JP5891165B2 - Laminated body, polarizing plate, and liquid crystal display device - Google Patents

Description

  The present invention relates to a laminate, a cellulose ester film, a method for producing a cellulose ester film, a polarizing plate, and a liquid crystal display device. More specifically, the present invention relates to a 2D-3D combined video display panel and video display system capable of displaying a stereoscopic video (3D video) and also displaying a two-dimensional video (2D video), and a pattern retardation film used for the video display panel.

  In the 3D image display field, where the projected image can be viewed stereoscopically and the powerful image can be enjoyed, in recent years, 3D movies have been accepted rapidly in recent years. 3D video display has started to receive a lot of attention. Conventionally, various methods for stereoscopic viewing with the naked eye and various methods using dedicated glasses are known for stereoscopic display (3D display). Unlike 3D movies sitting in a movie theater, daily life is different. From the viewpoint of being able to see images while moving, special attention has been paid to the method using dedicated glasses.

  On the other hand, 3D video content for flat panel displays is still not sufficient. Therefore, there is a demand for a video display method that can easily switch between 2D display (two-dimensional display) and 3D display and that can display both 2D video and 3D video with high image quality. As a method satisfying these demands, two methods of a spectacle shutter method (active spectacle method) and a polarized spectacle method (passive spectacle method) are particularly attracting attention. Also, in the field of flat panel displays that have recently been improved in image quality, it is believed that only these two methods can maintain high image quality in conventional flat panel displays and provide high-quality 3D images. However, among these, from the viewpoint that it is relatively low cost and can be widely used, further improvement of the polarized glasses method is demanded.

  The polarized glasses method displays a left-eye image and a right-eye image on a display, and the left-eye image light and the right-eye image light emitted from the display are different from each other in two polarization states (for example, a right circle). Polarized light and left circularly polarized light), and a stereoscopic effect is obtained by observing the display through polarized glasses composed of a right circularly polarized light transmissive polarizing plate and a left circularly polarized light transmissive polarizing plate (see Patent Document 1). In addition, as a display method for the left eye image and right eye image on the display in the polarized glasses method, half of the original image is displayed on the display half for each of the left eye image and the right eye image. The screen division method is used. As the screen division method, a line-by-line method is widely adopted, and every other line of the original image for the left eye is arranged on the odd lines and even lines of the scanning lines (hereinafter also referred to as lines) of the display. In this method, half of the left-eye image with the number of pixels halved and half of the right-eye image with the number of pixels halved so that every other line of the original image for the right eye is displayed. In addition, as a method of changing the image light for the left eye and the image light for the right eye emitted from the display into two different polarization states, different phase differences according to the line width are repeatedly patterned in a band shape. The method of sticking the pattern retardation film on the display is widely adopted.

In recent years, further improvement and reduction in manufacturing cost have been demanded for the spread of 3D image display devices for pattern retardation films in which different phase differences are repeatedly patterned in a band shape according to the line width of such image display devices. It has been.
Here, various methods are known as a manufacturing method of such a pattern phase difference film (refer patent documents 1-5).

In a 3D display device using a patterned phase difference film produced on a polymer film described in Patent Documents 1 to 5 and the like, crosstalk generated due to a patterning interval and a time-dependent deviation in pixels after the panel is turned on Has been found to be visually recognized, and Patent Document 6 describes that the dimensional change is suppressed by suppressing the expansion of the polymer film as a factor.
In the description of Patent Document 6, it is said that a dimensional change in a specific direction can be suppressed by stretching a cellulose ester film in one direction and reducing a thermal expansion coefficient and a humidity expansion coefficient in one direction.

US Pat. No. 5,327,285 JP 2001-59949 A JP 10-161108 A JP-A-10-160933 Japanese Patent Laid-Open No. 10-153707 International Publication No. 2011/102492

In recent years, 3D-TV, which has been spreading widely, has been subjected to stricter quality requirements in order to improve durability and manufacturability, and in particular, the adhesion between the cured resin layer disposed on the viewer side and the support. Improvement is required when it is assumed to be used as the outermost surface.
Therefore, in the present invention, the dimensional change that occurs in a high-humidity environment is suppressed, the influence due to the environmental change is reduced, and the adhesiveness with the cured resin layer is improved, and the sandwiched between the cured resin layer and the hydrophilic resin layer. Another object of the present invention is to provide a cellulose ester film laminate and a cellulose ester film suitable for the laminate.

As described above, Patent Document 6 proposes a technique for suppressing a dimensional change in a specific direction by stretching a cellulose ester film. Thus, until now, the dimensional change in a specific direction (for example, a direction orthogonal to the orientation direction) of the polymer film has been suppressed by orienting the polymer by a stretching treatment.
However, the stretching treatment suppresses the dimensional change, but the adhesiveness between the support and the cured resin layer is lowered, and thus the problem that it cannot meet the demand for the adhesiveness more than before has been found.

  The present inventors have found that the following means can achieve both the suppression of the dimensional change and the adhesion. The present inventors suppress the reversible dimensional change by determining the direction of expansion while reducing the region where water molecules can enter by orienting the polymer molecular chains of cellulose ester by stretching treatment, and curing the cellulose ester film It is estimated that adhesion can be improved by reducing the plasticizer on the surface of the resin layer.

  That is, the said subject is solved by the following means.

<1>
A laminate having a cured resin layer, a cellulose ester film, and a hydrophilic resin layer in this order,
The cellulose ester film contains a plasticizer, and the plasticizer concentration on the cured resin layer side surface is 95% by mass or less of the plasticizer concentration on the hydrophilic resin layer side,
The cellulose ester film has a direct direction and a parallel direction with respect to an arbitrary side after 24 hours at 25 ° C. and 80% relative humidity with reference to a time after 24 hours at 25 ° C. and 10% relative humidity. A laminate having a dimensional change rate of at least one of 0.40% or less.
<2>
The laminate according to <1>, wherein the hydrophilic resin comprises polyvinyl alcohol.
<3>
The laminate according to <1> or <2>, having a layer formed by fixing the alignment state of the liquid crystalline compound on the surface of the hydrophilic resin layer opposite to the surface having the cellulose ester film.
<4>
The layer formed by fixing the alignment state of the liquid crystalline compound has a plurality of retardation values.
<5>
The layer formed by fixing the alignment state of the liquid crystalline compound is the laminate according to <4>, in which band-like regions having two kinds of retardation values are alternately arranged in a plane.
<6>
The laminate according to <5>, wherein a dimensional change rate in a direction orthogonal to a direction in which the band-shaped regions are alternately arranged is 0.40% or less.
<7>
The laminate according to any one of <1> to <6>, wherein the cured resin layer is a layer formed from a material that is cured by heat or light.
<8>
The laminate according to any one of <1> to <7>, wherein the cured resin layer is at least one of a hard coat layer, an antiglare layer, and an antireflection layer.
<9>
The polarizing plate which has a laminated body as described in any one of <1>-<8>.
<10>
<1>-<8> The laminated body as described in any one of <8>, or the liquid crystal display device which has a polarizing plate of <9>.
The present invention relates to the above <1> to <10>, but other matters are also described for reference.
[1]
A laminate having a cured resin layer, a cellulose ester film, and a hydrophilic resin layer in this order,
The cellulose ester film contains a plasticizer, and the plasticizer concentration on the cured resin layer side surface is 95% by mass or less of the plasticizer concentration on the hydrophilic resin layer side,
The cellulose ester film has a direct direction and a parallel direction with respect to an arbitrary side after 24 hours at 25 ° C. and 80% relative humidity with reference to a time after 24 hours at 25 ° C. and 10% relative humidity. A laminate having a dimensional change rate of at least one of 0.40% or less.
[2]
The laminate according to [1], wherein the hydrophilic resin comprises polyvinyl alcohol.
[3]
The laminate according to [1] or [2], which has a layer formed by fixing the alignment state of the liquid crystalline compound on a surface opposite to the surface having the cellulose ester film of the hydrophilic resin layer.
[4]
The layer formed by fixing the alignment state of the liquid crystalline compound has a plurality of retardation values as described in [3].
[5]
The layer formed by fixing the alignment state of the liquid crystalline compound is a laminate according to [4], in which band-like regions having two kinds of retardation values are alternately arranged in a plane.
[6]
The laminate according to [5], wherein a dimensional change rate in a direction orthogonal to a direction in which the band-shaped regions are alternately arranged is 0.40% or less.
[7]
The laminate according to any one of [1] to [6], wherein the cured resin layer is a layer formed from a material that is cured by heat or light.
[8]
The laminate according to any one of [1] to [7], wherein the cured resin layer is at least one of a hard coat layer, an antiglare layer, and an antireflection layer.
[9]
The plasticizer concentration on one surface side is 95% or less of the plasticizer concentration on the other surface side, and after 24 hours aging at 25 ° C. and 10% relative humidity, at 25 ° C. and 80% relative humidity A cellulose ester film in which a dimensional change rate in at least one of a perpendicular direction and a parallel direction is 0.40% or less with respect to an arbitrary side after 24 hours.
[10]
A step of preparing a dope by dissolving cellulose acylate in an organic solvent, a solution casting film forming step of casting a dope on a casting support cooled to 0 ° C. or less, and a cellulose in a direction perpendicular to the casting direction The cellulose ester film according to [9], which has at least a step of orientating acylate and volatilizes the surface plasticizer in the casting step to change the amount of plasticizer on the casting support surface side and the air interface side. Production method.
[11]
The polarizing plate which has the laminated body as described in any one of [1]-[8], or the cellulose-ester film as described in [9].
[12]
A liquid crystal display device comprising the laminate according to any one of [1] to [8], the cellulose ester film according to [9], or the polarizing plate of [11].

ADVANTAGE OF THE INVENTION According to this invention, the cellulose-ester film with a small dimensional change by the environment of the support body of retardation film can be provided. Moreover, according to this invention, it can provide the laminated body which has an optically anisotropic layer on this cellulose-ester film, and can be used as a phase difference film, Furthermore, the polarizing plate using this cellulose ester and a laminated body And a liquid crystal display device. Particularly in a 3D combined image display panel, the polymer film has a first retardation region and a second retardation region having different birefringence, and the first retardation region and the second retardation region are 1 When applying a patterned retardation film with optically anisotropic layers patterned alternately for each line, if the polymer film shrinks in the direction perpendicular to the pattern, it is between the retardation area and the panel pixels. However, in the present invention, it can be effectively prevented.
Furthermore, it becomes the laminated body which has high adhesiveness with respect to the deformation | transformation by humidity or a heat | fever by making it equivalent to the adhesiveness of a cured resin layer and a support body.

It is the schematic which shows an example of the laminated body of this invention. It is the schematic which shows an example of the laminated body of this invention. It is the schematic which shows an example of the layer formed by fixing the orientation state of the liquid crystalline compound in this invention.

  Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the specification of the present application, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

  In the present specification, “parallel” and “orthogonal” mean that the angle is within a range of strictly less than ± 10 °. In this range, an error from a strict angle is preferably less than ± 5 °, and more preferably less than ± 2 °. Further, “substantially vertical” means within a range of less than ± 20 ° from a strict vertical angle. In this range, an error from a strict angle is preferably less than ± 15 °, and more preferably less than ± 10 °. Further, the “slow axis” means a direction in which the refractive index is maximized. Further, the measurement wavelength of the refractive index is a value at λ = 550 nm in the visible light region unless otherwise specified. In addition, the longitudinal direction and the width direction refer to the direction of transport in the case of assuming a continuously produced film or a long body of a laminate, that is, the longitudinal direction and the direction orthogonal to the transport direction, respectively. , Sometimes referred to as TD direction.

  In this specification, unless otherwise specified, the “polarizing plate” is cut into a size to be incorporated into a long polarizing plate and a liquid crystal display device (in this specification, “cutting” includes “punching” and The term “includes“ cutout ”and the like” is used to include both polarizing plates. In this specification, “polarizing film” and “polarizing plate” are distinguished from each other. “Polarizing plate” means a laminate having a transparent protective film for protecting the polarizing film on at least one side of the “polarizing film”. It shall be.

In the present specification, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).
When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (if there is no slow axis, Rth (λ) With respect to the film normal direction (with an arbitrary direction as the rotation axis), the light of wavelength λ nm is incident from each inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side, and a total of 6 points are measured. KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Rth can also be calculated from the following formula (A) and formula (B) based on the value, the assumed value of the average refractive index, and the input film thickness value.

The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
In formula (A), nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. . d is the film thickness.

Formula (B)
Rth = ((nx + ny) / 2−nz) × d

  In the formula (B), nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction orthogonal to nx in the plane, and nz represents the refractive index in the direction orthogonal to nx and ny. . d is the film thickness.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) and the tilt axis (rotating axis). In each of the 10 degree steps, light of wavelength λ nm is incident from the inclined direction and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or WR is calculated.

In the above measurement, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. Examples of the average refractive index values of main optical films are given below:
Cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).
The KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness.
In this specification, the measurement wavelength is 550 nm unless otherwise specified.

The laminate of the present invention is a laminate having a cured resin layer, a cellulose ester film, and a hydrophilic resin layer in this order,
The cellulose ester film contains a plasticizer, and the plasticizer concentration on the cured resin layer side surface is 95% by mass or less of the plasticizer concentration on the hydrophilic resin layer side,
The cellulose ester film has a direction perpendicular to and parallel to an arbitrary side after 24 hours at 25 ° C. and 80% relative humidity with reference to the time after 24 hours at 25 ° C. and 10% relative humidity. The dimensional change rate of at least one of is 0.40% or less.
The schematic of an example of the laminated body of this invention is shown in FIG. The laminated body 10 of FIG. 1 has the cured resin layer 1, the cellulose-ester film 2, and the hydrophilic resin layer 3 in this order.

(Cellulose ester film)
In general, a retardation film in which an optically anisotropic layer is provided on a polymer film has a patterning period in units of pixels, particularly when used for 3D display using circularly polarized light or linearly polarized glasses. In this case, for example, when the display is turned on, the surface temperature of the display rises due to heat radiation of the backlight, and the dimensions of the polymer film may change due to the influence. A pixel shift occurs along with the dimensional change, and so-called crosstalk occurs in which the right-eye image is recognized by the left eye or the left-eye image is recognized by the right eye. Therefore, it is desirable to suppress the dimensional change of the polymer film.
In the cellulose ester film of the present invention (hereinafter also referred to as the film of the present invention), the ratio of the sound speed in the width direction to the sound speed in the longitudinal direction is preferably 0.9 or more and 1.1 or less. The cellulose ester film of the present invention has a dimensional change rate in the width direction of 0.4% or less.
Hereinafter, the film of the present invention will be described.

<Cellulose ester>
The cellulose ester film in the present invention contains a cellulose ester.
As said cellulose ester, a powder or a particulate thing can be used, and the pelletized thing can also be used.
The cellulose ester film in this invention may be comprised from one type of cellulose ester, and may be comprised from two or more types of cellulose esters.
As the cellulose ester, cellulose acylate is preferable.

  The cellulose acylate used in the present invention is not particularly defined. Examples of the cellulose as the acylate material include cotton linter and wood pulp (hardwood pulp, conifer pulp). Cellulose acylate obtained from any of the raw material celluloses can be used, and in some cases, they may be mixed and used. Detailed descriptions of these raw material celluloses can be found in, for example, Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin”, published by Nikkan Kogyo Shimbun (published in 1970), and the Japan Society of Invention and Innovation Technical Bulletin No. 2001. The cellulose described in No.-1745 (pages 7 to 8) can be used.

First, the cellulose acylate preferably used in the present invention will be briefly described. Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by esterifying some or all of these hydroxyl groups with an acyl group having 2 or more carbon atoms. The degree of acyl substitution means the ratio of the cellulose hydroxyl groups located at the 2nd, 3rd and 6th positions being esterified (100% esterification has a degree of substitution of 1).
The total acyl substitution degree, that is, DS2 + DS3 + DS6 is preferably 1.5 to 3.0, more preferably 2.0 to 3.0, and further preferably 2.5 to 3.0. It is preferably 2.7 to 3.0, more preferably 2.70 to 2.98. Further, from the viewpoint of film forming property, it is preferably 2.80 to 2.95, and particularly preferably 2.85 to 2.90. Here, DS2 is the degree of substitution of the hydroxyl group at the 2-position of the glucose unit with an acyl group (hereinafter also referred to as “degree of acyl substitution at the 2-position”), and DS3 is the degree of substitution of the hydroxyl group at the 3-position with an acyl group (hereinafter, referred to as “acyl group”). DS6 is the substitution degree of the hydroxyl group at the 6-position with an acyl group (hereinafter also referred to as “acyl substitution degree at the 6-position”). DS6 / (DS2 + DS3 + DS6) is the ratio of the acyl substitution degree at the 6-position to the total acyl substitution degree, and is hereinafter also referred to as “acyl substitution ratio at the 6-position”.

  Regarding these celluloses, the description of paragraph numbers 0034 to 0039 of International Publication No. 2011/102492 can be referred to.

The cellulose ester according to the present invention preferably has a moisture absorption rate of 0.5% or more. The moisture absorption rate of the polymer can be controlled by adjusting the chemical structure of the polymer by introducing hydrophilic groups or hydrophobic groups, or by adding hydrophilic or hydrophobic additives. It becomes possible to control the hygroscopic expansion coefficient. The relationship between the moisture absorption rate and the hygroscopic expansion coefficient varies depending on the magnitude of polymer interaction in the film, such as crystallinity, molecular weight, and degree of entanglement. Generally speaking, the hygroscopic expansion coefficient can be increased by increasing the hydrophilicity of the polymer and increasing the moisture absorption rate.
The moisture absorption rate of the polymer is preferably 0.5% or more. More preferably, it is 0.7% or more, More preferably, it is 1.0% or more. Further, although there is no particular upper limit, it is preferably 10% or less, more preferably 7.0% or less, from a practical viewpoint.
The moisture absorption is measured using a moisture measuring device, a sample drying apparatus “CA-03” and “VA-05” {both Mitsubishi Chemical Co., Ltd. )}, Measured by the Karl Fischer method. It is calculated by dividing the amount of water (g) by the sample mass (g).

<Additives>
In the cellulose ester film of the present invention, an additive can be added, which can help control the rate of change in humidity. The molecular weight of the additive is not particularly limited, but the additives described below can be preferably used.
By adding additives, in addition to controlling the rate of change in humidity, the film can be modified to improve thermal properties, optical properties, mechanical properties, impart flexibility, absorb water resistance, reduce moisture permeability, etc. It shows useful effects in terms of quality.
The amount of the additive added is preferably 5% by mass or more, more preferably 9% by mass or more, and more preferably 12% by mass or more with respect to the cellulose ester from the viewpoint of developing the various effects described above. More preferably. As an upper limit, it is preferable that it is 50 mass% or less, and it is preferable that it is 25 mass% or less. When two or more kinds of additives are used, the total amount is preferably within the above range.

(Plasticizer)
The cellulose ester film in the present invention contains a plasticizer.
The mechanical properties can be controlled by adding a plasticizer. As the plasticizer, various known ester plasticizers such as phosphate ester, citrate ester, trimellitic acid ester, sugar ester, and polyester polymers described in paragraph numbers 0042 to 0068 of International Publication No. 2011/102492 pamphlet are described. Can be helpful.

  In addition, as a control of optical properties, the description of paragraph numbers 0069 to 0072 of International Publication No. 2011/102492 pamphlet can be referred to for imparting ultraviolet or infrared absorption ability, and adjustment of the retardation of the film In addition, a known retardation adjusting agent can be used for controlling expression.

[Method for producing cellulose ester film]
The manufacturing method of the cellulose-ester film of this invention is demonstrated. Hereinafter, cellulose acylate will be described as an example. However, other cellulose esters can be similarly formed.
A film containing cellulose acylate can be formed using a solution casting film forming method or a melt film forming method. The case of the solution casting film forming method will be described below as an example.

(Polymer solution)
In the solution casting film forming method, a web is formed using the cellulose acylate or a polymer solution (cellulose acylate solution) containing various additives as required. Hereinafter, the polymer solution in the present invention (hereinafter also referred to as a cellulose acylate solution as appropriate) that can be used in the solution casting film forming method will be described.

  As the main solvent of the polymer solution in the present invention, an organic solvent which is a good solvent for cellulose acylate can be preferably used. As such an organic solvent, an organic solvent having a boiling point of 80 ° C. or lower is more preferable from the viewpoint of reducing the drying load. The boiling point of the organic solvent is more preferably 10 to 80 ° C, and particularly preferably 20 to 60 ° C. Moreover, the organic solvent whose boiling point is 30-45 degreeC depending on the case can also be used suitably as said main solvent. In the present invention, among the solvent groups described below, a halogenated hydrocarbon can be preferably used as the main solvent. Among the halogenated hydrocarbons, chlorinated hydrocarbons are preferred, dichloromethane and chloroform are more preferred, and dichloromethane is preferred. Most preferred. In addition, a solvent containing 1 to 15% by mass of a solvent having a low boiling point of 95 ° C. or higher and gradually concentrated with respect to the total solvent can be used. It is preferable to use a solvent containing 1% by mass, and it is more preferable to use a solvent containing 1.5 to 8% by mass. And it is preferable that the solvent whose boiling point is 95 degreeC or more is a poor solvent of a cellulose acylate. Specific examples of the solvent having a boiling point of 95 ° C. or higher include solvents having a boiling point of 95 ° C. or higher among the specific examples of the “organic solvent used in combination with the main solvent” described later, but butanol, pentanol, It is preferable to use 1,4-dioxane. Furthermore, the solvent of the polymer solution in the present invention used in the present invention contains 5 to 40% by mass of alcohol, preferably 10 to 30% by mass, more preferably 12 to 25% by mass, and more preferably 15 to 15% by mass. It is more preferable to contain 25 masses. Specific examples of the alcohol used herein include the solvents exemplified as the alcohol of the “organic solvent used in combination with the main solvent” described later. Among them, methanol, ethanol, propanol, and butanol are preferably used. . In addition, when said "solvent whose boiling point is 95 degreeC or more" is alcohol, such as butanol, the content is also counted by alcohol content here. By using such a solvent, it is possible to increase the mechanical strength at the heat treatment temperature of the produced cellulose acylate film, so that the obtained film is stretched more than necessary and prevents the resulting film from being easily broken. be able to.

  As such a main solvent, halogenated hydrocarbons can be particularly preferably mentioned, and in some cases, esters, ketones, ethers, alcohols and hydrocarbons can also be mentioned, and these have a branched structure or a cyclic structure. It may be. The main solvent may have two or more functional groups of esters, ketones, ethers and alcohols (that is, —O—, —CO—, —COO—, —OH). Furthermore, the hydrogen atom in the hydrocarbon portion of the ester, ketone, ether and alcohol may be substituted with a halogen atom (particularly a fluorine atom). In addition, the main solvent of the polymer solution in the present invention used for the production of the cellulose acylate film used in the production method of the present invention, when composed of a single solvent, indicates that solvent, from a plurality of solvents In this case, the solvent having the highest mass fraction among the constituent solvents is shown. Preferred examples of the main solvent include halogenated hydrocarbons.

As said halogenated hydrocarbon, a chlorinated hydrocarbon is more preferable, for example, a dichloromethane, chloroform, etc. are mentioned, A dichloromethane is still more preferable.
Examples of the ester include methyl formate, ethyl formate, methyl acetate, and ethyl acetate.
Examples of the ketone include acetone and methyl ethyl ketone.
Examples of the ether include diethyl ether, methyl tert-butyl ether, diisopropyl ether, dimethoxymethane, 1,3-dioxolane, 4-methyldioxolane, tetrahydrofuran, methyltetrahydrofuran, 1,4-dioxane and the like.
As said alcohol, methanol, ethanol, 2-propanol etc. are mentioned, for example.
Examples of the hydrocarbon include n-pentane, cyclohexane, n-hexane, benzene, toluene and the like.

  Examples of the organic solvent used in combination with these main solvents include halogenated hydrocarbons, esters, ketones, ethers, alcohols and hydrocarbons, and these may have a branched structure or a cyclic structure. The organic solvent may have any two or more of ester, ketone, ether and alcohol functional groups (that is, —O—, —CO—, —COO—, —OH). Furthermore, the hydrogen atom in the hydrocarbon portion of the ester, ketone, ether and alcohol may be substituted with a halogen atom (particularly a fluorine atom).

As said halogenated hydrocarbon, a chlorinated hydrocarbon is more preferable, for example, a dichloromethane, chloroform, etc. are mentioned, A dichloromethane is still more preferable.
Examples of the ester include methyl formate, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, and pentyl acetate.
Examples of the ketone include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone.
Examples of the ether include diethyl ether, methyl tert-butyl ether, diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, 4-methyldioxolane, tetrahydrofuran, methyltetrahydrofuran, anisole, and phenetole. Etc.
Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-methyl-2-butanol, cyclohexanol, and 2-fluoro. Examples include ethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol. Preferred is an alcohol having 1 to 4 carbon atoms, more preferred is methanol, ethanol or butanol, and most preferred is methanol or butanol.
Examples of the hydrocarbon include n-pentane, cyclohexane, n-hexane, benzene, toluene, xylene and the like.
Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol, 2-butoxyethanol, and methyl acetoacetate.

In this invention, since the polymer which comprises a cellulose-ester film contains hydrogen bonding functional groups, such as a hydroxyl group, ester, and ketone, 5-30 mass% in all the solvents, More preferably, 7-25 mass%, Furthermore It is preferable from a viewpoint of reducing the peeling load from a casting support body to contain preferably 10-20 mass% alcohol.
By adjusting the alcohol content, it is possible to easily adjust the expression of Re and Rth of the cellulose acylate film produced by the production method of the present invention. Specifically, by increasing the alcohol content, the heat treatment temperature can be set relatively low, and the reach range of Re and Rth can be further increased.
In the present invention, it is effective to contain a small amount of water to increase the solution viscosity and the film strength of the wet film during drying, or to increase the dope strength during casting by the drum method. 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and particularly 0.2 to 2% by mass.

  Examples of combinations of organic solvents preferably used as the solvent for the polymer solution in the present invention are described in JP-A-2009-262551.

  In addition, if necessary, a non-halogen organic solvent can be used as a main solvent, and detailed description can be found in the Japan Institute of Invention Publication (Publication No. 2001-1745, published on March 15, 2001, Invention Association). There is a description.

The cellulose acylate concentration in the polymer solution in the present invention is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and most preferably 15 to 30% by mass.
The cellulose acylate concentration can be adjusted to a predetermined concentration at the stage of dissolving the cellulose acylate in a solvent. Further, after preparing a solution with a low concentration (for example, 4 to 14% by mass) in advance, the solution may be concentrated by evaporating the solvent or the like. Furthermore, you may dilute after preparing a high concentration solution beforehand. Moreover, the density | concentration of a cellulose acylate can also be reduced by adding an additive.

  The timing of adding the additive can be appropriately determined according to the type of the additive.

  As the additive amount of the additive used in the cellulose acylate film of the present invention increases, the glass transition temperature (Tg) of the cellulose acylate film tends to decrease and the additive volatilization problem in the film production process tends to occur. The additive amount of 3000 or less is preferably 0.01 to 30% by mass, more preferably 2 to 30% by mass, and still more preferably 5 to 20% by mass with respect to the cellulose acylate.

(Preparation of polymer solution)
Preparation of the polymer solution in the present invention is, for example, disclosed in JP-A-58-127737, JP-A-61-106628, JP-A-2-276830, JP-A-4-259511, JP-A-5-163301, No. 9-95544, No. 10-45950, No. 10-95854, No. 11-71463, No. 11-302388, No. 11-322946, No. 11-322947, No. 11 No.-323017, JP-A 2000-53784, 2000-273184, 2000-273239, and the like. Specifically, the polymer and the solvent are mixed and stirred to swell, and optionally cooled or heated to dissolve and then filtered to obtain the polymer solution in the present invention.

In this invention, in order to improve the solubility to the solvent of a polymer, it is preferable to include the process of cooling and / or heating the mixture of a polymer and a solvent.
When a halogen-based organic solvent is used as the solvent and the mixture of cellulose acylate and the solvent is cooled, it is preferable to include a step of cooling the mixture to −100 to 10 ° C. Moreover, it is preferable to include the process swollen at -10-39 degreeC in the process before a cooling process, and the process heated to 0-39 degreeC in the process after cooling.

When using a halogen-based organic solvent as a solvent and heating a mixture of cellulose acylate and solvent, the step of dissolving cellulose acylate in the solvent by one or more methods selected from the following (a) or (b) It is preferable to include.
(A) Swell at −10 to 39 ° C. and warm the resulting mixture to 0 to 39 ° C.
(B) Swell at −10 to 39 ° C., heat the obtained mixture to 40 to 240 ° C. at 0.2 to 30 MPa, and cool the heated mixture to 0 to 39 ° C.
Furthermore, when a non-halogen organic solvent is used as the solvent and the mixture of cellulose acylate and the solvent is cooled, it is preferable to include a step of cooling the mixture to −100 to −10 ° C. Moreover, it is preferable to include the process of swelling at -10-55 degreeC in the process before a cooling process, and the process heated to 0-57 degreeC in the process after cooling.

When using a halogen-based organic solvent as a solvent and heating a mixture of cellulose acylate and solvent, a step of dissolving cellulose acylate in the solvent by one or more methods selected from the following (c) or (d) It is preferable to include.
(C) Swell at −10 to 55 ° C. and warm the resulting mixture to 0 to 57 ° C.
(D) Swell at −10 to 55 ° C., heat the obtained mixture to 40 to 240 ° C. at 0.2 to 30 MPa, and cool the heated mixture to 0 to 57 ° C.

(Web film formation)
The web in the present invention can be formed by the solution casting film forming method using the polymer solution in the present invention. In carrying out the solution casting film forming method, a known apparatus can be used according to a conventional method. Specifically, the dope (polymer solution in the present invention) prepared with a dissolving machine (kettle) is filtered and then temporarily stored in a storage kettle, and the foam contained in the dope is defoamed to be finally prepared. The dope is kept at 30 ° C., and is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the rotational speed, and the dope runs endlessly from the die (slit) of the pressure die. It casts uniformly on the metal support body of the casting part which has been (dope casting process). Next, at the peeling point where the metal support has almost gone around, the dough film (web) which has been dried is peeled from the metal support, and then transported to the drying zone, and drying is completed while being transported by a roll group. Details of the casting process and the drying process of the solution casting film-forming method are also described in pages 120 to 146 of JP-A-2005-104148, and can be applied to the present invention as appropriate.

  In the present invention, a metal band or a metal drum can be used as the metal support used in the film formation of the web.

(Adjustment of plasticizer concentration on front and back)
It is preferable to adjust the plasticizer concentration on the front and back surfaces during the dope casting step. As an adjustment method, as described in JP-A No. 2001-151902, a method of forming a single film by laminating a plurality of types of dopes having different plasticizer concentrations, and volatilizing a plasticizer on the surface on the air interface side It can be performed by the method of making it.
In the former, since component adjustment can be performed independently for each layer, the facility becomes complicated and it is difficult to control the film formation conditions, but the composition of each layer is easily controlled.
On the other hand, the latter has a limited choice of plasticizers that can be used, but if the plasticizer in a very thin area on the air interface side that becomes the interface with the cured resin layer is volatilized together with the solvent, it contributes to the adhesion improvement effect Therefore, the latter method is preferable.

The method of volatilizing the plasticizer on the surface on the air interface side can be specifically performed by a method such as applying a heated dry air to the dope extending upstream of the metal support with a high air volume.
In order to obtain the effect of the present invention, it is preferable to adjust the condition of applying the drying air so that the plasticizer concentration on the air interface side is 95% or less of the plasticizer concentration on the casting support side by the method described above. .
The ratio of the plasticizer concentrations is preferably controlled to 70 to 95%.
The laminated body of the present invention can be obtained by disposing a hydrophilic resin on the casting support surface side of a film formed through the steps described below and a cured resin layer on the air interface side.

(Stretching process)
The manufacturing method of the cellulose-ester film which concerns on this invention includes the process of extending | stretching the whole film containing a cellulose ester to a specific direction. By stretching the cellulose ester film according to the present invention, the coefficient of thermal expansion in the stretching direction and the rate of change in humidity can be reduced. The stretching is preferably performed in the width direction orthogonal to the longitudinal direction (corresponding to the transport direction for transporting the film) by 10% or more and 40% or less. Furthermore, biaxial stretching combined with stretching in a direction that does not coincide with the width direction (for example, the longitudinal direction) may be used.
The draw ratio in the width direction is preferably 10 to 40%, and more preferably 10 to 30%. Moreover, 0-20% is preferable, as for the draw ratio to a longitudinal direction, 0-10% is more preferable, and 0-5% is still more preferable.
About the method of extending | stretching without raising the haze of a film and controlling the anisotropy of an elastic modulus, after extending | stretching a haze once, the extending | stretching method as described in Unexamined-Japanese-Patent No. 2007-176164 etc. extended | stretched on specific conditions. A stretching method described in JP2009-137289A or the like that reduces haze can be preferably used. Moreover, about the method of extending | stretching in the state which left the solvent in the film and controlling the anisotropy of an elasticity modulus, the extending | stretching method as described in Unexamined-Japanese-Patent No. 2007-119717 etc. can be used preferably.
As used herein, “stretch ratio (%)” means that obtained by the following formula relating to the length of the film in the stretching direction.
Stretch ratio (%) = 100 × {(Length after stretching) − (Length before stretching)} / (Length before stretching)

  Further, the web stretching speed in the stretching step is not particularly limited, but is preferably 1 to 1000% / min, more preferably 1 to 100% / min from the viewpoint of proper stretching (wrinkle, handling, etc.). . Stretching may be performed in one stage or in multiple stages. Further, stretching may be applied in a direction (lateral direction) perpendicular to the transport direction.

  The web that has undergone the stretching process may be subsequently conveyed to a drying zone and the drying process may be performed after the stretching process. In the drying step, the web is dried while being clipped at both ends by a tenter or conveyed by a group of rolls.

[Humidity dimensional change rate]
The cellulose ester film according to the present invention has a direction perpendicular to an arbitrary side after 24 hours of aging at 25 ° C. and 80% of relative humidity, based on the lapse of 24 hours at 25 ° C. and 10% of relative humidity. The dimensional change rate (humidity dimensional change rate) of at least one of the parallel directions is 0.40% or less.
When measuring the humidity dimensional change rate of the cellulose acylate film in the present invention, a film sample having a length of 12 cm and a width of 3 cm is cut out in the measurement direction with the width direction of the film as the measurement direction. Pin holes are made in the sample at intervals of 10 cm along the measurement direction, the humidity is adjusted for 24 hours at 25 ° C. and a relative humidity of 10%, and the distance between the pin holes is measured with a pin gauge (measured value is L0). . Next, the sample is conditioned at 25 ° C. and a relative humidity of 80% for 24 hours, and the distance between the pin holes is measured with a pin gauge (measured value is L1). Using these measured values, the humidity dimensional change rate can be calculated by the following equation.
Humidity dimensional change rate [%] = (L1-L0) × 100 / L0
The width dimensional change in the width direction of the cellulose ester film of the present invention is preferably 0 to 0.40% or less, more preferably 0 to 0.38% or less, and 0 to 0.35. % Is particularly preferred.

The variation in the width direction of the humidity dimensional change rate is preferably 10% or less, more preferably 0 to 7%, and most preferably 0 to 5%.
Here, the variation in humidity dimensional change is measured by measuring the humidity dimensional change at five locations selected at equal intervals in the width direction, and dividing the difference between the maximum and minimum values by the average value at the five locations. To calculate.
When the variation in humidity dimensional change rate is large, the local difference in humidity dimensional change increases, so the laminated optical anisotropic layer follows the deformation, and the optical anisotropic layer is formed in a pattern. Further, pattern deformation is likely to occur, and the deterioration in display performance is more emphasized. It is presumed that the variation in the dimensional change rate of humidity is caused by the state of molecular chains in the film being uneven due to variations in the film temperature and the amount of solvent in the film in the width direction stretching region. In the present invention, the stretching conditions are made uniform for the purpose of suppressing residual stress (for example, the drying air volume and drying air temperature are preferably uniform in the width direction), so that the molecular chains in the film In order to improve the uniformity in this state, it was thought that the variation in the free volume in which moisture, solvent, etc. were taken in was reduced, and the variation in the width direction of the humidity dimensional change rate was reduced.

[Sound speed]
In the present invention, the sound velocity in the width direction and the longitudinal direction of the cellulose ester film is controlled by adjusting the film for 24 hours at 25 ° C. and a relative humidity of 60%, and then an orientation measuring machine (SST-2500: manufactured by Nomura Corporation). Can be measured. From the measurement result, the ratio of the sound speed in the width direction to the sound speed in the longitudinal direction can be calculated.
In the cellulose ester film of the present invention, the ratio of the sound speed in the width direction to the sound speed in the longitudinal direction is preferably 0.9 or more and 1.1 or less. More preferably, it is 0.95 or more and 1.10 or less. A film having a sound speed ratio in this range has a reduced residual stress and can suppress a wet heat dimensional change.

[Plasticizer surface ratio]
The cellulose ester film in the present invention contains a plasticizer, and the plasticizer concentration on the surface of the cured resin layer side is 95% or less of the plasticizer concentration on the hydrophilic resin layer side.
That is, plasticizer surface abundance ratio = {(plasticizer concentration on the surface of the cured resin layer side) / (plasticizer concentration on the hydrophilic resin layer side)} × 100 is 95% or less. Thus, the calculation is performed.
Each of the surfaces of the film was scraped by 10 μm using a knife, measured for mass, dissolved in acetone, and the amount of the plasticizer contained therein was quantitatively analyzed by gas chromatography. The plasticizer surface abundance ratio was calculated from the obtained results using the above formula.

[Retardation of cellulose ester film]
The cellulose ester film of the present invention has an in-plane retardation (in-plane retardation) Re of 0 nm or more and 5 nm or less, and a thickness direction retardation (thickness direction retardation) Rth of 0 nm or more and 50 nm or less. It is preferable that a pattern retardation layer is provided on the film because the optical influence on the pattern retardation layer can be reduced.

[Width of cellulose ester film]
The cellulose ester film of the present invention preferably has a film width of 1.8 m or more, more preferably 1.9 to 4 m, and still more preferably 2.2 to 3 m.

Even if the cellulose ester film obtained by the above method is sandwiched between layers having different physical properties such as a curable resin and a hydrophilic resin, the deformation in a wet heat environment is small and the adhesiveness is high.
Since it also has resistance to curling due to deformation of the resin layer, it is also useful as a polarizing plate protective film.

(Laminate)
The laminate of the present invention has a cured resin layer on one surface of the cellulose ester film and a hydrophilic resin layer on the other surface. Preferable specific examples of the cured resin layer and the hydrophilic resin layer are as follows.

(Cured resin layer)
The cured resin layer in the present invention is a layer formed by curing a curable compound.
A curable compound is a compound that is cured by light or heat. Specifically, a material having a curable functional group having a vinyl group, an allyl group, a (meth) acryloyl group, a glycidyl group, an epoxy group, or the like is an example. Can be mentioned.
The curable compound may be a low molecular compound, an oligomer, or a polymer (resin).
More specifically, examples of the curable compound include esters of polyhydric alcohol and (meth) acrylic acid, vinylbenzene and derivatives thereof, vinyl sulfone, (meth) acrylamide, polyester resin, polyether resin, acrylic resin, epoxy. Examples thereof include oligomers or prepolymers such as polyfunctional compounds such as resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols.

(Pencil hardness of cured resin layer)
After the cellulose ester film having a cured resin layer is conditioned at 25 ° C. and a relative humidity of 60% for 2 hours, a pencil hardness evaluation method specified by JIS-K5400 is performed using a test pencil specified by JIS-S6006. The pencil hardness was evaluated. Specifically, the surface of the cured resin layer was scratched 5 times with a pencil having each hardness using a weight of 500 g, and the hardness of up to one scratch was measured. Practically, 3H or more is preferable, and a higher numerical value is preferable because of higher hardness.

(Hydrophilic resin layer)
The hydrophilic resin is a resin having a polar group such as a hydroxyl group, and specific examples thereof include polyvinyl alcohol (PVA). Polyvinyl alcohols having various saponification degrees exist. In the present invention, those having a saponification degree of about 85 to 99 are preferably used. Commercial products may be used. For example, “PVA103”, “PVA203” (manufactured by Kuraray Co., Ltd.) and the like are PVA having the above saponification degree.

In the laminated body of this invention, the layer formed by fixing the orientation state of a liquid crystalline compound can be provided on the surface opposite to the surface which has a cellulose-ester film of a hydrophilic resin layer. A laminate having an optically anisotropic layer in which a liquid crystalline compound is aligned and the alignment state is fixed is preferred using the hydrophilic resin layer as an alignment film.
A schematic view of an example of the laminate of the present invention having an optically anisotropic layer is shown in FIG. The laminated body 10 of FIG. 2 has the layer 4 formed by fixing the orientation state of the cured resin layer 1, the cellulose ester film 2, the hydrophilic resin layer 3, and the liquid crystalline compound in this order.
Such a laminate can be used as an optical film having a retardation (for example, a retardation film). Furthermore, the optically anisotropic layer can be a patterned retardation layer having different retardation regions in the plane.
The layer formed by fixing the alignment state of the liquid crystal compound is preferably a layer having a plurality of retardation values, and is a layer in which strip-like regions having two kinds of retardation values are alternately arranged in a plane. More preferably. It is preferable that a dimensional change rate in a direction orthogonal to a direction in which the band-like regions are alternately arranged is 0.40% or less.

(Pattern retardation layer)
As a preferable aspect of the optically anisotropic layer, an aspect comprising a plurality of regions having different refractive indexes and arranged in a pattern in the longitudinal direction (the optically anisotropic layer in this aspect is also referred to as a pattern retardation layer). Is mentioned.
Further, the longitudinal direction of the patterning pattern (the direction of the long side of the pattern) may be substantially orthogonal or substantially parallel to the maximum sound velocity direction of the cellulose ester film, but is substantially orthogonal from the viewpoint of suppressing dimensional change. Is preferred.
Further, from the viewpoint that roll-to-roll is easily possible and wrinkles are less likely to occur even if a dimensional change occurs, it is preferable that they are substantially parallel.

The pattern retardation layer preferably includes first retardation regions (also simply referred to as first regions) and second retardation regions (also simply referred to as second regions) arranged alternately in the width direction. . Examples of the first phase difference region and the second phase difference region include a mode in which the refractive indexes are different from each other and a mode in which the direction of the slow axis is different.
FIG. 3 shows an example of a layer formed by fixing the alignment state of the liquid crystal compound in the present invention. FIG. 3 is a schematic view of a layer formed by fixing the alignment state of the liquid crystal compound in plan view, in which strip-shaped first retardation regions 41 and strip-shaped second retardation regions 42 are alternately arranged. . It is preferable that a dimensional change rate in a direction (direction indicated by an arrow A in FIG. 3) perpendicular to the direction in which the band-shaped regions are alternately arranged is 0.40% or less.

(Shape of the first area and the second area)
It is preferable that the first phase difference region and the second phase difference region are alternately patterned for each line. From the viewpoint of use for a 3D video display system, it is preferable that the first region and the second region have a strip shape in which the lengths of the short sides are substantially equal and are alternately and repeatedly patterned.

In the laminate of the present invention, the slow axis of the first region and the slow axis of the second region are substantially orthogonal to each other when passing through the first region and the second region when displaying a 3D image. This is preferable from the viewpoint of changing the polarization state of light from linearly polarized light to circularly polarized light, or from circularly polarized light to linearly polarized light.
In the laminate of the present invention, the slow axis of the first region and the slow axis of the second region are orthogonal to each other so that the first region and the second region pass when 3D video display is performed. It is more preferable from the viewpoint that the polarization state of the obtained light can be changed from linearly polarized light to circularly polarized light, or from circularly polarized light to linearly polarized light without being elliptically polarized light.

  In the laminated body of the present invention, the direction of the long side of the pattern and the direction in which the sound speed of the support is maximized are substantially orthogonal from the viewpoint of reducing the shift between the pattern area and the pixel and suppressing crosstalk. preferable.

(Retardation)
As described above, the pattern retardation layer having a function of converting from linearly polarized light to circularly polarized light or from circularly polarized light to linearly polarized light preferably has a retardation of ¼ of the wavelength. In general, it is called a quarter-wave plate, and Re = 137.5 nm is an ideal value at a visible light wavelength of 550 nm.
Further, the pattern retardation layer for converting linearly polarized light into circularly polarized light or circularly polarized light into linearly polarized light is not limited to having a retardation of ¼ wavelength. For example, a retardation of -1/4 or 3/4 of the wavelength may be used, and the retardation may be ¼ ± n / 2 (n is an integer) of the wavelength when expressed by a general formula.
Patterning in which the slow axis of the first region and the slow axis of the second region are orthogonal to each other may be performed by alternately forming regions having a retardation of -1/4 or 1/4 of the wavelength. At this time, the slow axes of each region are almost orthogonal. Further, the retardation of 1/4 and 3/4 of the wavelength may be patterned, and the slow axes of the mutual regions at this time are substantially parallel. However, the rotation directions of the circularly polarized light in the respective regions are reversed.
Further, in the patterning of the quarter of the wavelength and the retardation of the quarter, the retardation of 1/2 or −1/2 of the wavelength may be formed after the quarter of the wavelength is formed on the entire surface.
When the laminate of the present invention has a retardation of ¼ of the wavelength, the Re (550) value of the first region contained in the laminate and the Re of the second region contained in the laminate. (550) The value is preferably 30 to 250 nm, more preferably 50 to 230 nm, particularly preferably 100 to 200 nm, more preferably 105 to 180 nm, and more preferably 115 to 160 nm. Is more preferable, and it is more preferable that it is 130-150 nm.

  Also, from the viewpoint of changing the polarization state of the light that has passed through the first region and the second region when displaying 3D images from linearly polarized light to circularly polarized light, or from circularly polarized light to linearly polarized light, The total Re (550) of the retardation layer and the cellulose ester film is preferably 110 to 165 nm, more preferably 110 to 155 nm, and still more preferably 120 to 145 nm. In particular, the entire Re (550) of the pattern retardation layer and the cellulose ester film is in the above range, and the slow axes of the first region and the second region are substantially orthogonal to each other with the right eye image accurately. This is preferable from the viewpoint that the polarization state of the left-eye image can be changed.

(Pattern formation method)
The first region and the second region can be formed by various methods. Although the example of the method is given to the following, this invention is not limited to this.

[Pattern exposure]
Pattern exposure can be performed for patterning of the retardation layer.
Pattern exposure means performing exposure under different exposure conditions on two or more regions of the birefringence pattern builder. The “two or more regions” at this time may or may not have overlapping portions, but preferably does not have overlapping portions. The pattern exposure may simply be pattern exposure that produces only unexposed portions and exposed portions. In this case, a region where a normal phase difference is to be left is exposed. Further, the pattern exposure may be a pattern exposure including an exposed portion under one or more exposure conditions that are halftone between the unexposed portion and the exposed portion. The pattern exposure may be performed by a single exposure or a plurality of exposures. For example, the exposure may be performed by one exposure using a mask having two or more regions showing different transmission spectra depending on the region, or the two may be combined.

  The exposure conditions are not particularly limited, and examples include exposure peak wavelength, exposure illuminance, exposure time, exposure amount, temperature during exposure, atmosphere during exposure, and the like. Among these, from the viewpoint of ease of condition adjustment, the exposure peak wavelength, the exposure illuminance, the exposure time, and the exposure amount are preferable, and the exposure illuminance, the exposure time, and the exposure amount are more preferable. The areas exposed under different exposure conditions during pattern exposure then exhibit birefringence that is different through firing and controlled by the exposure conditions. In particular, different phase difference amounts are given. Note that the exposure conditions between two or more exposure regions exposed under different exposure conditions may be changed discontinuously or may be changed continuously.

[Mask exposure]
Exposure using an exposure mask is useful as a means for generating exposure regions with different exposure conditions. For example, after performing exposure using an exposure mask that exposes only one region, the temperature, atmosphere, exposure illuminance, exposure time, and exposure wavelength are changed to perform exposure using another mask or overall exposure. The exposure conditions for the previously exposed area and the later exposed area can be easily changed. Further, a mask having two or more regions showing different transmission spectra depending on the region is particularly useful as a mask for changing the exposure illuminance or the exposure wavelength. In this case, exposure with different exposure illuminances or exposure wavelengths can be performed on a plurality of regions by performing only one exposure. It goes without saying that different exposure amounts can be given by performing exposure for the same time under different exposure illuminances.
When scanning exposure using a laser or the like is used, it is possible to change the exposure conditions for each region by a method such as changing the light source intensity or changing the scanning speed depending on the exposure region.

As a pattern exposure method, contact exposure using a mask, proxy exposure, projection exposure, or the like may be used, or direct drawing may be performed by focusing on a predetermined position without using a mask using a laser or an electron beam. The irradiation wavelength of the exposure light source preferably has a peak at 250 to 450 nm, and more preferably has a peak at 300 to 410 nm. In the case where a step is simultaneously formed by the photosensitive resin layer, it is also preferable to irradiate light in a wavelength region that can cure the resin layer (eg, 365 nm, 405 nm, etc.). Specifically, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a blue laser, and the like can be given. Usually 3~2000mJ / cm ² about the preferred amount of exposure, and more preferably 5~1000mJ / cm ² or so, more preferably 10 to 500 mJ / cm ² or so, and most preferably at about 10 to 100 mJ / cm ² .

[Heating (Bake)]
By baking the phase-exposed retardation layer at 50 ° C. or more and 400 ° C. or less, the retardation amount is patterned with a pattern according to the exposure conditions during the pattern exposure. When the retardation disappearance temperature before exposure of the used retardation layer is T1 [° C.] and the retardation disappearance temperature after exposure is T2 [° C.] (when the retardation disappearance temperature is not in the temperature range of 250 ° C. or lower). Is T2 = 250 ° C.), and the baking temperature is preferably T1 ° C. or higher and T2 ° C. or lower, more preferably (T1 + 10) ° C. or higher and (T2-5) ° C. or lower, and (T1 + 20) ° C. or higher (T2-10) ° C. The following are most preferred.
When using a retardation layer in which the retardation disappearance temperature rises, the exposure reduces the retardation of the unexposed area in the layer by exposure, while the exposed area has little or no decrease in retardation. As a result, the retardation of the unexposed portion becomes smaller than the retardation of the exposed portion, and a pattern of the presence or absence of an axis or a phase difference amount is produced.

[Axial patterning]
The method of patterning in the axial direction is not particularly limited, but patterning in the direction of the optical axis (slow axis) of the retardation layer can be preferably performed using an alignment layer.
A layer containing a liquid crystal compound provided on the photo-alignment layer, preferably a layer containing a liquid crystal compound provided directly on the photo-alignment layer is a polarized light from which the photo-alignment layer was produced when irradiated with ultraviolet light. Liquid crystal molecules are aligned in the polarization direction of ultraviolet light. Similarly, a layer containing a liquid crystal compound provided on the rubbing alignment layer, preferably a layer containing a liquid crystal compound provided directly on the rubbing alignment layer, is liquid crystal in the rubbing direction when irradiated with ultraviolet light. The molecules are oriented.

  Therefore, when the pattern retardation layer is provided on the photo-alignment layer, the pattern exposure technique used when the pattern retardation layer is formed on the layer formed from the composition for forming the photo-alignment layer including the alignment material; By a similar method, polarized ultraviolet light is pattern-irradiated and the photo-alignment property of this layer is patterned. A composition containing a liquid crystal compound is applied on the obtained photo-alignment layer, dried, and the like, and then irradiated with ultraviolet light to obtain a retardation layer whose axial direction is patterned. Similarly, when providing the pattern retardation layer on the rubbing alignment layer, the layer before rubbing formed from the rubbing alignment layer forming composition is rubbed through a mask or the like, and the rubbing direction of this layer is determined. Pattern. A composition containing a liquid crystal compound is applied onto the obtained rubbing alignment layer, dried, and the like, and then irradiated with ultraviolet light to obtain a retardation layer whose axial direction is patterned.

  Also in this embodiment, the optically anisotropic layer may be formed on the alignment film. That is, an alignment film may be formed in advance, and the fluid may be discharged to a fine region of the alignment film. The alignment film that can be used in this embodiment is the same as the alignment film that can be used in the embodiment of the transfer method. A method for forming the alignment film is not particularly limited, but in the present embodiment, it is preferable to form the alignment film by an ink jet method as in the formation of the optically anisotropic layer. After the ejection of the fluid is completed, the fluid layer is optionally dried to form a liquid crystal phase and cured by exposure to form an optically anisotropic layer. In order to form a liquid crystal phase, it may be heated as desired, and in that case, a heating device may be used.

  The fluid is preferably curable, that is, a fluid prepared from the curable composition as a fluid such as a solution. As the polymerization initiator and the like to be contained in the curable composition, various polymerization initiators described in the embodiment of the transfer method can be used. The fluid may contain an additive such as an orientation control agent, and these examples are the same as the various additives described in the embodiments of the transfer method. Also, examples of the solvent used for the preparation of the fluid are the same as the examples of the solvent that can be used for the preparation of the coating liquid in the embodiment of the transfer method.

  There are no particular restrictions on the ejection conditions of the ink or the like when forming the optically anisotropic layer, but when the viscosity of the fluid for forming the optically anisotropic layer is high, it may be at room temperature or under heating (for example, 20 to 70 ° C. ), It is preferable from the viewpoint of injection stability that the ink is ejected at a reduced viscosity. It is preferable to keep the temperature of the ink or the like as constant as possible because the viscosity fluctuation of the ink or the like greatly affects the droplet size and the droplet ejection speed as it is and causes image quality degradation.

  The ink jet head used in the above method (hereinafter also simply referred to as a head) is not particularly limited, and various known ones can be used. A continuous type and a dot-on-demand type can be used. Among the dot-on-demand types, the thermal head is preferably a type having an operation valve as described in JP-A-9-323420 for discharging. As the piezo head, for example, the heads described in European Patent A277,703, European Patent A278,590 and the like can be used. The head preferably has a temperature control function so that the temperature of the composition can be controlled. It is preferable to set the injection temperature so that the viscosity at the time of injection of the fluid is 5 to 25 mPa · s, and to control the fluid temperature so that the fluctuation range of the viscosity is within ± 5%. Moreover, as a drive frequency, it is preferable to operate | move at 1-500 kHz.

  The laminate of the present invention is particularly suitable for use in a large screen liquid crystal display device. When used as an optical film for a large-screen liquid crystal display device, for example, the film width is preferably 1470 mm or more. In addition, the laminate of the present invention is produced not only in the form of a film piece cut into a size that can be incorporated into a liquid crystal display device as it is, but also in a long shape by continuous production and in a roll shape. A film in a rolled up form is also included. The film of the latter mode is stored and transported in that state, and is cut into a desired size and used when actually incorporated into a liquid crystal display device or bonded to a polarizer or the like. Similarly, it is cut into a desired size when it is actually assembled into a liquid crystal display device after being bonded to a polarizing film made of a polyvinyl alcohol film or the like, which is produced in a long shape, in a long shape. Used. As an aspect of the film wound up in a roll shape, an embodiment in which the roll length is rolled up into a roll having a length of 2500 m or more can be mentioned.

[Polarizer]
The polarizing plate of the present invention is characterized in that at least one cellulose ester film or laminate of the present invention is used as a protective film.
Examples of the polarizing plate include a conventionally known polarizing plate having a general configuration. The specific configuration of the polarizing plate is not particularly limited, and a known configuration can be employed. The configuration described in FIG. 6 of Japanese Patent No. 262161 may be employed. The laminate of the present invention can be laminated on one surface of a general polarizing plate to form a pattern retardation film that can be used in a polarized glasses type 3D video display system. The embodiment of the polarizing plate is not only a polarizing plate in the form of a film piece cut into a size that can be incorporated into a liquid crystal display device as it is, but also is produced in a strip shape, that is, a long shape by continuous production, and a roll The polarizing plate of the aspect wound up in the shape (for example, roll length 2500m or more, 3900m or more aspect) is also contained. In order to use for a large-screen liquid crystal display device, the width of the polarizing plate is preferably 1470 mm or more as described above.

[Adhesive layer]
In the polarizing plate of this invention, you may laminate | stack a cellulose-ester film or a laminated body, and a polarizing film through an adhesion layer.
In the present invention, the pressure-sensitive adhesive layer used for laminating the cellulose ester film or laminate and the polarizing film is, for example, a ratio of G ′ and G ″ measured with a dynamic viscoelasticity measuring apparatus (tan δ = G ″). / G ′) represents a substance having a value of 0.001 to 1.5, and includes a so-called pressure-sensitive adhesive, a substance that easily creeps, and the like.

[Video display panel]
The video display panel can be configured by including at least one cellulose ester film of the present invention, a laminate, or a polarizing plate. A preferred embodiment is that the cellulose ester film or laminate of the present invention is used as a protective film close to the viewing side. Thereby, for example, when the pattern retardation layer is provided, the polarization state of the light that has passed through the first region and the light that has passed through the second region among the light from the image display panel can be changed, The video display panel can display a 3D stereoscopic video display.
The video display panel used in the video display device of the present invention is not particularly limited and may be a CRT or a flat panel display, but is preferably a flat panel display. As the flat panel display, a PDP, an LCD, an organic ELD, or the like can be used. However, the present invention can be applied particularly preferably when the video display panel is a liquid crystal display panel. By using the liquid crystal display panel as the video display panel, it is possible to provide a video display system with high image quality and low cost among flat panel displays.
The liquid crystal display device is a liquid crystal display device having a liquid crystal cell and a pair of polarizing plates disposed on both sides of the liquid crystal cell, wherein at least one of the polarizing plates is the polarizing plate of the present invention. It is preferable to arrange so that the cellulose ester film or the protective film which is the laminate is the protective film closest to the viewing side. In particular, an IPS, OCB, or VA mode liquid crystal display device is preferable.
There is no restriction | limiting in particular as a concrete structure of the said liquid crystal display device, A well-known structure is employable. Further, the configuration described in FIG. 2 of JP-A-2008-262161 can also be preferably employed.

[Video display system]
The cellulose ester film, laminate, polarizing plate, or liquid crystal display device of the present invention can also be used in an image display system. Thus, for example, when the pattern retardation layer is provided, the left-eye image and the right-eye image are input to the video display panel, and the left-eye image and the right-eye image are input from the video display panel to the optical film of the present invention. Left eye image (or right eye image) that has passed through the first region of the pattern phase difference layer according to the present invention, and right eye image that has passed through the second region ( Alternatively, the polarization state of the left eye image) can be changed. Furthermore, a left-eye lens with a polarizing plate that transmits only the image for the left eye that has passed through the first region, and a right-eye lens with a polarizing plate that transmits only the image for the right eye that has passed through the second region. By using the polarized glasses provided together, it is possible to obtain a video display system that allows only the left-eye image and the right-eye image to enter the left and right eyes and observe 3D video display.
Such a video display system is described in US Pat. No. 5,327,285. An example of polarized glasses is described in JP-A-10-232365.
In addition, among the commercially available video display systems, the pattern retardation film may be peeled off and replaced with the optical film of the present invention.

  In the present invention, as a preferable video display system, the following liquid crystal display device is exemplified. That is, the liquid crystal display device includes a pair of substrates having electrodes arranged at least on one side, a liquid crystal layer between the pair of substrates, and a liquid crystal layer sandwiched between the polarizing film and the polarizing film. A protective film provided on at least the outer surface, a first polarizing plate disposed on the light source side, a second polarizing plate disposed on the viewing side, and further viewing the second polarizing plate A liquid crystal display device for visually recognizing an image through a third polarizing plate having a polarizing film and at least one protective film on the side, and a liquid crystal using the polarizing plate having the laminate of the present invention as the second polarizing plate It is a display device. Since the laminated body of the present invention uses a support having a small dimensional change accompanying a temperature change, a good 3D display performance without crosstalk can be obtained even after a lapse of time.

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

(Degree of acetyl substitution)
The acetyl substitution degree of cellulose acylate was measured by the following method.
The degree of acetyl substitution was measured according to ASTM D-817-91. The viscosity average degree of polymerization was measured by Uda et al.'S intrinsic viscosity method {Kazuo Uda, Hideo Saito, "Journal of Textile Society", Vol. 18, No. 1, 105-120 (1962)}.

1. Production of retardation film (preparation of film 1)
(1) Preparation of intermediate layer dope 1 An intermediate layer dope 1 having the following composition was prepared.
――――――――――――――――――――――――――――――――――――
Composition of Dope 1 ――――――――――――――――――――――――――――――――――――
Cellulose acetate 100 parts by weight (acetylation degree 2.86, number average molecular weight 88000)
Methylene chloride (first solvent) 320 parts by mass Methanol (second solvent) 83 parts by mass 1-butanol (third solvent) 3 parts by mass Triphenyl phosphate 7.6 parts by mass Biphenyl diphenyl phosphate 8 parts by mass

Specifically, it was prepared by the following method.
While stirring and dispersing the above mixed solvent well into a 4000L stainless steel dissolution tank with stirring blades, gradually add cellulose acetate powder (flakes), triphenyl phosphate and biphenyl diphenyl phosphate to a total weight of 2000 kg. It was prepared as follows. In addition, all the solvents used that the water content is 0.5 mass% or less. First, cellulose acetate powder is a dissolver type in which powder is put into a dispersion tank and stirred at a peripheral shear speed of 5 m / sec (shear stress 5 × 10 ⁴ kgf / m / sec ² ) at first. Dispersion was performed for 30 minutes under the condition of having an eccentric stirring shaft and an anchor blade on the central shaft and stirring at a peripheral speed of 1 m / sec (shear stress of 1 × 10 ⁴ kgf / m / sec ² ). The starting temperature of dispersion was 25 ° C., and the final temperature reached 48 ° C. After completion of the dispersion, the high-speed stirring was stopped, and the peripheral speed of the anchor blade was set to 0.5 m / sec and further stirred for 100 minutes to swell the cellulose acetate flakes. Until the end of swelling, the inside of the tank was pressurized to 0.12 MPa with nitrogen gas. At this time, the oxygen concentration in the tank was less than 2 vol%, and the state of no problem was maintained in terms of explosion protection. The water content in the dope was confirmed to be 0.5% by mass or less, specifically 0.3% by mass.

The swollen solution was heated from the tank to 50 ° C. with a jacketed pipe, and further heated to 90 ° C. by pressurization at 2 MPa to completely dissolve. The heating time was 15 minutes.
Next, the temperature was lowered to 36 ° C., and a dope was obtained by passing through a filter medium having a nominal pore diameter of 8 μm. At this time, the primary pressure of filtration was 1.5 MPa, and the secondary pressure was 1.2 MPa. The filters, housings, and pipes exposed to high temperatures were made of Hastelloy alloy and had excellent corrosion resistance, and those having a jacket for circulating a heat medium for heat insulation and heating were used.

The pre-concentration dope thus obtained was flushed at 80 ° C. in a normal pressure tank, and the evaporated solvent was recovered and separated by a condenser. The solid concentration of the dope after flashing was 21.8% by mass. The condensed solvent was sent to a recovery process to be reused as a solvent in the preparation process (recovery is carried out by a distillation process, a dehydration process, etc.). A flash tank having an anchor blade on the central axis was used for defoaming by stirring at a peripheral speed of 0.5 m / sec. The temperature of the dope in the tank was 25 ° C., and the average residence time in the tank was 50 minutes. The shear viscosity measured at 25 ° C. after collecting this dope was 450 (Pa · s) at a shear rate of 10 (sec ⁻¹ ).

  Next, bubbles were removed by irradiating the dope with weak ultrasonic waves. Thereafter, under a pressure of 1.5 MPa, first, a sintered fiber metal filter having a nominal pore diameter of 10 μm was passed, and then, a 10 μm sintered fiber filter was also passed. Respective primary pressures were 1.5 and 1.2 MPa, and secondary pressures were 1.0 and 0.8 MPa. The dope temperature after filtration was adjusted to 36 ° C. and stored in a 2000 L stainless steel stock tank. By using a stock tank having an anchor blade on the central axis and stirring constantly at a peripheral speed of 0.3 m / sec, an intermediate layer dope 1 was obtained. In addition, when the dope was prepared from the dope before concentration, no problem such as corrosion occurred at all in the wetted part of the dope.

  Subsequently, the dope 1 in the stock tank was fed by a feedback pump control using an inverter motor so that the primary pressure of the high precision gear pump was 0.8 MPa with a gear pump for primary pressure increase. The high-precision gear pump had a volume efficiency of 99.2% and a discharge rate variation of 0.5% or less. The discharge pressure was 1.5 MPa.

(2) Preparation of dope 2 for support layer Matting agent (silicon dioxide (particle size 20 nm)) and release accelerator (citric acid ethyl ester (citric acid, monoethyl ester, diethyl ester, triethyl ester mixture)) and the intermediate The layer dope 1 was mixed through a static mixer to prepare a support layer dope 2. The addition amount was such that the total solid content concentration was 20.5% by mass, the matting agent concentration was 0.05% by mass, and the release accelerator concentration was 0.03% by mass.

(3) Preparation of Air Layer Dope 3 A matting agent (silicon dioxide (particle size: 20 nm)) was mixed with the intermediate layer dope 1 through a static mixer to prepare an air layer dope 3. The amount added was such that the total solid content concentration was 20.5% by mass and the matting agent concentration was 0.1% by mass.

(4) Film formation by co-casting Equipped with a feed block adjusted for co-casting as a casting die, an apparatus that can form a three-layer film by laminating on both sides in addition to the main stream Was used. In the following description, a layer formed from the mainstream is referred to as an intermediate layer, a layer on the support surface side is referred to as a support layer, and a surface on the opposite side is referred to as an air layer. In addition, the dope liquid supply flow path used three flow paths for the intermediate layer, the support layer, and the air layer.

The intermediate layer dope, support layer dope 2 and air layer dope 3 were co-cast from a casting port onto a drum cooled to -5 ° C. At this time, the flow rate of each dope was adjusted so that the thickness ratio was air layer / intermediate layer / support layer = 4/73/3. The cast dope film was dried by applying a drying air of 34 ° C. at 230 m ³ / min on the drum, and the residual solvent was peeled off from the drum in a state of 150%. During peeling, 8% stretching was performed in the transport direction (longitudinal direction). Thereafter, the film is stretched by 10% in the width direction while holding both ends of the film in the width direction (direction perpendicular to the casting direction) with a pin tenter (the pin tenter described in FIG. 3 of JP-A-4-1009). Processed. Furthermore, it dried further by conveying between the rolls of the heat processing apparatus, and the film 1 was manufactured. The produced cellulose acylate film had a residual solvent amount of 0.2% and a thickness of 80 μm.

(Preparation of film 2)
When film 1 was formed, film 2 was formed in the same manner as film 1 except that the thickness of the film after film formation was adjusted to 60 μm and the drying air on the drum was adjusted to 200 m ³ / min. Produced.

(Preparation of film 3)
Film 3 was produced in the same manner as film 2 except that the film 2 was prepared so that the drying air on the drum was adjusted to 260 m ³ / min.

(Preparation of film 4)
When the film 2 was formed, the drying air on the drum was 250 m ³ / min, the thickness of the film after the film formation was 66 μm, and the stretching ratio in the width direction when holding the pin tenter was 0%. An unstretched film was produced without changing the conditions. The width direction of the unstretched film was held with a tenter clip, heated to 175 ° C., stretched 10% in the width direction, and a film 4 having a thickness of 60 μm was produced.

(Preparation of film 5)
Film 5 was produced by performing film formation in the same manner as film 3 except that the stretching ratio in the width direction during gripping the pin tenter was adjusted to 20% when film 3 was formed.

(Preparation of film 6)
Film 6 was produced by performing film formation in the same manner as film 2 except that the film 2 was adjusted to have a thickness of 40 μm when the film 2 was formed.

(Preparation of film 7)
Film 7 was produced by carrying out film formation in the same manner as film 1 except that the film 1 was adjusted so that the stretching in the conveyance direction was 3% and the thickness of the film after film formation was 25 μm.

(Preparation of film 8)
(Preparation of cellulose ester solution for air layer)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an air layer cellulose ester solution.

Composition of cellulose ester solution for air layer
・ Cellulose ester (acetyl substitution degree 2.86) 100 parts by mass
-3 parts by mass of sugar ester compound of formula (I)
-1 mass part of sugar ester compound of formula (II)
・ Ultraviolet absorber 2.4 parts by weight ・ Silica particle dispersion (average particle size 16 nm) “AEROSIL R972”, manufactured by Nippon Aerosil Co., Ltd.
0.026 parts by mass
・ Methylene chloride 339 parts by mass
・ 74 parts by mass of methanol
・ 3 parts by weight of butanol

Formula (I)

Formula (II)

UV absorber

(Preparation of cellulose ester solution for drum layer)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose ester solution for a drum layer.

Composition of cellulose ester solution for drum layer
・ Cellulose ester (acetyl substitution degree 2.86) 100 parts by mass
-3 parts by mass of sugar ester compound of formula (I)
-1 mass part of sugar ester compound of formula (II)
・ Ultraviolet absorber 2.4 parts by weight ・ Silica particle dispersion (average particle size 16 nm) “AEROSIL R972”, manufactured by Nippon Aerosil Co., Ltd.
0.091 parts by mass
・ Methylene chloride 339 parts by mass
・ 74 parts by mass of methanol
・ 3 parts by weight of butanol

(Preparation of cellulose ester solution for core layer)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose ester solution for the core layer.

Composition of cellulose ester solution for core layer
・ Cellulose ester (acetyl substitution degree 2.86) 100 parts by mass
-Sugar ester compound of formula (I) 8.3 parts by mass
-2.8 mass parts of sugar ester compound of formula (II)
・ Ultraviolet absorber 2.4 parts by weight ・ Methylene chloride 266 parts by mass
・ Methanol 58 parts by mass
・ 2.6 parts by weight of butanol

(Filming by co-casting)
As a casting die, an apparatus equipped with a feed block adjusted for co-casting so that a film having a three-layer structure can be formed was used. The cellulose ester solution for the air layer, the cellulose ester solution for the core layer, and the cellulose ester solution for the drum layer were co-cast on a drum cooled to −7 ° C. from the casting port. At this time, the flow rate of each dope was adjusted so that the thickness ratio was air layer / intermediate layer / support layer = 7/90/3.
It casted on the mirror surface stainless steel support body which is a drum of diameter 3m. A dry air of 34 ° C. was applied on the drum at 200 m ³ / min.
The cellulose ester film cast and rotated 50 cm before the end point of the casting part was peeled off from the drum, and then both ends were clipped with a pin tenter. During peeling, 8% stretching was performed in the transport direction (longitudinal direction).

The cellulose ester web held by the pin tenter was conveyed to the drying zone. In the initial drying, a drying air of 45 ° C. was blown and then dried at 110 ° C. for 5 minutes. At this time, the cellulose ester web was conveyed while stretching in the width direction at a magnification of 10%.
After the web was detached from the pin tenter, the portion held by the pin tenter was continuously cut out, and unevenness with a width of 15 mm and a height of 10 μm was made at both ends in the width direction of the web. The width of the web at this time was 1610 mm. The film was dried at 140 ° C. for 10 minutes while applying a tension of 210 N in the conveying direction. Furthermore, the end in the width direction was continuously cut so that the web had a desired width, and a film 8 having a thickness of 60 μm was produced. At this time, the film thickness of the width direction edge part cut off after 140 degreeC drying and the web center part was the same.

(Preparation of film 9)
Film 9 was produced by carrying out film formation in the same manner as film 8 except that the drying air on the drum was adjusted to be 300 m ³ / min when the film 8 was formed.

(Preparation of film 10)
When the film 8 was formed, the drying air on the drum was 250 m ³ / min, the thickness of the film after film formation was 66 μm, and the draw ratio in the width direction when pinter was gripped was 0%. An unstretched film was produced without changing the conditions. The width direction of the unstretched film was held with a tenter clip, heated to 195 ° C., and stretched by 10% in the width direction to produce a film 10 having a thickness of 60 μm.

(Preparation of film 11)
When film 8 was formed, film formation was performed in the same manner as film 8 except that the stretching ratio in the width direction when holding the pin tenter was adjusted to 20% and the drying air on the drum was adjusted to 300 m ³ / min. Thus, a film 11 was produced.

(Preparation of film 12)
When the film 9 was formed, the film 12 was formed in the same manner as the film 9 except that the tension during web conveyance was set to 130 N.

(Preparation of film 13)
When the film 12 was formed, a film 13 was prepared by performing film formation in the same manner as the film 12 except that the following alternative cellulose ester solution was used as the dope for the air layer.
(Preparation of alternative cellulose ester solution)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an air layer cellulose ester solution.

Composition of cellulose ester solution for air layer
・ Cellulose ester (acetyl substitution degree 2.86) 100 parts by mass
-3 parts by mass of sugar ester compound of formula (I)
-1 mass part of sugar ester compound of formula (II)
・ Ultraviolet absorber 2.4 parts by weight ・ Silica particle dispersion (average particle size 16 nm) “AEROSIL R972”, manufactured by Nippon Aerosil Co., Ltd.
0.026 parts by mass
・ Methylene chloride 377 parts by mass
・ Methanol 61 parts by mass
・ 2.6 parts by weight of butanol

(Preparation of film 14)
When the film 13 was formed, the film 14 was formed in the same manner as the film 13 except that the average thickness of the end portion in the width direction cut after drying at 140 ° C. was adjusted to be 6 μm thicker than the center of the web. Produced.

(Preparation of film 15)
A film 15 was produced by forming the film 13 in the same manner as the film 13 except that the web width when dried at 140 ° C. was adjusted to 1650 mm when the film 13 was formed.

(Preparation of film 16)
Film 16 was produced in the same manner as film 13 except that the height of the unevenness applied to the web edge after drying at 110 ° C. was adjusted to 30 μm when film 13 was formed.

(Preparation of film 21)
Except for adjusting the film 1 so that the stretching in the conveying direction is 15%, the stretching ratio in the width direction when holding the pin tenter is 0%, and the drying wind on the drum is 150 m ³ / min. Film 21 was produced in the same manner as film 1.

(Preparation of film 22)
Film 22 was produced in the same manner as film 1 except that the film was formed such that the drying air on the drum was adjusted to 150 m ³ / min when the film 1 was formed.

(Preparation of film 23)
Except for adjusting the stretching direction in the conveying direction to 15%, the stretching ratio in the width direction when holding the pin tenter to 0%, and the drying wind on the drum being 150 m ³ / min. Film 23 was produced by film formation in the same manner as film 2.

(Preparation of film 24)
A film 24 was produced by forming the film 23 in the same manner as the film 23 except that the drying air on the drum was adjusted to be 200 m ³ / min when the film 23 was formed.

(Preparation of film 25)
Film 25 was produced by performing film formation in the same manner as film 2 except that the film 2 was adjusted so that the drying air on the drum was 150 m ³ / min.

(Preparation of film 26)
Except for adjusting the film 6 so that the stretching in the conveyance direction is 15%, the stretching ratio in the width direction when holding the pin tenter is 0%, and the drying wind on the drum is 140 m ³ / min. Film formation was performed in the same manner as film 6 to produce film 26.

(Preparation of film 27)
Film 27 was produced by performing film formation in the same manner as film 6 except that the film 6 was formed such that the drying air on the drum was adjusted to 140 m ³ / min.

(Preparation of film 28)
Except for adjusting the film 7 so that the stretching in the conveying direction is 11%, the stretching ratio in the width direction when holding the pin tenter is 0%, and the drying wind on the drum is 120 m ³ / min. Film 28 was produced by film formation in the same manner as film 7.

(Preparation of film 29)
Film 29 was produced by performing film formation in the same manner as film 7 except that the film 7 was formed so that the drying air on the drum was adjusted to 120 m ³ / min.

(Preparation of film 30)
Except for adjusting the film 8 so that the stretching in the conveying direction is 11%, the stretching ratio in the width direction when holding the pin tenter is 0%, and the drying air on the drum is 150 m ³ / min. Film 30 was produced in the same manner as film 8.

(Preparation of film 31)
Film 31 was formed in the same manner as film 8 except that the film 8 was adjusted to 11% in the conveyance direction and 0% in the width direction when the pin tenter was gripped. Was made.

(Preparation of film 32)
Film 32 was produced in the same manner as film 8 except that the film 8 was formed so that the drying air on the drum was adjusted to 150 m ³ / min.

Table 1 below shows the film performance of the films 1-16 and 21-32 produced as described above.
In addition, when the width direction dispersion | variation in the TD direction humidity dimensional change rate was measured about the films 1-16 quoted as an Example, all the films satisfy | filled 10% or less.

(Humidity dimensional change rate)
A film sample having a length of 12 cm and a width of 3 cm is cut out in the measurement direction with the width direction of the film as the measurement direction. Pin holes were formed in the sample at intervals of 10 cm along the measurement direction, and after adjusting the humidity for 24 hours at 25 ° C. and a relative humidity of 10%, the distance between the pin holes was measured with a pin gauge (measured value is L0). . Next, the sample was conditioned at 25 ° C. and 80% relative humidity for 24 hours, and the distance between the pin holes was measured with a pin gauge (measured value is L1). Using these measured values, the humidity dimensional change rate was calculated by the following formula.
Humidity dimensional change rate [%] = (L1-L0) × 100 / L0

[Plasticizer surface ratio]
Each of the surfaces of the film was scraped by 10 μm using a knife, measured for mass, dissolved in acetone, and the amount of the plasticizer contained therein was quantitatively analyzed by gas chromatography. From the obtained results, the plasticizer ratio on the film surface was calculated using the following formula.
Plasticizer ratio on film surface = (Amount of plasticizer on air interface side surface) / (Plasticizer content on casting support side surface)
A cured resin layer is applied to the air interface side surface of the cellulose acylate film, and a hydrophilic resin layer is applied to the casting support side surface.

Preparation of Hard Coat Layer Coating Liquid 1 The hard coating layer coating liquid 1 has a solid content concentration of 55% by mass, and the monomer and UV initiator have a mass ratio of 53.5 / 1.5. Moreover, Nippon Kayaku Co., Ltd. PET30 was used as a monomer, and ethyl acetate was used as a solvent. As a UV initiator, IRGACURE127 manufactured by Ciba Japan Co., Ltd. was used.

Application of Hard Coat Layer Application of a hard coat layer, which is a cured resin layer, to the films 1-16 and 21-32 obtained above was performed in the following manner. The hard coat layer coating solution was applied by hand with a number 8 bar coater, dried at 100 ° C. for 60 seconds, and irradiated with ultraviolet rays under a condition of 0.1% nitrogen or less at 300 mJ with a 1.5 kW metal halide lamp. Cured. The hard coat hardness after curing was 3H or more in any sample.
The cured resin layer 1 was applied to the air interface side surface of the cellulose acylate film.

(Synthesis of (a) ion conductive compound IP-15)
It is carried out in the same manner as in Synthesis Example 2 of Japanese Patent No. 46006065, and as a compound corresponding to (A-2) of the patent document, IP-15 (30% by mass) which is a quaternary ammonium base-containing polymer having an ethylene oxide chain Ethanol solution) was synthesized.

(Synthesis of (a) ion conductive compound IP-16)
This was carried out in the same manner as in Synthesis Example 5 of Japanese Patent No. 4678451, and as a compound corresponding to (A-5) of this patent document, IP-16 (30% by mass) which is a quaternary ammonium base-containing polymer having an ethylene oxide chain Ethanol solution) was synthesized.

(Synthesis of (a) ion conductive compound IP-17)
Except that the reaction time was changed to 70 ° C. for 6 hours, the reaction was carried out in the same manner as in Synthesis Example 6 of Japanese Patent No. 4678451, and a quaternary compound having an ethylene oxide chain as a compound corresponding to (A-6) of the patent document IP-17 (30% by mass ethanol solution), which is an ammonium base-containing polymer, was synthesized. The weight average molecular weight measured by GPC was about 60,000.

(Synthesis of (a) ion conductive compound IP-18)
Except that the reaction time was changed to 70 ° C. for 6 hours, the reaction was carried out in the same manner as in Synthesis Example 7 of Japanese Patent No. 4678451, and a quaternary compound having an ethylene oxide chain as a compound corresponding to (A-7) of the patent document IP-18 (30% by mass ethanol solution), which is an ammonium base-containing polymer, was synthesized. The weight average molecular weight measured by GPC was about 60,000.

(Preparation of coating solution for antistatic hard coat layer)
Each component was added so that it might become the composition of the coating liquid A-1 for antistatic hard-coat layers of Table 2 below, the obtained composition was put into a mixing tank, stirred, and a pore diameter of 0.4 μm It filtered with the filter made from a polypropylene, and was set as antistatic hard-coat layer coating liquid A-1.
In the same manner as the coating solution A-1 for antistatic hard coat layer, each component was mixed as shown in Table 2 below and dissolved in a solvent to adjust the composition ratio as shown in Table 2 to prevent antistatic. -Resistant hard coat layer coating solutions A-2 to A-4 were prepared.

The compounds used are shown below.
A-TMMT: Pentaerythritol tetraacrylate (Shin Nakamura Chemical Co., Ltd. NK Ester)
ADTMP: Ditrimethylolpropane tetraacrylate (Shin-Nakamura Chemical Co., Ltd. NK Ester)
Irg. 127: Photopolymerization initiator, Irgacure 127 (manufactured by Ciba Japan Co., Ltd.)

  In addition, it confirmed that all the weight average molecular weights of IP-15, IP-16, IP-17, and IP-18 which are the conductive polymers used in the Example were in the range of 20,000 to 500,000.

Preparation of Antistatic Hard Coat Layer As shown above, antistatic hard coat layer coating solutions A-1 to A-4 were prepared, and charged to films 13 to 16 obtained above according to Table 3 below. Prevention hard coat layers A-1 to A-4 are formed, and films with hard coat layers No. 41-44 were produced. The coating conditions for the coating solution for the antistatic hard coat layer were after manually coating with a count 11 bar coater, dried at 60 ° C. for 60 seconds, and with an air-cooled metal halide lamp with 160 W / cm of ultraviolet rays under conditions of 0.1% nitrogen or less ( The anti-static hard coat layer having a thickness of about 10 μm is cured by irradiating with ultraviolet rays having an illuminance of 400 W / illuminance of 400 mW / cm ² and an irradiation amount of 60 mJ / cm ^2. A film with a hard coat was prepared.
The hard coat hardness after curing was 3H or more in any sample.
An antistatic hard coat layer was applied to the air interface side surface of the cellulose acylate film.

[Preparation of antireflection film]
(Synthesis of perfluoroolefin copolymer P-1)
Perfluoroolefin copolymer P-1 was prepared in the same manner as perfluoroolefin copolymer (1) described in JP 2010-152111 A. The resulting polymer had a refractive index of 1.422.

  In the above structural formula, 50:50 represents a molar ratio.

(Preparation of hollow silica dispersion A-1)
A hollow silica particle dispersion having an average particle diameter of 60 nm, a shell thickness of 10 nm, and a silica particle refractive index of 1.31 by adjusting the conditions using the same method as dispersion A-1 described in JP-A-2007-298974. A-1 (solid content concentration 18.2 mass%) was prepared.

(Preparation of composition A-1 for forming a low refractive index layer)
The following composition was charged into a mixing tank and stirred to obtain a composition A-1 for forming a low refractive index layer (solid content concentration 5% by mass).
Perfluoroolefin copolymer P-1 14.8 parts by weight Ethyl methyl ketone 157.7 parts by weight DPHA 3.0 parts by weight Hollow silica particle dispersion A-1 21.2 parts by weight Irgacure 127 1.3 parts by weight X22- 164C 2.1 parts by mass

The compounds used are shown below.
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)
X22-164C: Reactive silicone (manufactured by Shin-Etsu Chemical Co., Ltd.)
・ Irgacure 127: Photopolymerization initiator (manufactured by Ciba Japan Co., Ltd.)

(Preparation of low refractive index layer)
The prepared film with hard coat No. The composition A-1 for forming a low refractive index layer was applied on the hard coat layer of No. 41 using a gravure coater, and the film No. 1 with a hard coat having an antireflection function was applied. 51 was obtained. Drying conditions are 90 ° C. and 30 seconds, and UV curing conditions are 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the oxygen concentration is 0.1 volume% or less. The irradiance was 600 mW / cm ² and the irradiation amount was 600 mJ / cm ² . The film thickness of the low refractive index layer was 95 nm.

  Similarly, the low refractive index layer forming composition A-1 was applied to the hard coated films No. 42 to No. 44 having an antireflection function, and antireflection film samples No. 52 to No. 54 were applied. Got.

(Evaluation of hard coat adhesion)
The adhesion evaluation after light irradiation was performed by the following method.
A cross cut test according to JIS K 5600 was conducted. Specifically, eleven notches were made vertically and horizontally at intervals of 1 mm on the hard coat layer surface of the film with a hard coat layer after UV curing to make 100 1 mm square grids. A transparent pressure-sensitive adhesive tape (Cellotape (registered trademark, manufactured by Nichiban Co., Ltd.) CT405AP-12) was affixed thereto, and the peeled off and quickly peeled off portion was evaluated by visual observation. The samples were evaluated after conditioning for 2 hours or more in a room at a temperature of 25 ° C. and a humidity of 60% before the adhesion evaluation.

Table 4 shows the results of adhesion evaluation after irradiation with Xe at 150 W / m ² for 48 hours.
Adhesiveness A: Peeling location 0 to 10 squares Adhesiveness B: Peeling location 11 to 49 squares Adhesiveness C: Peeling location 50 to 99 squares Adhesiveness D: Peeling location 100 squares or more (all parts pasted with tape)
Super Xenon weather meter SX75 manufactured by Suga Test Instruments Co., Ltd. was used for Xe irradiation.

[Production of retardation film]
With reference to “Part 2” and “Part 5” in Example 1 of JP-A-2009-222001, Re = 137.5 nm and the direction of the slow axis is 45 degrees with respect to the direction of the long side of the pattern. A pattern retardation layer A patterned so that a part (first region) and a part (second region) of 135 degrees were repeated at a cycle of 300 μm was produced on a glass substrate by coating. On the surface opposite to the hard coat layer of the cellulose acylate film with a hard coat layer produced above, a 4% water / methanol solution (PVA103 (4.0 g) of polyvinyl alcohol “PVA103” manufactured by Kuraray Co., Ltd., 72 g of water and methanol. A 12 g bar with a viscosity of 4.35 cp and a surface tension of 44.8 dyne) dissolved in 24 g was applied and dried at 80 ° C. for 5 minutes to form a film.
The phase retardation layer A was transferred to the PVA-coated surface of the cellulose acylate film to prepare retardation films 1-16, 21-26, 41-44, 51-54. Table 3 shows the correspondence between the film, the film with the hard coat layer, and the retardation film.

  The following evaluation was performed about retardation film 1-16, 21-32, 41-44, 51-54.

(Production of 3D display)
LW5700 (manufactured by LG) is peeled off the retardation film bonded with an adhesive on the viewing side of the front polarizing plate, and instead the retardation films 1-16, 21-32, 41-44, 51-54 are positioned. Bonding was performed so that the longitudinal direction of the phase difference region was the horizontal direction and the hard coat layer was on the viewing side.

(Crosstalk evaluation)
After the 3D display produced above is lit continuously for 48 hours, the right eye pixel is displayed in white and the left eye pixel is displayed in black, and a spectral radiance meter (SR-3 Topcon) is placed at the eye position. / Luminance was measured through each of the circular polarizing glasses for the left eye.
The luminance when passing through the circular polarizing glasses for the right eye is YRR, and the luminance when passing through the circular polarizing glasses for the left eye is YRL.
Since the 3D feeling is lost when the right eye image enters the left eye and the left eye image enters the right eye, the degree of crosstalk is defined as CRO = (YRR−YRL) / (YRR + YRL) and evaluated. The CRO immediately after lighting was CRO_0, the CRO after 48 hours of lighting was CRO_48, and the display performance during continuous lighting was evaluated according to the following criteria based on the value of 100 × CRO_48 / CRO_0.
A: 95% or more B: Less than 95% to 92.5% or more C: Less than 92.5% to 90% or more D: Less than 90% As an allowable evaluation value, “A” is most preferable, and “B” is Next, “C” is the next most preferable. “D” is an unacceptable evaluation value that needs improvement.

  The results are shown in Table 4 below. From the results in Table 4, it was clarified that the retardation film using the cellulose ester film of the present invention is effective in crosstalk in continuous lighting of a 3D display. This is considered because the dimensional change of the cellulose ester film over time was suppressed.

In addition, when the retardation film 3 was left in the measurement environment of the humidity dimensional change rate and the change was observed, the occurrence of the deformation (curl) of the retardation film was practically acceptable, and in terms of visibility There was no change.
Similarly, a VA retardation film (film 8 of JP2012-108452) as a protective film provided on the opposite side of the liquid crystal cell in the VA mode polarizing plate with the film 3 and the hard coat layer-attached film 3 described above When used in combination, curling of the polarizing plate in the direction perpendicular to the absorption axis is reduced and suppressed in the same manner as the retardation film, and the cellulose ester film of the present invention has good results as a polarizing plate protective film. I understood that.

DESCRIPTION OF SYMBOLS 1 Hardened resin layer 2 Cellulose ester film 3 Hydrophilic resin layer 4 Layer 41 which fixes the orientation state of a liquid crystalline compound Band-shaped 1st phase difference area | region 42 Band-shaped 2nd phase difference area | region 10 Laminate A Band-shaped phase difference A direction perpendicular to the direction in which the region is placed

Claims (10)

A laminate having a cured resin layer, a cellulose ester film, and a hydrophilic resin layer in this order,
The cellulose ester film contains a plasticizer, and the plasticizer concentration on the cured resin layer side surface is 95% by mass or less of the plasticizer concentration on the hydrophilic resin layer side,
The cellulose ester film has a direction perpendicular to and parallel to an arbitrary side after 24 hours at 25 ° C. and 80% relative humidity with reference to the time after 24 hours at 25 ° C. and 10% relative humidity. A laminate having a dimensional change rate of at least one of 0.40% or less.   The laminate according to claim 1, wherein the hydrophilic resin comprises polyvinyl alcohol.   The laminated body of Claim 1 or 2 which has a layer formed by fixing the orientation state of a liquid crystalline compound on the surface opposite to the surface which has the said cellulose-ester film of the said hydrophilic resin layer.   The layered product according to claim 3, wherein the layer formed by fixing the alignment state of the liquid crystalline compound has a plurality of retardation values.   The layered product according to claim 4, wherein the layer formed by fixing the alignment state of the liquid crystalline compound has band-like regions having two kinds of retardation values alternately arranged in a plane.   The laminate according to claim 5, wherein a dimensional change rate in a direction orthogonal to a direction in which the band-like regions are alternately arranged is 0.40% or less.   The laminate according to any one of claims 1 to 6, wherein the cured resin layer is a layer formed of a material that is cured by heat or light. The laminate according to any one of claims 1 to 7, wherein the cured resin layer is at least one of a hard coat layer, an antiglare layer, and an antireflection layer . The polarizing plate which has a laminated body as described in any one of Claims 1-8. The liquid crystal display device which has the laminated body as described in any one of Claims 1-8, or the polarizing plate of Claim 9 .

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