JP5724850B2 - Method for producing cellulose ester film - Google Patents

Description

  The present invention relates to a method for producing a cellulose ester film having improved film conveyance stability at the start of production.

  A cellulose ester film is used as a protective film for a polarizing plate of a liquid crystal display device (LCD). As a conventional method for producing a cellulose ester film, for example, by a solution casting film forming method, a cellulose ester solution (hereinafter also referred to as a dope) has a mirror-treated surface and is endlessly supported. The dope is cast from a casting die onto a body (stainless steel belt or drum), the formed dope film (hereinafter also referred to as web) is peeled off by a peeling roller (peeling point), and then the web is subjected to a drying process. After moving and drying while transporting and forming a cellulose ester film, the cellulose ester film was finally produced by winding it into a roll with a winder.

  Conventionally, in the production of a cellulose ester film, production of a roll film having a volume of about 2000 m has been common, but in recent years, there has been a demand for a cellulose ester film as a protective film for a polarizing plate of a liquid crystal display (LCD). The film production scale per lot is mainly 2500m to 4000m, and in the future, the roll length per roll will be increased from the viewpoint of further expansion of production capacity and high film production. Is expected to exceed 5000 m.

  However, by increasing the winding diameter of the cellulose ester film in this way, the force applied to the film laminated in a roll shape is increased, and the deterioration of the winding appearance and the slipperiness of the films, that is, the winding quality. There was a phenomenon that deterioration occurred.

  Conventionally, the above problem has been dealt with by appropriately adjusting (increasing) the amount of matting agent that contributes to the improvement of slipperiness. For example, it has a step of forming a cellulose ester film containing a matting agent and a step of detecting the friction coefficient of the cellulose ester film immediately after winding, and in the film forming step, detection of the film friction coefficient from the detection step A method for producing a cellulose ester film that adjusts the amount of matting agent added to the dope based on the information is disclosed (for example, see Patent Document 1). According to Patent Document 1, the slipperiness of the film relating to the winding quality of the cellulose ester film is detected in the production process of the cellulose ester film, and the result is reflected in the production conditions (content of the matting agent in the dope). Thus, for example, even when a laminated roll having a winding length of 5000 m or more is manufactured, deterioration of roll quality can be suppressed. However, simply increasing the amount of the matting agent with respect to the quality required for the cellulose ester film (for example, transparency and contrast) is a factor that deteriorates the characteristics such as quality, for example, transparency, and the added amount is naturally You will be restricted.

  Moreover, in the method for producing cellulose acylate by a solution casting method, a cellulose acylate film in which the content of the matting agent in the cellulose acylate film is controlled to be in the range of 0.03 to 0.15% by mass is disclosed. (For example, refer to Patent Document 2). According to the invention described in Patent Document 2, it is said that a cellulose acylate film excellent in transportability and scratch resistance can be obtained without impairing the transparency of the film.

  On the other hand, as a result of studying the problem in producing a long cellulose ester film in which the winding length per roll exceeds 5000 m, the present inventor has optimized winding conditions and the like with respect to winding quality. Thus, to a certain extent, it became possible to produce a long roll cellulose ester film without increasing the amount of matting agent, but the initial stage of starting film formation, that is, the film formation speed during production In the low-speed film-forming stage that does not reach the point, the frictional characteristics (slidability) with respect to the transport rolls and the like become insufficient, and problems such as wrinkles and clipping mistakes in the tenter occur. In such a state, a low-speed film-forming product having a low friction coefficient is wound on a winding roll by a winder unit, and then a product produced at a regular film-forming speed is laminated on the roll to form a roll length of 5000 m. When a roll-shaped cellulose ester film that exceeds the length of the film is formed, the surface quality of the roll-shaped laminate (eg, wrinkle failure, roll-out failure, etc.) will be damaged, and continuous from the start of film formation. Thus, it is a great obstacle to stably producing a long roll cellulose ester film online.

Japanese Patent Laying-Open No. 2005-313467 JP 2002-317059 A

  The present invention has been made in view of the above problems, and a solution to the problem is that a long cellulose ester film can be continuously formed on-line, has a low haze, and film surface quality (wrinkle at the start of film formation). It is providing the manufacturing method of the cellulose-ester film which can obtain the cellulose-ester film excellent in the tolerance and the fracture | rupture tolerance.

  The above-described problems of the present invention are solved by the following means.

  1. In the cellulose ester film production method for producing a cellulose ester film by a solution casting film formation method, a dope is prepared by adding a matting agent-containing solution in an in-line manner to the main dope, and according to the film formation speed after the start of film formation A method for producing a cellulose ester film, wherein the matting agent concentration in the dope is controlled on-line.

  2. When the film forming speed is less than 50 m / min, the matting agent content with respect to the total solid content in the dope is 0.3% by mass or more, and when the film forming speed is 50 m / min or more, the total solid content in the dope. 2. The method for producing a cellulose ester film according to item 1, wherein the content of the matting agent is controlled to less than 0.3% by mass.

  3. The cellulose ester film according to item 1 or 2, wherein the matting agent content with respect to the total solid content in the dope when the film forming speed of the production condition is reached is 0.15% by mass or less. Manufacturing method.

  4). When the concentration of the matting agent contained in the main dope is A (mass%) and the concentration of the matting agent contained in the matting agent-containing solution is B (mass%), the mating agent concentration ratio (B / A) The value of is in the range of 2.0 to 80.0. The method for producing a cellulose ester film according to any one of Items 1 to 3.

  5. The cellulose ester according to any one of Items 1 to 4, wherein the matting agent solution is not added to the main dope by the in-line method after reaching the film forming speed of the production conditions. A method for producing a film.

  6). 6. The method for producing a cellulose ester film according to any one of Items 3 to 5, wherein a film forming speed under the production conditions is in a range of 50 to 150 m / min.

  7). The method for producing a cellulose ester film according to any one of claims 1 to 6, wherein a film thickness of the cellulose ester film is 35 µm or less.

  8). The method for producing a cellulose ester film according to any one of Items 1 to 7, wherein the winder portion has a guide roller.

  By the above means of the present invention, a long cellulose ester film can be continuously formed online, and a cellulose ester film having low haze and excellent film surface quality (wrinkle resistance, break resistance) at the start of film formation is obtained. The manufacturing method of the cellulose-ester film which can be provided can be provided.

It is a flow sheet which shows an example of the manufacturing line of the solution casting film forming apparatus applicable to the manufacturing method of the cellulose-ester film of this invention.

  The cellulose ester film production method of the present invention is a cellulose ester film production method for producing a cellulose ester film by a solution casting film forming method. In the upstream portion of a casting die, a mat agent is contained in an inline manner with respect to the main dope. A facility for preparing a dope by adding a solution is provided, and the matting agent concentration in the dope is controlled on-line in accordance with the film forming speed after the start of film formation. This feature is a technical feature common to the inventions according to claims 1 to 9.

  When producing a long cellulose ester film, the film has low winding tension under low-speed conveyance conditions from the start of film formation to the conveyance speed (film formation speed) set in the production conditions. If the surface roughness is low, the frictional properties of each transport roller provided in the casting process, drying process or winding process will be reduced, making it slippery and preventing stable transport, resulting in low speed. Wrinkles may occur during transportation. Furthermore, clipping mistakes are likely to occur in the tenter clip provided in the stretching process, and stable conveyance becomes difficult. To some extent, it is possible to cope with the above problems by increasing the amount of matting agent in the dope, but there are problems with the transparency and contrast suitability of the film formed.

  As a result of diligent investigation on the above problems, the present inventors have been in the period from the start of film formation until reaching the conveyance speed (film formation speed) of production conditions (the film formed during this time is a non-product target) In a film, which functions as a leader film), a matting agent-containing solution containing a matting agent at a high concentration is added to the main dope in an in-line manner to prepare a dope having a desired high matting agent concentration. By using this dope, it is possible to form a cellulose ester film as a leader film with an appropriate surface roughness or friction coefficient by film formation under conditions of low transport speed, and stable even at low transport speed. Can be carried out. After that, when the conveyance speed reaches the production conditions, the cellulose ester film with transparency and contrast suitability is stably produced with high productivity by reducing the matting agent content to the design conditions online. can do.

  As an embodiment of the present invention, on the condition that the film forming speed is less than 50 m / min, the matting agent content with respect to the total solid content in the dope according to the present invention is set to 0.3% by mass or more, and the film forming speed is Under the condition of 50 m / min or more, controlling the matting agent content with respect to the total solid content in the dope to less than 0.3% by mass makes the production stability / conveyance stability and the quality of the cellulose ester film more compatible. This is a preferred embodiment from the viewpoint of achieving the above.

  In addition, the content of the matting agent with respect to the total solid content in the dope at the time when the film forming speed of the production conditions is reached is 0.15% by mass or less, thereby obtaining a cellulose ester film having low haze and high contrast. It is preferable in that it can be performed.

  When the concentration of the matting agent contained in the main dope is A (mass%) and the concentration of the matting agent contained in the matting agent-containing solution is B (mass%), the matting agent concentration ratio (B / A ) In the range of 2.0 to 80.0, the desired matting agent under low-speed conveyance conditions from the start of film formation until reaching the conveyance speed (film formation speed) of production conditions This is preferable from the viewpoint of obtaining a dope containing a concentration.

  Moreover, after reaching the film forming speed of the production conditions, do not add the matting agent solution to the main dope by the in-line method, the film forming speed in the production conditions is in the range of 50 to 150 m / min, It is preferable that the film thickness of the cellulose ester film is 35 μm or less and that the winder portion has a guide roller from the viewpoint of more manifesting the object effects of the present invention.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, "-" shown in this invention is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

<< Method for producing cellulose ester film >>
First, the solution casting film forming method applied to the method for producing a cellulose ester film of the present invention will be described.

  The method for producing the cellulose ester film according to the present invention is not particularly limited, and may be a method generally used in the art. For example, U.S. Pat. Nos. 2,492,978 and 2,739,070, 2,739,069, 2,492,977, 2,336,310, 2,367,603, 2,607,704, British Patent 64,071 Gazette, 735,892 gazette, Japanese Examined Patent Publication No. 45-9074, 49-4554 gazette, 49-5614 gazette, 60-27562 gazette, 61-39890 gazette, 62-4208 gazette. Reference can be made to the method described in the Gazette.

  FIG. 1 schematically shows a dope preparation step, a casting step, a drying step, and a winding step of a solution casting film forming apparatus applicable to the method for producing a cellulose ester film of the present invention. In addition, the example shown here is an example of the solution casting film forming method, and the implementation of the present invention is not limited to the process of FIG. In addition, the detail of the embodiment regarding the in-line method of the main dope and matting agent containing solution which concerns on this invention in a dope preparation process is mentioned later.

  In FIG. 1, preparation of a dope containing a cellulose ester resin is carried out by adding the cellulose ester resin and, if necessary, an additive in a dissolving tank 1 to a main solvent mainly composed of a good solvent for the cellulose ester resin. Is dissolved with stirring to prepare a main dope.

  For dissolving the cellulose ester-based resin, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, JP-A-9-95544, JP-A-9-95557. Various dissolution methods can be used, such as a method performed by a cooling dissolution method as described in JP-A-9-95538, or a method performed at a high pressure as described in JP-A-11-21379. However, a method in which pressure is applied above the boiling point of the main solvent is particularly preferable.

  The heating temperature with the addition of the main solvent is preferably at or above the boiling point of the organic solvent used and in a range where the organic solvent does not boil. For example, the heating temperature is set to 60 ° C. or more, more specifically 80 to 110 ° C. It is preferable to do this. Further, the pressure is set to a condition where the main solvent does not boil at the set temperature. The concentration of the cellulose ester resin in the main dope is preferably in the range of 10 to 35% by mass.

  For the main dope, in addition to the cellulose ester resin and the main solvent, additives such as plasticizers and UV absorbers are mixed with the solvent in advance and dissolved or dispersed as required, and then the cellulose ester resin is dissolved. It may be added to the previous solvent or may be added to the main dope after dissolving the cellulose ester resin.

  The main dope according to the present invention preferably contains at least a matting agent, and more preferably 0.15% by mass or less with respect to the total solid content of the main dope.

  There is no restriction | limiting in particular in the structure of the melting pot (pressurization container) 1, What is necessary is just a structure which can endure a predetermined pressure and can be heated and stirred under pressure. In addition, the pressurization-type melting pot 1 is appropriately provided with instruments such as a pressure gauge and a thermometer. 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 production method of the cellulose ester film of the present invention is mainly composed of the cellulose ester resin prepared in the above-described dissolution vessel (pressurized container) 1 in producing the cellulose ester film by the solution casting film forming method. A matting agent-containing solution is added to the main dope by in-line addition described later to prepare a dope for casting, and a film is formed through the casting die using this dope for casting.

  Specifically, a matting agent dispersion liquid (matting agent addition liquid) in which matting agent particles and a solvent are mixed with a high-pressure dispersing device is prepared in a separate kettle, and the matting agent dispersion is introduced into the dissolving kettle 1 to obtain cellulose. In some cases, it is added to the ester resin solution (dope) at the time of dissolution, or the whole or part of the additive such as a plasticizer is added to this dope.

  Next, the main dope is sent to the first dope stationary pot 3 which is a dope stock pot by the operation of the liquid feed pump 2, and is temporarily stored there. Furthermore, the main dope after standing is guided to the primary filter 5 by the operation of the liquid feed pump 4 and subjected to primary filtration to remove aggregates. In the primary filter 5, the main dope after standing is filtered with a filter medium such as filter paper or a sintered metal filter. Thereafter, the main dope is stored in the second dope stationary pot 6 which is a dope stock pot.

  The main dope after standing is guided to the secondary filter 8 by the operation of the liquid feed pump 7 and subjected to secondary filtration. In the secondary filter 8, the main dope is filtered with a filter medium such as filter paper or a sintered metal filter.

  Here, the temperature at the time of dissolution in the dope melting pot 1, the holding time at that temperature, the temperature in the first dope standing pot 3 and the second dope standing pot 6, and the holding time at that temperature are as follows: Adjust each one.

  On the other hand, after the matting agent-containing solution that has been subjected to a dispersion treatment so as to have a desired dispersed particle diameter by a high-pressure dispersing device (not shown) is stocked in the matting agent-containing solution preparation kettle 9, the liquid feeding pump 11 is operated. While leading to the matting agent-containing solution circulation filter 12 and circulating filtration, the matting agent-containing solution is filtered by the matting agent-containing solution feeding filter 10.

  At this time, the matting agent-containing solution according to the present invention contains at least a matting agent, and the concentration of the matting agent with respect to the total solid content of the main dope and the dope after in-line mixing is 0.3% by mass or more. It preferably contains a matting agent, and more preferably contains a matting agent at a concentration in the range of 2.0 to 80.0 times the matting agent concentration contained in the main dope.

  In addition, a method in which the matting agent-containing solution according to the present invention is prepared with the same composition as the main dope described above except for the concentration of the matting agent can be applied. By adopting such a configuration, even if the mixing ratio of the matting agent-containing solution to the main dope is changed, the film can be formed under exactly the same conditions except the matting agent concentration, for example, under the same dope physical property conditions. From the viewpoint of stability.

  When a matting agent-containing solution having the same composition as the main dope is prepared except for the matting agent concentration as described above, the dissolution vessel 1, the feed pump 2, the first dope are prepared in the same manner as the preparation of the main dope. It is preferable to prepare using the stationary kettle 3, the liquid feeding pump 4, the primary filter 5, the second dope stationary kettle 6, the liquid feeding pump 7, and the secondary filter 8.

  Next, the main dope mainly composed of the cellulose ester resin prepared in the melting pot (pressurized container) 1 and subjected to secondary filtration is introduced into the static mixer 13, and before the static mixer 13, A dope for casting is prepared by adding a matting agent-containing solution to the dope in-line. Next, the dope for casting is introduced into the casting die 14 and cast on the support 20 by a solution casting film forming method to form a dope film (web).

  As an apparatus that can be used for in-line addition and mixing in the present invention, for example, an in-line mixer such as a static mixer (manufactured by Toray Engineering), SWJ (Toray static type in-tube mixer Hi-Mixer) or the like is preferably used. It is done.

  The casting die 14 is preferably a pressure die that can adjust the slit shape of the die portion of the die and easily make the film thickness uniform. The pressure die 14 includes a coat hanger die and a T die, and any of them is preferably used. Further, as the support 20 in the casting step, a stainless steel rotary drive belt or a support 20 having a mirror-finished drum is used. The temperature of the support 20 in the casting step can be cast at a temperature in a general temperature range of 0 ° C. to less than the boiling point of the solvent, but it is more preferable to cast on the support 20 at 5 to 30 ° C. It is preferable because the dope can be gelled and the separation limit time can be increased, and it is more preferable that the dope is cast on the support 20 at 5 to 15 ° C. Here, the peeling limit time means the time during which the cast dope is on the support 20 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.

  In the drying step on the support, after the cast dope is once gelled, the dope temperature is set to 40% within 30% from the casting when the time from casting to peeling by the peeling roller 21 is 100%. By setting the temperature to ˜70 ° C., the evaporation of the solvent is promoted, and it can be peeled off from the support 20 as soon as possible. Further, the peeling strength is further increased. Is more preferable. Thereafter, this temperature is preferably maintained at 20% or more, and further preferably maintained at 40% or more.

  For drying on the support 20, it is preferable to peel the support 20 from the support 20 with a separation solvent amount of 60 to 150% because the peel strength from the support 20 is reduced, and 80 to 120% is more preferable. . The temperature of the dope at the time of peeling is preferably in the range of 0 to 30 ° C because the base strength at the time of peeling can be increased and the base breakage at the time of peeling can be prevented, and the range of 5 ° C to 20 ° C is more preferable. .

  In the production of the cellulose ester film by the solution casting film forming method, the residual solvent amount is represented by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Here, M is the mass of the web (film) at an arbitrary time point, and N is the mass of the film when the mass M is heat-treated at 115 ° C. for 1 hour.

  In the film drying step, the web 22 peeled from the support 20 by the peeling roller 21 is further dried, and the residual solvent amount is 3% by mass or less, preferably 1% by mass or less, more preferably 0.5% by mass or less. It is preferable for obtaining a film having good dimensional stability.

  After peeling, using a tenter device 23 that grips and conveys the web 22 with clips or pins, and a drying device 24 that alternately conveys the web 22 through conveying rollers 25 arranged in the drying device, The web 22 is dried. For the liquid crystal display member, it is preferable to dry while maintaining the width by a tenter method in order to improve the dimensional stability. In particular, it is preferable to hold the width where there is a large amount of residual solvent immediately after peeling from the support 20 because the effect of improving dimensional stability is more exhibited.

  In particular, in the drying process after peeling from the support 20, the web 22 tends to shrink in the width direction due to evaporation of the solvent. Shrinkage increases with drying at higher temperatures. In order to improve the flatness of the finished film, it is preferable to dry while suppressing the shrinkage as much as possible. From this point, for example, the entire drying process or a part of the drying process as disclosed in Japanese Patent Application Laid-Open No. 62-46625 is dried while holding the width of both ends of the web 22 in the width direction with a clip. The method / tenter method is preferred.

  The means for drying the film is not particularly limited, and is generally performed with hot air, infrared rays, a heating roller, microwaves, or the like. In terms of simplicity, it is preferable to carry out with hot air. The drying temperature is preferably divided into 3 to 5 stages in the range of 40 to 150 ° C, and gradually increased, and it is more preferable to carry out in the range of 80 to 140 ° C in order to improve the dimensional stability. .

  These steps from casting to post-drying may be performed in an air atmosphere or in an inert gas atmosphere such as nitrogen gas. It goes without saying that the dry atmosphere is carried out in consideration of the explosion limit concentration of the solvent.

  After the amount of residual solvent in the film 26 after drying becomes 2% by mass or less, the cellulose ester resin film is wound into a roll by a winder 27, and the residual solvent amount is made 0.4% by mass or less. Thus, a film having good dimensional stability can be obtained.

  The winder 27 to be used may be one generally used, and can be wound by a winding method such as a constant tension method, a constant torque method, a taper tension method, a program tension control method with a constant internal stress, or the like. .

  In order to stabilize the winding property, a so-called knurling process may be performed in which unevenness is imparted to both ends in the width direction of the cellulose ester-based resin film to make the ends bulky.

  Further, in the present invention, from the viewpoint of improving the winding stability in the winding process, it is possible to obtain a cellulose ester film with high uniformity by performing winding while being supported by the guide roller 30 having elasticity. It is preferable from the viewpoint that

  In the manufacturing method of the cellulose acetate film of this invention, it is preferable that it is 50-150 m / min as setting film-forming speed | velocity V of production conditions.

  In the present invention, the thickness of the cellulose ester film according to the present invention is generally 20 to 200 μm, but the thickness and weight of the polarizing plate used in a liquid crystal display (LCD) is reduced. In view of the above-mentioned demand and the viewpoint that the effects of the present invention can be exhibited, it is preferably 35 μm or less, and more preferably in the range of 20 to 35 μm. Further, the film length per laminated roll is preferably 4000 m or more, more preferably 4500 m or more, and particularly preferably 5000 m or more.

  Next, the details of the mixing condition by the in-line method of the main dope and the matting agent-containing solution in the method for producing a cellulose acetate film of the present invention will be described. Part of the description is duplicated.

  In the present invention, in the method for producing a cellulose acetate film by the solution casting method described above, a matting agent-containing solution is added in an inline manner to the main dope prepared by the above method before the casting die 14. When the dope is prepared, the concentration of the matting agent in the dope is controlled in accordance with the rising film forming speed while the film forming speed of the production condition is reached after starting the film forming.

  Specifically, under low-speed film-forming conditions where the film-forming speed is less than 50 m / min, the matting agent content with respect to the total solid content in the dope is set to a high concentration of 0.3% by mass or more during low-speed conveyance. Slip resistance (coefficient of friction) with respect to the transport rollers of the film is ensured, and when the film forming speed is 50 m / min or more, the matting agent content with respect to the total solid content in the dope is controlled to a low concentration of less than 0.3 mass%. It is preferable to do.

  The total solid content in the dope as used in the present invention is a material constituting the film after film formation, and includes a plasticizer, ultraviolet absorption, etc. in addition to the cellulose ester film.

  Further, as a preferred embodiment, the matting agent content with respect to the total solid content in the dope when the film formation speed V reaches the set production condition is preferably 0.15% by mass or less. After reaching the film forming speed V, the matting agent-containing solution is not added to the main dope by the in-line method, that is, the matting agent concentration with respect to the total solid content in the main dope is set to 0.15% by mass or less, A method of forming a film only with main dope is a more preferable embodiment.

  In addition, as described above, the main dope and the matting agent-containing solution according to the present invention both contain the matting agent at different concentrations, and, except for the matting agent content, The same composition is preferable from the viewpoint of realizing stable film forming conditions. When both the main dope and the matting agent-containing solution according to the present invention contain matting agents at different concentrations, the concentration of the matting agent contained in the dope is A (mass%), and the matting agent-containing solution contains the matting agent. When the concentration is B (mass%), the matting agent concentration ratio (B / A) is preferably in the range of 2.0 to 10.0.

  Next, each constituent material of the cellulose ester film according to the present invention will be described.

(Cellulose ester)
Examples of the cellulose ester according to the present invention include cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, and cellulose acetate propionate.

  In the case of cellulose triacetate, cellulose triacetate having a polymerization degree of 250 to 400 and a bound acetic acid amount of 54 to 62.5% is particularly preferable, and a base strength having a bound acetic acid amount of 58 to 62.5% is strong and more preferable. As the cellulose triacetate, either cellulose triacetate synthesized from cotton linter or cellulose triacetate synthesized from wood pulp can be used alone or in combination.

  It is preferable to use a large amount of cellulose triacetate synthesized from a cotton linter that has good releasability from a belt or a drum because of high productivity efficiency. Since the ratio of cellulose triacetate synthesized from cotton linter is 60% by mass or more and the effect of releasability becomes remarkable, 60% by mass or more is preferable, more preferably 85% by mass or more, and further, it can be used alone. Most preferred.

(Matting agent)
The type of matting agent applicable to the present invention is not particularly limited and may be an inorganic compound or an organic compound, but more preferably an inorganic compound. Examples of the inorganic compound include fine particles such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, and tin oxide. In this, it is preferable that it is a compound containing a silicon atom, and especially a silicon dioxide fine particle is preferable. Examples of the silicon dioxide fine particles include AEROSIL200, 200V, 300, R972, R972V, R974, R976, R976S, R202, R812, R805, OX50, TT600, RY50, RX50, NY50, NAX50, NA50H, manufactured by Aerosil Co., Ltd. NA50Y, NX90, RY200S, RY200, RX200, R8200, RA200H, RA200HS, NA200Y, R816, R104, RY300, RX300, R106, and the like. Among these, AEROSIL 200V and R972V are preferable in terms of controlling dispersibility and particle size.

  The average particle size of the matting agent particles in the film is preferably in the range of 50 nm to 2 μm from the viewpoint of imparting slipperiness and ensuring transparency. More preferably, it is the range of 100 nm-1000 nm, More preferably, it is the range of 100 nm-500 nm. The average particle diameter in the film can be confirmed by taking a cross-sectional photograph and observing it.

  The particle size of the matting agent particles is different from the primary particle size, the particle size after being dispersed in the solvent, and the particle size in the film. Among these, the particle size of the matting agent particles in the final film affects the cracking failure during storage of the film raw material, the convex failure due to the generation of foreign matter, and haze. Therefore, it is important to control the particle size of the fine particles in the film.

  In the present invention, the average secondary particle size of the matting agent in the film is preferably in the range of 100 nm to 500 nm. More preferably, it is the range of 150 nm-400 nm, More preferably, it is the range of 200 nm-350 nm. The average secondary particle size in the film can be confirmed by taking and observing a cross-sectional photograph. When the average secondary particle size of the matting agent exceeds 500 nm, haze deterioration or the like is observed, which may cause a failure in a wound state as a foreign matter. Moreover, when smaller than 100 nm, sufficient winding-up improvement effect is not seen, and the case where the film thickness of a cellulose-ester film is the range of 20-65 micrometers becomes remarkable especially.

  The haze of a cellulose ester film can be measured according to ASTM-D1003-52, for example. The haze is preferably in the range of 0 to 0.6%, more preferably in the range of 0 to 0.4%, and still more preferably in the range of 0.1 to 0.2%.

The matting agent can be dispersed by treating a matting agent mixed solution obtained by mixing matting agent particles and a solvent with a high-pressure dispersing device. As the high-pressure dispersion device used for dispersion, use a high-pressure dispersion device that creates special conditions such as high shear and high pressure by passing a mixture of matting agent and solvent at high speed through a narrow tube. Can do. It is preferable that the maximum pressure condition inside the apparatus is 980 N / cm ² or more in a thin tube having a tube diameter of 1 to 2000 μm, for example, by processing with a high-pressure dispersion apparatus. More preferably, it is 1960 N / cm ² or more. At that time, it is preferable that the maximum reaching speed reaches 100 m / sec or more, and the heat transfer speed reaches 418 kJ / hr or more.

  Examples of the high-pressure dispersion apparatus having the above-described characteristics include an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation or a nanomizer manufactured by Nanomizer, and other high pressure dispersions such as Manton Gorin type. Examples thereof include a homogenizer manufactured by Izumi Food Machinery.

  The matting agent is a fine particle dispersion dilution in which a water-soluble solvent is dispersed in a solvent containing 25 to 100% by mass and then diluted by adding a non-water-soluble organic solvent 0.5 to 1.5 times with respect to the water-soluble solvent. It can be used as a liquid. In addition, a matting agent dispersion in which the matting agent is dispersed in a dissolving step of dissolving the cellulose ester resin in a solvent can be added to prepare a main dope containing a constant concentration of the matting agent. Furthermore, the matting agent concentration in the main dope can be set high and used as an in-line solution (mating agent-containing solution) that differs only in the matting agent concentration.

  As the water-soluble solvent, lower alcohols are mainly used. Preferred examples of lower alcohols include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like.

  Although it does not specifically limit as a water-insoluble solvent, It is preferable to use the solvent used at the time of film formation of a cellulose resin, and the solubility with respect to water is 30 mass% or less, and a methylene chloride, chloroform, methyl acetate, etc. are mentioned. It is done.

  The matting agent particles are dispersed in the solvent at a concentration of 1 to 30% by mass. Dispersing at a concentration higher than this is not preferable because the viscosity increases rapidly. The concentration of the matting agent particles in the matting agent dispersion is preferably in the range of 5 to 25% by mass, more preferably in the range of 10 to 20% by mass.

(Plasticizer)
A plasticizer may be added to the cellulose ester film according to the present invention. Although it does not specifically limit as a plasticizer which can be used in the present invention, in the phosphate ester system, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate In the phthalate ester system, diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, etc., in the glycolate system, triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl Use phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate alone or in combination It is preferred.

  If necessary, two or more plasticizers may be used in combination. In this case, the proportion of phosphate ester plasticizer used is 50% or less, which hardly causes hydrolysis of the cellulose ester film and is durable. It is preferable because of its excellent properties.

  It is more preferable that the ratio of the phosphate ester plasticizer is small, and it is particularly preferable to use only a phthalate ester or glycolate ester plasticizer.

(UV absorber)
In the cellulose ester film according to the present invention, it is preferable to use an ultraviolet absorber, and the ultraviolet absorber is excellent in the ability to absorb ultraviolet light having a wavelength of 370 nm or less and has good liquid crystal display properties from the viewpoint of preventing deterioration of the liquid crystal. In view of the above, those that absorb as little visible light as possible with a wavelength of 400 nm or more are preferably used.

  In the present invention, in particular, the transmittance at a wavelength of 370 nm is preferably 10% or less, more preferably 5% or less, and particularly preferably 2% or less.

  Examples of commonly used ultraviolet absorbers include, but are not limited to, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like.

  In this invention, it is preferable to use 1 or more types of these ultraviolet absorbers, and you may contain 2 or more types of different ultraviolet absorbers.

  The ultraviolet absorber preferably used in the present invention is a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber, or the like. An embodiment in which a benzotriazole-based ultraviolet absorber with less unnecessary coloring is added to the cellulose resin film is particularly preferable.

  As a method of adding the ultraviolet absorber into the dope, the ultraviolet absorber may be added to the dope after being dissolved in an organic solvent such as alcohol, methylene chloride, dioxolane, or directly into the dope. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and the cellulose ester resin to disperse and then added to the dope.

  In this invention, the usage-amount of a ultraviolet absorber is the mass% with respect to a cellulose-ester resin, and is the range of 0.1 mass%-2.5 mass%, Preferably, 0.5 mass%-2.0 mass% It is a range, More preferably, it is the range of 0.8 mass%-2.0 mass%. When the amount of the ultraviolet absorber used is more than 2.5% by mass, the transparency tends to deteriorate, which is not preferable.

(solvent)
Examples of the solvent for the cellulose ester according to the present invention include lower alcohols such as methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, and n-butanol, lower aliphatic hydrocarbons such as cyclohexanedioxane, and methylene chloride. Chlorides can be used. As the solvent ratio, for example, methylene chloride is preferably in the range of 70 to 95% by mass, and other solvents are preferably in the range of 5 to 30% by mass. The concentration of the cellulose ester is preferably in the range of 10 to 50% by mass.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

Example 1
[Production of Cellulose Ester Film 1: Present Invention]
(Preparation of main dope 1)
Cellulose ester (cellulose triacetate synthesized from linter cotton, number average molecular weight = 148000, mass average molecular weight = 310000, acetyl group substitution degree = 2.9)
100 parts by mass Trimethylolpropane tribenzoate 5.0 parts by mass Ethylphthalyl ethyl glycolate 5.5 parts by mass Methylene chloride 440 parts by mass Ethanol 40 parts by mass Silicon dioxide dispersion (0.166 as solid content of silicon dioxide as a matting agent) Part by mass)
2.60 mass parts Main dope 1 was prepared according to the manufacturing process flow of the cellulose-ester film of FIG. Each of the above-mentioned constituent materials was put into a melting pot 1 which is a closed container and stirred while heating to be completely dissolved. Next, the liquid feeding pump 2 fed the liquid to the first dope stationary pot 3 which was a dope stock tank pot, and temporarily stored there. Next, the main dope 1 was filtered by the primary filter 5 with the pump 4. Filtration was performed using Azumi Filter Paper No. 24. The main dope 1 after filtration was stored in the second dope stationary pot 6.

  The content of the matting agent with respect to the total solid content in the main dope 1 is 0.15% by mass.

<Preparation of silicon dioxide dispersion>
Aerosil R972V (Nippon Aerosil Co., Ltd., silicon dioxide fine particles, average particle size of primary particles 16 nm, apparent specific gravity 90 g / liter) 12 parts by weight ethanol 88 parts by weight After stirring and mixing the above silicon dioxide and ethanol with a dissolver for 30 minutes, Further, 88 parts by mass of methylene chloride was added while stirring, and the mixture was stirred and mixed with a dissolver for 30 minutes to prepare a silicon dioxide dispersion.

(Preparation of matting agent-containing solution 1)
The silicon dioxide dispersion prepared above was used as the matting agent-containing solution 1 used for in-line addition.

  In the manufacturing process flow of the cellulose ester film shown in FIG. 1, the matting agent-containing solution 1 (silicon dioxide dispersion) that has been subjected to the dispersion treatment is stocked in the matting agent-containing solution preparation kettle 9, and then the liquid feeding pump 11 is operated to perform matting. It led to the agent-containing solution circulation filter 12 and was subjected to circulation filtration to stand by.

(Production of cellulose ester film)
According to the manufacturing process flow of the cellulose ester film shown in FIG. 1, the cellulose ester film 1 was produced by the following procedure using the prepared main dope 1 and the matting agent-containing solution 1.

  An in-line mixer which is a static mixer 13 in which the main dope 1 stored in the second dope stationary pot 6 and the mat agent-containing solution 1 stored in the mat agent-containing solution preparation pot 9 are provided immediately before the casting die 14. The first dope 1 was prepared by mixing at a ratio of 593 parts by mass of the main dope: 2.60 parts by mass of the matting agent-containing solution (Toray static type in-tube mixer Hi-Mixer, SWJ). The content of the matting agent with respect to the total solid content of the first dope 1 is 0.30% by mass.

  The supply of the first dope 1 is started on the support 20 (also called a casting belt) by the casting die 14 when the transportation speed of 10 m / min is reached while gradually increasing the transportation speed of the manufacturing process. Then, a prior film was formed. The casting temperature during film formation was 35 ° C., and the width of the cast film was 1.8 m. After the solvent was evaporated on the casting belt 20 until the amount of residual solvent reached 120%, the solvent was peeled off from the casting belt 20. In the stretching step 23, the film was stretched 1.2 times in the width direction of the film while further evaporating the solvent at 120 ° C. The film thickness after winding was 40 μm.

  Next, after the previous film formation, when the conveyance speed exceeds 50 m / min, the supply of the matting agent-containing solution 1 to the in-line mixer is stopped, and the second dope (total amount of dope is added only by the main dope 1. The content of the matting agent with respect to the solid content is 0.15% by mass), and the film formation is continued. After the conveyance speed is increased to 100 m / min, the conveyance speed during production is 5000 m long. A cellulose ester film was produced, a preceding film was wound around the core, and a cellulose ester film continuously formed at 100 m / min was laminated thereon to produce a cellulose ester film 1 having a film thickness of 40 μm. . In producing the cellulose ester film 1, the guide roller in the winder portion was not used and the rolls were laminated in a roll shape.

[Production of Cellulose Ester Film 2: Present Invention]
In the production of the cellulose ester film 1, a cellulose ester film 2 was produced in the same manner except that the film thickness of the cellulose ester film was changed from 40 μm to 35 μm.

[Production of Cellulose Ester Film 3: Present Invention]
(Preparation of main dope 2)
Cellulose ester (cellulose triacetate synthesized from linter cotton, number average molecular weight = 148000, mass average molecular weight = 310000, acetyl group substitution degree = 2.9)
100 parts by mass Trimethylolpropane tribenzoate 5.0 parts by mass Ethylphthalylethyl glycolate 5.5 parts by mass Methylene chloride 440 parts by mass Ethanol 40 parts by mass Silicon dioxide dispersion (0.055 as the solid content of silicon dioxide as a matting agent) Part by mass)
0.86 parts by mass Main dope 2 was prepared according to the manufacturing process flow of the cellulose ester film shown in FIG. Each of the above-mentioned constituent materials was put into a melting pot 1 which is a closed container and stirred while heating to be completely dissolved. Next, the liquid feeding pump 2 fed the liquid to the first dope stationary pot 3 which was a dope stock tank pot, and temporarily stored there. Next, the main dope 2 was filtered by the primary filter 5 with the pump 4. Filtration was performed using Azumi Filter Paper No. 24, and the main dope 2 after filtration was stored in the second dope stationary pot 6.

  The content of the matting agent with respect to the total solid content in the main dope 2 is 0.05% by mass.

(Production of cellulose ester film)
An in-line mixer which is a static mixer 13 in which the main dope 2 stored in the second dope stationary pot 6 and the mat agent-containing solution 1 stored in the mat agent-containing solution preparation pot 9 are provided immediately before the casting die 14. (Toray static type in-pipe mixer Hi-Mixer, SWJ manufactured by Toray Industries, Inc.) The mixing ratio of the main dope 2 and the matting agent-containing solution 1 was 593 parts by mass (main dope 2): 4.34 parts by mass (mating agent) A first dope 3 was prepared as a containing solution 1). The content of the matting agent with respect to the total solid content of the first dope 3 is 0.30% by mass.

  Next, in the production of the cellulose ester film 2, instead of the first dope 1 (mat agent content 0.30% by mass), the first dope 3 (mat agent content 0.30% by mass) was used. As the dope 3 of 2, a cellulose ester film 3 having a film thickness of 35 μm was produced in the same manner except that the film was formed using only the main dope 2 prepared as described above (matte agent content: 0.05 mass%).

[Production of Cellulose Ester Film 4: Present Invention]
(Preparation of matting agent-containing solution 4)
Cellulose ester (cellulose triacetate synthesized from linter cotton, number average molecular weight = 148000, mass average molecular weight = 310000, acetyl group substitution degree = 2.9)
100 parts by mass Trimethylolpropane tribenzoate 5.0 parts by mass Ethylphthalylethyl glycolate 5.5 parts by mass Methylene chloride 440 parts by mass Ethanol 40 parts by mass Silicon dioxide dispersion (1.66 as the solid content of silicon dioxide as a matting agent) Part by mass)
26.0 parts by mass The main dope 1 described in the production process flow of the cellulose ester film in FIG. 1 contains a mat agent having the same composition as the main dope 1 except for the content of the mat agent by the same line as the preparation step. Solution 4 was prepared. The content of the matting agent with respect to the total solid content of the matting agent-containing solution 4 is 1.50% by mass.

(Production of cellulose ester film)
The main dope 1 stored in the second dope stationary pot 6 and the above-prepared matting agent-containing solution 4 are combined with an in-line mixer (Toray static tube manufactured by Toray Industries, Inc.) which is a static mixer 13 provided immediately before the casting die 14. The mixing ratio of the main dope 1 and the matting agent-containing solution 4 is 593 parts by mass (main dope 1): 59.3 parts by mass (the matting agent-containing solution 4) by the mixer Hi-Mixer, SWJ). The dope 4 was prepared. The content of the matting agent with respect to the total solid content of the first dope 4 is 0.30% by mass.

  Next, in the production of the cellulose ester film 2, instead of the first dope 1 (mat agent content 0.30% by mass), the first dope 4 (mat agent content 0.30% by mass) was used. As the dope 2, a cellulose ester film 4 having a thickness of 35 μm was produced in the same manner except that the main dope 1 prepared above (the matting agent content 0.15% by mass) was used.

[Production of Cellulose Ester Film 5: Comparative Example]
In the production of the cellulose ester film 2, only the main dope 1 (the content of the matting agent relative to the total solid content of the dope is 0.15% by mass) without in-line addition of the matting agent-containing solution 1 is used. A cellulose ester film 5 having a film thickness of 35 μm and a winding length of 5000 m was produced under the same conditions from the start of film formation (conveyance speed 10 m / min) to the final film formation (production condition conveyance speed 100 m / min).

[Production of Cellulose Ester Film 6: Comparative Example]
In producing the cellulose ester film 5, a cellulose ester film 6 was produced in the same manner except that the film thickness during film formation was changed to 40 μm.

[Production of Cellulose Ester Film 7: Comparative Example]
In the production of the cellulose ester film 6, instead of the main dope 1 (the content of the matting agent relative to the total solid content of the dope is 0.15% by mass), the following main dope 7 (of the matting agent relative to the total solid content of the dope) The cellulose ester film 7 was produced in the same manner except that the content was 0.30% by mass).

(Preparation of main dope 7)
In the preparation of the main dope 1, except that the addition amount of the silicon dioxide dispersion was changed to 5.20 parts by mass, the main dope having a matting agent content of 0.30% by mass relative to the total solid content of the dope was obtained. 7 was prepared.

[Production of Cellulose Ester Film 8: Comparative Example]
In the production of the cellulose ester film 1, the preceding film formation at a conveyance speed of 10 m / min to 50 m / min is performed on the main dope 7 (the content of the matting agent is 0.30% by mass with respect to the total solid content of the dope). Then, the dope liquid supply line is switched, the transport speed exceeds 50 m / min, and the main dope 1 (the content of the matting agent with respect to the total solid content of the dope is The cellulose ester film 8 was produced in the same manner except that 0.15% by mass) was used, and the dope was switched by the batch method.

<< Evaluation of cellulose ester film >>
[Measurement of internal haze]
In accordance with the following method, the internal haze of each cellulose ester film produced at a production speed (100 m / min) was measured.

(measuring device)
As a haze meter (turbidity meter), (model: NDH 2000, manufactured by Nippon Denshoku Co., Ltd.) was used. This haze meter uses a 5V9W halogen bulb as a light source, and uses a silicon photocell (with a relative visibility filter) as a light receiving part. In addition, the measurement was performed according to JISK-7136.

(Measurement procedure)
<Measurement of blank haze 1>
1. One drop (0.05 ml) of glycerin was dropped on a clean glass slide, taking care not to allow bubbles to enter.

  2. A cover glass was placed on the dropped glycerin. Glycerin spreads without pressing the cover glass.

  3. It set to the said haze meter and the blank haze 1 was measured.

<Measurement of haze 2 including film sample>
4). 0.05 ml of glycerin was dropped on a clean glass slide.

  5. A sample film to be measured was placed on glycerin.

  6). 0.05 ml of glycerin was dropped on the sample film.

  7). A cover glass was placed thereon.

  8). This sample was set in a haze meter, and haze 2 was measured.

  The internal haze was calculated according to the following formula.

Internal haze value = (Haze 2) − (Blank haze 1)
(Used parts)
Glass slide: MICRO SLIDE GLASS S9213MATUNAMI
Glycerin: Kanto Chemical deer special grade [Evaluation of wrinkle resistance]
In the manufacturing process of each cellulose ester film, when the conveyance speed reaches 27 m / min from the start of conveyance, the film surface quality (immediately before being wound in a roll by the winder 27 shown in FIG. 1) The presence or absence of wrinkle failure occurrence) was visually observed, and wrinkle resistance during low-speed conveyance was evaluated according to the following criteria.

○: No wrinkling is observed during transportation △: Slightly weak wrinkling is observed during transportation but does not affect the roll quality after winding ×: Strong wrinkling is observed during transportation, winding It affects the roll quality (rolling uniformity) afterwards [Evaluation of suitability for drawing process]
In the manufacturing process of each cellulose ester film, when the conveyance speed reaches 27 m / min from the start of conveyance, the film is observed visually at the end of the tenter device 23 shown in FIG. The suitability of the stretching process (clipping stability) during low-speed conveyance was evaluated according to the following criteria.

○: No occurrence of clipping mistakes at all △: Slight clipping mistakes are observed during transport, but not at a level that affects transportability ×: Clipping mistakes occur during transport, stable stretching and transport [Evaluation of fracture resistance]
For each cellulose ester film, 100 laminate rolls each having a volume of 5000 m were prepared, and the number of times the film was broken was counted from the start of conveyance until the conveyance speed of 100 m / min, which is the production conveyance condition, was counted. Occurrence frequency (%) (number of occurrence of broken rolls per 100 rolls) was determined.

[Evaluation of productivity]
The time required for film production from the start of conveyance of the cellulose ester film 1 to 1000 m was taken as 100, the respective relative production times were determined, and productivity was evaluated according to the following criteria.

表１に記載の結果より明らかなように、本発明で規定する条件で製造したセルロースエステルフィルムは、製膜開始から生産時の搬送速度に到達するまでの低速搬送領域で、搬送不良（搬送シワやクリッピングミス）の発生が無く、安定に搬送でき、透明性及びコントラスト特性に優れたセルロースエステルフィルムを高い生産性で得ることができる。 ○: Relative production time is 90 to 100 Δ: Relative production time is 101 to 120 ×: Relative production time is 121 or more Table 1 shows the results obtained as described above.

As is clear from the results shown in Table 1, the cellulose ester film produced under the conditions specified in the present invention has a conveyance failure (conveyance wrinkle) in the low-speed conveyance region from the start of film formation to the conveyance speed during production. In addition, a cellulose ester film that can be stably conveyed and has excellent transparency and contrast characteristics can be obtained with high productivity.

Example 2
<< Production of cellulose ester film >>
[Production of Cellulose Ester Film 2B]
In the production of the cellulose ester film 2 described in Example 1, in the winder part, the cellulose ester film 2B is formed in the same manner except that a wind-up part is provided with a guide roller 30 having elasticity as shown in FIG. Produced.

[Production of Cellulose Ester Film 3B]
In the production of the cellulose ester film 3 described in Example 1, in the winder part, the guide roller 30 having elasticity as shown in FIG. Produced.

<< Evaluation of cellulose ester film >>
Regarding the cellulose ester films 2B and 3B produced above and the cellulose ester films 2 and 3 produced in Example 1, the winding quality characteristics were evaluated according to the following method.

[Evaluation of winding quality]
In the manufacturing process shown in FIG. 1 for each of the above cellulose ester films, the winding quality of the sample laminated and wound up by the winding 27 (wound wrinkles, occurrence of winding deviation, horse spine failure due to loose winding) The polygonal deformation failure) was visually observed, and the winding quality was evaluated according to the following criteria.

表２に記載の結果より明らかなように、本発明のセルロースエステルフィルムの製造方法で長尺の積層ロールを作製する際、ワインダー部でガイドローラを用いて積層することにより、巻き取り品質がより一層向上することが分かる。 A: No winding wrinkles or misalignment in the laminated roll, no horse back failure due to loose winding, or any polygonal deformation failure. O: Almost no wrinkles or misalignment in the laminated roll. Occurrence of horseback failure or polygonal deformation failure due to loose winding is not observed. △: Very weak winding wrinkles or winding misalignment on the laminated rolls, horseback failure or polygonal deformation failure due to loose winding Is observed, but there is no problem in practical use. ×: Rolling rolls, wrinkles, misalignment, horse back failure or polygonal deformation failure due to loose winding are observed. Table 2 shows the results of the above-mentioned quality of concern.

As is clear from the results shown in Table 2, when a long laminated roll is produced by the method for producing a cellulose ester film of the present invention, the winding quality is further improved by laminating using a guide roller in the winder part. It turns out that it improves further.

1 Melting pot (pressurized container)
2, 4, 7, 11 Liquid feed pump 3 First dope static pot 5 Primary filter 6 Second dope static pot 8 Secondary filter 9 Matting agent-containing solution preparation pot 10 Matting agent-containing solution liquid feeding filter 12 Matting agent-containing solution circulation filter 13 Static mixer 14 Casting die 20 Support 21 Peeling roller 22 Web 23 Tenter device 24 Drying device 25 Transport roller 26 Film after drying 27 Winder 30 Guide roller

Claims (8)

  In the cellulose ester film production method for producing a cellulose ester film by a solution casting film formation method, a dope is prepared by adding a matting agent-containing solution in an in-line manner to the main dope, and according to the film formation speed after the start of film formation A method for producing a cellulose ester film, wherein the matting agent concentration in the dope is controlled on-line.   When the film forming speed is less than 50 m / min, the matting agent content with respect to the total solid content in the dope is 0.3% by mass or more, and when the film forming speed is 50 m / min or more, the total solid content in the dope. The method for producing a cellulose ester film according to claim 1, wherein the content of the matting agent is controlled to less than 0.3% by mass.   The production of a cellulose ester film according to claim 1 or 2, wherein the content of the matting agent with respect to the total solid content in the dope when the film forming speed of the production conditions is reached is 0.15% by mass or less. Method.   When the concentration of the matting agent contained in the main dope is A (mass%) and the concentration of the matting agent contained in the matting agent-containing solution is B (mass%), the mating agent concentration ratio (B / A) The value of is in the range of 2.0 to 80.0. The method for producing a cellulose ester film according to any one of claims 1 to 3.   The cellulose ester film according to any one of claims 1 to 4, wherein the matting agent solution is not added to the main dope by the in-line method after reaching the film forming speed of production conditions. Production method.   The method for producing a cellulose ester film according to any one of claims 3 to 5, wherein a film forming speed under the production conditions is in a range of 50 to 150 m / min.   The film thickness of the said cellulose-ester film is 35 micrometers or less, The manufacturing method of the cellulose-ester film as described in any one of Claim 1 to 6 characterized by the above-mentioned.   The method for producing a cellulose ester film according to any one of claims 1 to 7, wherein the winder portion includes a guide roller.

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