KR20140118738A - Method of manufacturing multilayer film - Google Patents

Abstract

Provided is a method for producing a multilayer film which has excellent adhesion with a film base and a hardening layer, transparency, and hardness. A first solution (31) contains a hardening compound but does not contain cellulose acylate. A second solution (32) contains cellulose acylate and does not contain a hardening compound. The first solution (31) and the second solution (32) are co-cast so that a cast film (41) is formed. By means of a preliminary hardening device (48), ultraviolet rays are irradiated onto the caste film (41) having a ratio of the amount of a first solvent and a second solvent for a dried film produced by drying the cast film (41) at 100% or more. The cast film (41) passed through the preliminary hardening device (48) is dried and applied with magnetic supporting properties in order to be peeled from a drum (46). A wet film (42) formed through peeling is dried so that a dried film (51) is produced. Ultraviolet rays are irradiated onto the dried film (51) by means of a film hardening device (37), so that the hardening compound is hardened.

Description

METHOD OF MANUFACTURING MULTILAYER FILM < RTI ID = 0.0 >

The present invention relates to a method for producing a multilayered film comprising a film base and a cured layer.

BACKGROUND ART [0002] Sheet members used in optical devices such as liquid crystal displays are often made of polymer films. Most of the polymer films have scratches due to contact or friction with other objects. Therefore, in the sheet member, a hard coat is formed on the polymer film so as not to cause friction scratches during the manufacturing process or use of optical devices have. Thus, the film on which the hard coat is formed is called a hard coat film.

The hard coat film having such so-called scratch resistance is obtained by applying a coating liquid for hard coating to form a hard coat on a polymer film to form a coating film and subjecting the coating film to a predetermined hardening treatment And a hard coat is formed as a hardened layer. In the curing step of performing the curing treatment, for example, the curing component contained in the coating film is cured by irradiating light onto the coating film.

However, the hard coat film produced by applying the coating liquid for hard coating to the polymer film to form a coating film and curing the coating film has a small adhesion force to the support (film base) comprising the hard coat and the polymer film, The coat sometimes peels off the support. In addition, this production method has a low production efficiency because of the long time required for both the step of forming the polymer film used as the support and the step of forming the hard coat on the support.

Therefore, Japanese Patent Application Laid-Open No. 2005-224754 proposes a method of producing a hard coat film by applying a coating solution for hard coating to a polymer film being produced in a solution film formation. Japanese Patent Laid-Open Publication No. 2012-096523 discloses a method for producing a cellulose acylate solution for forming a film base comprising cellulose acylate and a hard coat solution for forming a hard coat by using a solution film forming method Casting) to produce a hard coat film. These methods have a certain effect on both the production efficiency and the improvement of the adhesion between the hard coat and the film base.

However, in the method of Japanese Patent Application Laid-Open No. 2005-224754, a hard coat is formed in the process of forming a solution, but it is necessary to form the transport path as long as possible for the drying treatment of drying the applied hard coat. Because of this, the manufacturing time from the softening to the commercialization is still long and the production efficiency is not good.

Further, in the method of Japanese Patent Laid-Open Publication No. 2012-096523, since the cellulose acylate solution and the hard coat solution are laminated at the initial stage of the solution film formation, the conventional solution film-forming equipment for producing a film which does not form a hard coat It is possible to sufficiently dry the hard coat solution, thereby improving the production efficiency and improving the adhesion between the hard coat and the film base. However, according to the method of JP-A-2012-096523, a hard coat film in which transparency and hardness (hardness) of a hard coat are insufficient may be obtained, and there is room for improvement.

Accordingly, an object of the present invention is to provide a method for producing a multilayered film which improves the transparency and the intended function of the cured layer while maintaining the adhesion between the cured layer and the film base and the production efficiency.

A method for producing a multilayered film according to the present invention is a method for producing a multilayered film comprising a flexible step (A step), a magnetic support step (B step), a first curing step (C step), a peeling step (D step) E step) and a second curing step (F step), and the multilayered film has a cured layer formed by curing a curable compound on a film base made of cellulose acylate. Step A forms a flexible film by softening the first solution and the second solution onto a flexible support. The first solution contains a curable compound and a first solvent of a curable compound, and does not contain a cellulose acylate. The curable compound is cured by irradiation of an active ray. The second solution contains a cellulose acylate and a second solvent of cellulose acylate, and does not contain a curing compound. The B step imparts self-supporting property to the flexible film by performing at least one of drying and cooling of the flexible film. The C step increases the viscosity of the flexible film to 50 mPa · s or more by curing the curable compound by irradiating the flexible film with an active ray. The active film is irradiated to a coherent film in which the ratio of the sum of the masses of the first solvent and the second solvent to the mass of the dried film of the coherent film is 100% or more. In the D step, the flexible film after the B step is peeled from the flexible support to form a film. Step E is to dry the film. The F step cures the curable compound by irradiating the active line between at least one of the flexible film between the B step and the D step and the film after the E step.

The curable compound is preferably a monomer or an oligomer.

The step B is performed by a curing device disposed upstream of the blowing device or a curing device provided in the blowing device to dry the coherent film by a blowing device disposed opposite to the flexible support and supplying the dry gas to the flexible film, It is preferable to irradiate the line.

According to the present invention, transparency and a desired function of the cured layer can be improved while maintaining the adhesion between the cured layer and the film base and the production efficiency.

The above objects and advantages will be readily apparent to those skilled in the art by reading the detailed description of the preferred embodiments with reference to the accompanying drawings.
1 is a cross-sectional view of a hard coat film of the present invention.
2 is a schematic view of a film production apparatus for producing the hard coat film of the present invention.
3 is a schematic cross-sectional view of a flexible die.
4 is a cross-sectional view of the distal end of the flexible die.
5 is a cross-sectional view of the distal end of the flexible die.
6 is a cross-sectional view of the distal end of the flexible die.

1, a hard coat film 10 manufactured by a film production facility and a method described later is formed of a hard coat 11, a film base 12, and a multi-layer film 13 having a mixed layer 13 to be. The mixed layer 13 is formed between the hard coat 11 and the film base 12. Thus, the hard coat film 10 has the hard coat 11 on one of the film surfaces.

The hard coat 11 is for imparting resistance to the film base 12. The hard coat 11 contains a polymer obtained by polymerizing a curable compound, and the hard coat 11 contains no cellulose acylate. As a result, the hardness is higher than in the case where cellulose acylate is contained. The hard coat 11 is a cured layer formed by polymerization of a curable compound as described later. Further, since the hardening agent is used in forming the hard coat 11, a hardening agent remains in the hard coat 11 as well. The curing agent is for promoting curing of the curable compound.

The film base 12 contains a cellulose acylate and does not contain a polymer obtained by polymerizing the above-mentioned curable compound. The mixed layer 13 contains both cellulose acylate and the above-mentioned polymer and is a layer in which both are mixed.

The thickness of the hard coat film 10 is TA, the thickness of the hard coat 11 is T11, the thickness of the film base 12 is T12, and the thickness of the mixed layer 13 is T13. The ratio of the sum of the thickness T11 of the hard coat 11 to the thickness T13 of the mixed layer 13 with respect to the thickness TA of the hard coat film 10 It is bigger than that. The sum of the thickness T11 of the hard coat 11 and the thickness T13 of the mixed layer 13 is at least 10% with respect to the thickness TA of the hard coat film 10. [ As a result, the adhesion of the hard coat 11 is higher than that of the conventional coating. The ratio of the sum of the thickness T11 of the hard coat 11 to the thickness T13 of the mixed layer 13 with respect to the thickness TA of the hard coat film 10 is defined as {(T11 + T13) / TA} × 100 (unit:%). It is preferable that the sum of the thickness T11 of the hard coat 11 and the thickness T13 of the mixed layer 13 is in the range of 10% or more and 30% or less with respect to the thickness TA of the hard coat film 10 desirable.

Also in the conventional hard coat film produced by coating, there is a case where a film-like cellulose acylate to which a coating liquid is applied and a mixed layer in which a hard coat-forming polymer is mixed are identified. However, in order to increase the ratio of the sum of the thickness of the hard coat and the thickness of the mixed layer to the thickness of the hard coat film as described above, it is necessary to apply the coating liquid plural times in order. As the number of coatings is increased in this way, the number of steps for producing a hard coat film increases and the thickness of the hard coat film also increases. On the other hand, according to the production method described later, the thickness of the film is kept at the same level as that of the conventional hard coat film by coating, and the number of steps required for production is lower than that of the conventional method of hard coat film production The hard coat film 10 is produced with a small number of process steps. In addition to these advantages, the adhesion of the hard coat 11 is larger than that of the conventional hard coat film.

The thickness T11 of the hard coat 11 is in the range of 1 m to 20 m. By setting the thickness to 1 m or more, the hardness becomes higher as compared with the case of less than 1 m, and the durability is more reliably exhibited.

1, the boundary between the hard coat 11 and the mixed layer 13 and the boundary between the film base 12 and the mixed layer 13 are shown for convenience. However, this boundary is conceptual based on the constitution of the constituent material, and can not be admitted. However, the existence of the mixed layer 13 is not limited to the time-of-flight secondary ion mass spectrometer described in paragraphs [0027] to [0033] of the aforementioned Japanese Patent Laid- , Hereinafter abbreviated TOF-SIMS).

TOF-SIMS is a device that performs secondary ion mass spectrometry (SIMS) to detect ions (secondary ions) emitted from the surface of a sample by irradiating the primary ion beam to a sample to be analyzed Lt; / RTI > For the analysis, the sample sampled from the hard coat film 10 to be analyzed is embedded in an epoxy resin. The sample in the embedding state is cut obliquely at an angle of, for example, about 15 degrees with respect to the film surface of the hard coat film 10 by using a microtome, and the sample is exposed on the surface to form an analytical surface. The primary ion is irradiated on the exposed part of the film. The mass spectrometer uses a time-of-flight mass spectrometer (TOF-MS). In this embodiment, when TOF-SIMS is performed, TOF-SIMS5 and Bi3 ⁺ primary ion gun manufactured by ION-TOF Corporation are used.

According to this method, it is confirmed that the amount of the cellulose acylate in the mixed layer 13 gradually increases from the hard coat 11 toward the film base 12, and this increment is continuous. It is also confirmed that the amount of the polymer in the mixed layer 13 decreases from the hard coat 11 toward the film base 12, and this diminution is continuous. By the distribution in the thickness direction of the cellulose acylate and the polymer, the adhesion force of the hard coat 11 is surely high.

In addition, in the conventional hard coat film produced by coating, even if the amount of cellulose acylate in the mixed layer increases from the hard coat toward the film base by performing a plurality of coatings, this increase is gradual . Similarly, even if the amount of the polymer decreases from the hard coat toward the film base, this diminution is stepwise.

A method of producing a hard coat film will be described with reference to Fig. As shown in Fig. 2, the film production facility 30 is a solution film production facility for producing the hard coat film 10 from the first solution 31 and the second solution 32 by solution casting. The first solution 31 is for forming the hard coat 11 and the mixed layer 13. The second solution 32 is for forming the film base 12 and the mixed layer 13 as a support.

The first solution 31 contains a curable compound as a component to be cured by irradiation with ultraviolet ray and a solvent of the curable compound (hereinafter referred to as a first solvent). In the present embodiment, the first solution 31 contains a curing agent that promotes curing of the curable compound. Further, since the first solution 31 contains no cellulose acylate, the hard coat film 10 having high transparency and hardness can be reliably obtained under the manufacturing method described later.

The concentration of the curable compound in the first solution 31 is preferably in the range of 40 mass% or more and 60 mass% or less, but is not limited to this range. This concentration is obtained by {Z11 / X11} x 100 when the mass of the first solution 31 is X11 and the mass of the curable compound is Z11. Details of the curable compound and the curing agent will be described later.

When the concentration of the curable compound is 40 mass% or more, the hard coat 11 having a higher hardness is formed, as compared with the case of less than 40 mass%. When the concentration of the curable compound is 60 mass% or less, since the viscosity of the second solution 32 is lower than that when the concentration of the second solution 32 is larger than 60 mass% .

The second solution 32 contains a solvent of cellulose acylate and cellulose acylate (hereinafter referred to as a second solvent). The details of the cellulose acylate will be described later. The second solution 32 does not contain a curing compound and a curing agent. Further, it is assumed that the first solution 31 contains no cellulose acylate as described above. As a result, the hard coat film 10 is obtained in which the amount of cellulose acylate in the mixed layer 13 gradually increases from the hard coat 11 toward the film base 12. Since the first solution 31 contains the curable compound as described above, the amount of the above-mentioned polymer in the mixed layer 13 can be controlled by the first solution 31 and the second solution 32, The hard coat film 10 is obtained which is continuously decreased from the hard coat 11 toward the film base 12.

The concentration of the cellulose acylate in the second solution 32 is in the range of 15 mass% or more and 30 mass% or less. This concentration is obtained by {Y12 / X12} x 100 when the mass of the second solution 32 is X12 and the mass of the cellulose acylate is Y12. Further, it is preferable that the first solvent and the second solvent have components common to each other. As a result, the adhesion between the film base 12 and the hard coat 11 becomes stronger, and recovery and reuse are easier. Common components include, for example, dichloromethane, methanol, and butanol.

The film forming portion 35 is formed by forming a flexible film 41 composed of the first solution 31 and the second solution 32 and peeling the first and second solvents in a state containing the first and second solvents, To form a wet film (42). The film manufacturing facility 30 includes a film forming section 35, a film drying section 36, a curing device (hereinafter referred to as a film curing device) 37, a winding device 38, and the like.

The film forming portion 35 is provided with a flexible die 43, a drum 46, a blowing device 47, a curing device (hereinafter referred to as a preliminary curing device) 48, a curing device A hardening device) 49, a roller 50, and the like. The flexible die 43 continuously flows out the first solution 31 and the second solution 32 supplied thereto. The drum 46 is an endless flexible support which is disposed below the flexible die 43 and rotates in the circumferential direction.

The first solution 31 and the second solution 32 are all flexible from one flexible die 43 to the drum 46. That is, this flexible method is a well-known shared method. This common streak is formed on the drum 46 by discharging the first solution 31 and the second solution 32 by superimposing the flows from each other through the flexible die 43, (31) are superimposed on one another. The second solution 32 comes into contact with the drum 46 and the first solution 31 is brought into contact with the first solution 31 because the flexible film is difficult to peel off from the drum when the first solution 31 is directly contacted on the drum 46. [ A flexible film 41 in a state of being superposed on the second solution 32 is formed. Details of the flexible die 43 will be described later with reference to other drawings.

In the present embodiment, the first solution 31 and the second solution 32 are joined together in the flexible die 43, and both are flown out from the flexible die 43 while overlapping the flow of both. Instead of this, for example, two flexible dies may be arranged along the rotational direction of the drum 46, and the second solution 32 may flow out from the flexible die on the upstream side, The first solution 31 and the second solution 32 may be independently inflexible by superposing the solution 31 on the drum 46 by superposing the solution 31 on the drum 46.

The drum 46 has a rotary shaft 46a fixed to the center of the side surface of the circular shape and a driving mechanism (not shown) for rotating the rotary shaft 46a. The driving mechanism rotates the drum 46 in the circumferential direction integrally with the rotary shaft 46a by rotating the rotary shaft 46a. The drum 46 is provided with a temperature adjusting section (not shown) for adjusting the peripheral surface temperature to a predetermined temperature. In the present embodiment, the peripheral surface of the drum 46 is cooled by the temperature control unit to cool the flexible film 41 to a predetermined temperature to gel. However, the temperature of the flexible film 41 may be increased by heating the peripheral surface of the drum 46 by the temperature adjusting unit. When the gelation is promoted only by the drying process without cooling the flexible film 41, it is preferable to heat the peripheral surface of the drum 46 by the temperature regulating section.

The flexible support for forming the flexible film 41 is not limited to the drum 46. For example, instead of the drum 46, a belt (not shown) supported by at least two backup rollers (not shown) and running in the longitudinal direction may be a flexible support. The belt travels by rotating at least one backup roller. In the so-called cooling and fusing system in which the flexible film 41 is gelled by cooling, the flexible support is often formed of the drum 46. On the other hand, in the case of the so-called dry flexible method in which the gelation is promoted only by the drying treatment without cooling the flexible film 41, the flexible support is often made of a belt.

It is preferable to provide a pressure reducing chamber (not shown) on the upstream side of the flexible die 43 in the rotating direction of the drum 46. [ The decompression chamber separates the space to be decompressed from the outer space and sucks the gas in the space to be decompressed by sucking the gas in the decompression chamber by a suction device (not shown). Thereby, the area on the upstream side of the bead formed from the flexible die 43 to the drum 46 is decompressed.

The preliminary curing device 48 is intended to suppress the diffusion of the cellulose acylate by increasing the viscosity of the first solution 31 in the flexible film 41. [ The preliminary curing device 48 is disposed to face the circumferential surface of the drum 46 and is disposed in the vicinity of the flexible die 43 on the downstream side of the flexible die 43 in the rotating direction of the drum 46 . The preliminary curing device 48 emits ultraviolet rays toward the circumferential surface of the drum 46.

The flexible film 41 is gradually dried after being formed. The pre-curing device 48 is disposed at or below the following 100% position. The 100% position is a position at which the ratio of the sum of the masses of the first solvent and the second solvent to the mass of the dried film obtained by drying the flexible film 41 reaches 100%. The mass of the dry film obtained by drying the flexible film 41, that is, the mass of the solid component in the flexible film 41. The mass ratio is calculated by multiplying the sum of the masses of the first solvent and the second solvent in the flexible film 41 by MS and the mass of the dried film of the flexible film 41 by M41, to be. More preferably, the preliminary curing device 48 is disposed upstream of a position at which the ratio of the mass of the first solvent to the mass of the second solvent with respect to the mass of the dried film of the flexible film 41 reaches 150% It is more preferable that it is disposed upstream of the position where it reaches.

The position of the preliminary curing device 48 is set based on the mass ratio of the second solvent in the flexible film (not shown) formed only when the second solution 32 is flexible, The effect of inhibition is higher. This is because the position of the pre-curing device 48, which sets the mass ratio of the second solvent as follows, is located upstream of the above-mentioned 100% position. First, the position at which the mass ratio of the second solvent to the mass of the dry film of the coagulated film of the second solution 32 reaches 100% (hereinafter referred to as the second solvent 100% position) is specified. This mass ratio is a percentage obtained by (MB / MA) x 100 when the mass of the second solvent in the flexible film 41 is MB and the mass of the dried film of the flexible film of the second solution 32 is MA. The 100% position of the second solvent is formed by forming a flexible film (hereinafter referred to as a second solution flexible film) with only the second solution 32 using the film forming portion 35, (HB-HA) / HA} 100 when the thickness of the second solution coextrusion film is denoted by HB, the thickness of the second solution coffering film is denoted by HB, and the thickness of the dried film obtained by drying the second solution coercive- (HB) is detected. The dried dry film is a film which is dried to a mass ratio of 0.5% by mass or less based on the solid content of the second solvent. More preferably, the preliminary curing device 48 is disposed upstream of the position at which the mass ratio of the second solvent to the mass of the dried film of the second solution flexible film reaches 150%, and more preferably, It is more preferable to be disposed.

In the present embodiment, the preliminary curing device 48 is disposed close to the flexible die 43 and upstream of the duct 53 described later of the air blowing device 47, but the position of the preliminary curing device 48 is not limited to this. For example, it may be provided in the duct 53. In this case, for example, the pre-hardening device 48 may be provided on the opposite surface of the duct 53 opposed to the drum 46. However, from the viewpoint of further suppressing the diffusion of the cellulose acylate as described later, the position where the preliminary curing device 48 is disposed is preferably the upstream side in the rotational direction of the drum 46.

The air blowing device 47 is for imparting self-supporting property by drying the flexible film 41 and includes a duct 53, a blower 54, a controller 55, and the like. The duct 53 is for supplying a dry substrate sent from the blower 54 (hereinafter referred to as a dry substrate) to the flexible film 41. The duct 53 extends along the circumferential surface of the drum 46 and is disposed close to the downstream side of the preliminary curing device 48 and is disposed with a certain distance from the circumferential surface of the drum 46. [ The duct 53 has a plurality of nozzles 53a on the opposing surface facing the drum 46 and discharges the drying gas from the openings formed at the tips of these nozzles 53a. The controller 55 is connected to the blower 54 to control the flow rate and temperature of the dry gas from the blower 54. [ The flow rate, the flow rate, the temperature, and the like of the dry gas ejected from the duct 53 are controlled by the control of the blower 54 by the controller 55.

The flexible film hardening device 49 hardens the surface of the layer formed from the first solution 31 so that a layer formed from the first solution 31 of the flexible film 41 peeled off from the drum 46 is transferred to the roller 50 So as to prevent the roller 50 from being contaminated. The flexible film hardening device 49 is for preventing ripping or wrinkling at the time of peeling when the flexible film 41 is a thin film, particularly a problem. The flexible film hardening device 49 is provided between the duct 53 and the roller 50 and emits ultraviolet rays.

The flexible film 41 is peeled from the drum 46 when the flexible film 41 has self-supporting property. The roller 50 is provided close to the peeling position for peeling the flexible film 41 from the drum 46. The rollers 50 are disposed so as to face the circumferential surface of the drum 46 with the longitudinal direction thereof coinciding with the longitudinal direction of the drum 46. The roller 50 supports the wet film 42 when the flexible film 41 is peeled from the drum 46, whereby the peeling position is kept constant. A roller 52 for guiding the wet film 42 to the tenter 56 is provided on the conveying path between the film forming portion 35 and the tenter 56 of the film drying portion 36 described later.

The film drying unit 36 is for drying the flexible film peeled from the drum 46 in the state containing the first and second solvents, that is, the wet film 42 to be described later. The film drying section 36 includes a tenter 56, a cutting device 57, and a drying chamber 58, for example.

The tenter 56 is provided with a plurality of clips 61 for gripping the side end portions of the wet film 42 on both sides of the conveying path of the wet film 42. In the case where the wet film 42 can not withstand the gripping by the clip 61 and the wet film 42 is torn by the grasping due to the content ratio of the first and second solvents being too high, The pin may be inserted into the side end portion of the wet film 42 by using a pin instead of the wet film 42 to thereby support the wet film 42. [

The plurality of clips 61 are provided on an endless chain (not shown) running continuously, and the running trajectory of the clip 61 can be changed by displacing the running path of the chain. The width of the wet film 42 may be regulated by appropriately adjusting the distance between the clip 61 and the clip 61 disposed on both sides of the wet film 42. [

The tenter 56 is provided with a duct 62 for jetting dry gas such as dry air or the like to the wet film 42. By this air blowing, The drying of the wet film 42 is advanced. Further, when the wet film 42 is supported by the peripheral surface of the roller and can be transported by the rotation of the roller, the tenter 56 need not be disposed.

The wet film 42 from which the holding of the clip 61 is released is guided to the cutting device 57 provided downstream of the tenter 56. [ At the gripping position held by the clip 61 of the wet film 42, there is a sign of gripping. The ablation device 57 continuously cuts the side end portion of the wet film 42 so that the grip trace is separated from the central portion that becomes the product of the hard coat film 10.

Downstream of the ablation device 57 is a drying chamber 58 having a plurality of rollers 63 for supporting the wet film 42 cut off at both ends circumferentially and provided with a drying gas (for example, dry air) . The roller 63 includes a driving roller for carrying the wet film 42 by rotating in the circumferential direction. The dry gas to be supplied is adjusted to a predetermined temperature and humidity, and the wet film 42 is dried further by the dry gas to be completely dried. The degree of this " complete " is the degree of drying to the extent that there is no problem as a product, and the residual solvent amount may not necessarily be zero (0). In the following description, the dried film 51 is referred to as a dry film 51.

The film hardening device 37 provided downstream of the film drying section 36 is for forming the hard coat 11 by advancing the hardening of the hardening compound. The film hardening device 37 emits ultraviolet rays toward the passing dry film 51.

The film curing device 37 may be provided in the film drying section 36 instead of downstream of the film drying section 36 as in the present embodiment.

The winding device 38 is for rolling a long hard coat film 10 into a roll shape. The winding spindle 64 is set in the winding device 38 and has a driving mechanism (not shown) for rotating the winding spindle 64.

The flexible die 43 will be described with reference to Fig. The flexible die 43 is provided with an outlet 70 for discharging the first solution 31 and the second solution 32 toward the drum 46, a first supply port 71, a second supply port 72, A first flow path 73 and a second flow path 74 are formed. The first solution 31 is supplied from the first supply port 71 and the second solution 32 is supplied from the second supply port 72. The first and second flow paths 73 and 74 are formed so that the shapes of the respective cross sections orthogonal to the direction in which the first solution 31 and the second solution 32 flow are parallel to the width direction of the flexible film 22 And the longitudinal direction is a long slit-shaped flow path. The second flow path 74 is formed so as to connect the second supply port 72 and the outlet port 70 and the first flow path 73 connects the first supply port 71 and the outlet port 70 .

As described above, in the flexible die 43, the outermost ends of the first and second flow paths 73, 74 are connected to the outflow port 70, and the first and second solutions 31, (Merged portion) in the vicinity of the outflow port 70, and then flows out from the outflow port 70 to the drum 46.

As shown in Fig. 4, when the most upstream position of the confluence portions in contact with the first and second solutions 31 and 32 is defined as the most upstream confluence point P1, The distance L1 from the most upstream side confluence point P1 to the outlet port 70 is in a range of 0 mm to 5 mm, which is extremely short compared to a common shared facility. However, the smaller the distance L1 is, the more preferable it is 0 mm.

In the flexible die 43, the slit clearance W1 of the first flow path 73, that is, the thickness of the first flow path 73 (slit gap) is 1 mm or less. The flexible die 43 is provided such that the distance L2 between the outlet 70 and the drum 46 is greater than 0 mm and less than or equal to 3 mm.

As described above, the distance L1 from the most upstream side confluence point P1 to the outlet port 70 is 0 mm or more and 5 mm or less, and the distance L1 is extremely short as compared with a general shared facility. Therefore, even when the viscosity ratio of the first and second solutions 31 and 32 is high, specifically, even if the viscosity of the second solution 32 is 10 times or more the viscosity of the first solution 31, It is hardly affected by the flow of the solution (hereinafter referred to as the second solution flow) by the flow of the first solution (hereinafter referred to as the first solution flow), and the thickness of the hard coat 11 becomes uniform .

In addition, since the slit clearance W1 of the first flow path 73 is set to 1 mm or less, the first solution 31 having a low viscosity is prevented from flowing unlimitedly, and the thickness of the hard coat 11 becomes uniform . From the viewpoint that it is difficult to be affected by the pressurization of the first solution flow as described above, the slit clearance W1 is preferably narrow, and specifically, it is preferably 1 mm or less. By doing so, the second solution flows stably with respect to the first solution flow, and the thickness of the hard coat 11 becomes uniform.

In addition, since the distance L2 from the outlet 70 to the drum 46 is 3 mm or less, the thickness of the hard coat 11 becomes more uniform. That is, if the distance from the outlet to the drum is too large, the thickness of the first solution having a low viscosity can not be maintained during the drop from the outlet to the drum, so that the desired film thickness is not obtained and the thickness of the flexible film becomes nonuniform in the longitudinal direction , And the distance L2 is 3 mm or less, the occurrence of such a problem is avoided.

The specific viscosity of the first and second solutions 31 and 32 supplied to the flexible die 43 and the slit clearance W2 of the second flow path 74 can be appropriately changed. The distance L2 from the outlet 70 to the drum 46 is 3 mm or less, but the effect of making the thickness of the hard coat 11 uniform is significant, but it is not necessarily limited to 3 mm or less.

In addition, the slit clearance of the outlet 70 can be appropriately set. For example, as shown in Fig. 5, the slit clearance WE of the outlet 70 may be the same as the slit clearance W2 of the second flow path 74. Fig. 6, the slit clearance WE of the outlet port 70 is equal to the sum of the slit clearance W2 of the second flow path 74 and the slit clearance W1 of the first flow path 73, That is, WE = W1 + W2. 5 and 6, the same members as those of the above-described embodiment are denoted by the same reference numerals and the description thereof is omitted, and the illustration of the drum 46 is omitted.

However, if the slit clearance WE is smaller than the slit clearance W2, the first solution 31 is pressurized by the second solution 32 to join the first solution 31, It becomes difficult to make the thickness constant. Therefore, the slit clearance WE is preferably equal to or greater than the slit clearance W2.

If the slit clearance WE is larger than the sum of the slit clearance W1 and the slit clearance W2, the adhesion between the first solution 31 and the second solution 32 may be deteriorated. Therefore, the slit clearance WE is preferably equal to or less than the sum of the slit clearance W1 and the slit clearance W2.

As described above, it is preferable that the slit clearance WE be equal to or larger than the slit clearance W2 and equal to or smaller than the sum of the slit clearance W1 and the slit clearance W2. However, if WE < W1 + W2, And the quality of the hard coat film 10 (see Fig. 1) as a product deteriorates. That is, by comparing the method (Dry on Wet) in which the layer formed from the second solution 32 is dried and then the first solution 31 is applied thereon to form a hard coat thereon, In the method of simultaneously forming the layer formed from the first solution 31 and the layer formed from the second solution 32, the fluidity of the first solution 31 is high, and the flow rate of the solution between the first and second solutions Diffusion occurs, and the mixed layer 13 is formed, so that the original adhesion property is high. As a result, when WE < W1 + W2, unnecessarily diffusing occurs and the mixed layer becomes too thick, and the hardness of the hard coat film is lowered or clouding occurs. Therefore, the most preferable slit clearance WE is "WE = W1 + W2". As a result, the film base 12 and the hard coat 11 can be brought into close contact with each other while the thickness of the hard coat 11 is kept constant.

Although the flexible die 43 is used to share the first and second solutions 31 and 32 in common, it is also possible to share the third solution (not shown) in addition to the first and second solutions 31 and 32 It may also be applied to the case of softening.

The operation of the above configuration will be described. When the first solution 31 and the second solution 32 are supplied, the flexible die 43 joins the first solution 31 and the second solution 32 so that the flow of the first solution 31 and the second solution 32 are overlapped, . The outflow is made such that the flow of the first solution 31 is superimposed on the downstream side of the flow of the second solution 32 in the rotating direction of the drum 46. The first solution 31 and the second solution 32 are continuously flowed toward the peripheral surface 46a of the drum 46 on which the flexible die 43 rotates, A flexible film 41 is formed on the drum 46 so that the flexible film 41 is superimposed. Thus, since the drying of the layer formed from the first solution 31 is performed together with the drying of the layer formed from the second solution 32, the hard coat film 10 is produced with high production efficiency.

The first solution 31 and the second solution 32 gradually diffuse into each other from the point of merging inside the flexible die 43. The diffusion proceeds into the flexible film 41 even after the flexible film 41 is formed, and the mixed layer 13 is formed by this diffusion.

The flexible film 41 passes through the preliminary curing device 48, the duct 53 of the blowing device 47 and the flexible film curing device 49 in this order in accordance with the rotation of the drum 46. The flexible film 41 passes through the pre-curing device 48, whereby ultraviolet rays are irradiated. As a result, the viscosity of the first solution 31 increases as the curing compound in the first solution 31 of the flexible film 41 is polymerized and polymerization proceeds. By increasing the viscosity of the first solution 31, diffusion of the cellulose acylate, which has been carried out until reaching the pre-curing unit 48, is suppressed. Thus, the mixed coat layer 13 containing the cellulose acylate and the above-described polymer and the hard coat 11 containing no cellulose acylate are formed on the obtained hard coat film 10.

In order to reliably form the hard coat 11 containing no cellulose acylate, it is preferable to increase the viscosity of the first solution 31 to 50 mPa · s or more by the preliminary hardening device 48. That is, ultraviolet irradiation (preliminary curing process) is performed by the preliminary curing device 48 (first curing process) until the viscosity becomes at least 50 mPa · s. The ultraviolet rays are irradiated by the pre-curing device 48 until the viscosity becomes 80 mPa · s or more, more preferably 100 mPa · s or more.

In the case where the pre-hardening treatment is not performed, the diffusion of the cellulose acylate proceeds even while passing through the duct 53. As a result, the hard coat 11 containing no cellulose acylate may be thinner than the intended thickness, or hard coat may not be formed, and a film composed of the mixed layer and the film base may be formed. In such a case, the thickness of the mixed layer becomes too thick than the desired thickness, resulting in poor transparency or a hard coat film with low hardness. Since the viscosity of the first solution 31 is extremely lower than that of the second solution 32 unless the cellulose acylate is contained in the first solution 31 in order to reliably manifest sufficient hardness in the hard coat 11, These phenomena due to the diffusion of the acylate are particularly remarkable. On the other hand, when the preliminary hardening treatment is performed, the subsequent diffusion of the cellulose acylate into the first solution 31 is suppressed, so that the mixed layer 13 for securing the adhesion between the hard coat 11 and the film base 12 And a hard coat 11 having a thickness sufficient to exhibit high hardness is reliably formed. In addition, the mixed layer 13 is formed to a thickness sufficient to exhibit a high adhesion force and to such an extent that transparency can be ensured.

It is difficult to detect the viscosity of the first solution 31 on-line. Therefore, in the present embodiment, a sample of the first solution 31 is previously softened to form a flexible film sample, and the flexible film sample is irradiated with the ultraviolet rays by the pre-hardening device 48. [ Then, the relationship between the irradiation time and the viscosity of the flexible film sample is obtained. The irradiation time by the preliminary curing device 48 for the flexible film 41 on the drum 46 is obtained based on this relationship and the rotational speed of the drum 46 when the hard coat film 10 is manufactured. The length of the irradiation area in the rotational direction of the drum 46 is changed by increasing or decreasing the number of the preliminary curing devices 48 installed in accordance with the obtained irradiation time. In place of this method, on the basis of the above-described relationship between the irradiation time and the viscosity of the flexible film sample and the length of the irradiation area of the pre-hardening device 48 in the rotating direction of the drum 46, The rotation speed may be set.

The flexible film 41 is dried by passing through the duct 53 so that magnetic support is imparted to the extent that the peeling by the roller 50 and the conveyance by the roller 52 can be carried out ). By drying with the duct 53, the viscosity of the layer formed from the first solution 31 in the flexible film 41 is further increased. As a result, diffusion of the cellulose acylate in the flexible film 41 after ultraviolet irradiation is reliably suppressed. In this embodiment, the self-supporting treatment is performed after the pre-hardening treatment.

When the preliminary curing device 48 is provided on the opposite side of the duct 53 facing the drum 46, the ultraviolet rays are irradiated by the preliminary curing device 48 and the supply of the drying gas from the duct 53 The viscosity of the first solution 31 can be raised to 50 mPa · s or more. In this embodiment, the pre-hardening treatment is performed during the self-sustaining treatment, that is, during drying.

The flexible film 41 passes through the flexible film curing device 49 to be irradiated with ultraviolet rays. As a result, the curing compound contained in the flexible film 41 is further polymerized and cured further, so that the hard coat 11 and the mixed layer 13 of the hard coat film 10 are formed into a more rigid It becomes. This prevents the flexible film 41 from peeling off from the drum 46 while preventing the flexible film 41 from being torn or wrinkled, which is particularly problematic when the flexible film 41 is thin. More specifically, the curing treatment (the curing treatment before peeling) by the flexible film curing device 49 is performed so that the polymerization rate of the curable compound becomes 50% or more and the maximum value of the polymerization rate of the curable compound becomes constant As shown in Fig.

The wet film 42 formed by the peeling of the flexible film 41 from the drum 46 is guided by the tenter 56 and dried in a state in which the width is regulated. The wet film 42 is guided from the tenter 56 to the cutting device 57 and the gripping by the clip 61 is cut off and then the drying is further carried out by the drying chamber 58, ). As described above, in the film drying section 36, the wet film 42 is dried to perform a film drying process using the dry film 51. [

The dry film 51 is irradiated with ultraviolet rays from the film curing device 37 by passing through the film curing device 37. By this irradiation, the hardening of the uncured hardening compound is promoted (hardening treatment after peeling). Concretely, the curing proceeds to such an extent that the maximum polymerization rate of the polymer is kept constant and does not increase. Thereby, the hard coat 11 made of a polymer is formed on one side of the film surface of the dry film 51, and the hard coat film 10 is obtained. However, when the film hardening device 37 is installed in the film drying section 36, the hard coat 11 is formed during the process of forming the dry film 51, that is, during drying of the wet film 42, The hard coat film 10 is obtained.

Further, another layer (not shown) may be formed on the hard coat 11 by applying a coating liquid containing a curable compound to the film after passing through the film hardening device 37. In this case, in the film hardening device 37, the polymerization rate of the curable compound is set to 50% or more, and the irradiation is finished before the maximum polymerization rate is kept constant. When the curable compound in the coating film is sufficiently cured together with the uncured curable compound contained in the first solution 31 by using another curing device (not shown) for the coated film formed by coating do. As a result, the adhesion between the hard coat 11 and the layer formed thereon is reliably manifested.

The obtained hard coat film 10 is wound on the winding spindle 64 in the form of a roll when supplied to the winding device 38. The above example is also applicable to the case of producing the hard coat film 10, but it is also effective in the case of forming another hardened layer in which the hardening compound is hardened instead of the hard coat 11. As a result, the diffusion of the curable compound is suppressed, and the intended function of the cured layer is expressed.

In the above embodiment, the flexible film hardening device 49 advances the hardening of the hardening compound in the hard coat 11 to such an extent as not to contaminate the roller 50, and the wet film 42 tears or peel Curing of the curing compound is progressed to such an extent that the occurrence of the curing compound is suppressed. However, curing of the curable compound by the flexible film curing device 49 may be further advanced. Thus, for example, the production speed of the hard coat film 10 can be increased without forming the transport path of the film drying section 36 longer. As described above, the flexible film hardening device 49 is used in order to avoid occurrence of the above problem in the peeling process, in addition to being used for forming the hard coat 11 by hardening the uncured hardening compound at a faster timing .

In the above embodiment, both the flexible film curing device 49 and the film curing device 37 are disposed. However, either one of them may be arranged. That is, in the above-described embodiment, both of the pre-peeling hardening treatment and the post-peeling hardening treatment are performed as the second hardening step, but the second hardening step may be performed either one of them. For example, even if the ultraviolet rays are not irradiated by the flexible film hardening device 49, the hard coat 11 is hardened enough not to contaminate the roller 50, or the wet film 42 is torn or wrinkled The flexible film curing device 49 may not be provided. In the case where the hardening compound in the hard coat 11 has already been cured without irradiation of ultraviolet rays by the film hardening device 37, the film hardening device 37 may not be provided.

The components of the first solution 31 and the second solution 32 will be described below.

  [Cellulose Acylate]

The cellulose acylate is a cellulose acylate in which the ratio of esterification of the hydroxyl group of cellulose with carboxylic acid, that is, the substitution degree of the acyl group (hereinafter referred to as the acyl group substitution degree) satisfies all the conditions of the following formulas (1) to Particularly preferred. In (1) to (3), A and B are both an acyl group substitution degree, the acyl group in A is an acetyl group, and the acyl group in B has 3 to 22 carbon atoms.

 2.5? A + B? (One)

 0? A? 3.0 ... (2)

 0? B? 2.9? (3)

The glucose unit constituting the cellulose and having? -1,4 bonding has hydroxyl groups liberated at the 2nd, 3rd and 6th positions. The cellulose acylate is a polymer in which a part or all of the hydroxyl groups of such cellulose are esterified and the hydrogen of the hydroxyl group is substituted with an acyl group having 2 or more carbon atoms. When the esterification of one hydroxyl group in the glucose unit is 100%, the degree of substitution is 1. Therefore, in the case of cellulose acylate, when the hydroxyl groups at the second, third and sixth positions are each esterified to 100% .

Here, the total acyl group substitution degree obtained by "DS2 + DS3 + DS6", in which the substitution degree of the acyl group at the second position is DS2, the substitution degree of the acyl group at the third position is DS3, and the substitution degree of the acyl group at the sixth position is DS6, More preferably 2.22 to 2.90, and still more preferably 2.40 to 2.88. Further, "DS6 / (DS2 + DS3 + DS6)" is preferably 0.32 or more, more preferably 0.322 or more, and further preferably 0.324 to 0.340.

The acyl group may be only one kind or two or more kinds. When two or more kinds of acyl groups are present, one of them is preferably an acetyl group. The sum of the degree of substitution of acetyl groups of the hydrogen atoms at the 2nd, 3rd, and 6th hydroxyl groups by DSA, and the total degree of substitution by the acyl groups other than the acetyl groups at the 2nd, 3rd, , The value of " DSA + DSB " is preferably 2.2 to 2.86, and particularly preferably 2.40 to 2.80. The DSB is preferably 1.50 or more, particularly preferably 1.7 or more. It is preferable that 28% or more of the DSB is a substitution of the sixth hydroxyl group, more preferably 30% or more, still more preferably 31% or more, particularly preferably 32% . The value of " DSA + DSB " at the sixth position of the cellulose acylate is preferably 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more. By using the cellulose acylate as described above, it is possible to obtain a polymer solution having a desired solubility to make a polymer solution used for solution film formation and a low viscosity, which is preferable for filtration. Particularly, in the case of using a non-chlorine-based organic solvent, the above-mentioned cellulose acylate is preferable.

As the acyl group having 2 or more carbon atoms, an aliphatic group or an aryl group is not particularly limited. For example, an alkylcarbonyl ester, an alkenylcarbonyl ester or an aromatic carbonyl ester, an aromatic alkylcarbonyl ester, etc. of cellulose, and they may each have a further substituted group. Propanoyl group, butanoyl group, pentanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, iso-butanoyl group, t -Butanoyl group, cyclohexanecarbonyl group, aureoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like. Of these, more preferred are a propionyl group, a butanoyl group, a dodecanoyl group, an octadecanoyl group, a t-butanoyl group, a peroyl group, a benzoyl group, a naphthylcarbonyl group and a cinnamoyl group, and a propionyl group and a butanoyl group Particularly preferred.

[Curable compound]

The curable compound in the present embodiment is an ultraviolet curable compound which is cured by irradiation with ultraviolet rays, but the curable compound is not limited thereto. For example, it may be cured by irradiation of an active ray such as a heat ray or an electron beam. The preliminary curing device 48, the flexible film curing device 49 and the film curing device 37 are selected in accordance with the kind of the curable compound and correspond to the light which cures the curable compound.

The curable compound may be either a monomer or an oligomer. The curable compound preferably contains a polyfunctional acrylate. More preferred as the monomer is dipentaerythritol hexaacrylate (DPHA) represented by the following formula (I). The oligomer is more preferably a urethane acrylate. DPHA and urethane acrylate may be used in combination.

However,

[Curing agent]

As the curing agent, a known photopolymerization initiator can be used. For example, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one is preferred. The concentration of the curing agent is preferably in the range of 1% by mass or more and 8% by mass or less with respect to the mass of the curable compound. The concentration of the curing agent is a value obtained by {V11 / Z11} x 100 when the mass of the curable compound is Z11 and the mass of the curing agent is V11.

[Example]

The first solution (31) and the second solution (32) were made into the following prescription respectively.

[First solution]

Curing compound: 100 parts by mass of UV-1700B (registered trademark)

Curing agent: Irg907, 5 parts by mass (registered trademark)

KAYACURE DETX-S (registered trademark) 1 part by mass

Solvent: 100 parts by mass of dichloromethane

[Second solution]

Cellulose acylate: 100 parts by mass of cellulose triacetate (TAC)

Solvent: dichloromethane (first component of solvent) 261 parts by mass

Methanol (second component of solvent) 65 parts by mass

In Examples 1 to 7, the hard coat film 10 was produced from the first solution 31 and the second solution 32 by the film production facility 30 shown in Fig. That is, in Examples 1 to 7, the wet film 42 is formed by the film forming portion 35, the pre-hardening treatment by the pre-hardening device 48, the magnetic holding treatment by the air blowing device 47, The hard coat film 10 was produced by the curing treatment before peeling by the device 49, the film drying treatment by the film drying part 36, and the hardening treatment after peeling by the film hardening device 37. [

The self-supporting treatment was performed by cooling the flexible film 41 by the drum 46, in addition to the drying of the flexible film 41 by the air blowing device 47.

The preliminary curing treatment by the preliminary curing device 48 is carried out in such a manner that the mass ratio of the second solvent to the mass of the dry film of the coercive film of the second solution 32 is larger than the mass ratio of the second solvent Quot; ratio " (unit: mass%). The value in the column of Table 1 is a value in the flexible film 41 when passing through the upstream end of the pre-curing device 48. [

The preliminary curing treatment was terminated when the viscosity of the first solution reached the value shown in the column of " viscosity of the first solution at the end of pre-curing " (unit: mPa s) in Table 1. This value is a value in the flexible film 41 when passing through the downstream end of the preliminary curing device 48.

The obtained hard coat film 10 was evaluated for the thickness, hardness and haze of the hard coat 11.

≪ Evaluation of hardness &

The hardness was evaluated by a pencil hardness test according to Japanese Industrial Standard JIS K5600-5-4. In this test, first, a pencil having a predetermined hardness is set on the pencil support portion of the test apparatus. Press the hard coat (11) of the hard coat film (10) to be measured with the core end of the pencil. With the pressing, the operator shifts the pencil support at least 7 mm at a speed of 0.5 mm / s to 1 mm / s. The hard coat 11 after the displacement is visually inspected for the presence of a scratch. It is exchanged with a pencil having a higher hardness, i.e., a harder pencil, and the presence or absence of a scratch is similarly examined. In this way, the hardness level is raised to confirm the presence or absence of scars. The hardness level is increased until a 3 mm or more scar is formed on the test site where the core tip is touched by the displacement. The hardness of the hardest pencil that has not scarred is the pencil hardness test result.

The hardness was evaluated according to the following criteria. A corresponds to acceptance, and B corresponds to rejection.

A: 2H or more

B: H or less

<Evaluation of Hayes>

The evaluation of the haze was carried out according to the haze test method according to JIS K 7136: 2000. In this test, all the light rays that have passed through the sample sampled from the hard coat 11 and enter from the entrance opening into the integrating sphere) are taken as the total light transmittance. When a light beam passing through the sample enters the integrating sphere through the entrance opening, and only diffused light in the sphere is taken as the diffusion transmittance, the haze value is determined by the following formula.

Haze (turbidity value) = (diffuse transmittance divided by total light transmittance) x 100

Hayes was evaluated based on the following criteria. A corresponds to the acceptance, B has the certain haze, but there is no problem on the product, and the acceptance corresponds to C, and the rejection corresponds to C.

A: less than 1%

B: 1% or more and 10% or less

C: Greater than 10%

[Comparative Example]

In Comparative Example 1 and Comparative Example 2, the hard coat film 10 was produced by the film production facility 30 shown in Fig. The timing of the initiation and the timing of the initiation of the preliminary curing process were set to be different from those in the examples. Concretely, the preliminary curing process is started for the flexible film 41 having the value shown in the column of "mass ratio of the second solvent at the start of preliminary curing" in Table 1, and the viscosity of the first solution is " The viscosity of the first solution in the &quot; viscosity &quot; column.

The thickness, hardness, and haze of the obtained hard coat film were evaluated by the same methods and standards as those of the examples.

At the start of the pre-curing
The mass ratio of the second solvent
(mass%) At the end of pre-curing
Viscosity of the first solution
(mPa · s) Flexible film hardening process
Hardness
Hayes Example 1 100 50 U A B Example 2 100 80 U A B Example 3 100 100 U A B Example 4 270 50 U A A Example 5 270 100 U A A Example 6 100 50 radish B A Example 7 100 100 radish B A Comparative Example 1 100 40 radish B C Comparative Example 2 270 40 radish B C

Claims (4)

A process for producing a multilayered film comprising a cured layer formed by curing a curable compound on a film base comprising cellulose acylate,
(A) forming a flexible film by softening a first solution and a second solution onto a flexible support;
(B) applying self-supporting property to the flexible film by performing at least one of drying and cooling of the flexible film;
(C) irradiating the active film with the curable film to cure the curable compound, thereby raising the viscosity of the curable film to 50 mPa · s or more;
(D) forming a film by peeling the flexible film after the step B from the flexible support;
(E) drying the film; And
(F) curing the curable compound by irradiating an active line to at least one of the flexible film between the B step and the D step and the film after the E step;
And,
Wherein the first solution contains a curable compound and a first solvent of the curable compound and does not contain the cellulose acylate, the curable compound is cured by irradiation of an active ray, and the second solution contains the cellulose acylate and the A second solvent of cellulose acylate, which contains no curing compound,
Wherein the active film is irradiated to the flexible film having a ratio of the sum of the masses of the first solvent and the second solvent to the mass of the dry film of the flexible film being 100% or more. The method according to claim 1,
Wherein the curable compound is a monomer or an oligomer. 3. The method according to claim 1 or 2,
Wherein the step B is performed by a blowing device disposed opposite to the flexible support and supplying a dry gas to the flexible film, and the step C is performed by a curing device disposed upstream of the blowing device, Ray is irradiated with a laser beam. 3. The method according to claim 1 or 2,
The step B is carried out by drying the flexible film by an air blower arranged to face the flexible support and supplying a dry gas to the flexible film, and the step C is a step of irradiating the active line with a curing device provided in the air blowing device Wherein the film has a thickness of 100 nm or less.

Images