JPH10198044A - Developing device for photosensitive planographic printing plate and morton roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device for photosensitive planographic printing plates capable of eliminating the need for executing the adjustment of a development accelerating means at every time and eventually prolonging the life of this development accelerating means and stably executing development with good image quality for a long period of time and a Morton roller. SOLUTION: This developing device executes accelerated development by bringing a developer into contact with the photosensitive planographic printing plate 2 and rubbing the surface of the photosensitive planographic printing plate 2 by the Morton roller 15 covered with a sliding contact material consisting of a flexible and soft material on its outer peripheral surface. In such a case, the Morton roller is constituted by putting the cylindrical sliding contact material on a roller base body and fixing the sliding contact material in the state that the material is twisted over the entire length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for a photosensitive lithographic printing plate subjected to image exposure. More specifically,
The present invention relates to a photosensitive lithographic developing machine capable of continuously and automatically developing a large number of photosensitive lithographic printing plates, having good image quality over a long period of time, and capable of performing stable development.

[0002]

2. Description of the Related Art Conventionally, as a method for developing a large number of photosensitive lithographic printing plates subjected to image exposure, for example, JP-A-1-310
As described in No. 354, the photosensitive lithographic printing plate is transported and immersed in a developing tank in which a developer is stretched, and is subjected to a developing treatment.
A so-called dip development method has been proposed. Also, in order to perform good development processing with less residual film in the non-image area and to shorten the time required for development, a development accelerating means is arranged in the developing tank, and the surface of the photosensitive material is rubbed in the processing solution. While developing, a method has been proposed.

Conventionally, a brush roller driven separately from a transport system has been used as the development accelerating means. Recently, a Molton roller is often used from the viewpoint of eliminating the trace of the developing brush. However, in the case of the Molton roller, when the surface of the Molton is worn, the contact between the Molton roller and the plate changes, and there is a problem that the developing property becomes uneven under the initial development setting conditions. Therefore, in this case, periodically according to the number of processed photosensitive lithographic printing plates,
Development control such as adjusting the contact strength between the Molton roller and the plate (pressing pressure, pressing amount, number of revolutions, etc.) was required, and eventually the Molton roller had to be replaced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art, eliminate the need for frequent adjustments of the development promoting means, and thus extend the life of the development promoting means, and improve image quality over a long period of time. An object of the present invention is to provide a photosensitive lithographic printing plate developing device and a Molton roller capable of performing stable development. Another object of the present invention is to provide a printing plate having a better developing property than that of the prior art, enabling a more accurate printing plate developing process, and thereby enabling a printing plate developing process capable of supporting high-definition printing. It is another object of the present invention to provide a developing device having a development promoting means.

[0005]

Means for Solving the Problems The present inventor has conducted intensive studies in order to achieve the above object, and as a result, the surface sliding contact material of the Molton roller for promoting development has been twisted about the axis of the roller. By fixing it with, it was made to find that the purpose can be achieved, and the developer is brought into contact with the photosensitive lithographic printing plate and the outer peripheral surface is covered with a Molton roller covered with a sliding contact material made of a flexible material. In a developing device for a photosensitive lithographic printing plate, which performs an accelerating phenomenon by rubbing the surface of the photosensitive lithographic printing plate, a Molton roller covers a roller base with a cylindrical sliding contact material, and the sliding contact material extends over the entire length. A developing device for a photosensitive lithographic printing plate characterized by being fixed in a twisted state, and the Molton roller.

[0006]

FIG. 1 shows an embodiment of a developing device for a photosensitive lithographic printing plate according to the present invention.
Are feed rollers 3a, 3 for supplying the photosensitive lithographic printing plate 2;
b, a developing mechanism 5 for performing development by bringing the developing solution 4 into contact with the fed printing plate 2, and feed rollers 6 a and 6 b for feeding the developed printing plate 2. The printing plate 2 has a washing or rinsing mechanism 7 for washing or rinsing the developed printing plate 2 and a gumming mechanism 8 for protecting the surface of the printing plate 2.

When the printing plate 2 has a water-soluble protective layer on the surface of the photosensitive layer, such as when the printing plate 2 is formed of a photosensitive layer using a photopolymerizable composition, the feed rollers 3a, 3b
A pre-rinsing mechanism (not shown) for removing the protective layer before the process can be provided. In addition, a drying mechanism or the like may be added. In the present invention, the type of the developing mechanism 5 is not particularly limited, and a developing solution spray system, a shower system, an immersion system and the like can be used. In FIG. 1, the developing mechanism 5 based on the immersion system is used. ,
The printing plate 2 supplied by the feed rollers 3a and 3b is fed downward while being inclined along a guide plate 11 provided in a developing solution tank 10 of the developing mechanism 5, and is immersed in the developing solution 4 at a minimum. It is configured to be fed upward from the point 11a. The developing solution 4 is supplied with pressure from a pipe 13 provided at the bottom of the developing solution tank 10 by a pump 14, and is ejected and supplied in a shower form from a developing solution supply pipe 12.
It is designed to be used cyclically.

Further, the printing plate 2 immersed in the developing solution 4 and coming into contact with the developing solution 4 is rubbed in sliding contact with the Molton rollers 15, 15 to promote development. Although two Molton rollers 15 are provided in the figure, any number of Molton rollers 15 may be used as needed, and generally 1 to 5 rollers are used. As shown in FIG. 2, the Molton roller 15 is composed of a roller base 19 and a sliding contact member 20, and the roller base 19 is made of a metal rotating shaft 16 and a hard plastic made of the rotating shaft 16 as shown in FIG. A roller unit 17 formed by fitting a cylindrical body having reduced diameter portions 17a at both ends and a gear 18 for rotating and driving the Molton roller 15 are provided. As shown in FIG. 2, it is covered with a sliding contact material 20 made of a flexible material, so-called Molton.

The sliding contact material 20 is used for accelerating the developing speed by rubbing the surface of the printing plate 2 in contact with the developing solution 4, and is made of a material which is not affected by the developing solution, and is generally resistant to alkali. Any synthetic resin such as polypropylene, polyethylene, polyamide, and polyvinyl chloride can be used. Particularly, polypropylene is preferable. Further, those having elasticity as well as flexibility are desirable. Therefore, it is desirable to use a fibrous body as a nonwoven fabric, a knitted woven fabric, that is, a woven fabric and a knitted fabric as the sliding contact material. The woven fabric may have a short pile on the surface.

The sliding contact member 20 is formed in a tubular shape, and after the roller base 19 of the Molton roller 15 is inserted, one end 2 thereof is formed.
After tightening Oa to the end of the roller portion 17 with a metal wire or the like, the other end is brought into a state in which the torsional contact member 20 is spirally twisted, and then the other end 20b is tightened.

In order to prevent the Moulton roller 15 from sagging during use, it is desirable to twist the Moulton roller 15 in a direction B that is opposite to the rotation direction A of the Moulton roller 15. The amount of twist is such that the entire sliding contact material 20 is
It is desirable that the tension is applied to the torsional contact material as much as possible to the extent that it is twisted so as to make close contact. Generally, sliding contact material 20
However, it is twisted about 1 to 10 rotations, preferably about 2 to 7 rotations per meter.

When the photosensitive lithographic printing plate developing apparatus 1 of the present invention is used for developing, the photosensitive lithographic printing plate 2 is made of an aluminum plate, a zinc plate, an iron plate, a paper plate having a photosensitive layer whose solubility is changed by light irradiation. An aluminum plate is one that is applied on a support such as a plastic plate, and the mainstream of the support is an aluminum plate. The surface of these plate bodies is grained, subjected to chemical etching and electrolytic etching as required, and then subjected to anodic oxidation, silicate treatment and the like. The photosensitive layer includes an orthoquinonediazide compound, a diazonium salt compound, an azide compound, a photopolymerizable compound, a photocrosslinkable compound, and the like. Therefore, any of the conventional positive and negative types can be used without any problem.

The exposure light source applicable to the photosensitive lithographic printing plate 2 used in the present invention is not particularly limited. A helium cadmium laser, an argon ion laser, a YAG laser, a helium ion laser and the like can be particularly preferably used. In FIG.
The printing plate 2 which has been exposed to form a latent image and which has been preliminarily washed with water is supplied to a developing mechanism 5 by feed rollers 3a and 3b, and is brought into contact with a developing solution 4 supplied from a developing solution supply pipe 12. You.

The developer and replenisher which can be used in the present invention are those which elute or remove the photosensitive layer of the photosensitive lithographic printing plate 2. For example, in the case of a photosensitive layer comprising an orthoquinonediazide compound, sodium silicate or potassium silicate is used. An aqueous solution is used. The diazonium salt compound varies depending on the binder used for the photosensitive layer. For example, when the binder is an alkali-soluble resin, the main component is an alkali agent. As described above, a developer and a replenisher which are conventionally used can be used as they are. The printing plate 2, which has started the developing process by contacting with the developer 4, comes into contact with the independently rotating Molton rollers 15, 15, and is rubbed by the sliding contact material 20 to perform accelerated development. Printing plate 2 after development
Is fed to the washing or rinsing mechanism 7 by the feed rollers 6a and 6b, washed or rinsed, and further sent to the gumming mechanism 8 to form a surface protective layer, and the developing process is completed.

[0015]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Preparation of printing plate for photosensitive lithographic plate After an aluminum plate having a thickness of 0.24 mm was degreased, the surface was polished and grained using a nylon brush while flowing a liquid in which pumice powder was suspended in water. . The aluminum plate was treated with a 30% phosphoric acid aqueous solution as an electrolytic bath at a liquid temperature of 3%.
Anodizing was performed at 5 ° C. for 1 minute under the conditions of a current density of 4 A / dm ² to obtain an aluminum support having an oxide film having a film weight of 17 mg / dm ² . A coating solution of the photopolymerizable composition having the following composition was applied to the obtained support using a bar coater to a dry weight of 2 g / m ² and dried.

Coating solution of photopolymerizable composition 30 parts by weight of trimethylolpropane triacrylate 20 parts by weight of an ethylenic compound having the following structure 50 parts by weight of a polymer binder shown in Table 1 Sensitizer having the following structure 2 parts by weight Activator having the following structure Chemical formula-3 2 parts by weight 2-methylcaptobenzothiazole 5 parts by weight Copper phthalocyanine pigment 3 parts by weight Methyl ethyl ketone 900 parts by weight

[0017]

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[0018]

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[0019]

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[0020]

[Table 1]

On a plate obtained by dry coating, a protective layer solution having the following composition containing a water-soluble polymer binder was applied using a bar coater so that the dry weight was 4 g / m ² , and dried. Thus, a photosensitive lithographic printing plate of a high sensitivity photopolymer type comprising a photopolymerizable photosensitive layer and a protective layer was obtained. Protective layer solution containing water-soluble polymer binder polyvinyl alcohol GL-03 10 parts by weight [manufactured by Nippon Gohsei Co., Ltd.] Liponox NC-95 [manufactured by Lion Corporation] 0.02 parts by weight Demineralized water 90 parts by weight Department

(Exposure of a photosensitive lithographic printing plate) Image exposure was performed using an argon ion laser type plate setter PI-R1080 manufactured by Dainippon Screen Mfg. Co., Ltd. The exposure conditions at this time are as follows. Plate surface exposure amount: 3.5 mW, resolution: 4000 dpi. Screen dots were square, and screen gradation was performed without correction.

(Preparation of developer and replenisher) A developer having the following composition diluted three times with water and a replenisher having the following composition diluted two times with water were prepared. Developer potassium hydroxide 1.5% by weight Perex NBL [manufactured by Kao Corporation] 11% by weight (sodium alkyl sulfonate content 35%) Water 82.5% by weight Replenisher potassium hydroxide 2.5% by weight Perex NBL [Kao Corporation] 11% by weight (Sodium alkyl sulfonate content 35%) Water 81.5% by weight

(Preparation of Development Acceleration Means) A Molton roller 15 having the structure shown in FIG. 2 was used. That is, the length is 942 mm
A polyurethane sleeve having a diameter of 30 mm and a length of 895 mm is mounted on the rotary shaft 16 of the above to form a roller portion 17, and a cylindrical sliding contact member 20 made of a knitted material made of polypropylene fiber is covered thereon, and a driving gear 18 were tightened at the mounting end. Next, the sliding contact member 20 was twisted in a direction opposite to the rotation direction of the Molton roller. At this time, it was noted that the Molton sleeve was twisted uniformly and that the surface of the Molton sleeve was not wrinkled. Twisting about 5 turns, the surface of the Moulton roller became dense and could not be twisted any further. Therefore, the end of the sliding contact member 20 at the end of the roll opposite to the part where the driving gear was mounted was attached. I was tight. Two of these were produced and used as the Molton roller 15 of the example.
A Molton roller 15 was similarly formed using the same roller base 19 and sliding contact material 20 except that no twist was applied to the sliding contact material 20, and used in Comparative Examples.

(Development of a photosensitive lithographic printing plate) The development accelerating means (Molton roller) of the present invention is provided with an automatic developing machine HL-86.
0X (manufactured by Mitsubishi Chemical Corporation) and the developer 24
When the photosensitive lithographic printing plate is charged and subjected to development processing, the photosensitive lithographic printing plate passes through a pre-washing zone, a developing zone, is subsequently washed with a water in a washing zone, further passes through a drying zone, and exits from an automatic developing device. It was confirmed that a photosensitive lithographic printing plate having development reproducibility was obtained. Also,
40 ml / replenishment of the photosensitive lithographic printing plate developer
m ^2, and the above-mentioned replenisher was used as the replenisher.

Example 1 and Comparative Examples 1 and 2 The photosensitive lithographic printing plate (size 1030 mm × 800 mm) was processed into 500 plates using an automatic developing machine under the above conditions.
The weight of the developing member was measured at a ratio of one plate to the 00 plate, and the amount of abrasion corresponding to the number of processed sheets was examined. At the same time, the image reproducibility (removal of minute spots) at that time was examined. The results are shown in the column described in Example 2 in Table 2. Further, as a comparative example, an experiment was also performed in which the moleton was installed in a straight line without giving a twist. The results are shown in Comparative Example-1 in Table 2. Further, an experiment in which the strength (pressing amount) of the development accelerating means against the plate was changed was also performed. The results are shown as Comparative Example-2 in Table 2. Here wear amount in A, the weight of Morton before development processing M _0, if the weight of the Molton after development was M _n (n denotes the number of processed), the value indicated by the formula (1) Yes, indicates the degree of wear of the development accelerating means. That is, a wear amount of 0 indicates no wear, and a wear amount of 100 indicates all wear.

[0027]

## EQU1 ## Wear amount (Δ%) = {(M ₀ −M _n ) / M ₀ } × 100 (1)

[0028]

[Table 2] ：: good, Δ: slightly poor, ×: poor.

In Example 1, the abrasion loss was as small as 2% or less even after the 500-plate processing, and the image reproducibility was unchanged, and a stable image was obtained. In contrast, Comparative Example-1
In the case of No., it can be seen that the molton needs to be replaced from the viewpoint of image reproducibility at the time of processing the 400 plate. Further, in the case of Comparative Example-2, the image reproducibility can be stabilized by changing the contact strength of the plate with the developing member during the development (in this case, the adjustment was performed at the time of processing the 200 plate). ), It was found that the wear was advanced even in that case. That is, even in the case of Comparative Example-2, if the influence of the wear amount on the developability exceeds the adjustment range, it is necessary to replace the development accelerating means, and it is conceivable that a large amount of labor is required for maintenance. As can be seen from the above results, it was found that the amount of abrasion can be suppressed by using the development accelerating means of the present invention.

(Example-2 and Comparative Examples-3 and 4) The image shown in FIG. 4 was exposed to a photosensitive lithographic printing plate so that the removability in development could be evaluated. This was processed using an automatic processor under the above conditions (size 1030 mm × 800 m
m), and the image reproducibility (removal of minute points) at that time was examined. The results are shown in Example 2 of Table 3. As a comparative example, an experiment in which the moleton was installed in a straight line was also performed. The results are shown in Comparative Example-3 in Table 3. Further, an experiment was conducted in which the strength (pressing amount) of the developing member against the plate during the development was changed. The results are shown in Comparative Example-4 of Table 3.

[0031]

[Table 3] ：: good, Δ: slightly poor, ×: poor.

In the present embodiment-2, 175 lpi to 350
A good image reproducibility was obtained up to lpi, and a printing plate of an image having a large number of lines corresponding to high-definition printing was obtained. For it,
In the case of Comparative Example-3, an image cannot be reproduced at 350 lpi, and printing plate processing that can support high-definition printing cannot be performed.
In the case of Comparative Example-4, a good image could be obtained at 200 lpi by changing the contact strength of the developing member to the plate.
At pi, the image became slightly jumpy. Also, 350 lpi
Then, the omission was still insufficient. As can be seen from the above results, by using the development accelerating means of the present invention, it is possible to satisfactorily develop a high number of lines and obtain a printing plate of an image corresponding to high-definition printing.

[0033]

As is clear from the above-mentioned Example-1,
By using a photosensitive lithographic printing plate developing machine using the development accelerating means of the present invention, it is possible to suppress abrasion of a developing member for developing a photosensitive lithographic printing plate, which occurs when a large number of photosensitive lithographic printing plates are processed. This eliminates the need for adjustment and replacement over a long period of time, and can always maintain stable developing properties. Further, as is apparent from the above-mentioned Example-2, by using the developing device for a photosensitive lithographic printing plate using the development accelerating means of the present invention, a more accurate printing plate developing process becomes possible. This makes it possible to develop a printing plate capable of supporting high-definition printing.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an example of a photosensitive lithographic printing plate developing device of the present invention.

FIG. 2 is a perspective view showing an example of a Molton roller.

FIG. 3 is a side view of a roller base for a Molton roller.

FIG. 4 is an image of a printing plate used in a test in Example 2.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 developing device 2 photosensitive lithographic printing plate 5 developing mechanism 7 washing or rinsing mechanism 8 gumming mechanism 12 developer supply pipe 15 molton roller 19 roller base 20 sliding contact material

Claims (5)

[Claims] An accelerated development is achieved by bringing a developer into contact with a photosensitive lithographic printing plate and rubbing the surface of the photosensitive lithographic printing plate with a Molton roller whose outer peripheral surface is covered with a sliding contact material made of a flexible material. In a photosensitive lithographic printing plate developing apparatus to be performed, a Molton roller is formed by covering a roller base with a cylindrical sliding contact member and fixing the sliding contact member in a twisted state over its entire length. Developing device for lithographic printing. 2. The developing device for a photosensitive lithographic printing plate according to claim 1, wherein the sliding contact material of the Molton roller is given a twist of 1 to 10 rotations per 1 m in length. 3. The photosensitive lithographic printing plate developing device according to claim 1, wherein the sliding member of the Molton roller is made of a knitted and woven fabric of polypropylene fibers. 4. The developing apparatus for a photosensitive lithographic printing plate according to claim 1, wherein the photosensitive lithographic printing plate has a photosensitive layer composed of a photopolymerizable composition. 5. A molton roller which accelerates development by rubbing the surface of a printing plate in a state in which the photosensitive plate is in contact with a developing solution, wherein the molton roller comprises:
A Molton roller, comprising a roller base material covered with a cylindrical sliding material made of a flexible material, and the sliding material fixed in a twisted state over its entire length.