TWI417325B - Cellulose acylate film and method for manufacturing the same, polarizing plate and liquid crystal display - Google Patents

Description

Deuterated cellulose film, manufacturing method thereof, polarizing plate, liquid crystal display device

The present invention relates to a deuterated cellulose film and a method of producing the same. More specifically, it relates to a method comprising a deuterated cellulose, a wavelength dispersion of reverse dispersion, a large Rth per unit film thickness, and a uniform display in the plane when attached to the panel after the polarizing plate is processed. Cellulose film and its method of manufacture. Further, it relates to a polarizing plate and a liquid crystal display device using the deuterated cellulose film.

The liquid crystal display device of the VA (Vertically Aligned) mode has a high contrast ratio and a high manufacturing yield, and has been attracting attention as a liquid crystal display device for televisions. In order to broaden the viewing angle of the VA mode liquid crystal display device, a cellulose film for deuteration has been used as an optical film such as an optical compensation film.

In the optical film for VA, it is required to exhibit a reverse dispersion film in which the retardation Re in the in-plane direction increases as the wavelength becomes larger from the viewpoint of changing the color tone when the display is observed from the oblique direction. Further, at the same time, in order to reduce the manufacturing cost, it is required to increase the retardation Rth in the thickness direction per unit film thickness to reduce the thickness of the panel. On the other hand, with the increase in size of liquid crystal display devices, it is required to have an optical film having suitable physical properties that can achieve in-plane uniformity of the panel.

For example, in Japanese Laid-Open Patent Publication No. 2006-030962, a method of forming a film by adding a retardation agent or a method of satisfying a specific elastic modulus reveals a front side and a film thickness retardation performance. An optical film and a polarizing plate which are excellent in the change in the retardation value due to environmental changes such as humidity. In this document, it is disclosed that wavelength dispersion can be controlled by extension. In the examples of the document, an example is disclosed in which a material such as CAP (cellulose acetate propionate) or CAB (cellulose acetate butyrate) is used. In the solution film forming method, the film which is peeled off in a state in which the residual volatile component is in the range of 25 wt% to 35 wt% is biaxially stretched in the film transport direction and the film width direction.

Further, in Japanese Patent Laid-Open Publication No. 2009-263619, by controlling the water content or the SP value by using a solvent and a specific thiol-substituted degree of deuterated cellulose resin, a haze fiber having a good haze and a good shape is disclosed. Membrane. In the example of the document, an example is disclosed in which, in the solution film forming method, the film which is peeled off in a state in which the residual volatile component is from 25 wt% to 35 wt% is 10% to 50 in the film width direction. The range of % is extended.

However, the current situation is that it is difficult to balance the performance of reverse dispersion with the improvement of Rth per unit film thickness, having to sacrifice productivity, or sacrificing cost due to the use of expensive special additives. Further, the inventors of the present invention have conducted research on a method of adding a special additive for controlling optical properties, and as a result, it has been clarified that unevenness in the in-plane display when attached to a panel after processing of a polarizing plate using only a previously known additive is clarified. It does not become uniform and the residue is unsatisfactory. Further, it has also been clarified that the drying conditions of the film on the support at the time of casting film formation are changed, and as a result, the previously known composition or extension condition which can balance Rth and wavelength dispersion is similarly applied to the panel. The in-plane display unevenness does not become uniform. Therefore, it is very difficult to improve the in-plane display uniformity of the panel in addition to the reverse dispersion and the improvement of the Rth per unit film thickness. Therefore, in addition to the above-mentioned optical characteristics, it is necessary to change the physical properties of the film to a degree that the film properties can be improved to the extent that the in-plane display uniformity is improved. Improve the film forming conditions.

That is, the object of the present invention is to provide a deuterated cellulose film and a method for producing the same, wherein the wavelength dispersion of the deuterated cellulose film is inversely dispersed, and the Rth per unit film thickness is large, after the polarizing plate is processed. The display when attached to the panel becomes uniform in the plane.

It is known that, in general, the more the stretching ratio in the TD direction (the direction orthogonal to the film transport direction, that is, the film width direction), the more the axial unevenness of the optical film can be improved (refer to Japanese Patent Laid-Open No. 2006-- Bulletin No. 030962). Therefore, the present inventors have studied the production method described in Japanese Laid-Open Patent Publication No. 2006-030962, and as a result, the film obtained in the literature example also contains a film which becomes a reverse dispersion, CAP (cellulose acetate propionate). Or a material such as CAB (cellulose acetate butyrate) has a low modulus of elasticity, and there is a problem from the viewpoint of in-plane uniformity when processed into a polarizing plate. Further, in this document, the manufacturing method does not specifically study the details of the residual volatile components of the longitudinal extension and the lateral extension, and the stretching ratio in each direction at this time, and it is impossible to refer to the description of the document. Improve film properties.

Further, even if it is described in the example of Japanese Patent Laid-Open Publication No. 2009-263619, only the extension in the TD direction is carried out, and the solvent residual amount or the drying condition at the time of stretching is not controlled to solve the above problem.

Therefore, the present inventors have studied a combination of a formulation for improving in-plane unevenness and a production method for a film formed by a solution of various additives and different types of deuterated cellulose. As a result, it is found that the film exhibiting the target Rth expression and the inverse dispersion property increases the elastic modulus in the MD direction to a specific value or more, and controls the TD/MD ratio of the elastic modulus to a specific range, and TD When the film having a variation in the elastic modulus of the direction is controlled to a specific value or less after being attached to the panel after the polarizing plate is processed, the display unevenness in the in-plane is remarkably lowered, and the present invention has been completed.

In addition, the inventors of the present invention have found that various types of deuterated cellulose films which can achieve the above-mentioned problems and achieve the above-mentioned physical and optical properties by using specific extension conditions corresponding to the type of deuterated cellulose, thereby completing the production of the film of the present invention. method.

Specifically, the above problems are solved by the following means.

[1] A cellulose-deposited film comprising: deuterated cellulose having a total thiol substitution degree of 2.1 to 2.8, an elastic modulus of a film transport direction of 3200 MPa or more, and an elastic modulus of a film width direction. Not all of 0.5 GPa or less, and the following formulas (1) to (3) are satisfied:

Formula (1) 0 nm ≦ΔRe≦15.0 nm

(wherein ΔRe represents the value obtained by subtracting the in-plane retardation value at a wavelength of 450 nm from the in-plane direction at a wavelength of 630 nm (in nm)

Formula (2) 2 × 10 ^-3 ≦ Rth / d ≦ 6 × 10 ^-3

(wherein, Rth represents the retardation value (in nm) in the film thickness direction at a wavelength of 550 nm, and d represents the film thickness (unit: nm))

Equation (3) 1.0≦E'(TD)/E'(MD)≦1.43

(wherein E' (MD) represents the elastic modulus (unit: MPa) in the film transport direction, and E' (TD) represents the elastic modulus (unit: MPa) in the film width direction.

[2] The cellulose-degraded film according to [1], wherein the elastic modulus of the film transport direction is 3,500 MPa or more.

[3] The cellulose-deposited film according to [1] or [2], wherein the retardation value Re of the in-plane direction at a wavelength of 590 nm and the retardation value Rth of the film thickness direction at a wavelength of 590 nm satisfy the following formula:

35 nm≦Re≦80 nm, 100 nm≦Rth≦300 nm.

[4] The cellulose-deposited film according to any one of [1] to [3] wherein the deuterated cellulose is cellulose acetate.

[5] The cellulose-deposited film according to any one of [1] to [4] wherein a polycondensed ester is contained.

[6] The cellulose-deposited film according to any one of [1] to [5], wherein a less than 3 wt% of Re manifest is contained with respect to the deuterated cellulose.

[A] The cellulose-deposited film according to any one of the above-mentioned [1], wherein the organic acid represented by the following formula (1) is contained:

General formula (1)

XL-(R ¹ ) _n

(In the formula (1), X represents a substituent having an acid group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher linking group, and R ¹ represents an alkyl group having a carbon number of 6 to 30, An alkenyl group having 6 to 30 carbon atoms, an alkynyl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms or a heterocyclic group having 6 to 30 carbon atoms, and further having a substituent; In the case where L is a single bond, it is 1, and when L is a linking group of 2 or more valences, it is (valence of L - 1)).

[8] The cellulose-deposited film according to [7], wherein R ¹ in the formula (1) represents an alkyl group having 6 to 24 carbon atoms, an alkenyl group having 6 to 24 carbon atoms, or The alkynyl group having 6 to 24 carbon atoms (which may further have a substituent).

[9] The cellulose-deposited film according to [7] or [8], wherein X in the formula (1) has at least one member selected from the group consisting of a carboxyl group, a sulfonic acid group, a sulfinic acid group, and a phosphoric acid group. At least one group of the group consisting of a sulfoximine group and an ascorbate group.

[10] The cellulose-deposited film according to any one of [7] to [9] wherein L in the formula (1) is a single bond or is selected from the group of the following groups of 2 a linking group having a valence or higher or a linking group obtained by combining two or more units selected from the group of units: -O-, -CO-, -N(R ² )- (the R ² represents carbon a number of 1 to 5 alkyl groups, -OH, -CH=CH-, -CH(OH)-, -CH ₂ -, -SO ₂ -,

[11] The cellulose-degraded cellulose film according to any one of [7], wherein the organic acid represented by the general formula (1) is bonded to one molecule of a fatty acid on one molecule of the polyol. It is one molecule of a polycarboxylic acid and has at least one unsubstituted carboxyl group derived from a polycarboxylic acid.

[12] The cellulose-deposited film according to any one of [7], wherein the organic acid represented by the formula (1) has a molecular weight of from 200 to 1,000.

[13] The cellulose-deposited film according to any one of [1] to [12] wherein, in the laminated structure having two or more layers, the average total thiol substitution degree of the deuterated cellulose contained in each layer Different from each other.

[14] The cellulose-deposited film according to any one of [1] to [13] wherein the standard deviation (?) of the unevenness of the azimuth direction of the end portion in the film width direction is 0.10 or less.

[15] A method for producing a cellulose-deposited film, comprising: casting a solution containing a cellulose acetate having a total thiol substitution degree of 2.1 to 2.8 on a metal support to obtain a film a step of peeling the film from the metal support by satisfying the residual volatile component H1 of the following formula (i); and peeling the film on the residual volatile component H2 satisfying the following formula (ii) In the state of the film, the film is stretched by 5% to 100% in the film transport direction; and the peeled film is extended by 20% in a direction orthogonal to the film transport direction in a state in which the residual volatile component H3 of the following formula (i) is satisfied. ～150% of the steps; the extending step satisfies the following formula (iv);

Formula (i) 20% ≦ H1 ≦ 60%

Formula (ii) 10%≦H2≦60%

Formula (iii) 5% ≦ H3 ≦ 45%

Formula (iv) (MD stretching ratio +100%) / (TD stretching ratio +100%) ≧0.70

(In the formula, the MD stretching ratio indicates the stretching ratio (unit: %) in the film conveying direction, and the TD stretching ratio indicates the stretching ratio (unit: %) in the direction orthogonal to the film conveying direction).

[16] A method for producing a cellulose-deposited film, comprising: doping a dopant comprising cellulose butyrate or cellulose propionate having a total thiol substitution degree of 2.1 to 2.8 on a metal support; a step of casting a solution to obtain a film; a step of peeling the film from the metal support by satisfying the residual volatile component H1 of the following formula (i); and peeling off the film to satisfy the following formula (ii) a step of extending 20% to 100% in the film transport direction in the state of the residual volatile component H2; and the peeled film is in the direction of transporting the film in a state in which the residual volatile component H3 of the following formula (i) is satisfied a step of extending the direction of the intersection by 35% to 150%; the extending step satisfies the following formula (iv);

Formula (i) 20% ≦ H1 ≦ 60%

Formula (ii) 10%≦H2≦60%

Formula (iii) 5% ≦ H3 ≦ 45%

Formula (iv) (MD stretching ratio +100%) / (TD stretching ratio +100%) ≧0.70

(In the formula, the MD stretching ratio indicates the stretching ratio (unit: %) in the film conveying direction, and the TD stretching ratio indicates the stretching ratio (unit: %) in the direction orthogonal to the film conveying direction).

[17] The method for producing a cellulose-degraded film according to [15], wherein the film transfer direction is performed while controlling a tension variation value to less than 10 N/m. Extension on the top.

[18] The method for producing a cellulose-deposited cellulose film according to any one of [15], wherein the dopant is a mixture of two different thiol substitution degrees of deuterated cellulose. The above dopants co-cast the dopants onto the support.

[19] The method for producing a cellulose-deposited cellulose film according to any one of [15] to [18] wherein, in the transition portion from the peeling step to the extending step, the film passes through 3 A path roll having a wrap angle of 60 or more above the root.

[20] The method for producing a cellulose-deposited cellulose film according to any one of [15], wherein the path roller comprises at least one pulsating device.

The method for producing a cellulose-deposited film according to any one of the aspects of the present invention, wherein the metal support is applied to both the back surface and the surface of the metal support. The cast dopants blow dry wind.

The method for producing a cellulose-deposited cellulose film according to any one of the aspects of the present invention, wherein the stretching in a direction orthogonal to a film conveying direction is performed by a tenter. Satisfying the following formula (v);

Formula (v) W×30≧L≧W×2

(wherein, L represents the distance from the stripping step to the tenter (in mm), and W represents the width (unit: mm) of the peeled film).

[23] A fluorinated cellulose film produced by the method for producing a cellulose fluorite film according to any one of [15] to [22].

[24] A polarizing plate comprising a polarizing element, the cellulose-deposited film according to any one of [1] to [14] or [23].

[25] A liquid crystal display device according to any one of [1] to [14] or [23] or a polarizing plate according to [24].

[Effects of the Invention]

A deuterated cellulose film and a method for producing the same can be provided. The wavelength dispersion of the deuterated cellulose film is inversely dispersed, and the Rth per unit film thickness is large, and is displayed in the plane when attached to the panel after the polarizing plate is processed. Become uniform. Further, even when the liquid crystal display device using the cellulose-degraded film of the present invention is enlarged, the front contrast is good.

Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below is based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In addition, in the specification of the present application, "~" is used in the following sense: the numerical values described before and after are included as the lower limit and the upper limit. In the present specification, the film transport direction is referred to as a longitudinal direction, a film longitudinal direction, or an MD direction, and a direction orthogonal to the film transport direction is referred to as a lateral direction, a film width direction, or a TD direction.

[醯化cellulose film]

The deuterated cellulose film of the present invention (hereinafter also referred to as the film of the present invention) comprises deuterated cellulose having a total thiol substitution degree of 2.1 to 2.8, characterized in that the elastic modulus of the film transport direction is 3,200 MPa or more. The modulus of elasticity in the film width direction is not more than 0.5 GPa, and the following formulas (1) to (3) are satisfied.

Equation (1) 0≦ΔRe≦15.0

(wherein ΔRe represents a value (in nm) obtained by subtracting the in-plane retardation value at a wavelength of 450 nm from the retardation value in the in-plane direction at a wavelength of 630 nm.)

Formula (2) 2 × 10 ^-3 ≦ Rth / d ≦ 6 × 10 ^-3

(In the formula, Rth represents the retardation value (unit: nm) in the film thickness direction at a wavelength of 550 nm, and d represents the film thickness (unit: nm).)

Equation (3) 1.0≦E'(TD)/E'(MD)≦1.43

(wherein E'(MD) represents the elastic modulus (unit: MPa) in the film transport direction, and E'(TD) represents the elastic modulus (in MPa) in the film width direction.)

Further, the film of the present invention can be produced by the method for producing a film of the present invention. Hereinafter, the film of the present invention will be described.

<film characteristics>

(delay)

In the present specification, Re(λ) and Rth(λ) respectively represent the retardation in the plane at the wavelength λ and the retardation in the thickness direction. In the specification of the present application, the wavelength λ is 550 nm unless otherwise specified. Re (λ) is measured by injecting light having a wavelength of λ nm into the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments Co., Ltd.). When the measurement wavelength λ nm is selected, the wavelength selective filter can be manually exchanged or measured by converting a measured value by a program or the like.

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 a tilt axis (rotation axis) with respect to the in-plane retardation axis (determined by KOBRA 21ADH or WR) (when there is no slow phase axis, any direction in the plane of the film is taken as The normal direction of the film of the rotating shaft), from the normal direction to 50 degrees on one side, the light having a wavelength of λ nm is incident from the oblique direction every 10 degrees, and the total of 6 points of the Re(λ) is measured. It is calculated from KOBRA 21ADH or WR based on the measured retardation value and the assumed value of the average refractive index and the input film thickness value.

In the above, when there is a film in which the retardation axis in the plane is the rotation axis and the retardation value becomes zero at a certain inclination angle from the normal direction, the delay of the inclination angle larger than the inclination angle is delayed. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.

In addition, the retardation axis (rotation axis) can be used as the tilt axis (rotation axis) (when there is no slow phase axis, any direction in the film plane is used as the rotation axis), and the delay value is measured from two directions of arbitrary inclination, based on The value and the assumed value of the average refractive index and the input film thickness value are calculated by the following equations (11) and (12).

Formula (11)

The above Re(θ) represents a retardation value in the direction of the inclination angle θ from the normal direction. Nx in the formula (11) represents the refractive index in the direction of the slow axis in the plane, ny represents the refractive index in the direction orthogonal to nx in the plane, nz represents the refractive index in the direction orthogonal to nx and ny, and d is Film thickness.

Formula (12)

Rth={(nx+ny)/2-nz}×d

The film to be measured is a film which cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no optical axis (opic axis), and Rth(λ) is calculated by the following method.

Rth(λ) is the in-plane retardation axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis), every 10 degrees from -50 degrees to +50 degrees with respect to the normal direction of the film. The ground is irradiated with light having a wavelength of λ nm from the oblique direction, and the Re (λ) of 11 points is measured. Based on the measured retardation value and the assumed value of the average refractive index and the input film thickness value, KOBRA 21ADH is used. Or WR to calculate.

In the above measurement, the assumed value of the average refractive index can be used as a catalogue value of various optical films in the Polymer Handbook (JOHN WILEY & SONS, INC). The value of the average refractive index is not known and can be measured by an Abbe refractometer. The values of the average refractive index of the main optical film are shown below: deuterated cellulose (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), polyphenylene Ethylene (1.59). By inputting the assumed values of the average refractive indices and the film thickness, nx, ny, and nz can be calculated from KOBRA 21ADH or WR. Further, Nz = (nx - nz) / (nx - ny) is calculated by the calculated nx, ny, and nz.

Re is preferably 35 nm ≦ Re ≦ 70 nm, more preferably 40 nm ≦ Re ≦ 60 nm.

Moreover, Rth preferably satisfies 60 nm ≦Rth ≦ 300 nm, and more preferably satisfies 80 nm ≦Rth ≦ 150 nm. By setting such Rth, it is possible to produce a retardation film for VA having less color shift.

(wavelength dispersion)

The film of the present invention is the difference ΔRe between the retardation Re (630) in the in-plane direction at a wavelength of 630 nm and the retardation Re (450) at a wavelength of 450 nm (that is, ΔRe=Re(630)-Re(450). )) The inverse dispersion film of the following formula (1) is satisfied, and the change in the color tone of the viewing angle when incorporated in the liquid crystal display device can be improved.

Equation (1)0 nm≦ΔRe≦15.0 nm

(wherein ΔRe represents a value (in nm) obtained by subtracting the in-plane retardation value at a wavelength of 450 nm from the retardation value in the in-plane direction at a wavelength of 630 nm.)

More preferably, the film of the present invention has a ΔRe of from 0.5 nm to 10 nm, particularly preferably from 1.0 nm to 9.0 nm.

(Rth/d)

The film of the present invention is a film satisfying the following formula (2), which can achieve both film thinning and sufficient Rth performance, and can reduce the raw material cost of the film.

Equation (2) 2 × 10 ^-3 ≦ Rth / d ≦ 6 × 10 ^-3

(In the formula, Rth represents the retardation value (unit: nm) in the film thickness direction at a wavelength of 550 nm, and d represents the film thickness (unit: nm).)

The Rth/d is preferably 2.0 × 10 ^-3 to 5.0 × 10 ^-3 , more preferably 2.5 × 10 ^-3 to 4.5 × 10 ^-3 .

(Standard deviation of the azimuth direction of the longitudinal direction of the film in the longitudinal direction σ600 and σ-600)

The film of the present invention preferably has a standard deviation (σ) of unevenness in the direction of the retardation axis at the end portion in the film width direction of 0.10 or less. The end portion in the film width direction is a portion that is separated from the center portion in the film width direction by 600 mm to 1000 mm in the direction of the film width, and is separated from the end portion in the film width direction by any portion of 100 mm or more. , depending on the width of the film.

From the viewpoint of sufficiently exerting the effects of the present invention when used in a wide-format liquid crystal display device, it is preferred that the film of the present invention has a film width of 1340 mm or more and satisfies the following formula (4) and formula ( 5) More preferably, the following formula (4') and formula (5') are satisfied.

Equation (4) σ600≦0.13°

Equation (5) σ-600≦0.13°

(In equations (4) and (5), σ600 represents the delay from the center line in the width direction of the film to the direction of the retardation axis in the direction of the long side of the film in a direction of 600 mm from the end of one of the film ends. The standard deviation of the phase-axis orientation, σ-600 represents the direction of the slow-phase axis from the center line in the width direction of the film, and the direction of the slow-axis axis of the long-side direction of the film is detected on the line 600 mm away from the end of the other film. standard deviation.)

Formula (4') σ600≦0.10°

Formula (5') σ-600≦0.10°

Here, the σ600 and σ-600 are preferably in the longitudinal direction of the film and last for 2000 m, and satisfy the formulas (4) and (5) when measured, and more preferably continue in the longitudinal direction of the film. When measured at 4000 m, the formula (4) and the formula (5) are satisfied.

The standard deviation σ600 and σ-600 of the azimuth direction of the longitudinal direction of the film in the longitudinal direction of the film can be measured off-line or in-line, and the balance deviation from the longitudinal direction of the film is eliminated from the viewpoint of eliminating the cutting. Preferably, the in-line assay is performed.

Further, if the in-line measurement in the longitudinal direction is performed under the condition that the film is shaken up and down, the retardation of each of the slow phase axes is detected more than actually. Therefore, it is preferable to suppress the sway of the film up and down to 2 mm. The measurement was carried out under the following conditions. As a method of suppressing the sloshing of the film up and down, for example, a method of measuring the film of the present invention on a path roller which is transmitted in parallel is used, and it is preferable to use a path roller which is fed in parallel within 0.5 mm.

When the standard deviations σ600 and σ-600 of the azimuth direction of the longitudinal direction of the film in the longitudinal direction are measured in the line, the interval between the transport speed and the detection time is not particularly limited, and can be measured by any method. In the present invention, when transporting at 20 m/min, data of 2000 m was continuously measured at intervals of 0.1 second at intervals of 0.033 m, and each standard deviation was calculated.

Further, the standard deviations σ600 of the retardation axis directions in the longitudinal direction of the film and other measurement conditions of σ-600 are set as follows, and detection and calculation are performed by the following methods.

Device: High-speed delay measuring device Re100 manufactured by Otsuka Electronics Co., Ltd.

Measuring length: 2000 m

Measuring pitch: continuous measurement every 0.1 seconds at 20 m/min

For approximately 60000 points of data, by

And calculate (here, x _i is the angle of the slow phase axis, n is 60000). By the following

The dispersion σ is calculated.

(elastic modulus)

The film of the present invention has an elastic modulus E' (MD) of 3200 MPa or more in the film transport direction, and an elastic modulus E' (TD) of the film width direction of not more than 0.5 GPa, and satisfies the following formula (3). .

Equation (3) 1.0≦E'(TD)/E'(MD)≦1.43

(wherein E'(MD) represents the elastic modulus (unit: MPa) in the film transport direction, and E'(TD) represents the elastic modulus (in MPa) in the film width direction.)

The use of a film that satisfies such physical properties is not clear in the details of the reason why the unevenness in the surface when the polarizing plate is attached to the panel and is significantly reduced in the plane. Although it is not limited to any reason, in fact, in the extension of the film containing the residual volatile component peculiar to the solution film forming method, the result can further improve the value of the elastic modulus of the film itself and the uneven modulus of the film. (The elastic modulus unevenness of the film is considered to be due to the low modulus of elasticity). On the other hand, in the case of the polarizing plate processing, when the film of the present invention after film formation is attached as a polarizing plate protective film to the polarizing element, the film is bonded while applying a tensile force to the film. However, the optical characteristics of the film after film formation cause a problem of unevenness in the broad side and the long side direction due to the different tensile forces in the width direction and the long side direction applied to the film during the processing of the polarizing plate. Not well studied before. Therefore, when the film of the present invention having improved physical properties such as elastic modulus is used, it is possible to suppress the unevenness in the wide side and the long side direction of the tensile force applied to the film during the processing of the polarizing plate, and to make the performance of the polarizing plate uniform.

The elastic modulus E' (MD) of the film transport direction is preferably 3,200 MPa to 4,500 MPa, more preferably 3,300 MPa to 4,100 MPa, and particularly preferably 3,500 MPa to 4,000 MPa.

On the other hand, the elastic modulus E'(TD) of the film transport direction is preferably 3,200 MPa to 5,000 MPa, more preferably 3,300 MPa to 4,800 MPa, and particularly preferably 4,000 MPa to 4,700 MPa.

Further, E'(TD)/E'(MD) is preferably 1.05 to 1.40, more preferably 1.10 to 1.35, and particularly preferably 1.15 to 1.30.

The elastic modulus E' (TD) in the film width direction is not more than 0.5 GPa, preferably 0.4 GPa or less, and particularly preferably 0.3 GPa or less.

(film thickness)

The thickness of the film of the present invention is appropriately determined depending on the type of the polarizing plate to be used, etc., and is preferably from 30 μm to 60 μm, more preferably from 35 μm to 55 μm. By making the thickness of the film 60 μm or less, the cost can be reduced and it is preferable.

(layer structure of bismuth cellulose film)

The film of the present invention may be a single layer film or may have a laminated structure of two or more layers. In particular, when the degree of substitution of deuterated cellulose is 2.6 to 2.8, a single layer is preferred, and in the case of a degree of substitution of 2.1 to 2.6, preferably 2 or more layers. In this case, it is preferred that the film of the present invention has a laminated structure of two or more layers, and the average total thiol substitution degree of the cellulose-deposited cellulose contained in each layer is different from each other.

(film width)

The film of the present invention preferably has a film width of 1000 mm or more, more preferably 1500 mm or more, and particularly preferably 1800 mm or more.

<Deuterated cellulose>

(raw material)

The cellulose deuterated cellulose used in the present invention is not particularly limited, except that it contains at least one deuterated cellulose having a total thiol substitution degree of 2.1 to 2.8. Deuterated cellulose is preferably cellulose deuterated. As the cellulose of the deuterated raw material, there are lint or wood pulp (broadwood pulp, conifer pulp), etc., regardless of the raw material cellulose obtained from the deuterated fiber. Both can be used and can be mixed as appropriate. For the detailed description of the raw material cellulose, for example, Maruzawa and Uda, "Plastic Materials Lecture (17) Cellulose Resin", Nikkan Kogyo Shimbun (issued in 1970), or Invention Association Public Technical Report No. 2001 Cellulose described in No. 1745 (pages 7 to 8).

First, the cellulose deuterated cellulose preferably used in the present invention will be described in detail. The glucose unit constituting the β-1,4 bond of cellulose has a free hydroxyl group at the 2, 3 and 6 positions. The deuterated cellulose is a polymer obtained by esterifying a part or all of the hydroxyl groups with a mercapto group having 2 or more carbon atoms. The thiol substitution degree indicates the ratio of hydroxy esterification of cellulose at the 2, 3, and 6 positions (100% esterification to degree of substitution 1).

The total thiol substitution degree of the deuterated cellulose of the film of the present invention, that is, DS2+DS3+DS6 is 2.1 to 2.8, preferably 2.2 to 2.7, more preferably 2.3 to 2.7, particularly preferably 2.4 to 2.6. Further, DS6/(DS2+DS3+DS6) is preferably from 0.08 to 0.66, more preferably from 0.15 to 0.60, still more preferably from 0.20 to 0.45. Here, DS2 is the thiol substitution degree of the hydroxyl group at the 2-position of the glucose unit (hereinafter also referred to as "the thiol substitution degree of the 2-position"), and DS3 is the thiol substitution degree of the hydroxyl group at the 3 position (hereinafter also referred to as " The thiol substitution degree of the 3 position is "), and DS6 is the thiol substitution degree of the 6-position hydroxy group (hereinafter also referred to as "6-position thiol substitution degree"). Further, DS6/(DS2+DS3+DS6) is a ratio of the thiol substitution degree of the 6-position to the total thiol substitution degree, and is also referred to as a "6-position thiol substitution rate" hereinafter.

The mercaptan group used in the film of the present invention may have only one type of mercapto group, or two or more kinds of mercapto groups may be used. When two or more kinds of fluorenyl groups are used, it is preferred that one of them is an ethyl group, and the fluorenyl group having a carbon number of 2 to 4 is preferably a fluorenyl group or a butyl group. If the sum of the degree of substitution of the ethyl group of the hydroxyl groups at the 2, 3, and 6 positions is DSA, and the sum of the substitution degrees of the propyl group or the butyl group of the 2, 3, and 6 hydroxyl groups is referred to as DSB, The value of DSA+DSB is preferably 1.5 to 2.7. The value of DSB is preferably 0 to 1.70, more preferably 0 to 1.2, particularly preferably 0 to 0.5, and further preferably 0 in the present invention, that is, the cellulose deuterated cellulose is cellulose acetate. . By setting the values of DSA and DSB to the above range, it is preferable to obtain a film having a small change in Re value and Rth value due to environmental humidity.

Further, as DSB, 28% or more is a substituent of a hydroxyl group at the 6-position, more preferably 30% or more is a substituent of a hydroxyl group at the 6-position, and still more preferably 31% or more is a substituent of a hydroxyl group at the 6-position, particularly It is also preferred that 32% or more of the substituents of the 6-position hydroxyl group. By these membranes, a solution having a better solubility can be produced, and in particular, in a non-chlorine-based organic solvent, a good solution can be produced. In addition, a solution having low viscosity and good filterability can be obtained.

The mercapto group having 2 or more carbon atoms in the deuterated cellulose in the present invention may be an aliphatic group or an allyl group, and is not particularly limited. These compounds are, for example, alkylcarbonyl esters, alkenylcarbonyl esters or aromatic carbonyl esters of cellulose, aromatic alkylcarbonyl esters, and the like, and may each have a further substituted group. Preferred examples of the bases include a propyl group, a butyl group, a fluorenyl group, a hexyl group, a decyl group, a fluorenyl group, a fluorenyl group, a decyl group, a fluorenyl group, a hexadecanyl group, a hexadecanyl group, and a decyl group. An octadecyl group, an isobutyl sulfhydryl group, a tert-butyl fluorenyl group, a cyclohexylmethyl fluorenyl group, an oil sulfhydryl group, a benzamidine group, a naphthylmethyl group, a cinnamyl group, and the like. More preferred among these groups are propyl, butyl, decyl, octadecyl, tert-butyl, oleyl, benzhydryl, naphthyl, cinnamyl, etc. It is a propyl group and a butyl group.

In the case of the deuteration of cellulose, when an acid anhydride or hydrazine chloride is used as the deuteration agent, an organic acid (for example, acetic acid), dichloromethane or the like can be used as the organic solvent of the reaction solvent.

As the catalyst, in the case where the oximation agent is an acid anhydride, a protonic catalyst such as sulfuric acid can be preferably used, and in the case where the oximation agent is ruthenium chloride (for example, CH ₃ CH ₂ COCl), a base can be used. Sex compounds.

The most common industrial synthesis method of mixed fatty acid esters of cellulose is by mixing organic acids containing fatty acids (acetic acid, propionic acid, valeric acid, etc.) corresponding to ethyl hydrazino groups and other sulfhydryl groups or anhydrides of the acids. A method of deuterating cellulose by a component.

The deuterated cellulose used in the present invention can be synthesized, for example, by the method described in Japanese Laid-Open Patent Publication No. Hei 10-45804.

<additive>

The film of the present invention may also contain various additives.

In the present invention, as the additive, a high molecular weight additive and a low molecular weight additive which are known as additives for the deuterated cellulose film can be widely used.

In the film of the present invention, the additive is preferably added in an amount of from 1 wt% to 35 wt%, more preferably from 4 wt% to 30 wt%, still more preferably 10 wt%, relative to the deuterated cellulose. %~25 wt%. When the amount of the additive added is 1 wt% or more, the temperature and humidity change are easily dealt with, and when the amount added is 35 wt% or less, the film is less likely to be whitened. In addition, the physical properties are also excellent.

Here, the term "additive" in the present invention means a component added for the purpose of improving the functions and the like of the cellulose fluorite film of the present invention. That is, impurities, residual solvents, and the like are not additives in the present invention.

Further, in the present invention, two or more kinds of additives may be used. By using two or more types, there are advantages in that optical properties, film elastic modulus, film brittleness, or web handling adaptability can be achieved due to the respective additives.

As the additive, for example, a polycondensation ester; a retardation adjuster (a delayed expression agent and a retardation reducing agent; a plasticizer such as a phthalate or a phosphate compound; a deterioration (oxidation) inhibitor; Agent; matting agent; organic acid (may also be a stripping accelerator); additives such as sugar ester compounds.

Hereinafter, the additives which can be used in the film of the present invention will be described in detail.

(polyester)

The polycondensation of the present invention is preferably a mixture of at least one dicarboxylic acid having an aromatic ring (also referred to as an aromatic dicarboxylic acid) and at least one aliphatic dicarboxylic acid (for example, an average carbon number of 5.5 or more and 10.0) The following dicarboxylic acid) is obtained by at least one aliphatic diol having an average carbon number of 2.5 or more and 7.0 or less.

The calculation of the average carbon number of the aliphatic dicarboxylic acid residue is carried out individually in the dicarboxylic acid residue and the diol residue.

The value calculated by multiplying the composition ratio (mole fraction) of the dicarboxylic acid residue by the carbon number is defined as the average carbon number. For example, in the case where the adipic acid residue is 50 mol% and the phthalic acid residue is 50 mol%, the average carbon number is 7.0.

Further, in the case of the diol residue, the average carbon number of the aliphatic diol residue is a value calculated by multiplying the composition ratio (molar fraction) of the aliphatic diol residue by the carbon number. For example, when the ethylene glycol residue is 50 mol% and the 1,2-propanediol residue is 50 mol%, the average carbon number is 2.5.

The number average molecular weight of the polycondensation ester is preferably from 500 to 2,000, more preferably from 600 to 1,500, still more preferably from 700 to 1200. When the number average molecular weight of the polycondensation ester is 600 or more, the volatility becomes low, and it becomes difficult to cause film failure or step contamination due to volatilization of the cellulose ester film under high temperature conditions during elongation. Further, when the ratio is 2,000 or less, the compatibility with the cellulose ester becomes high, and it becomes difficult to cause bleeding at the time of film formation and heating extension.

The number average molecular weight of the polycondensation ester of the present invention can be measured and evaluated by gel permeation chromatography. Further, in the case of a polyester polyol which is not terminated at the end, it may be calculated by the amount of hydroxyl groups per unit weight (hereinafter referred to as a hydroxyl value). The hydroxyl value is the amount (mg) of potassium hydroxide necessary to neutralize excess acetic acid after the polyester polyol is ethoxylated.

The dicarboxylic acid which is a mixture of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid of the present invention is preferably a dicarboxylic acid having an average carbon number of 5.5 or more and 10.0 or less. More preferably, it is 5.6 or more and 8 or less.

When the average number of carbon atoms is 5.5 or more, a polarizing plate excellent in durability can be obtained. When the average carbon number is 10 or less, the compatibility with the cellulose ester is excellent, and the occurrence of bleeding during the film formation of the cellulose ester film can be suppressed.

The polycondensation polyester of the present invention can be used as a plasticizer.

The aromatic dicarboxylic acid residue is contained in a polycondensate obtained from a diol and a dicarboxylic acid containing an aromatic dicarboxylic acid.

In the present specification, the residue is a partial structure which has a characteristic of a monomer which forms a polycondensation in a partial structure of a polycondensation. For example, the dicarboxylic acid residue formed from the dicarboxylic acid HOOC-R-COOH is -OC-R-CO-.

It is preferred that the ratio of the aromatic dicarboxylic acid residue of the polycondensation ester used in the present invention is 40 mol% or more, preferably 40 mol% to 95 mol%. More preferably, it is 45 mol% to 70 mol%, and still more preferably 50 mol% to 70 mol%.

When the ratio of the aromatic dicarboxylic acid residue is 40 mol% or more, a cellulose ester film exhibiting sufficient optical anisotropy can be obtained, and a polarizing plate excellent in durability can be obtained. Further, when it is 95 mol% or less, the compatibility with the cellulose ester is excellent, and bleeding can be prevented from occurring even during film formation of the cellulose ester film and during heating and stretching.

Examples of the aromatic dicarboxylic acid used in the present invention include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, and 1,8-naphthalene. Dicarboxylic acid, 2,8-naphthalenedicarboxylic acid or 2,6-naphthalenedicarboxylic acid, and the like. Preferred are phthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, more preferred are phthalic acid, terephthalic acid, and still more preferably terephthalic acid.

In the polycondensation, an aromatic dicarboxylic acid residue is formed by mixing an aromatic dicarboxylic acid.

Specifically, the aromatic dicarboxylic acid residue preferably contains at least one of a phthalic acid residue, a terephthalic acid residue, and an isophthalic acid residue, and more preferably contains phthalic acid. At least one of a residue and a terephthalic acid residue, and more preferably a terephthalic acid residue.

That is, in the mixing of the formation of the polycondensation, by using terephthalic acid as the aromatic dicarboxylic acid, the compatibility with the cellulose ester is more excellent, even when the cellulose ester film is formed and heated. When extended, a cellulose ester film which is hard to bleed out can also be produced. Further, one type of the aromatic dicarboxylic acid may be used, or two or more types may be used. In the case of using two kinds, it is preferred to use phthalic acid and terephthalic acid.

By using a combination of two kinds of aromatic dicarboxylic acids, phthalic acid and terephthalic acid, the polyester can be softened at room temperature, which is preferable in terms of ease of handling.

The content of the terephthalic acid residue in the dicarboxylic acid residue of the polycondensation ester is preferably from 40 mol% to 95 mol%, preferably from 45 mol% to 70 mol%, preferably 50 mol%. ~70 mol%.

By setting the terephthalic acid residue ratio to 40 mol% or more, a cellulose ester film exhibiting sufficient optical anisotropy can be obtained. Further, when it is 95 mol% or less, the compatibility with the cellulose ester is excellent, and bleeding can be prevented from occurring even during film formation of the cellulose ester film and during heating and stretching.

The aliphatic dicarboxylic acid residue is contained in the polycondensate obtained from the diol and the dicarboxylic acid containing the aliphatic dicarboxylic acid.

In the present specification, the residue is a partial structure which has a characteristic of a monomer which forms a polycondensation in a partial structure of a polycondensation. For example, the dicarboxylic acid residue formed from the dicarboxylic acid HOOC-R-COOH is -OC-R-CO-.

Examples of the aliphatic dicarboxylic acid preferably used in the present invention include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, and softwood acid. Azelaic acid, sebacic acid, dodecanedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid, and the like.

In the polycondensation, an aliphatic dicarboxylic acid residue is formed from a mixed aliphatic dicarboxylic acid.

The dicarboxylic acid residue preferably has an average carbon number of 5.5 or more and 10.0 or less, more preferably 5.5 to 8.0, still more preferably 5.5 to 7.0. If the average carbon number of the aliphatic diol is 7.0 or less, the heating loss of the compound can be reduced, and the occurrence of a planar failure can be prevented (it is considered that the cause of the planar failure is caused by the bleed out of the cellulose expanded web. Step pollution). Further, when the average carbon number of the aliphatic diol is 2.5 or more, the compatibility is excellent, and precipitation of the polycondensation is less likely to occur, which is preferable.

Specifically, it is preferred to contain a succinic acid residue, and in the case of using two kinds, it is preferred to contain a succinic acid residue and an adipic acid residue.

In other words, in the mixing of the polycondensation polyester, one type of the aliphatic dicarboxylic acid may be used, or two or more types may be used. When two types are used, succinic acid and adipic acid are preferably used. In the case of using one type, it is preferred to use succinic acid. The average carbon number of the diol residue can be adjusted to a desired value, and is preferable in terms of compatibility with the cellulose ester.

In the present invention, it is preferred to use two or three kinds of dicarboxylic acids. When two types are used, one type of aliphatic dicarboxylic acid and one type of aromatic dicarboxylic acid must be used. When three types are used, one type of aliphatic dicarboxylic acid and two kinds of aromatic dicarboxylic acids can be used. Or two aliphatic dicarboxylic acids and one aromatic dicarboxylic acid. The reason for this is that the value of the average carbon number of the dicarboxylic acid residue can be easily adjusted, and the content of the aromatic dicarboxylic acid residue is preferably in a range, and the durability of the polarizing element can be improved.

The aliphatic diol residue is contained in the polycondensate obtained from the aliphatic diol and the dicarboxylic acid containing the dicarboxylic acid.

In the present specification, the residue is a partial structure which has a characteristic of a monomer which forms a polycondensation in a partial structure of a polycondensation. For example, the diol residue formed from the diol HO-R-OH is -O-R-O-.

Examples of the diol forming the polycondensation ester include an aromatic diol and an aliphatic diol, and at least an aliphatic diol.

It is preferred to include an aliphatic diol residue having an average carbon number of 2.5 or more and 7.0 or less in the polycondensation polyester. Preferred are aliphatic diol residues having an average carbon number of 2.5 or more and 4.0 or less. When the average carbon number of the aliphatic diol residue is 3.0 or less, the compatibility with the cellulose ester is not lowered, and it becomes difficult to cause bleed out, and the heating loss of the compound is not excessively increased, and it is difficult to cause a planar failure. (The reason for the planar failure is that the step of the deuterated cellulose web is contaminated when it is dry). Further, if the average carbon number of the aliphatic diol residue is less than 2.0, the synthesis becomes difficult.

The aliphatic diol used in the present invention may, for example, be an alkanediol or an alicyclic glycol such as ethylene glycol, 1,2-propanediol, 1,3-propanediol or 1,2-butanediol. , 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol ( Neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dihydroxymethylpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3 , 3-dimethylol heptane), 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecane The alcohol, diethylene glycol, cyclohexane dimethanol, etc., are preferably used in combination with ethylene glycol in one or a mixture of two or more.

The aliphatic diol is preferably at least one selected from the group consisting of ethylene glycol, 1,2-propylene glycol, and 1,3-propanediol, and more preferably at least one of ethylene glycol and 1,2-propylene glycol. In the case of using two kinds, it is preferred to use ethylene glycol and 1,2-propanediol. Crystallization of the polycondensation can be prevented by using 1,2-propanediol or 1,3-propanediol.

In the polycondensation, a diol residue is formed from a diol which is used in combination.

The diol residue preferably contains at least one of an ethylene glycol residue, a 1,2-propanediol residue, and a 1,3-propanediol residue, more preferably an ethylene glycol residue or 1,2- Propylene glycol residue.

In the aliphatic diol residue, it is preferred that the ethylene glycol residue is from 20 mol% to 100 mol%, more preferably from 50 mol% to 100 mol%.

The end of the polycondensation polyester of the present invention may be maintained as a diol or a carboxylic acid without being blocked, or may be further reacted with a monocarboxylic acid or a monool to carry out so-called end capping.

As the monocarboxylic acid used in the capping, acetic acid, propionic acid, butyric acid or the like is preferred, and acetic acid or propionic acid is more preferred, and acetic acid is most preferred. As the monool used in the capping, methanol, ethanol, propanol, isopropanol, butanol, isobutanol or the like is preferred, and methanol is most preferred. When the number of carbon atoms of the monocarboxylic acid used in the end of the polycondensation is 3 or less, the heating loss of the compound does not become large, and no planar failure occurs.

The end of the polycondensate of the present invention is more preferably not sealed to remain as a diol residue, or more preferably blocked with acetic acid or propionic acid.

Both ends of the polycondensate of the present invention may be blocked or uncapped.

In the case where both ends of the condensate are not blocked, it is preferred that the polycondensation ester is a polyester polyol.

As one of the aspects of the polycondensation of the present invention, the aliphatic diol residue has a carbon number of 2.5 or more and 7.0 or less, and examples thereof include a polycondensation product in which both ends of the condensate are not blocked.

In the case where both ends of the condensate are blocked, it is preferred to carry out blocking with a monocarboxylic acid. At this time, both ends of the polycondensate become monocarboxylic acid residues. In the present specification, the residue is a partial structure which has a characteristic of a monomer which forms a polycondensation in a partial structure of a polycondensation. For example, the monocarboxylic acid residue formed from the monocarboxylic acid R-COOH is R-CO-. Preferred is an aliphatic monocarboxylic acid residue, more preferably the monocarboxylic acid residue is an aliphatic monocarboxylic acid residue having a carbon number of 22 or less, and even more preferably an aliphatic single having a carbon number of 3 or less. Carboxylic acid residue. Further, an aliphatic monocarboxylic acid residue having 2 or more carbon atoms is preferred, and an aliphatic monocarboxylic acid residue having 2 carbon atoms is particularly preferred.

One of the aspects of the polycondensation of the present invention is a polycondensation ester in which the number of carbon atoms of the aliphatic diol residue is more than 2.5 and 7.0 or less, and both ends of the condensate are monocarboxylic acid residues.

If the carbon number of the monocarboxylic acid residue at both ends of the polycondensate is 3 or less, the volatility is lowered, and the reduction of the polycondensation due to heating does not become large, and the step contamination or the planar failure can be reduced. Produced.

That is, as the monocarboxylic acid used in the capping, an aliphatic monocarboxylic acid is preferred. More preferably, the monocarboxylic acid is an aliphatic monocarboxylic acid having 2 to 22 carbon atoms, still more preferably an aliphatic monocarboxylic acid having 2 to 3 carbon atoms, and particularly preferably an aliphatic single having 2 carbon atoms. Carboxylic acid residue.

For example, acetic acid, propionic acid, butyric acid, benzoic acid and derivatives thereof and the like are preferred, and acetic acid or propionic acid is more preferred, and acetic acid is most preferred.

Two or more kinds of monocarboxylic acids used for blocking may be mixed.

Preferably, the ends of the polycondensate of the present invention are blocked with acetic acid or propionic acid, and most preferably the ends of the polycondensate are blocked with acetic acid to form an ethyl phthalate residue (sometimes referred to as acetamidine). Base residue).

When the both ends are blocked, it is possible to obtain a cellulose ester film which is difficult to be in a solid state at a normal temperature, has a good operation, and is excellent in humidity stability and durability of a polarizing plate.

Specific examples of the polycondensation ester of the present invention are described in Table 1 below, but are not limited to these specific examples.

The synthesis of the polycondensation ester of the present invention can be carried out by a hot melt condensation method (the hot melt condensation method utilizes a polyesterification reaction or a transesterification reaction of a diol with a dicarboxylic acid by a usual method), or It is easily synthesized by any method of interfacial condensation of acid and hydrazine with a diol. Further, the polycondensation of the present invention is described in detail in "Editor, Theory and Application" (fortunately, Shusuke Co., Ltd., and the first edition of the first edition of the Showa Warranty, March 1, 2008). In addition, Japanese Patent Laid-Open No. Hei 05-155809, Japanese Patent Laid-Open No. Hei 05-155810, Japanese Patent Laid-Open No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei. The materials described in Japanese Laid-Open Patent Publication No. Hei. No. 2006-342227, and Japanese Patent Laid-Open No. 2007-003679.

The content of the polycondensate in the cellulose ester film is preferably from 5 wt% to 40 wt%, more preferably from 8 wt% to 30 wt%, most preferably 10%, based on the amount of the cellulose ester. Wt% to 25 wt%.

The content of the aliphatic diol, the dicarboxylic acid ester or the diol ester of the raw material contained in the polycondensate of the present invention in the cellulose ester film is preferably less than 1% by weight, more preferably less than 0.5% by weight. Examples of the dicarboxylic acid esters include dimethyl phthalate, di(hydroxyethyl) phthalate, dimethyl terephthalate, di(hydroxyethyl) terephthalate, and adipic acid. (Hydroxyethyl) ester, di(hydroxyethyl) succinate, and the like. Examples of the glycol ester include ethylene glycol diacetate and propylene glycol diacetate.

The type and ratio of each residue of the dicarboxylic acid residue, the diol residue, and the monocarboxylic acid residue contained in the polycondensation ester used in the present invention can be measured by a usual method using H-NMR. . In general, deuterated chloroform can be used as a solvent.

The number average molecular weight of the polycondensation ester can be measured by a usual method using GPC (Gel Permeation Chromatography), and polystyrene can usually be used as a standard material.

The measurement of the hydroxyl value of the polycondensation ester can be carried out by the acetic anhydride method described in Japanese Industrial Standard JIS K3342 (obsolete). In the case where the polycondensate is a polyester polyol, the hydroxyl value is preferably 50 or more and 190 or less, more preferably 50 or more and 130 or less.

(delayed performance agent)

The film of the present invention preferably does not contain 3 wt% or more of the Re manifest agent with respect to the deuterated cellulose. On the other hand, in order to exhibit a retardation value, a retardation agent may be contained, but it is preferable that the content of the Re agent is less than 3 wt% with respect to the deuterated cellulose. The retardation agent is not particularly limited, and examples thereof include a retardation agent containing a rod-shaped or disk-shaped compound. As the rod-like or disc-shaped compound, it is preferred to use a compound having at least two aromatic rings as a retardation agent.

The amount of the delayed expression agent containing the rod-like compound is preferably 0.1 part by weight or more and less than 3 parts by weight, more preferably 0.5 part by weight or more and less than 2 parts by weight based on 100 parts by weight of the deuterated cellulose component. . The discotic compound contained in the delayed expression agent is preferably 0.1 part by weight or more and less than 3 parts by weight, more preferably 0.5 part by weight or more and less than 100 parts by weight of the deuterated cellulose. 2 parts by weight, particularly preferably 0.5 parts by weight or more and less than 1 part by weight.

The discotic compound is superior to the rod compound in terms of Rth retardation performance, and thus can be preferably used particularly in the case where a large Rth retardation is required. It is also possible to use two or more kinds of delayed expression agents in combination.

Preferably, the retardation agent has a maximum absorption in the wavelength region from 250 nm to 400 nm, and preferably does not substantially absorb in the visible region.

The discotic compound will be described. As the discotic compound, a compound having at least two aromatic rings can be used.

In the present specification, the "aromatic ring" includes an aromatic heterocyclic ring in addition to the aromatic hydrocarbon ring.

Particularly preferred for the aromatic hydrocarbon ring is a 6-membered ring (i.e., a benzene ring).

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

As the aromatic ring, a benzene ring, a condensed benzene ring, and a biphenyl group are preferable. In particular, a 1,3,5-triazine ring can be preferably used. Specifically, for example, a compound disclosed in Japanese Laid-Open Patent Publication No. 2001-166144 can be preferably used.

The carbon number of the aromatic ring which the delayed expression agent has is preferably from 2 to 20, more preferably from 2 to 12, still more preferably from 2 to 8, most preferably from 2 to 6.

The bonding relationship of the two aromatic rings can be classified into (a) a case where a condensed ring is formed, (b) a case where a bond is directly bonded by a single bond, and (c) a case where a bond is bonded via a linking group (because it is aroma) Family ring, so can not form a spiro button). The bonding relationship may be any of (a) to (c).

Examples of the condensed ring (a condensed ring of two or more aromatic rings) of (a) include an anthracene ring, a naphthalene ring, an anthracene ring, an anthracene ring, a phenanthrene ring, an anthracene ring, an anthracene ring, an azo ring, a condensed tetraphenyl ring, Anthracene ring, anthracene ring, isoindole ring, benzofuran ring, benzothiophene ring, pyridazine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, hydrazine Ring, carbazole ring, benzopyran ring, quinoline ring, isoquinoline ring, quinazoline ring, quinazoline ring, porphyrin ring, quinoxaline ring, pyridazine ring, acridine ring, indazole ring , acridine ring, pyridine ring, dibenzopyran ring, phenazine ring, phenothiazine ring, morphine ring, phenoxazine ring and thioindole ring. Preferred are naphthalene rings, anthracene rings, anthracene rings, benzoxazole rings, benzothiazole rings, benzimidazole rings, benzotriazole rings and quinoline rings.

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

The linking group of (c) is also preferably bonded to the carbon atoms of the two aromatic rings. Preferred linking groups are alkylenes, alkenylenes, alkynylenes, -CO-, -O-, -NH-, -S- or combinations of such groups. Examples of the combination of the linked groups are shown below. In addition, the left-right relationship of the examples of the following linkages may be reversed.

C1:-CO-O-

C2:-CO-NH-

C3:-alkylene-O-

C4:-NH-CO-NH-

C5:-NH-CO-O-

C6:-O-CO-O-

C7:-O-alkylene-O-

C8: -CO-alkenylene-

C9: -CO-alkenylene-NH-

C10: -CO-alkenylene-O-

C11:-alkylene-CO-O-alkylene-O-CO-alkylene-

C12:-O-alkylene-CO-O-alkylene-O-CO-alkylene-O-

C13:-O-CO-alkylene-CO-O-

C14: -NH-CO-alkenylene-

C15:-O-CO-alkenylene-

The aromatic ring and the linking group may have a substituent.

Examples of the substituent include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amine group, a nitro group, a sulfo group, an amine carbaryl group, an amine sulfonyl group, a ureido group, an alkyl group, an alkene group. Alkyl, alkynyl, aliphatic fluorenyl, aliphatic decyloxy, alkoxy, alkoxycarbonyl, alkoxycarbonylamino, alkylthio, alkylsulfonyl, aliphatic guanylamine, aliphatic A sulfonamide group, an aliphatic substituted amine group, an aliphatic substituted amine carbenyl group, an aliphatic substituted amine sulfonyl group, an aliphatic substituted ureido group, and a non-aromatic heterocyclic group.

The number of carbon atoms of the alkyl group is preferably from 1 to 8. The chain alkyl group is more preferred than the cyclic alkyl group, and particularly preferably a linear alkyl group. The alkyl group may further have a substituent (for example, a hydroxyl group, a carboxyl group, an alkoxy group, an alkyl group substituted with an alkyl group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl and 2-diethyl Each group of a benzylamino group.

The number of carbon atoms of the alkenyl group is preferably from 2 to 8. The chain alkenyl group is more preferred than the cyclic alkenyl group, and particularly preferably a linear alkenyl group. The alkenyl group may further have a substituent. Examples of alkenyl groups include vinyl, allyl and 1-hexenyl.

The number of carbon atoms of the alkynyl group is preferably from 2 to 8. The chain alkynyl group is more preferred than the cyclic alkynyl group, and particularly preferably a linear alkynyl group. The alkynyl group may further have a substituent. Examples of alkynyl groups include ethynyl, 1-butynyl and 1-hexynyl.

The number of carbon atoms of the aliphatic fluorenyl group is preferably from 1 to 10. Examples of the aliphatic thiol group include an ethyl group, a propyl group, and a butyl group.

The number of carbon atoms of the aliphatic methoxy group is preferably from 1 to 10. Examples of the aliphatic methoxy group include an ethoxy group.

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

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

The alkoxycarbonylamino group preferably has 2 to 10 carbon atoms. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

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

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

The aliphatic guanamine group preferably has 1 to 10 carbon atoms. Examples of the aliphatic guanamine group include an ethenyl group.

The number of carbon atoms of the aliphatic sulfonamide group is preferably from 1 to 8. Examples of the aliphatic sulfonamide group include a methylsulfonylamino group, a butylsulfonylamino group, and an n-octylsulfonylamino group.

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

The number of carbon atoms of the aliphatic substituted amidoxime group is preferably from 2 to 10. Examples of the aliphatically substituted amine mercapto group include methylamine methyl thiol and diethylamine methyl fluorenyl.

The number of carbon atoms of the aliphatic substituted aminoxime group is preferably from 1 to 8. Examples of the aliphatic substituted aminoxime group include methylamine sulfonyl group and diethylamine sulfonyl group.

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

Examples of the non-aromatic heterocyclic group include N-piperidinyl and N-morpholinyl.

The molecular weight of the delayed expression agent is preferably from 300 to 800.

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

General formula (I)

In the above formula (I):

R ²⁰¹ each independently represents an aromatic ring or a heterocyclic ring having a substituent at least at any of the ortho, meta and para positions.

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

The aromatic ring represented by R ²⁰¹ is preferably a phenyl group or a naphthyl group, and particularly preferably a phenyl group. The aromatic ring represented by R ²⁰¹ may have at least one substituent at any of the substitution positions. Examples of the substituent include a halogen atom, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an alkenyloxy group, an aryloxy group, a decyloxy group, an alkoxycarbonyl group, An oxycarbonyl group, an aryloxycarbonyl group, an amine sulfonyl group, an alkyl-substituted amine sulfonyl group, an alkenyl-substituted amine sulfonyl group, an aryl-substituted sulfonyl group, Base, amine mercapto group, alkyl substituted amine carbenyl group, alkenyl substituted amine carbenyl group, aryl group substituted amine carbenyl group, decylamino group, alkylthio group, alkylthio group, aryl group Sulfur and sulfhydryl groups.

It is preferred that the heterocyclic group represented by R ²⁰¹ has aromaticity. The aromatic heterocyclic ring is usually an unsaturated heterocyclic ring, and preferably a heterocyclic ring having the most double bond. The heterocyclic ring is preferably a 5-membered ring, a 6-membered ring or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the hetero ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the aromatic hetero ring, a pyridine ring (heterocyclic group is 2-pyridyl or 4-pyridyl) is particularly preferred. The heterocyclic group may also have a substituent. Examples of the substituent of the heterocyclic group are the same as those of the substituent of the above aryl moiety.

The heterocyclic group in the case where X ²⁰¹ is a single bond is preferably a heterocyclic group having a free valence in a nitrogen atom. The heterocyclic group having a free valence of a nitrogen atom is preferably a 5-membered ring, a 6-membered ring or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 5-membered ring. The heterocyclic group may also have a plurality of nitrogen atoms. Further, the heterocyclic group may have a hetero atom other than a nitrogen atom (for example, O, S). The following is an example of a heterocyclic group having a free valence of a nitrogen atom. Here, -C ₄ H ₉ ⁿ represents nC ₄ H ₉ .

The alkyl group represented by R ²⁰² may be a cyclic alkyl group or a chain alkyl group, preferably a chain alkyl group, and more preferably a linear alkyl group than a branched chain alkyl group. base. The number of carbon atoms of the alkyl group is preferably from 1 to 30, more preferably from 1 to 20, still more preferably from 1 to 10, still more preferably from 1 to 8, most preferably from 1 to 6. The alkyl group may also have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (e.g., methoxy group, ethoxy group), and a decyloxy group (e.g., acryloxy group, methacryloxy group).

The alkenyl group represented by R ²⁰² may be a cyclic alkenyl group or a chain alkenyl group, preferably a chain alkenyl group, and more preferably a linear chain than a branched chain alkenyl group having a branch. Alkenyl. The number of carbon atoms of the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, most preferably 2 to 6. The alkenyl group may also have a substituent. Examples of the substituent are the same as the substituent of the aforementioned alkyl group.

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

The compound represented by the formula (I) can be synthesized, for example, by a known method such as the method described in JP-A-2003-344655. Details of the delayed performance agent are described on page 49 of the published Technical Bulletin 2001-1745.

As the retardation agent of the present invention, a polymer additive can be used similarly to the low molecular compound. Here, the polymer used as the polycondensation ester in the present invention may also function as a retardation expression agent. The polymer-based delayed expression agent which may be present in the polycondensation ester is preferably a copolymer of the aromatic polyester-based polymer and the aromatic polyester-based polymer and another resin.

It is more preferable that the retardation agent of the present invention is a Re manifest agent from the viewpoint of efficiently expressing Re and achieving an appropriate Nz factor. In the retardation agent, for example, a discotic compound, a rod compound, or the like can be given.

(delay reducing agent)

In the present invention, as the retardation reducing agent, a phosphate-based ester compound or a compound known as an additive of a cellulose-deposited cellulose film can be widely used.

The polymer-based retardation reducing agent is selected from the group consisting of a phosphate-based polyester polymer, a styrene-based polymer, an acrylic polymer, and a copolymer of these compounds, preferably an acrylic polymer and a styrene-based polymer. polymer. Further, it is preferred to contain at least one polymer having a negative intrinsic birefringence such as a styrene polymer or an acrylic polymer.

The following compounds are exemplified as the low molecular weight retardation reducing agent. These compounds may be either solid or oily. That is, it is not particularly limited in its melting point or boiling point. For example, mixing of 20 ° C or less and 20 ° C or more of the ultraviolet absorbing material, or similarly, mixing of the inhibitor. Further, as an infrared absorbing dye, for example, it is described in Japanese Laid-Open Patent Publication No. 2001-194522. Further, the addition period thereof may be arbitrarily added in the step of preparing the deuterated cellulose solution (dopant), or may be carried out by adding a step of preparing the additive in the final preparation step of the dopant preparation step. In addition, the amount of addition of each material is not particularly limited as long as it can exhibit a function.

The low molecular weight retardation reducing agent is not particularly limited, and the details are described in [0066] to [0085] of JP-A-2007-272177.

The compound of the formula (1) described in [0066] to [0085] of JP-A-2007-272177 can be produced by the following method.

The compound of the formula (1) in the publication can be obtained by a condensation reaction of a sulfonium chloride derivative with an amine derivative.

Japanese Laid-Open Patent Publication No. 2007-272177. The compound described in the formula (2) can be subjected to dehydration condensation reaction of a carboxylic acid and an amine using a condensing agent (for example, dicyclohexylcarbodiimide (DCC) or the like). Or a substitution reaction of a carboxy hydrazine derivative with an amine derivative or the like.

(Plasticizer)

As the plasticizer used in the present invention, various compounds known as plasticizers for deuterated cellulose can also be used. As the plasticizer, a phosphate or a carboxylate is used. Examples of phosphates include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Carboxylic esters are represented by phthalates and citrates. Examples of phthalates include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate ( DOP), diphenyl phthalate (DPP) and diethylhexyl phthalate (DEHP). Examples of citrate esters include O-ethyl decyl triethyl citrate (OACTE) and O-ethyl decyl tributyl citrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methyl decyl ricinoleate, dibutyl sebacate, and various trimellitates. A phthalate-based plasticizer (DMP, DEP, DBP, DOP, DPP, DEHP) can be preferably used. Particularly good are DEP and DPP.

(deterioration inhibitor)

In the present invention, a known deterioration (oxidation) inhibitor such as 2,6-di-tert-butyl-4-methylphenol or 4,4'-thiobis- can be added to the deuterated cellulose solution. (6-Tertibutyl-3-methylphenol), 1,1'-bis(4-hydroxyphenyl)cyclohexane, 2,2'-methylenebis(4-ethyl-6- Tributylphenol), 2,5-di-t-butyl hydroquinone, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid] Phenolic or hydroquinone based antioxidants. Further, it is preferably tris(4-methoxy-3,5-diphenyl) phosphite, tris(nonylphenyl) phosphite, and tris(2,4-di-) Tributylphenyl) ester, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol Phosphorus-based antioxidants such as diphosphite. The amount of the deterioration inhibitor added is 0.05 parts by weight to 5.0 parts by weight based on 100 parts by weight of the cellulose resin.

(UV absorber)

In the present invention, from the viewpoint of suppressing deterioration of a polarizing plate or a liquid crystal or the like, an ultraviolet absorber is preferably used in the deuterated cellulose solution. As the ultraviolet absorber, it is preferable to use an ultraviolet absorber having a small absorption of visible light having a wavelength of 400 nm or more from the viewpoint of excellent absorption of ultraviolet light having a wavelength of 370 nm or less and good liquid crystal display property. Specific examples of the ultraviolet absorber to be preferably used in the present invention include a hindered phenol compound, a hydroxybenzophenone compound, a benzotriazole compound, and a salicylate compound. A benzophenone-based compound, a cyanoacrylate compound, a nickel-salt-based compound, or the like. Examples of the hindered phenol-based compound include 2,6-di-t-butyl-p-cresol, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propane. Acid]ester, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-phenylpropanamide), 1,3,5-trimethyl-2,4, 6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, etc. . Examples of the benzotriazole-based compound include 2- (2 '- hydroxy - 5' - methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3 ,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol), 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5 -di-t-butylanilino)-1,3,5-triazine, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionic acid ] ester, N, N'-hexamethylene bis(3,5-di-t-butyl-4-hydroxy-phenylpropanamide), 1,3,5-trimethyl-2,4,6 -Tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 2(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzo Triazole, 2(2'-hydroxy-3',5'-di-third-pentylphenyl)-5-chlorobenzotriazole, 2,6-di-t-butyl-p-cresol, pentaerythritol -tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid]ester. The amount of the ultraviolet inhibitor to be added is preferably from 1 ppm to 1.0% by weight, more preferably from 10 ppm to 1000 ppm, based on the total weight of the cellulose film.

(matting agent)

From the viewpoint of film slidability and stable production, it is preferred that the film of the present invention contains a matting agent. The matting agent may be a matting agent for an inorganic compound or a matting agent for an organic compound.

As preferred examples of the matting agent for the inorganic compound, a cerium-containing inorganic compound (for example, cerium oxide, calcined calcium citrate, calcium citrate citrate, aluminum citrate, magnesium citrate, etc.), titanium oxide is preferable. , zinc oxide, aluminum oxide, cerium oxide, zirconium oxide, cerium oxide, cerium oxide, tin oxide, antimony tin oxide, calcium carbonate, talc, clay, calcined kaolin and calcium phosphate, etc., more preferably an antimony-containing inorganic compound or oxidation Zirconium, particularly, can effectively use cerium oxide because the turbidity of the fluorinated cellulose film can be reduced. As the fine particles of the cerium oxide, for example, commercially available products having the names of Aerotech R972, R974, R812, 200, 300, R202, OX50, TT600 (above, manufactured by Japan Aerosil Co., Ltd.) can be used. As the fine particles of the zirconia, for example, those sold under the trade names of Aerotech R976 and R811 (above, manufactured by Japan Aerosil Co., Ltd.) can be used.

As a preferable specific example of the matting agent of the organic compound, for example, a polymer such as a silicone resin, a fluororesin or an acrylic resin is preferable, and a silicone resin can be preferably used. Among the oxime resins, particularly those having a three-dimensional network structure, for example, Tospearl 103, Tospearl 105, Tospearl 108, Tospearl 120, Tospearl 145, Tospeatl 3120 and Tospearl 240 (above by Toshiba Silicone) can be used. A commercial item such as a manufacturing company).

In the case where the matting agents are added to the deuterated cellulose solution, there is no problem particularly if the desired deuterated cellulose solution can be obtained by any method which does not limit the method. For example, in the stage of mixing the deuterated cellulose and the solvent, an additive may be contained, and after the mixed solution is prepared by deuterated cellulose and a solvent, an additive may be added. In addition, it is also possible to carry out the addition and mixing before the casting of the dopant, that is, the so-called direct addition method, and the mixing is used on a line-provided spiral kneader. Specifically, a static mixer such as an in-line mixer is preferred, and, as an in-line mixer, for example, a static mixer such as a static mixer SWJ (Dongli static in-line mixer) is preferred. Hi-Mixer) (manufactured by Toray Engineering Co., Ltd.) such a mixer. In addition, in the in-line addition, in order to eliminate density unevenness, particle agglomeration, and the like, the following invention is described in Japanese Laid-Open Patent Publication No. 2003-053752: In the method for producing a cellulose-deposited cellulose film, a pipe is added The distance L between the tip end of the nozzle and the starting end of the in-line mixer is set to be less than 5 times the inner diameter d of the main material pipe, and the concentration unevenness, the extinction particle, and the like can be eliminated, and the above-mentioned addition nozzle is the main raw material dopant. Mix the different compositions of the additive. As a more preferable aspect, it is described that the distance (L) between the opening end portion of the additive liquid supply nozzle having a different composition from the main raw material dopant and the start end portion of the in-line mixer is set as the front end opening of the supply nozzle. Below 10 times the inner diameter (d) of the section, the in-line mixer is a static non-stirred in-line mixer or a dynamic agitated in-line mixer. More specifically, it is disclosed that the flow ratio of the main raw material dopant/in-line addition liquid of the deuterated cellulose film is from 10/1 to 500/1, preferably from 50/1 to 200/1. In addition, Japanese Patent Publication No. 2003-014933 (which is an invention for the purpose of a phase difference film having a small amount of bleed out of the additive and having no delamination between the layers and having excellent slidability and excellent transparency) is described as an additive. The method may be added to the dissolution vessel, or may be added between the dissolution vessel and the co-casting mold, and the additive or the solution in which the additive is dissolved or dispersed is added to the dopant in the liquid supply, and the latter may improve the mixing. Therefore, it is preferable to provide a mixing mechanism such as a static mixer.

(organic acid)

It is preferred that the film of the present invention contains an organic acid represented by the following formula (1).

General formula (1)

XL-(R ¹ ) _n

(wherein, X represents an acidic group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher linking group, and R ¹ represents an alkyl group having 6 to 30 carbon atoms and an alkenyl group having 6 to 30 carbon atoms. Further, the alkynyl group having 6 to 30 carbon atoms, the aryl group having 6 to 30 carbon atoms or the heterocyclic group having 6 to 30 carbon atoms may further have a substituent. n is 1 when L is a single bond. In the case where L is a linking group of two or more valences, it is (the valence of L-1).

In the organic acid represented by the above formula (1), the peeling property from the solution film forming apparatus (the metal support when the dopant is flowed) can be improved by the X portion as the acidic group.

Further, the X portion as the acidic group is attached to the metal surface of the support, and the R ¹ portion which is a hydrophobic group of a specific structure is blocked on the metal surface of the support by an oxidizing agent such as oxygen, and thus Corrosion of metals can be prevented as compared to organic acids having a hydrophobic group outside the range of R ¹ .

Hereinafter, the peeling accelerator which can be used for the film of this invention is demonstrated.

In the formula (1), X represents an acid having an acid dissociation constant of 5.5 or less, preferably a carboxyl group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group, a sulfonimide group, an ascorbic acid group, and more preferably The carboxyl group and the sulfonic acid group are most preferably a carboxyl group. Further, when X represents an ascorbic acid group, it is preferred that hydrogen atoms at the 5-position and the 6-position of the hydrogen atoms of ascorbic acid fall off and are linked to L.

In the present specification, the acid dissociation constant is a value described in the chemical handbook and Maruzen Co., Ltd. publication.

In the formula (1), R ¹ represents a hydrogen atom, an alkyl group having 6 to 30 carbon atoms (may also have a substituent), an alkenyl group (which may have a substituent), an alkynyl group (may also have a substituent) An aryl group (which may also have a substituent) or a heterocyclic group (which may have a substituent). Examples of the substituent include a halogen atom, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a decyl group, a hydroxyl group, a decyloxy group, an amine group, an alkoxycarbonyl group, and an anthracene group. Alkylamino group, oxycarbonyl group, amine mercapto group, sulfonyl group, amine sulfonyl group, sulfonylamino group, sulfo group, carboxyl group and the like.

More preferably, R ¹ is an alkyl group, an alkenyl group or an alkynyl group having a carbon number of 8 to 24, and most preferably a linear alkyl group or an alkenyl group having a carbon number of 10 to 24.

L in the general formula (1) is preferably a single bond or a divalent or higher linking group obtained by the following unit group or a combination of two or more units selected from the following unit groups. The above link.

Unit: -O-, -CO-, -N(-R ² )- (the R ² is an alkyl group having 1 to 5 carbon atoms), -CH=CH-, -CH(OH)-, -CH ₂ -, -SO ₂ -,

Particularly preferred in the formula (1) is a linking group having a single bond, derived from an ester group (-COO-, -OCO-), or a linking group derived from a mercapto group (-CONR ² -, -NR) ² CO-) as part of the structure.

Further, the L may further have a substituent, and the substituent is not particularly limited, and examples thereof include a substituent which the R ¹ may have, and among them, an -OH group is preferred.

In these, it is more preferred that the L is a linking group containing a group derived from glycerin.

As the L, specifically, the following structure is preferable. In the following, p, q, and r each represent an integer of 1 to 40, preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6. Further, it is particularly preferable that q is 2 to 4.

-(CH ₂ ) _p -CO-O-(CH ₂ ) _q -O-;-(CH ₂ ) _p -CO-O-(CH ₂ ) _q -(CH(OH))-(CH ₂ ) _r - O-;-(CH ₂ ) _p -CO-O-(CH ₂ ) _q -(CH(OCO-R ³ ))-(CH ₂ ) _r -O-;-(CH ₂ ) _p -CO-O- (CH ₂ ) _q -(CH(OH))-(CH ₂ ) _r -O-CO-;-(CH ₂ ) _p -CO-O-(CH ₂ ) _q -(CH(OCO-R ³ )) -(CH ₂ ) _r -O-CO-.

Further, R ³ contained in the specific example of the above L is synonymous with R ¹ in the above formula (1). That is, the linking group _{- (CH 2) p -CO-} O- (CH 2) q - (CH (OCO-R 3)) - (CH 2) r -O- in R ³ for convenience of description only Inside L, the linking group L indicates a portion from which R ³ is removed. That is, in this case, L is 3 valence. When expressed by the formula (1), it can be described as XL-(R ¹ ) ₂ , wherein L represents -(CH ₂ ) _p -CO-O-(CH ₂ ) _q -(CH(OCO-)) -(CH ₂ ) _r -O-], that is, the linking group L at this time becomes a trivalent linking group.

Preferably, the L and the X are bonded by an ester bond or a guanamine bond, and more preferably an ester bond. Moreover, it is preferred that no ester bond or guanamine bond is present in said X.

Preferably, the L and the R ¹ are bonded by an ester bond, an ether bond or a guanamine bond, more preferably an ester bond or a guanamine bond, and particularly preferably an ester bond. Knot. Moreover, it is preferred that no ester bond or ether bond or guanamine bond is present in said R ¹ .

Hereinafter, preferred specific examples of the organic acid represented by the above formula (1) are listed below.

"fatty acid"

Myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linoleic acid, ricinoleic acid, undecanoic acid.

Alkyl Sulfate

Myristyl sulfate, cetyl sulfate, oleyl sulfate.

"Alkylbenzenesulfonic acid"

Dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid.

Alkylnaphthalenesulfonic acid

Sesquibutyl naphthalenesulfonic acid, diisobutylnaphthalenesulfonic acid.

Dialkyl sulfosuccinic acid

Dioctylsulfosuccinic acid, dihexylsulfosuccinic acid, dicyclohexyl succinic acid, dipentyl sulfosuccinic acid, ditridecylcyclosuccinic acid.

"Some derivatives of polybasic organic acids"

The organic acid represented by the above formula (1) is preferably a partial derivative of a polybasic organic acid. In the present specification, a partial derivative of a polybasic organic acid refers to a structure having one molecule of a fatty acid and a polybasic organic acid bonded to one molecule of a polyol, and having at least one unsubstituted from a polycarboxylic acid. An acidic group of compounds. Further, in the present specification, the fatty acid means an aliphatic monocarboxylic acid. That is, the fatty acid in the present specification is not limited to the so-called higher aliphatic group, and includes a lower fatty acid having 12 or less carbon atoms such as acetic acid or propionic acid.

A part of the derivative of the polybasic organic acid is preferably a partial derivative of a polycarboxylic acid. That is, the organic acid represented by the formula (1) preferably has a structure in which one molecule of a fatty acid and one molecule of a polycarboxylic acid are bonded to one molecule of a polyol, and at least one is derived from a plurality of molecules. An unsubstituted carboxyl group of a carboxylic acid. The polycarboxylic acid to be used as a partial derivative of the polyvalent carboxylic acid is not particularly limited, and for example, succinic acid, citric acid, tartaric acid, diterpene tartaric acid, malic acid, adipic acid is preferable.

Examples of the polyhydric alcohol used in the partial derivative of the polybasic organic acid include adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene. Alcohol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6 - hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane-1,3,5-triol, pinacol, sorbitol, trimethylolpropane, three Hydroxymethylethane, xylitol, glycerin, and the like. Among them, preferred is glycerin, and it is preferred that the organic acid represented by the above formula (1) is a so-called organic acid glyceride.

The organic acid represented by the above formula (1) is preferably an organic acid glycerol in which an acidic group X of an organic acid is bonded to the hydrophobic portion R ¹ via a linking group L containing a glycerol-based group. Ester (glycerol fatty acid organic acid ester). Here, the term "organic acid glyceride" as used herein means a compound having one or two of the three hydroxyl groups of glycerol forming an ester bond with a fatty acid, and one or two of the remaining hydroxyl groups and a polybasic organic compound. The acid forms an ester bond and has an acidic group derived from the polybasic organic acid.

Among them, organic acid monoglycerides or organic acid diglycerides are more preferred, and organic acid monoglycerides are particularly preferred. The term "organic acid monoglyceride" as used herein refers to a compound having a structure in which one of three hydroxyl groups of glycerol forms an ester bond with a fatty acid, and one or two of the remaining hydroxyl groups form an ester bond with a polybasic organic acid. And having an acidic group derived from the polybasic organic acid. The term "organic acid diglyceride" as used herein refers to a compound having a structure in which two of the three hydroxyl groups of glycerol form an ester bond with a fatty acid, and the remaining one of the hydroxyl groups forms an ester bond with the polybasic organic acid, and has An acidic group of a polybasic organic acid.

Further preferably, in the organic acid monoglyceride, a compound having a structure in which one of three hydroxyl groups of glycerol forms an ester bond with a fatty acid, and one of the remaining hydroxyl groups is an unsubstituted hydroxyl group, and the rest One of the hydroxyl groups forms an ester bond with the polybasic organic acid and has an acidic group derived from the polybasic organic acid. Preferably, the hydroxyl group of the organic acid monoglyceride ester-bonded with the fatty acid is an asymmetric position (so-called position of the α-monoglyceride), and preferably the organic acid monoglyceride and the polybasic organic The hydroxyl group in which the acid is ester-bonded is likewise an asymmetric position (the position of the so-called alpha monoglyceride). That is, among the organic acid monoglycerides, preferred are compounds having a structure in which a carbon atom having an unsubstituted hydroxyl group and a hydroxyl group bonded to a fatty acid is directly bonded, and a polybasic organic acid. The carbon atoms directly bonded to the hydroxyl group of the ester bond are not adjacent.

Further among the organic acid monoglycerides, a monoglyceride of a polyvalent carboxylic acid is further preferable. The monoglyceride of the polyvalent carboxylic acid means an organic acid having at least one unsubstituted carboxyl group in the polyvalent carboxylic acid and the other carboxyl group substituted by the monoglyceride. That is, a carboxyl group-containing organic acid monoglyceride in which one molecule of a fatty acid and one molecule of a polyvalent carboxylic acid are bonded to one molecule of glycerin is particularly preferable.

The polyvalent carboxylic acid used in the monoglyceride of the polyvalent carboxylic acid is not particularly limited, and for example, succinic acid, citric acid, tartaric acid, diterpene tartaric acid, malic acid, adipic acid is preferred. .

The fatty acid used in the monoglyceride of the polycarboxylic acid is not limited, and a saturated or unsaturated fatty acid having a carbon number of 8 to 22 is preferred, and specific examples thereof include caprylic acid, capric acid, and dodecane. Acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, and the like.

Hereinafter, the organic acid monoglyceride containing a carboxyl group which can be used in the present invention will be described in detail.

The organic acid monoglyceride containing a carboxyl group which can be used in the present invention can be used as an acid anhydride of a polybasic organic acid and a fatty acid single according to the method described in Japanese Patent Laid-Open No. Hei 4-218597, No. 3,832,524, and the like. Obtained by glyceride reaction.

The reaction is usually carried out under solvent-free conditions, for example, in the reaction of succinic anhydride with a fatty acid monoglyceride having a carbon number of 18, and the reaction is terminated at a temperature of about 120 ° C for about 90 minutes. The organic acid monoglyceride thus obtained is usually a mixture containing an organic acid, an unreacted monoglyceride, a diglyceride, and other oligomers. In the present invention, such a mixture can also be used as it is.

When it is desired to increase the purity of the carboxyl group-containing organic acid monoglyceride, the carboxyl group-containing organic acid monoglyceride in the mixture as described above may be purified by distillation or the like, and as a high purity An organic acid monoglyceride containing a carboxyl group can be used as a distilled monoglyceride. As a commercial item of the carboxyl group-containing organic acid monoglyceride, for example, POEM K-37V (glycerol citrate oleate) and STEP SS (glycerol stearic acid/palmitate succinate) can be cited. )Wait.

The amount of the organic acid represented by the above formula (1) contained in the film of the present invention is from 0.1 wt% to 20 wt%, more preferably 0.5 wt%, based on the deuterated cellulose. From % to 10 wt%, further preferably from 0.6 wt% to 5 wt%, further preferably from 1.5 wt% to 5 wt%.

When the amount of addition is 0.1% or more, the effect of improving the durability of the polarizing element and the effect of improving the peeling property are sufficient. In addition, when the amount is 20 wt% or less, it is difficult for the organic acid to bleed out during high temperature and high humidity, and it is difficult to increase the orthogonal transmittance of the polarizing plate.

The molecular weight of the organic acid represented by the above formula (1) is preferably from 200 to 1,000.

(sugar ester compound)

- sugar residue -

The sugar ester compound refers to a compound in which at least one of a substitutable group (for example, a hydroxyl group or a carboxyl group) in the polysaccharide constituting the compound is ester-bonded to at least one substituent. That is, the so-called sugar ester compound herein also includes a generalized sugar derivative, and for example, a compound containing a sugar residue such as gluconic acid as a structure. That is, the sugar ester compound also includes an ester of glucose and a carboxylic acid, and an ester of gluconic acid and an alcohol.

The substitutable group in the polysaccharide constituting the sugar ester compound is preferably a hydroxyl group.

The sugar ester compound contains a structure derived from a polysaccharide constituting the sugar ester compound (hereinafter also referred to as a sugar residue). The structure of each monosaccharide of the sugar residue is referred to as a structural unit of a sugar ester compound. The structural unit of the sugar ester compound preferably contains a pyranose structural unit or a furanose structural unit, and more preferably all of the sugar residues are pyranose structural units or furanose structural units. Further, in the case where the sugar ester is composed of a polysaccharide, it is preferred to contain a pyranose structural unit or a furanose structural unit together.

The sugar residue of the sugar ester compound may be derived from 5 monosaccharides or 6 monosaccharides, preferably 6 monosaccharides.

The number of structural units contained in the sugar ester compound is preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2. That is, the sugar constituting the sugar ester compound is preferably 2 saccharides to 4 saccharides, more preferably 2 saccharides to 3 saccharides, and particularly preferably 2 saccharides.

In the present invention, the sugar ester compound is more preferably a sugar ester compound containing at least one hydroxyl group containing two to four pyranose structural units or a furanose structural unit, more preferably a hydroxyl group. At least one esterified sugar ester compound comprising two pyranose structural units or furanose structural units.

Examples of the monosaccharide or a saccharide containing two to four monosaccharide units include erythrose, threose, ribose, arabinose, xylose, and lyxose. Allose, altrose, glucose, fructose, mannose, gulose, idose, galactose, talose, trehalose, iso-trehalose, new trehalose, trehalose , kojibiose, nigerose, maltose, maltitol, isomaltose, sucrose, kelp, cellobiose, gentiobiose, lactose, lactosamine, lactitol, lactone Sugar, melibiose, primrose, chewing gum, scillabiose, sucrose, sucralose, pine disaccharide, podobiose, cellotriose, potato trisaccharide, gentian trisaccharide, iso-mai Bud triose, isoglucosyl maltose, maltotriose, mannotriose, pine trisaccharide, panose, psyllium, raffinose, eggplant trisaccharide, umbelliferous, lycopene, malt Sugar, stachyose, maltopentaose, , maltohexaose, xylitol, sorbitol, and the like.

Preferred are ribose, arabinose, xylose, lyxose, glucose, fructose, mannose, galactose, bacteriocin, maltose, cellobiose, lactose, sucrose, sucralose, xylitol, sorbitol More preferably, arabinose, xylose, glucose, fructose, mannose, galactose, maltose, cellobiose, sucrose, especially xylose, glucose, fructose, mannose, galactose, maltose, fiber double Sugar, sucrose, xylitol, sorbitol.

Preferable examples of the substituent of the sugar ester compound include an alkyl group (preferably an alkyl group having 1 to 22 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms). Is an alkyl group having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, hydroxyethyl, hydroxypropyl, 2-cyanoethyl, benzyl, etc.), aryl (preferably carbon number) It is an aryl group of 6 to 24, more preferably an aryl group of 6 to 18, particularly preferably an aryl group of 6 to 12, such as a phenyl group, a naphthyl group, or a fluorenyl group (preferably having a carbon number of 1 to ～). The thiol group of 22 is more preferably a fluorenyl group having a carbon number of 2 to 12, particularly preferably a fluorenyl group having a carbon number of 2 to 8, such as an ethyl group, a propyl group, a butyl group, a butyl group, a pentylene group, or a hexyl group. Base, octyl decyl, benzhydryl, tolylmethyl, phthalic acid, etc.), guanamine group (preferably a decyl group having a carbon number of 1 to 22, more preferably a carbon number of 2) ～12 醯 醯 ,, particularly preferred is a decylamino group having a carbon number of 2 to 8, such as a carbamide group, an etidamine group, etc., and a quinone imine group (preferably having a carbon number of 4 to 22) Further, the imine group is more preferably an anthranylene group having a carbon number of 4 to 12, particularly preferably an anthranylene group having a carbon number of 4 to 8, such as a Peryleneimine, phthalimido, etc.). More preferably, it is an alkyl group or a mercapto group, more preferably a methyl group, an ethyl fluorenyl group or a benzamidine group, and particularly preferably at least one of a benzamidine group and an ethenyl group, and further preferably Benzoyl thiol.

Specific examples of the sugar ester compound which can be used in the present invention are listed below, but the present invention is not limited thereto. Further, in the specific examples described below, the degree of ester substitution of each of the sugar ester compounds is not described. However, any sugar ester compound having an ester substitution degree may be used as long as it does not contradict the gist of the present invention, and a mixture of sugar ester compounds may be prepared. And use.

In the following structural formula, R each independently represents an arbitrary substituent, and a plurality of R may be the same or different.

In addition, as the sugar ester compound, Japanese Patent Laid-Open No. 2001-247717, Japanese Patent Laid-Open Publication No. 2005-515285, International Publication No. WO2007/125764, International Publication No. WO2009/011228, and International Publications A sugar ester compound described in WO2009/031464 or the like.

The method for obtaining the sugar ester compound can be commercially obtained in the form of a commercially available product, manufactured by Tokyo Chemical Industry Co., Ltd., manufactured by Aldrich, or the like, or by a known ester derivatization method for a commercially available carbohydrate (for example). It is synthesized by the method described in Japanese Laid-Open Patent Publication No. Hei 8-245678.

The number average molecular weight of the sugar ester compound is preferably from 200 to 3,500, more preferably from 420 to 3,000, particularly preferably from 450 to 2,000.

The sugar ester compound preferably contains 2 wt% to 30 wt%, more preferably 5 wt% to 20 wt%, relative to the deuterated cellulose.

[Method of manufacturing film]

The film of the present invention can be produced by using a method for producing a film of the present invention (hereinafter also referred to as a production method of the present invention) as described below, depending on the case of using cellulose acetate as the cellulose hydride, and the use of cellulose butyrate. Alternatively, cellulose propionate can be produced efficiently by using different film forming conditions as the case of deuterated cellulose.

In the case of using cellulose acetate as the deuterated cellulose, the production method of the present invention comprises: casting a dopant containing cellulose acetate having a total thiol substitution degree of 2.1 to 2.8 onto a metal support for solution casting. a step of obtaining a film; a step of peeling the film from the metal support by satisfying the residual volatile component H1 of the following formula (i); and removing the film from the residual volatilization satisfying the following formula (ii) a step of extending 5% to 100% in the film transport direction in the state of the component H2; and the peeled film is extended in a direction orthogonal to the film transport direction in a state in which the residual volatile component H3 of the following formula (i) is satisfied. a step of 20% to 150%; characterized in that the extending step satisfies the following formula (iv).

Formula (i) 20% ≦ H1 ≦ 60%

Formula (ii) 10% ≦ H2 ≦ 60%

Formula (iii) 5% ≦ H3 ≦ 45%

Formula (iv) (MD stretching ratio + 100%) / (TD stretching ratio + 100%) ≧ 0.70

(In the formula, the MD stretching ratio indicates the stretching ratio (unit: %) in the film conveying direction, and the TD stretching ratio indicates the stretching ratio (unit: %) in the direction orthogonal to the film conveying direction.)

In the case of using cellulose butyrate or cellulose propionate as the cellulose deuterated, it comprises: doping a metal containing cellulose butyrate or cellulose propionate having a total thiol substitution degree of 2.1 to 2.8 to the metal a step of performing solution casting on the support to obtain a film; a step of peeling the film from the metal support by satisfying the residual volatile component H1 of the following formula (i); and the peeled film is satisfied a step of extending 20% to 100% in the film transport direction in the state of the residual volatile component H2 of the formula (ii); and the peeled film is in a state of satisfying the residual volatile component H3 of the following formula (i) a step of extending the direction in which the film transport direction is orthogonal to 35% to 150%; wherein the extending step satisfies the following formula (iv).

Formula (i) 20% ≦ H1 ≦ 60%

Formula (ii) 10% ≦ H2 ≦ 60%

Formula (iii) 5% ≦ H3 ≦ 45%

Formula (iv) (MD stretching ratio + 100%) / (TD stretching ratio + 100%) ≧ 0.70

(In the formula, the MD stretching ratio indicates the stretching ratio (unit: %) in the film conveying direction, and the TD stretching ratio indicates the stretching ratio (unit: %) in the direction orthogonal to the film conveying direction.)

Hereinafter, the production method of the present invention will be described.

<Step of forming deuterated cellulose into a film shape>

In the production method of the present invention, in the step of forming the deuterated cellulose into a film form, a solution casting film forming method or a melt film forming method may be used. Among them, it is preferred to use a solution casting film forming method, and it is more preferred to use a method in which a doping stream containing deuterated cellulose and a solvent is placed on a support. Further, in the production method of the present invention, it is particularly preferable to extend the doping stream onto the support to evaporate the solvent to form a cellulose-deposited film.

(manufacturing of dopants)

In the manufacturing method of the present invention, preferred components contained in the dopant are described. Among them, it is preferred that the Re-presentant is not contained in an amount of 3 wt% or more with respect to the cellulose butyrate or cellulose propionate. Other additives may be preferably used within the range exemplified in the description of the film of the present invention, and the period of addition in the dopant is not particularly limited.

In the dopant used in the present invention, it is preferred to adjust the amount of deuterated cellulose to 10 to 40% by weight in the resulting dopant. The amount of deuterated cellulose is more preferably from 10 wt% to 30 wt%.

In the production method of the present invention, if the solvent used in the dopant is a solvent used for solution casting, a known solvent may be used. However, from the viewpoint of further reducing the haze, it is preferable to include A solvent selected from the group consisting of an ether having 3 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms, an ester having 3 to 12 carbon atoms, and a halogenated hydrocarbon having 1 to 6 carbon atoms. The ethers, ketones and esters may also have a cyclic structure. A compound having two or more functional groups of an ether, a ketone, and an ester (that is, -O-, -CO-, and -COO-) may be used as a solvent. The solvent may also have other functional groups such as an alcoholic hydroxyl group. In the case of a solvent having two or more functional groups, the number of carbon atoms may be within a predetermined range of a compound having a functional group.

Examples of the ether having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, Anisole and phenylethyl ether.

Examples of the ketone having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone, and methylcyclohexanone.

Examples of the ester having 3 to 12 carbon atoms include ethyl formate, propyl formate, amyl formate, methyl acetate, ethyl acetate and amyl acetate.

Examples of the organic solvent having two or more functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol, and 2-butoxyethanol.

The number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, and most preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of the halogen atom of the halogenated hydrocarbon to be substituted with halogen is preferably 25 mol% to 75 mol%, more preferably 30 mol% to 70 mol%, still more preferably 35 mol% to 65 mol%, most preferably The best is 40 mol% to 60 mol%. Examples of the halogenated hydrocarbons include dichloromethane, chloroform, methyl chloride, carbon tetrachloride, trichloroacetic acid, methyl bromide, and iodination. And tris(tetra)vinyl chloride or the like, preferably containing at least dichloromethane.

In the present invention, it is further preferred to include a poor solvent in a ratio of 3 wt% to 30 wt%, more preferably a poor solvent in a ratio of 5 wt% to 20 wt%. Since the poor solvent is contained in the above range, it is preferable that the compatibility with the cellulose halide is improved and the haze is further lowered.

Further, the boiling point of the poor solvent is preferably 120 ° C or lower, more preferably 40 ° C to 100 ° C. By setting the boiling point to 120 ° C or lower, the drying speed of the solvent can be further increased, which is preferable. As such a poor solvent, methanol, ethanol, propanol, butanol, and water are preferable, and methanol is more preferable.

The dopant can be modulated by conventional methods. The usual method is to carry out treatment at a temperature of 0 ° C or higher (normal temperature or high temperature). The preparation of the solution can be carried out by using a method and apparatus for preparing a dopant in a usual solvent casting method. The dopant can be prepared by stirring the deuterated cellulose and the solvent at normal temperature (0 ° C to 40 ° C). The high concentration solution can also be stirred under pressure and heating. Specifically, the deuterated cellulose and the solvent are placed in a pressurized container, sealed, and heated under pressure while being heated to a temperature equal to or higher than the boiling point of the solvent at a normal temperature and at a temperature at which the solvent does not boil. The heating temperature is usually 40 ° C or higher, preferably 60 ° C to 200 ° C, more preferably 80 ° C to 110 ° C.

Each component may also be coarsely mixed in advance and placed in a container (storage tank, etc.). Moreover, it can be sequentially put into the container. The container must be constructed in a stirrable manner. The container may be pressurized by injecting an inert gas such as nitrogen. Moreover, it is also possible to use an increase in the vapor pressure by heating the solvent. Alternatively, the container may be sealed and the components may be added under pressure.

In the case of heating, it is preferred to carry out heating from the outside of the container. For example, a jacket type heating device can be used. Further, a heating plate may be provided outside the container, and piping may be performed to circulate the liquid, thereby heating the entire container.

It is preferred to provide a stirring blade inside the container and stir using the stirring blade. The agitating blades are preferably agitating blades that reach the length of the container wall. At the end of the agitating wing, in order to renew the liquid film of the container wall, it is preferred to provide a scraping wing.

A measuring instrument such as a pressure gauge or a thermometer may be provided in the container. The ingredients are dissolved in a solvent in a container. The prepared dopant can be taken out of the container after cooling, or cooled after being taken out using a heat exchanger or the like.

The dopant can also be prepared by a cooling dissolution process.

(film forming step)

In the present invention, it is preferred to manufacture from the prepared dopant by solvent casting. membrane.

The method and apparatus for producing the film of the present invention can use the same solution casting film forming method and solution casting film forming apparatus as those previously provided for the cellulose triacetate film manufacturer. The dopant (deuterated cellulose solution) prepared by the dissolving machine (tank) is temporarily stored in a storage tank, and the bubbles contained in the dopant are defoamed to be finally prepared. It is preferable to adjust the shape of the slit of the nozzle portion of the mold, and it is easy to pressurize the mold with uniform film thickness. As the press mold, there are a coat hanger die or a T-die, and any of them can be preferably used. The surface of the metal support becomes a mirror surface. In order to increase the film forming speed, two or more press molds may be provided on the metal support, and the amount of the dopant may be divided into a plurality of layers. Or a method of obtaining a film of a laminate structure by co-casting a plurality of dopants simultaneously.

Preferably, the dopant is sent from the dopant discharge port to a pressurizing die by, for example, a pressure type quantitative gear pump that can accurately feed the liquid by a rotation speed, and is self-pressurizing. The nozzle (notch) of the mold uniformly casts the dopant on the metal support of the casting portion of the circulating operation, and the semi-dry doping film is also formed at the peeling point of the metal support substantially one round. Stripped from the metal support for the web). Both ends of the obtained web were clamped by a jig, conveyed by a tenter, dried, and then conveyed by a roll group of a drying device to complete the drying, and the coil was taken up to a predetermined length. The combination of the tenter and the drying device of the roller group can be changed as needed. In the solution casting film forming method used for the functional protective film for electronic displays, in addition to the solution casting film forming apparatus, the surface processing of the film such as the undercoat layer, the static electricity preventing layer, the anti-corona layer, and the protective layer is performed. , additional coating equipment. The respective manufacturing steps will be briefly described below, but are not limited thereto.

The modulated dopant is preferably cast onto a non-edge metal support, such as a metal drum or metal support (belt or belt), to evaporate the solvent to form a film. The dopant before casting is preferably adjusted in such a manner that the amount of cellulose becomes 10 wt% to 35 wt%. The surface of the drum or belt is preferably pre-finished to have a mirrored state. The method of casting and drying in the solvent casting method is disclosed in U.S. Patent No. 2,313,310, U.S. Patent No. 2,367,603, U.S. Patent No. 2,492,078, U.S. Patent No. 2,492,977, U.S. Patent No. 2,492,978, U.S. Patent No. 2,607,704, U.S. Patent No. 2,739,069, U.S. Patent. No. 2,739,070, British Patent No. 640,731, and British Patent No. 736,892, Japanese Patent Publication No. Sho 45-4554, Japanese Patent No. Sho 49-5614, Japanese Patent Laid-Open No. Sho 60-176834, Japanese Patent Laid-Open No. 60 Japanese Laid-Open Patent Publication No. SHO-62-115035, the entire disclosure of which is hereby incorporated by reference.

In addition, Japanese Patent Laid-Open No. 2000-301555, Japanese Patent Laid-Open No. 2000-301558, Japanese Patent Laid-Open No. Hei No. Hei 7-032391, Japanese Patent Laid-Open No. Hei No. 3-193316, and Japanese Patent Laid-Open No. 5- Japanese Patent Application Laid-Open No. Hei No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. The cellulose-based film forming technology described in each of the publications.

The dopant is preferably cast on a drum or belt having a surface temperature of 30 ° C or less, and more preferably a metal support temperature of -50 ° C to 20 ° C. In the manufacturing method of the present invention, it is preferred that the dopant cast on the metal support blows dry air from both the back surface and the surface of the metal support. It is preferred to carry out the drying by contacting the wind for 2 seconds or more after casting. The obtained film may also be peeled off from a roll or a belt, and further dried by a high-temperature wind which is continuously changed in temperature between 100 ° C and 160 ° C to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. By this method, the time from self-casting to peeling can be shortened. In order to carry out the method, the dopant must be gelled at the surface temperature of the roller or belt at which the flow is delayed.

In the production method of the present invention, it is preferred to use two or more kinds of dopants having different total thiol substitution degrees of deuterated cellulose as the dopant, and to co-cast the respective dopants on the support.

In the formation of the film of the present invention, it is preferred to use a lamination casting method such as a co-casting method, a sequential casting method, a coating method, or the like, in particular, from the viewpoint of stable production and reduction in production cost, particularly preferably The co-casting method is also used.

In the case of production by a co-casting method and a sequential casting method, first, a cellulose acetate solution (dopant) for each layer is prepared. The co-casting method (multi-layer simultaneous casting) is a self-casting molding machine (gisser) (the casting molding machine is a casting doping for each layer (three layers or more) from different notches) At the same time, the doping is pressed against the support for the casting (belt or drum) while casting the layers, peeling off from the support at an appropriate period, and drying to form a film casting method.

The successive casting method is carried out by first casting the first layer casting dopant from a casting machine by a casting machine, casting it, and drying it or drying it without casting it. The purpose of casting the dopant for casting of the second layer by a molding machine is carried out, and if necessary, the doping stream is successively stretched and laminated to the third layer or more, and is peeled off from the support at an appropriate period. A casting method of drying to form a film. In the coating method, a core film is usually formed on a film by a solution film forming method, and a coating liquid applied on the surface layer is prepared, and a single coater is used on each single side or both sides simultaneously. A method in which a coating liquid is applied onto a film and dried to form a film of a laminated structure.

(stripping)

The step of peeling off the web formed by evaporating the solvent on the metal support at the peeling position. The stripped web is sent to the subsequent step. Further, if the residual volatile component (the following formula) of the web at the time of peeling is too large, peeling is difficult; on the contrary, if the metal support is sufficiently dried and then peeled off, the web is formed on the way. Part of it peeled off.

Here, as a method of increasing the film forming speed (the film forming speed can be increased by peeling as much as possible when the amount of residual solvent is as large as possible), there is a gel casting method (gel casting). For example, there are a method of adding a poor solvent of deuterated cellulose to a dopant, a method of gelation after the doping stream is delayed, a method of reducing the temperature of the metal support, and gelation. By the gelation of the metal support, the strength of the film at the time of peeling is increased, and the peeling can be accelerated to increase the film forming speed.

It is preferable to carry out the peeling in the range of 5 wt% to 150 wt% of the residual solvent when the web on the metal support is peeled off according to the strength of the drying conditions, the length of the metal support, etc., and the amount of residual solvent is further When the peeling is performed at a plurality of time points, the amount of residual solvent at the time of peeling is determined in consideration of economic speed and quality. In the present invention, it is preferred that the temperature at the peeling position on the metal support is from -50 ° C to 40 ° C, more preferably from 10 ° C to 40 ° C, most preferably from 15 ° C to 30 ° C.

The production method of the present invention includes a step of peeling the film from the metal support by satisfying the residual volatile component H1 of the following formula (i) regardless of the type of the deuterated cellulose.

Formula (i) 20% ≦ H1 ≦ 60%

The H1 is preferably from 22% to 55%, particularly preferably from 25% to 45%.

The amount of residual solvent can be expressed by the following formula.

Residual solvent amount (wt%)={(M-N)/N}×100

Here, M is the weight of the web at any time point, and N is the weight when the weight is M and dried at 110 ° C for 3 hours.

(using the tension control of the dancer mechanism)

In the production method of the present invention, from the viewpoint of improving the unevenness of the orientation of the slow phase axis in the longitudinal direction of the film, it is more preferable to use a flow film forming apparatus when the cellulose deuterated cellulose is formed into a film shape. The step of controlling the tension applied to the film is performed using a bounce mechanism between the film is peeled from the casting film forming device and before the stretching step. The tension control by the pulsating mechanism means that the tension applied to the film is maintained at a fixed amount by being controlled by a pulsating mechanism having a dancer roll.

The tension control using the pulsating mechanism in the present invention is not particularly limited to the following aspect. In the manufacturing method of the present invention, it is preferred that the web (film) which is dried and peeled off on a drum or a conveyor belt is extended as described later. Before the step, the dancer group is variably driven by the roller group arranged as shown in Fig. 1 or Fig. 2 to carry out the conveyance while the fluctuation of the specific center value to be applied to the film is not large. Further, it is preferable that the tension control portion of the bounce mechanism is provided before or after the drying step before the device for performing the stretching step. In the case where the tenter method is used in the extending step described later, it is preferable to hold the film at both ends while holding the film by a tenter, and to dry the film, that is, preferably After the film is peeled off from the roll or belt of the film forming apparatus, the tension control unit is used by the beating mechanism in the state of the film soft film before the drying step.

As such a bounce mechanism, a known device can be used, and in particular, the bounce mechanism 10 described in Figs. 1 and 2 can be cited. Figure 2 is a schematic illustration of a bounce mechanism 10 that can be preferably used in the present invention. The pulsating mechanism 10 includes a dancer roller 11, a guide roller 17a, a guide roller 17b, a load control device (bounce device load control portion) 13 for controlling the load applied to the dancer roller 11, and an angle detection for detecting the position of the dancer roller 11. (Bouncer position detection sensor) 12. The dancer roller 11 is movably attached between the guide roller 17a and the guide roller 17b in the vertical direction in the drawing. Further, the magnitude of the tension applied to the film (web) soft film 24 peeled off from the peeling roller 21 is determined by the magnitude of the load applied to the dancer roller 11.

The magnitude of the tension applied to the film (web) film 24 peeled off from the peeling roller 21 is preferably in the range of 0 N to 300 N. Further, it is preferable that the variation in the magnitude of the tension applied to the film (web) peeled off from the peeling roller 21 is the center value of the set tension ± 30 N or less.

Further, the load control method may be any of the following methods: (1) using the load control of the cylinder, and (2) a method of controlling the load by carrying the weight on the opposite side to the side in contact with the upper and lower films.

In FIG. 2, the position of the dancer roller 11 is detected by an angle detector (bouncer position detecting sensor) 12. Further, the method of controlling the response of the dancer roller 11 based on the position detection result may be any of the following methods: (1) a method of causing the tenter to drive the acceleration and deceleration when the dancer is raised or lowered, and (2) reducing the pair. The method of loading the beating device. For example, the dancer roller 11 may be a carrier speed in the step of the beating mechanism (for example, when the film is conveyed and extended by using a tenter device in the extending step), the tenter driving speed is used. The deceleration is controlled to maintain the dancer roller 11 in an intermediate position between its movable upper limit position and lower limit position. For example, when the dancer roller 11 moves from the neutral position to the lower limit direction, the dancer roller 11 can be returned to the neutral position by increasing the tenter driving speed.

As the film of the self-flowing film forming apparatus or the film peeled off from the belt, the higher the temperature, the softer. Therefore, in the present invention, it is preferred that the temperature of the beating device portion is in the range of 25 ° C to 100 ° C, preferably in such a temperature range, so as to be peeled off from the peeling roller 21 . The magnitude of the load applied by the dancer roller 11 is set such that the magnitude of the tension applied by the film (web) soft film 24 is within a range of ±30 N or less of the center value of the set tension.

The surface temperature of the film (web) soft film 24 peeled off from the peeling roller 21 can be disposed between the peeling roller 21 and the dancer mechanism 10, and is connected to the temperature measuring probe for measuring the surface temperature of the film. The temperature sensor 14 measures. Further, as the probe for temperature measurement, if the surface of the film to be conveyed is not damaged, a probe of any shape and material can be used. Further, in the present invention, the position of the temperature sensor 14 of FIG. 2 is not limited thereto, and may be disposed at other positions on the upstream side of the pulsating mechanism 10, for example.

The control of each unit of the above-described tension control unit using the pulsating mechanism can be performed by a system controller (not shown). As the system controller, for example, the system controller described in the paragraph [0041] of JP-A-2005-306019 can be used, and the operation of the film manufacturing apparatus can be collectively controlled. For example, a drive motor (not shown), a tension sensor 15, a load control device 13, an angle detector 12, and a control unit for controlling the wind temperature are connected to the system controller (not shown) (not shown). ), temperature sensor 14, operation panel (not shown), and the like. The system controller can adjust the driving speed of the tenter device 23 in such a manner that the load control device 13 of the jumping device is controlled based on the set value of the tension input via the operation panel (not shown), and the load is loaded on the dancer roller 11 Based on the position detection result of the angle detector 12, the drive motor (not shown) is controlled to maintain the dancer roller 11 in a preferred position. Further, the system controller can control a control unit (not shown) for controlling the wind temperature based on the film surface temperature detection result of the temperature sensor 14, and adjust the warmth blown from an air blower (not shown). The temperature of the wind.

In addition, the tension control unit using the pulsating mechanism is provided in one position on the film transport path in FIG. 1, but the present invention is not limited to this aspect, and two or more positions may be provided corresponding to the length of the transport path. Further, as described in Japanese Laid-Open Patent Publication No. 2005-306019, the pulsating mechanism can also be used in combination with a suction drum.

A method of drying the web which is dried and peeled off on a drum or a conveyor belt will be described. Preferably, the web which is peeled off at the peeling position before the drum or the belt is rotated one week is conveyed by: a method of conveying the piles arranged in a zigzag pattern alternately or by holding them by a jig or the like. The method of conveying the both ends of the web, not the contact.

In the production method of the present invention, in the transition portion from the stripping step to the stretching step, it is preferred that the film passes through three or more path rolls having a corner angle of at least 60°, more preferably It is passed through 5 or more path rollers, and it is particularly preferable to pass 7 to 51 path rollers. Further, in the manufacturing method of the present invention, as described above, it is preferable that the path roller having a wrap angle of 60 or more includes at least one pulsating device, and preferably one of the pulsating devices. In addition, the so-called beating device herein also includes the guide roller described in 17a or 17b of Fig. 2, preferably in Fig. 1 and Fig. 2, between the self-guide roller 17a and the extension device 23, through the above-mentioned root. More than a few path rolls having a corner angle of at least 60°. In addition, the wrap angle in the present specification means the size of the central angle formed by joining the circular arc area of the film around the roll to the center of the roll, for example, when the film passes through a roller which is completely arranged in a zigzag shape, the wrap angle becomes 180. degree.

Drying can be carried out by a method of blowing a wind of a predetermined temperature on both surfaces of a web (film) being conveyed, or a method of using a heating mechanism such as a microwave. Rapid drying may damage the planarity of the formed film. Therefore, it is preferred to carry out drying in a preliminary stage of drying by a temperature at which the solvent does not foam, and to perform drying at a high temperature after drying. dry. In the drying step after peeling off from the support, the film shrinks in the longitudinal direction or the width direction due to evaporation of the solvent. The more the drying is performed at a higher temperature, the larger the shrinkage. In order to improve the planarity of the produced film, it is preferred to carry out drying while suppressing the shrinkage as much as possible. From this point of view, for example, as shown in Japanese Laid-Open Patent Publication No. Sho 62-46625, the width of both sides of the wide side of the web is maintained by a jig or a pin in the width direction. The method of performing the entire step or partial steps of drying (triangulation). The drying temperature in the above drying step is preferably from 100 ° C to 145 ° C. The drying temperature, the drying air amount, and the drying time vary depending on the solvent to be used, and can be appropriately selected depending on the type and combination of the solvent to be used.

As a manufacturing method of the present invention, from the viewpoint of reducing the standard deviation of the azimuth direction of the retardation axis in the longitudinal direction of the film, it is preferable to extend in a direction orthogonal to the film transport direction by a tenter. And the following formula (v) is satisfied.

Formula (v) W×30≧L≧W×2

(wherein, L represents the distance from the stripping step to the tenter (in mm), and W represents the width (in mm) of the stripped film.)

More preferably, the manufacturing method of the present invention satisfies W × 28 ≧ L ≧ W × 2.5, and particularly preferably satisfies W × 25 ≧ L ≧ W × 3.

(extension step)

In the manufacture of the film of the present invention, the step of extending the web (film) peeled off from the support is included. (1) The case where cellulose acetate is used as the cellulose deuterated is different from the case where (2) cellulose butyrate or cellulose propionate is used as the cellulose halide, and therefore, the following will be sequentially described.

(1) The case of using cellulose acetate as the cellulose halide

In the case where cellulose acetate is used as the cellulose-deposited cellulose, the production method of the present invention comprises: stretching the peeled film in the film transport direction by 5% in a state in which the residual volatile component H2 of the following formula (ii) is satisfied. a step of -100%; a step of extending the peeled film in a direction orthogonal to the film transport direction by 20% to 150% in a state in which the residual volatile component H3 of the following formula (i) is satisfied; : The extending step satisfies the following formula (iv).

Formula (ii) 10%≦H2≦60%

Formula (iii) 5% ≦ H3 ≦ 45%

Formula (iv) (MD stretching ratio +100%) / (TD stretching ratio +100%) ≧0.70

(In the formula, the MD stretching ratio indicates the stretching ratio (unit: %) in the film conveying direction, and the TD stretching ratio indicates the stretching ratio (unit: %) in the direction orthogonal to the film conveying direction.)

In the case where cellulose acetate is used as the cellulose deuterated cellulose, the stretching ratio in the film transport direction is preferably 5% to 25%, more preferably 8% to 22%.

In addition, the "stretching magnification (%)" here means the one obtained by the following formula.

Extension ratio (%) = 100 × {(length after extension) - (length before extension)} / length before extension

The method of extending the web in the film transport direction is not particularly limited. For example, a method of applying a circumferential speed difference to a plurality of rolls and extending in the longitudinal direction by a difference in circumferential speed of the rolls may be used; fixing both ends of the webs by a jig or a pin to form a jig or pin interval A method in which the traveling direction is widened and extended in the longitudinal direction; or a method in which the vertical and horizontal directions are simultaneously widened and extended in both the vertical and horizontal directions. Of course, these methods can also be used in combination. Further, in the case of the so-called tenter method, if the clamp portion is driven by the linear driving method, smooth extension can be performed, and the risk of breakage or the like can be reduced, which is preferable. Preferably, the extension in the longitudinal direction is to use a device having two nip rolls so that the rotation speed of the nip roller on the outlet side is faster than the rotation speed of the nip roller on the inlet side, and is higher in the conveying direction (longitudinal direction). Preferably, the cellulose film is extended. By performing such an extension, the performance of the delay can also be adjusted.

Further, at this time, H2 is preferably from 20% to 55%, more preferably from 25% to 50%.

If the amount of residual volatile components in the web is too large, the effect of stretching cannot be obtained, and if it is too small, the elongation becomes difficult, and the occurrence of breakage of the web may occur.

In the production method of the present invention, it is preferable to control the film transport direction in a state in which the tensile force variation value is less than 10 N/m, and it is more preferable to control the film to be less than 8 N/m. It is controlled from 0 N/m to 6 N/m.

In the case where cellulose acetate is used as the deuterated cellulose, the stretching ratio in the direction orthogonal to the film conveying direction is preferably 15% to 60%, more preferably 20% to 50%.

The method of extending the web in the direction orthogonal to the film transport direction is not particularly limited. For example, a method in which both ends of the web are fixed by a jig or a pin, and the jig or the pin is widened in the lateral direction to extend in the lateral direction; or both the vertical and horizontal directions are widened in both directions. The method of extending the above. Of course, these methods can also be used in combination. Further, in the case of the so-called tenter method, if the clamp portion is driven by the linear driving method, smooth extension can be performed, and the risk of breakage or the like can be reduced, which is preferable. In the present invention, as a method of extending in a direction orthogonal to the film transport direction, it is preferable to use a tenter device to perform stretching.

Further, at this time, it is preferable that the H3 is 8% to 40%, more preferably 10% to 35%.

If the residual volatile component in the web is too large, the effect of stretching cannot be obtained, and if it is too small, the elongation becomes difficult, and the web is broken.

The manufacturing method of the present invention can improve the film elastic modulus by controlling the stretching ratio ratio so that the MD stretching ratio and the TD stretching ratio satisfy the following formula (iv).

Formula (iv) (MD stretching ratio +100%) / (TD stretching ratio +100%) ≧0.70

(In the formula, the MD stretching ratio indicates the stretching ratio (unit: %) in the film conveying direction, and the TD stretching ratio indicates the stretching ratio (unit: %) in the direction orthogonal to the film conveying direction.)

Further, in the case of extending in the film width direction, there is a case where the refractive index is distributed on the wide side. This phenomenon can be seen, for example, when using the tenter method. It is generally considered that this is caused by the fact that the extension in the width direction causes the contraction force at the central portion of the film, and the end portion is fixed, which is called a so-called zigzag. (bowing) phenomenon. In this case, by extending in the casting direction, the meandering phenomenon can be suppressed, and the improvement can be made so that the phase difference distribution of the wide sides is small. Further, the film thickness variation of the film obtained by stretching in the biaxial directions orthogonal to each other can be reduced. If the film thickness of the deuterated cellulose film is excessively changed, the phase difference becomes uneven. The film thickness variation of the deuterated cellulose film is preferably in the range of ±3%, more preferably in the range of n%. For the purpose as described above, a method of extending in mutually orthogonal biaxial directions in a manner satisfying the formula (iv) is also effective.

In the manufacturing method of the present invention, it is preferred that the extension temperature is Te+30 ° C or less, wherein

Extension temperature ≦Te+30°C (I)

Te=T[tanδ]-ΔTm (II)

ΔTm=Tm(0)-Tm(x) (III)

(In the formula (II), T[tan δ] represents the dynamic viscoelasticity tan δ of the deuterated cellulose when the residual solvent amount is 0%, and tan δ shows the peak temperature, and Tm (0) indicates the residual solvent amount. The crystal melting temperature of the deuterated cellulose at 0%, and Tm(x) represents the crystal melting temperature of the deuterated cellulose when the residual solvent amount of the deuterated cellulose is x%.

Hereinafter, the extension of such a temperature range is also referred to as low temperature extension. By lowering the film formed into a film shape at a low temperature, Rth performance can be improved without increasing the film thickness of the film of the present invention, and Rth (550)/d can be further improved, which is preferable. Although not limited to any theory, in the low-temperature extension, the alignment of the polymer or the additive in the extension is difficult to become large at a relatively high temperature extension, so that Re may be expressed without lowering Rth. More preferably, the extension temperature is Te-30 ° C to Te ° C. When extending in the film transport direction, when extending in the film width direction, the preferred range is also the same.

(2) The case of using cellulose butyrate or cellulose propionate as the cellulose

In the case where the cellulose acetate butyrate or the cellulose propionate is used in the production method of the present invention, the film is stretched in the film transport direction in a state where the peeled film satisfies the residual volatile component H2 of the formula (ii). a step of % to 100%; a step of extending the peeled film in a direction orthogonal to the film transport direction by 20% to 150% in a state in which the residual volatile component H3 of the formula (i) is satisfied; : the extending step satisfies the formula (iv).

When cellulose butyrate or cellulose propionate is used as the cellulose deuterated cellulose, the stretching ratio in the film transport direction is preferably from 20% to 60%, more preferably from 25% to 45%.

When cellulose butyrate or cellulose propionate is used as the cellulose deuterated cellulose, the stretching ratio in the direction orthogonal to the film transporting direction is preferably 38% to 80%, more preferably 40%. %~60%.

Further, in the case of using cellulose butyrate or cellulose propionate as the cellulose halide, the preferable range of other extension conditions is the same as the case of using cellulose acetate as the cellulose halide.

(heat treatment step)

The method for producing a film of the present invention may also be provided with a heat treatment step as described above after the drying step. The heat treatment in the heat treatment step may be carried out after the completion of the drying step, or may be carried out immediately after the stretching/drying step, or may be additionally carried out after the drying step is temporarily taken up by the method described later.

The heat treatment can be carried out by a method of blowing a wind of a predetermined temperature to the film being conveyed or a method of using a heating means such as a microwave.

The heat treatment is preferably carried out at a temperature of from 150 ° C to 200 ° C, more preferably from 160 ° C to 180 ° C. Further, the heat treatment is preferably carried out for 1 minute to 20 minutes, more preferably for 5 minutes to 10 minutes.

(rolling)

The coiler for winding the obtained film can use a coiler which is generally used, and can be wound by a constant tension method, a constant torque method, a taper tension method, a program tension control method in which internal stress is fixed, and the like. Take the method and take the roll. The deuterated cellulose film roll obtained as described above preferably has a retardation axis direction of the film of ±2 degrees with respect to the winding direction (longitudinal direction of the film), more preferably ±1 degree. The scope. Alternatively, it is preferably in the range of ±2 degrees with respect to the direction of the right angle (the width direction of the film) with respect to the winding direction, and more preferably in the range of ±1 degree. It is particularly preferable that the retardation axis direction of the film is within ±0.1 degrees with respect to the winding direction (longitudinal direction of the film). Alternatively, it is particularly preferable that it is within ±0.1 degrees with respect to the broad side direction of the film.

(residual volatile components)

As the deuterated cellulose film obtained by the above-described method for producing a film of the present invention, in terms of obtaining a film having good dimensional stability, it is preferred that the residual volatile component of the final finished film is 1 wt%. Hereinafter, it is more preferably 0.2 wt% or less.

Further, in the production method of the present invention, the step of producing a film while forming the retardation axis orientation of the long-hand method of the film in one line may be included. The preferred aspect in this case is the same as the standard deviation of the azimuthal axis orientation of the film long hand method for determining the film of the present invention in the line.

<Polarizing plate>

The polarizing plate of the present invention is characterized by comprising a polarizing element and a deuterated cellulose film of the present invention.

Since the film of the present invention has good optical properties and good film elastic modulus, it can be preferably used in a protective film for a polarizing plate. Further, since the film of the present invention has a good surface shape and is less uneven when the film surface is observed under the polarized light of the polarizing plate, it is suitable for a protective film for a polarizing plate. The polarizing plate can be formed by laminating a laminated protective film on at least one surface of the polarizing element. As the polarizing element, a previously known polarizing element can be used, for example, a hydrophilic polymer film such as a polyvinyl alcohol film is treated with a dichroic dye such as iodine and extended. The bonding of the deuterated cellulose film and the polarizing element is not particularly limited, and it can be carried out by an adhesive containing a water-soluble polymer aqueous solution. As the water-soluble polymer adhesive, a fully alkalized aqueous polyvinyl alcohol solution can be preferably used.

Further, the polarizing plate using the film of the present invention can provide a liquid crystal display device having less unevenness in the distribution of the slow phase axis and good display performance. Further, when the film of the present invention is in a wide-width preferred embodiment, when a polarizing plate is produced by bonding the film of the present invention to a polarizing element, the so-called polarizing plate can be equally divided in the film width direction. And 3 equal parts can reduce the manufacturing cost of the polarizing plate. Further, in the case where the σ600 and σ-600 in the film width direction are also good, the performance of the polarizing plate which is further divided into two equal parts and three equal parts can be improved.

<Liquid crystal display device>

The liquid crystal display device of the present invention is characterized by comprising a cellulose oxide film or a polarizing plate of the present invention.

The film of the present invention can be preferably used as follows: a protective film for a polarizing plate / a polarizing element / a protective film for a polarizing plate / a liquid crystal cell / a film of the present invention / a polarizing element / a protective film for a polarizing plate, or a polarizing film Protective film/polarizing element for sheet/film/liquid crystal cell of the present invention/protective film for polarizing plate/polarizing element/protective film for polarizing plate of the present invention. In particular, it can be used by being bonded to a liquid crystal cell such as a TN type, a VA type, or an OCB type, and it is possible to provide a liquid crystal display device which is excellent in viewing angle, excellent in visibility, and excellent in in-plane uniformity. Further, the polarizing plate using the film of the present invention has less deterioration under high temperature and high humidity conditions, and can maintain stable performance for a long period of time, that is, the durability of the liquid crystal display device of the present invention is also good.

[Example]

Hereinafter, the present invention will be more specifically described by way of examples. The materials, the amounts used, the ratios, the contents of the treatment, the order of treatment, and the like shown in the following examples can be appropriately changed without departing from the gist of the invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Example 1: Film formation of bismuth cellulose film]

(2) dopant modulation

<1-1> Deuterated cellulose solution

The following composition was placed in a mixing tank, stirred to dissolve each component, and further heated at 90 ° C for about 10 minutes, and then passed through a filter paper having an average pore diameter of 34 μm and a sintered metal filter having an average pore diameter of 10 μm. Filter.

<1-2> matting agent dispersion

Next, the following composition containing the deuterated cellulose solution prepared by the above method was placed in a disperser to prepare a matting agent dispersion.

<1-3> additive solution

The deuterated cellulose solution prepared by the above method was placed in a mixing tank, stirred while being heated, and dissolved, and each additive described in the following Table 6 was added to prepare an additive solution. Further, each additive will be described below. Additives A to C are the compositions shown in Table 5 below. Further, in Table 5, EG represents ethylene glycol, PG represents propylene glycol, BG represents butanediol, TPA represents terephthalic acid, PA represents phthalic acid, AA represents adipic acid, and SA represents succinic acid.

Compound D represents a delayed expression agent of the following structure.

Compound D

Compound E represents POEM K-37V manufactured by Riken Vitamin Co., Ltd. as a release promoter.

Compound U represents a delayed expression agent of the following structure.

Compound U

Compound T represents TPP/BDP (1/1, weight ratio).

Further, in Example 6 using CAP, Compound X of the following structure was used as an additive.

Compound X

100 parts by weight of the above-described deuterated cellulose solution, 1.35 parts by weight of the matting agent dispersion, and the additive solution were mixed to prepare a dopant for film formation.

In addition, the deuterated cellulose and various additives used as a raw material of the dopant were dried by using a silo manufactured by Nara Machinery Co., Ltd. at 120 ° C for 2 hours.

Here, in the following Table 6, the letters indicate the types of the respective additives, and the numerical values indicate the added amounts. In addition, the addition ratio of the additive solution is a ratio of the addition amount (parts by weight) of each additive when the amount of deuterated cellulose is 100 parts by weight to the values described in Table 6 below.

(casting)

Only in Example 5, Example 6, Example 7, Comparative Example 7, and Comparative Example 8, the above-described blending was carried out by the metal tape casting machine 20 as the apparatus having the pulsating mechanism described in Figs. 1 and 2. Sundries. Others are cast by a film forming machine that is identical except for the function of the jumper. The surface of the back and the surface of the self-belt is blown with a dry air having a gas supply temperature of 80 ° C to 130 ° C (exhaust gas temperature of 75 ° C to 120 ° C) and dried, and the residual volatile components are as shown in Table 6 below. In the case of H1 (wt%) described, the film is peeled off from the tape by peeling off the roll 21.

The film is passed through a bounce mechanism 10 including a dancer roller 11 before longitudinal extension and lateral extension by the extension device 23. While controlling the temperature of the beating device portion in the temperature sensor 14 of Fig. 2 to 50 ° C, and making the tension of the film in the tension sensor 15 200 N/m, film formation is performed; The manner of the tension variation shown in Table 6 is driven while the load is controlled by the load control device 13 and the angle detector 12 of the pulsating mechanism 10. After passing through the guide roller 17b, the film is passed through 15 path rollers 18 having a wrap angle of 60 degrees or more, and the film is introduced into the stretching device 23. At this time, the distance L from the stripping step to the tenter was 15000 mm, the width W of the peeled film was 1900 mm, and W × 30 ≧ L ≧ W × 2 was satisfied.

(extend)

Then, when the residual solvent concentration described in the following Table 6 is H2, the MD stretching ratio described in the following Table 6 is uniaxially extended by the fixed end in the film transport direction at 130 °C. Extend in the tenter area. At this time, the change in the tensile force at the time of MD extension was measured by a tension sensor, and it is described in the following Table 6.

Next, when the residual solvent concentration is H3, the TD stretching ratio described in the following Table 6 is extended at a tenter region by a uniaxial stretching at a fixed end in the film width direction at 160 ° C. A bismuth cellulose film is produced. Further, the MD/TD stretching ratio ratio was determined and described in Table 6 below. At this time, the thickness of the cast film was adjusted so that the film thickness after stretching and drying became the film thickness described in Table 7 below.

Films having the compositions shown in the following Table 6 were produced, and in order to judge the manufacturing suitability, a roll of a minimum of 24 rolls having a roll width of 1980 m and a roll length of 2000 m was produced by the above conditions. For one of the 24 rolls manufactured continuously, a sample of 1 m long side (width 1980 mm) was cut at intervals of 100 m. This was taken as the deuterated cellulose film of Example 1.

[Example 2 to Example 10 and Comparative Example 1 to Comparative Example 13]

The cellulose-deposited cellulose film of each of the examples and the comparative examples was obtained in the same manner as in Example 1 except that the conditions for the production of the deuterated cellulose resin, the additive, and the film were changed as described in the following Table 6. Further, in Example 10, three layers of co-casting were carried out in the order of the dopant/core layer dopant/outer layer dopant for the self-supporting body side outer layer.

<Measurement method>

(optical properties of the film)

The three-dimensional birefringence measurement was performed at a wavelength of 550 nm using an automatic birefringence meter KOBRA-WR (manufactured by Oji Scientific Co., Ltd.) by the method described above, and the in-plane retardation Re was obtained, and the retardation in the film thickness direction was Rth. It can be obtained by measuring the inclination angle Re.

Further, the measurement wavelength was changed to 450 nm and 630 nm, and the values of Re (450) and Re (630) were measured, and the wavelength dispersion ΔRe = Re (630) - Re (450) was calculated.

Further, the value of the obtained Rth (unit: nm) was divided by the film thickness d (unit: nm) of each film, and Rth and Rth/d per unit thickness of the film were determined.

These results are described in Table 7 below.

(Standard deviation of the retardation of the retardation axis at the end of the long side of the film (σ600, σ-600))

The standard deviations σ600 and σ-600 of the retardation of the retardation axes at the ends in the longitudinal direction of the film were measured by the following methods.

The sample film was conveyed at 20 m/min while controlling the unevenness of the vertical direction of the film between the path rollers which were fed in parallel within 0.5 mm to 2 mm or less. In the film transport direction (longitudinal direction) every 33 mm (measured at intervals of 0.1 second) from the center line in the film width direction to a line away from 600 mm in the direction of one of the film ends The position of each of the slow phase axes of 2000 m totaling 2000 m is continuously measured. The average values of these are obtained, and the standard deviations σ600 and σ-600 of the retardation of the slow phase axes are obtained by calculation.

Further, the standard deviations σ600 of the retardation axis directions in the longitudinal direction of the film and other measurement conditions of σ-600 are set as follows, and detection and calculation are performed by the following methods.

Device: High-speed delay measuring device Re100 manufactured by Otsuka Electronics Co., Ltd.

Measuring length: 2000 m

Measurement pitch: continuously measured every 0.1 s when transported at 20 m/min

For approximately 60000 points of data, by

And calculate (here, x _i is the angle of the slow phase axis, n is 60000). By the following

The dispersion σ is calculated.

The results obtained were evaluated by the following criteria.

◎: σ600 or σ-600 is 0.08 or less.

○: σ600 or σ-600 is 0.10 or less.

Δ: σ600 or σ-600 is 0.13 or less.

▲: σ600 or σ-600 is 0.15 or less.

×: σ600 or σ-600 is more than 0.15.

The results obtained are shown in Table 7 below.

(the elastic modulus of the film)

The sample 10 mm × 150 mm (TD × MD) was subjected to humidity control at 25 ° C and a relative humidity of 65% for 2 hours, and the universal tensile tester STM T50BP manufactured by TOYO BALDWIN CO., LTD. was used at 23 ° C. In an environment with a relative humidity of 60%, the stress-strain curve was measured by measuring the elongation of the initial sample length of 50 mm at 10%/min in the MD direction, and the elastic modulus E of the film in the MD direction was determined. '(MD) (in MPa). Similarly, the sample was stretched in the TD direction under the same conditions using a sample of 150 mm × 10 mm (TD × MD), and the elastic modulus E' (TD) (unit: MPa) of the film in the TD direction was obtained. Further, E'(TD)/E'(MD) is calculated from the obtained elastic modulus in each direction.

Further, E' (TD) was measured every 100 mm on the wide side among the 19 samples. The average value of these is determined, and the standard deviation σ (unit: GPa) of the elastic modulus E' (TD) in the film width direction is obtained by the following method. For the 19 materials obtained, by

And calculate (here, x _i is the unevenness of each E' (TD), and n is 19). By the following

Calculate the dispersion σ.

The results obtained are shown in Table 7 below.

(panel performance)

[Manufacture of polarizing plate]

A polarizing element was produced by adsorbing iodine on the stretched polyvinyl alcohol film.

The cellulose-deposited film of Example 1 subjected to the alkalization treatment was attached to one side of the polarizing element using a polyvinyl alcohol-based adhesive. The commercially available cellulose triacetate film (Fujitac TD80UF, manufactured by Fujifilm Co., Ltd.) was subjected to the same alkalization treatment, and a polarizing plate protective film was attached to the prepared example 101 using a polyvinyl alcohol-based adhesive. The alkalized cellulose triacetate film is attached to the surface of the polarizing element on the opposite side of the side.

At this time, the transmission axis of the polarizing element was arranged in parallel with the retardation axis of the polarizing plate protective film of Example 1 produced. Further, the transmission axis of the polarizing element is disposed so as to be orthogonal to the late phase axis of the commercially available cellulose triacetate film.

The polarizing plate of Example 1 was produced in this manner.

[Manufacture of liquid crystal display device]

The obtained polarizing plate was subjected to the following bonding on the panel.

The evaluation is based on the removal of the polarizing plates on the front side and the rear side of the LC-42DS6 liquid crystal display from Sharp Corporation, which is also referred to as a panel, and is manufactured in each of the examples and comparative examples using the above polarizing plate. Liquid crystal display device. In addition, the size of the panel is 1025 mm × 673 mm.

(1) viewing angle hue (contrast in oblique direction)

Using a measuring device (BM5A, manufactured by TOPCON Co., Ltd.), in the dark room, the brightness of the black display and the white display in three directions from the polar angle of the front surface of the device of 60 degrees and the azimuthal directions of 0 degrees, 45 degrees, and 90 degrees were measured. The value was calculated, and the viewing angle contrast (the whitest brightness/blackest brightness) was calculated, thereby evaluating the viewing angle characteristics of the liquid crystal display device.

○: The viewing angle contrast is 60 or more, and light leakage cannot be recognized.

Δ: The minimum value of the viewing angle contrast is less than 60 and 30 or more, and light leakage is slightly recognized, but it is tolerable.

×: The minimum value of the viewing angle contrast is less than 30, and a large light leakage is recognized and cannot be tolerated.

The column showing the evaluation result of the viewing angle contrast in the following table is based on the above criteria to evaluate the above three directions, and the average result is shown.

The results obtained are shown in Table 7 below.

(2) Durability evaluation

Each liquid crystal display device was allowed to stand in a hot state of 50 ° C and a relative humidity of 95% for 500 hours, and was taken out and then turned on. Then, using a measuring instrument (BM5A, manufactured by TOPCON Co., Ltd.), the viewing angle contrast from the polar angle direction of the front surface of the apparatus of 60 degrees and the azimuth direction of 45 degrees was measured in a dark room. The viewing angle contrast before and after continuous lighting was compared, and the durability was evaluated by the following criteria.

◎: The difference in viewing angle contrast is less than 5.

○: The difference in viewing angle contrast is 5 or more and less than 10 (a slight light leakage after continuous lighting, which is an allowable degree).

×: The difference in viewing angle contrast is 10 or more (a large light leakage can be recognized after continuous lighting, and cannot be tolerated).

The results obtained are shown in Table 7 below.

(3) In-plane uniformity of the panel

In each of the examples and the comparative examples, the panel of the liquid crystal display device was white-displayed, and the brightness was measured every 10 mm in the plane using a BM-5 luminance meter manufactured by TOPCON. Next, black display was performed, and the brightness was measured every 10 mm in the plane using a BM-5 luminance meter manufactured by TOPCON Corporation.

The brightness at the time of the white display is set to T white, the brightness at the time of black display is T black, and the T white/T black is defined as contrast. The resulting panel was evaluated for homogeneity by the following criteria.

◎: The contrast in the panel surface is not within 3%.

○: The contrast in the panel surface is not within 5%.

△: The contrast in the panel surface is not within 10%.

▲: The contrast ratio in the panel surface is less than 15%.

×: The contrast ratio in the panel surface is not within 20%.

The results obtained by the above evaluation are shown in Table 7 below.

According to Table 7, it is understood that the cellulose-deposited cellulose film of the present invention has a reverse wavelength dispersion of ΔRe &gt; 0 nm, and is excellent in the retardation in the film thickness direction per unit film thickness, and has a large elastic modulus in the longitudinal direction of the film. The unevenness of the elastic modulus in the wide-side direction is small, and the in-plane uniformity when incorporated in the polarizing plate and combined with the panel becomes good.

Further, the liquid crystal display device using the film of the present invention has good viewing angle hue and durability.

On the other hand, in Comparative Example 1 and Comparative Example 10, in the case where TD stretching was not performed, it was found that the obtained film had a difference in elastic modulus and had a problem in the in-plane uniformity of the panel. Comparative Example 2 and Comparative Example 3 are aspects in which the additional test is similar to the example of JP-A-2006-030962. Comparative Example 2 is an additive U obtained by adding deuterated butyric acid cellulose to 5 wt% as a retardation expression agent, and the MD stretching ratio and the TD stretching ratio are outside the range specified in the production method of the present invention, and it is understood that The reverse wavelength dispersion and the elastic modulus are also inferior. When incorporated in a liquid crystal display device, there is a problem in viewing angle hue and panel in-plane uniformity. In Comparative Example 3, in the case of Comparative Example 2, the addition of the additive U was not carried out, and the TD stretching ratio was increased to the range of the present invention, but the MD stretching ratio was outside the range specified in the production method of the present invention, and each unit was known. The retardation in the film thickness direction of the film thickness is poor, and the modulus of elasticity is also inferior. When incorporated in a liquid crystal display device, there is a problem in uniformity in the panel surface.

Comparative Example 4 to Comparative Example 6 are configurations similar to the examples of JP-A-2009-263619, and none of them are extended in the MD direction, and it is known that the film optical properties or the film elastic modulus are all. When it is mounted in a liquid crystal display device, there is a problem in uniformity in the panel surface.

Comparative Example 7 and Comparative Example 8 are examples in which 5 wt% of the additive U as a retardation agent is used, and it is understood that the total thiol substitution degree and the MD stretching ratio of the deuterated cellulose are outside the range of the production method of the present invention. In the case of Comparative Example 7, the expression of the retardation in the film thickness direction per unit film thickness is inferior to the elastic modulus in the MD direction, and when it is incorporated in the liquid crystal display device, there is a problem in the in-plane uniformity of the panel. Further, it is understood that when the MD stretching ratio is within the range of the production method of the present invention and only the total thiol substitution degree of the deuterated cellulose is outside the range of the production method of the present invention, it does not become It is dispersed in the reverse wavelength, and when it is incorporated in a liquid crystal display device, there is a problem in viewing angle hue and in-plane uniformity.

Comparative Example 9 is an aspect of the cellulose deuterated cellulose having a total substitution degree of less than the range of the total degree of substitution of the deuterated cellulose of the present invention, and it is understood that the retardation of the film thickness direction per unit film thickness is inferior to the film elastic modulus. When it is incorporated in a liquid crystal display device, there is a problem in uniformity in the panel surface.

In Comparative Example 11, the stretch ratio of the MD extension and the TD extension was outside the range of the production method of the present invention, and it was found that the film had a poor film elastic modulus and was incorporated in the liquid crystal display device. There is a problem with the uniformity of the panel surface.

In Comparative Example 12 and Comparative Example 13, the residual volatile component at the time of film formation was outside the range of the production method of the present invention, and in Comparative Example 12, the film was broken. Further, it is understood that the film obtained in Comparative Example 13 has a poor retardation in the film thickness direction per unit film thickness and a difference in film elastic modulus, and is in-plane uniformity when incorporated in a liquid crystal display device. There is a problem.

10. . . Bounce mechanism

11. . . Bounce device (as a path roller for the dancer roller. Free movement, non-motion) / dancer roller

12. . . Angle detector

13. . . Load control device

14. . . Temperature sensor

15. . . Tension sensor

16. . . Film transport direction

17a, 17b. . . Guide roller (one part of the path roller)

18. . . Path roller

20. . . Belt casting machine

twenty one. . . Peel off the roller

twenty two. . . Dopant

twenty three. . . Extension device

twenty four. . . Membrane (web) membrane

Fig. 1 is a schematic view showing a state in which a cellulose-deposited cellulose film of the present invention is produced by using a beating mechanism.

Fig. 2 is a schematic view showing a detailed configuration of a bounce mechanism which can be used in the method for producing a cellulose-deposited cellulose film of the present invention.

10. . . Bounce mechanism

11. . . Bounce roller

16. . . Film transport direction

18. . . Path roller

20. . . Belt casting machine

twenty two. . . Dopant

twenty three. . . Extension device

twenty four. . . Membrane (web) membrane

Claims (12)

A cellulose-deposited cellulose film comprising: deuterated cellulose having a total thiol substitution degree of 2.1 to 2.8, wherein the fluorenyl group has a carbon number of 2 to 4, and the deuterated cellulose The film contains at least one of a polycondensation polyester and a sugar ester, and the elastic modulus of the film-transferring direction of the deuterated cellulose film is 3200 MPa or more, and the elastic modulus of the deuterated cellulose film in the film width direction is not All are 0.5 GPa or less, and satisfy the following formula (1) to formula (3): Formula (1) 0 nm ≦ ΔRe ≦ 15.0 nm (wherein ΔRe represents a retardation value from the in-plane direction at a wavelength of 630 nm minus The value obtained by removing the in-plane retardation value at a wavelength of 450 nm (in nm)) (2) 2 × 10 ^-3 ≦ Rth / d ≦ 6 × 10 ^-3 (wherein Rth represents the film thickness at a wavelength of 550 nm) The retardation value of the direction (in nm), d is the film thickness (unit: nm)) Formula (3) 1.0≦E'(TD)/E'(MD)≦1.43 (where E'(MD) indicates The elastic modulus (unit: MPa) of the film transport direction, and E' (TD) indicates the elastic modulus (unit: MPa) in the film width direction. The cellulose-degraded cellulose film according to the first aspect of the invention, wherein the film has a direction of elasticity of 3500 MPa or more. The cellulose film according to claim 1, wherein The retardation value Re of the in-plane direction at a wavelength of 590 nm and the retardation value Rth in the film thickness direction at a wavelength of 590 nm satisfy the following formula: 35 nm ≦ Re ≦ 80 nm, and 100 nm ≦ Rth ≦ 300 nm. The deuterated cellulose film according to claim 1, wherein the deuterated cellulose is cellulose acetate. The cellulose-degraded cellulose film according to any one of the items 1 to 4, which contains the organic acid represented by the following formula (1): general formula (1) XL-(R ¹ ) _n (In the above formula (1), X represents a substituent having an acid group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher linking group, and R ¹ represents a carbon number of 6 to 30. An alkyl group, an alkenyl group having 6 to 30 carbon atoms, an alkynyl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms or a heterocyclic group having 6 to 30 carbon atoms, and further halogen Atom, aryl, heterocyclic, alkoxy, aryloxy, alkylthio, arylthio, decyl, hydroxy, decyloxy, amine, alkoxycarbonyl, decylamino, oxycarbonyl , alkalyl group, sulfonyl group, sulfonyl group, sulfonylamino group, sulfo group or carboxyl group; n is 1 when L is a single bond, and when L is a linking group of 2 or more valences (L price -1)). The fluorinated cellulose film according to claim 5, wherein R ¹ in the formula (1) represents an alkyl group having 6 to 24 carbon atoms, an alkenyl group having 6 to 24 carbon atoms, or The alkynyl group having a carbon number of 6 to 24 (may further be a halogen atom, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a decyl group, a hydroxyl group or a decyloxy group). , an amine group, an alkoxycarbonyl group, a decylamino group, an oxycarbonyl group, an amine methyl sulfonyl group, a sulfonyl group, an amine sulfonyl group, a sulfonylamino group, a sulfo group or a carboxyl group). The deuterated cellulose film according to claim 5, wherein X in the formula (1) has at least one member selected from the group consisting of a carboxyl group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group, and a sulfonium group. At least one group of the group consisting of an amine group and an ascorbate group. The deuterated cellulose film according to claim 5, wherein L in the formula (1) is a single bond or a linking group selected from the group of two or more of the following groups or selected a linking group obtained by combining two or more units of the following unit groups; units: -O-, -CO-, -N(R ² )- (the R ² represents an alkyl group having 1 to 5 carbon atoms) ), -OH, -CH=CH-, -CH(OH)-, -CH ₂ -, -SO ₂ -, The cellulose-deposited film according to the fifth aspect of the invention, wherein the organic acid represented by the formula (1) is obtained by bonding one molecule of a fatty acid and one molecule of a polyvalent carboxylic acid to one molecule of a polyol. And having at least one unsubstituted carboxyl group derived from a polycarboxylic acid. The fluorinated cellulose film according to claim 5, wherein the organic acid represented by the formula (1) has a molecular weight of 200 to 1,000. The cellulose-deposited cellulose film according to any one of claims 1 to 4, which has a laminated structure of two or more layers, the average of the cellulose-deposited cellulose contained in each of the layers Total base Generations are different from each other. The cellulose-deposited cellulose film according to any one of the first to fourth aspect, wherein the standard deviation (σ) of the unevenness of the azimuth direction of the end portion in the film width direction is 0.10 or less. .