JP5169571B2 - Curtain coating method and apparatus - Google Patents

Description

  The present invention relates to a curtain coating method and apparatus, and more specifically, at least one layer of coating liquid is discharged from a slit, and the discharged coating liquid is freely dropped by a curtain edge guide that guides in a curtain shape, thereby continuously running. The present invention relates to a curtain coating method and a curtain coating apparatus for coating on a web.

  The curtain coating method is a coating method often used in the manufacture of photographic photosensitive materials such as photographic film. As shown in FIG. 1, the coating liquid is ejected from the nozzle slit of the curtain coating head 1, and the ejection is performed. A method of forming a coating film while allowing the applied coating liquid to freely fall with a curtain edge guide 2 that guides in a curtain shape and causing the formed curtain film 3 to collide with a web 5 that runs continuously, as shown in FIG. Then, the coating liquid is discharged from the slit, the discharged coating liquid is moved on the slide surface 7, the coating liquid is freely dropped by the curtain edge guide 2 that guides the curtain, and the formed curtain film 3 is continuously formed. There is a method of forming a coating film while colliding with the traveling web 5. In multilayer coating, coating liquids having different functions are discharged from the nozzle slits, and the discharged coating liquid is freely dropped by a curtain edge guide that guides in a curtain shape. A method of forming a coating film while colliding with a web that runs continuously, or a coating liquid having different functions is ejected from a slit, and the ejected coating liquid is laminated on a slide surface. There is a method in which a coating film is formed while freely falling by a curtain edge guide guided in a curtain shape and colliding the formed curtain film on a continuously running web.

  By the way, in such a coating film forming method, when the coating liquid flows on the slide surface, there are portions where the flow of the coating liquid is slow at both ends of the slide surface. Causes the phenomenon of contracting to the side. For this reason, when the coating liquid is allowed to fall freely and the coating film is formed while colliding the formed curtain film on the continuously running web, the amount of the coating liquid adhering to the width direction end of the coating film is reduced. There is a disadvantage that it increases. For this reason, an undried part is generated when the coating film is dried, and blocking occurs when the product is wound, or the end is raised, so that the web is cut during winding, and the production efficiency is lowered. On the other hand, it is conceivable to increase the drying temperature. However, for example, in the application of thermal paper, there is a problem that color develops when the temperature of the coating film increases, resulting in product defects. Often not.

  In order to prevent such a phenomenon that the amount of the coating liquid adhering at the coating end increases, an auxiliary liquid is caused to flow along the edge portions at both ends of the slide surface, and the flow rate of the coating liquid at both ends of the slide surface is determined as the central flow rate. There are many known methods for bringing them close to (see, for example, Patent Documents 1 to 5). As shown in FIG. 3, the auxiliary liquid 9 is sucked and collected at the lower end of the curtain edge guide 2.

  However, when the auxiliary liquid is collected, the coating liquid is also collected a little, and as shown in FIG. 4, liquid smoke (S) is accumulated in the claw portion 10 and the suction port 11. This is because when the auxiliary liquid 9 is collected, a portion where the air flow is fast is generated by suction at the web traveling direction side of the curtain film on the liquid contact surface of the coating liquid of the nail portion 10 and the gas-liquid interface on the opposite side. This is a phenomenon that occurs because the coating solution with a slow flow at the contact portion dries. Then, the liquid smoke (S) accumulates with time at the lower end claw portion 10 of the curtain edge guide 2 during continuous production, and the curtain film 3 held at the tip of the claw portion 10 cannot be held by the liquid smoke (S). There is a drawback that the amount of adhesion of the end portion in the width direction of the coating film is increased by cutting off 3. Therefore, the product loss increases due to the nonuniform coating film width during production. In addition, due to an increase in the amount of edge coating in the width direction of the coating film, an undried part occurs due to poor drying during production, and the coating liquid adheres to the web transport roll during production, and the subsequent web coating film The surface is soiled, blocking occurs during winding of the product, or the end is raised, and the web may be cut during winding, resulting in a decrease in production efficiency.

  Patent Document 6 (Troller Schweizer Engineering) uses a porous material for the curtain edge guide and prevents contact with the curtain coating liquid in order to prevent the curtain film from shaking and cutting off in the curtain coating method. A curtain coating method in which an auxiliary liquid is allowed to flow evenly over the liquid surface, and Patent Document 7 (Mitsubishi Paper Co., Ltd.) describes a curtain coating method in which plate glass is used on the liquid contact surface of the curtain edge guide with the curtain coating liquid. ing. However, these Patent Documents 6 and 7 do not describe the removal of the coating liquid / auxiliary liquid at the lower end of the curtain edge guide.

  FIG. 18 schematically shows a state where there is no “cut-off” and a state where there is “cut-out”.

JP 2000-513 A JP 2000-218209 A JP 2001-104856 A JP-T-2005-512768 JP 2008-93656 A Japanese Patent Laid-Open No. 11-188299 JP 2001-46939 A

  The object of the present invention has been made in view of the above-described problems in the prior art, and prevents accumulation of liquid droplets at the curtain edge guide lower end claw and suction port as much as possible. It is providing the curtain coating method and curtain coating device which suppress a cut-off.

  In order to solve the above problems, the curtain coating method and the curtain coating apparatus according to the present invention, specifically, the technical features described in the following (1) to (36) are provided.

(1) At least one layer or more of coating liquid is discharged from the slit, the discharged coating liquid is freely dropped by a curtain edge guide that guides in a curtain shape, and from the entire surface in contact with the coating liquid in the curtain edge guide In the curtain coating method of pouring out the auxiliary liquid and coating the coating liquid on a continuously running web, the curtain liquid film wetted surface of the nail portion holding the curtain film at the lower end of the curtain edge guide is updated. Curtain application method.
(2) The curtain coating method according to (1), wherein the nail part is moved and reciprocated after at least a certain period of application to renew the curtain liquid film wetted surface of the nail part.
(3) The curtain coating method according to (1), wherein the coating is performed while continuously reciprocating the claw part, and the curtain liquid film wetted surface of the claw part is updated.
(4) The curtain coating method according to the above (2) or (3), wherein the speed of the reciprocating motion of the claw portion is 0.00005 to 0.005 m / sec.

(5) The claw portion is formed into a disc shape, and after application for at least a certain period, the disc-like claw portion is rotated to update the curtain liquid film wetted surface of the disc-like claw portion. The curtain coating method according to (1) above.
(6) The said nail | claw part is made into a disk shape, and while applying and rotating this disk-like nail | claw part continuously, the curtain liquid-film wetted surface of this nail | claw part is updated, (1) characterized by the above-mentioned. The curtain coating method of description.
(7) The curtain coating method according to (5) or (6) above, wherein a radius of the disk-shaped claw portion is set to 10 to 50 mm.
(8) The curtain coating method according to any one of (5) to (7) above, wherein a rotational speed of the disk-like claw portion is 0.0001 to 0.05 m / sec.

(9) The curtain coating method according to any one of (1) to (8), wherein the coating is performed with an inclination angle that lifts the edge of the tip of the claw portion upward .
(10) The curtain coating method as described in (9) above, wherein an inclination angle of the tip of the claw is set to 0 ° to 45 °.

(11) The claw portion can be attached by providing the curtain edge guide with a magnetic material and making the claw portion a part and the whole of the magnetic material or a material attracting the magnetic material of the curtain edge. The curtain coating method according to any one of (1) to (10) above, wherein

(12) The claw part is formed into a band shape, and after the curtain application for at least a certain period, the claw part is moved as a band to update the curtain liquid film wetted surface of the band-like claw part (1) ) Curtain application method.
(13) The above (1) is characterized in that the belt-like nail portion is formed into a belt-like shape, the coating is performed while continuously moving the belt-like nail portion as a belt-like shape, and the curtain liquid film wetted surface of the nail portion is updated. The curtain coating method described.
(14) The curtain coating method according to the above (12) or (13), wherein the moving speed of the belt-like claw is 0.00005 to 0.005 m / sec.

(15) The curtain coating method according to any one of (1) to (14) above, wherein the surface of the liquid contact surface of the nail part is a member having a hydrophobic function.

(16) The curtain coating method according to any one of the above (1) to (15), wherein a liquid tub accumulated in the claw portion is cleaned.
(17) The curtain coating method according to (16), wherein a brush is used for cleaning the liquid tank.
(18) The curtain coating method as described in (16) above, wherein a scraper blade is used for cleaning the liquid tank.

(19) At least one layer or more of the coating liquid is discharged from the slit, and the discharged coating liquid is freely dropped by a curtain edge guide that guides in a curtain shape, and from the entire surface in contact with the coating liquid in the curtain edge guide In the curtain coating apparatus that pours out the auxiliary liquid and coats the coating liquid on a continuously running web, the curtain liquid guide has a function of updating the curtain liquid film wetted surface of the nail portion that holds the curtain film at the lower end of the curtain edge guide. A curtain coating apparatus characterized by that.
(20) The curtain coating apparatus according to (19) above, which has a function of moving the claw portion to reciprocate.
(21) The curtain coating apparatus according to (19) above, which has a function of continuously reciprocating the claw portion.
(22) The curtain coating apparatus according to (20) or (21) above, wherein a speed of reciprocating motion of the claw portion is 0.00005 to 0.005 m / sec.

(23) The curtain coating device according to (19), wherein the claw portion is a disc-shaped claw portion and has a function of rotating the disc-shaped claw portion.
(24) The curtain coating device according to (19) above, wherein the claw portion is a disc-like claw portion and has a function of continuously rotating the disc-like claw portion.
(25) The curtain coating device according to (23) or (24) above, wherein a radius of the disk-like claw portion is 10 to 50 mm.
(26) The curtain coating device according to any one of (23) to (25) above, wherein a rotational speed of the disk-like claw portion is 0.0001 to 0.05 m / sec.

(27) The curtain coating apparatus according to any one of (19) to (26) above, wherein an inclination angle is provided to lift the edge of the tip of the claw portion upward .
(28) The curtain coating apparatus according to (27), wherein an inclination angle of the tip of the claw is set to 0 ° to 45 °.

(29) The curtain edge guide includes a magnetic substance, and a part and the whole of the claw part are made of a magnetic substance or a substance that attracts the magnetic substance of the curtain edge to attach the claw part. The curtain coating apparatus according to any one of (19) to (28), wherein

(30) The curtain coating apparatus according to (19), wherein the claw portion has a function of moving the claw portion in a belt shape and moving the belt claw portion as a belt shape.
(31) The curtain coating apparatus according to (19) above, wherein the belt-like claw portion has a function of continuously moving the belt-like claw portion as a belt-like shape.
(32) The curtain coating apparatus according to (30) or (31) above, wherein the moving speed of the belt-like claw portion is 0.00005 to 0.005 m / sec.

(33) The curtain coating apparatus according to any one of the above (19) to (32), wherein a member having a hydrophobic function is provided on the surface of the claw part on the surface of the coating liquid contacted.

(34) The curtain coating apparatus according to any one of the above (19) to (33), characterized in that it has means for cleaning the liquid scum accumulated in the claw portion.
(35) The curtain coating apparatus according to (34), wherein a brush is used as the cleaning means for the liquid tank.
(36) The curtain coating apparatus according to (34), wherein a scraper blade is used as the cleaning means for the liquid tank.

  According to the present invention, it is possible to provide a curtain coating method and a curtain coating apparatus that prevent liquid droplets from collecting at the lower edge of the curtain edge guide as much as possible and suppress the curtain film from being cut off at the curtain edge guide. it can.

  The present invention includes (A) discharging at least one layer of coating liquid from a slit, allowing the discharged coating liquid to fall freely with a curtain edge guide that guides in a curtain shape, and the coating liquid in the curtain edge guide In the curtain coating method in which the auxiliary liquid is poured out from the entire contact surface and the coating liquid is applied onto the continuously running web, the curtain liquid film wetted surface of the nail portion that holds the curtain film at the lower end of the curtain edge guide is updated. And (B) at least one layer of coating liquid is discharged from the slit, and the discharged coating liquid is freely dropped by a curtain edge guide that guides the curtain, and the curtain Curtain coating in which an auxiliary liquid is poured from the entire surface of the edge guide that is in contact with the coating liquid, and the coating liquid is applied onto a continuously running web. In location, a curtain coating apparatus characterized by having a function to update the curtain liquid film contacting surface of the claw portion for holding the curtain film of the curtain edge guide bottom.

  That is, according to the present invention, by updating the curtain liquid film wetted surface of the nail portion that holds the curtain film at the lower end of the curtain edge guide, liquid droplets accumulate on the nail curtain liquid film wetted surface and the suction port. By making the nail curtain liquid film wetted surface and its vicinity free of liquid before it breaks up, it is possible to suppress the curtain film from being cut off by the curtain edge guide, and to come off from the curtain liquid film wetted surface. The present invention provides a curtain coating method and a curtain coating apparatus that can prevent the curtain film from always being cut off by cleaning the liquid in the nail portion.

  As described above, in the curtain coating method and apparatus of the present invention, in order to stabilize the curtain film, the coating liquid is applied while flowing the auxiliary liquid from the surface in contact with the curtain film in the curtain edge guide. The auxiliary liquid is not particularly limited as long as it is liquid and has fluidity.For example, when the coating liquid is an aqueous liquid, water or a mixed liquid in which water, a resin, a surfactant, or the like is mixed is used. Preferably, in the case of a solvent-based liquid, it is preferable to use a solvent contained in the coating liquid or a mixed liquid obtained by mixing a resin, a surfactant or the like with the solvent.

  The shape of the claw portion is arbitrary as long as it holds the curtain film at the lower end of the curtain edge guide and can keep the auxiliary liquid flowing down, but generally a planar one is adopted. The material of the nail part can be arbitrarily selected as long as it is not affected by the coating liquid and the auxiliary liquid, but generally (stainless steel, brass, aluminum, iron, glass, PET) or the like is used.

Hereinafter, the present invention (curtain coating method and apparatus) will be described in more detail with reference to the drawings.
The embodiments described below are preferred embodiments of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

(First embodiment)
This is a form in which the claw portion is formed in a flat plate shape and curtain coating is performed.
In this curtain coating method, as shown in FIG. 5, the claw part (claw part to be reciprocated) 101 at the lower end of the curtain edge guide 2 is moved and reciprocated after a certain period of application, thereby claw part curtain liquid film contact. The liquid surface is renewed, or it is applied while continuously reciprocating the nail part 101 from the beginning of application or after a certain period of application, and the nail part curtain liquid film contact surface is always renewed. It is preferable not to accumulate liquid level on the liquid surface. In particular, when the claw 101 is applied while continuously reciprocating, the curtain film can be further prevented from being cut off by the curtain edge guide 2. For this reason, this curtain coating apparatus has a function of reciprocating the claw portion. Note that the liquid is removed by suction with a liquid suction vacuum device (not shown).
The reciprocating speed is set to 0.00005 to 0.005 m / sec. If it is less than 0.00005 m / sec, a liquid scum accumulates on the claw curtain liquid film wetted surface, and the curtain film is cut off. On the other hand, if it is greater than 0.005 m / sec, the curtain film cannot be held at the tip of the claw part, and the curtain film comes to be cut off.

(Second Embodiment)
This is a form in which the claw part is formed in a disc shape and curtain coating is performed.
FIG. 10A shows a state where the disc-shaped claw portion 102 can rotate. FIG. 10B shows that a disc-shaped claw portion 102 is disposed at the lower end of the curtain edge guide 2. The auxiliary liquid is made to flow through the porous member 13 from the surface in contact with the coating liquid in the curtain edge guide 2.

The nail part 102 at the lower end of the curtain edge guide 2 is rotated after a certain period of application to update the nail part curtain liquid film wetted surface, or the nail part 102 is continued from the beginning of application or after a certain period of application. It is preferable to apply while rotating and always update the liquid surface in contact with the nail curtain liquid film so as not to accumulate liquid droplets on the liquid surface in contact with the nail curtain liquid film. In particular, when the claw part 102 is applied while being continuously rotated, the curtain film can be further prevented from being cut off by the curtain edge guide 2. For this reason, this curtain coating apparatus has a function of rotating the claw part (including a function of continuously rotating the claw part). Note that the liquid is removed by suction with a liquid suction vacuum device (not shown).

The radius of the disc-shaped claw portion 102 is suitably 10 to 50 mm. If it is less than 10 mm, the curvature of the nail portion at the portion holding the curtain film is large, the curtain film shakes during application, and the application width becomes unstable. Moreover, if it is 50 mm or more, the apparatus will not be compact.
Moreover, the rotational speed of the nail | claw part 102 shall be peripheral speed 0.0001-0.05m / sec. If it is less than 0.0001 m / sec, liquid droplets accumulate on the surface of the nail curtain liquid film in contact with the curtain film, and the curtain film is cut off. Moreover, it becomes possible to further suppress the cut-off. If the rotational speed is greater than the peripheral speed of 0.0001 to 0.05 m, the curtain film cannot be held at the tip of the claw, and the curtain film comes up.

(Third embodiment)
This is a form in which the nail portion is strip-shaped and curtain coating is performed.
FIG. 15A shows that a belt-like claw 103 is disposed at the lower end of the curtain edge guide 2. FIG. 15B shows a state in which the belt-like claw 103 can move in one direction. In the figure, 14 is a drive rubber roll.
In this embodiment, after at least a certain period of application, the belt-like nail portion 103 is moved to update the nail curtain liquid film wetted surface, so that liquid drops accumulate on the nail curtain liquid wetted surface and the curtain film is cut off. It is possible to suppress the curtain film from being cut off at the curtain edge guide 2 by making the liquid surface of the nail part curtain liquid film contact surface free from liquid before. Also, by applying the belt-like nail 103 at the lower end of the curtain edge guide 2 while continuously moving, the nail curtain liquid film wetted surface is constantly renewed, and the liquid on the nail curtain liquid film wetted surface is not accumulated. By doing so, it becomes possible to further suppress the curtain film from being cut off by the curtain edge guide 2. Note that the liquid is removed by suction with a liquid suction vacuum device (not shown). For this reason, this curtain coating apparatus has a function of moving the claw portion as a band (including a function of continuous movement).

  The moving speed of the belt-like claw portion 103 is set to 0.00005 to 0.005 m / sec. If it is less than 0.00005 m / sec, liquid droplets accumulate on the nail curtain liquid film wetted surface and the curtain film is cut off. On the other hand, if it is greater than 0.005 m / sec, the curtain film cannot be held at the tip of the nail, and the curtain film is cut off.

(Fourth embodiment)
Curtain application is performed with an inclination angle θ on the tip of the claw part (claw part reciprocated) 101 and the tip part (peripheral part) of the disc-shaped claw part 102.
6 shows a state where one end of the tip of the claw portion 101 is lifted upward with an inclination angle θ, and FIG. 11 shows a state where the peripheral edge of the claw portion 102 is raised upward with an inclination angle θ. Is shown.
Thus, having the inclination angle θ at the tip of the claw portions 101 and 102 makes it easy for the curtain film to come into contact with the claw portion during web application, and the holding force (wet area: large) of the curtain film end portion. ) Is large, and it becomes possible to further suppress the cut-off of the nail curtain liquid film wetted surface due to the liquid drip.
The angle θ is preferably 0 ° to 45 °, and more preferably 10 ° to 35 °. If it is less than 0 °, the holding force at the end of the curtain film is not sufficient, and the curtain film may be cut off if a small amount of liquid droplets adheres to the nail part curtain liquid film contact surface. Further, when the angle exceeds 45 °, the coating liquid turns to the back side of the claw portions 101 and 102, and the amount of adhesion of the end portion in the coating width direction increases. The coating liquid adheres to the web conveyance roll, and the subsequent web coating surface is soiled, blocking occurs during product winding, or the web is cut during winding due to the rising edge.

(Fifth embodiment)
The curtain edge guide 2 is provided with a magnetic substance 15, and the claw part (claw part reciprocated) 101 and a part and the whole of the disk-shaped claw part 102 are attracted to the magnetic substance substance or the magnetic substance substance 15 of the curtain edge guide. As the substance 12, curtain coating is performed.
FIG. 7 shows how the claw portion 101 can reciprocate by adopting such a configuration. Similarly, FIG. 12 shows how the claw portion 102 can rotate.
As a result, as shown in FIG. 7B, the claw portion 101 can be easily slid, and the claw portion curtain liquid film wetted surface can be easily made free of liquid dregs. It becomes possible to suppress the cut-off of the film. Further, as shown in FIG. 12 (b), the disk-shaped claw portion 102 can be easily rotated, and the claw portion curtain liquid film wetted surface can be easily made free of liquid soot. The curtain film can be prevented from being cut off at 2.

  The magnetic substance is preferably magnetite, KS steel, MK steel, ferrite magnet, samarium cobalt magnet, alnico magnet, neodymium magnet, samarium iron nitrogen magnet, platinum magnet, praseodymium magnet, plastic magnet, manganese. Aluminum magnets, iron-chromium-cobalt magnets, bonded magnets, molecular magnets, and the like can be mentioned. Preferred materials attracting the magnetic substance 15 include iron and stainless steel.

(Sixth embodiment)
Curtain coating is performed by using the liquid contact surface of the nail portion as a member having a hydrophobic function.
By configuring the surface of the nail part coating liquid (curtain liquid film) wetted surface with a member having a hydrophobic function, the nail part repels the moisture of the coating liquid and auxiliary liquid, and the nail part curtain liquid film The liquid dripping on the wetted surface can be suppressed, and the curtain film can be prevented from being cut off. As the member having a hydrophobic function, Teflon (registered trademark) resin, silicon resin, and the like are preferable.

(Seventh embodiment)
The liquid scum accumulated in the nail part is cleaned or the curtain coating is performed while cleaning.
A brush, a scraper blade or the like is used for cleaning the liquid tank. Further, in the vicinity of a brush, a scraper blade or the like, a liquid tank suction vacuum device for liquid tank suction is disposed.

8 and 9 show that a device for cleaning the liquid stain adhering to the claw part 101 is provided while continuously reciprocating the claw part curtain liquid film wetted surface at the lower end of the curtain edge guide 2 of the claw part 101. Show. FIG. 8 shows an example in which the brush 16 is used for cleaning the liquid tank, and FIG. 9 is an example in which the scraper blade 18 is used for cleaning the liquid tank. In the figure, reference numeral 17 denotes a liquid tank suction vacuum device for liquid tank suction. According to this, liquid stains are scraped off with a brush, scraper, etc., and the dirt is sucked with a vacuum device. can do.
13 and 14 are provided with a device that cleans the liquid stain adhering to the claw part while continuously rotating the disk-shaped claw part 102, so that the liquid scum on the nail part wetted surface is always maintained during continuous production. This indicates that the curtain film can be prevented from being cut off. FIG. 13 shows an example in which the brush 16 is used for cleaning the liquid tank, and FIG. 14 shows an example in which the scraper blade 18 is used for cleaning the liquid tank.
16 and 17 are provided with a device for cleaning the liquid stain adhering to the claw part while moving the band-like claw part 103 in one direction, so that the liquid on the claw part wetted surface is always provided during continuous production. This shows that wrinkles can be prevented and curtain film break-up can be prevented. FIG. 16 shows an example in which the brush 16 is used for cleaning the liquid tank, and FIG. 17 shows an example in which the scraper blade 18 is used for cleaning the liquid tank.

    Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. “Parts” means all parts by mass.

[Example 1]
A disc-shaped claw portion 102 shown in FIG. 10 is attached to the lower end of the curtain edge guide of the slide curtain applicator shown in FIG. 2 so as to be able to rotate with an axis at the center of the disc, and the coating speed is 400 m on the web (paper). The following thermal recording layer coating liquid was applied at a coating width of 250 g / min, a nozzle slit discharge coating liquid flow rate of 3000 g / min. Disc (material: stainless steel) at this time: radius 20 mm × thickness 0.18 mm, amount of auxiliary liquid (water) flowing along the curtain edge guide: 30 cc / min, auxiliary liquid recovery vacuum device suction pressure: −8 kpa. Further, the protruding amount of the claw portion 102 was 2 mm from the curtain film wetted surface of the porous member 13 (ceramic: average pore diameter 50 μm, porosity 52%). The results are shown in Table 1.

(Thermosensitive recording layer coating solution: viscosity 150 mPa · s, static surface tension 38 mN / m)
* Static surface tension: Measured with FACE automatic surface tension meter CBVP-A3 type (manufactured by Kyowa Interface Science Co., Ltd.), 3-dibutylamino-6-methyl-7-anilinofluorane, 4 parts, 4-isopropoxy 4'-hydroxydiphenylsulfone 12 parts, silica 6 parts, 10% aqueous solution of polyvinyl alcohol 16 parts, water 41 parts

[Example 2]
The thermosensitive recording layer coating solution was applied in the same manner as in Example 1 except that the radius of the disc-shaped claw portion 102 was changed from 20 mm to 5 mm. The results are shown in Table 1.

Example 3
Using the slide curtain coating apparatus shown in FIG. 5, the flat claw portion 101 (material: stainless steel, thickness: 0.18 mm, moving length 60 mm × width 30 mm) is sandwiched between the drive rubber rolls 14 and reciprocated (0.005 m / sec). The heat-sensitive recording layer coating solution was applied in the same manner as in Example 1 except that the above was performed. The results are shown in Table 1.

Example 4
Using the slide curtain coating apparatus shown in FIG. 15, the belt-like claw portion 103 (material: stainless steel, thickness: 0.01 mm, movement length 80 mm × width 30 mm) is supported by the drive rubber roll 14 and moved (0. The heat-sensitive recording layer coating solution was applied in the same manner as in Example 1 except that 005 m / sec). The results are shown in Table 1.

Example 5
A thermosensitive recording layer coating solution was applied in the same manner as in Example 1 except that the peripheral edge portion of the disc-shaped claw portion 102 used in Example 1 was inclined at an angle of 30 ° as shown in FIG. The results are shown in Table 1.

Example 6
The thermosensitive recording layer coating solution was applied in the same manner as in Example 1 except that the peripheral edge of the disc-shaped claw 102 used in Example 1 was inclined at 45 ° as shown in FIG. The results are shown in Table 1.

Example 7
A thermosensitive recording layer coating solution was applied in the same manner as in Example 1 except that the peripheral edge portion of the disc-shaped claw portion 102 used in Example 1 was inclined at an angle of 50 ° as shown in FIG. The results are shown in Table 1.

Example 8
The thermosensitive recording layer coating solution was applied in the same manner as in Example 1 except that the peripheral edge of the disc-shaped claw portion 102 used in Example 1 was inclined at an angle of 5 ° as shown in FIG. The results are shown in Table 1.

Example 9
The thermal recording layer coating solution was applied in the same manner as in Example 3 except that one tip of the flat claw 101 used in Example 3 was inclined at an angle of 30 ° as shown in FIG. did. The results are shown in Table 1.

Example 10
The thermal recording layer coating solution was applied in the same manner as in Example 3 except that one tip of the flat nail portion 101 used in Example 3 was inclined at 45 ° as shown in FIG. did. The results are shown in Table 1.

Example 11
The thermal recording layer coating solution was applied in the same manner as in Example 3 except that one tip of the flat claw 101 used in Example 3 was inclined at 50 ° as shown in FIG. did. The results are shown in Table 1.

Example 12
The thermal recording layer coating solution was applied in the same manner as in Example 3 except that one tip of the flat nail portion 101 used in Example 3 was inclined at an angle of 5 ° as shown in FIG. did. The results are shown in Table 1.

Example 13
Using the slide curtain coating apparatus shown in FIG. 12, the magnetic member 15 (magnet) is attached to the curtain edge guide 2, and the disc-shaped claw portion 102 is made of stainless steel (SUS 420) that is hooked to the magnetic member (magnet). The thermosensitive recording layer coating solution was applied in the same manner as in Example 1 except that the rotation speed of the disc-shaped claw portion (radius 20 mm × thickness 0.18 mm) was changed to a peripheral speed of 0.01 m / sec. The results are shown in Table 1.

Example 14
Using the slide curtain coating apparatus shown in FIG. 7, a magnetic member (magnet) 15 is attached to the curtain edge guide 2, and the plate-like claw portion 101 is made of stainless steel (SUS 420) that is attracted to the magnetic member (magnet). The thermosensitive recording layer coating solution was applied in the same manner as in Example 1 except that the reciprocating speed of the flat nail portion (thickness: 0.18 mm, length 60 mm × width 30 mm) was 0.005 m / sec. . The results are shown in Table 1.

Example 15
Except for attaching a 100 μm thick Teflon (registered trademark) sheet on the surface of the liquid contact surface of the coating liquid (curtain liquid film) of the disk-shaped claw portion 102 of Example 1, A thermal recording layer coating solution was applied. The results are shown in Table 1.

Example 16
In the same manner as in Example 3, except that a Teflon (registered trademark) sheet having a thickness of 100 μm was attached to the surface of the contact surface of the coating liquid (curtain liquid film) of the plate-like claw portion 101 of Example 3, The recording layer coating solution was applied. The results are shown in Table 1.

Example 17
Thermosensitive recording was performed in the same manner as in Example 4 except that a 100 μm thick Teflon (registered trademark) sheet was attached to the surface of the coating liquid (curtain liquid film) wetted surface of the band-like claw part 103 of Example 4. A layer coating solution was applied. The results are shown in Table 1.

Example 18
Using the slide curtain coating apparatus shown in FIG. 13, the disk-shaped claw portion 102 of Example 1 is rotated at a peripheral speed of 0.0001 m / sec by a drive motor, and the round brush 16 is placed on the opposite side of the curtain edge guide 2. Continuous rotation (circumferential speed 0.05 m / sec) so as to oppose the rotation direction of the disc-shaped claw portion 102, and the liquid in the disc-shaped claw portion is sucked by the liquid cup suction vacuum device 17 (−0.01 MPa). The thermal recording layer coating solution was applied in the same manner as in Example 1 except that. The results are shown in Table 1.

Example 19
The thermal recording layer coating solution was applied in the same manner as in Example 18 except that the peripheral speed of the disk-like claw portion 102 in Example 18 was set to 0.1 m / sec. The results are shown in Table 1.

Example 20
Using the slide curtain coating apparatus shown in FIG. 14, the same disk-shaped claw portion 102 as used in Example 1 was rotated at a peripheral speed of 0.0001 m / sec by a drive motor, and on the side opposite to the curtain edge guide 2, A scraper blade 18 (material: polyethylene, thickness 0.4 mm) is mounted so as to be opposed to the disk rotation direction, and the liquid in the disk-shaped claw part is sucked with a liquid tank suction vacuum device 17 (−0.01 MPa). )did. The results are shown in Table 1.

Example 21
Using the slide curtain coating apparatus shown in FIG. 8, the same plate-like claw portion 101 as used in Example 3 is made as long as a moving distance of 100 mm, and this is sandwiched by the drive rubber roll 14, and the drive rubber roll 14 is rotated by the drive motor. The claw portion 101 is controlled to reciprocate at a moving speed of 0.0005 m / sec, and the round brush 16 is continuously moved against the claw portion moving direction between the claw portion curtain edge guide 2 and the drive rubber roll 14. It was rotated (peripheral speed 0.05 m / sec), and the liquid in the claw was sucked (−0.01 MPa) with the liquid suction vacuum device 17. The results are shown in Table 1.

[Example 22]
The thermal recording layer coating solution was applied in the same manner as in Example 21 except that the movement speed of the claw portion 101 in Example 21 was controlled to reciprocate at 0.01 m / sec. The results are shown in Table 1.

Example 23
Using the slide curtain coating apparatus shown in FIG. 9, the same plate-like claw portion 101 as used in Example 3 is made as long as a moving distance of 100 mm, and this is sandwiched by the drive rubber roll 14, and the drive rubber roll is rotated by the drive motor. The claw portion 101 is controlled to reciprocate at a moving speed of 0.00005 m / sec, and a scraper blade 18 (material: polyethylene, thickness 0.4 mm) is moved in the moving direction between the curtain edge guide of the claw portion and the driving rubber roll. It was tilted so as to be reversed, and the liquid in the nail portion was sucked (−0.01 MPa) with a liquid suction vacuum device 17. The results are shown in Table 1.

Example 24
Using the slide curtain coating apparatus shown in FIG. 16, the same belt-like claw portion 103 as used in Example 4 is supported by a drive rubber roll 14, and the drive rubber roll is rotated by a drive motor to move the claw portion at a moving speed of 0. It is moved in one direction at 00005 m / sec, and the round brush 16 is continuously rotated so as to oppose the moving direction of the claw portion 103 (peripheral speed 0.05 m / sec). 17 (-0.01 MPa). The results are shown in Table 1.

Example 25
A thermosensitive recording layer coating solution was applied in the same manner as in Example 24 except that the moving speed of the claw portion 103 in Example 24 was set to 0.01 m / sec. The results are shown in Table 1.

Example 26
Using the slide curtain coating apparatus shown in FIG. 17, the same belt-like claw portion 103 as used in Example 4 is supported by a drive rubber roll 14, and the drive rubber roll is rotated by a drive motor to move the claw portion 103 at a moving speed of 0. The scraper blade 18 (material: polyethylene, thickness 0.4 mm) is tilted and attached so that it moves in one direction at 0.0005 m / sec and counters the direction of movement of the nail part. Suction (−0.01 MPa) was performed with a vacuum device 17. The results are shown in Table 1.

[Comparative Example 1]
As shown in FIG. 2, the lower end of the curtain edge guide of the slide curtain coating apparatus was fixed, and the same coating as in Example 1 was performed. The results are shown in Table 1.

[Comparative Example 2]
Coating was performed in the same manner as in Example 1 except that the nail part of Example 1 was not rotated. The results are shown in Table 1.

[Comparative Example 3]
Coating was performed in the same manner as in Example 3 except that the claw part of Example 3 was not reciprocated. The results are shown in Table 1.

[Comparative Example 4]
Coating was performed in the same manner as in Example 4 except that the nail part of Example 4 was not moved. The results are shown in Table 1.

It is a perspective view which shows the structural example of the conventional curtain coating device. It is a cross-sectional perspective view which shows the other structural example of the conventional curtain coating device. It is the schematic which shows the structure of the coating liquid curtain film | membrane edge part periphery in the conventional curtain coating device. It is the schematic for demonstrating that a curtain film cuts out. (A) is the upper surface schematic diagram which shows the structural example of the curtain coating device provided with the nail | claw part 101 holding the curtain film | membrane of a curtain edge guide lower end. (B) is the front schematic diagram. (C) is a schematic side view thereof. It is the front schematic which shows the structural example of the curtain coating device in which the one end of the nail | claw part 101 had the inclination angle. (A) is a schematic front view showing a configuration example of a curtain coating apparatus in which the claw portion 101 is easily attached to the curtain edge guide 2. (B) is the schematic perspective view. (A) is an upper surface schematic diagram showing a configuration example of a curtain coating apparatus provided with means for cleaning the liquid tub accumulated in the claw portion 101. FIG. (B) is the front schematic diagram. (A) is a schematic top view showing an example of the configuration of a curtain coating apparatus provided with other means for cleaning the liquid tub accumulated in the claw portion 101. FIG. (B) is the front schematic diagram. (A) is the disk-shaped nail | claw part 102 which a nail | claw part rotates, and is a figure which shows the positional relationship of this and a curtain edge guide. (B) is a schematic front view showing a configuration example of a curtain coating apparatus provided with a claw portion 102 for holding the curtain film at the lower end of the curtain edge guide. It is the front schematic which shows the structural example of the curtain coating device in which the one end of the nail | claw part 102 had the inclination angle. (A) is a schematic front view showing a configuration example of a curtain coating apparatus in which the claw portion 102 is easily attached to the curtain edge guide 2. (B) is the perspective view. (A) is a schematic top view showing an example of the configuration of a curtain coating apparatus provided with means for cleaning the liquid scum accumulated in the claw portion 102. FIG. (B) is the front schematic diagram. (A) is a schematic top view showing an example of the configuration of a curtain coating apparatus provided with other means for cleaning the liquid soup collected in the claw portion 102. FIG. (B) is the front schematic diagram. (C) is a schematic side view thereof. (A) is a schematic front view showing a configuration example of a curtain coating apparatus provided with a claw portion 103 that holds the curtain film at the lower end of the curtain edge guide. (B) is the schematic side view. (C) is a schematic top view thereof. (A) is a schematic top view showing an example of the configuration of a curtain coating apparatus provided with means for cleaning the liquid soup collected in the claw portion 103. FIG. (C) is a schematic front view. (A) is a schematic top view showing an example of the configuration of a curtain coating apparatus provided with other means for cleaning the liquid scum accumulated in the claw portion 103. FIG. (C) is a schematic front view. FIG. 2 schematically shows a state where there is no “cut-off” of the curtain film and a state where “curvature” exists.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Curtain coating head 1 'Slide curtain coating head 2 Curtain edge guide 2' Curtain edge guide 3 Coating liquid 4 Vacuum apparatus 5 Web 6 Backup roll 7 Slide surface 8 Slide part edge guide 9 Auxiliary liquid 10, 101, 102, 103 Claw part 11 Suction port 12 Magnetic substance or substance attracting magnetic substance 13 Porous member 14 Driving roll 15 Magnetic substance 16 Brush 17 Liquid suction vacuum device 18 Scrabble blade S Liquid

Claims (36)

  At least one layer or more of the coating liquid is discharged from the slit, the discharged coating liquid is freely dropped by a curtain edge guide that guides in a curtain shape, and auxiliary liquid is applied from the entire surface of the curtain edge guide in contact with the coating liquid. In a curtain coating method for pouring out and coating the coating liquid on a continuously running web, the curtain liquid film wetted surface of the nail portion holding the curtain film at the lower end of the curtain edge guide is updated. Method.   2. The curtain coating method according to claim 1, wherein the claw portion is moved and reciprocated after at least a certain period of application to update the curtain liquid film wetted surface of the claw portion.   2. The curtain coating method according to claim 1, wherein the coating is performed while continuously reciprocating the claw portion, and the curtain liquid film wetted surface of the claw portion is updated.   The curtain coating method according to claim 2 or 3, wherein a speed of reciprocation of the claw portion is 0.00005 to 0.005 m / sec.   The said nail | claw part is made into a disk shape, and after application | coating for a fixed period, this disk-like nail | claw part is rotated and the curtain liquid-film wetted surface of this disk-like nail | claw part is renewed. The curtain coating method of description.   2. The curtain according to claim 1, wherein the claw portion is formed in a disc shape, coating is performed while the disc-like claw portion is continuously rotated, and the curtain liquid film wetted surface of the claw portion is renewed. Application method.   The curtain coating method according to claim 5 or 6, wherein a radius of the disc-shaped claw portion is set to 10 to 50 mm.   The curtain coating method according to any one of claims 5 to 7, wherein a rotation speed of the disc-shaped claw portion is 0.0001 to 0.05 m / sec. The curtain coating method according to any one of claims 1 to 8, wherein the coating is performed with an inclination angle that lifts the edge of the tip of the claw portion upward .   The curtain coating method according to claim 9, wherein an inclination angle of the tip of the claw is set to 0 ° to 45 °.   The curtain edge guide is provided with a magnetic substance, and the claw part can be attached by making a part and the whole of the claw part attractive with the magnetic substance or the magnetic substance of the curtain edge. The curtain coating method according to any one of claims 1 to 10.   The said nail | claw part is made into a strip | belt shape, and the curtain liquid film wetted surface of this strip | belt-shaped nail | claw part is renewed by moving this strip | belt-shaped nail | claw part as a strip | belt shape after a curtain application | coating for a fixed period. Curtain application method.   2. The curtain coating according to claim 1, wherein the strip-shaped claw portion is formed into a strip shape, the coating is performed while continuously moving the strip-shaped claw portion in a strip shape, and the curtain liquid film wetted surface of the claw portion is updated. Method.   The curtain coating method according to claim 12 or 13, wherein a moving speed of the belt-like claw part is 0.00005 to 0.005 m / sec.   The curtain coating method according to any one of claims 1 to 14, wherein a surface of the nail part which is in contact with the coating liquid is a member having a hydrophobic function.   The curtain coating method according to any one of claims 1 to 15, wherein a liquid scum accumulated in the claw portion is cleaned.   The curtain coating method according to claim 16, wherein a brush is used for cleaning the liquid tank.   The curtain coating method according to claim 16, wherein a scraper blade is used for cleaning the liquid tank.   At least one layer or more of the coating liquid is discharged from the slit, the discharged coating liquid is freely dropped by a curtain edge guide that guides in a curtain shape, and auxiliary liquid is applied from the entire surface of the curtain edge guide in contact with the coating liquid. In a curtain coating apparatus for pouring out and coating the coating liquid on a continuously running web, the curtain coating apparatus has a function of renewing the curtain liquid film wetted surface of the nail portion that holds the curtain film at the lower end of the curtain edge guide. Curtain coating device.   The curtain coating apparatus according to claim 19, further comprising a function of moving the claw portion to reciprocate.   The curtain coating apparatus according to claim 19, which has a function of continuously reciprocating the claw part.   The curtain coating apparatus according to claim 20 or 21, wherein a speed of reciprocating motion of the claw portion is 0.00005 to 0.005 m / sec.   20. The curtain coating apparatus according to claim 19, wherein the claw portion is a disc-like claw portion and has a function of rotating the disc-like claw portion.   20. The curtain coating apparatus according to claim 19, wherein the claw portion is a disc-like claw portion and has a function of continuously rotating the disc-like claw portion.   The curtain coating apparatus according to claim 23 or 24, wherein a radius of the disc-shaped claw portion is set to 10 to 50 mm.   The curtain coating device according to any one of claims 23 to 25, wherein a rotation speed of the disc-shaped claw portion is 0.0001 to 0.05 m / sec. The curtain coating apparatus according to any one of claims 19 to 26, wherein an inclination angle is provided to lift an edge of a tip of the claw portion upward .   The curtain coating apparatus according to claim 27, wherein an inclination angle of the tip of the claw portion is set to 0 ° to 45 °.   The curtain edge guide includes a magnetic substance, and a part and the whole of the claw part is made of a magnetic substance or a substance that attracts the magnetic substance of the curtain edge, and has a mechanism for attaching the claw part. The curtain coating apparatus according to any one of claims 19 to 28.   20. The curtain coating apparatus according to claim 19, further comprising a function of moving the claw part into a band shape and moving the band claw part as a band shape.   The curtain coating apparatus according to claim 19, wherein the belt-like claw portion has a band shape, and the belt-like claw portion has a function of continuously moving the belt-like claw portion as a belt shape.   32. The curtain coating apparatus according to claim 30 or 31, wherein a moving speed of the belt-like claw portion is 0.00005 to 0.005 m / sec.   The curtain coating apparatus according to any one of claims 19 to 32, wherein a member having a hydrophobic function is provided on a surface of the nail portion on the surface of the coating liquid in contact with the coating liquid.   The curtain coating apparatus according to any one of claims 19 to 33, further comprising means for cleaning the liquid scum accumulated in the claw portion.   The curtain coating apparatus according to claim 34, wherein a brush is used as the cleaning means for the liquid tank.   The curtain coating apparatus according to claim 34, wherein a scraper blade is used as the cleaning means for the liquid tank.

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