JP6435731B2 - Coating film manufacturing method, coating apparatus and coating head - Google Patents

Description

  The present invention relates to a coating film prepared by applying various coating liquids to a film material.

  Conventionally, by applying various coating liquids to a long film material, a desired layer structure is formed on the film material to produce various coating films. More specifically, for example, a pattern retardation film which is one of the coating films of this type is used in the passive three-dimensional display method, and has a pattern-like orientation regulating force on the surface of the transparent film material. An alignment layer is produced. In addition, a coating liquid made of a liquid crystal material is applied onto the alignment layer, and the liquid crystal material is solidified in a state of being aligned in a pattern by the alignment regulating force of the alignment layer, thereby producing a retardation layer. The pattern retardation film is held on the panel surface of the liquid crystal display panel, gives a desired phase difference to the transmitted light by this retardation layer, and selectively from each pixel of the image display panel to the viewer's right eye and left eye. Provides outgoing light.

  Moreover, in such an antiglare film, which is one of such coating films, an antiglare layer is formed on a transparent film material by coating a coating solution, and incident light is scattered by this antiglare layer to prevent reflection. Plan.

  Such a film material to be coated is provided by a roll material, and after a coating liquid is coated by a coating head such as a die, it is dried and cured to form a phase layer, an antiglare layer, and the like. .

  With respect to such coating, Patent Document 1 discloses a configuration for removing mist generated in a hot-melt ink coating apparatus. Patent Document 2 proposes a device for collecting a coating liquid with respect to a blade coater.

  By the way, such a coated film may cause a defect due to adhesion of foreign matter. Generation | occurrence | production of such a fault will reduce the yield of a coating film. As a result of various investigations, this type of defect is derived from the coating liquid, which occurs when the mist of the coating liquid adheres, or the mist of the coating liquid temporarily adheres to other members. It was found that this occurs when the solidified component adheres.

Japanese Patent No. 3494728 JP 2002-301419 A

  This invention is proposed in view of such a situation, and it aims at reducing the fault originating in the mist of a coating liquid compared with the past, and improving a yield.

  This inventor repeated earnest examination in order to solve the subject mentioned above. As a result, the present invention is based on the idea of reducing the mist that floats in the coating environment and causes defects by providing an intake mechanism on the downstream side of the part related to coating and sucking and removing it. Was completed.

  Specifically, the present invention provides the following.

(1) In the manufacturing method of the coating film which manufactures a coating film by applying a coating liquid while conveying a long film,
The manufacturing method of the coating film which attracts | sucks the mist of the said coating liquid with an intake mechanism in the downstream of the site | part used for coating of the said coating liquid.

  According to (1), the mist can be sucked and removed immediately after the occurrence, thereby reducing the defects derived from the mist.

(2) In a coating apparatus for coating a coating liquid while conveying a long film,
A coating head for coating the coating liquid;
A coating apparatus comprising: an intake mechanism that sucks mist of the coating liquid downstream of the coating head.

  According to (2), the mist can be sucked and removed immediately after the occurrence, thereby reducing the defects derived from the mist.

(3) In (2),
The intake mechanism is
An air intake is provided downstream of the coating head;
The mist of the coating liquid is sucked through the intake part,
A coating apparatus in which the intake section is integrally held by the coating head.

  According to (3), since the air intake part is integrally held by the coating head, the work related to installation and maintenance such as positioning related to the air intake part can be simplified, and defects caused by mist can be reduced. Can do.

(4) In (2),
The intake mechanism is
An air intake is provided downstream of the coating head;
The mist of the coating liquid is sucked through the intake part,
A coating apparatus in which the intake section is held separately from the coating head.

  According to (4), it is possible to reduce defects caused by mist by using a highly versatile coating head and by simply improving an existing apparatus.

(5) In the coating head used for coating the coating liquid,
A coating head in which an air intake section that sucks mist of the coating liquid is provided at a site downstream of the site to which the coating liquid is applied.

  According to (5), the mist can be sucked and removed immediately after the occurrence, thereby reducing the defects derived from the mist.

  (6) In (5), the coating head is a die head.

  According to (6), the defect derived from mist can be reduced by a more specific configuration.

  According to the present invention, defects derived from the mist of the coating liquid can be reduced as compared with the conventional case, and the yield can be improved.

It is a figure which shows the pattern phase difference film which concerns on 1st Embodiment of this invention. It is a figure which shows the manufacturing process of the pattern phase difference film of FIG. It is a figure which shows the coating apparatus which concerns on the coating process of FIG. It is a figure which shows the intake part in the coating apparatus of FIG. It is a figure which shows the coating apparatus which concerns on 2nd Embodiment of this invention.

[First Embodiment]
FIG. 1 is a view showing a pattern retardation film according to the first embodiment of the present invention. In the image display device according to the first embodiment, the pixels of the liquid crystal display panel that are continuous in the vertical direction (left-right direction in FIG. 1) are alternately displayed in the order of the right-eye pixel and the left-eye pixel. The images are distributed to the left-eye pixels that display the image, and are driven by the image data for the right eye and the left eye, respectively. As a result, the image display device alternately divides the display screen into a band-like region for displaying an image for the right eye and a band-like region for displaying an image for the left eye, so that the image for the right eye and the image for the left eye are divided. Display at the same time. In this image display device, the pattern phase difference film 1 shown in FIG. 1 is disposed on the panel surface of the liquid crystal display panel, and the pattern phase difference film 1 corresponds to light emitted from pixels for the right eye and the left eye, respectively. To give the phase difference. Thereby, this image display apparatus displays a desired three-dimensional image by a passive method.

  In the pattern retardation film 1, for example, an alignment layer 3 and a retardation layer 4 are sequentially formed on a base material 2 made of a transparent film material such as triacetyl cellulose. In the pattern retardation film 1, the retardation layer 4 is formed of a liquid crystal material, and the alignment of the liquid crystal material is patterned by the alignment regulating force of the alignment layer 3. The orientation of the liquid crystal molecules is indicated by a long and narrow ellipse in FIG. By this patterning, the pattern phase difference film 1 is formed in a band shape alternately with the right-eye area A and the left-eye area B sequentially with a certain width corresponding to the pixel assignment in the liquid crystal display panel. A phase difference corresponding to each of the light emitted from the right-eye and left-eye pixels is given.

  In the pattern retardation film 1, after a photo-alignment material film made of a photo-alignment material is produced, the alignment layer 3 is formed by irradiating the photo-alignment material film with ultraviolet rays by linearly polarized light by a so-called photo-alignment technique. Here, the ultraviolet rays applied to the photo-alignment material film are set so that the direction of polarization differs between the right-eye region A and the left-eye region B by 90 degrees. The retardation layer 4 is formed by solidification (curing) in a state where the liquid crystal material is aligned by the alignment regulating force of the alignment layer 3, thereby transmitting the transmitted light in the region A for the right eye and the region B for the left eye. Give the corresponding phase difference.

  FIG. 2 is a flowchart showing manufacturing steps of the pattern retardation film 1. In the manufacturing process of the pattern retardation film 1, the base material 2 is provided by a long transparent film material wound up on a roll, and the base material 2 is fed out from the roll to sequentially produce a photo-alignment material film (step SP1- SP2). Here, although various manufacturing methods can be applied to the photo-alignment material film, in this embodiment, a film-forming liquid in which the photo-alignment material is dispersed in a solvent such as benzene is applied by a die and then dried. Is produced. As the photo-alignment material, various materials to which a photo-alignment technique can be applied can be applied.

  Subsequently, in this manufacturing process, a photo-alignment layer is produced by irradiating ultraviolet rays in the exposure process (step SP3). Subsequently, in the manufacturing process, in the coating process (step SP4), the retardation layer coating liquid is applied by a die or the like, and in the subsequent drying and curing process (step SP5), the coated coating liquid is dried. Then, it hardens | cures by irradiation of an ultraviolet-ray, and produces the phase difference layer 4 (step SP5). Subsequently, in the manufacturing process, after performing an antireflection film manufacturing process or the like as necessary, in the cutting process, the pattern phase difference film 1 is manufactured by cutting out to a desired size (steps SP6 to SP7).

  FIG. 3 is a diagram for explaining the coating apparatus 12 used for coating a coating liquid in the coating process SP4. In the coating apparatus 12, the base material 2 made of the alignment layer 3 is wound around the coating roller 20 and conveyed, and the coating head 21 is disposed so as to face the coating roller 20. Here, in this embodiment, the coating head 21 is a coating head using a die head, which extrudes the coating liquid from a slit extending in parallel with the axial direction of the coating roller 20, and uses the extruded coating liquid as a base material. It is made to adhere to 2, and a coating liquid is applied by this.

  As shown by the arrow A, the coating head 21 is held so as to be movable in a direction away from the coating roller 20 from the coating state shown in FIG. When the process is to be completed, the coating roller 20 is moved away from the coating roller 20, and the supply of the coating liquid to the substrate 2 is stopped. Here, when separating from the coating roller 20 in this way, the bead 22 from the tip of the coating head 21 to the base material 2 changes greatly, and the bead 22 is torn off. As a result, in the coating apparatus 12, mist of the coating liquid is generated. This mist of the coating liquid drifts in the coating process and becomes a defect due to adhesion to the substrate 2. Moreover, it may adhere to the coating head 21 etc. and solidify, and this solidified component may adhere to the base material 2 drifting through the coating process, which is also a drawback.

  Most of such mist is distributed in the vicinity of the coating roller 20 and on the downstream side of the bead 22 when compared between the upstream side and the downstream side of the bead 22. Here, the downstream side of the bead 22 is the conveyance direction of the base material 2 (the rotation direction of the coating roller 20) from the portion used for coating of the coating head 21. Therefore, in this embodiment, an air intake portion 25 related to the air intake mechanism 24 is provided on the downstream side of the coating head 21, and the mist immediately after the occurrence is sucked and removed through the air intake portion 25 by the air intake mechanism 24, thereby creating a coating environment. Reduces mist that floats and causes defects.

  That is, in the intake mechanism 24, the intake portion 25 is provided separately from the coating head 21 and downstream of the coating head 21, and the intake portion 25 is connected to a pump (not shown) via the exhaust pipe 26. Here, as shown in FIG. 4A, the state seen from the coating roller 20 side indicated by the arrow B is a cylindrical member having at least the coating width of the coating head 21. Exhaust pipes 26 are connected to both ends, and a cavity 25 </ b> A that is an inner space is configured to communicate with the exhaust pipe 26. Further, the intake portion 25 is provided with an intake port 25B communicating with the cavity 25A on the peripheral side surface. Here, the air inlet 25B is formed by a round hole, and the air inlet 25 is provided with a constant interval in the longitudinal direction. The intake mechanism 24 has a pump connected to the other end of the exhaust pipe 26, and thereby sucks mist from the intake portion 25 by the negative pressure generated by driving the pump. A blower, a fan or the like may be applied instead of the pump.

  As shown by the alternate long and short dash line, the intake section 25 is set so that the intake port 25 </ b> B used for suction faces the bead 22, thereby efficiently suctioning the upstream area and the downstream area centering on the bead 22. Arranged as possible. In addition, the mist generated by retracting the coating head 21 as indicated by an arrow A is efficiently removed by suction.

The intake portion 25 is formed so that the intake port 25B gradually increases as it moves away from the exhaust pipes 26 connected to both ends in the longitudinal direction, thereby uniformly holding the suction force by the intake port 25B in each portion in the longitudinal direction. To do. In this embodiment, by operating the intake mechanism 24 at all times, not only the mist immediately after the occurrence but also the mist floating in the coating environment is sucked and removed. However, when the intake mechanism 24 is moved even during coating, there is a concern about the influence on the coating film. However, if the suction pressure is low, mist cannot be removed sufficiently. Therefore, in this embodiment, the suction pressure is set in consideration of these points.

  In FIG. 4 (A), the intake port 25 is formed with circular holes 25B arranged at regular intervals, but instead of this, as shown in FIG. The air inlet 25B may be manufactured by a long hole depending on the shape, or these may be combined, and various configurations can be widely applied. Further, instead of or in addition to the configuration in which the exhaust pipe 26 is connected at both ends in the longitudinal direction, the exhaust pipe 26 may be connected at the center in the longitudinal direction, or the exhaust pipe 26 may be connected only at one end in the longitudinal direction. Good.

Further, the intake mechanism 24 may be operated only for a certain period of time when the coating head is retracted.

[Second Embodiment]
FIG. 5 is a diagram showing a coating apparatus according to the second embodiment of the present invention in comparison with FIG. In the coating apparatus 42, an intake portion 45 related to the intake mechanism is formed integrally with the coating head 21. That is, the coating head 21 is configured such that, of the two members 21A and 21B constituting the slit, the downstream member 21B extends to the coating roller 20 side, and the inlet 25B is formed at the extended portion. Is formed. This embodiment is configured in the same manner as in the first embodiment except that the air intake portion 45 is integrated with the coating head 21.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above. However, the present invention can be variously combined or modified with the configuration of the above-described embodiment without departing from the spirit of the present invention. Can do.

  That is, in the above-described embodiment, the case where the present invention is applied to a coating film using a pattern retardation film has been described. However, the present invention is not limited thereto, and is widely applied to coating films having various configurations such as an antiglare film. can do.

  Further, in the above-described embodiment, the case where the coating liquid is applied by the die head has been described. However, the present invention is not limited to this, and can be widely applied in the case of applying by various methods such as gravure coating.

DESCRIPTION OF SYMBOLS 1 Pattern phase difference film 2 Base material 3 Orientation layer 4 Phase difference layer 12, 42 Coating apparatus 20 Coating roller 21 Coating head 21A, 21B Member 22 Bead 24 Intake mechanism 25, 45 Intake part 25A Cavity 25B Inlet 26 Exhaust pipe

Claims (4)

In the manufacturing method of the coating film which coats the coating liquid while transporting the long film and manufactures the coating film,
Manufacture of a coating film in which the mist of the coating liquid is sucked by an intake mechanism only for a certain period of time during which the coating head, which is a die head, is retracted from the coating roller on the downstream side of the portion to be coated with the coating liquid Method. In the coating device that coats the coating liquid while conveying a long film,
A coating head which is a die head for coating the coating liquid;
A coating roller,
A coating apparatus comprising: an intake mechanism that sucks mist of the coating liquid for a certain period of time when the coating head is retracted from the coating roller on a downstream side of the coating head . The intake mechanism is
An air intake is provided downstream of the coating head;
The mist of the coating liquid is sucked through the intake part,
The coating apparatus according to claim 2, wherein the intake portion is integrally held by the coating head. The intake mechanism is
An air intake is provided downstream of the coating head;
The mist of the coating liquid is sucked through the intake part,
The coating apparatus according to claim 2, wherein the intake section is held separately from the coating head.

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