KR20100047152A - Method and installation for manufacturing retardation film - Google Patents

Abstract

PURPOSE: A manufacturing method and manufacturing facility of a retardation film are provided to ensure stable optical characteristics even if there is a temperature or humidity change in the place where a film is used. CONSTITUTION: A manufacturing method of a retardation film is as follows. A strip-shaped flexible film(86) is formed by enabling dope(81) to continuously flow into a support(82). The dope contains polymer and solvent. The flexible film peels off the support as a polymer film. The polymer film is stretched in the width direction. The solvent evaporates from the polymer film. Steam contacts with the polymer film and the temperature of the polymer film remains in the range of 100~150 °C.

Description

The manufacturing method of retardation film, and its manufacturing facility {METHOD AND INSTALLATION FOR MANUFACTURING RETARDATION FILM}

This invention relates to the manufacturing method of retardation film, and its manufacturing equipment.

Polymer films (hereinafter referred to as films) have been used in various fields as optical functional films because of their particular advantages such as excellent light transmittance, flexibility, and light weight thinning. Among the films, TAC films formed of cellulose acylate, especially cellulose triacetate (hereinafter referred to as TAC) having an average degree of acetylation of 57.5% to 62.5%, are rapidly expanding in the market. It is used as optical functional films, such as a protective film for polarizing plates of a device, and retardation film.

Main methods for producing the film include a melt extrusion method and a solution film forming method. The melt extrusion method is a method in which a polymer is melted by heating as it is, and then extruded with an extruder to produce a film. This method is characterized by high productivity and relatively low equipment cost. However, it is difficult to control the thickness precision of the film, and thin stripes (dielines) are likely to occur on the film. For this reason, this manufacturing method is unsuitable for the manufacturing method of an optical functional film. On the other hand, the solution film-forming method flows the polymer solution (henceforth dope) containing a polymer and a solvent on a support body, and forms the cast film which consists of dope on a support body. Next, after the flexible film has a self-supporting property, the flexible film is peeled off from the support to form a wet film. Thereafter, the wet film is dried and wound as a film. This solution film forming method can obtain a film with less foreign matter compared to the melt extrusion method. For this reason, a solution film forming method is suitable as a manufacturing method of an optical functional film.

The method of expressing self-supportability in the casting film in the solution film-forming method is described, for example, in Unexamined-Japanese-Patent No. 2002-179819, When the casting film on a support body is dried, and the amount of residual solvent of a casting film becomes a predetermined range. The method of reducing to below (hereinafter referred to as a drying method) and the method of cooling the casting film to gelate the casting film (hereinafter referred to as cooling gelation method) are known.

As a method for adjusting the optical properties of a film, as described in JP-A-2003-90915 or JP-A-2003-62899, the film is immersed in water or the film is exposed to water vapor so that the moisture content is in a predetermined range. The method of extending | stretching the film which became old is known.

By the way, the endurance test is performed like the film used for a liquid crystal display device similarly to a liquid crystal display device. The endurance test is a test for investigating whether constant characteristics and quality can be ensured under predetermined environmental conditions. By the way, when the endurance test was performed to this film, it turned out that the phenomenon which the optical characteristic of a film fluctuates occurs. In particular, before and after an endurance test (hereinafter, referred to as a wet heat endurance test) under conditions of high temperature and high humidity (for example, a temperature of 60 ° C. or higher and 90% RH), the retardation Rth in the thickness direction is greatly varied. As a result, the phenomenon that the retardation (Rth) of the film which passed the endurance test greatly deviates from the range suitable for a liquid crystal display device was frequent.

Japanese Unexamined Patent Application Publication No. 2002-179819 discloses a method in which a film obtained by a solution film forming method is subjected to a humidification process to suppress dimensional change of a film under a high temperature and high humidity environment. This removes the distortion in a film using the phenomenon which glass transition temperature (Tg) falls because of the increase of the water content of a film. However, Unexamined-Japanese-Patent No. 2002-179819 did not describe the influence of the humidification process with respect to retardation (Re, Rth) which is an important optical characteristic in retardation film, and was unclear.

Moreover, the method of Unexamined-Japanese-Patent No. 2003-90915 and Unexamined-Japanese-Patent No. 2003-62899 relates to the manufacturing method of the film which obtains a different Nz factor in Re of (lambda) / 4 vicinity, Retardation (Re, Rth) It is not suitable for the manufacturing method of this high retardation film.

Then, this invention solves the said subject and provides the manufacturing method of retardation film which can manufacture retardation film with low fluctuation | variation of retardation (Rth) before and after an endurance test, and its manufacturing equipment.

In the method for producing a retardation film, a dope containing a polymer and a solvent is continuously flown on a running support to form a band-like flexible film (step A), and the flexible film is peeled off from the support as a polymer film. (Step B), stretching the polymer film in the width direction (step C), evaporating the solvent from the polymer film passed through the step C (step D), contacting the polymer film with water vapor, Maintaining the temperature of the polymer film in the range of 100 ° C. to 150 ° C. (step E), wherein step E of contacting the water vapor and maintaining the temperature of the polymer film is carried out in conjunction with step D. It is done.

In the manufacturing method of this retardation film, it is preferable to perform said step E for 5 second or more and 60 minutes or less. In the above step E, it is preferable that a gas containing the water vapor and a relative humidity of 20% RH or more are brought into contact with the polymer film. It is preferable that in-plane retardation (Re) of the said polymer film which passed through the said step E is 30 nm or more and 100 nm or less, and thickness direction retardation (Rth) of the said polymer film which passed through the said step E is 70 nm or more and 300 nm or less. . Preferably, the polymer is cellulose acylate.

Before the step B, one of cooling the flexible membrane until the flexible membrane becomes self supporting and evaporating the solvent from the flexible membrane until the flexible membrane becomes self supporting is preferred. . It is preferable to perform the said step E about the said polymer film whose residual solvent amount is 5 mass% or less.

The manufacturing equipment of the retardation film extends | stretches in the width direction the film formation apparatus which flows the dope containing a polymer and a solvent on the support body which runs, and forms the strip | belt-shaped flexible film, and the flexible film which peeled continuously from the said support body. Water vapor contact to keep the temperature of the polymer film within a range of 100 ° C. to 150 ° C. by bringing water vapor into contact with the stretching device and the polymer film drawn by the stretching device in order to evaporate the solvent from the polymer film. An apparatus is provided.

In the production equipment of this retardation film, the water vapor contact device makes the polymer film and the gas containing the water vapor contact, and the water vapor contact device includes a humidity controller for adjusting the relative humidity of the gas to 20% RH or higher. It is desirable to have.

A polarizing plate is equipped with a polarizer and a pair of transparent protective film arrange | positioned on both surfaces of the said polarizer, and one of the said pair of transparent protective films is a retardation film obtained by the manufacturing method of this invention.

A liquid crystal display device is provided with the light source, the VA system liquid crystal cell which can transition between the state which transmits the light from the said light source, and the state which blocks the transmission of the said light, and the polarizing plate of this invention, The polarizing plate, The liquid crystal cell The light that passes toward or the light that has passed through the liquid crystal cell is incident.

In this liquid crystal display device, the polarizing plate is preferably formed such that the phase difference film is positioned between the light source and the liquid crystal cell.

In this invention, a solvent evaporation process and a water vapor contact process are performed. The solvent evaporation step is a step of evaporating the solvent from the stretched polymer film, and the water vapor contact step is a step of keeping the temperature of the polymer film within a range of 100 ° C to 150 ° C by bringing water vapor into contact with the polymer film. According to this invention, since these both processes are performed together, it becomes possible to manufacture the film with a small amount of fluctuation | variation in the optical characteristic and dimension before and after an endurance test. Therefore, according to this invention, the retardation film which exhibits stable optical characteristics can be provided, without being influenced by the big change of the temperature and humidity of a use environment.

The above objects and advantages will be readily understood by those skilled in the art by reading the detailed description of the preferred embodiments with reference to the accompanying drawings.

(Offline drawing facility)

The offline stretching facility 2 shown in FIG. 1 extends the TAC film 3. This offline stretching equipment 2 includes a supply part 4 for supplying the TAC film 3, a tenter part 5 for stretching the TAC film 3 conveyed from the supply part 4, and a stretched TAC. The wet gas contact casing 6 for contacting the wet gas to the film 3, the cooling part 7 for cooling the TAC film 3 conveyed from the wet gas contact casing 6, and the TAC film 3. It is provided with the winding-up part 8 wound up to a core and making a film roll. In the supply part 4, the film roll 9 in which the strip | belt-shaped TAC film 3 is wound around the core 4a is formed. In addition, the strip | belt-shaped TAC film 3 is manufactured by the solution film forming installation mentioned later. The supply roller 4b formed in the supply part 4 takes out the strip | belt-shaped TAC film 3 from the film roll 9, and supplies it to the tenter part 5.

(Tenter part)

As shown in FIG. 2, the tenter part 5 conveys the strip | belt-shaped TAC film 3 to a film longitudinal direction (henceforth X direction), and it extends | stretches to a film width direction (henceforth Y direction). The stretching treatment is performed. The tenter portion 5 is a pair of endless chains (hereinafter referred to as first and second chains) guided by the first rail 11, the second rail 12, and these rails 11 and 12. : 13 and 14). A conveyance path of the TAC film 3 is formed between the first rail 11 and the second rail 12. By the air conditioner which is not shown in figure, the atmospheric conditions inside the tenter part 5 are maintained so that it may become constant within a predetermined range. In addition, as needed, you may divide the conveyance path of the TAC film 3 in the X direction, and change the heating conditions of the TAC film 3 for every zone. For example, a preheating zone for preheating the TAC film 3, a heating zone for heating the TAC film 3 to a stretchable degree, and a stretching zone for stretching the TAC film 3, in order in the X direction. In addition to each of these zones, a heat relaxation zone for stopping the stretching of the TAC film 3 and heating the TAC film 3 so as to relieve strain remaining in the TAC film 3 is less than the stretching zone. You may provide in the X direction downstream.

The film holding position PA is formed in the upstream of the conveyance path of the TAC film 3, and the holding release position PB is formed in the downstream of the conveyance path of the TAC film 3. As shown in FIG. The rails 11 and 12 are arranged so that the width Wb of the TAC film 3 at the grip release position PB becomes larger than the width Wa of the TAC film 3 at the film grip position PA. . The endless first and second chains 13 and 14 circulate along the rails 11 and 12. A plurality of clips 15 are provided in the first and second chains 13 and 14 at regular intervals. In this way, when the clip 15 moves along each rail 11 and 12, holding the side edge part of the Y direction of the TAC film 3, the TAC film 3 will extend | stretch in a Y direction.

The first and second chains 13 and 14 are hung over the prime sprockets 21 and 22 and the driven sprockets 23 and 24. Between these sprockets 21-24, the 1st chain 13 is guided by the 1st rail 11, and the 2nd chain 14 is guided by the 2nd rail 12. As shown in FIG. The prime sprockets 21 and 22 are formed on the tenter outlet 27 side, and they are rotationally driven by a drive mechanism (not shown), and the driven sprockets 23 and 24 are formed on the tenter inlet 26 side.

As shown in FIG. 1, the edge cutting device 30 is formed between the tenter portion 5 and the wet gas contact casing 6. The edge cutting device 30 separates the side edge portion of the TAC film 3 in the Y direction (see FIG. 2) as the slit edge residue. A cut blower 31 connected to the edge cutting device 30 cuts the edge remainder finely. A blower not shown in the drawing sends the cut edge residue to a crusher 32, which crushes the edge residue to chips. Since this chip is reused for dope preparation, this method is effective in terms of cost.

The winding core 8 is formed with a winding core 36 and a press roller 37. The TAC film 3 transferred to the winding-up part 8 is wound around the winding core 36 while being pressed by the press roller 37.

(Wet gas contact chamber)

The wet gas contact casing 6 has a wet gas contact chamber 6a and an inlet 6b and an outlet 6c that open in the wet gas contact chamber 6a. A plurality of rollers 41 are arranged in a zigzag shape in the wet gas contact chamber 6a. The roller 41 guides the TAC film 3 introduced into the wet gas contact chamber 6a through the inlet 6b to the cooling unit 7 through the outlet 6c. The wet gas contact casing 6 and the wet gas supply facility 45 are connected by a transfer duct 42 and a return duct 43 formed between the wet gas contact casing 6 and the wet gas supply facility 45. . The wet gas supply facility 45 collects the gas inside the wet gas contact chamber 6a as the recovery gas 300 via the return duct 43, and makes the wet gas 400 adjusted to predetermined conditions. The wet gas supply facility 45 supplies the wet gas 400 to the wet gas contact chamber 6a via the transfer duct 42.

(Wet gas supply equipment)

As shown in FIG. 3, the wet gas supply facility 45 includes a boiler 51 for heating soft water 410 to produce steam 411, a blower 52 for blowing air 420, and To mix the heat exchanger 53 for heating the air 420 conveyed by the blower 52 with the air 420 and the water vapor 411 passing through the heat exchanger 53 to form a wet gas 400. Recovered from the apparatus 54, the heating apparatus 55 which heats the wet gas 400, and sends it to the wet gas contact chamber 6a (see FIG. 1), and the wet gas contact chamber 6a (see FIG. 1). It has the condensation apparatus 61 which condenses the recovery gas 300 and produces the heating gas 310 and the condensate 320.

In addition, the piping connecting the boiler 51 and the mixing device 54 includes a pressure reducing valve 65 for reducing the pressure of the steam 411 to a predetermined value and a flow rate regulating valve for adjusting the flow rate of the steam 411. 66) is formed. Moreover, the control apparatus 70 connects the flow regulating valve 66 and the heating apparatus 55. The controller 70 controls the flow rate and temperature of the wet gas 400.

The cooling device 71 is connected to the condensation device 61. The cooling device 71 transfers the cold water 330 to the condensation device 61. The cold water 330 transferred to the condensation device 61 is used for condensation of the recovery gas 300. By condensation of the recovery gas 300, the cold water 330 becomes hot water 331. The cooling device 71 performs a cooling process on the collected hot water 331, and again transfers it to the condensation device 61 as the cold water 330.

Part of the gas not condensed by the condenser 61 (hereinafter referred to as heating gas: 310) is transferred to the heat exchanger 53 by the blower 72, whereby heat is reused. In addition, the excess heating gas 310 is discarded.

The condensate 320, which is condensed water, a solvent, or a mixture thereof, is transferred to the storage tank 73. In the storage tank 73, a concentration sensor for detecting the concentration of the solvent is formed. The condensate 320 is disposed of through a predetermined treatment.

Next, the operation of the present invention in the offline stretching facility 2 will be described. As shown in FIG. 1, the supply roller 4b supplies the TAC film 3 to the tenter portion 5 from the supply chamber 4.

By the air conditioner which is not shown in figure, atmospheric temperature, humidity, a solvent dew point, etc. in the tenter part 5 are adjusted. The solvent dew point refers to a temperature at which the solvent gas reaches a saturation state and the solvent gas starts to liquefy when the temperature of the atmosphere containing the gaseous solvent (solvent gas, solvent vapor) is lowered. Thereby, the temperature of the TAC film 3 which passes through the tenter part 5 can be adjusted in a desired range. The drive mechanism not shown rotates the sprockets 21-24, and the 1st, 2nd chains 13 and 14 drive continuously along the 1st, 2nd rails 11 and 12. As shown in FIG. The clips 15 provided on the first and second chains 13 and 14 hold both side edges in the direction Y of the TAC film 3 at the film holding position PA, and the clips 15 are fixed at the holding release position PB. Release the grip on the side edges. In this way, in the tenter part 5, the extending | stretching process to the direction Y is performed to the TAC film 3 from the film holding position PA to the holding | gripping release position PB. It is preferable that elongation (ER) {= (Wb-Wa) / Wa} of the TAC film 3 in the tenter part 5 is 0.5% or more and 200% or less, and it is more preferable that they are 10% or more and 80% or less. . In the TAC film 3 conveyed from the tenter part 5, both side edges are cut off by the edge cutting device 30, and are conveyed to the wet gas contact chamber 6a.

As shown in FIG. 1, the wet gas supply facility 45 adjusts the temperature Ta of the wet gas 400, the humidity Hu1, the solvent dew point TR, and the like to contact the wet gas 400 with the wet gas. Transfer to thread 6a. Thereby, the wet gas 400 adjusted to predetermined conditions is filled in the wet gas contact chamber 6a. The some roller 41 conveys the TAC film 3 conveyed from the edge cutting device 30, winding it on a roller, and guides it to the cooling part 7. As shown in FIG. In this way, in the wet gas contact chamber 6a, the wet gas 400 of desired conditions contacts the TAC film 3, and the water vapor contact process which makes water vapor contact the TAC film 3 is performed.

The TAC film 3 subjected to the steam contact treatment is transferred to the cooling unit 7. The TAC film 3 is cooled to approximately room temperature in the cooling section 7. The cooled TAC film 3 is transferred to the winding-up section 8 and wound around the winding core 36 while being pressed by the press roller 37.

The present invention performs a water vapor contact treatment on the TAC film 3. When the water vapor contact treatment is performed, the TAC film 3 is heated while absorbing water molecules, and as a result, the glass transition temperature Tg of the polymer contained in the TAC film 3 is lowered and the TAC film 3 The diffusion of water molecules in () is promoted. By promoting the diffusion of water molecules in the TAC film 3, the higher order structure of the polymer molecules tends to transition to a more stable structure. As a result, the structure stabilization of a polymer molecule can be performed in a short time compared with the process of simply heating the TAC film 3.

Therefore, according to the present invention, the variation (ΔRth _WET) of a thickness direction retardation (Rth) in the before and after the moist heat durability tests can be manufactured in small TAC film 3.

It is preferable that the minimum of the temperature Tf1 of the TAC film 3 in a water vapor contact process is 100 degreeC or more, It is more preferable that it is 101 degreeC or more, It is especially preferable that it is 102 degreeC or more. In addition, the upper limit of temperature Tf1 should just be below the glass transition temperature of a polymer. For example, it is preferable that the upper limit of temperature Tf1 is 150 degrees C or less, It is more preferable that it is 140 degrees C or less, It is especially preferable that it is 120 degrees C or less. If temperature Tf1 is less than 100 degreeC, since the time of the water vapor contact process required to suppress the optical characteristic change amount before and behind a wet heat endurance test becomes long, it is unpreferable. When temperature Tf1 exceeds 150 degreeC, since the curl of the TAC film 3 becomes remarkable, it is unpreferable. Therefore, what is necessary is just to adjust the temperature Ta of the wet gas 400 suitably so that temperature Tf1 may become the said range. For example, the temperature Ta of the wet gas 400 is preferably 70 ° C. or higher and 200 ° C. or lower, more preferably 90 ° C. or higher and 160 ° C. or lower, and most preferably 95 ° C. or higher and 140 ° C. or lower.

In order to increase the inhibitory effect of ΔRth _WET, humidity (Hu1) of the wet gas 400 it may be a high-side. It is preferable that the humidity Hu1 of the wet gas 400 is 20% RH or more and 100% RH or less, It is more preferable that they are 40% RH or more and 100% RH or less, It is especially preferable that they are 70% RH or more and 100% RH or less. When humidity Hu1 is 20% RH or more, (DELTA) Rth _WET can be suppressed reliably.

In addition, the range of the processing time P1 of a steam contact treatment is not specifically limited. However, as long as it is within the range where the effect of the present invention is exhibited, the processing time P1 of the steam contact treatment is preferably as short as possible. As an upper limit of processing time P1, it is preferable that it is 60 minutes or less, for example, and it is more preferable that it is 10 minutes or less. On the other hand, as a minimum of processing time P1, it is preferable that it is 5 second or more, for example, it is more preferable that it is 10 second or more, and it is especially preferable that it is 30 second or more.

As water for producing the steam 411, hard water, pure water, or the like can be used in addition to the soft water 410 shown in FIG. 3. It is preferable to use soft water 410 from the viewpoint of protecting the boiler 51. If foreign matters are mixed into the TAC film 3, it causes deterioration of optical characteristics and mechanical properties of the TAC film 3 as a product. Therefore, it is preferable to use water with as little foreign matter as possible. Therefore, in order to prevent the incorporation of foreign substances into the TAC film 3, soft water 410 or pure water is preferably used, and more preferably pure water is used.

In the present specification, the pure egg has an electrical resistivity of at least 1 MΩ or more, particularly, the concentration of metal ions such as sodium, potassium, magnesium, and calcium is less than 1 ppm, and anions such as chlorine and nitric acid are less than 0.1 ppm. Indicates concentration. Pure water can be easily obtained by at least one of a reverse osmosis membrane, an ion exchange resin, distillation, and the like.

Instead of the soft water 410 for producing the steam 411, an organic compound may be used, or a mixture of water and an organic compound may be used. Methanol, acetone, methyl ethyl ketone, etc. are mentioned as an organic compound.

Although the TAC film 3 was passed through the wet gas contact chamber 6a in which the wet gas 400 is filled in the above embodiment, the present invention is not limited to this, and the wet gas ( 400 may be shot on the TAC film 3.

In the said embodiment, although the water vapor contact process was performed in the wet gas contact chamber 6a, this invention is not limited to this, The TAC film between the tenter part 5 and the winding part 8 ( You may perform a water vapor contact process to 3). When steam contact processing is performed in the tenter part 5, you may perform simultaneously with an extending | stretching process, or you may perform steam contact processing as the heat relaxation process after an extending | stretching process.

Although the water vapor contact process of the said embodiment made water vapor contact the TAC film 3 conveyed, this invention is not limited to this. For example, as shown in FIG. 4, water vapor may be brought into contact with the TAC film 3 fixed to the pair of frames 77. The pair of frames 77 is fixed by a fixture (not shown) in a state where the TAC film 3 is sandwiched from both sides. In addition, in FIG. 4, TAC is used using a pair of frames 77 which have the 1st frame part 77a formed in the Y direction of the TAC film 3, and the 2nd frame part 77b formed in the X direction. The film 3 is fixed. However, the present invention is not limited to this. For example, you may fix the TAC film 3 using a pair of frames which have a frame part formed so that it may cross | intersect either one of the Y direction and the X direction of the TAC film 3. In addition, you may fix the TAC film 3 using a pair of frames which have only one of the 1st frame part 77a and the 2nd frame part 77b.

It is preferable that the TAC film 3 subjected to the water vapor contact treatment is sufficiently dried, that is, almost no solvent remains, and the fluidity of the polymer molecules is almost lost. For example, it is preferable that the amount of residual solvent on a dry basis is 5 mass% or less, It is more preferable that it is 2 mass% or less, It is especially preferable that it is 0.3 mass% or less. Here, the residual solvent amount based on a dry amount shows the amount of solvent remaining in the wet film or TAC film 3. The residual solvent amount is {(x-y) / y} × 100 when the sample film is taken from the target film, and the weight of the sample film at the time of collection is x and the weight after drying the sample film is y. Is displayed.

It is preferable that the width | variety of the TAC film 3 is 600 mm or more, It is more preferable that it is 1400 mm or more and 2500 mm or less, and even when larger than 2500 mm, the effect of this invention is expressed. Moreover, it is preferable that the thickness of the TAC film 3 is 20 micrometers or more and 200 micrometers or less, and it is more preferable that they are 40 micrometers or more and 100 micrometers or less.

It is preferable to use the thing manufactured by the solution film forming method for the TAC film 3, and it is especially preferable to use the thing manufactured by the cooling gelation system. Hereinafter, the outline | summary of a cooling gelation system is demonstrated. In addition, the same code | symbol is attached | subjected to the member etc. which are the same as the said embodiment, and the detailed description is abbreviate | omitted.

The solution film-forming installation 80 of FIG. 5 implements the solution film-forming method of a cooling gelation system. The temperature of the flexible dope 81 containing a polymer and a solvent is hold | maintained so that it may become substantially constant within the range of 30 degreeC or more and 40 degrees C or less. Under the control of a controller (not shown), the flexible drum 82 rotates about the axis 82a. By this rotation, the circumferential surface 82b travels in the travel direction Z1 at a predetermined speed (50 m / min or more and 200 m / min or less). In addition, by the heat transfer medium circulation device 83, the temperature of the circumferential surface 82b is kept substantially constant within the range of -10 ° C or more and 10 ° C or less.

The casting die 84 continuously discharges the casting dope 81 to the circumferential surface 82b. The discharged cast dope 81 spreads while flowing on the circumferential surface 82b, and forms the cast film 86 on the circumferential surface 82b. The discharged cast dope 81 forms beads between the cast die 84 and the circumferential surface 82b. The pressure reduction chamber 85 reduces the upstream side in the direction Z1 of the beads, and stabilizes the beads. The flexible film 86 is formed on the circumferential surface 82b. Gelling advances by casting on the peripheral surface 82b of the cast film 86. As a result of gelation, self-supporting property is expressed in the cast film 86. In this specification, gelation means that the solvent contained in the casting dope 81 loses fluidity in the state maintained in the molecular chain of a polymer, and as a result, the fluidity of the casting dope 81 is lost. After the flexible film 86 has self-supportability, it is peeled off from the circumferential surface 82b while being supported by the stripping roller 89 as the wet film 88. It is preferable that the residual solvent amount of the cast film 86 at the time of peeling is 250 mass% or more and 280 mass% or less.

The wet film 88 in which the gelation state was maintained is sequentially conveyed to the conveyance part 90, the pin tenter 91, and the tenter part 5. In the conveyance part 90, the pin tenter 91, and the tenter part 5, predetermined dry air is thrown into the wet film 88, and the solvent contained in the wet film 88 is evaporated. In the conveyance part 90, a plurality of conveyance rollers 90a are arranged in the X direction. It is preferable that the draw tension (= V2 / V1) in the conveyance part 90 shall be 1.00 or more and 1.05 or less. Here, V1 is the circumferential speed of the 1st conveyance roller 90a, and V2 is the circumferential speed of the 2nd conveyance roller 90a formed downstream of the 1st conveyance roller 90a.

Moreover, in the pin tenter 91 and the tenter part 5, the extending | stretching process of extending | stretching the wet film 88 to a predetermined direction is performed, performing the evaporation of the solvent from the wet film 88. FIG. Moreover, in the pin tenter 91, you may only evaporate a solvent from the wet film 88, without extending | stretching the wet film 88. FIG. It is preferable that the residual solvent amount of the wet film 88 introduced into the pin tenter 91 is 200 mass% or more and 250 mass% or less. It is preferable that the residual solvent amount of the wet film 88 introduced into the tenter part 5 is 30 mass% or more and 200 mass% or less.

In the drying chamber 97, predetermined dry air is thrown into the wet film 88, and the solvent contained in the wet film 88 is evaporated. It is preferable that the temperature of the wet film 88 in the drying chamber 97 is 140 degreeC or more and 180 degrees C or less.

The wet film 88 sufficiently dried in the drying chamber 97 becomes the TAC film 3, and in the cooling unit 7, cooling treatment is performed until a predetermined temperature is reached. In addition, the forced static elimination device 98 is charged so that the large voltage of the TAC film 3 is a predetermined range (for example, -3 kV to +3 kV). The knurling provision roller 99 imparts knurling to both edges of the TAC film 3 by embossing. Thereafter, the TAC film 3 is transferred to the winding-up section 8 and wound around the winding core 36 while being pressed by the press roller 37.

The solution film-forming equipment for implementing a solution film-forming method is not limited to the said solution film-forming equipment 80, The solution film-forming equipment 100 shown in FIG. 6 may be sufficient. In the solution film-forming facility 100, the wet film 88 is formed from the casting dope 81 similarly to the solution film-forming facility 80, and this wet film 88 is a conveyance part 90 and the pin tenter 91 ), While being guided to the drying chamber 97 sequentially, it is dried by a drying treatment to form a TAC film 3. And the TAC film 3 is guided to the tenter part 5 and the cooling part 7 sequentially, and is wound up by the winding-up part 8.

In the said embodiment, although the extending | stretching process was performed to the TAC film 3 manufactured by the solution film forming method in the offline stretching installation 2 (refer FIG. 1), the water vapor contact process was performed after that, but this invention does this. It is not limited to. In the case where the TAC film 3 wound around the core has already been subjected to the stretching treatment in the solution film forming method, steam contact treatment may be performed as it is without performing the stretching treatment on the TAC film 3 taken out from the core. . In this case, the tenter part 5 in the offline stretching installation 2 may be omitted.

In the said embodiment, after winding the TAC film 3 manufactured by the solution film-forming facilities 80 and 100, the water vapor contact process was performed to the TAC film 3 in the offline stretching installation 2 (refer FIG. 1). The present invention is not limited to this. For example, instead of performing the steam contact treatment with the off-line stretching equipment 2, the steam contact treatment may be performed with the solution film forming equipment 80, 100 (see FIGS. 5 and 6). In the case where the water vapor contact treatment is performed in the solution film forming equipment 80, 100 (see FIGS. 5 and 6), the water vapor contact treatment is applied to the TAC film 3 between the tenter portion 5 and the winding portion 8. You may carry out. In the case where the water vapor contact treatment is performed in the tenter portion 5, the water vapor contact treatment may be performed simultaneously with the stretching treatment or after the stretching treatment starts, or simultaneously with the heat relaxation treatment performed after the stretching treatment, or the thermal relaxation treatment. You may perform a steam contact process after the start of the process.

As an example in the case of performing a steam contact treatment with the solution film forming facility 80, the solution film forming facility 102 is shown in FIG. 7. In the solution film forming facility 102, a wet gas contact casing 6 is formed between the edge cutting device 30 and the drying chamber 97. As an example in the case of performing a steam contact treatment with the solution film forming facility 100, the solution film forming facility 104 is shown in FIG. 8. In the solution film forming facility 104, a wet gas contact casing 6 is formed between the edge cutting device 30 and the cooling unit 7. Thereby, in the wet gas contact casing 6, the solvent evaporation process which evaporates a solvent from the wet film 88 with water vapor contact treatment can be performed.

When water vapor contacts the wet film 88, water molecules are absorbed by the wet film 88. By absorption of water molecules, solvent molecules in the wet film 88 are easily diffused. For this reason, a solvent molecule becomes easy to reach the surface vicinity of the wet film 88. As a result, solvent molecules remaining in the wet film 88 are easily released to the outside. Therefore, by performing the solvent evaporation treatment together with the water vapor contact treatment, the total of the time taken for the evaporation of the solvent from the wet film 88 and the time taken for the evaporation of the solvent from the TAC film 3 can be shortened. Moreover, the temperature of the solvent evaporation process gas can be made lower than before from the effect of promoting the diffusion of solvent molecules. By lowering the temperature of the solvent evaporation treatment gas, it is possible to reduce the energy of the solution film and reduce the risk of harmful effects caused by the thermal history of the manufacturing process such as pyrolysis of the polymer.

In addition, the diffusion promoting effect of the solvent molecules is more remarkably exhibited in the case of the wet film 88 in a decreasing drying rate. Here, the reduced rate dry state refers to a state in which a process in which the solvent molecules existing in the wet film 88 and the like is diffused to the vicinity of the surface of the wet film 88 and then released to the outside is mainly used. The constant drying rate is an initial stage of the solvent evaporation treatment, and refers to a state in which a process in which solvent molecules, etc., present in the vicinity of the surface are released to the outside as it is mainly. Moreover, you may make the state whose residual solvent amount is 10 mass% or less as the reduction rate dry state C1.

In the said embodiment, although the flexible drum 82 was used as a support body in the solution film-forming installation 80, 100, 102, 104, this invention is not limited to this, You may use the endless band which travels. In addition, the self supporting property may be expressed in the casting film 86 by bringing dry air into contact with the casting film 86 to evaporate the solvent from the casting film 86.

(Heat treatment process)

It is preferable to apply a heat treatment process in which dry air is applied to the TAC film 3 which has undergone the water vapor contact treatment of the above embodiment, so that the temperature of the TAC film 3 is within a predetermined range. It is preferable to perform a water vapor contact process and a heat processing process sequentially continuously. By this heat treatment step, the TAC film 3 having a small amount of variation in each retardation, a change in dimension in the X direction, and a change in dimension in the Y direction as well as before and after the wet heat endurance test can be produced. . Here, a dry heat endurance test is an endurance test performed on the conditions of high temperature low humidity (for example, temperature 80 degreeC or more and humidity 5% RH or less).

It is preferable that it is 70 degreeC or more, and, as for the minimum of the temperature Tf2 of the TAC film 3 in a heat processing process, it is more preferable that it is 80 degreeC or more. Moreover, it is preferable that it is 160 degrees C or less, and, as for the upper limit of temperature Tf2, it is more preferable that it is 120 degrees C or less. Therefore, it is preferable to make the temperature of the drying gas 402 into the range equivalent to temperature Tf2. When temperature Tf2 is 70 degreeC or more and 160 degrees C or less, since the fluctuation amount of each retardation, the amount of dimensional change in the X direction, and the amount of dimensional change in the Y direction before and after a wet heat endurance test and a dry heat endurance test can be suppressed reliably, it is preferable. Do. In addition, it is preferable that temperature Tf2 is higher than temperature Tf1. It is preferable that the temperature Tf2 of the TAC film 3 in heat processing is kept constant. Moreover, it is good also as a wet film 88, without making into the TAC film 3 the object to heat-process.

It is preferable that it is 20% RH or less, and, as for the humidity (Hu2) of dry air, it is more preferable that it is 10% RH or less. When humidity (Hu2) exceeds 20% RH, since the water content of a film increases and the TAC film 3 deforms with time, such as a wound state of a film roll, it is unpreferable.

Moreover, it is preferable that it is 5 minutes or less, and, as for the upper limit of the processing time P2 of a heat processing process, it is more preferable that it is 4 minutes or less. On the other hand, it is preferable that the minimum of processing time P2 is 1 minute or more. When the processing time (P2) is 1 minute or more and 5 minutes or less, the amount of change in each retardation, the amount of change in the X direction, and the amount of change in the Y direction before and after the wet heat endurance test and the dry heat endurance test can be suppressed reliably. It is preferable because of that.

Heat treatment is performed in the heat treatment chamber 110a of the heat treatment casing 110 shown in FIG. 9. A plurality of rollers 41 are arranged in a zigzag shape in the heat treatment chamber 110a. The heat treatment casing 110 and the dry gas supply facility 111 are connected by the ducts 112 and 113. The dry gas supply facility 111 has the same structure as the wet gas supply facility 45. The dry gas supply facility 111 recovers a part of the dry gas 402 in the heat treatment chamber 110a via the duct 113 to form a new dry gas 402 having a predetermined temperature, and thus the duct 112. The new dry gas 402 is supplied to the heat treatment chamber 110a via the filter. Thereby, the drying gas 402 is filled in the heat processing chamber 110a. Moreover, you may convey, aligning the roller 41 to a X direction similarly to the conveyance part 90 (refer FIG. 5), and supporting the TAC film 3. It is preferable to form the heat processing casing 110 downstream of the wet gas contact casing 6, and it is preferable that the heat processing chamber 110a adjoins the wet gas contact chamber 6a.

(Condensation prevention processing)

In order to suppress condensation in the TAC film 3 of the water vapor contact treatment, a low dew point dry gas is applied to the TAC film 3 before the water vapor contact treatment is performed to determine the temperature of the TAC film 3 of the above embodiment. It is preferable to perform the dew condensation prevention process made into the range. It is preferable to perform a condensation prevention process and a water vapor contact process sequentially and continuously.

It is preferable that the temperature of the low dew point dry gas is lower than the temperature Ta of the wet gas 400. In addition, the dew point of the low dew point drying gas is preferably lower than the temperature Tf1 of the TAC film 3 in the water vapor contact treatment. If the dew point of the low dew point drying gas is equal to or higher than the temperature Tf1, condensation occurs on the TAC film 3 in the water vapor contact treatment. In addition, it is preferable to make the temperature (Tf0) range of the TAC film 3 at the time of completion of a dew condensation prevention process as temperature higher by (DELTA) T0 than the dew point of the wet gas (400). It is preferable that (DELTA) T0 is larger than 0 degreeC, and it is more preferable that it is 3 degreeC or more. When ΔT0 is 0 ° C. or lower, condensation occurs on the surface of the TAC film 3, and as a result, a surface failure of the film is caused, which is not preferable. Moreover, it is preferable that temperature Tf0 is lower than temperature Tf1, More specifically, it is preferable that Tf0 is 100 degreeC or more and 130 degrees C or less, and it is more preferable that it is 100 degreeC or more and 120 degrees C or less. It is preferable that the temperature Tf0 of the TAC film 3 in a dew condensation prevention process is kept constant. Moreover, it is good also as the wet film 88, without making into the TAC film 3 the object which performs a dew condensation prevention process.

The dew condensation prevention process is performed in the condensation prevention process chamber 120a of the condensation prevention process casing 120 shown in FIG. A plurality of rollers 41 are arranged in a zigzag shape in the condensation preventing processing chamber 120a. The condensation prevention processing casing 120 and the low dew point dry gas supply facility 121 are connected by the duct 122 and 123. The low dew point dry gas supply facility 121 has the same structure as the wet gas supply facility 45. This low dew point dry gas supply facility 121 collects a part of the low dew point dry gas 404 in the condensation prevention processing chamber 120a via the duct 123, and a new low dew point dry gas 404 having a predetermined temperature. The new low dew point dry gas 404 is supplied to the condensation prevention processing chamber 120a via the duct 122. Thereby, the low dew point drying gas 404 is filled in the condensation prevention process chamber 120a. Moreover, you may convey, aligning the roller 41 to a X direction similarly to the conveyance part 90 (refer FIG. 5), and supporting the TAC film 3. It is preferable to form the condensation prevention process casing 120 on the upstream side of the wet gas contact casing 6, and it is preferable that the condensation prevention process chamber 120a adjoins the wet gas contact chamber 6a.

In the present invention, when the dope is cast, a simultaneous lamination shared lead in which two or more types of dopes are covalently bonded and laminated at the same time, or a sequential lamination shared lead in which a plurality of dopes are successively shared and laminated can be performed. . Moreover, you may combine both covalent lead. When performing simultaneous lamination sharing, a flexible die equipped with a feed block may be used, or a multi-pocket flexible die may be used. However, it is preferable that at least one of the thickness of an air surface side layer and the thickness of a support body side layer is 0.5 to 30% of the thickness of the whole film of the film which consists of multilayers by covalent edge. In addition, in the case of performing simultaneous lamination sharing, it is preferable that the high-viscosity dope is wrapped by the low-viscosity dope when the dope is cast from the die slit to the support, and among the flexible beads formed over the support from the die slit, It is preferable that the dope to be in contact has a larger composition ratio of alcohol than the dope inside.

In the said embodiment, although the water vapor contact process was performed using the air 420 as a component of the wet gas 400, this invention is not limited to this. For example, any one of nitrogen and a rare gas may be used instead of the air 420, or a mixed gas containing at least one of air, nitrogen, and rare gas may be used. Similarly, as dry air or low dew point dry air, any one of nitrogen and a rare gas may be used instead of air, and a mixed gas containing at least one of air, nitrogen, and rare gas may be used. Instead of the wet gas 400, the steam contact treatment may be performed using the steam 411 adjusted to a predetermined temperature.

Although the TAC film was used in the said embodiment, this invention is not limited to a TAC film. For example, this invention can be applied also to the polymer film which consists of other polymers, such as a cellulose acylate and a cyclic polyolefin, and is obtained by the solution film forming method. Moreover, this invention can be applied also to the polymer film manufactured by the melt film forming method.

(Cellulose acylate)

In this invention, only one type may be sufficient as the acyl group used for a cellulose acylate, or two or more types may be sufficient as it. When using two or more types of acyl groups, it is preferable that one is an acetyl group. It is preferable that the ratio which esterifies the hydroxyl group of a cellulose with carboxylic acid, ie, the substitution degree of an acyl group, satisfy | fills all following formula (I)-(III). In the following formulas (I) to (III), A and B represent a degree of substitution of an acyl group, A is a degree of substitution of an acetyl group, and B is a degree of substitution of an acyl group having 3 to 22 carbon atoms. to be. Moreover, it is preferable that 90 mass% or more of TAC is 0.1 mm-4 mm of particle | grains.

A＋B

3.0 (I) 2.0

A + B

3.0

A

3.0 (II) 1.0

A

3.0

B

2.0 (III) 0

B

2.0

It is more preferable that all substitution degree (A + B) of an acyl group is 2.20 or more and 2.90 or less, and it is especially preferable that they are 2.40 or more and 2.88 or less. Moreover, it is more preferable that substitution degree B of the acyl group of C3-C22 is 0.30 or more, and it is especially preferable that it is 0.5 or more.

The cellulose which is a raw material of cellulose acylate may be obtained from either a linter or a pulp.

As a C2 or more acyl group of the cellulose acylate of this invention, it may be an aliphatic group, an aryl group, and is not specifically limited. They are alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkylcarbonyl ester, etc. of cellulose, for example, and may have a group substituted further, respectively. Preferred examples thereof include propionyl, butanoyl, pentanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t- Butanoyl, cyclohexanecarbonyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl group and the like. Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are more preferable, and particularly preferably propionyl and butanoyl .

(solvent)

Examples of the solvent for preparing the dope include aromatic hydrocarbons (for example, benzene and toluene), halogenated hydrocarbons (for example, dichloromethane, chlorobenzene and the like), alcohols (for example, methanol, ethanol, n-propanol, n Butanol, diethylene glycol and the like), ketones (e.g. acetone, methyl ethyl ketone and the like), esters (e.g. methyl acetate, ethyl acetate, propyl acetate and the like) and ethers (e.g. tetrahydrofuran, Methyl cellosolve, etc.) etc. are mentioned. In addition, in this invention, a dope means the polymer solution obtained by melt | dissolving or disperse | distributing a polymer in a solvent, and a dispersion liquid.

Among these, halogenated hydrocarbons having 1 to 7 carbon atoms are preferably used, and dichloromethane is most preferably used. From the viewpoints of physical properties such as TAC solubility, peelability from the support of the flexible membrane, mechanical strength of the film, and optical properties of the film, it is preferable to mix one or several kinds of alcohols having 1 to 5 carbon atoms in addition to dichloromethane. Do. 2 mass%-25 mass% are preferable with respect to the whole solvent, and, as for content of alcohol, 5 mass%-20 mass% are more preferable. Specific examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol and the like, and methanol, ethanol, n-butanol or a mixture thereof is preferably used.

By the way, in order to minimize the influence on the environment in recent years, the examination of the solvent composition in the case of not using dichloromethane is advanced, and about this purpose, the ether of 4-12 carbon atoms and carbon atoms Ketones of 3 to 12, esters of 3 to 12 carbon atoms, and alcohols of 1 to 12 carbon atoms are preferably used. These may be mixed and used suitably. For example, the mixed solvent of methyl acetate, acetone, ethanol, n-butanol is mentioned. These ethers, ketones, esters and alcohols may have a cyclic structure. Moreover, the compound which has two or more of functional groups of ether, ketone, ester, and alcohol (namely, -O-, -CO-, -COO-, and -OH) can also be used as a solvent.

(additive)

You may add a predetermined additive to dope. As an additive used by this invention, a plasticizer, a ultraviolet absorber, etc. are mentioned. Preference is given to using polycondensation esters as plasticizers.

(Polycondensation ester)

The polycondensation ester is a mixture of dicarboxylic acid (also referred to as aromatic dicarboxylic acid) having at least one aromatic ring and at least one aliphatic dicarboxylic acid (average of carbon number is 6.0 or more and 10.0 or less). Acid) and ethylene glycol and / or aliphatic diol having an average carbon number of 2.0 or more and 2.5 or less. The calculation of the average carbon number is carried out separately for the dicarboxylic acid and the diol. In the case of dicarboxylic acid, the value computed by multiplying the composition ratio (mole fraction) of dicarboxylic acid by the constituent carbon number is made into average carbon number (for example, it consists of 50 mol% of adipic acid and 50 mol% of phthalic acid). In this case, the average carbon number is 7.0). In the case of diol, it is the same as that of dicarboxylic acid, for example, when it consists of 50 mol% of ethylene glycol and 50 mol% of 1, 2- propanediol, average carbon number will be 2.5.

It is preferable that the number average molecular weights of a polycondensation ester are 700-2000, 800-1500 are more preferable, 900-1200 are further more preferable. The number average molecular weight of the polycondensation ester of this invention can be measured and evaluated by gel permeation chromatography. In addition, in the case of the polyester polyol which is not sealed at the terminal, it can also calculate by the quantity of hydroxyl groups per weight (henceforth a hydroxyl group). The hydroxyl value may be determined by measuring the amount (mg) of potassium hydroxide required for neutralizing excess acetic acid after acetylating the polyester polyol.

Dicarboxylic acid as a mixture of aromatic dicarboxylic acid and aliphatic dicarboxylic acid is dicarboxylic acid whose average carbon number is 6.0 or more and 10.0 or less. If the average of carbon number is less than 6, the performance change of a polarizing plate will be inadequate, and after time a film passes, water permeability will fall. When the average of carbon number exceeds 10, compatibility with a cellulose ester falls and bleed-out occurs in a film forming process.

As aromatic dicarboxylic acid, phthalic acid, terephthalic acid, isophthalic acid, 1, 5- naphthalenedicarboxylic acid, 1, 4- naphthalenedicarboxylic acid, 1, 8- naphthalenedicarboxylic acid, 2, 8- naphthalenedica Lenic acid, 2, 6- naphthalenedicarboxylic acid, etc. are used preferably, A phthalic acid, a terephthalic acid is used more preferable.

When phthalic acid, terephthalic acid, or isophthalic acid is used, it is preferable that the average carbon number of mixed dicarboxylic acid is 6 or more and 7.5 or less. The average carbon number is more preferably 6.5 or more and 7 or less. In the case of naphthalenedicarboxylic acid, the average carbon number of mixed dicarboxylic acid becomes like this. Preferably it is 6.5 or more and 10 or less, More preferably, it is 6.5 or more and 9.0 or less. In addition, 1 type may be sufficient as aromatic dicarboxylic acid, and 2 or more types may be sufficient as it. When using 2 types, it is preferable to use phthalic acid and terephthalic acid.

Aliphatic dicarboxylic acids preferably used in the present invention are, for example, oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dode Candidicarboxylic acid, 1, 4- cyclohexanedicarboxylic acid, etc. are mentioned. Preferred are succinic acid and adipic acid. In addition, 1 type of aliphatic dicarboxylic acid may be sufficient and 2 or more types may be sufficient as it. When using 2 types, it is preferable to use succinic acid and adipic acid.

As a diol which forms a polycondensation ester, it is ethylene glycol and / or mixed diol of 2.0 or more and 2.5 or less of average carbon numbers. If the average carbon number of aliphatic diol is larger than 2.5, the weight loss by heating of a compound will increase, and the surface shape fault which thinks to be a cause of process contamination at the time of drying will generate | occur | produce in the film which consists of cellulose acylate. Moreover, since synthesis becomes difficult when the average carbon number of aliphatic diol is less than 2.0, it is impossible to use this. Examples of the aliphatic diols include alkyldiols and alicyclic diols. For example, ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2- n-butyl-2-ethyl-1,3propanediol (3,3-dimethylolheptane), 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1 , 3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, Diethylene glycol and the like. These are preferably used as one kind or a mixture of two or more kinds together with ethanediol.

Preferred aliphatic diols are ethanediol, 1,2-propanediol, 1,3-propanediol, and particularly preferably ethanediol.

It is preferable that the terminal structure of a polycondensation ester is a polyester polyol whose terminal becomes a diol residue, or the terminal of a polycondensation ester is an ester formation derivative of aliphatic monocarboxylic acid of 3 or less carbon atoms. It is more preferable that the terminal of the polycondensation ester is an ester forming derivative of acetic acid or propionic acid.

The terminal of the polycondensation ester may be left unsealed and remain a diol residue, or may be sealed by so-called terminals by reacting monocarboxylic acids or monoalcohols. As monocarboxylic acids used for sealing, acetic acid, propionic acid, butanoic acid, etc. are preferable, acetic acid or propionic acid is more preferable, and acetic acid is most preferable. As monoalcohols used for sealing, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, etc. are preferable, and methanol is the most preferable. If carbon number of the monocarboxylic acids used at the terminal of a polycondensation ester is three or less, the weight loss by heating of a compound will not become large, and a planar failure does not arise in a film. The terminal of the polycondensation ester is more preferably a diol moiety without encapsulation, more preferably encapsulated with acetic acid or propionic acid, and most preferably the end of the polycondensation ester is an acetyl ester moiety.

(Specific example of polycondensation ester)

In the following Table 1, the specific example of the polycondensation ester which concerns on this invention is described. In addition, in Table 1, "PA" represents a phthalic acid. Similarly, "TPA" represents terephthalic acid, "IPA" represents isophthalic acid, "AA" represents adipic acid, and "SA" represents succinic acid. "NPA" represents naphthalenedicarboxylic acid, and the number in front of "-" shows the substitution position of carboxylic acid. In addition, "PD" represents a propanediol and the number before "-" shows the substitution position of a hydroxyl group. In addition, "D residue" represents a diol residue. Similarly, "AE residue" is an acetylester residue, "PE residue" is a propionyl residue, "BE residue" is a benzoyl ester residue, "BuE residue" is a butyryl ester residue, and "EHE residue" is 2- Ethyl hexyl ester residue is shown.

The polycondensation ester is a hot melt condensation method by a polyesterification reaction or transesterification reaction of the dicarboxylic acid with diol and, if necessary, terminal monocarboxylic acid or monoalcohol by a conventional method, or It can be synthesize | combined easily by any method of the interfacial condensation method of the acid chloride of these acids, and glycols. Regarding these polyester plasticizers, there is a detailed description in Murai Koichi horseshoe "Theory and Application of Plasticizers" (Showa, Saiwai, First Edition of March 1, 1973). In addition, Japanese Patent Laid-Open Publication No. Hei 05-155809, Japanese Laid-Open Patent Publication No. 05-155810, Japanese Laid-Open Patent Publication No. 5-197073, Japanese Laid-Open Patent Publication No. 2006-259494, Japanese Patent Laid-Open Publication No. 07-330670 The material described in each of Unexamined-Japanese-Patent No. 2006-342227, Unexamined-Japanese-Patent No. 2007-003679, etc. can also be used.

It is preferable that the addition amount of the polycondensation ester used by this invention is 0.1-60 mass% with respect to the amount of cellulose esters, It is more preferable that it is 1-55 mass%, It is most preferable that it is 3-50 mass%.

It is preferable that it is less than 1 mass%, and, as for content in the cellulose ester film of the aliphatic diol, dicarboxylic acid ester, or diol ester of the raw material which the polycondensation ester used by this invention contains, it is more preferable that it is less than 0.5 mass%. Examples of the dicarboxylic acid esters include dimethyl phthalate, di (hydroxyethyl) phthalate, dimethyl terephthalate, di (hydroxyethyl) terephthalate, di (hydroxyethyl) adipic acid and di (hydroxyethyl) succinate. . Ethylene diacetate, propylene diacetate, etc. are mentioned as diol ester.

It is preferable that the cellulose ester film in this invention contains the compound which has an at least 2 or more aromatic ring. Below, the compound which has at least 2 or more aromatic rings is demonstrated. It is preferable that the compound which has an at least 2 or more aromatic ring expresses optically positive monoaxiality, when it is orientated similarly. It is preferable that it is 300-1200, and, as for the molecular weight of the compound which has at least 2 or more aromatic rings, it is more preferable that it is 400-1000.

As a compound which has at least two aromatic rings, the triazine compound of Unexamined-Japanese-Patent No. 2003-344655, the rod-shaped compound of Unexamined-Japanese-Patent No. 2002-363343, Unexamined-Japanese-Patent No. 2005-134884, and the like are mentioned, for example. The liquid crystalline compound of Unexamined-Japanese-Patent No. 2007-119737, etc. are mentioned. More preferably, it is the said triazine compound or rod-shaped compound. The compound which has at least two aromatic rings can also be used in combination of 2 or more type.

The amount of the compound having at least two aromatic rings is preferably 0.05% or more and 20% or less, more preferably 0.5% or more and 15% or less, further preferably 1% or more and 15% or less by mass ratio with respect to the cellulose ester.

The details of the cellulose acylate are described in paragraphs [0140] to [0195] in paragraphs [0140] of JP 2005-104148 A. These descriptions can also be applied to the present invention. Moreover, also about additives, such as a solvent and a plasticizer, a deterioration inhibitor, a ultraviolet absorber (UV agent), an optically anisotropic control agent, a retardation control agent, a dye, a mat agent, a peeling agent, and a peeling accelerator, also of Japan Unexamined-Japanese-Patent No. 2005-104148 In the paragraph [0516] it is described in detail.

(Usage)

The polymer film of this invention is useful as a polarizing plate protective film or retardation film. An optically anisotropic layer, an antireflection layer, an antiglare functional layer, etc. may be provided to this polymer film, and it may be set as a high function film.

When using as a retardation film, it is preferable that in-plane retardation Re is 30 nm or more and 100 nm or less, and it is preferable that thickness direction retardation Rth is 70 nm or more and 300 nm or less.

(Melt film production facility)

Next, the melt film forming facility 210 which manufactures a polymer film by the melt film forming method is demonstrated. As shown in FIG. 10, the melt film forming facility 210 is an apparatus for manufacturing a thermoplastic film F that can be used for a liquid crystal display device or the like. A pellet-like thermoplastic resin, which is a raw material of the film F, is introduced into the dryer 212 and dried. Thereafter, the pellets are extruded by the extruder 214 and supplied to the filter 218 by the gear pump 216. Subsequently, the foreign matter is filtered by the filter 218, and the molten resin (molten thermoplastic resin) is extruded from the die 220. The molten resin is sandwiched between the first casting roll 228 and the touch roll 224 and press-molded, and then cooled to the first casting roll 228 to be hardened (solidified and hardened) to a film shape of a predetermined surface roughness. In this case, the unstretched film Fa is obtained by being conveyed by the 2nd casting roll 226 and the 3rd casting roll 227 again. This unstretched film Fa may be wound by this step, and may be supplied to the lateral stretch part 242 which continuously performs long span extending | stretching. Moreover, even if the unstretched film Fa wound up once is supplied to the lateral stretch part 242 again, the same effect as the case of supplying to the lateral stretch part 242 which performs continuous long stretch is acquired.

횡연신 온도, 횡연신 온도

열고정 온도로 함으로써 보잉을 저감할 수 있다. 예열 처리, 열고정 처리는 어느 한쪽만 해도 되고, 양쪽 모두 실시해도 된다.In the lateral stretched part 242, the unstretched film Fa is stretched in the width direction (hereinafter referred to as the B direction) orthogonal to the conveying direction (hereinafter referred to as the A direction), thereby forming a lateral stretched film Fb. The preheating part 236 may be provided upstream of the lateral stretch part 242, and the heat-extrusion part 244 may be formed downstream of the lateral stretch part 242. Thereby, the bowing (deviation of an optical axis) in extending | stretching can be made small. It is preferable that preheating temperature is higher than lateral stretch temperature, and it is preferable that heat setting temperature is lower than lateral stretch temperature. That is, in general, the boeing is concave in the width direction central portion toward the traveling direction, the preheating temperature

Transverse stretching temperature, transverse stretching temperature

By setting the heat setting temperature, the bowing can be reduced. The preheating treatment and the heat setting treatment may be either one or both.

After the heat setting treatment is performed after the transverse stretching, the transverse stretching film Fb is contracted in the A direction in the shrinkage treatment region 246. In the shrinkage processing region 246, as shown in FIG. 11, the side end portion of the lateral stretched film Fb is not held by the chuck, and a plurality of contractions are performed so that the shrinkage in the B direction does not occur and the contraction in the B direction occurs. The lateral stretched film Fb is conveyed by the roll 248a-248d of the. At this time, as shown in FIG. 12, some roll 248a-248d is arrange | positioned so that ratio (G / D) of the roll wrap length D and the roll-to-roll length G may be 0.01 or more and 3 or less. Thereby, shrinkage of the B direction is suppressed by the friction of the lateral stretched film Fb and each roll 248a-248d. And as for lateral stretched film Fb, ratio (Vd / Va) of the circumferential speed Va by the upstream roll 248a and the circumferential speed Vd by the downstream roll 248d is 0.6 or more and 0.999 or less. It shrinks while being conveyed. In short, the lateral stretched film Fb is contracted in the A direction in the shrinkage treatment region 246. Moreover, "roll wrap length" is a length in the circumferential direction of the lap part wrapped by the lateral stretched film Fb wound up among the circumferential surfaces of a roll.

In the shrinkage treatment zone 246, the shrinkage treatment is performed on the lateral stretched film Fb to produce a thermoplastic film F, which is the final product in which the orientation angle and the retardation are adjusted. This film F is wound up by the winding-up part 249.

You may extend in A direction before or after extending | stretching to B direction. Stretching of the A direction can be performed by conveying a film using several nip roll pairs arrange | positioned in A direction, and making the circumferential speed of a downstream nip roll pair faster than the circumferential speed of an upstream nip roll pair. The stretching method differs depending on the size of the distance L between the nip roll pairs in the A direction and the ratio L / W of the film width W in the upstream nip roll pair. If L / W is small, the extending | stretching system of A direction as described in Unexamined-Japanese-Patent No. 2005-330411 and 2006-348114 can be employ | adopted. This method is easy to increase Rth, but can compact the device. On the other hand, when L / W is large, the extending | stretching system of A direction as described in Unexamined-Japanese-Patent No. 2005-301225 can be used. This method can make Rth small, but the device is likely to be large.

The polymer which can be used for a melt film forming method will not be specifically limited if it is a thermoplastic resin. For example, a cellulose acylate, a lactone ring containing polymer, a cyclic polyolefin, polycarbonate, etc. are mentioned. Among them, preferred are cellulose acylate and cyclic polyolefin, more preferred are cellulose acylate containing acetate group and propionate group and cyclic polyolefin obtained by addition polymerization, and still more preferred cyclic polyolefin obtained by addition polymerization. to be.

(Cyclic polyolefin)

As cyclic polyolefin, what is polymerized from a norbornene-type compound is preferable. This polymerization may be any of ring-opening polymerization and addition polymerization. As addition polymerization, it is what was described, for example in Japanese Patent No. 357471, Japanese Patent No. 3559360, Japanese Patent No. 3867178, Japanese Patent No. 3871721, Japanese Patent No. 3907908, Japanese Patent No. 3945598, Japanese Patent Publication No. 2005- The thing of 527696, Unexamined-Japanese-Patent No. 2006-28993, and international publication 2006/004376 pamphlet is mentioned. Particularly preferable ones are described in Japanese Patent No. 3574751.

Examples of the ring-opening polymerization include International Publication No. 98/14499, Japanese Patent No. 3060532, Japanese Patent No. 3220478, Japanese Patent No. 3273046, Japanese Patent No. 3404027, Japanese Patent No. 3428176, Japanese Patent No. 3687231, and Japanese Patent. 3873934 and Japanese Patent No. 3912159 are mentioned. Among them, preferred are those described in International Publication No. 98/14499 Pamphlet and Japanese Patent No. 3060532.

Among these cyclic polyolefins, one by addition polymerization is more preferable.

(Lactone ring-containing polymer)

The thing which has a lactone ring structure represented by following (General formula 1) is pointed out.

[Formula 1]

In General Formula 1, R ¹ , R ² , and R ³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. Moreover, the organic residue may contain the oxygen atom.

The content rate of the lactone ring structure of General formula (1) becomes like this. Preferably it is 5-90 mass%, More preferably, it is 10-70 mass%, More preferably, it is 10-50 mass%.

In addition to the lactone ring structure represented by (General Formula 1), a polymer structural unit polymerized by at least one selected from (meth) acrylic acid ester, a hydroxyl group-containing monomer, an unsaturated carboxylic acid, and a monomer represented by the following (General Formula 2) is polymerized. (Repeated structural unit) is preferable.

[Formula 2]

In Formula (2), R ⁴ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an -OAc group, a -CN group, -CO-R ⁵ group, or -COR ⁶ groups are represented, and R ⁵ and R ⁶ represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. In addition, Ac group is an acetyl group.

For example, international publication 2006/025445 pamphlet, Unexamined-Japanese-Patent No. 2007-70607, Unexamined-Japanese-Patent No. 2007-63541, Unexamined-Japanese-Patent No. 2006-171464, and Unexamined-Japanese-Patent No. 2005-162835 are described, for example. Can be used.

(Liquid crystal display device)

As a structural member of a liquid crystal display device, the polymer film obtained by this invention can be used. As shown in FIG. 13, the liquid crystal display device 260 includes a backlight 261, a liquid crystal cell 262 that can transition between a state of transmitting light from the backlight 261 and a state of blocking light transmission; The first polarizing plate 263 to which light directed toward the liquid crystal cell 262 is incident, and the second polarizing plate 264 to which light transmitted through the liquid crystal cell 262 is incident is provided. Although the liquid crystal cell 262 is not specifically limited, It is preferable that it is a VA type liquid crystal cell.

(Polarizing plate)

The 1st polarizing plate 263 is the 1st polarizing film (polarizer) 263a, the transparent 1st phase difference film 263b formed in the surface of the liquid crystal cell 262 side among the surfaces of the 1st polarizing film 263a, and And the transparent first protective film 263c formed on the surface opposite to the surface on which the first retardation film 263b is formed among the surfaces of the first polarizing film 263a. The first retardation film 263b also has a function of protecting the first polarizing film 263a similarly to the first protective film 263c. Therefore, the 1st polarizing plate 263 has a pair of protective film called the 1st phase difference film 263b and the 1st protective film 263c. Similarly, the 2nd polarizing plate 264 is the 2nd polarizing film 264a, the 2nd phase difference film 264b formed in the liquid crystal cell 262 side surface among the surfaces of the 2nd polarizing film 264a, and the 2nd It has a 2nd protective film 264c formed in the surface on the opposite side to the surface in which the 2nd phase difference film 264b is formed among the surfaces of the polarizing film 264a. It is preferable to use the film of this invention as each retardation film 263b, 264b. In addition, the second retardation film 264b may be omitted.

Example 1

(Manufacture of Film)

The manufacturing method of each polymer film used for the Example is demonstrated.

(Sample No.A1)

The formulation at the time of preparation of the cast dope 81 used for film manufacture is shown below.

의 조제][Raw dope

Pharmacy]

의 처방 및 조제 방법을 하기에 나타낸다.Raw material dope

The prescription and preparation method of are shown below.

Cellulose triacetate X (substitution degree 2.86) 89.3 mass%

Plasticizer A (triphenyl phosphate) 7.1 mass%

Plasticizer B (biphenyldiphenyl phosphate) 3.6 mass%

Solid content (solute) which consists of composition ratio of

Dichloromethane 82 mass%

Methanol 15.0 mass%

n-butanol 3.0 mass%

를 조제하였다. 또, 원료 도프

에 있어서의 셀룰로오스 트리아세테이트 X 의 농도가 약 23 질량％ 가 되도록 조정하였다. 원료 도프를 여과지 (토요 여지 (주) 제조, #63LB) 로 여과 후 다시 소결 금속 필터 (닛폰 정선 (주) 제조 06N, 공칭 공경 10 ㎛) 로 여과하고, 또 메시 필터로 여과한 후에 스톡 탱크에 넣었다.It is added suitably to the mixed solvent which consists of these, and it melt | dissolves by stirring, and dope a raw material

Was prepared. In addition, raw material dope

It adjusted so that the density | concentration of cellulose triacetate X in might be about 23 mass%. The raw material dope was filtered with a filter paper (Toyo-Gyo Co., Ltd., # 63LB), followed by sintering again with a sintered metal filter (Nippon Jeongseon Co., Ltd. 06N, nominal pore size of 10 µm), followed by filtering with a mesh filter, and then into a stock tank. Put in.

[Cellulose Triacetate X]

Moreover, the cellulose triacetate X used here is 0.1 mass% or less of residual acetic acid, 57 ppm of Ca, 41 ppm of Mg, 0.4 ppm of Fe, 38 ppm of free acetic acid, and 13 ppm of sulfate ions. It was. Moreover, the substitution degree of the acetyl group with respect to hydrogen of the 6-position hydroxyl group was 0.89. In addition, the mass average molecular weight / number average molecular weight ratio of cellulose triacetate X was 2.5. This cellulose triacetate X is synthesize | combined using the cellulose collected from the pulp as a raw material.

의 조제] [Mat solution

Pharmacy]

를 조제하였다.Matte solution from the following prescription

Was prepared.

10.0 parts by mass of silica particle dispersion (average particle diameter 16 nm)

(Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.)

72.8 parts by mass of dichloromethane

3.9 parts by mass of methanol

0.5 parts by mass of n-butanol

10.3 질량부Raw material dope

10.3 parts by mass

를 조제하고, 애트라이터로 체적 평균 입경 0.7 ㎛ 가 되도록 분산한 후, 후지 필름 (주) 제조 아스트로포어 필타로 여과하였다. 그리고, 매트제액용 탱크에 넣었다.Matte liquid from the prescription

Was prepared and dispersed in an attritor so as to have a volume average particle diameter of 0.7 m, followed by filtration with Fujifilm Co., Ltd. product Astropore filter. And it put in the tank for mat liquids.

와 화학식 3 에 나타내는 리타데이션 제어제를 함유하는 액을, 인라인 믹서로 혼합 교반하여 혼합 첨가제를 얻었다. 리타데이션 제어제의 첨가량은, 유연 도프에 있어서 셀룰로오스 트리아세테이트 X 의 9.5 질량％가 되도록 조정하였다. 첨가제 공급 라인은, 원료 도프가 흐르는 배관 내에 혼합 첨가제가 유출되도록, 혼합 첨가제가 흐르는 배관을 원료 도프가 흐르는 배관에 접속하는 구성으로 하였다. 혼합 첨가제를 첨가제 공급 라인의 배관 내에 송액하였다. 인라인 믹서에서는 원료 도프 α 와 혼합 첨가제를 혼합 교반하였다. 이것에 의해 유연 도프 (81) 를 얻었다. 유연 드럼 (82) 을, 제어부의 제어하, 축 (82a) 을 중심으로 회전시켰다. 주행 방향 Z1 에 있어서의 둘레면 (82b) 의 속도를 50 m/분 이상 200 m/분 이하의 범위 내에서 거의 일정해지도록 유지하였다. 유연 드럼 (82) 의 둘레면 (82b) 의 온도를 -10 ℃ 이상 10 ℃ 이하의 범위 내에서 거의 일정해지도록 유지하였다. 유연 다이 (84) 로부터는 유연 도프 (81) 를 둘레면 (82b) 상에 유연하고, 이것에 의해 둘레면 (82b) 에 유연막 (86) 을 형성하였다. 냉각에 의해, 유연막 (86) 이 자기 지지성을 갖게 된 후, 박취 롤러 (89) 를 사용하여 유연 드럼 (82) 으로부터 유연막 (86) 을 습윤 필름 (88) 으로서 벗겨내었다. 박취 불량을 억제하기 위해, 유연 드럼 (82) 의 속도에 대한 박취 속도 (박취 롤러 드로우) 를 100.1 ％ ∼ 110 ％ 의 범위에서 적절히 조정하였다. 습윤 필름 (88) 은, 반송부 (90), 핀 텐터 (91), 및 건조실 (97) 로 순차적으로 안내되었다. 반송부 (90), 핀 텐터 (91), 및 건조실 (97) 에서는, 습윤 필름 (88) 에 건조 공기를 쏘여 소정의 건조 처리를 실시하였다. 이 건조 처리에 의해 얻어지는 TAC 필름 (3) 을 텐터부 (5) 로 이송하였다. 텐터부 (5) 에서는 TAC 필름 (3) 에 연신 처리를 실시하였다. 이 연신 처리에 있어서, TAC 필름 (3) 의 온도 (Tfe), 연신율 (ER) 은 표 2 에 나타내는 바와 같다. 연신 처리를 거친 TAC 필름 (3) 을 냉각부 (7) 로 이송하였다. 냉각부 (7) 에서는, TAC 필름 (3) 을 30 ℃ 이하가 될 때까지 냉각하였다. 그 후, TAC 필름 (3) 에, 제전 처리, 널링 부여 처리 등을 실시한 후, 권취부 (8) 에 반송하였다. 권취부 (8) 에서는, 프레스 롤러 (37) 에 의해 원하는 텐션을 부여하면서, TAC 필름 (3) 을 권심 (36) 에 감았다. 용액 제막 설비 (100) 에 의해 제조된 TAC 필름 (3) 은, 폭이 2000 ㎜ 였다. 시료 No.A1 의 TAC 필름의 두께, 면내 리타데이션, 두께 방향의 리타데이션 및 헤이즈를 측정하였다. 시료 No.A1 의 TAC 필름의 막두께, Re, Rth 및 헤이즈의 측정값은 각각 표 2 에 나타낸다.The TAC film 3 was manufactured using the solution film forming installation 100 shown in FIG. Matte solution

And the liquid containing the retardation control agent shown by General formula (3) were mixed and stirred with the in-line mixer, and the mixing additive was obtained. The addition amount of the retardation control agent was adjusted so that it might become 9.5 mass% of cellulose triacetate X in casting dope. The additive supply line was configured to connect the pipe through which the mixed additive flows to the pipe through which the raw material dope flows so that the mixed additive flows out into the pipe through which the raw material dope flows. The mixed additive was fed into the piping of the additive supply line. In an inline mixer, the raw material dope (alpha) and the mixed additive were mixed and stirred. This obtained the casting dope 81. The casting drum 82 was rotated about the axis 82a under the control of the control unit. The speed of the circumferential surface 82b in the traveling direction Z1 was maintained to be substantially constant within the range of 50 m / min or more and 200 m / min or less. The temperature of the peripheral surface 82b of the casting drum 82 was maintained to be substantially constant within the range of -10 deg. From the casting die 84, the casting dope 81 was cast on the circumferential surface 82b, and the casting film 86 was formed in the circumferential surface 82b by this. After the casting film 86 became self-supporting by cooling, the casting film 86 was peeled off from the casting drum 82 as the wet film 88 using the stripping roller 89. In order to suppress a deterioration defect, the dermabrasion speed (dermabrasion roller draw) with respect to the speed | rate of the casting drum 82 was adjusted suitably in 100.1%-110% of range. The wet film 88 was sequentially guided to the conveyance part 90, the pin tenter 91, and the drying chamber 97. In the conveyance part 90, the pin tenter 91, and the drying chamber 97, dry air was thrown into the wet film 88, and predetermined | prescribed drying process was performed. The TAC film 3 obtained by this drying process was transferred to the tenter part 5. In the tenter portion 5, the stretching treatment was performed on the TAC film 3. In this extending | stretching process, temperature Tfe and elongation ER of the TAC film 3 are as showing in Table 2. The stretched TAC film 3 was transferred to the cooling unit 7. In the cooling part 7, the TAC film 3 was cooled until it became 30 degrees C or less. Then, after performing antistatic treatment, a knurling provision process, etc. to the TAC film 3, it conveyed to the winding-up part 8. In the winding-up part 8, the TAC film 3 was wound around the winding core 36 while giving the desired tension by the press roller 37. The TAC film 3 manufactured by the solution film forming facility 100 was 2000 mm in width. The thickness, in-plane retardation, retardation of the thickness direction, and haze of the TAC film of sample No. A1 were measured. The measured value of the film thickness, Re, Rth, and haze of the TAC film of sample No.A1 is shown in Table 2, respectively.

In Table 2, substitution degree A of each cellulose triacetate W-Z is substitution degree by an acetyl group. Plasticizer A is triphenyl phosphate, plasticizer B is biphenyldiphenyl phosphate, and plasticizer C is a compound of P-41 shown in Table 1. The addition amount shown in Table 2 is an addition amount of the retardation control agent shown by General formula (3).

[Formula 3]

(Measurement method of in-plane retardation Re)

The sample film was humidified for 2 hours (adjustment of humidity) at a temperature of 25 ° C and a humidity of 60% RH, and the retardation value measured in the vertical direction at 589.3 nm with an automatic birefringence meter (KOBRA 21ADH Oji measurement Co., Ltd.) The extrapolated value was calculated according to the following equation.

Re = | nX-nY | × d

nX represents the refractive index in the X direction, nY represents the refractive index in the Y direction, and d represents the thickness (film thickness) of the film.

(Measurement method of thickness direction retardation (Rth))

The sample film sampled from the obtained TAC film was humidified for 2 hours at the temperature of 25 degreeC, and 60% of humidity. About the sample film after this humidity control, the extrapolation of the value measured in the vertical direction at 589.3 nm by the automatic birefringence meter (KOBRA 21ADH Oji measurement Co., Ltd.) and the retardation value measured similarly while tilting the film plane. Rth was computed from the value according to the following formula.

Rth = {(nX + nY) / 2-nTH} × d

nTH is a refractive index in the thickness direction.

(Measuring method of haze)

What cut out to the size of 40 mm x 80 mm from the TAC film was made into the sample film. The measurement of haze was performed about this sample film. The measurement was performed in accordance with JIS K-6714 using a haze meter (model: HGM-2DP, Suga Tester) at 25 ° C and 60% RH.

(Sample No.A2)

Except as shown in Table 2, it carried out similarly to the TAC film of sample No.A1, and created the TAC film 3 of sample No.A2.

(Sample No.A3)

The cellulose triacetate Y shown in Table 2 in place of the cellulose triacetate X, the addition amount of the retardation control agent of the formula (3) changed to the value shown in Table 2, the elongation (ER) and the TAC film (3) Except having made temperature Tfe the value shown in Table 2, it carried out similarly to sample No. A1, and produced the TAC film of sample No. A3.

[Cellulose Triacetate Y]

The cellulose triacetate Y has a degree of substitution of 2.76, an amount of residual acetic acid of 0.1 mass% or less, a Ca content of 1 ppm, a Mg content of 45 ppm, a Fe content of 0.5 ppm, a free acetic acid of 0.023 mass%, and a sulfate ion It contained 0.013 mass%. Moreover, the substitution degree of the acetyl group with respect to hydrogen of the 6-position hydroxyl group was 0.84. Moreover, 30.4% in all the acetyl groups was the acetyl group which the hydrogen of the hydroxyl group of 6-position substituted. In addition, the mass average molecular weight / number average molecular weight ratio of cellulose triacetate Y was 2.5. Cellulose triacetate Y is synthesized using cellulose taken from conifer pulp as a raw material.

(Sample No.A4)

The cellulose triacetate Y shown in Table 2 in place of the cellulose triacetate X, the addition amount of the retardation control agent of the formula (3) changed to the value shown in Table 2, the elongation (ER) and the TAC film (3) Except having made temperature Tfe the value shown in Table 2, it carried out similarly to sample No. A1, and produced the TAC film of sample No. A4. The thickness, in-plane retardation, retardation of the thickness direction, and haze of the TAC film of sample No. A4 were measured. The measured value of the film thickness, Re, Rth, and haze of the TAC film of sample No.A4 is shown in Table 2, respectively.

(Sample No. A5)

를 대신하여 원료 도프 β 를 사용한 것, 매트제액

를 대신하여 매트제액 β 를 사용한 것, 리타데이션 제어제의 첨가량을 표 2 에 나타낸 값으로 변경한 것, 연신율 (ER) 및 TAC 필름 (3) 의 온도 (Tfe) 를 표 2 에 나타낸 값으로 한 것 이외에는 시료 No.A1 과 동일하게 하여, 시료 No.A5 의 TAC 필름을 얻었다. 시료 No.A5 의 TAC 필름의 두께, 면내 리타데이션, 두께 방향의 리타데이션 및 헤이즈를 측정하였다. 시료 No.A5 의 TAC 필름의 막두께, Re, Rth 및 헤이즈의 측정값은 각각 표 2 에 나타낸다.Raw material dope

Using raw material dope β in place of

Using the matting agent liquid β instead of changing the addition amount of the retardation control agent to the value shown in Table 2, the elongation (ER) and the temperature (Tfe) of the TAC film (3) as the value shown in Table 2 A TAC film of Sample No. A5 was obtained in the same manner as Sample No. A1 except for the above. The thickness, in-plane retardation, retardation of the thickness direction, and haze of the TAC film of sample No. A5 were measured. The measured value of the film thickness, Re, Rth, and haze of the TAC film of sample No. A5 is shown in Table 2, respectively.

[Preparation of raw material dope β]

와 동일하다.Preparation of raw material dope β is a raw material dope except what is shown below

Is the same as

Cellulose triacetate Y (substitution degree 2.76) 89.3 mass%

Plasticizer C (Compound NoP-41 described in Table 1) 9.0 mass%

Solid content (solute) which consists of composition ratio of

Dichloromethane 82 mass%

Methanol 15.0 mass%

n-butanol 3.0 mass%

It added to the mixed solvent which consists of these suitably, stirred and melt | dissolved, and prepared raw material dope β. The concentration of cellulose triacetate Y in the starting material dope β was 23.5 mass%.

[Preparation of Matte Liquid Solution β]

와 동일하다.The preparation of the mat preparation liquid β is a mat preparation liquid except as shown below.

Is the same as

10.0 parts by mass of silica particle dispersion (average particle diameter 16 nm)

(Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.)

72.8 parts by mass of dichloromethane

3.9 parts by mass of methanol

0.5 parts by mass of n-butanol

10.3 질량부Raw material dope

10.3 parts by mass

(Sample No.A6-A7)

A TAC film of Sample No. A6 and Sample No. A7 in the same manner as Sample No. A5 except that a blend polymer was used in place of cellulose triacetate X, and the conditions of the stretching treatment were changed to the values shown in Table 2. Got. The blend polymer mixes cellulose triacetate X and cellulose triacetate Y in the weight ratio shown in Table 2.

(Sample No.A8)

A TAC film of Sample No. A8 was obtained in the same manner as Sample No. A5 except that cellulose triacetate X was used in place of cellulose triacetate Y, and the conditions of the stretching treatment were changed to the values shown in Table 2.

At this time, the tendency for the indentation angle from a drum to become large was observed, so that the ratio of TAC of substitution degree 2.76 was large at the time of film forming. However, no indentation angle was a level that would be a problem at the time of manufacture.

(Sample No.A9)

The cellulose triacetate W (degree of substitution 2.44) was used instead of the cellulose triacetate Y. Other than this, it carried out similarly to sample No. A5, and obtained the TAC film of sample No. A9.

(Sample No. A10 to A12)

Except having changed the conditions of extending | stretching process into the value shown in Table 2, it carried out similarly to sample No.A5-A8, and obtained the TAC film of sample No.A10-12.

The thickness, in-plane retardation, retardation of the thickness direction, and haze of the TAC film of sample No.A2-A12 were measured. The measured value of the film thickness, Re, Rth, and haze of the TAC film of sample No.A2-A12 is shown in Table 2, respectively.

(Sample No.B1)

Film No. 1 (cellulose acetate propionate: width 1900 mm) was obtained using the solution film-forming method which has an extending | stretching process. The obtained film is called the film of sample No. B1. Each condition of the solution film-forming method was based on what was described in Example 1 of Unexamined-Japanese-Patent No. 2001-188128. Moreover, the elongation rate (ER) of an extending | stretching process, and the temperature (Tfe) of the film in an extending | stretching process are as showing in Table 3.

Moreover, "CAP" shown in Table 3 represents a cellulose acetate propionate, "lactone" shows a lactone ring containing polymer resin, and "cycloolefin" shows cycloolefin resin A, respectively. Substitution degree A is a substitution degree by an acetyl group, and substitution degree B is a substitution degree by a propionyl group. The addition amount shown in Table 3 is an addition amount of the retardation control agent shown by General formula (3). Film thickness, Re, Rth, and haze are thickness of the obtained polymer film, in-plane retardation, retardation of a thickness direction, and haze.

(Sample No.B2)

The film of sample No. B2 was obtained using the solution film forming method which has an extending | stretching process. The elongation rate (ER) of the stretching treatment and the temperature (Tfe) of the film in the stretching treatment are as shown in Table 3. Each condition of the other solution film-forming method was based on description of Example 1 of the international publication 2007/125764 pamphlet, and the film of sample No. B2 is the cellulose ester film No. 1 of Example 1 of the international publication 2007/125764 pamphlet. It is equivalent to 119.

(Sample No.C1)

The polymer film (width 1500mm) which consists of lactone ring containing polymer resin was obtained using the melt film forming method which has an extending | stretching process. This is called the film of sample No.C1. The elongation rate (ER) of the stretching treatment and the temperature (Tfe) of the film in the stretching treatment are as shown in Table 3. Each condition of the other melt film-forming method was according to Example 1 described in the international publication 2006/025445 pamphlet.

(Sample No.D1)

The melt film forming method was performed and the polymer film (width 1500mm) which consists of cycloolefin resin A was obtained. This is called the film of sample No.D1.

Cycloolefin resin A (addition polymerization system): Polyplastics Co., Ltd. TOPAS6013 (Tg = 130 ℃)

The detail of the melt film forming method which produced the film of sample No.D1 is as follows. After drying cycloolefin resin A with 110 degreeC vacuum dryer to make water content 0.1% or less, it melt | dissolves at 260 degreeC using a single screw kneading extruder, and it is sent out from a gear pump, and it uses the leaf disc filter of 5 micrometers of filtration precisions. 3 sets of casting rolls (228, 226) which were filtered and set to (Tg-5) ° C, Tg ° C, and (Tg-10) ° C from a hanger coat die having a slit interval of 0.8 mm and 270 ° C via a static mixer. 227), the melt (melt resin) was extruded. At this time, the touch roll 224 was made to contact the casting roll 228 of the most upstream side among three casting rolls 226-228 by surface pressure 0.1 MPa, and the unstretched film of thickness 100micrometer was formed into a film. The touch roll 224 was temperature-controlled by (Tg-5) degreeC using what was described in Example 1 of Unexamined-Japanese-Patent No. 11-235747 (it was described as a double press roll), but the thickness of a thin metal outer cylinder Was 2 mm).

Then, the unstretched film before winding was transferred to the tenter, and the extending | stretching process was performed. The elongation rate (ER) of the stretching treatment and the temperature (Tfe) of the film in the stretching treatment are as shown in Table 3. After trimming both ends (each 3% of the full width) of the film in which the extending | stretching process was performed, the thickness formation process (knurling) of width 10mm and height 20micrometer was performed at both ends. At each level, the width was 1.5 m and the 3000 m was wound at 30 m / min.

(Sample No.A1H1)

TAC of sample No. A1H1 using the installation which added the heat processing casing 110 (refer FIG. 9) between the wet gas contact casing 6 and the cooling part 7 of the solution film forming installation 104 shown in FIG. A film was prepared. The manufacturing conditions of the TAC film of sample No.A1H1 are the same as that of the TAC film of sample No.A1 except what is described below.

In the wet gas contact chamber 6a, steam contact treatment was performed on the TAC film subjected to the stretching treatment for 1 minute. The absolute humidity VM of the wet gas 400 in the wet gas contact chamber 6a was 490 g / cm 3, and the relative humidity Hu1 was 79% RH. In addition, the dew point of the wet gas 400 was adjusted so that it might become a temperature 10 degreeC or more higher than the temperature (Tf0) of the TAC film 3. In the wet gas contact chamber 6a, the temperature Tf1 of the TAC film 3 was 102 ° C. In the heat treatment chamber, heat treatment was performed on the TAC film which had undergone the steam contact treatment for 2 minutes. The temperature (Tf2) of the TAC film during heat processing was 130 degreeC. The film thickness, in-plane retardation, thickness direction retardation, and haze of the TAC film of sample No.A1H1 are as showing in Table 4.

(Sample No. A2H1 to A12H1, B1H1 to B2H1, C1H1, D1H1)

The conditions of the steam contact treatment, the heat treatment conditions, and other conditions were the same as those of the TAC film of Sample No. A1H1 to prepare polymer films of Sample Nos. A2H1 to A12H1, B1H1 to B2H1, C1H1, and D1H1. The film thickness, in-plane retardation, thickness direction retardation, and haze of the polymer films of sample No.A1H2-A12H1, B1H1-B2H1, C1H1, and D1H1 are as Table 4 showing.

Each polymer film (Samples No.A1H1 to A12H1, B1H1, B2H1, C1H1, D1H1) that had been subjected to water vapor contact treatment, and a polymer film (Samples No.A1 to A12, B1, B2, C1, D1) that had not been subjected to water vapor contact treatment The wet heat endurance test and the dry heat endurance test were performed respectively, and the state change of each polymer film before and after each endurance test was investigated.

(Hot Heat Endurance Test)

From each polymer film, the sample film of X direction length X0 and the Y direction length Y0 was cut out, and the wet heat durability test was done about this sample film. In the wet heat endurance test, the sample film was continuously placed in the test room for 21 days. The environmental conditions inside the test chamber were kept substantially constant at a temperature of 60 ° C. and a humidity of 90% RH. About the sample film after a wet heat endurance test, in-plane retardation (Re1 _WET ), thickness direction retardation (Rth1 _WET ), the length (X1 _WET ) of the X direction, and the length (Y1 _WET ) of the Y direction were measured.

(Dry heat endurance test)

From each polymer film, the sample film of X direction length X0 and the Y direction length Y0 was cut out, and the dry heat durability test was done about this sample film. In the dry heat endurance test, the sample film was continuously placed in the test room for 21 days. The environmental conditions inside the test chamber were kept almost constant at a temperature of 80 ° C. and a humidity of 5% RH. The in-plane retardation (Re1 _DRY ), the thickness direction retardation (Rth1 _DRY ), the length (X1 _DRY ) of the X direction, and the length (Y1 _DRY ) of the Y direction were measured about the sample film after a dry heat durability test.

ΔX _WET , ΔY _WET , ΔRe _WET , and ΔRth _WET are the ratios of the amount of dimensional change in the X direction before and after the wet heat endurance test in the sample film {(X1 _WET- X0) / X0}, and the amount of dimensional change in the Y direction. The ratio {(Y1 _WET -Y0) / Y0}, the variation amount of in-plane retardation (Re1 _WET -Re0), and the variation amount of thickness direction retardation (Rth1 _WET -Rth0). Also, _DRY ΔX, ΔY _{DRY, DRY} ΔRe, and ΔRth _DRY is, the sample dry heat endurance test before and after the ratio of, the amount of change of dimension in the X direction in the film _{{(X1 DRY -X0) / X0} }, the dimension in the Y direction It is the ratio {(Y1 _DRY- Y0) / Y0} of the fluctuation amount, the fluctuation amount (Re1 _DRY- Re0) of in-plane retardation, and the fluctuation amount (Rth1 _DRY- Rth0) of thickness direction retardation.

ΔRe _WET and ΔRth _WET at 1 day, 5 days, 10 days, and 21 days after the start of the wet heat endurance test were measured. @ 1d, @ 5d, @ 10d, and @ 21d in Table 5 show measured values of ΔRe _WET and ΔRth _WET at 1 day, 5 days, 10 days, and 21 days, respectively. Similarly, ΔRe _DRY and ΔRth _DRY at 1 day, 5 days, 10 days, and 21 days after the start of the dry heat endurance test were measured. The numerical values described in the columns of @ 1d, @ 5d, @ 10d, and @ 21d in Table 6 are measured values of ΔRe _DRY and ΔRth _DRY at 1 day, 5 days, 10 days, and 21 days, respectively. .

[Example 2]

(Sample No.A13)

A sample was prepared in the same manner as in Sample No. A1 of Example 1, except that cellulose triacetate Z having an acetyl substitution degree of 2.81 was used according to the example of JP 2006-28479 A using a solution film forming method having an stretching treatment. A TAC film of No. A13 was obtained. The amount of residual solvent of the TAC film at the time of extending | stretching process is 35 mass%, the conditions of extending | stretching process were changed to the value shown in Table 2, and the extending | stretching process was adjusted so that the slow-axis angle of the film width direction might become substantially flat. Except having performed, the extending | stretching process was performed like sample No. A5 of Example 1. The measured value of the film thickness, Re, Rth, and haze of the TAC film of sample No.A13 is shown in Table 2, respectively. In addition, the internal haze of the TAC film of sample No.A13 was 0.05%.

(Measurement method of internal haze)

Internal haze was measured as follows. After humidifying a sample film at 25 degreeC 60% RH for 2 hours or more, the sample film was measured with the haze meter (HGM-2DP, Suga test machine) through the slide paraffin between two slide glass plates. Moreover, the blank sample of the state which only inserted the liquid paraffin without the sample film between two slide glass plates was produced, and the haze of this blank sample was measured. And the thing which subtracted the measured value of the haze of a blank sample from the measured value of the haze of a sample film was made into internal haze.

(Measuring method of ground shaft angle)

The slow-axis angle of the TAC film of sample No. A13 was measured using the automatic birefringence measuring apparatus (AD200S by Eto Corporation). The slow axis angle is an angle between the slow axis of the sample film and the x direction of the sample film. In the TAC film of sample No.A13, 20 measuring points of the slow axis angle were formed at equal intervals over the Y direction. 20 sample films (11 cm in the X direction and 7 cm in the Y direction) were cut out from the TAC film of Sample No. A13 to include each measurement point, and the slow axis angle was measured for each sample film. It was. The slow shaft shift amount was calculated by subtracting the minimum value of the slow shaft angle from the maximum value of the slow shaft angle. The slow axis shift amount was 0.1 degrees.

(Sample No.A13H1)

A TAC film of Sample No. A13H1 was prepared in the same manner as the TAC film of Sample No.A13 except that the TAC film subjected to the stretching treatment in the same manner as the TAC film of Sample No.A1H1 was sequentially subjected to steam contact treatment and heat treatment. It was. Steam contact treatment was performed for 1 minute. The absolute humidity (VM) of the wet gas was 400 g / cm 3, and the relative humidity Hu1 was 57% RH. In addition, the dew point of the wet gas was adjusted to be at least 10 ° C higher than the temperature (Tf0) of the TAC film. In the wet gas contact chamber, the temperature (Tf1) of the TAC film was 105 ° C. Heat treatment was performed for 2 minutes. The temperature (Tf2) of the TAC film during heat processing was 120 degreeC. The film thickness, in-plane retardation, thickness direction retardation, and haze of the TAC film of sample No.A13H1 are as showing in Table 4. In addition, the internal haze of the TAC film of sample No.A13H1 was 0.05%. The slow-axis angle of the TAC film of sample No.A13H1 was measured, and the slow-axis shift | offset | difference amount was calculated by subtracting the minimum value of the slow-axis angle from the maximum value of the slow-axis angle. The slow axis shift amount was 0.1 degrees.

About the TAC film of sample No. A13 and sample No. A13H1, the wet heat durability test was each performed for 60 minutes. The environmental conditions of the wet heat durability test were 80 degreeC, and humidity was 90% RH. As a result of examining the variation of the slow shaft shift amount before and after the wet heat endurance test, the slow shaft shift amount of the sample No. A13 increased from 0.1 ° to 1.0 ° by the wet heat endurance test. On the other hand, the slow-axis shift amount of sample No. A13H1 hardly changed from 0.1 degree to 0.2 degree by the wet heat durability test.

Example 3

(Sample No. A1H2 to A13H2)

Sample No. 1 of Example 1 was used except that the equipment which added the heat processing casing 110 (refer FIG. 9) between the wet gas contact casing 6 and the drying chamber 97 of the solution film forming installation 102 shown in FIG. In the same manner as the TAC film of A1H1 to A13H1, a TAC film of Sample No.A1H2 to A13H2 was produced. The film drying time in the manufacturing process of sample No.A1H2-A13H2 was short by about 10% compared with the film drying time in the manufacturing process of sample No.A1H1-A13H1. The film drying time here means the total of the steam contact treatment time, the heat treatment time, and the drying treatment time in the drying chamber 97.

Example 4

(Experiment 1)

A heat treatment casing 110 (see FIG. 9) is added between the wet gas contact casing 6 and the drying chamber 97 of the solution film forming facility 102 shown in FIG. 7, and the edge cutting device 30 and the wet gas contact casing are added. The same thing as the TAC film of sample No.A1H1 of Example 1 except having used the installation which added the condensation prevention process casing 120 (refer FIG. 9) between (6), and the following is described, A TAC film of .A1H (1) was prepared.

The condensation prevention treatment, the water vapor contact treatment, and the heat treatment were sequentially performed on the TAC film 3 subjected to the stretching treatment in the tenter portion 5. Then, it cooled to room temperature and wound up the TAC film (sample No. A1H (1)). In the dew condensation prevention treatment, dry air was applied to the TAC film 3 to adjust the temperature Tf0 of the TAC film 3. The temperature Tf0 in the dew condensation prevention process is as showing in Table 7. In the water vapor contact treatment, the absolute humidity (VM) and the relative humidity (Hu1) of the wet gas 400 in the wet gas contact chamber 6a are adjusted to the values shown in Table 7, and the dew point of the wet gas 400 is adjusted. To a temperature 10 ° C. or more higher than the temperature Tf0 of the TAC film 3, so that the temperature Tf1 of the TAC film 3 becomes the value shown in Table 7. The TAC film 3 was conveyed, maintaining as much as it was. The conveyance tension F in the wet gas contact chamber 6a is as showing in Table 7. In the heat treatment, the relative humidity Hu2 of the gas in the heat treatment chamber is adjusted to be the value shown in Table 7, and the state in which the temperature Tf2 of the TAC film 3 becomes the value shown in Table 7 by the processing time P2. Maintained. Moreover, "*" shown in Table 7 shows that the said process was not performed and the corresponding parameter was not able to be measured.

In addition, TH0, Re0, Rth0, Ha1, and Ha2 in Table 8 are the film thickness, in-plane retardation, and thickness direction retardation of the TAC film of sample No.A1H (1) before performing a wet heat endurance test and a dry heat endurance test. , Haze, and internal haze. In addition, "-" shown in Table 8 shows that the corresponding parameter was not measured.

The sample No. A1H (1) was subjected to a wet heat endurance test and a dry heat endurance test, respectively. The state change of the sample No.A1H (1) before and after a wet heat endurance test is shown in Table 9, and the state change of the sample No.A1H (1) before and after a dry heat endurance test is shown in Table 10, respectively.

(Experiment 2-35)

Sample No.A1H (2) to A1H (35) were prepared in the same manner as in Experiment 1 except that the conditions of the condensation prevention treatment, the steam contact treatment, and the heat treatment were the values shown in Table 7. Got. About the TAC film of obtained sample No.A1H (2)-A1H (35), film thickness, in-plane retardation, thickness direction retardation, haze, and internal haze were measured. The measured value of each parameter is shown in Table 8. The wet heat endurance test and the dry heat endurance test were performed about the TAC films of sample No.A1H (2) -A1H (35), respectively. The state change of the TAC film of sample No.A1H (2) -A1H (35) before and after each endurance test is shown to Table 9 and Table 10. FIG.

(Experiment 101)

In the equipment which omitted the tenter part 5 among the solution film forming equipment 80 shown in FIG. 5, the TAC film was manufactured by the solution gelation method of the cooling gelation method using the dope containing a polymer and a solvent. The produced TAC film 3 was wound around the core 36 to form a film roll. The film roll was conveyed to the offline stretching installation 2 shown in FIG. In the offline stretching facility 2, the stretching treatment, the dew condensation prevention treatment, the water vapor contact treatment, and the heat treatment were sequentially performed on the TAC film. The conditions in each treatment are the same as in Experiment 1. It was found that the absolute values of ΔX _WET and ΔY _WET of the TAC film obtained in this experiment were 0.02% to 0.10% larger than the absolute values of ΔX _WET and ΔY _WET of the TAC film obtained in Experiment 1.

(Experiment 102-Experiment 135)

Each condition in each treatment was the same as in Experiment 101 except that the conditions were the same as those in Experiment 2 to Experiment 35 to produce a TAC film 3.

It was found that the absolute values of ΔX _WET and ΔY _WET of the TAC films obtained in Experiments 102 to 135 were 0.02% to 0.10% larger than the absolute values of ΔX _WET and ΔY _WET of the TAC films obtained in Experiments 2 to 35, respectively. .

As for each polymer film of sample No.A2-A13, B1, B2, C1, and D1 shown in Table 1, each process was performed similarly to experiment 1-experiment 135, and the result of the same tendency as experiment 1-experiment 135 was shown. Could get

It was found that by subjecting the polymer film to water vapor contact treatment, variations in retardation before and after the wet heat endurance test can be suppressed. In addition, it was found that after the steam contact treatment was performed on the polymer film, heat treatment was performed to suppress variation in retardation and variation in dimensions before and after each durability test. And it turned out that condensation prevention process in a water vapor contact process can be prevented in a polymer film by performing condensation prevention process before a water vapor contact process. Moreover, it turned out that the drying process time in a solution film forming method can be shortened by performing a water vapor contact process before a drying process.

Example 5

(Manufacture of Polarizing Plate)

The liquid crystal display device was manufactured using each polymer film produced in Examples 1-2.

(Production of Polarizing Film)

A polyvinyl alcohol film having a thickness of 80 µm was dipped by immersing for 60 seconds in an iodine aqueous solution (iodine concentration 0.05 mass%, temperature 30 ° C). Next, the polyvinyl alcohol film was immersed for 60 second in boric acid aqueous solution (boric acid concentration 4 mass%). The polyvinyl alcohol film immersed in the boric acid aqueous solution was stretched. Before and after stretching, the dimensional change in the stretching direction of the polyvinyl alcohol film was five times. On the finished polyvinyl alcohol film taken out from the boric acid aqueous solution, the drying process which shoots 50 degreeC dry air for 4 minutes was performed. The 20-micrometer-thick polarizing film was obtained by the drying process.

(Manufacture of Polarizing Plate)

Both films taken out from the aqueous sodium hydroxide solution after the saponification process of immersing the polymer film prepared in Examples 1 and 2 and FujiTak TD80 (manufactured by Fujifilm Co., Ltd.) at 1.5 mol / liter in a 55% aqueous sodium hydroxide solution. Washed with water. Next, after immersing both films in 35 degreeC dilute sulfuric acid aqueous solution at 0.005 mol / liter for 1 minute, both films taken out from the dilute sulfuric acid aqueous solution were washed with water. Third, the drying process which puts 120 degreeC dry wind on both films was performed. Fourth, the film on which the saponification process was performed was affixed on one surface of the polarizing film, and the film on which the saponification process was performed was attached to the other surface of the polarizing film, and the polarizing plate was produced. Polyvinyl alcohol adhesive was used for adhesion of both films and a polarizing film. The drying wind of 80 degreeC was put into a polarizing plate for 30 minutes. In the above procedure, polarizing plates P001 to 028 shown in Table 11 were obtained. The combination of each film which comprises polarizing plates P001-028 is as showing in Table 11.

In Table 11, "UF" represents Fuji Tak TD80UF (manufactured by Fuji Film Co., Ltd.), and "UL" represents Fuji Tak TD80UL (manufactured by Fuji Film Co., Ltd.).

Polarizing plate P001 is a polarizing plate 270 shown in FIG. 14, and has a polarizing film 271, a retardation film 272, and a protective film 273. The retardation film 272 and the protective film 273 are Fuji Tak (TD80UF). The slow axis As ₂₇₂ of the retardation film 272 and the slow axis As 273 of the protective film ₂₇₃ are orthogonal to each other. The transmission axis At ₂₇₁ of the polarizing film ₂₇₁ is parallel to the slow axis As ₂₇₂ of the retardation film 272. Polarizing plates P002-P025, 27, 28 are the polarizing plates 280 shown in FIG. 15, and are the same as polarizing plate P001 except having used each polymer film manufactured in Examples 1-2 as retardation film 272. Polarizing plate P026 is the polarizing plate 290 shown in FIG. 16, and is the same as polarizing plate P001 except having omitted the retardation film 272. FIG.

(Measurement of ground shaft angle change)

About the TAC films (sample No. A13 and A13H1), the slow-axis angle change before and after polarizing plate manufacture was measured. AxoScan (manufactured by Axometrics) was used to measure the slow axis angle change. In sample No. A13 which was not subjected to the water vapor contact treatment, the amount of slow axis shift (maximum slow axis angle-minimum slow axis angle) increased from 0.1 ° to 1.0 ° before and after the polarizing plate was deteriorated. On the other hand, in sample No. A13H1 subjected to the water vapor contact treatment, the amount of slow axis shift (maximum slow axis angle-minimum slow axis angle) was hardly changed from 0.1 ° to 0.2 ° before and after polarizing plate processing.

(Manufacture of Liquid Crystal Display Device)

The pair of polarizing plates formed in the liquid crystal display device (KDL-40J5000, Sony Corporation make) using the vertical alignment liquid crystal cell (henceforth a VA type liquid crystal cell) was peeled off. Then, polarizing plates P001-P028 were affixed on the glass surface of VA type liquid crystal cell so that the structure of a polarizing plate might be Table 11. Acrylic adhesive was used for adhesion of VA type liquid crystal cell and each polarizing plate P001-P028. The transmission axis of one polarizing plate was parallel to the transmission axis of the other polarizing plate. Thus, liquid crystal display devices C01 to C10 and 101 to 122 were manufactured.

(Evaluation before and after the moist heat durability test of the viewing angle)

The wet heat endurance test was done about each liquid crystal display device manufactured as mentioned above. After arrange | positioning a liquid crystal display device for 5 hours in the environment of the temperature of 25 degreeC, and 60% of humidity, the viewing angle of the liquid crystal display device was measured. Next, the wet heat durability test was done about the liquid crystal display device. In the wet heat endurance test, the liquid crystal display device was arrange | positioned for 120 hours in the environment of the temperature of 60 degreeC, and the humidity of 90% RH. Finally, after arranging a liquid crystal display device for 5 hours in the environment of the temperature of 25 degreeC, and 60% of humidity, the viewing angle of the liquid crystal display device was measured. EZ-Contrast160D (made by ELDIMI Corporation) was used for the viewing angle measurement of the liquid crystal display device. Table 11 shows the evaluation results before and after the wet heat endurance test of the viewing angle.

E (Excellent): Viewing angles and color variations before and after the wet heat endurance test are hardly recognized.

G (Good): Although the viewing angle and color variation before and after the wet heat endurance test are recognized slightly, there is no problem in practical use.

F (Fail): Viewing angle and color variation before and after the wet heat endurance test are recognized.

The liquid crystal display device using the polarizing plate showed good viewing angle characteristics. In addition, the liquid crystal display devices C06, C07, and C08 in which the viewing angle changes before and after the wet heat durability test are slightly recognized are also used in a good state in which the viewing angle changes before and after the durability test are hardly recognized by using the polymer film subjected to the water vapor treatment. (Liquid crystal display devices 117, 118, 119, 120).

1 is an explanatory diagram showing an outline of an offline stretching facility.

2 is a plan view showing an outline of a tenter portion.

3 is an explanatory diagram showing an outline of a wet gas supply facility.

4 is a perspective view showing an outline of a fixing member for fixing a TAC film in a water vapor contact process.

It is explanatory drawing which shows the outline | summary of the 1st solution film forming installation which performs the solution film forming method of a cooling gelation system.

It is explanatory drawing which shows the outline | summary of the 2nd solution film forming installation which performs the solution film forming method of a cooling gelation system.

It is explanatory drawing which shows the outline | summary of the 3rd solution film forming installation which performs the solution film forming method of a cooling gelation system.

It is explanatory drawing which shows the outline | summary of the 4th solution film forming installation which performs the solution film forming method of a cooling gelation system.

It is explanatory drawing which shows the outline | summary of a 5th solution film forming installation.

It is explanatory drawing which shows the outline | summary of a molten film forming facility.

11 is a perspective view illustrating an arrangement state of a plurality of rolls in a shrinkage treatment region.

It is explanatory drawing which shows the roll wrap length D and the roll length G of the some roll in a shrinkage processing area.

It is explanatory drawing which shows the outline | summary of the liquid crystal display device which has a phase difference film of this invention.

It is an exploded perspective view which shows the outline of the structure of a polarizing plate (P001 in Table 11).

15 is an exploded perspective view showing an outline of the configuration of the polarizing plates (P002 to 025 in Table 11, P027, and P028).

16 is an exploded perspective view showing the outline of the configuration of the polarizing plate (P026 in Table 11).

Claims (14)

(A) continuously flowing a dope containing a polymer and a solvent onto a support traveling with the dope to form a band-like flexible film; (B) peeling off said flexible film from said support body as a polymer film; (C) stretching the polymer film in a width direction; (D) evaporating the solvent from the polymer film through step C; And, (E) contacting the polymer film with water vapor and maintaining the temperature of the polymer film in a range of 100 ° C. or more and 150 ° C. or less, Contacting the water vapor and maintaining the temperature of the polymer film is carried out in conjunction with step D. The method of claim 1, The manufacturing method of retardation film which carries out the said step E for 5 second or more and 60 minutes or less. The method of claim 1, In the said step E, the manufacturing method of the retardation film which makes the polymer film contact the gas which contains the said water vapor and whose relative humidity is 20% RH or more. The method of claim 1, The in-plane retardation (Re) of the polymer film which passed through the said step E is 30 nm or more and 100 nm or less, and the thickness direction retardation (Rth) of the polymer film which passed through the said step E is 70 nm or more and 300 nm or less Manufacturing method. The method of claim 1, The said polymer is a manufacturing method of retardation film which is a cellulose acylate. The method of claim 1, Before the said step B, the manufacturing method of the retardation film which cools the said flexible film until the said flexible film becomes self-supporting. The method of claim 1, Before the said step B, the manufacturing method of the phase difference film which evaporates the said solvent from the said flexible film until the said flexible film becomes self-supporting. The method of claim 6, The said step E is a manufacturing method of the retardation film performed with respect to the said polymer film whose residual solvent amount is 5 mass% or less. The method of claim 7, wherein The said step E is a manufacturing method of the retardation film performed with respect to the said polymer film whose residual solvent amount is 5 mass% or less. A film forming apparatus for flowing a dope containing a polymer and a solvent onto a support to run to form a band-like flexible film; Stretching apparatus which extends the polymer film which is a flexible film peeled continuously from the said support body in the width direction; And, In order to evaporate the said solvent from the said polymer film, the phase difference which includes the water vapor contact apparatus which contacts water vapor with the said polymer film extended | stretched by the said stretching apparatus, and maintains the temperature of the said polymer film in the range of 100 degreeC or more and 150 degrees C or less. Film production equipment. The method of claim 10, The said water vapor contact apparatus makes the said polymer film contact the gas containing the said water vapor, This water vapor contact apparatus manufactures the phase difference film which has a humidity control part which adjusts the relative humidity of the said gas to 20% RH or more. Polarizer; And, It includes a pair of transparent protective film disposed on both sides of the polarizer, One of said pair of transparent protective films is a polarizing plate which is a retardation film obtained by the manufacturing method of Claim 1. Light source; A VA type liquid crystal cell capable of transitioning between a state of transmitting light from the light source and a state of blocking transmission of light; And, The liquid crystal display device of Claim 12 containing the polarizing plate which the said light which passed toward the said liquid crystal cell, or the said light which permeate | transmitted the liquid crystal cell injects into. The method of claim 13, And a polarizing plate formed such that the retardation film is positioned between the light source and the liquid crystal cell.

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