. Dispersers can be broadly divided into media dispersers and medialess dispersers. For dispersion of silicon dioxide fine particles, a medialess disperser is preferred because of low haze. Examples of media dispersers include ball mills, sand mills, and dyno mills. Examples of the medialess disperser include an ultrasonic type, a centrifugal type, and a high pressure type. In the present invention, a high pressure disperser is preferable. A high-pressure dispersion device is a device that creates special conditions such as high shear and high pressure by passing a composition in which fine particles and a solvent are mixed at high speed through a narrow tube.

[0130] When processing with a high-pressure dispersion apparatus, for example, the maximum pressure condition inside the apparatus is preferably 9.807 MPa or more in a thin tube having a tube diameter of 1 to 2000 m. More preferably, it is 19.613 MPa or more. At that time, the maximum speed reached 100m / sec or more, heat transfer It is preferable that the speed reaches 420 kj / hour or more.

 [0131] Examples of the high-pressure dispersion apparatus as described above include an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation or a nanomizer manufactured by Nanomizer. Izumi Food Machinery Homogenizer, Sanwa Machinery Co., Ltd. UHN-01, etc.

 [0132] In addition, casting a dope containing fine particles so as to be in direct contact with the casting support is preferable because the film has a high sliding property and low haze.

 [0133] Further, after being cast and peeled off and dried and wound into a roll, a functional thin film such as a hard coat layer or an antireflection layer is provided. Until it is processed or shipped, packaging is usually done to protect the product from dirt and electrostatic dust. The packaging material is not particularly limited as long as the above purpose can be achieved, but a material that does not hinder volatilization of the residual solvent from the film is preferable. Specific examples include polyethylene, polyester, polypropylene, nylon, polystyrene, paper, and various non-woven fabrics. A fiber having a mesh cloth shape is more preferably used.

 [0134] The retardation film of the present invention preferably contains a retardation control agent to adjust the retardation.

 (Bar compound)

 The retardation film of the present invention preferably contains a rod-like compound having a maximum absorption wavelength (λ max) in the ultraviolet absorption spectrum of the solution shorter than 250 nm as a retardation control agent.

 [0135] From the viewpoint of the function of the retardation control agent, it is more preferable that the rod-like compound has at least two aromatic rings, which preferably have at least one aromatic ring. The rod-like compound preferably has a linear molecular structure. The linear molecular structure means that the molecular structure of the rod-shaped compound is linear in the most thermodynamically stable structure. The thermodynamically most stable structure can be obtained by crystal structure analysis or molecular orbital calculation.

[0136] For example, molecular orbital calculation is performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited) to obtain the molecular structure that minimizes the heat of compound formation. The power to seek is S. The linear molecular structure means that the angle of the molecular structure is 140 degrees or more in the thermodynamically most stable structure obtained by calculation as described above. The rod-shaped compound preferably exhibits liquid crystallinity. It is further preferred that the rod-like compound exhibits liquid crystallinity upon heating (has thermopick liquid crystallinity). The liquid crystal phase is preferably a nematic phase or a smectic phase.

 [0137] The rod-like compound is preferably a trans 1,4-cyclohexanedicarboxylic acid ester compound represented by the following general formula (4)!

 [0138] General formula (4) Arl -Ll -Ar2

 In the general formula (4), Arl and Ar2 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 aromatic ring of an 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 the hetero atom, a nitrogen atom, a sulfur atom or a nitrogen atom or a sulfur atom is more preferable. Examples of aromatic heterocycles include furan, thiophene, pyrrole, oxazole, isoxazole, thiazole, isothiazole, imidazole, pyrazole, furazane, triazole, pyran, and pyridine. Rings, pyridazine rings, pyrimidine rings, pyrazine rings, and 1,3,5-triazine rings are included. As the aromatic ring of the aromatic group, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring and pyrazine ring are preferred. Particularly preferred.

[0139] 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 (e.g., Methylamino, ethylamino, butylamino, dimethylamino), nitro, sulfo, rubamoyl, alkyl rubamoyl groups (eg, N methylcarbamoyl, N ethylcarbamoyl, N, N dimethylcarbamoyl), sulfamoyl, alkylsulfamoyl groups (eg, N— Ureido, alkylureido groups (eg, N-methylureido, N, N-dimethylureido, N, N, N'-trimethylureido), alkyl groups (eg, methyl, ethyl, propyl, butyl, pentyl, heptyl, octyl) , Isopropyl, s-butyl, t-amyl, cyclohexyl, cyclopentyl), alkenyl group (eg, buyl, allyl, hexenyl), alkynyl group (eg, ethul, butyur), isyl group (eg, honoreminole, acetyl, butyryl) , Hexanoyl, lauryl), acyloxy group (eg, acetoxy, butyryloxy, hexanoyloxy, lauryloxy), alkoxy group (eg, methoxy, ethoxy, propoxy, butoxy, pentinoreoxy, heptyloxy, octyloxy), allyloxy group (eg, phenoxy) ), Al Koki Sicarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, heptyloxycarbonyl), aryloxycarbonyl group (eg, phenoxycarbonyl), alkoxycarbonylamino group ( Eg, butoxycarbonylamino-substituted hexyloxycarbonylamino), alkylthio group (eg, methylthio, ethylthio, propylthio, butylthio, pentylthio, heptylthio, octylthio), arylthio group (eg, phenylthio), alkylsulfonyl group (Eg, methinolesnorehoninore, ethinoresnorehoninore, propinolesnorehoninore, butinolesnorehoninore, pentylsulfonyl, heptylsulfonyl, octylsulfonyl), amide groups (eg, acetate Bromide, butyramide group to, Kishiruamido, lauryl amide) and a non-aromatic Hajime Tamaki (e.g., morpholyl, Pirajuru) include.

Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom, cyano, carboxyl, hydroxynore, amino, alkyl-substituted amino group, asinole group, acyloxy group, amido group, and alkoxycarbonyl group. , An alkoxy group, an alkylthio group and an alkyl group are preferable. The alkyl part and the alkyl group of the alkylamino group, alkoxycarbonyl group, alkoxy group and alkylthio group further have a substituent! /, May /! Examples of the alkyl moiety and the substituent of the alkyl group include a halogen atom, hydroxyl, carboxyl, cyan, amino, anolequinolamino group, nitro, sulfo, rubamoyl, alkynole rubamoyl group, sulfamoyl, alkylsulfamoyl. Group, ureido, alkylureido group, alkenyl group, alkynyl group, acyl group, acyloxy group, alkoxy group, Examples include a ryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylamino group, an alkylthio group, an aryloxy group, an alkylsulfonyl group, an amide group, and a non-aromatic heterocyclic group. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, hydroxynore, amino, anolenoquinoamino group, asinole group, acyloxy group, acylamino group, alkoxycarbonyl group and alkoxy group are preferable.

 [0141] —In the general formula (4), L1 is a divalent linking group selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, a divalent saturated heterocyclic group, O 2 CO 3, and combinations thereof. It is. The alkylene group may have a cyclic structure. As the cyclic alkylene group, 1,4-cyclohexylene is particularly preferred, and cyclohexylene is preferred. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group. The number of carbon atoms in the alkylene group is 120, preferably S, more preferably 1 15, more preferably 1 to 10, and even more preferably! To 8. Most preferably, it is! ~ 6.

 [0142] The alkenylene group and the alkynylene group preferably have a linear structure rather than a branched chain structure, which preferably has a chain structure rather than a cyclic structure. The number of carbon atoms of the alkenylene group and the alkynylene group is 2 to; 10 is preferably 2 8, more preferably S 2, and 2 6 is more preferably 2 4 Most preferred is 2 (vinylene or ethynylene). The divalent saturated heterocyclic group preferably has a 3- to 9-membered heterocycle. The heterocyclic hetero atom is preferably an oxygen atom, a nitrogen atom, a boron atom, a sulfur atom, a silicon atom, a phosphorus atom or a germanium atom. Examples of saturated heterocycles include piperidine rings, piperazine rings, morpholine rings, pyrrolidine rings, imidazolidine rings, tetrahydrofuran rings, tetrahydropyran rings, 1,3 dioxane rings, 1,4 dioxane rings, tetrahydro rings. Thiophene ring, 1,3-thiazolidine ring, 1,3-oxazolidin ring, 1,3-dioxolane ring, 1,3-dithiolane ring and 1,3,2-dioxaborolane are included. Particularly preferred divalent saturated heterocyclic groups are piperazin 1,4-diylene, 1,3 di-aged xylene 2,5 diylene and 1,3,2 di-xiaborane 2,5-diylene.

[0143] Examples of a divalent linking group comprising a combination are shown. L- 1: O—CO—Alkylene group—CO o—

 L- 2: CO — o—alkylene group O— CO—

 L- 3: o— CO—Alke: Diylene group CO o—

 L- 4: CO — o—Alke: Diylene group O— CO—

 L-5: o—CO—alkynylene group CO o—

 L- 6: CO — o—alkynylene group O— CO—

 L-7: o—CO—Divalent saturated heterocyclic group CO o

 L- 8: CO — o—Divalent saturated heterocyclic group O— CO

 In the molecular structure of the general formula (4), the angle formed by Arl and Ar2 across L1 is preferably 140 ° or more. The rod-like compound is more preferably a compound represented by the following general formula (5).

 [0145] General formula (5) Arl -L2-X-L3-Ar2

 In the general formula (5), Arl and Ar2 are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Arl and Ar2 in the general formula (4).

 [0146] In the general formula (5), L2 and L3 are each independently a divalent linking group selected from the group consisting of an alkylene group, O 2 CO 3 and a combination thereof. More preferably, the alkylene group has a linear structure rather than a chain structure having a branch, which preferably has a chain structure rather than a cyclic structure. The number of carbon atoms of the alkylene group is preferably 1 10, more preferably 18, still more preferably 16; and even more preferably 4 1 or 2 (methylene Or ethylene). L2 and L3 are particularly preferably —O—CO— or CO—O.

 [0147] In the general formula (5), X represents 1,4-cyclohexylene, vinylene or ethynylene.

[0148] The retardation film of the present invention is produced by a step of preparing a dope by dissolving an additive such as cellulose ester and the plasticizer in a solvent, and flowing the dope onto a belt-shaped or drum-shaped metal support. A step of stretching, a step of drying a cast dope as a web, a step of peeling from a metal support, a step of stretching, a step of further drying, and a film obtained Further, a heat treatment step and a winding step after cooling are performed. Der ones retardation Fi Lum which is preferably in the solids have 70 to 95 mass _^0/0 containing a cellulose ester of the present invention

[0149] The step of preparing the dope will be described. The concentration of cellulose ester in the dope is preferable because the concentration is high and the drying load after casting on the metal support can be reduced! /, But if the concentration of cellulose ester is too high, The load increases and the filtration accuracy deteriorates. The concentration that achieves both of these is preferably 10 to 35% by mass, more preferably 15 to 25% by mass.

 [0150] The solvent used in the dope of the present invention may be used alone or in combination of two or more. However, it is possible to use a mixture of a good solvent and a poor solvent of cellulose ester in terms of production efficiency. The more good solvent is preferable in terms of the solubility of the cellulose ester. 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. A good solvent or a poor solvent is defined as a solvent that dissolves the cellulose ester used alone, a good solvent, the ability to swell alone, or a substance that does not dissolve! Therefore, depending on the degree of acyl substitution of the cellulose ester, the good solvent and poor solvent change. For example, when acetone is used as the solvent, the ester of cellulose ester (acetyl group substitution degree 2.4) and cellulose acetate propionate It becomes a good solvent, and it is a poor solvent for cellulose acetate ester (degree of substitution of acetyl group 2.8).

 [0151] The good solvent used in the present invention is not particularly limited, and examples thereof include organic halogen compounds such as methylene chloride, dioxolanes, acetone, methyl acetate, and methyl acetate acetate. Particularly preferred is methylene chloride or methyl acetate.

 [0152] The poor solvent used in the present invention is not particularly limited. For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, and the like are preferably used. Further, the dope preferably contains water in an amount of 0.0;! To 2% by mass.

[0153] As a method for dissolving the cellulose ester when preparing the dope described above, a general method can be used. When heating and pressurization are combined, it can be heated above the boiling point at normal pressure. If the solvent exceeds the boiling point at normal pressure and does not boil under pressure, stirring and dissolving while heating at a temperature in the range will generate a massive undissolved material called gel or mamaco It is preferable to prevent this. In addition, a method in which a cellulose ester is mixed with a poor solvent and moistened or swollen, and then a good solvent is added and dissolved is also preferably used.

[0154] The pressure is more preferably Pa or lower. 1. More preferably, the pressure is OMPa or lower.

Yes

 [0155] Here, the dope casting will be described.

 [0156] The metal support in the casting process is preferably a mirror-finished surface. As the metal support, a stainless steel belt or a drum whose surface is finished with a porcelain is preferably used. The cast width can be l ~ 4m. The surface temperature of the metal support in the casting process is set between 50 ° C and below the temperature at which the solvent boils and does not foam.

 [0157] A higher temperature is preferable because the drying speed of the web can be increased. However, if the temperature is too high, the web may foam or the flatness may deteriorate. A 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 hot air or cold air, and a method of bringing hot water into contact with the back side of the metal support. It is preferable to use hot water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using hot air, considering the decrease in web temperature due to the latent heat of vaporization of the solvent, there are cases in which hot air above the boiling point of the solvent is used and wind at a temperature higher than the target temperature is used while preventing foaming. is there. In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air between casting and peeling!

 [0158] In order for the cellulose ester film to exhibit good flatness, the amount of residual solvent when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass. Or it is 60-130 mass%, Most preferably, it is 20-30 mass% or 70-; 120 mass%. In addition, 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.

[0160] Residual solvent amount (mass%) = {(MN) / N} X 100 M is the mass of the sample collected at any time during or after the production of the web or film, and N is the mass after heating M at 115 ° C for 1 hour.

[0161] Further, in the drying step of the cellulose ester film, the web is peeled off from the metal support, further dried, and dried until the residual solvent amount is 0.5 mass% or less.

[0162] In the film drying process, a roll drying method (a method in which a plurality of rolls arranged above and below are alternately dried by passing through a web) or a tenter method is used for drying while transporting the web.

 [0163] When peeling from the metal support, the web is stretched in the longitudinal direction due to the peeling tension and the subsequent conveying tension. In the present invention, when peeling the web from the casting support, It is preferable to carry out with the conveying tension as low as possible. Specifically, for example, 50 to 170 N / m or less is effective. At that time, it is preferable to apply cold air of 20 ° C. or less to fix the web rapidly.

 [0164] An example of a stretching process (also referred to as a tenter process) for producing a retardation film made of a cellulose ester film according to the present invention will be described with reference to Figs.

 [0165] In Figs. 1 and 2, A, B, and C indicate each step of the stretching step, and an arrow S indicates the traveling direction of the film. Process A is a process of gripping the web conveyed from the web conveying process DO (not shown). In the next step B, the web is stretched in the width direction (direction perpendicular to the web traveling direction) at a stretching angle Θ shown in FIG. 1, and in step C, the stretching is finished and the web is conveyed while being held.

 [0166] In the method for producing a retardation film of the present invention, in the production process in which means for gripping the film edge and stretching in a direction perpendicular to the transport direction is provided in a part of the film production process. The stretching conditions for stretching are in the range of the following formula (2).

 [0167] Equation (2) 60≤XXY≤450

 In the formula, X is the stretching speed [m / min], and Υ is the stretching ratio [%].

[0168] According to the present invention, in the film stretching step, the orientation of the film can be improved also by controlling the stretching speed, and the cellulose ester resin can be controlled together with the stretching ratio of the film. Suppression of crystallization and micro-phase separation of polymer and additive, while maintaining film transparency A retardation film that can be improved is obtained.

 [0169] Next, it is preferable to provide a slitter for cutting off the end portion in the web width direction after the web is peeled from the casting support and before the start of the step B and / or immediately after the step C. In particular, it is preferable to provide a slitter that cuts off the end of the web immediately before the start of step A. When the same stretching in the width direction is performed, especially when the web edge is cut before the start of process B and the web edge is not cut! The effect of improving the distribution (also called the orientation angle distribution) is obtained.

 [0170] This is considered to be an effect of suppressing unintended stretching in the longitudinal direction from the peeling with a relatively large amount of residual solvent to the width stretching step of Step B.

 [0171] In the stretching step, it is also preferable to intentionally create sections having different temperatures in order to improve the orientation angle distribution. It is also preferred to have a neutral zone between the different temperature zones so that each zone will not interfere! /.

 [0172] Note that the stretching operation may be performed in multiple stages, and biaxial stretching is preferably performed in the casting direction and the width direction. Also, when biaxial stretching is performed, simultaneous biaxial stretching may be performed or may be performed stepwise. In this case, stepwise means that, for example, stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any one of the stages. Is also possible.

 [0173] In order to obtain the effect of the present invention, the web peeled off from the metal support is conveyed while being dried, and is further stretched in the width direction by a tenter method in which both ends of the web are held by pins or clips. By this, a predetermined phase difference can be given. At this time, it may be stretched only in the width direction, or simultaneous biaxial stretching is also preferred. A preferable stretching ratio is 1.05 to 2 times, preferably 1.15 to 1.5 times. In the simultaneous biaxial stretching, the film may be contracted in the longitudinal direction, and may be contracted so as to be 0.8 to 0.99, preferably 0.9 to 0.99. Preferably, the area force is 1.12 times to 1.44 times due to transverse stretching and longitudinal stretching or shrinkage, and preferably 1.15 times to 1.32 times. . This can be determined by the draw ratio in the machine direction X and the draw ratio in the transverse direction.

[0174] The "stretching direction" in the present invention is usually used in the meaning of a direction in which a stretching stress is directly applied when performing a stretching operation, but is biaxially stretched in multiple stages. In some cases, the term is used to mean the one having a finally increased draw ratio (that is, the direction that usually becomes the slow axis).

 [0175] When the web is stretched in the width direction, it is well known that the orientation angle distribution deteriorates in the width direction of the web. A preferred web temperature relative relationship exists in step A B C in order to carry out lateral stretching with a constant ratio of Rt and Ro and a good orientation angle distribution. Step A B C When the web temperature at the end point is Ta ° C Tb ° C Tc ° C, respectively, it is preferable that Ta ≦ Tb−10. Moreover, it is preferable that Tc≤Tb. More preferably, Ta≤Tb-l 0 and Tc≤Tb.

 [0176] The web heating rate in step B is preferably in the range of 0.5 to 10 ° C / sec in order to improve the orientation angle distribution.

 [0177] The stretching time in step B is preferably a short time. However, the minimum required stretch time range is specified from the viewpoint of web uniformity. Specifically, the force is preferably in the range of !! to 10 seconds S, preferably 4 to 10 seconds. In addition, the temperature of step B and step C is effective when the temperature of the film is in the range of 301 ° C. of glass transition point, preferably 100 to 160 ° C.

[0178] In the stretching step, the heat transfer coefficient may be constant or may be changed. The heat transfer coefficient preferably has a heat transfer coefficient in the range of 41.9 9 419 X 103j / m ² hr. More preferably, 41. 9-209. In the range of 5 X 103j / m ² hr, and most preferred range of ^{41. 9-126 X 103j / m 2 hr} .

 [0179] The stretching speed in the width direction in the step B may be constant or may be changed. The stretching speed is preferably 50 500% / min, and more preferably 100 400% / min 200 300% / min! / ヽ.

 [0180] It is preferable to control the stress at the first 10 cm in the above step B within a range of 100 200 N / mm, which is preferable for obtaining the effect of the present invention.

[0181] In the stretching process, the temperature distribution in the width direction of the atmosphere is small. From the viewpoint of improving the uniformity of the web, the temperature distribution in the width direction in the stretching process is preferably within ± 5 ° C. Within ± 2 ° C is more preferred. Within ± 1 ° C is most preferred. By reducing the above temperature distribution, it can be expected that the temperature distribution at the width of the web will also be reduced. [0182] In step C, relaxation in the width direction is preferable. Specifically, the web width is preferably adjusted to be in the range of 95 to 99.5% with respect to the final web width after stretching in the previous step.

 [0183] Further, in the present invention, in order to accurately orient the polymer, a tenter that can independently control the gripping length of the web (distance from the start of gripping to the end of gripping) by the left and right gripping means of the tenter is used. I also liked it!

 [0184] Gripping the left and right ends of the web with a tenter stretching device! For example, as shown in Figure 3.

 [0185] FIG. 3 schematically shows an example of a tenter stretching apparatus (10a) that is preferably used in producing the polymer film used in the present invention.

 [0186] In the figure, the grip start position of the left and right gripping means (clip) (2a) (2b) of the tenter stretching device (10a) is changed left and right, that is, the installation position of the clip closer (3a) (3b) is changed. By changing left and right and changing the grip start position on the left and right, the left and right grip length of the film (F) is changed, which generates a force that twists the resin film (F) in the tenter (10a). In addition, misalignment due to conveyance other than the tenter (10) can be corrected, and even if the conveyance distance from peeling to the tenter is increased, the occurrence of web meandering, slipping and wrinkles can be effectively prevented. Power S can be.

 [0187] The tenter stretching device (10a) shown in the figure is a schematically described force. Normally, one row of a pair of left and right rotational drive devices (ring-shaped chain) (la) (lb) consisting of an endless chain Among the many clips (2a) and (2b) provided in the state, the clip (2a) and (2b) at the straight transition portion of the chain forward path that holds and pulls the left and right ends of the film (F) are the film (F). The tracks of the left and right chains (la) (lb) are installed so as to gradually separate in the width direction of the film, and the film (F) is stretched in the width direction.

[0188] Further, in the present invention, it is preferable to add a device for preventing meandering of a long film in order to correct wrinkles, strains, distortions and the like with higher accuracy, as described in JP-A-6-8663. A meandering correction device such as a diposition controller (sometimes referred to as EPC) or a center position controller (sometimes referred to as CPC) is preferably used. these This device detects the edge of the film with an air servo sensor or optical sensor, controls the transport direction based on the information, and ensures that the end of the film and the center in the width direction are at a certain transport position. As an actuator, specifically, one or two guide rolls or a flat expander roll with drive can be corrected by meandering by touching the left and right sides up and down with respect to the line direction. Install a pair of small pinch rolls on the left and right (one on the front and back of the film, and it is on both sides of the film). Yes (cross guider method). The principle of the meandering correction of these devices is that when the film is moving, for example, when trying to move to the left, the former method tilts the roll so that the film goes to the right, and the latter method uses one set on the right side. This pinch roll is nipped and pulled to the right. It is preferable to install at least one of these meandering prevention devices between the film peeling point and the tenter stretching device.

 [0189] After the treatment in the stretching step, it is preferable to further provide a post-drying step (hereinafter, step D1).

Yes

 [0190] The web conveyance tension in step D1 is a force that is influenced by the physical properties of the dope, the amount of residual solvent at the time of peeling and in step DO, the temperature in step D1, etc. 120 to 200 N / m force S, preferably 140 to 2 OON / m is more preferable. 140 ~; 160 N / m is most preferred.

 [0191] A tension cut roll is preferably provided for the purpose of preventing the web from stretching in the transport direction in step D1.

 [0192] The means for drying the web is not particularly limited, and it is generally preferable to use hot air from the viewpoints of force S that can be performed by hot air, infrared rays, a heating roll, a microphone mouth wave, and the like, and simplicity.

 [0193] The drying temperature in the web drying step is preferably a heat treatment of not less than 5 ° C and not less than 100 ° C and not less than 10 ° C and not more than 60 minutes. The drying is performed at a drying temperature of 100 to 200 ° C, more preferably 110 to 160 ° C. More preferably, heat treatment is carried out while transporting in an atmosphere of 105 to 155 ° C. and an atmosphere substitution rate of 12 times / hour or more, preferably 12 to 45 times / hour.

[0194] The retardation film of the present invention preferably has a free volume radius of 0.250-0.350nm determined by the positron annihilation lifetime method in order to obtain the elastic modulus relationship according to the present invention. In particular, it is preferably 0.250 to 0.310 nm.

[0195] The free volume referred to here represents a void portion not occupied by the cellulose resin molecular chain. This can be measured using the positron annihilation lifetime method. Specifically, the time from the incidence of positrons to the sample until annihilation is measured, and information on the size and number concentration of free vacancies from the annihilation lifetime is observed nondestructively. The power S can be obtained with S.

 [0196] The retardation film according to the present invention has an elastic modulus (E) in the film stretching direction of 3.4 to 4.4 GPa measured under measurement conditions of a temperature of 23 ° C and a humidity of 55% RH, and Temperature 50 ° C,

 twenty three

 The difference from the elastic modulus (E) in the direction of stretching of the film measured under the measurement conditions at a humidity of 55% RH

 50

(E 1) satisfies the following formula (1).

 23 -50

 [0197] Equation (1) 0. 30≤E ≤0.8.

 23-50

 However, E = E -E.

 23 -50 23 50

 [0198] Here, if the elastic modulus (E) in the stretching direction of the retardation film measured under the measurement conditions at a temperature of 23 ° C and a humidity of 55% RH is less than 3.4 GPa, it is caused by environmental fluctuations. Polarizer

 twenty three

 This is not preferable because the retardation film loses its shrinkage force and the dimensions of the polarizing film itself change greatly. This is especially a problem with large polarizing films for large screens.

 [0199] In addition, the elastic modulus (E) force in the stretching direction of the retardation film measured under the measurement conditions at a temperature of 23 ° C and a humidity of 55% RH. 4. If it exceeds 4 Gpa, the curling of the polarizing film will increase.

 twenty three

 This is not preferable because it becomes a major obstacle in the liquid crystal panel manufacturing process.

[0200] And in the present invention, the elastic modulus (E) in the film stretching direction measured under the measurement conditions at a temperature of 23 ° C and a humidity of 55% RH, and a temperature of 50 ° C and a humidity of 55 Measured under% RH measurement conditions

 twenty three

 The difference (E) from the determined elastic modulus (E) in the film stretching direction satisfies the above formula (1)

 50 23 -50

 That is, for example, when the panel backlight is turned on, the temperature of the retardation film may reach close to 50 ° C. In this state, the elastic modulus (E) force temperature of the retardation film itself is 23 ° C.

 50

 When the elastic modulus (E) is low in the range of 0.3 to 0.8 GPa, the contraction force of the polarizer

 twenty three

Accordingly, the protective film has a remarkable effect that the retardation film itself can be deformed and the corner unevenness in the large screen VA type liquid crystal panel can be improved. is there.

 [Cycloolefin polymer film]

 The cycloolefin polymer film preferably used in the present invention will be described below.

[0201] The cycloolefin polymer used in the present invention comprises a polymer resin containing an alicyclic structure.

 [0202] A preferred cycloolefin polymer is a resin obtained by polymerizing or copolymerizing cyclic olefin. Cyclic olefins include norbornene, dicyclopentagen, and tetracyclodode.

0, 110, 13. 02, 7] Trideca unsaturated hydrocarbons with a polycyclic structure such as 2,4,6,11-tetraene and derivatives thereof; cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3 Methylcyclohexene, 2- (2 methylbutyl) 1-cyclohexene, cyclootaten, 3a, 5, 6, 7a-tetrahydro-1,4,7-methanoyl 1H-indene, cycloheptene, cyclopentagen, cyclohexagen, etc. And unsaturated hydrocarbons having a monocyclic structure and derivatives thereof. These cyclic olefins may have a polar group as a substituent. Examples of polar groups include hydroxyl group, carboxyl group, alkoxyl group, epoxy group, glycidyl group, oxycarbonyl group, carbonyl group, amino group, ester group, carboxylic anhydride group, etc. A carboxyl group or a carboxylic anhydride group is preferred.

 [0203] A preferred cycloolefin polymer may be one obtained by addition copolymerization of a monomer other than cyclic olefin. Addition copolymerizable monomers include ethylene, propylene, 1-butene, 1-pentene and other ethylene or α-olefin; 1,4 monohexagen, 4-methyl-1,4 monohexagen, 5-methyl-1,4 Gens such as monohexagen and 1,7 octagens.

[0204] Cyclic olefins can be obtained by an addition polymerization reaction or a metathesis ring-opening polymerization reaction. The polymerization is carried out in the presence of a catalyst. Examples of the addition polymerization catalyst include a polymerization catalyst composed of a vanadium compound and an organoaluminum compound. Polymerization comprising a metal halide such as ruthenium, rhodium, palladium, osmium, iridium, platinum, nitrate or acetylacetone compound as a catalyst for ring-opening polymerization, and a reducing agent. A catalyst; or a polymerization catalyst comprising a metal halide such as titanium, vanadium, zirconium, tungsten, or molybdenum or a acetylethylacetone compound and an organoaluminum compound. The polymerization temperature and pressure are not particularly limited, but the polymerization is usually carried out at a polymerization temperature of 50 ° C to 100 ° C and a polymerization pressure of 0 to 490 N / cm ² .

 [0205] The cycloolefin polymer used in the present invention is a polymer obtained by polymerizing or copolymerizing cyclic olefin and then hydrogenating it so that the unsaturated bond in the molecule is changed to a saturated bond. preferable. The hydrogenation reaction is carried out by blowing hydrogen in the presence of a known hydrogenation catalyst. Hydrogenation catalysts include transition metal compounds such as cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n butyllithium, zirconocene dichloride / sec butyllithium, tetrabutoxytitanate / dimethylmagnesium / Homogeneous catalyst consisting of a combination of alkyl metal compounds; heterogeneous metal catalyst such as nickel, palladium, platinum; nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, norradium / Examples thereof include a heterogeneous solid-supported catalyst in which a metal catalyst such as diatomaceous earth or noradium / alumina is supported on a support.

 [0206] Alternatively, examples of the cycloolefin polymer also include the following norbornene-based polymers. The norbornene-based polymer preferably has a norbornene skeleton as a repeating unit. Preferred examples thereof include JP-A-62-252406, JP-A-62-252407, and JP-A-2-133413. No. 1, JP-A 63-145324, JP-A 63 264626, JP-A 1-2240517, JP-B 57-8815, JP 5-39403, JP 5-43663 JP-A-5-43834, JP-A-5 70655, JP-A-5-279554, JP-A-6-206985, JP-A-7-62028, JP-A-8-176411, The force that can be preferably used is described in, for example, Kaihei 9-241484, but is not limited thereto. These may be used alone or in combination of two or more.

 [0207] In the present invention, among the norbornene-based polymers, those having a repeating unit represented by the following structural formulas (I) to (IV) are preferable.

[0208] [Chemical 7]

[0209] In the structural formulas (I) to (IV), A, B, C and D each independently represent a hydrogen atom or a monovalent organic group.

 [0210] Further, among the norbornene-based polymers, at least one compound represented by the following structural formula (V) or (VI) is metathesis-polymerized with an unsaturated cyclic compound copolymerizable therewith. A hydrogenated polymer obtained by hydrogenating the obtained polymer is also preferred.

[0211] [Chemical 8]

[0212] In the structural formula, A, B, C and D each independently represent a hydrogen atom or a monovalent organic group.

 [0213] Here, A, B, C and D are not particularly limited, but preferably an organic group is linked through a hydrogen atom, a halogen atom, a monovalent organic group, or at least a divalent linking group. However, these may be the same or different. A or B and C or D may form a monocyclic or polycyclic structure. Here, the at least divalent linking group includes a hetero atom typified by an oxygen atom, a nitrogen atom, and a nitrogen atom, and includes, for example, ether, ester, carbonyl, urethane, amide, thioether and the like. However, it is not limited to these. Further, the organic group may be further substituted via the linking group.

 [0214] Other monomers copolymerizable with the norbornene monomer include, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dedecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1 eicosene and other α-olefins having 2 to 20 carbon atoms, and their derivatives; cyclobutene, cyclopentene, cyclohexene, cyclootaten, 3a, 5, 6, 7a— 1,4-Hexagen, 4-Methyl-1,4 monohexagen, 5-Methyl-1,4 monohexagen, 1,7 —Non-conjugated gens such as otagen; Among these, α-olefin, particularly ethylene is preferable.

[0215] These other monomers copolymerizable with the norbornene-based monomer can be used alone or in combination of two or more. In the case of addition copolymerization of a norbornene monomer and another monomer copolymerizable therewith, Ratio force between the structural unit derived from the norbornene-based monomer in the coalescence and the structural unit derived from the other monomer copolymerizable Usually 30: 70-99: 1, preferably 50: 50-97: 3, more preferably in mass ratio Is appropriately selected to be in the range of 70: 30-95: 5.

 [0216] When the unsaturated bond remaining in the molecular chain of the synthesized polymer is saturated by a hydrogenation reaction, the hydrogenation rate is 90% or more, preferably 95 from the viewpoint of light resistance and weather resistance. % Or more, particularly preferably 99% or more.

 [0217] In addition, examples of the cycloolefin polymer used in the present invention include thermoplastic saturated norbornene resins described in paragraphs [0014] to [0019] of JP-A-5-2108, and JP-A-2001-277430. Thermoplastic norbornene polymers described in paragraphs [0015] to [0031] of the publication, thermoplastic norbornene resins described in paragraphs [0008] to [0045] of JP 2003-14901, and JP 2003-139950 A The norbornene-based resin composition described in Paragraph Nos. [0014] to [0028], the norbornene-based resin described in JP-A No. 2003-161832, paragraph Nos. [0029] to [0037], and the Paragraph No. in JP-A No. 2003-195268 [27] to [0036], norbornene-based resin, paragraph number [0009] of JP-A-2003-211589, polymer resin containing alicyclic structure, paragraph number [0008] of JP-A-2003-211588 [0024] The norbornene-based polymer resin or bull alicyclic hydrocarbon polymerization as described Such as resin and the like.

 [0218] Specifically, ZEONEX, ZEONOR manufactured by Nippon Zeon Co., Ltd., Aaton manufactured by JSR Co., Ltd., and APPEL manufactured by Mitsui Chemicals, Inc. (APL8008T, APL6509T, APL6013T, APL5014DP, APL6015T) and the like are preferably used.

 [0219] The molecular weight of the cyclohexylene polymer used in the present invention is appropriately selected depending on the purpose of use, but it is a gel of cyclohexane solution (the polymer resin does not dissolve! / In this case, a toluene solution). Permeation The mass average molecular weight of polyisoprene or polystyrene measured by chromatographic method, usually in the range of 5000 to 500,000, preferably <is 8000 to 200,000, more preferably 10,000 to 100,000. In addition, the mechanical strength of the molded body and the molding processability are well balanced.

[0220] The cycloolefin polymer film may contain an additive that can be generally blended into a plastic film, if necessary. Such additives include heat Stabilizers, light-resistant stabilizers, ultraviolet absorbers, antistatic agents, lubricants, plasticizers, fillers and the like can be mentioned, and their contents can be selected within a range that does not impair the object of the present invention.

 [0221] The method of forming the cycloolefin polymer film is not particularly limited, and any of the hot melt molding method and the solution casting method can be used. The heat-melt molding method can be further classified into an extrusion molding method, a press molding method, an inflation molding method, an injection molding method, a blow molding method, a stretch molding method, etc. Among these methods, mechanical strength, surface accuracy In order to obtain an excellent film, the extrusion molding method, the inflation molding method, and the press molding method are preferred, and the extrusion molding method is most preferable. The molding conditions are appropriately selected according to the purpose of use and the molding method. In the case of the hot melt molding method, the cylinder temperature is usually 150 to 400. C, preferably 200-350. C, more preferably 230-330. It is set appropriately within the range of C. If the resin temperature is too low, fluidity will deteriorate, causing shrinkage and distortion in the film. If the resin temperature is too high, voids due to thermal decomposition of the resin will cause silver streaks, and the film will turn yellow. There is a risk that a molding defect will occur. The thickness of the finale (usually 5 to 300 mm 111, preferably 10 to 200 mm 111, more preferably (20 to 100). If the thickness is too thin, handling during lamination becomes difficult. On the other hand, if it is too thick, the drying time after lamination becomes longer and the productivity is lowered.

 [0222] The surface tension of the cycloolefin polymer film is preferably 40 mN / m or more, more preferably 50 mN / m or more, and further preferably 55 mN / m or more. When the surface wetting tension is within the above range, the adhesive strength between the film and the polarizing film is improved. In order to adjust the surface wetting tension, for example, corona discharge treatment, ozone spraying, ultraviolet irradiation, flame treatment, chemical treatment, and other known surface treatments can be performed.

 [0223] The sheet before stretching needs to have a thickness of about 50 to 500 m, and the smaller the thickness unevenness is, the better it is within ± 8%, preferably within ± 6%, more preferably Within ± 4%.

[0224] In order to make the above-mentioned cycloolefin polymer film into the retardation film of the present invention, it can be obtained by the same production method as the cellulose ester film described above. It can also be obtained by stretching the sheet at least in the uniaxial direction. It should be noted that substantial uniaxial stretching, for example, stretching in a range that does not affect the orientation of the molecules, and then in the uniaxial direction to orient the molecules. Biaxial stretching may be used. It is preferable to use the tenter device or the like for stretching.

 [0225] The draw ratio is 1 .;! To 10 times, preferably 1.3 to 8 times, and a desired retardation may be set within this range. If the draw ratio is too low, the absolute value of the retardation will not rise to a predetermined value, and if it is too high, it may break.

 [0226] Stretching is usually performed in the temperature range of the glass transition temperature (Tg) to Tg + 50 ° C, preferably Tg to Tg + 40 ° C of the resin constituting the sheet. If the stretching temperature is too low, the film is broken, and if it is too high, the molecular orientation is not achieved, so that a desired retardation film cannot be obtained.

 [0227] In the film thus obtained, the molecules are oriented by stretching so that a retardation having a desired size can be obtained. In the present invention, the in-plane retardation value Ro at 589 nm is 30 to;! OOnm, and more preferably 40 to 70 nm. Further, the thickness direction retardation Rt is 70 to 300 nm, and more preferably 100 to 250 nm.

 [0228] The retardation can be controlled by the retardation of the sheet before stretching, the stretching ratio, the stretching temperature, and the thickness of the stretched oriented film. When the sheet before stretching has a certain thickness, the absolute value of the retardation tends to increase as the stretching ratio of the film increases. Therefore, by changing the stretching ratio, the stretched oriented film of the desired retardation can be obtained. Get power S

 [0229] The cyclorefin polymer film of the present invention is more preferable as the variation in retardation is smaller. The variation in retardation at a wavelength of 589 nm is usually within ± 50 nm, preferably within ± 30 nm, more preferably Smaller than ± 20nm.

 [0230] In-plane variation and thickness unevenness of the retardation film can be reduced by using the small unstretched sheet and by applying stress to the sheet evenly during stretching. S can. For this purpose, the film is stretched in a controlled temperature environment under a uniform temperature distribution, preferably within ± 5 ° C, more preferably within ± 2 ° C, and particularly preferably within ± 0.5 ° C. desirable.

 [Polycarbonate film]

There are various types of polycarbonate resins used to make polycarbonate films, and aromatic polycarbonate is preferred from the viewpoint of chemical properties and physical properties. Bisphenol A-based polycarbonate is particularly preferable. Among them, a force using a bisphenol A derivative in which a benzene ring, a cyclohexane ring or an aliphatic hydrocarbon group is introduced into bisphenol A is more preferable. A polycarbonate having a structure in which the anisotropy in the unit molecule is reduced, which is obtained by using a derivative having such a group introduced as a symmetric group, is preferred. For example, two methyl groups in the central carbon of bisphenol A are replaced with benzene rings, and one hydrogen in each benzene ring of bisphenol A is substituted asymmetrically with respect to the central carbon with a methyl group or a phenyl group. Polycarbonate obtained by use is preferred.

[0231] Specifically, 4,4'-dihydroxydiphenylalkane or a halogen-substituted product thereof can be obtained by a phosgene method or a transesterification method. For example, 4,4'-dihydroxydiphenylmethane, 4, A′-dihydroxydiphenylethane, 4, A′-dihydroxydiphenylbutane and the like can be mentioned.

 [0232] The retardation film made of the polycarbonate resin used in the present invention may be used by mixing with a transparent resin such as a polystyrene-based resin, a methyl methacrylate resin, or a cellulose acetate-based resin, or cellulose. A polycarbonate resin may be laminated on at least one surface of the acetate film.

 [0233] The method for producing a polycarbonate film that can be used in the present invention is not particularly limited. In other words, film by extrusion method, film by solvent cast method, film by force render method, etc.! In the present invention, either uniaxial stretching or biaxial stretching is used, and by the production method similar to the preferred production method of the cellulose ester film, the temperature of the present invention is 23 ° C and the humidity is 55% RH. Elastic modulus (E) in the direction of film stretching measured under the measurement conditions at 50 ° C and humidity at 55% RH.

 twenty three

 The difference (E) from the elastic modulus (E) in the film stretching direction measured below is a function of the above formula (1).

 50 23 -50

 Thus, a polycarbonate film satisfying the relationship and satisfying the in-plane and thickness direction retardation value ranges can be obtained.

[0234] The polycarbonate film used in the present invention has a glass transition point (Tg) of 110 ° C or higher and a water absorption rate (measured under conditions of 23 hours at 23 ° C in water) of 0.3. It is recommended to use less than%. More preferably, Tg is 120 ° C or more and water absorption is 0.2% Use the following! /

 Here, in order to increase the front contrast of the liquid crystal display device, which is the object of the present invention, it is important to minimize the distortion of the polymer constituting the film disposed between the polarizing film and the liquid crystal cell. It is. As described above, in a stretched film, the force that is necessary to quickly orient the polymer constituting the film and eliminate the cause of light leakage as much as possible. The film thickness is also important, and the retardation film of the present invention preferably has a film thickness of 100 m or less. As the film thickness increases, the above-mentioned factors causing light leakage increase not only by the film thickness.In particular, when the film thickness exceeds 100 m, light leakage easily occurs due to the increase in film thickness. There is a trend. A preferred film thickness is 80 m or less, and a more preferred film thickness is 35-60111. If the film thickness of the retardation film according to the present invention is in the range of 35 to 60 111, it is possible to reduce the thickness of the retardation film used for thin displays in recent years, particularly thin displays such as large TVs. It can respond to the request sufficiently.

(Polarizer)

The polarizing plate can be produced by a general method. The back side of the retardation film of the present invention is subjected to an alkali hatching treatment, and is bonded to at least one surface of a polarizing film prepared by immersing and stretching in an iodine solution using a completely hatched polybula alcohol aqueous solution. Is preferred. The film may be used on the other surface, or another polarizing plate protective film may be used. Commercially available cellulose ester films (for example, Konica Minoltac KC8UX, KC 4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC8UY- HA, HAC, C8UX—RHA—N, Konica Minoltatop Co., Ltd., Fujitac TD80UF, T80UZ, T40UZ, antireflection film (Fuji Film CV Clearview UA), Fuji Photo Film Co., Ltd., etc. are preferably used. In contrast to the retardation film of the present invention, the polarizing plate protective film used on the other surface is an optically isotropic polarized light having an in-plane retardation Ro of 0 to 20 nm and an Rt of -50 to 50 nm. A plate protective film is preferred. In addition, the polarizing plate protective film has a hard coat layer or antistatic layer with a thickness of 8 to 20 m. It is also preferable to have a glare layer. For example, polarized light having a node coat layer or an antiglare layer described in JP-A-2003-114333, JP-A-2004-203009, 2004-354699, 2004-354828, etc. A plate protective film is preferably used. Further, it is preferable that an antireflection layer, an antifouling layer or the like is laminated on the hard coat layer or the antiglare layer.

[0236] Alternatively, it is also preferable to use a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning liquid crystal compounds such as discotic liquid crystals, rod-shaped liquid crystals, and cholesteric liquid crystals. For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348. By using it in combination with the polarizing plate of the present invention, it is possible to obtain a liquid crystal display device having excellent flatness and a stable viewing angle expansion effect.

 [0237] A polarizing film, which is a main component of a polarizing plate, is an element that passes only light having a plane of polarization in a certain direction. A typical polarizing film that is currently known is a polybulualcohol-based polarizing film. There are two types: polybutalol-based films dyed with iodine and dichroic dyes. The polarizing film is formed by forming a polybulualcohol aqueous solution, uniaxially stretching it and dyeing it, and uniaxially stretching after dyeing, and preferably having been subjected to a durability treatment with a boron compound. Yes. On the surface of the polarizing film, one side of the optical film of the present invention is bonded to form a polarizing plate. It is preferably bonded with a water-based adhesive mainly composed of fully hatched polybulal alcohol.

 [0238] Ethylene-modified polybulal alcohol is also preferably used as the polarizing film. The thickness of the polarizing film is preferably 5 to 30 μm, particularly preferably 10 to 25 μm.

 (Display device)

 A liquid crystal display device composed of a polarizing plate using the retardation film of the present invention is used to develop a higher display quality than a normal polarizing plate. In particular, the effect of the present invention can be further exerted when used in a multi-domain liquid crystal display device, more preferably in a multi-domain liquid crystal display device by a birefringence mode.

[0239] Multidomaining is also suitable for improving the symmetry of image display, and various methods have been reported "Okita, Yamauchi: Liquid Crystal, 6 (3), 303 (2002)". The liquid crystal display cell is “Yamada, Yama Hara: Liquid Crystals, 7 (2), 184 (2003) "Force S, which is also shown, but not limited to these.

[0240] The polarizing plate of the present invention is an MVA (Multi-domestic Vertical Alignment) mode represented by a vertical alignment mode, in particular, a four-part MVA mode, and a known PVA (Patterned Vertical Alignment) that is multi-domained by electrode arrangement. It can be used effectively in the CPA (Continuous Pinwheel Alignment) mode that combines the mode, electrode arrangement and chirality. In addition, the proposal of an optically biaxial film in conformity with the OCB (Optical Compensated Bend) mode has been disclosed, “T.Miyashita, T.Uchida: J.SID, 3 (l), 29 ( 19 95) ”, the polarizing plate of the present invention can also exhibit the effect of the present invention in display quality. If the effect of the present invention can be expressed by using the polarizing plate of the present invention, the arrangement of the liquid crystal mode and the polarizing plate is not limited. In particular, the retardation film of the present invention is preferably used for a vertical alignment mode liquid crystal display device, and particularly preferably for an MVA (Multi_domein Vertical Alignment) mode liquid crystal display device.

[0241] The display quality of the display cell is preferably symmetric for human observation! Therefore, when the display cell is a liquid crystal display cell, the domain can be multiplied substantially giving priority to the symmetry on the observation side. Domain demarcation IJ can be determined by a known method, and can be determined by a two-division method, more preferably a four-division method in consideration of the properties of a known liquid crystal mode.

 [0242] Liquid crystal display devices are being applied to devices for colorization and moving image display, and the display quality in the present invention is improved due to improvement in contrast and resistance to polarizing plates. Image display is possible.

 [0243] In the liquid crystal display device of the present invention, a polarizing plate using the retardation film of the present invention is disposed only on one surface of a liquid crystal cell, or on both surfaces. At this time, by using the retardation film of the present invention contained in the polarizing plate so as to be on the liquid crystal cell side, the display quality can be improved.

 Example

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

Example 1 (Preparation of main dope)

 Senorelose acetate propionate 100 mass

 (Total substitution degree 2.50, number average molecular weight 70000, mass average molecular weight 180000, intrinsic viscosity (I

V) l. 4: Cellulose ester A)

 Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) benzotriazole (ultraviolet absorber) 1 part by weight dichloromethane 450 parts by weight

 50 parts by weight of ethyl alcohol

 A main dope solution having the above composition was prepared. First, methylene chloride and ethyl alcohol were added to the pressure dissolution tank. Cellulose ester A was added to a pressurized dissolution tank containing a solvent while stirring. This was heated and stirred to completely dissolve, and a plasticizer and an ultraviolet absorber were further added and dissolved. This was filtered using Azumi Filter Paper No. 244 manufactured by Azumi Filter Paper Co., Ltd. to prepare a main dope solution.

<Preparation of fine particle dispersion>

 Fine particles (Aerosil R972V (made by Nippon Aerosil Co., Ltd.) 11 parts by mass

 (Average primary particle diameter 16nm, apparent specific gravity 90g / liter)

 89 parts by mass of ethyl alcohol

 The above materials were stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin to prepare a fine particle dispersion.

<Preparation of fine particle additive solution>

 99 parts by mass of methylene chloride

 Cellulose Estenole A 4 parts by mass

 Particulate dispersion 11 parts by mass

The cellulose ester A described above was added to a dissolution tank containing methylene chloride, heated and completely dissolved, and then filtered using Azumi filter paper No. 244 manufactured by Azumi Filter Paper Co., Ltd. While stirring the cellulose ester solution after filtration, The fine particle dispersion was slowly added. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered with a fine pore NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution.

[0245] Next, 100 parts by mass of the main dope solution and 5 parts by mass of the fine particle additive solution were added and mixed thoroughly with an in-line mixer (Toray Static In-Pipe Mixer, Hi-Mixer, SWJ). Using a casting apparatus, casting was uniformly performed on a stainless steel band support having a width of 2 m. Peeling was performed on a stainless steel band support under the conditions of a peeling tension of 130 N / m and a residual solvent amount of 100% by mass.

 [0246] The temperature of the stainless steel band was divided into two equal parts from the fluent to the peeling, and the belt was so divided that the average temperature in the first half was kept at 32 ° C and the average temperature in the second half was kept at 28 ° C. The temperature of the hot air supplied to the front and back surfaces was controlled.

 [0247] Next, the both ends of the web (film) in the width direction were held with a tenter, and stretched at a temperature of 140 ° C, a stretching ratio of 1.25 times, and a stretching speed of 40 mm / sec. Heat treatment was performed at 130 ° C for 20 minutes while maintaining the width, after releasing the tension in the width direction, the width maintenance was released, and the product was further transported for 30 minutes in the third drying zone set at 125 ° C. A 45 m thick retardation film having a width of 1.4 m, a width of 1 cm at the end and a knurling of 6 m in height was prepared.

 Example 2

 The main dope and the fine particle addition solution were the same as those in Example 1, and the film was formed by changing the temperature of the stainless steel band and the stretching conditions using the tenter as follows.

 The first half average temperature of the stainless steel band is 35 ° C and the second half average temperature is 25 ° C. did. Except for the above conditions, the same procedure as in Example 1 was performed.

 Example 3

 The main dope and the fine particle addition liquid were the same as those in Example 1, and the film was formed by changing the temperature of the stainless steel band and the stretching conditions by the tenter as follows.

The first half average temperature of the stainless steel band is 30 ° C, the second half average temperature is 33 ° C, the tenter stretching conditions are temperature 135 ° C, stretching ratio 1.3 times, stretching speed 34mm / sec. Was made. Except for the above conditions, the same procedure as in Example 1 was performed.

 Example 4

 The main dope was adjusted under the following conditions.

 The raw material used was the same as in Example 1, and the dope was prepared by changing the ratio of dichloromethane and ethyl alcohol.

[0248] 100 parts by mass of cellulose acetate propionate

 (Total substitution degree 2.50, number average molecular weight 70000, mass average molecular weight 180000, intrinsic viscosity (IV) 1.4: cellulose ester Α)

 Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

 2-{2 '-Hydroxy-3 5' —Di-t-butylphenol) Benzotriazolene (UV absorber) 1 part by mass

 4 parts by mass

 400 parts by weight

 100 parts by weight

 Thereafter, film formation is performed by the same means as in Example 1.

 At this time, the temperature of the hot air supplied to the belt front and back surfaces was controlled so that both the first half temperature and the second half temperature of the stainless steel band were kept at 28 ° C.

 A retardation film was produced under the conditions of tenter stretching conditions: a temperature of 145 ° C, a stretching ratio of 1.35 times, and a stretching speed of 30 mm / sec.

 Other parts not described were formed in the same manner as in Example 1.

 Example 5

 (Main dope adjustment)

 The raw material used was the same as in Example 1, and the dope concentration was adjusted as follows.

[0249] 100 parts by mass of cellulose acetate propionate

 (Total substitution degree 2.50, number average molecular weight 70000, mass average molecular weight 180000, intrinsic viscosity (IV) 1.4: cellulose ester Α)

 Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

2-2 '-Hydroxy 3', 5 '-G t-butylphenol) benzotriazole (UV absorber)

Thereafter, film formation is performed by the same means as in Example 1.

At this time, the temperature of the hot air supplied to the belt front and back surfaces was controlled so that both the first and second half temperatures of the stainless steel band were maintained at 25 ° C.

A retardation film was produced under the conditions of tenter stretching conditions: temperature 130 ° C, stretching ratio 1.35 times, stretching speed 50 mm / sec.

Other parts not described were formed in the same manner as in Example 1.

Examples 6 and 7

(Main dope adjustment)

The raw material used was the same as in Example 1, and the dope concentration and the solvent mixing ratio were adjusted as follows.

 Senorelose acetate propiate 100 mass

 (Total substitution degree 2.50, number average molecular weight 70000, mass average molecular weight 180000, intrinsic viscosity (IV) 1.4: cellulose ester Α)

 Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

 2-2 '-Hydroxy 3' 5 '— tert-butylphenol) benzotriazole

(UV absorber)

Thereafter, film formation is performed by the same means as in Example 1.

In Example 6, the temperature of the hot air supplied to the belt front and back surfaces was controlled so that the first half temperature of the stainless steel band was maintained at 38 ° C and the second half temperature at 40 ° C. The tenter conditions were as follows: temperature 155 ° C, draw ratio 1.35 times, draw speed 30mm / sec. In Example 7, the temperature of the hot air supplied to the front and back surfaces of the belt was controlled so that the first half temperature of the stainless steel band was maintained at 35 ° C and the second half temperature at 33 ° C.

In addition, a retardation film was produced under the conditions of tenter stretching conditions: a temperature of 150 ° C., a stretching ratio of 1.35 times, and a stretching speed of 15 mm / sec.

Other parts not described were formed in the same manner as in Example 1.

Example 8

The same main dope as in Example 5 was used, and the temperature of the hot air supplied to the belt front and back surfaces was controlled so that the first half temperature of the stainless steel band was maintained at 22 ° C and the second half temperature at 33 ° C. In addition, a retardation film was produced under the stretching conditions of a temperature of 160 ° C., a stretching ratio of 1.45 times, and a stretching speed of 25 mm / sec.

Other parts not described were formed in the same manner as in Example 1.

Example 9

 When adjusting the main dope, instead of cellulose ester A, the following cellulose ester was used, and a retardation film having a stretching temperature of 135 ° C, a stretching ratio of 1.29 times, and a film thickness of 45 m was prepared. The temperature of the stainless steel band at this time was the same as in Example 1 except that the temperature of the hot air supplied to the belt front and back surfaces was controlled so that the first half temperature was maintained at 30 ° C and the second half temperature at 35 ° C. It carried out similarly.

(Preparation of main dope)

100 parts of senorelose acetate butyrate

 (Total substitution degree 2.42, number average molecular weight 110000, weight average molecular weight 230000 intrinsic viscosity (IV)

14)

Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

2— (2 ′ —Hydroxy— 3 ′, 5 ′ —Di-t-butylphenyl) benzotriazole (ultraviolet absorber) 1 part by mass A main dope solution having the above composition was prepared.

 Thereafter, the conditions until casting were the same as in Example 1.

 The temperature of the hot air supplied to the belt front and back was controlled so that the stainless steel band temperature was maintained at 20 ° C for the first half and 30 ° C for the second half. A retardation film was produced under the conditions of tenter stretching conditions: a temperature of 158 ° C, a stretching ratio of 1.34 times, and a stretching speed of 15 mm / sec.

 Example 10

 When preparing the main dope, the following cellulose ester is used instead of cellulose ester A, and when adjusting the main dope, the following cellulose ester is used instead of cellulose ester A, and the stretching temperature is 145 ° C. A retardation film was produced at a draw ratio of 1.36 times and a draw speed of 45 mm / sec. The temperature of the stainless steel band at this time was controlled by the temperature of the hot air supplied to the belt front and back surfaces so that the first half temperature was maintained at 40 ° C and the second half temperature at 35 ° C.

 Except for the above, the same procedure as in Example 1 was performed.

[0252] Cellulose acetate butyrate: total substitution degree 2.42, number average molecular weight 110000, mass average molecular weight 230000, intrinsic viscosity (IV) 1.4

 Example 11

 When adjusting the main dope, the following cellulose ester was used in place of cellulose ester A, and a retardation film was produced at a stretching temperature of 175 ° C., a stretching ratio of 1.55 times, and a stretching speed of 15 mm / sec. At this time, the temperature of the hot air supplied to the belt front and back surfaces was controlled so that the temperature of the stainless steel band was kept at 20 ° C for both the first half and the latter half.

 Except for the above, the same procedure as in Example 1 was performed.

[0253] Cellulose acetate butyrate: Total substitution degree 2.79, number average molecular weight 150,000, mass average molecular weight 300,000, intrinsic viscosity (IV) 2.2

 Example 12

 Preparation of cycloolefin polymer film by melt casting method

In a nitrogen atmosphere, mix 500 parts of dehydrated cyclohexane, 1.2 parts of 1xene, 0.15 part of dibutyl ether, and 0.30 part of triisobutylaluminum at room temperature. Then, while maintaining the temperature at 45 ° C, tricyclo [4 · 3.0.12,5] deca-1,3 gen (dicyclopentagen, abbreviated as DCP) 20 parts, 1, 4, methanol 1, 4, 4a , 9a Tetrahydrophenololene (hereinafter abbreviated as MTF) 140 and 8 Methylenoltetracyclo [4. 4. 0. 12, 5. 17. 17, 10] —Dodeca 3-en (hereinafter abbreviated as MTD) 40 A norbornene-based monomer mixture consisting of 4 parts and 40 parts of tungsten hexachloride (0.7% toluene solution) were continuously added over 2 hours for polymerization. To the polymerization solution, 1.06 part of butyl daricidyl ether and 0.52 part of isopropyl alcohol were added to deactivate the polymerization catalyst and stop the polymerization reaction.

[0254] Next, 270 parts of cyclohexane was added to 100 parts of the reaction solution containing the obtained ring-opening polymer, and 5 parts of a nickel-alumina catalyst (manufactured by JGC Chemical Co., Ltd.) was added as a hydrogenation catalyst. Then, the pressure was increased to 5 MPa with hydrogen, and the mixture was heated to 200 ° C. with stirring, and then reacted for 4 hours to obtain a reaction solution containing 20% of a hydrogenated polymer of a DCP / MTF / MTD ring-opening polymer.

 [0255] After removing the hydrogenation catalyst by filtration, a soft polymer (Kuraray Co., Ltd .; Septon 2002) and an antioxidant (Ciba Specialty Chemicals Co., Ltd .; Ilganox 1010) were added to the resulting solutions. And dissolved (0.1 parts per 100 parts of polymer).

[0256] With! /, The solvent cyclohexane and other volatile components are removed from the solution using a cylindrical concentrated dryer (manufactured by Hitachi, Ltd.), and the hydrogenated polymer is extruded in a molten state. Extruded into a strand from the machine, cooled, pelletized and recovered.

[0257] The copolymerization ratio of each norbornene-based monomer in the polymer was calculated from the composition of residual norbornenes (by gas chromatography) in the solution after polymerization. DCP / MT

F / MTD = 10/70/20, almost equal to the feed composition.

[0258] This hydrogenated ring-opened polymer had a mass average molecular weight (Mw) of 31,000 and a molecular weight distribution (

Mw / Mn) was 2.5, hydrogenation rate was 99.9%, and Tg was 134 ° C.

[0259] The obtained ring-opened polymer hydrogenated pellets were dried at 70 ° C for 2 hours using a hot air dryer in which air was circulated to remove moisture.

[0260] Next, the pellet was mixed with a single-screw extruder having a coat hanger type T die with a lip width of 1.5 m (manufactured by Mitsubishi Heavy Industries, Ltd .: screw diameter 90 mm, T die lip material made of tungsten carbide, molten resin) Using a peel strength of 44 N), melt extrusion molding to obtain a length of 2500 An annular olefin resin film having a thickness of 60 m was produced. Extrusion molding was performed in a clean room of class 1000 or lower under molding conditions of a molten resin temperature of 240 ° C and a T-die temperature of 240 ° C.

 [0261] For this film, in the same manner as the retardation film of Example 1, peeling was performed under the conditions of a peeling tension of 85 N / m, a residual solvent amount of 5 mass%, and a cold air temperature of 23 ° C. The obtained cyclic olefin resin is obtained by holding both ends and stretching under the conditions of 135N / mm, stress 160 ° C and stretch ratio 1.3 times from the start of process B shown in Fig. 2 to 10cm. The film was slit at both ears and processed to a width of 1/4 m to obtain a retardation film 17 having a thickness of 80 m. Moreover, when winding, the polyester film was wound up together as a protective film. The distribution of the UV absorber in the thickness direction of the film thus prepared was measured according to the method for measuring the amount of additive described below, and the results are shown in Table 1.

 Example 13

 Preparation of polycarbonate film by solution casting method

 <Dope composition>

 Polycarbonate resin

 (Viscosity average molecular weight 40,000, bisphenol A type) 100 parts by mass

 2— (2 ′ —Hydroxy 3 ′, 5 ′

 (Phenyl) benzotriazole (UV absorber) 1 · 0 parts by mass

 430 parts by mass of methylene chloride

 90 parts by mass of methanol

 The above composition was put into a sealed container, kept at 80 ° C. under pressure, and completely dissolved with stirring to obtain a dope composition.

[0262] Next, this dope composition was filtered, cooled and kept at 33 ° C, uniformly cast on a stainless steel band support, and dried at 33 ° C for 5 minutes. Subsequently, when the web (film) was peeled off from the support, the same conditions as in the retardation film of Example 1 above were applied, with a peel tension of 120 N / m, a residual solvent amount of 45% by mass, and a cold air temperature of 23 ° C. The web is peeled off with a tenter, and both ends of the web are gripped, and stretched under the conditions of 140 N / mm, temperature 125 ° C, and draw ratio 1.21 times from the start of process B shown in Fig. 2 to 10 cm. Perform the stretching process A retardation film having a width of 1.4 m and a film thickness of 65 m was obtained. The distribution of the UV absorber in the thickness direction of the film thus prepared was measured according to the method for measuring the amount of additive described later, and as a result, it was as shown in Table 1.

Comparative Example 1

 (Preparation of main dope)

Senorelose acetate propionate 100 mass

 (Total substitution degree 2.50, number average molecular weight 70000, weight average molecular weight 180000, intrinsic viscosity (IV

1. 4: Senorelose Estenole A)

Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

 2-2 '-Hydroxy 3', 5 '—G

Benzotriazole (UV absorber) 1 part by weight Dichloromethane 470 parts by weight

30 parts by weight of ethyl alcohol

 A main dope solution having the above composition was prepared. First, methylene chloride and ethyl alcohol were added to the pressure dissolution tank. Cellulose ester A was added to a pressurized dissolution tank containing a solvent while stirring. This was heated and stirred to completely dissolve, and a plasticizer and an ultraviolet absorber were further added and dissolved. This was filtered using Azumi Filter Paper No. 244 manufactured by Azumi Filter Paper Co., Ltd. to prepare a main dope solution.

Adjustment of the fine particle dispersion and adjustment of the fine particle addition liquid were performed in the same manner as described in Example 1.

Next, 100 parts by mass of the main dope solution and 5 parts by mass of the fine particle additive solution are added and mixed thoroughly with an in-line mixer (Toray static type in-pipe mixer, Hi-Mixer, SWJ), and then a belt casting apparatus. Was cast uniformly onto a stainless steel band support having a width of 2 m. Peeling was performed on a stainless steel band support under conditions of a peeling tension of 130 N / m and a residual solvent amount of 100% by mass.

As for the temperature of the stainless steel band, the temperature of the hot air supplied to the belt front and back surfaces was controlled so that the average temperature in the first half was maintained at 30 ° C and the average temperature in the second half was maintained at 25 ° C. Tenter Stretching conditions were as follows: a temperature of 120 ° C, a draw ratio of 1.2, and a draw speed of 40 mm / sec.

Comparative Example 2

 (Preparation of main dope)

Senorelose acetate propionate 100 mass

 (Total substitution degree 2.50, number average molecular weight 70000, weight average molecular weight 180000, intrinsic viscosity (IV) 1.4: referred to as senorelose esterol A)

Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

2-2 '-Hydroxy 3', 5 '—G

 / 'One (UV absorber) 1 part by mass

 '4 parts by mass

 630 parts by mass

70 parts by weight of ethyl alcohol

A main dope solution having the above composition was prepared.

Thereafter, the conditions until casting were the same as in Example 1.

As for the temperature of the stainless steel band, the temperature of the hot air supplied to the belt surface and the back surface was controlled so that the average temperature in the first half was maintained at 15 ° C and the average temperature in the second half was maintained at 20 ° C. A retardation film was produced under the tenter stretching conditions of a temperature of 110 ° C, a stretching ratio of 1.15 times, and a stretching speed of 20 mm / sec.

Comparative Example 3

The main dope was adjusted in the same manner as in Example 1, and the temperature of the hot air supplied to the belt surface and back surface was controlled so that the stainless steel band temperature was maintained at 55 ° C in both the first half and the second half. A retardation film was produced under the conditions of tenter stretching conditions: a temperature of 140 ° C., a stretching ratio of 1.30 times, and a stretching speed of 70 mm / sec.

Comparative Example 4

The main dope was adjusted in the same manner as in Example 1, and the hot air supplied to the belt surface and back surface was maintained so that the temperature of the stainless steel band was maintained at 25 ° C for the first half and 15 ° C for the second half. The temperature was controlled. Tenter stretching conditions: temperature 100 ° C, draw ratio 1.17 times, draw A retardation film was produced at a speed of 20 mm / sec.

Comparative Example 5

The main dope was adjusted in the same manner as in Example 1, and the hot air supplied to the belt front and back surfaces was maintained so that the stainless steel band temperature was maintained at 35 ° C for the first half average temperature and 20 ° C for the second half average temperature. The temperature was controlled. A retardation film was produced under the conditions of tenter stretching conditions: a temperature of 105 ° C, a stretching ratio of 1.17 times, and a stretching speed of 40 mm / sec.

Comparative Example 6

The main dope was adjusted in the same manner as in Example 1, and the hot air supplied to the belt front and back surfaces was maintained so that the stainless steel band temperature was maintained at 15 ° C for the first half average temperature and 30 ° C for the second half average temperature. The temperature was controlled. A retardation film was produced under the tenter stretching conditions of a temperature of 175 ° C., a stretching ratio of 1.43 times, and a stretching speed of 30 mm / sec.

Comparative Example 7

 (Preparation of main dope)

Senorelose acetate propionate 100 mass

 (Total substitution degree 2.60, number average molecular weight 80000, weight average molecular weight 190000, intrinsic viscosity (IV

) 1. 7)

Aromatic terminal ester plasticizer (example of compound (1)) 6 parts by mass

 2-2 '-Hydroxy 3', 5 '—G

 / 'One (UV absorber) 1 part by mass

 4 parts by mass

 400 parts by weight

100 parts by weight of ethyl alcohol

 A main dope solution having the above composition was prepared.

Thereafter, the conditions until casting were the same as in Example 1.

The temperature of the hot air supplied to the belt front and back surfaces was controlled so that the average temperature of the stainless steel band was maintained at 15 ° C in both the first and second half. A retardation film was produced under the conditions of tenter stretching conditions: a temperature of 100 ° C., a stretching ratio of 1.30 times, and a stretching speed of 10 mm / sec. Comparative Example 8 (Preparation of main dope)

100 parts of senorelose acetate butyrate

 (Total substitution degree 2.42, number average molecular weight 110000, weight average molecular weight 230000, intrinsic viscosity (IV) l. 4)

Aromatic terminal stellar plasticizer (Example of compound (1)) 6 parts by mass

2— (2 ′ —Hydroxy 3 ′, 5 ′ —Di-t-ennore)

 Zulu (UV absorber) 1 part by mass

 4 parts by mass

 350 parts by weight

150 parts by weight

 A main dope solution having the above composition was prepared.

Thereafter, the conditions until casting were the same as in Example 1.

The temperature of the hot air supplied to the belt front and back was controlled so that the stainless steel band temperature was maintained at 35 ° C for the first half and 25 ° C for the second half. A retardation film was produced under the conditions of a tenter stretching condition of a temperature of 135 ° C, a stretching ratio of 1.28 times, and a stretching speed of 35 mm / sec.

Comparative Example 9

 (Preparation of main dope)

100 parts of senorelose acetate butyrate

 (Total substitution degree 2.42, number average molecular weight 110000, weight average molecular weight 230000, intrinsic viscosity (IV) l. 4)

Aromatic terminal cocoon plasticizer (example of compound (1))

2-2 '-Hydroxy 3', 5 '—G

 ^ (UV absorber) 1 part by mass

 4 parts by mass

 225 parts by mass

25 parts by weight

_C prepared the main dope solution of the above composition Thereafter, the conditions until casting were the same as in Example 1.

 The temperature of the hot air supplied to the belt front and back was controlled so that the stainless steel band temperature was maintained at 20 ° C for the first half and 30 ° C for the second half. A retardation film was produced under the conditions of tenter stretching conditions: a temperature of 158 ° C, a stretching ratio of 1.34 times, and a stretching speed of 15 mm / sec.

 Evaluation test

 About the retardation films obtained in the above Examples;! To 13 and Comparative Examples;! To 9, the elastic modulus (E) in the film stretching direction under the measurement conditions of a temperature of 23 ° C. and a humidity of 55% RH, And temperature

 twenty three

 Elastic modulus (E) of the film stretching direction measured under the measurement conditions of 50 ° C and humidity 55% RH

 50

) And calculate the difference (E) between the elastic modulus (E) and the elastic modulus (E).

 The results obtained are shown in Table 1 below.

 (Measurement of elastic modulus)

 Each sample of the retardation film obtained in Examples 1 to 13 and Comparative Examples 1 to 9 was allowed to stand for 24 hours in an environment of temperature 2 3 ± 2 ° C and humidity 55 ± 5% RH. The sample was cut into strips with a width of 10 mm and a length of 200 mm so that the TD direction of the sample was long. Next, using the TG-2KN type tensile tester manufactured by Minibear, set the above strip sample with a chucking pressure of 0.25 MPa and a distance between marked lines of 100 ± 10 mm, and pulling speed of 100 ± 10 mm / min. pull. The tensile test was performed in the same environment as when cutting.

[0263] Then, based on the obtained tensile stress-strain curve, the elastic modulus calculation start point was 10N, the end point was 3 ON, the tangent line drawn between them was drawn, and each sample was measured in the MD and TD directions. Elastic modulus).

 twenty three

 [0264] Furthermore, a unit that can be arbitrarily heated and humidified is installed on the film set and chuck of the above tensile tester, and the chamber is at a temperature of 50 ± 2 ° C and humidity of 55 ± 5% RH. Kept. Each sample was allowed to stand in the storage for 2 hours, and then a tensile test was performed in the same manner as described above to obtain the elastic modulus) for each sample.

 50

[0265] For the retardation films obtained in Examples 1 to 13 and Comparative Examples 1 to 9, the in-plane retardation value Ro and the thickness direction retardation value Rt were measured, and the obtained results were obtained. It is shown in Table 1 below. [Measurement of surface plasticizer amount]

 The amount of the additive on the film surface is scraped about 10 microns from the surface of the film using a knife, and after measuring the mass, this is dissolved in acetone, and the amount of the additive contained therein is measured by gas chromatography (Hewlett). (Using a gas chromatography 5890 type SERISII manufactured by Packard)).

 (Measurement of phase difference values Ro and Rt)

 Using an Abbe refractometer (1T) and a spectral light source, the average refractive index of each sample of the retardation film obtained in the above Examples;! To 13 and Comparative Examples; In addition, the thickness of each sample of the retardation films obtained in Examples 1 to 13 and Comparative Examples 1 to 9 was measured using a commercially available micrometer.

[0266] Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments), temperature 23

For each sample of the retardation film obtained in Examples 1 to 13 and Comparative Examples 1 to 9 that were allowed to stand for 24 hours in an environment of ° C and humidity 55% RH, the retardation film of the retardation film at a wavelength of 589 nm was measured in the same environment. Retardation measurement of each sample was performed.

[0267] The above-described average refractive index and film thickness were input to the following equation, and the in-plane retardation value Ro and the thickness direction retardation Rt were determined. The direction of the slow axis was also measured at the same time.

[0268] Ro = (nx-ny) X d

 Rt = {(nx + ny) / 2-nz} X d

 Where nx is the refractive index in the slow axis direction in the film plane, ny is the refractive index in the fast axis direction in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness (nm). It is.

[0269] Next, using each sample of the retardation film obtained in Examples 1 to 13 and Comparative Examples 1 to 9, polarizing plates were prepared in the following manner, and the following evaluations were performed.

 <Production of polarizing plate>

 A 120 m thick polybulu alcohol film was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution consisting 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. consisting 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 polarizing film.

[0270] Then, according to the following steps;! To 5, this polarizing film and the above examples;! To 13 and Comparative Example 1 Bond the surface side film consisting of each sample of the retardation film obtained in ~ 9 and the Konica Minoltack KC8UX-RHA film (manufactured by Konica Minoltabuto Co., Ltd.) as the cell mouth ester film on the back side. A polarizing plate was prepared.

 [0271] Step 1: Each sample of the retardation film obtained in Examples 1 to 13 and Comparative Examples 1 to 9 was immersed in a 1 mol / L sodium hydroxide solution at a temperature of 50 ° C for 60 seconds. Then, it was washed with water and dried to obtain a cellulose ester film hatched on the side to be bonded to the polarizing film. In addition, each sample of the retardation film obtained in Examples 12 and 13 and Comparative Examples 6 and 7 was subjected to plasma treatment instead of the saponification treatment step to be hydrophilized.

 [0272] Step 2: The polarizing film is placed in a polybulol alcohol adhesive tank having a solid content of 2% by mass by 1 to

 Soaked for 2 seconds.

 [0273] Step 3: Gently wipe off excess adhesive adhering to the polarizing film in Step 2, and place it on each sample of the retardation film processed in Step 1, with the antireflection layer on the outside To be laminated

 And arranged.

Step 4: The retardation film, the polarizing film and the cellulose ester film sample 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.

[0275] Step 5: Respective samples of the retardation films obtained in Step 4 above in a dryer at 80 ° C in Step 4;! To 13 and Comparative Examples;! To 9; a polarizing film; and cellulose The laminated film bonded with the ester film was dried for 2 minutes to produce a polarizing film.

 <Production of liquid crystal display device>

 The polarizing plate of a commercially available liquid crystal TV (Shatao Phat 32AD5) was peeled off, and the above example

; ~ 13 and the polarizing film produced using the retardation film obtained in Comparative Examples 1-9, respectively, was bonded to the glass surface of the liquid crystal cell.

[0276] At that time, the polarizing plate is bonded so that the surface of each retardation film is on the liquid crystal cell side and the absorption axis is in the same direction as the previously bonded polarizing plate. The liquid crystal display devices were respectively fabricated.

 <Evaluation of corner unevenness>

The retardation films obtained in Examples 1 to 13 and Comparative Examples 1 to 9 were used. Each liquid crystal display device using a polarizing film was stored for 24 hours in an environment of temperature 45 ° C ± 2 ° C and humidity 95 ± 3% RH. Immediately after that, move to a room with a temperature of 23 ° C and humidity of 55% RH, and turn on the panel backlight. 24 hours after lighting, measure the front brightness of the four corners in black and calculate the average value. The “four corners” here are on the diagonal of the effective display screen, and the distance from the corner is 50 mm! /

[0277] For each liquid crystal display device, the occurrence of corner unevenness was evaluated according to the following five levels based on the ratio of the average value of the front luminance at the four corners to the front luminance at the center of the screen. The evaluation rank is as follows. The front luminance at the center of the screen of the liquid crystal display device was set to 1. The results obtained are shown in Table 1 below.

 Evaluation rank

 A: No corner unevenness

 (Fourth front brightness average; 1. 00-1. 05)

 B: Uneven corners cannot be recognized with the naked eye! / ヽ

 (Four-corner front average brightness; 1. 06〜;! · 10)

 C: Power that appears as corner irregularities

 (Four-corner front brightness average; 1.11 ~;! · 20)

 D: There is a display quality problem

 (Fourth front brightness average; 1. 21 ~;! · 30)

 E: There is a serious problem in display quality

 (Fourth front brightness average; 1. 31 or higher)

[0278] [Table 1]

[0279] As is clear from the results in Table 1 above, in the liquid crystal panel using the polarizing film produced using the retardation film obtained in Example of the present invention ~; ^, the corner unevenness evaluation result Was rank AC, and it was possible to improve the occurrence of uneven corners on LCD panels.

[0280] According to the retardation film obtained in Examples 1 to 13 of the present invention, Of these, by reducing the amount of plasticizer on the surface in contact with the polarizer to be less than the amount of plasticizer on the surface in contact with the glass side, the occurrence of corner unevenness could be significantly suppressed.

 [0281] This is because the surface of the retardation film on the polarizer side has a low plasticizer amount, so that the bonding force between the retardation film and PVA (polarizer) is increased, while the surface of the retardation film on the glass side is increased. The reason is that the amount of plasticizer is large, and when the stress generated by the PVA contraction due to temperature change is transmitted to the phase difference finale, the force is relatively weakened, so that the disorder of birefringence hardly occurs. Think of it as something.

 [0282] On the other hand, in the liquid crystal panel using the polarizing film produced using the retardation film obtained in Comparative Examples 1 to 9, the average value of the front luminance at the four corners of the liquid crystal panel is 1.21 to 1. It was 30 and the evaluation result of corner unevenness was rank D. In rank D, corner unevenness occurs, and there is a problem in the display quality of the liquid crystal panel. In addition, in the liquid crystal panel using the polarizing film prepared using the phase difference film obtained in Comparative Examples 8 and 9, the average value of the front luminance at the four corners of the liquid crystal panel was 1.31 or more, and the evaluation of the corner unevenness The result was rank E. In rank E, there are obvious corner irregularities, and there is a serious problem in the display quality of the liquid crystal panel.

Claims

The scope of the claims  [1] A retardation film manufactured in a manufacturing process in which means for gripping an end portion of a film and stretching in a direction perpendicular to a transport direction is provided in a part of the film forming process. Elastic modulus (E) force in the film stretching direction measured under the measurement conditions at a temperature of 23 ° C and a humidity of 55% RH. 3.4-4GPa and at a temperature of 50 ° C and a humidity of 55% RH Under measurement conditions twenty three  The difference (Δ Ε) from the elastic modulus (E) satisfies the following formula (1) and is bonded to the polarizer.  50 23-50  When the amount of additive present on the surface of the retardation film on the side to be coated is 100 in terms of mass ratio, the amount of additive present on the surface of the phase difference film to be adhered to the glass surface is 20 to 70 in terms of mass ratio. A retardation film characterized by that.  Formula (1) 0. 30≤ Δ Ε ≤0. 80  23-50  Where Δ Ε = E − E.  23 -50 23 50  The additive herein refers to a material other than the main resin and solvent among the materials constituting the retardation film.  [2] The retardation film according to claim 1, wherein the film has a film thickness of 35-60 m.  [3] The retardation film according to claim 1 or 2, wherein the intrinsic viscosity (IV) of the resin is 1.3 to 1.7.  [4] The main component of the resin is cellulose ester, and the cellulose ester contains at least one selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. The retardation film according to any one of claims 1 to 3, wherein:  [5] The retardation film according to claim 4, which has an ester group substitution degree of cellulose ester strength S, 2.42-2.60.