KR101684809B1 - Cellulose ester film having an improved reliable property at high temperature/humidity condition and method for preparing the same - Google Patents

Abstract

The present invention relates to a retardation film for VA (Vertical Alignment) having high reliability and a plasticizer for an asymmetric ester compound containing an aromatic group represented by the following formula (1) capable of improving the high temperature and high humidity reliability of a cellulose ester phase difference film capable of producing a polarizing plate And a method for producing the cellulose ester film.
[Chemical Formula 1]
T + [D + P] n + D
T is a benzene carboxylic acid residue, D is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, P is an alkylene glycol residue having 4 to 12 carbon atoms Or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.
The benzene carboxylic acid residue is preferably a toluene acid residue, and the alkylene glycol residue is preferably selected from the group consisting of propylene glycol, neopentyl glycol, diethyleneglycol, dipropyleneglycol, Triethyleneglycol residue, and the aryl dicarboxylic acid residue is preferably a phthalic acid residue.

Description

[0001] The present invention relates to a cellulose ester film having excellent reliability and a method for producing the cellulose ester film,

The present invention relates to a cellulose ester film having excellent reliability and a method for producing the same. More particularly, the present invention relates to a cellulose ester film capable of improving the reliability of a high-temperature high-humidity cellulose ester phase difference film capable of producing a VA (Vertical Alignment) reliable polarizer and a polarizer, and a method for producing the same.

Recently, a liquid crystal display (LCD) has been used in various fields, so that it is desired to have high visibility when viewing an image. In particular, a polarizing plate or a retardation plate used in an LCD is required to have high flatness such as glass, . Also, in an LCD used in outdoor such as a car navigation system or a PDA, it is necessary to incorporate an ultraviolet absorber into a polarizing plate protective film in order to prevent deterioration of the polarizer.

In particular, a film used for the outermost surface due to the spread of a large-area television or a large-area monitor is required to have a high planarity and a high image quality, and defects such as spot defects become image defects, leading to deterioration of LCD quality. In addition, although cellulose triacetate (TAC) films are mainly used as protective films for polarizers currently used in LCDs, there is a problem that films used in LCDs tend to stick to each other due to their transparency and smoothness. Therefore, in order to improve the handling properties during film formation of these resin films and the surface treatment of these resin films, fine particles are added to the film to provide lubricity without impairing the transparency of the film, thereby improving handleability and stabilizing the winding property .

The cellulose ester film is usually produced by a solution casting film-forming method. Namely, a film is produced by softening a dope (thickened solution) of a cellulose ester from a flexible die on an endless support, releasing the self-supporting property of the dope, and peeling off the endless support. This film often contains additives such as fine particles, a plasticizer, and an ultraviolet absorber in addition to the cellulose ester. The fine particles are used for ease of lubrication and adhesion resistance of the film thus formed, and the ultraviolet absorber is used, for example, to prevent deterioration of the polarizing plate when used in a polarizing plate. These components are usually mixed together when preparing the dope.

However, the cellulose ester type polarizing plate produced by the existing retardation film is poor in resistance to high temperature and high humidity environments, and the barrier property of the retardation film is deteriorated when exposed to a high temperature and high humidity reliability environment and the reliability quality is lowered in the production of the polarizing plate and LCD There was a problem.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a cellulose ester film capable of improving the reliability of a cellulose ester phase difference film with high reliability and a polarizer, It has its purpose.

The cellulose ester film having excellent reliability according to the first embodiment of the present invention has an in-plane retardation Ro of 20 to 60 占 퐉 in total substitution degree of the acyl group of 2.10 to 2.70 and an in-plane retardation Ro of 20 To 100 nm in the thickness direction and 100 to 300 nm in the thickness direction retardation, and contains an aromatic-containing asymmetric ester compound represented by the following formula (1) The amount of change in the moisture vapor permeability expressed by the following formula (2) is within 50% after 500 hours' standing in the environment.

[Chemical Formula 1]

T + [D + P] n + D

T is a benzene carboxylic acid residue, D is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, P is an alkylene glycol residue having 4 to 12 carbon atoms Or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.
The benzene carboxylic acid residue is preferably a toluene acid residue, and the alkylene glycol residue is preferably selected from the group consisting of propylene glycol, neopentyl glycol, diethyleneglycol, dipropyleneglycol, Triethyleneglycol residue, and the aryl dicarboxylic acid residue is preferably a phthalic acid residue.

[Equation 1]

Ro = (nx - ny) xd

Rth = {(nx + ny) / 2-nz} xd

Ny is the maximum refractive index in the vertical direction in the film plane and nz is the maximum refractive index in the thickness direction of the film and is 23 DEG C and 55% RH, respectively, where d is the film thickness (nm), nx is the maximum refractive index in the horizontal direction in the film plane, Under the environment of 550 nm.

&Quot; (2) "

? MVP = (MVP_reliability-MVP_reliability) / (MVP_reliability x100 (%)) <50%

Here, Moisture Vapor Permeability (MVP) was allowed to stand for 24 hours under a 40 ° C and 90% RH environment of a high temperature and high humidity chamber using a humudity cup (model name: KP-M6680, application standard: KS A1013, KS M6886) Is the amount of water that passes (permeates) through the cellulose ester film. The MVP_reliability before and MVP_reliability are the MVP values measured by the above described moisture permeability evaluation conditions for the cellulose ester film before and after being left for 500 hours under a 60 DEG C, 90% RH reliability environment.

The cellulose ester film according to the present invention has an effect of improving the reliability of high-temperature high-humidity of the VA retardation film having high reliability and the cellulose ester phase difference film capable of producing a polarizing plate.

1 is a schematic view of an apparatus for producing a general cellulose ester film.
2 is an exploded perspective view of polarizer lamination.
3 is a perspective view of a conventional breathable cup.

The cellulose ester film having excellent reliability according to the first embodiment of the present invention has an in-plane retardation Ro of 20 to 60 占 퐉 in total substitution degree of the acyl group of 2.10 to 2.70 and an in-plane retardation Ro of 20 To 100 nm in the thickness direction and 100 to 300 nm in the thickness direction retardation, and contains an aromatic-containing asymmetric ester compound represented by the following formula (1) The amount of change in the moisture vapor permeability expressed by the following equation (2) is within 50% after 500 hours in the environment.

[Chemical Formula 1]

T + [D + P] n + D

T is a benzene carboxylic acid residue, D is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, P is an alkylene glycol residue having 4 to 12 carbon atoms Or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.
The benzene carboxylic acid residue is preferably a toluene acid residue, and the alkylene glycol residue is preferably selected from the group consisting of propylene glycol, neopentyl glycol, diethyleneglycol, dipropyleneglycol, Triethyleneglycol residue, and the aryl dicarboxylic acid residue is preferably a phthalic acid residue.

[Equation 1]

Ro = (nx-ny) xd

Rth = {(nx + ny) / 2-nz} xd

Ny is the maximum refractive index in the vertical direction in the film plane and nz is the maximum refractive index in the thickness direction of the film and is 23 DEG C and 55% RH, respectively, where d is the film thickness (nm), nx is the maximum refractive index in the horizontal direction in the film plane, Under the environment of 550 nm.

&Quot; (2) &quot;

? MVP = (MVP_reliability-MVP_reliability) / (MVP_reliability x100 (%)) <50%

Here, Moisture Vapor Permeability (MVP) is the amount of water that passes through (passes through) the cellulose ester film after being left in a high temperature and high humidity chamber at 40 ° C and 90% RH environment for 24 hours using a humidity cup. The MVP_reliability before and MVP_reliability are the MVP values measured by the above described moisture permeability evaluation conditions for the cellulose ester film before and after being left for 500 hours under a 60 DEG C, 90% RH reliability environment.

The method for producing a cellulose ester film having excellent reliability according to the second embodiment of the present invention is characterized by comprising 10 to 30 parts by weight of a cellulose ester having an acyl group with a total degree of substitution of 2.1 to 2.7 and an asymmetric ester plasticizers from 2 to 8 parts by weight of methylene chloride and methanol 9: 1 mixed solvent of 70 to 80 parts by weight of the blend ratio by weight%, and silica as the metal oxide (SiO ₂₎ 1 to 3 parts by weight, mixed with cellulose as a main dope solution Preparing a solution;

Forming a flexible film by uniformly softening the cellulose solution on a support and drying under an environment of 150 to 200 캜;

 Peeling the flexible film from the support and stretching in the width direction; And

And drying the stretched flexible film in an environment of 100 to 150 ° C. in a drying section to produce a film having a thickness of about 20 to 60 μm.

The cellulose esters can be used alone or in combination of cellulose esters synthesized from cellulose ester synthesized from linter pulp, wood pulp and kenaf pulp, and other raw materials.

According to the present invention, the cellulose ester film may contain a specific plasticizer, and the plasticizer may be an asymmetric ester plasticizer containing an aromatic group represented by the general formula (1) as a barrier property of the cellulose ester film before and after the reliability treatment. It is particularly preferable to set it to a predetermined range.

Specific compounds of the aromatic-containing asymmetric ester compound according to the present invention are as follows, but the present invention is not limited thereto.

(2)

Mw = 400.4

(3)

Mw = 456.5

[Chemical Formula 4]

Mw = 460.5

[Chemical Formula 5]

Mw = 516.6

[Chemical Formula 6]

Mw = 548.6

(7)

Mw = 606.6

[Chemical Formula 8]

Mw = 690.8

[Chemical Formula 9]

Mw = 696.7

[Chemical formula 10]

Mw = 780.9

(11)

Mw = 828.9

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a film production apparatus which can be used for producing a cellulose ester film having an acetyl group, a propionyl group and a butyl group according to the present invention.

According to the second embodiment of the present invention, the main dope solution is extruded onto the surface of the belt 20 through the die 10 and applied in the form of a sheet. After evaporating the solvent present in the dope solution, And the stretching in the longitudinal direction MD and the transverse direction TD is performed in the tenter 40 (the first drying section), the residual solvent is evaporated in the second drying section 50, 60). &Lt; / RTI &gt;

The die 10 may be a conventional T-die 20 and the belt 20 is a high temperature band support that dries and forms a film by transferring the dope liquid, for example, a stainless steel conveyor belt is preferred Do. The thickness (for example, the final thickness after stretching and drying) of such a cellulose ester film can be appropriately adjusted as necessary, but according to the present invention, it is preferable that the thickness is in the range of 20 to 60 탆.

Hereinafter, the present invention will be described in more detail with reference to examples, but the following examples are for illustrative purposes only and the present invention is not limited thereto.

Example  One

(1) Preparation of cellulose solution Dope )

17.95% by weight of a cellulose ester A having an acetyl group of 2.1, a butyryl group of 0.2 and a total degree of substitution of an acyl group of 2.3 (see Tables 1 and 2), a plasticizer A (terminal asymmetric plasticizer 1: see Tables 1 and 3) %, the diluted cellulose solution was prepared in a mixed solvent of methylene chloride as a 72% by weight, 8% by weight of methanol, and the main dope solution was mixed with silica (SiO ₂₎ 0.05% by weight as the metal oxide.

(2) Production of film of cellulose

100 parts by weight of the main dope liquid A and 5 parts by weight of the fine particle addition liquid were mixed thoroughly with an inline mixer (main dope liquid A), and then uniformly plied to a stainless steel band support having a width of 2000 mm by using a belt smoothing device. The solvent was evaporated on the stainless steel band support and peeled off from the stainless band support. Then, both ends of the web were held with a tenter and stretched so that the stretching magnification in the TD direction was 1.3 times in a temperature environment of 170 占 폚. After the stretching, the stretching was maintained for a few seconds, the tensile force in the width direction was relaxed, the stretching in the width direction was carried out, the stretching was continued for 35 minutes in the drying section set at 110 DEG C, A cellulose ester film (CF-40-1) (see Table 4) having a thickness of 40 탆 and a knurling width of 10 mm and a height of 8 탆 was prepared.

(3) Measurement of physical properties of cellulose ester film

The cellulose ester film thus obtained was a retardation film having an in-plane retardation value Ro of 40 to 60 nm and a retardation value Rth in the thickness direction of 110 to 140 nm according to the following measurement.

Ro = (nx-ny) xd

Rth = ((nx + ny) / 2-nz) xd

Nx and ny represent refractive indices in the in-plane direction of the film, nz represent refractive indices in the thickness direction of the film, nx &gt; = ny, , And d represents the thickness (nm) of the film.

The retardation values Ro and Rt were measured at 550 nm in an environment of 23 ° C and 55% RH using an AxoScan (OPMF-1, Axometrics) optical measuring instrument. The cellulose ester film prepared above was subjected to reliability treatment for 500 hours at 60 ° C and 90% RH using a high temperature and high humidity chamber, and the moisture permeability of the cellulose ester film was measured using a moisture permeation cup (FIG. 3). The results are shown in Table 4.

(4) PVA  Preparation of polarizer using film

The polyvinyl alcohol film having a thickness of 120 占 퐉 was uniaxially stretched (temperature: 110 占 폚, stretching magnification: 5 times). This was immersed in an aqueous solution containing 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds and then immersed in an aqueous solution at 68 DEG C containing 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizer (PF-1).

Subsequently, a TAC film (thickness: 40um: TF (thickness: 30 μm)) was laminated on the back side of the polarizer (PF-1) and the cellulose ester film (polarizing plate protective film B: CF- -40-1) was bonded to a polarizer protective film B as a polarizer and a cellulose ester film according to the following steps to prepare a polarizing plate (POL-1).

Step 1: The film was immersed in a 2 mol / L sodium hydroxide solution at 60 占 폚 for 90 seconds, followed by washing with water and drying to obtain a polarizing film which was a saponified cellulose ester film.

Step 2: The polarizing membrane was immersed in a polyvinyl alcohol adhesive tank (tank) having a solid content of 2 mass% for 1 to 3 seconds.

Step 3: In step 2, excess glue adhered to the polarizing film was lightly wiped off, and placed on a cellulose ester film treated in step 1.

Step 4: The cellulose ester film laminated in Step 3, the polarizer, and the back side cellulose ester film were bonded at a pressure of 20 to 30 N / cm ² and a conveying speed of about 2 m / min.

Step 5: A sample obtained by bonding the polarizer prepared in Step 4 to the cellulose ester film and the back side cellulose ester film in a dryer at 80 占 폚 was dried for 2 minutes to prepare a polarizing plate (POL-1).

In the accompanying drawings, FIG. 2 illustrates a polarizing plate lamination with reference to an exploded perspective view, wherein reference numeral 100 denotes a transparent glass substrate of 0.5 mm, reference numeral 110 denotes a lower polarizer plate, and reference numeral 120 denotes an upper polarizer plate. Reference numerals 111 and 123 denote a polarizing plate protective film A (TAC film), 112 and 122 denote polarizers (PVA films), and reference numerals 113 and 121 denote a polarizing plate protective film B (cellulose ester phase difference film). In Fig. 2, the arrows indicated by a indicate the absorption axis of the polarizer, and the arrows indicated by b indicate the optical axis of the cellulose ester phase difference film.

(5) Reliability measurement and result of polarizer

The pressure-sensitive adhesive was coated on the surface of the polarizing plate protective film with respect to the prepared polarizing plate, and laminated so that the transmission axis of the polarizing plate was orthogonal to both surfaces of the glass substrate having a thickness of 0.5 mm (FIG. 2). The sample (SPL-1) prepared as shown in the following Table 6 was subjected to reliability at 60 ° C and 90% RH using a high temperature and high humidity chamber, and light leakage and optical staining were observed on the backlight. As shown in Table 6, when the cellulose ester film contains the plasticizer as proposed in the present invention and falls within the range of the degree of substitution of the cellulose ester film, the barrier properties of the cellulose ester film before and after the reliability treatment are superior to those of the comparative example, Light leakage and optical stain characteristics are excellent.

Example  2 to 5

The main dope liquids (B to E) were prepared in the same manner as in Example 1, except that the cellulose ester and the plasticizer as shown in the following Tables 1 to 3 were used, and then the cellulose ester film (CF-40-2 to CF -40-5) was prepared and its physical properties were measured in the same manner as in Example 1 above. The results are shown in Table 4.

Example Dope Cellulose ester Plasticizer Example 1 A A * A ** Example 2 B B * A ** Example 3 C C * A ** Example 4 D D * A ** Example 5 E E * A ** Comparative Example 1 F A * B ** Comparative Example 2 G E * B ** Comparative Example 3 H A * C ** Comparative Example 4 I E * C **

* See Table 2, ** See Table 3

Cellulose ester Acetyl group Propionyl group Butyryl group Total degree of substitution A 2.1 0 0.2 2.3 B 2.1 0 0.5 2.6 C 1.7 0 0.5 2.2 D 1.7 0 0.8 2.5 E 1.8 0.5 0 2.3

Plasticizer Type Compound structure A (terminal asymmetric plasticizer 1)

B (terminal symmetric plasticizer 1)

C (end symmetric plasticizer 2)

Polarizers POL-2 to POL-5 were prepared in the same manner as in Example 1 using the PVA film in the same manner as in Table 5 below, and samples (SPL-2 to SPL-5 ) Were measured. The results are shown in Table 6 below.

Comparative Example  1 to 4

After preparing the main dope (F to I) in the same manner as in Example 1 except that the cellulose ester and the plasticizer as shown in Tables 1 to 3 were used, the cellulose ester film (CF-40-6 to CF -40-9) was prepared and its physical properties were measured in the same manner as in Example 1 above. The results are shown in Table 4.

Polarizers POL-6 to POL-9 were produced in the same manner as in Table 5 using a PVA film in the same manner as in Example 1, and the samples (SPL-6 to SPL-9 ) Were measured. The results are shown in Table 6 above.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the appended claims. There will be.

10: Die
20: Belt
30: peeling roll
40: Tender (first drying section)
50: Second drying section
60: Winder
111, 123: Polarizing plate protective film A
112, 122: Polarizer
113,121: Polarizing plate protective film B

Claims (15)

A cellulose ester film with excellent reliability, characterized by containing an asymmetric ester compound having an aromatic group represented by the following general formula (1) and having a total substitution degree of an acyl group of 2.10 to 2.70, a film thickness of 20 to 60 탆, .
[Chemical Formula 1]
T + [D + P] n + D
T is a benzene carboxylic acid residue, D is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, P is an alkylene glycol residue having 4 to 12 carbon atoms Or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more. The cellulose ester film according to claim 1, wherein the in-plane retardation Ro of the film is 20 to 100 nm and the retardation Rth of the thickness direction of the film is 100 to 300 nm.
[Equation 1]
Ro = (nx-ny) xd
Rth = {(nx + ny) / 2-nz} xd
Ny is the maximum refractive index in the vertical direction in the film plane and nz is the maximum refractive index in the thickness direction of the film and is 23 DEG C and 55% RH, respectively, where d is the film thickness (nm), nx is the maximum refractive index in the horizontal direction in the film plane, Under the environment of 550 nm. The cellulose ester film according to claim 1, wherein the film has a variation in water vapor permeability expressed by the following formula (2) is within 50%.
&Quot; (2) &quot;
? MVP = (MVP_reliability-MVP_reliability) / (MVP_reliability x100 (%)) <50%
Here, Moisture Vapor Permeability (MVP) is the amount of water that passes through (passes through) the cellulose ester film after being left in a high temperature and high humidity chamber at 40 ° C and 90% RH environment for 24 hours using a humidity cup. The MVP_reliability before and MVP_reliability are the MVP values measured by the above described moisture permeability evaluation conditions for the cellulose ester film before and after being left for 500 hours under a 60 DEG C, 90% RH reliability environment. An asymmetric ester plasticizer containing an aromatic group represented by the following general formula (1), a mixed solvent in which methylene chloride and methanol are mixed at a ratio of 9: 1 by weight, and a silica (SiO ₂ ) to prepare a cellulose solution as a main doping liquid;
Forming a flexible film by uniformly softening the cellulose solution on a support and drying under an environment of 150 to 200 캜;
Peeling the flexible film from the support and stretching in the width direction; And
And drying the stretched flexible film in an environment of 100 to 150 ° C. in a drying section. The method for producing a cellulose ester film according to claim 1,
[Chemical Formula 1]
T + [D + P] n + D
T is a benzene carboxylic acid residue, D is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, P is an alkylene glycol residue having 4 to 12 carbon atoms Or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more. 5. The method of producing a cellulose ester film according to claim 4, wherein the film is formed to have a film thickness of 20 to 60 mu m. 5. The cellulose ester film according to claim 4, wherein the film is made to have an in-plane retardation Ro of 20 to 100 nm and a thickness direction retardation Rth of 100 to 300 nm, &Lt; / RTI &gt;
[Equation 1]
Ro = (nx-ny) xd
Rth = {(nx + ny) / 2-nz} xd
Ny is the maximum refractive index in the vertical direction in the film plane and nz is the maximum refractive index in the thickness direction of the film and is 23 DEG C and 55% RH, respectively, where d is the film thickness (nm), nx is the maximum refractive index in the horizontal direction in the film plane, Under the environment of 550 nm. 5. The method according to claim 4, wherein the film has a variation in water vapor permeability expressed by the following formula (2) within a range of 50% or less.
&Quot; (2) &quot;
? MVP = (MVP_reliability-MVP_reliability) / (MVP_reliability x100 (%)) <50%
Here, Moisture Vapor Permeability (MVP) is the amount of water that passes through (passed through) the cellulose ester film after being left in a high temperature and high humidity chamber at 40 ° C and 90% RH environment for 24 hours using a humidity cup. The MVP_reliability before and MVP_reliability are the MVP values measured by the above described moisture permeability evaluation conditions for the cellulose ester film before and after being left for 500 hours under a 60 DEG C, 90% RH reliability environment. 5. The process for producing a cellulose ester film according to claim 4, wherein the plasticizer is at least one selected from the group consisting of aromatic asymmetric ester plasticizers having the following general formulas (2) to (11).
(2)

,
(3)

,
[Chemical Formula 4]

,
[Chemical Formula 5]

,
[Chemical Formula 6]

,
(7)

,
[Chemical Formula 8]

,
[Chemical Formula 9]

,
[Chemical formula 10]

,
(11)

. [Claim 5] The method according to claim 4, wherein the cellulose ester is 10 to 30 parts by weight, the asymmetric ester plasticizer having the aromatic group represented by Formula 1 is 2 to 8 parts by weight, the mixed solvent of methylene chloride and methanol is 70 to 80 parts by weight , and silica as the metal oxide (SiO ₂₎ 1 to 3 parts by weight of a process for producing a blend that is excellent in reliability wherein the cellulose ester film. The cellulose ester film according to claim 1, wherein the benzene carboxylic acid residue is a toluene acid residue. The method according to claim 1, wherein the alkylene glycol residue is selected from the group consisting of propylene glycol, neopentyl glycol, diethyleneglycol, dipropyleneglycol, and triethyleneglycol residues. By weight based on the total weight of the cellulose ester film. The cellulose ester film according to claim 1, wherein the aryldicarboxylic acid residue is a phthalic acid residue. The method for producing a cellulose ester film according to claim 4, wherein the benzene carboxylic acid residue is a toluene acid residue. The method of claim 4, wherein the alkylene glycol residue is selected from the group consisting of propylene glycol, neopentyl glycol, diethyleneglycol, dipropyleneglycol, and triethyleneglycol residues. By weight based on the total weight of the cellulose ester film. 5. The method for producing a cellulose ester film according to claim 4, wherein the aryldicarboxylic acid residue is a phthalic acid residue.

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