JPH0342595B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a printing original plate rinsing device, and in particular, a printing original plate having a photoconductive photosensitive layer is used, and a developed toner image is formed by an electrophotographic method. The present invention relates to a printing original plate rinsing device for rinsing a lithographic printing plate using an improved rinsing process.

[Prior art] Conventionally, a conductive metal plate such as an aluminum plate is used as a support, and a photoconductive photosensitive layer, in particular copper phthalocyanine, is formed on the support by dispersing a photoconductive organic material in a resin such as a phenolic resin. Using a printing original plate coated with a photoconductive photosensitive layer in which is dispersed in a novolac resin, the electrostatic latent image is formed on the photosensitive layer by completing the charging and exposure process using an electrophotographic method. A developed toner image is obtained by passing through a developing process, and then a plate on which the toner image has been fixed is obtained through the steps of rinsing, drying, fixing, and cooling. A technique is known in which an image-sensitive layer is swollen and then rinsed using a rinsing liquid.

The present invention provides a means for solving the unresolved problems that existed in the etching process and the rinsing process in the rinsing process following the etching process.

The present inventor previously proposed a method for etching a lithographic printing plate as described in JP-A-58-25477. In the previously proposed technique, as shown in FIG. 1, in the final step A of etching, a roll 5 is used to squeeze the etching liquid on the printing plate. As a result, the pressure of the roll 5 causes organic pigments such as copper phthalocyanine to be pressed and adhered to the grained surface of the aluminum support.
When pigments adhere to the grained surface in this way,
There was a problem in that it was not removed in the subsequent rinsing steps B and C and remained as a stain on the non-image surface.

Conventionally, in multiple rinsing steps B and C following the etching step A, the non-image area photosensitive layer is removed using a rinsing liquid and brushing rolls 6A and 6B. When the rinsing liquid on the plate surface is squeezed by the roll 5 at the rear, the organic pigment in the non-image area will adhere to the grained surface of the aluminum support in the same way as described above, and will eventually become a stain on the non-image area. There was a problem of remaining.

Furthermore, in order to solve the problems in the etching step A and the rinsing steps B and C described above, it is also possible to use an air squeeze instead of the roll squeeze. However, according to the air squeeze method, there is a problem that when the amount of liquid on the plate increases, the squeezing performance deteriorates and the liquid is brought into the next process.Especially in rinsing processes B and C, the cleaner the rinsing process that follows Since the rinsing liquid is used as a rinsing liquid, if a large amount of the liquid is carried over to the next process, the rinsing liquid used in the final process becomes dirty, leaving stains on the finished printing original plate.

Furthermore, conventionally, full-surface rolls have been used as transport rolls for printing original plates, but when such full-face rolls are used, if organic pigments, toner, etc. adhere to the roll surface, they are transferred onto the clean non-image area of the printing original plate. There was a problem that the plates were smudged.

[Object of the Invention] The present invention has been made to solve the above-mentioned problems, and its first purpose is to prevent the occurrence of stains on printing original plates caused by carrying dirty rinsing liquid into the next step in the rinsing process. An object of the present invention is to provide a printing original plate rinsing device that can prevent the above problems.

A second object of the present invention is to provide a printing original plate rinsing device that can eliminate stains on the printing original plate caused by transport rolls.

[Summary of the Invention] The printing original plate rinsing device according to the present invention is a printing original plate formed by coating a photoconductive photosensitive layer on a support, and a printing original plate on which a toner image is formed on the photosensitive layer. A conveyance roll that conveys the toner with the image surface facing upward, a shower that supplies a rinsing liquid for rinsing while being conveyed by the conveyance roll, and a shower that scrapes the non-image area photosensitive layer on the conveyance surface of the printing original plate. In a printing original plate rinsing device having a scraping part for removing the toner and a squeeze part for squeezing the rinsing liquid, the upper roll of the conveying roll is conveyed in contact with both ends in the width direction of the toner image surface. An air squeeze section is provided near the exit of at least the first rinsing step among the plurality of rinsing steps and behind the plate transport path of the scraping section. .

[Structure of the invention] The present invention will be explained in detail below.

First, in order to clarify the structure of the present invention, a rinsing process using a conventional rinsing device and the steps before and after the rinsing process will be described based on FIG.

In the figure, reference numeral 1 denotes a printing original plate having a photoconductive photosensitive layer coated on an aluminum plate or other support, on which a visible toner image is formed through processes including charging, exposure, development, and fixing. The plate 1 is first sent to the transport system of the etching process A, and is transported in the horizontal direction by transport rolls 2. In this etching process A, an etching liquid 3 made of an alkaline liquid controlled at a constant temperature is supplied by a shower 4 from above the surface of the plate to remove the non-image area (the area to which no tony is attached). After etching with an etching liquid 3 that swells the photosensitive layer, the etching liquid layer remaining on the surface of the horizontal plate is removed by using a squeeze roll 5 such as a mirror roll.

Thereafter, the plate 1 enters a first rinsing step B, and subsequently enters a second rinsing step C. In the first rinsing step B and the second rinsing step C, the photosensitive layer in the non-image area swollen in the etching step A is scraped off by brushing rolls 6A and 6B made of nylon fibers, respectively. The plate 1 is rotated in the same direction as the traveling direction of the plate 1 to scrape it off, and the surface of the plate 1 moving in the horizontal direction is washed by showers 8A and 8B with rinsing liquids 7A and 7B made of water or the like. This rinsing liquid layer on the plate surface is removed by the squeeze roll 5 in the same manner as described above, and then the plate is conveyed to the gumming step D.

In the gumming process D, the horizontally moving plate 1 is coated with a thin and uniform gum liquid 1 by the shower 9.
A layer of 0 is applied. Next, the plate 1 is transported to a drying process E, where it is placed in a drying container 11 controlled at a constant temperature.
(It is desirable to be isolated from the outside by an air curtain.) After passing through the interior and being dried, plate making is completed.

In the figure, 12A and 12B are rinsing liquid tanks provided separately for the first rinsing process B and the second rinsing process C, 13 is an etching liquid tank,
14 is a gum liquid tank, 15 is a pump, 16 is a blower, and 17 is a return tank for returning each liquid to each tank.

Next, a preferred embodiment of the present invention will be described based on FIGS. 2 to 6. In the figure, parts with the same numbers as those shown in FIG. 1 indicate the same equipment and materials. FIG. 6 is an explanatory diagram showing the preferred embodiment of FIGS. 2 to 6, and shows only the first rinsing step.

The embodiment shown in FIG. 2 is an example in which an edge transport roll 20 configured to transport the toner in contact with both ends in the width direction (direction perpendicular to the transport direction) of the toner image surface is used as the upper roll of the transport roll. It is. In the figure, 21 is an air squeezer for squeezing the rinsing liquid on the printing plate, and is provided near the exit of the first link step B. 22 is a blower for supplying air to the air squeeze 21. 6A is a brushing roll, which rotates in the same direction as the printing plate conveyance direction (counterclockwise in FIGS. 1 to 6).

By using the edge conveying roll 20 as described above, the plate can be conveyed without the risk of staining the image surface of the plate. Furthermore, by providing the brushing roll 6A and the air whiz 21 in the first rinsing process B, a liquid pool can be created at the tips of both, improving squeezing properties and carrying dirty liquid into the second rinsing process. I can't.

The embodiment shown in FIG. 3 is obtained by adding an air squeeze 23 to the embodiment shown in FIG. In the figure, 24 is a blower.

With the above configuration, the rotation of the brushing roll 6A can prevent the liquid from flowing back to the previous process (for example, the etching process). This is effective when the etching process and the rinsing process are configured separately and independently.

The embodiment shown in FIGS. 4 and 5 is different from the embodiment shown in FIG.
After passing through A, a guide 25 is provided to raise the position of the conveyance surface and create a slight inclination.
In the figure, the height is not particularly limited and may be determined so that θ is several degrees (for example, 1 degree to 10 degrees, preferably 2 degrees to 5 degrees).

By providing the guide 25 as described above, the squeezing property of the air squeeze 20 at the exit portion of the first rinsing step can be increased.

The embodiment shown in FIG. 6 differs from the embodiment shown in FIG. 2 in that a new brushing roll 26 is arranged in parallel near the air squeeze 21.

Constructed as above, brushing roll 26
By rotating the plate in a direction opposite to the plate conveyance direction (clockwise in FIGS. 1 to 6), squeezing properties in the vicinity of the exit of the first rinsing step B can be ensured.

Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited thereto, and various other embodiments can be adopted.

For example, as shown in FIG. 7, it is possible to improve the brushing roll 6A. That is, in the figure, 27 is a shaft of the brushing roll 6A, 28 is a bearing, 29 is a grooved cam, 30 is a guide section, 31 is a motor, and 32 is a conveyance table.

By configuring as above, motor 3
1 rotates the brushing roll 6A, and at the same time, due to the action of the cam 29, the brushing roll 6A reciprocates in the width direction of the shaft 27, that is, the width direction of plate conveyance. Therefore, it is possible to increase the scraping effect on non-image areas.

Further, in each of the above embodiments, the case of the first rinsing step has been described, but it goes without saying that this may be used in the second rinsing step. 2
0 can be used not only in the first rinsing step B and the second rinsing step C, but also in the drying step E, making it possible to maintain good image quality on the printing plate.

The present invention has been described above. According to the present invention, since the edge conveying roll is used, the printing original plate is not stained by the conveying roll, and the scraping part is not scraped off. After the rinsing process is completed, the rinsing liquid is squeezed by air squeezing and is also reliably squeezed at the exit of the first rinsing process during the rinsing process, so that the contaminated rinsing liquid is not brought into the next process. Therefore, staining of the original printing plate can be prevented.

[Brief explanation of drawings]

Fig. 1 is a process diagram showing a conventional example, Figs. 2 to 6 are partial process diagrams showing a preferred embodiment of the present invention, and Fig. 7 is an example of an installation state of a brushing roll preferably used in the present invention. FIG. In the figure, A is the etching process, B is the first rinsing process, C is the second rinsing process, D is the gumming process, and E
is a drying process, 1 is a printing original plate, 2 is a conveyance roll, 5
is a squeeze roll, 6A and 6B are scraping parts, 7
A, 7B are rinsing liquids, 20 is an edge conveying roll,
21 and 23 indicate air squeeze, respectively.

Claims (1)

[Claims] 1. A printing original plate comprising a photoconductive photosensitive layer coated on a support, which comprises: a conveying roll for transporting the printing original plate on which a toner image is formed on the photosensitive layer with the toner image surface facing upward; A shower for supplying a rinsing liquid for rinsing while being conveyed by a conveying roll, a scraping part for scraping off the non-image area photosensitive layer on the conveying surface of the printing original plate, and a scraping part for squeezing the rinsing liquid. In the printing original plate rinsing device having a squeeze section, the upper roll of the transport roll is configured to be an edge transport roll configured to transport the toner image surface in contact with both ends in the width direction, and a plurality of rinsing steps are performed. An apparatus for rinsing a printing original plate, characterized in that an air squeeze section is provided at least near the exit of the first rinsing step and behind the plate conveyance path of the scraping section.