JP2007072160A - Automatic developing machine and developing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic developing machine for developing a photopolymerization type planographic printing plate exposed in a Violet CTP system (computer-to-plate system by a violet laser), the machine responding to the Violet CTP system that can prevent uneven development but achieve excellent dot reproducibility, and to provide a developing method using the automatic developing machine. <P>SOLUTION: The automatic developing machine responding to a Violet CTP system develops a photopolymerization type planographic printing plate exposed in a Violet CTP system while conveying the plate in a developing bath, and is characterized in that the machine is equipped with a rubbing member to rub the planographic printing plate in the developing bath, that the rubbing member is composed of a plurality of brush members arranged in the conveying direction of the planographic printing plate, and that the brush bristles of the brush member have diameters of 0.05 to 0.09 mm. The developing method is carried out by using the above automatic developing machine. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to preparation of an offset printing plate, and more particularly to an automatic processor used for developing a photosensitive lithographic printing plate exposed by Violet CTP, and a development processing method using the automatic processor.

  In recent years, a wide range of efforts have been made to improve image quality from the arrangement of halftone dots for printing in response to a demand for a more beautiful printed product. Conventionally, a so-called AM (Amplitude Modulation) screen called a screen that displays shades by changing the size of dots arranged at equal intervals has been used. In this AM screen, a network of moire and rosetta is used. There has been a problem that image quality deterioration occurs due to the angle factor of the point arrangement. As a method for solving such image quality degradation, an FM (Frequency Modulation) screen in which generation of moire or the like is suppressed by randomly arranging halftone dots has been proposed. The FM screen uses a small halftone dot to change the density of randomly arranged halftone dots to display light and shade, but since each dot (dot) area is very small, The halftone dot reproducibility at the time of printing plate preparation is unstable, and management at the time of printing is difficult, so that it is only used in part despite its advantages.

On the other hand, the development of lasers and computers has been remarkable in recent years, and in the printing industry, technological innovation has been promoted in the form of CTP (Computer to Plate), in which a printed document edited on a computer is directly drawn on a printing plate with a laser beam. ing. In particular, with the development of a violet laser using a blue LED, Violet CTP which employs this violet laser as a drawing laser has attracted attention.
With the spread of this CTP, the stability of halftone dot reproduction when making a printing plate has been dramatically improved, and comparison of plate making (preparation) of lithographic printing plates using FM screens, which was difficult with conventional PS plates, has been made. As a result, FM screens are beginning to be used more widely.
In addition, with the spread of CTP, there are increasing opportunities to use high-definition AM screens, for example, high-definition AM screens having 240 lines or more, as compared with the prior art.

Here, when the above-described VioletCTP and a high-definition AM screen or FM screen are used in combination for making a photopolymerization type lithographic printing plate, a conventional AM screen of about 175 lines is used. However, there is a problem that unevenness of the flat screen on the plate and in-plane unevenness of the halftone dot size occur, and the halftone dot reproducibility deteriorates.
This is a problem that occurs because the violet laser beam has a skirt as a characteristic of the optical design of Violet CTP, and an incompletely hardened portion is generated in the non-image area around the image area on the plate surface. . In particular, when a high-definition AM screen or FM screen is applied to VioletCTP, the perimeter of the halftone dot becomes long, so that it is easily affected by the beam bottom.
As a method for removing the incompletely hardened portion generated in the non-image area in this way, generally, a method of rubbing the lithographic printing plate being conveyed in the developing bath using a rubbing member such as a developing brush is known. (For example, refer to Patent Document 1). However, if the rubbing force of the plate surface by the rubbing member is increased and the removability is increased, nonuniformity occurs in the contact condition of the brush, and on the contrary, unevenness of the flat mesh or non-uniformity in the halftone dot size plane occurs. There was concern that uniformity would occur.
JP 2003-107728 A

An object of the present invention is to solve the conventional problems and achieve the following objects.
That is, an object of the present invention is an automatic processor for developing a photopolymerization type lithographic printing plate exposed by Violet CTP, which prevents development processing from becoming non-uniform and has excellent halftone dot reproducibility. An object is to provide a Violet CTP-compatible automatic processor that can be achieved, and a development processing method using the automatic processor.

As a result of intensive studies, the inventors have used a specific brush member as the rubbing member installed in the developing bath, thereby preventing uneven development processing and achieving excellent halftone dot reproducibility. As a result, the present invention was completed.
That is, the VioletCTP-compatible automatic processor of the present invention is a VioletCTP-compatible automatic processor that develops a photopolymerization type lithographic printing plate exposed by VioletCTP while transporting it in a developing bath,
A rubbing member for rubbing the lithographic printing plate in the developing bath,
The rubbing member is composed of a plurality of brush members arranged in the transport direction of the planographic printing plate, and the brush bristle diameter of the brush member is 0.05 to 0.09 mm.

The VioletCTP-compatible development processing method of the present invention is a VioletCTP-compatible development processing method using an automatic developing machine that develops a photopolymerization type lithographic printing plate exposed by VioletCTP while transporting it in a developing bath. There,
The automatic processor comprises a rubbing member in which a plurality of brush members having a brush bristle diameter of 0.05 to 0.09 mm are arranged in the developing bath in the transport direction of the planographic printing plate, and the rubbing member A step of rubbing the lithographic printing plate.

  In the present invention, it is preferable that an FM screen or an AM screen exceeding 240 lines is applied for exposure by VioletCTP.

  According to the present invention, in the development processing for the photopolymerization type lithographic printing plate exposed by VioletCTP, in addition to immersion in a developing bath, rubbing with a plurality of brush members having a brush bristle diameter in the above range is performed. The incompletely hardened portion generated in the non-image portion can be removed without affecting the image portion.

According to the present invention, an automatic developing machine for developing a photopolymerization type lithographic printing plate exposed by Violet CTP, which prevents development processing from becoming uneven and achieves excellent halftone dot reproducibility. A Violet CTP-compatible automatic processor and a development processing method using the automatic processor can be provided.
In addition, the above automatic developing machine and development processing method are more effective when applied to a photosensitive lithographic printing plate exposed in combination with Violet CTP and a high-definition AM screen or FM screen. It is done.

Hereinafter, the automatic processor and the developing method of the present invention will be described in detail.
The automatic developer corresponding to Violet CTP of the present invention is an automatic developer corresponding to Violet CTP for developing a photopolymerization type lithographic printing plate exposed by Violet CTP while being conveyed in a developing bath,
A rubbing member for rubbing the lithographic printing plate in the developing bath,
The rubbing member is composed of a plurality of brush members arranged in the transport direction of the planographic printing plate, and the brush bristle diameter of the brush member is 0.05 to 0.09 mm.

The VioletCTP-compatible development processing method of the present invention is a VioletCTP-compatible development processing method using an automatic developing machine that develops a photopolymerization type lithographic printing plate exposed by VioletCTP while transporting it in a developing bath. There,
The automatic processor comprises a rubbing member in which a plurality of brush members having a brush bristle diameter of 0.05 to 0.09 mm are arranged in the developing bath in the transport direction of the planographic printing plate, and the rubbing member A step of rubbing the lithographic printing plate.
That is, the Violet CTP-compliant development processing method of the present invention is characterized by being performed using the above-described automatic processor of the present invention. For this reason, it demonstrates collectively below.

An automatic developing machine compatible with Violet CTP of the present invention (hereinafter sometimes simply referred to as “automatic developing machine”) will be described with reference to an exemplary embodiment shown in FIG. FIG. 1 is a schematic diagram showing an exemplary embodiment of an automatic processor 100 compatible with Violet CTP according to the present invention.
In this aspect, the rubbing member (brush member) in the present invention corresponds to the brush rollers 142a and 142b.
The lithographic printing plate 102 shown in FIG. 1 is a photopolymerization type lithographic printing plate, and has a structure in which a photopolymerization type photosensitive layer and an overcoat layer are provided in this order on a support. It is what has.

  As shown in FIG. 1, the lithographic printing plate 102 reaches the pre-heating unit 110 located at the left end of FIG. 1 after the exposure processing by Violet CTP is completed.

In the pre-heating unit 110, two transport roller pairs 112 and 114 for transporting the lithographic printing plate 102 while holding it horizontally are disposed, and a heater unit 116 is provided therebetween. A guide plate 118 is provided on the lower side of the transport path of the planographic printing plate 102 so as to face the heater unit 116, and the distance between the heater surface of the heater unit 116 and the planographic printing plate 102 is kept constant. .
By the heating by the heater unit 116, the degree of polymerization of the exposed portion (image portion) of the recording layer of the planographic printing plate 102 is increased, and the printing durability necessary for printing is improved.

A pre-water washing section 120 is provided on the downstream side of the pre-heating section 110 so that the lithographic printing plate 102 that has been pre-heated is fed in a horizontal state.
The pre-wash unit 120 is provided with two conveyance roller pairs 122 and 124 for horizontally holding the lithographic printing plate 102 and conveying the brush, and a brush roller 126 is disposed above the conveyance path therebetween. ing. Further, a spray pipe 128 is disposed slightly upstream from the brush roller 126 so that water is discharged toward the conveyance path. Here, when water is discharged from the spray pipe 128 and the lithographic printing plate 102 is conveyed while the brush roller 126 is rotating (counterclockwise rotation in FIG. 1), the uppermost layer of the lithographic printing plate 102 is transported. Some overcoat layers are wetted and removed by the brush roller 116.
That is, the lithographic printing plate 102 reaches the developing unit 130 in the next step with the overcoat layer removed.

The developing unit 130 is provided with a developing bath 132 in which a developing solution is stored. By immersing the planographic printing plate 102 in the developing solution, the unexposed part (non-image part) of the recording layer is swollen, The unexposed part is removed.
Conveying roller pairs 134 and 136 are provided in the vicinity of the insertion port and the discharging port of the planographic printing plate 102 in the developing unit 130, respectively, and the conveying roller pair 134 guides the planographic printing plate 102 to the developing bath 132. The conveying roller pair 136 has a function of guiding the planographic printing plate 102 to the water washing section 138 after the next process.

The developing bath 132 is provided with a guide plate 140, and the planographic printing plate 102 is guided by the guide plate 140 and conveyed in a large arc. The developing bath 132 is provided with brush rollers 142a and 142b above the conveyance path. A pair of receiving rollers 144a and 146a are opposed to the brush roller 142a below the conveying path, and a pair of receiving rollers 144b are opposed to the brush roller 142b and below the conveying path. 146b is disposed. Accordingly, the planographic printing plate 102 is conveyed while being sandwiched between the brush roller 142a and the receiving rollers 144a and 146a and between the brush roller 142b and the receiving rollers 144b and 146b.
Therefore, the photopolymerization layer of the planographic printing plate 102 is hit by the brush rollers 142a and 142b with a predetermined pressure, and the unexposed portion (non-image portion) of the photopolymerization layer is caused by the rotation of the brush rollers 142a and 142b. Removed.
Further, the incompletely hardened portion generated in the non-image portion is surely removed by brushing the brush rollers 142a and 142b.

The rear washing unit 138 is provided with two transport roller pairs 148 and 150 for horizontally holding and transporting the planographic printing plate 102, and spray pipes 152 and 154 are disposed in the vertical direction of the transport path therebetween. It is installed. Washing water is discharged from the spray pipes 152 and 154.
Here, when the planographic printing plate 102 is discharged from the developing unit 130 and reaches the post-water washing unit 138, water is discharged from the spray pipes 152 and 154, and the front and back surfaces of the planographic printing plate 102 are washed. The washed planographic printing plate 102 is sent to the finisher unit 156 in the next process.

The finisher unit 156 is provided with two conveyance roller pairs 158 and 160 for horizontally holding the lithographic printing plate 102 and conveying it, and a spray pipe 162 is disposed above the conveyance path between them. Yes. A finisher liquid (desensitizing liquid) is discharged from the spray pipe 162.
Here, the finisher liquid is discharged from the spray pipe 162 in a state where the planographic printing plate 102 is being transported horizontally through the finisher unit 156 to coat the image forming surface.

  The above is the process of developing the lithographic printing plate 102. The lithographic printing plate 102 after the completion of these processes is conveyed to a drying section (not shown), and all the processes are completed.

Here, in the automatic developing machine 100, brush rollers 142a and 142b are applied as rubbing members (brush members) in the present invention. Hereinafter, the detailed configuration of the brush rollers 142a and 142b will be described. In addition, what is suitable as a brush member in this invention may be a brush member in which the bristle material exists in the whole circumference | surroundings of a base material, or a bristle material exists in a part of circumference | surroundings of a base material. It may be a brush member.
Hereinafter, the brush member in the present invention will be described in more detail by taking as an example the form of a brush roller in which bristle material exists around the entire circumference of a cylindrical base material. The brush member in the present invention is such a brush. Forms other than a roller may be sufficient.

The brush member in the present invention must have a brush bristle diameter in the range of 0.05 to 0.09 mm. Here, “brush bristle diameter” refers to the diameter of the bristle used in the brush.
The brush bristle diameter is preferably in the range of 0.07 to 0.09 mm.
When the brush bristle diameter is smaller than 0.05 mm, the removability of the incompletely hardened portion generated in the non-image portion is lowered. In addition, when the brush bristle diameter is larger than 0.09 mm, the force for rubbing the plate surface is too strong, which affects the exposed area (image area), and unevenness of the flat mesh occurs.

As the bristle material constituting the brush member, natural fiber, artificial fiber material, metal fiber, or the like is used. Specifically, the following bristle material is used.
・ Natural fiber: plant fiber, animal fiber ・ artificial fiber: polyamide system such as nylon 6, nylon 66, nylon 6/10, nylon 11; polyester system such as polyethylene terephthalate and polybutylene terephthalate; polyacrylontolyl, poly Polyacrylic such as alkyl acrylate, polypropylene, polystyrene, etc., metal fibers: stainless steel, brass, etc.

In addition, the length of the bristle material of the brush member in the present invention (brush hair length) is not particularly limited, but usually the one in the range of 3 mm to 50 mm is used. When the hair length is shorter than 3 mm, the contact with the lithographic printing plate becomes non-uniform, and the plate surface may be easily scratched. On the other hand, when the hair length is longer than 50 mm, there is no merit in development processing by making it long, which is economically disadvantageous.
Here, the “brush hair length” refers to the length L of the hair material protruding from the surface of the base material as shown in FIG.

Moreover, although the density of the bristle material of the brush member in this invention, ie, the flocking density of a brush member, it changes according to the thickness (hair diameter) of the bristle material to be used, Generally, it is 50-200,000. it is preferably in the range of the present / cm ^2, more preferably in the range of 100 to 50,000 present / cm ^2. If the density of the hair material is less than 50 / cm ² , the effect as a rubbing member may be insufficient. Further, the upper limit of the bristle density is determined by the bristle diameter, and for example, the choice of bristle diameter becomes narrower when the bristle density is greater than 200,000 / cm ² .

  Furthermore, when the brush member in the present invention is a brush roller, the roller diameter is preferably in the range of 1 to 12 cm, and more preferably in the range of 2 to 7 cm. The roller diameter indicates the diameter of the roller-shaped substrate. If the roller diameter is less than 1 cm, rubbing tends to be non-uniform. On the other hand, if the roller diameter is larger than 12 cm, it is disadvantageous in terms of the load of the roller rotation motor.

In the automatic processor of the present invention, it is essential that a plurality of brush members as described above are arranged in the transport direction of the planographic printing plate. By using a plurality of brush members in this way, even if the rubbing force of each brush member is reduced, the removability of incompletely hardened portions generated in the non-image area can be improved, and the dot reproducibility is improved. It becomes possible to improve.
In the present invention, from the viewpoint of development processing efficiency and apparatus design, it is a preferable aspect that two brush members are arranged as shown in FIG.
When this brush member is one, even if the brush bristle diameter is in the range of 0.05 to 0.09 mm, the incompletely cured portion generated in the non-image portion is not sufficiently removed, Unevenness is likely to occur.
Moreover, these brush members may use the same thing, respectively, and may use it combining different things.

Next, VioletCTP used in the present invention will be described. Violet CTP is a type of CTP that employs a violet laser as a drawing laser with the development of a violet laser using a blue LED.
Here, the violet laser is a laser having a wavelength of 390 to 420 nm, and is mass-produced as a consumer device such as a DVD. Therefore, the violet laser is said to be low in price and high in reliability.
The feature of VioletCTP is
1. 1. The internal drum system is easier to make and faster than thermal CTP. 2. Imaging units such as lasers are cheaper, and the internal drum can reduce the size of the motor, etc. Also, it generates less heat than thermal, and there are few problems with plate elongation (registration accuracy) due to temperature changes. It is possible to work under yellow safety light.

  Examples of such VioletCTP include Vx9600CTP and Vx6000CTP manufactured by Fuji Photo Film Co., Ltd., MAKO4 manufactured by ECRM, and the like.

In addition, each screen that performs gradation expression by controlling the state of halftone dots in combination with such VioletCTP will be described.
A so-called AM screen that has been used in the past performs gradation expression by changing the size of dots (halftone dots). When a plurality of halftone images are overlaid by printing or the like, there is a problem that nonuniformity called moire occurs due to interference with the original document image or a hexagonal pattern called rosette.
In recent years, there has been an increasing demand for more beautiful printed materials, and there has been a demand for a method for producing printed materials with higher definition than before.

One of the methods for obtaining a higher-definition printed material is a method using a higher number of lines (finer) halftone dots. For example, by using a 240-line or 300-line AM screen, a cleaner printed product can be obtained.
Another method is to use a so-called FM screen. The FM screen does not change the halftone dot size, but changes the halftone dot arrangement interval to express the gradation, but the halftone dot arrangement is performed randomly to eliminate the influence of the angle. The above-mentioned problems such as moire and rosetta do not occur theoretically. Furthermore, a high-definition printed matter can be obtained by using a fine halftone dot.

In recent years, as a result of the advancement of computers, it has become possible to easily calculate the network layout pattern on FM screens, which has been considered a problem in the past. An improvement has been achieved.
The FM screen is easily available as a commercial product. For example, “TAFFETA” manufactured by Fuji Photo Film Co., “Staccato” manufactured by Creo Co., “Diamond Screen” manufactured by Heidelberg Co., Ltd. “Satin Screen”, “Landot” manufactured by Dainippon Screen Co., Ltd., “Landot X” (both are trade names), and the like are known.

  In the method of the present invention, from the viewpoint of forming a high-quality image, the effect of the present invention is remarkable when the dot diameter of the FM screen used is 50 μm or less, more preferably in the range of 20 to 30 μm. It is.

  High-definition AM screens and FM screens of 240 lines or more as described above can be used mainly in combination with each manufacturer's Violet CTP setter. By this combination, the stability of halftone dot reproduction when creating a lithographic printing plate has been dramatically improved, so that a printing original plate capable of forming a high-definition image can be produced relatively easily. Have advantages.

<Photopolymerization planographic printing plate>
Next, the photopolymerization type lithographic printing plate used in the present invention will be described.
In the present invention, any photopolymerization planographic printing plate capable of forming an image by exposure according to the Violet CTP can be used without any limitation. Examples of the photopolymerization type lithographic printing plate include a so-called photopolymer type lithographic printing plate.
Hereinafter, a photopolymer type lithographic printing plate suitable for the present invention will be briefly described.

The photopolymer type lithographic printing plate has at least a photosensitive layer sensitive to a violet laser on a hydrophilic support represented by an aluminum plate.
The photopolymerizable composition constituting the photosensitive layer contains an ethylenically unsaturated bond-containing compound capable of addition polymerization, a photopolymerization initiator, and a polymer binder as essential components, and may be colored as necessary. Various compounds such as an agent, a plasticizer and a thermal polymerization inhibitor are contained.
When such a photopolymerizable composition is irradiated with a violet laser, the ethylenically unsaturated bond-containing compound is addition-polymerized and cured by the action of a photopolymerization initiator.

  The ethylenically unsaturated bond-containing compound can be arbitrarily selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more, and examples thereof include monomers and prepolymers (that is, 2 , Trimers and oligomers), mixtures thereof, and copolymers thereof. Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid) and aliphatic polyhydric alcohol compounds, unsaturated carboxylic acids and aliphatic polyhydric compounds. And amides with a polyvalent amine compound. Urethane addition polymerizable compounds are also suitable.

  Moreover, as a photoinitiator contained in a photopolymerizable composition, according to the wavelength of the light source to be used, various photoinitiators or a combination system (photoinitiator) of two or more photoinitiators is used. For example, it is preferable to use an initiation system indicated by paragraph numbers [0021] to [0023] of JP-A-2001-22079.

  Furthermore, the polymer binder contained in the photopolymerizable composition not only functions as a film-forming agent for the photopolymerizable composition, but also needs to dissolve the photosensitive layer in an alkali developer. Organic polymers that are soluble or swellable are used. As such a polymer binder, those shown in paragraph numbers [0036] to [0063] of JP-A-2001-22079 are useful.

  In addition, an additive (for example, a surfactant for improving coatability) shown in paragraph numbers [0079] to [0088] of JP-A-2001-22079 is included in the photopolymerizable composition. It is also preferable to add.

Further, it is preferable to provide an oxygen-blocking overcoat layer on the photosensitive layer in order to prevent the action of inhibiting the polymerization of oxygen. Examples of the polymer contained in the overcoat layer include polyvinyl alcohol and its copolymer.
Furthermore, it is also preferable to provide an intermediate layer or an adhesive layer as shown in paragraphs [0124] to [0165] of JP-A-2001-228608 between the photosensitive layer and the hydrophilic support. It is.

  As a developer or a replenisher used for developing the photopolymerization type lithographic printing plate as described above, a conventionally known alkaline aqueous solution can be appropriately selected and used. Examples of the alkali agent that can be used in the alkaline aqueous solution include inorganic alkali salts such as sodium silicate and potassium, and organic alkali agents such as monomethylamine, dimethylamine, trimethylamine, triethanolamine, ethyleneimine, and pyridine. These may be used alone or in combination of two or more.

  The lithographic printing plate after being developed by the automatic processor of the present invention is subjected to post-treatment with water-washing water, a rinsing liquid containing a surfactant and the like, a desensitizing liquid containing gum arabic and starch derivatives, and is applied to the printing cylinder. Set and used for printing.

According to the present invention, the lithographic printing plate exposed by Violet CTP is developed by the above-described automatic developing machine of the present invention, so that the incompletely cured portion in the non-image portion caused by Violet CTP is obtained. It can be removed without affecting the image area. As a result, according to the present invention, halftone dot reproducibility can be improved.
In particular, when the Violet CTP is combined with a high-definition AM screen or FM screen having 240 lines or more, the above-described effects of the present invention are remarkably exhibited.

EXAMPLES Hereinafter, although this invention is demonstrated according to an Example, the scope of the present invention is not limited to these Examples.
(Examples 1-2, Comparative Examples 1-3)
As a photopolymerization type lithographic printing plate, PV-N manufactured by Fuji Photo Film Co., Ltd. was used, and the entire flat screen was exposed by VioletCTP as described below. Then, it developed with the following automatic developing machine.

[VioletCTP]
Fuji Photo Film Co., Ltd. CTP setter LuxelV9600CTP
-Screen used: FM screen TAFFETA20 manufactured by Fuji Photo Film Co., Ltd.
[Automatic processor]
Remodeling machine of RaptorFLV85 manufactured by G & J Co., Ltd. (installed with brush rollers having brush bristle diameter, brush roller diameter, brush bristle length, and bristle material density described in Table 1 below)
・ Developer / Replenisher: Developer DV-2 / Replenisher DV-2R manufactured by Fuji Photo Film Co., Ltd.
Finisher liquid: Finisher FP-2W manufactured by Fuji Photo Film Co., Ltd.

The unevenness of the flat net in the lithographic printing plate after the development treatment was visually evaluated.
Moreover, the in-plane difference of the halftone dot size in the lithographic printing plate after the development processing was measured using iCPlate II manufactured by GRETAGMACBETH.
These results are shown in Table 1 below.

As is apparent from Table 1, the lithographic printing plate developed by the automatic processor of the present invention has some level of unevenness in the flat screen, but has a practically no problem level. The internal difference proved to be good. Thereby, in Example 1 and Example 2, it turned out that it is excellent in halftone dot reproducibility.
On the other hand, it was found that when an automatic processor having a brush member outside the scope of the present invention was used as in the comparative example, unevenness of the flat mesh and / or in-plane difference of the dot size deteriorated.

(Example 3, Comparative Examples 4-6)
As a photopolymerization type lithographic printing plate, PV-N manufactured by Fuji Photo Film Co., Ltd. was used, and the entire flat screen was exposed by VioletCTP as described below. Then, it developed with the following automatic developing machine.

[VioletCTP]
Fuji Photo Film Co., Ltd. CTP setter LuxelV9600CTP
・ Screen used: CoRe300 manufactured by Fuji Photo Film Co., Ltd.
[Automatic processor]
A modified machine of RaptorFLV85 manufactured by G & J Co., Ltd. (installed with brush rollers having brush bristle diameter, brush roller diameter, brush bristle length, and bristle material density as shown in Table 1 below)
・ Developer / Replenisher: Developer DV-2 / Replenisher DV-2R manufactured by Fuji Photo Film Co., Ltd.
Finisher liquid: Finisher FP-2W manufactured by Fuji Photo Film Co., Ltd.

  The same method as in Example 1 was used to evaluate flat screen unevenness and halftone dot size difference in the lithographic printing plate after development. These results are shown in Table 2 below.

As is apparent from Table 2, the lithographic printing plate developed by the automatic processor of the present invention was found to be excellent in both flat screen unevenness and in-plane difference in halftone dot size. It turned out to be excellent.
On the other hand, it was found that when an automatic processor having a brush member outside the scope of the present invention was used as in the comparative example, unevenness of the flat mesh and / or in-plane difference of the dot size deteriorated.

1 is a schematic view illustrating an exemplary embodiment of a VioletCTP-compatible automatic processor according to the present invention. It is sectional drawing of the brush member for specifying brush bristle length.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Automatic processor 102 Planographic printing plate 110 Preheating part 112,114 Conveying roller pair 116 Heater unit 118 Guide plate 120 Pre-washing part 122 Conveying roller pair 126 Brush roller 128 Spray pipe 130 Developing part 132 Developing bath 134, 136 Conveying roller pair 138 After-water washing part 140 Guide plate 142a, 142b Brush roller (Rubbing member, Brush member)
144a, 144b, 146a, 146b Receiving roller 156 Finisher 148, 150 Conveying roller pair 152 Spray pipe 156 Finisher 158, 160 Conveying roller pair 162 Spray pipe

Claims (2)

An automatic developing machine compatible with VioletCTP that develops a photopolymerization type lithographic printing plate exposed by VioletCTP while transporting it in a developing bath,
A rubbing member for rubbing the lithographic printing plate in the developing bath,
VioletCTP-compatible automatic, characterized in that the rubbing member comprises a plurality of brush members arranged in the transport direction of the lithographic printing plate, and the brush bristle diameter of the brush member is 0.05 to 0.09 mm Developing machine. A development processing method corresponding to Violet CTP using an automatic developing machine that develops a photopolymerization type lithographic printing plate exposed by Violet CTP while transporting it in a developing bath,
The automatic processor comprises a rubbing member in which a plurality of brush members having a brush bristle diameter of 0.05 to 0.09 mm are arranged in the developing bath in the transport direction of the planographic printing plate, and the rubbing member A development process method compatible with Violet CTP, comprising the step of rubbing the lithographic printing plate.

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