JP5417725B2 - Pattern coating apparatus and pattern coating method using the same - Google Patents

Description

  The present invention uses a slit die to apply a coating solution on the surface of a sheet of paper, plastic film, cloth, metal foil, and a web sheet (hereinafter referred to as a base material) comprising these laminates conveyed by continuous feeding. The present invention relates to a pattern coating apparatus and a pattern coating method for intermittent application. More specifically, various coating liquids are applied to the surface of a substrate such as a liquid crystal display or a plastic sheet for manufacturing an optical filter by a die coating method, and the functionalities such as a conductive film, an insulating film, and a photoresist film are applied. The present invention relates to a pattern coating apparatus and a pattern coating method used for forming a film.

  2. Description of the Related Art Conventionally, there is a technique for applying a coating solution to a substrate at a predetermined interval using a slit die. For example, in Patent Document 1, a constant gap is provided between the peripheral surface of the backup roll and the slit die, and the metering pump is rotated and stopped while the substrate is running between them, and the coating liquid is intermittently supplied from the slit die. A coating apparatus is disclosed in which a pattern is applied to a substrate by ejecting the substrate.

  Further, in Patent Document 2, in order to make the start and end of the application section in the case of intermittent application straight and prevent thick application at the start of application, the flow of paint to the application liquid supply port of the slit die when application is stopped Intermittent application using a so-called suck-back mechanism that shuts off the liquid and guides it to other than the coating liquid supply port, and at the same time sucks the paint inside the coating liquid supply port and the slit outlet to a predetermined place provided inside the coating liquid supply port An apparatus is disclosed. However, even if the sucking back is performed at the coating terminal portion, the unnecessary coating liquid cannot be sufficiently removed due to the adhesive force between the base material and the coating liquid, and as a result, there remains a problem of causing uneven thickness at the coating terminal portion. .

Therefore, in Patent Document 3, although the base material is not a web sheet, as a technique for forming a uniform coating film on almost the entire surface of the single-wafer substrate, the coating start portion includes a substrate surface and a slit die tip. With an interval narrower than the regular interval, an initial bead is formed between this slit and the coating start portion, and immediately, the die is slightly raised while discharging the coating solution from the slit of the die to shift to a regular bead, Next, the die is run along the substrate surface while maintaining the steady bead by synchronizing the coating liquid supply speed to the slit and the running speed of the die, and then the substrate surface and the die A method for manufacturing a single-wafer substrate is disclosed, in which a steady bead is sucked back while adjusting the distance from the tip of the slit to a regular interval or less.
Japanese Patent No. 2997637 Japanese Patent No. 2842347 Japanese Patent Application Laid-Open No. 2002-153795

However, in the coating method using the conventional suck-back method, it is possible to produce at a high speed with respect to the substrate conveyed in a web shape, and various coating materials can be uniformly and accurately applied to the substrate. There was no equipment. Therefore, in view of the above-described conventional problems, the present invention provides a web substrate pattern coating apparatus and a pattern coating method capable of improving thickness unevenness by controlling the coating amount at the coating end portion and the coating start end portion. For the purpose.

The invention according to claim 1 of the present invention includes at least a transport mechanism composed of a backup roll and a guide roll for transporting the base material at a predetermined speed, and the base material held on the peripheral surface of the backup roll. A slit die for applying the coating liquid, a coating liquid supply mechanism for intermittently supplying the coating liquid to the nozzle of the slit die, a circulation pipe for circulating the coating liquid connected to the coating liquid supply mechanism, and the coating liquid In the pattern coating apparatus having a discharge pipe for discharging the liquid and a suck back mechanism for sucking the coating liquid, the slit die is connected to a rotating shaft so as to be able to fix and hold the coating direction of the coating liquid . A cylinder having a linear actuator that is pivotally supported by the container and moves forward and backward, and the slit die is connected to and fixed to the rotating shaft via a rod-shaped member It is arranged in a state of being pressed against the linear actuator, and the discharge port of the slit die approaches and separates from the peripheral surface of the backup roll by an arc motion around the rotation axis by the forward / backward movement of the linear actuator. Thus, the distance between the slit die and the backup roll is adjusted.

  Next, an invention according to claim 2 of the present invention is a pattern coating method characterized by repeatedly controlling the following operations using the pattern coating apparatus according to claim 1, wherein (1) The operation of adjusting the coating amount on the base material to the coating amount at the time of continuous application by operating the linear actuator at the coating start end to discharge the coating liquid by bringing the slit die close to the base material, (2) (3) an operation of adjusting the coating amount to a coating amount at the time of continuous coating by operating the linear actuator to widen the gap between the slit die and the base material, and maintaining the spacing and the discharge amount of the coating liquid; Subsequently, in the application terminal portion, the linear actuator is operated to perform a suck back by bringing the slit die closer to the base material than a regular interval. (4) Further, the linear actuator Is operated, than to spread than the steady interval distance between the slit die and the substrate, is an operation to cut the coating liquid.

  According to the pattern coating apparatus of the present invention, the operation of the linear actuator is converted into the arc motion of the slit die, and the change in the interval between the slit die discharge port and the backup roll is amplified. The application amount control of the application start end portion and the application end portion can be easily performed even on the web-like substrate conveyed at high speed. Further, since the slit die is held in a state of being pressed against the linear actuator by a cylinder via a rod-like member connected and fixed to the rotating shaft, it is possible to prevent the thickness unevenness of the pattern application portion from occurring.

  Furthermore, according to the pattern coating method of the present invention, the gap between the slit die and the backup roll can be quickly changed to discharge and suck back the coating liquid. Even a coating solution with low fluidity has little thickness unevenness and good cutting at the end, so that a stable pattern coating property can be obtained.

Hereinafter, a pattern coating apparatus and a pattern coating method using the same according to the present invention will be described based on an embodiment with reference to the drawings. FIG. 1 is a schematic diagram of a configuration in the vicinity of a slit die of a pattern coating apparatus of the present invention. 2 (a), 2 (b), and 2 (c) are explanatory diagrams of a series of operations in one embodiment of the pattern coating method of the present invention, and FIGS. ), (D) are explanatory diagrams of the operation following FIG.
In the pattern coating apparatus of the present invention, for example, as shown in FIG. 1, the substrate 1 is unwound from an unillustrated unillustrated portion, conveyed from the guide roll 8 to the backup roll 2, and applied from the slit die 3 to the coating liquid 10. Can be used as a device for intermittently applying the coating liquid 10 onto the substrate. Here, the slit die 3 is pivotally supported by a container 7 connected to the rotary shaft 6, has a linear actuator 4 that moves forward and backward, and is connected via a rod-like member 5 that is connected and fixed to the rotary shaft 6. are arranged at all times pressed against the state in the linear actuator 4 in the cylinder 9, the forward-backward movement of the linear actuator 4 (a vertical movement in FIG. 1) by an arc movement indicated by the line 60 of the virtual about the rotation axis 6 The distance between the slit die 3 and the backup roll 2 is adjusted as the discharge port of the slit die 3 approaches and separates from the peripheral surface of the backup roll 2, and the distance between the substrate 1 and the tip of the slit die 3 is changed. It can be made. As for the linear actuator, it is preferable to use a linear actuator having sufficient self-holding force and resolution of 1 μm or less in order to maintain high accuracy.

  Although not shown, the slit die nozzle has a coating liquid supply mechanism for intermittently supplying the coating liquid, a circulation pipe for circulating the coating liquid connected to the coating liquid supply mechanism, and a discharge pipe for discharging the coating liquid. And are connected. When the application is stopped, the flow of the application liquid to the application liquid supply port is shut off and guided to the circulation pipe. At the same time, the application liquid in the application liquid supply port and the slit die discharge port is sucked into a predetermined place by the suck back mechanism. . The suck back mechanism sucks the excess coating liquid at the coating end portion, improves the pattern cut and prevents the coating liquid from being dragged or dulled, and any structure can be used as long as it fulfills this function. . At the time of application, the flow of the application liquid to the application liquid supply port is released, and the application liquid sucked into a predetermined place is returned to the inside of the application liquid supply port.

  Here, the coating liquid supply mechanism intermittently supplies a predetermined amount of coating liquid from a predetermined coating liquid tank to the nozzle of the slit die. For example, a positive displacement pump such as a gear pump, a diaphragm pump, or a syringe pump The coating solution is supplied from the coating solution tank to the slit die nozzle through a pipe. Usually, the supply of a predetermined intermittent application liquid is controlled by controlling the flow of the application liquid to a circulation pipe that circulates the application liquid connected through a three-way switching valve or the like and a discharge pipe that discharges the application liquid.

  Next, the operation of the pattern coating method of the present invention will be described. At the start of application, that is, at the start of application, the amount of the application liquid applied to the substrate increases due to the surface tension of the application liquid. As shown in FIG. 2, the pattern coating method of the present invention is characterized in that, at the start of coating, the gap between the substrate and the slit die is narrowed and the coating amount is made equal to the coating amount during continuous coating. As shown in FIG. 2A, the discharge port is kept close to the substrate at the start of application. And as shown in FIG.2 (b), a coating liquid is discharged from a slit die. And when a base material gets wet, the influence of the surface tension of a coating liquid reduces. Therefore, in order to keep the coating amount constant, it is necessary to increase the distance between the base material and the slit die immediately after the base material is applied. Therefore, as shown in FIG. 2 (c), the linear actuator is driven, and the slit die is retracted obliquely upward in FIG. 2 by an arc motion to widen the distance between the base material and the slit die.

  During application, the linear actuator is not driven, and the slit die is held in a state of being pressed against the linear actuator by a cylinder via a rod-like member connected and fixed to the rotating shaft, and the interval between the base material and the discharge port is shown in FIG. The discharge amount of the coating liquid is maintained with the interval shown in (c). This makes it possible to prevent the thickness unevenness of the pattern application part from occurring.

  At the end of coating, the coating liquid is sucked by a suck back mechanism in order to remove a liquid pool of the coating liquid formed in the interval between the base material and the discharge port. In the pattern coating method of the present invention, at the end of coating, by narrowing the distance between the base material and the discharge port, the suction amount of the coating liquid by the suck back mechanism is increased. And widen the gap between the discharge ports. Fig.3 (a) is a figure in process of application | coating. At the coating end, as shown in FIG. 3B, the linear actuator is driven to narrow the distance between the base material and the discharge port. Simultaneously with this operation, the coating liquid is sucked by the suck back mechanism. Next, as shown in FIG.3 (c), a linear actuator is driven and the space | interval of a base material and a discharge outlet is expanded. Thereby, a coating liquid can be cut. And as shown in FIG.3 (d), a linear actuator is driven for the next application | coating and the space | interval of a base material and a discharge outlet is narrowed.

  As described in detail above, by using the pattern coating apparatus of the present invention, the coating amount at the coating start end portion and the coating amount at the coating end portion can be controlled. For example, when applying a coating solution for an electrode plate such as a battery in which a large amount of carbon powder is mixed, the coating shape is controlled by intentionally reducing the distance between the base material and the discharge port at the coating start end, and The convex part (swelling) at the coating start end can be eliminated. In addition, the suction amount in the suck back mechanism can be controlled by intentionally reducing the distance between the base material and the discharge port at the application terminal part, and the convex part (swell) at the application terminal part can be eliminated. In other words, by using the pattern coating apparatus and the pattern coating method of the present invention, it is possible to apply more uniformly than in the past by using a slit die, and a liquid crystal display, an optical filter, or a plastic sheet for manufacturing a fuel cell. Very useful in pattern coating used to form functional films such as conductive films, insulating films, and photoresist films by applying various coating solutions to the surface of a substrate such as a die coating method. It is.

The schematic of the structure of the slit die vicinity of the pattern coating device of this invention. Explanatory drawing of a series of operation | movement in one Embodiment of the pattern application | coating method of this invention. Explanatory drawing of a series of subsequent operation | movement in one Embodiment of the pattern application | coating method of this invention.

DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Backup roll 3 ... Slit die 4 ... Linear actuator 5 ... Bar-shaped member 6 ... Rotating shaft 7 ... Container 8 ... Guide roll 9. ··Cylinder
10 ... coating liquid 60 ... virtual line (arc motion)

Claims (2)

At least a transport mechanism comprising a backup roll and a guide roll for transporting the base material at a predetermined speed, a slit die for applying a coating liquid onto the base material held on the peripheral surface of the backup roll, and the slit A coating liquid supply mechanism that intermittently supplies the coating liquid to the nozzle of the die, a circulation pipe that circulates the coating liquid connected to the coating liquid supply mechanism, a discharge pipe that discharges the coating liquid, and a suction of the coating liquid In a pattern coating apparatus having a suck back mechanism
The slit die has a linear actuator pivotally supported by a container connected to a rotating shaft so as to be able to fix and hold the coating direction of the coating liquid , and to move forward and backward, and the slit die Is arranged in a state where it is pressed against the linear actuator by a cylinder via a rod-like member connected and fixed to the rotating shaft, and the slit is an arc motion around the rotating shaft by the forward / backward movement of the linear actuator. The pattern coating apparatus is characterized in that the interval between the slit die and the backup roll is adjusted by the die outlet opening approaching and separating from the peripheral surface of the backup roll. A pattern coating method using the pattern coating apparatus according to claim 1 to repeatedly control the following operations.
(1) The linear actuator is operated at the coating start end to bring the slit die close to the substrate to discharge the coating solution, and the coating amount applied to the substrate is adjusted to the coating amount during continuous coating.
(2) Next, the linear actuator is actuated to widen the gap between the slit die and the base material, and the gap and the discharge amount of the coating liquid are maintained, and the coating amount is adjusted to the coating amount at the time of continuous coating. Operation,
(3) Subsequently, at the coating end portion, the linear actuator is operated to perform a suck back by bringing the slit die closer to the base material than the normal interval.
(4) Furthermore, the operation | movement which cuts a coating liquid by operating the said linear actuator and expanding the space | interval of the said slit die and the said base material from a regular space | interval.

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