JP2007240862A - Lithographic printing plate development processing method and development apparatus - Google Patents

Abstract

[PROBLEMS] To significantly reduce the use of processing chemicals in the development processing of a lithographic printing plate without reducing the quality of a lithographic printing plate obtained after processing, and to suppress the amount of washing water used after development. To provide a processing method and a developing device for a lithographic printing plate.
A processing method and a developing apparatus for a lithographic printing plate in which a lithographic printing plate having a photosensitive layer or a heat-sensitive layer on a support is exposed and then developed, and the exposed lithographic printing plate after exposure is granular. The dry ice is sprayed with a compressed gas to remove the one that is less closely adhered to the support in the unexposed part or exposed part of the photosensitive layer or heat-sensitive layer.
[Selection] Figure 1

Description

  The present invention relates to a processing method and a developing apparatus for a lithographic printing plate in which a lithographic printing plate is exposed and then developed.

  In recent years, the development of lasers has been remarkable, and high-power and small-sized lasers have become readily available. These lasers are very useful as a recording light source when directly making a printing plate from digital data of a computer or the like.

  In order to form such a lithographic printing plate, it is common to perform development after recording on the printing plate by laser exposure. A developing device is used for the development processing of the printing plate. As the developing device, a device including steps including heating, pre-water washing, development, water washing, and finishing is widely used (Patent Document 1).

JP 2003-107728 A

In such a developing device, it is necessary to use a plurality of chemical substances and to treat the waste liquid in processing such as water washing processing, development processing, and finishing. In addition, a large amount of water is used to wash the lithographic printing plate after development.
In recent years, interest in the environmental impact of chemical substances has increased and interest in recycling has also increased, with the reliable treatment of chemical substances used in each of these treatments, as well as the reduction and reuse of water. Is now required.

  The present invention has been made based on the background as described above. Its purpose is to greatly reduce the use of processing chemicals in the development processing of lithographic printing plates without reducing the quality of the lithographic printing plate obtained after processing, and to suppress the amount of washing water used after development. It is an object of the present invention to provide a processing method and a developing device for a lithographic printing plate that can be used.

That is, the above object of the present invention is achieved by the following configuration.
(1) A processing method for a lithographic printing plate, in which a lithographic printing plate having a photosensitive layer or a heat-sensitive layer on a support is exposed and then developed.
A lithographic printing plate that sprays granular dry ice onto the exposed surface of the lithographic printing plate after exposure with a compressed gas to remove the unexposed portion of the lithographic printing plate or the one that is less closely attached to the support in the exposed portion. Processing method.

  In this way, the process of spraying granular dry ice with compressed gas is used to remove portions that are not necessary for printing because the adhesion to the printing plate support is weak and leave portions that are necessary for printing with high adhesion. As a result, the developer itself during the development process can be made unnecessary. Moreover, since dry ice becomes carbon dioxide, it can be recovered and is originally a gas that exists in the atmosphere, and is harmless as long as it leaks into the atmosphere. Accordingly, all that remains is the residue of the removed photosensitive layer or heat-sensitive layer, which is easily recovered.

(2) The method for processing a lithographic printing plate as described in (1) above, wherein the spraying of dry ice is performed on the lithographic printing plate after immersion in a developing solution after the exposure.

  Thus, by immersing the photosensitive lithographic printing plate after exposure in the developing solution, it is possible to widen the difference between the unnecessary portion and the required portion regarding the degree of adhesion with the support. In this state, by spraying granular dry ice with compressed gas, it becomes possible to remove unnecessary portions at the time of printing more quickly and accurately. Although washing with water is also necessary in some cases, the developer is almost blown off by dry ice, and can be completed with simple washing. Furthermore, since the unnecessary portions are not peeled off by simply immersing the lithographic printing plate in the developer, the deterioration of the solution is very small, and it is possible to use it repeatedly by replenishing the reduced amount.

(3) The spray strength by the compressed gas is such that the strong adhesion to the support in the unexposed part or the exposed part of the lithographic printing plate is not removed, as described in (1) or (2) above Processing method for lithographic printing plates.
The spray strength of the dry ice by the compressed gas includes the spray pressure, spray time, spray amount, and the like, and is set to such an extent that a portion necessary for printing the photosensitive layer is not removed.

(4) A lithographic printing plate developing device having a development processing section for a photosensitive lithographic printing plate after exposure having a photosensitive layer or a heat-sensitive layer on a support, and having a granularity on the exposed surface of the lithographic printing plate after exposure A lithographic printing plate developing device comprising dry ice spraying means for spraying dry ice with compressed gas.

  In this configuration, it is not necessary to print the photosensitive layer or the heat-sensitive layer by dry ice spraying means for spraying granular dry ice with compressed gas over the entire exposed surface of the lithographic printing plate after exposure that is conveyed. You can remove important parts. In this case, since it is not necessary to use a developing solution or washing water, these processing tanks, pipes, supply tanks, waste liquid tanks and the like are not necessary. In other words, although means for supplying granular dry ice is required, the entire apparatus can be simplified and a reduction in size can be expected. In addition, in order to collect the residue of the removed photosensitive layer or heat sensitive layer, it can also collect | recover easily using a brush etc.

(5) The lithographic printing plate developing device according to the above (4) or (5), wherein the spray position of the dry ice spraying means is disposed downstream of the development processing section.
In this configuration, an immersion process in a developing solution is performed by the development processing unit, and an unnecessary portion of the photosensitive layer or the heat-sensitive layer is removed by dry ice spraying means disposed downstream thereof. In this case, the degree of adhesion between the unexposed portion and the exposed portion of the photopolymerizable photosensitive layer is weakened by the processing with the developing solution, the removal becomes easier, the processing speed is increased, and accurate removal is performed.

(6) The above (4), wherein the dry ice spraying means has a compressed gas blowing strength that does not remove the strong contact with the support in the unexposed or exposed portion of the planographic printing plate. Development equipment for lithographic printing plates.
In this case, the jetting strength of the dry ice compressed gas includes the jetting pressure, jetting time, jetting amount, etc., depending on the preset values corresponding to the type of lithographic printing plate to be developed. It is processed.

The present invention greatly reduces the use of processing chemicals in the development processing of a lithographic printing plate without degrading the quality of the lithographic printing plate obtained after processing when developing the lithographic printing plate, and the water washing used in the development. It has an excellent effect that the amount of water can be suppressed. Furthermore, the processing liquid supply / disposal system configuration is unnecessary, and the entire apparatus can be miniaturized.
As a further effect, the developer itself at the time of the development processing is not required, and all that remains is the residue of the removed photosensitive layer or heat-sensitive layer, which can be easily recovered. Also, in the case of using the treatment liquid, the total amount of use can be reduced by suppressing deterioration of the liquid performance.

A planographic printing plate developing method and developing apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic diagram showing a basic configuration of a developing device according to an embodiment of the present invention.
The developing device 10 is applied to the development processing of the lithographic printing plate S having the photopolymerizable photosensitive layer image-exposed by the exposure device 200 indicated by the phantom line. The printing plate S developed in the present embodiment is the same as a generally used plate, and a plate in which a photosensitive layer or a heat-sensitive layer is formed on a support surface of a thin plate using aluminum or the like via an adhesive layer. It is. A protective layer may be provided thereon.

  As shown in FIG. 1, the printing plate S sent out from the feeding roller pair 216 of the exposure apparatus 200 is carried in from an introduction port 14 provided in the housing 12 of the developing apparatus 10. In the housing 12 of the developing device 10, a conveyance roller pair 16 is disposed immediately downstream of the introduction port 14, and a platen 18 for holding the printing plate S to be conveyed is disposed further downstream thereof. Then, the printing plate S is carried out from the delivery port 32 by the conveying roller pair 19 arranged downstream thereof.

  A dry ice spraying unit 20 is disposed above the platen 18. The dry ice spraying section 20 is provided with a dry ice introduction bar 22 that can reciprocate in the width direction H of the printing plate S. An injection nozzle 24 is disposed at the tip of the dry ice introduction bar 22. The dry ice introduction bar 22 is connected to a dry ice supply unit that supplies granular dry ice together with compressed gas, although not shown.

FIG. 2 is a schematic perspective view showing a form of spraying dry ice onto the printing plate S.
In FIG. 2, the printing plate S is transported on the platen 18 along the transport direction P by the transport roller pair 16 and enters between the platen 18 and the dry ice introduction bar 22. When the printing plate S is conveyed directly below the spray nozzle 24 of the dry ice introduction bar 22, the spray of granular dry ice is started. The dry ice introduction bar 22 continues to eject dry ice by reciprocating in the movement direction H, and the ejection locus L (one-dot chain line) covering the entire surface of the printing plate S in synchronization with the movement of the printing plate S in the transport direction P. Draw.

  Thus, when granular dry ice is sprayed, for example, when the photopolymerizable photosensitive layer is cured by exposure, the cured portion is left and the unexposed portion is removed. First of all, the unexposed portion, which is a weakly adhered portion, is cracked and peeled off due to the impact caused by the injection of granular dry ice and the sudden temperature drop of the collision portion. Furthermore, due to the impact of the granular dry ice, the cracked portion of the unexposed portion, which is also a weakly adhered portion, is peeled off and repelled. Since the spray strength of the dry ice supply unit needs to be adjusted depending on the type of printing plate used for development, the spray strength is set for each type of printing plate in advance by a test.

As the compressed gas, air may be used as it is. As long as it is an inert gas, for example, nitrogen, carbon dioxide or the like can be used alone or in combination.
Conventionally, in order to remove this unexposed part, it was immersed in a developing solution and combined with a chemical reaction and physical treatment such as a roller or a brush. In this embodiment, granular dry ice is compressed. By the process of spraying with gas, the developer itself at the time of the development process can be made unnecessary. Moreover, since dry ice becomes carbon dioxide, it can be collected separately, and is originally a gas that exists in the atmosphere and is harmless as long as it leaks into the atmosphere. Finally, only the residue of the removed photosensitive layer or heat-sensitive layer is obtained, and is easily collected and discarded by, for example, the brush roller 26 disposed downstream of the spray nozzle 24 of the dry ice introduction bar 22. In addition to this, this residue can be recovered by blowing gas or by suction.

  In addition to the brush roller 26, it is also possible to arrange a brush or the like that can always be removed on the printing plate S at the same position. Further, in the case of this embodiment, it is not necessary to use a developing solution or washing water, so that these processing tanks, pipes, supply tanks, waste liquid tanks and the like are not necessary.

In addition, in order to improve the processing speed and further improve the finished quality of the printing plate S, a pretreatment water washing step and a heating step can be introduced. Furthermore, you may introduce | transduce the finishing water-washing process as needed.
The particle size of dry ice is optimally about 0.3 mm to 3 mm. If it is too small, it will sublime before reaching the printing plate S. If it is too large, there will be no fine collisions, and there will be a portion that cannot be removed.
Although not shown, a carbon dioxide gas recovery unit for sucking and recovering carbon dioxide after the dry ice is vaporized can be provided.

FIG. 3 is a schematic perspective view showing another embodiment of the form of spraying dry ice onto the printing plate S.
In the dry ice spray unit 20a of the present embodiment, the dry ice spray bars 22a and 22b are long tubular members, and for example, spray pipes can be used. The dry ice ejection bars 22a and 22b are respectively arranged so as to be parallel to the width direction (direction perpendicular to the arrow P) of the printing plate S conveyed in the arrow P direction. Further, the dry ice jet bars 22a and 22b are formed with a plurality of nozzle portions 24a (for example, 20 pieces at intervals of 5 cm) at intervals in the longitudinal direction.
The dry ice jet bars 22a and 22b are connected to a dry ice supply unit (not shown) and supply granular dry ice together with compressed gas.

FIG. 4 is a schematic diagram showing a basic configuration of a developing device according to another embodiment of the present invention.
The developing device 100 shown in FIG. 4 includes a developer processing unit 110 that immerses the lithographic printing plate S in the developer at the front stage of the granular dry ice spraying device 120 that is the developing device shown in FIG.
As in FIG. 1, the lithographic printing plate S image-exposed by the exposure apparatus is nipped and conveyed by the conveying roller pair 116, and is further guided by the conveying roller pair 117 disposed in the processing tank 140 filled with the developer 112. The printing plate S is immersed in the developer 112 along An immersion roller 118 is disposed at the downstream end of the guide 142, and the printing plate S is nipped and conveyed to adjust the immersion time. Then, the printing plate S is sent to the downstream where the granular dry ice spraying device 120 is arranged along the downstream delivery guide 144.

In the granular dry ice spraying device 120, the printing plate S is transported to the transport roller pair 119. A platen 126 for holding the printing plate S to be transported is disposed further downstream of the transport roller pair 119. And the printing plate S is carried out by the conveyance roller pair 130 arrange | positioned downstream.
A dry ice introduction bar 122 that is a dry ice spraying portion is provided above the platen 126 so as to be reciprocally movable in the width direction H of the printing plate S. An injection nozzle 124 is disposed at the tip of the dry ice introduction bar 122. The dry ice introduction bar 122 is connected to a dry ice supply unit that supplies granular dry ice together with the compressed gas, although not shown.

The developing device 100 can be surrounded by a housing (not shown). This configuration facilitates application of a carbon dioxide gas recovery configuration together with dust prevention.
In the treatment tank 140, the immersion time is 2 to 60 seconds, preferably 5 to 30 seconds. The immersion temperature is preferably 15 to 50 ° C, more preferably 20 to 50 ° C.

The configuration and operation of the dry ice spraying device 120 are the same as the device shown in FIG. 2 or 3 and the description thereof.
In the processing section using the developer, a shielding lid (not shown) may be provided, and deterioration due to the developer in the processing tank 140 coming into contact with carbon dioxide gas in the air or evaporation of moisture can be prevented. . In addition, a blade-shaped shielding member (not shown) formed of silicon rubber or the like is provided between the shielding lid and the processing tank 140 and each conveyance roller pair, and the developer in the processing tank 140 comes into contact with fresh outside air. More preferably, the water in the developer may be prevented from evaporating.

  There are many types of photosensitive lithographic printing plates that can be used in the present invention. For example, the photosensitive composition is generally coated in a thin layer on an aluminum plate, and this photosensitive lithographic printing plate is developed after image exposure to obtain a lithographic printing plate. This aluminum plate is usually subjected to a roughening treatment such as a mechanical method such as a brush grain method or a ball grain method, an electrochemical method such as an electrolytic grain method, or a combination of the two, and the surface thereof is textured. After that, it is etched with an aqueous solution of acid or alkali, and further subjected to an anodizing treatment, followed by a hydrophilization treatment as desired to obtain a support for lithographic printing, and a photosensitive layer is provided on this support and is photosensitive. A lithographic printing plate.

Photosensitive lithographic printing plates used for preparing lithographic printing plates include positive and negative types.
As the positive photosensitive composition, for example, a composition composed of an o-quinonediazide compound is widely used. Such a photosensitive substance is used alone or mixed with an alkali-soluble resin such as a novolac-type phenol resin or cresol resin, and a support. Painted on top.

  When a support having a hydrophilic surface is used, the exposed portion of the o-quinonediazide compound decomposes and changes to alkali-soluble, so that it is easily removed with an alkali developer to expose the hydrophilic surface of the support. Accepts water and repels ink. On the other hand, the unexposed area remaining as an image is oleophilic and accepts ink. In the present invention, the exposed portion is removed by spraying granular dry ice.

  Many negative photosensitive compositions, for example, use a large amount of a diazonium salt, an azide compound or a photopolymerizable compound, and such a photosensitive material is used alone or mixed with an additive such as an appropriate resin to form a support on the support. Painted. When a support having a hydrophilic surface is used, the unexposed portion is removed by spraying granular dry ice to expose the hydrophilic surface of the support, and this portion accepts water and repels ink. On the other hand, the portion that is cured by exposure and remains as an image during development is oleophilic and accepts ink.

Furthermore, it can be applied to a waterless planographic printing plate. This planographic printing plate has, for example, a structure in which a primer layer, a photosensitive layer, and a silicone rubber layer are sequentially provided on a support. For the support, an aluminum plate that is extremely dimensionally stable is used. The primer layer is, for example, an unsaturated monomer or oligomer thereof using a hardener, a photoinitiator, a polymer or inorganic powder as a filler for imparting shape retention of the photosensitive layer, and a thermal polymerization inhibitor as necessary. Etc.
The silicone rubber layer can be represented by the following chemical formula, for example.

  The main component is a linear organic polysiloxane having a molecular weight of several thousands to several hundred thousand having such a repeating unit. Here, R is an alkyl group having 1 to 10 carbon atoms or a phenyl group, and preferably 60% or more of R is a methyl group. Such a linear organic polysiloxane is generally made into a crosslinked silicone rubber by adding a reactive crosslinking agent.

Furthermore, there are the following positive types and negative types as thermal plates.
(1) Positive type The positive type thermal plate has, for example, a structure in which an undercoat layer and a heat sensitive layer are provided on a support. For example, the light energy of the laser light applied to the positive thermal plate is converted into thermal energy, the association state of the binder in the photosensitive layer is changed, and the heat-sensitive layer becomes alkali-soluble. This portion is removed by development, which is spraying granular dry ice, to form a non-image portion.

(2) Negative type The negative type thermal plate has a structure in which, for example, an adhesion layer and a heat sensitive layer are provided on a support. For example, the light energy of laser light applied to this negative thermal plate is converted into thermal energy, and the acid generator of the heat sensitive layer generates acid. Thereafter, the thermal crosslinking reaction is promoted and cured by pre-heating using this acid as a catalyst to form an image portion. The heat-sensitive layer in the non-image area is removed by development, which is spraying granular dry ice.

  Still further, as a lithographic printing plate for a photopolymer plate, an Ar ion laser (488 nm) or an FD-YAG laser (532 nm) is used as a recording light source, and a photosensitive material having a photopolymerizable photosensitive layer suitable for these light sources. A lithographic printing plate has been developed and put into practical use. Recently, an InGaN-based semiconductor laser (violet laser, 350 nm to 450 nm) has been developed, and a bright room, lower cost of the exposure machine, and higher productivity are expected. Lithographic printing plates having a polymerizable photosensitive layer have been developed. A photopolymerizable photosensitive layer is provided on an aluminum plate as a support layer. An overcoat layer is usually overlaid on the photopolymerized photosensitive layer.

Next, an example of development processing by actually spraying granular dry ice is shown below.
(Examples 1-3)
A high-sensitivity photosensitive lithographic printing plate PN-V (product name) for violet laser manufactured by Fuji Photo Film Co., Ltd. was developed by the method shown in Table 1. High sensitivity photosensitive lithographic printing plate PN-V for violet laser is produced by FUJIFILM Electronic Imaging Ltd. Violet Semiconductor Laser Setter Vx9600 (product name) (InGaN semiconductor laser 405 nm plus or minus 10 nm light emission / output) 30 mW), a 50% flat mesh was drawn with an FM screen manufactured by Fuji Photo Film, TAFFET A20 (product name) at a resolution of 2438 dpi at an exposure amount of 90 μJ / cm ² .

For the dry ice treatment, Superblast DSC-II (product name) manufactured by Kyodo International Co., Ltd. was used.
Examples 2 and 3 were performed after dipping the developer DV-2 (product name) manufactured by Fuji Photo Film Co., Ltd. 5 times diluted with water before the dry ice treatment.

Good images were obtained in Examples 1 to 3.
In Example 1, only the residue from which the non-image area was removed remained and there was almost no waste.
Examples 2 and 3 were pretreated with a developer, but an image could be obtained in a short time. In this pretreatment, a highly alkaline developer having a pH of 12.0 was used. However, since it was only immersed, there was almost no fatigue, and it could be used repeatedly over a long period of time simply by replenishing the reduced developer.

(Comparative Example 1)
Fuji Photo Film Co., Ltd. development machine LP-1250PLX (product name) consisting of pre-water washing, development, water washing, and finishing, Fuji Photo Film Co., Ltd. violet laser sensitive lithographic printing plate PN-V (Product name) is loaded into a violet semiconductor laser setter Vx9600 (product name) (InGaN semiconductor laser 405 nm plus or minus 10 nm emission / output 30 mW) manufactured by FUJIFILM Electronic Imaging Ltd. A lithographic printing plate on which 50% flat mesh was drawn was developed with an FM screen manufactured by Fuji Photo Film and TAFFETA20 (product name) at an exposure amount of ² and a resolution of 2438 dpi.

48 liters of tap water for pre-washing, 45 liters of developer DV-2 (product name) manufactured by Fuji Photo Film Co., Ltd. diluted 5 times with water, 35 liters of tap water for washing The finisher was charged with 14 liters of a 2 × diluted gum solution FP-2W (product name) manufactured by Fuji Photo Film Co., Ltd.
Although a good image could be obtained, the total amount of processing waste liquid reached 142 liters. In addition, every time a 1030 × 800 size plate was processed, 100 ml of replenishment of developer was required. It is necessary to collect all of these processing waste liquids and to perform waste liquid treatment, which is expensive compared to this embodiment.

Example 4
An original HP-S for lithographic printing plates (thermal positive multi-layer printing plate manufactured by Fuji Photo Film Co., Ltd.) is used with a Trend setter VX (product name) manufactured by Creo, with a beam intensity of 8 W, a drum rotation speed of 150 rpm, and 50% of an AM screen of 175 lpi. After drawing the flat mesh, it was immersed for 12 seconds in a solution obtained by diluting the developer DT-2 (product name) for thermal positive manufactured by Fuji Photo Film Co., Ltd. with water at 1: 8. Thereafter, dry ice was discharged onto the plate surface for 60 seconds using Superblast DSC-II (product name) manufactured by Kyodo International Co., Ltd. The planographic printing plate had a size of 10 × 10 cm.
An image faithfully reproducing a 50% flat screen of the AM screen 175 lpi could be obtained.

1 is a schematic diagram illustrating a basic configuration of a developing device according to an embodiment of the present invention. 2 is a schematic perspective view showing a form of spraying dry ice on the printing plate S. FIG. It is a schematic perspective view which shows other embodiment of the injection form of the dry ice with respect to the printing plate S. FIG. It is the schematic which shows the basic composition of the image development apparatus which is other embodiment of this invention.

DESCRIPTION OF SYMBOLS 10,100 Developing device 12 Case 18 Platen 20 Dry ice spraying part 22, 22a, 22b Dry ice introduction bar 24, 24a Spray nozzle 140 Processing tank 112 Developer 200 Exposure part

Claims (6)

A processing method of a lithographic printing plate, wherein a lithographic printing plate having a photosensitive layer or a heat-sensitive layer on a support is exposed and then developed.
A lithographic printing plate that sprays granular dry ice onto the exposed surface of the lithographic printing plate after exposure with a compressed gas to remove the unexposed portion of the lithographic printing plate or the one that is less closely attached to the support in the exposed portion. Processing method.   The processing method of a lithographic printing plate according to claim 1, wherein the spraying of the dry ice is performed on the lithographic printing plate after immersion in a developing solution after the exposure.   The processing method of the lithographic printing plate according to claim 1 or 2, wherein the jetting strength by the compressed gas is such that it does not remove a non-exposed portion of the lithographic printing plate or an exposed portion of the lithographic printing plate that has a strong contact with the support. . A development apparatus for a lithographic printing plate having a development processing unit for a lithographic printing plate after exposure having a photosensitive layer or a heat-sensitive layer on a support,
A lithographic printing plate developing device comprising dry ice spraying means for spraying granular dry ice with a compressed gas onto an exposed surface of the lithographic printing plate after exposure.   The lithographic printing plate developing device according to claim 4, wherein a spraying position of the dry ice spraying means is disposed downstream of the developing processing section. The lithographic printing according to claim 4 or 5, wherein the compressed gas strength of the dry ice spraying means is such that it does not remove a non-exposed portion or an exposed portion of the lithographic printing plate that has a strong contact with the support. Plate development device.

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