JP4171181B2 - Coating apparatus and coating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating liquid coating method and a coating apparatus, and is particularly suitable for coating a coating liquid on a long and flexible object to be coated, such as a lithographic printing plate support. The present invention relates to a coating apparatus and a coating method that can be used for the above.
[0002]
[Prior art]
Currently, it is widely practiced to form an oxidation protective layer comprising a thin film of an oxygen-impermeable resin such as polyvinyl alcohol on the surface of a photosensitive layer of a lithographic printing original plate to protect the photosensitive layer from oxygen in the air.
[0003]
The oxidation protective layer is usually formed by a discharge slit that discharges a coating liquid mainly composed of the oxygen-impermeable resin solution and a slide surface through which the coating liquid discharged from the discharge slit flows. Generally, a slide bead applicator is provided, which includes a slide bead gies portion and a backing roller that is provided in the vicinity of the tip of the slide bead gies portion and winds the lithographic printing original plate and conveys it in a certain direction. ing.
[0004]
In the slide bead coating apparatus, the lithographic printing plate is transported by the backing roller so that the photosensitive layer faces outward, and the coating solution is discharged from the discharge slit to flow down along the slide surface. The solution was applied by forming a coating solution bridge (coating bead) between the tip of the slide surface and the photosensitive layer surface of the lithographic printing original plate.
[0005]
[Problems to be solved by the invention]
However, in the slide bead coating apparatus, when foreign matter adheres to the backing roller, the foreign matter forms a bridge of the coating liquid between the surface of the backing roller and the slide bead gusset portion, and the surface of the backing roller. There is a problem in that the coating liquid adheres to the surface and at the same time, roller transfer occurs between the backing roller and the lithographic printing original plate.
[0006]
When the roller transfer occurs, a coating solution adheres to the back surface of the lithographic printing original plate to generate a defective product, or the coating solution around the back surface is dried, and it is shaved in a later process to form a wrinkled material. In some cases, the soot-like material is scattered and adheres to the surface of the lithographic printing original plate before or after application of the coating solution, causing a coating failure.
[0007]
When the roller transfer occurs, the slide bead coating device may be stopped. However, the operator monitors the presence / absence of the roller transfer and stops the slide bead coating device when the roller transfer occurs. It is unrealistic to cause the operation to be interrupted.
[0008]
In view of the above-described facts, an object of the present invention is to provide a coating apparatus and a coating method capable of automatically interrupting coating of a coating liquid when the roller transfer occurs.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, a long sheet-like object to be coated is wound around and conveyed in a certain direction, and is disposed close to the backing roller longer than the width of the object to be coated, and the backing roller. By discharging the coating liquid to be applied to the object to be coated in a band shape, by forming a coating liquid bridge between the coating liquid discharged in the band shape and the object to be coated conveyed by the backing roller, Application means for applying the application liquid onto the surface of the object to be applied, and application liquid transfer detection for detecting that the application liquid discharged from the application means adheres to the backing roller surface during application of the application liquid. And the coating liquid transfer detection means detect that the coating liquid adheres to the backing roller surface, the coating means is moved away from the backing roller. Be provided with a withdrawal means for moving the that direction relates to a coating apparatus according to claim.
[0010]
In the coating apparatus, as described above, when roller transfer occurs, the coating liquid transfer detection unit detects the occurrence of the roller transfer, and the separation unit moves in a direction to move the coating unit away from the backing roller. To stop the application of the coating solution.
[0011]
As the application means, for example, in addition to the above-described slide bead Gies, there is a discharge slit that discharges the coating liquid in a strip shape, and an extrusion formed in a roof shape or a substantially wedge shape that reduces toward the discharge slit. Examples include mold injectors.
[0012]
Examples of the coating liquid transfer detection means include an optical detection type coating liquid transfer detection apparatus that optically detects roller transfer in addition to a pressure fluctuation detection apparatus described later. The optical detection type coating liquid transfer detection device can be preferably used for coating a darkly colored coating liquid.
[0013]
As an object to be coated, for example, the surface of an aluminum web is sharpened, and the sharpened surface is anodized as necessary. A lithographic printing original plate in which the surface of the photosensitive layer is matted as necessary, a photographic film base material, a baryta paper for photographic paper, a recording tape base material, a video tape base material, and a floppy disk Examples of the base material include a continuous belt-like body and a flexible base material.
[0014]
As the coating solution, in addition to the above-mentioned oxidation protective layer forming solution, a photosensitive layer forming solution used for forming a photosensitive layer of a lithographic printing plate precursor by coating the surface of the lithographic printing plate support on which the anodized film is formed. A photographic film colloid solution used for forming a photosensitive layer in a photographic film, a photographic paper colloid solution used to form a photographic paper photosensitive layer, a recording tape, a video tape, and Examples thereof include a magnetic layer forming liquid used for forming a magnetic layer of a floppy disk.
[0015]
The invention according to claim 2 is adjacent to the upstream side of the application unit with respect to the conveyance direction of the application object, the inside is formed so as to be able to be depressurized, and is opened close to the backing roller, A pressure reducing chamber having an opening for sucking the coating liquid that has not been applied to the coating object among the coating liquid that has formed the coating liquid bridge, and the coating liquid transfer detecting means is configured to reduce the pressure in the pressure reducing chamber. The present invention relates to a coating apparatus that is a pressure fluctuation detection apparatus that detects fluctuation and detects adhesion of the coating liquid to a backing roller surface.
[0016]
In the coating apparatus, even during the coating of the coating liquid, there is a slight gap between a portion of the backing roller outside the coating object and the decompression chamber, and the clearance from the gap into the decompression chamber. There is a certain amount of outside air. Here, when roller transfer occurs, the width of the gap in the direction along the longitudinal direction of the backing roller is reduced, so that the inside of the decompression chamber is further decompressed and the pressure is lowered. The pressure fluctuation detection device detects roller transfer by detecting a decrease in the pressure.
[0017]
The coating device has a feature that it can reliably detect roller transfer even when a colorless and transparent coating solution such as an oxidation protection layer forming solution is applied.
[0018]
According to a third aspect of the present invention, the pressure fluctuation detecting device measures the pressure in the decompression chamber, and the coating liquid adheres to the surface of the backing roller based on the measurement result in the pressure measuring unit. When the determination unit that determines the presence or absence of the coating and the determination unit determine that the transfer of the coating liquid has occurred on the surface of the backing roller, the coating unit is moved away from the backing roller. The present invention relates to a coating apparatus including a release means control unit that outputs a command to that effect to the release means.
[0019]
Examples of the pressure measuring unit include a pressure sensor that converts a change in pressure into an electrical signal. Examples of the pressure sensor include one that receives pressure by a pressure element such as a Bourdon tube, a bellows, or a diaphragm and converts the pressure into an electric resistance, an interelectrode capacitance, an inductance, or the like. The pressure sensor can be provided in, for example, the inside of a decompression tube that decompresses the decompression chamber, the inner wall surface of the decompression tube, and the inner wall surface of the decompression chamber.
[0020]
According to a fourth aspect of the present invention, the pressure measurement unit is configured to cause the pressure p inside the decompression chamber to be constant at regular intervals. _i (I is a positive integer) is measured and input to the determination unit. ₁ = (P ₁ + P ₂ + P _Three + ... + p _k ) / K, P ₂ = (P ₂ + P _Three + P _Four + ... + p _{k + 1} ) / K, P _Three = (P _Three + P _Four + P _Five + ... + p _{k + 2} ) / K, ..., P _i = (P _i + P _{i + 1} + P _{i + 2} + ... + p _{i + k-1} ) / K, ..., P _n = (P _n + P _{n + 1} + P _{n + 2} + ... + p _{n + k-1} ) / K (where k and n are integers of 2 or more) _i To calculate the average pressure P _i Maximum value P _max And the minimum value P _min And the maximum value P _max And the minimum value P _min When the difference c is greater than or equal to a specific value, the coating apparatus determines that the coating liquid has adhered to the surface of the backing roller.
[0021]
Since the backing roller expands or contracts when the ambient temperature changes, the size of the gap between the backing roller and the decompression chamber also increases / decreases in accordance with the ambient temperature change, and accordingly, the inside of the decompression chamber The pressure also fluctuates.
[0022]
However, in the coating apparatus, since the pressure inside the decompression chamber is measured at a specific time interval and the average value is obtained every specific number of times based on the above formula, the pressure inside the decompression chamber varies. Malfunction does not occur. In addition, the time from the occurrence of roller transfer to the release of the coating means can be shortened.
[0023]
The specific value can be experimentally determined according to the conveyance speed of the object to be coated, the type / viscosity / coating amount of the coating liquid, the dimensions of each part of the coating means in the coating apparatus, and the like.
[0024]
The invention according to claim 5 wraps a long sheet-like object to be wound and conveys it in a fixed direction, and is disposed in the vicinity of the backing roller longer than the width of the object to be coated, By discharging the coating liquid to be applied to the object to be coated in a band shape, by forming a coating liquid bridge between the coating liquid discharged in the band shape and the object to be coated conveyed by the backing roller, An application method for applying the application liquid to the application object using an application apparatus comprising an application means for applying the application liquid to the surface of the object to be applied. In the coating liquid transfer detection process for detecting that the discharged coating liquid has adhered to the backing roller surface, and in the coating liquid transfer detection process, the coating liquid adheres to the backing roller surface. When it is detected with the means with the coating, it relates to a coating method characterized by having a detachment step of moving in a direction away from the backing roll.
[0025]
Also in the application method, when roller transfer occurs, the occurrence of the roller transfer is detected by a change in pressure or the like, and in the separation step, the application means is moved away from the backing roller to interrupt application of the application liquid. To do.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
1. Embodiment 1
The structure of a slide bead type coating apparatus which is an example of the coating apparatus of the present invention is shown in FIGS. FIG. 1 shows an overall configuration of the slide bead type coating apparatus, and FIG. 2 shows an internal structure of the slide bead type coating apparatus.
[0027]
As shown in FIGS. 1 and 2, the slide bead type coating apparatus 100 according to the first embodiment has a planographic printing original web W that is a web of a planographic printing original wrapped around the surface, and the timepiece in FIG. 1 and FIG. 2. The backing roller 2 that rotates around and conveys the lithographic printing original web W along the conveying direction a and the lithographic printing original web W that is wound around the backing roller 2 and conveyed are described in the section of the prior art. The slide bead beamer unit 4 for applying the same oxidation protective layer forming liquid as that of the first embodiment, and the decompression chamber adjacent to the slide bead beamer unit 4 and positioned upstream of the slide bead beamer unit 4 with respect to the transport direction a 6. The lithographic printing original web W and the oxidation protective layer forming liquid are examples of an object to be coated and a coating liquid, respectively, in the present invention.
[0028]
Below the slide bead gieser portion 4, the slide bead giesa portion 4 is disposed between the rails 12 and a pair of parallel rails 12 extending toward the backing roller 2 and moving on the slide bead giesa portion 4. A Giesa unit separation hydraulic cylinder 10 is provided that moves the bead Giesa unit 4 along the rail 12 in a first direction close to the backing roller 2 or in a second direction away from the backing roller 2. The Giesa section release hydraulic cylinder 10 is an example of a release means in the present invention.
[0029]
The Giesa section separation hydraulic cylinder 10 protrudes from a cylindrical hydraulic cylinder 10B fixed in parallel to the rail 12 between the rails 12, and an end surface of the hydraulic cylinder 10B facing the backing roller 2, and is hydraulically driven by the hydraulic cylinder. And a piston 10A that protrudes or retracts from 10B. A propulsive force transmission member 10C that transmits the propulsive force from the Giesa section detachable hydraulic cylinder 10 to the slide bead gussa section 4 is attached to the tip of the piston 10A. 4 is fixed to the bottom surface. Therefore, the slide bead gieser portion 4 moves along the first or second direction as the piston 10A protrudes or retracts from the hydraulic cylinder 10B.
[0030]
The slide bead type coating apparatus 100 has a ball screw that is rotated by a motor or the like in place of the Giesa unit separation hydraulic cylinder 10, and a ball screw type slide that moves the slide bead Giesa unit 4 by the rotation of the ball screw. A bead-gieser detachment device, and an active cam and a driven cam that reciprocates by the rotation of the active cam. A cam-type slide bead gieser detaching device can also be used.
[0031]
The slide bead geisa portion 4 has a substantially rectangular parallelepiped block shape as a whole, and is arranged in parallel to the backing roller 2. And it has the front-end | tip part 4D which protrudes toward the backing roller 2. As shown in FIG. The lower surface of the tip portion 4D is formed in a cylindrical surface shape, and the edge is formed in parallel to the surface of the backing roller 2, that is, the surface around which the lithographic printing original web W is wound. The slide bead Giesa unit 4 is held by the Giesa unit separation hydraulic cylinder 10 so that a gap of 0.1 to 1 mm is formed between the tip 4D and the lithographic printing plate web W during application.
[0032]
A slide surface 4B is formed on the upper surface of the slide bead gieser portion 4 so as to be parallel to the rotation axis of the backing roller 2 and inclined downward toward the tip portion 4D. The discharge slit 4A, which is a slit-like flow path for discharging the oxidation protection layer forming liquid, is opened in parallel to the edge of the tip portion 4D. Inside the slide bead gies portion 4, a solution supply hole 4C which is a bottomed hole communicating with the discharge slit 4A is formed in the horizontal direction. When a plurality of coating layers are formed on the surface of the lithographic printing original web W, a plurality of ejection slits 4A may be provided in parallel with each other.
[0033]
A pair of side plates 4 </ b> E that form the side walls of the decompression chamber 6 are fixed to both end surfaces of the slide bead gieser 4. The portion near the backing roller 2 at the upper edge of the side plate 4E is formed in an arc shape that is recessed downward in accordance with the shape of the surface of the backing roller 2. The size of the gap between the arc-shaped portion of the side plate 4E and the surface of the backing roller 2 at the time of application of the oxidation protection layer forming liquid can be determined as appropriate according to the degree of decompression inside the decompression chamber 6. About 0.1-0.5 mm is preferable and the range of 0.2-0.3 mm is especially preferable.
[0034]
In the solution supply hole 4C, a solution supply pipe 4F for supplying the oxidation protective layer forming liquid discharged from the discharge slit to the slide bead beamer unit 4 passes through one of the side plates 4E and communicates with the solution supply hole 4C. Yes. On the slide surface 4B, a pair of discharge width defining plates 4G for defining the discharge width of the oxidation protective layer forming liquid in the discharge slit 4A is perpendicular to the discharge slit 4A and from both side edges of the lithographic printing original web W. Is also fixed to be located on the outside.
[0035]
As shown in FIGS. 1 and 2, a bottom plate 4 </ b> H that forms the bottom surface of the decompression chamber 6 is fixed to the bottom surface of the slide bead gies unit 4. The bottom plate 4H extends toward the backing roller 2, bends upward at the edge portion, and has a gap of about 0.1 to 0.5 mm between the edge and the surface of the backing roller 2 at the time of application. Is formed.
[0036]
The decompression chamber 6 is formed on the side edge plate 4E and the bottom plate 4H so as to be adjacent to the slide bead beamer portion 4 and below the tip portion 4D. Inside the decompression chamber 6, a bowl-shaped surplus liquid receiver 6 </ b> B that extends from the lower surface of the tip end portion 4 </ b> D toward the backing roller 2 and receives the oxidation protection layer forming liquid flowing down from the edge of the tip end portion D, and surplus A liquid drain pipe 6C for extracting the oxidation protective layer forming liquid collected in the liquid receiver 6B is provided. Further, a pressure reducing pipe 6A for reducing the pressure inside the chamber 6 is provided in the vicinity of the bottom plate 4H. A pressure sensor 8 that measures the pressure inside the decompression chamber 6 is provided inside the decompression pipe 6A. The pressure sensor 8 corresponds to a pressure measurement unit in the coating apparatus of the present invention. At the time of application of the oxidation protective layer forming liquid, the inside of the decompression chamber 6 is decompressed to about 0.5 to 10 cm by a decompression unit such as a vacuum pump or an aspirator connected to the decompression pipe 6A.
[0037]
The pressure sensor 8 is electrically connected to a determination circuit 14 that determines whether or not the coating liquid is transferred on the surface of the backing roller 2 based on the measurement result of the pressure sensor 8. Is electrically connected to a hydraulic cylinder control device 16 for controlling. The determination circuit 14 and the hydraulic cylinder control device 16 correspond to a determination unit and a detachment means control unit in the coating apparatus of the present invention, respectively. For example, a microcomputer and various sequencers can be used as the determination circuit 14, and a microcomputer, a sequencer, an air circuit, a hydraulic circuit, and the like can be used as the hydraulic cylinder control circuit 16.
[0038]
The determination circuit 14 includes a pressure p inside the decompression chamber 6 measured by the pressure sensor 8. _i (Where i is a positive integer) is input at regular time intervals (a seconds).
[0039]
The determination circuit 14 is based on the input pressure value, as shown in FIG.
P ₁ = (P ₁ + P ₂ + P _Three + ... + p _k ) / K,
P ₂ = (P ₂ + P _Three + P _Four + ... + p _{k + 1} ) / K,
P _Three = (P _Three + P _Four + P _Five + ... + p _{k + 2} ) / K, ...
P _i = (P _i + P _{i + 1} + P _{i + 2} + ... + p _{i + k-1} ) / K, ...
P _n = (P _n + P _{n + 1} + P _{n + 2} + ... + p _{n + k-1} ) / K
(However, k and n are integers of 2 or more.)
According to mean pressure P _i To calculate the average pressure P _i Maximum value P _max And the minimum value P _min And the maximum value P _max And the minimum value P _min When the difference c is a specific value, for example, 5 Pascals or more, it is determined that the transfer of the coating liquid has occurred on the surface of the backing roller.
[0040]
In the determination circuit 14, the average pressure P _{n + 1} If it is calculated, it is preferable to discard the pressure data so far because the memory capacity can be reduced.
[0041]
The interval (a second) at which the pressure is input to the determination circuit 14 is preferably in the range of 0.1 to 1 second, and particularly preferably in the range of 0.3 to 0.6 second. Average pressure P _i The interval for calculating (b seconds = a (seconds) × k) is preferably in the range of 2 to 20 seconds, particularly preferably in the range of 3 to 10 seconds. Therefore, k (times) is preferably 2 to 10 times, and more preferably 5 to 10 times. The average pressure P _i Said maximum value P _max And the minimum value P _min It is preferable to set the determination circuit 14 so that it is determined that the roller transfer has occurred when the difference c is 5 Pascals or more. If a, b, and c are set within the above ranges, the gusset section release hydraulic cylinder 10 will not malfunction due to pressure hunting inside the decompression chamber 6, and when roller transfer occurs, it takes 30 seconds at most. Roller transfer can be detected to a certain extent.
[0042]
In the determination circuit 14, the following formula:
P ₁ = (P ₁ + P ₂ + P _Three + ... + p _k ) / K,
P ₂ = (P _{k + 1} + P _{k + 2} + P _{k + 3} + ... + p _2k ) / K,
P _Three = (P _{2k + 1} + P _{2k + 2} + P _{2k + 3} + ... + p _3k ) / K, ...
P _i = (P _i + P _{i + 1} + P _{i + 2} + ... + p _{i + k-1} ) / K, ...
P _n = (P _{nk + 1} + P _{nk + 2} + P _{nk + 3} + ... + p _nk ) / K
(However, k and n are integers of 2 or more.)
According to mean pressure P _i May be calculated. Also in this case, the average pressure P _i Said maximum value P _max And the minimum value P _min What is necessary is just to judge that there was roller transfer when the difference c between and a specific value, for example, 5 Pascals or more.
[0043]
Further, in the determination circuit 14, the pressure p _i Instead of obtaining an average value based on _i Maximum value of p _max And the minimum value p _min For example, when the difference is a specific location, for example, 5 Pascals or more, it may be determined that there is roller transfer.
[0044]
If the determination circuit 14 determines that the roller transfer has occurred, the hydraulic cylinder control issues a command to control the Giesa unit separation hydraulic cylinder 10 so that the slide bead Giesa unit 4 moves along the second direction. Output to the circuit 16.
[0045]
Based on the command, the hydraulic cylinder control circuit 16 operates the Giesa unit separation hydraulic cylinder 10 to move the slide bead Giesa unit 4 along the second direction so that it is separated from the vicinity of the backing roller 2. Note that the slide bead type coating apparatus 100 may be configured such that the backing roller 2 stops at the same time that the slide bead gieser unit 4 is detached from the vicinity of the backing roller 2.
[0046]
The operation of the slide bead type coating apparatus 100 will be described below.
[0047]
First, as shown in FIG. 2, the slide bead Giesa unit 4 is advanced along the first direction by the Giesa unit separation hydraulic cylinder 10 and is held at a first position close to the backing roller 2.
[0048]
Next, the lithographic printing plate web W is wound around the backing roller 2 so that the photosensitive layer of the lithographic printing plate web W is outside, and the backing roller 2 is rotated in the clockwise direction in FIG. Start transporting.
[0049]
Then, the oxidation protective layer forming liquid is supplied to the slide bead geisa section 4 through the solution supply pipe 4F and the solution supply hole 4C and discharged from the discharge slit 4A, and flows down on the slide surface 4B toward the lithographic printing original web W. Between the front end portion 4D and the lithographic printing original web W, the oxidation protection layer forming liquid is crosslinked, that is, a coating bead is formed. When the formation of the coating bead is started, water droplets or the above-mentioned oxidation protective layer forming solution is formed by an appropriate means such as a syringe on the upstream side of the transport direction a from the position where the coating bead is formed on the lithographic printing original web W. It is preferable that the coating bead is reliably and quickly formed.
[0050]
When a coating bead is formed between the front end portion 4D and the lithographic printing original web W and the coating of the oxidation protective layer forming liquid starts, the pressure sensor 8 measures the pressure inside the decompression chamber 6 at regular intervals. The determination circuit 14 determines the presence or absence of roller transfer on the backing roller 2 in accordance with the above procedure.
[0051]
During the coating, a gap of about 0.1 to 0.5 mm is formed between a portion of the backing roller 2 outside the planographic printing original web W and the decompression chamber 6. Accordingly, when the pressure inside the pressure reducing chamber 6 is reduced through the pressure reducing pipe 6A, the outside air flows from the gap and the inside of the pressure reducing chamber 6 is maintained at a substantially constant pressure. _i Is almost constant, and the maximum value P _max Is almost equal to
[0052]
When the roller transfer occurs, the oxidation protective layer forming liquid adheres to the outer side of the lithographic printing original web W in the backing roller 2, so that the width of the gap between the decompression chamber 6 and the backing roller 2 becomes narrower. Finally, the gap disappears. Therefore, since the amount of outside air flowing into the decompression chamber 6 decreases and the pressure decreases, the average pressure P _i Also decreases. Average pressure P _i Maximum value P _max And the minimum value P _min When the difference is 5 Pascals or more, the determination circuit 14 determines that roller transfer has occurred.
[0053]
When the determination circuit 14 detects the occurrence of the roller transfer, as described above, in response to a command from the hydraulic cylinder control device 16, the Giesa section release hydraulic cylinder 10 is operated, and as shown in FIG. Is released to a second position away from the backing roller 2.
[0054]
When the slide bead beamer 4 is retracted to the second position, the coating bead is no longer formed between the tip 4D and the lithographic printing plate web W and the backing roller 2, so that the oxidation protection that has flowed down the slide surface 4B. The film-forming liquid flows around the lower surface of the front end portion 4D of the slide bead beamer 4 and flows into the excess liquid receiver 6B without adhering to the surface of the backing roller 2.
[0055]
In the slide bead type coating apparatus 100, the roller transfer is automatically detected and the slide bead beamer unit 4 is separated from the position at the time of coating, so that the oxidation protective layer forming liquid adheres to the back surface of the lithographic printing original plate W. The occurrence of defective products is minimized. Further, it is not necessary to monitor whether or not the roller transfer is generated by the operator.
[0056]
Further, since the roller transfer is detected based on the pressure change in the decompression chamber 6, the roller transfer can be easily detected even when a colorless and transparent coating solution such as an oxidation protection layer forming solution is applied.
[0057]
Furthermore, the pressure inside the decompression chamber 6 is measured at a constant time interval (a second), an average value is calculated based on the measured value of the pressure, and the difference between the maximum value and the minimum value of the average value is specified. Since it is determined that the roller transfer has occurred when the value exceeds the value, the hunting of the pressure due to the expansion and contraction of the backing roller 2 causes the Giesa section release hydraulic cylinder 10 to malfunction, and the roller transfer occurs. In spite of this, there is no possibility that the slide bead gies portion 4 retracts to the second position and the application is not interrupted.
[0058]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to the range shown by the following examples.
[0059]
(Example 1)
Using the slide bead type coating apparatus 100 shown in FIGS. 1 and 2, a is set to 0.5 seconds, b is set to 5 seconds, and c is set to 6 pascals, and the lithographic printing original web is conveyed at a feeding speed of 470 m / min. Meanwhile, an oxidation protective layer forming solution was applied to the surface of the photosensitive layer of the lithographic printing plate web to cause roller transfer.
[0060]
Twenty seconds after the roller transfer occurred, the slide bead gear 4 separated from the backing roller 2 and moved back to the position shown in FIG. 3, and the application of the oxidation protective layer forming liquid was stopped.
[0061]
Operation continued for 5 days, but no malfunction occurred during that time.
[0062]
(Example 2)
Except that c was set to 1 pascal <c <5 pascal, the oxidation protective layer forming liquid was applied to the surface of the photosensitive layer of the lithographic printing plate web in the same manner as in Example 1. Occurred.
[0063]
(Example 3)
Except that c was set to c> 10 Pascals, an oxidation protective layer forming solution was applied to the surface of the photosensitive layer of the lithographic printing plate web in the same manner as in Example 1 to generate roller transfer. However, there were cases where it was not detected.
[0064]
(Example 4)
Except that a is set to 1.0 second, b is set to 10 seconds, and c is set to 6 Pascals, an oxidation protective layer forming liquid is applied to the surface of the photosensitive layer of the lithographic printing original web in the same manner as in Example 1, and roller transfer is performed. Generated.
[0065]
After 30 seconds from the occurrence of the roller transfer, the slide bead spacer 4 moved away from the backing roller 2 and moved back to the position shown in FIG. 3, and the application of the oxidation protective layer forming liquid was stopped.
[0066]
Operation continued for 5 days, but no malfunction occurred during that time.
[0067]
If the transport speed of the lithographic printing original web, the coating amount of the oxidation protective layer forming liquid, and the dimensions of the respective parts of the slide bead gusset part 4 in the coating apparatus are different, the preferred ranges of a, b, and c are as described above. It may differ from the suitable range of a, b, and c in Examples 1 to 4.
[0068]
【The invention's effect】
As described above, according to the present invention, there is provided a coating apparatus and a coating method capable of automatically stopping coating of a coating liquid when roller transfer occurs.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of an example of a coating apparatus according to the present invention.
FIG. 2 is a schematic cross-sectional view showing the mutual positional relationship of each component of the coating apparatus in the coating apparatus shown in FIG. 1 in a state where an oxidation protective film forming liquid is coated on the lithographic printing original web. FIG.
FIG. 3 shows the mutual positional relationship among the constituent elements of the coating apparatus when the slide bead geeseer is detached from the position during coating in the coating apparatus shown in FIGS. 1 and 2; It is a schematic sectional drawing.
FIG. 4 shows the measurement of the pressure in the vacuum chamber and the average pressure P _i It is explanatory drawing about the method of calculating | requiring (i is an integer of 1-n and n is an integer greater than or equal to 2).
[Explanation of symbols]
2 Backing roller
4 Slide beads
6 Vacuum chamber
8 Pressure sensor
10 Giesa release hydraulic cylinder
14 Judgment circuit
16 Hydraulic cylinder control circuit

Claims (5)

A long sheet-shaped object to be wound is wound and conveyed in a certain direction, and a backing roller longer than the width of the object to be coated;
The coating liquid is disposed in the vicinity of the backing roller and discharges the coating liquid to be applied to the coating object in a band shape, and between the coating object conveyed by the backing roller by the coating liquid discharged in the band shape. Coating means for coating the coating liquid on the surface of the object to be coated by forming a coating liquid bridge on the surface;
During application of the application liquid, application liquid transfer detection means for detecting that the application liquid discharged from the application means has adhered to the surface of the backing roller;
When the coating liquid transfer detection unit detects that the coating liquid has adhered to the surface of the backing roller, the coating liquid transfer detection unit includes a detaching unit that moves the coating unit in a direction away from the backing roller. Coating device. A coating solution that is adjacent to the upstream side of the coating unit with respect to the conveying direction of the coating object, the inside of which is formed to be able to be depressurized, opens close to the backing roller, and forms the coating solution bridge Among them, comprising a vacuum chamber having an opening for sucking what was not applied to the coating object,
The coating apparatus according to claim 1, wherein the coating liquid transfer detection unit is a pressure fluctuation detection device that detects pressure fluctuation in the decompression chamber and detects adhesion of the coating liquid to a backing roller surface. The pressure fluctuation detecting device is
A pressure measuring unit for measuring the pressure in the decompression chamber;
Based on the measurement result in the pressure measurement unit, a determination unit that determines the presence or absence of adhesion of the coating liquid on the backing roller surface;
When the determination unit determines that adhesion of the coating liquid has occurred on the backing roller surface, it outputs a command to the detachment unit to move the application unit away from the backing roller. The coating apparatus according to claim 2, further comprising a release means control unit. The pressure measurement unit measures a pressure p _i (i is a positive integer) inside the decompression chamber at a constant time interval and inputs the pressure p _i to the determination unit,
The determination unit has the following formula:
P ₁ = (p ₁ + p ₂ + p ₃ +... + P _k ) / k,
P ₂ = (p ₂ + p ₃ + p ₄ +... + P _{k + 1} ) / k,
_{P 3 = (p 3 + p} 4 + p 5 + ... + p k + 2) / k, ...
_{P i = (p i + p} i + 1 + p i + 2 + ... + p i + k-1) / k, ...
P _n = (p _n + p _{n + 1} + p _{n + 2} +... + P _{n + k-1} ) / k
(However, k and n are integers of 2 or more.)
The average pressure P _i is calculated according to the following, the maximum value P _max and the minimum value P _{min of} the average pressure P _i are compared, and when the difference c between the maximum value P _max and the minimum value P _min is equal to or greater than a predetermined value, The coating apparatus according to claim 3, wherein the coating liquid is determined to have adhered to the surface of the backing roller. A long sheet-like object to be coated is wound and conveyed in a certain direction, and a coating roller which is disposed in the vicinity of the backing roller longer than the width of the object to be coated and is applied to the object to be coated is applied. The coating liquid is discharged on the surface of the coating object by forming a coating liquid bridge between the coating liquid discharged in the band shape and the coating object conveyed by the backing roller. A coating method for coating the coating liquid on the object to be coated using a coating apparatus comprising:
During the application, a coating liquid transfer detection step of detecting that the coating liquid discharged from the coating means has adhered to the backing roller surface;
In the coating liquid transfer detection step, when it is detected that the coating liquid has adhered to the backing roller surface, the coating liquid transfer detecting step includes a separation step of moving the coating means in a direction away from the backing roller. Application method.

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