JP3126203B2 - Protective gum liquid application processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective gum liquid coating apparatus for applying and processing a protective gum liquid while rolling and transporting a lithographic printing plate in which a non-image portion is dissolved and removed by an alkaline processing liquid. Protective gum solution coating process that not only suppresses coating unevenness by uniformly supplying the protective gum solution to the plate surface, but also prevents long-term fluctuations in the protective gum solution process and enables long-term stable coating process Related to the device.

[0002]

2. Description of the Related Art A non-image area alkali dissolving lithographic printing plate contains, on a hydrophilic support, at least an actinic ray-inducing treatment liquid solubilizing substance or an actinic ray curable substance accompanied by a change in chemical structure due to actinic rays. A photosensitive lithographic printing plate (so-called PS plate) provided with a photosensitive layer to be formed is known, and is widely used for heavy printing requiring high printing durability. However, a printing plate which has a sensitivity capable of forming an image in a light source region of a scanning exposure (for example, a semiconductor laser or the like) and is easy to handle in a bright room has not been generalized yet. These are exposed by bringing a silver halide photographic film original plate on which an image is recorded in advance into close contact with a printing plate photosensitive surface,
As a result, a cured portion corresponding to the image portion or a processing solution solubilized portion corresponding to the non-image portion in the final printed matter is formed, and the non-image portion photosensitive layer is dissolved and removed by the alkaline processing solution.

Also, an electrophotographic lithographic printing plate for forming an image by using an electrophotographic technique is known, and a printing plate corresponding to scanning exposure is also manufactured. A non-image area alkali-removal type lithographic printing plate utilizing electrophotographic technology is generally provided with an ink-receiving photoconductive layer in which an organic photoconductive substance is dispersed in a resin on a hydrophilic support. If the adhesion to the PS plate is strong, the ink receiving layer is thicker than the PS plate, and thus has a printing durability equal to or higher than that of the PS plate. These are used as a printing plate after forming a toner image on a photoconductive layer by electrophotography and then eluting a non-image portion with an eluent comprising an alkali agent.

Usually, these non-image area alkali dissolving and removing lithographic printing plates are provided with a plate surface protective agent (a so-called protective gum solution) as a final step of the plate making process. The purpose of this is not only to maintain the hydrophilicity of the surface of the non-image portion support by coating the entire plate surface with a plate surface protective agent, but also to preserve the period of time from plate making until printing or reuse. To prevent contamination induced by the attachment of fingerprints, oils and fats, dust, etc. in the handling before mounting on the surface, and to improve the scratch resistance. It is to prevent the occurrence of.

Conventionally, as an apparatus (structure) for applying a protective gum liquid to a lithographic printing plate, a protective gum liquid is supplied from a shower pipe to a carry-in roll to an upper roll, and an excessive amount of the protective gum liquid is carried out. A protective gum solution is intermittently supplied from a bellows pump or the like to a device that measures with a roll or a pipe passed at right angles to the printing plate transport direction, and lithographic printing is performed through a plurality of through holes provided in the pipe axis direction. There is known an apparatus which spreads by rolling after dropping on a plate and performs coating by supplying a smaller amount of liquid.
In particular, the latter does not require liquid circulation.

Further, the upper roll of the transport roll pair of the protective gum liquid application section described in Japanese Utility Model Application Laid-Open No. 59-30141 is made of a high liquid holding material and adheres to the lower roll. An apparatus for transferring the applied liquid to the upper roll to improve the uniform application of the protective gum liquid on both sides of the printing plate.
JP-A No. 2000-205, a protective gum solution is supplied to a wedge portion on the side of the conveying roll biting side (forward of the conveying direction) with respect to a roll pair in which the axial center of the upper roll is shifted rearward in the conveying direction. In particular, an apparatus for improving poor coating at the front and rear ends is disclosed in Japanese Patent Application Laid-Open No. 63-1673.
Japanese Patent Application Laid-Open No. 65-26564 discloses a device which conveys a plate downward in the horizontal direction of plate conveyance and arranges only a pair of drawing rolls on the downstream side to achieve a simplified and compact structure.

[0007] In addition, a circular groove described in JP-A-1-200993 for limiting the amount of protective gum liquid applied to a printing plate on a part of the outer periphery of a drawing roll and for making it uniform in the axial direction. A control roll having a contact roll is provided, and a contact portion between the squeezing roll and the control roll is filled with a protective gum solution,
In particular, there has been disclosed an apparatus for achieving uniform coating in the plate conveying width direction.

As described above, in the conventional protective gum solution applying apparatus, the liquid is supplied from the protective gum solution storage tank by a pump and discharged from a shower pipe to a roll and / or a printing plate. In general, the uniformization of the protective gum solution is based on only the arrangement and materials of the rolls for transporting, applying, spreading, and squeezing the protective gum solution. Little attention was paid to various problems in actual processing caused by fluctuations in the liquid properties mainly due to the temporal change of the protective gum solution, especially the supply means and supply conditions.

Therefore, in many conventional protective gum liquid application apparatuses, if the liquid is intermittently discharged by intermittent processing, the protective gum liquid remaining in the discharge hole of the shower pipe dries and induces clogging. In many cases, if some of the ejection holes are clogged, application failure due to uneven supply in the width direction of the plate may be induced, or all the ejection holes may be clogged and supply may not be possible at all. In addition, even if the discharge hole of the shower pipe is enlarged, clogging will eventually occur, and the occurrence of processing defects will be delayed, but the solution cannot be solved essentially. On the other hand, when the protective gum solution is continuously discharged to prevent clogging of the discharge holes,
The surplus liquid circulation and reuse method causes a change in liquid properties including an increase in the liquid concentration, and the surplus liquid disposable (removable) method results in an increase in waste liquid.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a protective gum solution applying apparatus for applying and processing a protective gum solution while rolling and transporting a lithographic printing plate in which a non-image portion is dissolved and removed with an alkaline treating solution. This not only suppresses coating unevenness by uniformly supplying the protective gum solution to the plate surface, but also prevents temporal fluctuations in the treatment of the protective gum solution, more specifically, clogging of the liquid discharge holes due to drying of the protective gum. It is an object of the present invention to provide a protective gum solution application processing apparatus which prevents the protective gum solution from being uniformly supplied and applied for a long period of time.

[0011]

As a result of repeated studies to solve the above problems, a lithographic printing plate in which the non-image area has been dissolved and removed with an alkaline processing liquid is roll-transported and coated with a protective gum liquid for processing. A protective gum solution application processing device, which transports a lithographic printing plate and applies and spreads a protective gum solution on a plate surface; A liquid measuring roll that limits the amount of the protective gum liquid applied to the lithographic printing plate in contact with the lithographic printing plate;
This is achieved by a protective gum liquid application processing device having a protective gum liquid supply means for controlling the closing and opening of the liquid discharge hole disposed above the contact portion of the protective gum liquid applying roll and the liquid measuring roll with compressed air.

[0012]

According to the present invention, there is provided a protective gum solution applying apparatus for transporting a lithographic printing plate and applying and spreading the protective gum solution on a plate surface. A liquid metering roll that restricts the amount of the protective gum solution applied to the lithographic printing plate in contact with a part, and squeezes the closure / opening of the liquid discharge hole located above the contact part between the protective gum solution application roll and the solution measuring roll The protective gum liquid supply means is controlled by air. The protective gum liquid is supplied by forcibly opening the protective gum liquid discharge hole of the protective gum liquid supply means with compressed air and supplied. Even if the protective gum liquid adhering and remaining near the liquid discharge hole is dried and solidified, clogging of the liquid discharge hole is prevented.

The protective gum solution discharged from the protective gum solution supplying means conveys the planographic printing plate and applies and spreads the protective gum solution on the plate surface, and a plate conveying direction of the roll. A liquid metering roll, which is in front of the plate and contacts a part of the outer periphery thereof to limit the amount of protective gum liquid applied to the lithographic printing plate, and a groove formed in the roll axis direction (plate width direction) formed by the roll. The protective gum solution is supplied to and stored in a primary storage section of the protective gum solution, and is continuously supplied to the printing plate from the gap between the protective gum solution application roll and the solution measuring roll over the entire width in the roll axis direction. As a result, the protective gum solution can be supplied substantially uniformly in the width direction of the printing plate, and is further spread by the protective gum solution application roll, so that the protective gum solution is more uniformly applied to the printing plate surface.

As described above, when the protective gum liquid coating apparatus of the present invention is used for applying the protective gum liquid to a lithographic printing plate in which the non-image area is dissolved and removed with an alkaline processing liquid, the protective gum liquid is uniformly applied to the plate surface. Not only suppresses coating unevenness, but also prevents time-dependent fluctuations in the processing of the protective gum solution, thereby enabling stable coating processing for a long period of time.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, based on the processing apparatus illustrated in FIG.
The respective steps in the protective gum solution application processing apparatus according to the present invention and the details of the functions possessed or intended for them will be described. It should be noted that the present invention is not limited to the description and the examples at all without departing from the gist thereof.

A lithographic printing plate (hereinafter abbreviated as printing plate) 1 in which a non-image portion is dissolved and removed through a non-image portion removing step through an exposure device (not shown) and an alkali treatment device, as shown in FIG. The protective gum solution is transported to the protective gum solution applying step, and the driving force is transmitted by driving means (not shown) to be sandwiched between the pair of the protective gum solution applying roll 5 and the backup roll 6 which are rotated. The liquid is applied and carried out to a protective gum liquid drying step (not shown).

As shown in FIG. 1 and FIG. 2, the protective gum solution coating process includes a primary storage tank 2, a secondary storage tank 3, a protective gum liquid supply mechanism, a drainage primary storage tank 17, The protective gum solution supply mechanism comprises a protective gum solution applying roll 5, a backup roll 6, a solution measuring roll 7,
It comprises a protective gum liquid supply means and a waste liquid tank 8. Protective gum solution application roll 5, backup roll 6,
The liquid measuring roll 7 is supported by a pair of side plates (not shown), and a protective gum liquid applying roll 5 and a backup roll are provided.
The roll 6 is configured such that both ends of the roll are pressed by a pressing mechanism (not shown) provided above the bearing. Liquid measuring roll 7
Are supported by a bearing (not shown) cut toward the center of the rotation axis of the protective gum solution application roll 5 so that the driving force is transmitted in contact with the protective gum solution application roll 5. I have.

The protective gum solution applying roll 5 and the backup roll 6 have an acid-resistant and rust-proof rotating shaft and a rubber hardness of 25 to 50.
Degree of acid-resistant rubber is wrapped around the
For example, a material having the same quality as the rotating shaft such as a metal or a hard plastic is used, and a peripheral surface thereof is finished to a specific roughness and shape to supply a desired amount of the protective gum solution to the printing plate 1.

As shown in FIG. 2, the spray guns 10, 11, and 12, which are the protective gum liquid supply means for controlling the closing and opening of the liquid discharge hole by compressed air, are provided with protective gum liquid application rollers.
Roll 5 and liquid measuring roll 7 are arranged above the contact portion. The spray guns 10, 11, and 12 are spray guns (not shown).
It is held by the gun holding mechanism and is arranged at regular intervals along the roll axis direction. The liquid discharge holes (liquid nozzles) of the spray guns 10, 11, and 12 have the protective gum liquid application roller located vertically below. Roll 5 and liquid metering roll 7 are directed to the contact portion.

Above the spray gun, a secondary storage tank 3 held by holding means (not shown) is arranged. The spray guns 10, 11, and 12 are connected to conduits 60, 61, and 62, respectively, which communicate with the secondary storage tank 3, and the protective gum liquid stored in the secondary storage tank 3 is connected to the spray guns 10, 11, and 12, respectively. 16
Are supplied to their respective spray guns by opening respective valves 37, 38 and 39. Also,
One end of the secondary storage tank 3 is connected to a pipe 65 communicated below the primary storage tank 2. A liquid supply pump 28 and an electromagnetic valve 35 are disposed in the middle of the pipe 65, and protection of the primary liquid storage tank 2 is performed by operating the liquid supply pump and opening the electromagnetic valve 35 by control means (not shown). The gum solution 15 is supplied to the secondary storage tank 3.

In general, a needle is inserted into a liquid nozzle liquid discharge hole in a spray gun (when not in use) by a spring or the like to be closed by being pressed, so that a protective gum liquid is applied. The protective gum liquid, which is formed by the roll 5 and the liquid metering roll 7, is supplied to the primary storage section 26 by operating the needle with compressed air, and is opened from the secondary storage tank 3. The protective gum solution 16 is supplied dropwise. The compressed air is branched from the compressor 18 to individual spray guns via the pipe 51, the filter 23, and the pressure reducing valve 25,
The electromagnetic valve 3 is controlled by a compressed air supply control unit (not shown).
When 1, 32 and 33 are released, pipes 56, 57,
Or 58 through spray guns 10, 11, and 12, respectively.
To be supplied to

The protective gum liquid 16 supplied to the protective gum liquid primary storage section 26 is measured by the liquid measuring roll 7 together with the rotation of the protective gum liquid applying roll 5, and the protective gum liquid applying roll 5 is measured.
The printing plate 1 is retained in the protective gum solution secondary storage section 27 formed by the protective roll and the backup roll 6, and the protective gum solution application roll is formed.
The sheet is nipped and conveyed by a pair of a roll 5 and a backup roll 6 and applied on the printing plate 1 and squeezed. The liquid squeezed from the printing plate 1 and the surplus liquid from the protective gum liquid secondary storage section 27 are discharged to the drainage primary storage tank 17 via the backup roll 6.
Pipe 6 connected to the bottom of the primary drainage tank 17
7, only the valve 42 is opened for circulation, the valve is returned to the primary storage tank 2 via the pipe 68, and the valve 43 is released for disposal, and the valve 44 is released for disposal. 8 and can be recycled or thrown away.

Next, the operation of this embodiment will be described. The printing plate 1 in which the non-image portion is dissolved and removed through a non-image portion removing step in an exposure device and an alkali treatment device (not shown).
Is transported and carried into the protective gum solution applying step, and is sandwiched between the protective gum solution applying roll 5 and the backup roll 6 to apply the protective gum solution on the printing plate 1,
It is carried out to a protection gum solution drying step (not shown). The protective gum solution 15 in the primary storage tank 2 is supplied to the secondary storage tank 3 by the operation of the liquid feed pump and the opening of the electromagnetic valve 35 by control means (not shown), and is stored in the secondary storage tank 3. The protective gum solution 16 is supplied to each spray gun by opening the valves 37, 38 and 39.

Roll 5 for applying protective gum liquid and roll 7 for measuring liquid
The needle, which is inserted into the liquid nozzle liquid discharge hole in the spray gun and closed, is inserted into the protective gum liquid primary storage section 26 formed by the compressor 18, the filter 23, and the pressure reducing valve 25.
The protective gum solution 16 is opened by being opened by being actuated by the compressed air supplied through the container, and is naturally dropped from the secondary storage tank 3. When the supply of the protective gum solution 16 is unnecessary, the needle is closed at the liquid discharge hole. However, when the liquid is supplied, the needle is forcibly swept with compressed air, so that the needle is dried near the liquid discharge hole. Even if the protective gum remains and covers the liquid discharge holes, the protective gum liquid can be supplied without delay.

The protective gum liquid 16 supplied to the protective gum liquid primary storage section 26 flows in the width direction of the protective gum liquid application roll 5 to fill the entire storage section, and the protective gum liquid application roll 5 With the rotation, the liquid is uniformly rectified by the liquid measuring roll 7 and is measured to a predetermined amount, and is further retained in the protective gum liquid secondary storage section 27, so that the printing plate 1 is protected with the protective gum liquid applying roll 5 and the backup roll. And is applied to the printing plate 1 while being nipped and transported by the six pairs of rollers. Thereby, the protective gum solution is not supplied more than necessary, and a uniform coating film can be obtained in the width direction of the plate.

[0026]

As described above, if the protective gum liquid applying apparatus of the present invention is used for applying a protective gum liquid to a lithographic printing plate in which non-image areas are dissolved and removed with an alkaline treating liquid,
The protective gum solution is evenly supplied to the plate surface with a liquid supply amount that is close to the required minimum, which not only suppresses coating unevenness, but also changes over time in the processing of the protective gum solution, that is, protection by intermittent operation of the processing device. An excellent effect of preventing clogging of the gum solution supply means and enabling stable coating treatment for a long time is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic vertical cross-sectional view showing a protective gum solution application processing apparatus to which the present invention is applied.

FIG. 2 is a schematic cross-sectional configuration diagram showing a pipe for supplying compressed air and a protective gum solution to a spray gun of the protective gum solution application processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lithographic printing plate 2 Primary storage tank 3 Secondary storage tank 5 Protective gum liquid application roll 6 Backup roll 7 Liquid measuring roll 10, 11, 12 Spray gun 15, 16 Protective gum liquid 17 Drain Liquid primary storage tank 18 Compressor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03F 7/40 B41N 3/08

Claims (1)

(57) [Claims] An apparatus for applying a protective gum solution to a lithographic printing plate in which a non-image portion is dissolved and removed by an alkaline processing solution while rolling and transporting the lithographic printing plate, and comprising:
A protective gum solution applying roll for applying and spreading the protective gum solution on the plate surface while transporting the lithographic printing plate, and applied to the lithographic printing plate by contacting a part of the outer periphery of the roll in front of the plate in the plate transport direction. It has a liquid measuring roll for limiting the amount of the protective gum liquid, and a protective gum liquid supplying means for controlling the closing and opening of the liquid discharge hole arranged above the contact portion of the protective gum liquid applying roll and the liquid measuring roll with compressed air. Protective gum liquid application processing equipment.