JPS62278555A - Developing method for photosensitive lithographic printing plate to improve film remaining - Google Patents

Abstract

PURPOSE:To prevent the generation of film remaining at the front end and both side parts of a photosensitive lithographic printing plate by immersing the photosensitive lithographic printing plate into a liquid developer while conveying said plate, then supplying the substantially unused liquid developer in the form of a liquid film onto the printing plate at every processing. CONSTITUTION:Conveying rollers 1, a guide roller 4, and a squeeze roller 10 are rotated by a PS plate detecting switch to convey the photosensitive lithographic printing plate (PS plate) 2 when the PS plate 2 is inserted into the device from the inlet thereof. THe PS plate 2 advances into the liquid developer in a developing tank 3 and is conveyed in the liquid developer while the plate is held pressed by the guide rollers 4. The PS plate rises along the slope of the liquid developer tank 3 and emerges from the inside of the liquid developer. The unused liquid developer is uniformly supplied over the entire surface of the PS plate 2 by a liquid developer supplying member 8.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for developing a photosensitive lithographic printing plate (hereinafter referred to as a "PS plate"). P in an automatic developing machine that supplies unused developer to each plate for development.
This invention relates to an improved method for developing S plates.

[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 psrJi, or using a developing tank containing a large amount of developer. A method has been used in which a PS plate is immersed and developed while being transported in a curved manner. In such processing method 1, it is necessary to prepare a large amount of developer to process one PS plate. In addition, in order to use the developer economically, we recycle it and reuse it.
In addition to deterioration of the developer due to processing, deterioration of the developer occurs due to absorption of carbon dioxide gas from the air, resulting in 1! It is necessary to replace a developing solution that has deteriorated, making it extremely troublesome to manage the developing work.

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. 502, No. 55-115039, No. 58-95:1
It is disclosed in No. 49. Although this replenishment method reduces the frequency of fluid replacement, it is still necessary to replace the fluid.
In addition, the problem of the M degree of replenishment and the replenishment variation due to product differences between PS versions could not be resolved. Moreover, it requires a replenishment device, and not only is the replenishment device itself expensive, but also the replenishment v.
There is also a need for adjustment and maintenance of the t-position.

By eliminating the troublesome replenishment method, J! l! The device was published in Japanese Patent Publication No. 55-32044:
It is described in Publication I. This is equipped with a developer diffusion plate close to the photosensitive material transfer path in an automatic developing machine, and stretches the developer applied on the 25 plate surface. The method of processing an I'S plate with a small amount of developer using a c-position requires a relatively large amount of developer1 (300-500 m1/m").
If a relatively large amount is not supplied, uneven development will occur, and even if a relatively large amount is supplied, approximately 0.5
There is a problem that a residual film of one width occurs.

[Purpose of the invention]

The purpose of the present invention is to develop PS with a small amount of developer such as 4tf.
It is an object of the present invention to provide a developing method in which residual film on the leading edge and both side portions of a PS plate is improved in a method for developing a plate, and a developing device for implementing this method.

[Structure of the invention]

The above object of the present invention is achieved by a developing method having the following configuration. That is, the developing method of the present invention is a developing method in which a photosensitive plain printing plate is automatically conveyed and developed using an automatic developing machine, after the photosensitive planographic printing plate is conveyed and immersed in a developer, This method is characterized in that substantially unused developer is supplied in the form of a liquid film onto the lithographic printing plate each time it is processed.

Hereinafter, the present invention will be described in detail based on the drawings.

The developing device used in the method of the present invention is an automatic developing device that automatically conveys and develops a photosensitive lithographic printing plate. a means for supplying and developing the photosensitive lithographic printing plate;
After being immersed in the Il tank, it has a means for transporting the developer so that the developer is supplied by the developer supply means. FIG. 1 is a needle perspective view of such a developing device, and FIG. It is a side sectional view.

tjS1 and FIG. 2, reference numeral 1 denotes a conveyor roller that conveys 15 plates 2 by 27 times, and is arranged so as to be conveyed in a downward direction in the conveyance direction. 3 is a developer tank, and 4 is an idle roller that guides the 15 plate 2 so that it is immersed in the developer in the developer tank 3.

In order to make it easier for the PS plate 2 to come out of the developer tank 3, the side surface on the outlet side of the developer f'ff3 may be made into an inclined surface as shown in FIG. Provide a competent guide. β in FIG. 2 is preferably in the range of lO to 60°.

The material of the developer 13 is stainless steel or plastic.
(For example, hard vinyl chloride resin) and other commonly used materials can be used.

5 is a developer storage tank for storing substantially unused developer;
Reference numeral 6 denotes a liquid feeding pump which pressure-feeds the developer to the developer supply pipe 7 . A plurality of holes are provided in the side surface of the developer supply pipe 7 for allowing the developer α to flow out. Reference numeral 8 denotes a developer supply member, which is composed of two plates, and has a slit formed by the two plates at the lower end, and the slit gap is adjusted according to the amount of developer flowing out from the developer supply pipe 7. Create a structure that allows for increases and decreases.

Is the lower end of the developer supply member 8 used for development? [[! 3, and when the plate 2 is not passing through, a developer reservoir 9 is formed in the four parts formed by the lower end of the developer supply member 8 and the outlet side slope. It is preferable.

As the plate material forming the developer supply member 8, for example, a sheet of plastic such as polyester, polyvinyl chloride, polypropylene, polyethylene, or polystyrene, a sheet of metal such as stainless steel, a sheet of rubber, etc. can be used.

If the plate material is not visible but is hard enough to damage the 25th printing plate, it is preferable to place the lower end at a different position so that it does not come into contact with the 25th printing plate.

If at least one of the two plates is flexible, the increase or decrease of the slit gap can be automatically adjusted according to the amount of developer coming out from the developer supply pipe 7, which simplifies the device. Become something.

Preferred fruit M of the above slit! ! As shown in FIG. An example is an embodiment in which the plate material on the outlet side has a shorter tip (lower end) than the plate material on the inlet side (preferably 3 to 10 m) when viewed from the conveyance direction.

25th edition 2 development? The entrance angle σ into the II tank 3 is preferably 10 to 60°.

The developer is applied to the developer supply member 8 in the form of a liquid film.
The S plate is conveyed while almost retaining its liquid film, and then the developer is removed by means such as a squeeze roller 10, but if necessary, a development accelerator such as a rotary plan cooler 11 may be added before removing the developer. can do.

25th edition 2 is developed W! 3. Time immersed in developer within 1
+, 25% of substantially unused developer after exiting the developer.
Time t2 until a uniform liquid film is supplied onto the plate surface of plate 2
, and the time t3 from the time when the liquid film is supplied until the liquid film is removed by means such as the squeeze roller 10 is preferably in the following range (at a developer temperature of 25° C.) tl: 3 to 10 seconds. , t2: 0 to 5 seconds, t3:
4-15 seconds.

Next, the developing method of the present invention using this apparatus will be described.

When the 25th plate 2 is inserted from the entrance of the apparatus, an 18th plate detection switch (not shown) causes the transport roller pair 1, e-roller 4, and squeeze roller 10 to rotate to convey the 25th plate 2. In addition, the developer is supplied with a liquid feed pump 6 activated by the 18th plate detection switch, and the developer is supplied to the developer supply pipe 7 for a predetermined period of time and in a predetermined amount. Amount control is performed.

The 25 plate 2 is transported by the transport roller pair 1 and developed [! 3
The liquid enters the developer, is held down by the idle roller 4, is conveyed within the developer, ascends and is conveyed along the slope of the outlet of the developer tank 3, exits from the developer, and is supplied with the developer. Substantially unused developer is uniformly supplied to the entire surface of the 25 plate 2 by the member 8.

At this time, the developer flowing out from the plurality of holes of the developer supply pipe 7 flows down along the inner slopes of the two plate materials that constitute the developer supply member 8, but is blocked by a slit near the outlet at the lower end. ! Did it continue? By forming IIfJ, it is possible to supply the liquid with a uniform liquid film on the surface of the PS plate being transported.6 In Fig. 1, an arrow is attached at one end.
The straight chain line indicates the direction in which the developer flows.

In the method of the invention, the amount of developer supplied is preferably 50-500+1 per m@2 of 13 plates.

In the method of the present invention, it is necessary to supply substantially unused developer onto the PS plate after each treatment.

Here, the term "unused developer" refers to a developer that has not been used to process the PS plate, and the term "substantially unused developer" refers to
Even if it is not an unused developer, it refers to a developer that has a developing ability higher than that of an unused developer.

In the present invention, the developer placed in the developer tank may be the same as the developer supplied onto the PS plate, and recovery from deterioration due to processing and absorption of carbon dioxide can be achieved by the "J!" supplied onto the PS plate. , a portion of qualitatively unused developer and/or P
It is only necessary to allow the substantially unused developing solution to be supplied onto the S plate to flow into the developing solution tank. Therefore, as shown in FIG.
The supply position of the substantially unused developer onto the S plate is preferably located as close as possible to the bottom surface of the developer in the developer tank and above the level of the developer. If the above deterioration exceeds the limit, the solution can be replaced or replenished.
Appropriately, it is about 0.5 to 31 ml per 25 plates, and the appropriate amount of the developer to be introduced is about 50 to 500 ml, which is equivalent to 2 ml of 25 plate.

In the present invention, a development accelerator can be added after the developer is supplied onto the PS plate. As the development accelerating means, all physical, chemical, electrical, mechanical, etc. means for accelerating development can be used.

Mechanical acceleration means include a method of rubbing the plate surface, for example, a method of rubbing using a rotating a-ra-shaped rubbing member, a method of rubbing by rotating a flat rubbing member, a method of rubbing the plate surface by rotating a flat rubbing member, and a method of rubbing the plate surface by rotating a flat rubbing member. Alternatively, examples include a method of rubbing by moving left and right, and a method of rubbing by moving a roller-shaped rubbing member or a plate-shaped rubbing member back and forth and/or left and right while rotating. Note that a plurality of these rubbing members may be used in combination, and these rubbing members can be created using, for example, a brush, a subonno, cloth, or the like.

Other development accelerating means include, for example, a method of blowing high-pressure air, a method of irradiating ultrasonic waves, a method of applying vibration to the PS plate, and an electrochemical development method as described in JP-A-58-42042. A method of instantly heating the developing solution on the 18th plate by microfabe irradiation, a method of honing the layer surface using a processing solution containing abrasive powder, etc.

A preferred embodiment of the present invention includes a development accelerator that rubs the surface of the PS plate with a rotating brush roller after the PS plate passes through the developer in the developer tank and before the developer is removed by a squeeze roller or the like. Add! ! Examples include: In this case, as shown in FIG. 1 and FIG.
is provided immediately before the squeeze roller 10, and the squeeze roller 1
It is preferable that a developer pool is created in the area of the brush roller 11 with the developer squeezed at 0, and that this solution is used to promote development by rotating the brush.

There are no restrictions on the processing after development according to the present invention.
Any means can be applied.

In addition to the development process according to the present invention, an automatic developing machine to which the present invention is applied can carry out individual processes such as after the development process, water washing process, desensitization process, and aqueous solution treatment process including 1 before surface activation, etc., if necessary. It may also include a treatment step in which the above-mentioned steps are successively combined, such as a water washing step followed by a desensitization treatment step.

The unnecessary liquid used in the above-mentioned development process and post-development process is treated as waste liquid, but it is desirable to temporarily store it by providing a waste liquid tank or the like.

The PS 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 renost layer can be formed by electrophotography etc. is provided on a support.

The above-mentioned photosensitive layer contains a photosensitive substance as an essential component, and typical examples of the photosensitive substance include a photosensitive diazo compound, a photosensitive AND 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 an acid generator.

Examples of photosensitive noazonium compounds include 0-quinone noanodo compounds, which are bon-type compounds that become alkali-soluble when exposed to light, and aromatic noazonium salts, which are ne-type compounds whose solubility decreases when exposed to light.

Examples of the developing solution for the PS plate used in the method of the present invention include those described in JP-A-51-77401, JP-A-51-80228, JP-A-53-44202 and JP-A-55-52054. An aqueous solution consisting of an anionic surfactant, an organic solvent having a solubility in water of 10TfLffi% or less at room temperature, an alkaline abrasive, water, and, if necessary, an antifouling agent.

The developing solution for the positive PS plate used in the method of the present invention includes an alkali metal hydroxide, an alkali metal silicate, an alkali metal wanate, or an alkali metal flumate, water, and if necessary, a surfactant and a water bath. A strong alkaline aqueous solution with a pH of 12 or more consisting of additives is included. The iJc format is JP-A-48-15535, JP-A No. 53-82334, JP-A No. 54-
No. 62004, No. 52-127338, No. 53-96
No. 307, No. 50-144502, No. 55-2275
No. 9, No. 55-25100, No. 55-95946,
Developers made of sodium silicate or potassium silicate described in Japanese Patent Nos. 55-115039, 56-142528, and 50-51324 can be mentioned.

In addition, a GL liquid can also be used for the combination of the Ne-type PS plate and the Bo-type PS plate, such as those described in JP-A-60-130741.

〔Example〕

Hereinafter, specific examples of the present invention will be shown.

Example 1 Figure 1 and ! as a developing device! ! ') An apparatus of the embodiment shown in Figure 2 was used. For the developer tank A 3, stainless steel (thickness 2 degrees) GL with β = 30° is used, and the developer supply member 8
Upper g111 (exit 1
) with a thickness of 75 μm, length (perpendicular to the conveyance direction) of 900 + am, width (a in Figure 2) of 50 wheels, and a board of lower 1'III (inlet I) with a thickness of 175 μm, Length 901) + n, width (b in PIS2 diagram) 5
5 sheets of rectangular polyethylene tele 7 grade were used.

Put 1.5N of the following developer into the developer tank 8, and
The height C from the developer level inside to the lower end of the slit 7 is 3-
The PS plate that passed through the lower end of the slit was conveyed horizontally at a height d of 30 mm from the developer surface.

The PS plate used was a 10010O3800-Rin size of SMP-N (trade name, Bottai PS plate, Konishiroku Photo Industry Co., Ltd. 9I), and the developer had the following composition.

Developer potassium silicate aqueous solution (Si02/KzO molar ratio 1.03
iO2a degree 2% by weight) 500g Perex NBL (sodium alkylnaphthalene sulfonate, Kao Atlas Co., Ltd.) 0.25g water

500g Other conditions are as follows.

Development p: Amount of developer supplied from the L supply member 8 to the PS plate -
1---160mj per PS version! Developing in developer tank 8? I! Amount -------Amount of developer water flowing into the 1,5Z developer tank 8 -------Approximately 200 p transport speed per ps plate
------20a+m/sec Developer temperature ------25°C above t+
------5 seconds above L2
----- 0.3 seconds t3---
-- 14.7 seconds As a result of processing the above 25 plates and 100 plates in succession under the above conditions, and offset printing the 1st and 100th plates of the obtained plates, the leading edge and both sides of the PS plate A good printed matter was obtained with no stains on the side portions due to poor development.

Comparative Example 1 Using the same PS plate and developer as in Example 1, the third
Do not perform development using the equipment shown in the figure. The developer is dripped onto the 25th plate from the nozzle of the developer supply vibrator 37, and the developer droplets are spread over the PSS by the plastic sheet diffusion plate 38 for development, and are conveyed on the guide layer 39 to complete the development.

Distance from the developer dropping position to the squeeze row 240, that is, the development zone 1400 mm, development time 20 seconds, development i
When developing with 160 t'w per plate, the developer was spread evenly over 28 plate surfaces, but as a result of continuous processing of 100 plates, the performance was poor due to uneven development. All I could get was stable clothes. Further, there was a residual film on the tip and both sides of the pig, and when the resulting stain was printed under the same conditions as in Example 1, stains were generated on the residual film.

〔Effect of the invention〕

According to the present invention, residual film on the leading edge and both sides of a PS plate in a method of developing the PS plate with a small amount of developer is improved.

[Brief explanation of drawings]

1 and 2 are a perspective view and a side sectional view of a developing device showing one embodiment of the present invention], and FIG. 3 is a perspective view of the developing device used for comparison. 1, 31----1 feed row 2 vs. 2, 32----PS plate 3----1 development! *, Tank 4----Guide roller 5, 35----Developer tank 6, 36----Liquid feed pump 7, 37---Developer supply pipe 8---- -Developer supply member 9---m-Developer reservoir 10, 40---Squeeze roller 12---Over 70----11---1・Brush roller 38----1 Expansion plate 39・--m-Guide plate applicant: Roku Konishi Photo Industry Co., Ltd.■...Transport roller pair 3...Developer tank 4...Guide roller 5, i, w, 1 6...Liquid feeding Pump 7...Developer supply pipe 8...Developer supply member 10...Squeeze roller 11...Brush roller

Claims (1)

[Claims] In a developing method in which a photosensitive lithographic printing plate is automatically conveyed and developed using an automatic developing machine, after the photosensitive lithographic printing plate is immersed in a developer while being conveyed, the photosensitive lithographic printing plate is coated with each treatment. 1. A method for developing a photosensitive lithographic printing plate, characterized by supplying substantially unused developer in the form of a liquid film.