JP2010051839A - Cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device having an improved cleaning capacity relative to a prior art device for use in a die coater. <P>SOLUTION: The cleaning device for use in cleaning a tip of a slit nozzle of a die coater, which device includes a cleaning unit and a means for moving the cleaning unit along the direction of the width of the slit nozzle, with the cleaning unit comprising a group of two-fluid nozzles for cleaning the tip of the slit nozzle by ejecting a mixed fluid of a cleaning liquid and a transfer gas thereonto, a group of air knives for removing waste of the cleaning liquid resulting from the cleaning and sticking to the tip of the slit nozzle, and a means for discharging the ejected gas and the waste of the cleaning liquid, is characterized in that the group of the two-fluid nozzles includes a combination of two or more kinds of spray nozzles at least comprising a round spray nozzle having a narrow ejection range and a flat spray nozzle having a wide ejection range. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cleaning apparatus for cleaning and removing coating liquid residue adhering to a slit nozzle tip of a die coater.

  Die coaters that perform coating by discharging a coating liquid from a slit-shaped die are applied in various fields because high-precision coating can be performed efficiently. Unlike the continuous application to a long sheet, the application operation becomes intermittent when applying to a plate, so the coating liquid adhering to the slit nozzle tip is dried and solidified. In some cases, the coating liquid becomes debris, which causes unevenness in the stripes, or mixes with the coating film to cause adhesion of foreign matter. In order to prevent this problem, a cleaning device for periodically cleaning the tip of the slit nozzle and removing the coating liquid residue is required.

  The coating apparatus with a cleaning device described in Patent Document 1 filed by the applicant of the present application includes one or more two-fluid nozzles that eject two fluids, which are a mixture of a cleaning chemical and an inert gas, outside the slit nozzle tip, Two sets of liquid cutting nozzles for injecting inert gas are installed so as to sandwich the outside of the slit nozzle tip, and further provided with a cleaning head having an exhaust section for forcibly exhausting mist waste liquid generated in the cleaning process. This is a coating apparatus with a cleaning device.

Patent Document 1 describes that the specification of the two-fluid nozzle used in the cleaning head is provided with three circular outlets as an example (page 6, paragraph 0022). However, with the recent increase in substrate size, the slit nozzle size of the die coater has also increased, and as a result, higher cleaning performance of the cleaning head has been required. The cleaning head based on the specifications described in No. 1 has not been sufficient in terms of cleaning performance.
JP 2006-281101 A

  The subject of this invention is providing the washing | cleaning apparatus for die-coaters which improved the washing | cleaning capability rather than before.

  As means for solving the above-mentioned problems, the invention according to claim 1 is a cleaning device for cleaning a tip portion of a slit nozzle of a die coater, and includes a cleaning unit and a width of the slit nozzle. A cleaning unit moving means for moving along the direction, the cleaning unit ejecting a fluid mixture of cleaning liquid and carrier gas to clean the slit nozzle tip, and the slit generated by the cleaning. An air knife group for removing cleaning waste liquid adhering to the nozzle tip, and a discharge means for discharging the injected gas and cleaning waste liquid. The two-fluid nozzle group includes a round spray nozzle having a narrow injection range, and an injection unit. A washing apparatus comprising a combination of two or more types of spray nozzles including at least a flat spray nozzle having a wide range It is a device.

  According to a second aspect of the present invention, the two-fluid nozzle group includes at least a round spray nozzle having a narrow spray range and a large spray impact force, and a flat spray nozzle having a wide spray range and a small spray impact force. The cleaning apparatus according to claim 1, wherein the cleaning apparatus includes a plurality of combinations of spray nozzles of more than one type.

  According to a third aspect of the present invention, the air knife group removes the cleaning waste liquid adhering to the slit nozzle tip and the upper air knife that removes the cleaning waste liquid adhering to the slit nozzle tip downward. The cleaning apparatus according to claim 1, further comprising a lower air knife that is removed in a direction.

  The invention according to claim 4 is the cleaning apparatus according to any one of claims 1 to 3, wherein the gas supplied to the two-fluid nozzle and the air knife is an inert gas. is there.

  A cleaning apparatus according to the present invention is a cleaning apparatus for cleaning a tip portion of a slit nozzle of a die coater, and includes a cleaning unit and a cleaning unit moving means for moving the cleaning unit along the width direction of the slit nozzle. The cleaning unit includes a two-fluid nozzle group that sprays a fluid mixture of a cleaning liquid and a carrier gas to clean the slit nozzle tip, and an air that removes cleaning waste liquid generated by cleaning and adhering to the slit nozzle tip. Since it has a knife group and discharge means for discharging the jetted gas and cleaning waste liquid, the cleaning unit can be a die coater having slit nozzles of different lengths only by changing the specifications of the cleaning unit moving means. Can be attached in common, and is highly versatile.

  The cleaning unit of the cleaning apparatus according to the present invention includes a combination of two or more types of spray nozzles including at least a round spray nozzle having a narrow spray range and a flat spray nozzle having a wide spray range, and thus has a wide spray range. The liquid spray adhering to a wide range can be removed by the flat spray nozzle, and the liquid smudge easily adhering to a specific portion can be intensively washed by the round spray nozzle having a narrow spraying range.

  Further, the cleaning unit of the cleaning apparatus according to the present invention includes two or more types of sprays including at least a round spray nozzle having a narrow spray range and a large spray impact force and a flat spray nozzle having a wide spray range and a small spray impact force. In the case of including a plurality of nozzle combinations, the cleaning power is remarkably enhanced, and as a result, it is possible not only to prevent the occurrence of poor coating due to poor cleaning of the tip of the slit nozzle of the die coater, Even a die coater having a slit nozzle having a longer length can be cleaned at the same tact time as before by cleaning at a higher speed than before.

  Further, when a round spray nozzle with a narrow spray range and a large spray impact force is combined with a flat spray nozzle with a wide spray range and a small spray impact force, a sufficient cleaning effect can be obtained with a small amount of cleaning liquid. Therefore, there is an effect that the amount of the cleaning liquid used is small.

  In addition, the air knife group removes the cleaning waste liquid adhering to the slit nozzle tip part downward, and the lower air knife removing the cleaning waste liquid adhering to the slit nozzle tip part obliquely downward. Is included, the cleaning waste liquid after cleaning is reliably removed, and the effect of preventing the occurrence of coating failure due to the remaining removal is enhanced.

  In addition, when the gas supplied to the two-fluid nozzle and the air knife is an inert gas, the coating liquid can be used without any problem even if it has a property that inhibits curing by oxygen. .

Embodiments of a cleaning apparatus according to the present invention will be described with reference to the drawings.
FIG. 2 is a cross-sectional explanatory view showing the relationship between the slit nozzle 6 of the die coater and the cleaning unit 1, and FIG. 3 is a perspective explanatory view showing the relationship between the slit nozzle 6 of the die coater and the cleaning unit 1. As shown in FIG. 2, the slit nozzle 6 is provided with a manifold 8 and a slit 9, and the coating liquid 10 supplied from a liquid feed pump (not shown) passes through the manifold 8 and the slit 9. It is applied to the surface of the object to be coated with a constant coating thickness from the slit nozzle tip 7 over the entire width direction.

When the object to be coated is a continuous wound-like article such as a wound paper, a winding cloth, or a metal coil, and the coating liquid is continuously applied to these, the tip of the slit nozzle becomes dirty. However, when the object to be coated is a plate-shaped article, the coating must be intermittent, so that the coating liquid adhering to the slit nozzle tip 7 is dried to form the coating liquid. The problem is that the residue 11 becomes a cause of coating defects such as streak unevenness, or the coating liquid residue is mixed into the coating film to cause foreign matter adhesion.
Therefore, it is necessary to clean the slit nozzle tip 7 with a cleaning device periodically or for each coating.

  As shown in FIG. 3, the cleaning device according to the present invention is a cleaning device for cleaning the tip portion 7 of the slit nozzle 6 of the die coater, and the cleaning unit 1 and the cleaning unit are connected to the slit nozzle 6. And a cleaning unit moving means 13 for moving along the width direction. The cleaning unit 1 is disposed so as to sandwich the tip 7 of the slit nozzle 6 from both sides, and moves horizontally along the width direction of the slit nozzle 6 while cleaning the slit nozzle tip 7. The slit nozzle 6 of the die coater generally has a V-shaped cross-sectional shape with a sharp tip, but the cleaning unit 1 constituting the cleaning apparatus according to the present invention has a slight V-shaped cross section. It has a cross-sectional shape that fits with a small gap.

The cleaning unit moving means 13 is not particularly limited in its specification and structure as long as it can move the cleaning unit 1 horizontally along the slit nozzle tip 7. In consideration of speed controllability, durability, etc. during start-up, travel and stop, use precision linear motion equipment such as a linear motion unit with a built-in servo motor and ball screw, or a linear motion unit with a built-in linear motor. It is preferable.
If a linear motion unit having a necessary stroke is selected, a common cleaning unit can be used for different die coaters, so that a highly versatile cleaning apparatus can be realized.

  In order to set the slit nozzle 6 and the cleaning unit 1 in a predetermined positional relationship, the cleaning device is installed at a predetermined location, and the slit nozzle 6 is moved to the position of the cleaning device. There is a method in which the nozzle 6 is fixed or only moved up and down, and the cleaning device is moved to the position of the slit nozzle, or a method in which these are combined. What kind of method is taken is arbitrary, and is determined by the specification and use conditions of the target die coater.

FIG. 1 is a perspective explanatory view showing an embodiment of a cleaning unit constituting a cleaning apparatus according to the present invention.
The cleaning unit 1 in the present embodiment removes a cleaning fluid and a two-fluid nozzle group for cleaning the slit nozzle tip 7 by jetting a fluid mixture of cleaning liquid and carrier gas, and cleaning waste liquid generated by cleaning and adhering to the slit nozzle tip 7 And a discharge means for discharging the injected gas and cleaning waste liquid. The two-fluid nozzle group includes a round spray nozzle 2 having a narrow injection range and a flat spray nozzle 3 having a wide injection range. Two combinations of two types of spray nozzles 16 are included.

In the embodiment shown in FIG. 1, a spray nozzle combination 16 consisting of one round spray nozzle 2 and one flat spray nozzle 3 on one wall surface of the cleaning chamber 18.
2 are arranged to form a two-fluid nozzle group. Although not shown in FIG. 1, a similar two-fluid nozzle is provided on the opposite wall surface in order to clean the tip of the opposite slit nozzle. One group is installed. In the embodiment shown in FIG. 1, two combinations of spray nozzles form a two-fluid nozzle group. However, when the cleaning capability is not so much required, one set may be used as a two-fluid nozzle group. Good.

The cleaning chamber 18 is a space provided inside the cleaning unit 1, and the slit nozzle tip 7 is cleaned in the cleaning chamber 18.
The cleaning liquid is sprayed from the two-fluid nozzle into the cleaning chamber 18 to dissolve and remove the coating liquid residue 11 attached to the slit nozzle tip 7. Since the cleaning liquid in which the coating liquid residue 11 is dissolved becomes cleaning waste liquid and adheres to the surface of the slit nozzle, it is peeled off by an air knife. A discharge duct 12 as discharge means is connected to the lower portion of the cleaning chamber 18 and sucks and removes the cleaning liquid sprayed into the cleaning chamber, the generated cleaning waste liquid, the gas sprayed from the air knife, and the like from the cleaning chamber.

  FIG. 4A is a schematic diagram showing a spray pattern 14 of the round spray nozzle 2, and FIG. 4B is a schematic diagram showing a spray pattern 15 of the flat spray nozzle 3. The round spray nozzle 2 is designed to have a narrow spray range as described above. For example, the spray range at a spray distance of 3 mm is a circle having a diameter of about 3 mm. The flat spray nozzle 3 is designed to have a wide spray range. For example, the spray range at an injection distance of 3 mm is an elliptical shape having a size of about 10 mm × 50 mm or a circular shape having a diameter of about 10 mm. These differences are mainly due to the difference in the tip shape of the spray nozzle.

  By combining these two types of spray nozzles, an effect that cannot be achieved by a single unit occurs. That is, the coating liquid residue 11 adhered over a wide area by the flat spray nozzle 3 is swollen, and the coating liquid residue 11 adhered to a specific portion is dissolved and removed by the round spray nozzle 2, thereby efficiently dissolving and removing the coating liquid residue 11. Is done.

  In the round spray nozzle 2, the spray range is narrow and the spray impact force is large. For example, the spray range at a spray distance of 3 mm is a circle having a diameter of about 3 mm, and the spray impact force is about 15 to 17 mN (millinewton). There is. In the flat spray nozzle 3, the spray impact force is small, but the spray range is wide. For example, the spray range at an injection distance of 3 mm is an elliptical shape of about 10 mm × 50 mm, and the spray impact force is 0.6-1. Some are about 5 mN.

  In this example, the absolute amount of the cleaning liquid to be sprayed is almost the same for both types. However, by combining the spray nozzles having the opposite properties in this way, it can be obtained by a single spray nozzle combination. It is possible to exert a powerful cleaning effect over a wide range, and by arranging two or more combinations 16 of the spray nozzles, a sufficient cleaning effect can be obtained even in a short time of cleaning. Even when a long slit nozzle is cleaned, it is possible to perform cleaning at a high speed, and therefore the time required for cleaning can be shortened.

  In addition, when a round spray nozzle with a narrow spray range and a large spray impact force and a flat spray nozzle with a small spray impact force but a wide spray range are combined, a high cleaning effect is obtained with a small amount of cleaning liquid. Therefore, there is an advantage that a small amount of cleaning liquid is used.

FIGS. 5A, 5 </ b> B, and 5 </ b> C are schematic diagrams illustrating an example of the arrangement of spray nozzles.
FIG. 5A is a schematic diagram showing the arrangement of the spray nozzles in the cleaning unit shown in FIG. 1, and a combination 16 of spray nozzles composed of one round spray nozzle 2 and one flat spray nozzle 3 is slanted. Two sets are arranged. Two arrays are arranged in parallel with respect to the cleaning unit moving direction 17 to form one two-fluid nozzle group.
In the cleaning unit 1 in this embodiment, there is an additional two-fluid nozzle group consisting of this combination for cleaning both sides of the slit nozzle 6, but depending on the shape of the slit nozzle, only cleaning from one side is possible. It may be enough.

FIG. 5B is a schematic diagram illustrating another example of the arrangement of spray nozzles.
In this example, two sets 16 of spray nozzles composed of one round spray nozzle 2 and one flat spray nozzle 3 are arranged horizontally and arranged in the height direction.
FIG. 5C is a schematic diagram showing another example of the arrangement of spray nozzles in the same manner.
In this example, two sets 16 of spray nozzles composed of two round spray nozzles 2 and one flat spray nozzle 3 are arranged horizontally and arranged in the height direction.

Thus, as an array of spray nozzles, it is significant to make a combination including at least two types of spray nozzles, a round spray nozzle and a flat spray nozzle, and how to arrange this combination is a slit. What is necessary is just to determine suitably according to the structure of a nozzle, the place where coating liquid residue tends to adhere, the range to which coating liquid residue adheres, etc. It is beneficial to have a structure that allows easy replacement of the spray nozzle tip so that the spray nozzle arrangement can be easily changed.
Further, by making it possible to change the mounting angle of the spray nozzle, it may be possible to obtain a more optimal cleaning effect.

  As shown in FIG. 1, the cleaning unit 1 is provided with an upper air knife 4 and two lower air knives 5, which form an air knife group. In the air knife, since the cleaning waste liquid generated when the cleaning liquid sprayed from the two-fluid nozzle group dissolves the coating liquid residue 11 adheres to the surface of the slit nozzle 6, the cleaning waste liquid is removed from the surface of the slit nozzle 6. It has the effect of removing and further drying.

  The air knife efficiently collects and removes the cleaning waste liquid that adheres to the surface of the slit nozzle 6 in the direction of the discharge duct 12 that is a discharge means. There may be at least two air knives: an air knife that pushes cleaning waste liquid downward and an air knife that is behind the cleaning unit 1 in the traveling direction and pushes cleaning waste liquid forward. desirable.

  In the embodiment of the cleaning unit 1 shown in FIG. 1, since the cleaning operation is performed while moving in only one direction, the lower air knife 5 is disposed only in the rearward direction of the cleaning chamber 18. However, when the cleaning operation is performed in both reciprocating directions, it is necessary to dispose the cleaning chamber 18 on both sides.

  In the embodiment of the cleaning unit 1 shown in FIG. 1, an upper air knife 4 provided horizontally at the upper part of the cleaning unit 1 and two lower air knives provided obliquely rearward in the traveling direction of the cleaning unit. 5 is installed. As shown in this embodiment, the lower air knife 5 is provided at an angle inclined forward with respect to the traveling direction of the cleaning unit, so that the cleaning waste liquid can be removed more efficiently than when provided in the vertical direction. Can do. The forward tilt angle at this time is preferably in the range of 55 ° to 75 ° empirically. By providing a plurality of lower air knives 5 as in this embodiment, the effect of preventing the cleaning waste liquid from being removed is improved.

The cleaning unit 1 shown in FIG. 1 is provided with a discharge duct 12 at the bottom.
The discharge duct 12 is sucked by an exhaust fan (not shown), and acts as a discharge means for discharging the gas injected into the cleaning unit and the cleaning waste liquid generated in the cleaning unit to the outside. Since the cleaning waste liquid is actually mixed with a large amount of gas, it is discharged in a mist state rather than a liquid. The cleaning liquid component contained in the cleaning waste liquid mist is recovered by a recovery device.

  Although not shown in the drawing, the cleaning unit 1 is provided with a cleaning liquid supply port for supplying a cleaning liquid and a carrier gas supply port for supplying a carrier gas, one for each of the two fluid nozzles. The pressurized cleaning solution tank is supplied to the cleaning solution supply port by a flexible hose via a valve, a filter and the like. Also, the carrier gas is supplied from the carrier gas supply source to the carrier gas supply port by the flexible hose through the valve, the pressure adjusting valve, the filter and the like.

  The cleaning liquid is selected according to the coating liquid to be used, and a cleaning liquid mainly containing a solvent that dissolves the coating liquid well is used. The cleaning performance and the drying performance can be made compatible by injecting two types of cleaning liquids, one that focuses on the solubility of the coating liquid and the other that focuses on the drying property, in this order.

As the carrier gas used for the two-fluid nozzle, it is desirable to use dry air from which moisture has been removed or clean dry air from which moisture and fine particles have been removed. If the coating liquid has a property that inhibits curing by oxygen, as seen in some UV-curable coatings, an inert gas such as nitrogen gas may be used as the carrier gas. desirable.
The same applies to the gas used for the air knife.
Hereinafter, based on an Example, the cleaning device concerning the present invention is explained still more concretely.

In a production line for a color filter for a large liquid crystal display, a cleaning device for a die coater used for coating a color resist on a glass substrate was prepared. As the cleaning unit, a cleaning unit having the structure shown in FIG. 1 was used. The detailed specifications are shown below.
Glass substrate thickness 0.7mm alkali-free glass size 2,460mm × 2,160mm
Slit nozzle width dimension 2,454mm (effective width)
Types of coating liquid RGB pigment dispersion resist (including pigment, resin, monomer, initiator, etc.)
Mu)
Components of cleaning liquid Cyclohexanone / butyl acetate mixed solution carrier gas Nitrogen gas Air knife gas Same as above Cleaning unit moving means 1 way scan system Stroke 2,550mm
Cleaning unit moving speed 400mm / sec
Cleaning tact time 6.4 sec (cleaning every time)
Configuration of two-fluid nozzle group (1 round spray + 1 flat spray) x 2 x double-sided round spray specifications Cleaning fluid volume 25mL / min
Air volume 2.5L (normal) / min
Air pressure 0.065MPa
Fluid pressure 0.019MPa
Spray range Diameter 3mm (Distance 3mm)
Injection impact force up to 17.4mN
Flat spray specifications Cleaning fluid volume 25mL / min
Air volume 2.0L (normal) / min
Air pressure 0.18MPa
Fluid pressure 0.055MPa
Spray range Diameter 10mm (Distance 3mm)
Injection impact force up to 1.5mN
Air knife specifications Upper air knife Air pressure 0.6MPa
Air volume 15L (normal) / min (per bottle)
Lower air knife forward tilt angle 50 ° x 2 (one side)
Air pressure 0.6MPa
Air volume 7.0L (normal) / min (per bottle)
When 300 glass substrates were continuously coated using the above-described cleaning apparatus, no coating failure due to contamination of the slit nozzle was observed.

The perspective explanatory view showing one embodiment of the washing unit which constitutes the washing device concerning the present invention. Cross-sectional explanatory drawing which shows the relationship between the slit nozzle of a die coater, and a washing | cleaning unit. Explanatory perspective view showing the relationship between the slit nozzle of the die coater and the cleaning unit. (A) The schematic diagram which shows an example of the spray pattern of a round spray nozzle. (B) The schematic diagram which shows an example of the spray pattern of a flat spray nozzle. (A) The schematic diagram which shows the arrangement | sequence of the spray nozzle in the washing | cleaning unit shown in FIG. (B) The schematic diagram which shows the other example of the arrangement | sequence of a spray nozzle. (C) The schematic diagram which shows the other example of the arrangement | sequence of a spray nozzle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cleaning unit 2 ... Round spray nozzle 3 ... Flat spray nozzle 4 ... Upper air knife 5 ... Lower air knife 6 ... Slit nozzle 7 ... Slit nozzle tip 8 ..Manifold 9 ... Slit 10 ... Coating liquid 11 ... Coating liquid 12 ... Discharge duct 13 ... Cleaning unit moving means 14 ... Spray pattern 15 of round spray nozzle ... Flat Spray pattern 16 of spray nozzles ... Combination of spray nozzles 17 ... Moving direction of cleaning unit 18 ... Cleaning chamber

Claims (4)

  A cleaning device for cleaning the tip of a slit nozzle of a die coater, comprising: a cleaning unit; and a cleaning unit moving means for moving the cleaning unit along the width direction of the slit nozzle, the cleaning unit comprising a cleaning liquid A two-fluid nozzle group for cleaning the tip of the slit nozzle by injecting a fluid mixture of the carrier gas and the air, a group of air knives for removing cleaning waste liquid generated by cleaning and adhering to the tip of the slit nozzle, and the injected gas The two-fluid nozzle group includes a combination of two or more types of spray nozzles including at least a round spray nozzle having a narrow spray range and a flat spray nozzle having a wide spray range. A cleaning device, characterized by   The two-fluid nozzle group includes a plurality of combinations of two or more types of spray nozzles including at least a round spray nozzle having a narrow spray range and a large spray impact force and a flat spray nozzle having a wide spray range and a small spray impact force. The cleaning apparatus according to claim 1, wherein the cleaning apparatus is included.   The air knife group includes an upper air knife that removes cleaning waste liquid adhering to the slit nozzle tip and a lower air knife that removes cleaning waste liquid adhering to the slit nozzle tip downward and diagonally. The cleaning apparatus according to claim 1, further comprising:   The cleaning apparatus according to claim 1, wherein a gas supplied to the two-fluid nozzle and the air knife is an inert gas.

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