JPH09101633A - Method and device for forming electrophotographic process printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer method of high durability in repeatedly using a photoreceptor and an intermediate transfer body by contact-transferring a toner image formed on the photoreceptor by liquid developer through the intermediate transfer body, forming an excellent transfer image on a planographic printing supporting body and forming a process printing plate. SOLUTION: The toner image is formed on the surface of the electrophotographic photoreceptor 11 provided with a stripping resistant surface by introducing an electrophotographic process using the liquid developer, and at least after a dispersion medium is dried so as to generate the partial melting between toner particles, the toner image is contact-transferred onto the intermediate transfer body 20 provided with the adhesive surface >=3g.f at a temperature T1 , and <=40g.f at a temperature T2 higher than the temperature T1 , as for the adhesion force by an adhesive tape and adhesive sheet inspecting method of JISZ0237-1980, besides, at printing, the toner image is contact-transferred on to the transferred material 30 having a planographic printing adaptive hydrophilic surface, then, the process printing plate is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for producing a lithographic printing plate, which transfers a toner image formed on an electrophotographic photosensitive member through an adhesive intermediate transfer member using a liquid developer, More specifically, it relates to a method and an apparatus for producing an electrophotographic plate-making printing plate which is excellent in transferability of a toner image and has good plate-making image quality and print image quality.

[0002]

2. Description of the Related Art A lithographic offset printing plate, in particular, an electronic editing system that can be operated by computer from input, correction, editing, layout, and page setting consistently, and can be immediately output to a remote terminal plotter by high-speed communication network or satellite communication. In the above, an electrophotographic photoreceptor is used as a photoreceptor having high photosensitivity capable of providing a direct type printing plate for directly producing a printing plate from an output of a terminal plotter.

As a method of preparing a lithographic printing plate using an electrophotographic photosensitive member, a method of forming a toner image by an electrophotographic process, desensitizing a non-image portion with a desensitizing solution, and using the resulting non-image portion as a printing plate, A method of removing a photoconductive layer in a non-image portion after formation is known. However, in the method in which the photosensitive layer is subjected to a hydrophilic treatment or the photosensitive layer is eluted to expose the surface hydrophilic support, and the surface of the electrophotographic photosensitive member itself is modified to form a hydrophilic non-image portion, There are various restrictions on the photoconductor, especially the photoconductive compound and the binder resin used for the photoconductive layer, and there are many problems in the image quality and printing durability of the obtained printing plate.

In order to solve such a conventional problem, a transfer layer made of a thermoplastic resin that can be removed by a chemical reaction treatment is provided on the surface of an electrophotographic photosensitive member, and a normal electrophotographic process is performed on the transfer layer. A liquid toner is used to form a toner image, and the toner image is transferred to a transfer material that forms a hydrophilic surface as a lithographic printing plate together with a transfer layer, and then the transfer layer is removed to transfer the toner image. International Publication WO 93
No. 16418.

In the method utilizing the transfer layer, a printing plate having a good image quality can be obtained without being subjected to various restrictions required for the conventional photoconductive layer. A step of removing the transfer layer by a chemical treatment is required to make it, and there is a limit in simplifying the steps from plate making to making a printing plate and improving work efficiency.

On the other hand, a method is known in which an electrostatic latent image on a photoconductor is developed with a liquid developer and the developed toner image is transferred to a transfer material such as transfer paper. The occurrence of problems peculiar to liquid developers is described, for example, in Eiichi Inoue's "Basics of Photographic Engineering: Non-Silver Photographs", page 364, edited by The Photographic Society of Japan, published by Corona Publishing Co., Ltd. (1982). There is. That is, when developing with toner particles having a particle size of 0.2 to 2 μm, the surface area of the photoconductor emerging from the developing area is 100 to 100 μm.
A carrier liquid layer having a thickness of 200 μm is formed, and even if the carrier liquid layer is transferred onto the transferred material in this state, the adhesion between the liquid layer and the transferred material deteriorates and the transfer efficiency decreases. Further, when the carrier liquid is removed, the mechanical force becomes stronger and the transfer image rate rather deteriorates, so that the deterioration of the image quality of the transferred image is an unavoidable phenomenon.

In order to solve this problem, attempts to improve the conventional liquid developer for transfer and the transfer method have been earnestly studied.

As one method, after developing the electrostatic latent image on the photoconductor with a liquid developer, the developed image on the photoconductor and the transfer material are overlapped while the carrier liquid remains sufficiently, and corona transfer or A method of transferring by bias roller transfer may be mentioned. However, in this method, the carrier liquid existing between the transfer material and the photoconductor at the time of transfer is caused to flow,
Flow may occur in the transferred image.

As a method for preventing this defect, for example, Japanese Patent Publication No. 51-46454 discloses a method of transferring after controlling the liquid thickness of the carrier liquid on the photosensitive member to 5 to 30 μm by corona discharge after development. Has been done. This method improves the drawbacks of the above method by interposing a sufficient amount of carrier liquid required for wet transfer between the photoconductor and the transfer material to improve transfer efficiency and unnecessary liquid to the transfer material. It is the one that reduces the penetration of. According to this method, the flow of the transferred image due to the excess carrier liquid existing at the time of transfer can be prevented to some extent by controlling the liquid thickness. Has the drawback that the image of is distorted.

Japanese Unexamined Patent Publication (Kokai) No. 1-225975 proposes a method in which a drying step is performed after development to adjust the remaining carrier liquid, and then transfer is performed in a precharge step by corona discharge. There is a problem that stable high image quality cannot be obtained unless the gap between the materials is controlled extremely precisely.

As another method, there is a method in which the developed photoconductor and the transfer material are directly brought into close contact with each other by a roller to perform the transfer. However, in this method, the carrier liquid on the photoconductor may flow during contact, which may disturb the image on the photoconductor or cause flow in the transferred image.

As a method for preventing this drawback, Japanese Patent Publication No.
No. 6-1799 discloses a method in which two transfer rollers are provided and a bias opposite to that of the second roller is applied to the first roller. According to this method, the disorder of the transferred image can be prevented to some extent, but it is still insufficient.

Further, in JP-A-55-95971, a method of interposing a resin solution between a photoreceptor and a transfer sheet to uniformly control the amount of transfer adhered, JP-A-59-100.
458, JP-A-60-95550, JP-A-62-1.
No. 4168 and the like disclose a method in which spacer particles are used in combination in a liquid developer to prevent deviation of toner particles at the time of contact transfer, but the transfer efficiency is insufficient,
It was still unsatisfactory, for example, the disorder of the image at the time of transfer was not sufficiently improved. Further, when the transfer material obtained by this method is applied to a printing plate, there is a problem that the resins used in combination adhere to the printing plate, and scumming easily occurs.

As another method, various methods of transferring a toner image on a photoconductor through an intermediate transfer body instead of directly transferring the material to be transferred have been studied. For example, JP-A-63-34573, JP-A-2-264280, JP-A-3-243973, JP-A-4-50968, and JP-A-4-34968.
No. 507303, No. 5-503166, No. 6-508.
No. 444, etc., the transfer from the photosensitive member to the intermediate transfer member is performed by electrostatic transfer by the corona discharge described above, and the transfer to the final transfer target material is performed by pressure contact transfer using heating and the like. There is. However, even with these methods, the toner image is not completely transferred from the photoconductor, the photoconductor must be cleaned, and it is difficult to completely eliminate the disorder of the transferred image at the time of heating contact transfer. It was still insufficient for the required high-definition image formation.

Further, as means for solving various inconveniences associated with the transfer to the final transfer target material, for example, JP-A-5-100
In No. 579, etc., transfer is carried out through two intermediate transfer bodies, the surface of the second intermediate transfer body is made sticky or adhesive, and the transfer to the first is electrostatically transferred, and after the carrier liquid is dried. A method of performing contact transfer to a second intermediate transfer member and a final transfer target is shown. However, even in this method, since the number of transfers increases, stable high image quality cannot be obtained unless each process is precisely controlled, and the structure of the transfer machine becomes complicated, making it difficult to make a simple and small plate-making machine. There was a problem.

On the other hand, in the case of the conductive dry toner, a method of interposing an intermediate transfer member on the adhesive surface is shown in, for example, Tadashi Ogasawara, Masatoshi Kimura, "4th Non-Impact Printing Technology Symposium Proceedings" 101 (1987) and the like. Has been done. However, even if this method via the adhesive intermediate transfer body is applied to a liquid developer, the adhesiveness of the adhesive surface is lowered due to contact with the carrier liquid, and transfer failure occurs, or the transfer is performed at the time of transfer to the final transfer material. Defects and image disturbances tend to occur, and the problems peculiar to liquid developers could not be solved.

[0017]

Accordingly, the first aspect of the present invention is as follows.
It is an object of the invention to provide a transfer method capable of forming an excellent transfer image when transferring a toner image formed on a photoconductor with a liquid developer onto a lithographic printing support. A second object of the present invention is to provide a transfer method in which a photoreceptor and an intermediate transfer member have good repetition durability due to excellent transfer efficiency. A third object of the present invention is to provide a method for producing a lithographic printing plate that can obtain a printed matter with high definition image quality without scumming. Further, a fourth object of the present invention is to provide an apparatus for producing a lithographic printing plate having excellent plate making quality from a toner image formed by an electrophotographic process using a liquid developer via an adhesive intermediate transfer member. It is in.

[0018]

The above object of the present invention is to form a toner image on the surface of an electrophotographic photoreceptor having a releasable surface by an electrophotographic process using a liquid developer, and dry at least a dispersion medium to form a toner. After causing partial fusion between the particles, the toner image is contact-transferred onto an intermediate transfer member having an adhesive surface at a temperature (T ₁ ), and further a lithographically printable hydrophilic surface is obtained at the time of printing. A method for producing a plate-making printing plate by contact-transferring a toner image at a temperature (T ₂ ) higher than the temperature (T ₁ ) onto a final transfer material, wherein the adhesive force of the surface of the intermediate transfer member is JIS Z 0237-1980 "Adhesive tape
Adhesive strength according to "Adhesive sheet test method", 3 gram force or more at temperature (T ₁ ) and 40 gra at temperature (T ₂ ).
It has been found to be achieved by a method of making an electrophotographic plate-making printing plate characterized by being less than m · force.

According to the present invention, after the toner image is formed on the photoreceptor having the releasable surface by using the liquid developer, the drying means is provided before the contact transfer to the intermediate transfer body, and the toner is attached to the photoreceptor. Then, by drying at least the dispersion medium contained in the toner layer, the dispersion medium that causes image distortion during contact transfer is removed, and, for example, 2 to 99% of halftone dots of 175 lines on the intermediate transfer body, A high-definition image portion such as a thin line of 10 μm and Mincho characters of Class 2 or higher can be completely transferred without causing disturbance such as defect deformation. This excellent transfer effect is
Evaporation of solvent molecules in the toner image layer increases the entanglement of the toner particles, and at least partial fusion between the toner particles occurs. This is because the cohesive failure of the toner layer is prevented even when the toner layer is peeled off to the transfer body. If necessary, such as the thermophysical properties of the toner particles used, a heating and drying means can be applied to promote partial fusion between the toner particles.

Further, in the present invention, the surface temperature (T ₁ at the time of the first transfer in which the transfer of the toner image through the intermediate transfer member is carried out by contact transfer, and the toner image is transferred from the photosensitive member to the intermediate transfer member by heating. ), The adhesive force of the adhesive surface of the intermediate transfer member is 3 g.
· F or more, preferably 5 g · f or more, and the surface temperature (T) during the second transfer from the intermediate transfer member to the final transfer target material (that is, the printing support) performed at a temperature higher than the temperature (T ₁ ).
_{In 2} ), the adhesive strength of the adhesive surface is 40 g · f or less, preferably 35 g · f or less, and more preferably 20 g · f or less.

The surface of the intermediate transfer member of the present invention is tacky and has sufficient adhesiveness to peel off the toner image layer from the surface of the photoreceptor having excellent releasability at the temperature (T ₁ ) during the first transfer. (3
g / f or more), and the adhesiveness is sufficiently low even at high temperature (T ₂ ) during the second transfer (40 g / f or less), and the adhesion to the final transfer material is sufficiently good. As a result, the high-definition toner image portion as described above can be completely transferred without causing image distortion.
That is, the surface adhesiveness of the intermediate transfer member of the present invention is such that the adhesive force changes depending on the contact temperature at the time of contact under heating / pressurizing conditions, and the low adhesive force is maintained even at high temperatures. It is a feature.

The adhesive strength of the surface of the intermediate transfer member according to JIS Z 0237-1980 "Adhesive tape / adhesive sheet test method" is measured at a temperature (T ₁ ) or a temperature (T ₂ ) of 8.3.1-1.
According to the 80-degree peeling method, the following modification is made. As the “test plate”, an intermediate transfer member having an adhesive surface is used. Fuji P with a width of 20 mm and a thickness of 25 μm
T film 50 (Fuji Photo Film Co., Ltd., thickness 50
μm). Using a constant-speed tension-type tensile tester, peel off at a speed of 50 mm / min. That is, the roller is reciprocated from the test piece by one reciprocation at a speed of about 300 mm / min under a nip pressure of 4 kgf / cm ² from above the test piece. Between 20 and 40 minutes after the crimping, the film is peeled off at a speed of 50 mm / min after peeling off about 25 mm using a constant-speed tension type tensile tester. The force is read every 20 mm peeling, for a total of 4 readings. The test was performed on three test pieces, and an average value of 12 pieces measured from the three test pieces was obtained.
This is proportionally converted per 10 mm width.

In the present invention, the electrostatic latent image on the photosensitive member is developed with toner particles and is subsequently adhered to the non-image area, which becomes fog, when the toner is rinsed with an insulating solvent similar to the developer. The surface tackiness of the intermediate transfer member does not come into contact with the carrier liquid by drying a thin layer of the carrier liquid having a thickness of several hundreds of μm and at least partially fixing the toner image layer. Therefore, the durability is repeatedly maintained without deterioration in performance. Furthermore, the cohesive force of the toner image layer is maintained during heat contact transfer with the intermediate transfer member, and by using an intermediate transfer member with a specific surface adhesiveness, complete contact transfer is possible even if the transfer speed is improved. Becomes

In the present invention, it is preferable that the intermediate transfer member having an adhesive surface has an elastic layer having a film thickness that is at least the thickness of the formed toner image. The function of the intermediate transfer body as an elastic body during the pressure contact transfer (cushion effect) allows the cushioning effect of the thickness of the toner image layer itself to be taken over by the intermediate transfer body, thereby improving the transferability of the toner image layer itself. In addition, the deformation of the image can be suppressed.

Further, in the present invention, the surface temperature of the electrophotographic photosensitive member during the electrophotographic process using the liquid developer is substantially the same as the temperature (T ₁ ) at which contact transfer is made from the photosensitive member to the intermediate transfer member. Is preferably carried out. By performing the electrophotographic process and the transfer process at the same temperature, the speed of the entire system can be improved, and a device relating to temperature control of the photosensitive material surface temperature for each process is not required, thereby enabling simplification.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic photosensitive member according to the present invention will be described. As the electrophotographic photosensitive member, any conventionally known one can be used. What is important is that the surface of the photoconductor has a peeling property at the time of forming the toner image so that the toner image formed on the photoconductor can be easily peeled. In particular, in the present invention, JIS Z 0237-1980 "adhesive tape /
It is preferable that the adhesive force according to the “adhesive sheet test method” is 20 g · f or less. By adjusting the adhesive strength in this manner, the toner image formed on the photoconductor can be easily and completely transferred onto the intermediate transfer member.

The adhesion of the above-mentioned photoreceptor according to JIS Z 0237-1980 “Adhesive tape / adhesive sheet test method” was measured at the temperature (T ₁ ) according to the 180 degree peeling method of 8.3.1, and the following corrections were made. And add. An electrophotographic photosensitive member on which a toner image is to be formed is used as a “test plate”. As a “test piece”, an adhesive tape manufactured according to JIA C 2338-1984 having a width of 6 mm is used. Peel off at a speed of 120 mm / min using a constant speed tension type tensile tester. That is, a roller is reciprocated from the top of the test piece at a speed of about 300 mm / min, with the adhesive surface of the test piece facing down, and pressure-bonded to the test plate. During 20 to 40 minutes after crimping, using a constant speed tension type tensile tester, after peeling off about 25 mm, 120
Peel off at a speed of mm / min. The force is read every 20 mm peeling, for a total of 4 readings. The test is performed on three test pieces, and an average value of twelve pieces measured from the three test pieces is obtained, and this is converted into a proportional value per 10 mm width. The adhesive strength of the electrophotographic photoreceptor surface is preferably 15 g · f or less, more preferably 10 g · f or less, particularly preferably 8 g · f or less.

Examples of the photoreceptor having a releasable surface used in the present invention include a photoreceptor having a releasable surface in advance. Specifically, a method of using a photoconductor obtained by modifying the surface of an electrophotographic photoreceptor mainly containing amorphous silicon to have a releasable property, at least one of a silicon atom and a fluorine atom near the surface on the photoconductive layer. A method of providing an overcoat layer containing a polymer containing a polymer component (containing a silicon atom and / or a fluorine atom) and cross-linking the polymer is included.

The surface of such a photoreceptor has extremely excellent releasability, it is wet with a carrier liquid in the developing process using a liquid developer, and the non-image area of the non-image area in the heating and pressure transfer process is increased. The releasability of the surface of the photoconductor and the tackiness of the intermediate transfer body were not deteriorated even after repeated contact with the intermediate transfer body, and the electrophotographic process in the above overcoat layer was heated at a temperature (T ₁ ). It has characteristics such that the film hardly swells even if it is subjected to an electrophotographic process or gets wet with a carrier liquid under the conditions, and the toner image formed on the photoconductor does not cause distortion and has a high definition image quality. It is possible to form a copy image of.

As a method for modifying the surface of the electrophotographic photosensitive member mainly containing amorphous silicon to be releasable, a coupling agent (silane coupling agent, titanium coupling agent, etc.) containing a fluorine atom and / or a silicon atom is used. ) Or the like to treat the surface of the amorphous silicon layer.
No. 318, JP-A-60-170860 and JP-A-59-10
Nos. 2244 and 60-17750.

As another method, a method of adsorbing and fixing a peeling compound (S) containing a fluorine atom and / or a silicon atom as a substituent can be mentioned. For example, the compound (S) can be adsorbed and fixed by dissolving the compound (S) in a solvent to form a solution having a concentration of about 0.1 to 5% by weight, immersing the photoreceptor in this solution, and then drying.

Examples of the peeling compound (S) include compounds containing at least a fluorine atom and / or a silicon atom, and the structure thereof is not particularly limited as long as it improves the peeling property of the surface of the amorphous silicon photoreceptor. It may be a low molecular weight compound, an oligomer, or a polymer, not a substance. In the case of an oligomer or polymer, the substituent containing a fluorine atom and / or a silicon atom may be incorporated into the main chain of the polymer, or may be present as a substituent on the side chain of the polymer. Preferably, an oligomer or a polymer containing a repeating unit containing the substituent as a block is used, and these can particularly effectively express the adsorptivity and the releasability to the surface of the amorphous silicon photoreceptor.

As the compound (S) containing a fluorine atom and / or a silicon atom used in the present invention, specifically,
"New edition surfactant surfactant handbook" edited by Tokiyuki Yoshida, etc., published by Kogyo Tosho Co., Ltd. (1987), supervised by Takao Karimei "Latest surfactant application technology", CMC Corporation (1990), edited by Kunio Ito "Silicone Handbook" published by Nikkan Kogyo Shimbun (19
1990), supervised by Takao Karimei "Specially Functional Surfactant" C.
MC (1986), AM Schwartz et al. "Surface Act"
ive Agents and Detergents vol. II "and the like. Furthermore, Nobuo Ishikawa "Synthesis and Function of Fluorine Compounds" CM
C. (1987), edited by Jiro Hirano et al., "Fluorine-Containing Organic Compounds-Synthesis and Application-", Technical Information Association (1991), edited by Mitsuo Ishikawa, "Organic Silicon Strategic Materials", Chapter 3 Science, Inc. Compound (S) can be synthesized using a synthesis method described in a document such as Forum (1991).

When the compound (S) is a so-called block copolymer, the polymer component containing a fluorine atom and / or a silicon atom may be composed of a block. Here, the term "consisting of blocks" means that the polymer has a polymer segment containing at least 70% by weight of a component having a fluorine atom and / or a silicon atom.
-B type block, ABA type block, BAB type block, graft type block or star type block. Specific compounds and embodiments of compound (S) are the same as those described in JP-A-7-5727.

In the second method, the overcoat layer provided as the uppermost layer on the surface of the photoconductor may be any one as long as the surface energy of the coating film is 30 erg.cm ^-1 or less. By adjusting the value within the above range, the adhesive force becomes 20 g · f or less, and complete transfer of the toner image layer is achieved. The coating surface energy is preferably 28 erg · cm ⁻¹ or less, more preferably 25 erg · cm ^−1.
-1 or less, more preferably 15 erg · cm ^{−1 to} 25 erg · cm ⁻¹
It is.

Specific examples of the method for adjusting the coating surface energy of the overcoat layer to the above range include a method in which a fluorine resin, a silicon resin or the like is contained in the layer. Another feature of such a layer is that the coating forms a cured film structure.

The fluororesin is a resin mainly containing a polymer component containing a substituent containing a fluorine atom. The substituent may be incorporated into the polymer main chain of the polymer, or may be contained in a substituent on the side chain of the polymer. As a substituent containing a fluorine atom, for example,-
_{C h (F) 2n + 1} (n is 1 to 22 integer), - CFH _2, -
(M is an integer _{1~17) (CF 2) m CF} 2 H, - CF
₂ -, - CFH-, such monovalent or divalent organic residues and the like.

These fluorine-atom-containing organic residues may be combined and constituted, in which case they may be directly bonded or may be combined via another linking group. Specific examples of the linking group include divalent organic residues, and include —O—, —S—, —N (d ¹ ) —, and —CO—.
-, - SO -, - SO 2 -, - COO -, - OCO-,
-CONHCO -, - NHCONH -, - CON (d 1)
A divalent aliphatic group or a divalent aromatic group, which may have a bonding group selected from —, —SO ₂ N (d ¹ ) — and the like,
Alternatively, it represents an organic residue composed of a combination of these divalent residues. Here, d ¹ represents an alkyl group having 1 to 3 carbon atoms. The fluorine-containing polymer component is preferably contained in an amount of 80 to 99 parts by weight based on 100 parts by weight of the whole polymer component of the resin.

Further, the resin contains a curable functional group, and the content thereof is 1 to 20% by weight. Examples of the contained curable functional group include those described in the below-mentioned silicon-based resin. The weight average molecular weight of the resin is
Preferably it is 5 × 10 ³ to 1 × 10 ⁶ , more preferably 2 × 10 ^{4 to} 5 × 10 ⁵ .

The silicon-based resin is a resin mainly containing a polymer component containing a substituent containing a silicon atom. In the present invention, a polymer mainly composed of a component having a repeating unit of an organosiloxane structure represented by the following general formula (I) can be mentioned as a specific example.

[0041]

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In the above formula (I), R ₁ and R ₂ may be the same or different and each represents an aliphatic group, an aromatic group or a heterocyclic group.

R ₁ and R ₂ may be the same as or different from each other, and preferably have 1 carbon atoms which may be substituted.
~ 18 linear or branched alkyl group {for example, methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, Hexadecyl group,
Octadecyl, 2-fluoroethyl, trifluoromethyl, 2-chloroethyl, 2-bromoethyl, 2-
Cyanoethyl group, 2-methoxycarbonylethyl group, 2
- methoxyethyl group, 3-bromopropyl group, 2-methylcarbonyl ethyl group, 2,3-dimethoxy _{propyl, - (CH 2) p C} n F 2n + 1 group (wherein p is an integer of 1 or 2, n represents an integer of _{1~12), - (CH 2)} p -
(CF ₂ ) _m —R ′ group (where p is an integer of 1 or 2, m is 1
12 integer, R 'is -CFHCF ₃ or -CFHCF ₂
H), etc., and an optionally substituted alkenyl group having 4 to 18 carbon atoms (eg, 2-methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-
2-pentenyl group, 1-pentenyl group, 1-hexenyl group, 2-hexenyl group, 4-methyl-2-hexenyl group, decenyl group, dodecenyl group, tridecenyl group, hexadecenyl group, octadecenyl group, linolel group, etc.), carbon Aralkyl groups of the formulas 7 to 12 which may be substituted (for example, benzyl, phenethyl, 3-phenylpropyl, naphthylmethyl, 2-naphthylethyl, chlorobenzyl, bromobenzyl, methylbenzyl, ethyl A benzyl group, a methoxybenzyl group, a dimethylbenzyl group, a dimethoxybenzyl group or the like, an alicyclic group having 5 to 8 carbon atoms which may be substituted (for example, cyclopentyl group, cyclohexyl group, 2-cyclohexylethyl group, 2-cyclopentylethyl) Group, polyfluorohexyl group, methylcyclohexyl group, meth Shi cyclohexyl group, a carbon number 6
To 12 optionally substituted aromatic groups (for example, phenyl, naphthyl, tolyl, xylyl, propylphenyl, butylphenyl, octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, Butoxyphenyl group, fluorophenyl group, chlorophenyl group, difluorophenyl group, bromophenyl group,
Cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, trifluoromethylphenyl group and the like.

Further, R ₁ and R ₂ are heterocyclic groups which may be condensed with at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom (for example, the heterocycle is a pyran ring). , Furan ring, thiophene ring, morpholine ring, pyrrole ring, thiazole ring, oxazole ring, pyridine ring, piperidine ring, pyrrolidone ring, benzothiazole ring, benzoxazole ring, quinoline ring, tetrahydrofuran ring, etc.).

A methyl group is preferred as R ₁ and R ₂ . The total amount of organosiloxane units in the silicone resin is preferably 60% by weight or more, more preferably 75% by weight or more, of dimethylsiloxane units in which R ₁ and R ₂ are methyl groups. Thereby, the releasability is more favorably maintained, and complete transfer of the toner image layer is easily achieved.

Further, in order to sufficiently strengthen the adhesiveness between the overcoat layer and the surface of the photosensitive member, as a specific component, the substituted alkyl group (for example, a halogen atom or a cyano group-substituted product) described above in the above silicon-based resin, Examples thereof include a substituent R ₁ or R ₂ selected from an optionally substituted aralkyl group, an aromatic group and a heterocyclic group. Further, those containing a polar group such as a carboxyl group, a hydroxyl group, a mercapto group, a phospho group, or an amide group in the substituents of R ₁ and / or R ₂ , or a ureide group (—NHCONH
-), Thioether group (-S-), urethane group (-NH
Those containing a divalent linking group such as COO-) are also included.

The organosiloxane unit containing the substituent is less than 40% by weight, more preferably less than 30% by weight, based on the total amount of all the organosiloxane units. In addition, it is preferable that the dimethylsiloxane unit, which is a good component for improving the peeling property, and the other organosiloxane unit, which has a good adhesiveness with the above-mentioned photoreceptor, satisfy the above-mentioned abundance ratio, and each polymerized unit is a random copolymer. It may be a polymer, a block copolymer, or a star-type copolymer, and is not limited. This makes it possible to improve the adhesiveness on the photoreceptor side while maintaining the releasability on the surface side.

The weight average molecular weight of the resin is preferably 5
× 10 ³ to 1 × 10 ⁶ , more preferably 2 × 10 ⁴
５5 × 10 ⁵ . In the present invention, a resin containing both of the above-mentioned fluorine atom and silicon atom can be used as the resin for releasability.

Further, the resin layer serving as the overcoat layer used in the present invention forms a crosslinked structure and is a cured resin layer. Any conventionally known method can be used to cure the resin layer and form a crosslinked structure inside the layer. Hereinafter, a description will be given of a silicon resin as an example.

That is, the silicone resin itself is self-crosslinking, the silicone resin is crosslinked with various crosslinking agents or curing agents containing a component having a reactive group, or the silicone resin is crosslinked with various crosslinking agents. Alternatively, a method of crosslinking with a curing agent may be used. It may be some combination of these methods. Further, the reaction mode of the crosslinking reaction between the polymers of the resins may be any conventionally known chemical bonding reaction, or may be a combination of several reaction modes.

Specific examples of these reaction modes include the following reactions i) to iv). i) polyvalent metal ions (for example, Ca, Mg, Ba, Al, Zn, Fe, Sn, Zr,
Crosslinking by ionic bonding by a chelate reaction with a cation of a polyvalent metal such as Ti).

Ii) Organic reactive group (specifically, hydroxyl group, thiol group, halogen atom (eg chlorine atom,
Bromine atom, iodine atom), carboxyl group, acid anhydride group, amino group, isocyanate group, protected isocyanate group (blotted isocyanate group), acid halide group, epoxy group, imino group, formyl group, diazo Cross-linking by a chemical bond due to an addition reaction, substitution reaction or elimination reaction between combinations of reactive groups selected from a group, an azide group and the like.

Iii) self-coupling groups {eg --CON
Self-crosslinking with an HCH ₂ OR ₁ ′ group (R ₁ ′ represents a hydrogen atom or an alkyl group), the following groups and the like.

[0054]

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(R ₂ ′ and R ₃ ′ may be the same or different and each represents a hydrogen atom or an alkyl group, and R ₂ ′ and R ₃ ′ may form 5 to 6 alicyclic rings. ), A cinnamoyl group, a -Si (R ₄ ′) _n (OR ₅ ′) _m group (R ₄ ′ represents an alkyl group, an alkenyl group or an aryl group, R ₅ ′ represents an alkyl group, and n is 0 or An integer from 1 to 2, m is 1
Represents an integer of ~ 3. However, n + m = 3)｝

Iv) Crosslinking by addition polymerization reaction with a polymerizable double bond group or a triple bond group. Examples of the polymerizable double bond group include, for example, CH ₂ ＣC (p) COO— and C (CH ₃ ) H
ＣＨCHCOO—, CH ₂ （C (CH ₂ COOH) COO
_{-, CH 2 = C (p} ) CONH-, CH 2 = C (p) CO
_{NHCOO-, CH 2 = C (p} ) CONHCONH-,
_{C (CH 3) H = CHCONH-} , CH 2 = CHCO-,
_{CH 2 = CH (CH 2)} n OCO- (n is 0 or an integer of 1 to _{3), CH 2 = CHO-, CH} 2 = CH-C 6 H 4 -CH 2
= CH-S- or the like (where p is -H or-
CH ₃ ). Examples of the polymerizable triple bond group include those having the same linking group as described above.

These arbitrarily selected reactive groups can be contained at least in the polymer of the silicone resin. As the content form, specifically, the reactive group is directly attached to one or both of R _{1 and} R ₂ of the substituent of the siloxane unit represented by the repeating unit represented by the general formula (I). Substituted or contained in either or both of the substituents R ₁ or R ₂ , contained in a copolymer component of another polymer chain bonded to the polymer chain of the siloxane unit by a block. It may be bonded to the terminal of the polymer chain of the silicone resin (may be bonded via another linking group).

Further, a conventionally known crosslinking reaction specific to an organosiloxane polymer is also an effective reaction. For example, "Silicone Handbook" edited by Kunio Ito, published by Nikkan Kogyo Shimbun (1990), supervised by Makoto Kumada and Tadashi Wada, "Latest Silicone Technology-" Development and application- ", CMC Co., Ltd. (published in 1986), etc. As an example, those having the following substituents are exemplified.

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As described above, the curable reactive group may be contained in the polymer chain as a random copolymer together with the siloxane unit represented by the general formula (I) exhibiting releasability. It may be a so-called block copolymer in which a block that becomes releasable and a curable block are combined to form a polymer. Examples of the form of the block copolymer include forms such as a graft type, an AB type block (including an ABA type), and a star type. When provided with these block copolymers, the releasable block component preferably contains at least 30% by weight or more of all polymer components of the polymer, more preferably 5% by weight or more.
0% by weight or more.

As the cross-linking agent or curing agent capable of forming a cross-linking structure with the above-mentioned silicon-based resin, any of conventionally known low molecular weight compounds known as heat-, light- or moisture-curable compounds, oligomers and polymers can be used. These may be used alone or in combination of two or more.

Specific examples of these compounds used as the cross-linking agent or the curing agent include Shinzo Yamashita and Tosuke Kaneko, "Handbook of Cross-linking Agents" published by Taiseisha (1981), edited by The Society of Polymer Science, "Polymer Data Handbook, Basic Edition". ”Baifukan (1986
Tsuyoshi Endo, "Precision of Thermosetting Polymer" (CMC
Ltd., 1986), Yuji Harasaki, "Handbook of Latest Binder Technologies", Chapter II-1 (General Technology Center, 1985), Takayuki Otsu, "Synthesis and Design of Acrylic Resins and Development of New Applications" (published by Chubu Business Development Center) 1985), and the compounds cited in the above-mentioned reviews such as "Silicone Handbook".

For example, an organic silane compound (for example, vinyltrimethoxysilane, vinyltriethoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, vinyltrichlorosilane, vinyltris (t-butylperoxide) silane, γ-
(Β-aminoethyl) aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, silane coupling agent, etc.), polyisocyanate compounds (for example, toluylene diisocyanate, diphenylmethane) Diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenylisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, polymer polyisocyanate, etc.), and polyisocyanate-based polyisocyanate-protected polyisocyanates. Blocked isocyanate compounds (examples of compounds used for protecting isocyanate groups include alcohols, β-diketones,
β-ketoesters, amines, etc.), polyol compounds (eg, 1,4-butanediol, polyoxypropylene glycol, polyoxyethylene glycol,
1,1,1-trimethylolpropane, etc.), polyamine-based compounds (for example, ethylenediamine, γ-hydroxypropylated ethylenediamine, phenylenediamine, hexamethylenediamine, N-aminoethylpiperazine,
Modified aliphatic polyamines, etc.), titanate coupling compounds (eg, tetrabutoxytitanate, tetrachlorooxytitanate, isopropyl tristearoyl titanate, etc.), aluminum coupling compounds (eg, aluminum butyrate, aluminum acetyl acetate, aluminum oxide octate) , Aluminum tris (acetyl acetate), etc.) polyepoxy group-containing compounds and epoxy resins (eg, "New Epoxy Resin" edited by Hiroshi Kakiuchi, Shokodo (1985), "Epoxy Resin" edited by Kuniyuki Hashimoto, Nikkan Kogyo Shimbun (1969) Compounds), poly (meth) acrylates (eg, compounds described in “Urea Melamine Resin”, edited by Ichiro Miwa, Hideo Matsunaga, Nikkan Kogyo Shimbun (1969)) and the like. Compound ( In example, Shin Okawara, Takeo Saegusa, Higashimura Satoshinobe ed., "Oligomer" Kodansha (1976 annual), Eizo Omori "functional acrylic resin" Techno System (1985
Compounds) described in the annual publication) and the like.

Specific examples of the polymerizable functional group of a polyfunctional monomer [also referred to as a polyfunctional monomer (d)] or a polyfunctional oligomer containing two or more polymerizable functional groups to be coexisted with each other. Include CH ₂ ═CHCH ₂ —, CH ₂ ═CHCOO
_{-, CH 2 = CH-, CH} 2 = C (CH 3) -COO-, C
_{H (CH 3) = CHCOO-,} CH 2 = CHCONH-,
_{CH 2 = C (CH 3)} -CONH-, CH (CH 3) = CH
_{CONH-, CH 2 = CHOCO-, CH} 2 = C (CH 3)
_{-OCO-, CH 2 = CHCH 2 OCO-} , CH 2 = CH
_{NHCO-, CH 2 = CHCH 2 NHCO-} , CH 2 = C
HSO ₂ —, CH ₂ ＣＨCHCO—, CH ₂ ＣＨCHO—, C
H ₂ = CHS- or the like can be mentioned. Any monomer or oligomer having two or more of these same or different polymerizable functional groups may be used.

Specific examples of the monomer having two or more polymerizable functional groups include, for example, monomers or oligomers having the same polymerizable functional group, styrene derivatives such as divinylbenzene and trivinylbenzene: polyhydric alcohol. (For example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol # 20
0, # 400, # 600, 1,3-butylene glycol, neopentyl glycol, dipropylene glycol, polypropylene glycol, trimethylolpropane, trimethylolethane, pentaerythritol, etc., or polyhydroxyphenol (eg, hydroquinone, resorcin, catechol) And their derivatives)
Methacrylic acid, acrylic acid or crotonic acid esters, vinyl ethers or allyl ethers: dibasic acids (eg, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, itaconic acid, etc.) Vinyl esters, allyl esters, vinyl amides or allyl amides: polyamines (eg, ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, etc.) and carboxylic acids containing vinyl groups (eg, methacrylic acid, acrylic Acid, crotonic acid, allyl acetic acid, etc.).

In the present invention, in order to accelerate the crosslinking reaction of the overcoat layer, a reaction accelerator may be added if necessary. In the case of a reaction mode in which a crosslinking reaction forms a chemical bond between functional groups, for example, organic acids (acetic acid, propionic acid, butyric acid, benzenesulfonic acid, p-toluenesulfonic acid, etc.), phenols (phenol, chlorophenol, Nitrophenol, cyanophenol, bromophenol, naphthol, dichlorophenol, etc.), organometallic compounds (acetylacetonato zirconium salt, acetylacetone zirconium salt, acetylacetocobalt salt, dibutoxytin dilaurate, etc.), dithiocarbamic acid compounds (diethyldithiocarbamate, etc.) ), Thiouram disulfide compounds (such as tetramethylthiouram disulfide), carboxylic anhydrides (phthalic anhydride, maleic anhydride, succinic anhydride, butyl succinic anhydride,
3,3 ', 4,4'-tetracarboxylic acid benzophenone dianhydride, trimellitic anhydride, etc.).
When the crosslinking reaction is a polymerizable reaction mode, thermal polymerization initiators (peroxides, azobis compounds, photopolymerization initiators and sensitizers (eg P. Walker, NJ Webers, et al. J. Pht
o.Sci., 18, 150 (1970), Katsumi Tokumaru, Shin Okawara, "Sensitizers" (Kodansha) (1987), etc. Organic sulfur compounds, azine-based compounds, azo compounds and the like can be mentioned.
Platinum catalysts, methylvinyltetrasiloxane, acetylene alcohols and the like can be used as a curing accelerator or a reaction control agent for silicone rubber.

As a matter of course, the curing conditions for curing these films are appropriately selected depending on the characteristics of the materials used in combination. To perform heat curing, for example, 60 ° C. to 15 ° C.
Treat at 0 ° C. for 5 to 120 minutes. When the above-mentioned reaction accelerator is used in combination, the treatment can be performed under milder conditions.

As a method for curing the specific functional group in the resin by irradiation with light, a step of irradiating light with a chemically active ray may be included. The optically active light beam may be any of visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray, γ-ray, α-ray and the like, but is preferably ultraviolet light, more preferably a light ray having a wavelength of 310 nm to 500 nm. . Generally, a low-pressure, high-pressure or ultra-high-pressure mercury lamp, a halogen lamp, or the like is used. Light irradiation is usually 5 cm to 5
Irradiation from a distance of 0 cm for 10 seconds to 10 minutes is sufficient.

The content of the peeling resin in the overcoat layer is preferably 60 to 100% by weight, more preferably 80 to 100% by weight.

Further, the overcoat layer used in the present invention contains another resin together with the above-mentioned releasable resin to the extent that the releasability is not impaired, and the adhesion between the surface of the photoreceptor and the releasable resin layer is improved. It is also possible to improve.

As the other resin (adhesive resin) which can be used in combination, various conventionally known resins can be used as long as they have a softening point of 35 ° C or higher, preferably 40 ° C or higher. Specifically, olefin polymers and copolymers, vinyl chloride copolymers, vinylidene chloride copolymers, vinyl alkanoate polymers and copolymers, allyl alkanoate polymers and copolymers, styrene and its derivatives, Polymers and copolymers, butadiene-styrene copolymer, isoprene-styrene copolymer, butadiene-unsaturated carboxylic acid ester copolymer, acrylonitrile copolymer, methacrylonitrile copolymer, alkyl vinyl ether copolymer, Acrylic acid ester polymer and copolymer, methacrylic acid ester polymer and copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, itaconic acid diester polymer and copolymer, maleic anhydride Acid copolymer, acrylamide copolymer, methacrylamide copolymer, water Group modified silicone resins, polycarbonate resins, ketone resins, polyester resins, silicone resins,
Amide resin, alkyl-modified nylon resin, hydroxyl and carboxyl group-modified polyester resin, butyral resin,
Polyvinyl acetal resin, cyclized rubber-methacrylate copolymer, cellulose acetate resin, urethane resin,
Cyclic rubber-acrylic ester copolymer, copolymer containing a nitrogen-free heterocycle (for example, as a heterocycle, a furan ring, a tetrahydrofuran ring, a thiophene ring,
Dioxane ring, dioxofuran ring, lactone ring, benzofuran ring, benzothiophene ring, 1,3-dioxetane ring, etc.), epoxy resin and the like.

The preferred proportion of these adhesion resins used in the overcoat layer is less than 80% by weight, and more preferably less than 60% by weight, based on the total resins in the layer.
In addition, a reactive group that is cured by heat, light, or moisture as described above may be contained in these adhesive resins.

As a method of compatibilizing these adhesion resins with a releasable resin to make both releasability and adhesion in an overcoat layer compatible, for example, "Compatibilization and Evaluation Technology of Polymer" edited by Technical Information Society (1992) Annual publication) Seiichi Nakahama et al. “High-performance polymer alloy” edited by The Polymer Society of Japan, Maruzen (published in 1991), etc. Particularly preferred examples of the adhesive resins include vinyl alkanoate polymers and copolymers, acrylic resins, methacrylic resins, vinyl chloride resins, cellulose acetate resins, urethane resins, and epoxy resins.

Further, in a film in which the peelable resin and the adhesion resin are mixed, a method of utilizing the characteristic that the peelable resin is concentrated and present on the surface side of the film may be used. As the method, the adhesive resin is optional, and in order to further enhance the interaction between the two resins and improve the cohesive force of the film, one of the adhesive resins is a fluorine atom similar to the peelable resin. Further, a small amount of a copolymer obtained by block-bonding a polymer component containing a silicon atom can be used.

On the other hand, the overcoat layer used in the present invention may have a multilayer structure. That is, a laminated structure in which a resin layer having good adhesion (adhesion functional layer) is provided on the side in contact with the photoreceptor, and a peelable resin layer having good peelability is provided thereon. The adhesion strength maintenance between the adhesion functional layer and the peelable resin layer having good releasability is, as described above, a polymer component having good compatibility with the resin for adhesion and a polymer component having good compatibility with the peelable resin. Is preferably made to coexist in the adhesion functional layer.

As the constitution and materials of the electrophotographic photosensitive member to be used in the present invention, any conventionally known one can be used,
It is not limited. For example, RMSchaffert, “El
ectrophotography ”Focal Press London (1980), SW
Ing, MDTabak, WEHaas “Electrophotography Fourt
h InternationalConference ”SPSE (1983), Isao Shinohara, Hidetoshi Tsuchida, Hideaki Kusakawa,“ Recording Materials and Photosensitive Resins ”
Published by Gakkai Shuppan Center (1979), Hiroshi Komon, Chemistry and Industry, 39 (3) 161 (1986), Comprehensive technical materials, "Development and practical use of recent photoconductive materials and photoconductors", Japan Publishing Division of Scientific Information Co., Ltd. (1986), "The Basics and Applications of Electrophotographic Technology" edited by the Society of Electrophotography, Corona Co., Ltd. (1986) Various photoconductors described in books and review articles such as Proceedings (1985). That is, a single layer composed of the photoconductive compound itself,
Alternatively, a photoconductive layer in which a photoconductive compound is dispersed in a binder resin may be mentioned, and the dispersed photoconductive layer may be a single layer type or a stacked type.

The photoconductive compound used in the present invention may be either an inorganic compound or an organic compound. As the inorganic compound used as the photoconductive compound of the present invention, for example, zinc oxide, titanium oxide, zinc sulfide,
Conventionally known inorganic photoconductive compounds such as cadmium sulfide, selenium, selenium-tellurium, amorphous silicon, and lead sulfide are exemplified. These may form a photoconductive layer together with a binder resin, or may be independently formed by vapor deposition or sputtering. When an inorganic photoconductive compound such as zinc oxide or titanium oxide is used, the binder resin is used in an amount of 10 to 100 parts by weight, preferably 15 to 40 parts by weight, based on 100 parts by weight of the inorganic photoconductive compound. .

On the other hand, the photoconductive layer using an organic compound may be any conventionally known one, and specifically, a photoconductive layer mainly composed of an organic photoconductive compound, a sensitizing dye, and a binder resin, a second Examples of the photoconductive layer include a photoconductive layer mainly composed of a charge generating agent, a charge transporting agent, and a binder resin, and a photoconductive layer having a two-layer structure containing a charge generating agent and a charge transporting agent in separate layers.
The electrophotographic photoreceptor of the present invention may take any form of the above-described photoconductive layer. In the case of the second example, the organic photoconductive compound functions as a charge transport agent.

Examples of the organic photoconductive compound used in the present invention include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives and azurenium salts. Derivatives, amino-substituted chalcone derivatives, N, N-bicarbazyl derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, benzidine derivatives, stilbene derivatives, polyvinylcarbazole and its derivatives, polyvinylpyrene, polyvinylanthracene, poly-2-vinyl -4- (4'-
(Dimethylaminophenyl) -5-phenyl-oxazole, vinyl polymers such as poly-3-vinyl-Nethylcarbazole, polyacenaphthylene, polyindene, polymers such as a copolymer of acenaphthylene and styrene, triphenylmethane polymer, Condensed resins such as a pyrene-formaldehyde resin, a bromopyrene-formaldehyde resin, and an ethylcarbazole-formaldehyde resin. Note that the organic photoconductive compound is not limited to these compounds, and all known organic photoconductive compounds can be used. These organic photoconductive compounds can be used in combination of two or more in some cases.

As the sensitizing dye contained in the photoconductive layer,
Conventionally known sensitizing dyes used for electrophotographic photoreceptors can be used. These are "electrophotography" 12 , 9 (1973),
“Synthetic Organic Chemistry” 23 (11), 1010 (1966) and the like. For example, pyrylium-based dyes described in U.S. Pat.
Applied Optics Supplement 3 50 (1969) , JP-A-50
Triazole methane dyes described in -39548 and the like;
Cyanine dyes described in U.S. Pat. No. 3,597,196 and the like;
No. 8, No. 60-252517, etc. are advantageously used.

As the charge generating agent contained in the photoconductive layer, various organic and inorganic charge generating agents known in the prior art for electrophotographic photoreceptors can be used. For example, selenium, selenium-tellurium, cadmium sulfide, zinc oxide, and the organic pigments described below can be used, and these are arbitrarily selected as charge generating agents having spectral sensitivity suited to the wavelength range of the light source of the printer. .

Examples of the organic pigment include azo pigments such as monoazo, bisazo and trisazo pigments, phthalocyanine pigments such as metal-free or metal phthalocyanine, perylene pigments, indigo, thioindigo derivatives, quinacridone pigments, polycyclic quinone pigments, Examples thereof include bisbenzimidazole-based pigments, squalium salt-based pigments, and azurenium salt-based pigments, and these may be used alone or in combination of two or more. Further, in the photoconductive layer used in combination with the charge transporting agent, a material having good compatibility with the type of the charge generating agent used in combination is selected. Specifically, the organic photoconductive compound described above is used. A group of compounds known as

With respect to the mixing ratio of the organic photoconductive compound and the binder resin, the upper limit of the content of the organic photoconductive compound is determined by the compatibility between the organic photoconductive compound and the binder resin, and if the amount exceeds the upper limit. Crystallization of the organic photoconductive compound occurs, which is not preferable. Since the electrophotographic sensitivity decreases as the content of the organic photoconductive compound decreases, it is preferable to include as many organic photoconductive compounds as possible within the range where crystallization of the organic photoconductive compound does not occur. The content of the organic photoconductive compound is 5 to 120 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the binder resin.

The binder resin that can be used in the photoreceptor of the present invention may be any of the resins used in conventionally known electrophotographic photoreceptors, and the weight average molecular weight is preferably 5 × 10 5.
^{It is 3} to 1 × 10 ⁶ , more preferably 2 × 10 ^{4 to} 5 × 10 ⁵ . Further, the glass transition point of the binder resin is preferably from -40C to 200C, more preferably from -10C to 14C.
0 ° C. For example, Ryuji Shibata and Jiro Ishiwatari, Polymer, Dai
Vol. 17, p. 278 (1968) Harumi Miyamoto, Hidehiko Takei, Imaging, 1973 (No. 8), Koichi Nakamura, Ed., "Practical Technology of Binders for Recording Materials", Chapter 10, CHC Publishing (1985) Electrophotography Proceedings of the Conference of Society, "Present Symposium on Organic Photoconductors for Electrophotography" (1985), edited by Hiroshi Komon, "Recent Development and Practical Use of Photoconductive Materials and Photoconductors", Japan Science Information Co., Ltd. (1986) The Electrographic Society of Japan, "Basics and Application of Electrophotographic Technology," Chapter 5, Corona Corporation (1988), D. Tatt, SCHeidecker, Tappi,
49 (No.10), 439 (1966), ESBaltazzi, RGBlanclot
teet al., Phot. Sci. Eng. 16 (No. 5), 354 (1972),
Compounds described in books and reviews such as Nguyen Chan K, Isamu Shimizu, Eiichi Inoue, Journal of the Society of Electrophotographic Photography 18 (No. 2), 22 (1980), etc.

Specifically, olefin polymers and copolymers, vinyl chloride copolymers, vinylidene chloride copolymers, vinyl alkanoate polymers and copolymers, allyl alkanoate polymers and copolymers, styrene and Polymers and copolymers of the derivatives, butadiene-styrene copolymers, isoprene-styrene copolymers, butadiene-unsaturated carboxylic acid ester copolymers, acrylonitrile copolymers, methacrylonitrile copolymers, alkyl vinyl ether copolymers. Polymers, acrylic acid ester polymers and copolymers, methacrylic acid ester polymers and copolymers, styrene-acrylic acid ester copolymers, styrene-methacrylic acid ester copolymers, itaconic acid diester polymers and copolymers , Maleic anhydride copolymer, acrylamide copolymer, methacrylamide Polymer, hydroxyl-modified silicone resin, polycarbonate resin, ketone resin, polyester resin, silicone resin, amide resin, hydroxyl and carboxyl group-modified polyester resin, butyral resin, polyvinyl acetal resin, cyclized rubber-methacrylate copolymer, ring Rubber-acrylate copolymer, a copolymer containing a nitrogen-free heterocycle (for example, as a heterocycle, a furan ring, a tetrahydrofuran ring, a thiophene ring, a dioxane ring, a dioxofuran ring, a lactone ring, a benzofuran ring, Benzothiophene ring, 1,3-dioxetane ring, etc.), epoxy resin and the like.

In particular, when a resin having a relatively low molecular weight (about 10 ³ to 10 ⁴ ) containing an acidic group such as a carboxyl group, a sulfo group or a phosphono group is used as a binder resin for the photoconductor, The electrical characteristics can be improved. For example, the resins described in JP-A-64-70761, JP-A-2-67563, JP-A-3-181948, and JP-A-3-249659 are exemplified. Also, by using a specific medium to high molecular weight resin, stable performance can be maintained even when the environment fluctuates significantly. For example, JP-A-3-299
No. 54, No. 3-77954, No. 3-92961, and No. 3-53257. A resin or an acidic group which binds an acidic group to the end of the graft portion of the graft copolymer. Resin contained in graft portion,
Examples of the graft type copolymer having an AB block type copolymer comprising an A block containing an acidic group and a B block not containing an acidic group described in JP-A-2064664 and JP-A-3-223762 in a graft portion. it can. By using these resins, the photoconductor is uniformly dispersed,
A photoconductive layer having good smoothness can be formed, and excellent electrostatic characteristics can be maintained even when a scanning exposure method using a semiconductor laser beam or a change in environment is used.

The thickness of the photoconductive layer is 1 to 100 μm, especially 1
0 to 50 μm is preferred. When a photoconductive layer is used as the charge generation layer of the photoreceptor having the charge generation layer and the charge transport layer, the thickness of the charge generation layer is preferably 0.01 to 5 μm, and more preferably 0.05 to 2 μm. .

In the present invention, various dyes can be used together as a spectral sensitizer depending on the type of light source such as visible light exposure or semiconductor laser light exposure. For example, review-literature on the electrophotographic photosensitive member described above, "electrophotographic" 12 9 (1973), "Synthetic Organic Chemistry" 24 (11),
1010 (1966), Harumiya Miyamoto, Hidehiko Takei: Imaging 1973
(No.8) p. 12, CJ Young et al .: RCA Review 15 , p. 469 (1954), Kohei Kiyota: IEICE Transactions , J63-
C (No.2), p. 97 (1980), Yuji Harazaki et al., Industrial Chemistry Magazine, 66 , 78 and 188 (1963), Tadaaki Tani, Photographic Society of Japan 35 , 208 (1972), " Research Disclosur
e '' 1982, 216 117-118, FMHamer `` The Cyanine D
yes and Related Compounds, etc., such as carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, phthalein dyes, polymethine dyes (eg, oxonol dyes, merocyanine dyes, cyanine dyes, rhodacyanine dyes, styryl dyes, etc.) ), Phthalocyanine dyes (which may contain metals) and the like.

Further, if necessary, various conventionally known additives for electrophotographic photoreceptors can be used.
These additives include a chemical sensitizer for improving electrophotographic sensitivity, various plasticizers for improving film properties,
A surfactant and the like are included.

Examples of the chemical sensitizer include halogen, benzoquinone, chloranil, fluoranyl, bromanil,
Dinitrobenzene, anthraquinone, 2,5-dichlorobenzoquinone, nitrophenol, tetrachlorophthalic anhydride, phthalic anhydride, maleic anhydride, N-hydroxymaleimide, N-hydroxyphthalimide, 2,
Electron-withdrawing compounds such as 3-dichloro-5,6-dicyanobenzoquinone, dinitrofluorenone, trinitrofluorenone, tetracyanoethylene, nitrobenzoic acid, dinitrobenzoic acid, etc .; Development and Practical Use ”Chapters 4-6: Japan Science Information Co., Ltd.
Examples include polyarylalkane compounds, hindered phenol compounds, p-phenylenediamine compounds, and the like, which are reviewed in the publication section (1986). Also, JP-A-58-65
No. 439, No. 58-102239, No. 58-1294
Compounds described in JP-A-39-62 and JP-A-62-71965 can also be mentioned.

Examples of the plasticizer include dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, diphenyl phthalate, triphenyl phosphate, diisobutyl adipate, dimethyl sebacate, dibutyl sebacate, butyl laurate, methyl phthalyl glycolate, dimethyl glycol phthalate. Can be added to improve the flexibility of the photoconductive layer. These plasticizers are preferably contained in a range that does not deteriorate the electrostatic properties of the photoconductive layer. The amounts of these various additives are not particularly limited, but are usually 0.1 to 100 parts by weight of the photoconductor.
001 to 2.0 parts by weight.

The electrophotographic photosensitive member can be provided on a conventionally known support. In general, the support of the electrophotographic photosensitive layer is preferably conductive. As the conductive support, a substrate such as a metal, paper, or a plastic sheet may be impregnated with a low-resistance substance in the same manner as in the related art. And a substrate coated with at least one layer for the purpose of imparting conductivity to the back surface of the substrate (the surface opposite to the surface on which the photosensitive layer is provided) and further preventing curling. A substrate provided with a water-resistant adhesive layer on its surface, a substrate provided with at least one precoat layer as necessary on the surface layer of the support, a substrate obtained by laminating a base conductive plastic on which aluminum or the like is deposited on paper, or the like. Can be used. Specifically, as an example of a conductive substrate or a conductive material, Yukio Sakamoto, Electrophotography, 14 (No. 1), pp. 2-11 (1975),
Hiroyuki Moriga "Chemistry of Introductory Special Papers" Polymer Publishing Association (1975), MFHoover, J. Macromol. Sci. Chem. A-4 (6), 1
Those described on pages 327 to 1417 (published in 1970) and the like are used.

Next, a method of forming a toner image on the electrophotographic photosensitive member will be described. As described above, a toner image is formed on an electrophotographic photoreceptor having a peelable surface by a usual electrophotographic process. That is, each of the charging-exposure-development processes is performed by a conventionally known method (for example, the above-mentioned “Basic and Application of Electrophotographic Technology”, “Electrophotograph”).
y ”etc.).

The developer used in the present invention is preferably a conventionally known liquid developer for electrostatic photography. For example,
"Basics and Application of Electrophotographic Technology", pp. 497-505, supervised by Koichi Nakamura, "Development and Practical Use of Toner Materials", Chapter 3 (Nippon Kagaku Joho, 1985), Gen Machida, "Recording Materials and Photosensitivity" Specific Examples are shown in "Resin", pages 107 to 127 (1983), Society of Publishing Co., Ltd., and the Electrophotographic Society, "Imaging No. 2-5 Electrophotographic Development, Fixation, Charging, and Transfer". I have.

The basic constitution of a concrete liquid developer is as follows.
Electrically insulating organic solvents {eg, isoparaffinic aliphatic hydrocarbons: Ansoper H, Isopar G (manufactured by Esso),
Shellsol 70, Shellsol 71 (manufactured by Shell),
IP-Solvent 1620 (manufactured by Idemitsu Petrochemical) as a dispersion medium, and dispersion stability of an inorganic or organic pigment or dye as a colorant and alkyd resin, acrylic resin, polyester resin, styrene butadiene resin, rosin, etc.
A resin for imparting fixability and chargeability is dispersed, and various additives are added as required to enhance charge characteristics or improve image characteristics. As the colorant, known dyes and pigments are arbitrarily selected. For example, benzidine, azo, azomethine, xanthene, anthraquinone, phthalocyanine (including metal-containing), titanium white, nigrosine, Aniline black, carbon black and the like.

As other additives, those specifically described in Yuji Harazaki, "Electrophotography" Vol. 16, No. 2, p. 44 are used. For example, a metal salt containing a metal salt of di-2-ethylhexylsulfosuccinic acid, a metal salt of naphthenic acid, a metal salt of a higher fatty acid, a metal salt of an alkylbenzenesulfonic acid, a metal salt of an alkyl phosphate, lecithin, poly (vinylpyrrolidone), and a hemimaleamide component Polymers, coumarone indene resin, higher alcohols, polyethers,
Examples include polysiloxane and waxes.

The amount of each main component of the liquid developer is usually as follows. The toner particles mainly composed of a resin (and a coloring agent optionally used) are used as the carrier liquid 100.
0.5 to 50 parts by weight per 0 parts by weight is preferred. If the amount is less than 0.5 parts by weight, the image density becomes insufficient,
When the amount exceeds the weight part, fogging to the non-image part is apt to occur. The carrier liquid-soluble resin for dispersion stabilization is also used as needed, and 0.5 parts by weight to 1000 parts by weight of the carrier liquid is used.
About 100 parts by weight can be added. The charge control agent is used in an amount of 0.001 part by weight to 1,000 parts by weight per 1000 parts by weight of the carrier liquid.
0 parts by weight is preferred. If desired, various additives may be added. The upper limit of the total amount of these additives is regulated by the electric resistance of the liquid agent. That is, if the electric resistance of the liquid developer from which the toner particles have been removed is lower than 10 ⁹ Ωcm, it becomes difficult to obtain a high-quality continuous tone image, and the amount of each additive is controlled within this limit. .

Specific examples of the method for producing a liquid developer include:
A method of producing colored particles by mechanically dispersing a colorant and a resin using a disperser such as a sand mill, a ball mill, a jet mill, and an attritor is disclosed in, for example, Japanese Patent Publication No. 35-55.
No. 11, 35-13424, and 50-40017
No. 49-98634, No. 58-129438,
It is described in JP-A-61-180248.

As another method for producing colored particles, for example, a method of producing dispersed resin particles by a non-aqueous dispersion polymerization method which obtains fine particles having good monodispersity and coloring them can be mentioned. . As one of the coloring methods, there is a method of dyeing a dispersion resin with a preferable dye as described in JP-A-57-48738. In addition, Japanese Unexamined Patent Publication No.
A method of chemically bonding a dispersing resin and a dye as disclosed in JP-A-3-54029;
As described in the above publication, there is a method of producing a dye-containing copolymer by using a monomer containing a dye in advance when producing by a polymerization granulation method.

The combination of the scanning exposure method using laser light for exposing on the basis of digital information and the developing method using a liquid developer is an effective process because a high-definition image can be formed. An example is shown below. First, the photosensitive material is positioned on a flat bed by a register pin method, and then suctioned and fixed by air suction from the back surface. Next, the photosensitive material is charged by the charging device described on page 212 et seq. Of, for example, "Basics and Application of Electrophotographic Technology" (edited by the Electrophotographic Society of Japan, Corona, published on June 15, 1988). The corotron or scotron system is common. At this time, it is also preferable to control the charging conditions by applying feedback so that the surface potential always falls within a predetermined range based on information from the charging potential detecting means of the photosensitive material. Then, for example, 254
Scanning exposure with a laser light source is performed by using the method described on and after page.

Then, a toner image is formed using the liquid developer. The photosensitive material charged and exposed on the flatbed can be removed therefrom and the wet developing method described on page 275 and thereafter of the cited reference can be used. The exposure mode at this time corresponds to the toner image development mode. For example, in the case of reversal development, a negative image, that is, an image portion is irradiated with laser light to charge the photosensitive material with the same charge polarity. The toner having the toner is used and a developing bias voltage is applied so that the toner is electrodeposited on the exposed portion. Details of the principle are described on page 157 et seq. In order to remove excess developer after development, squeeze such as rubber roller, gap roller and reverse roller, corona squeeze and air squeeze are performed as shown on page 283 of the document. It is also preferable to rinse only the carrier liquid of the developer before squeezing.

Next, before the toner image layer formed as described above on the photoconductor is contact-transferred to the intermediate transfer body, the dispersion medium (solvent attached to the photoconductor remaining without being removed even by squeezing) is used. ) And a dispersion medium (solvent) contained in the toner layer
Is evaporated to dryness. For example, a method of sucking the liquid with a blotting paper, a cold air or hot air method, an infrared lamp, a method of radiant heat using a xenon flash method, a method of heating from the back surface of the photoreceptor, etc. can be used alone or in combination, and specifically, The fixing method described on page 317 and after of the above cited material can be used.

By the above drying step, the toner layer is fixed until the adhesive force between the toner particles increases, and at least the cohesive force of the toner layer becomes larger than the peeling force between the toner layer and the photosensitive member surface. The means for drying these solvents, the heating means for causing the toner layer provided as necessary to fix the toner, and the conditions thereof differ depending on the type of the liquid developer used and the combination of the squeezing device, and can be appropriately combined. . The temperature on the surface of the photoreceptor is preferably about the same as the temperature (T ₁ ) in the next transfer step, and is preferably adjusted in the range of 40 ° C. to 80 ° C., particularly 45 to 70 ° C.

Then, the toner image layer provided on the photoconductor having a releasable surface is contact-transferred onto the surface-adhesive intermediate transfer member, and further transferred onto the transfer-receiving material which is a printing support.

The intermediate transfer member receives the toner image formed on the surface of the photosensitive member by the contact transfer method under the condition of heating and / or pressure (that is, the first transfer) and further transfers it to the material to be transferred (support for printing). And peeling transfer under the condition of heating and / or pressure (that is, second transfer).

In the present invention, the surface temperature (T ₁ ) at the time of the first transfer and the surface temperature (T ₂ ) at the time of the second transfer in the intermediate transfer member are different temperatures, and the second transfer temperature (T ₂ ) is high. Is set. The temperature difference is preferably from 10C to 80C, more preferably from 20C to 60C. First transfer surface temperature (T ₁ )
Is preferably 35 ° C to 70 ° C, more preferably 40 ° C
To 65 ° C, and the second transfer surface temperature (T ₂ ) is preferably 45 ° C to 120 ° C, more preferably 50 ° C to 9 ° C.
It is in the range of 5 ° C.

The surface of the intermediate transfer member used in the present invention is sticky, the adhesive force is 3 gram force or more at the first transfer temperature (T ₁ ), and the second transfer temperature (T ₁ ). _{In 2} ), it has a characteristic of being 40 gram · force or less. In this way, by adjusting the adhesive force of the intermediate transfer member by making a difference in the transfer temperature between the first transfer and the second transfer, the transfer from the photosensitive member to the intermediate transfer member and from the intermediate transfer member to the transfer target material are performed. Complete transfer of the toner image is achieved.

Known methods and apparatuses can be used for this thermal transfer. For example, a toner image having a toner image is brought into close contact with the intermediate transfer member, and the toner image is transferred onto the intermediate transfer member by passing it between rollers under heating. Similarly, the toner image is transferred to the transfer material by bringing the intermediate transfer material and the transfer material into close contact with each other and passing them between the rollers while heating. A conventionally known method is used for heating to the respective heating surface temperatures as described above in the first transfer and the second transfer. For example, a heating means as described in the drying process after the development can be appropriately selected.

The roller nip pressure is preferably 0.2.
１５15 kgf / cm ² , more preferably 0.5-8 kgf / cm ² . As the roller pressing means, an air cylinder using a spring or compressed air at both ends of the roller shaft can be used. Transport speed is preferably 0.1-3
00 mm / sec, more preferably 1-250 mm / sec.
The transport speed may be different between the electrophotographic process and the thermal transfer step, and may also be different between the first transfer and the second transfer.

In the present invention, any intermediate transfer body device satisfying the above conditions may be used. Examples of methods used for transferring the toner image from the photoconductor to the intermediate transfer member include a drum method and an endless belt method that can be repeatedly used. In the drum system, on the drum,
Any elastic layer / adhesive resin layer may be provided as long as they satisfy the above conditions by sequentially forming and providing them.

In the endless belt system, known members can be used, for example, US Pat. No. 3,893,
Nos. 761, 4,684,238 and 4,690,5
No. 39 and the like. In the belt carrier layer of the belt-type intermediate transfer member, for example,
A method of providing a layer serving as a heating medium as described in JP-A-265-265 or the like is also used.

The surface of the intermediate transfer member of the present invention is a pressure-sensitive adhesive or a cured film of an adhesive which has tackiness, adhesiveness at low temperature side and releasability at high temperature side, and satisfies the above-mentioned physical properties. Any one may be used. Specifically, using a material called a removable pressure-sensitive adhesive or a removable pressure-sensitive adhesive mainly containing an acrylic ester copolymer, a methacrylic ester copolymer or a vinyl ether copolymer as a main component, respectively. Cured films. Preferred are JP-A-52-91041, JP-A-58-104974, and JP-A-5-104974.
Pressure-sensitive adhesive (adhesive) compositions containing a (meth) acrylate-based resin as a main component, such as those described in JP-A-8-141271, and pressure-sensitive adhesive compositions containing a silyl group-modified polyether as a main component, as described in JP-A-4-36368, etc. And the like.

The adhesive resin layer of the present invention is a cured film,
Cured by light and / or heat treatment. The curing method may be any of conventionally known methods, and specific examples include the same methods as described in the overcoat layer. The thickness of the adhesive resin layer is preferably from 0.05 μm to 1 mm, more preferably from 0.1 to 100 μm. By using the adhesive resin layer having the above-described configuration, the toner image can be completely transferred quickly and the durability can be sufficiently maintained without increasing the heating temperature during thermal transfer.

Further, the intermediate transfer member of the present invention preferably has an elastic layer having a film thickness equal to or larger than the thickness of the toner image formed below the adhesive resin layer. The thickness of the elastic layer provided is preferably from 0.01 to 10 mm, more preferably from 0.05 to 5 mm. As a result, the pressure applied to the toner image layer during pressure contact transfer under heating is relieved by the elastic layer (cushion effect), so that distortion such as distortion or deformation in the high-definition toner image layer is caused. , And faithful transfer can be performed. The elastic layer may be an elastic layer made of the following resin exhibiting elasticity, or a laminated structure including the elastic layer and a reinforcing layer support.

As the elastic body, conventionally known natural resins,
And synthetic resins. These can be used alone or in combination of two or more to form a single layer or a plurality of layers. For example, ADRpberts "Natural Rubber Science a
nd Technology, Oxford Science Publications (1988), W. Hofmann, Rubber and Technology Hanfboo
k ", Hanser Pubisheras (1989), Plastic Materials Course, 18 volumes, various resins described in Nikkan Kogyo Shimbun, etc. are used. Specifically, styrene-butadiene rubber, butadiene rubber, acrylonitrile-butadiene rubber, cyclized rubber, chloroprene rubber, ethylene-propylene rubber, butyl rubber, chlorosulfonated polyethylene rubber, silicone rubber, fluorine rubber, polysulfide rubber, natural rubber , Isoprene rubber, urethane rubber and the like,
It is not limited to these, and can be arbitrarily selected in consideration of the releasability from the transfer layer, durability, and the like. As the reinforcing layer of the elastic layer, cloth, glass fiber, resin-impregnated special paper, aluminum, stainless steel, or the like is used. A sponge-like rubber layer may be provided between the elastic layer and the reinforcing layer.

Next, in the present invention, the toner image on the intermediate transfer member is thermally transferred onto the final transfer material. The transfer material used in the present invention may be any material that provides a hydrophilic surface suitable for lithographic printing, and a support conventionally used for offset printing plates can be used as it is. Specifically, plastic sheets, paper with printing durability, aluminum plates, zinc plates,
Substrates having a hydrophilic surface, such as bimetal plates such as copper-aluminum plates, copper-stainless steel plates, and chromium-copper plates, and trimetal plates such as chromium-copper-aluminum plates, chromium-lead-iron plates, and chromium-copper-stainless steel plates. Is used. The thickness is preferably 0.1 to 3 mm, particularly preferably 0.1 to 1 mm.

In the case of a support having an aluminum surface, it is subjected to surface treatment such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like, or anodic oxidation treatment. Is preferred. Further, as described in U.S. Pat. No. 2,714,066, an aluminum plate grained and then immersed in an aqueous solution of sodium silicate is disclosed in JP-B-47-51.
As described in No. 25, an aluminum plate subjected to anodizing treatment and then immersed in an aqueous solution of an alkali metal silicate is also preferably used. The anodizing treatment is, for example, electrolysis of an inorganic acid such as phosphoric acid, chromic acid, sulfur, boric acid, or an organic acid such as oxalic acid or sulfamic acid or an aqueous solution or a non-aqueous solution of a salt thereof alone or in combination of two or more. It is carried out by flowing a current in the liquid using an aluminum plate as an anode.

Further, silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective. The treatment with polyvinyl sulfonic acid described in West German Patent Publication No. 1,621,478 is also suitable.

These hydrophilization treatments are carried out not only to make the surface of the support hydrophilic, but also to improve the adhesion to the toner image provided thereon.
A surface layer may be provided on the surface of the support in order to adjust the adhesiveness between the support and the transfer layer on which the toner image has been formed. When a plastic sheet or paper is used as a support, it is a matter of course that a material provided with a surface layer having hydrophilicity is provided because portions other than the toner image portion must be hydrophilic. Specifically, a known direct-drawing lithographic printing original plate or a transfer material having a layer similar to the image receiving layer of the original plate can be used.

A known method and apparatus can also be used for thermal transfer from the intermediate transfer member to the material to be transferred. The preferable range of the heating temperature during the transfer, the range of the nip pressure between the intermediate transfer body and the material to be transferred, and the range of the transport speed are the same as the ranges of the above-described thermal transfer conditions of the photosensitive body and the intermediate body transfer body. The first transfer and the second transfer may be performed under the same condition or under different conditions.

Depending on the type of liquid developer or the type of transfer material, a cooling means may be provided on the peeling backup roller in order to ensure sufficient stability of rapid transfer to the transfer material. As a result, the toner image layer heated by the heating roller of the intermediate transfer member and having increased adhesiveness adheres to the material to be transferred, and then passes under the cooling roller for peeling, after which the temperature decreases and the toner image layer It is presumed that the fluidity and tackiness are reduced, and the intermediate transfer body is always stably and completely peeled off.

It is desirable that the cooling roller is made of a heat conductive metal such as aluminum or copper with a silicone rubber coating, and a cooling means is attached to the inside of the roller or the outer peripheral portion which is not in contact with the transferred material to radiate heat. . As the cooling means, it is preferable to use a cooling fan, a refrigerant circulation or an electronic cooling element or the like, and to keep the temperature in a predetermined temperature range in combination with a temperature controller. The transfer of the toner image from the photoconductor to the intermediate transfer member and the transfer of the toner image from the intermediate transfer member to the transfer material may be performed simultaneously within one screen, or the transfer of the entire one screen to the intermediate transfer member. After completion of the process, the image may be transferred to the transfer target material.

In the method for producing a printing plate of the present invention, the conditions for transferring the toner image are set as follows: the photoconductor (photosensitive layer and support) used, the toner image layer, the physical properties of the surface of the intermediate transfer member,
Further, it is natural that the transfer material is optimized depending on the physical properties. In particular, it is important to determine the temperature conditions in the thermal transfer step in consideration of factors such as the glass transition point, softening temperature, fluidity, adhesiveness, film properties, and film thickness of the transfer layer. Depending on the type of the liquid developer to be used, a step of further fixing the toner image layer transferred onto the transfer-receiving material to form a uniform film which does not lose film even with mechanical force during printing may be added.

Further, in the present invention, when the plate making is repeatedly carried out, dust such as paper dust brought into the plate making machine when a paper support or the like is used as the material to be transferred, is generated in the adhesive surface of the present invention. In order to prevent the occurrence of defects in the transfer due to the adhesion to the intermediate transfer body, a cleaning unit for cleaning the adhered dust on the surface of the intermediate transfer body may be provided. The cleaning unit is not particularly limited as long as it can simply remove dust attached to the cleaning unit. For example, a cleaning pad such as an adhesive tape for dust removal, a method of applying a thermoplastic resin to the intermediate transfer body over the entire surface by an electrodeposition method, a hot melt method, a transfer method from release paper, and the like, and a method of peeling off the resin are used. .

The method for producing the electrophotographic plate-making printing plate of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 3
Is a schematic diagram of an electrophotographic prepress printing plate making apparatus suitable for performing the method of the present invention, as an intermediate transfer member,
FIG. 1 shows a drum system, and FIGS. 2 and 3 show an endless belt system. This will be described below with reference to FIG.

First, the photoconductor 11 is charged with the corona charging device 18
Then, for example, after positively charging uniformly, when an image is exposed based on image information by an exposure device (for example, a semiconductor laser) 19, the potential of the exposed portion is reduced and a potential contrast is obtained between the exposed portion and the unexposed portion. The liquid developing unit set 1 includes a liquid developing unit 14T containing a liquid developer in which resin particles having a positive electrostatic charge are dispersed in an electrically insulating dispersion medium.
From the position 4, approach the surface of the photoconductor and fix it with a gap of 1 mm.

The photoconductor 11 is pre-bused by the pre-bus means provided in the developing section, and then a developing bias voltage is applied between the photo conductor 11 and the developing electrode by a bias power source and electric connection not shown in the figure, and the liquid is applied. A developer is supplied to the surface of the photoconductor. The bias voltage at this time is connected so that the developing electrode side is positive and the photoconductor side is negative, and the applied voltage is slightly lower than the surface potential of the unexposed portion. If the applied voltage is too low, a sufficient toner image density cannot be obtained.

Then, the rinsing means built in the liquid developing unit set 14 is used to wash away the developer adhering to the surface of the photoconductor, and then the squeeze means to remove the rinsing liquid adhering to the surface of the photoconductor. Dry by passing under. During this time, the intermediate transfer member 20 is placed away from the surface of the photoconductor 11. As the prebath and the rinsing liquid, a carrier of a usual liquid developer is preferably used.

Further, in the embodiment of the present invention, the surface of the photoconductor is preliminarily heated and adjusted to a predetermined temperature by the preheating means 16 and then charged and exposed as described above, and the developing solution and the rinsing solution have the same temperature. Can be adjusted for development and rinsing. The temperature at which the electrophotographic process is performed under preheating is preferably 35 ° C to 60 ° C, more preferably 40 ° C to 55 ° C. In this range, a faithful copy image can be stably formed on the original.

Then, the toner image on the photoconductor 11 is transferred to the intermediate transfer body 20. If necessary, the preheating means 16 for thermal transfer of the photosensitive drum performs predetermined preheating, and if necessary, the intermediate transfer body 20 also performs predetermined preheating by using the preheating means 16 so that the surface of the photosensitive body is exposed. The toner image is pressed against the intermediate transfer body 20 and transferred by heat. Further, as shown in FIG. 3, the cleaning unit 21 and the cooling device 2 described above are used.
Two may be provided. The cooling device 22 can be installed to quickly adjust the temperature adjustment from the temperature (T ₂ ) to the temperature (T ₁ ).

Next, the toner image completely transferred onto the intermediate transfer member 20 is further pressed against the transfer material 30 to perform thermal transfer. If necessary, the preheating means 16 of the intermediate transfer body 20 performs a predetermined preheat, and the transfer material 30 is also subjected to a predetermined preheat by the transfer backup roller 31 to transfer the toner image on the intermediate transfer body 20 to the transfer material 30. After pressure contact with the toner, the toner image is transferred onto the transfer target material 30 by cooling with the peeling back roller 32 if necessary, and the series of steps is completed.

[0132]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

Example 1 X-type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc.) 2
g, 14.4 g of the following binder resin (P-1), 3.6 g of the following binder resin (P-2), 0.15 g of the following compound (A), and 80 g of cyclohexanone were placed in a 500-ml glass container with glass beads. The mixture was dispersed with a paint shaker (manufactured by Toyo Seiki Seisaku-sho) for 60 minutes, and then the glass beads were separated by filtration to obtain a photosensitive layer dispersion.

[0134]

Embedded image

Next, this dispersion was degreased to a density of 0.
Apply on a 2mm thick aluminum plate with a wire bar,
After being dried by touch, it was heated in a circulating oven at 110 ° C. for 20 seconds. The film thickness of the obtained photosensitive layer was 8 μm.

Formation of releasable surface layer (overcoat layer) 10 g of silicone resin having the following structure, crosslinking agent 1 having the following structure
g, a coating material containing 0.2 g of a crosslinking controller having the following structure and 0.1 g of platinum as a crosslinking catalyst in 250 g of n-octane was formed into a film having a thickness of 0.5 μm using a wire round rod.
And dried to the touch, and then at 120 ° C for 10
Heated for minutes. The adhesive strength of the obtained surface was 1 g · f or less.

[0137]

Embedded image

The photoreceptor having surface releasability obtained as described above was attached to the apparatus shown in FIG. 1 as the electrophotographic photoreceptor 11, and the intermediate transfer member 20 having the following contents was attached.

Intermediate transfer member A blanket 9600-A for offset printing (total thickness: 1.6 mm, made by Meiji Rubber) was coated on the surface thereof with an acrylic ester-based removable adhesive: Cybinol MS-102 (Siden Chemical Co., Ltd. )) Is applied to a film thickness of 5 μm,
After touch drying, the film was further heated at a temperature of 120 ° C. for 5 minutes to form a cured film. The blanket having the surface of the adhesive cured film was treated with JI
"Adhesive tape / adhesive sheet test method" of SZ 0237-1980
When the adhesive strength was measured using a PET film, the value was 5 g · f at a temperature of 50 ° C. and 1.8 g · f at a temperature of 90 ° C. The blanket prepared in this way was pasted on a hollow drum in which a temperature controller was incorporated.

Next, an electrophotographic process was performed. The photoconductor 11 was adjusted in a dark place so that the surface temperature of the photoconductor was 50 ° C., and then passed under the corona charging device 18 to +450 V
After corona charging, the information was read in advance from a manuscript with a color scanner, color-separated, corrected for some system-specific color reproduction, and stored as digital image data on the hard disk in the system. Using a semiconductor laser writing apparatus as the exposure apparatus 19, a beam spot diameter of 15 μm, a pitch of 10 μm, and a scan speed of 300 μm were used.
Exposure was at a speed of cm / sec (ie 2500 dpi). Exposure was performed so that the exposure amount on the photoconductor at this time was 25 erg / cm ² .

Subsequently, as a liquid developer, ELP-TX (manufactured by Fuji Photo Film Co., Ltd.) for electrophotographic plate-making printing original plate
Is supplied to the liquid developing unit 14T, a bias voltage of +350 V is applied to the liquid developing unit side, and reversal development is performed so that the toner is electrodeposited on the unexposed portion. After removing the stain on the non-image area, the sheet was dried by passing it under the suction / exhaust unit 15.

Next, 11 drums of the photoconductor having the surface temperature of 50 ° C. and 20 drums of the intermediate transfer body having the surface temperature of 50 ° C. were brought into contact with each other, the nip pressure was 4 kgf / cm ² , and the drum peripheral speed was 10.
When heating and pressing were performed under the conditions of 0 mm / sec, the entire toner image was transferred onto the intermediate transfer member.

Subsequently, between the intermediate transfer member 20 drum with the surface temperature kept at 50 ° C., the transfer backup roller 31 set at 100 ° C. and the peeling backup roller 32 set at 25 ° C., the transferred material 30 is transferred. As Fuji
Guide the aluminum support used for PS plate FPD (manufactured by Fuji Photo Film Co., Ltd.) and set the nip pressure to 4 kg.
When heating and pressurization were performed at f / cm ² and a drum peripheral speed of 100 mm / sec, all the toner images were transferred onto the aluminum support.

Visual observation of the plate thus obtained using a 200 × optical microscope revealed that no toner particles were found in the non-image area and that high-resolution areas such as fine lines and fine characters in the image area were observed. No omissions were observed, and 2 to 99 of halftone dots of 175 lines
%, Fine lines of 10 μm and Mincho class 2 or higher were resolved, and there was no deformation such as bending of the image.

Next, after the above plate was gummed to form a printing plate, its printing performance was examined. The printing plate was dipped in water using a PS plate dipping water (SG-23, manufactured by Tokyo Ink Co., Ltd.) diluted 130 times with distilled water (pH 7.0), and a Oliver 94 type (( Sakurai Mfg. Co., Ltd.) was used, and neutral paper was used as the printing paper, and printing was performed with various color inks for offset printing. As a result, irrespective of the type of the color ink, more than 60,000 prints of clear images with no background stain were obtained in any case.

Furthermore, after printing with the printing plate of the present invention, printing was then performed using a normal PS plate with the normal operation, and no problems occurred. That is, it was confirmed that the printing press can be easily shared with another offset printing plate such as a PS plate. Further, when a printing plate was prepared by the same operation as described above for 1000 plates, the printed matter obtained from the 1000th printing plate showed exactly the same performance as the first plate, and no change was observed. . Further, when the peeling force of the photosensitive member and the adhesive force of the intermediate transfer member at each temperature were measured again, they showed almost the same value, which confirmed the result of the above-mentioned practical technique.

Comparative Example In the operation of Example 1, the surface temperature of the photosensitive member was set to room temperature (about 2
(5 ° C.), a toner image is formed on the photosensitive member by an electrophotographic process, squeezed, and immediately transferred to an intermediate transfer member without being dried. As is known, significant flow of toner images and significant loss of images were also visually observed with a 20X loupe. Further, transfer of the toner image was left on the surface of the photoconductor, and 100% was not transferred.

Further, the squeezed photoreceptor which had been developed at room temperature was naturally dried for 10 minutes to reduce the amount of the rinse liquid, and transfer was performed in a state where the residual amount of Isopar G per toner weight (mg) was 1 mg. In the toner image on the intermediate transfer member, no image deletion was observed, but a partial omission occurred in the fine line / fine character portion. Further, although the toner remained on the surface of the photosensitive member, it was slightly observed, and 100% transfer was not achieved.

As another comparative example, instead of the adhesive surface layer of the present invention, a cured adhesive surface resin having a film thickness of 5 μm was prepared in the same manner as in the present invention by using the adhesives of the following Table-A. The transferability was examined in the same manner as in Example 1 except that an intermediate transfer member provided with a layer was used.

[0150]

[Table 1]

In Comparative Examples 1 and 2, the first transfer was completely transferred, but in the second transfer, a slight transfer residue was generated in Comparative Example 1, and the transfer image on the FPD plate was disturbed. Example 2 was not transcribed at all. Comparative Example 3 using a non-removable acrylic ester-based adhesive is the first
The transfer was insufficient, and the transferability was further deteriorated in the second transfer (here, the transfer rate represents the ratio of the transferred image surface to the total toner image area ratio, and was calculated by observation with a 200 × optical microscope. ).

As described above, according to the present invention, the toner image formed on the surface of the releasable photosensitive member using the liquid developer is contact-transferred through the intermediate transfer member to prepare a high-quality printing plate. It was possible, and the performance did not change at all even after repeated plate making.

Example 2 An amorphous silicon photoconductor (manufactured by Kyocera Corp.) was dipped for 10 seconds in a solution prepared by dissolving 1.5 g of a surface releasing compound (S-1) having the following content in 1 liter of Isopar G,
Thereafter, it was rinsed in Isopar G and dried. As a result, the surface of the amorphous silicon photoreceptor having an adhesive force of 220 g · f was modified into a peelable surface having an adhesive force of 1.5 g · f.

[0154]

Embedded image

A photosensitive member having this surface releasability was prepared as in Example 1.
In the same manner as described above, it was loaded into the apparatus shown in FIG. The same intermediate transfer member as in Example 1 was used.

Next, the amorphous silicon photoconductor 11 having releasability is corona charged to +700 V in a dark place, and then it is read in advance from a document by a color scanner and color separation is performed to reproduce some system-specific colors. After the correction related to the above, the semiconductor laser was used to expose with light of 780 nm based on the information stored in the hard disk in the system as digital image data. The potential of the exposed part was +220 V, and that of the unexposed part was +600 V.

Next, after pre-bathing with Isopar H (manufactured by Esso Standard Petroleum) by a pre-bathing device incorporated in the developing unit, the following wet type developer (L
D-1) was supplied from the developing unit to the surface of the photoreceptor. At this time, a developing bias voltage of +500 V was applied to the developing unit, and reversal development was performed so that the toner was electrodeposited on the unexposed portion. Next, rinsing was performed in a single bath of Isopar H to remove stains in the non-image area, and dried with a suction and exhaust unit.

Preparation of Liquid Developer (LD-1) -Synthesis of Toner Particles Methyl methacrylate 30 g, methyl acrylate 70
g, 20 g of a dispersed polymer having the following structure and Isopar H6
80 g of the mixed solution was stirred at a temperature of 65 while stirring under a nitrogen stream.
Warmed to ° C. To this, 1.2 g of 2,2'-azobis (isovaleronitrile) (abbreviated as AIVN) was added and reacted for 2 hours, and 0.5 g of AIVN was further added and reacted for 2 hours.
0.5 g of AIVN was added and reacted for 2 hours. Next, the reaction temperature was raised to 90 ° C., and the mixture was stirred for 1 hour under a reduced pressure of 30 mmHg to remove unreacted monomers. After cooling to room temperature, the mixture was filtered through a 200-mesh nylon cloth to obtain a white dispersion. The conversion of the monomer in the obtained dispersion was 95% by weight, the average particle size of the resin particles was 0.22 μm, and the monodispersibility was good. The particle size was measured using CAPA-500.

[0159]

Embedded image

Production of colored particles Tetradecyl methacrylate / methacrylic acid (95/5
(Weight ratio) 10 g of the copolymer, 10 g of nigrosine and 30 g of Isopar G were placed in a paint shaker (manufactured by Tokyo Seiki Co., Ltd.) together with glass beads, and dispersed for 4 hours to obtain a fine dispersion of nigrosine.

Manufacture of liquid developer 45 g of the resin dispersion of the toner particles, 25 g of the nigrosine dispersion, 0.2 g of hexadecene / semi-maleic acid octadecylamide copolymer and branched octadecyl alcohol (FOC-1800, manufactured by Nissan Chemical Co., Ltd. )) Was diluted to 1 liter of Isopar G to prepare a liquid developer for electrostatic photography (LD-1).

Next, the infrared line heater is turned on and passed underneath to bring the surface temperature of the photoconductor to 60 ° C., the intermediate transfer member whose surface temperature is adjusted to 60 ° C. and the photoconductor are brought into contact with each other, and the nip pressure is increased. All the toner images were transferred onto the intermediate transfer member under the conditions of 4 kgf / cm ² and drum peripheral speed of 100 mm / sec. Subsequently, an aluminum support for FPD as the material to be transferred 30 is guided between the intermediate transfer drum and the transfer backup roller 31 and the peeling backup roller 32 set at 100 ° C., and the nip pressure is 4 kgf / cm ² , When heating and pressurizing at a drum peripheral speed of 100 mm / sec,
The toner image was all transferred onto an aluminum support.

The printing original plate thus obtained was subjected to RIC.
After heating using OH FUSER model 592 (manufactured by Ricoh Co., Ltd.) to sufficiently fix the toner portion, visual observation using a 200 × optical microscope showed no contamination in the non-image portion, and No loss of high-resolution areas such as fine lines and fine characters in the image portion was observed. The printing plate thus obtained was gummed to form a printing plate, and then offset printing was carried out in the same manner as in Example 1. As a result, regardless of the type of color ink, in all cases, 80,000 or more prints of clear images with no background stain were obtained.

As described above, depending on the type of liquid developer used for toner image formation, in order to maintain sufficient adhesion between the toner image portion and the transfer material, and to maintain the toner image strength during printing. Alternatively, the adhesion improving means may be combined after the toner image is transferred to the transfer target. The same effect was obtained by a method using flash fixing or a method using heat roll fixing as a means for improving adhesion. Furthermore,
The same operation as described above was repeated to prepare 5,000 printing plates and printing was carried out. As a result, printing results having completely the same performance as the first plate were obtained.

Example 3 5 g of a bisazo pigment having the following structure, tetrahydrofuran 95
g of polyester resin (Byron 200, manufactured by Toyobo Co., Ltd.) was sufficiently pulverized in a ball mill. Next, the mixture was taken out, and 520 g of tetrahydrofuran was added with stirring. This dispersion was coated on the same aluminum plate as used in Example 1 using a wire round rod to form a charge generation layer of about 0.7 μm. Next, 20 g of a hydrazone compound having the following structural formula, a polycarbonate resin (Lexane 121, manufactured by GE) 20
g and a mixed solution of 160 g of tetrahydrofuran were applied on the charge generation layer using a wire round rod,
After drying at 60 ° C. for 30 seconds and further heating at a temperature of 100 ° C. for 20 seconds, a charge transport layer having a thickness of about 18 μm was formed to obtain an electrophotographic photosensitive member having a two-layer photosensitive layer.

[0166]

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Further, in order to form a surface layer for imparting releasability on the photosensitive layer, a resin (PP
-1) 6 g, phthalic anhydride 0.1 g, phthalic acid 0.02
g and a mixed solution of 100 g of toluene were applied using a wire round rod so as to have a film thickness of 0.7 μm, dried by touch, and further heated at 140 ° C. for 1 hour. The tackiness of the surface of the obtained photoreceptor was 1 g · f or less.

[0168]

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This photosensitive material was subjected to a surface potential of -500 in a dark place.
V, and 633 using a He-Ne laser.
Exposure was performed with light of nm so that the exposure amount on the plate surface was 25 erg / cm ² . Subsequently, ELP-TX was used for liquid development, and positive development was performed with a bias voltage of 50 V applied, followed by rinsing with Isopar G. Thereafter, a printing plate was prepared in the same manner as in Example 1, and offset printing was performed. The obtained results were as good as in Example 1. In addition, the same repetition characteristics of plate-making as in Example 1 were obtained.

Example 4 As an organic photoconductive substance, 4,4'-bis (diethylamino) -2,2'-dimethyltriphenylmethane (5 g),
4 g of a binder resin (P-3) having the following structure, 40 mg of a dye (D-1) having the following structural formula, 0.2 g of an anilide compound (B) having the following structure as a chemical sensitizer, and 30 ml of methylene chloride:
And 30 ml of ethylene chloride to obtain a photosensitive layer dispersion. The photosensitive layer dispersion was applied to a conductive transparent support (a polyethylene terephthalate support having a thickness of 100 μm, having a vapor-deposited film of indium oxide, surface resistance of 10 ³ Ω) using a wire round rod, and was coated for about 4 hours.
A photoconductor having a photosensitive layer having a thickness of μm was obtained.

[0171]

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Ultraviolet curable silicone rubber TFC7700 (manufactured by Toshiba Silicon Co., Ltd.) was applied to the surface of this photoreceptor, and a silicone rubber layer was coated with a wire bar in the same manner as in Example 1, and the high pressure mercury lamp UM102 ( Ushio Electric Co., Ltd.) was irradiated for 30 seconds from a distance of 5 cm. At this time, the thickness of the silicone rubber layer was 0.6 μm. The resulting photoreceptor had an adhesive strength of 1 g · f on the surface.

A printing plate was formed and printing was performed in the same manner as in Example 1 except that this photosensitive member was used instead of the photosensitive member used in Example 1. As in Example 1, the obtained image on the printed matter was clear without fog, and the printing durability was good.

Example 5 Instead of the peelable surface layer used in Example 1, 9 g of a silicone rubber polymer having the following structure, 400 mg of a crosslinking agent having the following structure, and a catalyst X92-1114 (Shin-Etsu Silicon Co., Ltd.) were used on the surface of the photoreceptor. A mixed solution of 40 mg of heptane and 150 g of heptane was uniformly applied with a wire bar, heated at 90 ° C. for 2 minutes to dry and crosslink to form a silicone rubber layer. At this time, the thickness of the surface layer was 1.0 μm. The adhesive strength of this surface was 1 g · f or less.

[0175]

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Printing was carried out by forming a printing plate in the same manner as in Example 1 except that this photoconductor was used instead of the photoconductor used in Example 1. As in Example 1, the obtained image on the printed matter was clear without fog, and the printing durability was good. Further, even when the 1000th printing plate was repeatedly prepared, the same good results as in Example 1 were obtained.

Example 6 In the peelable surface layer of Example 3, the resin (PP-
1) 6 g of resin (PP-2) having the following structure instead of 6 g
A photoconductor was prepared in exactly the same manner as in Example 3 except that was used.

[0178]

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Printing was carried out by forming a printing plate in the same manner as in Example 3 except that this photoconductor was used instead of the photoconductor used in Example 3. The image on the obtained printed matter was clear without background fog and had good printing durability as in Example 3. In addition, a printing plate is repeatedly prepared and 10
The printing plate after the 00 plate also showed exactly the same performance as the first plate.

Example 7 The surface-releasing photosensitive member used in Example 1 was mounted on the apparatus shown in FIG. 2, and the endless belt type intermediate transfer member prepared as described below was mounted on it.

<Intermediate transfer member> First, a 0.5 mm thick natural rubber resin layer (rubber hardness 75 degrees, manufactured by Kokugo Co., Ltd.) was attached as an elastic layer on a stainless steel film having a thickness of 100 μm. A re-peelable adhesive: Boncoat 868 (latex of acrylic ester type main component, manufactured by Dainippon Ink and Chemicals, Inc.) on this layer has a film thickness of 1 μm after drying.
It was applied so as to have a thickness of m, and further heat-cured at a temperature of 120 ° C. for 3 minutes to form a surface adhesive layer. Transfer temperature (T ₁ ) of 50
Adhesive force at 65 ° C is 65gf, transfer temperature (T ₂ ) is 110 ° C.
Then, the value was 8 g · f.

In the same manner as in Example 1, a toner image is formed on the photoconductor, and the toner image is transferred under the conditions of a transfer temperature (T ₁ ) of 50 ° C., a nip pressure of 3.5 kgf / cm ² and a transfer speed of 50 mm / sec. The layers were transferred onto an intermediate transfer. Subsequently, an OK master (Nippon Foil Co., Ltd.) was used as a material to be transferred between the transfer backup roller 31 adjusted so that the transfer temperature (T ₂ ) was 110 ° C. and the peeling backup roller not adjusted in temperature. The toner image layer was transferred onto the OK master by heating and pressurizing at a nip pressure of 4 kgf / cm ² and a transfer speed of 50 mm / sec.

Visual inspection of the plate thus obtained using a 200 × optical microscope revealed that no toner particles were found in the non-image area and that high-resolution areas such as fine lines and fine characters in the image area were observed. No deficiency was observed and the performance was the same as in Example 1. Offset printing was performed on this printing plate in the same manner as in Example 1. As a result, regardless of the type of color ink, in any case, a clear image printed matter without scumming was produced.
I got more than 10,000 copies. The endless belt intermediate transfer member after the second transfer was cooled to the surface temperature of the first transfer temperature (T ₁ ) at the site of the cooling device 22 and adjusted so as to enable repeated plate making. In this way, even when the printing plate was repeatedly prepared for 1000 or more printing plates, the printing plate of the 1000th printing plate was exactly the same as the first printing plate.

Example 8 A printing plate was prepared in the same manner as in Example 1 except that the intermediate transfer member having the following contents was used. However, the temperature (T ₂ ) during the second transfer was 100 ° C.

<Intermediate Transfer Body> A silicone rubber layer having a rubber hardness of 45 ° and a thickness of 2 mm is formed on a hollow drum having a temperature controller incorporated therein to form a heat resistant elastic body layer. The pressure-sensitive adhesive solution of 1 was applied so that the dry film thickness would be 1 μm, and heat-cured at 120 ° C. for 5 minutes to form an adhesive layer.

Adhesive Solution Cyril 5A-01 (Kanefuchi Chemical Industry Co., Ltd.) 8 g Methyldimethoxysilyl group-terminated polypropylene oxide Tackifier: Steperite ester 10 (Rika Hercules Co., Ltd.) 3.8 g Aluminum triethyl Acetate 1.3 g of a 10% solution of toluene

The adhesive strength of the surface of the intermediate transfer member thus prepared was 80 g · f at 50 ° C. at temperature (T ₁ ) and 10 g · f at 100 ° C. at temperature (T ₂ ). The obtained results were exactly the same as in Example 1 and were good.

[0188]

According to the intermediate transfer method of the present invention, when a toner image formed on a photoreceptor with a liquid developer is transferred onto a lithographic printing support, an excellent transfer image can be formed. Further, due to excellent transfer efficiency, repetitive durability of the photoreceptor and the intermediate transfer member is possible. In addition, a lithographic print with high definition and no image quality can be obtained. Further, it is possible to provide an apparatus for preparing a lithographic printing plate having excellent plate making quality by contact-transferring a toner image formed by an electrophotographic process using a liquid developer via an intermediate transfer member.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of an apparatus for implementing a method of the present invention employing a drum system as an intermediate transfer member.

FIG. 2 employs an endless belt method as an intermediate transfer member.
FIG. 3 is a diagram showing an example of an apparatus for performing the method of the present invention.

FIG. 3 employs an endless belt method as an intermediate transfer member.
FIG. 3 is a diagram showing an example of an apparatus for performing the method of the present invention.

[Explanation of symbols]

 11 Photoreceptor 14 Liquid Developing Unit Set 14T Toner Forming Unit 15 Intake / Exhaust Unit 15a Intake Part 15b Exhaust Part 16 Preheating Means 17 Temperature Adjusting Means 18 Corona Charging Device 19 Exposure Device 20 Intermediate Transfer Unit 21 Cleaning Unit 22 Cooling Part 30 Transfer material 31 Backup roller for transfer 32 Backup roller for peeling

Claims (6)

[Claims] 1. A toner image is formed on the surface of an electrophotographic photosensitive member having a peelable surface by an electrophotographic process using a liquid developer, and at least a dispersion medium is dried to cause partial fusion between toner particles. After that, the toner image is contact-transferred onto an intermediate transfer member having an adhesive surface at a temperature (T ₁ ), and then the toner image is transferred onto a final transfer material which becomes a hydrophilic surface capable of lithographic printing during printing. Temperature (T ₁ ) higher than temperature (T ₁ ).
₂ ) is a method for producing a plate-making printing plate by contact-transferring, and the adhesive force of the surface of the intermediate transfer member is JIS Z 0237-1.
An electrophotographic plate-making printing plate characterized by having an adhesive force according to "Adhesive tape / adhesive sheet test method" of 980, 3 gram force or more at temperature (T ₁ ) and 40 gram force or less at temperature (T ₂ ). How to create. 2. The electrophotographic plate making method according to claim 1, wherein the intermediate transfer member having the adhesive surface has an elastic layer having a thickness at least equal to or greater than the thickness of the formed toner image. How to make a printing plate. 3. The electrophotographic plate-making printing plate according to claim 1, wherein the electrophotographic process using the liquid developer is carried out at the surface temperature of the electrophotographic photosensitive member (T ₁ ). How to make. 4. The adhesive force according to the “adhesive tape / adhesive sheet test method” at least when a toner image is formed on the surface of the electrophotographic photosensitive member, is 20 gram · force or less. 4. The method for preparing an electrophotographic printing plate according to any one of 1 to 3 above. 5. A means for forming a toner image by a wet electrophotographic process on an electrophotographic photosensitive member having a peelable surface, a means for drying a dispersion medium in the toner layer, and an intermediate transfer member having an adhesive surface. Means for transferring the toner image from the photoconductor at a temperature (T ₁ ), and the toner image on the intermediate transfer member to a final transfer material at a temperature (T ₂ ) higher than the temperature (T ₁ ). An electrophotographic plate making printing plate making apparatus comprising at least a means for 6. The wet electrophotographic process is further performed at a temperature (T
6. The electrophotographic plate making printing plate making apparatus according to claim 5, further comprising means for carrying out in ₁ ).