JP2006276744A - Photoreceptor sheet and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend the lifetime of a photoreceptor sheet by preventing peeling and breakage of a photosensitive layer of the photoreceptor sheet obtained by disposing a conductive layer and the photosensitive layer on a substrate layer, and to achieve price-reduction of an image forming apparatus by achieving stable high-quality image formation over a prolonged period of time. <P>SOLUTION: In the image forming apparatus, cut faces of the photoreceptor sheet 12 are heat-treated to thermally modify the interface between the substrate layer 12a and the conductive layer 12b and the interface between the conductive layer 12b and the photosensitive layer 12c. By the thermal modification, binding layers 38a, 38b are formed in the interfaces, whereby the strength of the interfaces is enhanced and peeling of the photosensitive layer 12c is prevented or infiltration of liquid developers 20Y-20BK into the interfaces is prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photoreceptor sheet, and more particularly to a photoreceptor sheet that reinforces an end surface and an image forming apparatus that forms an image using the photoreceptor sheet.

  In an electrophotographic image forming apparatus, the cost of a photoconductor device is reduced as one of means for reducing the cost of the device or reducing the running cost. For example, since a high-speed, high-quality color image forming apparatus requires an expensive large-diameter photosensitive drum, conventionally a drum-shaped support is used to reduce the cost associated with the replacement of the photosensitive member. A photoreceptor device in which a flexible photoreceptor sheet is wound around is used. In this photoreceptor device, a photoreceptor sheet is formed by winding a photoreceptor sheet around a drum-shaped support. When the photoreceptor sheet is deteriorated, the used photoreceptor sheet is wound up from the surface of the support, and a new photoreceptor sheet is wound around the support for use.

  In general, a photosensitive sheet is obtained by laminating and forming a conductive layer and a photosensitive layer on a wide and long base layer, and then cutting to a predetermined size to obtain a desired size. In the photoreceptor sheet cut into a predetermined size, the interface between the base layer, the conductive layer, and the organic photosensitive layer is exposed at the cut end face. In addition, the interface between the base layer, the conductive layer, and the organic photosensitive layer is in a state where it is easily peeled off at the interface with the adjacent layer due to distortion during cutting.

In such a photoreceptor sheet, there is a technique for reinforcing the outer peripheral surface of the side edge portion of the photoreceptor sheet in order to prevent peeling of the photosensitive layer on the surface due to the bending of the side edge portion. (For example, refer to Patent Document 1.)
However, Japanese Patent Laid-Open No. 10-186701 (page 3, FIG. 1, FIG. 2) discloses that the outer peripheral surface of the side edge portion of the photosensitive sheet is covered with a reinforcing band having a predetermined width. Although it prevents the layer from peeling off, it does not attempt to prevent the interface between the base layer, the conductive layer and the organic photosensitive layer from being easily separated from the adjacent layers in the cut surface of the photoreceptor sheet.

  For this reason, when such a conventional photoreceptor sheet having a cut surface is used in, for example, a wet image forming apparatus using a liquid developer, the liquid developer is removed from the gap between the interface between the base layer, the conductive layer and the organic photosensitive layer. It becomes easy to penetrate. As a result, the interface between the base layer, the conductive layer, and the organic photosensitive layer is further weakened in adhesion between adjacent layers, and the interface is liable to be peeled off. Further, when the toner particles of the liquid developer soaked from the interface are solidified, the toner particles solidified in the interface affect the surface of the photoreceptor and cause unevenness on the surface of the photoreceptor sheet. When the irregularities on the surface of the photosensitive sheet come into contact with the photosensitive member cleaning member, the surface of the photosensitive layer may be partially damaged, and there is a problem that the life of the photosensitive sheet is further shortened.

  As described above, when a photoconductor sheet of a desired size is obtained by cutting a large photoconductor sheet, the interface between the base layer, the conductive layer, and the organic photoconductive layer that appears on the cut surface is easily peeled off. Conventionally, it has been difficult to extend the life of the photosensitive sheet. For this reason, it has been required to extend the life of the photosensitive sheet by making it difficult for the interface of the cut surface of the photosensitive sheet to be peeled off and preventing the liquid developer from penetrating into the interface.

  Accordingly, the present invention solves the above-mentioned problems, and makes it difficult to peel off the interface between the base layer, the conductive layer, and the photosensitive layer that appears on the cut surface of the photosensitive sheet, thereby extending the life of the photosensitive sheet and reducing the cost. It is an object of the present invention to provide a photosensitive sheet and an image forming apparatus that can suppress the rise.

  As a means for solving the above-mentioned problems, the present invention provides a photoreceptor sheet formed by laminating a base layer, a conductive layer provided on the base layer, and a photosensitive layer provided on the conductive layer, Formed at an interface with the conductive layer or the adjacent layer of the photosensitive layer at an end surface parallel to the sub-scanning direction of the photosensitive sheet, and the conductive layer or the photosensitive layer is bonded to the adjacent layer. A layer is provided.

  According to another aspect of the present invention, there is provided a photosensitive sheet comprising a base layer, a conductive layer provided on the base layer, and a photosensitive layer provided on the conductive layer. And a covering member that covers an interface between the conductive layer and the adjacent layer of the photosensitive layer at an end face parallel to the sub-scanning direction of the body sheet.

  According to the present invention, there are provided as a means for solving the above-mentioned problems a photosensitive sheet obtained by laminating a conductive layer and a photosensitive layer on a base layer, an image forming means for forming a toner image on the photosensitive sheet, and the photosensitive element. And a transfer unit configured to transfer the toner image on the photosensitive sheet to a transfer medium. The photosensitive sheet is the conductive layer or the photosensitive layer on the end surface parallel to the sub-scanning direction of the photosensitive sheet. It has a binding layer formed by binding the conductive layer or the photosensitive layer to an adjacent layer at the interface of the layers.

  According to the present invention, there are provided as a means for solving the above-mentioned problems a photosensitive sheet obtained by laminating a conductive layer and a photosensitive layer on a base layer, an image forming means for forming a toner image on the photosensitive sheet, and the photosensitive element. And a transfer unit configured to transfer the toner image on the photosensitive sheet to a transfer medium. The photosensitive sheet is the conductive layer or the photosensitive layer on the end surface parallel to the sub-scanning direction of the photosensitive sheet. It has a covering member formed by covering an interface between adjacent layers.

  According to the present invention, the interface between the base layer, the conductive layer, and the organic photosensitive layer that appears on the end face of the photosensitive sheet is bound or covered with a covering member, thereby preventing the interface from peeling off and developing the liquid on the interface. The agent can be prevented from permeating. Therefore, it is possible to extend the life of the photosensitive sheet, thereby reducing the frequency of replacement of the photosensitive sheet, and to reduce the cost of the image forming apparatus.

  In the present invention, the interface of a plurality of layers appearing on the end face of the photosensitive sheet is strengthened to prevent the peeling of the interface and to prolong the life of the photosensitive sheet.

[Example 1]
Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 shows an image forming unit 10 of a wet type full-color electrophotographic apparatus which is an image forming apparatus of the present invention. The image forming unit 10 has a photoreceptor device 13 formed by surrounding a long photoreceptor sheet 12 on the surface of a hollow drum-like support 11. The drum-like support 11 is a cylindrical body made of a material such as aluminum and having a diameter of 262 mm, a length of 490 mm, and a wall thickness of 3 mm. The drum-shaped support 11 has a slit hole 11a having a width of 2 mm through which the photosensitive sheet 12 passes. As shown in FIG. 2, the photosensitive sheet 12 is formed by sequentially laminating a conductive layer 12b and a photosensitive layer 12c on a flexible substrate sheet 12a that is a substrate layer.

  Around the photosensitive device 13, yellow (Y), magenta (M), magenta (M), and yellow are sequentially formed on the photosensitive sheet 12 in accordance with the rotation of the drum-shaped support 11 in the sub-scanning direction of the photosensitive sheet 12 in the arrow q direction. First to fourth image forming units 14Y, 14M, 14C, and 14BK, which are image forming units that form toner images using cyan (C) and black (BK) liquid developers, are arranged. As a liquid developer, toner particles (a mixture of a resin and a colorant) are dispersed in a carrier liquid (insulating and nonpolar liquid).

  The yellow (Y), magenta (M), cyan (C), and black (BK) image forming units 14Y to 14BK have basically the same configuration except for the color of the liquid developer to be used. is there. As shown in FIG. 3, each of the image forming units 14Y to 14BK is composed of a well-known corona charger or scorotron charger, etc., and charging devices 16Y to 16BK for uniformly charging the surface of the photosensitive sheet 12 to, for example, 600 V, and image information. The exposure apparatus 18 selectively irradiates exposures 17Y to 17BK with yellow (Y) to black (BK) laser beams or LEDs or the like modulated according to the above. The exposure device 18 attenuates the potential of the exposed portion of the photoreceptor sheet 12 to 20V to 200V. As a result, an electrostatic latent image is formed on the surface of the photoreceptor sheet 12.

  Further, the image forming units 14Y to 14BK contain liquid developers 20Y to 20BK of the respective colors, and are provided with developing rollers 21Y to 21BK for supplying the liquid developers 20Y to 20BK to the surface of the photosensitive sheet 12 to form toner images. The devices 22Y to 22BK and the diaphragm devices 24Y to 24BK including the diaphragm rollers 23Y to 23BK that simultaneously remove the fog of the developed toner image and remove the carrier liquid are included. The developing rollers 21Y to 21BK are arranged with a gap of about 150 .mu.m with respect to the photosensitive sheet 12, and are supplied with a developing bias of about 400V to 650V.

  The aperture rollers 23Y to 23BK are provided while maintaining a gap of about 50 μm with respect to the photoreceptor sheet 12. By applying a diaphragm potential of about 300 V to 750 V to the diaphragm rollers 23Y to 23BK, toner is pressed against the photosensitive sheet 12 side in the development region. On the other hand, in the non-development area, the toner can be drawn toward the squeeze rollers 23Y to 23BK, and excess toner that floats can be removed.

  A carrier liquid removing device 26 that removes excess carrier liquid in the toner image formed on the photosensitive sheet 12 after completion of development is provided downstream of the image forming units 14Y to 14BK around the photosensitive sheet 12. The carrier liquid removing device 26 may remove the carrier liquid using, for example, a squeeze roller, an absorber, or a drying device. The squeeze roller rotates a roller disposed opposite to the photoreceptor sheet 12 with a gap in the same direction as the photoreceptor sheet 12 to scrape and remove the carrier liquid on the surface of the photoreceptor sheet 12. A porous material such as a sponge is used as the absorber, and the carrier liquid on the surface of the photoreceptor sheet 12 is absorbed and removed. The drying device uses a heating device that heats the photoreceptor sheet 12 or a nozzle that supplies a drying gas to the photoreceptor sheet 12 to dry and remove the carrier liquid on the surface of the photoreceptor sheet 12.

  Further, downstream of the carrier liquid removing device 26 around the photosensitive sheet 12, a transfer device 27, a cleaner 28 for removing the liquid developer remaining on the photosensitive sheet 12 after the transfer, and a residual charge on the photosensitive sheet 12. A static eliminator 30 for erasing is provided. The transfer device 27 includes an intermediate transfer roller 27a having a diameter of 150 mm and rotating in the direction of arrow r, and a pressure roller 27b being pressed by the intermediate transfer roller 27a and rotating in the direction of arrow s. The intermediate transfer roller 27a has an elastic layer on the surface.

  The toner image formed on the photosensitive sheet 12 is primarily transferred to the intermediate transfer roller 27a, which is pressed against the photosensitive sheet 12 with a pressing force of 0.4 kg / mm, using the adhesive force of the toner particles. Then, the toner image is secondarily transferred to a sheet P, which is a medium to be transferred, which is pressed against the intermediate transfer roller 27a by the pressure roller 27b. The pressure contact force between the intermediate transfer roller 27a and the pressure roller 27b is 0.5 kg / mm. Further, during the transfer, the intermediate transfer roller 27a is heated to 80 ° C. by the heater 27c, and the pressure roller 27b is heated to 100 ° C. by the heater 27d. Further, the temperature of the photosensitive sheet 12 at the time of transfer is set to 25 ° C.

  The cleaner 28 uses, for example, an elastic blade such as urethane rubber, and the elastic blade may be pressed against the surface of the photoreceptor sheet 12 to scrape off the toner particles on the surface of the photoreceptor sheet 12, or may be a woven fabric or a nonwoven fabric. The toner particles may be wiped off. When the toner particles are fixed on the surface of the photosensitive sheet 12, the resin fibers constituting the toner particles are deagglomerated and physically decomposed with an organic solvent or the like, and then the decomposed toner particle components are scraped off. Or you may wipe off. For the static eliminator 30, an LED or the like can be used.

  Next, the photoreceptor sheet 12 will be described in detail. The long photosensitive sheet 12 is housed in a supply roll 31 that is built in the hollow portion of the drum-shaped support 11 on the unused side. The used side of the photoreceptor sheet 12 is taken up by a take-up roll 32 built in a hollow portion of the drum-like support 11. The conductive layer 12 b of the photosensitive sheet 12 is grounded via a take-up roll 32.

  A resin material such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or polyimide, which is an insulating material, can be used for the flexible base sheet 12a of the photoreceptor sheet 12 shown in FIG. The thickness of the base sheet is 50 to 200 μm, preferably 75 to 125 μm.

  The conductive layer 12b can be formed of a metal or an alloy such as aluminum, an aluminum alloy, copper, zinc, nickel, stainless steel, or titanium by a method such as a sputtering method, an electron beam evaporation method, or a plating method. In this case, the thickness of the conductive layer is about several tens to several hundreds of nm. Alternatively, a method of laminating a metal foil or a method of applying a conductive material powder together with an appropriate binder resin may be used.

  The photosensitive layer 12c is, for example, an organic photosensitive layer having a functional separation structure formed by separating the charge generation layer and the charge transport layer, or a single layer structure in which the charge generation agent and the charge transport agent are formed in the same layer. It can also be used. The organic photosensitive layer may be formed to a thickness of about 10 μm to 40 μm, for example.

  Examples of charge generating materials that can be used in the organic photosensitive layer include phthalocyanine pigments, azo pigments, anthanthrone pigments, perylene pigments, perinone pigments, polycyclic quinone pigments, squarylium pigments, thiapyrylium pigments, quinacridone pigments, and mixtures thereof. And so on. Examples of azo pigments include disazo pigments, trisazo pigments, and perylene pigments such as N, N′-bis (3,5-dimethylphenyl) -3,4,9,10-perylene-bis (carboximide). Can be used. As the phthalocyanine pigment, for example, metal-free phthalocyanine, copper phthalocyanine, titanyl phthalocyanine and the like can be used.

  Examples of hole transport materials that can be used in the organic photosensitive layer include hydrazone compounds, pyrazoline compounds, pyrazolone compounds, oxadiazole compounds, oxazole compounds, arylamine compounds, benzidine compounds, stilbene compounds, styryl compounds, and poly-N-. Examples thereof include vinyl carbazole, polysilane, and a mixture thereof.

  Examples of electron transport materials that can be used in the organic photosensitive layer include succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, and pyromellitic anhydride. , Pyromellitic acid, trimellitic acid, trimellitic anhydride, phthalimide, 4-nitrophthalimide, tetracyanoethylene, tetracyanoquinodimethane, chloranil, bromanyl, o-nitrobenzoic acid, malononitrile, trinitrofluorenone, trinitrothioxanthone , Dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, thiopyran compounds, quinone compounds, benzoquinone compounds, diphenoquinone compounds, naphthoquinone compounds, anthraquinone compounds, Rubenkinon based compounds include Azokinon compounds, and the like mixtures thereof.

  Examples of binder resins that can be used in the organic photosensitive layer include polycarbonate resins, polyester resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, vinyl chloride resins, vinyl acetate resins, polyethylene, polypropylene, acrylic resins, polyurethane resins, Examples thereof include an epoxy resin, a melamine resin, a silicone resin, a polyamide resin, a polystyrene resin, a polyacetal resin, a polyarylate resin, a polysulfone resin, a polymer or copolymer of methacrylic acid ester, and a mixture thereof.

  The organic photosensitive layer may contain a deterioration preventing agent such as an antioxidant or a light stabilizer for the purpose of improving environment resistance and light resistance. Examples of compounds used for such purposes include chromanol derivatives such as tocopherol and esterified compounds, polyarylalkane compounds, hydroquinone derivatives, etherified compounds, dietherified compounds, benzophenone derivatives, benzotriazole derivatives, thioether compounds, phenylene Examples thereof include diamine derivatives, phosphonic acid esters, phosphite esters, phenol compounds, hindered phenol compounds, linear amine compounds, cyclic amine compounds, hindered amine compounds, and the like.

  For the purpose of improving the leveling property of the formed film and imparting lubricity to the organic photosensitive layer, for example, a leveling agent such as silicone oil or fluorine-based oil can be contained. In addition, for the purpose of reducing the friction coefficient and imparting lubricity to the organic photosensitive layer, for example, metal oxides such as silicon oxide, titanium oxide, zinc oxide, calcium oxide, aluminum oxide, zirconium oxide, barium sulfate, Metal sulfate fine particles such as calcium sulfate, metal nitride fine particles such as silicon nitride and aluminum nitride, fluorine-based resin particles such as tetrafluoroethylene resin, fluorine-based comb-type graft polymerization resin, and the like may be included. Further, the organic photosensitive layer may contain other known additives.

  Furthermore, the photosensitive layer 12c may further include, for example, an intermediate layer 12d containing a resin as a main component on the conductive layer 12b side, as indicated by a dotted line in FIG. The intermediate layer 12d may have a single layer structure or may have a multilayer structure. The intermediate layer 12d is provided, for example, for the purpose of preventing unnecessary charge injection from the surface of the conductive layer 12b to the photosensitive layer 12c and improving the adhesion between the conductive layer 12b and the photosensitive layer 12c.

  Examples of resins that can be used for the intermediate layer 12d include copolymers of vinyl chloride, vinyl acetate, and other resin components, polycarbonate resins, polyester resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, vinyl chloride resins, Vinyl acetate resin, polyethylene, polypropylene, acrylic resin, polyurethane resin, epoxy resin, melamine resin, silicone resin, polyamide resin, polystyrene resin, polyacetal resin, polyarylate resin, polysulfone resin, methacrylate polymer or copolymer, And mixtures thereof.

  The intermediate layer 12d can contain at least one of metal oxide fine particles, metal nitride fine particles, and metal sulfate. As the metal oxide fine particles, for example, titanium oxide, silicon oxide, zinc oxide, calcium oxide, aluminum oxide, zirconium oxide, and a mixture thereof can be used. As the metal nitride fine particles, for example, silicon nitride, aluminum nitride, and a mixture thereof can be used. As the metal sulfate, for example, calcium sulfate can be used.

  When the intermediate layer 12d contains a binder resin as a main component, the intermediate layer 12d may contain a charge transport material for the purpose of imparting charge transportability, reducing charge trapping, or the like. Further, the intermediate layer 12d may contain other known additives.

  Further, the photosensitive layer 12c may further include a protective layer 12f containing a resin as a main component on the surface side as indicated by a dotted line in FIG. Examples of the binder resin that can be used for the protective layer 12f include polycarbonate resin, polyester resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, vinyl chloride resin, vinyl acetate resin, polyethylene, polypropylene, acrylic resin, polyurethane resin, Examples thereof include an epoxy resin, a melamine resin, a silicone resin, a polyamide resin, a polystyrene resin, a polyacetal resin, a polyarylate resin, a polysulfone resin, a polymer or copolymer of methacrylic acid ester, and a mixture thereof.

  For the purpose of improving the leveling property of the formed film and imparting lubricity, the protective layer 12f can contain a leveling agent such as silicone oil or fluorine-based oil. In addition, for the purpose of reducing the friction coefficient and imparting lubricity, the protective layer 12f is made of, for example, a metal oxide such as silicon oxide, titanium oxide, zinc oxide, calcium oxide, aluminum oxide, zirconium oxide, barium sulfate, Metal sulfate fine particles such as calcium sulfate, metal nitride fine particles such as silicon nitride and aluminum nitride, fluorine-based resin particles such as tetrafluoroethylene resin, fluorine-based comb-type graft polymerization resin, and the like may be included. Furthermore, the protective layer 12f may contain other known additives.

  In order to reduce the cost of the photoreceptor sheet 12, for example, aluminum is deposited by about 200 nm on a wide and long base layer 12 a made of a PET (polyethylene terephthalate) sheet having a width of 600 mm × length of 70 m × thickness of 100 μm. Thus, the conductive layer 12b is formed. Next, a photosensitive layer 12c made of a single-layer positively-charged organic photosensitive layer having a thickness of about 20 μm is coated on the conductive layer 12b by controlling the pulling speed in the dip coating method. For the formation of the organic photosensitive layer, 100 parts by weight of polycarbonate as a binder resin, 3 parts by weight of a phthalocyanine pigment as a charge generating substance, and 75 parts by weight of an aromatic amine derivative as a hole transporting substance in tetrahydrofuran as an organic solvent. A coating solution in which a naphthoquinone derivative was dispersed and dissolved in an amount of 45 parts by weight as an electron transporting material was used.

  Next, the photosensitive sheet 12 is cut into a size of 490 mm wide × 3 m long by a cutting machine to obtain a desired size. At this time, in the cut surface of the photosensitive sheet 12, as shown in FIG. 4, a gap 34 due to a crack or the like is easily generated between the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c. If the gap 34 is left as it is, the photosensitive layer 12c or the conductive layer 12b may be peeled off or damaged. Therefore, the interface of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c appearing on the cut surface of the photosensitive sheet 12 is strengthened by heat treatment.

  That is, as shown in FIG. 5, a non-image forming area [S] of 10 mm × 3 m in length on both sides in the direction parallel to the sub-scanning direction of the photosensitive sheet 12 is represented by a heat roller. 37, heat treatment is performed from the surface side of the photosensitive layer 12c. The heat roller 37 is formed, for example, by forming a heat-resistant urethane rubber layer on a cylindrical support and further forming a surface layer made of Teflon, and incorporates a halogen heater inside. By heat treatment with the heat roller 37, almost 100% of the cut surface 38 of the photosensitive sheet 12 is thermally denatured. As a result, all regions at the interface of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are also thermally denatured.

  For example, heat treatment is performed on the cross section of the photoreceptor sheet 12 at a surface temperature of the heat roller 37 of 150 ° C. and a scanning speed of 0.5 sec / cm, and the cross-sectional structure is abbreviated as a scanning electron microscope (hereinafter referred to as SEM). ), It was confirmed that the cut surface 38 of the photoreceptor sheet 12 was thermally denatured as shown in FIG. That is, the adjacent layers of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are also bonded by heat denaturation to form the binding layers 38a and 38b, and the interface of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c It has been strengthened.

  The photosensitive sheet 12 having the cut surface 38 thus heat-treated is wound around the drum-shaped support 11 to form the photosensitive device 13.

  Next, the operation will be described. When the image forming process is started, the photosensitive device 13 is rotated in the direction of the arrow q at a peripheral speed of 220 mm / sec. First, a first toner image is formed using a yellow (Y) liquid developer. A toner image forming operation is performed on the photosensitive sheet 12 by the image forming unit 14Y. That is, the photosensitive sheet 12 is uniformly charged to 600 V by the charging device 16Y, and then the yellow image area is selectively exposed by the exposure device 18 to form a yellow (Y) electrostatic latent image. Further, a yellow (Y) toner image is formed on the photosensitive sheet 12 by a reversal developing method with a yellow (Y) developing device 22Y. At this time, the developing bias supplied to the yellow (Y) developing roller 21Y rotated in the arrow v direction was set to 450V. Next, a squeezing potential of 450 V is applied, and the fogging of the image and the excess carrier liquid are removed by a squeezing roller 23Y rotating in the direction of arrow w, thereby forming a yellow (Y) toner image.

  Similarly, magenta (M), cyan (C), and black (BK) toner images are sequentially superimposed on the photosensitive sheet 12 by the subsequent second to fourth image forming units 14M to 14BK to form a full color. A toner image is formed. Thereafter, as the photoconductor device 13 rotates, the excess color of the full color toner image is removed by the carrier liquid removing device 26 and reaches the transfer device 27. In the transfer device 27, the full-color toner image on the photosensitive sheet 12 is heated to 80 ° C. and is primarily transferred to an intermediate transfer roller 27a that is pressed against the photosensitive sheet 12 with a pressure contact force of 0.4 kg / mm. The Further, the full color toner image is secondarily transferred onto the paper P from the intermediate transfer roller 27a.

  After the transfer, the photosensitive sheet 12 is freed of residual toner particles by the cleaner 28 and the residual charge is erased by the static eliminator 30 to complete a series of image forming steps and prepare for the next image forming step. When the photosensitive sheet 12 reaches the end of its life while repeating the image forming process in this way, the winding roll 32 is driven in the direction of the arrow t to wind up the used photosensitive sheet 12 on the surface of the drum-shaped support 11. Then, the unused photoreceptor sheet 12 is supplied from the supply roller 31 to the surface of the drum-shaped support 11, and the surface of the drum-shaped support 11 is surrounded by a new photoreceptor sheet 21 to form a new photoreceptor device 13.

  In this way, the cut surface 38 of the photosensitive sheet 12 is heat-treated to form the binding layers 38a and 38b at the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c. The interface of the surface 38 is strengthened, and even though the liquid developers 20Y to 20BK are used, there is no risk of the toner permeating from the interface, and the interface of the base layer 12a, the conductive layer 12b and the photosensitive layer 12c is peeled off or the conductive layer Damage to 12b and photosensitive layer 12c is prevented.

  In this example, a continuous output test was performed using a standard image of Japan Color. From the initial image output until the output of “100,000” images, the photosensitive surface 12 was exposed on the cut surface 38. It was confirmed that the photosensitive layer 12c was not damaged due to the peeling of the layer 12c and the liquid developer soaked into the interface, and almost the same high quality image quality was obtained. On the other hand, as a comparative example, a photoconductor sheet on which the heat treatment of the cut surface 38 is not performed is surrounded by the drum-shaped support 11 to form a photoconductor device, and a Japan Color standard image continuous output test was performed. However, it was confirmed that almost the same high image quality can be obtained from the initial image output to the output of “10,000” images. However, when the cut surface of the photosensitive sheet is visually observed after outputting “10,000 sheets”, the photosensitive layer is peeled off or the liquid developer soaked into the interface of each layer of the photosensitive sheet is fixed. Layer breakage was observed.

  If comprised in this way, the cut surface will be heat-processed in the photoreceptor sheet 12 which obtains the reduction in manufacturing cost by obtaining the photoreceptor sheet 12 of desired size by cutting a wide and long photoreceptor sheet. Thus, the interface of the base layer 12a, the conductive layer 12b and the photosensitive layer 12c is thermally denatured to form the binding layers 38a and 38b, thereby increasing the strength of the interface. From this, it is possible to prevent the photosensitive layer 12c from being peeled off at the cut surface 38 of the photosensitive sheet 12, and the liquid developers 20Y to 20BK soaked into the interfaces of the respective layers of the photosensitive sheet 12 are fixed. It is possible to prevent the photosensitive layer 12c from being damaged. Accordingly, the manufacturing cost of the photosensitive sheet 12 can be reduced, the life of the photosensitive sheet 12 can be extended, and the cost of the photosensitive apparatus 13 and thus the image forming apparatus can be reduced by reducing the running cost. I can do it.

  In this embodiment, the entire area of the interface portion of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c along the end surface parallel to the sub-scanning direction of the photosensitive sheet 12 is heat-treated. As long as peeling of the photosensitive layer 12c and damage to the photosensitive layer 12c in the 12 cut surfaces 38 can be prevented, the entire interface portion may be set as the processing region, or 80% or more of the interface portion may be set as the processing region. .

[Example 2]
Next, Embodiment 2 of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment described above in the heat treatment conditions for the photosensitive sheet, and the other components are the same as those in the first embodiment. Therefore, the same configuration as that described in the first embodiment is used. Parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, the non-image forming area [S] of 10 mm × length 3 m on both sides in the direction parallel to the sub-scanning direction of the photosensitive sheet 12 is heated by the heat roller 37 from the surface side of the photosensitive layer 12c. The surface temperature of the heat roller 37 is set to a high temperature of 240 ° C., and the scanning speed of the heat roller 37 is set to 0.5 seconds / cm. After the heat treatment of the cut surface 40 of the photosensitive sheet 12 by the heat roller 37 set at a high temperature, when the cross-sectional structure is observed with an SEM, the cut surface 40 of the photosensitive sheet 12 is thermally denatured as shown in FIG. It was confirmed that

  That is, the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are bonded together by heat denaturation to form the binding layers 40a and 40b, and the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are It has been strengthened. Further, not only the interface between the base layer 12a and the conductive layer 12b but also the inside of the base layer 12a is heat-treated, and the heat-denaturing part 41 is generated.

  By heat-treating the cut surface 40 at a higher temperature in this way, the heat-denatured region becomes deeper and the binding force of the binding layers 40a and 40b is further strengthened, and the interface between the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c. Is more difficult to peel off.

  In this example, a continuous output test was performed using a standard image of Japan Color. From the initial image output until the output of “140,000 sheets”, the cut surface 40 of the photosensitive sheet 12 was peeled off. In addition, it was confirmed that the photosensitive layer 12c was not damaged due to the liquid developer soaked in the interface, and almost the same high image quality was obtained.

  With this configuration, as in Example 1, it is possible to prevent the photosensitive layer 12c from peeling off at the cut surface 40 of the photosensitive sheet 12, and the liquid developer soaked into the interface of each layer of the photosensitive sheet 12 It is possible to prevent the photosensitive layer 12c from being damaged due to the fixing of 20Y to 20BK. Accordingly, the manufacturing cost of the photosensitive sheet 12 can be reduced, the life of the photosensitive sheet 12 can be extended, and the cost of the photosensitive apparatus 13 and thus the image forming apparatus can be reduced by reducing the running cost. I can do it. Further, since the heat treatment temperature of the photosensitive sheet 12 is set higher than that in Example 1, it is possible to further enhance the difficulty of peeling due to the modification of the cut surface 40 of the photosensitive sheet 12.

[Example 3]
Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment is different from the first embodiment described above in the heat treatment conditions for the photosensitive sheet, and the other components are the same as those in the first embodiment. Therefore, the same configuration as that described in the first embodiment is used. Parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, a hot press process is performed in which the non-image forming area [S] of 10 mm × 3 m in length on both sides in the direction parallel to the sub-scanning direction of the photosensitive sheet 12 is heated while applying pressure to the heat roller 37. . That is, the pressure roller 42 is provided together with the heat roller 37 for the cutting process of the photosensitive sheet 12. The heat roller 37 has a surface temperature of 150 ° C. and a scanning speed of 0.5 seconds / cm. The pressure roller 42 presses the heat roller 37 at a pressure of 1 kg / mm while rolling on the heat roller 37. still. The surface temperature of the heat roller 37 or the pressing force of the pressure roller 42 can be adjusted as necessary.

  When the cross-sectional structure is observed with an SEM after hot pressing the photosensitive sheet 12 from the surface side of the photosensitive layer 12c by the heat roller 37 and the pressure roller 42, the cut surface 42 of the photosensitive sheet 12 is as shown in FIG. It was confirmed that the product was heated and pressurized. That is, the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are bonded to each other by heat and pressure denaturation to form the binding layers 42a and 42b, and the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c. The interface is strengthened. Furthermore, not only the interface between the base layer 12a and the conductive layer 12b, but also a small portion of the base layer 12a is heated and pressurized to produce a heat-denatured portion 43.

  By hot-pressing the cut surface 42 in this manner, the modified region becomes deeper and the binding force of the binding layers 42a and 42b is further strengthened compared to the case of only the heat treatment, and the base layer 12a, the conductive layer 12b and The interface of the photosensitive layer 12c is more difficult to peel off.

  In this example, when a continuous output test was performed using a standard image of Japan Color, the cut surface 42 of the photoconductor sheet 12 was peeled off from the initial image output to the output of “120,000 sheets”. In addition, it was confirmed that the photosensitive layer 12c was not damaged due to the liquid developer soaked in the interface, and almost the same high image quality was obtained.

  With this configuration, as in Example 1, it is possible to prevent the photosensitive layer 12c from being peeled off at the cut surface 42 of the photosensitive sheet 12, and the liquid developer soaked into the interface of each layer of the photosensitive sheet 12 It is possible to prevent the photosensitive layer 12c from being damaged due to the fixing of 20Y to 20BK. Accordingly, the manufacturing cost of the photosensitive sheet 12 can be reduced, the life of the photosensitive sheet 12 can be extended, and the cost of the photosensitive apparatus 13 and thus the image forming apparatus can be reduced by reducing the running cost. I can do it. In addition, although the heating temperature is the same as in Example 1, pressure is applied when the cut surface 42 is processed, so that the photosensitive sheet 12 is not easily peeled off due to the modification of the cut surface 42 without adversely affecting the heat. Can be strengthened.

[Example 4]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. The fourth embodiment is different from the first embodiment described above in that the processing conditions of the cut surface of the photosensitive sheet are different, and the others are the same as in the first embodiment. The same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, the non-image forming area [S] of 10 mm × 3 m in length on both sides of the photosensitive sheet 12 in the direction parallel to the sub-scanning direction is subjected to solvent treatment. That is, the application roller 44 applies a solvent to the cut surface from the surface side of the photosensitive layer 12 c of the photosensitive sheet 12. The application roller 44 is formed by winding a nonwoven fabric around a cylindrical support. Tetrahydrofuran was used as the solvent. The scanning speed of the application roller 44 for solvent treatment is set to 1 second / cm. The type of the solvent is not limited, and the supply to the photoreceptor sheet is arbitrary such as using a brush.

  When the photosensitive sheet 12 is solvent-treated from the surface side of the photosensitive layer 12c by the application roller 44 and the cross-sectional structure is observed with an SEM, the cut surface of the photosensitive sheet 12 is modified by the solvent as shown in FIG. Was confirmed. That is, the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are bonded together by a solvent to form the binding layers 46a and 46b, and the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are strengthened. Has been.

  In this example, a continuous output test was performed using a standard image of Japan Color. From the initial image output until the output of “90,000 sheets”, the cut surface of the photoreceptor sheet 12 was peeled off. It was confirmed that the photosensitive layer 12c was not damaged due to the liquid developer soaked into the interface, and almost the same high image quality was obtained.

  With this configuration, it is possible to prevent the photosensitive layer 12c from being peeled off at the cut surface of the photosensitive sheet 12 as in the first embodiment, and the liquid developer 20Y soaked into the interface of each layer of the photosensitive sheet 12 can be prevented. It is possible to prevent the photosensitive layer 12c from being damaged due to the sticking of ~ 20BK. Accordingly, the manufacturing cost of the photosensitive sheet 12 can be reduced, the life of the photosensitive sheet 12 can be extended, and the cost of the photosensitive apparatus 13 and thus the image forming apparatus can be reduced by reducing the running cost. I can do it.

[Example 5]
Next, a fifth embodiment of the present invention will be described with reference to FIGS. The fifth embodiment is different from the first embodiment described above in that the processing conditions for the cut surface of the photosensitive sheet are different, and the others are the same as in the first embodiment. The same components are denoted by the same reference numerals, and detailed description thereof is omitted.

In this embodiment, the non-image forming area [S] of 10 mm × 3 m in length on both sides of the photosensitive sheet 12 in the direction parallel to the sub-scanning direction is subjected to ultrasonic fusion processing. That is, as shown in FIG. 12, for example, an ultrasonic fusion device (SONOPET Σ series) 47 manufactured by Seidensha Electronics Industry Co., Ltd. is used to apply an ultrasonic wave with an output of 10 W / cm ² to the photosensitive layer 12 c of the photosensitive sheet 12. Irradiate from the surface side at a scanning speed of 1 second / cm. The output value of the ultrasonic wave or the scanning speed is not limited.

  When the cross-sectional structure of the photosensitive sheet 12 was observed with an SEM after the ultrasonic fusion treatment, it was confirmed that the cut surface 48 of the photosensitive sheet 12 was modified by ultrasonic waves as shown in FIG. That is, the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are combined with each other to form the binding layers 48a and 48b, and the interfaces of the base layer 12a, the conductive layer 12b, and the photosensitive layer 12c are strengthened. Yes. Further, not only the interface between the base layer 12a and the conductive layer 12b but also a very small part, but the inside of the base layer 12a is ultrasonically treated to produce the ultrasonically denatured portion 50, and the denatured region is deepened.

  In this example, a continuous output test was performed using a standard image of Japan Color. From the initial image output to the output of “130,000 sheets”, the cut surface 48 of the photosensitive sheet 12 was peeled off. In addition, it was confirmed that the photosensitive layer 12c was not damaged due to the liquid developer soaked in the interface, and almost the same high image quality was obtained.

  With this configuration, it is possible to prevent the photosensitive layer 12c from being peeled off at the cut surface 48 of the photoreceptor sheet 12 as in the first embodiment, and the liquid developer soaked into the interface of each layer of the photoreceptor sheet 12 It is possible to prevent the photosensitive layer 12c from being damaged due to the fixing of 20Y to 20BK. Accordingly, the manufacturing cost of the photosensitive sheet 12 can be reduced, the life of the photosensitive sheet 12 can be extended, and the cost of the photosensitive apparatus 13 and thus the image forming apparatus can be reduced by reducing the running cost. I can do it. Even if the ultrasonic wave is irradiated deeply into the base layer 12a, the irradiation area can be narrowed down, and the cut surface 48 can be modified and the difficulty of peeling can be further enhanced without adversely affecting the image area side. .

[Example 6]
Next, Embodiment 6 of the present invention will be described with reference to FIG. In the sixth embodiment, the cut surface of the photosensitive sheet is coated in the above-described first embodiment, and the others are the same as those in the first embodiment. Therefore, the configuration is the same as that described in the first embodiment. Constituent parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, both sides of the photosensitive sheet 12 in the direction parallel to the sub-scanning direction are coated with the polycarbonate resin 51. The polycarbonate resin is impregnated into a cloth and applied to the cut surface of the photoreceptor sheet 12 with a film thickness of about 20 μm. The coating agent that protects the cut surface of the photoreceptor sheet 12 is not limited, and may be a polyester resin or the like.

  In this example, a continuous output test was performed using a standard image of Japan Color. From the initial image output to the output of “100,000 sheets”, the cut surface of the photoreceptor sheet 12 was peeled off. It was confirmed that the photosensitive layer 12c was not damaged due to the liquid developer soaked into the interface, and almost the same high image quality was obtained.

  With this configuration, it is possible to prevent the photosensitive layer 12c from being peeled off at the cut surface of the photosensitive sheet 12 as in the first embodiment, and the liquid developer 20Y soaked into the interface of each layer of the photosensitive sheet 12 can be prevented. It is possible to prevent the photosensitive layer 12c from being damaged due to the sticking of ~ 20BK. Accordingly, the manufacturing cost of the photosensitive sheet 12 can be reduced, the life of the photosensitive sheet 12 can be extended, and the cost of the photosensitive apparatus 13 and thus the image forming apparatus can be reduced by reducing the running cost. I can do it.

[Example 7]
Next, Embodiment 7 of the present invention will be described with reference to FIG. The seventh embodiment is different from the first embodiment described above in the manufacturing process of the photosensitive sheet, and the other parts are the same as those in the first embodiment. Therefore, the same components as those described in the first embodiment are used. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, when the photosensitive sheet 52 is manufactured, for example, about 200 nm of aluminum is formed on a wide and long base layer 52a made of a PET (polyethylene terephthalate) sheet having a width of 600 mm, a length of 70 m, and a thickness of 100 μm. The conductive layer 52b is formed by vapor deposition. Next, before forming the photosensitive layer, the base layer 52a and the conductive layer 52b are cut into dimensions of 490 mm wide × 3 m long. When the photosensitive layer 52c made of an organic photosensitive layer is applied to the base layer 52a and the conductive layer 52b cut to a desired size, the interface between the base layer 52a and the conductive layer 52b is also coated with the photosensitive layer 52c.

  In this example, a continuous output test was performed using a standard image of Japan Color. From the initial image output until the output of “90,000” images, the cut surface of the photoreceptor sheet 52 was peeled off. It was confirmed that the photosensitive layer 52c was not damaged due to the fixing of the liquid developer soaked into the interface, and almost the same high image quality was obtained.

  With this configuration, it is possible to prevent the photosensitive layer 52c from being peeled off at the cut surface of the photosensitive sheet 52 as in the first embodiment, and the liquid developer 20Y soaked into the interface of each layer of the photosensitive sheet 52. It is possible to prevent the photosensitive layer 52c from being damaged due to sticking of ~ 20BK. Accordingly, the manufacturing cost of the photosensitive sheet 52 can be reduced, and the lifetime of the photosensitive sheet 12 can be increased. As a result, the cost of the photosensitive apparatus 13 and thus the image forming apparatus can be reduced by reducing the running cost. I can do it.

  The present invention is not limited to the above embodiment, and various design changes can be made. For example, the thickness of the base layer, the conductive layer, or the photosensitive layer, the manufacturing method, etc. are arbitrary, the size of the photosensitive sheet before cutting, or The size of the photoreceptor sheet after cutting is not limited. The method for cutting the photoreceptor sheet is also arbitrary. Further, the processing area to be bound at the interface portion along the end face parallel to the sub-scanning direction of the photosensitive sheet is not limited, and it is within a range in which the peeling of the photosensitive layer is surely prevented and the image quality is not adversely affected. For example, the entire interface portion may be set as the processing region, or 80% or more of the interface portion may be set as the processing region.

  Further, the usage form of the photosensitive sheet is not limited. For example, as in the first modification shown in FIG. 16, the supply roll in which the unused side of the photosensitive sheet 12 is built in the hollow portion of the drum-shaped support 11. 54, and the used side 56 may be free, and the parts that have reached the end of their life may be sequentially cut and discarded. Further, as in the second modification shown in FIG. 17, the photosensitive sheet is formed so that the front end and the rear end in the longitudinal direction are joined to form an endless belt-shaped photosensitive body 57, and the tension roller 58a. , 58b may be used. In this belt-shaped photoconductor 57, toner images are formed by the first to fourth image forming units 14 Y to 14 BK, dried by the drying device 60, and then formed on the paper P by the transfer device 27. . The image forming apparatus is not limited to a color image forming apparatus, and may be a monochrome image forming apparatus.

1 is a schematic configuration diagram illustrating an image forming unit of a full-color electrophotographic apparatus according to a first exemplary embodiment of the present invention. It is a schematic explanatory drawing which shows the photoreceptor sheet of Example 1 of this invention. 1 is a schematic configuration diagram illustrating an image forming unit according to a first exemplary embodiment of the present invention. It is a schematic explanatory drawing which shows the layer defect of the photoreceptor sheet | seat of Example 1 of this invention. It is a schematic explanatory drawing which shows the heat processing of the photoreceptor sheet cutting cross section of Example 1 of this invention. It is a schematic explanatory drawing which shows the cut surface of the photoreceptor sheet after the heat processing of Example 1 of this invention. It is a schematic sectional drawing which shows the cut surface of the photoreceptor sheet after the heat processing of Example 2 of this invention. It is a schematic explanatory drawing which shows the hot press process of the photoreceptor sheet cutting surface of Example 3 of this invention. It is a schematic explanatory drawing which shows the cut surface of the photoreceptor sheet after the hot press process of Example 3 of this invention. It is a schematic explanatory drawing which shows the solvent process of the photoreceptor sheet cutting surface of Example 4 of this invention. It is a schematic explanatory drawing which shows the cut surface of the photoreceptor sheet after the solvent process of Example 4 of this invention. It is a schematic explanatory drawing which shows the ultrasonic fusion process of the photoreceptor sheet cutting surface of Example 5 of this invention. It is a schematic explanatory drawing which shows the cut surface of the photoreceptor sheet after the ultrasonic fusion process of Example 5 of this invention. It is a schematic explanatory drawing which shows the coating process of the photoreceptor sheet cutting cross section of Example 6 of this invention. It is a schematic explanatory drawing which shows the covering process of the photoreceptor sheet cutting cross section of Example 7 of this invention. It is a schematic explanatory drawing which shows accommodation of the photoreceptor sheet | seat of the 1st modification of this invention. It is a schematic explanatory drawing which shows the form of the photoreceptor sheet of the 2nd modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image forming part 11 ... Drum-shaped support body 12 ... Photoconductor sheet 12a ... Base layer 12b ... Conductive layer 12c ... Photosensitive layer 13 ... Photoconductor apparatus 14Y-14BK ... Image forming unit 16Y-16BK ... Charging apparatus 17Y-17BK ... Exposure
DESCRIPTION OF SYMBOLS 18 ... Exposure apparatus 20Y-20BK ... Liquid developer 21Y-21BK ... Developing roller 22Y-22BK ... Developing apparatus 23Y-23BK ... Diaphragm roller 24Y-24BK ... Diaphragm apparatus 26 ... Carrier liquid removal apparatus 27 ... Transfer apparatus 27a ... Intermediate transfer roller 27b ... Pressure roller 31 ... Supply roll 32 ... Take-up roll 37 ... Heat roller 38a, 38b ... Binding layer

Claims (4)

A substrate layer;
A conductive layer provided on the base layer;
A photosensitive sheet formed by laminating a photosensitive layer provided on the conductive layer,
The photosensitive sheet is formed at an interface with the conductive layer or an adjacent layer of the photosensitive layer at an end surface parallel to the sub-scanning direction, and the conductive layer or the photosensitive layer is bonded to the adjacent layer. A photosensitive sheet comprising a binder layer. A substrate layer;
A conductive layer provided on the base layer;
In the photoreceptor sheet formed by laminating a photosensitive layer provided on the conductive layer,
A photosensitive sheet comprising: a covering member that covers an interface between the conductive layer or an adjacent layer of the photosensitive layer at an end surface parallel to the sub-scanning direction of the photosensitive sheet. A photoreceptor sheet formed by laminating a conductive layer and a photosensitive layer on a base layer;
Image forming means for forming a toner image on the photoreceptor sheet;
An image forming apparatus comprising transfer means for transferring the toner image on the photosensitive sheet to a transfer medium;
The photosensitive sheet is a binding layer formed by binding the conductive layer or the photosensitive layer to an adjacent layer at an interface between the conductive layer or the photosensitive layer on an end surface parallel to the sub-scanning direction of the photosensitive sheet. An image forming apparatus comprising: A photoreceptor sheet formed by laminating a conductive layer and a photosensitive layer on a base layer;
Image forming means for forming a toner image on the photoreceptor sheet;
An image forming apparatus comprising transfer means for transferring the toner image on the photosensitive sheet to a transfer medium;
The image forming apparatus, wherein the photosensitive sheet includes a covering member that covers an interface with the conductive layer or an adjacent layer of the photosensitive layer on an end surface parallel to the sub-scanning direction of the photosensitive sheet. .

Images