JP2008246415A - Apparatus and method for manufacturing coated material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for manufacturing a coated material which can at least maintain the rate of drying more rapidly than natural drying while suppressing generation of slight drying irregularity and improve planarity and productivity. <P>SOLUTION: In the apparatus for manufacturing the coated material, an air feed opening and an air discharge opening are arranged so that the flow of air generated in a drying furnace by using an air feed means and an air discharge means flows in both directions of a ceiling plate side gap between the ceiling plate of the drying furnace and a coating film, and of a bottom plate side gap between the base material and the bottom plate, and the air feed opening arranged at either the right side plate or the left side plate of the drying furnace is provided with an air adjusting member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for manufacturing a coated product. In particular, the present invention relates to a manufacturing apparatus and a manufacturing method for an optical film and the like in which an organic solvent is included in the coating liquid and a coating film of the formed coating is recognized as a film defect with a film thickness accuracy with an error of 1% or less.

  In recent years, optical film products manufactured using wet coating technology are increasingly required to have an error of 1% or less in terms of film thickness accuracy. In the production of such an optical film, an organic solvent is generally used as a solvent for a coating solution. However, an organic solvent has a higher evaporation rate than water and must be accurately dried in the drying process after coating. It is known to cause wind-like unevenness.

  Conventionally, there are many techniques aimed at increasing the drying efficiency of a coating film. For example, Patent Document 1 proposes a method in which hot air is applied to both surfaces of a traveling substrate. In this method, hot air is applied to the surface of the coating film. As a result, the film is uneven and cannot be used in products that require high film thickness accuracy.

On the other hand, a technique that emphasizes drying more precisely than drying efficiency for the formation of a precise coating film has also been proposed. For example, in Patent Document 2, it is proposed to lower the wind speed of the drying air on the film surface in the initial stage of drying.
Patent Document 3 also proposes that precise drying is performed as a result of suppressing the drying speed as much as possible by saturating the atmosphere solvent concentration during drying.
However, these methods are intended to achieve a uniform surface shape by slowing the drying speed, and have a drawback that productivity is lowered.

Therefore, as a method of drying while efficiently removing the evaporated solvent in order to increase the drying speed as much as possible, Patent Document 4 discloses a solvent that is evaporated by dividing a traveling base material into a base material transport section and a solvent removal section. There has been proposed a method of drying while always removing with a cross wind of the solvent removal section. This method is characterized in that the substrate transport section is narrowly divided in the vicinity of the substrate.
Further, Patent Document 5 proposes a method in which the solvent evaporated on the condensing plate is condensed and removed instead of being removed by cross wind.

  In order to increase the drying speed, there has also been proposed a method in which a cross wind is directly applied to a base material while straightening the dry air. However, for example, the method described in Patent Document 6 is based on the premise that no wind is applied until the coating liquid viscosity in the initial stage of drying rises to 1.5 times, and the drying speed cannot be dramatically improved. . These methods have a problem that the drying rate cannot be increased more than the drying rate of so-called natural drying in which the drying rate is left in the atmosphere, and the productivity cannot be dramatically improved.

JP 2002-59074 A JP 2003-126768 A JP 2002-320898 A JP 2003-93954 A JP 2002-515585 A JP 2005-81256 A

  An object of the present invention is to provide an apparatus and a method for manufacturing a coated product that can maintain a drying speed faster than at least natural drying while suppressing generation of slight drying unevenness, and can improve surface properties and productivity. That is.

  In order to solve the above-mentioned problem, the invention according to claim 1 includes: a coating apparatus that forms a coating film by applying a coating solution containing an organic solvent to a belt-shaped substrate being conveyed; and a coating film formed on the substrate. In the coated product manufacturing apparatus provided with a drying device that dries while transporting, the drying device includes at least a top plate, a bottom plate, a right side plate, a left side plate, and a carry-in port into which the coating film is carried. A drying furnace having a carry-out port for carrying out the coating film, and the drying furnace includes an air supply port disposed on either the right side plate or the left side plate of the drying oven, and the air supply port. An air supply means for supplying air into the drying furnace, an exhaust port disposed on either the left side plate or the right side plate of the drying oven facing the air supply port, and the inside of the drying furnace via the exhaust port Exhaust means for exhausting air from the air supply, and using the air supply means and the exhaust means The air supply port so that the air flow generated in the drying furnace flows in both the top plate side gap between the top plate of the drying oven and the coating film and the bottom plate side gap between the base material and the bottom plate. And an exhaust port, and an air supply port disposed on either the right side plate or the left side plate of the drying furnace includes an air conditioning member.

  According to a second aspect of the present invention, the air conditioning member comprises a first perforated plate, a second perforated plate, and a third perforated plate in order toward the inside of the drying furnace, and the first perforated plate The plate is a member having a large number of holes in the entire air supply port and an opening ratio of 20% to 50%, and the second porous plate has a ME (number of meshes per inch) of 10 to 200. And the third porous plate is a plate-like member having a thickness of 10 mm or more and 100 mm or less, and a columnar hole whose maximum inner diameter is 1 mm or more and 10 mm or less in the thickness direction. The apparatus for producing a coated product according to claim 1, wherein the device is a member having the entire air supply port.

  According to a third aspect of the present invention, the drying apparatus includes an internal pressure measuring unit that measures the pressure inside the drying furnace, an external pressure measuring unit that measures the pressure outside the drying furnace, and the internal pressure measurement. An internal / external differential pressure calculating means for calculating a differential pressure between the pressure inside the drying furnace measured by the means and the pressure outside the drying furnace measured by the external pressure measuring means, and the differential pressure calculated by the internal / external differential pressure calculating means −2 Pa or more and 2 Pa or less, the air supply amount of the air supplied to the drying furnace by the air supply means, or the air discharge amount of the air exhausted from the drying furnace by the exhaust means, or the The apparatus for producing a coated product according to claim 1 or 2, further comprising a control means for controlling both.

  Moreover, as invention which concerns on Claim 4, the distance L of the said top plate and a baseplate is the range of 10 mm or more and 100 mm or less, The coating material of any one of Claim 1 thru | or 3 characterized by the above-mentioned. A manufacturing apparatus was used.

  According to a fifth aspect of the present invention, the height L1 of the top plate side gap between the top plate and the coating film and the height L2 of the bottom plate side gap between the bottom plate and the substrate are L1 ≦ L2. The application manufacturing apparatus according to any one of claims 1 to 4, wherein the relationship is satisfied.

  According to a sixth aspect of the present invention, the drying furnace is divided into a plurality of drying zones in the conveying direction of the coating film, and an air supply means for supplying air into each drying zone; An exhaust means for exhausting the air is provided. The coated article manufacturing apparatus according to any one of claims 1 to 3.

  An invention according to claim 7 is an optical film formed by using the manufacturing apparatus according to any one of claims 1 to 4.

  According to an eighth aspect of the present invention, there is provided a coating step in which a coating liquid containing an organic solvent is applied to a belt-shaped substrate being transported to form a coating film, and then the coating film formed on the substrate is dried. In a manufacturing method of a coated product comprising a drying step of drying while transporting in a furnace, a coating step of applying a coating liquid containing an organic solvent to the belt-shaped substrate being transported to form a coating film, and A transporting step of applying a coating liquid to the substrate and transporting the coating film to a carry-in port of the drying furnace; then, a top plate, a bottom plate, a right side plate, a left side plate, and the coating film A carry-in port for carrying in, a carry-out port for carrying out the coating film, and an air supply port arranged on either the right side plate or the left side plate, and the inside of the drying furnace via the air supply port An air supply means for supplying air to either the left plate or the right plate of the drying furnace facing the supply port An exhaust port arranged and an exhaust means for exhausting air from the inside of the drying furnace through the exhaust port, and the air supply port arranged on either the right side plate or the left side plate of the drying oven has a wind regulation The air generated in the drying furnace using the air supply means and the exhaust means is provided between the top plate-side gap between the top plate of the drying furnace and the coating film, and between the base material and the bottom plate. A drying step of drying the coating film by transporting the coating film formed on the base material from the carry-in port to the carry-out port in the drying furnace that flows in both of the gaps on the bottom plate side, and then the carry-out port of the drying furnace And a step of unloading the coating film from the substrate.

  According to a ninth aspect of the present invention, the air conditioning member comprises a first porous plate, a second porous plate, and a third porous plate in order toward the inside of the drying furnace, and the first porous plate The plate is a member having a large number of holes in the entire air supply port and an opening ratio of 20% to 50%, and the second porous plate has a ME (number of meshes per inch) of 10 to 200. And the third porous plate is a plate-like member having a thickness of 10 mm or more and 100 mm or less, and a columnar hole whose maximum inner diameter is 1 mm or more and 10 mm or less in the thickness direction. The method for producing a coated product according to claim 8, wherein the material is a member having the entire air supply port.

  In the invention according to claim 10, in the drying step, the drying furnace includes an internal pressure measuring means for measuring the pressure inside the drying furnace, an external pressure measuring means for measuring the pressure outside the drying furnace, An internal / external differential pressure calculating means for calculating a differential pressure between the pressure inside the drying furnace measured by the pressure measuring means and the pressure outside the drying furnace measured by the external pressure measuring means, and calculating by the internal / external differential pressure calculating means. An air supply amount of air supplied to the drying furnace by the air supply means, or an air discharge amount of air exhausted from the drying furnace by the exhaust means so that the differential pressure is in a range of −2 Pa to 2 Pa, 10. The coating according to claim 8 or 9, wherein both are controlled by a control means, and the coating film formed on the substrate is dried while being transported in a drying furnace. It was set as the manufacturing method of the thing.

  The invention according to claim 11 is characterized in that the distance between the top plate and the bottom plate is in the range of 10 mm or more and 100 mm or less, wherein the coated product according to any one of claims 8 to 10 is manufactured. It was a method.

  According to a twelfth aspect of the present invention, the height L1 of the top plate side gap between the top plate and the coating film and the height L2 of the bottom plate side gap between the bottom plate and the base material are L1 ≦ L2. The manufacturing method for a coated product according to claim 8, wherein the relationship is satisfied.

  According to a thirteenth aspect of the present invention, the drying furnace is divided into a plurality of drying zones in the transport direction of the coating film, and an air supply means for supplying air into each drying zone, and each drying zone It was set as the manufacturing method of the coating material in any one of Claims 8 thru | or 12 provided with the exhaust means which exhausts the inside air.

  An invention according to claim 14 is an optical film formed by using the manufacturing method according to any one of claims 8 to 13.

  By using the production apparatus and production method of the coated product in the present invention, it is possible to maintain a drying speed faster than at least natural drying while suppressing slight drying unevenness, and to improve surface and productivity. it can.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, the side surface schematic when the manufacturing apparatus of the coating material in this invention is seen from the side surface was shown. A coating film is coated on the base material 9a in the coating section 1b of the coating apparatus 1a. The substrate 9a on which the coating film is formed is conveyed to the drying device 2. The drying apparatus 2 includes a cylindrical drying furnace 5 having a carry-in port 3 and a carry-out port 4 and surrounding a base material 9a, an air supply port 6a installed on a side surface of the drying furnace 5, and an air supply (not shown) An exhaust port 6b installed at a position facing the port 6a, an air supply means (not shown) for supplying air into the drying furnace 5 through the air supply port 6a, and an exhaust port (not shown) Exhaust means for exhausting air from the inside of the drying furnace 5 through 6b, internal pressure measuring means 7a for measuring the pressure inside the drying furnace 5, external pressure measuring means 7b for measuring the pressure outside the drying furnace 5, Although not shown, an internal / external differential pressure calculating means for calculating a differential pressure between the pressure inside the drying furnace 5 measured by the internal pressure measuring means 7a and the pressure outside the drying furnace 5 measured by the external pressure measuring means 7b is shown. The air supply means supplies air into the drying furnace 5 based on the differential pressure calculated by the internal / external differential pressure calculation means. Supply amount of air or the exhaust volume of air exhaust means for exhausting the drying furnace 5 outside, or, and a control means for controlling both.

  The coating film 9 b formed on the base material 9 a is carried into the drying furnace 5 from the carry-in port 3 and carried out from the carry-out port 4 to the outside of the drying furnace 5. Here, four exhaust ports 6b installed at positions facing the air supply port 6a and the air supply port 6a are provided four by one, and the internal pressure measuring means 7a is provided near the carry-in port 3 and the carry-out port 4 one by one. Although the external pressure measuring means 7b is installed in the vicinity of the carry-in entrance 3, this represents one embodiment of the present invention and is not limited to this.

  FIG. 2 is a schematic cross-sectional view taken along the line A-A ′ of the drying apparatus illustrated in FIG. 1. An air supply port 6 a is installed on the right side plate of the drying furnace 5, and an exhaust port 6 b is installed at a position facing the air supply port 6 a of the left side plate of the drying oven 5. In the present invention, air is supplied into the drying furnace 5 from the air supply port 6a using the air supply means 6A, and air is exhausted from the inside of the drying furnace 5 using the exhaust means 6B from the exhaust port 6b. That is, an air flow 17 is generated in a direction perpendicular to the conveying direction of the base material 9a from the air supply port 6a toward the exhaust port 6b. In FIG. 2, an air flow 17 is generated from the right side to the left side in the conveyance direction of the base material 9, and this represents one embodiment of the present invention, and in the conveyance direction of the base material 9 a. An air flow may be generated from the left side to the right side. That is, the air supply port may be provided on the left side plate of the drying furnace 5, and the exhaust port may be provided at a position facing the air supply port on the right side plate of the drying oven 5.

  In the present invention, the air flow generated in the drying furnace using the air supply means 6A and the exhaust means 6B is such that the top plate side gap between the top plate of the drying furnace and the coating film, the base material, and the bottom plate The air supply port 6a and the exhaust port 6b are arranged so as to flow in both of the bottom plate side gaps between them. By flowing air to both the coating film side and the substrate side, it is possible to suppress the occurrence of unevenness in the coating film to be dried. When air is tried to flow only through the coating film, unevenness is likely to occur.

  In the present invention, an air conditioning member is provided at the air supply port. As the air conditioning member, a perforated plate having a large number of holes in the entire air supply port can be used. By using the perforated plate, it was possible to stabilize the flow of air supply and to produce a coated product with high surface quality and high productivity. In addition, in the present invention, a highly planar coated material is a coated material having high film thickness uniformity within the surface of a coating film formed on a substrate. Optical film products are required to have a highly planar coated product with little variation in in-plane film thickness. In addition, as a perforated plate which is a wind regulation member, at least 1 can be used among the 1st perforated plate mentioned later, a 2nd perforated plate, and a 3rd perforated plate. Moreover, you may combine 2 or more of the 1st perforated plate mentioned later, the 2nd perforated plate, and the 3rd perforated plate. At this time, you may combine the same kind of perforated plate.

  The coating apparatus 1 in the present invention can use a gravure, a wire bar, a die or the like, but is not limited to these.

  The drying device 2 in the present invention is installed in a range of 0.2 m to 0.8 m at a coating film transport distance 8 from the coating unit 1b of the coating device 1a. Here, the coating film transport distance 8 refers to the length along the transported base material 9a, not the linear distance between the coating section 1a and the carry-in port 3. Although the conveyance speed of the base material 9a is not a restriction | limiting matter, the drying apparatus 2 which has a general speed | rate about 20 m / min-100 m / min is used. If the coating film conveyance distance 8 is longer than 0.8 m, the naturally drying region cannot be ignored, and unevenness due to natural drying occurs, which is not preferable. Also, if it is less than 0.2 m, the outside air is blocked at the carry-in entrance 3 for carrying in the base material 9a, which is not preferable.

  The drying furnace 5 has a cylindrical shape surrounding the base material 9, and includes a carry-in port 3 for carrying in the base material 9 a, and a carry-out port 4 installed facing the carry-in port 3. The top plate 12 installed on the side of the base material 9a where the coating film 9b is formed, the bottom plate 13 installed facing the top plate 12 across the base material 9a, and the direction of transport of the base material 9a It is the right side, and is composed of a right side plate installed in the width direction of the base material 9a and a left side plate installed facing the right side plate. Here, it does not matter whether the coating film 9b is formed on the upper surface side in the gravity direction or the coating film 9b is formed on the lower surface side of the substrate 9a to be conveyed.

  The carry-in port 3 and the carry-out port 4 have an opening shape because a structure for sealing the inside of the drying furnace 5 is not preferable. In particular, the reason why the carry-in port 3 has an opening shape is that a structure that blocks outside air at the carry-in port 3 that carries the base material 9a is not preferable.

  A blower is generally used as the air supply means 6A and the exhaust means 6B in the present invention, but is not limited to the blower as long as the air supply amount and the exhaust amount can be adjusted.

FIG. 3 shows an enlarged view of the air supply port shown in FIG.
In the present invention, the air conditioning member includes the first porous plate 14, the second porous plate 15, and the third porous plate 16 in this order toward the inside of the drying furnace, and the first porous plate 14 is supplied. It is a member having a large number of holes in the entire mouth and an opening ratio of 20% to 50%, and the second porous plate 15 is a mesh having a ME (number of meshes per inch) of 10 to 200. The third porous plate 16 is a plate-like member having a thickness of 10 mm or more and 100 mm or less, and a columnar hole having a maximum inner diameter of 1 mm or more and 10 mm or less in the thickness direction is provided as an air supply port. It is preferable that it is the member which has in the whole.

  As described above, by providing the first porous plate 14, the second porous plate 15, and the third porous plate 16 in this order toward the inside of the drying furnace at the air supply port 6 a, the in-plane film thickness variation is further increased. It is possible to obtain a coating with a small surface area.

  FIG. 4 shows a perspective view of three perforated plates provided in the air supply port of the present invention. The first perforated plate 14 of the present invention uses a plate-like member having a large number of holes in the entire air supply port and an opening ratio of 20% to 50%. Specifically, holes are uniformly processed in the entire air supply port, and a plate-like member having an opening ratio of 20% or more and 50% or less, such as a metal net or punching metal, can be used. If the aperture ratio of the first perforated plate exceeds 50%, the airflow may not be uniformly dispersed. Moreover, when the aperture ratio is less than 20%, the pressure loss due to the first porous plate may increase.

  In the first perforated plate 14, the maximum value of the inner diameter of the hole is 0.35 mm or more and 3 mm or less, and the interval between the holes is 1.5 to 3 times the maximum value of the inner diameter of the hole. It is preferable to disperse in the above. In order to make the air flow uniform, a plurality of the first perforated plates of the present invention may be used.

  The second perforated plate 15 uses a mesh having a ME (number of meshes per inch) of 10 or more and 200 or less. When ME is less than 10, the effect of further dispersing the airflow that has passed through the first porous plate may not be obtained. On the other hand, when ME exceeds 200, pressure loss may increase. The thickness of the second porous plate is preferably 0.04 mm or more and 2 mm or less. When the thickness of the second porous plate is less than 0.04 mm, the mechanical strength may be insufficient. When the thickness exceeds 2 mm, it is difficult to make the mesh 10 to 200 mesh.

  The third porous plate 16 of the present invention has a plate shape with a thickness of 10 mm or more and 100 mm or less and a columnar hole whose maximum inner diameter is 1 mm or more and 10 mm or less in the thickness direction. The member which has in the whole air mouth can be used. Specifically, it may be a structure in which a large number of small columnar holes are arranged, and the shape of the columnar holes is arbitrary. A typical example is a honeycomb shape composed of hexagonal holes. The columnar holes are fine, and the thicker the thickness, the better the rectifying effect can be obtained.

  In the present invention, the first porous plate, the second porous plate, and the third porous plate are arranged in this order toward the air supply port. The air generated by the air supply means passes through the air supply port and flows to the drying furnace. At this time, by using the first perforated plate made of a plate-like member having an opening ratio of 20% or more and 50% or less, the air flowing toward the air supply port is spread over the entire air supply port, and the air supply surface is within the plane. Can be made uniform. Next, the air that has passed through the first perforated plate is passed through a second perforated plate having a mesh (number of meshes per inch) of 10 or more and 200 or less to finely disperse the air flow. It becomes possible. Finally, the finely dispersed airflow is rectified by passing through the cells having columnar holes which are the third porous plate, and the airflow supplied from the third porous plate into the drying furnace is a layer. It becomes a flow.

  The present inventors use the first porous plate, the second porous plate, and the third porous plate for the air supply port so that the air sucked into the drying furnace is made into a laminar flow, and the laminar flow is used as a basis. By drying the coating film formed on the material, it was possible to produce a coated product with higher surface and productivity.

  In the present invention, when the thickness of the third porous plate is less than 10 mm, it is difficult to make the air that has passed through the third porous plate into a laminar flow. Moreover, when the thickness of the third perforated plate exceeds 100 mm, it is difficult to easily provide the drying device from the viewpoint of space saving. Further, when the inner diameter of the columnar hole of the third porous plate is less than 1 mm, the pressure loss may increase. On the other hand, when the inner diameter of the columnar hole of the third porous plate exceeds 10 mm, it is difficult to make the air that has passed through the third porous plate into a laminar flow. The aperture ratio of the third porous plate is preferably close to 100%, and the aperture ratio is preferably 90% or more and less than 100%. If the aperture ratio is less than 90%, the airflow may become a jet and not a laminar flow.

  Temporarily, in the present invention, the first porous plate spreads the air flowing toward the air supply port over the entire air supply port, makes it uniform in the surface of the air supply port, the second porous plate, The air flow made uniform in the air supply port surface by the perforated plate is made into a laminar flow. Here, in the case of using only the second perforated plate, the air supplied from the air supply port into the drying furnace may not be made into a laminar flow. On the other hand, in the case of using only the third porous plate, it is possible to make a laminar flow by increasing the thickness of the third porous plate and increasing the length of the columnar hole, It is necessary to increase the size of the device, which is not realistic. In the present invention, a laminar flow is efficiently created by finely dispersing the airflow with the second perforated plate having fine pores and passing the fine airflow through the columnar holes of the third perforated plate. It is.

  The internal pressure measuring means 7a and the external pressure measuring means 7b in the present invention are not particularly limited as long as the pressure inside the drying furnace 5 and the pressure outside the drying furnace 5 can be measured. The difference in pressure is controlled in the range of −2 Pa or more and 2 Pa or less from the pressure inside the drying furnace 5 measured by the measuring means 7a and the pressure outside the drying furnace 5 measured by the external pressure measuring means 7b. A resolution that can be achieved is necessary.

  As the internal / external differential pressure calculation means in the present invention, an analog display such as a Manostar gauge or a digital differential pressure gauge can be used, but is not limited thereto. However, in order to control the differential pressure between the pressure inside the drying furnace 5 measured by the internal pressure measuring means 7a and the pressure outside the drying furnace 5 measured by the external pressure measuring means 7b in the range of −2 Pa to 2 Pa. The resolution that can grasp the difference is necessary.

  As the control means in the present invention, the amount of air supplied to the drying furnace 5 by the air supply means so that the differential pressure calculated by the internal / external differential pressure calculation means is in the range of −2 Pa to 2 Pa. As long as the amount of air exhausted from the drying furnace 5 can be controlled by the exhaust means, it is not particularly limited.

  When the base material 9a is carried into the drying furnace 5 from the carry-in port 3, outside air enters the drying furnace 5 from the carry-in port 3, thereby causing unevenness. If the pressure difference between the pressure inside the drying furnace 5 and the pressure outside the drying furnace 5 is in the range of −2 Pa or more and 2 Pa or less, the wind speed of the outside air entering from the carry-in port 3 can be reduced to an appropriate range, causing unevenness. It becomes difficult and preferable.

  However, the internal pressure measuring means 7a and the external pressure measuring means 7b are used for pressure measurement before the start of coating, and the internal / external differential pressure calculating means is the pressure inside the drying furnace 5 before the start of coating and the outside of the drying furnace 5 It is used to measure the differential pressure from the pressure. The differential pressure referred to in the present invention refers to a difference in pressure between the inside of the drying furnace 5 and the outside of the drying furnace 5 before the start of coating. The control means is used for controlling the air supply amount before the start of coating, the exhaust amount, or both.

  During coating, fluctuations in the atmospheric pressure outside the drying apparatus 2 are unavoidable due to entering and leaving the coating chamber. When the change is made, the control means is used to change the amount of air supplied to the drying furnace 5 and the amount of air exhausted from the drying furnace 5. The airflow inside becomes turbulent and causes unevenness. Therefore, the internal pressure measuring means 7a and the external pressure measuring means 7b are used for static pressure measurement before the start of coating, and the internal and external differential pressure calculating means are used for static differential pressure calculation before starting the coating. The control means is used for controlling the static air supply amount before starting and / or the exhaust amount. However, the base material 9 may be transported or stopped during pressure measurement, differential pressure calculation, and control of the air supply amount and the exhaust amount.

  The distance L between the top plate and the bottom plate in the present invention indicates the distance in the direction perpendicular to the base material surfaces of the top plate 12 and the bottom plate 13. In order to keep the air supply amount at the air supply port 6a and the exhaust amount at the exhaust port 6b small and to increase the drying speed, it is necessary to restrict the space in which the air flow 17 is generated to some extent. Therefore, the distance L between the top plate and the bottom plate is preferably in the range of 10 mm to 100 mm. If it is less than 10 mm, it causes a trouble such as contact with the top plate 12 or the bottom plate 13 when the substrate 9a is conveyed, which is not preferable. On the other hand, if it is higher than 100 mm, it is necessary to increase the air supply amount and the exhaust amount in order to increase the drying speed.

  When the height of the air supply port installed in the right side plate of the drying furnace 5 and the height of the exhaust port installed in the left side plate is set to a diameter perpendicular to the base material surfaces of the air supply port 6a and the exhaust port 6b, It is preferable that the distance L from the bottom plate and the heights of the openings of the air supply port and the exhaust port are substantially the same. By doing so, an air flow 17 generated between the air supply port 6a and the exhaust port 6b is uniformly generated between the top plate 12 and the bottom plate 13 of the drying furnace 5, and the coating film 9b of the base material 9a. An air flow 17 is generated on the side opposite to the side on which the coating film 9b is formed on the substrate 9a. Thereby, it becomes difficult to produce blur in the height which conveys the base material 9a, stability is ensured, and generation | occurrence | production of a nonuniformity can be prevented.

  If an air flow is generated only on either the side of the base material 9a where the coating film 9b is formed or the side of the base material 9a opposite to the side where the coating film 9b is formed, the height of the transport of the base material 9a is increased. It must be strictly determined. However, in reality, when the base material 9a is transported, the height at which the base material 9a is transported is blurred, which may cause unevenness. In order to more stably generate the air flow 17 generated between the air supply port 6a and the exhaust port 6b, it is preferable to match the air supply amount at the air supply port 6a with the exhaust amount at the exhaust port 6b. .

  Furthermore, it is preferable to manage the air supply amount and the exhaust amount. The amount can be controlled by the height L1 of the top plate side gap between the coating film 9b and the top plate 12 formed on the base material 9a and the height L2 of the bottom plate side gap between the base material 9a and the bottom plate 13. At this time, it is preferable that the height L1 and the height L2 have a relationship of height L1 ≦ height L2. When the distance L between the top plate and the bottom plate is in the range of 10 to 100 mm and the relationship of height L1 ≦ height L2 is satisfied, surface properties and productivity can be improved most.

  In addition, one or more air supply ports 6a and exhaust ports 6b should be provided with respect to the entire length of the drying furnace 5, but the drying furnace 5 may be divided into a certain length in order to facilitate the control. More preferred. Here, one divided drying furnace is referred to as one drying zone. Each drying zone is cylindrical, and each adjacent drying zone may be arranged linearly or may be refracted. Each drying zone includes an air supply means, an exhaust means, an internal pressure measuring means for measuring a pressure in each drying zone, and an inter-zone differential pressure calculating means for calculating a differential pressure in each adjacent drying zone. And control means for controlling the air supply amount and / or the exhaust amount by the differential pressure calculated by the inter-zone differential pressure calculating means.

  FIG. 5 shows a schematic side view when a drying apparatus according to another embodiment of the present invention is viewed from the side. The coating film 9 b formed on the base material 9 a is carried into the drying furnace 5 from the carry-in port 3 and carried out from the carry-out port 4 to the outside of the drying furnace 5. The drying furnace 5 has four drying zones 18 arranged in a straight line. In each drying zone 18, an exhaust port 6b (not shown) is installed at a position facing the air supply port 6a and the air supply port 6a. Are provided one by one, and although not shown, an air supply means for supplying air into the drying zone 18 through the air supply port 6a, and a drying zone which is also not shown through the exhaust port 6b One exhaust means for exhausting air from inside 18 is installed one by one. Further, one internal pressure measuring means 7 a is installed in each drying zone 18, and an external pressure measuring means 7 b is installed in the vicinity of the carry-in entrance 3. This represents one embodiment of the present invention, and the present invention is not limited to this.

  At this time, it is preferable that the pressure difference between the pressures in the adjacent drying zones 18 is in the range of −2 Pa to 2 Pa. When the base material 9a is transported in the adjacent drying zones 18, an air flow is generated in the transport direction of the base material 9a, thereby causing unevenness. By setting the differential pressure of the pressure in the adjacent drying zone 18 to a range of −2 Pa or more and 2 Pa or less, the wind speed of the air current causing the unevenness can be reduced to an appropriate range, and thus unevenness is suppressed. be able to.

  In the present invention, the length of the drying device 2 in the conveyance direction of the base material is not particularly limited. The length of the drying device 2 is determined by whether or not the coating film is dried, and varies depending on the product. However, in the present invention, the drying apparatus 2 having a general length of about 5 m to 100 m is used.

  The drying apparatus 2 according to the present invention can maintain the drying speed faster than at least natural drying while suppressing the occurrence of slight drying unevenness, and thus the effect is most apparent in the initial stage of drying. The entire length of the drying apparatus does not depend on the drying apparatus 2 of the present invention, and the drying apparatus 2 of the present invention can be introduced only in the initial stage of drying including the carry-in port 3. In that case, as shown in FIG. 1, the drying apparatus 2 of the present invention may be introduced as the first drying apparatus in the first half, and a known drying apparatus may be introduced as the second drying apparatus 10 in the second half.

  As the second drying device 10, a method of applying a jet flow with a raised temperature to a coating film formed on a base material from a slit nozzle or punching metal may be introduced, or a quick return type nozzle or base material A system in which hot air is ejected from a nozzle of a system in which a parallel flow is made in the transport direction may be used. Moreover, you may provide a heating means not only from one side but from both sides. The use of any commercially available drying apparatus does not interfere with the effects of the present invention.

  Further, FIG. 1 shows a case where the drying device 2 of the present invention and the known second drying device 10 are made independent of each other, but the first half of one drying device is the drying device of the present invention. The effect of the present invention remains the same even when the latter part is based on a known drying apparatus.

  The apparatus and method for producing a coated product of the present invention can be used for various products, and is particularly effective for coating a dispersion using an organic solvent as a solvent. Among them, it is effective for a product with less tolerance for unevenness, such as an optical film, which has been in increasing demand in recent years.

  Here, the optical film is a film used mainly on or on the outermost surface of a display device such as a liquid crystal or a plasma display, and is a hard coat film, an antireflection film, an antiglare film, an optical compensation film, a light diffusion film. A film etc. are mentioned.

  Examples of the organic solvent used in the present invention include alcohols such as methanol, ethanol, isopropanol, butanol and 2-methoxyethanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl, methyl acetate, ethyl acetate and butyl acetate. Esters, ethers such as diisopropyl ether, glycols such as ethylene glycol, propylene glycol, hexylene glycol, glycol ethers such as ethyl cellosolve, butyl cellosolve, ethyl carbitol / butyl carbitol, fats such as hexane, heptane / octane Aromatic hydrocarbons such as aromatic hydrocarbons, halogenated hydrocarbons, benzene, toluene and xylene, N-methylpyrrolidone, dimethylformamide and the like, and one kind or a mixture of two or more kinds It may be used as an object, but is not limited thereto.

  Examples of the binder used in the coating liquid of the present invention include ionizing radiation curable resins and thermosetting resins such as ultraviolet curable resins and electron beam curable resins. Agent is included.

  Examples of the ionizing radiation curable resin include polyfunctional acrylate resins such as polyhydric alcohol acrylic acid or methacrylic ester, diisocyanate, polyhydric alcohol and acrylic acid or methacrylic hydroxy ester. Examples include functional urethane acrylate resins. Besides these, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can also be used.

  Examples of the thermosetting resin include thermosetting urethane resins, phenol resins, urea melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins.

  Any photopolymerization initiator may be used as long as it generates radicals when irradiated with active energy rays. For example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane-1- ON, 2-methyl [4- (methylthio) phenyl] morpholinopropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, benzophenone, 1- [4- (2-hydroxyethoxy) ) Phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, bis (2,6- And dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide. 0.1-10 mass parts is preferable with respect to 10-80 mass parts of active energy ray hardening monomers, and, as for the addition amount of a photoinitiator, 1-7 mass parts is more preferable, and 1-5 mass parts is. Further preferred.

  As the base material 9 used in the present invention, various materials can be used depending on applications. Examples of the component constituting the substrate 9 include cellulose films such as acetyl cellulose and triacetyl cellulose, polyester films such as polyethylene terephthalate and polyethylene naphthalate, acrylic films such as polymethyl methacrylate, and the like. It is not limited to these. Moreover, the base material 9 may consist of a single layer, or may consist of multiple layers. In addition, the thickness of the base material 9 is generally 10 to 500 μm.

  The optical film of the present invention may contain functional particles. Functional particles include particles that exhibit a light diffusing function and an antiglare function for light incident on the coating film, and a function that lowers the refractive index of the coating film. Specifically, inorganic particles such as silica particles and alumina particles are used. Examples thereof include organic particles such as particles and acrylic particles, styrene particles, melamine particles, and acrylic styrene particles.

An antiglare film was formed on the substrate as follows.
Silica particles having an average particle size of 3.0 μm are 4.2 wt%, pentaerythritol triacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) 36.0 wt% as a binder, and Irgacure 184 (manufactured by Ciba Specialty Chemicals) 1.8 wt% as a photopolymerization initiator. %, 34.8 wt% toluene as a solvent and 23.2 wt% dioxolane were prepared as a coating solution. The viscosity prepared was 3.0 mPas.
Next, using a triacetylcellulose (TAC) substrate having a width of 1340 mm and a film thickness of 80 μm as a belt-like substrate to be continuously conveyed, a coating solution is applied with an extrusion type die head, followed by drying and ultraviolet curing steps. After that, an anti-glare film was prepared by applying a wet film thickness of 8.5 μm on the substrate with a coating width of 1310 mm and a conveying speed of 50 m / min.

  The drying device has a distance between the top plate and the bottom plate of 17 mm, a height of the opening of the air supply port and the exhaust port of 17 mm, and a height of the top plate side gap between the coating film 9 b formed on the substrate 9 a and the top plate 12. The length L1 was 7 mm, and the height L2 of the bottom plate side gap between the base material 9a and the bottom plate 13 was 10 mm. The carry-in port of the drying furnace and the coating unit are installed at a distance of 0.2 m in terms of the coating film transport distance, and the internal blower rotation speed is adjusted so that the pressure difference inside and outside the drying furnace near the carry-in port is within the range of 0 ± 1 Pa. Controlled. The length of the drying apparatus of the present invention was 10 m, and then a drying apparatus having a length of 5 m for blowing hot air from the slit nozzle was installed.

  And the 1st perforated plate, the 2nd perforated plate, and the 3rd perforated plate were provided in the air supply port of the drying furnace toward the air supply port. As the first porous plate, a punching metal having an aperture ratio of 20% and an inner diameter of 1 mm is used. As the second porous plate, a metal mesh having an ME of 200 and a thickness of 0.1 mm is used. As the perforated plate, a member having a columnar honeycomb shape having a thickness of 20 mm, a maximum inner diameter of the hole of 50 mm, and an opening ratio of 99% was used.

As a result of inspecting the surface shape of the anti-glare film obtained by cutting the longitudinal direction to a length of 2 m obtained in the examples over a fluorescent lamp, and confirming unevenness by clearly forming a non-uniform surface shape, Unevenness was not confirmed, and it could be used as an antiglare film on the display surface.

(Comparative example)
As a comparative example, the first perforated plate, the second perforated plate, and the third perforated plate provided in (Example) were removed, and the antiglare film was prepared in the same manner as in (Example).

As a result of inspecting the surface shape of the antiglare film obtained by cutting the longitudinal direction to a length of 2 m obtained in the comparative example over a fluorescent lamp, and confirming unevenness by clearly forming a non-uniform surface shape, Tuft-like unevenness was confirmed and could not be used as an antiglare film on the display surface.

FIG. 1 is a schematic side view of a coated product manufacturing apparatus according to the present invention as viewed from the side. FIG. 2 is a schematic cross-sectional view taken along the line A-A ′ of the drying apparatus illustrated in FIG. 1. FIG. 3 is an enlarged view of the air supply port shown in FIG. FIG. 4 is a perspective view of three perforated plates provided in the air supply port of the invention. FIG. 5 is a schematic side view of a drying device according to another embodiment of the present invention as viewed from the side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating device 2 Drying device 3 Carrying-in port 4 Carrying-out port 5 Drying furnace 6a Air supply port 6b Exhaust port 7a Internal pressure measuring means 7b External pressure measuring means 8 Coating film conveyance distance 9a Base material 9b Coating film 10 Second drying apparatus 11 Top Distance 12 between plate and bottom plate Top plate 13 Bottom plate 14 First porous plate 15 Second porous plate 16 Third porous plate 17 Air flow 18 Drying zone L Distance between top plate and bottom plate L1 Coating film and top plate Top plate side gap height L2 Bottom plate side gap height between base material and bottom plate

Claims (14)

An apparatus for producing a coated product, comprising: a coating apparatus that forms a coating film by applying a coating solution containing an organic solvent to a belt-shaped substrate being transported; and a drying apparatus that dries while transporting the coating film formed on the substrate. In
The drying apparatus includes a drying furnace having at least a top plate, a bottom plate, a right side plate, a left side plate, a carry-in port into which the coating film is carried in, and a carry-out port through which the coating film is carried out,
The drying oven
An air supply port arranged on either the right side plate or the left side plate of the drying oven;
An air supply means for supplying air into the drying furnace through the air supply port;
An exhaust port disposed on either the left side plate or the right side plate of the drying furnace facing the air supply port;
Exhaust means for exhausting air from the inside of the drying furnace through the exhaust port,
The flow of air generated in the drying furnace using the air supply means and the exhaust means is such that the top plate side gap between the top plate of the drying furnace and the coating film, and the bottom plate side between the base material and the bottom plate An air supply port and an exhaust port are arranged to flow in both of the gaps,
And the air supply port arrange | positioned in either the right side board or the left side board of a drying furnace is provided with a wind regulation member, The manufacturing apparatus of the coating material characterized by the above-mentioned. The air conditioning member comprises a first perforated plate, a second perforated plate, and a third perforated plate in order toward the inside of the drying furnace,
The first perforated plate is a member having a large number of holes in the entire air supply port and an opening ratio of 20% to 50%.
The second porous plate is a mesh having a ME (number of meshes per inch) of 10 or more and 200 or less,
The third porous plate is a plate-like member having a thickness of 10 mm or more and 100 mm or less, and a columnar hole having a maximum inner diameter of 1 mm or more and 10 mm or less in the thickness direction is provided for the entire air supply port. The device for manufacturing a coated product according to claim 1, wherein The drying device is
An internal pressure measuring means for measuring the pressure in the drying furnace;
An external pressure measuring means for measuring the pressure outside the drying furnace;
An internal / external differential pressure calculating means for calculating a differential pressure between the pressure inside the drying furnace measured by the internal pressure measuring means and the pressure outside the drying furnace measured by the external pressure measuring means;
The supply amount of air supplied to the drying furnace by the supply unit or the exhaust unit is dried so that the differential pressure calculated by the internal / external differential pressure calculation unit is in the range of −2 Pa to 2 Pa. The apparatus for producing a coated product according to claim 1, further comprising: a control unit that controls an exhaust amount of air exhausted from the furnace or both.   The distance L between the top plate and the bottom plate is in a range of 10 mm or more and 100 mm or less, and the apparatus for manufacturing a coated product according to any one of claims 1 to 3.   The height L1 of the top plate side gap between the top plate and the coating film and the height L2 of the bottom plate side gap between the bottom plate and the base material satisfy a relationship of L1 ≦ L2. The manufacturing apparatus of the coated material of any one of 1-4. The drying furnace is divided into a plurality of drying zones in the transport direction of the coating film,
An air supply means for supplying air into each drying zone;
Exhaust means for exhausting air in each drying zone;
An apparatus for manufacturing a coated product according to any one of claims 1 to 3, comprising:   An optical film formed using the manufacturing apparatus according to claim 1. A coating step in which a coating solution containing an organic solvent is applied to the belt-shaped substrate being transported to form a coating film; and a drying step in which the coating film formed on the substrate is then dried while being transported in a drying furnace; In a method for producing a coated product comprising:
An application step of applying a coating liquid containing an organic solvent to the belt-shaped substrate being transported to form a coating film;
Next, a conveying step of applying a coating liquid to the substrate and conveying the coating film to a carry-in port of the drying furnace;
Next, a top plate, a bottom plate, a right side plate, a left side plate, a carry-in port into which the coating film is carried in, a carry-out port through which the coating film is carried out, and
An air supply port arranged on either the right side plate or the left side plate;
An air supply means for supplying air into the drying furnace through the air supply port;
An exhaust port disposed on either the left side plate or the right side plate of the drying furnace facing the air supply port;
Exhaust means for exhausting air from the inside of the drying furnace through the exhaust port, and
The air supply port arranged on either the right side plate or the left side plate of the drying furnace is provided with an air conditioning member,
The air generated in the drying furnace using the air supply means and the exhaust means is a gap between the top plate side gap between the top plate of the drying furnace and the coating film and the bottom plate side gap between the base material and the bottom plate. A drying process in which the coating film formed on the base material is transported from the carry-in port to the carry-out port in a drying furnace that flows to both,
Next, a step of carrying out the coating film from the carry-out port of the drying furnace. The air conditioning member comprises a first perforated plate, a second perforated plate, and a third perforated plate in order toward the inside of the drying furnace,
The first perforated plate is a member having a large number of holes in the entire air supply port and an opening ratio of 20% to 50%.
The second porous plate is a mesh having a ME (number of meshes per inch) of 10 or more and 200 or less,
The third porous plate is a plate-like member having a thickness of 10 mm or more and 100 mm or less, and a columnar hole having a maximum inner diameter of 1 mm or more and 10 mm or less in the thickness direction is provided for the entire air supply port. The method for producing a coated product according to claim 8, wherein:   In the drying step, the drying furnace measures internal pressure measuring means for measuring the pressure inside the drying furnace, external pressure measuring means for measuring pressure outside the drying furnace, and pressure inside the drying furnace measured by the internal pressure measuring means. And an internal / external differential pressure calculating means for calculating a differential pressure between the pressure outside the drying furnace measured by the external pressure measuring means, and the differential pressure calculated by the internal / external differential pressure calculating means is -2 Pa or more and 2 Pa or less. The control means controls the air supply amount of air supplied to the drying furnace by the air supply means or the exhaust amount of air exhausted from the drying furnace by the exhaust means, or both, The method for producing a coated product according to claim 8 or 9, wherein the coated film formed on the substrate is dried while being conveyed in a drying furnace.   The distance between the top plate and the bottom plate is in a range of 10 mm or more and 100 mm or less, and the method for producing a coated product according to any one of claims 8 to 10.   The height L1 of the top plate side gap between the top plate and the coating film and the height L2 of the bottom plate side gap between the bottom plate and the base material satisfy a relationship of L1 ≦ L2. The manufacturing method of the coated material of any one of 8 thru | or 11. The drying furnace is divided into a plurality of drying zones in the transport direction of the coating film,
An air supply means for supplying air into each drying zone;
The manufacturing method of the coating material in any one of Claims 8 thru | or 12 provided with the exhaust means which exhausts the air in each drying zone.   An optical film formed by using the manufacturing method according to claim 8.

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