JP2007260639A - Slit coater nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slit coater nozzle capable of uniformly applying a coating liquid even if a surface to be coated on a substrate is in a bad state. <P>SOLUTION: In the slit coater nozzle 11 formed by interposing a slit 17 for discharging the coating liquid between an one side lip part 13 forming a nozzle 12 and an another side lip part 15, a lyophilic film layer 18 having good wettability is formed on the tip surface 14 of the one side lip part 13 which is positioned on the applying side of the coating liquid 111 and is opposed to the surface 102 to be coated on the substrate 101 and a liquid repellent film layer 19 are formed on the tip surface 16 of the another side lip part 15 which is positioned on the non-applying side of the coating liquid 111 and is opposed to the surface 102 to be coated on the substrate 101. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique relating to a slit coater nozzle that can always apply a coating liquid to a substrate in a fixed amount.

  In the field of color filter production and the like, it is required to apply a paint thinly and uniformly on a substrate having a relatively short length in the application direction. In response to this requirement, a substrate is supplied one by one, and a leaf application device that repeatedly applies the coating is used.

  Examples of the technique adopted for the above-mentioned every-leaf coating apparatus include a spin coater, a roll coater, and a bar coater. Among them, the spin coater is a method in which a coating solution is dropped onto a rotating substrate, and a coating film having a uniform thickness is formed on the substrate according to the number of rotations, the concentration of the coating solution, and the flow characteristics. This method has a problem that the use efficiency of the coating liquid is inferior because the coating liquid needs to be used 20 to 100 times as much as the coating liquid remaining on the substrate as the coating film. In addition, when the spin coater is employed, the adhesion of the coating liquid to the back side of the substrate, which is referred to as the back side, cannot be avoided, resulting in a quality problem.

  The roll coater is a technique for transferring a coating solution to a substrate through a rubber roll or a metal roll, and has a problem that a pattern of the rubber roll or the metal roll is likely to appear. In addition, since the coating liquid in the roll coater is used after being stored in an open-type liquid reservoir called a pan, the contact time with the air until it is applied to the substrate is long, and moisture absorption, oxidation, solvent It is easy to cause alteration due to evaporation. Further, since the liquid reservoir is an open type, there is a problem that foreign substances that cause defects in the coating film are likely to be mixed.

  The bar coater is a method of forming a coating film on a substrate using a bar obtained by winding a thin metal wire around a metal rod called a rod. In this method, since the wire contacts the substrate or the coating film on the substrate, there is a problem that the substrate or the coating film on the substrate is easily damaged or stripes are likely to enter the coating film.

  On the other hand, the slit die coater is a method in which a substrate is placed at a predetermined interval from a slit provided in a coater head, and the coater head is relatively moved while discharging a coating liquid from the slit to form a coating film. In the case of this method, it is possible to solve the problem of wasteful use of the coating liquid and the backside, the coating liquid supply path can also be a sealed system, and the substrate and the base are kept relative to each other with a predetermined gap. Therefore, the substrate or the coating film can be prevented from being damaged.

  However, the slit die coater is originally a method of continuously forming a coating film on a long substrate of several meters or more, and thus has been considered unsuitable for a leaf-by-leaf coating apparatus. In addition, when the coating liquid is mainly composed of a polymer, a pigment, and a solvent, the pigment aggregates and deposits due to shear stress in the land portion inside the slit having a narrow gap of several tens of μm, and streaks are formed on the coating film. There was a cause to occur.

In view of the above-mentioned problems observed in the slit die coater, the technology disclosed in Patent Document 1 described below not only allows the slit die coater to be suitably applied to a leaf-by-leaf coating apparatus, but also causes defects such as streaks in the coating film. The present invention provides a slit die coater nozzle that is difficult to generate.
JP 2000-189877 A

  FIG. 3 is an explanatory view showing the structure of the nozzle tip portion of the slit die coater disclosed in the above-mentioned Patent Document 1. The nozzle 1 made of stainless steel is composed of one side lip portion 2 and the other side lip portion 4. The one-side lip 2 and the other-side lip 4 are arranged with a slit 6 for discharging a coating liquid between the inner side surfaces 2a and 4a.

  The one-side lip portion 2 and the other-side lip portion 4 are arranged to face each other in parallel with the surface to be coated 102 on the substrate 101 side through respective front end surfaces 3 and 5. Further, a coating layer 7 having good wettability is applied to each of the tip end surfaces 3 and 5 from each inner side surface 2a and 4a side located in the vicinity of each tip end surface 3 and 5 to each intermediate position of each tip end surface 3 and 5. A coating layer 8 having good liquid repellency (poor wettability) is formed from the remaining position to the outer side surfaces 2b and 4b located in the vicinity of the front end surfaces 3 and 5, respectively.

  For this reason, in the case of the disclosed technique disclosed in Patent Document 1, a gap t is interposed between each of the tip surfaces 3 and 5 of the nozzle 1 and the surface to be coated 102 of the substrate 101, and then the substrate 101 is fed out. When the coating liquid 111 is ejected from the slit 6 along the slit 6, it is smoothly applied through the coating layer 7 having good wettability.

  Further, since the coating layer 8 having good liquid repellency is provided from the remaining position of the tip surfaces 3 and 5 to the outer surfaces 2b and 4b located in the vicinity of the tip surfaces 3 and 5, the coating By suppressing the spread of the coating liquid 111 by the layer 8, the generation of scratches resulting from the partial drying of the coating liquid 111 is prevented, and the thickness uniformity and reproducibility of the coating film 112 are improved. Will be able to.

  However, when using the nozzle 1 of the slit die coater disclosed in Patent Document 1, the ink adheres to the other lip portion 4 opposite to the application direction, and adheres dry and adsorbs dust in the air. When solidified, the ink flowing in the direction of the one-side lip portion 2 is bent in the opposite direction, so that the coating amount cannot be stabilized.

  An object of the present invention is to provide a slit coater nozzle that can uniformly apply a coating solution to a substrate in view of the above-described problems found in conventional slit die coaters including Patent Document 1.

  The present invention has been made to achieve the above object, and the first invention (nozzle) has a slit for discharging coating liquid between one lip portion and the other lip portion constituting the nozzle. In the slit coater nozzle interposed, a lyophilic film layer having good wettability is applied to the tip surface of the one side lip portion facing the surface to be coated of the substrate located on the coating liquid coating side. The main feature is that a liquid-repellent film layer is formed on the tip surface of the other side lip facing the coated surface of the substrate located on the coating side.

  In this case, it is preferable that the width of the slit be a variable width that can be automatically adjusted in relation to the coating film thickness data of the coating liquid fed back.

  According to the present invention, a lyophilic film layer having good wettability is formed on the tip surface of the one side lip portion, and a liquid repellent film layer is formed on the tip surface of the other side lip portion. Since it can be smoothly fed to the surface to be coated so as to be pulled in the traveling direction of the substrate, a certain amount can always be applied even to the surface to be coated of the substrate having a poor surface condition.

  Also, if the slit width is a variable width that can be automatically adjusted in relation to the coating film thickness data of the coating liquid fed back, an amount of coating liquid corresponding to the coating film thickness at that time is discharged from the slit. Thus, a certain amount can always be applied to the coated surface of the substrate.

  FIG. 1 is an explanatory view showing an arrangement relationship of a substrate placed on a suction table as an example of the present invention, and FIG. 2 shows a coating state on the lower surface of the substrate using the present invention shown in FIG. It is explanatory drawing.

  According to these figures, the slit coater nozzle 11 made of an appropriate metal material including stainless steel has a nozzle 12 composed of a one-side lip portion 13 and an other-side lip portion 15. The one-side lip portion 13 and the other-side lip portion 15 are arranged by forming a slit 17 for discharging the coating liquid between the inner side surfaces 13a and 15a. Reference numeral 20 in the figure denotes a manifold for the purpose of diffusing the supplied coating liquid 111 in the slit width direction. Moreover, as the coating liquid 111 in this invention, polytetrafluoroethylene modified resin, an acrylic resin, a polypropylene, etc. can be used.

  In this case, it is preferable that the slit 17 has a variable width that allows automatic adjustment of the width in relation to the coating film thickness data of the coating liquid 111 to be fed back. Specifically, for example, the thickness of the coating film 112 formed on the coating surface 102 of the substrate 101 for the current coating process sent to a leaf coating apparatus (not shown) is fed back to the apparatus body as data, and the feedback data The discharge amount of the coating liquid 111 can be automatically adjusted by making the width of the slit 17 variable by bringing the one-side lip portion 13 and the other-side lip portion 15 into contact with each other via a drive mechanism that is driven and controlled based on the drive mechanism. It can be done.

  Further, the one-side lip portion 13 and the other-side lip portion 15 are arranged to face each other in parallel with the coated surface 102 of the substrate 101 via the respective front end surfaces 14 and 16.

  In this case, the one-side lip portion 13 is arranged in a positional relationship in which the front end surface 14 faces the coated surface 102 of the substrate 101 positioned on the coating liquid 111 coating side as shown in FIG. . Further, a lyophilic film layer 18 having good wettability is formed on the distal end surface 14 of the one-side lip portion 13.

  The lyophilic film layer 18 having good wettability can be formed by coating the front end surface 14 of the one-side lip portion 13 using the same material as the coated surface 102 of the substrate 101.

  On the other hand, the other-side lip portion 15 is disposed in a positional relationship where the front end surface 16 faces the coated surface 102 of the substrate 101 located on the non-coated side of the coating liquid 111 as shown in FIG. . Further, a liquid repellent film layer 19 is formed on the distal end surface 16 of the other side lip portion 15.

  In this case, the liquid repellent film layer 19 is made of an appropriate liquid repellent resin including a silicon polymer film, a fluororesin such as polytetrafluoroethylene, a polypropylene resin, a polyethylene resin, and a polyester resin. It can be formed on the tip surface 16.

  Next, the operation and effect of the present invention will be described. In the nozzle 12, the tip surface 14 of the one-side lip portion 13 and the tip surface 16 of the other-side lip portion 15 are arranged on a suction table (not shown). In order to face each other in parallel with the coated surface 102 located on the lower surface side of 101, the distal end surfaces 14 and 16 are disposed facing upward as shown in FIG.

  When the coating liquid 111 is applied to the substrate 101, the nozzle 12 and the substrate 101 are applied to the lyophilic film layer 18 formed on the distal end surface 14 of the one side lip portion 13 and the distal end surface 16 of the other side lip portion 15. With respect to the formed liquid repellent film layer 19, the surface 102 to be coated of the substrate 101 is disposed by being controlled up and down relatively so as to be separated by a predetermined gap t.

  Thus, the nozzle 12 and the substrate 101 are separated from the tip surface 16 side of the other side lip portion 15 from the front end surface 16 side, for example, as shown in FIG. They are moved relative to each other, such as moving horizontally toward the distal end surface 14 side.

  By moving in this way, the nozzle 12 can apply the coating liquid 111 to the coated surface 102 located on the lower surface side of the substrate 101 through the slit 17.

  At this time, the lyophilic film layer 18 having good wettability is formed on the front end surface 14 of the one side lip portion 13, and the liquid repellent film layer 19 is formed on the front end surface 16 of the other side lip portion 15. Since the coating liquid 111 discharged through a pump (not shown) is always pulled in the advancing direction of the substrate 101 in affinity with the lyophilic film layer 18, the coating surface is smoothly moved from the slit 17 to the coated surface 102. Can be sent out.

  For this reason, the coating liquid 111 is always kept at a constant amount without being left on the surface of the coated surface 102 of the substrate 101 on the tip surface 16 side of the other side lip portion 15 via the liquid repellent film layer 19. Thus, it is possible to form the coating film 112 along the moving direction of the coated surface 102 of the substrate 101.

  In this case, when the slit width is a variable width that can be automatically adjusted in relation to the coating film thickness data of the coating liquid 111 to be fed back, the optimum amount of the coating liquid 111 corresponding to the coating film thickness at that time is applied. A coating film 112 having a desired film thickness can be formed on the coated surface 102 of the substrate 101 by discharging from the slit 17.

  The above is the description of the present invention based on the illustrated examples, and various modifications can be made to the specific contents without departing from the gist of the present invention. For example, the nozzle 12 is used corresponding to the case where the front end surface 14 of the one side lip 13 and the front end surface 16 of the other side lip 15 are directed downward, and the upper surface of the substrate is the coated surface. You can also

Explanatory drawing which shows the arrangement | positioning relationship for the example of the board | substrate arrange | positioned at a suction table as an example of 1st invention. Explanatory drawing which shows the application | coating state with respect to the lower surface of a board | substrate using 1st invention shown in FIG. Explanatory drawing which shows the structural example of the nozzle front-end | tip part of the conventional slit die coater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Slit coater nozzle 12 Nozzle 13 One side lip | rip part 13a Inner side surface 14 Front end surface 15 Other side lip | rip part 15a Inner side surface 16 End surface 17 Slit 18 Lipophilic film layer 19 Liquid repellent film layer 20 Manifold 101 Substrate 102 Coating surface 111 Coating liquid 112 Coating film t gap

Claims (2)

In a slit coater nozzle in which a slit for discharging the coating liquid is interposed between the one side lip portion and the other side lip portion constituting the nozzle,
A lyophilic film layer having good wettability is applied to the tip surface of the one-side lip portion facing the coated surface of the substrate located on the coating liquid coating side, and the substrate coated on the coating liquid non-coated side is coated. A slit coater nozzle, wherein a liquid-repellent film layer is formed on the tip surface of the other lip portion facing the surface. The slit coater nozzle according to claim 1, wherein the slit has a variable width that can be automatically adjusted in relation to the coating film thickness data of the coating liquid fed back.

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