JP2016126210A - Image forming apparatus, process cartridge, and device set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that prevents alteration of the outer peripheral surface of a photoreceptor due to contact of a conductive roll from shipment until the start of use of the image forming apparatus.SOLUTION: There is provided an image forming apparatus comprising: a photoreceptor; and a conductive roll that applies voltage to a toner image formed on the outer peripheral surface of the photoreceptor to transfer the toner image directly from the photoreceptor to a recording medium, the conductive roll directly in contact with the photoreceptor, where when an acetone extract in an outer peripheral surface layer of the conductive roll is stored while in contact with the outer peripheral surface of the photoreceptor in an environment of a temperature of 45°C and a humidity of 85% for 10 days, the rate of change in hardness of the outer peripheral surface of the photoreceptor is 10% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus, a process cartridge, and an apparatus set.

  In an electrophotographic image forming apparatus, as a transfer roll for transferring a toner image formed on the outer peripheral surface of a photoreceptor to a recording medium, for example, Patent Document 1 discloses that a polyurethane foam layer is placed around a core metal in a molding die. In the formed transfer roller, the average opening diameter (A) of the surface of the polyurethane foam layer is 0.05 mm or more and 0.5 mm or less, and the average cell diameter of the polyurethane foam layer on the 1 mm core side from the surface A transfer roll in which (B) is 0.1 mm to 1.0 mm and the average cell wall (C) between open cells on the surface is 0.03 mm to 0.5 mm is disclosed.

JP 2012-145811 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which the outer peripheral surface of a photoreceptor is less likely to be denatured due to contact with a conductive roll during the period from shipment to use.

  The above problem is solved by the following means.

The invention according to claim 1
A photoreceptor,
A conductive roll for applying a voltage to a toner image formed on the outer peripheral surface of the photoconductor to directly transfer the toner image from the photoconductor to a recording medium, and a conductive roll in direct contact with the photoconductor;
With
When the acetone extract of the outer peripheral surface layer of the conductive roll is kept in contact with the outer peripheral surface of the photosensitive member for 10 days in an environment of 45 ° C. and 85% humidity, the outer peripheral surface of the photosensitive member is hardened. The rate of change of the height is 10% or less,
Image forming apparatus.

The invention according to claim 2
The image forming apparatus according to claim 1, wherein the image forming apparatus is shipped in a state where the outer peripheral surface of the photoconductor and the outer peripheral surface of the conductive roll are in direct contact with each other.

The invention according to claim 3
The image forming apparatus according to claim 1, wherein an outer peripheral surface layer of the conductive roll is a polyurethane foam layer.

The invention according to claim 4
A photoreceptor,
A conductive roll for applying a voltage to a toner image formed on the outer peripheral surface of the photoconductor to directly transfer the toner image from the photoconductor to a recording medium, and a conductive roll in direct contact with the photoconductor;
With
When the acetone extract of the outer peripheral surface layer of the conductive roll is kept in contact with the outer peripheral surface of the photosensitive member for 10 days in an environment of 45 ° C. and 85% humidity, the outer peripheral surface of the photosensitive member is hardened. The rate of change of the height is 10% or less,
A process cartridge that can be attached to and detached from an image forming apparatus.

The invention according to claim 5
The process cartridge according to claim 4, wherein the process cartridge is shipped in a state where the outer peripheral surface of the photoconductor and the outer peripheral surface of the conductive roll are in direct contact with each other.

The invention according to claim 6
The process cartridge according to claim 4 or 5, wherein the conductive roll has a polyurethane foam layer as an outer peripheral surface layer.

The invention according to claim 7 provides:
A photoreceptor,
A conductive roll for applying a voltage to a toner image formed on the outer peripheral surface of the photoconductor to directly transfer the toner image from the photoconductor to a recording medium, and is applied to the photoconductor when mounted on an image forming apparatus; A conductive roll in direct contact;
Equipment set,
When the acetone extract of the outer peripheral surface layer of the conductive roll is kept in contact with the outer peripheral surface of the photosensitive member for 10 days in an environment of 45 ° C. and 85% humidity, the outer peripheral surface of the photosensitive member is hardened. The rate of change of the height is 10% or less,
Device set for image forming apparatus.

The invention according to claim 8 provides:
The said conductive roll is an apparatus set of Claim 7 whose outer peripheral surface layer is a polyurethane foam layer.

  According to the first, second, and third aspects of the invention, the outer peripheral surface of the photoreceptor due to the contact of the conductive roll during the period from the shipment to the start of use, compared with the case where the rate of change is more than 10%. There is provided an image forming apparatus in which the denaturation is unlikely to occur.

  According to the inventions according to claims 4, 5, and 6, the outer peripheral surface of the photosensitive member due to contact with the conductive roll before the start of use from shipment compared to the case where the rate of change exceeds 10%. A process cartridge is provided that is less susceptible to denaturation.

  According to the inventions according to claims 7 and 8, there is provided an apparatus set in which the outer peripheral surface of the photoreceptor is less likely to be denatured even when the conductive roll is kept in contact as compared with the case where the rate of change is more than 10%. The

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows the other example of the image forming apparatus which concerns on this embodiment. 4 is a photograph of the outer peripheral surface of a photoconductor of Test Example 2.

  Embodiments of the present invention will be described below. These descriptions and examples are illustrative of the invention and are not intended to limit the scope of the invention.

  The inventor has studied and studied the image forming apparatus and obtained the following knowledge.

As one of toner image transfer methods employed by the image forming apparatus, a recording medium is sandwiched in a nip formed by direct contact between a photoconductor and a conductive roll (hereinafter also referred to as “transfer roll”). There is a method of transferring a toner image from the outer peripheral surface of the toner to a recording medium.
The transfer roll used in the transfer method generally has an elastic layer as an outer peripheral surface layer, but a component exuded from the outer peripheral surface layer of the transfer roll (hereinafter referred to as “bleed material”) is the outer peripheral surface of the photoreceptor. The outer peripheral surface of the photoreceptor may be denatured. This denaturation proceeds slowly, and when the image forming apparatus is stored in a warehouse or the like for a long period (for example, one year) until use is started, spots and cracks may occur on the outer peripheral surface of the photoreceptor.
Therefore, conventionally, in the image forming apparatus employing the above-described transfer method, the photoreceptor and the transfer roll are in direct contact with each other until the start of use in order to protect the outer peripheral surface of the photoreceptor from the above-described modification and other mechanical stresses. In order to avoid this, a protective film is sandwiched between the two, or a separating member for separating the two is installed. The protective film and the separation member are removed from between the photoreceptor and the transfer roll when the use of the image forming apparatus is started.

  It is desirable that the protective film and the separation member are not from the viewpoint of reducing the manufacturing cost of the image forming apparatus or reducing waste. As a combination of the photosensitive member and the transfer roll, it is possible to know in advance a combination in which the outer peripheral surface of the photosensitive member is not easily denatured by the bleed material from the transfer roll even if the direct contact state continues. If manufactured, an image forming apparatus is provided in which the outer peripheral surface of the photoreceptor is less likely to be denatured between shipment and use even when the photoreceptor and transfer roll are in direct contact. it can.

Accordingly, the present inventor studied an accelerated evaluation method for evaluating the possibility that the transfer roll denatures the outer peripheral surface of the photoreceptor, and obtained the following knowledge. That is,
Acetone extract is prepared from the outer peripheral surface layer of the transfer roll and brought into contact with the outer peripheral surface of the photoconductor to enable accelerated evaluation of the modification of the outer peripheral surface of the photoconductor;
The hardness of the outer peripheral surface of the photoreceptor changes due to the continuous contact of the acetone extract prepared from the outer peripheral surface layer of the conductive roll, and the rate of change reflects the degree of penetration of the substance causing denaturation;
The condition for observing the rate of change is “storage for 10 days in an environment of temperature 45 ° C. and humidity 85%”, and if the rate of change is 10% or less under this condition, the photosensitive member and the transfer roll have a long period (for example, 1 year) Even if the direct contact state continues, the outer peripheral surface of the photoreceptor is less likely to be denatured by the bleed material from the transfer roll;
I found.

  Obtaining the above knowledge, the image forming apparatus, the process cartridge, and the apparatus set according to the present invention have been completed. Hereinafter, embodiments of the present invention will be described in detail.

<Image forming apparatus>
The image forming apparatus according to this embodiment includes a photosensitive member and a conductive roll that applies a voltage to a toner image formed on the outer peripheral surface of the photosensitive member and directly transfers the toner image from the photosensitive member to a recording medium. A conductive roll in direct contact with the photoconductor. In the image forming apparatus according to the present embodiment, a photosensitive member and a conductive roll are in direct contact to form a nip, a recording medium is sandwiched in the nip, and a toner image is transferred from the photosensitive member to the recording medium. This is an image forming apparatus.

  The image forming apparatus according to the present embodiment is 10 under an environment of 45 ° C. and 85% humidity in a state where the acetone extract prepared from the outer peripheral surface layer of the conductive roll is in contact with the outer peripheral surface of the photoconductor. When stored for days, the rate of change in the hardness of the outer peripheral surface of the photoreceptor is 10% or less. With this combination of the photoconductor and the conductive roll, the image forming apparatus according to the present exemplary embodiment can be used even when the conductive roll is in direct contact with the photoconductor from the shipment to the start of use. Further, the outer peripheral surface of the photoreceptor is hardly denatured by the bleed material from the conductive roll.

  Therefore, the image forming apparatus according to the present embodiment can be shipped in a state where the outer peripheral surface of the photoconductor and the outer peripheral surface of the conductive roll are in direct contact. Conventionally, an image forming apparatus that employs the same transfer method as the image forming apparatus according to the present embodiment has been shipped with a protective film and a separation member disposed between the photosensitive member and the conductive roll, that is, the photosensitive member. And the conductive roll were not shipped in a state where the outer peripheral surfaces were in direct contact with each other, the image forming apparatus according to this embodiment has a protective film or a gap between the photosensitive member and the conductive roll. It is not necessary to arrange members, and the outer peripheral surface of the photoreceptor and the outer peripheral surface of the conductive roll may be in direct contact with each other at the time of completion of manufacture, and can be shipped from the manufacturing site while maintaining this contact state. According to this embodiment, even if the photosensitive member and the conductive roll are shipped in direct contact, the outer peripheral surface of the photosensitive member is unlikely to denature.

  With regard to the image forming apparatus and the process cartridge according to the present embodiment, “shipment” refers to completion of manufacture and removal from the manufacturing site. include.

  In other words, the image forming apparatus according to the present embodiment satisfies the evaluation criteria of the accelerated evaluation method described below for the photosensitive member and the conductive roll.

[Accelerated evaluation method]
The accelerated evaluation method referred to in the present embodiment is a method for evaluating the possibility that the conductive roll denatures the outer peripheral surface of the photoreceptor when the direct contact state continues,
Obtaining an acetone extract obtained by extracting acetone from the outer peripheral surface layer of the conductive roll as a solvent;
Storing the photoreceptor in an environment of a temperature of 45 ° C. and a humidity of 85% for 10 days with the acetone extract in contact with the outer peripheral surface of the photoreceptor;
Measuring the hardness of the outer peripheral surface of the photoreceptor, and determining the rate of change in hardness due to contact with the acetone extract;
This is a method for evaluating a combination of a photoconductor and a conductive roll.
When the rate of change is 10% or less and the rate of change is 10% or less, the combination of the photoreceptor and the conductive roll is accepted.

  The “acetone extract” in the present embodiment is an extract prepared from the outer peripheral surface layer of the conductive roll using acetone as a solvent. The extraction method is not particularly limited, and examples include Soxhlet extraction. The form of the acetone extract depends on the material of the outer peripheral surface layer of the conductive roll, but is, for example, a viscous liquid or powder.

  The acetone extract is brought into contact with the outer peripheral surface of the photoreceptor by applying, for example, an amount of acetone extract that hides the outer peripheral surface of the photosensitive layer with a pipette or a spoon.

  The hardness of the outer peripheral surface of the photosensitive layer is measured by a nanoindentation method using a nanoindenter, and the rate of change is calculated.

The image forming apparatus according to the present embodiment is preferably manufactured by evaluating a combination of a photoreceptor and a conductive roll by the above-described accelerated evaluation method and passing the combination.
That is, the image forming apparatus according to the present embodiment has a temperature of 45 ° C. and a humidity of 85% with respect to the photoreceptor and the conductive roll in a state where the acetone extract of the outer peripheral surface layer of the conductive roll is in contact with the outer peripheral surface of the photoreceptor. It is desirable that the product is stored for 10 days under the above environment, and is manufactured by confirming that the rate of change in hardness of the outer peripheral surface of the photoreceptor is 10% or less.

Specifically, it is preferable to perform the above-described accelerated evaluation method on a production lot or a material used for production to confirm that the evaluation standard is satisfied, and to combine the photoconductor and the conductive roll.
In other words, when the above-described accelerated evaluation method is performed on a part of a photosensitive member of a certain manufacturing lot and a part of a conductive roll of a certain manufacturing lot, and the evaluation criteria are satisfied, If the image forming apparatus is manufactured by combining the body and the conductive roll, the image forming apparatus according to the present embodiment can be obtained.
In addition, the above accelerated evaluation method is performed for a material (for example, an elastic material such as polyurethane foam) used as the outer peripheral surface layer of the conductive roll and a part of the photosensitive member of a certain production lot to satisfy the evaluation standard. In this case, the image forming apparatus according to this embodiment can be obtained by manufacturing the image forming apparatus by combining the conductive roll manufactured from the material and the photoconductor of the manufacturing lot.

  Hereinafter, the photoreceptor and the conductive roll included in the image forming apparatus according to the present embodiment will be described.

[Photoconductor]
The photoreceptor provided in the image forming apparatus according to the present embodiment is not particularly limited, and may be selected from known electrophotographic photoreceptors. The photoreceptor generally has a photosensitive layer provided on a conductive substrate. In addition, for example, the photoreceptor may have an undercoat layer between the conductive substrate and the photosensitive layer, and a protective layer on the outermost surface.
According to the combination of the photoreceptor and the conductive roll employed in this embodiment, the photoreceptor may not have a protective layer on the outermost surface, and the outermost surface may be the photosensitive layer.

  The photosensitive layer is generally a layer containing a functional material (a charge generation material and a charge transport material) and a binder resin. The photosensitive layer may be a multi-layer type photosensitive layer in which functions are separated into a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material, and the charge generation material and the charge transport material are the same. A single-layer type photosensitive layer contained in the layer may be used.

  Examples of the binder resin contained in the photosensitive layer include polycarbonate resin, acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene copolymer resin, and acrylonitrile-butadiene copolymer. Polymer, polyvinyl acetate resin, polyvinyl formal resin, polysulfone resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, phenol-formaldehyde resin , Polyacrylamide resin, polyamide resin, poly-N-vinylcarbazole resin and the like. Among these, a polycarbonate resin is suitable as the binder resin.

The charge generation material and charge transport material may be selected from known charge generation materials and charge transport materials.
Examples of the charge generating material include azo pigments such as bisazo and trisazo; fused aromatic pigments such as dibromoanthanthrone; perylene pigments; pyrrolopyrrole pigments; phthalocyanine pigments; zinc oxide; trigonal selenium.
Examples of the charge transport material include quinone compounds such as p-benzoquinone, chloranil, bromanyl and anthraquinone; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone; xanthone compounds; benzophenone And electron transporting compounds such as cyanovinyl compounds, ethylene compounds, and the like. In addition, examples of the charge transport material include hole transporting compounds such as triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, and the like. Also mentioned.

  The thickness of the photosensitive layer is set, for example, in the range of 5 μm to 50 μm, 10 μm to 30 μm.

[Conductive roll]
The electroconductive roll with which the image forming apparatus which concerns on this embodiment is provided is not specifically limited, You may select and use from a well-known electroconductive roll. The conductive roll is generally a roll member having a cylindrical or columnar support and an elastic layer provided on the outer peripheral surface of the support. In addition, for example, the conductive roll may have an intermediate layer between the elastic layer and the support.

  The support is a conductive member that functions as an electrode and a support member of the conductive roll. The support may be a hollow member (tubular member) or a non-hollow member. As a support body, metal members, such as iron (free-cutting steel etc.), copper, brass, stainless steel, aluminum, nickel, are mentioned, for example. Examples of the support include a member (for example, a resin or a ceramic member) whose outer surface is plated, a member in which a conductive agent is dispersed (for example, a resin or a ceramic member), and the like.

  The elastic layer is a conductive layer and includes, for example, a rubber material (elastic material), and may further include a conductive agent and other additives. The elastic layer may be a conductive foamed elastic layer, a conductive non-foamed elastic layer, or a conductive foamed elastic layer and a conductive non-foamed elastic layer.

  Examples of the rubber material (elastic material) include an elastic material having a double bond in at least a chemical structure. Specific examples of rubber materials include epichlorohydrin, polyurethane, nitrile rubber, isoprene rubber, butadiene rubber, epichlorohydrin-ethylene oxide rubber, ethylene-propylene-diene rubber (EPDM), and styrene-butadiene rubber (SBR). Chlorinated polyisoprene, acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), hydrogenated polybutadiene, butyl rubber, silicone rubber, and the like, and rubber materials obtained by mixing these. Among these rubber materials, polyurethane, nitrile rubber, epichlorohydrin-ethylene oxide rubber, ethylene-propylene-diene rubber (EPDM), and a rubber obtained by mixing them are preferable, and polyurethane is more preferable.

  The polyurethane used for the elastic layer is not particularly limited, and polyol (for example, polyester polyol, polyether polyol, acrylic polyol, etc.) and isocyanate (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diene). Isocyanate, 4,4-diphenylmethane diisocyanate, tolidine diisocyanate, 1,6-hexamethylene diisocyanate, etc.), and chain extenders such as 1,4-butanediol and trimethylolpropane are mixed. It is preferable.

Examples of the foaming agent for making the elastic layer foamable include water; azo compounds such as azodicarbonamide, azobisisobutyronitrile, diazoaminobenzene; bicarbonate such as sodium bicarbonate that generates carbon dioxide by thermal decomposition. Salt; a mixture of NaNO ₂ and NH ₄ Cl that generates nitrogen gas; a peroxide that generates oxygen; and the like. You may use a foaming auxiliary agent, a foam stabilizer, a catalyst, etc. as needed.

The conductive agent is used when the rubber material has low conductivity or when the rubber material does not have conductivity. Examples of the conductive agent include an electronic conductive agent and an ionic conductive agent.
Examples of the electronic conductive agent include carbon black such as furnace black, thermal black, channel black, ketjen black, acetylene black, and color black; pyrolytic carbon; graphite; various metals such as aluminum, copper, nickel, and stainless steel; Fine powders such as alloys; various metal oxides such as tin oxide, indium oxide, titanium oxide, tin oxide-antimony oxide solid solution, tin oxide-indium oxide solid solution; Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium, alkaline earth metal perchlorates and chlorates, etc. Is mentioned.

  These conductive agents may be used alone or in combination of two or more. The content of the electronic conductive agent may be, for example, from 1 part by mass to 30 parts by mass, and preferably from 10 parts by mass to 20 parts by mass with respect to 100 parts by mass of the rubber material. The content of the ionic conductive agent is, for example, preferably in the range of 0.1 parts by mass or more and 5.0 parts by mass or less, and preferably 0.5 parts by mass or more and 3.0 parts by mass with respect to 100 parts by mass of the rubber material. Or less.

  The thickness of the elastic layer is, for example, preferably from 2 mm to 20 mm, preferably from 5 mm to 20 mm, and preferably from 5 mm to 15 mm.

  A suitable example of the conductive roll is a conductive roll having a polyurethane foam layer as an outer peripheral surface layer. Polyurethane foam is excellent in flexibility and compression set, and is suitable as an outer peripheral surface layer of a conductive roll that is in direct contact with the photoreceptor during image formation. The polyurethane foam usually contains unreacted monomers, oligomers, etc., which may ooze out and cause the outer peripheral surface of the photoreceptor to be modified, but the conductive roll employed in this embodiment According to the combination of the photosensitive member and the photosensitive member, even if the direct contact state continues for a long period of time (for example, one year), the outer peripheral surface of the photosensitive member is hardly denatured by the bleed material from the conductive roll.

  Hereinafter, an image forming apparatus according to the present embodiment will be described with reference to the drawings. 1 and 2 are schematic configuration diagrams illustrating an example of an image forming apparatus according to the present embodiment. The image forming apparatus 100 shown in FIG. 1 and the image forming apparatus 110 shown in FIG. 2 may be shipped in a state where the outer peripheral surface of the photoconductor and the outer peripheral surface of the transfer roll are in direct contact.

  An image forming apparatus 100 shown in FIG. 1 includes a photoconductor 10, a charging device 20, an exposure device 30, a developing device 40, a transfer roll 50, and a fixing device 60 inside an apparatus main body (not shown). . The photoconductor 10 and the transfer roll 50 may be integrated into a process cartridge that is detachable from the apparatus main body.

  The charging device 20 is a charging unit that charges the outer peripheral surface of the photoreceptor 10. The charging device 20 is, for example, a corona discharge charging device.

  The exposure device 30 is an electrostatic image forming unit that exposes the charged photoconductor 10 to form an electrostatic image on the outer peripheral surface of the photoconductor 10. Examples of the light source of the exposure apparatus 30 include a multi-beam surface emitting laser.

  The developing device 40 is a developing unit that develops an electrostatic image formed on the outer peripheral surface of the photoreceptor 10 as a toner image with an electrostatic image developer containing toner. The developing device 40 includes, for example, a rotatable roll-shaped developing device and a container that stores toner, and operates the developing device to generate an electrostatic charge image formed on the outer peripheral surface of the photoconductor 10 with toner. To form a toner image on the outer peripheral surface of the photoreceptor 10.

  The transfer roll 50 is a conductive roll that applies a voltage to the toner image formed on the outer peripheral surface of the photoreceptor 10 and directly transfers the toner image from the photoreceptor 10 to a recording medium. The transfer roll 50 is disposed at a position in contact with the photoconductor 10 and is connected to a power source (not shown) that applies a transfer bias. When a transfer bias is applied to the transfer roll 50, electrostatic force from the photoconductor 10 toward the transfer roll 50 acts on the toner image, and the toner image on the outer peripheral surface of the photoconductor 10 is transferred onto the recording medium P.

  The fixing device 60 is a fixing unit that fixes the toner image transferred to the surface of the recording medium. The fixing device 60 includes a set of roll members including a heat source, and the recording medium P is passed between the roll members to melt and fix the toner image transferred onto the recording medium P.

  The image forming apparatus 100 may further include a cleaning device 70. The cleaning device 70 includes a cleaning blade and removes deposits (for example, discharge products) on the outer peripheral surface of the photoreceptor 10.

  The image forming apparatus 100 includes a photoconductor 10, a charging device 20, an exposure device 30, a developing device 40, a transfer roll 50, and a cleaning device 70 as one unit, and a tandem-type full-color image in which four units are mounted side by side. It may be a forming device.

  An image forming apparatus 110 shown in FIG. 2 is a multiple development type image forming apparatus that performs color superposition on the outer peripheral surface of the photoreceptor 10. The image forming apparatus 110 includes a photoconductor 10, a charging device 20, an exposure device 30, a developing device 45, a transfer roll 50, and a fixing device 60 inside an apparatus main body (not shown). The photoconductor 10 and the transfer roll 50 may be integrated into a process cartridge that is detachable from the apparatus main body. The image forming apparatus 110 may further include a cleaning device 70.

  The photoreceptor 10, the charging device 20, the exposure device 30, the transfer roll 50, the fixing device 60, and the cleaning device 70 in the image forming apparatus 110 have the same configuration as those included in the image forming apparatus 100 shown in FIG.

  The developing device 45 is a developing device in which non-contact developing devices 45Y, 45M, 45C, and 45K are integrated and arranged so as to be rotatable in accordance with the rotation of the photosensitive member 10. The developing units 45Y, 45M, 45C, and 45K store toners of yellow (Y), magenta (M), cyan (C), and black (K), respectively.

  The full-color image is formed by the image forming apparatus 110 by sequentially laminating Y, M, C, and K toner images on the outer peripheral surface of the photoreceptor 10. The toner images stacked on the outer peripheral surface of the photoreceptor 10 are transferred to the recording medium P by the transfer roll 50. The transfer roll 50 and the cleaning device 70 are separated from the photoconductor 10 while the toner images are stacked on the outer peripheral surface of the photoconductor 10.

  The toner and developer used in the image forming apparatus according to the exemplary embodiment are not particularly limited, and any known electrophotographic toner and electrostatic image developer can be used. The recording medium used in the image forming apparatus according to the present embodiment is not particularly limited, and examples thereof include paper used for electrophotographic copying machines and printers; OHP sheet;

<Process cartridge>
The process cartridge according to the present embodiment is a photosensitive roll and a conductive roll that applies a voltage to the toner image formed on the outer peripheral surface of the photosensitive drum and directly transfers the toner image from the photosensitive drum to a recording medium. And a process cartridge that is attached to and detached from the image forming apparatus.
In the process cartridge according to the present embodiment, a photosensitive member and a conductive roll are in direct contact to form a nip, and a recording medium is sandwiched in the nip, and a toner image is transferred from the photosensitive member to the recording medium. It is applied to an image forming apparatus.
The process cartridge according to the present embodiment includes at least one selected from a charging device, an exposure device, a developing device, a fixing device, and a cleaning device in addition to the photosensitive member and the conductive roll. May be.

  When the process cartridge according to the present embodiment is stored for 10 days in an environment having a temperature of 45 ° C. and a humidity of 85% in a state where the acetone extract of the outer peripheral surface layer of the conductive roll is in contact with the outer peripheral surface of the photoreceptor, The change rate of the hardness of the outer peripheral surface of the photoreceptor is 10% or less. Due to this combination of the photoconductor and the conductive roll, the process cartridge according to this embodiment is modified from the outer periphery of the photoconductor by the bleed from the conductive roll until the use is started from the shipment. Is unlikely to occur. Therefore, the process cartridge according to the present embodiment may be shipped in a state where the outer peripheral surface of the photoreceptor and the outer peripheral surface of the conductive roll are in direct contact.

  The photoreceptor and the conductive roll included in the process cartridge according to the present embodiment are not particularly limited, and may be selected from known photoreceptors and conductive rolls. For example, the image forming apparatus according to the present embodiment is used. Examples include the above-described photoreceptor and conductive roll.

The process cartridge according to the present embodiment is preferably manufactured by evaluating a combination of the photoreceptor and the conductive roll by the above-described accelerated evaluation method and passing the combination.
That is, the process cartridge according to the present embodiment has a temperature of 45 ° C. and a humidity of 85% in a state where the acetone extract of the outer peripheral surface layer of the conductive roll is in contact with the outer peripheral surface of the photosensitive member. It is desirable that it is manufactured by combining it after storing it in an environment for 10 days, confirming that the rate of change in hardness of the outer peripheral surface of the photoreceptor is 10% or less.
Specifically, as described above for the image forming apparatus according to the present embodiment, it is confirmed that the accelerated evaluation method described above is performed on the production lot or the material used for the production and the evaluation standard is satisfied, It is preferable to combine a photoconductor and a conductive roll.

<Device set>
The apparatus set according to the present embodiment includes a photosensitive member and a conductive roll that applies a voltage to a toner image formed on the outer peripheral surface of the photosensitive member and directly transfers the toner image from the photosensitive member to a recording medium. The apparatus set for an image forming apparatus is a combination of a conductive roll that comes into direct contact with the photosensitive member when mounted on the image forming apparatus.

  In the apparatus set according to the present embodiment, the photosensitive member and the conductive roll are in an environment having a temperature of 45 ° C. and a humidity of 85% in a state where the acetone extract of the outer peripheral surface layer of the conductive roll is in contact with the outer peripheral surface of the photosensitive member. When stored for 10 days, the rate of change in the hardness of the outer peripheral surface of the photoreceptor is 10% or less. Due to this combination of the photoconductor and the conductive roll, the apparatus set according to the present embodiment allows the photoconductor by the bleed material from the conductive roll to remain in direct contact for a long period (for example, one year). It is difficult for the outer peripheral surface of the material to be denatured. Therefore, the apparatus set according to the present embodiment is suitable for the image forming apparatus and the process cartridge according to the present embodiment.

  The photoreceptor and the conductive roll included in the apparatus set according to the present embodiment are not particularly limited, and may be selected from known photoreceptors and conductive rolls. For example, the image forming apparatus according to the present embodiment may be used. Examples include the above-described photoreceptor and conductive roll.

The apparatus set according to the present embodiment is preferably manufactured by evaluating a combination of the photoreceptor and the conductive roll by the above-described accelerated evaluation method and passing the combination.
That is, the apparatus set according to the present embodiment has a temperature of 45 ° C. and a humidity of 85% in a state where the acetone extract of the outer peripheral surface layer of the conductive roll is in contact with the outer peripheral surface of the photosensitive member. It is desirable to store them in an environment for 10 days and combine them after confirming that the rate of change in the hardness of the outer peripheral surface of the photoreceptor is 10% or less.
Specifically, as described above for the image forming apparatus according to the present embodiment, it is confirmed that the accelerated evaluation method described above is performed on the production lot or the material used for the production and the evaluation standard is satisfied, It is preferable to combine a photoconductor and a conductive roll.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Test Example 1>
A conductive roll A having a polyurethane foam as an outer peripheral surface layer was prepared.

  7 g of polyurethane foam was cut out from the outer peripheral surface layer of the conductive roll A and placed in a Soxhlet extractor. After acetone was refluxed for 8 hours using acetone as a solvent, acetone was distilled off from the extract to obtain 1.6 mass% acetone extract. The acetone extract in this case was a viscous liquid.

A photoreceptor C was prepared in which the outer peripheral surface layer was a photosensitive layer and the binder resin of the layer was a polycarbonate resin.
The acetone extract obtained above was applied to the outer peripheral surface of the photoreceptor C (hereinafter referred to as “patch”), stored for 10 days in an environment of temperature 45 ° C. and humidity 85%, and then a cotton swab impregnated with ethanol. Then, the acetone extract was removed from the outer peripheral surface of the photoreceptor C.

About the patched part of the photosensitive layer of the photoreceptor C, the hardness of the outer peripheral surface of the photosensitive layer was measured by a nanoindentation method using a nanoindenter (HM500 manufactured by Fischer Instruments). The measurement was performed with a Belkovic indenter under the condition of a maximum indentation depth of 5 μm. Before and after the patch, each of the three points was arbitrarily measured to determine the average value, and the rate of change (%) “(after patch-before patch) ÷ before patch × 100” was calculated from the average value of both.
Further, the outer peripheral surface of the photoreceptor C after the patch was observed with the naked eye, and the presence or absence of spots and cracks was confirmed.

  Ten conductive rolls of the same production lot as the conductive roll A and ten photoconductors of the same production lot as the photoconductor C were prepared. A conductive roll and a photoconductor were set one by one, and the outer peripheral surfaces of both were brought into contact with each other. Ten sets were stored for 1 year in an environment of a temperature of 20 ° C. and a humidity of 60%, and then the outer peripheral surface of 10 photoconductors was observed with the naked eye to confirm the presence or absence of spots and cracks.

  The photoconductor after storage for one year is mounted on an image forming apparatus (DocuPrint P350 manufactured by Fuji Xerox) to form an image (combined pattern of characters and figures) on paper (P paper manufactured by Fuji Xerox), and image formation is performed. The image was confirmed by observing the paper with the naked eye.

<Test Example 2>
A conductive roll B having a polyurethane foam as an outer peripheral surface layer was prepared.

An acetone extract was obtained from the polyurethane foam on the outer peripheral surface layer of the conductive roll B in the same manner as in Test Example 1. The acetone extract in this case was a viscous liquid.
Using the acetone extract from the conductive roll B and the photoconductor of the same production lot as the photoconductor C, the test was performed in the same manner as in Test Example 1.

  FIG. 3 shows photographs of the outer peripheral surface of the photoconductor during (A) and after (B) the test in Test Example 2. In FIG. 3A, the applied acetone extract has a slightly darker color. FIG. 3B shows the outer peripheral surface of the photoreceptor after the acetone extract is removed, and it can be seen that a spot is generated at a location where the acetone extract is applied. A line that appears obliquely at the center of FIG. 3B is a crack.

  The results of Test Examples 1 and 2 are shown in Table 1 below. Note that “fogging” is a phenomenon in which an unintended image appears on the image forming surface of a recording medium.

DESCRIPTION OF SYMBOLS 100,110 Image forming apparatus 10 Photoconductor 20 Charging apparatus 30 Exposure apparatus 40 Developing apparatus 45 Developing apparatus 50 Transfer roll 60 Fixing apparatus 70 Cleaning apparatus

Claims (8)

A photoreceptor,
A conductive roll for applying a voltage to a toner image formed on the outer peripheral surface of the photoconductor to directly transfer the toner image from the photoconductor to a recording medium, and a conductive roll in direct contact with the photoconductor;
With
When the acetone extract of the outer peripheral surface layer of the conductive roll is kept in contact with the outer peripheral surface of the photosensitive member for 10 days in an environment of 45 ° C. and 85% humidity, the outer peripheral surface of the photosensitive member is hardened. The rate of change of the height is 10% or less,
Image forming apparatus.   The image forming apparatus according to claim 1, wherein the image forming apparatus is shipped in a state where the outer peripheral surface of the photoconductor and the outer peripheral surface of the conductive roll are in direct contact with each other.   The image forming apparatus according to claim 1, wherein an outer peripheral surface layer of the conductive roll is a polyurethane foam layer. A photoreceptor,
A conductive roll for applying a voltage to a toner image formed on the outer peripheral surface of the photoconductor to directly transfer the toner image from the photoconductor to a recording medium, and a conductive roll in direct contact with the photoconductor;
With
When the acetone extract of the outer peripheral surface layer of the conductive roll is kept in contact with the outer peripheral surface of the photosensitive member for 10 days in an environment of 45 ° C. and 85% humidity, the outer peripheral surface of the photosensitive member is hardened. The rate of change of the height is 10% or less,
A process cartridge that can be attached to and detached from an image forming apparatus.   The process cartridge according to claim 4, wherein the process cartridge is shipped in a state where the outer peripheral surface of the photoconductor and the outer peripheral surface of the conductive roll are in direct contact with each other.   The process cartridge according to claim 4 or 5, wherein the conductive roll has a polyurethane foam layer as an outer peripheral surface layer. A photoreceptor,
A conductive roll for applying a voltage to a toner image formed on the outer peripheral surface of the photoconductor to directly transfer the toner image from the photoconductor to a recording medium, and is applied to the photoconductor when mounted on an image forming apparatus; A conductive roll in direct contact;
Equipment set,
When the acetone extract of the outer peripheral surface layer of the conductive roll is kept in contact with the outer peripheral surface of the photosensitive member for 10 days in an environment of 45 ° C. and 85% humidity, the outer peripheral surface of the photosensitive member is hardened. The rate of change of the height is 10% or less,
Device set for image forming apparatus.   The said conductive roll is an apparatus set of Claim 7 whose outer peripheral surface layer is a polyurethane foam layer.