JPH01150141A - Development processing device for photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To uniformly develop a planographic printing plate with a small volume of developing soln. by specifying the position of a guide roller for carrying. CONSTITUTION:The guide roller 3 for carrying to be positioned between carrying rollers 1 and an inclined roller 4 is provided on the position lower than the rollers 1, 4. The planographic printing plate 2 is nipped and carried by the rollers 1. The plate 2 is retained by the roller 3 and is carried in an ascending direction. The plate 2 is then passed along the bottom end of a developing soln. supplying material 7 and a liquid pool 9 by the developing soln. supplied from a slit of the member 7 is formed. The plate 2 is in succession carried while the plate 2 is raised by the roller 4 so as to pass along a brush roller 10. The development is finished by squeezing the developing soln. with a squeezing roller 11. The surface of the roller 3 is preferably roughened.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for developing a photosensitive lithographic printing plate (hereinafter referred to as a "PS plate") and an apparatus used therein, and more specifically to an automatic development method that supplies unused developer to each PS plate for development. The present invention relates to a PS plate development processing device suitable for the printing press.

[Conventional technology]

When processing a large number of exposed PS plates, it is common to use an automatic developing machine. When processing an exposed PS plate in an automatic developing machine, there are two methods: developing by spraying a developer while horizontally transporting the PS plate, or placing the PS plate in a developing tank containing a large amount of developer. A method is used in which the printing plate is immersed and developed while being conveyed in a curved manner. In all of these processing methods, it is necessary to prepare a large amount of developer to process one PS plate. In addition, in order to use the developer economically, it is recycled and reused, and during this process, the developer deteriorates due to the absorption of carbon dioxide gas from the air, in addition to deterioration due to processing, and the deteriorated developer is often used. It has to be replaced, which makes managing the developing work extremely troublesome. In order to improve the above-mentioned drawbacks, a method is known in which when a PS plate is processed with a large amount of circulating and reused developer, a replenisher is added to keep the development process stable.
No. 4502, No. 55-115039, No. 58-953
No. 49, etc. Although this replenishment method reduces the frequency of fluid exchange, it is still necessary to replace the fluid.
In addition, the problem of replenishment accuracy and replenishment fluctuations due to product differences between PS plates could not be resolved. In addition, a replenishment device is required, and not only is the replenishment device itself expensive, but it also requires adjustment and maintenance of the replenishment device. JP-A-55-32044 discloses a processing apparatus which eliminates the troublesome replenishment method and saves developer. This device is equipped with a developer diffusion plate close to the photosensitive material transfer path in the automatic processor, and stretches the developer applied on the 23rd plate. In the processing method, the 13th plate being transported is not necessarily horizontal and is slightly distorted up and down, so the amount of developer tends to be uneven, which tends to cause uneven development, and the 13th plate being processed and the developer diffusion plate There is a disadvantage that it takes time to adjust the gap between the developer plate and the 23 plate, and especially when a small amount of developer is dropped directly onto the 23 plate surface, there is a difference in development speed between the dripping part and the non-dropping part, and after passing through the development diffusion plate, This difference may remain, resulting in uneven development, resulting in an undesirable printing plate. We have improved this drawback and developed a 28-plate developing method and device that can stably perform development using a small amount of developer.
I have already filed an application as No. 1. Base slit supply was carried out as a means for stably coating and developing, but if the developer was supplied from the slit to the 28 plate on the horizontal plane, there would be thick and thin parts of the developer. It has been found that in order to stably obtain a uniform film thickness, it is sufficient to create a liquid pool at the exit of the slit. As a means of dealing with this, we took measures by transporting the material upward. The conveyance guide roller and the inclined roller create an upward slope, which creates a liquid pool in the slit area, making stable development possible. However, we have found that there is a problem in that the developer leaks from the slit and adheres to the conveyance roller, causing stains on the subsequent 28th plate.

[Problems to be solved by the invention]

In view of the above-mentioned problems, an object of the present invention is to provide a stable, uniform, and highly accurate developing device in a method for developing 13 plates using a small amount of developer.

[Means to solve the problem]

The above-mentioned object of the present invention is to provide a method for automatically conveying and developing a photosensitive lithographic printing plate using an automatic developing machine, in which a substantially unused developer is transferred to one part of the photosensitive lithographic printing plate. In an apparatus that feeds and develops each plate, a conveying guide roller positioned between a conveying roller and an inclined roller presses down the photosensitive planographic printing plate from above, and the conveying guide roller is positioned between a conveying roller and an inclined roller. This was achieved by a photosensitive lithographic printing plate development processing device that is located at a low position. Further, it is preferable that the surface of the conveyance guide roller of the development processing apparatus is roughened. The present invention will be described in detail below based on embodiments shown in the drawings. FIG. 1 is a side sectional view showing an example of an apparatus for carrying out the present invention. In Fig. 1, 1 is a pair of transport rollers that nip and transport the 25-plate 2, and 3 is a transport guide roller, hereinafter referred to as a press roller, which keeps the 25-plate 2 in the proper transport position. It is located at a lower position than the transport roller pair l. Therefore, the 25 plate 2 is carried into the press roller 3 while descending. 4 is an inclined roller, and 25 is supplied with developer.
It is provided so that the plate 2 is conveyed in an upward direction toward the conveyance direction. Therefore, the 28th plate that has passed the presser roller 3 is conveyed while being slightly raised. Reference numeral 5 denotes a developer tank, and the developer therein is sent to a developer supplying vibro by a pump 5a. Reference numeral 7 denotes a developer supply member, which has a slit formed by two plates at its lower end, and the developer flowing down from the developer supply vibro is supplied to the 25 plate 2 through this slit. When the 25 plate 2 has not passed the lower end of the developer supply member 7, the lower end of the developer supply member 7, that is, the lower end of the slit is in contact with the developer roller 8, and the developer supply member 7
When the PS plate being transported is in this position, the developer supply member 7 A developer pool 9 is formed in a concave portion in the medial direction formed at the contact portion between the lower end of the plate 2 and the 23rd plate 2. It is preferable that each of the above-mentioned rollers is provided so that the back surface of the PS plate does not come into contact with the developing roller except for its leading and trailing ends. The 23rd plate 2 being conveyed is first conveyed through the press roller 3. At this time, as described above, the 23rd plate 2 enters the presser roller 3 while descending and exits while rising. FIG. 2 is a partially enlarged sectional view of the vicinity of the presser roller in FIG. 1. In FIG. 2, 01 is the angle at which the PS plate enters the presser roller, and θ2 is the angle at which it exits. Due to the angle θ1, the developer leaks from between the developer supply member 7 and the PS plate or the developer roller 8 and is transferred to the transport roller l.
It is possible to stop the flow towards. The angle is 06
~60°, preferably 5° to 20°. FIG. 3 is a perspective view showing one embodiment of the presser roller 3, in which rubber O-rings 14 as shown are attached to a metal or plastic roller 13 at intervals of 5 to 10 cm. It is preferable to roughen the surface of the presser roller 3 in this way. That is, by roughening the surface in this manner, the contact area with the PS plate is reduced, thereby minimizing the influence of developer stains on the PS plate, and furthermore, the effect of speeding up the drying of the presser roller 3 can be expected. Note that the above plastic roller 1
Bakelite is suitable as the material for 3. Further, it is preferable that the position of the pressing roller 3 is as close to the developer supplying member 7 as possible. This is to reduce the effect of the end of the 23rd plate 2 passing through the roller 3 and leaving the roller 3, since the end jumps up and hits the developer supply member 7 strongly. Next, the tip of the 23rd plate 2 enters the liquid pool 9 in the recess formed by the developer roller 8. After the tip of the 23 plate 2 passes through the developer reservoir 9 formed in the recess in the mid-car direction formed by the developer supply member 7 and the developer roller 8,
A developer reservoir 9 is formed in a concave portion in the medial direction formed by the third printing plate 2 and the developer supply member 7. Due to the presence of these developer reservoirs 9 on the plate surface of the 23rd plate 2,
Problems caused by poor development at the edge of the PS plate, especially at the leading edge, are eliminated. Also,
As a means of transporting the PS plate in an upward direction in the transport direction, there is also a means of sliding it on an inclined guide plate, but in this case, the back side of the PS plate is rubbed by the guide plate, causing streaks. If the scratches are deep, they will affect the surface shape, making it difficult to obtain good halftone dot reproduction in printing.In addition, when forming the developer pool, the developer may There is a drawback that it accumulates on the back side, corrodes the aluminum plate of the support, dissolves, gels, and adheres to the PS plate, causing stains. The occurrence of scratches on the back side of the PS plate is improved to a level that does not cause any practical problems, and the attack of the back side of the PS plate by the developer is also improved. It is preferable that the slit formed by the two plates of the developer supply member 7 has a structure in which the slit gap is adjusted according to the amount of developer flowing out from the developer supply vibro.
The amount of developer supplied is 30 to 1010 per m2 of 23 plates.
0O is possible, but 50-500mQ is preferred. Examples of the above-mentioned plate materials include sheets of plastics such as polyester, polyvinyl chloride, polypropylene, polyethylene, and polystyrene, metals such as stainless steel,
A sheet of rubber or the like can be used. If at least one of the two plate materials is visible, the adjustment of the slit gap is automatically made according to the amount of developer coming out from the developer supply vibro, which simplifies the device. . In a preferred embodiment of the above-mentioned slit, the two plates whose lower ends form the slit each have a portion having flexibility at least in a direction parallel to the conveyance plane and perpendicular to the conveyance direction; In the upper position, an embodiment may be mentioned in which the plate material on the exit side is shorter (preferably 3 to 10 mm) at the tip (lower end) than the plate material on the inlet side when viewed from the conveyance direction. The angle between the conveying direction and the horizontal plane rising toward the conveying direction is preferably in the range of 0° to 30°, particularly in the range of 2° to 10°. This angle is also angle θ2 in FIG. The conveyance length rising in the conveyance direction is preferably in the range of 1 to 40 cm, particularly preferably in the range of 3 to 10 cm, and the conveyance time is 0.
．． A range of 5 to 20 seconds, particularly 2 to 10 seconds is preferred. The developer supply member 7 supplies the developer uniformly to each other in the medial direction.
It is advantageous that the developer can be supplied onto the S plate and can form a developer pool as described above. The developer reservoir is formed by providing another means, such as a roller extending in the direction of the center, and blocking the developer flowing down the surface of the developer roller 8, etc., or the surface of the 28 plate 2 that is conveyed at an angle. You may let them. Further, the developing section roller 8 does not need to be a roller, and may be a semi-cylindrical plate material, for example. The developed 28 plate 2 is rubbed by a brush roller 10 during the conveyance process of moving upward in the conveyance direction, and the developer is squeezed by a squeeze roller 11 to complete the development. Next, the operation of the apparatus shown in FIG. 1 will be supplemented. 28
When the plate 2 is inserted from the entrance of the apparatus, the plate detection switch 25 (not shown) rotates the conveying device such as the conveying roller pair 1, the brush roller lO1, the squeeze roller 11, etc.
Transport the plate. Further, the pump 5a is activated by the 25th plate detection switch, and a predetermined amount of developer is sent to the developer supply vibro for a predetermined period of time. The developer flowing out from the developer supply vibro flows down the inside of the two plates that make up the developer supply member 7, and forms a continuous liquid film in the medial direction at the slit at the lower end on the plate surface of the 28 plate 2. is supplied to When the 28 plate 2 has not passed through the slit portion, the developer flowing out from the slit portion forms the liquid pool 9 as described above. Seventh, a development acceleration operation can be added to the development processing method of the present invention. For the development promotion operation, all physical, chemical, electrical, mechanical, and other means for promoting development can be used. Furthermore, in addition to the development process according to the present invention, an automatic developing machine to which the method of the present invention is applied may include, if necessary, a development stop process after the development process (the stop process solution includes a disposable method or a cyclic use method). Each individual treatment step of the desensitization treatment step,
A development stop treatment step followed by a desensitization treatment step, a treatment step that combines a development treatment step and a desensitization treatment, or a combination of a development stop treatment step and a desensitization treatment step, for example, JP-A-1983-1983- It may also include the treatment steps described in No. 8002. The 28 plates used in the method of the present invention include those in which a photosensitive layer whose solubility changes upon irradiation with light is coated on a support, and a soluble layer in which an image-like resist layer is formed by an electrophotographic method or the like. is provided on a support. The above photosensitive layer contains a photosensitive substance as an essential component, and typical examples of the photosensitive substance include a photosensitive diazo compound, a photosensitive azide compound, a compound having an ethylenically unsaturated double bond, Epoxy compounds that polymerize with acid catalysts, silyl ether polymers and C-
Examples include a combination of a compound having an 0-C- group and a prior generator. Examples of photosensitive diazo compounds include O-quinonediazide compounds, which are positive type compounds that become alkali-soluble when exposed to light, and aromatic diazonium salts, which are negative compounds whose solubility decreases when exposed to light. Examples of the negative PS plate developer used in the method of the present invention include JP-A-51-77401, JP-A-51-80228;
Anionic surfactants such as those described in No. 53-44202 and No. 55-52054, organic solvents whose solubility in water is 10% by weight or less at room temperature,
It includes an aqueous solution consisting of an alkaline agent, water and, if necessary, an antifouling agent. The developing solution for the positive 23rd plate used in the method of the present invention includes an alkali metal hydroxide, an alkali metal silicate, an alkali metal phosphate or an alkali metal aluminate, water and, if necessary, a surfactant. A strong alkaline aqueous solution with a pH of 12 or higher consisting of other additives is included. Specifically, Japanese Patent Publication No. 4
No. 8-15535, No. 53-82324, No. 54-6
No. 2004, No. 52-127338, No. 53-963
No. 07, No. 50-144502, No. 55-22759
No. 55-25100, No. 55-95946, No. 55-115039, No. 56-142528, No. 5
A developing solution comprising sodium silicate or potassium silicate described in Japanese Patent No. 0-51324 can be mentioned. Further, a developer solution for both negative type 23 plate and positive type 23 plate, such as described in JP-A No. 60-130741, can also be used. [Example] Specific examples of the present invention will be shown below. Example 1 Using the apparatus shown in FIG. 1, the upper (outlet side) plate material for forming the slits was 75 μm thick and 900 mm long (in the direction perpendicular to the transport direction). The width is 50mm, and the thickness of the lower (inlet side) board is 175mm.
Rectangular polyethylene terephthalate sheets each having a length of 900 mm and a width of 55 mm were used. The roller 8 is made of rubber, β-20°, and the diameter of the roller 8 is 80III11. The total developing section transport length is 40
The ps plate used was SMP-N (trade name, positive ps plate, manufactured by Konishiroku Photo Industry Co., Ltd.) with a size of 1003 m + n x 800 mm, and the developing solution had the following composition. (Developer) Sodium silicate (JIS standard No. 3) 75g Sodium hydroxide 5g Pellex NB
L (manufactured by Kao Atlas Co., Ltd.) 0.5g water
909
．． The supply amount of 5g developer is 160m (2
Then, 100 editions were processed in succession, and among the obtained editions,
As a result of offset printing the 1st plate and the 100th plate, good printed matter was obtained with no stains due to poor development at the leading edge and both sides of the PS plate. Comparative Example 1 The treatment was carried out under the same conditions as in the example except that the apparatus shown in FIG. 4 was used. That is, this device does not have a presser roller 3,
The PS plate 2 is conveyed upward from the conveyance roller 1 toward the inclined roller 4 . For this reason, the developer leaking from between the slit of the developer supply member 7 and the PS plate or the developing unit roller 8 flows, adheres to the conveyance roller, and is transferred to the subsequent PS plate.
That part was developed, resulting in uneven development. [Effects of the Invention] The present invention provides a PS plate development processing device in which the development uniformity is improved in a method of developing a PS plate with a small amount of developer, and the developability of the leading edge and both side portions in particular is improved. I was able to do it.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a developing device showing one embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 is a perspective view of a presser roller, and FIG. 4 is a developing device used for comparison. FIG. 3 is a partial side cross-sectional view of the device. l... Conveyance roller pair 2... 28 plate 3... Holder roller 4... Inclined roller 5... Developer tank 5a... Developer supply pump 6... Developer supply pipe 7. ...Developer supply member 8...Development section roller 9...
・Developer reservoir 10... Brush roller 11... Squeeze roller 12... Waste liquid tank

Claims (2)

[Claims] (1) In a method in which a photosensitive lithographic printing plate is automatically conveyed and developed using an automatic developing machine, substantially unused developer is supplied to each plate of the photosensitive lithographic printing plate. In a developing device, a conveying guide roller located between a conveying roller and an inclined roller presses the photosensitive planographic printing plate from above, and the conveying guide roller is located at a lower position than the conveying roller and the inclined roller. A developing processing device for photosensitive planographic printing plates, which is characterized by: (2) The development processing device for a photosensitive lithographic printing plate according to claim 1, wherein the surface of the conveyance guide roller of the development processing device is roughened.