JP3403935B2 - Image forming apparatus, image forming method, pattern forming method, and photoreceptor used for them - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus. Further, the present invention relates to a photoconductor used in the image forming apparatus and an image forming method. Further, the present invention also relates to a pattern forming method using the photoconductor.

[0002]

2. Description of the Related Art Conventionally, a dry method used in an electrophotographic image forming apparatus uses a powder toner, and therefore a powder toner having a small particle diameter is used to output a high quality image. There is a need. However, the particle size of the powder is 5-6μ
When the particle size is less than m, if the person handling it inhales the toner floating in the air, the powder inhaled in the lungs may not be metabolized and may become a disease such as pneumoconiosis. There was a limit to the method using. On the other hand, there is a method of preventing the powder from scattering into the atmosphere by using a developer in which toner is dispersed in an organic solvent. In this method, the toner is used as an image recording medium. There was a problem that the organic solvent was volatilized in the atmosphere when the toner was fixed on the sheet. On the other hand, most of the printing machines used in the printing field use organic solvents, but it is also possible to use water, which has a low impact on the environment, as the solvent without using organic solvents. However, in a printing machine, it is necessary to print an original plate, and it is not suitable for on-demand printing such as electrophotography. Further, in the field of semiconductors and the like, in the case of forming a metal pattern, conventionally, it was necessary to mask a portion not covered with metal. Therefore, in order to form the metal pattern, the masking step and the mask material removing step after the metal pattern formation are essential. In addition to being extremely complicated in these steps, a mask material removing solution containing a strong acid is often used, and there are many problems from the viewpoint of worker safety and environmental load.

[0003]

From such a background,
In the electrophotographic image forming field and the printing field, an image forming apparatus is desired which has less influence on the human body or the environment and can also perform on-demand printing. Further, in the field of semiconductors and the like, there is a demand for a metal pattern forming method that is simpler, safer, and has less environmental load.

[0004]

[Means for Solving the Problems]

[Outline of the Invention] <Summary> The first image forming apparatus of the present invention is characterized by including the following means. (1) A photoconductor comprising a photocatalyst layer containing a photocatalyst and a hydrophobic layer provided on the photocatalyst layer, wherein the photocatalyst is irradiated with light to be irradiated with light on the surface of the photoconductor. The contact angle with water of the exposed part is changed to cause a difference from the contact angle with the water of the part which is not irradiated with light.
A photoconductor, (2) an initialization means for homogenizing the hydrophobic layer so as to make the contact angle of the photoconductor surface with water uniform, (3)
Exposure means for forming a latent image on the photoconductor initialized by the initialization means, and (4) developing means for developing the formed latent image.

The second image forming apparatus of the present invention is characterized by comprising the following means. (1) A photoconductor comprising a photocatalyst layer containing a photocatalyst and a hydrophobic layer provided on the photocatalyst layer, wherein the photocatalyst is irradiated with light to be irradiated with light on the surface of the photoconductor. A photosensitive member for changing the contact angle of the exposed portion with water, (2) an initialization means for uniformizing the hydrophobic layer so as to make the contact angle of the photosensitive member surface with water uniform, (3) ) Exposure means capable of irradiating light onto the photoconductor initialized by the initialization means to form a latent image, and controlling the irradiation amount of light, and (4) supplying ink to the surface of the photoconductor, A means for developing ink by attaching ink to the formed latent image.

A third image forming apparatus of the present invention is characterized by comprising the following means. (1) A photoconductor comprising a photocatalyst layer containing a photocatalyst and a hydrophobic layer provided on the photocatalyst layer, wherein the photocatalyst is irradiated with light to be irradiated with light on the surface of the photoconductor. The contact angle with water of the exposed part is changed to cause a difference from the contact angle with the water of the part which is not irradiated with light.
A photoconductor, (2) an initialization means for homogenizing the hydrophobic layer so as to make the contact angle of the photoconductor surface with water uniform, (3)
Exposure means for forming a latent image on the photoconductor initialized by the initialization means, (4) curing means for curing the hydrophobic layer in the area where the latent image is not formed, and (5) formed latent image Developing means for developing.

A fourth image forming apparatus of the present invention is characterized by comprising the following means. (1) A photoconductor comprising a hydrophobic photosensitive layer containing a photocatalyst and an organic compound, wherein the photocatalyst is irradiated with light to decompose the organic compound, and the photocatalyst surface is irradiated with light. A photoconductor, which changes the contact angle of the part with water to cause a difference from the contact angle with the water of the part not irradiated with light, and (2) an exposure unit for forming a latent image on the photoconductor. And (3) developing means for developing the formed latent image.

The photoconductor of the present invention is a photoconductor comprising a hydrophobic layer containing a photocatalyst and an organic compound, and is formed on the surface of the surface irradiated with light by being irradiated with light. The hydrophobic layer is decomposed and the contact angle with water changes,
This is characterized in that there is a difference from the contact angle with water in the part not irradiated with light.

The first pattern forming method of the present invention is characterized by comprising the following steps. (1) A photoconductor comprising a photocatalyst layer containing a photocatalyst and a hydrophobic layer provided on the photocatalyst layer, wherein the photocatalyst is irradiated with light to be irradiated with light on the surface of the photoconductor. The contact angle with water of the exposed part is changed to cause a difference from the contact angle with the water of the part which is not irradiated with light.
A photoconductor is prepared, (2) the contact angle of the photoconductor surface with water is made uniform, (3) the photoconductor is exposed to form a latent image, and (4) a metal is formed on the formed latent image portion. An ion-containing aqueous solution is attached to deposit a metal or metal oxide.

<Effect> According to the present invention, an image forming apparatus and an image forming method capable of performing on-demand printing and reducing the influence on the human body or the environment are provided. Further, according to the present invention, there is provided a pattern forming method which is simple and reduces the influence on the human body or environment.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

<Image Forming Apparatus> One of image forming processes by the image forming apparatus according to the present invention will be described with reference to FIG. First, a substrate having a photocatalyst layer containing a photocatalyst is prepared. By forming a hydrophobic film on the surface of this substrate to make the contact angle of the surface with water uniform (hereinafter referred to as initialization), when light is irradiated, the light-irradiated portion is the photocatalyst. The contact angle of water changes by the action, in other words, the hydrophobicity becomes smaller and the hydrophilicity becomes relatively higher.
It has the following characteristics (details below). Hereinafter, the substrate provided with the photocatalyst layer and the hydrophobic layer is referred to as a photoreceptor (FIG. 1). A hydrophobic coating is formed on the surface of this substrate (FIG. 2 (a)) to form a photoreceptor, and the surface is initialized, and then light is irradiated imagewise (FIG. 2 (b)). A portion of the surface of the photoconductor that has been irradiated with light undergoes a chemical change due to the action of the photocatalyst to increase its hydrophilicity, and the contact angle with water changes. This change in contact angle occurs continuously according to the irradiation amount of light, and accordingly, the degree of hydrophilicity also changes continuously.

In some cases, the hydrophobic substance forming the hydrophobic coating may be chemically decomposed and lost. Figure 2
(C) shows the case where such a hydrophobic coating is lost. In this way, a latent image is formed on the surface of the photoconductor. When the water-based ink is supplied to the photoreceptor on which the latent image is formed, the ink can be image-wise adhered to the surface of the photoreceptor (FIG. 2 (d)). At this time, the amount of ink attached to the latent image portion changes according to the degree of hydrophilicity of the latent image portion.
When an image recording medium, for example, paper, is pressure-bonded to the photoreceptor on which the ink is imagewise attached (FIG. 2 (e)), and then peeled off,
The image irradiated with light on the photoconductor is transferred as an image by ink onto the image recording medium (FIG. 2 (f)).

One of the processes of image formation in the image forming apparatus according to the present invention is as described above. This will be described by applying it to that of electrophotography. In writing of the electrostatic latent image, the adhesion of the water-based ink to the hydrophilic portion corresponds to the adhesion of the toner to the electrostatic latent image. In addition, although the process using the water-based ink as the ink is described here, when the hydrophobic ink is used, it is also possible to form an image as a so-called negative image in a portion not irradiated with light.

This process will be described more specifically with reference to FIG. First, the hydrophobic coating 32 is formed on the surface of the substrate 30 having the photocatalyst layer by an initialization member (detailed later). FIG. 3A shows the film formation by the initialization member (initialization roller) 31. The formed hydrophobic coating is made into a uniform coating by a homogenizing member (described later in detail), if necessary.

The surface of the substrate thus coated with the hydrophobic coating is irradiated with light from the light source 33 (that is, exposure means, which will be described later in detail) to form a latent image. FIG. 3B shows imagewise exposure using the mask 34. The exposed portion 34 of the substrate surface becomes more hydrophilic due to the action of the photocatalyst. That is, a latent image is formed on the exposed portion 35. Then, if necessary, the surface of the substrate may be treated with a water roller or the like in order to facilitate the attachment of the water-based ink to the latent image portion or to remove the chemically changed hydrophobic substance in the latent image portion. it can.

Then, development is performed by the developing means. Figure 3
(C) shows the development by supplying the ink 37 to the substrate surface by the ink supply member (ink roller) 36. Ink is supplied by a method using an ink roller as shown in FIG.
And other methods to supply ink, or a method in which a part or all of the exposed substrate is directly immersed in the ink storage tank, and any other method. With either method, most of the ink that adheres to the substrate adheres to the portion of the substrate surface where the latent image is formed. However, there is a possibility that the ink may adhere to the portion where the latent image is not formed, and the excess ink may be removed by a squeeze member if necessary. As the squeeze member, a squeeze roller made of a material that absorbs ink, a rubber blade for scraping the ink, or any other one can be used.

In this way, after the ink is attached to the latent image portion on the surface of the substrate, the ink is transferred onto the image recording medium 38. Paper is generally used as the image recording medium on which the ink is transferred, but cloth, a resin or metal film whose surface is hydrophilized, or the like can be used. These image recording media 38 are often pressed against the substrate by a pressure-bonding member.
An electrostatic attraction method and any other method can be used.

In an image forming apparatus using a flat substrate as shown in FIG. 3, generally, an image formed by one exposure is duplicated on a plurality of image recording media. It is normal. Therefore, in the example shown in FIG. 3, generally, the substrate after transfer is further transferred to the process of FIG. 3C to which ink is applied, and then transferred to the transfer process of FIG. Is repeated, and the process of transferring is repeated. At this time,
After the transfer step of FIG. 3D, a cleaning process is performed by a cleaning member, if necessary, in order to remove the ink remaining on the latent image and the ink adhering to portions other than the portion where the latent image is formed. You can The cleaning member is
A cleaning roller made of a material that absorbs ink,
A blade-shaped member having a shape for scraping off the ink, and any other member can be used.

On the other hand, it is also possible to initialize the substrate after the ink transfer again to form another image. In such a case, in principle, only the hydrophobic coating is present on the substrate after the transfer, and therefore the substrate may be directly transferred to the initialization step (FIG. 3A). However, actually, the substrate surface after transfer is divided into a hydrophilic portion and a hydrophobic portion. If the substrate in this state is directly transferred to the initialization step, the thickness of the hydrophobic coating newly provided by the initialization member may not be constant. If the thickness of the hydrophobic coating is not constant, it becomes impossible to control the amount of light depending on the amount of light in the hydrophilic treatment by light irradiation, and it may be difficult to form a latent image according to an input signal. For this reason, it is preferable to remove the hydrophobic coating with a history erasing member (described later in detail) and then move to the initialization step. FIG. 3E shows a history erasing step by light irradiation from the light source 39.

The image forming apparatus according to the present invention is an apparatus for forming an image by the method as described above, but is not limited to the one in which the photoconductor is a flat plate. On the contrary, when it is intended to be subjected to on-demand printing, it is more advantageous to form the image on a photoreceptor as a drum and to continuously form an image as described below. An example of such an image forming apparatus capable of continuously forming images will be described below with reference to FIG. The image forming apparatus shown in FIG. 4 includes a plate forming drum 40 corresponding to a substrate of a photoconductor, an initialization member 42 having initialization means, a uniformization member 43 having homogenization means, an exposure member 44 having exposure means, It has a water roller 45, an ink supply member 46 having a developing means, a squeeze member 47, a pressure bonding member 48, and a cleaning member 41.

A drum, eg of aluminum,
A photocatalyst layer containing a photocatalyst is formed on the surface of the plate to form the plate forming drum 30. The plate-forming drum is rotating as the image forming process progresses. Hereinafter, how part of the surface of the plate-forming drum is processed according to the rotation of the drum will be described. A hydrophobic coating is formed on one portion of the plate forming drum by the initialization member 32 (details described later). Here, the one in which a hydrophobic coating is formed on the plate forming drum corresponds to the photoreceptor. The formed hydrophobic coating is made into a uniform coating by the homogenizing member 43 (details described later) if necessary.

Light is emitted from the light source 44 (that is, exposure means, which will be described later in detail) to the portion of the plate forming drum thus coated with the hydrophobic coating to form a latent image. Then
In order to facilitate the attachment of the water-based ink to the latent image portion or to remove the chemically changed hydrophobic substance in the latent image portion,
Then, the surface of the relevant portion of the plate forming drum is treated by the water roller 45.

Next, the ink is supplied to the surface of the relevant portion of the plate forming drum by the ink supply member 46. The ink is supplied by a method using an ink roller as shown in FIG. 4, a method of supplying ink by a spray, a brush, and the like, or a method of directly immersing a part of the plate forming drum in an ink storage tank, And any other method. With either method, most of the ink adheres to the portion of the surface of the plate forming drum where the latent image is formed. However, there is a possibility that the ink may adhere to the portion where the latent image is not formed, and the squeeze member 47 may be used to remove the excess ink as necessary. As the squeeze member, a squeeze roller made of a material that absorbs ink, a rubber blade for scraping the ink, or any other one can be used.

In this way, after the ink is attached to the latent image portion on the surface of the plate forming drum, the ink is transferred onto the image recording medium 48. Paper is generally used as the image recording medium on which the ink is transferred, but cloth, a resin or metal film whose surface is hydrophilized, or the like can be used. These image recording media 48 are used for the pressure bonding member 4
9 is pressure-bonded to the plate-forming drum. The pressure-bonding method includes a method using a pressure roller as shown in FIG.
A method of blowing high-pressure gas, a method of electrostatic attraction, and any other method can be used.

In an apparatus intended for continuous image formation as shown in FIG. 4, after the ink is transferred from the plate-forming drum to the image recording medium, the relevant part of the plate-forming drum is used for further image formation. Therefore, it is usually initialized again. Prior to the initialization, there is a possibility that the ink that has not been completely transferred to the image recording medium may remain on the surface of the plate forming drum. Therefore, the cleaning member 41 may remove the residual ink as necessary. it can.
As the cleaning member, a cleaning roller made of a material that absorbs ink, a blade-shaped member that scrapes off ink, or any other member can be used.

Further, since only the hydrophobic coating is in principle present on the plate forming drum after the transfer, it may be initialized as it is. However, actually, the surface of the plate forming drum after transfer is divided into a hydrophilic portion and a hydrophobic portion. When the plate forming drum in this state is initialized as it is,
The thickness of the hydrophobic coating newly provided by the initialization member may not be constant. If the thickness of the hydrophobic coating is not constant, it becomes impossible to control the amount of light depending on the amount of light in the hydrophilic treatment by light irradiation, and it may be difficult to form a latent image according to an input signal. For this reason, it is preferable that the history erasing member (detailed later) also removes the hydrophobic coating and then the initialization is performed.

The cleaning member and the history erasing member can be arranged at any position between the portion where the ink is transferred from the plate forming drum and the portion where the ink is initialized. Further, either one or both of the cleaning member and the history erasing member can be arranged. If necessary, a member having the functions of both a cleaning member and a history erasing member, which simultaneously removes the residual ink and the hydrophobic coating, can be used. If a cleaning member or a history erasing member is used, the plate forming drum is initialized by the initialization member again after the site is processed by the cleaning member or the history erasing member. As a result, the surface of the portion of the plate forming drum is coated with the hydrophobic coating. This completes one cycle.

In such an image forming apparatus, when a different image is formed every time like a general copying machine, the object is achieved by repeating the above cycle. However, in the case of forming a plurality of the same images as in a general printer, the processes of initialization, homogenization, and light irradiation are not necessary after the second cycle and can be omitted.

Here, when a plurality of the same images are formed, it is preferable that the latent images have printing durability. Printing durability of the latent image can be achieved by curing the hydrophobic layer. This curing process (details below)
Is generally performed between the exposure process and the development process. This curing process can be omitted after the second cycle or can be repeated intermittently.

Further, in a further aspect of the image forming apparatus of the present invention, as a photoreceptor, a photoreceptor comprising a hydrophobic photosensitive layer containing a photocatalyst and an organic compound, is irradiated with light, The hydrophobic photosensitive layer formed on the surface irradiated with light is decomposed to change the contact angle with water, which causes a difference from the contact angle with water on the area not irradiated with light. Characteristic features can also be used (details described later). By using such a photoreceptor in the above-mentioned image forming apparatus, an image can be formed in the same manner as described above. In this case, the hydrophobicity of the photocatalyst-containing layer itself changes, but other than that, image formation can be performed by the same process as described above.

<Photoreceptor> One of the photoreceptors that can be used in the image forming apparatus of the present invention is a photocatalyst layer 1 comprising a photocatalyst 13 and a binder material 14 holding the photocatalyst 13.
2 is provided on the substrate 11, and the hydrophobic layer 15 is further provided on the photocatalyst layer. A schematic view of the cross section is shown in FIG.

This photoconductor is initialized prior to image formation. This initialization is performed by making the hydrophobic coating on the surface of the photoconductor uniform. Then, when the coated photoreceptor is imagewise irradiated with light, a contact angle with water differs between the light-irradiated portion and the non-irradiated portion. Such a behavior is such that when the photocatalyst is irradiated with light, it chemically changes the hydrophobic substance in the vicinity thereof,
It occurs to make it hydrophilic. The mechanism of the chemical change is not clear, but it is considered that when the photocatalyst is excited by light irradiation, hole separation occurs, followed by generation of active oxygen and active hydrogen, which react with organic substances in the vicinity. ing.

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.
b ₂ O ₅ , Ta ₂ O ₅ , Fe ₂ O ₃ , SrTiO ₃ , CdS,
ZnS, PbS, CdSe, GaP, and others. Moreover, you may mix and use several photocatalysts as needed. As described above, as the photocatalyst, any one can be used, and among these, high sensitivity and
TiO ₂ is particularly preferable because it has little influence on the environment or the human body. As TiO ₂ , rutile type, anatase type and the like are known, but any of them may be used. The particle size of TiO ₂ used as a photocatalyst is preferably 10 nm to 5 μm in terms of secondary particle size measured by observation with a transmission electron microscope from the viewpoint of increasing the activity of the photocatalyst.

As the binder material 14 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 typified 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, 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 the binder material for the photocatalyst layer, the binder material in the portion of the photoconductor where the light is irradiated may undergo a chemical change. Even so, when the same image can be repeatedly obtained from the photo-irradiated photoreceptor, the purpose of image formation can be achieved if the light-irradiated portion has a desired hydrophilicity. However, when a different image is formed every time like a copying machine, the photocatalyst layer should be restored on the photoreceptor after the ink image is transferred to the image recording medium. Therefore, when such an application is intended, a binder material for the photocatalyst layer is preferably one that is less likely to undergo a chemical change due to the photocatalyst, and is at least more chemically than the hydrophobic coating formed on the surface of the photoconductor by initialization. You should select one that is unlikely to change. Particularly preferred are metal oxides, carbides, or nitride ceramics, and when these are used as the binder material, the life of the photoconductor can be extended even when the initialization and image formation are repeated.

The substrate 11 to be used can be generally made of ceramics, metals, and others, and is not particularly limited, but is preferably metal. Since metal has high mechanical strength and high workability due to its properties, it is easy to form a hollow drum as used in the plate forming drum as described above, for example, an outer diameter of 30 mm,
250 mm long aluminum drum is at most 1
It can be manufactured as a hollow drum having a wall thickness of mm and sufficient mechanical strength. This contributes to reducing the weight of this component alone, and thus of the entire image forming apparatus, and enables the manufacture of large drums. In addition, when a metal material is used, it is advantageous in terms of dimensional stability as compared with a substance such as a ceramic material (for example, glass) that needs to be sintered, and the outer diameter is kept constant in the length direction, It is easy to suppress eccentricity, and it is easy to obtain a high quality image.

Further, since the metal is a good conductor of electricity, electrons can easily move inside the metal substrate, and the photocatalyst in the photocatalyst layer provided on the surface of the substrate can also receive electrons and be reduced. is there. Further, if necessary, a bias voltage can be applied to the substrate or it can be grounded. Further, an oxide film is usually formed on the metal surface in the air, which is advantageous for coating a hydrophobic film. Furthermore, the hydrophobic coating can be dried by heating after applying the hydrophobic coating or after forming the latent image by exposure, but it is dimensionally stable even at a high temperature (for example, 300 to 350 ° C.). Is maintained, and high thermal conductivity enables cooling in a short time, which is advantageous.

The metal used is a commonly used metal,
Suitable are, for example, aluminum, nickel, iron, copper, titanium, and others, as well as alloys thereof, such as stainless steel, duralumin, and others. Of these, aluminum and aluminum alloys are particularly preferable because they are lightweight, have high strength, and are excellent in workability.

The photoconductor of the present invention is usually prepared by applying a coating solution containing the photocatalyst 13 and the binder material 14 on the substrate 11 to form a photocatalyst layer. As such a coating liquid, generally, water or an organic solvent, for example, an alcohol such as methanol, an aromatic compound such as toluene, the photocatalyst, and, if necessary, a solution in which the binder material is dissolved or dispersed is used. In such a case, the mixing ratio of the photocatalyst and the binder material is not particularly limited. This is because when the type of ink changes, the contact angle with water may change in the part that is irradiated with light or the part that is not irradiated with light. The ratio may be changed as appropriate.

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

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

The film thickness of the photocatalyst layer thus formed is preferably 0.01 to 100 μm, and particularly preferably 0.05 to 10 μm at which the strength of film formation becomes stronger. When the film thickness of the photocatalyst layer is less than 0.01 μm, the difference in contact angle of water between the light-irradiated portion and the non-light-irradiated portion does not significantly appear, which is a phenomenon corresponding to so-called fog in electrophotography. May appear. Further, if the film thickness of the photocatalyst layer exceeds 100 μm, the film forming strength may be rather deteriorated, and cracks may occur.

The photocatalyst layer 12 may contain a sensitizer, if necessary. This sensitizer absorbs light having a specific wavelength and is excited, and transfers the excitation energy to the photocatalyst to increase the sensitivity of the photosensitizer at the specific wavelength. Such sensitizers are not particularly limited, and specific examples thereof include aromatic sensitizers such as pyrene, perylene, triphenylene, and other xanthene sensitizers such as rhodamine B and rose bengal. And other, cyanine sensitizers, such as thiacarbocyanine, oxacarbocyanine, and others, thiazine sensitizers, such as thionine, methylene blue, toluidine blue, and others, acridine sensitizers, such as acridine orange, Chloroflavin, acriflavine, and other phthalocyanine sensitizers, such as phthalocyanine, metal phthalocyanine, and others, porphyrin sensitizers, such as tetraphenylporphyrin, metalporphyrin, and others, chlorophyll sensitizer, chlorophyll Kororofirin, central metal-substituted chlorophyll, and other,
Metal complex-based sensitizers, such as ruthenium bipyridine complex,
And other fullerene sensitizers such as C ₆₀ and C
₇₀ , and others, 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 polymer compounds are mentioned. In addition, compounds used as charge generating agents and charge transporting agents for electrophotographic photoreceptors can also be used as sensitizers.

As the sensitizer, any one can be used, and a plurality of sensitizers can be used in combination if necessary. Generally, the light used for forming a latent image is also used. It is decided according to the wavelength of. From such a viewpoint, a metal porphyrin or a ruthenium bipyridine complex is particularly preferable as the sensitizer. When a sensitizer is used, its addition amount is not particularly limited, but generally 0.001-1 mol is added per 1 mol of the photocatalyst. Also,
The performance of the photocatalyst layer can also be controlled by adjusting the addition amount.

Another photoreceptor that can be used in the image forming apparatus of the present invention is one in which a hydrophobic photosensitive layer 52 containing a photocatalyst 53 and an organic compound 55 is provided on a substrate 51. A schematic view of the cross section is shown in FIG.
This photoconductor contains a photocatalyst in the hydrophobic layer itself, the hydrophobicity of which changes when exposed to light. That is, the photocatalyst 53 is not directly held on the substrate 51, but is held by the organic compound 54 whose hydrophobicity is changed by light irradiation. Here, as the substrate 51, the same one as the above-mentioned first photoconductor can be used. The type of photocatalyst 53, the addition amount, the particle size, and the like are the same as those of the first photoconductor described above.

As the organic compound 54, those whose hydrophobicity is changed by light irradiation can be used. Specific examples of such a material include (a) polymer 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, povinyl acetal resin, vinyl acetate resin, diallyl phthalate resin, polystyrene resin, polysulfone resin, acrylic resin, polyphenylene oxide resin, alkyd resin, styrene-butadiene copolymer resin, styrene-maleic anhydride copolymer Polymer resin, urethane resin, and others,
(B) hydrocarbons such as paraffin, waxes, and others, and (c) fatty acids such as lauric acid, myristic acid,
Palmitic acid, oleic acid, stearic acid, linoleic acid, and others, and their derivatives, for example,
Amides, esters, and others, (d) higher aliphatic alcohols, (e) fats and oils having less than 100 carbon atoms, (f) silicone oils having a degree of polymerization of less than 200 (that is, less than 200 Si), and other organic compounds. Can be used. These organic materials can be selected arbitrarily,
If necessary, a plurality of these materials may be mixed and used at an arbitrary ratio.

The photocatalyst layer 52 may contain a sensitizer if necessary. The type and addition amount of the sensitizer that can be used are the same as the sensitizer that can be used for the first photoreceptor. Further, as a method of applying the hydrophobic photosensitive layer containing the photocatalyst on the substrate, spin coating, dip coating, bar coating, spray coating, and any other method can be used.

The film thickness of the thus formed hydrophobic photosensitive layer is preferably 0.01 to 100 μm, and 0.0
It is particularly desirable that the thickness is 5 to 50 μm. When the film thickness of the photocatalyst layer is less than 0.01 μm, the difference in contact angle of water between the light-irradiated portion and the non-light-irradiated portion does not significantly appear, which is a phenomenon corresponding to so-called fog in electrophotography. May appear. Further, when the film thickness of the hydrophobic photosensitive layer exceeds 100 μm, problems such as deterioration of film forming strength and occurrence of cracks may occur.

<Initializing Means> The initializing means is a means for making the contact angle of the surface of the photoconductor with water uniform. In order to make the contact angle between the surface of the photoconductor and water uniform, the hydrophobic layer or the hydrophobic photosensitive layer on the surface of the photoconductor may be made uniform. Hereinafter, the hydrophobic layer and the hydrophobic photosensitive layer are collectively referred to as the hydrophobic layer. In addition, the term hydrophobizing agent is meant to include those containing a photocatalyst and an organic material used in the second photoreceptor of the present invention.

As the initialization member having such a function, any one can be used, and its concrete example is as shown in FIGS. The initialization member shown in FIG. 6 sprays the hydrophobizing agent in a mist state. The ultrasonic transducer 61 atomizes the hydrophobizing agent 63 contained in the hydrophobizing agent storage tank 62, and the plate forming drum. Spray over 40.
Spraying the hydrophobizing agent in the form of mist as in this example is advantageous for forming a thin and uniform film.

The initialization member shown in FIG. 7 fills the hydrophobizing agent storage tank 62 with the hydrophobizing agent 63 and immerses the plate forming drum therein to form a film of the hydrophobizing agent. When the film is formed by such a method, the film tends to be thick. When such an initialization member is used, the hydrophobizing agent is usually a liquid at normal temperature and pressure. The initialization member shown in FIG. 8 is for contacting an intermediate medium containing or carrying a hydrophobizing agent. In FIG. 8, when the hydrophobizing agent is supplied to the plate forming drum through the intermediate medium 81, the intermediate medium is particularly in the shape of a roller, and the roller-shaped member is rotatable about an axis. Therefore, it is advantageous in that only one place can be prevented from being deteriorated by always contacting the plate forming drum. However, even when using such an intermediate medium, it is possible to select a shape other than the roller shape.

The initialization member shown in FIG. 9 is for pouring the hydrophobizing agent 63 from the hydrophobizing agent storage tank 62 to form a film of the hydrophobizing agent on the plate forming drum. Also in this case, as in the example of FIG. 7, the coating tends to be thick. Figure 1
The initialization member indicated by 0 sprays the hydrophobizing agent onto the plate forming drum 40 from the spray nozzle 101. Also in this case, it is advantageous to form a thin and uniform film as in the example of FIG.

The hydrophobic layer on the plate forming drum can be made uniform by such a method, but the thickness of the hydrophobic coating is
It affects the quality of images. The thickness of the hydrophobic coating is generally 0.01 to 10 μm. Within this range, if the coating is thinner, the sensitivity is increased, and the interval between image formation and initialization can be shortened. On the contrary, if the coating is thicker, the image of the image when the light irradiation amount is changed is changed. Gradation control becomes easy. However, if it is more than 0.01 μm and exceeds this range, the difference in contact angle with water between the light-irradiated portion and the light-unirradiated portion does not significantly appear, and it is difficult to obtain a clear image. Become. If it exceeds 10 μm, the sensitivity tends to decrease.

For this reason, it is possible to select an initialization member that can obtain a suitable hydrophobic coating. In addition, it is possible to form a thicker hydrophobic coating once and then make it thinner by a homogenizing member described later.

<Uniformizing Means> The uniformizing means is a means for further thinning the hydrophobic coating uniformized by the initialization member. Further, when the hydrophobic coating initialized by the initialization member is not sufficiently smooth, it also has a function of making the surface uniform. The homogenizing member having these functions is provided as needed, but when provided, any one can be used. Specific examples of such a uniformizing member are shown in FIGS. 11 to 14, for example.

The uniformizing member shown in FIG. 11 has a scraping effect by bringing the edges of a blade-shaped member into contact with each other to facilitate the formation of a thin layer. At this time, if an elastic body is used as the material of the member, the adhesion with the plate forming drum is increased, and the layer thickness is stabilized. The initialization member shown in FIGS. 12 and 13 is for bringing the surface of the member into contact with the plate forming drum, and the scraping effect is smaller than that of the uniformization member illustrated in FIG. Excellent stability, with little change in contact area due to wear. Also in this case, if an elastic body is used as the material of the member, the same effect as in the example of FIG. 11 can be obtained. In particular, the roller-shaped member as shown in FIG. 13 can rotate around the shaft, which is advantageous in that deterioration of the member due to constant contact at only one place can be avoided.

The homogenizing member shown in FIG. 14 is intended to remove excess hydrophobizing agent in the rotational direction by bringing the edges of the blade-shaped member into contact with each other. Although the effect is similar to that of the uniformizing member shown in FIG. 11, there is a difference in the scraping effect, and thus such a uniformizing member can be applied. In addition, it is also possible to make the hydrophobic layer thin by absorbing a hydrophobizing agent by using a foam, such as a sponge, as the homogenizing member.

<Exposure Means> The exposure means in the present invention is
It is a means for irradiating the initialized photoconductor with light to form a latent image. An exposure member having such a function,
That is, any light source can be used, but in general, (a) laser, for example, gas laser, solid-state laser, liquid laser, semiconductor laser, dye laser, and others, and (b) phosphor Heads such as ZnO-based phosphor heads, SnO ₂ -based phosphor heads, (ZnCd) S-based phosphor heads, ZnS-based phosphor heads, and others are used. When using a phosphor head, in order to reduce the operating voltage,
A conductive material such as In ₂ O ₃ may be mixed. The type of light source used as the exposure member is usually selected according to the absorption wavelength of the photocatalyst used in combination, the sensitizer used in combination with the photocatalyst, the intensity of the light source, and other conditions. However, the wavelength of the light to be radiated is 40 because it is easy to obtain with a commonly used light source.
It is preferably 0 to 800 nm. Further, by using a laser having a high energy, it is possible to expect decomposition by heat or ablation in addition to the decomposition of organic substances by the photocatalyst as described above, and thus it may be preferable to use a laser as a light source.

In the image forming apparatus of the present invention, the contact angle of the surface of the photoconductor with water continuously changes depending on the amount of light to be irradiated. Therefore, by appropriately controlling the intensity of the light source and / or the light irradiation time, the degree of hydrophilicity of the latent image portion of the photoconductor is arbitrarily controlled, that is, the amount of ink attached to the latent image portion of the photoconductor is controlled. Then, it is possible to control the gradation of the image.

<Curing means> The curing means in the present invention is
It is a means for curing the portion of the hydrophobic layer where the latent image is not formed by the exposing means, and improving the printing durability. The method of curing the hydrophobic layer is optional, but specifically, the method of curing the organic compound itself that forms the hydrophobic layer, and the hydrophobic layer in the portion where the latent image is not formed can be selectively cured. And a method of curing the curable substance, and the like, and the like, but the hydrophobic layer in the portion where the latent image is not formed is selectively covered with the curable substance, and then the curable substance. The method of curing is preferred.

Any method may be used to cure the substance, such as a method for curing by heating, a method for curing by a photoreaction by irradiating with light, or a substance for causing or promoting a curing reaction to a curable substance. Methods and the like can be mentioned, but a method of irradiating light and curing by a photoreaction is preferable.

Here, as the curable substance, any substance can be used as long as it can be cured by the method applicable in the method of the present invention, but a substance curable by light irradiation is used. In this case, it is preferable that the transmittance of the irradiated light is high. Any substance can be used as long as it satisfies such conditions, and a substance that causes a photoreaction by itself and cures,
It is possible to use a mixture of a photopolymerization initiator and a monomer that is crosslinked by its action, and others. Specifically, acryloyls (for example, acrylamides, acrylates, especially phenylene diacrylates, and others), unsaturated polyesters, unsaturated polyurethanes,
Azides, diazos, and others.

When the hydrophobic layer in the portion where the latent image is not formed is selectively covered with a curable substance and then the curable substance is cured, a method for supplying the curable substance to the hydrophobic layer is Although any method can be used, the same method as the above-described initialization can be used. Therefore,
As the member for supplying the curable substance, one having the same structure as the above-mentioned initialization member can be used.

Further, the supplied curable substance can be homogenized on the hydrophobic layer. Although any method can be used for this method, the same method as the above-described homogenization can be used. Therefore, as a member for homogenizing the curable substance on the hydrophobic layer, a member having the same structure as the above-mentioned homogenizing member can be used. In addition,
The curable substance that covers the hydrophobic layer does not necessarily have a dense layered structure, and the hydrophobic layer may be exposed on the surface. That is, the curable substance may cover the hydrophobic layer in a mesh shape, or the curable substance may be discontinuously scattered on the surface of the hydrophobic layer.

The shape of the exposure light source for causing the curing reaction is not particularly limited as long as it is a light source which does not form a latent image and can be irradiated with light having a wavelength capable of causing the curing reaction. There is no limitation, and for example, it can be selected from those that can be used for the above-mentioned exposure means.

<Developing Means> The developing means in the present invention is
It is a means for developing the latent image formed by the exposing means. The developing member having such a function is optional, but is preferably an ink supply member for applying ink to the exposed photoreceptor. The ink may be supplied to the surface of the photoconductor by any method, but may have the same structure as the above-mentioned initialization member. Further, the ink used is optional, but considering the influence on the environment, it is preferable that the content of the organic solvent is small.

<History Erasing Means> The history erasing means of the present invention is means for removing the hydrophobic coating remaining on the surface of the photoconductor after the ink adhering to the surface of the photoconductor is transferred to the image recording medium. When the history erasing process by such means is replaced with an electrophotographic process, it corresponds to a charge eliminating member. As the history erasing member having such a function, any member can be used as long as it removes the hydrophobic coating remaining on the substrate. Specifically, a blade-shaped squeeze member (such a member is
Mechanical function (which also has a function as a cleaning member for removing residual ink), a chemical one that decomposes a hydrophobic coating made of an organic substance by light irradiation, heating, and the like, and the like. Among these, those that chemically decompose the hydrophobic coating, especially those that remove the hydrophobic coating by light irradiation, are preferable.

Any light source can be used as a light source that can be used as a history erasing member for removing the hydrophobic coating by light irradiation. Specifically, a mercury lamp, a sodium lamp, a metal halide lamp, a halogen lamp, and a fluorescent lamp can be used. , Incandescent lamps, ultraviolet lamps, lasers, LED light emitting elements, EL light emitting elements, photoluminescent elements, cathodoluminescent elements, and others. Among these, lasers capable of emitting coherent light are preferable, and examples thereof include He—Ne, CO ₂ —N ₂ , and He—C.
d, N ₂ , Ar, Kr, F ₂ , ArF, KrF, XeC
Gas lasers using l, XeF, and others, 2,
Examples include die lasers using 5-diphenyloxazole, 4-methylambelliferone, and others, and other liquid lasers, ruby lasers, YAG lasers and other solid-state lasers, semiconductor lasers, and the like.

When a light source for irradiating light is used as the history erasing member, the method of irradiating the photoconductor with light is arbitrary, but a concrete example thereof is as shown in FIGS. The history erasing member shown in FIG. 15 irradiates the light emitted from the light source 151 with the polygon mirror 153 in the length direction of the plate forming drum. The lens 152 and the fθ lens 154 can be provided if necessary.
The history erasing member shown in FIGS. 16 and 17 uniformly irradiates the light from the light source through the lens 161 in the longitudinal direction of the plate forming drum. The history erasing member shown in FIG. 18 uniformly irradiates the light emitted from the light source 151 with the reflecting plate 181 in the length direction of the plate forming drum and irradiates the light. In addition to these, light is emitted from a light source such as a laser to a surface-emitting type optical fiber to uniformly irradiate light in the length direction of the plate forming drum, and various light emitting elements are arranged in the length direction of the plate forming drum. It is also possible to arrange them uniformly and irradiate them with light. Further, it is also possible to irradiate the plate forming drum with harmonics obtained by passing the light of the various light sources through the non-linear material. Also, pulsed light such as strobe light generated by exciting a xenon tube or the like with a high voltage can be irradiated.

FIG. 19 shows an example of an image forming apparatus provided with a hardening means and a history erasing means. This apparatus is different from the image forming apparatus shown in FIG. 4 in that a member 191 for supplying a curable substance, a member 192 for equalizing the supplied curable substance, a means 193 for curing the curable substance, And a history erasing member 194. In the apparatus shown in FIG. 19, the curable substance is a photocurable resin, and the history erasing member is a light source for performing light irradiation.

In such an apparatus, the photo-curable substance is supplied by the member 191 to the portion where the latent image is not formed by the curing means between the image forming exposure of the plate forming drum 40 and the development thereof. Then, it is homogenized by the member 192, and further cured and exposed by the member 193,
The portion where the latent image is not formed is cured. This improves the printing durability of the plate forming drum.

Further, in such an apparatus, after the development plate forming drum 40 is cleaned after the image transfer and before it is initialized again, the hydrophobic layer in the portion where the latent image is not formed has a history. The history is erased by being decomposed by the action of the photocatalyst layer activated by the light emitted from the erasing member 194.

When the same image is repeatedly formed using such an apparatus, the development is repeated after the steps of initialization, exposure, curing and development. During this period, the history erasing, initializing, uniformizing, exposing, and curing processes can be omitted. Then, after a series of image formation is completed, the following processes such as history erasing, initialization, homogenization, exposure, curing, and development are performed as necessary. Note that such an image forming apparatus is an example of the image forming apparatus of the present invention, and each member can be replaced with the above-mentioned members or other members.

<Pattern Forming Method> The pattern forming method of the present invention utilizes any one of the above-described photoconductors. That is, the first pattern forming method of the present invention is characterized by comprising the following steps. (1) A photoconductor comprising a photocatalyst layer containing a photocatalyst and a hydrophobic layer provided on the photocatalyst layer, wherein the photocatalyst is irradiated with light to be irradiated with light on the surface of the photoconductor. The contact angle with water of the exposed part is changed to cause a difference from the contact angle with the water of the part which is not irradiated with light.
By preparing a photoconductor, and (2) by making the thickness of the hydrophobic layer uniform, the contact angle of the surface of the photoconductor with water is made uniform,
(3) The photoreceptor is exposed to form a latent image having a higher hydrophilicity than the unexposed portion, and (4) a metal ion-containing aqueous solution is attached to the formed latent image portion, and a metal is formed by an appropriate method. Alternatively, a metal oxide is deposited.

The second pattern forming method of the present invention is the same as the above-mentioned first pattern forming method, except that a hydrophobic photosensitive layer containing a photocatalyst and an organic compound is used as a photosensitive member instead of the photosensitive member. The photocatalyst comprises a photocatalyst that is irradiated with light, thereby changing the contact angle of water on the surface of the photoconductor where the light is irradiated.
It uses a photoconductor.

That is, the pattern forming method of the present invention is different from the above-mentioned image forming method in the developing means. The pattern forming method of the present invention will be described below, focusing on the differences from the image forming method. In the pattern forming method, it is rare that a plurality of patterns are continuously formed using one photoconductor. For this reason, in general, a photoreceptor having a flat plate shape is often used. One pattern forming method of the present invention using such a plate-shaped photoreceptor will be described with reference to FIG. First, a substrate having a photocatalyst layer 202 containing a photocatalyst (FIG. 20A) is prepared. A hydrophobic coating 203 is formed on the surface of this substrate to form a photoconductor 204, and after the surface is initialized, light is irradiated imagewise (FIG. 20 (b)). A portion of the surface of the photoconductor that has been irradiated with light undergoes a chemical change due to the action of the photocatalyst to increase its hydrophilicity, and the contact angle with water changes.

In some cases, the hydrophobic substance forming the hydrophobic coating may be chemically decomposed and lost. Figure 20
(C) shows the case where such a hydrophobic coating is lost. It should be noted that in forming the pattern, it is desirable that there is no shading of the formed pattern, and that it is preferable that the metal pattern is fixed to the substrate.
It is preferable that the exposed portion of the hydrophobic coating such as 0 (c) is completely lost.

When the aqueous solution containing metal ions 205 is supplied to the photoconductor on which the latent image is formed, the aqueous solution can be attached imagewise to the photoconductor surface (FIG. 20 (d)). If necessary, the aqueous solution attached to other than the portion where the latent image is formed is removed by a squeeze member, and then metal ions in the aqueous solution are deposited as the metal 206 or the metal oxide 206 by an appropriate method. The method of depositing the metal or metal oxide is arbitrary, but the photoreduction method, the electroless plating method, and the electrolytic plating method are preferable. FIG. 20E shows a photo-reduction method in which light from the light source 207 is applied to the entire substrate to deposit metal. After the metal or metal oxide pattern is formed in this way, the hydrophobic coating remaining on the substrate is removed as necessary to form the pattern (FIG. 20 (f)). To remove the hydrophobic coating, the means described as the history erasing means in the image forming method can be used. The metal ion-containing aqueous solution used is not particularly limited, but when the pattern is used as wiring, those commercially available as electroless plating solutions, such as gold, copper, nickel, tin, palladium, and other electroless plating solutions, are used. It is also possible to use a solution in which silver nitrate or the like is dissolved when the pattern is used as a hologram.

[0079]

EXAMPLES Example 1 <Photoreceptor> 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 used in a solid content weight ratio of 50:
50% by weight, solid concentration 10% by weight, pH 1.
The coating liquid was prepared by adjusting to 5. This coating solution was applied onto an aluminum drum by spray coating to a film thickness of 3.5 μm to form a film.
The plate forming drum 30 (that is, dried at 0 ° C. for 1 hour)
To obtain a photoconductor. <Initialization Member> In this embodiment, the vaporization device using an ultrasonic transducer shown in FIG. 4 was used as the initialization member 32. Linoleic acid was used as the hydrophobizing agent. <Equalizing Member> In the present embodiment, the equalizing member 33 is
The blade shape shown in FIG. 9 was used. Silicone rubber was used as the material of the uniformizing member. <Light Source> In this embodiment, the light source 3 for forming a latent image
As 4, an argon ion laser was used and ultraviolet light of 388 nm was selected as the exposure wavelength.

<Image Forming Apparatus and Image Formation Using the Image Forming Apparatus> An image forming apparatus as shown in FIG. 3 was prepared from the above-mentioned members and other members, and images were formed. In the image forming apparatus as shown in FIG. 3, the plate forming drum is rotating in the direction of the arrow in the drawing, and the image forming process proceeds with the rotation.

First, the plate forming drum 30 includes an initialization member 32.
Thereby applying a hydrophobizing agent (linoleic acid), which forms a hydrophobic film on the plate forming drum. This coating is then made uniform in thickness by the homogenizing member 33.
Next, the plate forming drum provided with the uniform hydrophobic coating is imagewise exposed by the light source 34. The hydrophobizing agent on the exposed portion on the plate forming drum is chemically changed, and subsequently, the hydrophobizing agent on the exposed portion is removed by being treated by the water roller 35. Subsequently, ink is supplied to the plate forming drum by the ink supply member 36. The ink adheres to the area where the hydrophobizing agent has been removed, but since the excess ink also adheres to other areas, this excess ink is removed by the squeeze member 37. Further, by pressing the support 39 to the plate forming drum by the transfer member 38, the ink on the plate forming drum is transferred to the support 39, so that a clear image can be obtained.
The ink remaining on the support 39 without being transferred is subsequently removed by the cleaning member 31. In this way, a clear image could be obtained by the image forming apparatus of the present invention.

Further, by further proceeding the process, the portion of the plate forming drum used for image formation is reset again.
Then, the entire surface of the plate forming drum was initialized to a hydrophobic state before exposure by processing with the homogenizing member 33. From this state, the exposure, the ink supply, the transfer of the ink to the support, the cleaning, and the initialization were set as one cycle, and the image formation was performed again by this process, and the image could be obtained with excellent reproducibility. .

Example 2 Image output was attempted in the same manner as in Example 1 except that liquid paraffin was used instead of linoleic acid as the hydrophobizing agent used for initialization, and an image with excellent reproducibility was obtained. I was able to get

Example 3 The same as Example 1 except that a silicone foam member having a roller shape as shown in FIG. 8 and having a hydrophobizing agent absorbed therein was used as the initialization member. When an image output was attempted by the method, an image could be obtained with excellent reproducibility.

Example 4 Image output was tried in the same manner as in Example 1 except that a silicone foam member having a roller shape as shown in FIG. 11 was used as the uniformizing member. An image could be obtained with excellent reproducibility.

Example 5 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed in a solid content weight ratio of 50:50 to adjust the solid content concentration to 10% by weight and the pH to 1.5. Furthermore, a propanol solution of Zn porphyrin was added to this solution so that the amount of Zn porphyrin added was 30% by weight of the total solid content of the coating solution to prepare a coating solution. This coating liquid was pulled up and coated on an aluminum drum by a coating method to form a photocatalyst layer, and dried at 100 ° C. for 24 hours. This coating and drying were repeated until the thickness of the photocatalyst layer after drying was 5 μm, and a plate forming drum was obtained. The resulting plate-forming drum was initialized and then imagewise exposed to a He-Ne laser at 543.5 nm light and then treated with a water roller moistened with water to wash the exposed areas. Next, the ink roller immersed in the ink reservoir containing the water-based ink was pressed against the plate-forming drum to supply the water-based ink to the exposed portion of the plate-forming drum. The excess ink adhering to the unexposed areas of the plate-forming drum was then removed and treated with a squeeze roller to control the thickness of the ink layer in the exposed areas. Further, by pressing a transfer roller via paper against the drum, the ink on the plate forming drum was transferred to the paper, and a clear image was obtained. The ink remaining on the drum without being transferred to the paper is removed by the cleaning roller, and then the part irradiated with light is initialized by the initialization roller, and the plate forming drum is in the state where the whole is initialized again. It was

When this light irradiation, ink adhesion, ink transfer to paper, cleaning, and initialization were set as one cycle, and an image was output again in this cycle, an image could be obtained with excellent reproducibility. . Further, when the light irradiation amount by the laser was changed and an image of a gray pattern was output, 20 gradations were obtained.

Example 6 T with a secondary particle size of 50 nm 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 solid content of the coating liquid, siloxane clear
The coating resin was added in an amount of about 30% by weight of the total solid content of the coating liquid, and the Zn porphyrin as a sensitizer for the photocatalyst was added in an amount of about 30% by weight of the total solid content of the coating liquid. This coating liquid is pulled up to an aluminum drum and applied by a coating method, and the formed photocatalyst layer is dried at 100 ° C. for a whole day and night,
A plate-forming drum having a photocatalytic layer having a film thickness of 10 μm was obtained.
When an image was output using this plate-forming drum in the same manner as in Example 5, an image could be obtained with good reproducibility. Further, when the light irradiation amount by the laser was changed and an image of a gray pattern was output, 20 gradations were obtained.

Example 7 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed in a solid content weight ratio of 50:50 to adjust the solid content concentration to 10% by weight and the pH to 1.5. Furthermore, a propanol solution of Zn porphyrin was added to this solution so that the amount of Zn porphyrin added was 30% by weight of the total solid content of the coating solution to prepare a coating solution. This coating liquid was pulled up and coated on an aluminum drum by a coating method to form a photocatalyst layer, and dried at 100 ° C. for 24 hours. This coating and drying were repeated until the thickness of the photocatalyst layer after drying was 5 μm, and a plate forming drum was obtained. An image was output in the same manner as in Example 5 except that a ZnO-based phosphor head with a peak wavelength of 505 nm was used as an exposure light source, and an image could be obtained with excellent reproducibility. Further, here, when the light irradiation amount by the phosphor head was changed to output an image of a gray pattern, 20
Gradation was obtained.

Example 8 T having a secondary particle size of 50 nm 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 solid content of the coating liquid, siloxane clear
The coating resin was added in an amount of about 30% by weight of the total solid content of the coating liquid, and the Zn porphyrin as a sensitizer for the photocatalyst was added in an amount of about 30% by weight of the total solid content of the coating liquid. This coating liquid is pulled up to an aluminum drum and applied by a coating method, and the formed photocatalyst layer is dried at 100 ° C. for a whole day and night,
A plate-forming drum having a photocatalytic layer having a film thickness of 10 μm was obtained.
Using this plate-forming drum, Zn with a peak wavelength of 505 nm
An image was output in the same manner as in Example 5 except that exposure was performed using an O-based phosphor head, and it was possible to obtain an image with good reproducibility. Further, when the light irradiation amount by the laser was changed and an image of a gray pattern was output, 20 gradations were obtained.

Example 9 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed in a solid content weight ratio of 50:50 to adjust the solid content concentration to 10% by weight and the pH to 1.5. This coating solution is applied to an aluminum drum by a spray coating method to form a photocatalyst layer,
After being allowed to stand at 1 ° C. for 1 hour, a plate-forming drum having a photocatalyst layer thickness of 3.5 μm was obtained. After initializing the resulting plate-forming drum, it was imagewise exposed to UV light at a wavelength of 388 nm and then treated with a water roller moistened with water to wash the exposed areas. Next, the ink roller immersed in the ink reservoir containing the water-based ink was pressed against the plate-forming drum to supply the water-based ink to the exposed portion of the plate-forming drum.
The excess ink adhering to the unexposed areas of the plate-forming drum was then removed and treated with a squeeze roller to control the thickness of the ink layer in the exposed areas. Further, by pressing a transfer roller via paper against the drum, the ink on the plate forming drum was transferred to the paper, and a clear image was obtained. The ink remaining on the drum without being transferred to the paper is removed by the cleaning roller, and then the part irradiated with light is initialized by the initialization roller, and the plate forming drum is in the state where the whole is initialized again. It was This light irradiation, ink adhesion, transfer of ink to paper, cleaning, and initialization were set as one cycle, and the image was output again by this cycle. As a result, an image could be obtained with excellent reproducibility.

Example 10 T with a secondary particle size of 50 nm adjusted to pH 0.8 with nitric acid
A coating solution was obtained by adding a siloxane clear coat resin having water repellency and a propanol solution containing a curing agent to the iO ₂ sol. TiO ₂ was added in an amount of about 40% by weight of the total solid content of the coating liquid, and the siloxane clear coat resin was added in an amount of about 50% by weight of the total solid content of the coating liquid. This coating liquid was pulled up on an aluminum drum and applied by a coating method, and the formed photocatalytic layer was dried at 150 ° C. for 1 hour to obtain a plate forming drum having a photocatalytic layer with a film thickness of 5 μm. When an image was output using this plate-forming drum in the same manner as in Example 9, an image could be obtained with good reproducibility.

Example 11 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed in a solid content weight ratio of 50:50 to adjust the solid content concentration to 10% by weight and the pH to 1.5. Furthermore, a propanol solution of Zn porphyrin was added to this solution so that the amount of Zn porphyrin added was 30% by weight of the total solid content of the coating solution to prepare a coating solution. This coating solution was pulled up and coated on an aluminum drum by a coating method to form a photocatalyst layer, which was dried at 100 ° C. for a whole day and night to obtain a plate forming drum having a photocatalyst layer thickness of 5 μm after drying. An image was output in the same manner as in Example 9 except that this plate-forming drum was used and visible light having a wavelength of 532 nm was used as the exposure light, and an image could be obtained with excellent reproducibility.

Example 12 T having a secondary particle size of 50 nm 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 solid content of the coating liquid, siloxane clear
The coating resin was added in an amount of about 30% by weight of the total solid content of the coating liquid, and the Zn porphyrin as a sensitizer for the photocatalyst was added in an amount of about 30% by weight of the total solid content of the coating liquid. This coating liquid is pulled up to an aluminum drum and applied by a coating method, and the formed photocatalyst layer is dried at 100 ° C. for a whole day and night,
A plate-forming drum having a photocatalytic layer having a film thickness of 10 μm was obtained.
Using this plate-forming drum, the irradiation light has a wavelength of 532.2.
When an image was output in the same manner as in Example 9 except that visible light of nm was used, the image could be obtained with good reproducibility.

Example 13 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
m SiO ₂ sol is mixed at a predetermined ratio to obtain a solid content concentration of 1
After adjusting to 0 wt% and pH 1.5, the coating solution was applied onto an aluminum drum by a spray coating method to obtain a film having a film thickness of 3.5 μm. The coating 150
The plate-forming drum was obtained by drying at 0 ° C. for 1 hour. After initializing the prepared plate-forming drum, information was written by irradiating with ultraviolet light of 388 nm, and the information writing portion on the drum was washed with a water roller moistened with water. Next, press the ink roller immersed in the ink reservoir against the plate forming drum,
The aqueous ink was supplied to the hydrophilic part of the plate forming drum. Excess ink adhering to the area where no information was written on the plate forming drum was removed with a squeeze roller. Further, a transfer roller via paper was pressed against the drum to transfer the ink on the plate forming drum to the paper, and a clear image sample was obtained. Ink remaining on the drum without being transferred to paper was removed by a cleaning roller. The hydrophilic portion in which the information was written was passed through an initializing roller for returning it to the hydrophobic state again, and the entire surface of the image forming body was made in the hydrophobic state before the damage to the information. This writing, ink adhesion, transfer of ink to paper, cleaning, and initialization were set as one process, and the image sample was output again by this process, and an image with good reproducibility was obtained.

[0096] The TiO ₂ sol secondary particle diameter 50nm, adjusted to pH about 0.8 by Example 14 nitric acid, siloxane clear having water repellency
A coating agent obtained by adding a propanol containing a coating resin and a curing agent was applied onto an aluminum drum by a coating method. The film was dried at 150 ° C. for 1 hour to obtain a plate forming drum having a hydrophobic film with a film thickness of 5 μm. The ratio of the siloxane clear coat resin added was about 50 wt% of the solid content of the TiO ₂ sol. When an image sample was output using the same image output process as in Example 13, an image was obtained with good reproducibility.

Example 15 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
m SiO ₂ sol was mixed at a predetermined ratio. At this time, the solid content concentration was adjusted to 10 wt% and the pH was adjusted to 1.5. Further, propanol containing Zn porphyrin was added to this solution to obtain a coating agent. A hydrophobic photosensitive layer having a film thickness of 10 μm was obtained by pulling it up on an aluminum drum and coating it by a coating method. The layer was dried overnight at 100 ° C. to obtain a plate-forming drum. Example 13 except using visible light of 532 nm
When an image sample was output using the same image output process as above, an image with good reproducibility was obtained.

Example 16 A TiO ₂ sol having a secondary particle size of 50 nm adjusted to a pH of about 0.8 with nitric acid was added to water-repellent siloxane clear.
The coating agent obtained by adding the coating resin, the curing agent and the propanol containing Zn porphyrin was applied onto the aluminum drum by the coating method. The coating 10
It was dried at 0 ° C for a whole day and night to obtain a plate-forming drum having a hydrophobic photosensitive layer with a film thickness of 10 µm. The ratio of siloxane clear coat resin added is about 30% of the solid content of TiO ₂ sol.
Zn porphyrin, which is a photocatalyst sensitizer, was also added in an amount of about 30 wt% of the solid content of the TiO ₂ sol. 532
An image sample was output using the same image output process as in Example 13 except that visible light of nm was used.
Images were obtained with good reproducibility.

Example 17 Titanium pipe having a diameter of 30 mm (length 250 mm, thickness 1)
(mm) surface was heated in air to form a titanium oxide film, and a plate forming drum holding titanium oxide having a photocatalytic ability on the surface was produced. After initializing this drum,
Information was written by irradiating with 388 nm ultraviolet light, and the information writing portion on the drum was washed with a water roller moistened with water. Next, the ink roller immersed in the ink reservoir was pressed against the plate forming drum to supply the water-based ink to the hydrophilic portion of the image forming body. Excess ink adhering to the area where no information was written on the plate forming drum was removed with a squeeze roller. Furthermore, the ink on the plate forming drum was transferred onto the paper by pressing the transfer roller via the paper against the drum, and a clear image sample was obtained. Ink remaining on the drum without being transferred to paper was removed by a cleaning roller. The hydrophilic portion in which the information was written was passed through an initialization roller for returning it to the hydrophobic state again, and the entire surface of the image forming body was made in the hydrophobic state before writing the information. This writing, ink adhesion, transfer of ink to paper, cleaning, and initialization were set as one process, and image samples were output again by this process, and an image with good reproducibility was obtained.

Example 18 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
m SiO ₂ sol is mixed at a predetermined ratio to obtain a solid content concentration of 1
After adjusting to 0 wt% and pH 1.5, the coating solution was applied onto an aluminum drum by a spray coating method to obtain a film having a thickness of 3.2 μm. The coating 15
The plate-forming drum was obtained by drying at 0 ° C. for 1 hour. This plate forming drum was attached to the image forming apparatus shown in FIG. A hydrophobic coating is formed on the plate forming drum with an initialization roller. Next, information was written by irradiating 388 nm ultraviolet light as image information, and the information writing portion on the drum was washed with a water roller moistened with water. Next, the ink roller immersed in the ink reservoir was pressed against the plate forming drum to supply the water-based ink to the hydrophilic portion of the image forming body. Excess ink adhering to the area where no information was written on the plate forming drum was removed with a squeeze roller. Furthermore, the ink on the plate forming drum was transferred onto the paper by pressing the transfer roller via the paper against the drum, and a clear image sample was obtained. The ink remaining on the drum without being transferred to the paper was removed by a cleaning roller.
Then, light was irradiated by a history erasing device provided in FIG. 4B in which a fluorescent lamp-shaped ultraviolet lamp was arranged to forcibly decompose the undecomposed hydrophobic substance. In addition,
A 20 W ultraviolet lamp was used. This initialization, writing, ink adhesion, ink transfer to paper,
When cleaning and history erasure were set as one process, and an image sample was output again by this process, an image with good reproducibility was obtained. The image density measured by a Macbeth densitometer by this method was 1.48. There was no dirt on the ground.

Example 19 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
m SiO ₂ sol is mixed at a predetermined ratio to obtain a solid content concentration of 1
After adjusting to 0 wt% and PH 1.5, the coating solution was applied onto an aluminum drum by a spray coating method to obtain a film having a thickness of 3.2 μm. The coating 15
The plate-forming drum was obtained by drying at 0 ° C. for 1 hour. This plate forming drum was attached to the image forming apparatus shown in FIG. A hydrophobic coating is formed on the plate forming drum with an initialization roller. Next, information was written by irradiating 388 nm ultraviolet light as image information, and the information writing portion on the drum was washed with a water roller moistened with water. Next, the ink roller immersed in the ink reservoir was pressed against the plate forming drum to supply the aqueous ink to the hydrophilic portion of the plate forming drum. Excess ink adhering to the area where no information was written on the plate forming drum was removed with a squeeze roller. Furthermore, the transfer roller via paper was pressed against the drum to transfer the ink on the plate forming drum to the paper, and a clear image sample was obtained. Thereafter, light was irradiated by a history erasing device provided with a fluorescent lamp-shaped ultraviolet lamp provided in A of FIG. 4 to forcibly decompose the undecomposed hydrophobic substance. It should be noted that the ultraviolet lamp 20W
I used the one. Next, the ink which was not transferred to the paper and remained on the drum was removed by a cleaning roller. This process of initialization, writing, ink adhesion, ink transfer to paper, history deletion, and cleaning was one process, and when image samples were output again by this process, images with good reproducibility were obtained. The image density measured by a Macbeth densitometer by this method was 1.47. There was no dirt on the ground.

Embodiment 20 Explanation will be given with reference to FIG. 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 predetermined ratio to adjust the solid content concentration to 10 wt% and the pH to 1.5, and then the coating solution was applied onto an aluminum drum. It was applied by a spray coating method to obtain a film having a thickness of 4.2 μm. The film was dried at 150 ° C. for 1 hour to obtain a plate forming drum. This plate forming drum was attached to the image forming apparatus shown in FIG. A hydrophobic coating is formed on the plate forming drum 40 by the initialization roller 42. Next, as the image information, the information is written by irradiating 388 nm ultraviolet light from the light source 44, and the water roller 45 is moistened with water.
The information writing part on the drum was washed with. Next, the ink roller 46 immersed in the ink reservoir was pressed against the plate forming drum 40 to supply the aqueous ink to the hydrophilic portion of the plate forming drum. Excess ink adhering to the portion of the plate forming drum where no information was written was removed by the squeeze roller 47. Further, by pressing the transfer roller 48 via the paper 49 to the drum, the ink on the plate forming drum was transferred to the paper, and a clear image sample was obtained. Thereafter, light was irradiated by a history erasing device provided with a fluorescent lamp-shaped ultraviolet lamp provided in A of FIG. 4 to forcibly decompose the undecomposed hydrophobic substance. The UV lamp used was 10 W. Next, the ink which was not transferred to the paper and remained on the drum was removed by a cleaning roller. Further, by irradiating light with a history erasing device arranged with a fluorescent lamp-shaped ultraviolet lamp arranged in B of FIG. 4,
Undegraded hydrophobic material was forced to degrade. The UV lamp used was 10 W. This initialization, writing, ink adhesion, ink transfer to paper, history erasure, cleaning, history erasure were set as one process, and an image sample was output again by this process, and an image with good reproducibility was obtained. The image density measured by a Macbeth densitometer by this method was 1.47.
There was no dirt on the ground.

Embodiment 21 With the structure of Embodiment 18, the history erasing device has a structure as shown in FIG. The light source 151 has a wavelength of 333.7 nm and an output of 1.
The polygon mirror 153 that rotates at a high speed was irradiated with a 2 W nitrogen laser and reflected, and the plate forming drum shape was scanned in the length direction. Image formation was performed under the same conditions as in Example 18. The image was output repeatedly, but an image with good reproducibility was obtained even in this process. The image obtained by this method has an image density of 1.46 measured by a Macbeth densitometer.
Met. There was no dirt on the ground.

Embodiment 22 With the structure of Embodiment 18, the history erasing device has a structure as shown in FIG. The light source 151 has a wavelength of 330 nm and an output of 55 mw
The He-Cd laser was used to irradiate the polygon mirror 153 which rotates at a high speed and reflect the polygon mirror 153 to scan the plate forming drum shape in the length direction. Image formation was performed under the same conditions as in Example 18. The image was output repeatedly, but an image with good reproducibility was obtained even in this process. The image obtained by this method had an image density of 1.4 measured by a Macbeth densitometer. There was no dirt on the ground.

Twenty- third Embodiment With the structure of the eighteenth embodiment, the history erasing device has a structure as shown in FIG. A polygon mirror 1 that rotates at a high speed by using a semiconductor laser having a wavelength of 440 nm and an output of 5 mW as a light source 151.
The plate forming drum shape was scanned in the lengthwise direction by irradiating it to 53 and reflecting it. Image formation was performed under the same conditions as in Example 18. The image was output repeatedly, but an image with good reproducibility was obtained even in this process. The image obtained by this method had an image density of 1.42 measured by a Macbeth densitometer. There was no dirt on the ground.

Embodiment 24 With the structure of Embodiment 18, the history erasing device has a structure as shown in FIG. Light source 151 has wavelength 420 nm, output 1500
An LED with mcd and diameter of 5φ arranged in the longitudinal direction at intervals of 1 mm was used. Image formation was performed under the same conditions as in Example 18. The image was output repeatedly, but an image with good reproducibility was obtained even in this process. The image density of the image obtained by this method was 1.44 as measured by a Macbeth densitometer. There was no dirt on the ground.

Embodiment 25 With the structure of Embodiment 18, the history erasing device has a structure as shown in FIG. As the light source 151, an EL light emitting element that emits ultraviolet rays, for example, one using ZnF ₂ : Cd ³⁺ was arranged. Image formation was performed under the same conditions as in Example 18. The image was output repeatedly, but an image with good reproducibility was obtained even in this process. An image obtained by this method had an image density of 1.48 measured by a Macbeth densitometer. There was no dirt on the ground.

Embodiment 26 With the structure of Embodiment 18, the history erasing device has a structure as shown in FIG. A ball-shaped mercury lamp was used as the light source 151. A quartz lens was used to collect the light and create a rectangular light so that it could be applied to the plate-forming drum. Image formation was performed under the same conditions as in Example 18. I output the image repeatedly,
Images with good reproducibility were obtained even in this process. The image density of the image obtained by this method was 1.41 as measured by a Macbeth densitometer. There was no dirt on the ground.

Embodiment 27 With the structure of Embodiment 18, the history erasing device has a structure as shown in FIG. FIG. 18 is a side perspective view. Light source 1
A 81 xenon lamp was installed. Furthermore, a cover with a mirror surface is placed on the inner surface of the semi-cylindrical shape to increase the light collection rate. This xenon lamp is driven by a high voltage power source (not shown), and has the capability of continuously emitting white pulsed light. Example 1
Image formation was performed under the same conditions as in No. 8. The image was output repeatedly, but an image with good reproducibility was obtained even in this process. The image density of the image obtained by this method measured by a Macbeth densitometer was 1.4. There was no dirt on the ground.

Example 28 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 predetermined ratio to obtain a solid concentration of 1
After adjusting to 0 wt% and pH 1.5, apply the coating solution to SU
Applying to S flat plate by dipping method, film thickness is 4.7μ
m coating was obtained. The film was dried at 150 ° C. for 1 hour to obtain a plate forming plate. An image was formed using this plate forming plate by the process shown in FIG. First, an initialization step of forming a hydrophobic coating on the plate forming plate with an initialization roller is performed. Next, a latent image forming step of writing information by irradiating 388 nm ultraviolet light through a mask image as image information, then a developing step of supplying an aqueous ink to a hydrophilic portion with an ink roller to develop the image, and a paper A transfer step of transferring the ink on the plate-forming drum to the paper by pressing the transfer roller via the transfer roller to the drum was performed, and a clear image sample was obtained. Finally, a history erasing device provided with an ultraviolet lamp was irradiated with light to forcibly decompose the undecomposed hydrophobic substance. The UV lamp used was 20W. This initialization step, latent image forming step, developing step, transfer step, and history erasing step were repeated 200 times. The image sample output was an image with good reproducibility. The image density of the obtained image by the Macbeth densitometer was always 1.45. There was no dirt on the ground.

Comparative Example 1 In the structure of Example 28, when the history erasing step was not carried out, a decrease in density was observed after three times of repeated printing, and
At the first time, the image density dropped to 0.55. It is presumed that the cause is that the hydrophobic coating applied in the initialization step gradually became thicker due to the repetition of image formation, and it became difficult to form a hydrophilic portion on the plate forming plate to which the hydrophilic ink could adhere.

Comparative Example 2 In the structure of Example 18, when the history erasing step was not carried out, a decrease in density was recognized after four repeated printings, and
At the first time, the image density dropped to 0.21. It is presumed that the cause is that the hydrophobic coating applied in the initialization step gradually became thicker due to the repetition of image formation, and it became difficult to form a hydrophilic portion on the plate forming plate to which the hydrophilic ink could adhere.

Example 29 TiO ₂ fine particles having a secondary particle size of 50 nm and linoleic acid were mixed at a weight ratio of 50:50 to obtain a coating agent for a hydrophobic photosensitive layer. The coating agent for the hydrophobic photosensitive layer was supplied to the layer forming roller so that the hydrophobic photosensitive layer was formed on the substrate from the layer forming roller (initializing member). Information was written by irradiating 388 nm ultraviolet light to the image forming body having the hydrophobic photosensitive layer in this way, and the information writing portion on the image forming body was washed with a water roller moistened with water. Next, the ink roller immersed in the ink reservoir was pressed against the image forming body to supply the aqueous ink to the hydrophilic portion of the image forming body. Excess ink adhering to a portion of the image forming body where no information was written was removed with a squeeze roller. Furthermore, the ink on the image forming body is transferred to the paper by pressing the transfer roller via the paper to the image forming body,
A clear image sample was obtained. Ink remaining without being transferred to the paper was removed by a cleaning roller. It is possible to return the hydrophilic portion in which the information has been written to the hydrophobic state again by passing the hydrophilic portion again through the layer forming roller.
That is, the image forming body is initialized by supplying a new hydrophobic photosensitive coating agent by the layer forming roller and homogenizing the layer. This writing, ink adhesion, ink transfer to paper, cleaning, and initialization were set as one process, and an image sample was output again by this process, and an image with good reproducibility was obtained.

Example 30 Image similar to Example 29 except that TiO ₂ fine particles having a secondary particle size of 50 nm and liquid paraffin were mixed at a weight ratio of 50:50 to prepare a coating agent for the hydrophobic photosensitive layer. When an image sample was output using the output process, an image was obtained with good reproducibility.

Example 31 TiO ₂ fine particles having a secondary particle size of 50 nm, palmitic acid, and Zn porphyrin as a sensitizer were added in a weight ratio of 45:
The mixture was mixed at a ratio of 45:10 to obtain a coating agent for hydrophobic photosensitive layer. Example 2 except that visible light of 532 nm was used for exposure
An image sample was output using the same image output process as in No. 9, and an image was obtained with good reproducibility.

Example 32 <Photoreceptor> 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 are used in a solid content weight ratio of 50: 5.
Mix at a ratio of 0, solid content concentration 10 wt%, pH 1.5
To adjust the coating solution. This coating liquid was applied on an aluminum drum by a spray coating method to a film thickness of 1 μm to form a film, and the film was dried at 150 ° C. for 1 hour to obtain a plate forming drum.

<Initializing Member> In this embodiment, the vapor generating device using the ultrasonic oscillator shown in FIG. 6 was used as the initializing member 32. Palmitic acid was used as the hydrophobizing agent.

<Uniformizing Member> In this embodiment, the uniformizing member 33 is a blade-shaped member shown in FIG. 11, and silicone rubber is used as the material for the uniformizing member.

<Light Source> In this example, an argon ion laser having a wavelength of 363.8 nm was used as the light source 34 for forming a latent image.

<Light source for erasing latent image> In this example, an ultraviolet fluorescent lamp was used as a light source for erasing the latent image.

<Image Forming Apparatus and Image Forming by It> An image forming apparatus as shown in FIG. 4 was produced from the above-mentioned members and other members, and images were formed. In the image forming apparatus as shown in FIG. 4, the plate forming drum is rotating in the direction of the arrow in the figure, and the image forming process proceeds with the rotation.

First, the plate forming drum 40 has an initialization member 42.
By means of which a hydrophobizing agent (palmitic acid) is applied, whereby a hydrophobic film is formed on the plate forming drum. This coating is then made uniform in thickness by the homogenizing member 43 . The plate forming drum provided with a uniform hydrophobic layer is then imagewise exposed by a light source 44 . The hydrophobizing agent in the exposed portion on the plate forming drum is removed by the photocatalytic decomposition reaction to remove the hydrophobizing agent in the exposed portion. Subsequently, the ink supply member 46 supplies the water-based ink to the plate forming drum. The water-based ink adheres to the area where the hydrophobizing agent has been removed, but since the excess ink also adheres to other areas, this excess ink is removed by the squeeze member 47 . Further, a clear image was obtained by pressing the support 49 to the plate forming drum by the transfer member 48 . The ink that is not transferred and remains on the support 49 is subsequently removed by the cleaning member 41 . Therefore, the entire cleaned photoreceptor was irradiated with light of an ultraviolet fluorescent lamp, and the strong oxidizing power of the photocatalyst was used for the hydrophobic agent on the surface of the photoreceptor, whereby the hydrophobic agent was decomposed and the latent image was erased. In this way, a clear image could be obtained by the image forming apparatus of the present invention.

[0123] In addition, further through the process, on the plate forming drum, the initial site subjected to the image formation again of member 42
And and and / or the uniform member 43 is used to initialize the entire surface of the plate-forming drum to a hydrophobic state before exposure. From this state, exposure, ink supply, transfer of ink to a support, cleaning, latent image formation Erase by exposure and initialization 1
When the image was formed by this process again in cycles, it was possible to obtain an image with excellent reproducibility.

Example 33 A siloxane clear having water repellency was added to a TiO ₂ sol having a secondary particle size of 50 nm adjusted to a pH of about 0.8 with nitric acid.
A coating resin was obtained by adding a coating resin and propanol containing a curing agent. TiO ₂ is about 5% of the total solid content of the coating liquid.
0% by weight, and the siloxane clear coat resin was added so that the ratio of the total solid content of the coating liquid was about 50% by weight. This coating liquid was pulled up to an aluminum drum and applied by a 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 with a film thickness of 1.5 μm. An image was output in the same manner as in Example 32 by using, and it was possible to obtain an image with good reproducibility.

Example 34 Image output was tried in the same manner as in Example 32 except that a CO ₂ laser was used instead of an argon ion laser as the exposure member 34 for forming a latent image, and excellent reproduction was obtained. I was able to get an image by sex.

Example 35 An image output was attempted in the same manner as in Example 32 except that linoleic acid was used instead of palmitic acid as the hydrophobizing agent used for initialization, and an image with excellent reproducibility was obtained. I was able to get

Example 36 Similar to Example 32, except that a silicone foam member having a roller shape as shown in FIG. 8 and having a hydrophobizing agent absorbed therein was used as the initialization member. When an image output was attempted by the method, an image could be obtained with excellent reproducibility.

Example 37 An image output was tried in the same manner as in Example 32 except that a silicone foam member having a roller shape as shown in FIG. 13 was used as the uniformizing member. An image could be obtained with excellent reproducibility.

Example 38 An image output was tried in the same manner as in Example 1 except that an oil-based ink was used in place of the water-based ink as the ink to be used. I was able to get an image, a negative.

Example 39 TiO ₂ sol having a secondary particle size of 50 nm and a secondary particle size of 10 n
The SiO ₂ sol of m was mixed at a solid content weight ratio of 50:50 to adjust the solid content concentration to 10 wt% and the pH to 1.5.
Furthermore, the amount of Zn porphyrin added to this solution was 3% of the total solids of the coating solution.
A coating solution was prepared by adding so as to be 0% by weight. This coating solution was pulled up and coated on an aluminum drum by a coating method to form a photocatalyst layer, and dried at 100 ° C. for 24 hours.
This step of coating and drying was repeated until the thickness of the photocatalyst layer after drying was 1 μm, and the plate forming drum was obtained. As a latent image erasing exposure member to be used, a wavelength of 543.5 nm was used instead of an ultraviolet fluorescent lamp. When an image output was tried in the same manner as in Example 32 except that the He-Ne laser of No. 1 was used, an image could be obtained with excellent reproducibility.

Example 40 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed at a ratio of 50:50 in terms of solid content weight ratio and adjusted to a solid content concentration of 10 wt% and pH 1.5 to prepare a coating solution. This coating solution is pulled up and coated on an aluminum drum by a coating method to form a photocatalyst layer.
It was dried overnight at 0 ° C. The thickness of the photocatalyst layer after drying is 1
This coating -drying process was repeated until the thickness became μm to obtain a plate forming drum. The plate forming drum was attached to an image forming apparatus to perform image formation.

First, the steps from the formation of the hydrophobic coating to the formation of a latent image by light irradiation were carried out in the same manner as in Example 32. after that,
A phenylene diacrylate photosensitive resin was spray-coated on the surface of the photosensitive member, and the photosensitive resin was irradiated with ultraviolet rays having a wavelength that hardens the photosensitive resin. As a result of visual inspection, the photosensitive resin adhered only to the hydrophobic layer of the photoconductor, and the resin was cured.

The same initializing, homogenizing and exposing steps as in Example 32, and further a photosensitive resin coating and curing exposing step, followed by ink adhesion and ink transfer to paper, as a result, a clear image is obtained. I was able to. Further, when this photoconductor was repeatedly used, the printing durability was very excellent.

After printing, when the entire surface of the photoconductor is irradiated with ultraviolet rays having a wavelength that causes a photocatalytic decomposition reaction, the photocurable resin on the photoconductor is decomposed by the strong oxidizing power of the photocatalyst, and the surface of the photoconductor is The entire surface of the photocatalyst layer was exposed.

After this step, further initialization, homogenization,
As a result of performing the steps of exposure, application of a photosensitive resin, and curing exposure, and ink adhesion and transfer of ink to paper, an image could be obtained with excellent reproducibility.

Example 41 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed at a solid content weight ratio of 50:50 to adjust the solid content concentration to 10 wt% and the pH to 1.5. Further, a propanol solution containing Zn porphyrin was added to this solution so that the amount of Zn porphyrin added was about 30% by weight of the total solids of the coating solution to prepare a coating solution. This coating liquid was pulled up to an aluminum drum and applied by a coating method, and the formed photocatalyst layer was dried at 100 ° C. for a day and night to obtain a plate forming drum having a photocatalyst layer with a film thickness of 1 μm. When an image was output using this plate-forming drum in the same manner as in Example 40, an image with excellent reproducibility could be obtained.

Example 42 A TiO ₂ sol having a secondary particle size of 50 nm adjusted to a pH of about 0.8 with nitric acid was added to water-repellent siloxane clear
A coating resin, a curing agent, and propanol containing Zn porphyrin were added to obtain a coating solution. TiO ₂ is about 40% by weight of the total solid content of the coating solution, siloxane clear coat resin is about 30% by weight of the total solid content of the coating solution, and Zn porphyrin which is a photocatalyst sensitizer is the coating solution. It was added in a proportion of about 30% by weight of the total solid content. This coating liquid is pulled up to an aluminum drum and applied by a coating method, and the formed photocatalyst layer is dried at 100 ° C. for a whole day and night to give a film thickness of 1 μm.
A plate-forming drum having the photocatalytic layer of was obtained. When an image was output using this plate-forming drum in the same manner as in Example 40, an image with excellent reproducibility could be obtained.

Example 43 An image output was tried in the same manner as in Example 40 except that an oil-based ink was used in place of the water-based ink as the ink to be used. I was able to get an image, a negative.

Example 44 Image output was carried out in the same manner as in Example 32 except that cooling water was caused to flow in the plate forming drum during the exposure step for writing a latent image to keep the temperature of the drum surface at 100 ° C. or lower. When we tried, we were able to obtain images with excellent reproducibility. Further, the number of times of rewriting the latent image on the plate-forming drum was improved twice as compared with the case where the plate-forming drum was not cooled.

Example 45 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed at a solid content weight ratio of 50:50 to adjust the solid content concentration to 10 wt% and the pH to 1.5 to adjust the coating solution. The coating solution was spray-coated to an aluminum drum. To form a photocatalyst layer and dried at 150 ° C. for 1 hour to obtain a plate-forming drum having a photocatalyst layer thickness of 1.5 μm.

The plate-forming drum obtained was imagewise exposed with a YAG laser and then treated with a water roller moistened with water to wash the exposed areas. Next, the ink roller immersed in the ink reservoir containing the water-based ink was pressed against the plate-forming drum to supply the water-based ink to the exposed portion of the plate-forming drum. The excess ink adhering to the unexposed areas of the plate-forming drum was then removed and treated with a squeeze roller to control the thickness of the ink layer in the exposed areas. Further, by pressing a transfer roller via paper against the drum, the ink on the plate forming drum was transferred to the paper, and a clear image was obtained. The ink remaining on the drum without being transferred to the paper is removed by the cleaning roller, and then the light-irradiated portion is initialized by the initialization roller, and the plate-forming drum is in the state of being initialized again. It was This light irradiation, ink adhesion, transfer of ink to paper, cleaning, and initialization were set as one cycle, and the image was output again by this cycle. As a result, an image could be obtained with excellent reproducibility.

Example 46 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
The SiO ₂ sol of m was mixed at a solid content weight ratio of 50:50 to adjust the solid content concentration to 10 wt% and the pH to 1.5. Furthermore, a propanol solution containing Zn porphyrin was added to this solution so that the added weight of Zn porphyrin would be about 30% by weight of the total solids of the coating solution to prepare a coating solution. This coating liquid was pulled up to an aluminum drum and applied by a coating method, and the formed photocatalyst layer was dried at 100 ° C. for a day and night to obtain a plate forming drum having a photocatalyst layer with a film thickness of 1 μm. When an image was output using this plate-forming drum in the same manner as in Example 45, an image with excellent reproducibility could be obtained.

Example 47 A TiO ₂ sol having a secondary particle size of 50 nm adjusted to a pH of about 0.8 with nitric acid was added to a water-repellent siloxane clear solution.
A coating resin, a curing agent, and propanol containing Zn porphyrin were added to obtain a coating solution. TiO ₂ is about 40% by weight of the total solid content of the coating solution, siloxane clear coat resin is about 30% by weight of the total solid content of the coating solution, and Zn porphyrin which is a photocatalyst sensitizer is the coating solution. It was added in a proportion of about 30% by weight of the total solid content. This coating liquid is pulled up to an aluminum drum and applied by a coating method, and the formed photocatalyst layer is dried at 100 ° C. for a whole day and night to give a film thickness of 1 μm.
A plate-forming drum having m photocatalytic layers was obtained. An image was output in the same manner as in Example 45 except that this plate forming drum was used and the exposure light source member was an argon ion laser, and an image with excellent reproducibility was obtained.

Example 48 An image output was tried in the same manner as in Example 45 except that an oil-based ink was used in place of the water-based ink as the ink to be used, and as a result, a portion of the portion not irradiated with light was excellent in reproducibility. I was able to get an image, a negative.

Example 49 TiO ₂ sol having a secondary particle size of 50 nm and a secondary particle size of 10 n
m SiO ₂ sol was mixed at a predetermined ratio to adjust the solid content concentration to 10 wt% and the pH to 1.5, and then the coating solution was applied onto a quartz substrate by spin coating at 1500 rpm for 10 seconds. A photocatalytic coating having a film thickness of 0.44 m was obtained. After the coating was dried at 150 ° C. for 1 hour, oleic acid as a hydrophobizing agent was applied to the surface of the coating to prepare an image forming body. To the produced image forming body 388n
A latent image was written by irradiating m of ultraviolet light with an Ar ⁺ laser, and a 1 mM silver nitrate aqueous solution was poured onto the latent image portion to irradiate white light to deposit silver. After that, the entire surface of the image forming body was irradiated with ultraviolet rays to decompose the oleic acid in the area where silver did not adhere, thereby forming a pattern.

Example 50 An image-formed body was prepared in the same manner as in Example 49, and a latent image was written by irradiating an ultraviolet light of 388 nm with an Ar ⁺ laser, and a commercially available electroless gold plating solution was poured onto the latent image portion to cast a metal. It was left to stand until it was deposited, and gold was deposited. After that, the entire surface of the image forming body was irradiated with ultraviolet rays to decompose the organic matter in the portion where the gold was not adhered, thereby preparing a pattern.

Example 51 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
m SiO ₂ sol was mixed at a predetermined ratio. At this time, the solid content concentration was adjusted to 10 wt% and the pH was adjusted to 1.5. Further, propanol containing Zn porphyrin was added to this solution to obtain a coating solution. This coating solution is spun onto a quartz substrate at a rotation speed of 150.
It was applied by spin coating at 0 rpm for 10 seconds to obtain a photocatalytic coating having a film thickness of 0.4 μm. After the coating was dried at 150 ° C. for 1 hour, oleic acid as a hydrophobizing agent was applied to the surface of the coating to prepare an image forming body. A 532 nm visible light was irradiated to the produced image forming body using an Nd: YAG laser, and a pattern was formed in the same manner as in Example 49.

Example 52 To a TiO ₂ sol having a secondary particle size of 50 nm adjusted to a pH of about 0.8 with nitric acid, a water-repellent siloxane clear
A coating solution obtained by adding a coating resin, a curing agent and propanol containing Zn porphyrin was applied onto a quartz substrate by a coating method, and the coating film was dried at 100 ° C. for one day to obtain a photocatalytic layer having a thickness of 10 μm. It was About 30 wt% ratio of siloxane clear coat resins of the TiO ₂ sol having a solid content to be added, which is a sensitizing agent photocatalyst Zn porphyrins also about 30 wt% of the solid of the TiO ₂ sol matter
Was added. A visible light of 532 nm was irradiated onto the produced image forming body using an Nd: YAG laser to form a pattern in the same manner as in Example 49.

Example 53 TiO ₂ sol having a secondary particle size of 50 nm and secondary particle size of 10 n
m SiO ₂ sol was mixed at a predetermined ratio. At this time, the solid content concentration was adjusted to 10 wt% and the pH was adjusted to 1.5. Further, propanol containing Zn porphyrin was added to this solution to obtain a coating solution. This coating solution is spun onto a quartz substrate at a rotation speed of 150.
It was applied by spin coating at 0 rpm for 10 seconds to obtain a photocatalytic coating having a film thickness of 0.44 m. After the coating was dried at 150 ° C. for 1 hour, oleic acid as a hydrophobizing agent was applied to the surface of the coating to prepare an image-formed body.
Visible light of 532 nm was applied to the produced image forming body by Nd: YA
A latent image was written by irradiating it with a G laser, and a commercially available electroless gold plating solution was poured onto the latent image portion and allowed to stand until metal was deposited to deposit gold. After that, by irradiating the entire surface of the image forming body with ultraviolet rays, the organic matter in the portion where the gold is not adhered was decomposed to form a pattern.

[0150]

According to the present invention, an image forming apparatus capable of on-demand printing and having a reduced influence on the human body or the environment, and a pattern formation which is simple and has a reduced influence on the human body or the environment. The method is provided as described above in the Summary of the Invention section.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a photoreceptor according to the present invention.

FIG. 2 is a schematic diagram showing an image forming process by the image forming method of the present invention.

FIG. 3 is a schematic diagram showing an example of an image forming apparatus of the present invention.

FIG. 4 is a schematic diagram showing an example of an image forming apparatus of the present invention.

FIG. 5 is a schematic sectional view of a photoreceptor according to the present invention.

FIG. 6 is a diagram showing an example of an initialization member according to the present invention.

FIG. 7 is a diagram showing an example of an initialization member according to the present invention.

FIG. 8 is a diagram showing an example of an initialization member according to the present invention.

FIG. 9 is a diagram showing an example of an initialization member according to the present invention.

FIG. 10 is a diagram showing an example of an initialization member according to the present invention.

FIG. 11 is a view showing an example of a uniformizing member according to the present invention.

FIG. 12 is a view showing an example of a uniformizing member according to the present invention.

FIG. 13 is a view showing an example of a uniformizing member according to the present invention.

FIG. 14 is a view showing an example of a uniformizing member according to the present invention.

FIG. 15 is a view showing an example of a history erasing member according to the present invention.

FIG. 16 is a view showing an example of a history erasing member according to the present invention.

FIG. 17 is a view showing an example of a history erasing member according to the present invention.

FIG. 18 is a view showing an example of a history erasing member according to the present invention.

FIG. 19 is a schematic diagram showing an example of an image forming apparatus of the present invention.

FIG. 20 is a schematic diagram showing a pattern forming process by the pattern forming method of the present invention.

[Explanation of symbols]

11 board 12 Photocatalyst layer 13 Photocatalyst fine particles 14 Binder material 15 Hydrophobic layer 21 Hydrophobic layer 22 ink 23 Image recording medium 30 Substrate having photocatalyst layer 31 Initialize roller 32 Hydrophobic coating 33 light source 34 mask 35 Latent image formation site 36 ink roller 37 ink 38 image recording medium 39 light source 40 Plate forming drum 41 Cleaning member 42 initialization member 43 Uniformizing member 44 Light source member 45 water roller 46 Ink supply member 47 Squeeze material 48 transfer member 49 Image recording medium 61 Ultrasonic transducer 62 Hydrophobizing agent storage tank 63 Hydrophobizing agent 81 Initialization roller 91 Open / close valve 101 spray nozzle 151 light source 152 lens 153 polygon mirror 154 fθ lens 161 lens 181 reflector 191 A member for supplying a curable substance 192 A member for homogenizing a curable substance 193 A member for curing a curable substance 194 History eraser 201 substrate 202 Photocatalyst layer 203 hydrophobic coating 204 photoconductor 205 Metal ion-containing aqueous solution 206 Metal or metal oxide 207 light source

Front Page Continuation (72) Inventor Yasushi Masatsune 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Research and Development Center (72) Inventor Koichi Tsunemi 1 Komukai-Toshiba, Saiwai-ku, Kawasaki-shi, Kanagawa Stock Company Toshiba Research and Development Center (72) Inventor Mitsunori Saito 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki City, Kanagawa Prefecture Toshiba Research and Development Center (72) Inventor Masahiro Hosoya Small, Kawasaki-shi, Kanagawa Prefecture Small Muko Toshiba-cho 1 Co., Ltd. Toshiba Research and Development Center (56) References JP-A-11-344804 (JP, A) JP-A-9-131914 (JP, A) JP-A-8-81222 (JP, A) Special Kaihei 2-216158 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 5/00

Claims (4)

(57) [Claims] 1. A photoconductor comprising a photocatalyst layer containing a photocatalyst and a hydrophobic layer provided on the photocatalyst layer, wherein the photocatalyst is irradiated with light, whereby the photoconductor surface The photoconductor, which changes the contact angle of the light-irradiated portion with water to cause a difference from the contact angle of the light-irradiated portion with water. (2) Vapor of the hydrophobizing agent To the surface of the photoreceptor,
Initialization means for uniformizing the hydrophobic layer so as to make the contact angle of the surface of the photoconductor with water uniform, (3) exposure means for forming a latent image on the photoconductor initialized by the initialization means, And (4) an image forming apparatus comprising a developing means for developing the formed latent image. 2. A developing means supplies ink to the surface of the photoconductor.
The device of claim 1, wherein the device is (1) A photoconductor comprising a photocatalyst layer containing a photocatalyst and a hydrophobic layer provided on the photocatalyst layer, wherein the photocatalyst is irradiated with light, whereby the photoconductor surface Of the photosensitive member, which changes the contact angle of the light-irradiated portion with water to produce a difference with the contact angle of the light-irradiated portion with water. (2) The surface of the photosensitive member Initialization means for uniformizing the hydrophobic layer so as to make the contact angle with water uniform, (3) exposure means for forming a latent image on the photoreceptor initialized by the initialization means, (4) latent image An image forming apparatus comprising: a curing unit configured to cure a hydrophobic layer in a portion where no image is formed; and (5) a developing unit configured to develop the formed latent image. 4. A developing means supplies ink to the surface of the photoconductor.
The device of claim 3, wherein the device is