JP2024033330A - Flexographic plate and manufacturing method of the same, and heat cut device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexographic plate which is lightweight, and is easy to be along a roller and prevents occurrence of printing contamination, and a manufacturing method and a manufacturing device of the same.

SOLUTION: A manufacturing method of a flexographic plate includes: a curing step of irradiating a photosensitive resin layer on a substrate through a mask with light; a cleaning step of cleaning the photosensitive resin layer after the curing step, and removing the uncured photosensitive resin layer; a cut step of providing a recess for separating a first photosensitive resin layer including a print part and a second photosensitive resin layer including no print part on the photosensitive resin layer, after the cleaning step; and a removal step of removing the second photosensitive resin layer from the substrate, after the cut step.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a flexo plate, its manufacturing (plate making) method, and a heat cut device. In particular, the present invention relates to a flexographic plate in which unnecessary parts are removed from a flexographic plate, and a method and apparatus for manufacturing the same.

As a method of printing on cardboard or the like, there is a printing technique using a flexo plate (Patent Document 1). For flexo printing, the flexo printing plate is set on rollers. Using the rotation of the rollers, ink is placed on the convex surface of the flexo plate and transferred to the cardboard. If you have a flexo plate, you can print easily.
When setting the flexo plate on the plate cylinder (roller), it is necessary to attach one end to the PET base material with double-sided tape. After that, the PET substrate is set on the roller.

Japanese Patent Application Publication No. 2004-268291

However, when setting a flexographic plate on a roller, a thick flexographic plate with a thickness of 7 mm or 5 mm to 2.84 mm is used, so the flexographic plate becomes heavy and difficult to follow the roller.
Further, since the difference in unevenness (relief depth) is 2.5 mm to 1.0 mm, ink adheres to parts of the flexo plate that should not be printed, resulting in printing stains.
Therefore, an object of the invention of the present application is to provide a flexo plate that is lightweight, easily follows the rollers, and does not cause printing stains, a method for manufacturing the same (plate making), and a heat cutting device.

In order to solve the above problems, a curing step of irradiating light onto the photosensitive resin layer on the substrate through a mask,
After the curing step, a cutting step of providing the photosensitive resin layer with a cutting portion for separating a first photosensitive resin layer including a printed portion and a second photosensitive resin layer not including the printed portion; and after the cutting step. , a removing step of removing the second photosensitive resin layer that does not include the printed portion from the substrate;
A cleaning step for cleaning and removing the uncured photosensitive resin layer, a drying step, a post-exposure step for curing the entire photosensitive resin layer, and a surface treatment step for preventing the photosensitive resin from becoming sticky. A flexographic plate manufacturing (plate making) method is used.

In addition, a stage for mounting photosensitive resin for flexo printing on the substrate,
a first head portion having a cut portion that heat-cuts the photosensitive resin layer;
a second head section having a processing section for processing the substrate;
A heat cutting device is used that includes a moving section that can change the position of a stage relative to the first head section and the second head section.

Furthermore, a substrate,
a photosensitive resin layer on the substrate,
A plurality of the photosensitive resin layers exist separately,
For each of the photosensitive resin layers, a flexographic printing plate is used in which the periphery is tapered and the corner portions are rounded.

According to the present invention, it is possible to provide a flexo plate that is lightweight, easily follows the rollers, and does not cause printing stains.

(a) Cross-sectional view of the flexo plate unit of the embodiment, (b) Plan view of the flexo plate unit of the first embodiment Cross-sectional view of a printing device using the flexo plate unit of Embodiment 1 (a) to (c) Cross-sectional views illustrating the method of assembling the flexo plate unit according to the embodiment (a) to (f) Cross-sectional views illustrating the manufacturing method of the flexo plate according to the embodiment (a) to (b) Diagrams explaining the cutting part of the flexo plate manufacturing method according to the embodiment (a) Perspective view of the flexo plate of the embodiment, (b) Enlarged plan view of the flexo plate of the embodiment, (c) Cross-sectional view of the flexo plate of the embodiment (a) to (b) Diagrams illustrating alignment marks in plan views of the substrate according to the embodiment, (c) to (d) Cross-sectional views when forming recesses in the photosensitive resin at the cut portions according to the embodiment (a) to (b) Diagrams explaining the heat cut device of the embodiment (a) to (b) Diagrams explaining the photosensitive resin layer of the embodiment

The present invention will be described below using embodiments, but the invention is not limited thereto.
(Embodiment)
First, the technology of flexo printing will be explained. The following is an example, and the scope of rights is not limited.

<Flexo printing>
FIG. 1(a) is a cross-sectional view of the flexo plate unit 200 according to the first embodiment. FIG. 1(b) is a plan view of the flexo plate unit 200.
The flexographic plate 100 has convex portions on its surface. The convex portion is a convex portion that is a pattern for printing characters or patterns. Printing is performed by applying ink to the tip of this convex portion and transferring the ink to the object.
The flexographic plate 100 is adhered to one side of the carrier sheet 12. A fixing portion 11 is bonded to the other surface.

FIG. 2 shows a cross-sectional view of a printing apparatus using this flexo plate unit 200. The flexo plate unit 200 is installed on a cylindrical roll 19. The fixing part 11 is fitted into the recess 13 of the roll 19, and the flexo plate unit 200 is fixed. An ink supply roll 16 that supplies ink to the flexo plate 100 is installed parallel to the roll 19.
On the other hand, below the roll 19, there is a stage 17. The stage 17 holds an object 18 to be printed.
The roll 19 and the ink supply roll 16 rotate, and the stage 17 moves. As a result, the ink is once attached to the flexo plate 100 and then to the object 18.

Note that ink is supplied to the ink supply roll 16 from an ink supply section 20. Ink in the tank 24 is supplied to the doctor chamber 21 by a supply mechanism 23 (for example, a pump). Ink is supplied from the doctor chamber 21 to the ink supply roll 16. Ink is supplied from the doctor chamber 21 as the ink supply roll 16 rotates.

<Assembling the flexo plate unit 200>
A method for assembling the flexo plate unit 200 will be described using cross-sectional views of FIGS. 3(a) to 3(c).
(1) As shown in FIG. 3(a), a carrier sheet 12 having a fixing part 11, a double-sided adhesive tape 22, and a flexographic plate 100 are prepared.

(2) As shown in FIG. 3(b), the flexographic plate 100 and one side of the double-sided adhesive tape 22 are adhered. At this time, the positional relationship between the double-sided adhesive tape 22 and the flexo plate 100 is arbitrary, and alignment is not performed. A double-sided adhesive tape 22 is attached to the entire back surface of the flexo plate 100.

(3) As shown in FIG. 3(c), attach the other side of the double-sided adhesive tape 22 to the carrier sheet 12. At this time, the flexo plate 100 and the carrier sheet 12 are aligned. Alignment marks are on the flexographic plate 100 and are aligned with the marks on the carrier sheet 12. As a result, the flexo plate unit 200 is completed.

<Manufacture of flexo plate 100>
A method for manufacturing (plate making) the flexographic plate 100 will be explained with reference to FIGS. 4(a) to 4(f). The flexographic plate 100 has a photosensitive resin layer 41 on a substrate 42.
In FIG. 4A, a photosensitive resin layer 41 is formed on a substrate 42. In FIG. The substrate 42 is a transparent resin sheet such as PET.
In FIG. 4B, a mask 43 is placed on the surface of the photosensitive resin layer 41 and exposed (irradiated with light). Light is irradiated onto the photosensitive resin layer 41 through the opening of the mask 43 . The portion of the photosensitive resin layer 41 that is irradiated with light is cured. Note that although the exposure was performed through the mask 43, the laser light irradiation may be performed without the mask 43.

In FIG. 4C, a second photosensitive resin layer 41b without a printed portion and a first photosensitive resin layer 41b with a printed portion are separated. Therefore, a recess 49 is provided in the photosensitive resin 41 at the cut portion 48 (FIG. 5(a)). After that, the second photosensitive resin layer 41b is removed. Physically remove the lumps. Remove manually or automatically. The cut portion 48 is heated, and by moving the cut portion 48 within the photosensitive resin layer 41, a recess 49 is formed (heat cut), and the second photosensitive resin layer 41b is removed from the substrate 42.

In FIG. 4(d), the second photosensitive resin layer 41b that does not include the printed portion 45 is excluded. If the second photosensitive resin layer 41b remains, it will be difficult for the flexo plate 100 to follow the roll 19. Furthermore, the flexo plate 100 is heavy, making it difficult to perform operations such as alignment. Further, in the later cleaning process, the second photosensitive resin layer 41b enters the cleaning liquid, making it necessary to frequently perform treatments such as replacing the cleaning liquid. Furthermore, since there are disadvantages such as ink adhesion and poor quality during printing, the area of the second photosensitive resin layer 41b is set as wide as possible and removed.

Note that when the first photosensitive resin layer 41a and the second photosensitive resin layer 41b are not distinguished, they will be described as the photosensitive resin layer 41.
Thereafter, it is cleaned with a cleaning liquid, resulting in the state shown in FIG. 4(e). That is, the printed portion 45 appears and the lower part of the first photosensitive resin 41a remains.
Thereafter, the whole was dried, exposed to light, cured, and surface treated. Specifically, an oxide film is formed on the surface of the photosensitive resin layer 41a by ultraviolet irradiation. This removes surface tackiness, improves ink receptivity, and prevents paper dust from adhering. The result is shown in FIG. 4(f). Except for the step in FIG. 4(f), the process is carried out in a room (environment) in which the entire photosensitive resin layer 41 is not cured.

<Photosensitive resin layer 41>
The material of the photosensitive resin layer 41 may be any material used in the flexo field. It may also be one that is used in other fields.

<Cut part 48>
The cutting portion 48 is, for example, a blade that generates heat, such as a soldering iron. Preferably, the blade is made of a metallic material. A high-temperature blade is moved within the photosensitive resin layer 41 to create a recess 49.
For example, a blade heated to a temperature that can melt the photosensitive resin layer 41 is moved within the photosensitive resin layer 41 and advanced while melting the photosensitive resin layer 41. As a result, a recess 49 is created after the blade moves. The passage portion after movement is made into a recess 49.
The temperature of the blade is, for example, 180 degrees to 250 degrees. The temperature may be around the temperature at which the photosensitive resin layer 41 melts.

The recess 49 is a recess between the first photosensitive resin layer 41a and the second photosensitive resin layer 41b.
Examples of the tip portion of the cut portion 48 are shown in FIGS. 5(a) to 5(b).
FIG. 5A is a cross-sectional view showing how a recess 49 is formed in the photosensitive resin layer 41 by the cut portion 48. As shown in FIG. The cutting part 48 has a blade-like tip 47, and preferably has an R value of 0.2 mm or more. The shape may be a truncated pyramid with a rounded tip. The tip portion 47 moves in contact with the substrate 42 . However, there are similar unevenness 61 on the two side surfaces. This is to reduce the contact surface properties of the molten photosensitive resin layer 41 by providing the unevenness, so that the molten photosensitive resin layer 41 is pushed away and the photosensitive resin layers 41 are prevented from adhering to each other again. . As a result, the recess 49 can be reliably formed. If there were no unevenness 61, the first photosensitive resin 41a and the second photosensitive resin 41b would be thermally fused in a mirror-like state, so that they would be refused and the second photosensitive resin b could be selectively removed. do not have.

FIG. 5(b) is a perspective view of the cut portion 48. It is preferable that the cut portion 48 is shaped like a knife and has a triangular top view (side view) of the tip. The cross section in the horizontal direction may be a polygon such as a quadrangle or a triangle, or may have some curved parts, as long as it has straight parts (planes) at two places. There are unevenness 61 on the two surfaces. Preferably, the unevenness is formed at the same period. It moves in the direction of the surface without the unevenness 61 (arrow direction, Z-axis direction in FIG. 5(a)).
The tip 47 of the blade is preferably rounded so as not to damage the substrate 42. As will be explained below, a tapered portion 71 (see FIG. 6B) is formed in the corner portion 93 of the printed portion 45 (see FIG. 6B) so that the flexo plate 100 can easily fit around the roller 19 when the flexo plate 100 is wound around the roller 19 (plate cylinder). Preferably, (c)) is formed.
The thickness of the blade is 1 to 10 mm, and the depth of the concave shape is approximately 0.5 to 2 mm. The approximate size is 20 mm to 50 mm in length. Note that these are exemplary dimensions.

As another example, a laser or the like may be scanned instead of or together with the blade. Alternatively, the recesses 49 may be formed in the photosensitive resin layer 41 by applying ultrasonic vibration to the blade and heating it.

<Flexo version>
The flexographic plate 100 produced above is shown in FIGS. 6(a) to 6(c).
In FIG. 6A, the second photosensitive resin layer 41b is excluded from the flexographic plate 100, and only the substrate 42 remains. Therefore, the flexographic plate 100 is lightweight, easily follows the roller 19, and does not cause printing stains. The first photosensitive resin layer 41a having the printed portion 45 exists in the form of a plurality of islands. The corner portion 93 has an R shape. The corner portion 93 has an R shape so that the recess can be formed continuously with the blade. Since it has an R shape, it is easy to follow the roll 19 and does not get ink easily.

FIG. 6(b) is an enlarged view. There are no angular areas around the first photosensitive resin layer 41a, and the shape is smooth. The corner portion 93 is an R-shaped portion 72 . The entire circumference is a tapered portion 71, which becomes wider as it approaches the substrate 42. The R value is approximately 10-100 mm.
FIG. 6(c) is a cross-sectional shape taken along the dotted line in FIG. 6(b). The first photosensitive resin layer 41a has a printed portion 45 located at the top, and has a tapered portion 71 around the entire periphery. The corner portion 93 has an R portion 72 . The corner portion 93 has the shape of a part of the side surface of a cone. The inclination of the tapered portion 71 is approximately 20 degrees to 60 degrees with respect to the horizontal direction (angle θ in FIG. 7(d)).

<Dragonfly>
The alignment marks will be described with reference to plan views of the substrate 42 in FIGS. 7(a) and 7(b). There are register marks on the substrate 42. Registration marks are alignment marks. A cross character or the like is displayed on the board 42. Register marks are required when aligning the flexographic plate 100 and the carrier sheet 12 in FIG. 3(c).
In FIG. 7A, the dragonfly has a convex portion 73 (convex shape). Like the printed portion 45, it is formed in a convex shape. The registration mark convex portion 73 is used when fixing the flexographic plate 100 to the carrier sheet 12. Thereafter, the registration mark convex portion 73 is shaved off after alignment. If left on, ink may adhere and cause printing defects.

However, it is time-consuming to scrape off the convex portions, and if you forget to do so, it will result in a printing defect and become the subject of a complaint.
In FIG. 7B, a mark 74 is formed on the substrate 42 without forming the registration mark convex portion 73. In FIG. The mark may be formed into a concave shape using a needle made of tungsten or the like. Alternatively, a through hole may be made. It serves as a mark for alignment.

As a result, the area of the photosensitive resin layer 41 is further reduced, and the flexo plate 100 is lightweight and easily follows the roller 19. There are four marks 74 on the top, bottom, left and right sides of one block of each printed portion 45, and the amount of the first photosensitive resin layer 41a was large, but due to the above, the remaining photosensitive resin layer (first photosensitive resin layer 41a) can be significantly reduced. When the printed portion 45 is small, the amount of the first photosensitive resin layer 41a can be reduced by nearly half, which is revolutionary. As explained above, by reducing the amount of the first photosensitive resin layer 41a, it prevents subsequent cleaning liquid from staining, improves the degree to which the flexo plate 100 follows the roller 19, makes it lighter and easier to handle, and improves printing. It is possible to reduce defects.

The movement of the cutting section 48 will be explained with reference to FIGS. 7(c) and 7(d). FIG. 7(c) is a diagram showing the movement of the cutting section 48 in FIG. 7(b). The movement of the cut portion 48 in order to form the first photosensitive resin layer 41a will be described. FIG. 7(c) shows the movement of the cutting part 48 (blade). FIG. 7(d) The blade moves at an angle of θ degrees (FIG. 7(d)) with respect to the horizontal direction. Proceed while tilting at a certain angle on each side. It rotates while maintaining the inclination at the corner portion 93. The entire circumference of the printed portion 45 is processed in one continuous operation. The angle θ is approximately 20 degrees to 60 degrees. The moving speed of the blade is 10 to 30 mm/min. About 10 min/m ² is preferable.

The flat part of the blade (the surface with the unevenness 61) faces the taper 71 of the first photosensitive resin layer 41a. The blade moves around the first photosensitive resin layer 41a while rotating so that the flat part of the blade (the surface with the unevenness 61) is on the taper 71 side. The blade moves in the direction of the surface without the unevenness 61 of the blade. It continuously moves around one first photosensitive resin layer 41a.

<Manufacturing equipment>
The heat cut device 80 used in the process of FIG. 4(d) will be explained with reference to FIGS. 8(a) and 8(b). That is, this is a device in which a recess 49 is formed between the first photosensitive resin layer 41a and the second photosensitive resin layer 41b by the cut portion 48.
8(a) is a top view of the heat cutting device 80, and FIG. 8(b) is a front view of the heat cutting device 80.

The heat cut device 80 includes a first head section 82a, a second head section 82b, a stage 89, and a control section 81.
The first head section 82a and the second head section 82b can move in one direction along the first moving section 83a. The first moving portion 83a is located in a gate shape.
The stage 89 carries the flexographic plate 100 and moves in one direction (vertical direction) different from the above. The stage 89 is moved by a second moving section 83b located at the bottom.

The second moving section 83b and the first moving section 83a include rails and a drive source, and move the object.
The control unit 81 controls the entire heat cut device 80 . The control unit 81 is a control device, a personal computer, or the like.
The first head part 82a has a rotating part 87 at the lower part, and the cutting part 48 is provided in the rotating part 87. The cutting part 48 can be rotated, tilted, etc. by the rotating part 87.

The second head portion 82b has a processed portion 86. The processing unit 86 forms marks 74 (FIG. 7(b)) on the substrate 42 of the flexo plate 100. These include through holes and dents. The processing portion 86 is a tungsten needle or the like.
Irrespective of the first moving part 83a and the second moving part 83b, the stage 89, the first head 82a, and the second head 82b may have a structure that allows them to move relative to each other.

<Process>
The flexo plate 100 is placed on the stage 89 with the origin positioned in advance at a location indicated by a laser point. Heat the blade.
The first moving section 83a, the second moving section 83b, and the first head section 82a are moved relatively. As a result, the cutting section 48 is operated by the rotating section 87 while moving the flexo plate 100. At this time, the blade is preferably inclined at 20 degrees to 60 degrees with respect to the horizontal direction. This forms the tapered portion 71. In particular, at the corner portion 93 of the printed portion 45, the direction of the blade is changed while maintaining the above-mentioned inclination. The tip of the blade preferably has a rounded shape.
As shown in FIG. 5(a), a recess 49 is provided around the first photosensitive resin layer 41a.

<First photosensitive resin layer 41a>
In the case where there are a plurality of printed portions 45, whether to form one first photosensitive resin layer 41a will be explained with reference to FIGS. 9(a) and 9(b).
In FIG. 9(a), the first photosensitive resin layer 41a is separated. On the other hand, in FIG. 9(b), there is only one first photosensitive resin layer 41a. In principle, when the plurality of printed portions 45 are separated by a printing interval distance of 90 or more, they are separated. If the printing interval distance is less than 90, one first photosensitive resin layer 41a is used. The print interval distance 90 is preferably 12 mm to 15 mm.

However, if a plurality of printed portions 45 are adjacent to each other in the printing direction (rotation direction of roller 19) and two or more colors are printed, even if the printing interval distance is 90 or more, one first photosensitive resin layer 41a do. This stretches because the flexographic plate 100 is bent along the rollers 19 in the printing direction. At this time, the flexographic plate 100 is different for each color. If the elongation of each 100 flexo plates is different, the overlapping colors will shift and the desired color will not be obtained. Therefore, the above conditions are set.
Note that a flat portion with a circumference distance of 91 is provided around the printed portion 45 . Preferably, the circumferential distance 91 is between 5 mm and 7 mm. This portion is an area where the printed portion 45 is not affected by the tapered portion 71. It is also not affected by the formation of the recess 49.

(as a whole)
Although the explanation was given for flexographic printing, it can be applied similarly to letterpress printing.

The flexo plate, its manufacturing method, and heat cut device of the present invention are used in the field of flexo plates. It is also used in the field of letterpress.

10 Pattern section 11 Fixing section 12 Carrier sheet 13 Concave section 16 Ink supply roll 17 Stage 18 Target object 19 Roll 20 Ink supply section 21 Doctor chamber 22 Adhesive layer 23 Supply mechanism 24 Tank 41 Photosensitive resin layer 41a First photosensitive resin layer 41b Second photosensitive resin layer 42 Substrate 43 Mask 44 Cut portion 45 Printed portion 47 Tip 48 Cut portion 49 Recessed portion 61 Unevenness 71 Tapered portion 72 R portion 73 Register mark 74 Mark 80 Heat cut device 90 Distance between prints 91 Peripheral distance 93 Corner portion 100 Flexo plate 200 Flexo plate unit

<Manufacturing equipment>
The heat cut device 80 used in the process of FIG. 4( c ) will be explained with reference to FIGS. 8(a) and 8(b). That is, this is a device in which a recess 49 is formed between the first photosensitive resin layer 41a and the second photosensitive resin layer 41b by the cut portion 48.
8(a) is a top view of the heat cutting device 80, and FIG. 8(b) is a front view of the heat cutting device 80.

Claims (8)

a curing step of irradiating light onto the photosensitive resin layer on the substrate through a mask;
a cleaning step of cleaning and removing the uncured photosensitive resin layer after the curing step;
After the cleaning step, a cutting step of providing the photosensitive resin layer with a recess that separates the first photosensitive resin layer including the printed portion from the second photosensitive resin layer not including the printed portion;
A method for manufacturing a flexo plate, comprising, after the cutting step, a removing step of removing the photosensitive resin layer that does not include the printed portion from the substrate. 2. The method for manufacturing a flexo plate according to claim 1, wherein in the cutting step, the first photosensitive resin layer and the second photosensitive resin layer are separated by a heated blade. 3. The method for manufacturing a flexo plate according to claim 2, wherein the blade has a triangular side surface and a concave portion. 3. The method of manufacturing a flexo plate according to claim 2, wherein the first photosensitive resin layer is smooth all around and tapers more widely as it approaches the substrate. 2. The method of manufacturing a flexographic plate according to claim 1, wherein the substrate around the printed portion has register marks for alignment, and the register marks are provided with through holes or recesses. Whether a plurality of printed portions are combined into one first photosensitive resin layer or a plurality of first photosensitive resin layers is determined by
2. The method for manufacturing a flexographic plate according to claim 1, wherein the plurality of adjacent printed portions exist in the printing direction by the flexographic plate, and when printing in two or more colors, one first photosensitive resin layer is formed. . a stage for mounting a flexographic plate having a photosensitive resin layer for a flexographic plate on a substrate; and a first head unit having a cutting portion for heat-cutting the photosensitive resin layer;
a second head section having a processing section for processing the substrate;
A flexo plate cutting device including: a moving section that can change the position of a stage relative to the first head section and the second head section. A substrate and
a photosensitive resin layer on the substrate,
A plurality of the photosensitive resin layers exist separately,
Each of the photosensitive resin layers has a tapered periphery and a rounded corner portion.