JP2008069267A - Cellulose ester film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cellulose ester film excellent in extensibility and excellent in slip characteristics of the film and having low haze. <P>SOLUTION: The cellulose ester film comprises saccharides or a derivative thereof and optionally further inorganic microparticles. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cellulose ester film.

  As for cellulose ester films, triacetyl cellulose esters are widely used in applications such as support for photographic films and movie films, and front films for displays such as notebook computers and liquid crystal televisions because of their rigidity and dimensional stability. In particular, in recent years, displays such as liquid crystal televisions have been developed. Triacetyl cellulose films have improvement items such as spreadability, slipperiness, and scratch resistance during production.

  The spreadability during production is an important matter for improving productivity, and it is known to contain and apply various particles to improve slipperiness (blocking resistance) and scratch resistance. Yes.

  For example, the slipperiness is improved by containing silicon dioxide particles having a primary average particle diameter of 20 nm or less and an apparent specific gravity in the range of 70 to 100 g / L (see, for example, Patent Document 1). A problem remains in coexistence with turbidity representing the clearness of the film.

  Triacetyl cellulose films are produced by a solution casting method or a melt casting method, and adding the spreadability of the film during production is an important matter for improving productivity. Furthermore, with regard to improvement of the spreadability at the time of manufacture, attempts have been made to add additives such as plasticizers and to improve the prescription at the time of manufacture, but it remains a problem.

On the other hand, a technique for adding a carboxylic acid type glycolipid derivative is disclosed (for example, see Patent Document 2). However, it is intended for use as a liposome membrane-forming material or lyotropic liquid crystal, and is not assumed to be added to cellulose esters.
JP 2006-77260 A JP 2001-261690 A

  An object of the present invention is to provide a cellulose ester film having excellent spreadability during production, excellent film slipperiness, and low haze.

  As a result of various studies on additive materials, the present inventor has found a compound that acts effectively in a cellulose ester film, and has reached the present invention. Effective compounds for the cellulose ester film include saccharides or derivatives thereof, more specifically monosaccharides, disaccharides, or derivatives thereof.

  The object of the present invention is achieved by the following means.

  1. A cellulose ester film comprising a saccharide or a derivative thereof.

  2. 2. The cellulose ester film as described in 1 above, wherein the saccharide or a derivative thereof is a monosaccharide, a disaccharide, or a derivative thereof.

  3. 3. The cellulose ester film as described in 1 or 2 above, wherein the derivative has a proton donating group.

  4). 4. The cellulose ester film as described in 3 above, wherein the proton donating group is a carboxyl group.

  5. Furthermore, inorganic fine particles are contained, The cellulose-ester film of any one of said 1-4 characterized by the above-mentioned.

  According to the present invention, a cellulose ester film having good sliding properties and haze and excellent spreadability can be produced.

  Hereinafter, the present invention will be described in detail.

  The cellulose ester film of the present invention is characterized by containing a saccharide or a derivative thereof.

Saccharides are also called saccharides, and are a general term for monosaccharides and oligosaccharides and polysaccharides in which a plurality of these are condensed. Those that cannot be divided into simpler saccharides by hydrolysis are called monosaccharides and have the general formula C _m (H ₂ O) _n . The basic unit of carbohydrate is called monosaccharide. Two monosaccharides connected by glycosidic bonds are called disaccharides.

  Examples of monosaccharides include glucose, mannose, gulose, galactose, talose, and disaccharides include maltose, sucrose, cellobiose, and lactose. Monosaccharide and disaccharide derivatives include derivatives in which a hydroxyl group is substituted with acetyl. Is preferably used.

The saccharide derivative preferably has a proton donating group. Examples of proton donating groups has an anionic group, e.g., -O anion (olate), - S anion (thiolate), - COO anion (carboxylate), - SO ₃ anion (sulfonate), - SO ₂ anion (sulfinate), - PO ₃ H anion (Hosufonato), - OPO ₃ H anions (phosphate), - OPO ₂ H anion (phosphite) each group, and the like. Of these, -COO anion (carboxylate) is particularly preferred.

  Specific examples include glucose-1-phosphate and glucose-6-phosphate, and glucuronic acid, glucosamine, galactosamine, and deoxyribose.

  The most preferred derivatives are the following compounds.

  Next, a method for adding these compounds will be described. Although there is no limitation about the addition method, For example, it is preferable to melt | dissolve in solvents, such as ethanol, ethanol, a methylene chloride, and to add to the solution (henceforth dope solution) of a cellulose-ester film as a solution.

  Moreover, when using it, mixing with microparticles | fine-particles, it is preferable to add to dope liquid, after mixing and stirring and mixing microparticles | fine-particles sufficiently in a solvent. Although there is no restriction | limiting in the fine particle density | concentration in a solvent, Preferably it is 10% or more and less than 80%, More preferably, it is 15% or more and less than 70%.

  In the case of dispersing together with fine particles, a normal dispersing machine can be used as the dispersing machine. Dispersers can be broadly divided into media dispersers and medialess dispersers. For dispersing silicon dioxide fine particles, a medialess disperser is preferred because of its low haze. Examples of the media disperser include a ball mill, a sand mill, and a dyno mill.

Examples of the medialess disperser include an ultrasonic type, a centrifugal type, and a high pressure type. In the present invention, a high pressure disperser is preferable. A high-pressure dispersion device is a device that creates special conditions such as high shear and high-pressure by passing a composition in which fine particles and a solvent are mixed at high speed through a narrow tube. For example, the maximum pressure condition inside the apparatus is preferably 9.8 × 10 ⁶ Pa or more in a thin tube having a tube diameter of 1 to 2000 μm by processing with a high-pressure dispersion apparatus. More preferably, it is 1.96 × 10 ⁷ Pa or more. Further, at that time, it is preferable that the maximum reaching speed reaches 100 m / sec or more and the heat transfer speed reaches 100 kcal / hr or more.

  Examples of the high-pressure dispersion apparatus include an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation or a nanomizer manufactured by Nanomizer, and a Manton Gorin type high-pressure dispersion apparatus such as a homogenizer manufactured by Izumi Food Machinery, Sanwa Kikai Co., Ltd. UHN-01 etc. are mentioned.

  As the dispersed fine particles, any fine particles necessary for improving the performance of the cellulose ester film may be used. Any filler that can be used as a general filler can be used, for example, calcium carbonate, strontium carbonate, barium carbonate, silica, titanium oxide, kaolin, barium sulfate, zinc oxide, aluminum hydroxide, etc., talc, mica Plates and needles such as wollastonite, potassium titanate, and sepiolite can be used, and conductive fillers such as carbon black, carbon fiber, carbon nanotube, carbon nanofiber, metal powder, and titanium black should also be used. Can do. Further, organic fine particles such as polystyrene, fine organic pigments and the like may be used. In addition, the dispersed fine particles may be surface-treated with a coupling agent such as a silane coupling agent, a titanium coupling agent, and a phosphoric acid coupling agent, stearic acid, zinc stearate, or the like in advance.

  As the slipping improver, inorganic fine particles are preferable, and silicon dioxide fine particles are particularly preferably used. For example, preferably used silicon dioxide fine particles have a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70 g / L or more. The average diameter of the primary particles is more preferably 5 to 16 nm, further preferably 5 to 12 nm. A smaller primary particle average diameter is preferred because haze is low. The apparent specific gravity is preferably 90 to 200 g / L or more, more preferably 100 to 200 g / L or more. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved. The silicon dioxide fine particles are commercially available under the trade names of Aerosil 200V and Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.), and can be preferably used.

  Further, nonionic dispersants, anionic dispersants, and cationic dispersants can be used as the dispersant according to the surface properties of the particles.

  The manufacturing method of the cellulose-ester film of this invention is demonstrated. The film production method may be any known method. For example, a melt casting method in which cellulose is melted by heat and applied to the cast, a dope solution is prepared by dissolving cellulose in a solvent, and the dope solution is applied to the cast. And the solution casting method.

  Hereinafter, the melt casting method will be described. The cellulose ester and additive mixture according to the present invention is dried with hot air or vacuum, then melt-extruded, extruded into a film from a T-shaped die, closely attached to a cooling drum by an electrostatic application method, etc., cooled and solidified, and film Can be obtained. The temperature of the cooling drum is preferably maintained at 90 to 150 ° C.

  Melt extrusion may be used by connecting a single screw extruder, a twin screw extruder, and a single screw extruder downstream of the twin screw extruder. From the viewpoint of the mechanical properties and optical properties of the obtained film, the single screw extruder is used. Is preferably used. Furthermore, it is preferable to replace or depressurize the raw material supply and melting processes such as the raw material tank, the raw material charging section, and the inside of the extruder with an inert gas such as nitrogen gas.

  In particular, in producing a film, a method of heating and melting without applying mechanical stress as much as possible is preferable. Examples of existing apparatuses include a single screw extruder and a hot press machine. In the case of a single screw extruder, it is desirable to extrude at a temperature as low as possible at a temperature at which a transparent film can be obtained. In the route from the inlet to the die, it is desirable to set the temperature to be the glass transition temperature (Tg) to the melting point (Tm) of the cellulose ester resin, and it is preferable to raise the temperature stepwise as the die is approached.

  The temperature of the die is preferably set at Tm to Tm + 30 ° C. This is because the cellulose ester resin is accelerated by heat, and is suppressed by extruding it at the lowest possible temperature. However, since it is necessary for the die to sufficiently melt the cellulose ester resin, a temperature higher than the melting point is required. In the path from the inlet to the die, when the temperature is in the vicinity of the melting point, the cellulose ester resin is significantly deteriorated. When the temperature of the die is lower than the melting point, the transparency and flatness of the resulting film are inferior, and when the melting point is higher than + 30 ° C., the deterioration may be significant.

  The residence time (extrusion time) is preferably as short as possible. If the residence time is long, the deterioration may be remarkable, and if it is too short, the melting may be insufficient. The residence time is adjusted by the number of rotations of the shaft, the viscoelasticity of the molded product, the heating temperature, and the like.

  Hereinafter, the solution casting method will be described.

  In the present invention, the dope solution in which the cellulose ester is dissolved is a state in which the cellulose ester is dissolved in a solvent (solvent), and an additive such as a plasticizer may be added to the dope solution. If necessary, other additives can be added. As a density | concentration of the cellulose ester in dope liquid, 10-30 mass% is preferable, More preferably, it is 18-20 mass%.

  Although the solvent used in the present invention may be used alone or in combination, it is preferable in terms of production efficiency to use a mixture of a good solvent and a poor solvent, and more preferably, the mixing ratio of the good solvent and the poor solvent is 70% for the good solvent. It is -95 mass%, and a poor solvent is 30-5 mass%.

  With the good solvent and the poor solvent used in the present invention, those that dissolve the cellulose ester used alone are defined as good solvents, and those that swell or do not dissolve alone are defined as poor solvents. Therefore, the good solvent and the poor solvent change depending on the amount of acetic acid bonded to the cellulose ester. For example, when acetone is used as the solvent, the good solvent is obtained when the amount of acetic acid bonded to the cellulose ester is 55%, and the poor solvent is obtained when the amount of acetic acid bound is 60%. turn into.

  Examples of the good solvent used in the present invention include organic halogen compounds such as methylene chloride and dioxolanes. Moreover, as a poor solvent used for this invention, methanol, ethanol, n-butanol, a cyclohexane etc. are used preferably, for example.

  As a method for dissolving the cellulose ester when preparing the dope solution, a general method can be used. However, as a preferable method, the cellulose ester is mixed with a poor solvent and wetted or swollen. A method of mixing is preferably used. At this time, the method of heating at a temperature above the boiling point of the solvent under pressure and at a temperature where the solvent does not boil and dissolving while stirring is to prevent the generation of massive undissolved material called gel or mamako More preferred.

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

  The heating temperature with the addition of the solvent is preferably at or above the boiling point of the solvent used and in a range where the solvent does not boil. For example, the heating temperature is preferably set in the range of 60 ° C. or more and 70 to 110 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  After dissolution, it is taken out from the container while cooling, or extracted from the container with a pump or the like and cooled with a heat exchanger or the like, and used for film formation. Although the cooling temperature at this time may be cooled to room temperature, it is more preferable to cool to a temperature 5 to 10 ° C. lower than the boiling point and perform casting at that temperature because the dope viscosity can be reduced.

  In the present invention, a dope solution in which cellulose ester is dissolved in a solvent and a solution in which an ultraviolet absorber and a small amount of cellulose ester are dissolved are added and mixed in-line, and then cast on a support (casting step). And heating to remove a part of the solvent (drying process on the support), peeling from the support, and drying the peeled film (film drying process) to obtain the cellulose ester film of the present invention.

  As the support in the casting step, a support obtained by mirror-finishing belt-shaped or drum-shaped stainless steel is preferably used. The temperature of the support in the casting process can be cast in a general temperature range of 0 ° C. to a temperature lower than the boiling point of the solvent, but the dope is gelled by casting on a support at 0 to 30 ° C. In order to increase the peeling limit time, it is preferable to cast it on a support at 5 to 15 ° C. The peeling limit time is the time during which the cast dope is on the support at the limit of the casting speed at which a transparent and flat film can be continuously obtained. A shorter peeling limit time is preferable because of excellent productivity.

  The surface temperature of the support to be cast (cast) is 10 to 55 ° C., the temperature of the solution is 25 to 60 ° C., and the temperature of the solution is preferably 0 ° C. or more higher than the temperature of the support. More preferably, it is set as described above. The higher the solution temperature and the support temperature, the higher the drying speed of the solvent, which is preferable. However, when the temperature is too high, foaming or flatness may be deteriorated.

  A more preferable range of the temperature of the support is 20 to 40 ° C, and a more preferable range of the solution temperature is 35 to 40 ° C. Moreover, since the adhesive force of a film and a support body can be reduced by making the support body temperature at the time of peeling into 10-40 degreeC, More preferably, 15-30 degreeC, it is preferable.

  In order for the cellulose ester film during production to exhibit good flatness, the residual solvent amount when peeling from the support is preferably 10 to 80%, more preferably 20 to 40%, and particularly preferably 20 to 20%. 30%.

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

  Residual solvent amount = (mass before heat treatment−mass after heat treatment) / (mass after heat treatment) × 100% The heat treatment when measuring the amount of residual solvent means heating the film at 115 ° C. for 1 hour. Represents processing.

  The peeling tension is usually 196 to 245 N / m when peeling the support and the film, but the content of the UV absorber per unit mass of the cellulose ester is large, and the film is made thinner than before. Since the cellulose ester film of the present invention is likely to wrinkle during peeling, it is preferably peeled off at a minimum tension of 166.7 N / m, more preferably peeled off at a minimum tension of 137.2 N / m. That is.

  Moreover, in the drying process of the cellulose ester film, the film peeled off from the support is further dried, and the residual solvent amount is preferably 3% by mass or less, more preferably 0.5% by mass or less.

  In the film drying step, generally, a method of drying while transporting the film by a roll suspension method or a pin tenter method is adopted. For the liquid crystal display member, it is preferable to dry while maintaining the width by a pin tenter method in order to improve the dimensional stability. In particular, it is particularly preferable to maintain the width in a large amount of residual solvent immediately after peeling from the support because the effect of improving dimensional stability is more exhibited. The means for drying the film is not particularly limited, and is generally performed with hot air, infrared rays, a heating roll, microwaves, or the like. It is preferable to carry out with hot air in terms of simplicity. The drying temperature is preferably divided into 3 to 5 stages in the range of 40 to 150 ° C. and gradually increased, and more preferably in the range of 80 to 140 ° C. in order to improve dimensional stability.

  When the film thickness of the cellulose ester film is too thin, the strength as a protective film of the polarizing plate is insufficient, and the dimensional stability of the polarizing plate and the storage stability with wet heat deteriorate. If the film thickness is thick, the polarizing plate becomes thick and it becomes difficult to reduce the thickness of the liquid crystal display. The film thickness of the cellulose ester film that achieves both of these is 20 to 60 μm, preferably 30 to 50 μm, more preferably 35 to 45 μm, and most preferably 40 μm.

  The cellulose ester film of the present invention preferably contains a plasticizer. The plasticizer that can be used is not particularly limited, but in the phosphate ester type, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. For phthalate esters, diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, etc. For glycolate esters, triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl Ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc. are preferably used alone or in combination. There.

  It is particularly preferable to use a plasticizer of a phosphate ester plasticizer and a plasticizer having a freezing point of 20 ° C. or less because of excellent dimensional stability and water resistance. The plasticizer having a freezing point of 20 ° C. or lower is not particularly limited as long as the freezing point is 20 ° C. or lower, and can be selected from the above plasticizers. Examples thereof include tricresyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, diethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, triacetin, ethyl phthalyl ethyl glycolate and the like. These plasticizers are preferably used alone or in combination.

  The freezing point in the present invention is defined as the freezing point described in the encyclopedia of chemistry published by Kyoritsu Publishing Co., Ltd.

  The amount of these plasticizers used is preferably 1 to 15% by mass with respect to the cellulose ester in terms of film performance and processability. For a liquid crystal display member, 5 to 15% by mass is more preferable from the viewpoint of dimensional stability, and particularly preferably 7 to 12% by mass.

  The content of the plasticizer having a freezing point of 20 ° C. or less with respect to the cellulose ester is preferably 1 to 10% by mass, and more preferably 3 to 7% by mass.

  A larger proportion of the plasticizer having a freezing point of 20 ° C. or lower among all the plasticizers is preferable because the flexibility of the cellulose ester film is improved and the processability is excellent. Most preferably, all of the plasticizers are plasticizers having a freezing point of 20 ° C. or lower.

  It is preferable to use 1% by mass of a plasticizer having a freezing point of 20 ° C. or less with respect to the cellulose ester because the flexibility of the cellulose ester film is improved and the processability is excellent. When a plasticizer having a temperature of 14 ° C. or lower is used, workability is further improved and preferable.

  Processability is when slitting or punching a base film or a liquid crystal display member. If the processability is poor, the cut surface will be saw-toothed and chips will be generated, which will be attached to the product and cause defects. Absent.

  EXAMPLES Specific examples of the present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1
(Preparation of dispersion A)
Aerosil 200V (Nippon Aerosil Co., Ltd.) 15% by mass
Ethanol 85% by mass
The above was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. The turbidity of the dispersion was 100 ppm.

(Preparation of dispersions B to D)
Dispersions B, C, and D were prepared in the same manner as dispersion A, except that 10% by mass of the compound shown in Table 1 as a surface treatment agent was added to Aerosil 200V with respect to the configuration of dispersion A. did. The turbidity of the dispersion is also shown in the table.

<Liquid turbidity>
It measured using Tokyo Denshoku Industries Co., Ltd. T-2600DA.

<< Preparation of fine particle additive liquid A >>
6 parts by mass of triacetyl cellulose 140 parts by mass of methylene chloride The above was put into a closed container, heated and stirred, and completely dissolved and filtered. To this, 9 parts by mass of the above dispersion A was added with stirring, followed by further stirring for 30 minutes, followed by filtration to prepare a fine particle addition liquid A.

<< Preparation of fine particle additive liquids B to D >>
Fine particle addition liquids B to D were prepared in the same manner except that the dispersion liquid A of the fine particle addition liquid A was replaced with the dispersion liquids B, C, and D.

[Production of cellulose triacetate film]
(Production of samples 1 to 6)
Preparation of dope solution Triacetyl cellulose 100 parts by weight Triphenyl phosphate 6.5 parts by weight Ethylphthalyl ethyl glycolate 4 parts by weight 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzo Triazole 1 part by weight Methylene chloride 475 parts by weight Ethanol 50 parts by weight The above was put into a sealed container, heated and stirred, dissolved completely, and filtered to prepare a dope solution. Using a belt casting apparatus, the dope solution was uniformly cast on a stainless steel band support at 33 ° C. and 1500 mm width. The solvent was evaporated with a stainless steel band support until the residual solvent amount was 25%, and the film was peeled off from the stainless steel band support with a peeling tension of 127.4 N / m.

The peeled cellulose triacetate film was slit to 1300 mm width, and then dried while being transported through a number of rolls, and slit to 1100 mm width to obtain a cellulose triacetate film sample 1 having a thickness of 40 μm. Sample 2 of a cellulose triacetate film was obtained in the same manner as Sample 1 except that 2% by mass of Compound C was added to the sample, and a prepared sample was used. 100 parts by mass of dope solution with respect to silicon dioxide fine particles (Aerosil 200V) (Nippon Aerosil Co., Ltd.)) is added to the fine particle additive solution A so that the ratio is 0.03 parts by mass, and an in-line mixer (manufactured by Toray Co., Ltd., static in-tube mixer Hi-Mixer, SWJ) Mix well and filter. Next, using a belt casting apparatus, the mixed solution of the dope liquid and the fine particle additive liquid A was uniformly cast on a stainless steel band support at 33 ° C. and a width of 1500 mm. The solvent was evaporated on the stainless steel band support until the residual solvent amount was 25%, and the peel tension was 127.4 N / m. The peeled cellulose triacetate film was slit to a width of 1300 mm, and then dried while being transported through a drying zone by a number of rolls, and slit to a width of 1100 mm to obtain a cellulose triacetate film sample 3 having a thickness of 40 μm.

  The fine particle additive solution A of Sample 3 was added to the fine particle additive solution B, the fine particle additive solution C, and the fine particle additive solution D, and cellulose triacetate film samples 4, 5, and 6 were obtained, respectively.

[Preparation of alkali saponified cellulose triacetate film]
(Production of samples 1 to 6)
Cellulose triacetate film sample 1 was subjected to alkali saponification treatment to produce alkali saponification treated cellulose triacetate film sample 1.

<Alkali saponification treatment>
Saponification step 2M-NaOH 50 ° C. 90 seconds Water washing step Water 30 ° C. 45 seconds Neutralization step 10% HCl 30 ° C. 45 seconds Water washing step Water 30 ° C. 45 seconds Saponification of cellulose triacetate film sample under the above conditions, water washing, neutralization, It was performed in the order of water washing, and then dried at 80 ° C.

  Instead of the cellulose triacetate film sample 1, it changed to the cellulose triacetate film samples 2-6, and produced the alkali saponification-treated cellulose triacetate film samples 2-6.

[Preparation of polarizing plate]
(Production of samples 1 to 6)
A 120 μm thick polyvinyl alcohol film was immersed in 100 parts by mass of an aqueous solution containing 1 part by mass of iodine and 4 parts by mass of boric acid, and stretched 6 times at 50 ° C. to prepare a polarizing film. The alkali saponified cellulose triacetate film samples 1 to 6 were bonded to both surfaces of the polarizing film, respectively, using a completely saponified polyvinyl alcohol 5% aqueous solution as an adhesive to prepare polarizing plate samples 1 to 6.

  About each produced polarizing plate sample, the haze, the aggregate, and the tensile strength were measured, and the dynamic friction coefficient was measured about the cellulose triacetate film sample. In addition, about each measurement of the haze, aggregate, dynamic friction coefficient, and tensile strength in Table 2, it carried out by the following methods.

<Dynamic friction coefficient>
The dynamic friction coefficient between the film surface and the back surface is in accordance with JIS-K-7125 (1987), cut out so that the front and back surfaces of the film are in contact with each other, loaded with a weight of 200 g, a sample moving speed of 100 mm / min, and a contact area of 80 mm × 200 mm. The weight was pulled horizontally under the conditions, the average load (F) while the weight was moving was measured, and the dynamic friction coefficient (μ) was determined from the following formula.

  Dynamic friction coefficient = F (gf) / weight of weight (gf).

<Haze>
Five samples were overlapped and measured according to ASTM-D1003-52.

<Tensile strength>
The spreadability was confirmed by applying a load using an A & D Co., Ltd. Tensilon tensile strength tester RTC. A film that did not break even when the extension width of the film was 1.2 times or more was marked with ◯, and a film that broke with 1.2 times or less was marked with x.

<Agglomerate>
The number of aggregates of 25 μm or more present on the obtained sample 1 m ² was counted.

  From Table 2, it can be seen that the sample of the present invention is superior to the comparative sample in any evaluation of haze, aggregates, dynamic friction coefficient, and tensile strength.

Claims (5)

A cellulose ester film comprising a saccharide or a derivative thereof. The cellulose ester film according to claim 1, wherein the saccharide or a derivative thereof is a monosaccharide, a disaccharide, or a derivative thereof. The cellulose ester film according to claim 1, wherein the derivative has a proton-donating group. The cellulose ester film according to claim 3, wherein the proton donating group is a carboxyl group. Furthermore, inorganic fine particles are contained, The cellulose-ester film of any one of Claims 1-4 characterized by the above-mentioned.