JP2697721B2 - Waterless lithographic printing plate developing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for a waterless lithographic printing plate, and more particularly, to a waterless lithographic plate having a silicone rubber layer lined with a substrate as an uppermost layer. The present invention relates to improvement of a printing plate developing device. 2. Description of the Related Art Waterless lithographic printing plates having a silicone rubber layer lined on a substrate as an uppermost layer are disclosed in, for example, JP-B-46-16444, JP-A-50-50102, and JP-A-50-50102. It has been proposed in, for example, JP-A-55-59466. [0003] These waterless lithographic printing plates are subjected to image exposure processing by a known method and are developed. When development processing is performed using an automatic developing machine, a plate-shaped printing original plate is transported by a roll. A developing device is used in which the brush roll is rotated so that the printing original plate is rubbed in the same direction as the traveling direction at the contact portion of the 1 to 4 brush rolls to remove the silicone rubber layer in the image portion. General. [0004] As described above, a brush roll is used for developing a waterless lithographic printing plate because the silicone rubber layer on the surface is generally insoluble and must be scraped off by mechanical force. In addition, it is the most practical means to meet this purpose. The reason why the brush roll is rotated so as to rub it in the same direction as the printing original plate is to prevent the brush roll from flipping the leading end of the printing original plate. [0005] When the THE INVENTION It is an object of Trying to solve Such developing device, a problem that the shape of the halftone dots to be developed is dependent on the rubbing direction of the brush roller, not dots of uniform shape can be obtained Often occur. That is, the silicone rubber layer is almost completely removed on the downstream side in the rubbing direction of the brush roll within the halftone dot, whereas the silicone rubber layer tends to remain on the upstream side, especially at the edge of the halftone dot. It is. As a result, even during printing, serious defects such as a decrease in tone reproducibility and a shift in color tone occur. Therefore, as an apparatus for improving the disadvantage, an apparatus described in JP-A-60-59351 has been proposed. This device uses two or more brush rolls when rubbing and developing an original printing plate, and rubs by rotating at least one of the brush rolls in a direction opposite to the other brush rolls. The silicone rubber layer at the edge of the halftone dot is removed. However, in the case of this apparatus, if the brush roll rotating in the direction opposite to the conveying direction of the printing plate is made to have a strong rubbing force, the printing plate is rejected, so that the rubbing force of the brush roll must be reduced. ,
As a result, especially for printing plates with a thick silicone rubber layer,
There is a problem that the silicone rubber layer at the edge of the halftone dot remains without being uniformly removed. Further, there is a problem that a defective shape of a halftone dot caused by non-uniformity of the brush material cannot be eliminated, and that the silicone rubber layer remains without being uniformly removed even by high-speed development. [0010] In view of the drawbacks of the prior art, the present invention provides
The silicone rubber layer remaining on the dot edge in the roll axis direction
Removal can be promoted, and uniform halftone dots with no orientation can be obtained.
The purpose of the present invention is to provide an automatic developing device capable of high-speed development . [0011] The present invention has been made to solve the above-mentioned problems.
Accordingly , the present invention provides a waterless lithographic printing plate in which a silicone rubber layer lined with a substrate is developed by rubbing the silicone rubber layer with at least two brush rolls while conveying the lithographic printing plate. (A) In the transport direction of the waterless lithographic printing plate, at least one brush roll rotating in the same direction as the transport direction and at least one brush roll rotating in the opposite direction to the transport direction are provided. And (B) at least one bra seal among the at least two brush rolls is 5 to 100 m in the roll axis direction.
(C) A waterless planographic printing plate characterized by physically removing the silicone rubber layer in the image area by providing a reciprocating mechanism for reciprocating with a swing width in the range of m. Of the developing device. Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a view schematically showing an embodiment of a developing device for a waterless lithographic printing plate according to the present invention. The lithographic printing plate without water used in the present invention has a top layer of a silicone rubber layer lined with a base, and comprises a base, a photosensitive layer and a silicone rubber layer laminated in this order, a base, For example, a silicone rubber layer having photosensitivity is laminated in this order, and a cover film may be provided on the silicone rubber layer. The substrate has a thickness of about 10 μm to 2 μm.
mm, preferably about 50 to 500 microns paper, plastic film or sheet, elastic sheet such as rubber, metal plate such as aluminum, or laminated composite material such as paper and plastic film, metal plate and rubber sheet, and the like. For these, those which have been subjected to surface treatment such as plating and coating are used. The photosensitive layer is a layer having the property of being photo-cured or photo-solubilized by irradiating an active light beam. This layer is uniformly applied to the substrate, and may have any thickness as long as it is in intimate contact with the substrate.
Submicron, more preferably about 1-10 microns are more useful. If necessary, it is also useful to provide an anchor coat between the substrate and the photosensitive layer to improve the adhesion between the photosensitive layer and the substrate or prevent halation. As the photosensitive substance, a known substance such as a composition containing a photopolymerizable monomer or oligomer, a photocurable diazo compound or an azide compound, and a compound containing a quinonediazide group can be used. The thickness of the silicone rubber layer is 0.5
~ 100 microns, preferably about 1-10 microns,
A known silicone rubber which is called a room temperature curing type or a low temperature curing type is preferable. These silicone rubbers contain a linear organic polysiloxane as a main component, and generally include a crosslinking agent and a catalyst. Further, the silicone rubber layer in the present invention may have photosensitivity, which can be obtained by chemically reacting or mixing an organic polysiloxane compound with a known photosensitizing compound. . The brush roll used in the present invention is generally formed by radially implanting a plastic material having a diameter of 20 to 500 microns or a brush material such as animal hair into a core made of plastic or metal. A brush material implanted in a base material such as a sheet, a film, or a cloth may be wound around a core, and a brush material implanted in a plastic or metal channel material attached to the core. Any of them may be used. A developing device for a printing plate comprising the above-described components according to the present invention will be described in detail with reference to the drawings. In FIG. 1, a printing original plate 1 having been subjected to an image exposure process is inserted into a developing machine main body 3 from a carry-in table 2 and discharged to a carry-out table 4 after undergoing the development processing. The developing solution sent by the pump 6 onto the printing original plate in the developing machine is sprayed from the spray nozzle 7. The developer swells the silicone rubber layer or weakens the adhesive force between the silicone rubber layer in the image area and the lower layer, thereby making it easier to remove the silicone rubber layer in the image area, and at the same time, removing the removed silicone rubber. It generally has a function of washing the rubber pieces from the printing original plate. Subsequently, the printing original plate is rubbed by brush rolls 8 and 9 which are arranged so as to be in uniform contact with each other, rotate in opposite directions, and are swingable in the axial direction, respectively. Is excluded. Reference numeral 10 denotes a printing plate support mechanism provided at a position facing the brush roll so that the printing plate does not escape from the brush roll. The support mechanism 10 may be a cylindrical object, but a plate-shaped object as shown in the figure is used. As the automatic developing machine, not only the above-mentioned basic mechanism, but also a pre-processing machine, a post-processing machine or a washing machine, a drying machine, etc. may be used, and the brush roll is also dispersed and arranged in the pre-processing machine, the post-processing machine or the washing machine. May be. The brush roll used in the present invention needs at least one roll rotating in the same direction as the transport direction of the printing original plate and at least one roll rotating in the opposite direction. , And the second and subsequent brush rolls are rotated in the opposite direction. Further, it is necessary to swing at least one of these brush rolls. More preferably, the two brush rolls 8 and 9 are oscillated together. The functions of the brush roll can be divided into a function of roughly removing the silicone rubber layer at the halftone dot portion and a function of finishing and removing the silicone rubber layer slightly remaining at the halftone dot edge portion. It is better to rotate the brush roll using a stiff brush material quickly, but if this is rotated in the direction opposite to the printing plate transport direction, there is a danger that the tip of the printing plate will splash. On the other hand, the latter function can be satisfied by slowly rotating a brush roll using a brush material having a weak stiffness, so that the above-mentioned danger can be reduced to a practically negligible level. For this reason, as the first brush roll, for example, nylon 610 having a diameter of 200 to 400 μm having a single yarn diameter of 100 to 200 mm is implanted at a bristle length of 10 to 20 mm.
mm in the direction of rubbing in the same direction as the transport direction of the printing original plate, rotating it at 200 to 500 revolutions per minute to roughly remove the silicone rubber layer. The brush for finishing and removing the remaining silicone rubber layer is, for example, a nylon 50 having a diameter of 50.
~ 250 microns single thread diameter 15-30m hair length
It is effective to use a brush roll having an outer diameter of 50 to 100 mm implanted in m, and rotate the brush roll at a speed of 50 to 500 revolutions per minute in a direction opposite to the conveying direction of the printing original plate. The swinging of the brush roll causes the brush roll to reciprocate 50 to 400 times per minute in a direction perpendicular to the conveying direction of the printing original plate, that is, in a roll axis direction of 5 to 100 mm. The swing width is a range in which the above range is effective in eliminating the dependence of the rubbing direction on the halftone dots on the printing original plate, that is, removing the silicone rubber layer present at the edge on the upstream side of the halftone dots. If the range is less than 5 mm, the rubbing force to the halftone dot edge portion of the brush tip is not sufficiently transmitted, and
If the thickness exceeds 00 mm, the rubbing force against the halftone dots becomes excessive and the halftone dots are damaged, resulting in poor tone reproducibility.
As a swinging method, a method of using a cam, a link, a shaft, or the like for swinging an inking roller of a printing press, or a method of cutting a thread groove inside the roll is common. The brush roll specifications, rotation and swing conditions are determined based on the ease of removal of the silicone rubber layer, the ease of damage of the silicone rubber layer, and the stiffness of the printing original plate. Not something. Examples and Comparative Examples Next, the present invention will be described more specifically with reference to Examples and Comparative Examples . Example 1 Commercially available positive type Toray waterless lithographic printing plate precursor (length 1030 m)
(m, width: 980 mm) by a halftone exposure process by a known method to peel off the polyester film, followed by development at a transport speed of 40 cm / min using an automatic developing machine having two brush rolls. The developing solution used was a solution containing an aliphatic saturated hydrocarbon-based solvent as a main component and a dye, a surfactant and the like added thereto. Brush roll is nylon 6 ・
10 single yarn with a diameter of 200 microns and hair length 15mm
Implanted to become 1160mm long, 130m outside diameter
m is the first brush roll, which is rotated at 300 revolutions per minute in the same direction as the transport direction of the printing original plate in the direction of rubbing the same, and has a swing width of 30 reciprocations at 120 revolutions per minute.
mm. As the second brush roll, a single yarn made of nylon 6.10 and having a diameter of 160 μm is implanted so as to have a bristle length of 26 mm, and has a length of 1160 m.
m and an outer diameter of 100 mm were rotated 180 times per minute in the direction opposite to the direction in which the printing original plate was conveyed. As a result, it was possible to obtain a uniform halftone dot from which the silicone rubber layer at the edge was also removed, and it was possible to obtain a high quality printed matter even during printing. Embodiment 2 In Embodiment 1, the second brush roll is rotated at 120 min / min.
Reciprocating rocking with a rocking width of 30 mm allows a higher speed 60
Development was performed at a transport speed of cm / min. As a result, it was possible to obtain a uniform halftone dot from which the silicone rubber layer at the edge was also removed, and it was possible to obtain a high quality printed matter even during printing. Comparative Example 1 The same waterless planographic printing plate precursor as in Example 1 was subjected to exposure processing by the same method, and development processing was performed at the same transport speed as in Example 1 using the same developing solution and the same automatic developing machine. . On this occasion,
A brush roll having the same shape as in Example 1 was used at the same number of revolutions, but the two rotating directions were both rotated in the same direction as the traveling direction of the printing original plate, and did not swing. As a result, only halftone dots with the silicone rubber layer remaining at the upstream edge in the rubbing direction with the brush roll were obtained. When printing, high-quality prints could not be obtained.In addition, when the dust adhered to the printing plate was wiped off with a cloth during printing, the silicone rubber layer remaining on the edges of the halftone dots was also removed at the same time. In the subsequent printing, only a printed material having a different color tone was obtained. Comparative Example 2 The same waterless planographic printing plate precursor as in Example 1 was subjected to an exposure process in the same manner, and the same lithographic printing plate was prepared using the same developing solution and the same automatic developing machine.
The developing process was performed at a transport speed of 0 cm / min. The first brush roll was rotated in the same direction as the printing plate precursor, and the second brush roll was rotated in the opposite direction, but did not swing. At this time, the brush roll having the same shape as that of Example 1 was used at the same rotation speed. As a result, only uneven halftone dots of the remaining portion of the silicone rubber layer can be obtained on the upstream edge in the rubbing direction by the first brush roll between the portion where the second brush roll is in good contact and the portion where it is not. Remained in shape. Even in printing, streaky patterns became apparent and high quality printed matter could not be obtained,
In addition, when the dust adhering to the printing plate was wiped off with a cloth during printing, the silicone rubber layer remaining on the edge of the halftone dot at that portion was also removed at the same time, and in subsequent printing, the color tone of only that portion was different. Only printed material was obtained. Example 3 The same waterless lithographic printing plate precursor as in Example 1 was exposed by the same method, and this was composed of a pre-processing machine, a developing machine and a post-processing machine. Were subjected to a developing process using an automatic developing machine having one brush roll. That is, a pre-treatment machine that sprays polypropylene glycol on the printing plate, and then water while spraying the printing plate.
The same brush roll as the first brush roll in the embodiment 1 makes 300 rotations per minute in the same direction as the printing plate advance direction, and oscillates with a swing width of 30 mm at 120 reciprocations per minute, and rubs it. Example 1 While spraying a developing machine and finally an aqueous solution of a dye and a surfactant on the printing original plate,
An automatic developing machine consisting of a post-processing machine rubbing the plate with the same brush roll as the second brush roll in the direction opposite to the advancing direction of the printing original plate by 180 rotations per minute was used. The transfer speed was 40 cm / min. As a result, a uniform halftone dot without leaving the silicone rubber layer on the edge was obtained without splashing the printing plate. High quality prints were obtained during printing. Example 4 In Example 3, the brush roll of the post-processing machine was set at 120 minutes per minute.
Reciprocating rocking with a rocking width of 30 mm allows a higher speed 60
Development was performed at a transport speed of cm / min. As a result, it was possible to obtain a uniform halftone dot from which the silicone rubber layer at the edge was also removed, and it was possible to obtain a high quality printed matter even during printing. Example 5 The same lithographic printing plate precursor as in Example 1 was exposed to light in the same manner as in Example 1, and was exposed to a pretreatment machine, a developing machine, a post-processing machine, and a washing machine. Post-processing machine,
The developing process was performed at a transport speed of 80 cm / min using an automatic developing machine having one brush roll for each washing machine. That is, a pretreatment machine for spraying polypropylene glycol on the printing plate precursor, and then, while spraying water on the printing plate precursor, Example 1
In the same brush roll as the first brush roll in the above, 300 rotations per minute in the same direction as the traveling direction of the printing original plate, and rocking with a rocking width of 30 mm at 120 reciprocations per minute,
The developer is rubbed, and an aqueous solution of a dye and a surfactant is sprayed on the printing plate precursor. The same brush roll as the second brush roll in Example 1 is used in the same direction as the printing plate precursor in the direction of 180 ° / min. The second brush roll in Example 1 was rotated while rubbing the post-processing machine, and finally spraying water on the printing plate to remove the dye and surfactant attached to the printing plate other than at the image area. 180 minutes per minute with the same brush roll
An automatic developing machine consisting of a water washing machine was used which oscillated with a swing width of 30 mm at 120 reciprocations per minute while rotating. As a result, a uniform halftone dot without leaving the silicone rubber layer on the edge was obtained without splashing the printing plate. High quality prints were obtained during printing. Example 6 A commercially available negative-working Toray waterless lithographic printing plate precursor was exposed to light in the same manner as in Example 1, and was subjected to the same automatic developing machine as in Example 5 to remove the chemicals from the pre-processing machine. The development was carried out under the same conditions as in Example 5 except that the solution was changed to a solution containing diethylene glycol as a main component. As a result, a uniform halftone dot without leaving the silicone rubber layer on the edge was obtained without splashing the printing plate. High quality prints were obtained during printing. According to the above Examples 1 to 6 and Comparative Examples 1 and 2.
To remove the halftone dots from which the silicone rubber layer at the edges has been removed.
In order to obtain it, rotate the brush roll 120 times per minute in the roll axis direction.
It is good to make it swing with a swing width of 30 mm.
Now we know what the reciprocating speed and swing
I considered whether it would be more effective to use the dynamic range
Are the following Examples 7 to 9 and Comparative Examples 3 to 5. Example 7 In Example 1, the first and second brush rolls were used.
Both brush materials are PBT (polybutylene terephthalate)
G) and make the first brush roll every minute
Example except that the swing width was 5 mm in 50 reciprocations.
The development was performed under the same conditions as in Example 1. As a result, tone reproducibility
(Dot shape) with good fringe (silicon at edge of dot)
Rubber layer remains) and uniform marks without streak-like unevenness
A printing plate was obtained. Also, when printing, reproduce the printing plate
Good printed matter was obtained. In addition, the operation of the automatic processor
The condition was good without vibration and noise. Example 8 In Example 7, the first brush roll was set at 40 minutes per minute.
Except for oscillating in 0 reciprocations, all conditions were the same as in Example 7
An image was made. As a result, the first brush roll
The plate jumps up despite swinging in 400 round trips per minute
No fringe or streak-like
A homogeneous printing plate free of rags was obtained. In addition, automatic processing machines
The driving state is such that you can hear a rhythmic sound if you listen carefully
The vibration was good with almost no vibration. Example 9 In Example 7, the first brush roll was set to a swing width of 1.
The same conditions as in Example 7 except that the rocking was performed by 00 mm.
Development. As a result, the first brush row
The plate jumps despite the rocking width of 100mm
Good tone reproducibility without fringing
A uniform printing plate having no zigzag unevenness was obtained. Also, development
If you listen to the operating state of the device, you can hear a rhythmic sound
And the vibration was only felt when touched. COMPARATIVE EXAMPLE 3 In Example 7, the first brush roll was set at 12 minutes per minute.
All examples except that the swing width was 3 mm in 0 reciprocations
The development was performed under the same conditions as in Example 1. As a result, the brush tip
The rubbing force on the edge of the dot
Fringes remain upstream in the rubbing direction due to
Was defective and streaky unevenness occurred in the transport direction of the printing plate
Only the printing version was obtained. However, the operation of the automatic processor
The condition was good without vibration and noise. COMPARATIVE EXAMPLE 4 In Example 7, the first brush roll was set to 40
All examples except that the swing width was 3 mm in 0 reciprocations
The development was performed under the same conditions as in Example 7. As a result, the net
The rubbing force on the edge is not sufficiently transmitted, and
Fringes remain on the upstream edge in the rubbing direction, and tone reproducibility
Was defective and streaky unevenness occurred in the transport direction of the printing plate
Only the printing version was obtained. In this case, the operation of the automatic processor
The rolling state was good without vibration and noise. COMPARATIVE EXAMPLE 5 In Example 7, the first brush roll was set at 12 minutes per minute.
Except for the swing width of 120mm in 0 reciprocations, all actual
Development was performed under the same conditions as in Example 7. As a result, the brush tip
Rubbing force on the silicone rubber layer at the halftone dot edges and non-image areas
There was no fringe or streak-like unevenness.
The halftone dot edge may be damaged or non-
Scratches occur in the silicone rubber layer in the image area, resulting in better tone reproducibility
Only a missing printing plate was obtained. In addition, automatic processing machines
The driving condition was intense vibration and noise. Results of Examples 7 to 9 and Comparative Examples 3 to 5
Table 1 summarizes the above. The method of evaluating the effect of each example is as follows.
I did it. A. Tone reproducibility (dot shape): The printing plate after development has no streaks or fringes described later,
Check that the silicone rubber layer at the edges and non-image areas is not damaged.
And If there is at least one of streaks, fringes, and scratches ×
And B. Streak: A state where no streak-like unevenness was found on the printing plate after development was evaluated as ○.
When streak-like unevenness was recognized, it was evaluated as x. C. Fringe: Silicone rubber layer remains on the halftone dot edge of the printing plate after development
The state without the mark was indicated by ○. Silicone rubber layer at the dot edge
Check that there is no residue and that the edge of the dot is scratched.
And Silicone rubber layer remains at the dot edge
Is indicated by x. D. Vibration: The degree to which vibration is felt when the automatic developing machine in operation is touched by hand
Is indicated by ○, and the degree of feeling without touching is indicated by ×. E. Noise: The noise of the brushes and the circulating pump of the automatic processor during operation
If the sound is smaller than the rotating sound,
The case where it was large was evaluated as x. Table 1 From Table 1, it can be seen that the silicone rubber layer at the edge was removed.
To obtain high quality halftone dots, it is necessary to shake the brush roll in the roll axis direction.
The dynamic speed ranges from 50 to 400 times / minute,
It is effective to adopt the range of 5-100mm as swing width
Of the swing speed and swing width.
Of the two conditions, the swing width must be
Was found to be dominant. Adjustment by swing speed
Is caused by vibration and noise.
Is the brush tip density by adjusting the embedding width of the brush.
High degree of freedom of adjustment because it can cover unevenness, swing
By adjusting the width, the plate surface can be easily and evenly rubbed
The halftone dot faithful to the film can be reproduced, and the tone reproducibility
Excellent printing plate is obtained. According to the present invention, in the developing device for a waterless lithographic printing plate precursor, at least one brush roll is provided in the transporting direction of the printing plate, the brush roll rotating in the transporting direction and the opposite direction. In addition to the above, a reciprocating mechanism for swinging at least one of these rolls in the roll axis direction with a swing width of 5 to 100 mm is provided. The removal of the silicone rubber layer remaining at the edge portion is promoted, a uniform halftone dot having no directivity can be surely obtained, and an automatic developing device capable of high-speed development can be obtained. As a result, the printed matter can maintain a stable ink density even during printing, and a high quality printed matter excellent in tone reproducibility can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an example of an automatic developing device according to the present invention. [Description of Signs] 1: Printing original plate 2: Carrying table 3: Developing machine body 4: Carrying table 5: Roll 6: Pump 7: Spray nozzle 8, 9: Brush roll 10: Support mechanism

Continuation of front page    (56) References JP-A-60-59351 (JP, A)                 US Patent 4588277 (US, A)                 "Journal of Paper and Paper Technology Association" Vol.40 No.11 (Akira               (Issued November 1, 61st, 61) 8-16                 "Toray Waterless Lithographic Automatic Developing Machine TW               L-1160D. 860D Instruction Manual ”(Akira               (Issued by Toray Industries, Inc. on April 1, 55)

Claims (1)

(57) [Claims] In a developing device for a waterless lithographic printing plate, which rubs and develops the silicone rubber layer with at least two brush rolls while transporting the waterless lithographic printing plate having a silicone rubber layer lined on a substrate as an uppermost layer, the conveying direction of a) the waterless planographic printing plate, by at least one and a brush roll rotating in opposite directions is provided to the brush roller and the conveying direction of rotation in the conveying direction and the same direction, and, (B) At least one brush seal of the at least two brush rolls is 5 to 100 m in the roll axis direction.
(C) A waterless planographic printing plate characterized by physically removing a silicone rubber layer in an image area by providing a reciprocating mechanism for reciprocating with a swing width in the range of m. Developing device. 2. The developing device for a waterless lithographic printing plate according to claim 1, wherein a cam is used for a reciprocating mechanism of the brush roll. 3. The developing device for a lithographic printing plate without water according to claim 1 or 2, wherein
A developing device for a waterless lithographic printing plate, comprising a support mechanism for preventing escape of the waterless lithographic printing plate.