JP5479259B2 - Coating apparatus and optical film manufacturing method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a coating apparatus and an optical film manufacturing method, and relates to a coating apparatus including a slit interval adjusting unit and an optical film manufacturing method using the coating apparatus.

  In the production of an optical film, a coating solution is applied to a continuously running substrate. As a device for applying such a coating liquid, a slot die having a slot communicating with a manifold is known. The coating liquid is discharged from the tip of a slot (also referred to as a slit) communicating with the manifold. The base material to which the coating liquid is applied is wound around a backup roller and continuously runs. A bead of coating liquid discharged from the slit is formed between the tip of the slot die and the base material, and the coating liquid is supplied to the base material through this bead.

  In recent years, it has been required to apply a coating film of an optical film with a uniform thickness. Therefore, it is necessary to keep the slot interval of the slot die constant over the width direction. In order to solve this problem, a method of adjusting the slot interval of the slot die has been proposed. Patent Document 1 discloses a slit die in which the slit width is adjusted by an adjustment bolt attached at a predetermined angle to the tip of the slit die. Liquid is discharged from the slit die in the direction of gravity. Patent Document 2 discloses a slot die in which a contact plate having a peak portion is arranged on the outer periphery of a die slot and fixed with a fixing bottle and an adjusting bolt. Liquid is discharged from the die slot in the direction opposite to gravity.

JP 2006-205031 A JP-A-5-293419

  In the manufacture of optical films, adjustment bolts are sometimes used to adjust the slot spacing of the slot die. At this time, in the method of Patent Document 1, it is necessary to arrange a large number of bolts on the slot die, and it takes a long time to adjust the slot interval.

  In the method of Patent Document 2, when a coating liquid is supplied from the lateral direction to a continuously running substrate, a contact plate is disposed on the upper portion of the slot die. Therefore, there is a problem that the slot interval is deformed by the weight of the backing plate. On the other hand, when the weight of the contact plate is excessively reduced, there is a problem that the rigidity of the contact plate is insufficient and the slot interval cannot be adjusted.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a coating apparatus and an optical film manufacturing method capable of adjusting the slot interval with high accuracy.

According to one aspect of the present invention, there is provided a coating apparatus that supplies a coating liquid to a traveling strip-shaped base material, and includes a manifold that is supplied with the coating liquid, a slot that communicates with the manifold , and a horizontal direction on the base material. A slot die for supplying the coating liquid from the slot die, and an adjusting means for adjusting the interval between the slots, and the adjusting means includes a block having legs, a fixing bolt and an adjusting bolt, The block is fixed to the slot die by the fixing bolt that is in contact with the slot die, and the fixing bolt that is inserted through the leg and the adjustment bolt that is inserted through other than the leg, and the block is 120 GPa or more. It has a Young's modulus and a pressure due to its own weight of 6000 N / m ² or less.

According to the present invention, the block is made of a light and highly rigid material, so that the pressure due to its own weight is 6000 N / m ² or less and the Young's modulus is 120 GPa or more. As a result, it is possible to eliminate the deformation of the slot interval due to the weight of the block and adjust the slot interval.

  According to another aspect of the coating apparatus of the present invention, preferably, the block is made of fiber reinforced plastic or ceramic.

  According to another aspect of the coating apparatus of the present invention, preferably, the slot die has a width of 1 m or more.

  According to another aspect of the coating apparatus of the present invention, preferably, the slot die has a plurality of sets of holes of the fixing bolts and holes of the adjusting bolts at an upper portion thereof, and the adjusting means has an arbitrary number of And placed in the position.

  According to another aspect of the coating apparatus of the present invention, it is preferable that a decompression chamber is further provided below the slot die.

According to another aspect of the present invention, there is provided a method for producing an optical film for supplying a coating liquid to a traveling belt-like substrate, comprising a manifold to which the coating liquid is supplied, a slot communicating with the manifold , and the base A slot die for supplying a coating solution from a horizontal direction to the material; and an adjusting means that is installed on the upper portion of the slot die and adjusts an interval between the slots. The adjusting means is adjusted with a block having leg portions and a fixing bolt. The block is fixed to the slot die by the fixing bolt that includes a bolt, the leg is in contact with the slot die, and the fixing bolt that passes through the leg and the adjustment bolt that passes through other than the leg. Preparing a coating apparatus having a Young's modulus of 120 GPa or more and a pressure due to its own weight of 6000 N / m ² or less; A step of adjusting an interval between lots, and a step of supplying a coating solution to a continuously running substrate by the coating apparatus.

  According to another aspect of the method for producing an optical film of the present invention, preferably, the block is made of fiber reinforced plastic or ceramic.

  According to another aspect of the method for producing an optical film of the present invention, preferably, the slot die has a width of 1 m or more.

  According to another aspect of the method of manufacturing an optical film of the present invention, preferably, the slot die has a plurality of sets of fixing bolt holes and adjusting bolt holes at an upper portion thereof, and the adjusting means is optional. Are arranged in the number and position.

  According to another aspect of the method for producing an optical film of the present invention, it is preferable that a vacuum chamber is further provided below the slot die.

According to the present invention, the block is made of a light and highly rigid material, whereby the pressure due to its own weight is 6000 N / m ² or less and the Young's modulus is 120 GPa or more. Therefore, the slot interval can be adjusted by eliminating the deformation of the slot interval due to the weight of the block.

It is sectional drawing of a coating device. It is a perspective view of a coating device. It is a block diagram of a slot die, a backup roller, and its periphery. The block diagram which shows the manufacturing line of an optical film.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention will be described with reference to the following preferred embodiments, but can be modified in many ways without departing from the scope of the present invention, and other embodiments than the present embodiment can be used. be able to. Accordingly, all modifications within the scope of the present invention are included in the claims. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to”.

  FIG. 1 shows a cross-sectional view of the coating apparatus. The coating apparatus 10 includes a slot die 12 and an adjusting unit 30 that adjusts the slot interval. The slot die 12 has a manifold 14 provided inside the main body and a slot 16 communicating with the manifold 14. The slot die 12 is composed of two blocks, a lower die block 18 and an upper die block 20. The manifold 14 and the slot 16 are formed by a lower die block 18 and an upper die block 20. Thus, the processing accuracy of the slot die 12 can be increased by making the slot die 12 have a multi-block structure. The lower die block 18 and the upper die block 20 are made of a material such as SUS having a Young's modulus of 200 GPa or more. These materials are used because they have high corrosion resistance and high processing accuracy. The lower die block 18 and the upper die block 20 can be integrally formed.

  The manifold 14 of the slot die 12 is a liquid reservoir that spreads the supplied coating liquid in the coating width direction (web width direction), and extends in the web width direction. The manifold 14 of the present embodiment has a substantially circular cross-sectional shape. The manifold 14 forms a cavity having substantially the same cross-sectional shape along the web width direction.

  An adjusting means 30 for adjusting the slot interval is installed on the upper die block 20. The slot interval t means the distance between the lower die block 18 and the upper die block 20 at the tip of the slot 16 (the coating solution outlet). The adjusting means 30 includes a block 31 having leg portions 32, a fixing bolt 33, and adjusting bolts 34 and 35. The block 31 is installed so that the leg portion 32 contacts the upper die block 20. The fixing bolt 33 extends through the upper die block 20 through the leg 32 of the block 31. The adjustment bolts 34 and 35 extend through the upper die block 20 through the region of the block 31 excluding the leg portion 32. The adjusting bolts 34 and 35 are rotatably attached. By tightening either or both of the adjusting bolts 34 and 35 to the upper die block 20 side, a force acts in the direction of increasing the slot interval t with the leg portion 32 as a fulcrum. Thereby, the slot interval t can be adjusted.

  Although the block 31 in which the leg portion 32 is integrally formed is shown, the present invention is not limited to this. The leg can be a separate member. Further, another plate material or the like is inserted between the block and the upper die block as necessary.

In the present embodiment, the block 31 has a Young's modulus of 120 GPa or more. Since the block 31 has high rigidity, even if a load is applied by the adjusting bolts 34 and 35, the lever principle can be applied to the leg portion 32 as a fulcrum. The block 31 has a pressure due to its own weight of 6000 N / m ² or less. Therefore, it is possible to prevent the slot interval t from being narrowed by the dead weight of the block 31. The block 31 is made of fiber reinforced plastic or ceramic. As the fiber reinforced plastic, FRP or the like can be used. According to the present embodiment, deformation of the slot interval due to its own weight can be eliminated, and the slot interval can be adjusted with high accuracy.

  FIG. 2 shows a perspective view of the coating apparatus. The coating apparatus 10 includes one slot die 12 and three adjustment means 30. In recent years, in order to increase productivity, the width of the web to which the coating liquid is supplied has been widened. Depending on the width of the web, a slot die 12 having a width L of 1 m or more is used. As the slot die 12 becomes larger, it becomes difficult to increase the processing accuracy when the slot die 12 is manufactured. As a result, the slot interval may vary in the width L direction of the slot die 12. In order to obtain a coating film having a uniform film thickness, it is necessary to arrange a plurality of adjusting means 30 at arbitrary locations on the slot die 12. As shown in FIG. 2, the upper die block 20 is formed with a plurality of combinations of holes 36 for fixing bolts 33 and holes 37 and 38 for adjusting bolts 34 and 35. Thereby, an arbitrary number of adjusting means 30 can be arranged at an arbitrary position.

  FIG. 3 is a configuration diagram of the coating apparatus 10, the backup roller 40, and the periphery thereof. The arrow in the vicinity of the backup roller 40 and the web W in the figure indicates the traveling direction of the web W. In order to facilitate understanding, the size and orientation of each device shown in FIG. 3 do not necessarily match those of an actual device.

  As shown in FIG. 3, in the present embodiment, the coating liquid is discharged from the slot 16 of the slot die 12 toward the surface of the web (base material) W that continuously runs while being supported by the backup roller 40. . The coating liquid is supplied to the web W from the horizontal direction. The horizontal direction means a direction substantially orthogonal to the direction of gravity. A bead 42 of coating liquid is formed between the slot die 12 and the web W. In order to form the coating film with high accuracy, it is preferable to stabilize the state of the bead 42. Therefore, in order to keep the pressure state in the vicinity of the bead 42 in an ideal state, the decompression chamber 50 is provided at a position adjacent to the lower die block 18.

  In addition, before or after the coating liquid is supplied to the web W, the interval between the slots 16 is accurately adjusted by the adjusting means 30. By this adjustment, the coating liquid can be supplied onto the web W with a uniform film thickness.

  As the coating liquid to be applied to the web W, an organic solvent coating liquid that requires low viscosity and thin film coating, such as an optical compensation film coating liquid, an antireflection film coating liquid, and a viewing angle widening coating liquid is preferably used. it can. For example, methyl ethyl ketone or the like is used.

  As the web W, various known webs can be used. In general, various known plastic films such as polyethylene terephthalate, polyethylene-2,6-naphthalate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyimide, polyamide, paper The surface of the belt-shaped substrate such as various laminated papers coated with α-polyolefins having 2 to 10 carbon atoms such as polyethylene, polypropylene, ethylene butene copolymer, etc. on paper, metal foils such as aluminum, copper, and tin In which a preliminary processed layer is formed, or various composite materials in which these are laminated.

  FIG. 4 is a diagram showing an overall configuration of the optical film production line 100. The arrows in the figure indicate the traveling direction of the web W. For the plurality of pass rollers 68 that convey the web W, only the pass rollers 68 arranged at representative positions are shown.

  In the production line 100 of the present embodiment, from the upstream side toward the downstream side, the feeder 66, the dust remover 74, the backup roller 40, the coating device 10, the drying device 76, the heating device 78, the ultraviolet irradiation device 80, and the winding The take-out machines 82 are sequentially installed. Here, “upstream” and “downstream” are based on the traveling direction of the web W.

  The feeder 66 sequentially feeds the web W, which is a transparent support having a polymer layer formed in advance, to the downstream side. The dust remover 74 removes foreign matters such as dust adhering to the web W.

  The coating liquid is discharged from the slot die 12 toward the web W conveyed and supported by the backup roller 40, and a coating film is formed on the web W. A decompression chamber 50 is disposed on the upstream side of the slot die 12. The decompression chamber 50 has two side plates 52 and a back plate 54. By reducing the pressure in the vacuum chamber 50, the beads can be formed with high accuracy. As described above, the adjusting means 30 is installed on the slot die 12.

  The drying device 76 and the heating device 78 form a zone for drying the coating film formed on the web W. The drying device 76 evaporates the solvent contained in the coating film. The heating device 78 may be used to remove the solvent or to cure the film by heating if necessary.

  In addition, it is preferable that drying of the solvent by the drying apparatus 76 and the heating apparatus 78 is performed in the state covered with the cover. As the drying air, a rectified air, a homogeneous air, or the like can be used. The evaporated solvent may be condensed and removed by a cooling condensing plate installed facing the coating film surface.

  The ultraviolet irradiation device 80 irradiates the coating film with ultraviolet rays by an ultraviolet lamp. A desired polymer is formed by cross-linking the monomer of the coating film with ultraviolet rays. The winder 82 winds and collects the web W on which the polymerized coating film is laminated in a roll shape.

  In addition, according to the component of a coating film, the heat processing zone for hardening a coating film with a heat | fever can also be provided, and hardening and bridge | crosslinking of a desired coating film may be performed. Moreover, you may perform other processes, such as heat processing, with respect to the coating film on the web W at a process different from the production line 100.

  A plurality of pass rollers 68 are provided between the devices. The web W is sent from the upstream side to the downstream side by these pass rollers 68. The position and number of the pass rollers 68, the distance between the rotation centers of the adjacent pass rollers 68, and the like are appropriately adjusted as necessary.

  Further, the backup roller 40 and the pass roller 68 function as a guide roller for conveying the web W. Further, other devices can be introduced into the production line 100 as necessary. For example, in the optical compensation film, rubbing treatment devices for adjusting the orientation of the liquid crystal part of the coating film can be installed before and after the dust remover 74.

  Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention. However, it is not limited to these.

  Table 1 shows data of the slot die material, block material, block shape, block density, pressure due to its own weight, block Young's modulus, and evaluation data in Examples and Comparative Examples. The evaluation was performed with three items: adjustment of the slit interval, change of the slit interval due to its own weight, and comprehensive evaluation. Regarding the adjustment of the slit interval, the case where the deformation adjustment was possible up to 5 μm was marked with “◯”, and the case where the deformation adjustment of 1 μm was impossible was made x. Regarding the change in the slit interval due to its own weight, the case where deformation of 1 μm or less occurred over time was indicated as “◯”, the case where deformation of 3 μm or less occurred over time, and the case where deformation of 5 μm or less over time occurred. Regarding the overall evaluation, the case where both of the above two evaluation results were ○ was indicated as ◯, one was Δ and one was ○, and one was ×.

表１に示すように、ブロックが自重による圧力を６０００Ｎ／ｍ^２以下、ヤング率１２０ＧＰａ以上を満たすとき、スリット間隔の調整、自重によるスリット間隔の変化、及び総合評価の全てにおいて○の評価を得た。

As shown in Table 1, when the block satisfies the pressure due to its own weight of 6000 N / m ² or less and the Young's modulus is 120 GPa or more, the evaluation of ○ is obtained in all of the adjustment of the slit interval, the change of the slit interval due to its own weight, and the comprehensive evaluation It was.

On the other hand, about Comparative Examples 1-3, since the pressure by own weight is larger than 6000 N / m < ² >, the change of the slit space | interval by own weight was evaluation below (triangle | delta). About Comparative Examples 4-6, since Young's modulus is smaller than 120 GPa, adjustment of a slit space | interval was evaluation of x.

  DESCRIPTION OF SYMBOLS 10 ... Application | coating apparatus, 12 ... Slot die, 14 ... Manifold, 16 ... Slot, 18 ... Lower die block, 20 ... Upper die block, 30 ... Adjustment means, 31 ... Block, 32 ... Leg part, 33 ... Fixing bolt, 34 35 ... adjusting bolt, 40 ... backup roller, 50 ... decompression chamber

Claims (10)

A coating apparatus for supplying a coating liquid to a traveling belt-like substrate,
A manifold to which a coating liquid is supplied, a slot die having a slot communicating with the manifold , and supplying the coating liquid to the base material from a horizontal direction;
The adjusting means is provided on an upper portion of the slot die and includes an adjusting means for adjusting an interval between the slots. The adjusting means includes a block having leg portions, a fixing bolt and an adjusting bolt, and the leg portions abut on the slot die. The block is fixed to the slot die by the fixing bolt that passes through the leg and the adjustment bolt that passes through other than the leg.
The coating apparatus, wherein the block has a Young's modulus of 120 GPa or more and a pressure due to its own weight of 6000 N / m ² or less.   The coating apparatus according to claim 1, wherein the block is made of fiber reinforced plastic or ceramic.   The coating apparatus according to claim 1 or 2, wherein the slot die has a width of 1 m or more.   The coating apparatus according to any one of claims 1 to 3, wherein the slot die has a plurality of sets of holes of the fixing bolts and holes of the adjusting bolts on an upper portion thereof, and the adjusting means has an arbitrary number. , And a coating device arranged at a position.   The coating apparatus according to claim 1, further comprising a decompression chamber below the slot die. A method for producing an optical film for supplying a coating liquid to a traveling belt-like substrate,
A manifold to which a coating liquid is supplied, a slot that communicates with the manifold , a slot die that supplies the coating liquid to the base material from a horizontal direction, and an upper part of the slot die, and adjusts the interval between the slots. The adjusting means includes a block having a leg portion, a fixing bolt and an adjusting bolt, and the leg portion is in contact with the slot die and passes through the leg portion, except for the fixing bolt and the leg portion. A step of preparing a coating apparatus in which the block is fixed to the slot die by the adjusting bolt that passes through the plate, the block has a Young's modulus of 120 GPa or more, and a pressure due to its own weight of 6000 N / m ² or less;
Adjusting the slot spacing by the adjusting means;
Supplying the coating solution to the continuously running substrate by the coating device;
The manufacturing method of the optical film containing this.   The method for manufacturing an optical film according to claim 6, wherein the block is made of fiber reinforced plastic or ceramic.   The method for producing an optical film according to claim 6 or 7, wherein the slot die has a width of 1 m or more.   9. The method of manufacturing an optical film according to claim 6, wherein the slot die has a plurality of holes of the fixing bolts and holes of the adjusting bolts at an upper portion thereof, and the adjusting means is The manufacturing method of the optical film arrange | positioned in arbitrary numbers and positions.   10. The method for producing an optical film according to claim 6, further comprising a vacuum chamber under the slot die.

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