JP6208964B2 - Method for producing laminated film - Google Patents

Description

In the present invention, a coating liquid containing at least a resin material and a solvent is applied to one surface of a film continuous in the longitudinal direction to form a coating film, and during the process until the coating film is dried, the solvent evaporates from the coating film, a method for manufacturing a laminated film using the coating control equipment for managing the amount and rate of the solvent to its volatilization from immediately after the application.

  Various displays such as a liquid crystal display and a plasma display have a laminated film in which a coating layer for imparting a specific function is formed on one surface of the film on the surface of the display. As an apparatus for forming this coat layer on a film, a coating solution containing a resin material and an organic solvent is applied to one surface of a long film transported in the longitudinal direction, and the coating solution is dried and cured. A laminated film manufacturing apparatus for forming a coat layer is known. The functions imparted to the film by the coating layer include, for example, a surface-reflected light that is reflected on the surface of the low refractive index layer by laminating a low refractive index layer on a high refractive index layer containing high refractive fine particles, Antireflection function to reduce reflected light by reversing and canceling the phase of the interface reflected light reflected at the interface between the refractive index layer and the low refractive index layer. There is an anti-glare function that suppresses reflection of light, sunlight, etc.), or an anti-scratch function that is obtained by laminating a coat layer having a hardness higher than that of the film on the film.

  Some laminated film manufacturing apparatuses are provided with a coating apparatus for coating a coating solution on one surface of a film. As this coating device, for example, a bar coating device such as a Mayer bar, a gravure coating device, a die coating device, or a screen printing device is used. The coating solution immediately after being applied to the film by these coating devices tends to boil because the concentration of the organic solvent in the coating solution is high. For this reason, when heat is applied to the coating solution immediately after coating and drying is performed, so-called bumping may occur in the coating layer. When bumping occurs, there is a problem that a portion of the coating layer where bumping occurs is whitened.

  In order to suppress this bumping, there is also a laminated film manufacturing apparatus provided with a pre-drying apparatus that performs a predetermined treatment on a film having a coating film formed on one surface. As this pre-drying device, a drying zone that generates drying air flowing from one side to the other side in the film width direction is provided immediately after the application position for applying the coating liquid to the film, so that heat is not applied. There has been proposed a pre-drying apparatus that performs pre-drying for reducing the organic solvent concentration of the coating solution to some extent (see, for example, Patent Document 1). Since the preliminary drying apparatus described in Patent Document 1 is a large-scale apparatus, once the installation location is determined, it is not usually moved after that. And after determining an installation location, the optimal manufacturing conditions of a preliminary drying apparatus will be determined. The same procedure is applied to other preliminary drying apparatuses.

Japanese Patent No. 4147370

  However, in the pre-drying apparatus described in Patent Document 1, once the installation location is determined, the manufacturing conditions are determined on the assumption of the installation location.

  In addition, the coating liquid applied to the film is leveled with the lapse of time in which the coating liquid tends to have a uniform thickness in the film width direction and the conveyance direction. In the preliminary drying apparatus described in Patent Document 1, since a drying zone for generating a drying air flowing in the width direction of the film is provided immediately after the application position for applying the coating liquid to the film, the composition of the paint and the solvent used Depending on the type of film, the coating film may swell due to the effect of the drying wind. If pre-drying is performed to reduce the concentration of the organic solvent contained in the coating film in a wavy state, the viscosity of the coating film becomes high with a non-uniform thickness of the coating film, making it difficult to level. . For this reason, in the preliminary drying apparatus described in Patent Document 1, the leveling is not sufficiently performed, and the thickness of the coating film may be uneven. In addition, the coating film may cause curing shrinkage when it is cured. This cure shrinkage is greater in the thick part of the coating than in the thin part. For this reason, when a coating film with non-uniform thickness is cured, wrinkles may occur in the laminated film due to a partial difference in the amount of cure shrinkage.

An object of this invention is to provide the manufacturing method of the laminated film using the coating-film control apparatus which can obtain the film which has a coating layer without a wrinkle in view of the said situation.

The manufacturing method of the laminated film of the present invention that solves the above-mentioned object is as follows.
A coating step of coating a coating liquid containing a resin material and a solvent on one surface of a long film being conveyed in the longitudinal direction;
A natural drying process in which the film on which the coating film is formed by the coating process is passed through a coating film control apparatus that adjusts the amount and speed of the solvent volatilized from the coating film;
A main drying step for volatilizing the solvent contained in the coating film;
A curing step of applying energy to the coating film to cure, and
A method for producing a laminated film that sequentially performs:
The natural drying step
As the coating film control device,
Two or more cover members that cover the thickness portions at both ends in the width direction of the coating film and the film,
The two or more cover members are one or more non-perforated cover members that are not provided with holes and one or more perforated cover members that are provided with holes connected in the transport direction of the film,
An exhaust means for exhausting the solvent volatilized from the coating film to the outside from the hole of the perforated cover member;
Using a device that can rearrange the installation location of the cover member,
By restricting the outside gas from flowing into the upstream space covered with the cover member, the concentration of the solvent volatilized from the coating film is increased in the upstream side of the film on which the coating film is formed by the coating process. Drying is performed first through a volatilization suppression zone that is enhanced in the side space, and then the air in the downstream space covered with the cover member is exhausted out of the downstream space to ventilate the downstream space. It is a process of passing through a zone.

  The perforated cover member may have a larger total hole area as it is disposed closer to the drying device.

Moreover, in the said coating-film control apparatus, the aspect with the substantially same length of the said perforated cover member and the said non-porous cover member in the conveyance direction of the said film may be sufficient.

  According to this aspect, it is easy not only to change the installation location of the cover member, but also the cover member can be easily manufactured, and cost reduction can be realized.

Moreover, the said coating-film control apparatus WHEREIN: The said 2 or more cover member may be connected via the cover member.

  The weathering member restricts the gas outside the cover member from flowing into the cover member from the gap between the cover members. Note that the weathering member can be removed, and does not hinder the rearrangement of the installation location of the cover member, and the two or more cover members after the rearrangement are connected again via the weathering member. .

Moreover, the said coating-film control apparatus WHEREIN: The said exhaust means may be provided with the rectification | straightening member which has a some through-hole penetrated in the direction which cross | intersects said one surface.

  By providing the rectifying member, the gas between the film and the cover member can be sucked while suppressing the occurrence of turbulent flow, and applied to one surface of the film without making the coating liquid rippling. The coating liquid can be more uniformly controlled.

  The exhaust means may suck gas between the film and the cover member in a direction substantially perpendicular to one surface of the film.

Further, in the coating film control device, wherein the rectifying member is preferably of the net.

  By providing the net-like rectifying member, a high rectifying effect can be obtained with a simple configuration.

Method for producing a product layer film includes a coating step of coating a coating solution containing a resin material and a solvent on one surface of the elongated film being transported in the longitudinal direction,
And adjust the amount and rate of the solvent to be evaporated from the coating film, and natural drying step of passing said coating controller,
A main drying step for volatilizing the solvent contained in the coating film;
A curing step of applying energy to the coating film to cure, and
Are sequentially performed.

According to the manufacturing method of the said laminated | multilayer film, the film which has a coating layer without a wrinkle can be obtained.

According to the manufacturing method of the product layer film of the present invention, it is possible to obtain a film having a wrinkle-free coating layer.

It is a schematic diagram which shows the laminated film manufacturing apparatus by which the coating-film control apparatus which is one Embodiment of this invention is arrange | positioned. (A) is the AA cross section of FIG. 1, (b) is the BB cross section of FIG. It is a disassembled perspective view which shows an exhaust means. It is a flowchart which shows the laminated film manufacturing process by the laminated film manufacturing apparatus shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. The coating-film control apparatus which is one Embodiment of this invention is a coating-film control apparatus used for the laminated film manufacturing apparatus which laminates | coats a coating layer on a resin film. In addition, although the coating-film control apparatus of this invention has a part of preliminary drying function as described in patent document 1, it is not mainly in preliminary drying, but the thickness of a coating film is made uniform. There is a Lord to do.

  Moreover, in the following description, before apply | coating to a film, it will be called a coating liquid, and after applying, it will be called a coating film.

  FIG. 1 is a schematic diagram showing a laminated film manufacturing apparatus in which a coating film control apparatus according to an embodiment of the present invention is arranged.

  The laminated film manufacturing apparatus 1 shown in FIG. 1 forms a coat layer on the resin film F while conveying the long resin film F at a substantially constant speed along the conveyance path in the longitudinal direction of the resin film F. It is an apparatus for producing a laminated film. In the present embodiment, as the resin film F, a film made of triacetyl cellulose having a film thickness of about 5 to 200 μm is used. Hereinafter, the upstream side of the transport path may be simply referred to as the upstream side, and the downstream side of the transport path may be simply referred to as the downstream side. In addition, a part of the long resin film F may be simply referred to as a resin film F.

  The laminated film manufacturing apparatus 1 includes a delivery roll 2, a coating apparatus 3, a coating film control apparatus 4, a drying apparatus 6, a light irradiation apparatus 7, and a take-up roll 8 in order from the upstream side. The long resin film F is wound around a feed roll 2 provided at the upstream end and set in the laminated film manufacturing apparatus 1. On the other hand, the resin film F conveyed to the downstream end is wound up by the winding roll 8. In the laminated film manufacturing apparatus 1, the long resin film F is conveyed at a substantially constant speed within a predetermined speed range. Therefore, a laminated film can be manufactured at a substantially constant speed. In this embodiment, the conveyance speed of the resin film F is set to 1-100 m / min. Although depending on the composition of the coating solution, the thickness of the coating tends to be non-uniform as the conveying speed increases. The lower limit of the conveyance speed is preferably 30 m / min or more, more preferably 40 m / min or more, and particularly preferably 50 m / min or more from the viewpoint of cost reduction. The upper limit value of the conveyance speed is not particularly limited.

  The coating apparatus 3 is a gravure type coating provided with a gravure roll 31 for applying a coating liquid W to a resin film F, a liquid supply pan 32 containing a predetermined amount of the coating liquid W before coating, and two guide rolls 33. Device. The coating liquid W applied to the resin film F by the coating device 3 is a liquid energy curable resin having a viscosity of 20 mPa · s containing an organic solvent. The energy curable resin is cured by energy such as heat or radiation. The viscosity of the coating liquid W is preferably 0.5 mPa · s or more and 200.0 mPa · s or less, more preferably 5.0 mPa · s or more and 150 mPa · s or less, and further preferably 10.0 mPa · s or more and 100 mPa · s or less. -S or less. The amount of the coating liquid W applied to the resin film F can be adjusted by this viscosity. Hereinafter, one surface of the resin film F coated with the coating liquid W is referred to as a coated surface of the resin film F, and the surface of the resin film F opposite to the surface coated with the coating liquid W is the resin film. It may be called the back surface of F. The gravure roll 31 has a cylindrical shape in which a spiral recess is formed on the roll surface. The gravure roll 31 rotates at a constant angular velocity in a direction opposite to the direction in which the resin film F is conveyed. The liquid supply pan 32 is provided below the gravure roll 31. The lower end portion of the gravure roll 31 is immersed in the coating liquid W in the liquid supply pan 32. One guide roll 33 is provided in the vicinity of the gravure roll 31 and on each of the upstream side and the downstream side of the gravure roll 31. The resin film F is pressed against the gravure roll 31 by the guide roll 33. The gravure roll 31 rakes up the coating liquid W from the liquid supply pan 32 by the recesses on the surface, and continuously applies the coating liquid W to the coating surface of the resin film F being conveyed by a certain amount. In addition, as the coating device 3, other coating devices which can apply | coat the coating liquid W continuously on the resin film F, such as a Mayer bar type, can also be used.

  The drying device 6 heats the coating solution W by spraying hot air directly onto the coating solution W applied on the resin film F by the coating device 3. The resin film F on which the coating liquid W is applied and the coating film is formed passes through the drying device 6, so that it is included in the coating film applied to the portion of the resin film F that has passed through the drying device 6. Most organic solvents are volatilized. In addition, this drying apparatus 6 should just be a thing which can volatilize the organic solvent contained in a coating film, For example, you may use the heating apparatus heated indirectly. When the organic solvent contained in the coating film volatilizes, the energy curable resin remains on the application surface of the resin film F, and an energy curable resin coating film is formed on the application surface of the resin film F.

  When a thermosetting resin is used as the light energy curable resin, the thermosetting resin can be cured by heating, and when using a photocurable resin, ionization such as ultraviolet rays and electron beams is performed. The photocurable resin can be cured by irradiation with radiation. The photocurable resin is simple because it is cured by ionizing radiation. The light irradiation device 7 that irradiates ultraviolet rays irradiates the energy curable resin coating film formed on the resin film F being conveyed with light, and cures the energy curable resin coating film. The cured energy curable resin coating film becomes a coat layer (energy curable resin layer), and the resin film F on which the coat layer is laminated becomes a laminated film. Note that the thermosetting resin can be cured by providing a heating device instead of the light irradiation device 7.

  The light irradiation device 7 includes a box-shaped chamber 71 having an opening on one side, an ultraviolet lamp 72, an irradiation roll 73, and a guide roll 74 for guiding the resin film F. The chamber 71 is disposed on the application surface side of the resin film F being conveyed. The opening of the chamber 71 has a rectangular shape defined by four edges. The chamber 71 is arranged so that the opening is close to the transport path. For this reason, the resin film F passes through the vicinity of the opening of the chamber 71.

  The ultraviolet lamp 72 irradiates light to the energy curable resin coating film formed on the resin film F. The ultraviolet lamp 72 is disposed in the chamber 71. Further, the ultraviolet lamp 72 is a single lamp that extends in the width direction of the resin film F (the direction orthogonal to the paper surface in FIG. 1, hereinafter simply referred to as “width direction”). The length of the ultraviolet lamp 72 in the extending direction is substantially equal to the width of the resin film F. In addition, when using resin hardened | cured with light other than an ultraviolet-ray as energy curable resin contained in the coating liquid W and a coating film, the lamp | ramp which irradiates corresponding light may be used. The irradiation roll 73 is disposed on the back side of the resin film F so as to face the ultraviolet lamp 72 across the transport path. Note that an inert gas discharge means for discharging an inert gas such as nitrogen gas may be provided in the chamber 71.

  The coating film control device 4 extends along the transport path from the vicinity of the coating device 3 to the vicinity of the drying device 6. The coating film control device 4 includes six backup rolls 41, a cover member 42 that covers one surface of the resin film F coated with the coating liquid W, and a gas that covers the gas between the resin film F and the cover member 42. And four exhaust means 43 for exhausting the air to the outside.

  Each of the six backup rolls 41 is arranged along the transport path on the back side of the resin film F and guides the resin film F. Of the six backup rolls 41, the resin film F is wound about 90 degrees around the backup rolls 41 arranged on the most upstream side and the most downstream side. By the backup roll 41 arranged on the most upstream side, the transport direction of the resin film F is changed from a substantially horizontal direction to a substantially vertical direction. Further, the transport direction of the resin film F is changed from the substantially vertical direction to the substantially horizontal direction by the backup roll 41 arranged on the most downstream side.

  The cover member 42 extends along the conveyance path from the vicinity of the coating position where the coating apparatus 3 applies the coating liquid W to the vicinity of the drying apparatus 6. In addition, the application position in this embodiment is a contact position of the gravure roll 31 and the resin film F. The cover members adjacent to each other are closed by the cover member 422. There are two types of cover member 42: one or more perforated cover members 420 provided with holes, and one or more non-porous cover members 421 provided with no holes. In FIG. 1, the three cover members 42 on the downstream side in the conveyance direction close to the drying device 6 are perforated cover members 420, and the two cover members 42 on the upstream side in the conveyance direction far from the drying device 6 (near the coating device 3). Is the non-porous cover member 421. It should be noted that the perforated cover member 420 may be such that the total area of the holes per unit area increases as it is disposed closer to the drying device 6. Further, among the one cover member 42, the total area of the holes per unit area may be larger on the downstream side in the transport direction than on the upstream side in the transport direction. Further, the arrangement positions of the perforated cover member 420 and the non-porous cover member 421 may be appropriately changed. For example, the cover member 42 on the most upstream side in the transport direction closest to the coating device 3 is defined as the non-porous cover member 421. The perforated cover member 420 and the non-porous cover member 421 may be alternately arranged in the order of the perforated cover member 420 and the non-porous cover member 421 in the transport direction. Further, the perforated cover member 420 may be provided on the upstream side or immediately after the coating position depending on the composition of the coating solution (for example, when a coating solution having a low viscosity or a solvent having a low boiling point is used).

  The temperature difference between the drying temperature of the drying device 6 and the drying temperature in a specific line of the resin film F having the cover member 42 of either the non-porous cover member 421 or the perforated cover member 420 may be within 100 ° C. preferable. As a result, bumping is less likely to occur in the drying device 6, so that the problem of whitening is less likely to occur in the laminated film. The drying temperature of the drying device 6 is preferably in the range of 30 ° C. to 200 ° C., more preferably 50 ° C. to 150 ° C., although it depends on the type (heat resistant temperature) of the resin film being conveyed. It is preferable that the drying temperature in the specific line of the resin film F which has the cover member 42 of either the non-porous cover member 421 or the perforated cover member 420 is in the range of 10 ° C to 100 ° C, and 20 ° C to 50 ° C. More preferably.

  By these cover members 42, the gas outside the cover member 42 is restricted from flowing between the resin film F and the cover member 42 (hereinafter sometimes referred to as the inside of the cover member 42). This effect can be obtained even when the perforated cover member 420 is used. This is because the perforated cover member 420 is connected to the exhaust means 43. The cover member 42 on the most upstream side and the most downstream side is detachably attached to a frame (not shown) provided in the coating film control device 4. Moreover, although the adjacent cover member is closed by the cover member, the cover member can be removed, and the adjacent cover member is also detachably attached. Thus, by making each cover member 42 into a detachable structure, the arrangement of the cover members can be easily rearranged. For example, it is possible to flexibly cope with a change in the type of coating liquid, a change in the transport path, and the like. That is, the positional relationship between the perforated cover member 420 and the non-porous cover member 421 can be easily changed. Further, the lid member 422 restricts the gas outside the cover member 42 from flowing into the cover member 42 from the gap between the cover members 42. Note that if the gap between the cover members 42 is narrow, the weathering member 422 may be omitted. For example, if both ends of each cover member are comb-like and connected so that the comb teeth of the adjacent cover members are staggered, the gap between the adjacent cover members can be narrowed. Can be omitted. That is, the adjacent cover members only need to be connected so that the inflow of gas is restricted. As a means for achieving this, the method using the weathering member as described above, or both ends of the cover member For example, there is a method in which the comb teeth of adjacent cover members are staggered after the portions are comb-shaped.

  Moreover, in the coating-film control apparatus 4 shown in FIG. 1, although the length of the film conveyance direction in each cover member differs, you may make the length of each cover member substantially the same. By doing so, the arrangement of the cover members can be more easily rearranged, and the cover member can be flexibly dealt with by changing the type of coating liquid, changing the transport path, and the like. Note that “substantially the same” is a concept including completely the same. The length of each cover member may be approximately an integral multiple. By doing so, the arrangement of the cover members can be rearranged, and it can be dealt with more flexibly by changing the type of coating liquid, changing the transport path, and the like.

  The shape of the cover member is not particularly limited. Examples of the shape include a flat plate shape, a curved surface shape, and an uneven shape. It is also possible to adjust the volatilization amount of the solvent by changing the shape of the cover member. The ineffective cover member for securing the volatile solvent may have a shape with an increased surface area, for example, a multi-layer structure plate made non-porous by stacking a plurality of metal meshes in multiple layers, or a wavy or dimple-shaped surface. It is possible to cope with the uneven shape and the like.

  2A is a cross-sectional view taken along the line AA in FIG. 1 and is a cross-sectional view of the perforated cover member 420. FIG. FIG. 2B is a cross-sectional view taken along the line BB in FIG. 1 and is a cross-sectional view of the non-porous cover member 421. In FIG. 2, the resin film F is indicated by a thick solid line.

  The cover member 42 is composed of a flat base plate 42a disposed to face the application surface of the resin film F, and two side plates 42b protruding from the base plate 42a to the resin film F side. The base plate 42a and the side plate 42b are made of a transparent acrylic plate so that the resin film F can be visually recognized from the outside of the base plate 42a and the side plate 42b. The base plate 42a is formed with a width wider than the width of the resin film F. In addition, the base plate 42a is disposed along the transport path at a position separated by about 10 mm from the application surface of the resin film F. The distance between the base plate 42a and the application surface of the resin film F is preferably as narrow as possible so that the coating liquid W applied to the resin film F can be reliably prevented from coming into contact with the base plate 42a, for example, 5 mm or more and 15 mm or less. It is desirable to make it.

  As shown in FIG. 2A, the base plate 42a of the perforated cover member 420 is provided with a plurality of holes 42c. On the other hand, as shown in FIG. 2B, the base plate 42a of the non-hole cover member 421 has no holes.

  In addition, the amount of volatilization of the organic solvent from the coating liquid W in the coating film control device 4 can be achieved by narrowing the distance between the base plate 42a and the application surface of the resin film F or changing the shape of the non-porous cover member. Can be limited. The limitation on the volatilization amount will be described in detail later.

  The side plates 42b are respectively formed in the vicinity of both ends in the width direction of the base plate 42a. The side plate 42 b protrudes from the base plate 42 a to the back side of the resin film F so as to cover the thickness portions at both ends in the width direction of the resin film F and cover the backup roll 41. The distance in the width direction between the width direction end of the backup roll 41 and the side plate 42b is about 10 mm. This interval is preferably as narrow as possible so long as the side plate 42 b does not contact the width direction end of the resin film F and the width direction end of the backup roll 41, and is preferably 3 mm or more and 15 mm or less, for example.

  As shown in FIG. 1, the exhaust means 43 is attached to the downstream portion of the perforated cover member 420. The exhaust means 43 sucks a gas between the resin film F and the cover member 42 (hereinafter sometimes referred to as “in-cover atmosphere”) in a direction substantially perpendicular to the application surface of the resin film F, and covers the cover member. 42 is exhausted to the outside. By sucking in the substantially vertical direction, the atmosphere in the cover can be sucked uniformly and exhausted to the outside of the cover member 42. The direction in which the exhaust means 43 sucks the atmosphere in the cover may be a direction that intersects the application surface of the resin film F. By sucking in the direction crossing the application surface of the resin film F, the atmosphere in the cover can be sucked substantially uniformly. However, in order to suck evenly, it is preferable to suck in the direction perpendicular to the coating surface of the resin film F. By sucking evenly, the concentration of the organic solvent in the coating liquid W applied to the resin film F can be uniformly reduced, and the coating film can be uniformly controlled.

  FIG. 3 is an exploded perspective view showing the exhaust means. In FIG. 3, one of the two exhaust means 43 is shown, but the other of the exhaust means 43 has the same configuration. Further, in FIG. 3, the direction of exhaust by the exhaust fan 436 is indicated by an arrow.

  As shown in FIG. 3, the exhaust means 43 includes a suction part 430, four exhaust tubes 434, a buffer container 435, and two exhaust fans 436. The suction part 430 includes a punching plate 431, a mesh-like mesh member 432, and an exhaust cover 433. The suction portion 430 is disposed on the downstream side of a later-described uniformizing position. The perforated cover member 420 is provided with a rectangular hole 420c penetrating the base plate 420a in the thickness direction. Each of the punching plate 431 and the mesh member 432 is formed in the same rectangular shape as the edge that defines the rectangular hole 420c, and is fitted into the rectangular hole 420c. The exhaust cover 433 has a box-like shape having an opening slightly larger than the rectangular hole 420c on one side. Further, the exhaust cover 433 is fixed to the base plate 420a by adhering the edge portion defining the opening to the base plate 420a, and surrounds the entire rectangular hole 420c into which the punching plate 431 and the mesh member 432 are fitted. . Although FIG. 3 shows the punching plate 431, the base plate 420a may have a punching plate function by providing a plurality of holes in the base plate 420a in the thickness direction of the base plate. . When a plurality of holes are provided in the base plate 420a, the punching plate 431 may not be stacked on the base plate 420a.

Each of the four exhaust tubes 434 connects the exhaust cover 433 and the buffer container 435. Any number of exhaust tubes 434 may be used. An exhaust fan 436 is attached to the buffer container 435. The exhaust fan 436 exhausts the gas in the buffer container 435 to the outside of the buffer container 435. By operating the exhaust fan 436, the pressure inside the exhaust cover 433 is reduced via the buffer container 435 and the exhaust tube 434, and the atmosphere inside the cover is sucked into the exhaust cover 433 and exhausted outside the cover member 42. The As the exhaust fan 436 operates, turbulence may occur around the exhaust fan 436. In this embodiment, since the atmospheric pressure in the exhaust cover 433 is reduced via the buffer container 435 and the exhaust tube 434, it is possible to prevent the turbulent flow from affecting the gas flow in the atmosphere in the cover. Further, since the buffer container 435 can be disposed away from the transport path, the atmosphere in the cover exhausted by the exhaust fan 436 is suppressed from flowing into the cover member 42. It is also possible to change the exhaust amount for each exhaust tube 434. For example, in the exhaust tube 434 shown in FIG. 3, assuming that the exhaust tubes 434a, 434b, 434c, 434d from the left in the figure, the exhaust amount of the exhaust tubes 434a and 434d is 0-5 m ³ / min, and the exhaust amount of the exhaust tubes 434b and 434c is Can be set to 10 to 20 m ³ / min. This makes it possible to partially control the dry state in the width direction of the resin film F, and it is also possible to improve the curling problem that occurs after the curing step by adjusting more detailed conditions.

  The punching plate 431 is an acrylic plate in which a plurality of through holes 431a are opened in the thickness direction. By providing the punching plate 431, the rectifying effect at the time of sucking the atmosphere in the cover is enhanced, and the atmosphere in the cover can be sucked almost uniformly by the entire rectangular hole 420c. The mesh member 432 is made of 300 mesh stainless steel. By providing the mesh member 432, the rectifying effect at the time of sucking the atmosphere in the cover is further increased, and the atmosphere in the cover can be sucked more uniformly by the entire rectangular hole 420c. The number of meshes of the mesh member 432 is preferably 100 mesh or more and 1000 mesh or less, more preferably 200 mesh or more and 1000 mesh or less, and further preferably 300 mesh or more and 1000 mesh or less. As the number of meshes increases, the rectification effect increases, and the atmosphere in the cover can be more evenly sucked by the entire rectangular hole 420c. However, if the number of meshes exceeds 1000, the gap between the meshes becomes too narrow and the suction efficiency is lowered. The number of meshes is the number of eyes per inch (25.4 mm). The punching plate 431 and the mesh member 432 of the present embodiment correspond to an example of a rectifying member in the present invention. Either one of the punching plate 431 and the mesh member 432 may be omitted. When either one is omitted, it is preferable to omit the punching plate 431 having a small number of holes and a relatively low rectifying effect.

  The coating liquid W applied to the resin film F forms a coating film on the resin film F, and the coating film is uniform in the width direction and the flow direction of the resin film F over time due to the surface tension of the coating liquid W. Leveling that is about to occur is caused. Further, in the coating liquid W contained in the coated film after coating, the organic solvent in the component gradually evaporates. When the organic solvent in the applied coating liquid W volatilizes and the organic solvent concentration decreases, the viscosity of the coating film increases and the fluidity of the coating film decreases, making it difficult to level. On the other hand, when the concentration of the organic solvent component in the coating film is high, leveling is promoted, and the resin film F tends to have a uniform thickness in the width direction.

  In the present embodiment, the coating film is coated with the coating film W from the vicinity of the coating position where the coating liquid W is applied to form the coating film. The cover member 42 covers the downstream side of the uniform position where the thickness is uniform in the direction and the flow direction. The coating thickness uniformity position varies depending on various conditions such as the components contained in the coating liquid W and the transport speed of the resin film F, but by conducting experiments based on the coating liquid W used and the desired transport speed. Can be sought. As described above, the suction portion 430 is disposed on the downstream side of the uniformization position. In the coating film control device 4, the upstream side of the position where the suction unit 430 is disposed is the volatilization suppression zone Z <b> 1 shown in FIG. 1, and the coating film control device 4 is downstream from the position where the suction unit 430 is disposed. The side becomes the drying zone Z2 shown in FIG.

  Next, the operation of this embodiment will be described.

  FIG. 4 is a flowchart showing a laminated film manufacturing process by the laminated film manufacturing apparatus shown in FIG. In the flowchart of FIG. 4, a process focusing on a specific line in the width direction of the resin film F during operation of the laminated film manufacturing apparatus 1 is shown.

  When the laminated film manufacturing apparatus 1 is started, after a predetermined initial operation, a specific line of the resin film F is sent out from the sending roll 2 and a sending process is performed (step S1). When the specific line of the resin film F is conveyed to the position where it is wound around the gravure roll 31, the coating liquid W is applied to the specific line of the resin film F by the coating device 3, and the coating process is performed (step S2).

  The specific line of the resin film F to which the coating liquid W has been applied is conveyed into the volatilization suppression zone Z1 of the coating film control device 4 immediately after being applied. In the volatilization suppression zone Z1, the cover member 42 restricts the gas outside the cover member 42 from flowing into the cover member 42, and the organic solvent volatilized from the coating film remains inside the cover member 42. As a result, the organic solvent concentration in the atmosphere in the cover is increased, and the organic solvent is less likely to volatilize from the coating film. Moreover, after the organic solvent concentration in the atmosphere in the cover is saturated, the organic solvent in the coating film does not volatilize. That is, the volatilization amount of the organic solvent from the coating film in the coating film control device 4 can be limited by appropriately setting the volume of the atmosphere in the cover determined by the distance between the cover member 42 and the application surface of the resin film F. .

  In the present embodiment, coating is performed by covering the coated surface of the resin film F and the thickness portions at both ends in the width direction of the resin film F with the cover member 42 until the coating film has a uniform thickness in the width direction of the resin film F. The organic solvent component concentration in the film is prevented from decreasing. By doing so, the viscosity of the coating film is prevented from increasing and leveling is promoted. By the specific line of the resin film F passing through the volatilization suppression zone Z1, a uniformizing process is performed in which the coating film has a uniform thickness in the specific line of the resin film F (step S3).

  The specific line of the resin film F that has been subjected to the homogenization process is subsequently conveyed into the drying zone Z2. In the upstream portion of the drying zone Z2, the atmosphere in the cover in which the organic solvent is saturated or the organic solvent concentration is high is discharged from the suction part 430, so that the organic solvent concentration is low or does not contain the organic solvent from the outside of the cover member 42. Gas enters and ventilates. Thereby, drying of a coating film is accelerated | stimulated and the natural drying process is implemented in the specific line of the resin film F which passes the drying zone Z2 (step S4). This natural drying step corresponds to an example of the drying step in the present invention. In this natural drying step, the atmosphere in the cover is sucked in the direction intersecting with one surface of the resin film F, so that the coating film can be uniformly controlled by sucking the atmosphere in the cover substantially evenly. Further, once ventilation is performed, a gas containing almost no organic solvent becomes an atmosphere in the cover. For this reason, the organic solvent in the coating film is volatilized in the downstream portion of the drying zone Z2, that is, the portion where the suction part 430 is not disposed, until the organic solvent concentration is saturated, and the coating liquid W is dried.

  Then, the specific line of the resin film F is conveyed to the drying apparatus 6, and this drying process is performed (step S5). In this main drying step, the coating liquid W applied to a specific line of the resin film F is heated by the drying device 6. By being heated, the organic solvent in the coating film on the specific line of the resin film F is completely volatilized, and an energy curable resin coating film is formed on the specific line of the resin film F.

  Subsequently, the specific line of the resin film F is conveyed to the light irradiation apparatus 7, and a light irradiation process is performed (step S6). This light irradiation step is a step of curing the photocurable resin coating film by irradiating the photocurable resin coating film formed in the resin film F shape with ultraviolet rays from the ultraviolet lamp 72. Note that when a thermosetting resin is used instead of a photocurable resin, a heating device may be provided instead of the light irradiation device.

  Finally, a winding process in which a specific line of the resin film F on which the coating layer formed by curing the energy curable resin coating is stacked is conveyed to the winding roll 8 and wound around the winding roll 8. Performed (step S7).

  Next, materials that are preferably used in the present embodiment will be described.

  As the resin film F, polyethylene terephthalate (PET), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polymethyl methacrylate (PMMA), polycarbonate having translucency and flexibility suitable for continuous production (PC), polyimide (PI), polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), cycloolefin copolymer (COC), norbornene resin, acrylic resin, polyethersulfone, Various resin films such as cellophane and aromatic polyamide can be suitably used. In addition, when manufacturing the laminated film used for a plasma display (PDP) and a liquid crystal display device (LCD), it is more preferable to use 1 type chosen from a PET film, a TAC film, and a norbornene-containing resin film.

  The higher the transparency of these resin films, the better. However, in optical applications, the total light transmittance (JIS K7105) is 80% or more, more preferably 90% or more.

  Resin film surface is subjected to treatment treatment such as alkali treatment, corona treatment, plasma treatment and sputtering treatment, primer coating such as surfactant and silane coupling agent, thin film dry coating such as Si deposition, etc. The adhesion between the coating layer and the coating layer can be improved, and the physical strength and chemical resistance of the coating layer can be improved. Moreover, you may use the resin film which provided the other layer in the coating layer side of the resin film. Even in that case, the adhesiveness of each layer interface can be improved by the same method as described above, and the physical strength and chemical resistance of the hard coat layer can be improved.

  The resin component contained in the coating liquid W is not particularly limited, but an ionizing radiation curable resin that can be efficiently cured by a simple processing operation by a curing treatment by ultraviolet irradiation is preferable. Examples of the ionizing radiation curable resin include monomers and oligomers having radical polymerizable functional groups such as acryloyl group, methacryloyl group, acryloyloxy group, and methacryloyloxy group, and cationic polymerizable functional groups such as epoxy group, vinyl ether group, and oxetane group. , Prepolymers, and compositions obtained by mixing polymers alone or as appropriate are used. Examples of monomers include methyl acrylate, methyl methacrylate, methoxy polyethylene methacrylate, cyclohexyl methacrylate, phenoxyethyl methacrylate, ethylene glycol dimethacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, and the like. it can. As oligomers and prepolymers, polyester acrylate, polyurethane acrylate, polyfunctional urethane acrylate, epoxy acrylate, polyether acrylate, acrylate compounds such as alkit acrylate, melamine acrylate, silicone acrylate, unsaturated polyester, tetramethylene glycol diglycidyl ether, Epoxy compounds such as propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, bisphenol A diglycidyl ether and various alicyclic epoxies, 3-ethyl-3-hydroxymethyloxetane, 1,4-bis {[((3- Oxeta such as ethyl-3-oxetanyl) methoxy] methyl} benzene, di [1-ethyl (3-oxetanyl)] methyl ether Mention may be made of the compound. Examples of the polymer include polyacrylate, polyurethane acrylate, and polyester acrylate. These can be used alone or in combination.

  A thickener may be added to the coating liquid W, but it is difficult to apply a thin film on the resin film F, and the time required for leveling increases. Liquid is preferred. Moreover, although a high boiling point solvent may be added to the coating liquid W, since the drying time increases, the coating liquid which does not contain a high boiling point solvent is preferable.

  When the ionizing radiation curable resin is cured by ultraviolet irradiation, it is necessary to add a photopolymerization initiator. In addition, as a radiation used, any of an ultraviolet-ray, visible light, and infrared rays may be sufficient. Further, these radiations may be polarized or non-polarized.

  Photopolymerization initiators include radical polymerization initiators such as acetophenone, benzophenone, thioxanthone, benzoin, and benzoin methyl ether, and cationic polymerization starts such as aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, and metallocene compounds. The agents can be used alone or in appropriate combination.

  Moreover, additives, such as a leveling agent and an antistatic agent, can be contained in energy curable resin. The leveling agent works to make the tension on the surface of the coating uniform and to repair defects before forming the coating.

  The resin composition may contain translucent fine particles. An energy curable resin obtained by adding a solvent to the resin composition is applied onto a resin film, and then the energy curable resin is cured to form a hard coat layer. By adding translucent fine particles to the resin composition, it becomes easy to adjust the shape and number of surface irregularities of the hard coat layer (antiglare layer) having antiglare properties. When the antiglare layer is formed, the portion where the fine particles are present rises, but the thickness is uniform at the portion where the fine particles are not present, and therefore the present invention can be applied.

  As the translucent fine particles, an organic translucent resin made of acrylic resin, polystyrene resin, styrene-acrylic copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, polyfluoroethylene resin, etc. Fine inorganic particles such as fine particles, silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, and antimony oxide can be used. The refractive index of the translucent fine particles is preferably 1.40 to 1.75. When the refractive index is less than 1.40 or more than 1.75, the difference in refractive index from the resin film or resin matrix becomes too large. , The total light transmittance decreases. Further, the difference in refractive index between the translucent fine particles and the resin is preferably 0.2 or less. The average particle diameter of the translucent fine particles is preferably in the range of 0.3 to 10 μm, more preferably 1 to 7 μm, and further preferably 2 to 6 μm.

  When the particle size is smaller than 0.3 μm, the antiglare property is lowered. When the particle size is larger than 10 μm, it is not preferable because glare occurs and the surface unevenness becomes too large and the surface becomes whitish. In addition, the ratio of the light-transmitting fine particles contained in the resin is not particularly limited, but it is 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin composition. It is preferable for satisfaction, and it is easy to control the fine uneven shape and haze value on the surface of the hard coat layer. Here, “refractive index” refers to a measured value according to JIS K-7142. Further, “average particle diameter” refers to an average value of the diameters of 100 particles actually measured with an electron microscope.

The refractive index (n) of the energy curable resin is approximately in the range of 1.40 to 1.60. When it is desired to lower the refractive index or increase the refractive index, a desired refractive index can be obtained by adding ultrafine particles having a particle size of 100 nm or less. Examples of the ultrafine particles having a high refractive index include TiO ₂ (refractive index: n = 2.3 to 2.7), CeO ₂ (n = 1.95), ZnO (n = 1.9), and Sb ₂ O _5. (N = 1.71), SnO ₂ (n = 1.95), ITO (n = 1.95), Y ₂ O ₃ (n = 1.87), La ₂ O ₃ (n = 1.95) , ZrO ₂ (n = 2.05), Al ₂ O ₃ (n = 1.63), HfO ₂ (n = 2.00), Ta ₂ O _{5 and} other metal oxide fine particles can be used. As the ultrafine particles having a low refractive index, it is preferable to use hollow ultrafine particles in which the inside of the ultrafine particles is empty.

  Examples of the organic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, butanol, isopropyl alcohol (IPA), and isobutanol; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, and methyl isobutyl ketone (MIBK). Ketone alcohols such as diacetone alcohol; aromatic hydrocarbons such as benzene, toluene and xylene; glycols such as ethylene glycol, propylene glycol and hexylene glycol; ethyl cellsolve, butylcellsolve, ethylcarbitol, Glycol ethers such as butyl carbitol, diethyl cellosolve, diethyl carbitol, propylene glycol monomethyl ether; N-methylpyrrolidone, dimethylformamide, milk Methyl, ethyl lactate, methyl acetate, ethyl acetate, esters such as amyl acetate; dimethyl ether, and diethyl ether, it is possible to use water or the like. These may be used alone or as an organic solvent, or a plurality of them may be used as an organic solvent.

  As described above, according to the coating film control device 4 of the present embodiment, the coating applied to the resin film F by the cover member 42 until the coating film has a uniform thickness in the width direction of the resin film F. Wind against the membrane is prevented. Moreover, since volatilization of the organic solvent in the coating film is suppressed, leveling is promoted, and the coating film tends to have a uniform thickness in the width direction and the flow direction of the resin film F. Further, after the applied coating liquid W has a uniform thickness in the width direction and the flow direction of the resin film F, the gas in the vicinity of the coating liquid W is sucked in the direction crossing the coating surface, so that the coating liquid is made to ripple. The coated film can be uniformly controlled, and a laminated film having a wrinkle-free and uniform thickness coating layer can be produced. In addition, since the coating film control apparatus of the present embodiment is a simple device composed of the backup roll 41, the cover member 42, and the exhaust means 43, the apparatus can be constructed at low cost.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope described in the claims. For example, in the above-described embodiment, the coating film control apparatus 4 including the two exhaust units 43 has been described as an example. However, the number of exhaust units may be one, or three or more. In the above-described embodiment, the cover member 42 includes one or more perforated cover members, one or more non-porous cover members 421, and a plurality of weathering members 422. As a cover member integrated by connecting one or more perforated cover members and one or more non-porous cover members, covering all the portions in the coating film control device of the resin film F Also good.

In addition, even if it is a structural requirement contained only in description of the modification demonstrated above, you may apply the structural requirement to another modification.
In the following, including what has been described so far.
(Supplementary note) After another coating film control apparatus has applied a coating liquid containing a resin material and a solvent to one surface of a long film being conveyed in the longitudinal direction to form a coating film. The coating film control apparatus includes two or more cover members that cover the coating film and the thickness portions at both ends of the film in the width direction until at least the solvent volatilized from the coating film is filled in the drying apparatus. And
The two or more cover members are connected in the transport direction of the film, and include one or more perforated cover members provided with holes and one or more non-porous cover members provided with no holes. ,
An exhaust means for exhausting the solvent that volatilizes from the coating film from the hole of the perforated cover member to the outside;
The installation location of the cover member can be rearranged.
According to this film processing apparatus, since the installation location of the cover member can be rearranged, the arrangement and ratio of the perforated cover member and the non-porous cover member can be adjusted as appropriate, and a coating layer without wrinkles Can be obtained.

DESCRIPTION OF SYMBOLS 4 Coating-film control apparatus 42 Cover member 43 Exhaust means 430 Suction part 431 Punching plate 432 Mesh member Z1 Volatilization suppression zone Z2 Drying zone F Resin film W Coating liquid

Claims (1)

  A coating step of coating a coating liquid containing a resin material and a solvent on one surface of a long film being conveyed in the longitudinal direction;
  A natural drying process in which the film on which the coating film is formed by the coating process is passed through a coating film control apparatus that adjusts the amount and speed of the solvent volatilized from the coating film;
  A main drying step for volatilizing the solvent contained in the coating film;
  A curing step of applying energy to the coating film to cure, and
A method for producing a laminated film that sequentially performs:
  The natural drying step
  As the coating film control device,
  Two or more cover members that cover the thickness portions at both ends in the width direction of the coating film and the film,
  The two or more cover members are one or more non-perforated cover members that are not provided with holes and one or more perforated cover members that are provided with holes connected in the transport direction of the film,
  An exhaust means for exhausting the solvent volatilized from the coating film to the outside from the hole of the perforated cover member;
  Using a device that can rearrange the installation location of the cover member,
  By restricting the outside gas from flowing into the upstream space covered with the cover member, the concentration of the solvent volatilized from the coating film is increased in the upstream side of the film on which the coating film is formed by the coating process. Drying is performed first through a volatilization suppression zone that is enhanced in the side space, and then the air in the downstream space covered with the cover member is exhausted out of the downstream space to ventilate the downstream space. A method for producing a laminated film, which is a step of passing through a zone.

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