JP2000033304A - Gravure coating device and gravure coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a coating film without leaving an uncoated part at a high printing speed and with desired film thickness. SOLUTION: This gravure coating device has a plurality of cells 8 formed on the surface of a gravure roll 4 and transfers a coating material held in the cells 8 onto a supporting body continuously traveling to form a coating film. An angle formed by edge parts 10 facing each other between the cells 8 adjacent to each other in the rotation direction and the rotation direction of the gravure roll 4 is 90±10 deg., and an angle formed by the arrangement direction of the plurality of cells 8 arranged in the rotation direction and the rotation axis of the gravure roll 4 is 90±10 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gravure coating apparatus and a gravure coating method for coating a coating material on a support such as an ink ribbon or a magnetic tape.

[0002]

2. Description of the Related Art Conventionally, there is a gravure coating apparatus for forming a coating film on a support such as an ink ribbon or a magnetic tape. This gravure coating apparatus transfers a solid paint onto a continuously running support to perform pattern printing, or forms a back coat layer on a magnetic tape support. This gravure coating apparatus has a gravure roll for applying a paint to a support, and the gravure roll is provided on a predetermined portion of an outer peripheral surface of the gravure roll in a rectangular shape corresponding to a region on the support to which the paint is applied. A paint holding portion is formed in which cells having a shape are concavely provided in a matrix. Then, the gravure roll forms a coating film by transferring the paint adhered and held on the paint holding unit onto the support.

In the coating material holding section, rectangular cells are provided in a matrix on the outer peripheral surface of the gravure roll, and a convex "dote" is formed at a boundary between adjacent cells. Each cell can hold a desired amount of paint by forming a dove at the boundary between adjacent cells.

In the gravure coating apparatus described above, the gravure roll is driven to rotate, and the coating material held in each cell of the coating material holding unit is transferred onto the support, so that a predetermined area on the support is coated. A film can be formed. At this time,
The coating material transferred onto the support is flattened, that is, leveled, on the support to form a coating film formed in a predetermined area on the support. Thus, the gravure coating apparatus transfers the paint held in the cells onto the support and flattens it, thereby performing pattern printing in which the ink paint for the ink ribbon is transferred to a predetermined area on the support. And a back coat layer of a magnetic tape can be formed.

In the case of performing the pattern printing as described above, if the leveling is forcibly performed, the transferred paint spreads and a coating film is formed on a portion other than a predetermined area of the support. The transferred paint cannot be forcibly leveled by a smoothing device or the like. Therefore, in pattern printing, the transferred paint spreads spontaneously without the forced leveling by a smoothing device or the like, and as a result, the paint transferred adjacent to the support from each cell is fused and integrated. Leveling is performed. That is, in the case of pattern printing, the paint transferred on the support is naturally leveled.

[0006]

However, when such forced leveling is not performed, there is a problem that once a leveling defect occurs, the product remains as a print defect as it is. .

In order to prevent this, in some gravure coating apparatuses, a plurality of cells are brought close to each other by narrowing a width of a groove located between the plurality of cells. According to this gravure coating apparatus, the paint transferred onto the support corresponding to each cell is easily integrated and integrated, and the occurrence of leveling failure can be reduced.

However, even in such a gravure coating apparatus, when the printing speed is increased and the amount of paint is increased, the transferred paint is difficult to be integrated and integrated, and discontinuous defects are generated in the rotation direction of the gravure roll. The resulting coating film is formed. In addition, when the coating film is formed thin, the amount of the paint held in each cell is reduced, so that the coating is likely to occur. Also, the conventional gravure coating device,
Normally, the rectangular cells arranged in the direction of rotation of the gravure roll are arranged so that the angle of the opposite side is 45 degrees with respect to a straight line perpendicular to the rotation axis of the gravure roll. As the process progresses, even if such a device is used, the paint-through will occur. That is, the paint transferred onto the support corresponding to each cell becomes discontinuous, and an uncoated area is formed on the support.

Therefore, the gravure coating apparatus further includes:
There is an apparatus in which a concave groove is formed by etching so as to connect rectangular cells arranged in the rotation direction of a gravure roll. However, even when a concave groove connecting adjacent cells is formed on the gravure roll, a continuous coating film should be formed when forming a thick coating film at high speed by pattern printing. Was difficult. In addition, forming a concave groove by etching is difficult to form a concave groove of an accurate shape because of poor formation accuracy of etching. If the groove formed by the etching is too wide, the ink holding function of the cell may be reduced and the coating may be lost.

As described above, when the conventional gravure coating apparatus is used, it has been difficult to improve the productivity by increasing the printing speed. Further, even when a gravure roll in which adjacent cells are connected by a concave groove is used, it is difficult to form a coating film having no coating defects in a thin coating.

Accordingly, the present invention provides a gravure which can increase the printing speed to form a thick coating film, and can prevent the occurrence of paint-through even when applying a thin layer with a small amount of paint in the cell. It is an object to provide a coating device and a gravure coating method.

[0012]

A gravure coating apparatus according to the present invention has a paint holding section in which a plurality of rectangular cells are arranged on the surface of a gravure roll in order to solve the above-mentioned problems.
A gravure coating apparatus for forming a coating film by transferring a coating material held in a coating material holding unit onto a continuously running support,
The paint holding unit is formed such that an angle formed between a straight line connecting the centers of the cells arranged in the rotation direction of the gravure roll and the rotation axis of the gravure roll is within a range of 90 ° ± 10 °, and is arranged in the rotation direction of the gravure roll. The angle between the opposite edge of the cell and a straight line perpendicular to the rotation axis is 90 ° ± 10 °
Is formed in the range. Thus, when the paint is transferred from each cell, the paint forms a stable meniscus at the transition portion of the support. Therefore, the paints transferred from the cells are naturally fused and integrated, and the leveling is performed well, so that the coating film formed on the support is likely to be continuous in the rotation direction of the gravure roll.

Further, the gravure coating method according to the present invention comprises:
A gravure coating method having a paint holding unit in which a plurality of cells for holding a paint are arranged on the surface of a gravure roll, and transferring the paint held in the paint holding unit onto a continuously running support to form a coating film The angle between a straight line connecting the centers of cells arranged in the rotation direction of the gravure roll and the rotation axis of the gravure roll is 90 °.
The angle formed between the facing edge of the cells arranged in the rotation direction of the gravure roll and a line perpendicular to the rotation axis is formed in the range of 90 ° ± 10 ° while being formed in the range of ± 10 °. . Thus, when the paint is transferred from each cell, the paint forms a stable meniscus at the transition portion of the support. Therefore, the paints transferred from the cells are naturally fused and integrated, and the leveling is performed well, so that the coating film formed on the support is likely to be continuous in the rotation direction of the gravure roll.

Here, each cell constituting the paint holding section is:
It may be formed so as to be discontinuous. Further, in order to form a coating film of a predetermined pattern on the support, the coating material holding portion may be formed on a part of the outer peripheral surface of the gravure roll, or the coating film may be formed on the entire surface of the support. Therefore, it may be formed over the entire circumference.

Each of the cells constituting the paint holding section is formed by etching.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A gravure coating apparatus according to the present invention and a gravure coating method using the gravure coating apparatus will be described below with reference to the drawings.

As shown in FIG. 1, a gravure coating apparatus 1 for coating a coating material on a support has a coating tank 3 for storing a coating material 2 and a part immersed in the coating material 2 in the coating tank 3. The gravure roll 4 for transferring the paint 2 to the running support 7, the doctor 5 for removing excess paint held by the gravure roll 4, and the support 7 together with the gravure roll 4.
And a back roll 6 for pressing the support 7 against the gravure roll 4. Support 7 to which paint 2 is transferred
Is sent out to a supply reel (not shown) and wound around a take-up reel (not shown), thereby traveling in the direction of arrow S in FIG. The gravure roll 4 and the back roll 6 are arranged between the supply reel and the take-up reel so that the take-up reel can take up the support 7 to which the paint 2 has been applied.

As shown in FIG. 1, the paint tank 3 in which the paint 2 to be applied to the support 7 is stored, as shown in FIG. A liquid paint for forming a back coat layer is stored on a support such as a tape. The lower part of the gravure roll 4 is immersed in the paint tank 3.

The gravure roll 4 for transferring the paint to the support 7 is disposed rotatably about a rotation shaft 12, and is disposed so that the lower side is immersed in the paint 2 in the paint tank 3. The gravure roll 4 is in contact with the traveling support 7 at a position facing the position of the paint tank 3 immersed in the paint 2. The gravure roll 4 is formed slightly wider than the width of the support 7. The gravure roll 4 is driven to rotate about a rotation shaft 12 in a direction indicated by an arrow R in FIG.

On the outer peripheral surface of the gravure roll 4, a paint holding portion 11 for holding the paint 2 when immersed in the paint 2 stored in the paint tank 3 is formed. As shown in FIG. 2, the paint holding unit 11 includes a plurality of cells 8 formed in a matrix. Each cell 8 constituting the paint holding unit 11 is, for example, mechanically engraved or etched.
The gravure roll 4 is formed on the outer peripheral surface so as to form a rectangular concave portion. The opening size and depth of each cell are determined so that the paint 2 can be held in the cell 8, and further determined according to the thickness of the coating film to be formed, the viscosity of the paint, and the like. That is, each cell 8 is formed of a rectangular recess and has a predetermined depth h.
Is formed around the recess having the concave portion 9 serving as a peripheral wall of the recess.

When a pattern is printed on an ink ribbon, for example, the paint holding section 11 is formed on a part of the outer peripheral surface of the gravure roll corresponding to the area to be coated with the paint. Is applied over the entire outer peripheral surface of the gravure roll.

As shown in FIG. 3, each of the rectangular cells 8 constituting the coating material holding unit 11 is located at the center of the cells 8 arranged in the direction of arrow B in FIG. The straight line L1 connecting the portions O ₁ and O ₂ and the straight line L2 extending in the direction of the arrow A in FIG. 3 which is the direction of the rotation axis of the gravure roll 4 are arranged so that the angle θ ₁ is 90 ± 10 °. Further, a rectangular cell 8 constituting the paint holding unit 11 is provided.
Is formed so that the angle θ ₂ formed between the facing edge portion 10 of the cells 8 arranged in the direction of arrow B in FIG. 3 and the straight line L 3 orthogonal to the rotation axis 12 of the gravure roll 4 is 90 ° ± 10 °. Have been. That is, the paint holding portion 11 is formed such that the length W ₁ of the facing edge portion 10 of the cells 8 arranged in the direction of arrow B in FIG. 3 is substantially the same as the width W ₂ of each cell 8. Thereby, when the paint 2 is pulled out from each cell 8, the paint 2 forms a stable meniscus. Therefore, the paint 2 transferred from each cell 8 is naturally fused and integrated, and the leveling is performed well, so that the coating film 14 formed on the support 7 is continuous in the rotation direction of the gravure roll 4. This facilitates the transfer of the coating material 2 to the support 7. In addition, the coating material holding part 11 formed in a matrix form is provided with a fixed width of 90 ° ± 10 ° at the angles θ ₁ and θ ₂ , thereby preventing moire at the time of plate making, and forming the support 7. The occurrence of thin coating unevenness in the longitudinal direction is prevented.

Hereinafter, the angle θ ₂ formed between the facing edge portion 10 between the cells 8 adjacent to each other in the rotation direction B and a straight line L 3 orthogonal to the rotation axis 12 of the gravure roll 4 is referred to as a “screen angle”. That is, the plurality of cells 8 shown in FIG.
The screen angle is formed to be 90 degrees.

A doctor 5 for removing excess paint 2 adhering to the surface of the gravure roll 4 is pressed against the gravure roll 4 just before the position where the paint 2 is transferred to the support 7. The doctor 5 has a width substantially equal to the width of the outer peripheral surface of the gravure roll 4 in order to scrape off excess paint adhered to the outer peripheral surface of the gravure roll 4. The tip of the doctor 5 is pressed against the outer peripheral surface of the gravure roll 4, and when the gravure roll 4 is rotated, of the paint 2 adhered to the surface of the gravure roll 4, the extra The paint 2 is scraped off. As a result, the excess paint 2 is removed from the gravure roll 4, the paint 2 is retained only in the cell 8, and the paint 2 can be transferred to the support 7 in an accurate pattern.

At the position where the gravure roll 4 and the support 7 are in contact with each other, the back roll 6 that presses the support 7 against the gravure roll 4 prevents the support 7 that slides on the gravure roll 4 from floating from the gravure roll 4. It is disposed so as to be rotatable about the rotation shaft 13. The back roll 6 is provided at a position facing the gravure roll 4 and at a position facing the gravure roll 4 with the support 7 interposed therebetween. The back roll 6 is the gravure roll 4 shown in FIG.
When rotated in the direction indicated by the middle arrow R, the support 7 rotates in the direction indicated by the arrow r in FIG. That is, the back roll 6 sandwiches the support 7 with the gravure roll 4 and presses the support 7 to prevent the support 7 from floating.
The paint 2 held in the paint holding unit 11 can be transferred to the support 7 reliably.

Next, the operation of the gravure coating apparatus 1 will be described. The support 7 to which the coating material 2 is applied is unreeled from a supply reel (not shown), and is wound around a take-up reel provided on the downstream side, and travels in the direction of arrow S in FIG. And it is sandwiched between the gravure roll 4 and the back roll 6 provided between the supply reel and the take-up reel.

At this time, the paint tank 3 contains the paint 2 enough to immerse at least a part of the peripheral surface of the gravure roll 4. Then, the gravure roll 4 is driven to rotate in the direction of the arrow R in FIG. 1 which is the feed direction of the support 7 while the lower part of the gravure roll 4 is immersed in the paint 2 of the paint tank 3. Thus, the paint 2 in the paint tank 3 is held in the paint holding unit 11 of the gravure roll 4 pulled up from the paint 2. When the gravure roll 4 rotates in the direction indicated by the arrow R in FIG.
The support 7 rotates in the direction shown by the middle arrow r, and
The vehicle travels continuously in the direction indicated by.

In front of the position where the coating material 2 is transferred to the support 7, the doctor 5 scrapes off only the coating material 2 attached to the dent portion 9 from the coating material 2 attached to the outer peripheral surface of the gravure roll 4. The paint 2 is held only in the cell 8. Therefore, the gravure roll 4 can transfer the paint 2 to the support 7 reliably.

Then, the paint holding section 11 holding the paint 2
Contacts the support 7, and transfers the paint 2 held by the paint holding unit 11 to the support 7. At this time, since the support 7 is sandwiched between the back roll 6 and the gravure roll 4, the support 7 rises from the gravure roll 4 at a position where the paint 2 held by the paint holding unit 11 is transferred to the support 7. This prevents the paint 2 from being reliably transferred onto the support 7.

As shown in FIG. 3, each of the rectangular cells 8 constituting the coating material holding portion 11 has a central portion O of the cells 8 arranged in the direction of arrow B in FIG. _1, the angle theta ₁ between the straight line L2 extending in FIG. 3 in the arrow a direction, which is the rotation axis direction of the straight line L1 and the gravure roll 4 connecting the O ₂ are arranged so as to be 90 ± 10 °. In addition, the rectangular cell 8 constituting the paint holding unit 11 is the same as that in FIG.
A straight line L3 orthogonal to the edge 10 facing the cells 8 arranged in the direction of the middle arrow B and the rotation axis 12 of the gravure roll 4
Angle theta ₂ between are formed so as to be 90 ° ± 10 °. That is, the paint holding portion 11 is formed such that the length W ₁ of the facing edge portion 10 of the cells 8 arranged in the direction of arrow B in FIG. 3 is substantially the same as the width W ₂ of each cell 8. Thereby, when the paint 2 is pulled out from the cell 8, the paint 2
Forms a stable meniscus. Therefore, each cell 8
The coatings 2 transferred from the base material are naturally fused and integrated, and the leveling is performed favorably, so that the coating film 14 formed on the support 7 is easily continuous in the rotation direction of the gravure roll 4, 2 is better transferred to the support 7.
That is, the coating material 2 transferred onto the support 7 is surely leveled, and the gravure coating apparatus 1 can reliably form the continuous coating film 14. Further, in the gravure coating apparatus 1, as described above, the coating film 14 that is continuous in the direction of the arrow B in FIG. 3, which is the rotation direction of the gravure roll 4, can be reliably formed. You can run. That is, in the gravure coating apparatus 1, a continuous coating film 14 can be reliably formed even on the support 7 traveling at high speed.

At this time, the viscosity of the coating material 2 is preferably 20 to 130 cps as measured using a B-type viscometer. As described above, when the paint viscosity is set to a low value, the leveling on the support 7 is particularly good. Therefore, by setting the viscosity of the coating material within the above-described range, it is possible to form the coating film 14 having a uniform film thickness, which is reliably leveled. Further, in the gravure coating apparatus 1, as described above, the low-viscosity paint 2
The coating material 2 can be applied to the support 7 traveling at a higher speed.

Further, when the low-viscosity paint as described above is used as the paint 2, the paint 2 is held in the cell 8 having a small opening size as compared with the case where a high-viscosity paint is used. Cheap. In other words, the low-viscosity paint is securely held even in the cell 8 having a small opening size. Therefore, by setting the viscosity of the coating material 2 within the above-described range, the coating film 14 can be formed without occurrence of coating loss.

When the low-viscosity paint 2 is used, the paint 2 transferred onto the support 7 is easily leveled as described above. For this reason, in the gravure coating apparatus 1, it is not necessary to form concave grooves arranged in the rotation direction between the plurality of cells 8. That is, in the gravure coating apparatus 1, the plurality of cells 8 formed on the peripheral surface of the gravure roll 4 are discontinuous with each other and formed as recesses independent of each other. 8 can be easily formed.

Incidentally, each cell 8 constituting the paint holding section 11 is formed by etching. Etching is
Generally, high-precision processing is more difficult than mechanical engraving. For this reason, when a groove or the like for connecting the plurality of cells 8 in the rotation direction is formed by etching as in the related art, there is a disadvantage that the groove width becomes relatively large. However, in the gravure coating apparatus 1, since it is not necessary to form the concave grooves as described above, each cell can be easily formed by etching, and the productivity is improved as compared with the case of forming by mechanical engraving. can do.

Further, when the cell 8 is formed by etching, compared with a cell formed by mechanical engraving, for example,
The capacity of the cell 8 can be increased. That is, as compared with the mechanical engraving, the etching is performed in the cell 8 shown by h in FIG.
Cell 8 having a large depth can be easily formed.
As described above, by increasing the volume of the cell 8, a large amount of the paint 2 can be held in the cell 8. Therefore, this gravure coating apparatus can also form the coating film 14 thick by forming the cells 8 by etching.

On the other hand, the gravure coating apparatus according to the present invention
The gravure roll 4 having the cells 8 as shown in FIG. 4 is not limited to the one having a plurality of cells as shown in FIG. 2, for example. That is, in the gravure roll 4 shown in FIG. 4, the screen angle is 80 degrees. As described above, by setting the screen angle of the plurality of cells 8 from 90 degrees shown in FIG. 3 to 80 degrees shown in FIG. 4, moire during plate making can be prevented, and thin coating unevenness in the longitudinal direction can be prevented. Can be prevented from occurring.

Further, in the gravure coating apparatus 1 according to the present invention, the shape of the cell 8 is not limited to a shape formed as a concave portion having a substantially rectangular opening as described above. For example, as shown in FIG. Alternatively, it may be formed in a so-called honeycomb shape. The concave portion of the gravure roll 4 shown in FIG. 5 has a substantially hexagonal shape, and the concave portion has a plurality of cells 20 formed as concave portions having a predetermined depth according to the thickness of the coating film to be formed, the viscosity of the paint, and the like. The plurality of cells 20 are the rotation axis direction of the gravure roll 4 and the straight line L6 connecting the centers O ₁ and O ₂ of the cells 20 arranged in the arrow B direction in FIG. the axis L4 extending in a direction of arrow a the angle theta ₄ is formed to be 90 ± 10 °. In addition, the plurality of cells 20 are formed in an application direction, that is, an angle between an edge 21 facing between the cells 20 arranged in the direction of arrow B in FIG. theta ₃ is formed to be 90 ± 10 °. That is, the screen angle of the plurality of cells 20 is 90 ± 10 °. Thus, the substantially hexagonal on the corner opposite to the length W ₃ of Kakuma because it is formed so as to approach the width W ₄ of the cell 20, the support member 7 even when caused to travel at high speed, the support In the transition part 7, paint 2
Can stabilize the meniscus. Therefore, the paint 2 transferred from each cell 8 is naturally fused and integrated, and the leveling is performed well, so that the coating film 14 formed on the support 7 is continuous in the rotation direction of the gravure roll 4. This facilitates the transfer of the coating material 2 to the support 7. Therefore, according to the gravure coating apparatus 1,
The continuous coating film 14 can be reliably formed.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the gravure coating apparatus as described above will be described below together with experimental examples.

<Experimental Example 1> In Experimental Example 1, an ink ribbon paint having the following composition was used as the paint. Further, the paint application section 11 was formed on a part of the outer peripheral surface of the gravure roll 4 corresponding to the application area of the support 7, and pattern printing was performed.

<Ink ribbon coating composition> Dye (styryl dye) 5 parts by weight Polyvinyl butyral 5 parts by weight Methyl ethyl ketone 45 parts by weight Toluene 45 parts by weight In Example 1, the ink ribbon coating composition having the above-described composition was used. With a diluent solvent consisting of 50 parts by weight of methyl ethyl ketone and 50 parts by weight of toluene,
Dilute to 0 cps.

As a support, polyethylene terephthalate (hereinafter, referred to as PET) having a thickness of 4.5 μm is used.
It was used.

In Experimental Example 1, the ink ribbon paint described above was applied on PET. At this time, the coating speed is 100 m / min and 200 m / min.
And two types.

Experimental Example 2 In Experimental Example 2, an ink ribbon paint having the following composition was used as the paint. Further, the paint holding unit 11 was formed on a part of the outer peripheral surface of the gravure roll 4 corresponding to the application area of the support 7 and pattern printing was performed.

<Coating Composition for Ink Ribbon> 100 parts by weight of polymethyl methacrylate 10 parts by weight of ultraviolet absorber (trade name: Seesorb 702, manufactured by Cipro Kasei Co., Ltd.) 200 parts by weight of methyl ethyl ketone 200 parts by weight of toluene The ink ribbon paint having the composition described above was diluted with a solvent consisting of 50 parts by weight of methyl ethyl ketone and 50 parts by weight of toluene to have a paint viscosity of 6 parts.
Dilute to 0 cps.

As a support, a PET having a thickness of 4.5 μm was used.

In Experimental Example 2, the ink ribbon paint as described above was applied on PET. At this time, the coating speed is 100 m / min and 150 m / min.
And two types.

<Experimental Example 3> In Experimental Example 3, a paint for a back coat of a magnetic tape having the following composition was used as the paint. Further, the paint holding unit 11 was formed over the entire outer peripheral surface of the gravure roll 4 corresponding to the application area of the support 7, and the back coat layer was coated.

<Coating composition for back coat> Carbon black 40 parts by weight Polyurethane 50 parts by weight Nitrocellulose 20 parts by weight Polyisocyanate 4 parts by weight Methyl ethyl ketone 300 parts by weight Toluene 200 parts by weight Cyclohexanone 150 parts by weight A backcoat paint having a suitable composition was diluted with a diluting solvent having the same solvent ratio as the paint composition so that the paint viscosity was 30 cps / 20 ° C.

Further, as a sheet-like substrate, a thickness of 4.5 μm was used.
m PET film was used.

In Experimental Example 3, the above-mentioned coating material for a back coat was applied on a PET film. At this time, the application speed was 200 m / min.

With respect to Experimental Examples 1 to 3 described above, coating films 14 were formed as in Examples 1 to 6 and Comparative Examples 1 to 12.

Example 1 In Example 1, as shown in FIG.
The center O of the cells 8 arranged in the direction of the arrow B which is the rotation direction of
_An angle θ ₁ formed by a straight line L 1 connecting the lines O ₁ and O ₂ and a straight line L ₂ extending in the direction of the arrow A which is the rotation axis direction of the gravure roll 4 is 9
0 °, and the screen angle θ ₂ is 90 °.
A gravure roll having a substantially rectangular cell shape was used. In this gravure roll, the number of cells arranged in the rotation direction is 150 lines / inch, the depth h of the cells 8 is 25 μm, and the width of the warp portion 9 is 10 μm.

In the following Examples 2 to 6, Comparative Examples 1 to 3, Comparative Examples 5 to 7, and Comparative Examples 9 to 11, the cells are formed in a matrix. Therefore, the straight line L1 connecting the central portions O ₁ and O ₂ of the cells 8 arranged in the direction of arrow B in FIG. 3 which is the direction of rotation of the gravure roll 4 and the arrow A which is the direction of the rotation axis of the gravure roll 4
The angle theta ₁ between the straight line L2 extending in the direction the same angle and the straight line L3 perpendicular to the the angle theta ₂ with respect to the rotation axis 12 and the edge 10 facing the cells 8 arranged in the rotation direction of the gravure roll 4 Becomes Accordingly, hereinafter, when describing the inclination of the paint holding unit 11, only the screen angle will be described.

Example 2 In Example 2, as shown in FIG. 4, a coating film 14 was formed in the same manner as in Example 1 except that the screen angle θ ₂ of the cell 8 was 80 degrees.

Comparative Example 1 In Comparative Example 1, a coating film 14 was formed in the same manner as in Example 1 except that the screen angle θ ₂ of the cell 8 was 75 degrees, as shown in FIG.

Comparative Example 2 In Comparative Example 2, as shown in FIG. 7, a coating film 14 was formed in the same manner as in Example 1 except that the screen angle θ ₂ of the cell 8 was changed to 60 degrees.

Comparative Example 3 In Comparative Example 3, as shown in FIG. 8, a coating film 14 was formed in the same manner as in Example 1 except that the screen angle θ ₂ of the cell 8 was 45 degrees.

Comparative Example 4 In Comparative Example 4, as shown in FIG. 9, cells 8 arranged in a matrix on a gravure roll 4 were arranged shifted in the direction of the rotation axis. Here, a straight line L7 connecting the central portions O ₁ and O ₂ of the cells 8 arranged in the direction of arrow B which is the direction of rotation of the gravure roll 4 and a straight line L8 extending in the direction of arrow A which is the direction of the rotation axis of the gravure roll 4 are formed. except that angle theta ₅ was a 45 ° was formed in the same manner as coating 14 as in example 1. At this time, the screen angle of the cell 8 was 90 degrees.

Embodiment 3 In Embodiment 3, as shown in FIG.
₂ was 90 degrees, and a gravure roll having a substantially rectangular cell shape was used. In this gravure roll,
The number of cells arranged in the rotation direction is 133 lines / inch
The depth h of the cell 8 is 60 μm, and the width of the bent portion 9 is 15 μm.

Example 4 In Example 4, as shown in FIG. 4, a coating film 14 was formed in the same manner as in Example 3, except that the screen angle of the cell 8 was changed to 80 degrees.

Comparative Example 5 In Comparative Example 5, as shown in FIG. 6, a coating film 14 was formed in the same manner as in Example 3 except that the screen angle θ ₂ of the cell 8 was 75 degrees.

Comparative Example 6 In Comparative Example 6, as shown in FIG. 7, a coating film 14 was formed in the same manner as in Example 3 except that the screen angle θ ₂ of the cell 8 was changed to 60 degrees.

Comparative Example 7 In Comparative Example 7, as shown in FIG. 8, a coating film 14 was formed in the same manner as in Example 3 except that the screen angle θ ₂ of the cell 8 was 45 degrees.

Comparative Example 8 In Comparative Example 8, as shown in FIG. 9, cells 8 arranged in a matrix on a gravure roll 4 were arranged shifted in the direction of the rotation axis. Here, a straight line L7 connecting the central portions O ₁ and O ₂ of the cells 8 arranged in the direction of arrow B which is the direction of rotation of the gravure roll 4 and a straight line L8 extending in the direction of arrow A which is the direction of the rotation axis of the gravure roll 4 are formed. except that angle theta ₅ was a 45 ° was formed in the same manner as coating 14 of example 3. At this time, the screen angle of the cell 8 was 90 degrees.

Embodiment 5 In Embodiment 5, as shown in FIG.
₂ was 90 degrees, and a gravure roll having a substantially rectangular cell shape was used. In this gravure roll,
The number of cells arranged in the rotation direction is 200 lines / inch
The depth h of the cell 8 is 20 μm, and the width of the bent portion 9 is 10 μm.

Example 6 In Example 6, as shown in FIG. 4, a coating film 14 was formed in the same manner as in Example 5, except that the screen angle of the cell 8 was changed to 80 degrees.

Comparative Example 9 In Comparative Example 9, as shown in FIG. 6, a coating film 14 was formed in the same manner as in Example 5 except that the screen angle θ ₂ of the cell 8 was changed to 75 degrees.

Comparative Example 10 In Comparative Example 10, as shown in FIG. 7, a coating film 14 was formed in the same manner as in Example 5 except that the screen angle θ ₂ of the cell 8 was changed to 60 degrees.

Comparative Example 11 In Comparative Example 11, as shown in FIG. 8, a coating film 14 was formed in the same manner as in Example 5, except that the screen angle θ ₂ of the cell 8 was 45 degrees.

Comparative Example 12 In Comparative Example 12, as shown in FIG.
The cells 8 arranged in a matrix on the top were shifted in the rotation axis direction. Here, a straight line L7 connecting the central portions O ₁ and O ₂ of the cells 8 arranged in the direction of the arrow B which is the direction of rotation of the gravure roll 4 and the arrow A which is the direction of the rotation axis of the gravure roll 4
Except that the angle theta ₅ and the straight line L8 extending direction is 45 ° was formed in the same manner as coating 14 of Example 5. At this time, the screen angle θ ₂ of the cell 8 was 90 degrees.

<Evaluation of Coating Film> The coating film 14 formed in Examples 1 to 6 and Comparative Examples 1 to 12 as described above.
The coating film was evaluated by visually observing the presence or absence of coating loss. In this coating film evaluation, the case where coating defects such as coating unevenness occurred was evaluated as x, and the case where a uniform coating film 14 was formed was evaluated as ○. Table 1 shows the results.

[0072]

[Table 1]

As is evident from Table 1, in Examples 1 and 2, the coating film 14 was uniformly formed even at a high-speed coating speed of 200 m / min, and good visual observation with no paint-through portion was observed. The results are shown. On the other hand, in Comparative Examples 1 to 4, coating unevenness occurred during high-speed coating, and a good coating film 14 could not be formed. That is, the screen angle is set to 45
As the temperature was approached from 90 ° to 90 °, a uniform coating film 14 with no paint-through was able to be formed even in high-speed coating.

Further, as shown in Experimental Example 2, Example 3
And, in Example 4, the coating film 14 is formed even when the coating film 14 is formed thickly, and the coating film 14 is formed even when the coating speed is as high as 150 m / min.
Good visual observation results with no painted-out spots were shown. In contrast, in Comparative Examples 5 to 8, it became clear that it was difficult to apply a thick film uniformly regardless of the application speed. That is, also in this case, as the screen angle was reduced from 45 ° to 90 ° in the related art, a uniform coating film 14 with no paint-through was able to be formed even in high-speed coating.

Further, as shown in Experimental Example 3, Example 5
And, in Example 6, even when the coating film 14 was formed thin by high-speed coating at 200 m / min, the coating film 14 was formed uniformly, and good visual observation results with no missing portions were shown. On the other hand, in Comparative Examples 9 to 12, it was found that it was difficult to form a good thin film 14. That is, even when the coating film 14 is formed thin,
As the screen angle was reduced from the conventional 45 ° to 90 °, it was possible to form a uniform coating film 14 with no erosion.

From the experimental examples 1 to 3, according to the gravure coating apparatus and the gravure coating method according to the present invention, the coating film 14 having a desired film thickness can be formed at a high speed.

[0077]

As described above in detail, according to the present invention, since the coating film is formed using the gravure roll having cells formed at predetermined positions, the coating film is transferred onto the support. The meniscus of the paint can be stabilized, and the paint transferred onto the support can be easily continued in the application direction. Therefore, the gravure coating apparatus according to the present invention can form a uniform coating film even when the coating speed is improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining a basic configuration of a gravure coating apparatus according to the present invention.

FIG. 2 is a cross-sectional perspective view of a main part of a paint holding unit formed on a gravure roll.

FIG. 3 is a plan view of a main part of a paint holding unit in which a screen angle of a cell is 90 °.

FIG. 4 is a plan view of a main part of a paint holding unit in which a screen angle of a cell is 80 °.

FIG. 5 is a plan view of a main part of a paint holding unit in which cells are formed in a honeycomb shape.

FIG. 6 is a plan view of a main part of a paint holding unit having a screen angle of 75 °.

FIG. 7 is a plan view of a main part of a paint holding unit having a screen angle of 60 °.

FIG. 8 is a plan view of a main part of a paint holding unit having a screen angle of 45 °.

FIG. 9 is a plan view of a main part of a paint holding unit in which cells arranged in a matrix on a gravure roll are arranged shifted in the direction of the rotation axis.

[Explanation of symbols]

1 Gravure coating device, 2 paints, 3 paint tanks, 4 gravure rolls, 5 doctors, 6 back rolls, 7 supports, 8 cells, 9 dents, 10 edges, 11 paint holding units, 12 gravure roll rotation axes, 13 Back roll rotation shaft, 14 coatings, 20 honeycomb cells, 21 edges

Claims (9)

[Claims] 1. A gravure roll having a paint holding portion made up of a plurality of cells for holding a paint on a surface, wherein the gravure roll is rotated to continuously run the paint held by the paint holding portion. In a gravure coating apparatus that forms a coating film by transferring the coating onto a support, the paint holding unit is configured such that an angle formed between a straight line connecting the centers of cells arranged in the rotation direction of the gravure roll and the rotation axis of the gravure roll. 90 ° ± 10 ° is formed in a range of 90 ° ± 10 °, and an angle formed by a facing edge between cells arranged in the rotation direction of the gravure roll and a straight line orthogonal to the rotation axis of the gravure roll is 90 ° ± 10 °. A gravure coating apparatus formed in a range. 2. The gravure coating apparatus according to claim 1, wherein the cells of the paint holding section are discontinuous with each other. 3. The gravure coating apparatus according to claim 1, wherein said coating material holding portion is formed on an outer peripheral surface of said gravure roll corresponding to a region where coating material is coated on said support. . 4. The gravure coating apparatus according to claim 1, wherein said coating material holding portion is formed on the entire outer peripheral surface of said gravure roll. 5. A gravure roll having a paint holding portion made up of a plurality of cells for holding a paint on the surface, wherein the gravure roll is rotated to continuously run the paint held by the paint holding portion. In the gravure coating method of forming a coating film by transferring onto a support to be performed, the paint holding portion, the angle between a straight line connecting the centers of the cells arranged in the rotation direction of the gravure roll and the rotation axis of the gravure roll. Formed within the range of 90 ° ± 10 °,
An angle formed by a facing edge between cells arranged in the rotation direction of the gravure roll and a straight line perpendicular to the rotation axis of the gravure roll was formed in a range of 90 ° ± 10 °, and the paint holding portion was formed. A gravure coating method, wherein a coating film is formed using a gravure roll. 6. The gravure coating method according to claim 5, wherein said coating material holding portion is formed on an outer peripheral surface of the gravure roll so as to correspond to a region where the coating material is coated on said support. 7. The gravure coating method according to claim 5, wherein said coating material holding portion is formed over the entire outer peripheral surface of the gravure roll. 8. The gravure coating method according to claim 5, wherein the plurality of cells are formed by etching. 9. The viscosity of the paint is 20 to 130 cps.
The gravure coating method according to claim 5, wherein