JPH11258860A - Plate forming method and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for forming a repetitively usable plate and an image forming device which allows on-demand printing and reduces the effect to be exerted on the human body or environment. SOLUTION: This plate forming method includes a stage of forming a photoreceptor by applying a tacky adhesive layer 13 decomposable by a photocatalyst irradiated with a laser beam on a substrate 11 including a photocatalyst layer 12 contg. the photocatalyst, a stage for forming a latent image by irradiating the photoreceptor with the laser beam thereby decomposing the tacky adhesive layer 13 and a stage for forming a hydrophobic resin layer 14 on the tacky adhesive layer 13 on the surface of the photoreceptor. This image forming device uses such plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate forming method. More specifically, the present invention irradiates a photoreceptor provided with an adhesive layer provided on a photocatalyst layer with a laser beam to decompose the adhesive substance by a photocatalyst and / or
The present invention relates to a method for forming a latent image by being decomposed by heat or a decomposition reaction due to ablation by laser light, and forming a plate having excellent printing durability having a hydrophobic resin layer on an adhesive layer. Further, the present invention relates to an image forming apparatus using the plate forming method.

[0002]

2. Description of the Related Art Conventionally, in a dry method used in an electrophotographic image forming apparatus, a powder toner is used as a developing material. It is necessary to use toner. However, when the particle size of the powder is 5-6 μm or less, if the person who handles it inhales the toner floating in the air, the powder inhaled in the lungs is not metabolized and the disease such as pneumoconiosis is caused. Therefore, there is a limit to the method using the small particle size toner. On the other hand, there is a method of preventing the powder from scattering into the atmosphere by using a toner in which an toner is dispersed in an organic solvent as a developing material. There is a problem that the organic solvent volatilizes in the air when fixing is performed. A printing machine used in the printing field is also one of the image forming apparatuses, but it requires plate making of an original, and is not suitable for on-demand printing due to the time required for plate making. When a container solvent is contained, environmental pollution sometimes becomes a problem.

[0003]

From such a background,
A method of forming a rewritable plate capable of coping with on-demand printing, and an image forming apparatus having the plate with reduced influence on a human body or an environment which may be a problem in an existing image forming apparatus A device was desired.

[0004]

[Summary of the Invention] According to the plate forming method of the present invention, the photocatalyst irradiated with laser light can be decomposed on a substrate provided with a photocatalyst layer containing a photocatalyst. Applying a pressure-sensitive adhesive layer to form a photoreceptor, irradiating the photoreceptor with laser light to decompose the pressure-sensitive adhesive layer to form a latent image, and forming a hydrophobic image on the pressure-sensitive adhesive layer on the surface of the photoreceptor. Forming a conductive resin layer.

[0005] In the image forming apparatus of the present invention, a photoreceptor is formed by applying an adhesive layer on which a photocatalyst containing a photocatalyst can be decomposed to a substrate provided with a photocatalyst containing the photocatalyst. Means, a means for irradiating the photosensitive member with a laser beam to decompose the adhesive layer to form a latent image, means for forming a hydrophobic resin layer on the adhesive layer on the surface of the photosensitive body, and And a means for developing the latent image.

<Effects> According to the present invention, there is provided a method for forming a plate which can be used repeatedly. Further, according to the present invention, there is provided an image forming apparatus capable of on-demand printing and reducing the influence on a human body or an environment.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Plate Forming Method> The plate forming method of the present invention comprises, in order from the bottom, (1) a substrate, (2) a photocatalyst layer in which a photocatalyst is held by a binder material, (3) an adhesive layer, and (4) ) A plate having a hydrophobic resin layer is formed by irradiating the plate with a laser beam in an imagewise manner, and a photochemical reaction by the action of a photocatalyst, or a thermal action by a laser beam, or an adhesive layer, or an adhesive layer and a hydrophobic layer. Writing is performed by decomposing the resin thin film layer.

The plate is formed by (1) forming a photoreceptor by applying an adhesive layer which can be decomposed by the action of the photocatalyst or the heat of laser light onto a substrate having a photocatalyst layer containing a photocatalyst. (2) irradiating the photoreceptor with a laser beam to decompose the adhesive layer to form a latent image;
And (3) a step of forming a hydrophobic resin layer on the adhesive layer on the surface of the photoreceptor. Further, the formation of the hydrophobic resin layer can be performed prior to laser beam irradiation. That is, another plate forming method is as follows.
(1) forming a photoreceptor by applying an adhesive layer decomposable by the action of the photocatalyst or the heat of laser light on a substrate having a photocatalyst layer containing a photocatalyst;
(2) a step of forming a hydrophobic resin layer on the adhesive layer on the surface of the photoconductor, and (3) a step of irradiating the photoconductor with laser light to decompose the adhesive layer to form a latent image. , In that order. In this case, it is preferable that the resin forming the hydrophobic resin layer also decomposes by the action of the laser beam.

After the printing plate formed by such a method is used for printing, the pressure-sensitive adhesive layer remaining on the substrate is irradiated with light to decompose the pressure-sensitive adhesive layer, thereby obtaining a state before the pressure-sensitive adhesive application. Since it can be returned, it can be used repeatedly, so that it is suitable for on-demand printing.

An example of the process of the plate forming method according to the present invention will be described with reference to FIG. A photocatalyst layer 12 containing a photocatalyst on a substrate 11 and a uniform adhesive layer 1 on the surface thereof
3 and a photoreceptor is prepared (FIG. 1A). This photoreceptor is irradiated imagewise with laser light (FIG. 1 (b)), and the adhesive layer is decomposed by the thermal action of the laser light or the photochemical action of the laser light and the photocatalyst to form the photocatalyst layer 1
2 is exposed imagewise (FIG. 1 (c)).

On the other hand, the adhesive layer remains on the portion not irradiated with the laser beam. For example, hydrophobic resin fine particles are attached to the surface of the adhesive layer and heated to form the hydrophobic resin layer 14 and form a plate (FIG. 1).
(D)).

In another plate forming process of the present invention,
A hydrophobic resin is adhered to the photoreceptor (FIG. 1A) to form a hydrophobic resin layer 14 (FIG. 1B '). The photoreceptor is imagewise exposed to laser light (FIG. 1 (c ')), and the adhesive layer and the hydrophobic resin layer are decomposed to expose the photocatalyst layer, thereby forming a plate (FIG. 1 (d)). ).

When the aqueous ink is supplied to the surface of the plate thus manufactured, the ink does not adhere to the surface of the hydrophobic resin layer, so that the plate can be used as a printing plate. Further, since a resin layer is provided on the surface of the plate, the plate has high durability even when used repeatedly for printing. Further, since the photocatalyst is held on the substrate, the used adhesive can be decomposed by the action of the photocatalyst by exposing the used plate to, for example, the entire surface to return to the state before the adhesive layer was provided.

An image forming apparatus according to the present invention is an apparatus for forming an image using a plate prepared by the above-described plate forming method. Here, in the above-described example, a method of forming a plate-shaped plate has been described. However, in a printing machine in which it is desired to continuously output an image, the plate may be preferably in a drum shape. Hereinafter, an example of the image forming apparatus of the present invention capable of continuously outputting images will be described with reference to FIG.

The image forming apparatus shown in FIG. 2 includes a plate forming drum 20 having a photocatalyst layer on the surface, an adhesive applying member 21 for applying an adhesive to the plate forming drum, and an exposing member 23 for forming a latent image. And a resin adhering member 24 for adhering a resin to the adhesive layer, and an ink supply member 26 for developing the written latent image. The image forming apparatus of FIG. 2 preferably further includes:
An adhesive layer uniformizing member 22, a heating roller 25 for heating and melting the attached resin to form a thin film, a transfer roller 27 for transferring an image developed by ink supply to a recording medium,
A cleaning member for cleaning the drum after the ink has been transferred to the recording medium, and a latent image erasing exposure member 30 for disassembling the adhesive layer remaining on the plate after use and returning to the state before applying the adhesive. It is provided. In addition, an ink squeeze member for removing excess ink after supplying ink may be provided between the ink supply member 26 and the transfer roller 27.

When an image is formed by using such an image forming apparatus, the plate forming drum rotates as the process proceeds, and a part of the surface of the plate forming drum depends on the rotation of the drum. The following describes how the processing is performed. First, the plate forming drum 20
The pressure-sensitive adhesive is applied by the pressure-sensitive adhesive applying member 21 to a portion having the mark. The applied pressure-sensitive adhesive forms a pressure-sensitive adhesive layer, and is then uniformed by the pressure-sensitive adhesive layer uniformizing member 22.

Next, a latent image is written on the plate forming drum 20 by the exposure member 23. That is, the adhesive layer is decomposed by the action of the laser light, and a portion where the adhesive is attached to the surface of the plate forming drum and a portion where the photocatalyst layer is exposed are formed.

Next, the resin is supplied to the plate forming drum 20 by the resin adhering member 24. The resin selectively adheres to the adhesive remaining on the plate forming drum, and the adhered resin is subsequently heated and melted by the heating roller 25 to form a hydrophobic resin layer.

A plate is thus formed, and ink is supplied to the plate by the ink supply member 26. When an aqueous ink is used, the ink does not adhere to the hydrophobic resin layer, and the ink selectively adheres to a portion where the photocatalytic layer is exposed. If the surplus ink remains on the hydrophobic resin layer, the surplus ink is supplied to an ink squeeze member (not shown).
It is preferable to remove by such as.

The image thus developed is usually
It is transferred to a recording medium. In the image forming apparatus shown in FIG. 2, an image is transferred onto a recording medium 28 pressed against the plate forming drum 20 by a transfer roller 27.

An image is formed in this manner. When a different image is subsequently formed, it is necessary to remove the adhesive layer and the hydrophobic resin layer remaining on the surface of the plate forming drum 20.

The removal of the adhesive layer and the hydrophobic resin layer is performed by the latent image erasing exposure member 30. That is, the plate forming drum 20 is irradiated with light from the latent image erasing exposure member 30,
The adhesive layer is decomposed by the action of the photocatalyst. Even if the hydrophobic resin layer is not decomposed by the action of the photocatalyst,
The lower pressure-sensitive adhesive layer can be removed by decomposition, but the hydrophobic resin layer is also preferably decomposed by the action of a photocatalyst.

Prior to the decomposition of the adhesive layer and the hydrophobic resin layer, it is preferable that the ink remaining on the plate-forming drum without being completely transferred has been removed by the cleaning member 29. This is because if ink remains on the drum, the amount of light transmitted for the decomposition of the adhesive layer may decrease.

With such a process, the image forming apparatus of the present invention is applicable to on-demand printing.

On the other hand, the image forming apparatus of the present invention forms the plate, transfers the supplied ink as an image to a recording medium, and repeats the process up to the subsequent ink supply, thereby repeating the same process. It is possible to output images continuously. The plate formed by the plate forming method of the present invention is durable because the surface is a resin layer,
Also suitable for continuous printing. Although an apparatus for forming an image using only one plate forming drum has been described here, a plurality of plate forming drums are prepared, and latent images are formed with respect to other plate forming drums during image formation. It is also possible to perform image erasing and latent image formation, and replace the plate-forming drum as necessary to form an image.

The plate forming method of the present invention or the image forming apparatus of the present invention will be described in more detail below.

<Photoreceptor> A photoreceptor that can be used in the present invention is provided with a photocatalyst 33 and a photocatalyst layer 32 including a binder material 34 holding the photocatalyst 33 on a substrate 31. The adhesive layer 35 is provided on the layer. FIG. 3 shows a schematic diagram of the cross section.

Prior to image formation, an adhesive is applied to a substrate having a photocatalyst layer to form a photoreceptor. When this photoreceptor is irradiated with laser light imagewise, the adhesive at the part irradiated with laser light is decomposed by photochemical reaction due to the action of photocatalyst, or thermally or ablation by laser light, and photocatalyst The layer is exposed. Here, the mechanism of the photochemical reaction is not clear, but when the photocatalyst is excited by light irradiation, hole separation occurs, followed by generation of active oxygen and active hydrogen, which react with nearby organic substances. It is considered. In the image forming apparatus of the present invention, it is preferable that the adhesive layer (that is, a latent image) remaining on the plate can be removed in order to reuse the plate after image transfer. For the removal of the latent image, a photochemical reaction by the action of the photocatalyst can be used.

As the photocatalyst used in the present invention, any photocatalyst can be used as long as it has such an action. Specifically, TiO ₂ , SnO ₂ , WO ₃ , V ₂ O ₅ , N _{2
b 2 O 5, Ta 2 O} 5, Fe 2 O 3, SrTiO 3, CdS,
ZnS, PbS, CdSe, GaP, and others. Further, if necessary, a plurality of photocatalysts may be mixed and used.

As described above, any photocatalyst can be used. Among them, TiO ₂ is particularly preferable because of its high sensitivity and little influence on the environment or the human body. As TiO ₂ , a rutile type, an anatase type, and the like are known, and any of them may be used. Further, as for the particle diameter of TiO ₂ used as a photocatalyst, the secondary particle diameter measured by observation with a transmission electron microscope is preferably 10 nm to 5 μm from the viewpoint of increasing the activity of the photocatalyst.

As the binder material 34 for holding the photocatalyst on the substrate, (a) a metal oxide such as SiO
₂ , Al ₂ O ₃ , In ₂ O ₃ , MgO, ZrO ₂ , Y ₂ O ₃ , S
nO ₂ , Cr ₂ O ₃ , La ₂ O ₃ , and others, (b) carbides such as SiC, WC, TiC, and others,
(C) nitride ceramics such as C ₃ N ₄ , Si ₃ N ₄ ,
Inorganic materials represented by BN, TiN, and others,
And (d) organic materials such as polycarbonate resin, phenol resin, nylon resin, silicon resin, siloxane resin, epoxy resin, polyethylene resin, polyester resin, vinyl alcohol resin, polyacrylate resin, butyral resin, polyvinyl acetal resin, and acetic acid. Vinyl resin, diallyl phthalate resin, polystyrene resin, polysulfone resin, acrylic resin, polyphenylene oxide resin, alkyd resin, styrene-butadiene copolymer resin, styrene-maleic anhydride copolymer resin, urethane resin, and other polymers, Can be used.

These binder materials can be arbitrarily selected, and if necessary, a plurality of binders can be mixed and used at an arbitrary ratio. However, when an organic material is selected as a binder material for the photocatalyst layer, the binder material in a portion of the photoconductor irradiated with light may be decomposed. However, when a different image is formed every time or periodically as in a printing machine, the photocatalyst layer of the photoconductor after the ink image is transferred to the image recording medium should be restored. Therefore, when such a use is intended, a binder material that does not easily decompose when irradiated with laser light should be selected as the binder material of the photocatalytic layer. Particularly preferred are metal oxides, carbides, or nitride ceramics. When these are used as a binder material, the life of the photoreceptor can be extended even when the initialization and image formation are repeated.

As the substrate 31 to be used, generally, a substrate made of ceramics, metal, and others can be used, and is not particularly limited, but is preferably metal. Further, a transparent substrate (for example, glass) can be used so that a latent image erasing exposure to be described later can be performed from the substrate side.

Since metal has high mechanical strength and high workability due to its properties, it is easy to form a hollow drum for use in the plate forming drum as described above.
An aluminum drum having a thickness of 0 mm and a length of 250 mm can be manufactured as a hollow drum having a thickness of at most 1 mm and having sufficient mechanical strength. This contributes to reducing the weight of the component alone, and thus the entire image forming apparatus, and makes it possible to manufacture a large-sized drum. Further, when a metal material is used, it is advantageous in terms of dimensional stability as compared with a material requiring sintering such as a ceramic material (eg, glass), and the outer diameter can be kept constant in the length direction, It is easy to suppress eccentricity, and it is easy to obtain a high-quality image.

Also, since metal is a good conductor of electricity, electrons can easily move inside the metal substrate, and the function of preventing the photocatalyst in the photocatalyst layer provided on the surface of the substrate from receiving and reducing electrons is also provided. is there. Furthermore, a bias voltage can be applied to the substrate or grounded as required.

An oxide film is usually formed on the metal surface in air, which is advantageous for applying a hydrophobic film. Further, after applying the hydrophobic film or after forming the latent image by exposure, the hydrophobic film can be dried by heating if necessary.
C), the dimensional stability is maintained and the heat conductivity is high, so that cooling can be performed in a short time, which is advantageous.

The metals used are generally used metals,
For example, aluminum, nickel, iron, copper, titanium, and others, as well as alloys thereof, such as stainless steel, duralumin, and others, are suitable. Among these, aluminum and aluminum alloys are particularly preferable because they are lightweight, have high strength and are excellent in workability.

The photocatalyst layer of the photoreceptor of the present invention is usually formed by applying a coating solution containing the photocatalyst 33 and the binder material 34 on the substrate 31 to form a photocatalyst layer. Such a coating solution is generally water or an organic solvent such as methanol, ethanol, n-
A material obtained by dissolving or dispersing the photocatalyst and, if necessary, the binder material in propanol, iso-propanol, and other aromatic compounds such as alcohol and toluene is used. In such a case, the mixing ratio between the photocatalyst and the binder material is not particularly limited. This is because if the type of ink changes, the contact angle with water may change between the hydrophobic resin layer and the photocatalyst layer. Therefore, the mixing ratio of the photocatalyst and the binder material should be appropriately changed for the adjustment. There is.

As a method for applying a coating solution containing a photocatalyst onto a substrate, spin coating, dip coating, bar coating, spray coating, or any other method can be used.

In addition, by forming a mixture of the binder material and the photocatalyst, the photocatalyst layer itself can also serve as a substrate. Further, for example, a substrate of Ti is formed, and its surface is
A photoreceptor can be obtained by chemically changing it to iO ₂ .

The thickness of the photocatalyst layer thus formed is desirably 0.01 to 100 μm, and particularly desirably 0.05 to 10 μm, at which the strength of the film formation becomes stronger. When the thickness of the photocatalyst layer is less than 0.01 μm, a difference in contact angle of water between a light-irradiated portion and a non-light-irradiated portion does not appear remarkably, which is a phenomenon corresponding to so-called fog in electrophotography. May appear. On the other hand, when the thickness of the photocatalyst layer exceeds 100 μm, problems such as deterioration of the film formation strength and occurrence of cracks may occur.

The photocatalyst layer 32 may contain a sensitizer, if necessary. The sensitizer absorbs light having a specific wavelength, is excited, and transfers the excitation energy to a photocatalyst, thereby increasing the sensitivity of the photosensitizer at a specific wavelength. Such sensitizers are not particularly limited, but specific examples thereof include aromatic sensitizers, for example, pyrene, perylene, triphenylene, and other xanthene sensitizers, for example, rhodamine B, rose bengal, And others, cyanine sensitizers, such as thiacarbocyanine, oxacarbocyanine, and other, thiazine sensitizers, such as thionin, methylene blue, toluidine blue, and other, acridine sensitizers, such as acridine orange, Chloroflavin, acriflavine, and others, phthalocyanine sensitizers such as phthalocyanine, metal phthalocyanine, and others, porphyrin sensitizers such as tetraphenylporphyrin, metal porphyrin, and others, chlorophyll sensitizer, chlorophyll Kororofirin, central metal-substituted chlorophyll, and other,
Metal complex sensitizers, for example, ruthenium bipyridine complex,
And other fullerene sensitizers such as C ₆₀ , C
₇₀ and other, hydrazone compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, thiadiazole compounds, imino compounds, ketazine compounds, enamine compounds, amidine compounds, stilbene compounds, butadiene compounds, carbazole compounds and other low molecular sensitizers, and Polymer sensitizers in which these low-molecular compounds are introduced into a high-molecular compound are exemplified. In addition, compounds used as a charge generating agent and a charge transporting agent in an electrophotographic photoreceptor can also be used as a sensitizer.

As the sensitizer, any sensitizer can be used, and a plurality of sensitizers can be used in combination, if necessary. In general, the sensitizer is used for forming a latent image. Is determined according to the wavelength of the light. From such a viewpoint, metal porphyrin or ruthenium bipyridine complex is particularly preferable as the sensitizer.

When a sensitizer is used, its addition amount is not particularly limited, but is generally 0.001 to 1 per mole of the photocatalyst.
Usually, 1 mole is added. Further, the performance of the photocatalyst layer can be controlled by adjusting the addition amount.

<Adhesive Coating Means> The adhesive applying means is a means for applying an adhesive to the surface of the photocatalyst layer to form an adhesive layer. Any pressure-sensitive adhesive that can be used can be applied on the photocatalyst layer, decomposes when irradiated with laser light in that state, and any resin can be attached as described below. Can be used.

As such an adhesive, for example, a synthetic adhesive such as a resin adhesive, an elastomer adhesive, or a mixed adhesive, or a natural adhesive such as a starch adhesive, a protein adhesive, a resin adhesive, or a turquoise adhesive is used. Can be used. Specifically, (a) urea-based, melamine-based, resorcinol-based, phenol-based (water-soluble, alcohol-soluble, novolak), epoxy-based, polyurethane-based, polyaromatic-based (polyimide, Polyvinyl benzimidazole), polyester (alkyd type, unsaturated polyester acrylate, acrylic acid diester), and other (b) resinous thermoplastic materials such as vinyl acetate (emulsion, solution), polyvinyl alcohol, and polyvinyl acetal (Butyral, acetal, formal), vinyl chloride, acrylic (emulsion, solution, reaction type) polyethylene (polyethylene, ethylene vinyl acetate), cellulose (nitrocellulose, ethylcellulose, water-soluble cellulose), polyiso Styrene, polyvinyl ethers, and other, chloroprene rubber as (c) an elastomeric material (solution, latex), nitrile rubber (solution, latex), styrene-butadiene rubber, SB
S ・ SIS system, polysulfide system, butyl rubber system, silicone rubber system (RTV type, vulcanization type, pressure sensitive type), and others (d) phenolic vinyl type, epoxy phenol type, phenol chloroprene as mixed type material System, phenol / nitrile system, epoxy / polyamide system, epoxy polysulfide system, nitrile / epoxy system, epoxy nylon system, and others. (E) Starch, dextrin, and others as starch materials, and (f) protein materials. , Casein, soy protein, albumin, and others, (g) pine resin (rosin), shellac, and others as resin-based materials,
(H) asphalt, gilsonite, silver, and others as lectic blue-based materials, and (li) other sticky substances (for example, hydrocarbons, for example, aliphatics,
For example, lauric acid, mysteric acid, palmitic acid, oleic acid, stearic acid, their amides, ester derivatives, and others, aliphatic alcohols, their ester derivatives, and other oily organic compounds including silicone oils) No.

As the pressure-sensitive adhesive applying member for applying the pressure-sensitive adhesive, any member can be used, and specific examples thereof are as shown in FIGS.

The pressure-sensitive adhesive application member shown in FIG. 4 sprays the pressure-sensitive adhesive in the form of a mist, and the ultrasonic vibrator 41 turns the pressure-sensitive adhesive 43 in the pressure-sensitive adhesive storage tank 42 into a mist to form a plate. Spray on drum 20. Spraying the adhesive in the form of a mist as in this example is advantageous for forming a thin and uniform coating.

The initialization member shown in FIG. 5 is one in which the pressure-sensitive adhesive storage tank 42 is filled with the pressure-sensitive adhesive 43, and the plate forming drum is immersed therein to form a pressure-sensitive adhesive film. When a film is formed by such a method, the film tends to be thick. Also, when using such an adhesive coated member,
The adhesive is usually liquid at normal temperature and normal pressure.

The pressure-sensitive adhesive application member shown in FIG. 6 is for contacting an intermediate medium containing or carrying a pressure-sensitive adhesive. FIG. 6 shows a case where the pressure-sensitive adhesive is supplied to the plate forming drum via the intermediate medium 61, in which the intermediate medium has a particularly roller shape, and the roller-shaped member is rotatable about an axis. This is advantageous in that it can be avoided that only one location is always in contact with the plate-forming drum and deteriorated. However, even when such an intermediate medium is used, it is possible to select a medium other than the roller shape.

The pressure-sensitive adhesive application member shown in FIG. 7 is for forming a pressure-sensitive adhesive film on the plate forming drum 20 by pouring the pressure-sensitive adhesive 43 from a pressure-sensitive adhesive storage tank 42. Also in this case, similarly to the example of FIG. 5, the coating tends to be thick.

The adhesive applying member shown in FIG. 8 sprays the adhesive onto the plate forming drum 20 from a spray nozzle 81. This case is also advantageous for forming a thin and uniform coating as in the example of FIG.

The pressure-sensitive adhesive can be applied to the plate-forming drum by such a method, but the thickness of the pressure-sensitive adhesive layer affects the quality of an image and the like. The thickness of the adhesive layer is generally 0.01 to
10 μm. Within this range, if the layer is thinner, the sensitivity increases, and the interval between image formation and initialization can be shortened. Conversely, if the layer is thicker, the image when the light irradiation amount is changed is improved. Gradation control becomes easy. However, if the thickness exceeds this range and the thickness is 0.01 μm or less, the adhesiveness is reduced and the adhesion of the resin becomes insufficient, and it becomes difficult to obtain a clear image. If it exceeds 10 μm, the sensitivity tends to decrease.

For such a reason, a pressure-sensitive adhesive coated member capable of obtaining an appropriate pressure-sensitive adhesive layer can be selected. Also, after a thicker adhesive layer is formed once, it can be made thinner by a homogenizing member described later.

<Uniformizing means> The uniformizing means is means for making the pressure-sensitive adhesive layer applied by the pressure-sensitive adhesive applying member uniform or thin. Further, when the pressure-sensitive adhesive layer applied by the pressure-sensitive adhesive applying member is not sufficiently smooth, the pressure-sensitive adhesive layer has a function of making the surface uniform. The homogenizing member having these functions is provided as needed, but if provided, any member can be used. Specific examples of such a uniformizing member are shown in, for example, FIGS.

The uniformizing member shown in FIG. 9 has a scraping effect by bringing the edges of the blade-shaped member into contact with each other, thereby facilitating the formation of a thin layer. At this time, if an elastic body is used as the material of the member, the adhesion to the plate forming drum 20 increases, and there is an effect of stabilizing the layer thickness.

The adhesive-applied member shown in FIGS. 10 and 11 has the surface of the member in contact with the plate-forming drum 20, and the scraping effect is smaller than that of the uniformizing member shown in FIG. Also, there is little abrupt change in the contact area due to wear of the uniformizing member, and the stability is excellent. Also in this case, when an elastic body is used as the material of the member, the same effect as the example of FIG. 9 can be obtained. In particular, a roller-shaped member as shown in FIG. 11 is rotatable about an axis, and is advantageous in that deterioration of the member due to constant contact at only one location can be avoided.

The homogenizing member shown in FIG. 12 is to contact the edge of the blade-shaped member to remove excess adhesive in the rotational direction. Although the effect is close to that of the uniformizing member shown in FIG. 9, since there is a difference in the scraping effect, such a uniformizing member can be applied. others,
By using a foam, for example, a sponge, as the homogenizing member, the pressure-sensitive adhesive layer can be made thin by absorbing the pressure-sensitive adhesive.

<Exposure Means> The exposure means in the present invention comprises:
This is a means for forming a latent image by irradiating a photoreceptor with laser light to decompose the adhesive layer. As the exposure member having such a function, that is, a laser light source, any one can be used. Generally, a gas laser such as a CO ₂ laser, a He—Ne laser, an Ar ⁺ laser, He-Cd ⁺ laser, excimer laser, and others, (b) solid-state laser such as ruby laser, YAG laser, Nd ³⁺ : YAG laser, and others, (c) dye laser, (d) liquid laser, (e) Semiconductor lasers and others are used.

The type of laser light source used as the exposure member is usually selected according to the type of the adhesive, the absorption wavelength, the absorption wavelength of the photocatalyst, and other conditions. The output power of the light source varies depending on the type of the light source, but is particularly preferably in the range of 1 mW to 1 kW.

<Resin Adhering Unit> The resin adhering unit is a unit for adhering a resin on the adhesive layer to form a hydrophobic resin layer. This hydrophobic resin layer is a layer having low hydrophilicity with respect to the photocatalyst layer. When the ink is supplied to the formed plate, the ink is selectively applied only to the exposed photocatalyst layer due to the difference in hydrophilicity. Adheres. This difference in hydrophilicity is
The description can be replaced with the difference in contact angle with water.
Generally, the difference in contact angle between the photocatalyst layer and the hydrophobic resin layer is 10
When the angle is not less than ゜, the latent image on the surface of the photoreceptor can be developed, but the difference in the contact angle is preferably not less than 30 °. Therefore, the binder of the photocatalyst layer and the resin of the hydrophobic resin layer should be selected so as to obtain such a difference in contact angle. Since the contact angle also depends on the thickness of the hydrophobic resin layer, it can be adjusted by the thickness.

The shape of the resin used is arbitrary, and may be a solid (for example, fine particles) or a liquid (for example, a solution or a melt), but is preferably a solid, particularly fine particles. In particular, fine particles having an average particle diameter of 100 μm or less are preferable. Here, the average particle diameter is measured by a standard sieve. When the fine particles having such a particle diameter are used, uneven contact angles with water are less likely to occur.

The type of the resin is not particularly limited.
In order to facilitate the erasure of the latent image by light irradiation, it is preferable that the film is transparent to light from a light source used for latent image erasure exposure described later. Further, in order to obtain a uniform hydrophobic resin layer, the hydrophobic resin layer can be made uniform by a heating means described later, and for that purpose, it is preferable to use a thermoplastic resin as the resin. As such a resin, for example,
Styrene resin, styrene / isoprene resin, acrylic / styrene resin, divinylbenzene resin, methyl methacrylate resin, methacrylate resin, ethyl methacrylate resin, ethyl acrylate resin, n
-Butyl acrylate resin, acrylic acid resin, acrylonitrile resin, acrylic rubber / methacrylate resin, ethylene resin, ethylene / acrylic resin,
Ethylene / ethyl acrylate resin, unsaturated carboxylic acid resin, ethylene / vinyl acetate resin, nylon resin, silicone resin, urethane resin, melamine resin, benzoguanamine resin, phenol resin, furan resin, Amino resin, fluorine resin, vinylidene chloride resin, cellulose resin, vinyl chloride resin, polyester resin, polycarbonate resin, polypropylene resin, vinyl ester resin, polyamide resin, polybutadiene resin, chlorinated polyethylene Resin, nitrile rubber resin, epoxy resin, phenoxy resin, diallyl phthalate resin, bismaleimide resin, ketone resin, ABS resin, other synthetic rubber resins, polyethylene terephthalate, polyethylene naphthalate, polybutylene Phthalate, polyarylate resin, polyoxybenzoyl, polyacetal, polyphenylene ether, polyphenylene sulfide, polyether sulfone, polysulfone, other sulfone polymers, polyimide resins, other copolymers, polymer blend resins, polymer alloys Resins, and others. Depending on the case, two or more of these resins may be used in combination.

The method of applying the resin may be a method of supplying the resin using a roller, a method of supplying the resin by a spray method, a brush or the like, a method of directly contacting a part of the plate forming drum with the resin storage tank, and any other method. It can be performed by the method of. The thickness of the hydrophobic resin layer provided on the pressure-sensitive adhesive layer by such a method, or the thickness of the hydrophobic resin layer thinned by heating means as described below, if necessary, is not particularly limited. It is preferably 10 μm. If the layer is thinner than this range, the printing durability may be insufficient, and if the layer is thicker, cracks may occur.

The hydrophobic resin layer does not necessarily have to have a dense layered structure, and the adhesive layer may be exposed on the surface. That is, the resin may cover the adhesive layer in a mesh shape, or the resin may be discontinuously scattered on the surface of the adhesive layer.

<Heating means> When the resin to be attached to the adhesive layer is a thermoplastic resin. By using the heating member, the resin layer can be made thinner. Any heating member can be used and is not particularly limited. For example, a heated rubber roller, hot air, a thermal head, or the like may be used.

<Developing Means> The developing means in the present invention comprises:
This is a unit for developing the latent image formed by the exposure unit. The developing member having such a function is optional, but is preferably an ink supply member for applying ink to the exposed photoconductor. The ink can be supplied to the surface of the photoreceptor by any method, but may have the same structure as that of the pressure-sensitive adhesive applying member. The ink used is also optional, but preferably has a low organic solvent content in consideration of the effect on the environment.

<Transfer Means> The transfer means in the present invention comprises:
This is a means for transferring the ink image on the plate forming drum to a recording medium. As shown in FIG. 2, one method is to interpose a recording medium 28 between the transfer roller 27 and the plate forming drum 20 and transfer an image. In addition, a method in which a recording medium is brought into close contact with a plate-forming drum by blowing a high-pressure gas instead of a transfer roller, a method in which an image on the plate-forming drum is once transferred to an intermediate transfer roller, and further transferred to a recording medium, and other methods A method can also be taken. Among these, a method using an intermediate roller, which can transfer an ink image to a recording medium with good reproducibility, is preferable.

<Cleaning Means> In the present invention, before applying the latent image erasing means, the ink remaining on the plate can be removed. Such cleaning means is not particularly limited, and can be performed by any method.

<Latent Image Erasing Exposure Means> The history erasing means of the present invention provides a latent image remaining on the surface of the photoreceptor after the ink attached to the surface of the photoreceptor is transferred to the recording medium, in other words, the adhesive layer and the hydrophobic layer. Means for removing the conductive resin layer. In the present invention, such a latent image is erased by irradiating the plate with light and decomposing the adhesive layer by the action of a photocatalyst.

As a light source that can be used as a latent image erasing exposure member for removing an adhesive layer by light irradiation, any light source can be used. Specifically, an ultraviolet fluorescent lamp, a fluorescent head, a gas laser, a solid laser, and the like can be used. , Liquid laser,
Semiconductor lasers, dye racers, and others.

The type of light source used for latent image erasing exposure is generally selected according to the absorption wavelength of the photocatalyst or sensitizer used, the intensity of the light source, and other conditions.
Generally, the wavelength is 350 to 800 because it is easily obtained as a light source.
It is preferable to use a light source that emits light of nm. Alternatively, the hydrophobic resin layer may be first decomposed by light from one light source, and then the adhesive layer may be decomposed by light from a different light source. When the same type of laser used for writing a latent image is used for erasing a latent image, it is easy to damage the photocatalyst layer, but using two types of light sources as described above,
Using a light source of the same type as a laser for writing a latent image to decompose the hydrophobic resin layer and using a light source that does not damage the photocatalyst layer to decompose the adhesive layer can reduce damage to the photocatalyst layer. It is valid.

The method of irradiating the photosensitive member with light by the latent image erasing member is arbitrary, and specific examples thereof are as shown in FIGS. The history erasing member shown in FIG. 13 irradiates the light emitted from the light source 131 with the polygon mirror 133 in the length direction of the plate forming drum. A lens 132 and an fθ lens 134 can be provided as needed. The history erasing member shown in FIGS. 14 and 15 irradiates the light from the light source uniformly through the lens 141 in the length direction of the plate forming drum. The history erasing member shown in FIG. 16 irradiates light radiated from the light source 131 while being uniformly converged in the length direction of the plate forming drum by the reflection plate 161. In addition to these, light from a light source such as a laser is incident on a surface-emitting type optical fiber to uniformly irradiate light in the length direction of the plate-forming drum, or various light-emitting elements are irradiated in the length direction of the plate-forming drum. Light irradiation can also be performed by uniformly disposing them. Further, it is possible to irradiate the plate-forming drum with harmonics obtained by passing the light of the various light sources through a nonlinear material. Further, pulsed light such as strobe light generated by exciting a xenon tube or the like with a high voltage can be applied.

[0074]

EXAMPLE 1 TiO ₂ sol having a secondary particle size of 50 nm and a secondary particle size of 10 n
m ₂ SiO ₂ sol was mixed in a ratio of 50:50 by weight of solid content, and the solid content concentration was adjusted to 10% by weight and pH was adjusted to 1.5 to prepare a coating solution. This coating solution was applied to an aluminum drum to a thickness of 0.5 μm by a spray coating method to form a coating, and the coating was heated and dried at 150 ° C. for 1 hour to obtain a plate forming drum. An acrylic rubber-based pressure-sensitive adhesive (emulsion type) was applied by a pressure-sensitive adhesive application device using a spray nozzle shown in FIG. 8, and the pressure-sensitive adhesive was made uniform by a silicone rubber blade shown in FIG. Next, in order to form a latent image, an adhesive layer is decomposed by imagewise irradiation with an argon ion laser of 363.8 nm, and acrylic / styrene-based resin fine particles having a particle diameter of 2 μm are applied to the remaining adhesive layer by a resin supply roller. To adhere to the adhesive layer,
The resin fine particles were melted by a silicon rubber roller heated to 180 ° C. to form a resin thin film layer. As a result, a plate having excellent printing durability could be formed.

Example 2 TiO ₂ sol having a secondary particle size of 50 nm and a secondary particle size of 10 n
m ₂ SiO ₂ sol was mixed in a ratio of 50:50 by weight of solid content, and the solid content concentration was adjusted to 10% by weight and pH was adjusted to 1.5 to prepare a coating solution. This coating solution was applied to an aluminum drum to a thickness of 0.5 μm by a spray coating method to form a coating, and the coating was heated and dried at 150 ° C. for 1 hour to obtain a plate forming drum. An acrylic rubber-based pressure-sensitive adhesive (emulsion type) was applied by a pressure-sensitive adhesive application device using a spray nozzle shown in FIG. 8, and the pressure-sensitive adhesive was made uniform by a silicone rubber blade shown in FIG. Next, acrylic / styrene-based resin fine particles having a particle size of 2 μm are adhered to the adhesive layer by a resin supply roller to the adhesive layer.
The resin fine particles were melted by a silicone rubber roller heated to 0 ° C. to form a resin thin film layer. Subsequently, in order to form a latent image, an argon ion laser of 363.8 nm was irradiated imagewise to decompose the adhesive layer and the resin thin film layer thereon. As a result, a plate having excellent printing durability could be formed.

Example 3 <Photoconductor> A TiO ₂ sol having a secondary particle size of 50 nm and a SiO ₂ sol having a secondary particle size of 10 nm were mixed at a solid content weight ratio of 50:
50 at a solids concentration of 10% by weight, pH 1.
5 to prepare a coating solution. This coating solution is applied on an aluminum drum by spray coating to a thickness of 0.5 μm to form a film.
After drying at 0 ° C. for 1 hour, a plate-forming drum was obtained.

<Adhesive Coating Member> In this embodiment, an adhesive applying device using a spray nozzle as shown in FIG. Note that an acrylic rubber-based adhesive (emulsion type) was used as the adhesive.

<Equalizing Member> In this embodiment, the blade-shaped member shown in FIG. 9 was used as the equalizing member 22. Silicone rubber was used as the material of the homogenizing member.

<Light Source> In this embodiment, an argon ion laser was used as the light source 23 for forming a latent image, and 388 nm ultraviolet light was selected as the exposure wavelength. <Resin Adhering Member> In the present embodiment, a resin supply roller was used as the resin adhering member 24. Thereby, acrylic / styrene-based resin fine particles having a particle size of 2 μm were adhered to the adhesive layer remaining after the exposure.

<Heating Member> In this embodiment, a heating roller made of silicone rubber was used as the heating member. The heating roller was heated to 180 ° C. and pressed against a plate forming drum to melt the resin on the adhesive layer to form a resin thin film layer.

<Latent Image Erasing Light Source> In this embodiment, an ultraviolet fluorescent lamp was used as a latent image erasing light source for erasing a latent image.

<Image Forming Apparatus and Image Formation Therewith> An image forming apparatus as shown in FIG. 2 was prepared from the above-described members and other members, and an image was formed. In the image forming apparatus as shown in FIG. 2, the plate forming drum rotates in the direction of the arrow in the figure, and the image forming process proceeds with the rotation.

First, an adhesive is applied to the plate forming drum 20 by the adhesive applying member 21 to form an adhesive layer on the plate forming drum. This coating is then made uniform by the homogenizing member 22. Next, the plate forming drum provided with the uniform adhesive layer is exposed imagewise by the light source 23. The adhesive on the exposed portion of the plate forming drum is decomposed and removed by the effect of the laser from the light source. Subsequently, the aqueous ink is supplied to the plate forming drum by the ink supply member 26. The aqueous ink adheres to the site from which the adhesive has been removed, but does not adhere to the resin thin film layer. Further, by pressing the recording medium 28 against the plate forming drum 20 by the transfer roller 27, a clear image was obtained on the recording medium.

Subsequently, in order to continuously obtain images from the second sheet onward, the same operations are repeated by omitting the steps of coating the adhesive layer, uniformizing, exposing, adhering the resin, and heating, and repeating the same clear operation. 1000 images could be printed continuously.

Further, a new plate was formed on the plate forming drum after the above-described treatment as follows. The ink remaining on the plate-forming drum 20 without being transferred is removed by a cleaning member 29, and the entire plate-forming drum is irradiated with ultraviolet rays from a latent image erasing light source, so that the pressure-sensitive adhesive and resin on the photoreceptor surface are converted into photocatalysts. The latent image was erased by decomposition by oxidizing power. Further, the pressure-sensitive adhesive was again applied onto the plate-forming drum 20 by the pressure-sensitive adhesive applying member 21 and was made uniform by the homogenizing member, thereby initializing the entire surface of the plate-forming drum.

From this state, by performing the processes of exposure, resin adhesion, heating, ink supply, and transfer of ink to a recording medium in the same manner as described above, an image was formed. The image could be obtained by the nature.
Further, when images were continuously output by the same method as described above, 1000 clear identical images could be output.

Example 4 T of 50 nm in secondary particle diameter adjusted to pH 0.8 with nitric acid
A propanol solution containing a water-repellent siloxane clear coat resin and a curing agent was added to the iO ₂ sol to obtain a coating solution. TiO ₂ is about 5% of the total solids of the coating solution.
0% by weight, and the siloxane clear coat resin was added so as to be about 50% by weight of the total solids of the coating solution.
The coating solution was applied to an aluminum drum by a pull-up coating method, and the formed photocatalyst layer was dried at 150 ° C. for 1 hour to obtain a plate forming drum having a photocatalyst layer having a thickness of 1.5 μm. When an image was output using the plate forming drum in the same manner as in Example 1, an image was obtained with good reproducibility.

Example 5 An image was output in the same manner as in Example 1 except that a CO ₂ laser was used instead of an argon ion laser as the exposure agent 34 for forming a latent image.
Images were obtained with excellent reproducibility.

Example 6 An image was obtained in the same manner as in Example 1 except that a polyester resin was used as the resin fine particle instead of the acrylic / styrene resin, and an image was obtained with excellent reproducibility. I was able to.

Example 7 The same adhesive member as in Example 1 was used except that a member made of a silicone foaming agent having a roller shape as shown in FIG. 6 and having an adhesive absorbed therein was used as the adhesive applying member. When an image was output by the method, an image could be obtained with excellent reproducibility.

Example 8 An image was output in the same manner as in Example 1 except that a member made of a silicone foaming agent having a roller shape as shown in FIG. 11 was used as a uniforming member. Images were obtained with good reproducibility.

Example 9 An image was output in the same manner as in Example 1 except that an oil-based ink was used instead of the water-based ink. The portion which was not irradiated with light with excellent reproducibility was obtained. Images were obtained.

Example 10 TiO ₂ sol having a secondary particle size of 50 nm and a secondary particle size of 10 n
m of SiO ₂ sol was mixed at a solid content weight ratio of 50:50, and the solid content concentration was adjusted to 10% by weight and the pH was adjusted to 1.5. Further, a propanol solution of Zn porphyrin was added to this solution so that the addition amount of Zn porphyrin was 30% by weight of the total solids of the coating solution to prepare a coating solution. The coating solution was applied to an aluminum drum by a pull-up coating method to form a photocatalyst layer, and dried at 100 ° C. for 24 hours. This coating and drying was repeated until the thickness of the photocatalyst layer after drying became 1 μm, to obtain a plate forming drum. Using this plate forming drum, He-Ne having a wavelength of 543.5 nm was used as a latent image erasing light source instead of an ultraviolet fluorescent lamp.
An image was output in the same manner as in Example 1 except that a laser was used, and an image was obtained with excellent reproducibility.

Example 11 TiO ₂ sol having a secondary particle size of 50 nm and a secondary particle size of 10 n
m ₂ SiO ₂ sol was mixed at a solid content weight ratio of 50:50, and the solid content concentration was adjusted to 10% by weight and the pH was adjusted to 1.5 to prepare a coating solution. This coating solution is applied to an aluminum drum by a pull-up coating method to form a photocatalyst layer,
It was dried at 100 ° C. overnight. This coating and drying was repeated until the thickness of the photocatalyst layer after drying became 1 μm, to obtain a plate forming drum. When image output was attempted using this plate forming drum in the same manner as in Example 1, an image was obtained with excellent reproducibility.

Example 12 TiO ₂ sol having a secondary particle size of 50 nm and a secondary particle size of 10 n
m of SiO ₂ sol was mixed at a solid content weight ratio of 50:50, and the solid content concentration was adjusted to 10% by weight and the pH was adjusted to 1.5. Further, a propanol solution of Zn porphyrin was added to this solution so that the addition amount of Zn porphyrin was 30% by weight of the total solids of the coating solution to prepare a coating solution. The coating solution was applied to an aluminum drum by a pull-up coating method to form a photocatalyst layer, and dried at 100 ° C. for 24 hours. This coating and drying was repeated until the thickness of the photocatalyst layer after drying became 1 μm, to obtain a plate forming drum. When image output was attempted using the plate forming drum in the same manner as in Example 10, an image of a portion not irradiated with light could be obtained with excellent reproducibility.

Example 13 T having a secondary particle size of 50 nm and adjusted to pH 0.8 with nitric acid
A propanol solution containing a water-repellent siloxane clear coat resin, a curing agent, and Zn porphyrin was added to the iO ₂ sol to obtain a coating solution. TiO ₂ is about 40% by weight of the total solids of the coating solution, siloxane clear.
The coating resin was added so as to have a ratio of about 30% by weight of the total solids of the coating solution, and Zn porphyrin as a sensitizer of the photocatalyst was added so as to have a ratio of about 30% by weight of the total solids of the coating solution. This coating solution was applied to an aluminum drum by pull-up coating, and the formed photocatalyst layer was dried at 100 ° C. for 24 hours.
A plate forming drum having a photocatalyst layer having a thickness of 1 μm was obtained. When an image was output using this plate forming drum in the same manner as in Example 10, an image was obtained with good reproducibility.

Example 14 An image was output in the same manner as in Example 13 except that an oil-based ink was used in place of the water-based ink as an ink to be used. Images were obtained.

Example 15 In the exposure step of writing a latent image, image output was attempted in the same manner as in Example 1 except that cooling water was flowed in the plate forming drum and the temperature of the drum surface was kept at 100 ° C. or lower. As a result, an image was obtained with excellent reproducibility. Also, the number of times the latent image can be rewritten on the plate forming drum is doubled compared to the case where the plate forming drum is not cooled.

Example 16 T of 50 nm in secondary particle diameter adjusted to pH 0.8 with nitric acid
A propanol solution containing a water-repellent siloxane clear coat resin, a curing agent, and Zn porphyrin was added to the iO ₂ sol to obtain a coating solution. TiO ₂ is about 40% by weight of the total solids of the coating solution, siloxane clear.
The coating resin was added so as to make up about 30% by weight of the total solids of the coating solution, and Zn porphyrin, which was a sensitizer for the photocatalyst, was made up to about 30% by weight of the coating solution. This coating solution was applied to an aluminum drum by a pull-up coating method, and the formed photocatalyst layer was dried at 100 ° C. for 24 hours, and a film thickness of 1 μm
A plate-forming drum having a photocatalyst layer was obtained. Using this plate forming drum, an image was output in the same manner as in Example 1 except that an argon ion laser was used as the exposure light source. When the image was output, an image could be obtained with good reproducibility.

Example 17 An image was output in the same manner as in Example 16 except that an oil-based ink was used instead of the water-based ink. Images were obtained.

[0101]

According to the present invention, there is provided an image forming apparatus capable of obtaining a reusable plate cylinder and reducing an influence on a human body or an environment. As described above.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a plate forming process according to a plate forming method of the present invention.

FIG. 2 is a schematic cross-sectional view of the image forming apparatus of the present invention.

FIG. 3 is a cross-sectional view of a photoreceptor that can be used in the present invention.

FIG. 4 is a schematic view showing an example of an adhesive application member according to the present invention.

FIG. 5 is a schematic view showing an example of an adhesive application member according to the present invention.

FIG. 6 is a schematic view showing an example of an adhesive application member according to the present invention.

FIG. 7 is a schematic view showing an example of an adhesive application member according to the present invention.

FIG. 8 is a schematic view showing an example of an adhesive application member according to the present invention.

FIG. 9 is a diagram showing an example of a uniformizing member that can be used in the present invention.

FIG. 10 is a diagram showing an example of a uniformizing member that can be used in the present invention.

FIG. 11 is a diagram showing an example of a uniformizing member that can be used in the present invention.

FIG. 12 is a diagram showing an example of a uniformizing member that can be used in the present invention.

FIG. 13 is a schematic view showing an example of a latent image erasing exposure member of the present invention.

FIG. 14 is a schematic view showing an example of a latent image erasing exposure member of the present invention.

FIG. 15 is a schematic view showing an example of a latent image erasing exposure member of the present invention.

FIG. 16 is a schematic view showing an example of a latent image erasing exposure member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Substrate 12 Photocatalytic layer 13 Adhesive layer 14 Hydrophobic resin layer 15 Water-based ink 20 Plate forming drum 21 Adhesive application roller 22 Adhesive layer uniformizing member 23 Exposure light source for latent image formation 24 Resin attaching member 25 Heating member 26 Ink supply member 27 Transfer member 28 Recording medium 29 Cleaning member 30 Latent image erasing light source 31 Substrate 32 Photocatalytic layer 33 Photocatalytic fine particles 34 Binder material 35 Adhesive layer 41 Ultrasonic vibrator 42 Adhesive storage tank 43 Adhesive 61 Adhesive applying roller 81 Spray nozzle 131 Light source 132 Lens 133 Polygon mirror 134 fθ lens 141 Lens 151 Reflector

Claims (4)

[Claims] 1. A step of applying a photocatalyst-containing photocatalyst layer to a substrate provided with a photocatalyst-containing photocatalyst layer to form a photoreceptor by applying an adhesive layer decomposable by the action of the photocatalyst or the heat of laser light. Irradiating a laser beam on the adhesive layer to decompose the adhesive layer to form a latent image, and forming a hydrophobic resin layer on the adhesive layer on the surface of the photoreceptor, Plate forming method. 2. The method according to claim 1, wherein the step of forming the hydrophobic resin layer comprises supplying a thermoplastic resin onto the adhesive layer, and melting the resin by heating to form a thin layer of the resin. 2. The plate forming method according to 1. 3. A means for forming a photoreceptor by applying an adhesive layer decomposable by the action of the photocatalyst or the heat of laser light on a substrate having a photocatalyst layer containing a photocatalyst, Means for irradiating the adhesive layer with a laser beam to decompose the adhesive layer to form a latent image, means for forming a hydrophobic resin layer on the adhesive layer on the surface of the photoreceptor, and developing the formed latent image An image forming apparatus comprising: 4. The image forming apparatus according to claim 3, further comprising a latent image erasing means for erasing a latent image formed on the photosensitive member.