JP2014089415A - Charging member for electrophotography, process cartridge, and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging member for electrophotography that suppresses the occurrence of white streaks on an image that occurs when a charging member is used for image formation, the charging member having been left unused for a long period with the presence of water droplets generated due to dew condensation in the vicinity of the charging member.SOLUTION: A charging member for electrophotography includes a conductive base material 1 and a surface layer 3; and the surface layer includes a binder resin, an electronic conductive agent, one or more metal ions selected from an alkali metal ion and an alkaline earth metal ion, and one or more cyclic compounds selected from a group of compounds.

Description

  The present invention relates to an electrophotographic charging member, a process cartridge using the same, and an electrophotographic apparatus.

  An electrophotographic image forming apparatus (hereinafter referred to as “electrophotographic apparatus”) that employs an electrophotographic system mainly includes an electrophotographic photosensitive member, a charging device, an exposure device, a developing device, a transfer device, and a fixing device. As a charging method for an electrophotographic photosensitive member, an electrophotographic method is applied by applying a voltage (a voltage of only a DC voltage or a voltage in which an AC voltage is superimposed on a DC voltage) to a charging member placed in contact with or close to the surface of the electrophotographic photosensitive member. A so-called contact charging method for charging the surface of the photoreceptor is known. Incidentally, the electrophotographic apparatus is used in various environments, and depending on the use environment, water droplets may be generated inside the electrophotographic apparatus due to condensation or the like. When water droplets adhere to the surface of the charging member, the electrical resistance value of the portion of the surface layer of the charging member that has absorbed moisture decreases, and when the electrophotographic photosensitive member is charged using such a charging member, the electrical resistance value of the charging member decreases. The charged portion corresponding to the portion that has been overcharged may cause white spots in the electrophotographic image.

  Patent Document 1 discloses a charging roll for an electrophotographic apparatus that is less susceptible to environmental fluctuations, in which the surface layer contains a hydrophobic surfactant so that the surface layer hardly absorbs water.

JP 2010-72405 A

  According to the study by the present inventors, it has been recognized that the technique according to Patent Document 1 has a certain effect. However, in order to form a stable and high-quality electrophotographic image even under various usage environments, it has been recognized that it is necessary to develop a charging member whose charging performance is less likely to deteriorate due to environmental changes. It came.

  Accordingly, an object of the present invention is to provide a charging member in which moisture absorption on the surface is suppressed and overcharging is unlikely to occur. It is another object of the present invention to provide a process cartridge and an electrophotographic apparatus that can stably form a high-quality electrophotographic image even in various environments.

  According to the present invention, there is provided an electrophotographic charging member having a conductive substrate and a surface layer, wherein the surface layer is at least one selected from a binder resin, an electroconductive agent, an alkali metal ion, and an alkaline earth metal ion. Including one or more cyclic compounds selected from the group consisting of metal ions and a compound having the structure represented by formula (1), the structure represented by formula (2), and the structure represented by formula (3). An electrophotographic charging member is provided.

  In formula (1), A is any structure selected from the group of the structure represented by formula (1-1), the structure represented by formula (1-2), and the structure represented by formula (1-3). It is.

In formula (1-1), formula (1-2), and formula (1-3), A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , and A ₆ are each independently represented by formula (1- 4) and any structure selected from the structure represented by formula (1-5).

In formula (1-4) and formula (1-5), X is independently any of O, S, or NH. R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each independently a hydrogen atom or a monovalent organic group.

  In formula (2), c, d and e are each independently 0, 1 or 2.

In formula (3), f is 4, 5 or 6. Z is CH ₂ , S or SO ₂ . R ₆ is a hydrogen atom or a monovalent organic group. R ₇ is a hydroxyl group or an alkoxyl group.

  In addition, according to the present invention, the electrophotographic charging member described above and a member to be charged that can be charged by the electrophotographic charging member can be attached to and detached from the main body of the electrophotographic apparatus. A process cartridge is provided.

  Furthermore, according to the present invention, there is provided an electrophotographic apparatus having the above-described electrophotographic charging member and a member to be charged arranged so as to be charged by the charging member.

  According to the present invention, even in the case where water droplets are generated in the vicinity of the charging member due to condensation or the like, even when left for a long period of time, it is possible to suppress the moisture absorption of the surface layer and to suppress the occurrence of white spots due to moisture absorption. A photographic charging member can be obtained.

  Further, according to the present invention, it is possible to obtain a process cartridge and an electrophotographic apparatus that can stably form a high-quality electrophotographic image.

It is sectional drawing of the roller-shaped charging member in this invention. FIG. 1A shows a charging roller composed of a conductive substrate and a surface layer, and FIG. 1B shows a charging roller in which an elastic layer is formed between the conductive substrate and the surface layer. It is the schematic of the electrical resistance measuring apparatus of a charging roller. It is the schematic of the process cartridge of this invention. 1 is a schematic view of an electrophotographic apparatus of the present invention. It is a figure which shows the state which forms an elastic layer in the outer peripheral part of an electroconductive base | substrate with the extrusion molding apparatus which comprises a crosshead. FIG. 3 is a schematic diagram illustrating a contact state between a charging roller and an electrophotographic photosensitive member in the present invention.

  As a result of diligent research, the inventors of the present invention have found that the decrease in the electrical resistance of the surface layer, which is the cause of overcharging, is caused by the presence of an alkali metal or alkaline earth metal derived from the electronic conductive agent added to the surface layer. It was found that they are distributed and generated by promoting moisture absorption.

<Charging member>
FIG. 1 shows a roller-shaped charging member as an example of an electrophotographic charging member according to the present invention. Hereinafter, the charging member will be described with a charging roller as a representative example of the charging member.

  FIG. 1A shows a charging roller having a conductive substrate 1 and a surface layer 2. FIG. 1B shows a charging roller having an elastic layer 3 between the conductive substrate 1 and the surface layer 2.

  Since the charging roller of the present invention is used in contact with the electrophotographic photosensitive member, it is more preferable to have an elastic layer. In particular, when durability is required, it is preferable to provide an elastic layer 3 and have two or more layers on the conductive substrate 1 as shown in FIG.

  The charging member for electrophotography according to the present invention has a conductive substrate and a surface layer. The surface layer contains at least one binder ion, an electronic conductive agent, one or more metal ions selected from alkali metal ions and alkaline earth metal ions, and a cyclic compound.

  The cyclic compound is one or more compounds selected from the group of compounds having the structure represented by formula (1), the structure represented by formula (2), and the structure represented by formula (3).

  In formula (1), A is any structure selected from the group of the structure represented by formula (1-1), the structure represented by formula (1-2), and the structure represented by formula (1-3). It is.

In formula (1-1), formula (1-2), and formula (1-3), A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , and A ₆ are each independently represented by formula (1- 4) and any structure selected from the structure represented by formula (1-5).

In formula (1-4) and formula (1-5), X is independently any of O, S, or NH. R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each independently a hydrogen atom or a monovalent organic group.

  In formula (2), c, d and e are each independently 0, 1 or 2.

In formula (3), f is 4, 5 or 6. Z is CH ₂ , S or SO ₂ . R ₆ is a hydrogen atom or a monovalent organic group. R ₇ is a hydroxyl group or an alkoxyl group.

  The cyclic compounds represented by the above formulas (1) to (3) are considered to include an alkali metal or an alkaline earth metal derived from the electronic conductive agent in the surface layer. Therefore, the moisture absorption promoting action by alkali metal or alkaline earth metal is suppressed, and even if it is left for a long time in the state where water droplets are generated in the vicinity of the charging roller due to condensation or the like, it is difficult to cause overcharging. It is considered that the occurrence of white spots in photographic images can be effectively suppressed.

The charging roller according to the present invention usually has an electric resistance value of 1 × 10 ³ Ω or more and 1 × 10 ³ in an environment having a temperature of 23 ° C. and a relative humidity of 50% in order to improve the charging of the photoreceptor. More preferably, it is ¹⁰ Ω or less.

  As an example, FIG. 2 shows a method of measuring the electric resistance value of the charging roller. Both ends of the conductive substrate 1 are brought into contact with a columnar metal 32 having the same curvature as that of the photoconductor by bearings 33a and 33b under load. In this state, the cylindrical metal 32 is rotated by a motor (not shown), and a DC voltage of −200 V is applied from the stabilized power supply 34 while the charging roller 5 that is in contact with the rotation is driven to rotate. The current flowing at this time is measured by an ammeter 35, and the electric resistance value of the charging roller is calculated. In the present invention, the load is 4.9 N each, the diameter of the metal cylinder is 30 mm, and the rotation of the metal cylinder is 45 mm / sec.

  The charging roller of the present invention preferably has a so-called crown shape in which the central portion in the longitudinal direction is the thickest and narrows toward both ends in the longitudinal direction from the viewpoint of making the nip width in the longitudinal direction uniform with respect to the photoreceptor. . The crown amount is preferably such that the difference (average value) between the outer diameter of the central portion and the outer diameter at positions 90 mm away from the central portion in the direction of both ends is not less than 30 μm and not more than 200 μm.

  In the charging roller of the present invention, it is more preferable that the surface ten-point average roughness Rzjis (μm) is 2 ≦ Rzjis ≦ 80, and the surface unevenness average interval RSm (μm) is 15 ≦ RSm ≦ 200. By setting the surface roughness Rzjis and the unevenness average interval RSm of the charging roller within these ranges, the contact state between the charging roller and the electrophotographic photosensitive member can be made more stable. This facilitates uniform charging of the photoreceptor.

  A method for measuring the surface ten-point average roughness Rzjis and the surface unevenness average interval RSm will be described below.

  Measured according to JIS B 0601-2001 surface roughness standards, and performed using a surface roughness measuring instrument (trade name: SE-3500, manufactured by Kosaka Laboratory Ltd.). Rzjis is an average value of the surface roughness measured at six locations randomly extracted from the surface of the charging member. Further, RSm is an average value of RSm at these six locations, by measuring the irregularity intervals at 10 points at 6 locations randomly extracted from the surface of the charging member and setting the average value as RSm at each location. Measurement conditions are cut-off value: 0.8 mm, filter: gauss, reserve length: cut-off × 2, leveling: straight line (entire area), evaluation length: 8 mm.

  In order to control Rzjis and RSm within the above ranges, it is more preferable that particles having an average particle diameter of 1 μm or more and 100 μm or less are added to each layer described below, particularly the surface layer. As for the particles, insulating particles described later can be exemplified.

  The charging roller of the present invention has a micro hardness (MD-1 type) of preferably 70 ° or less, and more preferably 60 ° or less. When the micro hardness (MD-1 type) exceeds 70 °, the nip width between the charging roller and the electrophotographic photosensitive member becomes small, and the contact force between the charging roller and the electrophotographic photosensitive member is concentrated on a small area. However, the contact pressure may increase. The “micro hardness (MD-1 type)” means the hardness of the charging roller measured using a micro rubber hardness meter (trade name: Asker micro rubber hardness meter MD-1 type, manufactured by Kobunshi Keiki Co., Ltd.). It is. Specifically, the hardness meter is a value measured in a 10 N peak hold mode with respect to a charging roller that has been allowed to stand for 12 hours or more in an environment of a temperature of 23 ° C. and a relative humidity of 50%.

[Conductive substrate]
The conductive substrate used in the charging roller of the present invention is conductive and has a function of supporting a surface layer or the like provided thereon. Examples of the material include metals such as iron, copper, stainless steel, aluminum, nickel, and alloys thereof. In addition, for the purpose of imparting scratch resistance to these surfaces, plating treatment or the like may be performed as long as the conductivity is not impaired. Furthermore, as the conductive substrate, a resin substrate whose surface is made conductive by coating the surface with a metal or the like, or a substrate manufactured from a conductive resin composition can be used.

  A conductive substrate and a layer laminated on the conductive substrate (for example, the elastic layer 3 shown in FIG. 1B), or a layer sequentially laminated on the conductive substrate (for example, the elastic layer shown in FIG. 1B) 3 and the surface layer 2) may be bonded via an adhesive. In this case, the adhesive is preferably conductive. Examples of the binder for the adhesive include thermosetting resins and thermoplastic resins, and known ones such as urethane, acrylic, polyester, polyether, and epoxy can be used. The conductive agent for imparting conductivity to the adhesive can be appropriately selected from the conductive agents described later, and can be used alone or in combination of two or more.

[Surface layer]
The surface layer used in the charging member of the present invention contains at least a binder resin, an electronic conductive agent, a metal ion, and a cyclic compound that includes the metal ion, and the cyclic compound is represented by the formula (1). It is one or more compounds selected from the group of compounds having the structure, the structure represented by formula (2) and the structure represented by formula (3), and the metal ions are selected from alkali metal ions and alkaline earth metal ions One or more metal ions.

[Binder resin]
As binder resin used for a surface layer, the material used for a well-known binder is employable. Examples thereof include resins, natural rubber, vulcanized products thereof, and rubbers such as synthetic rubber.

  As the resin, a resin such as a thermosetting resin or a thermoplastic resin can be used. Among these, fluorine resin, polyamide resin, acrylic resin, polyurethane resin, silicone resin, and butyral resin are more preferable. Synthetic rubbers include ethylene-propylene-diene copolymer (EPDM), styrene-butadiene copolymer rubber (SBR), silicone rubber, urethane rubber, isoprene rubber (IR), butyl rubber, acrylonitrile-butadiene copolymer rubber (NBR). Chloroprene rubber (CR), acrylic rubber and epichlorohydrin rubber can be used. These may be used alone or in combination of two or more. Among these, it is preferable to use a resin from the viewpoint that the photosensitive member and other members are not contaminated and the releasability is high.

The volume resistivity of the surface layer, the electrical resistance of the charging member to within the above range, temperature ^{23 ℃, 1 × 10 3 Ω} · cm or more under a relative humidity of 50%, 1 × ^{10 15} Ω · cm The following is more preferable.

  The volume resistivity of the surface layer is determined as follows. First, the surface layer is peeled off from the charging member, and cut into strips having a length of about 5 mm and a width of about 5 mm. Metal is vapor-deposited on both surfaces to produce an electrode and a guard electrode, and a measurement sample is obtained. Or it coat | covers on an aluminum sheet | seat, forms a surface layer coating film, vapor-deposits a metal on the coating-film surface, and obtains the sample for a measurement. A voltage of 200 V is applied to the obtained measurement sample using a microammeter (trade name: ADVANTEST R8340A ULTRA HIGH RESISTANCE METER, manufactured by Advantest Corporation). Then, the current after 30 seconds is measured and calculated from the film thickness and the electrode area. The volume resistivity of the surface layer can be adjusted by an electronic conductive agent and an ionic conductive agent described later.

[Electronic conductive agent]
The volume resistivity of the surface layer can be adjusted by a conductive agent such as an electronic conductive agent. Examples of the electronic conductive agent include the following. Metal fine particles and fibers such as aluminum, palladium, iron, copper and silver; Metal oxides such as tin oxide and zinc oxide; Electrolytic treatment, spray coating, mixed vibration on the surface of metal fine particles, fibers and metal oxides Composite particles surface-treated by means of carbon; carbon black and carbon-based fine particles.

  Examples of carbon black include black furnace black, thermal black, acetylene black, and ketjen black. As furnace black, SAF-HS, SAF, ISAF-HS, ISAF, ISAF-LS, I-ISAF-HS, HAF-HS, HAF, HAF-LS, T-HS, T-NS, MAF, FEF, GPF , SRF-HS-HM, SRF-LM, ECF, and FEF-HS. Examples of the thermal black include FT and MT. Examples of the carbon-based fine particles include PAN (polyacrylonitrile) -based carbon particles and pitch-based carbon particles.

  Moreover, these electronic conductive agents can be used individually or in combination of 2 or more types. The addition amount of the electronic conductive agent contained in the surface layer is suitably in the range of 2 to 100 parts by mass with respect to 100 parts by mass of the binder resin.

  The surface of the electronic conductive agent may be treated. As the surface treatment agent, organosilicon compounds such as alkoxysilanes, fluoroalkylsilanes, polysiloxanes, etc .; various silane, titanate, aluminate and zirconate coupling agents; oligomers or polymer compounds can be used. . These may be used alone or in combination of two or more. Preferred are organosilicon compounds such as alkoxysilanes and polysiloxanes, and various coupling agents of silane, titanate, aluminate or zirconate, and more preferred are organosilicon compounds.

  When carbon black is used as the electronic conductive agent, it is more preferably used as composite conductive fine particles in which metal oxide fine particles are coated with carbon black. Since carbon black forms a structure, it tends to be difficult to make it uniformly exist in the binder resin. When carbon black is used as composite conductive fine particles coated with a metal oxide, the electronic conductive agent can be uniformly present in the binder resin, and the volume resistivity can be controlled more easily.

  Examples of the metal oxide fine particles used for this purpose include metal oxides and composite metal oxides. Specifically, examples of the metal oxide include zinc oxide, tin oxide, indium oxide, titanium oxide (titanium dioxide, titanium monoxide, etc.), iron oxide, silica, alumina, magnesium oxide, zirconium oxide, and the like. it can. Examples of the composite metal oxide include strontium titanate, calcium titanate, magnesium titanate, barium titanate, and calcium zirconate.

  The metal oxide fine particles are more preferably surface-treated. As the surface treatment, organosilicon compounds such as alkoxysilanes, fluoroalkylsilanes, and polysiloxanes; various coupling agents such as silane, titanate, aluminate, and zirconate; oligomers or polymer compounds can be used. These may be used alone or in combination of two or more.

  The composite conductive fine particles preferably have an average particle size of 0.01 μm or more and 0.9 μm or less, and more preferably 0.01 μm or more and 0.5 μm or less. Within this range, the volume resistivity of the surface layer can be easily controlled.

[Metal ions]
Metal ions present in the surface layer are eluted from the electronic conductive agent into the binder resin. Examples of the metal ions include alkali metals such as potassium ions and sodium ions, and alkaline earth metals such as magnesium ions and calcium ions.

[Cyclic compound]
The cyclic compound contained in the surface layer is a cyclic compound having a structure represented by the formula (1), a structure represented by the formula (2) and a structure represented by the formula (3). A known cyclic compound having an inclusion ability with respect to an earth metal can be used. For example, crown ether can be exemplified as a compound having the structure represented by formula (1), cryptand can be exemplified as a compound having a structure represented by formula (2), and calixarene can be exemplified as a compound having a structure represented by formula (3). .

  Examples of the crown ether include the following. 12-crown-4-ether, 15-crown-5-ether, 18-crown-6-ether, 2- (hydroxymethyl) -12-crown-4-ether, 2- (hydroxymethyl) -15-crown- 5-ether, 2- (hydroxymethyl) -18-crown-6-ether, benzo-12-crown-4-ether, 2- (allyloxymethyl) -18-crown-6-ether, benzo-15-crown -5-ether, benzo-18-crown-6-ether, dibenzo-15-crown-5-ether, dibenzo-18-crown-6-ether, hexabenzo-18-crown-6-ether, 4'-acetylbenzo -15-crown-5-ether, 4'-acetylbenzo-18-crown-6-ether, 4'-cal Xylbenzo-15-crown-5-ether, 4'-carboxybenzo-18-crown-6-ether, 4'-formylbenzo-15-crown-5-ether, 4'-formylbenzo-18-crown-6 Ether, 4'-methoxycarbonylbenzo-15-crown-5-ether, 4'-nitrobenzo-15-crown-5-ether, 4'-nitrobenzo-18-crown-6-ether, 4'-aminobenzo-15- Crown-5-ether, 4'-bromobenzo-15-crown-5-ether, 4'-bromobenzo-18-crown-6-ether, 1-aza-12-crown-4-ether, 1-aza-15- Crown-5-ether, 1-aza-18-crown-6-ether, 4,10-diaza-12-crown 4-ether, 4,10-diaza-15-crown-5-ether, 4,13-diaza-18-crown-6-ether, 1-thia-12-crown-4-ether, 1-thia-15- Crown-5-ether, 1-thia-18-crown-6-ether, 4,10-dithia-12-crown-4-ether, 4,10-dithia-15-crown-5-ether, 4,13- Dithia-18-crown-6-ether.

  Examples of cryptands include the following. [1,1,1] -cryptand, [2,1,1] -cryptand, [2,2,1] -cryptand, [2,2,2] -cryptand, [3,2,2] -cryptand, [3,3,2] -cryptand, [3,3,3] -cryptand.

  Examples of calixarene include the following. Calix [4] arene, calix [5] arene, calix [6] arene, 4-terbutylcalix [4] arene, 4-terbutylcalix [5] arene, 4-terbutylcalix [6] arene, 4- Methyl-1-acetoxycalix [6] arene, 4-sulfocalix [4] arene, 4-terbutylthiacalix [4] arene, 4-terbutylsulfonylcalix [4] arene.

The above cyclic compounds can include an alkali metal or an alkaline earth metal. The cyclic compound includes an alkali metal or an alkaline earth metal having an ionic radius suitable for the size of the ring constituting the ring compound. The inclusion of the metal ion of the cyclic compound can be confirmed by the chemical shift of the ¹ H-NMR spectrum.

  As the crown ether, A is any structure selected from the group consisting of a structure represented by the formula (1-1), a structure represented by the formula (1-2), and a structure represented by the formula (1-3). It is preferable that In this structure, since the clathrate has a high clathrate ability with respect to alkali metal and alkaline earth metal, moisture absorption can be effectively suppressed. Furthermore, by making A into the structure represented by the formula (1-2), the inclusion ability with respect to sodium ions derived from the electronic conductive agent that is particularly abundant in the binder resin is increased, and moisture absorption suppression is more effectively expressed. Can do.

  As said cryptand, it is preferable that c, d, and e in Formula (2) are each independently 0, 1 or 2. Within this range, cryptand has a high clathrate ability with respect to alkali metals and alkaline earth metals, and therefore can effectively suppress moisture absorption. Further, by setting c + d + e = 1, the inclusion ability with respect to sodium ions derived from the electronic conductive agent present in a particularly large amount in the binder resin is increased, and moisture absorption suppression can be expressed more effectively.

  As the calixarene, f in the formula (3) is preferably 4, 5 or 6. Within this range, calixarene has a high clathrate ability with respect to alkali metals and alkaline earth metals, so that moisture absorption can be effectively suppressed. Furthermore, by setting f = 4, the inclusion ability with respect to the sodium ion derived from the electronic conductive agent which exists especially much in binder resin becomes high, and moisture absorption suppression can be expressed more effectively.

  The addition amount of the cyclic compound contained in the surface layer is preferably 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin. By setting it within this range, it is possible to effectively exhibit suppression of moisture absorption when left for a long time in the state where water droplets are present in the vicinity of the charging member.

[Other additives]
In the surface layer, as other additives, an ionic conductive agent, insulating particles, a filler, a release agent and the like can be contained.

(Ionic conductive agent)
The volume resistivity of the surface layer can be further adjusted with a conductive agent such as an ionic conductive agent. Examples of the ionic conductive agent include the following. Inorganic ionic substances such as lithium perchlorate, sodium perchlorate, calcium perchlorate, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, trioctylpropyl Cationic surfactants such as ammonium bromide, modified aliphatic dimethylethylammonium etosulphate, zwitterionic surfactants such as lauryl betaine, stearyl betaine, dimethylalkyl lauryl betaine, tetraethylammonium perchlorate, tetrachlorate perchlorate Quaternary ammonium salts such as butylammonium, trimethyloctadecylammonium perchlorate, Organic acid lithium salts such as trifluoromethanesulfonic lithium sulfonate. These can be used alone or in combination of two or more. Among ionic conductive agents, quaternary ammonium perchlorate is particularly preferably used because of its stable electrical resistance against environmental changes.

  The addition amount of these conductive agents contained in the surface layer is suitably in the range of 2 to 100 parts by mass with respect to 100 parts by mass of the binder resin.

(Insulating particles)
Insulating particles can be contained in the surface layer as long as the effects of the present invention are not impaired. Examples of the insulating particles include particles composed of the following polymer compounds. Polyamide resin, silicone resin, fluororesin, (meth) acrylic resin, styrene resin, phenol resin, polyester resin, melamine resin, urethane resin, olefin resin, epoxy resin, resins such as copolymers, modified products, and derivatives, Ethylene-propylene-diene copolymer (EPDM), styrene-butadiene copolymer rubber (SBR), silicone rubber, urethane rubber, isoprene rubber (IR), butyl rubber, acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber (CR ), Rubber such as epichlorohydrin rubber, polyolefin-based thermoplastic elastomer, urethane-based thermoplastic elastomer, polystyrene-based thermoplastic elastomer, fluororubber-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide Thermoplastic elastomers, polybutadiene type thermoplastic elastomers, ethylene vinyl acetate type thermoplastic elastomers, polyvinyl chloride thermoplastic elastomer, and thermoplastic elastomers such as chlorinated polyethylene based thermoplastic elastomer. In particular, (meth) acrylic resin, styrene resin, urethane resin, fluororesin, and silicone resin are preferable.

  The insulating particles may be used singly or in combination of two or more, and may be those subjected to surface treatment, modification, introduction of functional groups or molecular chains, coating, and the like. In order to improve the dispersibility of the particles, the particles are more preferably subjected to a surface treatment.

  As the surface treatment, the above-mentioned surface treatment agent can be used, and in addition, surface treatment with a fatty acid or a fatty acid metal salt can be exemplified. As the fatty acid, a saturated or unsaturated fatty acid can be used, and those having 12 to 22 carbon atoms are preferable. As the fatty acid metal salt, a salt of a saturated or unsaturated fatty acid and a metal can be used. The surface treatment agent is preferably used in an amount of 0.01 to 15.0 parts by mass with respect to 100 parts by mass of the insulating particles, and within this range, sufficient dispersibility can be imparted to the particles. . More preferably, it is 0.02 mass part to 12.5 mass parts, More preferably, it is 0.03 mass part to 10.0 mass parts.

(Filler)
The surface layer can contain a filler as long as the effects of the present invention are not impaired. Examples of the filler include the following. Indium oxide, titanium oxide (titanium dioxide, titanium monoxide, etc.), iron oxide, silica, alumina, magnesium oxide, zirconium oxide, strontium titanate, calcium titanate, magnesium titanate, barium titanate, calcium zirconate, barium sulfate , Molybdenum disulfide, calcium carbonate, magnesium carbonate, dolomite, talc, kaolin clay, mica, aluminum hydroxide, magnesium hydroxide, zeolite, wollastonite, diatomaceous earth, glass beads, bentonite, montmorillonite, hollow glass sphere, organic Particles such as metal compounds and organometallic salts. Further, iron oxides such as ferrite, magnetite, and hematite, activated carbon, and the like can also be used.

  These fillers may be used alone or in combination of two or more, and may be subjected to surface treatment, modification, introduction of functional groups and molecular chains, coating, and the like. In order to improve the dispersibility of the filler, it is more preferable that the filler is subjected to a surface treatment. As the surface treatment agent, the above-mentioned surface treatment agent can be used.

(Release agent)
In the surface layer, a release agent may be contained in order to improve the surface releasability. By including a release agent in the surface layer, it is possible to prevent dirt from adhering to the surface of the charging member and improve the durability of the charging member. When the release agent is a liquid, it also acts as a leveling agent when forming the surface layer.

  As such a release agent, those having low surface energy, those having slidability, and the like can be used, and those having solid and liquid properties can be used. Specific examples include the following. It is a metal oxide such as graphite, graphite fluoride, molybdenum disulfide, tungsten disulfide, boron nitride, lead monoxide. In addition, oil- or solid-state (release resin or powder thereof, a part of the polymer into which a part having release property is introduced) silicon or fluorine-containing compound, wax, higher fatty acid, salt thereof And esters and other derivatives.

  The surface layer preferably has a thickness of 0.1 μm or more and 100 μm or less. More preferably, they are 1 micrometer or more and 50 micrometers or less. The film thickness of the surface layer can be measured by cutting the roller with a sharp blade and observing it with an optical microscope or an electron microscope.

[Method for forming surface layer]
The surface layer can be formed by a coating method such as electrostatic spray coating or dipping coating. Or it can also form by adhere | attaching or coat | covering the sheet-shaped or tube-shaped layer beforehand formed into a predetermined film thickness. Alternatively, a method of curing and molding the material into a predetermined shape in the mold can also be used. Among these, it is preferable to apply a paint by a coating method to form a coating film.

  When a layer is formed by a coating method, the solvent used in the coating solution may be any solvent that can dissolve the binder. Specific examples include the following. Alcohols such as methanol, ethanol, isopropanol, ketones such as acetone, methyl ethyl ketone, cyclohexanone, amides such as N, N-dimethylformamide, N, N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran, dioxane, ethylene Ethers such as glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, aromatic compounds such as xylene, ligroin, chlorobenzene and dichlorobenzene.

  As a method for dispersing the binder, the conductive agent, and the like in the coating solution, known solution dispersing means such as a ball mill, a sand mill, a paint shaker, a dyno mill, and a pearl mill can be used.

[Elastic layer]
As a material used for the elastic layer, rubber or resin exemplified above as the binder component of the surface layer can be used. Preferably, the following are mentioned. Heat of epichlorohydrin rubber, acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber, urethane rubber, silicone rubber, SBS (styrene-butadiene-styrene-block copolymer), SEBS (styrene-ethylenebutylene-styrene-block copolymer), etc. Plastic elastomer.

  Among these, since it is easy to adjust the electric resistance value, it is more preferable to use polar rubber. Among these, epichlorohydrin rubber and NBR can be mentioned. These have the advantage that it is easier to control the electrical resistance and hardness of the elastic layer.

  In the epichlorohydrin rubber, the polymer itself has conductivity in the middle resistance region, and can exhibit good conductivity even if the amount of the conductive agent added is small. Moreover, since the variation in electric resistance depending on the position can be reduced, it is suitably used as a polymer elastic body. Examples of the epichlorohydrin rubber include the following. Epichlorohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-allyl glycidyl ether copolymer and epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer. Of these, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer is particularly preferably used since it exhibits stable conductivity in a medium resistance region. The epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer can control conductivity and workability by arbitrarily adjusting the degree of polymerization and composition ratio.

  The elastic layer may be epichlorohydrin rubber alone, but it may contain epichlorohydrin rubber as a main component and other general rubber as necessary. Other common rubbers include the following. Ethylene-propylene rubber (EPM), ethylene-propylene-diene copolymer (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber, natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, urethane rubber, Silicone rubber etc. Further, a thermoplastic elastomer such as SBS (styrene / butadiene / styrene block copolymer) or SEBS (styrene / ethylene butylene / styrene block copolymer) may be contained. When said general rubber | gum is contained, it is more preferable that the content is 1-50 mass parts with respect to 100 mass parts of elastic layer materials.

The volume resistivity of the elastic layer is preferably 10 ² Ω · cm or more and 10 ¹⁰ Ω · cm or less as measured in an environment at a temperature of 23 ° C. and a relative humidity of 50%. Moreover, in order to adjust volume resistivity, the electronic conductive agent or the ionic conductive agent illustrated above can be added suitably. When polar rubber is used as the material of the elastic layer, it is particularly preferable to use an ammonium salt.

  The volume resistivity of the elastic layer is a volume resistivity measurement sample obtained by molding all materials used for the elastic layer into a 1 mm thick sheet and depositing metal on both sides to form electrodes and guard electrodes. And can be measured in the same manner as the volume resistivity measuring method of the surface layer.

  The elastic layer may contain the insulating particles exemplified above. Moreover, in order to adjust hardness etc., you may add additives, such as softening oil and a plasticizer, in an elastic layer. The amount of the plasticizer or the like is preferably 1 to 30 parts by mass, more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the elastic layer material. It is more preferable to use a polymer type plasticizer. The molecular weight of the polymer plasticizer is preferably 2000 or more, more preferably 4000 or more.

  Furthermore, the elastic layer may appropriately contain materials that impart various functions. Examples of these include anti-aging agents and fillers.

  The hardness of the elastic layer is preferably 70 ° or less, more preferably 60 ° or less in terms of micro hardness (MD-1 type). When the micro hardness (MD-1 type) exceeds 70 °, the nip width between the charging member and the photosensitive member becomes small, and the contact force between the charging member and the photosensitive member concentrates in a small area, and the contact Pressure may increase. Micro hardness (MD-1 type) can be measured by the above-mentioned method.

  The elastic layer can be formed by adhering or coating a sheet-shaped or tube-shaped layer formed in advance to a predetermined film thickness on a conductive substrate. In addition, the conductive substrate and the elastic layer material can be integrally extruded by using an extruder equipped with a cross head.

  As a method for dispersing the conductive agent, insulating particles, filler, and the like in the elastic layer material, a known method such as mixing with a ribbon blender, nauter mixer, Henschel mixer, super mixer, Banbury mixer, pressure kneader, etc. Can be used.

<Process cartridge>
The charging member according to the present invention is used as a process cartridge that is integrated with a member to be charged so that it can be charged by the charging member and is configured to be detachable from the main body of the electrophotographic apparatus. it can. The process cartridge shown in FIG. 3 includes an electrophotographic photosensitive member, a charging device that charges the electrophotographic photosensitive member, a developing device that develops toner on the electrophotographic photosensitive member, a cleaning device that collects transfer toner on the electrophotographic photosensitive member, and the like. It is configured.

  The electrophotographic photoreceptor 4 is a rotary drum type having a photosensitive layer on a conductive substrate. The charging device includes a contact-type charging roller 5 that is placed in contact with the electrophotographic photosensitive member 4 by contacting with the electrophotographic photosensitive member 4 with a predetermined pressing force. The charging roller 5 is driven rotation that rotates in accordance with the rotation of the electrophotographic photosensitive member, and charges the electrophotographic photosensitive member to a predetermined potential by applying a predetermined DC voltage from a charging power source.

  The developing device includes a developing sleeve or a developing roller 6 disposed close to or in contact with the electrophotographic photosensitive member 4. The toner electrostatically processed to the same polarity as the charged polarity of the electrophotographic photosensitive member is reversely developed to develop the electrostatic latent image to form a toner image.

  The cleaning device includes a blade-type cleaning member 10 and a collection container, and after transfer, mechanically scrapes and collects transfer residual toner remaining on the electrophotographic photosensitive member. Here, it is possible to omit the cleaning device by adopting a development simultaneous cleaning system in which the transfer device collects the transfer residual toner.

<Electrophotographic device>
The charging member according to the present invention can be used in an electrophotographic apparatus together with a member to be charged arranged so as to be charged by the charging member. The process cartridge according to the present invention can be used in an electrophotographic apparatus having at least a process cartridge, an exposure device, and a developing device. FIG. 4 shows a schematic configuration of an example of an electrophotographic apparatus including the charging member according to the present invention. The electrophotographic apparatus includes an electrophotographic photosensitive member, a charging device that charges the electrophotographic photosensitive member, a latent image forming device that performs exposure, a developing device that develops a toner image, a transfer device that transfers to a transfer material, and an electrophotographic photosensitive member. A cleaning device for collecting the transfer toner, a fixing device for fixing the toner image, and the like are included.

  The electrophotographic photoreceptor 4 is a rotary drum type having a photosensitive layer on a conductive substrate. The electrophotographic photosensitive member is driven to rotate at a predetermined peripheral speed (process speed) in the direction of the arrow.

  The charging device includes a contact-type charging roller 5 that is placed in contact with the electrophotographic photosensitive member 4 by contacting with the electrophotographic photosensitive member 4 with a predetermined pressing force. The charging roller 5 is driven rotation that rotates in accordance with the rotation of the electrophotographic photosensitive member, and is configured to be able to charge the electrophotographic photosensitive member to a predetermined potential by applying a predetermined DC voltage from the charging power source 19. ing.

  As the latent image forming apparatus 11 that forms an electrostatic latent image on the electrophotographic photosensitive member 4, an exposure apparatus such as a laser beam scanner is used. An electrostatic latent image is formed by performing exposure corresponding to image information on the uniformly charged electrophotographic photosensitive member.

  The developing device includes a developing sleeve or a developing roller 6 disposed close to or in contact with the electrophotographic photosensitive member 4. The amount of toner adhering to the developing roller 6 is adjusted by the elastic regulation blade 13. The toner electrostatically processed to the same polarity as the charged polarity of the electrophotographic photosensitive member is reversely developed to develop the electrostatic latent image to form a toner image.

  The transfer device has a contact-type transfer roller 8. The toner image is transferred from the electrophotographic photosensitive member to a transfer material 7 such as plain paper (the transfer material is conveyed by a paper feeding system having a conveying member).

  The cleaning device has a blade-type cleaning member 10 and a collection container 14 and mechanically scrapes and collects transfer residual toner remaining on the electrophotographic photosensitive member after transfer. Here, it is possible to omit the cleaning device by adopting a development simultaneous cleaning system in which the transfer device collects the transfer residual toner.

  The fixing device 9 is constituted by a heated roll or the like, and fixes the transferred toner image on the transfer material 7 and discharges it outside the apparatus.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. Prior to the examples, a production example of conductive fine particles, a production example of a coating solution for a surface layer, and a production example of a compound for an elastic layer will be described. The cyclic compounds used in the production examples and examples are listed in Tables 4 to 6.

<Production Example 1> [Preparation of composite conductive fine particles]
To 7.0 kg of silica particles (average particle size 15 nm, volume resistivity 1.8 × 10 ¹² Ω · cm), 140 g of methyl hydrogen polysiloxane was added while operating the edge runner, and 588 N / cm (60 kg / cm ) Was mixed and stirred for 30 minutes. The stirring speed at this time was 22 rpm. Among them, 7.0 kg of carbon black (trade name: # 52, manufactured by Mitsubishi Chemical Corporation) was added over 10 minutes while operating the edge runner, and a linear load of 588 N / cm (60 kg / cm) was further added. And stirring for 60 minutes. The stirring speed at this time was 22 rpm. After carbon black (electronic conductive agent) was adhered to the surface of the silica particles coated with methylhydrogenpolysiloxane in this way, drying was performed at a temperature of 80 ° C. for 60 minutes using a dryer, and “composite conductive fine particles” 1 "was produced. The obtained composite conductive fine particles had an average particle size of 15 nm and a volume resistivity of 1.1 × 10 ² Ω · cm.

<Production Example 2> [Production of surface-treated titanium oxide particles]
1000 g of acicular rutile type titanium oxide particles (average particle size 15 nm, length: width = 3: 1, volume resistivity 2.3 × 10 ¹⁰ Ω · cm), 110 g of isobutyltrimethoxysilane as a surface treatment agent, and toluene as a solvent A slurry was prepared by blending 3000 g. This slurry was mixed with a stirrer for 30 minutes, and then supplied to Viscomill in which 80% of the effective internal volume was filled with glass beads having an average particle diameter of 0.8 mm, and wet crushing was performed at a temperature of 35 ± 5 ° C. . Toluene was removed from the slurry obtained by wet pulverization by vacuum distillation (bath temperature: 110 ° C., product temperature: 30-60 ° C., degree of vacuum: 100 Torr) using a kneader, and the surface was kept at a temperature of 120 ° C. for 2 hours. The treating agent was baked. The baked particles were cooled to room temperature and then pulverized using a pin mill to prepare “surface-treated titanium oxide particles 2” (filler).

<Production Example 3> [Preparation of surface layer coating solution 1]
Methyl isobutyl ketone was added to a caprolactone-modified acrylic polyol solution (trade name: Plaxel DC2016, manufactured by Daicel Corporation) to adjust the solid content to 17% by mass. With respect to 588.24 parts by mass of this solution (100 parts by mass of acrylic polyol solid content), the other 5 components of component (1) shown in Table 1 below were added to prepare a mixed solution. At this time, the blocked isocyanate mixture was such that the amount of isocyanate was “NCO / OH = 1.0”.

  In a glass bottle with an internal volume of 450 mL, 200 g of the mixed solution was put together with 200 g of glass beads having an average particle diameter of 0.8 mm as a medium, and dispersed for 24 hours using a paint shaker disperser. Next, 2.7 g of polymethyl methacrylate resin particles having an average particle diameter of 10 μm were added as insulating particles. This addition amount is equivalent to 10 parts by mass of polymethyl methacrylate resin particles with respect to 100 parts by mass of the acrylic polyol solid content. Then, after dispersing for 1 hour, the glass beads were removed to obtain “surface layer coating solution 1”. The surface layer coating solution 1 was analyzed by ICP emission spectroscopy. As a result, potassium ion, sodium ion, magnesium ion and calcium ion were detected.

<Production Example 4> [Preparation of surface layer coating solution 2]
Ethanol was added to polyvinyl butyral to adjust the solid content to 20% by mass. The other 4 components of the component (1) described in Table 2 below were added to 500 parts by mass of the solution thus obtained (100 parts by mass of polyvinyl butyral solid content) to prepare a mixed solution.

  In a glass bottle with an internal volume of 450 mL, 200 g of the mixed solution was put together with 200 g of glass beads having an average particle diameter of 0.8 mm as a medium, and dispersed for 24 hours using a paint shaker disperser. Next, 3.5 g of polymethyl methacrylate resin particles having an average particle diameter of 10 μm were added as insulating particles. This addition amount is equivalent to 10 parts by mass of polymethyl methacrylate resin particles with respect to 100 parts by mass of the polyvinyl butyral solid content. Thereafter, the dispersion was carried out for 1 hour, and the glass beads were removed to obtain “surface layer coating solution 2”. The surface layer coating solution 2 was analyzed by ICP emission spectroscopy. As a result, potassium ion, sodium ion, magnesium ion and calcium ion were detected.

<Production Example 5> [Preparation of compound for elastic layer]
The seven components listed in Table 3 below were kneaded for 10 minutes in a closed mixer adjusted to a temperature of 50 ° C.

  To this was added 0.8 part by mass of sulfur as a vulcanizing agent. Furthermore, 1 part by mass of dibenzothiazyl sulfide (trade name: Noxeller DM, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) as a vulcanization accelerator, tetramethylthiuram monosulfide (trade name: Noxeller TS, Ouchi Shinsei Chemical Industry) 0.5 part by mass was added. Subsequently, it knead | mixed for 10 minutes with the double roll machine cooled to the temperature of 20 degreeC, and the "compound 1 for elastic layers" was obtained.

<Example 1>
[1. Conductive substrate
A thermosetting adhesive containing 10% by mass of carbon black was applied to a stainless steel substrate having a diameter of 6 mm and a length of 252.5 mm, and the dried product was used as a conductive substrate.

[2. Production of elastic layer roller 1]
The elastic layer compound produced in Production Example 5 was coated in a cylindrical shape on the outer periphery of the conductive substrate as a central axis using an extrusion molding apparatus having a cross head shown in FIG. The thickness of the coated compound was adjusted to 1.75 mm. In FIG. 5, 1 is a conductive substrate, 40 is an extruder, 41 is a cross head, 42 is a feed roller, and 43 is a roller after extrusion.

  Subsequently, it was heated in an electric oven at a temperature of 160 ° C. for 1 hour to vulcanize and cure the adhesive, thereby forming an elastic layer on the outer periphery of the conductive substrate. Both ends of this elastic layer were removed to expose the ends of the conductive substrate, and the length of the elastic layer was 228 mm. Thereafter, the surface was polished so as to have a roller shape with an outer diameter of 8.5 mm to obtain an elastic roller 1 having an elastic layer formed on a conductive substrate. The crown amount of this roller (the average value of the difference between the outer diameter at the center and the outer diameter at positions 90 mm away from the center toward both ends) was 120 μm.

[3. Preparation of charging roller 1]
The elastic roller 1 was immersed in the surface layer coating solution 1 obtained in Production Example 3 with its longitudinal direction set to the vertical direction, and applied by a dipping method. The dipping time was 9 seconds, the pulling speed was 20 mm / s for the initial speed, 2 mm / s for the final speed, and the speed was changed linearly with respect to the time. The obtained coated product was air-dried at room temperature for 30 minutes, and then dried in a hot-air circulating dryer at a temperature of 80 ° C. for 1 hour and further at a temperature of 160 ° C. for 1 hour. In this way, a surface layer was formed on the outer peripheral surface of the elastic roller 1 to obtain the charging roller 1.

[4. Confirmation of inclusion of cyclic compounds)
The surface layer was cut out from the charging roller 1 and measured by ¹ H-NMR. The spectrum shifted to a high magnetic field, and it was confirmed that the cyclic compound formed an inclusion of metal ions.

[5. Measurement of electric resistance of charging roller)
The charging roller 1 was allowed to stand for 24 hours or more in an environment of a temperature of 23 ° C. and a relative humidity of 50%, and then the electrical resistance value was measured using the electrical resistance value measuring device shown in FIG.

First, the charging roller was brought into contact with the cylindrical metal 32 (diameter 30 mm) by the bearings 33a and 33b so as to be parallel. Here, the contact pressure was adjusted to 4.9 N at one end and 9.8 N in total at both ends by the pressing force of the spring. Next, the cylindrical metal 32 was rotated at a peripheral speed of 45 mm / sec by a motor (not shown), and the charging roller was driven to rotate. During the driven rotation, a DC voltage of −200 V was applied from the stabilized power source 34, and the current value flowing through the charging roller was measured with an ammeter 35. The electric resistance value of the charging roller was calculated from the applied voltage and current value. The electric resistance value was 3.0 × 10 ⁵ Ω.

[6. (Evaluation of white-out images due to moisture absorption)
As an electrophotographic apparatus having the configuration shown in FIG. 4, a color laser jet printer (trade name: HP Color LaserJet 4700dn, manufactured by Hewlett Packard) is modified to a recording medium output speed of 200 mm / sec (A4 vertical output). It was. The resolution of the image is 600 dpi, and the primary charging output is a DC voltage of −1100V. Further, as the process cartridge having the configuration shown in FIG. 3, the process cartridge for the printer was used (for black).

  The attached charging roller was removed from the process cartridge, and the charging roller 1 of the present invention was set. The charging roller 1 was brought into contact with the photosensitive member by a pressing force of a spring of 4.9 N at one end and a total of 9.8 N at both ends (FIG. 6).

0.05 ml of water droplets were placed in the vicinity of the charging roller 1, a process cartridge was assembled, and the process cartridge was sealed in a polyethylene bag. This process cartridge was left for 2 weeks (severely left) in an environment of a temperature of 40 ° C. and a relative humidity of 95%. Next, the process cartridge was allowed to stand for 6 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%, then opened, mounted on the electrophotographic apparatus, and an image was output in the same environment. A halftone image (an image in which a horizontal line having a width of 1 dot and an interval of 2 dots is drawn in the direction perpendicular to the rotation direction of the photoreceptor) was output as an evaluation image. The output image was evaluated for a blank image. Table 7 shows the evaluation results. Here, the evaluation criteria are as follows.
Rank 1: No white image is generated.
Rank 2: Only a slight blank image is recognized.
Rank 3: A partially blank image can be confirmed with the pitch of the charging member, but the image quality has no practical problem.
Rank 4: White-out images are conspicuous, and deterioration in image quality is observed.

  The charging roller of this example did not generate a blank image, and a good image was obtained.

<Examples 2 to 66>
[1. Preparation of coating solution for surface layer]
As the raw material for the binder resin, the polyurethane-based raw material of Production Example 3 or the polyvinyl butyral of Production Example 4 was used. As the electronic conductive agent, composite conductive fine particles 1, carbon black (trade name: # 52, manufactured by Mitsubishi Chemical Corporation) or tin oxide was used, and the amount used with respect to 100 parts by mass of the binder resin was 50 parts by mass. As the cyclic compound, any one of Compounds 1 to 15 shown in Tables 4 to 6 was used, and the amount used with respect to 100 parts by mass of the binder resin was set to 0.05 to 12 parts by mass. Under the conditions other than these, the surface layer coating solutions 3 to 66 were prepared in the same manner as in Production Example 3 or Production Example 4.

[2. (Production and evaluation of charging roller)
Next, charging rollers 2 to 66 were produced in the same manner as in Example 1 using each of the surface layer coating liquids 2 to 66. The evaluation results are shown in Tables 7-9.

<Comparative Examples 1-5>
Charge rollers C1 to C5 were produced in the same manner as in Example 1 except that the cyclic compound was changed to polyethylene glycol and the number of added parts was changed as shown in Table 10.

<Comparative Example 6>
A charging roller C6 was produced in the same manner as in Example 1 except that no cyclic compound was added.

DESCRIPTION OF SYMBOLS 1 Conductive base | substrate 2 Elastic layer 3 Surface layer 4 Electrophotographic photosensitive member 5 Charging roller 6 Developing roller 7 Transfer material 8 Transfer roller 9 Fixing device 10 Cleaning member 11 Latent image forming device 13 Elastic regulation blade 14 Recovery container 19 Charging power source 32 Cylindrical metal 33 Bearing 34 Stabilizing power supply 35 Ammeter 40 Extruder 41 Crosshead 42 Feed roller 43 Roller after extrusion

Claims (6)

An electrophotographic charging member having a conductive substrate and a surface layer, the surface layer comprising one or more metal ions selected from a binder resin, an electronic conductive agent, an alkali metal ion and an alkaline earth metal ion, and , One or more cyclic compounds selected from the group of compounds having the structure represented by formula (1), the structure represented by formula (2), and the structure represented by formula (3) Photographic charging member:

[In Formula (1), A is any one selected from the group of the structure represented by Formula (1-1), the structure represented by Formula (1-2), and the structure represented by Formula (1-3). Structure.
In formula (1-1), formula (1-2), and formula (1-3), A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , and A ₆ are each independently represented by formula (1- 4) and any structure selected from the structure represented by formula (1-5).
In formula (1-4) and formula (1-5), X is independently any of O, S, or NH. R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each independently a hydrogen atom or a monovalent organic group.
In formula (2), c, d and e are each independently 0, 1 or 2.
In formula (3), f is 4, 5 or 6. Z is CH ₂ , S or SO ₂ . R ₆ is a hydrogen atom or a monovalent organic group. R ₇ is a hydroxyl group or an alkoxyl group. ].

  A in the formula (1) is a structure represented by the formula (1-2), the structure represented by the formula (2) satisfies c + d + e = 1, and the structure represented by the formula (3) is f. The charging member for electrophotography according to claim 1, wherein: 4 is satisfied.   The electrophotographic charging member according to claim 1 or 2, wherein a content of the cyclic compound in the surface layer is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.   The charging member for electrophotography according to claim 1, wherein the cyclic compound includes the metal ions.   An electrophotographic charging member according to any one of claims 1 to 4 and a member to be charged that can be charged by the electrophotographic charging member. A process cartridge configured to be detachable from a main body.   It has the charging member for electrophotography according to any one of claims 1 to 4 and a member to be charged arranged so that it can be charged by the charging member for electrophotography. Electrophotographic device.

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