JPS63197950A - Developing process method for photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To permit a uniform and stable developing process with a smaller amt. of a developing soln. by supplying the unused developing soln. onto a photosensitive planographic printing plate (PS plate) from a slit, conveying the plate upward by using an inclining roller and passing the plate further through a developing tank by using a guide roller. CONSTITUTION:The substantially unused developing soln. is supplied from a slit constituted of two sheets of plate materials at the bottom end of a developing soln. supplying member 7 onto the PS plate 2 in the case of automatically conveying the PS plate 2 and subjecting the same to the developing process. The PS plate is conveyed upward by using the inclining roller 4 and is further passed through the developing tank 11 by using the guide roller 12. The slit formed of two sheets of the plate materials of the developing soln. supplying member 7 is preferably so constructed as to be adjusted to the slit spacing corresponding to the outflow rate of the developing soln. from the developing soln. supplying member 6. The uniformity in development is thereby improved and the developability particularly at the front end part and both side parts is improved in a method for develop the PS plate with a small amt. of the developing soln.

Description

[Detailed description of the invention]

[Industrial Application Field 1] 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. The present invention relates to a method for developing a PS plate suitable for an automatic developing machine, and an apparatus used therefor. [Prior Art 1] When processing a large number of exposed PS plates, an automatic developing machine is generally used. 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 of developing the plate by immersing it while conveying the plate in a curved manner has been used. 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, in addition to deterioration of the developer due to processing, deterioration of the developer occurs due to the absorption of carbon dioxide from the air. It is very troublesome to manage the developing process. In order to improve the above-mentioned drawbacks, there is a known method to keep the development process stable by replenishing a replenisher when a PS plate is processed with a large amount of circulating and reused developer. −
No. 144502, No. 55-115039, No. 58-9
No. 5349, etc. Such a replenishment method was necessary, and the problem of replenishment accuracy and replenishment fluctuations due to product differences between PS plates could not be solved. 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 an automatic processor, and stretches the developer applied on the 28-plate surface. The processing method is difficult because the PS plate being transported is not necessarily horizontal and is slightly distorted up and down, and the amount of developer tends to be uneven, which tends to cause uneven development. It has the disadvantage that it takes time to adjust the gap between the plate and the plate, and especially when a small amount of developer is dropped directly onto the 28 plate surface, there is a difference in development speed between the dripping part and the non-dropping part, and the developing solution passes through the development diffusion plate. This difference may remain even after printing, resulting in uneven development and resulting in an undesirable printing plate. We have improved this drawback and developed a PS plate development method and apparatus that can stably perform development using a small amount of developer, and have already filed an application as Japanese Patent Application No. 82900/1982. However, we have found that the technique of developing using a small amount of developer has a problem in that poor development occurs at the leading edge and both sides of the PS plate, which is presumed to be due to a lack of developer. . [Problems to be Solved by the Invention] As described above, in the method of developing a PS plate using a small amount of developer, there is a problem in that a residual film remains on the leading edge and both sides of the 28-plate due to poor development. That is, the purpose of the present invention is to
It is an object of the present invention to provide a stable and uniform method for developing a PS plate using a small amount of developer.

[Means to solve the problem]

The above 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.
Substantially unused developer is supplied onto the photosensitive lithographic printing plate through a slit made up of two plate materials, conveyed upward using inclined rollers, and further transferred to the developing tank using guide rollers. This can be achieved by a method for developing a photosensitive lithographic printing plate, which is characterized by passing through the lithographic printing plate. 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, reference numeral 1 denotes a conveyor roller for nipping and conveying the 25-plate 2, and 3 a holding roller for keeping the 25-plate 2 in an appropriate conveyance position. Reference numeral 4 denotes an inclined roller, which is provided so that the 25 plate 2 supplied with developer is conveyed in an upward direction toward the conveyance direction. Reference numeral 5 denotes a developer tank, and the developer therein is sent to a developer supplying vibro by a pump 5a. 7 is a developer supply member;
It has a slit formed by a sheet of plate material at its lower end,
The developer flowing down from the developer supply vibro is supplied to the 25 plate 2 through this slit. 25 When the plate 2 has not passed the lower end of the developer supply member 7, the developer supply member 7
The lower end of the slit, that is, the lower end of the slit, is in contact with the developing roller 8, and the lower end of the slit is in contact with the developing roller 8 in the horizontal direction (hereinafter referred to as the "medial direction") perpendicular to the conveyance direction formed by the lower end of the developer supplying member 7 and the developing roller 8. ), and when the PS plate being transported is in this position, the lower end of the developer supply member 7 and the 25th plate 2.
A developer pool 9 is formed in a concave portion in the metacarpal direction that is formed at the contact portion with the developer. 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 tip of the 25 plate 2 being conveyed first enters the four liquid pools 9 formed by the developer supply member 7 and the developing roller 8 . After the tip of the 25 plate 2 passes through the developer recesses 9 formed at the four parts in the medial direction formed by the developer supply member 7 and the developer roller 8, the 25 plate 2 and the developer supply member 7 are separated. Developing solution reservoirs 9 are formed in the four portions in the metacarpal direction formed by. Because these developer pools 9 exist on the plate surface of the 25 plate 2, the means for transporting the edges of the PS plate in the upward direction, especially the leading edge, is to slide on an inclined guide plate. There are other methods, but in this case,
The back side of the PS plate was rubbed by the guide plate, causing streak-like scratches.
If this scratch is deep, it will affect the shape of the surface, making it difficult to obtain good halftone dot reproduction in printing.In addition, when forming the developer pool, the developer will accumulate on the back side of the PS plate, and the support The disadvantage is that the aluminum plate is corroded and eluted, gels, and adheres to the PS plate, causing stains.However, by using the conveyance roller as the conveyance means as described above, the back side of the PS plate can be easily removed. The occurrence of scratches is improved to a level that is practically impractical, and the attack of the back surface 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 50 to 500 per 28 plates 112
m1 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 plates is flexible, the slit gap can be adjusted automatically according to the amount of developer coming out from the developer supply vibro, so the device can be simplified. Become. In a preferred embodiment of the slit, the two plates whose lower ends form the slit each have a portion having flexibility at least in a direction parallel to the conveying surface and perpendicular to the conveying direction, and In the above position, the tip (lower end) of the plate on the outlet side is shorter (preferably 3 to 10 mm) than the plate on the inlet side when viewed from the conveyance direction! ! ! Examples include: The angle θ between the transport direction and the horizontal plane rising toward the transport direction l2 is preferably in the range of 1° to 45°, particularly in the range of 3° to 10°. The conveyance length rising in the conveyance direction is 1 to 4.
A range of 0 cm, particularly a range of 3 to 10 CI11 is preferred, and a transport time of 0.5 to 20 seconds, particularly a range of 2 to 10 seconds is preferred. The developer supply member 7 distributes the developer evenly in two directions in the medial direction.
It is advantageous that the developer can be supplied onto three plates and can form a developer pool as described above. For the developer reservoir, another means is provided, for example, a-ra arranged opposite each other in the direction of the center, and these prevent the developer from flowing down the surface of the developer roller 8, etc., or the surface of the 28 plate 2 that is conveyed at an angle. Further, the developing section cooler 8 does not need to be a roller, and may be formed of a semi-cylindrical plate, for example. The developed 28 plate 2 is further immersed in the developer during the conveyance process of moving upward in the conveyance direction. This immersion can be performed using the developing tank 11 and the guide roller 12. The developer tank 11 is filled with a developer having the same composition as the developer supplied from the developer supply member 7, and it is sufficient to replenish the developer using the developer brought in by the PS plate. However, an unused developer may be replenished separately. Developer tank 11
The amount of developing solution inside is preferably 0.3 to 31 cm per meter during transportation, and the length of transportation immersed in the developer is preferably about 3 to 15 cm. The 28 plate 2 that has passed through the developer tank 11 is rubbed by the brush roller 13, and the developer is squeezed by the squeeze row 214 to complete the development. In such an embodiment, during the time t1 from when the developer is supplied onto the plate surface of the 28 plate 2 by the developer supply member 7 until it is immersed in the developer in the developer tank 11, the developer in the developer W111 is Immersed time t2 and developer tank 1
Time t until the developer is removed from the developer in 1
3 is preferably in the following range. (When developing temperature is 25°C) tl: 5 to 10 seconds, t2: 5 to 10 seconds, t: 1
-4 seconds The development temperature is suitably in the range of 10 to 40°C. Next, the operation of the apparatus shown in FIG. 1 will be supplemented. 28
When plate 2 is inserted from the entrance of the device, a plate detection switch 28 (not shown) causes the conveyor roller pair 1, etc.
The brush roller 13, squeeze roller 14, etc. rotate, and P
Transport the S plate. Further, the pump 5a is activated by the 28-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 plate materials that cover the developer supply member 7, and forms a continuous liquid film in the medial direction at the slit at the lower end of the plate 2. Supplied on the plate. Ps
When the plate 2 has not passed through the erroneous slit portion, the developer flowing out from the slit portion forms the liquid pool 9 as described above. FIG. 2 is a side sectional view showing another embodiment of the main parts of the apparatus for carrying out the present invention. The apparatus shown in FIG. 2 has a plurality of inclined rollers 4a and 4b, respectively, instead of the inclined roller 4 and developing section row 28 of FIG.
This is an example using a curved plate 8a. 16 is a skewer roller. In the development processing method of the present invention, a development promotion operation can be added. For the development promotion operation, any physical, chemical, electrical, or R-mechanical 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-1988- 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 can be formed by electrophotography 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 photoresin-generated waste. As a photosensitive noazo compound, it is a positive type that becomes alkali-soluble upon exposure to light. - Quinonediazide compounds, and aromatic diazonium salts are examples of compounds whose solubility decreases upon exposure to light. The developing solution for the black type PS plate used in the method of the present invention includes, for example, those described in JP-A-51-77401, JP-A-51-80228, JP-A-53-44202 and JP-A-55-52054. It includes an aqueous solution consisting of an anionic surfactant, an organic solvent having a solubility in water of 10% by weight or less at room temperature, an alkaline agent, water, and, if necessary, an antifouling agent. The developer for the Bott type 23 plate used in the method of the present invention contains an alkali metal hydroxide, an alkali metal silicate, an alkali metal phosphate or an alkali metal aluminate, water and, if necessary, a surfactant and other additives. A strong alkaline aqueous solution containing additives and having a pH of 12 or more is included. Specifically, Japanese Patent Application Publication No. 1973
-15535, 53-82324, 54-620
No. 04, No. 52-127338, No. 53-96307
No. 50-144502, No. 55-22759,
No. 55-25100, No. 55-95946, No. 55
-115039, 56-142528, 50-
A developing solution consisting of sodium silicate or potassium silicate described in No. 51324 can be mentioned. Further, a developer for both a negative-type PS plate and a positive-type PS plate, such as that 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 arrangement shown in Fig. 1, the upper (outlet side) plate material used to form the slit had a thickness of 75 μm, a length (perpendicular to the conveying direction) of 900 II 1 m, and a width of 50 mg m. , and the lower (inlet side) board has a thickness of 175 mm.
A rectangular polyethylene terephthalate sheet having a length of 900 mm and a width of 55 am was used. Low? The roller 8 is made of rubber, β=20°, and the diameter of the roller 8 is 80 mm. The transport length of the entire developing section is 4ooIIl.
1, the developer tank 11 contains a developer with the same composition as the developer supplied from the developer supply member 7, and the developer supplied to the 28th plate from the developer supply member 7 for each plate flows into the tank. The structure is such that the excess developer is discarded, the developer temperature is set to 25°C, and the above t1, t2 and 1 time are each held for 8 seconds.
8 seconds and 4 seconds, totaling 20 seconds. The PS version is SMP-N (KE product name, positive PS version, Konishiroku Photo Industry Co., Ltd. S! Rino 1003auaX 800
mm size was used, and a developer having the following composition was used. (Developer) Sodium silicate (JIS standard No. 3) 20g Sodium hydroxide 5g Pellex NDL (
Kako Atlas Co., Ltd.! ! ! ! ) 0.5g water
9
The amount of 75g developer supplied is 160+ai for one PS plate above.
', and as a result of processing 100 plates continuously and offset printing the 1st plate and 100th plate among the obtained plates, PS
A good printed matter was obtained with no stains due to poor development at the leading edge and both sides of the plate. Comparative Example 1 Using the same PS plate and developer as in Example 1, the third
Development was performed using the apparatus shown in the figure. The developer is dripped onto the PS plate from the nozzle of the developer supply vibro, the developer droplets are spread on the PS plate by the plastic sheet diffusion plate 17 for development, and are conveyed on the guide plate 18 to complete the development. The distance from the developer dripping position to squeeze roller 'N43 (development zone 1400mm, development time 20 seconds, developer amount 1 slope) When the development process was performed at 160+aN, the developer was uniformly distributed on the surface of the PS cloth. However, after processing 100 plates in succession, only plates with unstable performance and uneven development were obtained. Further, there was a residual film on the leading edge and both sides of the plate, and when the obtained plate was printed under the same conditions as in Example 1, stains occurred in the residual film area. [Effects of the Invention] The present invention provides a PS plate development processing power method 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 sides is particularly improved. I can provide it.

[Brief explanation of the drawing]

1 and 2 are side sectional views of a developing device showing one embodiment of the present invention, and FIG. fjS3 is a perspective view of a developing device used for comparison. 1... Conveyance roller pair 2... PS plate 3... Holding roller 4.4a, 4b... Inclined roller 5...
Developer tank 5a...Developer supply pump 6...
Developer supply pipe 7...Developer supply member 8...Development section roller 8a.
...Curved plate 9...Developer reservoir 11...
Developer tank 12...Guide roller 13...Brush roller 14...Squeeze roller 15...m
WL tank 16... Skewer roller 17... Diffusion plate 18... Guide plate applicant Konishiroku Photo Industry Co., Ltd. Figure 1 et al.

Claims (1)

[Claims] In a method in which a photosensitive lithographic printing plate is automatically conveyed and developed using an automatic developing machine, a substantially unused developer is passed through a slit made up of two plates into a photosensitive lithographic printing plate. 1. A method for developing a photosensitive lithographic printing plate, comprising supplying the plate upwardly, transporting the plate upwardly using an inclined roller, and further passing the developing tank using a guide roller.