JPH05197177A - Electrophotographic printing plate material and manufacture of printing plate therewith - Google Patents

Abstract

PURPOSE:To provide an electrophotographic printing plate material requiring no environmental pollution countermeasures such as waste water treatment and manufacture a printing plate with it. CONSTITUTION:An electrostatic latent image is formed by electrophotography on a printing plate material laminated with an organic semiconductor charge generating layer 2 and a polysilane charge transporting layer 3 in sequence on a conducting base, a toner image is formed in response to the electrostatic latent image, then ultraviolet irradiation is applied to the printing plate material, and the polysilane charge transporting layer 3 region located at the non-image section other than the toner image section is decomposed and removed to manufacture a printing plate. The manufacturing process of the printing plate is a completely dry process, and environmental pollution countermeasures such as waste water treatment are not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing plate material using an electrophotographic method and a method for producing a printing plate using the same in a completely dry process.

[0002]

2. Description of the Related Art A method for producing a printing plate by using an electrophotographic method has been conventionally known.

For example, according to the method proposed in Japanese Patent Laid-Open No. 51-143408, after a toner image is formed on a photoconductor, the toner image is transferred to a printing plate material made of a photosensitive resin, and the printing plate material is formed. Is exposed to the whole surface to cause a photochemical reaction in the non-toner portion, and then a developing elution treatment is performed to obtain a printing plate having unevenness according to image information.

However, the above proposed method has a problem that the number of members is increased and the process is complicated because a printing plate material is required in addition to the photoconductor. Further, since the development elution is performed by a wet process, a large-scale facility is required for pollution control such as wastewater treatment.

Further, in Japanese Patent Laid-Open No. 58-72145 proposed as another method, a photosensitive material is coated on the surface of a printing plate material, and a toner image is formed thereon by an electrophotographic method. The entire surface of the printing plate material is exposed to cause a photochemical reaction in the non-toner portion, and then development elution processing is performed to obtain a printing plate having irregularities according to image information.

However, this method is an improvement over the prior art in that a printing plate material is not required separately from the photoconductor, but on the other hand, since development elution is carried out by a wet process, pollution such as wastewater treatment is prevented. This is still a problem in that large-scale equipment is required for countermeasures.

In Japanese Patent Laid-Open No. 3-158861 proposed as still another method, an organic photoconductive compound and a binder resin are adopted as a photosensitive material used in the above wet process, and the binder resin is a specific material. This improves printing durability and image quality.

However, even in this method, the development elution is carried out by a wet process, which has the same problem as the above-mentioned technique.

As described above, a wet process has been proposed in the conventional electrophotographic plate making technique, and a complete dry process has been strongly desired from the viewpoint of pollution control.

[0010]

The present invention is for electrophotographic printing, characterized in that an organic semiconductor charge generation layer and a polysilane charge transport layer which is decomposed by ultraviolet irradiation are sequentially laminated on a conductive support. To provide printing materials.

According to the present invention, an electrostatic latent image is formed on a printing plate material in which an organic semiconductor charge generation layer and a polysilane charge transport layer are sequentially laminated on a conductive support by electrophotography. After forming a toner image corresponding to the electrostatic latent image, the printing plate material is irradiated with ultraviolet rays to decompose the area of the polysilane-based charge transport layer located in the non-image area other than the toner image area. Another object of the present invention is to provide a method for producing a printing plate, which is characterized by removing the printing plate.

FIG. 1 shows the structure of the electrophotographic printing plate material of the present invention. 1 is a conductive substrate, the material of which is
Examples include metals such as aluminum, copper, zinc, and brass, or heat-resistant resins having a conductive film deposited on their surfaces. Further, the shape thereof is appropriately selected such as a flat plate shape, a sheet shape and a drum shape. The organic semiconductor charge generation layer 2 is formed on the substrate 1.
And the polysilane-based charge transport layer 3 are sequentially formed to form a plate material.

The organic semiconductor type charge generation layer 2 has a function of enhancing the electrostatic latent image contrast as a photoconductor, and examples of the organic semiconductor material therefor include, for example, titanyl phthalocyanine, metal-free phthalocyanine, penylene type pigments, and multi-component pigments. Ring quinone pigment, metal phthalocyanine pigment, squarylium dye, azurenium dye, thiapyrylium dye,
An organic semiconductor having high carrier generation efficiency such as trisazo pigment is selected. The layer is formed as a vapor deposition layer or a fine particle dispersion layer, and the layer thickness is preferably in the range of 0.1 to 10 μm. Within this range, photocarriers are effectively generated, the internal stress of the film does not increase, and the film does not peel when repeatedly used as a printing plate. Particularly when the substrate is a flexible sheet, the thicker the organic semiconductor layer is, the poorer the flexibility becomes, and the more easily the film is cracked or peeled off. Therefore, the thickness is preferably 10 μm or less.

The material of the polysilane-based charge transport layer 3 is an ultraviolet-decomposable polysilane, for example, the polysilane of the chemical formula shown in Chemical formula 1 is selected.

[0015]

[Chemical 1]

Such polysilanes include diethyl polysilane, dipropyl polysilane, dibutyl polysilane,
Diamylpolysilane, dihexylpolysilane, dicumylpolysilane, ethylpropylpolysilane, ethylamylpolysilane, ethylhexylpolysilane, propylbutylpolysilane, propylamylpolysilane, propylhexylpolysilane, propylphenylpolysilane, propylcumylpolysilane, butylamylpolysilane, butylhexylpolysilane , Butylphenyl polysilane, butyl cumyl polysilane, amyl hexyl polysilane, amyl phenyl polysilane, amyl milk mil polysilane, hexyl phenyl polysilane, hexyl mil polysilane, phenyl cumyl polysilane, ethyl butyl polysilane, phenyl ethyl polysilane, cumyl ethyl polysilane, Examples include diphenyl polysilane. Above all, cumylethylpolysilane is desirable in that it has a high decomposition rate upon irradiation with ultraviolet rays.

The thickness of the polysilane type charge transport layer 3 is set so that the unevenness required for the printing plate can be obtained. For example, in the case of letterpress, it is usually 0.1 to 1 mm, but the range is not particularly limited. On the other hand, if it is a planoconcave or planoconvex plate,
1 to 10 μm is standard.

The charge transport layer 3 is formed by a dip coating method or a roll coater method. For example, when a charge transport layer of cumylethylpolysilane is formed, the starting material is cumylethyldichlorosilane, which is dechlorinated and polymerized to generate cumylethylpolysilane. This molecular weight is usually on the order of thousands to millions. The polysilane generated in this way is dissolved in a solvent such as toluene or tetrahydrofuran, and the photoreceptor substrate having the organic semiconductor charge generation layer 2 formed thereon is dipped and applied in the solution. Then about 10
By drying with hot air at 0 ° C., a polysilane-based charge transport layer is formed on the charge generation layer 2 and a printing plate material is completed.

Next, the plate making process according to the present invention will be described with reference to FIGS.

First step: (Whole surface charging) As shown in FIG. 2, the entire surface of the photosensitive member as a plate material is uniformly charged by corona discharge or the like. The charging polarity is negative because polysilane usually exhibits a negative charging property (hole transport property).

Second step: (exposure of recorded information / electrostatic latent image type)
In this step, as shown in FIG. 3, light corresponding to image information is selectively irradiated to form an electrostatic latent image on the surface of the photoconductor by negative charges. The light incidence means may be an analog recording system in which a plate-making original is irradiated with light from a halogen lamp or the like and the reflected light is directly imaged on a photoconductor, as in a copying machine, or He-Ne, Ar. , Semiconductor laser, L
A so-called digital recording method in which light is modulated according to recording information and irradiated using an ED head, an EL head, a liquid crystal shutter, or the like may be used. With this digital recording method, it is possible to make an original by directly making a manuscript sent from a remote place using a digital line and printing a newspaper, which allows newspaper printing to be performed quickly and in a simple process. It is useful. In this case, it is possible to configure a system in which a buffer stage is provided on the receiving side, and after performing the typesetting / calibration there, a signal is input to the recording unit. By doing so, for example, it becomes possible to manufacture newspapers by receiving individual newspaper article manuscripts from a plurality of transmitting sides at one receiving side and forming a plate.

Third Step: (Development) Next, as shown in FIG. 4, a toner 4 having an ultraviolet absorbing property (black) is dispersed on the surface of the photoconductor to form a toner image corresponding to image information. As the toner 4, positively charged toner and negatively charged toner are selectively used according to the type of plate making. For example, in the case of an intaglio plate, positively charged toner is used, and the toner is attached to the portion not irradiated with the recording light. As a result, the concave portion is formed only in the recording information exposure portion in the next step. Further, in the case of a relief printing plate, it is possible to perform reverse development using a negatively charged toner, thereby forming a projection portion in the recording information exposed portion.

This toner image may be fixed before the next step or after the next step, and finally the toner may be fixed on the surface of the plate material. When fixed before the next step, the toner is melted and deformed to increase the coverage of the surface of the plate material, prevent light leaking from the gaps of the toner particles, and produce a printing plate with good contrast. . Further, by fixing the toner, it is possible to improve matching with the oil-based ink for printing. For example, the wettability between the printing ink and the surface of the printing plate can be improved by modifying the surface of the toner to increase the lipophilicity and selecting the particle size thereof. Of course, it is not always necessary to fix the toner.

Fourth step: As shown in FIG. 5, when the entire surface of the photosensitive member is irradiated with ultraviolet rays, the ultraviolet rays applied to the toner adhering region are absorbed by the toner 4 and do not reach the polysilane type charge transport layer 3. On the other hand, when the area where the toner is not adhered is irradiated with ultraviolet rays, the area of the polysilane-based charge transport layer 3 located there is decomposed and removed as shown in FIG. As a result, a printing plate having irregularities is manufactured. The appropriately designed polysilane-based charge transport layer 3 is decomposed and removed only by irradiation of ultraviolet rays. However, if the removal is insufficient or the unevenness of the unevenness is small and the influence of the residue is large, the residue is removed. It is necessary to completely remove it. For this purpose, it can be completely removed by air blowing or by pressing an adhesive sheet on the surface of the plate material.

[0025]

Example 1 An aluminum vapor-deposited film whose surface was completely washed was immersed in a liquid in which titanyl phthalocyanine and a polyester resin were dispersed and mixed in methylene chloride, and then dried at 55 ° C. under reduced pressure to obtain a titanyl phthalocyanine charge. A generator layer was formed. Next, this film is dipped in a solution of cumylethylpolysilane having an average molecular weight of about 100,000, which is produced by dechlorinating and polymerizing cumylethyldichlorosilane, in toluene, and then dried with hot air at 100 ° C. did.
Thus, a polysilane-based charge transport layer having a thickness of 200 μm was formed to manufacture a printing plate material.

Next, the surface of the plate material is corona-charged with a DC voltage of -5 KV, and about -800 V is applied over the entire surface.
Was uniformly charged. Thereafter, a halogen lamp was used to form an image of reflected light from the original on the surface of the plate material to form an electrostatic latent image. Next, in the state where a bias of 600 V was applied to the substrate of the plate material, reverse development was performed using negatively charged toner. The entire surface of the plate material on which the toner image corresponding to the image information was formed in this manner was irradiated with ultraviolet light of a low-pressure mercury lamp having a wavelength of 253.7 nm (light amount of 500 to 1000 mJ / cm ² ). As a result, the polysilane layer region where the toner does not adhere is decomposed and removed, and finally, a small amount of residue is removed by air blow to manufacture a printing plate having an unevenness of 200 μm corresponding to the layer thickness of the polysilane layer. .

As a result of printing using this printing plate by a letterpress printing method, high resolution printing could be performed. Further, even when the abrasion resistance test corresponding to printing of 50,000 sheets was performed on this printing plate and then printing was performed again, it was possible to print with almost no deterioration in resolution from the initial stage.

[0028]

Example 2

On the aluminum vapor deposition film whose surface is completely washed,

In the same manner as in Example 1, a titanyl phthalocyanine charge generating layer was formed by immersing the titanyl phthalocyanine and a polyester resin in a liquid in which methylene chloride was dispersed and mixed, and then dried. Next, this film is dipped in a solution of cumylphenyl polysilane having an average molecular weight of about 100,000, which is produced by dechlorinating and polymerizing cumylphenyldichlorosilane, in tetrahydrofuran, and then dried with hot air at 100 ° C. did. Thus, a polysilane-based charge transport layer having a thickness of 200 μm was formed to manufacture a printing plate material.

Next,

In the same manner as in Example 1, the surface of the plate material was corona-charged with a DC voltage of -5 KV, and the entire surface was -80
It was uniformly charged to 0V. Thereafter, a halogen lamp was used to form an image of reflected light from the original on the surface of the plate material to form an electrostatic latent image. Next, in the state where a bias of 600 V was applied to the substrate of the plate material, reverse development was performed using negatively charged toner.
The wavelength of the low pressure mercury lamp is 253.7 nm on the entire surface of the plate material on which the toner image corresponding to the image information is formed.
Of the ultraviolet light (light amount of 500 to 1000 mJ / cm ² ) was irradiated. As a result, the polysilane layer region where the toner does not adhere is decomposed and removed, and finally, a small amount of residue is removed by air blow to manufacture a printing plate having an unevenness of 200 μm corresponding to the layer thickness of the polysilane layer. .

As a result of printing using this printing plate by a letterpress printing method, high resolution printing could be performed. Further, even when the abrasion resistance test corresponding to printing of 50,000 sheets was performed on this printing plate and then printing was performed again, it was possible to print with almost no deterioration in resolution from the initial stage.

The present invention is not limited to the above embodiment, but as described above, it can be applied to other printing methods such as intaglio printing and planographic printing.

[0033]

As described above, by using the printing plate material of the present invention and the method for producing a printing plate of the present invention, it is possible to perform printing with high resolution and high printing durability. Thus, it can be applied to printing a large number of copies.

Further, according to the present invention, unlike the conventional lead alloy plate making, there is no fear of lead pollution problem, and since the plate making process is a completely dry process, large-scale wastewater treatment like the conventional photosensitive resin plate making is performed. No measures are needed.

Furthermore, according to the present invention, automated rapid plate making can be realized by combining with a transmission system utilizing a digital communication line.

Further, since the printing plate material of the present invention is composed of the organic semiconductor type charge generation layer, it becomes easy to make the plate material into a sheet form, and it is easy to widen the A0 plate and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an electrophotographic printing plate material of the present invention.

FIG. 2 is a cross-sectional view showing a plate making process according to the present invention.

FIG. 3 is a cross-sectional view showing a plate making process according to the present invention.

FIG. 4 is a cross-sectional view showing a plate making process according to the present invention.

FIG. 5 is a cross-sectional view showing a plate making process according to the present invention.

FIG. 6 is a cross-sectional view showing a plate making process according to the present invention.

[Explanation of symbols]

 1 Substrate 2 Organic Semiconductor Charge Generation Layer 3 Polysilane Charge Transport Layer 4 Toner

Front page continuation (72) Inventor Keifumi Ejima 6 1166, Haseno, Jizo-cho, Yokaichi-shi, Shiga Prefecture Kyocera Corporation Shiga-Yokaichi Plant

Claims (2)

[Claims] 1. An electrophotographic printing plate material comprising an electrically conductive support and an organic semiconductor charge generation layer and a polysilane charge transport layer which is decomposed by irradiation of ultraviolet rays, which are sequentially laminated on the conductive support. 2. An electrostatic latent image is formed by an electrophotographic method on a printing plate material in which an organic semiconductor charge generation layer and a polysilane charge transport layer are sequentially laminated on a conductive support, and then the electrostatic latent image is formed. After forming a toner image corresponding to the latent image, the printing plate material is irradiated with ultraviolet rays to decompose and remove the polysilane-based charge transport layer region located in the non-image area other than the toner image area. A method for producing a printing plate, comprising: