WO2012118229A1 - Process for producing electrophotographic photosensitive member - Google Patents

Process for producing electrophotographic photosensitive member Download PDF

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Publication number
WO2012118229A1
WO2012118229A1 PCT/JP2012/055885 JP2012055885W WO2012118229A1 WO 2012118229 A1 WO2012118229 A1 WO 2012118229A1 JP 2012055885 W JP2012055885 W JP 2012055885W WO 2012118229 A1 WO2012118229 A1 WO 2012118229A1
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WO
WIPO (PCT)
Prior art keywords
oxlo
conductive layer
layer
particles
electrophotographic photosensitive
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2012/055885
Other languages
French (fr)
Inventor
Atsushi Fujii
Hideaki Matsuoka
Haruyuki Tsuji
Nobuhiro Nakamura
Kazuhisa Shida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to KR1020137025283A priority Critical patent/KR101476578B1/en
Priority to US13/983,994 priority patent/US9046797B2/en
Priority to CN201280011559.3A priority patent/CN103430103B/en
Priority to EP12752203.5A priority patent/EP2681627B1/en
Publication of WO2012118229A1 publication Critical patent/WO2012118229A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
    • G03G7/0053—Intermediate layers for image-receiving members
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/10—Bases for charge-receiving or other layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/10—Bases for charge-receiving or other layers
    • G03G5/104—Bases for charge-receiving or other layers comprising inorganic material other than metals, e.g. salts, oxides, carbon
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G03G5/142—Inert intermediate layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G03G5/142—Inert intermediate layers
    • G03G5/144—Inert intermediate layers comprising inorganic material
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G03G5/0503—Inert supplements
    • G03G5/0507—Inorganic compounds
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G03G5/0525—Coating methods

Definitions

  • This invention relates to a process for producing an electrophotographic photosensitive member.
  • photosensitive members organic electrophotographic photosensitive members
  • the electrophotographic photosensitive member is
  • a layer containing metal oxide particles is known as the layer formed for the purpose of covering any defects on the surface of the support.
  • the layer containing metal oxide particles commonly has a higher electrical conductivity than a layer not containing any metal oxide particles (e.g., ⁇ . ⁇ ⁇ ⁇ 8 to 5.0xl0 12 ⁇ -cm as volume resistivity) .
  • a layer not containing any metal oxide particles e.g., ⁇ . ⁇ ⁇ ⁇ 8 to 5.0xl0 12 ⁇ -cm as volume resistivity
  • conductive layer makes the support surface have a great tolerance for its defects. As the results, this makes the support have a vastly great tolerance for its use, and hence brings an advantage that the electrophotographic photosensitive member can be improved in productivity.
  • PTL 1 discloses a technique in which tin oxide
  • PTL 2 also discloses a technique in which tin oxide particles doped with tungsten are used in a protective layer formed on the photosensitive layer.
  • PTL 3 still also discloses a technique in which titanium oxide particles coated with oxygen deficient tin oxide are used in a conductive layer formed between the support and the photosensitive layer.
  • PTL 4 still also discloses a technique in which barium sulfate particles coated with tin oxide are used in an
  • photosensitive member employing as the conductive layer any layer containing such metal oxide particles as the above.
  • An object of the present invention is to provide a
  • photosensitive member that can not easily cause such fog due to an increase in dark attenuation even where it is an electrophotographic photosensitive member employing as the conductive layer the layer containing metal oxide particles.
  • he present invention is a process for producing an
  • electrophotographic photosensitive member the process comprising :
  • a conductive layer having a volume resistivity of from ⁇ . ⁇ ⁇ ⁇ 8 ⁇ -cm or more to 5.0> ⁇ 10 12 ⁇ -cm or less
  • the step of forming the conductive layer comprises: the step of preparing a coating liquid for the
  • the metal oxide particle (P) and binder material (B) in the coating liquid for the conductive layer are in a mass ratio (P/B) of from 1.5/1.0 to 3.5/1.0;
  • the metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus or a titanium oxide particle coated with tin oxide doped with tungsten; and where powder resistivity of the metal oxide particle is represented by x ( ⁇ -cm) and powder resistivity of the titanium oxide particle as a core particle constituting the metal oxide particle is represented by y (Q-cm), the y and the x satisfy the following relations (i) and (ii) :
  • electrophotographic photosensitive member can be any electrophotographic photosensitive member.
  • electrophotographic photosensitive member employing as the conductive layer the layer containing metal oxide particles .
  • Fig. 1 is a view showing schematically an
  • Fig. 2 is a view (plan view) to illustrate how to measure the volume resistivity of a conductive layer.
  • Fig. 3 is a view (sectional view) to illustrate how to measure the volume resistivity of a conductive layer.
  • he present invention is a process for producing an
  • electrophotographic photosensitive member has the step of forming on a support a conductive layer having a volume resistivity of from 1.0*10 8 ⁇ -cm or more to 5.0xl0 12 ⁇ -cm or less and the step of forming a
  • the electrophotographic photosensitive member produced by the production process of the present invention is an electrophotographic photosensitive member having a support, a conductive layer formed on the support, and a photosensitive layer formed on the conductive layer.
  • he photosensitive layer may be a single-layer type photosensitive layer which contains a charge-generating material and a charge-transporting material in a single layer, or may be a multi-layer type photosensitive layer formed in layers of a charge generation layer which contains a charge-generating material and a charge transport layer which contains a charge- transporting material.
  • An undercoat layer may also optionally be provided between the conductive layer formed on the support and the photosensitive layer.
  • the support it may preferably be one having
  • a metallic support which is made of a metal, formed of a metal such as aluminum, an aluminum alloy or stainless steel.
  • a metallic support which is made of a metal, formed of a metal such as aluminum, an aluminum alloy or stainless steel.
  • aluminum or an aluminum alloy usable are an aluminum pipe produced by a production process having the step of extrusion and the step of drawing, and an aluminum pipe produced by a production process having the step of extrusion and the step of ironing.
  • Such aluminum pipes can achieve a good dimensional precision and surface smoothness without requiring any surface cutting and besides are advantageous in view of cost as well.
  • burr-like protruding defects tend to come on the surfaces of these non-cut aluminum pipes, and hence it is especially effective to provide the conductive layer.
  • conductive layer having a volume resistivity of from l.OxlO 8 ⁇ -cm or more to 5.0*10 12 ⁇ -cm or less is provided on the support. If a layer having a volume resistivity of more than 5.0> ⁇ 10 12 ⁇ -cm is provided on the support as the layer for covering any defects of the surface of the support, the flow of electric charges comes to tend to stagnate therein when images are formed, to come to tend to increase in residual potential.
  • the conductive layer has a volume resistivity of less than ⁇ . ⁇ ⁇ ⁇ 8 ⁇ -cm, the electric charges flowing through the conductive layer may be so excessively large in quantity when the electrophotographic photosensitive member is charged that the fog due to an increase in dark attenuation of the electrophotographic photosensitive member may come to tend to occur.
  • Fig. 2 is a plan view to illustrate how to measure the volume resistivity of the conductive layer
  • Fig. 3 is a sectional view to illustrate how to measure the volume resistivity of the conductive layer.
  • a tape 203 made of copper (Type No.1181, available from Sumitomo 3M Limited) is stuck to the surface of a conductive layer 202 to make it serve as an electrode on the surface side of the conductive layer 202.
  • a support 201 is also made to serve as an electrode on the back side of the
  • a power source 206 and a current measuring instrument 207 are respectively set up; the former for applying voltage across the copper tape 203 and the support 201 and the latter for measuring electric current flowing across the copper tape 203 and the support 201.
  • a copper wire 204 is put on the copper tape 203, and then a tape 205 made of copper like the copper tape 203 is stuck from above the copper wire 204 to the copper tape 203 so that the copper wire 204 may not protrude from the copper tape 203, to fasten the copper wire 204 to the copper tape 203.
  • a tape 205 made of copper like the copper tape 203 is stuck from above the copper wire 204 to the copper tape 203 so that the copper wire 204 may not protrude from the copper tape 203, to fasten the copper wire 204 to the copper tape 203.
  • d thickness of the conductive layer 202
  • S area of the electrode (copper tape 203) on the surface side of the conductive layer 202
  • p volume resistivity p ( ⁇ -cm) of the conductive layer 202.
  • measuring instrument 207 an instrument that can measure an extremely small electric current.
  • an instrument may include, e.g., a pA meter (trade name: 4140B) manufactured by Yokogawa Hewlett-Packard Company.
  • the volume resistivity of the conductive layer shows the like value in either of measurement made in the state only the conductive layer has been formed on the support and measurement made in the state the respective layers (photosensitive layer and so forth) on the conductive layer have been stripped off the electrophotographic photosensitive member so as to leave only the conductive layer on the support.
  • the conductive layer is formed by using a coating liquid for conductive layer prepared with use of a solvent, a binder material and metal oxide particles.
  • conductive layer may be prepared by dispersing the metal oxide particles in the solvent together with the binder material.
  • a method for dispersion it may include, e.g., a method making use of a paint shaker, a sand mill, a ball mill or a liquid impact type highspeed dispersion machine.
  • the conductive layer may be formed by applying the coating liquid for conductive layer, thus prepared, onto the support and then drying and/or curing the wet coating formed.
  • titanium oxide (Ti0 2 ) particles coated with tin oxide (Sn0 2 ) doped with phosphorus (P) or titanium oxide (Ti0 2 ) particles coated with tin oxide (Sn0 2 ) doped with tungsten (W) are used as the metal oxide particles. These are hereinafter
  • titanium oxide coated titanium oxide particles
  • the tin oxide coated titanium oxide particles used in the present invention are particles having been made to have a powder resistivity x ( ⁇ -cm) by coating titanium oxide (Ti0 2 ) particles [ (particles composed of only titanium oxide (Ti0 2 ) ] having a powder resistivity y ( ⁇ -cm), with tin oxide (Sn0 2 ) doped with phosphorus (P) or tungsten (W) , where the y and the x satisfy the following relations (i) and (ii) :
  • oxide coated titanium oxide particles used in the present invention is represented by x ( ⁇ -cm) and powder resistivity of the titanium oxide (Ti0 2 ) particles that are core particles constituting the tin oxide coated titanium oxide particles used in the present invention is represented by y ( ⁇ -cm), the y and the x satisfy the above relations (i) and (ii) .
  • the core particles titanium oxide (Ti0 2 ) particles constituting the tin oxide coated titanium oxide particles has a powder resistivity y of less than
  • the powder resistivity y may preferably be ⁇ . ⁇ ⁇ ⁇ 8 or more ( ⁇ . ⁇ ⁇ ⁇ 8 ⁇ y) .
  • the core particle titanium oxide (Ti0 2 ) particle constituting the tin oxide coated titanium oxide particles has a powder resistivity y of more than 5.0 ⁇ 10 9 ⁇ -cm, the residual potential comes to tend to increase.
  • the core particles [the titanium oxide (Ti0 2 ) particles] has a high powder resistivity y, and hence the electric charges flowing through the core particles may inevitably become small in quantity at the time of exposure, so that it may come about that the electric charges flow chiefly only at the coats, as so considered. That is, it is because the electric charges come more not to easily flow at the time of exposure at which the quantity of electric charges flowing through the electrophotographic photosensitive member should be made large.
  • the powder resistivity y may preferably be ⁇ . ⁇ ⁇ ⁇ 9 or less (y ⁇ ⁇ . ⁇ ⁇ 9 ) .
  • binder resistivity ratio y/x is a parameter which means that the quantity of electric charges flowing through the core particles titanium oxide (Ti0 2 ) particles constituting the tin oxide coated titanium oxide particles and the quantity of electric charges flowing through the whole tin oxide coated titanium oxide particles inclusive of the coats are required to be balanced with each other within a specific range.
  • the fog due to an increase in dark attenuation of the electrophotographic photosensitive member comes to tend to occur.
  • the powder resistivity ratio y/x is less than 1.0*10 2 , the residual potential comes to tend to increase. This is caused by the fact that any low powder resistivity ratio y/x makes the balance between the quantity of electric charges flowing through the core particles titanium oxide (Ti0 2 ) particles constituting the tin oxide coated titanium oxide particles and the quantity of electric charges flowing through the whole tin oxide coated titanium oxide particles break when the electrophotographic photosensitive member is charged, as so considered. That is, it is because the electric charges come not to easily flow through the coats at the time of exposure at which the quantity of electric charges flowing through the electrophotographic photosensitive member should be made large.
  • the powder resistivity ratio y/x is required to be from ⁇ . ⁇ ⁇ ⁇ 2 or more to ⁇ . ⁇ ⁇ ⁇ 6 or less.
  • a preferable powder resistivity ratio y/x may be from ⁇ . ⁇ ⁇ ⁇ 3 or more to 1.0*10 5 or less, i.e.:
  • electrophotographic photosensitive member at its dark areas when a stated voltage is applied thereto.
  • titanium oxide (Ti0 2 ) particles coated with oxygen deficient tin oxide (Sn0 2 ) come oxidized in the presence of oxygen to lose their oxygen deficient portions, so that the latter particles may come to have a high resistance to make the flow of electric charges come to tend to stagnate in the
  • particles used in the present invention may have a particle shape which is granular, spherical, acicular, fibrous, columnar, rod-like, spindle-like or plate-like, or other similar shape, any of which may be used. From the viewpoint of less image defects such as black spots, spherical particles are preferred.
  • the core particles titanium oxide (Ti0 2 ) particles constituting the tin oxide coated titanium oxide particles may also have a crystal form of rutile, anatase, brookite or amorphous, any crystal form of which may be used.
  • any production method may be used, such as a sulfuric acid method or a hydrochloric acid method.
  • the tin oxide (Sn0 2 ) in the tin oxide coated titanium oxide particles may preferably be in a proportion
  • (Sn0 2 ) must be compounded when the tin oxide coated titanium oxide particles are produced.
  • tin chloride (SnCl 4 ) that is a tin raw material is used, it must be formulated taking account of the amount of the tin oxide (Sn0 2 ) to be formed from the tin chloride (SnCl 4 ) .
  • the tin oxide (Sn0 2 ) serving as the coats of the tin oxide coated titanium oxide particles used in the present invention stands doped with phosphorus (P) or tungsten (W) , where the coverage is defined as the value found by calculation from the mass of the tin oxide (Sn0 2 ) with respect to the total mass of the tin oxide (Sn0 2 ) and titanium oxide (Ti0 2 ) , without taking account of the mass of the phosphorus (P) or tungsten (W) with which the tin oxide (Sn0 2 ) stands doped.
  • resistivity ratio y/x to be from ⁇ . ⁇ ⁇ ⁇ 2 or more to
  • tin oxide (Sn0 2 ) in a coverage of more than 60% by mass tends to make non-uniform the covering of the titanium oxide (Ti0 2 ) with the tin oxide (Sn0 2 ) , and tends to result in a high cost.
  • the phosphorus (P) or tungsten (W) with which the tin oxide (Sn0 2 ) is doped may preferably be in an amount of from 0.1% by mass to 10% by mass based on the mass of the tin oxide (Sn0 2 ) [the mass not inclusive of the phosphorus (P) or tungsten ( ) ] . Any phosphorus (P) or tungsten (W) with which the tin oxide (Sn0 2 ) is doped in an amount of less than 0.1% by mass makes it
  • any phosphorus (P) or tungsten ( ) with which the tin oxide (Sn0 2 ) is doped in an amount of more than 10% by mass makes the tin oxide (Sn0 2 ) low crystallizable, and makes it difficult to control the powder resistivity ratio y/x to be from ⁇ . ⁇ ⁇ ⁇ 2 or more to 1.0x10 s or less.
  • the doping of the tin oxide (Sn0 2 ) with the phosphorus (P) or tungsten ( ) can commonly make the tin oxide coated titanium oxide particles have a lower powder resistivity than those not doped therewith.
  • titanium oxide particles titanium oxide coated titanium oxide particles
  • HIRESTA UP in the case of more than 10 7 ⁇ -cm)] is used as a measuring instrument.
  • the measurement object metal oxide particles (tin oxide coated titanium oxide particles) and so forth are each compacted at a
  • the tin oxide coated titanium oxide particles having the core particles are used as the metal oxide particles incorporated in the conductive layer, which are used in order to achieve an improvement in the dispersibility of the metal oxide particles in the coating liquid for conductive layer.
  • Any use of particles composed of only the tin oxide (Sn0 2 ) doped with phosphorus (P) or tungsten (W) or the oxygen deficient tin oxide (Sn0 2 ) tends to make the metal oxide particles have a large particle diameter in the coating liquid for conductive layer, so that protrusive seeding defects may occur on the surface of the
  • conductive layer and also the coating liquid for conductive layer may have a low stability.
  • the titanium oxide (Ti0 2 ) particles are used as the
  • the core particles which are used because they are greatly effective in keeping the fog due to an increase in dark attenuation of the electrophotographic photosensitive member from occurring. Details are unclear about the reason why such particles are greatly effective in keeping the fog due to an increase in dark attenuation from occurring, which, however, is considered to be concerned with the fact that their use makes small the electric current (dark electric current) flowing through the electrophotographic photosensitive member at its dark areas when a stated voltage is applied thereto.
  • the titanium oxide (Ti0 2 ) particles as the core particles have an advantage that they are so low transparent as the metal oxide particles as to easily cover any defects of the surface of the support. In contrast thereto, where, e.g., barium sulfate particles are used as the core particles, they are so high transparent as the metal oxide particles as to make it necessary to specially use a material for.
  • liquid for conductive layer it may include, e.g., resins such as phenol resin, polyurethane resin,
  • polyamide resin polyimide resin, polyamide-imide resin, polyvinyl acetal resin, epoxy resin, acrylic resin, melamine resin and polyester resin. Any of these may be used alone or in combination of two or more types. Also, of these, from the viewpoints of control of migration (transfer) to other layers, adhesion to the support, dispersibility and dispersion stability of the tin oxide coated titanium oxide particles and solvent resistance after layer formation, hardening resins are preferred, and heat-hardening resins (thermosetting resins) are much preferred. Still also, of the
  • thermosetting resins thermosetting phenol resins and thermosetting polyurethane resins are preferred. Where such a hardening resin is used as the binder material for the conductive layer, the binder material to be contained in the coating liquid for conductive layer serves as a monomer, and/or an oligomer, of the
  • conductive layer may include, e.g., alcohols such as methanol, ethanol and isopropanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone ; ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether and propylene glycol monomethyl ether; esters such as methyl acetate and ethyl acetate; and aromatic hydrocarbons such as toluene and xylene.
  • alcohols such as methanol, ethanol and isopropanol
  • ketones such as acetone, methyl ethyl ketone and cyclohexanone
  • ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether and propylene glycol monomethyl ether
  • esters such as methyl acetate and ethyl acetate
  • aromatic hydrocarbons such as toluene
  • conductive layer are required to be in a mass ratio (P/B) of from 1.5/1.0 to 3.5/1.0. If the metal oxide particles (tin oxide coated titanium oxide particles) (P) and the binder material (B) are in a mass ratio (P/B) of less than 1.5/1.0, the flow of electric charges comes to tend to stagnate in the conductive layer when images are formed, to come to tend to increase in residual potential. Also, those in such a ratio make it difficult to control the volume
  • resistivity of the conductive layer to be 5.0 ⁇ 10 12 ⁇ -cm or less. If the metal oxide particles (tin oxide coated titanium oxide particles) (P) and the binder material (B) are in a mass ratio (P/B) of more than
  • the conductive layer may preferably have a layer thickness of from 10 ⁇ or more to 40 ⁇ or less, and much preferably from 15 ⁇ im or more to 35 ⁇ or less.
  • the layer thickness of each layer, inclusive of the conductive layer, of the electrophotographic photosensitive member is measured with FISCHERSCOPE Multi Measurement System (MMS) , available from Fischer Instruments Co.
  • MMS FISCHERSCOPE Multi Measurement System
  • the tin oxide coated titanium oxide particles in the coating liquid for conductive layer may preferably have an average particle diameter of from 0.10 ⁇ or more to 0.45 ⁇ or less, and much preferably from 0.15 ⁇ or more to 0.40 ⁇ or less. If the tin oxide coated titanium oxide particles have an average particle diameter of less than 0.10 ⁇ , ' such tin oxide coated titanium oxide particles may come to agglomerate again after the coating liquid for conductive layer has been prepared, to make the coating liquid for conductive layer low stable or cause cracks in the surface of the conductive layer.
  • the surface of the conductive layer may come so rough as to come to tend to cause local injection of electric charges therefrom into the photosensitive layer, so that black dots may come to conspicuously appear in white background areas of reproduced images.
  • the average particle diameter of the tin oxide coated titanium oxide particles in the coating liquid for conductive layer may be measured by liquid-phase sedimentation in the following way.
  • the coating liquid for conductive layer is so diluted with the solvent used in preparing the same, as to have a transmittance between 0.8 and 1.0.
  • a histogram of average particle diameter (volume base D50) and particle size distribution of the tin oxide coated titanium oxide particles is prepared by using a centrifugal automatic particle size distribution measuring instrument.
  • a centrifugal automatic particle size distribution measuring instrument (trade name: CAPA700) manufactured by Horiba, Ltd. is used to make measurement under conditions of a number of revolutions of 3,000 rpm.
  • particles that are the core particles constituting the tin oxide coated titanium oxide particles it may preferably be from 0.05 i or more to 0.40 ⁇ or less, from the viewpoint of controlling the average particle diameter of the tin oxide coated titanium oxide
  • a surface roughness providing material for roughening the surface of the conductive layer may also be added to the coating liquid for conductive layer. Such a surface roughness providing material may
  • Such resin particles may include, e.g., particles of hardening rubbers and of hardening resins such as polyurethane , epoxy resin, alkyd resin, phenol resin, polyester, silicone resin and acryl-melamine resin. Of these, particles of silicone resin are preferred as being not easily agglomerative .
  • the specific gravity of resin particles (which is 0.5 to 2) is smaller than the specific gravity of the tin oxide coated titanium oxide particles (which is 4 to 7), and hence the surface of the conductive layer can efficiently be roughened at the time of formation of the conductive layer.
  • the conductive layer has a tendency to increase in volume resistivity with an increase in content of the surface roughness providing material in the conductive layer.
  • the volume resistivity of the conductive layer to be
  • the content of the surface roughness providing material in the coating liquid for conductive layer may preferably be from 1 to 80% by mass based on the mass of the binder material in the coating liquid for conductive layer.
  • a leveling agent may also be added in order to enhance the surface properties of the conductive layer.
  • Pigment particles may also be added to the coating liquid for conductive layer in order to improve covering properties of the conductive layer.
  • an undercoat layer (a barrier layer) having electrical barrier properties may be provided in order to block the injection of electric charges from the conductive layer into the photosensitive layer.
  • the undercoat layer may be formed by coating on the
  • conductive layer a coating liquid for undercoat layer containing a resin (binder resin) , and drying the wet coating formed.
  • the resin (binder resin) used for the undercoat layer may include, e.g., water-soluble resins such as
  • thermoplastic resins are preferred.
  • thermoplastic resins a thermoplastic resin selected from the thermoplastic resins.
  • thermoplastic polyamide is preferred.
  • copolymer nylon is preferred.
  • the undercoat layer may preferably have a layer
  • the undercoat layer may also be incorporated with an electron-transporting material (an electron-accepting material such as an acceptor) .
  • the electron-transporting material may include, e.g., electron-attracting materials such as 2,4, 7-trinitrofluorenone, 2,4,5, 7-tetranitrofluorenone, chloranil and tetracyanoquinodimethane, and those obtained by polymerizing these electron-attracting materials.
  • the photosensitive layer is formed on the conductive
  • photosensitive layer may include, e.g., azo pigments such as monoazo, disazo and trisazo, phthalocyanine pigments such as metal phthalocyanines and metal-free phthalocyanine, indigo pigments such as indigo and thioindigo, perylene pigments such as perylene acid anhydrides and perylene acid imides, polycyclic quinone pigments such as anthraquinone and pyrenequinone, squarilium dyes, pyrylium salts and thiapyrylium salts, triphenylmethane dyes, quinacridone pigments, azulenium salt pigments, cyanine dyes, xanthene dyes,
  • azo pigments such as monoazo, disazo and trisazo
  • phthalocyanine pigments such as metal phthalocyanines and metal-free phthalocyanine
  • indigo pigments such as indigo and thioindigo
  • perylene pigments
  • quinoneimine dyes and styryl dyes.
  • metal phthalocyanines such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine and chlorogallium phthalocyanine.
  • the charge generation layer may be formed by coating a coating liquid for charge generation layer obtained by dispersing the charge generating material in a solvent together with a binder resin, and drying the wet coating formed.
  • a method for dispersion a method is available which makes use of, e.g., a homogenizer, ultrasonic waves, a ball mill, a sand mill, an attritor or a roll mill.
  • layer may include, e.g., polycarbonate, polyester, polyarylate, butyral resin, polystyrene, polyvinyl acetal, diallyl phthalate resin, acrylic resin,
  • methacrylic resin vinyl acetate resin, phenol resin, silicone resin, polysulfone, a styrene-butadiene copolymer, alkyd resin, epoxy resin, urea resin,, and a vinyl chloride-vinyl acetate copolymer. Any of these may be used alone or in the form of a mixture or copolymer of two or more types.
  • charge generating material and the binder resin may preferably be in a proportion (charge generating material : binder resin) ranging from 10:1 to 1:10 (mass ratio), and much preferably from 5:1 to 1:1 (mass ratio) .
  • generation layer may include, e.g., alcohols,
  • the charge generation layer may preferably have a layer thickness of 5 ⁇ or less, and much preferably from 0.1 ⁇ or more to 2 ⁇ or less.
  • antioxidant an ultraviolet absorber, a plasticizer and so forth which may be of various types may also be used.
  • An electron transport material (an electron accepting material such as an acceptor) may also be incorporated in the charge generation layer in order to make the flow of electric charges not stagnate in the charge generation layer.
  • the electron- transporting material may include, e.g., electron- attracting materials such as 2 , 4 , 7-trinitrofluorenone, 2, 4, 5, 7-tetranitrofluorenone, chloranil and
  • photosensitive layer may include, e.g., triarylamine compounds, hydrazone compounds, styryl compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds .
  • the charge transport layer may be formed by coating a coating liquid for charge transport layer obtained by dissolving the charge transporting material and a binder resin in a solvent, and drying the wet coating formed.
  • layer may include, e.g., acrylic resin, styrene resin, polyester, polycarbonate, polyarylate, polysulfone, polyphenylene oxide, epoxy resin, polyurethane, alkyd resin and unsaturated resins. Any of these may be used alone or in the form of a mixture or copolymer of two or more types.
  • the charge transporting material and the binder resin may preferably be in a proportion (charge transporting material : binder resin) ranging from 2:1 to 1:2 (mass ratio) .
  • transport layer may include, e.g., ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, ethers such as
  • hydrocarbons such as toluene and xylene
  • hydrocarbons substituted with a halogen atom such as chlorobenzene, chloroform and carbon tetrachloride.
  • the charge transport layer may preferably have a layer thickness of from 3 ym or more to 40 ⁇ or less, and much preferably from 4 im or more to 30 ⁇ or less, from the viewpoint of charging uniformity and image reproducibility.
  • ultraviolet absorber a plasticizer and so forth may also optionally be added.
  • the single- layer type photosensitive layer may be formed by coating a coating liquid for single-layer type
  • photosensitive layer containing a charge generating material, a charge transporting material, a binder resin and a solvent, and drying the wet coating formed.
  • charge generating material charge transporting material, a binder resin and a solvent
  • a protective layer may also be provided on the photosensitive layer.
  • the protective layer may be formed by coating a coating liquid for protective layer containing a resin (binder resin) , and drying and/or curing the wet coating formed.
  • the protective layer may preferably have a layer
  • thickness of from 0.5 ⁇ or more to 10 ⁇ or less, and much preferably from 1 ⁇ or more to 8 ⁇ or less.
  • coating methods as exemplified by dip coating (immersion coating) , spray coating, spinner coating, roller coating, Mayer bar coating and blade coating.
  • FIG. 1 schematically shows an example of the
  • reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member, which is rotatingly driven around an axis 2 in the direction of an arrow at a stated peripheral speed.
  • photosensitive member 1 rotatingly driven is uniformly electrostatically charged to a positive or negative, stated potential through a charging device (a primary charging device; e.g., a charging roller) 3.
  • the electrophotographic photosensitive member thus charged is then exposed to exposure light (imagewise exposure light) 4 emitted from an exposing device (an imagewise exposing device; not shown) for slit exposure, laser beam scanning exposure or the like.
  • exposure light imagewise exposure light
  • an exposing device an imagewise exposing device; not shown
  • Voltage to be applied to the charging device 3 may be only direct-current voltage or may be direct-current voltage on which alternating- current voltage is kept superimposed.
  • photosensitive member 1 are developed with a toner of a developing device 5 to form toner images. Then, the toner images thus formed and held on the peripheral surface of the electrophotographic photosensitive member 1 are transferred to a transfer material (such as paper) P by applying a transfer bias from a
  • the transfer material P is fed through a transfer material feed device (not shown) to come to the part (contact zone) between the electrophotographic
  • the transfer material P to which the toner images have been transferred is separated from the peripheral surface of the electrophotographic photosensitive member 1 and is led into a fixing device 8, where the toner images are fixed, and is then printed out of the apparatus, as an image-formed material (a print or copy) .
  • photosensitive member 1 from which the toner images have been transferred is brought to removal of the toner remaining after the transfer, through a cleaning device (such as a cleaning blade) 7. It is further subjected to charge elimination by pre-exposure light 11 emitted from a pre-exposure device (not shown) , and thereafter repeatedly used for the formation of images.
  • a cleaning device such as a cleaning blade
  • pre-exposure light 11 emitted from a pre-exposure device (not shown) , and thereafter repeatedly used for the formation of images.
  • the pre-exposure is not necessarily required where the charging device is a contact
  • charging device such as a charging roller.
  • the apparatus may be constituted of at least one
  • electrophotographic photosensitive member 1 charging device 3, developing device 5, transferring device 6, cleaning device 7 and so forth which are received in a container to set up a process cartridge so that the process cartridge may be set detachably mountable to the main body of an electrophotographic apparatus.
  • the electrophotographic photosensitive member 1 and the charging device 3, developing device 5 and cleaning device 7 are
  • electrophotographic apparatus may also be constituted to have the electrophotographic photosensitive member 1 and the charging device 3, exposing device, developing device 5 and cleaning device 7.
  • silicone resin particles (trade name: TOSPEARL 120; available from Momentive Performance Materials Inc.; average particle diameter: 2 ⁇ ) as a surface roughness providing material, 0.014 part of silicone oil (trade name:
  • SH28PA available from Dow Corning Toray Co., Ltd.
  • Coating liquids 2 to 68 and CI to C83 for conductive layer were prepared in the same manner as Preparation Example for Coating liquid 1 for conductive layer except that, about the materials used in preparing the coating liquid for conductive layer, the type, powder resistivity and amount (parts) of the metal oxide particles, the powder resistivity of the core particles thereof, the amount of the phenol resin as a binder material and also the dispersion treatment time were each assigned or set as shown in Tables 1 and 2.
  • tin oxide is as Sn0 2
  • titanium oxide is as Ti0 2 .
  • OxlO 2 180 OxlO 7 l.OxlO 5 188 4 1.6/1.0
  • OxlO 4 195 OxlO 9 l.OxlO 5 163 4 2.0/1.0
  • OxlO 7 223 4.
  • OxlO 7 207 The OxlO 9 1. OxlO 2 144 4 2.4/1.0
  • OxlO 2 180 OxlO 7 1.0x10 s 188 4 1.6/1.0
  • OxlO 7 202 4.
  • Powder (resin time tive tivity conduclayer resissolid
  • he coating liquid 1 for conductive layer was dip- coated on the support in a normal-temperature and normal-humidity (23°C/50%RH) environment, and then the wet coating formed was dried and heat-cured at 140 °C for 30 minutes to form a conductive layer with a layer thickness of 30 ⁇ .
  • the volume resistivity of the conductive layer was measured by the method described previously, to find that it was 5.0xl0 10 ⁇ ⁇ cm.
  • cyclohexanone were put into a sand mill making use of glass beads of 0.8 mm in diameter, and put to dispersion treatment under conditions of a dispersion treatment time of 3 hours.
  • 250 parts of ethyl acetate was added to prepare a coating liquid for charge generation layer.
  • This coating liquid for charge generation layer was dip- coated on the undercoat layer, and then the wet coating formed was dried at 100°C for 10 minutes to form a charge generation layer with a layer thickness of 0.12 ⁇ .
  • an electrophotographic photosensitive member 1 was produced the charge transport layer of which was a surface layer.
  • Electrophotographic photosensitive members 2 to 68 and CI to C83 were produced in the same manner as
  • Photosensitive Member 1 except that the coating liquid for conductive layer, the coating liquid 1 for
  • electrophotographic photosensitive member was changed for the coating liquids 2 to 68 and CI to C83 for conductive layer, respectively.
  • electrophotographic photosensitive members 1 to 68 and CI to C83 each, the surfaces of their conductive layers were observed on an optical microscope, whereupon cracks were seen to have occurred in regard to the conductive layers of the electrophotographic
  • photosensitive members C13, C15, C29, C31, C39, C41, C48, C62, C64 and C71.
  • the electrophotographic photosensitive members 1 to 68 and CI to C83 were each put to a sheet feeding durability test in the same high-temperature and high- humidity environment as the above.
  • the sheet feeding durability test in the same high-temperature and high- humidity environment as the above.
  • printing was operated in an intermittent mode in which a character image with a print percentage of 2% was sheet by sheet reproduced on letter size sheet, to reproduce images on 500 sheets.
  • Each potential was measured using one sheet each of solid white images and solid black images.
  • the dark area potential at the initial stage (at the start of the sheet feeding durability test) and the light area potential at the initial stage (at the start of the sheet feeding durability test) were represented by Vd and VI, respectively.
  • the dark area potential after the finish of the image reproduction on 3,000 sheets and the light area potential after. the finish of the image reproduction on 3,000 sheets were represented by Vd' and VI', respectively.
  • Electrophotographic Photosensitive Member 1 was
  • a coating liquid for charge transport layer was dissolved in a mixed solvent of 60 parts of o- xylene, 40 parts of dimethoxymethane and 2.7 parts of methyl benzoate to prepare a coating liquid for charge transport layer.
  • This coating liquid for charge transport layer was dip-coated on the charge generation layer, and then the wet coating formed was dried at 120°C for 30 minutes to form a charge transport layer with a layer thickness of 7.0 m.
  • an electrophotographic photosensitive member 69 was produced the charge transport layer of which was a surface layer .
  • the dark area potential variation level AVd was +12 V
  • the light area potential variation level AVI was +25 V.

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Abstract

To provide a process for producing an electrophotographic photosensitive member that can not easily cause any fog due to an increase in dark attenuation, a conductive layer is formed with use of a coating liquid for conductive layer prepared with use of a solvent, a binder material and metal oxide particles. The metal oxide particles (P) and binder material (B) in the coating liquid for conductive layer are in a mass ratio (P/B) of from 1.5/1.0 to 3.5/1.0. The metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus or tungsten. Where powder resistivity of the metal oxide particle is represented by x (Ω. cm) and powder resistivity of the titanium oxide particle as a core particle constituting the metal oxide particle is represented by y (Ω. cm), the y and the x satisfy the following relations (i) and (ii): 5.0×107 ≤ y ≤ 5.0×109 (i) 1.0×102 ≤ y/x ≤ 1.0×106 (ii).

Description

DESCRIPTION
PROCESS FOR PRODUCING ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER
Technical Field
[0001] This invention relates to a process for producing an electrophotographic photosensitive member.
Background Art
[0002] In recent years, research and development are
energetically made on electrophotographic
photosensitive members (organic electrophotographic photosensitive members) making use of organic
photoconductive materials.
[0003] The electrophotographic photosensitive member is
basically constituted of a support and a photosensitive layer formed on the support. In the present state of affairs, however, various layers are often formed between the support and the photosensitive layer for the purposes of, e.g., covering any defects of the surface of the support, protecting the photosensitive layer from any electrical breakdown, improving its chargeability, improving the blocking of injection of electric charges from the support into the
photosensitive layer, and so forth.
[0004] Among such layers formed between the support and the photosensitive layer, a layer containing metal oxide particles is known as the layer formed for the purpose of covering any defects on the surface of the support. The layer containing metal oxide particles commonly has a higher electrical conductivity than a layer not containing any metal oxide particles (e.g., Ι.ΟχΙΟ8 to 5.0xl012 Ω -cm as volume resistivity) . Thus, even where the layer is formed in a large layer thickness, any residual potential at the time of image formation can not easily come to increase. Hence, any defects of the support surface can be covered with ease. [0005] The covering of defects of the support surface by providing between the support and the photosensitive layer such a layer having a higher electrical
conductivity (hereinafter "conductive layer") makes the support surface have a great tolerance for its defects. As the results, this makes the support have a vastly great tolerance for its use, and hence brings an advantage that the electrophotographic photosensitive member can be improved in productivity.
[0006] PTL 1 discloses a technique in which tin oxide
particles doped with phosphorus are used in an
intermediate layer formed between the support and the photosensitive layer. PTL 2 also discloses a technique in which tin oxide particles doped with tungsten are used in a protective layer formed on the photosensitive layer. PTL 3 still also discloses a technique in which titanium oxide particles coated with oxygen deficient tin oxide are used in a conductive layer formed between the support and the photosensitive layer. PTL 4 still also discloses a technique in which barium sulfate particles coated with tin oxide are used in an
intermediate layer formed between the support and the photosensitive layer.
Citation List
Patent Literature
[0007] PTL 1: Japanese Patent Application Laid-open No. H06- 222600
PTL 2: Japanese Patent Application Laid-open No. 2003- 316059
PTL 3: Japanese Patent Application Laid-open No. 2007- 047736
PTL 4: Japanese Patent Application Laid-open No. H06- 208238
Summary of Invention
Technical Problem
[ 0008 ] However, studies made by the present inventors have revealed that fog comes to tend to occur due to an increase in dark attenuation when images are repeatedly formed in a high-temperature and high-humidity
environment by using an electrophotographic
photosensitive member employing as the conductive layer any layer containing such metal oxide particles as the above.
[0009]An object of the present invention is to provide a
process for producing an electrophotographic
photosensitive member that can not easily cause such fog due to an increase in dark attenuation even where it is an electrophotographic photosensitive member employing as the conductive layer the layer containing metal oxide particles.
Solution to Problem
[0010] he present invention is a process for producing an
electrophotographic photosensitive member; the process comprising :
the step of forming on a support a conductive layer having a volume resistivity of from Ι.ΟχΙΟ8 Ω -cm or more to 5.0><1012 Ω-cm or less, and
the step of forming a photosensitive layer on the conductive layer, wherein;
the step of forming the conductive layer comprises: the step of preparing a coating liquid for the
conductive layer with use of a solvent, a binder material and metal oxide particles, and
the step of forming the conductive layer with use of the coating liquid for conductive layer;
the metal oxide particle (P) and binder material (B) in the coating liquid for the conductive layer are in a mass ratio (P/B) of from 1.5/1.0 to 3.5/1.0;
the metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus or a titanium oxide particle coated with tin oxide doped with tungsten; and where powder resistivity of the metal oxide particle is represented by x (Ω -cm) and powder resistivity of the titanium oxide particle as a core particle constituting the metal oxide particle is represented by y (Q-cm), the y and the x satisfy the following relations (i) and (ii) :
5.0*107 < y < 5.0xl09 (i)
Ι.ΟχΙΟ2 < y/x < Ι.ΟχΙΟ6 (ii)
Advantageous Effects of Invention
[0011] According to the present invention, an
electrophotographic photosensitive member can be
produced which can not easily cause any fog due to an increase in dark attenuation even where it is an
electrophotographic photosensitive member employing as the conductive layer the layer containing metal oxide particles .
[ 0012 ] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Brief Description of Drawings
[0013] [Fig. l]Fig. 1 is a view showing schematically an
example of the construction of an electrophotographic apparatus provided with a process cartridge having an electrophotographic photosensitive member.
[Fig. 2] Fig. 2 is a view (plan view) to illustrate how to measure the volume resistivity of a conductive layer.
[Fig. 3] Fig. 3 is a view (sectional view) to illustrate how to measure the volume resistivity of a conductive layer.
Description of Embodiments
[0014] he present invention is a process for producing an
electrophotographic photosensitive member, and has the step of forming on a support a conductive layer having a volume resistivity of from 1.0*108 Ω -cm or more to 5.0xl012 Ω-cm or less and the step of forming a
photosensitive layer on the conductive layer. The electrophotographic photosensitive member produced by the production process of the present invention is an electrophotographic photosensitive member having a support, a conductive layer formed on the support, and a photosensitive layer formed on the conductive layer.
[0015] he photosensitive layer may be a single-layer type photosensitive layer which contains a charge-generating material and a charge-transporting material in a single layer, or may be a multi-layer type photosensitive layer formed in layers of a charge generation layer which contains a charge-generating material and a charge transport layer which contains a charge- transporting material. An undercoat layer may also optionally be provided between the conductive layer formed on the support and the photosensitive layer.
[0016]As the support, it may preferably be one having
electrical conductivity (a conductive support). For example, a metallic support may be used which is made of a metal, formed of a metal such as aluminum, an aluminum alloy or stainless steel. Where aluminum or an aluminum alloy is used, usable are an aluminum pipe produced by a production process having the step of extrusion and the step of drawing, and an aluminum pipe produced by a production process having the step of extrusion and the step of ironing. Such aluminum pipes can achieve a good dimensional precision and surface smoothness without requiring any surface cutting and besides are advantageous in view of cost as well.
However, burr-like protruding defects tend to come on the surfaces of these non-cut aluminum pipes, and hence it is especially effective to provide the conductive layer.
[0017] In the present invention, for the purpose of covering any defects of the surface of the support, the
conductive layer having a volume resistivity of from l.OxlO8 Ω-cm or more to 5.0*1012 Ω -cm or less is provided on the support. If a layer having a volume resistivity of more than 5.0><1012 Ω-cm is provided on the support as the layer for covering any defects of the surface of the support, the flow of electric charges comes to tend to stagnate therein when images are formed, to come to tend to increase in residual potential. If on the other hand the conductive layer has a volume resistivity of less than Ι.ΟχΙΟ8 Ω-cm, the electric charges flowing through the conductive layer may be so excessively large in quantity when the electrophotographic photosensitive member is charged that the fog due to an increase in dark attenuation of the electrophotographic photosensitive member may come to tend to occur.
[0018] How to measure the volume resistivity of the conductive layer of the electrophotographic photosensitive member is described below with reference to Figs. 2 and 3. Fig. 2 is a plan view to illustrate how to measure the volume resistivity of the conductive layer, and Fig. 3 is a sectional view to illustrate how to measure the volume resistivity of the conductive layer.
[0019] he volume resistivity of the conductive layer is
measured in a normal-temperature and normal-humidity (23°C/50%RH) environment. A tape 203 made of copper (Type No.1181, available from Sumitomo 3M Limited) is stuck to the surface of a conductive layer 202 to make it serve as an electrode on the surface side of the conductive layer 202. A support 201 is also made to serve as an electrode on the back side of the
conductive layer 202. A power source 206 and a current measuring instrument 207 are respectively set up; the former for applying voltage across the copper tape 203 and the support 201 and the latter for measuring electric current flowing across the copper tape 203 and the support 201.
[0020] To make the voltage applicable to the copper tape 203, a copper wire 204 is put on the copper tape 203, and then a tape 205 made of copper like the copper tape 203 is stuck from above the copper wire 204 to the copper tape 203 so that the copper wire 204 may not protrude from the copper tape 203, to fasten the copper wire 204 to the copper tape 203. To the copper tape 203,
voltage is applied through the copper wire 204.
[0021]A background current value found when any voltage is
not applied across the copper tape 203 and the support 201 is represented by Io (A) , a current value found when a voltage of -1 V having only a direct-current component is applied across the copper tape 203 and the support 201 is represented by I (A) , the layer
thickness of the conductive layer 202 is represented by d (cm) and the area of the electrode (copper tape 203) on the surface side of the conductive layer 202 is represented by S (cm2) , where the value expressed by the following mathematical expression (1) is taken as volume resistivity p (Ω -cm) of the conductive layer 202. p = l/(I-I0 ) x S/d (Ω-cm) (1)
[0022] In this measurement, the level of electric current of extremely as extremely small as Ι χ Ι Ο"6 A or less as absolute value is measured, and hence it is preferable to make the measurement by using as the current
measuring instrument 207 an instrument that can measure an extremely small electric current. Such an instrument may include, e.g., a pA meter (trade name: 4140B) manufactured by Yokogawa Hewlett-Packard Company.
[ 0023 ] Incidentally, the volume resistivity of the conductive layer shows the like value in either of measurement made in the state only the conductive layer has been formed on the support and measurement made in the state the respective layers (photosensitive layer and so forth) on the conductive layer have been stripped off the electrophotographic photosensitive member so as to leave only the conductive layer on the support. [0024] In the present invention, the conductive layer is formed by using a coating liquid for conductive layer prepared with use of a solvent, a binder material and metal oxide particles. The coating liquid for
conductive layer may be prepared by dispersing the metal oxide particles in the solvent together with the binder material. As a method for dispersion, it may include, e.g., a method making use of a paint shaker, a sand mill, a ball mill or a liquid impact type highspeed dispersion machine. The conductive layer may be formed by applying the coating liquid for conductive layer, thus prepared, onto the support and then drying and/or curing the wet coating formed.
[0025] In the present invention, as the metal oxide particles, titanium oxide (Ti02) particles coated with tin oxide (Sn02) doped with phosphorus (P) or titanium oxide (Ti02) particles coated with tin oxide (Sn02) doped with tungsten (W) are used. These are hereinafter
generically termed also "tin oxide coated titanium oxide particles".
[0026] The tin oxide coated titanium oxide particles used in the present invention are particles having been made to have a powder resistivity x (Ω-cm) by coating titanium oxide (Ti02) particles [ (particles composed of only titanium oxide (Ti02) ] having a powder resistivity y (Ω-cm), with tin oxide (Sn02) doped with phosphorus (P) or tungsten (W) , where the y and the x satisfy the following relations (i) and (ii) :
5.0*107 < y < 5.0xl09 (i)
l.OxlO2 < y/x < Ι.ΟχΙΟ6 (ii)
[0027] In other words, where powder resistivity of the tin
oxide coated titanium oxide particles used in the present invention is represented by x (Ω-cm) and powder resistivity of the titanium oxide (Ti02) particles that are core particles constituting the tin oxide coated titanium oxide particles used in the present invention is represented by y (Ω-cm), the y and the x satisfy the above relations (i) and (ii) .
[0028] If the core particles titanium oxide (Ti02) particles constituting the tin oxide coated titanium oxide particles has a powder resistivity y of less than
5.0*107 Ω -cm, the fog due to an increase in dark attenuation of the electrophotographic photosensitive member comes to tend to occur. This is because, in addition to the coats (also "coat layers") [i.e., the part of the tin oxide (Sn02) doped with phosphorus (P) or tungsten ( ) ] that originally tend to flow electric current therethrough, even the core particles [the titanium oxide (Ti02) particles] covered with such coats has a low powder resistivity y, and hence the electric charges flowing through not only the coats but also the core particles tends to become large in quantity when the electrophotographic photosensitive member is charged, as so considered. That is, it is because the electric charges come to more tend to flow at the time of charging of the electrophotographic photosensitive member at which the quantity of electric charges flowing through the electrophotographic photosensitive member should be controlled or limited. The powder resistivity y may preferably be Ι.ΟχΙΟ8 or more (Ι.ΟχΙΟ8 < y) .
[0029] On the other hand, if the core particle titanium oxide (Ti02) particle constituting the tin oxide coated titanium oxide particles has a powder resistivity y of more than 5.0χ109 Ω -cm, the residual potential comes to tend to increase. This is because the core particles [the titanium oxide (Ti02) particles] has a high powder resistivity y, and hence the electric charges flowing through the core particles may inevitably become small in quantity at the time of exposure, so that it may come about that the electric charges flow chiefly only at the coats, as so considered. That is, it is because the electric charges come more not to easily flow at the time of exposure at which the quantity of electric charges flowing through the electrophotographic photosensitive member should be made large. The powder resistivity y may preferably be Ι.ΟχΙΟ9 or less (y ≤ Ι.ΟχΙΟ9) .
[0030] The value of y/x in the above relation (ii)
(hereinafter also "powder resistivity ratio y/x") is a parameter which means that the quantity of electric charges flowing through the core particles titanium oxide (Ti02) particles constituting the tin oxide coated titanium oxide particles and the quantity of electric charges flowing through the whole tin oxide coated titanium oxide particles inclusive of the coats are required to be balanced with each other within a specific range.
[0031] If the powder resistivity ratio y/x is more than
Ι.ΟχΙΟ6, the fog due to an increase in dark attenuation of the electrophotographic photosensitive member comes to tend to occur. This is caused by the fact that any high powder resistivity ratio y/x makes the balance between the quantity of electric charges flowing through the core particles titanium oxide (Ti02) particles constituting the tin oxide coated titanium oxide particles and the quantity of electric charges flowing through the whole tin oxide coated titanium oxide particles break when the electrophotographic photosensitive member is charged, as so considered. That is, it is because the electric charges come to tend to flow locally at the coats at the time of charging of the electrophotographic photosensitive member at which the quantity of electric charges flowing through the electrophotographic photosensitive member should be controlled or limited.
[0032] On the other hand, if the powder resistivity ratio y/x is less than 1.0*102, the residual potential comes to tend to increase. This is caused by the fact that any low powder resistivity ratio y/x makes the balance between the quantity of electric charges flowing through the core particles titanium oxide (Ti02) particles constituting the tin oxide coated titanium oxide particles and the quantity of electric charges flowing through the whole tin oxide coated titanium oxide particles break when the electrophotographic photosensitive member is charged, as so considered. That is, it is because the electric charges come not to easily flow through the coats at the time of exposure at which the quantity of electric charges flowing through the electrophotographic photosensitive member should be made large.
[0033] For the above reasons, the powder resistivity ratio y/x is required to be from Ι.ΟχΙΟ2 or more to Ι.ΟχΙΟ6 or less. A preferable powder resistivity ratio y/x may be from Ι.ΟχΙΟ3 or more to 1.0*105 or less, i.e.:
Ι.ΟχΙΟ3 < y/x < 1.0x10s (iii) .
[0034] The titanium oxide (Ti02) particles coated with tin
oxide (Sn02) doped with phosphorus (P) or tungsten (W) [in particular, phosphorus (P)] as used in the present invention are more greatly effective in keeping the fog due to an increase in dark attenuation of the
electrophotographic photosensitive member from
occurring, and also more greatly effective in keeping the residual potential from increasing when images are formed, than any titanium oxide (Ti02) particles coated with oxygen deficient tin oxide (Sn02) .
[ 0035 ] Details are unclear about the reason why the former particles are greatly effective in keeping the fog due to an increase in dark attenuation from occurring, which, however, is considered to be concerned with the fact that the use of the titanium oxide (Ti02)
particles coated with tin oxide (Sn02) doped with phosphorus (P) or tungsten (W) [in particular, phosphorus (P)] makes small the electric current (dark electric current) flowing through the
electrophotographic photosensitive member at its dark areas when a stated voltage is applied thereto.
[0036]About the reason why the former particles are greatly effective in keeping the residual potential from
increasing when images are formed, it is considered due to the fact that the latter titanium oxide (Ti02) particles coated with oxygen deficient tin oxide (Sn02) come oxidized in the presence of oxygen to lose their oxygen deficient portions, so that the latter particles may come to have a high resistance to make the flow of electric charges come to tend to stagnate in the
conductive layer, whereas the former particles
according to the present invention are not so.
[0037]The core particles titanium oxide (Ti02) particles
constituting the tin oxide coated titanium oxide
particles used in the present invention may have a particle shape which is granular, spherical, acicular, fibrous, columnar, rod-like, spindle-like or plate-like, or other similar shape, any of which may be used. From the viewpoint of less image defects such as black spots, spherical particles are preferred. The core particles titanium oxide (Ti02) particles constituting the tin oxide coated titanium oxide particles may also have a crystal form of rutile, anatase, brookite or amorphous, any crystal form of which may be used. As to their production method as well, any production method may be used, such as a sulfuric acid method or a hydrochloric acid method.
[0038] The tin oxide (Sn02) in the tin oxide coated titanium oxide particles may preferably be in a proportion
(coverage) of from 10% by mass to 60% by mass. To control the coverage of the tin oxide (Sn02), a tin raw material necessary for formation of the tin oxide
(Sn02) must be compounded when the tin oxide coated titanium oxide particles are produced. For example, where tin chloride (SnCl4) that is a tin raw material is used, it must be formulated taking account of the amount of the tin oxide (Sn02) to be formed from the tin chloride (SnCl4) .
[0039] Here, the tin oxide (Sn02) serving as the coats of the tin oxide coated titanium oxide particles used in the present invention stands doped with phosphorus (P) or tungsten (W) , where the coverage is defined as the value found by calculation from the mass of the tin oxide (Sn02) with respect to the total mass of the tin oxide (Sn02) and titanium oxide (Ti02) , without taking account of the mass of the phosphorus (P) or tungsten (W) with which the tin oxide (Sn02) stands doped.
[0040]Any tin oxide (Sn02) in a coverage of less than 10% by mass makes it difficult to control the powder
resistivity ratio y/x to be from Ι.ΟχΙΟ2 or more to
1.0x10s or less. Any tin oxide (Sn02) in a coverage of more than 60% by mass tends to make non-uniform the covering of the titanium oxide (Ti02) with the tin oxide (Sn02) , and tends to result in a high cost.
[0041] The phosphorus (P) or tungsten (W) with which the tin oxide (Sn02) is doped may preferably be in an amount of from 0.1% by mass to 10% by mass based on the mass of the tin oxide (Sn02) [the mass not inclusive of the phosphorus (P) or tungsten ( ) ] . Any phosphorus (P) or tungsten (W) with which the tin oxide (Sn02) is doped in an amount of less than 0.1% by mass makes it
difficult to control the powder resistivity ratio y/x to be from Ι.ΟχΙΟ2 or more to 1.0x10s or less. Any phosphorus (P) or tungsten ( ) with which the tin oxide (Sn02) is doped in an amount of more than 10% by mass makes the tin oxide (Sn02) low crystallizable, and makes it difficult to control the powder resistivity ratio y/x to be from Ι.ΟχΙΟ2 or more to 1.0x10s or less. The doping of the tin oxide (Sn02) with the phosphorus (P) or tungsten ( ) can commonly make the tin oxide coated titanium oxide particles have a lower powder resistivity than those not doped therewith.
[ 0042 ] Incidentally, how to produce the titanium oxide (Ti02) particles coated with tin oxide (SnC>2 ) doped with phosphorus (P) and the titanium oxide (Ti02) particles coated with tin oxide (Sn02) doped with tungsten ( ) is also disclosed in Japanese Patent Applications Laid- open No. H06-207118 and No. 2004-349167.
[0043] How to measure the powder resistivity of the metal
oxide particles (tin oxide coated titanium oxide particles) is as described below.
[0044] The powder resistivity of the metal oxide particles
(tin oxide coated titanium oxide particles) and that of the core particles [titanium oxide (Ti02) particles] constituting the metal oxide particles are measured in a normal-temperature and normal-humidity (23°C/50%RH) environment. In the present invention, a resistivity measuring instrument manufactured by Mitsubishi
Chemical Corporation [trade name: LORESTA GP (or
HIRESTA UP in the case of more than 107 Ω-cm)] is used as a measuring instrument. The measurement object metal oxide particles (tin oxide coated titanium oxide particles) and so forth are each compacted at a
pressure of 500 kg/cm2 to prepare a pellet-shaped measuring sample. The powder resistivity is measured at an applied voltage of 100 V.
[0045] In the present invention, the tin oxide coated titanium oxide particles having the core particles [titanium oxide (Ti02) particles] are used as the metal oxide particles incorporated in the conductive layer, which are used in order to achieve an improvement in the dispersibility of the metal oxide particles in the coating liquid for conductive layer. Any use of particles composed of only the tin oxide (Sn02) doped with phosphorus (P) or tungsten (W) or the oxygen deficient tin oxide (Sn02) tends to make the metal oxide particles have a large particle diameter in the coating liquid for conductive layer, so that protrusive seeding defects may occur on the surface of the
conductive layer and also the coating liquid for conductive layer may have a low stability.
[0046] The titanium oxide (Ti02) particles are used as the
core particles, which are used because they are greatly effective in keeping the fog due to an increase in dark attenuation of the electrophotographic photosensitive member from occurring. Details are unclear about the reason why such particles are greatly effective in keeping the fog due to an increase in dark attenuation from occurring, which, however, is considered to be concerned with the fact that their use makes small the electric current (dark electric current) flowing through the electrophotographic photosensitive member at its dark areas when a stated voltage is applied thereto. Further, the titanium oxide (Ti02) particles as the core particles have an advantage that they are so low transparent as the metal oxide particles as to easily cover any defects of the surface of the support. In contrast thereto, where, e.g., barium sulfate particles are used as the core particles, they are so high transparent as the metal oxide particles as to make it necessary to specially use a material for.
covering any defects of the surface of the support.
[0047]Not any uncoated titanium oxide (Ti02) particles, but the titanium oxide (Ti02) particles coated with tin oxide (Sn02) doped with phosphorus (P) or tungsten (W) are used as the metal oxide particles, which are used because such uncoated titanium oxide (Ti02) particles make the flow of electric charges come to tend to stagnate when images are formed, and come to tend to result in an increase in residual potential, whereas the latter particles according to the present invention are not so.
[0048]As the binder material used in preparing the coating
liquid for conductive layer, it may include, e.g., resins such as phenol resin, polyurethane resin,
polyamide resin, polyimide resin, polyamide-imide resin, polyvinyl acetal resin, epoxy resin, acrylic resin, melamine resin and polyester resin. Any of these may be used alone or in combination of two or more types. Also, of these, from the viewpoints of control of migration (transfer) to other layers, adhesion to the support, dispersibility and dispersion stability of the tin oxide coated titanium oxide particles and solvent resistance after layer formation, hardening resins are preferred, and heat-hardening resins (thermosetting resins) are much preferred. Still also, of the
thermosetting resins, thermosetting phenol resins and thermosetting polyurethane resins are preferred. Where such a hardening resin is used as the binder material for the conductive layer, the binder material to be contained in the coating liquid for conductive layer serves as a monomer, and/or an oligomer, of the
hardening resin.
[0049] The solvent used in preparing the coating liquid for
conductive layer may include, e.g., alcohols such as methanol, ethanol and isopropanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone ; ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether and propylene glycol monomethyl ether; esters such as methyl acetate and ethyl acetate; and aromatic hydrocarbons such as toluene and xylene.
[0050] In the present invention, the metal oxide particles
(tin oxide coated titanium oxide particles) (P) and binder material (B) in the coating liquid for
conductive layer are required to be in a mass ratio (P/B) of from 1.5/1.0 to 3.5/1.0. If the metal oxide particles (tin oxide coated titanium oxide particles) (P) and the binder material (B) are in a mass ratio (P/B) of less than 1.5/1.0, the flow of electric charges comes to tend to stagnate in the conductive layer when images are formed, to come to tend to increase in residual potential. Also, those in such a ratio make it difficult to control the volume
resistivity of the conductive layer to be 5.0χ1012 Ω-cm or less. If the metal oxide particles (tin oxide coated titanium oxide particles) (P) and the binder material (B) are in a mass ratio (P/B) of more than
3.5/1.0, this makes it difficult to control the volume resistivity of the conductive layer to be 1.0*108 Ω -cm or more, and also makes it difficult to bind the metal oxide particles (tin oxide coated titanium oxide particles), to come to tend to cause cracks in the conductive layer and come to tend to cause the fog due to an increase in dark attenuation.
[0051 ] Prom the viewpoint of covering any defects of the
surface of the support, the conductive layer may preferably have a layer thickness of from 10 μπι or more to 40 μιη or less, and much preferably from 15 \im or more to 35 μηα or less.
[0052] In the present invention, the layer thickness of each layer, inclusive of the conductive layer, of the electrophotographic photosensitive member is measured with FISCHERSCOPE Multi Measurement System (MMS) , available from Fischer Instruments Co.
[0053] The tin oxide coated titanium oxide particles in the coating liquid for conductive layer may preferably have an average particle diameter of from 0.10 μιη or more to 0.45 μπι or less, and much preferably from 0.15 μηα or more to 0.40 μπι or less. If the tin oxide coated titanium oxide particles have an average particle diameter of less than 0.10 μπι,' such tin oxide coated titanium oxide particles may come to agglomerate again after the coating liquid for conductive layer has been prepared, to make the coating liquid for conductive layer low stable or cause cracks in the surface of the conductive layer. If the tin oxide coated titanium oxide particles have an average particle diameter of more than 0.45 μιτι, the surface of the conductive layer may come so rough as to come to tend to cause local injection of electric charges therefrom into the photosensitive layer, so that black dots may come to conspicuously appear in white background areas of reproduced images.
[0054]The average particle diameter of the tin oxide coated titanium oxide particles in the coating liquid for conductive layer may be measured by liquid-phase sedimentation in the following way.
[0055] First, the coating liquid for conductive layer is so diluted with the solvent used in preparing the same, as to have a transmittance between 0.8 and 1.0. Next, a histogram of average particle diameter (volume base D50) and particle size distribution of the tin oxide coated titanium oxide particles is prepared by using a centrifugal automatic particle size distribution measuring instrument. In the present invention, as the centrifugal automatic particle size distribution measuring instrument, a centrifugal automatic particle size distribution measuring instrument (trade name: CAPA700) manufactured by Horiba, Ltd. is used to make measurement under conditions of a number of revolutions of 3,000 rpm.
[0056]As particle diameter of the titanium oxide (Ti02)
particles that are the core particles constituting the tin oxide coated titanium oxide particles, it may preferably be from 0.05 i or more to 0.40 μπι or less, from the viewpoint of controlling the average particle diameter of the tin oxide coated titanium oxide
particles within the above range.
[0057] In order to keep interference fringes from appearing on reproduced images because of interference of light having reflected from the surface of the conductive layer, a surface roughness providing material for roughening the surface of the conductive layer may also be added to the coating liquid for conductive layer. Such a surface roughness providing material may
preferably be resin particles having an average
particle diameter of from 1 μπι or more to 5 pm or less. Such resin particles may include, e.g., particles of hardening rubbers and of hardening resins such as polyurethane , epoxy resin, alkyd resin, phenol resin, polyester, silicone resin and acryl-melamine resin. Of these, particles of silicone resin are preferred as being not easily agglomerative . The specific gravity of resin particles (which is 0.5 to 2) is smaller than the specific gravity of the tin oxide coated titanium oxide particles (which is 4 to 7), and hence the surface of the conductive layer can efficiently be roughened at the time of formation of the conductive layer. However, the conductive layer has a tendency to increase in volume resistivity with an increase in content of the surface roughness providing material in the conductive layer. Hence, in order to control the volume resistivity of the conductive layer to be
5.0xl012 Ω-cm or less, the content of the surface roughness providing material in the coating liquid for conductive layer may preferably be from 1 to 80% by mass based on the mass of the binder material in the coating liquid for conductive layer.
[0058] o the coating liquid for conductive layer, a leveling agent may also be added in order to enhance the surface properties of the conductive layer. Pigment particles may also be added to the coating liquid for conductive layer in order to improve covering properties of the conductive layer.
[0059] Between the conductive layer and the photosensitive layer, an undercoat layer (a barrier layer) having electrical barrier properties may be provided in order to block the injection of electric charges from the conductive layer into the photosensitive layer.
[0060] The undercoat layer may be formed by coating on the
conductive layer a coating liquid for undercoat layer containing a resin (binder resin) , and drying the wet coating formed.
[0061] The resin (binder resin) used for the undercoat layer may include, e.g., water-soluble resins such as
polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acids, methyl cellulose, ethyl cellulose, polyglutamic acid, casein, and starch; and polyamide, polyimide, polyamide-imide, polyamic acid, melamine resin, epoxy resin, polyurethane, and polyglutamate . Of these, in order to bring out the electrical barrier properties of the undercoat layer effectively, thermoplastic resins are preferred. Of the thermoplastic resins, a
thermoplastic polyamide is preferred. As the polyamide, copolymer nylon is preferred.
[0062]The undercoat layer may preferably have a layer
thickness of from 0.1 μιη or more to 2 \i or less.
[0063] In order to make the flow of electric charges not
stagnate in the undercoat layer, the undercoat layer may also be incorporated with an electron-transporting material (an electron-accepting material such as an acceptor) . The electron-transporting material may include, e.g., electron-attracting materials such as 2,4, 7-trinitrofluorenone, 2,4,5, 7-tetranitrofluorenone, chloranil and tetracyanoquinodimethane, and those obtained by polymerizing these electron-attracting materials.
[0064] The photosensitive layer is formed on the conductive
layer (an undercoat layer) .
[0065] The charge-generating material used in the
photosensitive layer may include, e.g., azo pigments such as monoazo, disazo and trisazo, phthalocyanine pigments such as metal phthalocyanines and metal-free phthalocyanine, indigo pigments such as indigo and thioindigo, perylene pigments such as perylene acid anhydrides and perylene acid imides, polycyclic quinone pigments such as anthraquinone and pyrenequinone, squarilium dyes, pyrylium salts and thiapyrylium salts, triphenylmethane dyes, quinacridone pigments, azulenium salt pigments, cyanine dyes, xanthene dyes,
quinoneimine dyes, and styryl dyes. Of these,
preferred are metal phthalocyanines such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine and chlorogallium phthalocyanine.
[0066] In the case when the photosensitive layer is the multilayer type photosensitive layer, the charge generation layer may be formed by coating a coating liquid for charge generation layer obtained by dispersing the charge generating material in a solvent together with a binder resin, and drying the wet coating formed. As a method for dispersion, a method is available which makes use of, e.g., a homogenizer, ultrasonic waves, a ball mill, a sand mill, an attritor or a roll mill.
[0067]The binder resin used to form the charge generation
layer may include, e.g., polycarbonate, polyester, polyarylate, butyral resin, polystyrene, polyvinyl acetal, diallyl phthalate resin, acrylic resin,
methacrylic resin, vinyl acetate resin, phenol resin, silicone resin, polysulfone, a styrene-butadiene copolymer, alkyd resin, epoxy resin, urea resin,, and a vinyl chloride-vinyl acetate copolymer. Any of these may be used alone or in the form of a mixture or copolymer of two or more types.
[0068] he charge generating material and the binder resin may preferably be in a proportion (charge generating material : binder resin) ranging from 10:1 to 1:10 (mass ratio), and much preferably from 5:1 to 1:1 (mass ratio) .
[0069] he solvent used for the coating liquid for charge
generation layer may include, e.g., alcohols,
sulfoxides, ketones, ethers, esters, aliphatic
halogenated hydrocarbons and aromatic compounds.
[0070] The charge generation layer may preferably have a layer thickness of 5 μιη or less, and much preferably from 0.1 μπι or more to 2 μιη or less.
[0071] To the charge generation layer, a sensitizer, an
antioxidant, an ultraviolet absorber, a plasticizer and so forth which may be of various types may also
optionally be added. An electron transport material . (an electron accepting material such as an acceptor) may also be incorporated in the charge generation layer in order to make the flow of electric charges not stagnate in the charge generation layer. The electron- transporting material may include, e.g., electron- attracting materials such as 2 , 4 , 7-trinitrofluorenone, 2, 4, 5, 7-tetranitrofluorenone, chloranil and
tetracyanoquinodimethane, and those obtained by
polymerizing these electron-attracting materials.
[0072] The charge transporting material used in the
photosensitive layer may include, e.g., triarylamine compounds, hydrazone compounds, styryl compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds .
[0073] In the case when the photosensitive layer is the multi¬ layer type photosensitive layer, the charge transport layer may be formed by coating a coating liquid for charge transport layer obtained by dissolving the charge transporting material and a binder resin in a solvent, and drying the wet coating formed.
[0074] The binder resin used to form the charge transport
layer may include, e.g., acrylic resin, styrene resin, polyester, polycarbonate, polyarylate, polysulfone, polyphenylene oxide, epoxy resin, polyurethane, alkyd resin and unsaturated resins. Any of these may be used alone or in the form of a mixture or copolymer of two or more types.
[0075] The charge transporting material and the binder resin may preferably be in a proportion (charge transporting material : binder resin) ranging from 2:1 to 1:2 (mass ratio) .
[0076] The solvent used in the coating liquid for charge
transport layer may include, e.g., ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, ethers such as
dimethoxymethane and dimethoxyethane, aromatic
hydrocarbons such as toluene and xylene, and
hydrocarbons substituted with a halogen atom, such as chlorobenzene, chloroform and carbon tetrachloride.
[0077] The charge transport layer may preferably have a layer thickness of from 3 ym or more to 40 μιη or less, and much preferably from 4 im or more to 30 μπι or less, from the viewpoint of charging uniformity and image reproducibility.
[0078] To the charge transport layer, an antioxidant, an
ultraviolet absorber, a plasticizer and so forth may also optionally be added.
[0079] In the case when the photosensitive layer is the
single-layer type photosensitive layer, the single- layer type photosensitive layer may be formed by coating a coating liquid for single-layer type
photosensitive layer containing a charge generating material, a charge transporting material, a binder resin and a solvent, and drying the wet coating formed. As these charge generating material, charge
transporting material, binder resin and solvent, the above various ones may be used.
[0080] For the purpose of protecting the photosensitive layer, a protective layer may also be provided on the photosensitive layer. The protective layer may be formed by coating a coating liquid for protective layer containing a resin (binder resin) , and drying and/or curing the wet coating formed.
[0081] The protective layer may preferably have a layer
thickness of from 0.5 μιτι or more to 10 μηα or less, and much preferably from 1 μπι or more to 8 μηα or less.
[0082] When the coating liquids for the above respective
layers are coated, usable are coating methods as exemplified by dip coating (immersion coating) , spray coating, spinner coating, roller coating, Mayer bar coating and blade coating.
[0083] Fig. 1 schematically shows an example of the
construction of an electrophotographic apparatus provided with a process cartridge having the
electrophotographic photosensitive member.
[0084] In Fig. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member, which is rotatingly driven around an axis 2 in the direction of an arrow at a stated peripheral speed.
[0085] The peripheral surface of the electrophotographic
photosensitive member 1 rotatingly driven is uniformly electrostatically charged to a positive or negative, stated potential through a charging device (a primary charging device; e.g., a charging roller) 3. The electrophotographic photosensitive member thus charged is then exposed to exposure light (imagewise exposure light) 4 emitted from an exposing device (an imagewise exposing device; not shown) for slit exposure, laser beam scanning exposure or the like. In this way, electrostatic latent images corresponding to the intended image are successively formed on the
peripheral surface of the electrophotographic
photosensitive member 1. Voltage to be applied to the charging device 3 may be only direct-current voltage or may be direct-current voltage on which alternating- current voltage is kept superimposed.
[0086] The electrostatic latent images thus formed on the
peripheral surface of the. electrophotographic
photosensitive member 1 are developed with a toner of a developing device 5 to form toner images. Then, the toner images thus formed and held on the peripheral surface of the electrophotographic photosensitive member 1 are transferred to a transfer material (such as paper) P by applying a transfer bias from a
transferring device (such as a transferring roller) 6. The transfer material P is fed through a transfer material feed device (not shown) to come to the part (contact zone) between the electrophotographic
photosensitive member 1 and the transferring device 6 in the manner synchronized with the rotation of the electrophotographic photosensitive member 1.
[0087] The transfer material P to which the toner images have been transferred is separated from the peripheral surface of the electrophotographic photosensitive member 1 and is led into a fixing device 8, where the toner images are fixed, and is then printed out of the apparatus, as an image-formed material (a print or copy) .
[0088] The peripheral surface of the electrophotographic
photosensitive member 1 from which the toner images have been transferred is brought to removal of the toner remaining after the transfer, through a cleaning device (such as a cleaning blade) 7. It is further subjected to charge elimination by pre-exposure light 11 emitted from a pre-exposure device (not shown) , and thereafter repeatedly used for the formation of images. Incidentally, the pre-exposure is not necessarily required where the charging device is a contact
charging device such as a charging roller.
[0089] The apparatus may be constituted of at least one
constituents selected from the above
electrophotographic photosensitive member 1, charging device 3, developing device 5, transferring device 6, cleaning device 7 and so forth which are received in a container to set up a process cartridge so that the process cartridge may be set detachably mountable to the main body of an electrophotographic apparatus. In what is shown in Fig. 1, the electrophotographic photosensitive member 1 and the charging device 3, developing device 5 and cleaning device 7 are
integrally supported to form a cartridge to set up a process cartridge 9 that is detachably mountable to the main body of the electrophotographic apparatus through a guide device 10 such as rails provided in the main body of the electrophotographic apparatus. The
electrophotographic apparatus may also be constituted to have the electrophotographic photosensitive member 1 and the charging device 3, exposing device, developing device 5 and cleaning device 7.
EXAMPLES
[0090] The present invention is described below in greater detail by giving specific working examples. The present invention, however, is by no means limited to these. In the following working examples, "part(s)" refers to "part(s) by mass". Core particles titanium oxide (Ti02) particles in the tin oxide coated titanium oxide particles as used in the following working examples are all spherical ones having a BET value of 7.8 m2/g.
[0091]- Preparation Examples for Coating Liquid for
Conductive Layer -
[ 0092 ] Preparation Example for
Coating Liquid 1 for Conductive Layer
[0093] 192 parts of titanium oxide (Ti02) particles coated
with tin oxide (Sn02) doped with phosphorus (P) as metal oxide particles (powder resistivity: 5.0*104 Ω -cm; average primary particle diameter: 250 nm) , produced by using titanium oxide (Ti02) particles having a powder resistivity of 5.0><107 Ω -cm, 168 parts of phenol resin (monomer/oligomer of phenol
resin) (trade name: PLYOPHEN J-325; available from
Dainippon Ink & Chemicals, Incorporated; resin solid content: 60%) as a binder material and 98 parts of 1- methoxy-2-propanol as a solvent were put into a sand mill making use of 420 parts of glass beads of 0.8 mm in diameter, to carry out dispersion treatment
("dispersing" in Tables 1 and 2) under conditions of a number of revolutions of 1,500 rpm, a dispersion treatment time of 4 hours and a cooling water preset temperature of 18°C to obtain a liquid dispersion.
[0094]After the glass beads were removed from this liquid dispersion through a mesh, 13.8 parts of silicone resin particles (trade name: TOSPEARL 120; available from Momentive Performance Materials Inc.; average particle diameter: 2 μπι) as a surface roughness providing material, 0.014 part of silicone oil (trade name:
SH28PA; available from Dow Corning Toray Co., Ltd.) as a leveling agent, 6 parts of methanol and 6 parts of 1- methoxy-2-propanol were added to the liquid dispersion, followed by stirring to prepare a coating liquid 1 for conductive layer.
[0095] Preparation Examples for
Coating Liquids 2 to 68 & CI to C83 for Conductive Layer
[0096] Coating liquids 2 to 68 and CI to C83 for conductive layer were prepared in the same manner as Preparation Example for Coating liquid 1 for conductive layer except that, about the materials used in preparing the coating liquid for conductive layer, the type, powder resistivity and amount (parts) of the metal oxide particles, the powder resistivity of the core particles thereof, the amount of the phenol resin as a binder material and also the dispersion treatment time were each assigned or set as shown in Tables 1 and 2. In Tables 1 and 2, tin oxide is as Sn02 and titanium oxide is as Ti02.
]Table 1
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating
Amount Discoating liquid Powder perliquid for (parts )
resissing conducfor
Powder ( resin
tivity time tive conducresissolid layer (h)
Amt. of core tive
Type tivity (pt) y/x conpartilayer
(x) tent :
cles
(Ω · cm) 60 ms.%
(y) of the
(Ω - cm)
fol. )
1 5.0x10" 192 5. OxlO7 l.OxlO3 168 4 1.9/1.0
2 5. OxlO2 180 5. OxlO7 l.OxlO5 188 4 1.6/1.0
3 5.0xl06 207 5. OxlO9 l.OxlO3 144 4 2.4/1.0
4 5. OxlO4 195 5. OxlO9 l.OxlO5 163 4 2.0/1.0
5 l.OxlO5 198 1.0x10s 1. OxlO3 157 4 2.1/1.0
6 Ι . Ο χ Ι Ο4 192 l.OxlO8 1.0x10" 168 4 1.9/1.0
7 l.OxlO3 184 l.OxlO8 l.OxlO5 181 4 1.7/1.0
8 Ti02 5. OxlO3 184 5. OxlO7 1. OxlO4 181 4 1.7/1.0
9 parti5.0x10s 202 5. OxlO9 l.OxlO4 153 4 2.2/1.0
10 cles 1.0x10s 198 l.OxlO9 1.0x10" 157 4 2.1/1.0
11 coated 5. OxlO5 198 5. OxlO7 l.OxlO2 157 4 2.1/1.0
12 with 5. OxlO1 176 5. OxlO7 l.OxlO6 195 4 1.5/1.0
13 Sn02 5. OxlO7 214 5. OxlO9 l.OxlO2 132 4 2.7/1.0 doped
14 5. OxlO3 188 5. OxlO9 l.OxlO6 174 4 1.8/1.0 with P
15 l.OxlO6 204 l.OxlO8 l.OxlO2 ' 148 4 2.3/1.0
(ay.
16 l.OxlO2 180 l.OxlO8 1. OxlO6 188 4 1.6/1.0 prim,
17 par1. OxlO4 207 l.OxlO8 1. OxlO" 144 4 2.4/1.0
18 ticle 1. OxlO4 202 l.OxlO8 1.0x10" 153 4 2.2/1.0
19 diam. : l.OxlO4 188 l.OxlO8 1.0x10" 174 4 1.8/1.0
20 250 1. OxlO4 184 l.OxlO8 1.0x10" 181 4 1.7/1.0
21 nm) l.OxlO4 180 l.OxlO8 1.0x10" 188 4 1.6/1.0
22 5. OxlO7 228 5. OxlO9 l.OxlO2 109 4 3.5/1.0
23 5. OxlO7 223 5. OxlO9 l.OxlO2 116 4 3.2/1.0
24 5. OxlO7 212 5. OxlO9 l.OxlO2 136 4 2.6/1.0
25 5. OxlO7 207 5. OxlO9 1. OxlO2 144 4 2.4/1.0
26 5. OxlO7 202 5. OxlO9 1.OxlO2 153 4 2.2/1.0
27 l.OxlO4 207 l.OxlO8 l.OxlO4 144 1.5 2.4/1.0
28 1.0x10" 207 1.0x10s 1. OxlO4 144 6.5 2.4/1.0 8]Table 1 (cont'd)
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating
/Amount Discoating liquid Powder perliquid for (parts)
resissing conducfor
Powder (resin
tivity time tive conducresissolid layer (h)
Amt. of core tive
Type tivity (pt) y/x con• partilayer
(x) tent :
cles
(Ω - cm) 60 ms.%
(Y) of the
(Ω · cm)
fol. )
29 5.0*10" 192 5. OxlO7 l.OxlO3 168 4 1.9/1.0
30 5. OxlO2 180 5. OxlO7 1.0x10s 188 4 1.6/1.0
31 5. OxlO6 207 5. OxlO9 l.OxlO3 144 4 2.4/1.0
32 5.0x10" 195 5. OxlO9 l.OxlO5 163 4 2.0/1.0
33 1.0x10s 198 1.0x10s l.OxlO3 157 4 2.1/1.0
34 l.OxlO4 192 Ι.ΟχΙΟ8 1.0x10" 168 4 1.9/1.0
35 Ι.ΟχΙΟ3 184 1. OxlO8 1. OxlO5 181 4 1.7/1.0
36 Ti02 5. OxlO3 184 5. OxlO7 1.0x10" 181 4 1.7/1.0
37 parti5. OxlO5 202 5. OxlO9 l.OxlO4 153 4 2.2/1.0
38 cles 1. OxlO5 198 Ι.ΟχΙΟ9 l.OxlO4 157 4 2.1/1.0
39 coated 5. OxlO5 198 5. OxlO7 l.OxlO2 157 4 2.1/1.0
40 with 5. OxlO1 176 5. OxlO7 l.OxlO6 195 4 1.5/1.0
41 Sn02 5. OxlO7 214 5. OxlO9 l.OxlO2 132 4 2.7/1.0 doped
42 5. OxlO3 188 5. OxlO9 l.OxlO6 174 4 1.8/1.0 with W
43 Ι.ΟχΙΟ6 204 Ι.ΟχΙΟ8 l.OxlO2 148 4 2.3/1.0
(av.
44 Ι.ΟχΙΟ2 180 1.0x10s 1. OxlO6 188 . 4 1.6/1.0 prim,
45 par1.0x10" 207 Ι.ΟχΙΟ8 1.0x10" 144 4 2.4/1.0
46 ticle 1.0x10" 202 1. OxlO8 1. OxlO4 153 4 2.2/1.0
47 diam. : 1.0x10" 188 1. OxlO8 1. OxlO4 174 4 1.8/1.0
48 250 1.0x10" 184 1.0x10s 1.0x10" 181 4 1.7/1.0
49 nm) 1.0x10" 180 1. OxlO8 1. OxlO4 188 4 1.6/1.0
50 5. OxlO7 228 5. OxlO9 l.OxlO2 109 4 3.5/1.0
51 5. OxlO7 223 5. OxlO9 l.OxlO2 116 4 3.2/1.0
52 5. OxlO7 212 5. OxlO9 l.OxlO2 136 4 2.6/1.0
53 5. OxlO7 207 5. OxlO9 l.OxlO2 144 4 2.4/1.0
54 5. OxlO7 202 5. OxlO9 l.OxlO2 153 4 2.2/1.0
55 1.0x10" 207 l.OxlO8 1.0x10" 144 1.5 2.4/1.0
56 1.0x10" 207 l.OxlO8 1.0x10" 144 6.5 2.4/1.0 9]Table 1 (cont'd)
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating coating liquid Amount Dis¬
Powder perliquid for (parts)
resissing conducfor
Powder (resin time tive tivity conduclayer resissolid
of core (h)
Amt. tive
Type tivity (pt) o
partiy/x c nlayer
(x) tent:
cles
(Ω ·cm) 60 ms.%
(y) of the
(Ω · cm)
fol. )
Ti02
57 parti5.0xl05 176 5. OxlO7 1 OxlO2 195 4 1.5/1.0 cles
58 coated 5. OxlO5 228 5. OxlO7 1 OxlO2 109 4 3.5/1.0 ■ with
59 Sn02 5. OxlO1 228 5. OxlO7 1 OxlO6 109 4' 3.5/1.0 doped
with P
60 ( av . 5. OxlO7 176 5. OxlO.9 1 OxlO2 195 4 1.5/1.0 prim.
61 par5. OxlO3 176 ■5. OxlO9 1 OxlO6 195 4 1.5/1.0 ticle
diam. :
62 250 5. OxlO3 228 5. OxlO9 1 OxlO6 109 4 3.5/1.0
ran]
Ti02
63 parti5.0x10s 176 5. OxlO7 1 .OxlO2 195 4 1.5/1.0 cles
64 coated 5. OxlO5 228 5. OxlO7 1 .OxlO2 109 4 3.5/1.0 with
65 Sn02 5. OxlO1 228 5. OxlO7 1 OxlO6 109 4 3.5/1.0 doped
with W
66 ( a . 5. OxlO7 176. 5. OxlO9 1 . OxlO2 195 4 1.5/1.0 prim .
67 par5. OxlO3 176 5. OxlO9 1 .OxlO6 195 4 1.5/1.0 ticle
diam. :
68 250 5. OxlO3 228 5. OxlO9 1 .OxlO6 109 4 3.5/1.0 nm) 0]Tabie 2
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating
Amount Discoating liquid Powder perliquid for (parts )
resissing for conducPowder (resin time tive tivity conducresissolid (h) layer Amt. of core tive
Type tivity (pt) y/x conpartilayer
(x) tent :
cles
(Ω■ cm) 60 ms.%
(y) of the
(Ω - cm)
fol. )
CI Ι.ΟχΙΟ6 198 5. OxlO7 5. OxlO1 157 4 2.1/1.0
C2 Ti02 1.0x10s 195 1. OxlO7 1. OxlO2 163 4 2.0/1.0
C3 partiΙ.ΟχΙΟ1 171 1. OxlO7 1. OxlO6 204 4 1.4/1.0
C4 cles Ι.ΟχΙΟ1 166 5. OxlO7 5. OxlO6 212 4 1.3/1.0
C5 coated Ι.ΟχΙΟ3 184 5. OxlO9 5. OxlO6 181 4 1.7/1.0 with
C6 1. OxlO4 192 l.OxlO10 l.OxlO6 168 4 1.9/1.0
Sn02
C7 Ι.ΟχΙΟ8 216 l.OxlO10 l.OxlO2 129 4 2.8/1.0 doped
C8 Ι.ΟχΙΟ8 216 5. OxlO9 5. OxlO1 129 4 2.8/1.0 with P
C9 Ι.ΟχΙΟ3 184 l.OxlO7 1. OxlO4 181 4 1.7/1.0
(av.
CIO 2. OxlO1 176 l.OxlO8 5. OxlO6 195 4 1.5/1.0 prim .
Cll Ι.ΟχΙΟ4 212 l.OxlO8 1. OxlO4 136 2.5 2.6/1.0 par¬
C12 ticle Ι.ΟχΙΟ4 176 l.OxlO8 l.OxlO4 195 6 1.5/1.0
C13 diam. : 5. OxlO7 229 5. OxlO9 l.OxlO2 106 4 3.6/1.0
C14 250 5. OxlO7 198 5. OxlO9 1. OxlO2 157 6 2.1/1.0
C15 nm) 5. OxlO7 229 5. OxlO9 l.OxlO2 106 2.5 3.6/1.0
C16 Ι.ΟχΙΟ4 171 l.OxlO8 l.OxlO4 204 6 1.4/1.0
C17 Ι.ΟχΙΟ6 198 5. OxlO7 5. OxlO1 157 4 2.1/1.0
C18 Ti02 Ι.ΟχΙΟ5 195 l.OxlO7 l.OxlO2 163 4 2.0/1.0
C19 partiΙ.ΟχΙΟ1 171 l.OxlO7 l.OxlO6 - 204 4 1.4/1.0
C20 cles Ι.ΟχΙΟ1 166 5. OxlO7 5. OxlO6 212 4 1.3/1.0
C21 coated Ι.ΟχΙΟ3 184 5. OxlO9 5. OxlO6 181 4 1.7/1.0 with
C22 l.OxlO4 192 1. OxlO10 1. OxlO6 168 4 1.9/1.0
Sn02
C23 Ι.ΟχΙΟ8 216 1. OxlO10 1. OxlO2 129 4 2.8/1.0 doped
C24 Ι.ΟχΙΟ8 216 5. OxlO9 5. OxlO1 129 4 2.8/1.0 with W
C25 1. OxlO3 184 l.OxlO7 l.OxlO4 181 4 1.7/1.0
( av .
C26 2. OxlO1 176 1. OxlO8 5. OxlO6 195 4 1.5/1.0 prim,
C27 1.0x10" 212 1. OxlO8 1. OxlO4- 136 2.5 2.6/1.0 par¬
C28 ticle Ι.ΟχΙΟ4 176 l.OxlO8 1. OxlO4 195 6 1.5/1.0
C29 diam. : 5. OxlO7 229 5. OxlO9 1. OxlO2 106 4 3.6/1.0
C30 250 5. OxlO7 198 5. OxlO9 l.OxlO2 157 6 2.1/1.0
C31 nm) 5. OxlO7 229 5. OxlO9 1. OxlO2 106 2.5 3.6/1.0
C32 l.OxlO4 171 l.OxlO8 l.OxlO4 204 6 1.4/1.0 [OlOlJTable 2 (cont'd)
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating Discoating liquid Amount
Powder perliquid for (parts )
resissing conducfor
Powder ( resin
tive tivity time conduclayer resissolid
Amt. of core (h) tive
Type tivity (pt) y/x conpartilayer
(x) tent :
cles
(Ω · cm) 60 ms.%
(y) of the
(Ω · cm)
fol. )
Ti02
particles
coated
C33 with Ι.ΟχΙΟ4 192 Ι.ΟχΙΟ8 Ι.ΟχΙΟ4 168 4 1.9/1.0 oxygen
deficient
Sn02
(av.
prim,
par¬
C34 ticle 5.0xl07 214 5. OxlO9 Ι.ΟχΙΟ2 132 4 2.7/1.0 diam. :
250
nm)
Ti02
particles
coated
with
Sn02
doped
with
C35 1. OxlO2 176 1.0x10s 1. OxlO6 195 4 1.5/1.0
Sb
(av .
prim .
particle
diam. :
250
nm) ]Table 2 (cont'd)
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating coating liguid Amount Dis¬
Powder perliquid for (parts )
ducresissing con for
Powder (resin ve tivity time ti conduclayer resissolid
Amt. of core (h) tive
Type tivity (pt) partiy/x conlayer
(x) tent :
cles
(Ω - cm) 60 ms . %
(y) of the
(Ω ·cm)
fol. )
Ti02
particles
coated
with
un- doped
C36 Sn02 1. OxlO5 220 l.OxlO8 1. OxlO3 122 4 3.0/1.0
(av.
prim,
particle
diam. :
250
nm)
BaS04
particles
coated
with
Sn02
doped
C37 with P l.OxlO4 198 1. OxlO8 l.OxlO4 157 4 2.1/1.0
(av.
prim,
particle
diam. :
220
nm) ]Table 2 (cont'd)
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating
Amount Discoating liquid Powder perliquid for (parts )
resissing conducfor
Powder ( resin
tivity time tive conducresissolid layer e (h)
Amt. of cor tive
Type tivity (pt) y/ conpartilayer
(X) tent :
cles
(Ω · cm) 60 ms.%
(y) of the
(Ω · cm)
fol. )
C38 5.0xl05 171 5. OxlO7 1. OxlO2 204 4 1.4/1.0
C39 5. OxlO5 229 5. OxlO7 1. OxlO2 106 4 3.6/1.0
C40 5. OxlO1 171 5. OxlO7 Ι.ΟχΙΟ6 204 4 1.4/1.0
C41 5. OxlO1 229 5. OxlO7 1. OxlO6 106 4 3.6/1.0
C42 Ti02 Ι.ΟχΙΟ6 176 5. OxlO7 5.0x1ο1 195 4 1.5/1.0
C43 partiΙ.ΟχΙΟ1 176 5. OxlO7 5. OxlO6 195 4 1.5/1.0
C44 cles Ι.ΟχΙΟ6 228 5. OxlO7 5. OxlO1 109 4 3.5/1.0
C45 coated Ι.ΟχΙΟ1 228 5. OxlO7 5. OxlO6 109 4 3.5/1.0
C46 with 5. OxlO7 171 5. OxlO9 1. OxlO2 204 4 1.4/1.0
C47 Sn02 5.0xl03 171 5.0x10s l.OxlO6 204 4 1.4/1.0
C48 doped 5. OxlO3 229 5. OxlO9 l.OxlO6 106 4 3.6/1.0
C49 with P Ι.ΟχΙΟ8 176 5. OxlO9 5.0x1ο1 195 4 1.5/1.0
C50 ( a . Ι.ΟχΙΟ3 176 5. OxlO9 5. OxlO6 195 4 1.5/1.0
C51 prim, Ι.ΟχΙΟ8 228 5. OxlO9 5.0X101 109 4 3.5/1.0
C52 parΙ.ΟχΙΟ3 228 5. OxlO9 5. OxlO6 109 4 3.5/1.0
C53 ticle Ι.ΟχΙΟ5 176 Ι.ΟχΙΟ7 l.OxlO2 195 4 1.5/1.0
C54 diam. : 1.0x10s 176 Ι.ΟχΙΟ10 l.OxlO2 195 4 1.5/1.0
C55 250 1.0x10s 228 Ι.ΟχΙΟ7 l.OxlO2 109 4 3.5/1.0
C56 ran] 1.0x10s 228 Ι.ΟχΙΟ10 l.OxlO2 109 4 3.5/1.0
C57 Ι.ΟχΙΟ1 176 Ι.ΟχΙΟ7 1. OxlO6 195 4 1.5/1.0
C58 Ι.ΟχΙΟ4 176 Ι.ΟχΙΟ10 l.OxlO6 195 4 1.5/1.0
C59 Ι.ΟχΙΟ1 228 Ι.ΟχΙΟ7 l.OxlO6 109 4 3.5/1.0
C60 l.OxlO4 228 Ι.ΟχΙΟ10 1. OxlO6 109 4 3.5/1.0
]Table 2 (cont'd)
Binder
materi¬
Metal oxide particles (P) al (B)
(phenol
P/B in resin)
Coating Discoating liquid Amount
Powder perliquid for (parts )
resissing conducfor
Powder ( resin
tivity time tive conducresissolid layer (h)
Amt. of core tive
Type tivity (pt) y/x conpartilayer
(x) tent :
cles
(Ω · cm) 60 ms.%
(y) of the
(Ω · cm)
fol. )
C61 5. OxlO5 171 5. OxlO7 l.OxlO2 204 4 1.4/1.0
C62 5. OxlO5 229 5. OxlO7 l.OxlO2 106 4 3.6/1.0
C63 5.0X101 171 5. OxlO7 1. OxlO6 204 4 1.4/1.0
C64 5.0x1ο1 229 5. OxlO7 l.OxlO6 106 4 3.6/1.0
C65 Ti02 Ι . Ο χ Ι Ο6 176 5. OxlO7 5. OxlO1 195 4 1.5/1.0
C66 partiΙ . Ο χ Ι Ο1 176 5. OxlO7 5. OxlO6 195 4 1.5/1.0
C67 cles Ι . Ο χ Ι Ο6 228 5. OxlO7 5. OxlO1 109 4 3.5/1.0
C68 coated l.OxlO1 228 5. OxlO7 5. OxlO6 109 4 3.5/1.0
C69 with 5. OxlO7 171 5. OxlO9 l.OxlO2 204 4 1.4/1.0
C70 Sn02 5.0xl03 171 5. OxlO9 l.OxlO6 204 4 1.4/1.0
C71 doped 5. OxlO3 229 5. OxlO9 l.OxlO6 106 4 3.6/1.0
C72 with W l.OxlO8 176 5. OxlO9 5. OxlO1 195 4 1.5/1.0
C73 (av. l.OxlO3 176 5.0x10s 5. OxlO6 195 4 1.5/1.0
C74 prim . l.OxlO8 228 5. OxlO9 5. OxlO1 109 4 3.5/1.0
C75 parl.OxlO3 228 5. OxlO9 5. OxlO6 109 4 3.5/1.0
C76 ticle l.OxlO5 176 l.OxlO7 l.OxlO2 195 4 1.5/1.0
C77 diam. : 1. OxlO8 176 l.OxlO10 l.OxlO2 195 4 1.5/1.0
C78 250 1.OxlO5 228 l.OxlO7 l.OxlO2 109 4 3.5/1.0
C79 ran) l.OxlO8 228 l.OxlO10 l.OxlO2 109 4 3.5/1.0
C80 l.OxlO1 176 l.OxlO7 l.OxlO6 195 4 1.5/1.0
C81 l.OxlO4 176 1. OxlO10 1. OxlO6 195 4 1.5/1.0
C82 l.Ox.101 228 1.OxlO7 1.OxlO6 109 4 3.5/1.0
C83 l.OxlO4 228 1. OxlO10 1. OxlO6 109 4 3.5/1.0
[0105]- Electrophotographic Photosensitive Member Production Examples -
[0106] Production Example of
Electrophotographic Photosensitive Member 1
[0107]An aluminum cylinder (JIS A3003, aluminum alloy) of 246 mm in length and 24 mm in diameter which was produced by a production process having the step of extrusion and the step of drawing was used as a support.
[0108] he coating liquid 1 for conductive layer was dip- coated on the support in a normal-temperature and normal-humidity (23°C/50%RH) environment, and then the wet coating formed was dried and heat-cured at 140 °C for 30 minutes to form a conductive layer with a layer thickness of 30 μπι. The volume resistivity of the conductive layer was measured by the method described previously, to find that it was 5.0xl010 Ω■cm.
[0109] ext, 4.5 parts of N-methoxymethylated nylon (trade name: TORESIN EF-30T; available from Nagase ChemteX Corporation) and 1.5 parts of copolymer nylon resin (trade name: AMILAN CM8000; available from Toray
Industries, Inc.) were dissolved in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol to prepare a coating liquid for undercoat layer. This coating liquid for undercoat layer obtained was dip- coated on the conductive layer, and then the wet coating formed was dried at 70°C for 6 minutes to form an undercoat layer with a layer thickness of 0.85 μπι.
[0110] ext, 10 parts of hydroxygallium phthalocyanine
crystals (charge-generating material) with a crystal form having intense peaks at 1.5°, 9.9°, 16.3°, 18.6°, 25.1° and 28.3° of the Bragg' s angle 2Θ±0.2° in CuK characteristic X-ray diffraction, 5 parts of polyvinyl butyral resin (trade name: S-LEC BX-1; available from Sekisui Chemical Co., Ltd.) and 250 parts of
cyclohexanone were put into a sand mill making use of glass beads of 0.8 mm in diameter, and put to dispersion treatment under conditions of a dispersion treatment time of 3 hours. Next, to the resultant system, 250 parts of ethyl acetate was added to prepare a coating liquid for charge generation layer. This coating liquid for charge generation layer was dip- coated on the undercoat layer, and then the wet coating formed was dried at 100°C for 10 minutes to form a charge generation layer with a layer thickness of 0.12 μιτι.
ext, 4.0 parts of an amine compound (charge- transporting material) represented by the following formula (CT-1), 4.0 parts of an amine compound
represented by the following formula (CT-2):
Figure imgf000039_0001
and 10 parts of polycarbonate (trade name: Z200;
available from Mitsubishi Engineering-Plastics
Corporation) were dissolved in a mixed solvent of 30 parts of dimethoxymethane and 70 parts of chlorobenzene to prepare a coating liquid for charge transport layer. This coating liquid for charge transport layer was dip- coated on the charge generation layer, and then the wet coating formed was dried at 110°C for 30 minutes to form a charge transport layer with a layer thickness of 7.0 μιη.
[0112] Thus, an electrophotographic photosensitive member 1 was produced the charge transport layer of which was a surface layer.
[0113] Production Examples of
Electrophotographic Photosensitive Members 2 to 68 &
CI to C83
[ 0114 ] Electrophotographic photosensitive members 2 to 68 and CI to C83 were produced in the same manner as
Production Example of Electrophotographic
Photosensitive Member 1 except that the coating liquid for conductive layer, the coating liquid 1 for
conductive layer, used in producing the
electrophotographic photosensitive member was changed for the coating liquids 2 to 68 and CI to C83 for conductive layer, respectively. Here, in regard to the volume resistivity of the electrophotographic
photosensitive members 2 to 68 and CI to C83 each, too, it was measured like the electrophotographic
photosensitive member 1 by the method described
previously. Results obtained thereon are shown in Tables 3 and 4.
Table 3
Figure imgf000041_0001
Table 3 (cont'd)
Figure imgf000042_0001
able 4
Figure imgf000043_0001
able 4 (cont'd)
Figure imgf000044_0001
[0119] Incidentally, when the volume resistivity of the conductive layer was measured on the
electrophotographic photosensitive members 1 to 68 and CI to C83 each, the surfaces of their conductive layers were observed on an optical microscope, whereupon cracks were seen to have occurred in regard to the conductive layers of the electrophotographic
photosensitive members C13, C15, C29, C31, C39, C41, C48, C62, C64 and C71.
[0120] Examples 1 to 68 &
Comparative Examples 1 to 83
[0121] he electrophotographic photosensitive members 1 to 68 and CI to C83 were each set in a laser beam printer (trade name: HP LASERJET P1505) manufactured by
Hewlett-Packard Co., and the dark attenuation was measured in the following way in a high-temperature and high-humidity (30°C/80%RH) environment.
[0122] First, using a potential jig having a potential- measuring probe, charge potential (dark area potential) was measured while solid white images were reproduced on three sheets. On that occasion, during the
reproduction of images on three sheets, a power source of the potential-measuring probe was kept ON, in the state of which a power source of the laser beam printer was forcedly switched OFF. Charge potential Vdi immediately before the latter power source was switched OFF and charge potential ν¾ on lapse of one second after the latter power source was switched OFF were each measured to find the value of dark attenuation rate: (Vdi- Vd2) xlOO/Vdi (%). Here, it shows that, the smaller this dark attenuation rate is, the smaller the dark attenuation is. Also, this dark attenuation is herein "dark attenuation before sheet feeding
durability test".
[0123] ext, the electrophotographic photosensitive members 1 to 68 and CI to C83 were each put to a sheet feeding durability test in the same high-temperature and high- humidity environment as the above. In the sheet
feeding durability test, printing was operated in an intermittent mode in which a character image with a print percentage of 2% was sheet by sheet reproduced on letter size sheet, to reproduce images on 500 sheets.
[0124]After the image reproduction on 500 sheets was finished, each electrophotographic photosensitive member was left to stand for 10 minutes, and thereafter the dark
attenuation was again measured in the same way as the dark attenuation before sheet feeding durability test to likewise find the dark attenuation rate. The
results are shown in Tables 5 and 6.
[0125] In addition to the electrophotographic photosensitive members 1 to 68 and CI to C83 on which the sheet
feeding durability test was conducted, one more each of the electrophotographic photosensitive members 2 to 68 and CI to C83 was readied, and each of them was set in a laser beam printer (trade name: HP LASERJET P1505) manufactured by Hewlett-Packard Co., where the sheet feeding durability test was conducted in a low- temperature and low-humidity (15°C/10%RH) environment. In this sheet feeding durability test, printing was operated in an intermittent mode in which a character image with a print percentage of 2% was sheet by sheet reproduced on letter size sheet, to reproduce images on 3,000 sheets, and any potential variations were
measured .
[0126]At the start of the sheet feeding durability test and after the finish of the image reproduction on 3,000 sheets, charge potential (dark area potential) and potential at the time of exposure (light area
potential) were measured. Each potential was measured using one sheet each of solid white images and solid black images.
[0127]The dark area potential at the initial stage (at the start of the sheet feeding durability test) and the light area potential at the initial stage (at the start of the sheet feeding durability test) were represented by Vd and VI, respectively. The dark area potential after the finish of the image reproduction on 3,000 sheets and the light area potential after. the finish of the image reproduction on 3,000 sheets were represented by Vd' and VI', respectively.
Then, the value of dark area potential variation level AVd that is the difference between the dark area potential Vd' after the finish of the image
reproduction on 3,000 sheets and the dark area
potential Vd at the initial stage, AVd (= | Vd' | - | Vd | ) , and the value of light area potential variation level AVI that is the difference between the light area potential VI' after the finish of the image
reproduction on 3,000 sheets and the light area
potential VI at the initial stage, AVI (= | VI' | - | VI | ) , were each found. The results are shown in Tables 5 and 6.
able 5
Potential
ElectroDark attenuation
variation photoCracks rate (%)
level (V) graphic in
ExamAfter
photoconducple Before finish of
sensitive
running 500-sheet AVd AVI tive layer
test image
member
reprod.
1 1 No 2.5 5.5 +12 +25
2 2 No 2.6 5.6 +12 +24
3 3 No 2.0 5.0 +13 +28
4 4 No 2.4 5.4 +13 +27
5 5 No 2.4 5.4 +13 +27
6 6 No 2.5 5.5 +12 +25
7 7 No 2.6 5.6 +12 +24
8 8 No 2.6 5.6 +12 +24
9 9 No 2.2 5.2 +13 +28
10 10 No 2.4 5.4 +13 +27
11 11 No 2.4 5.4 +13 +27
12 12 No 3.8 7.8 +12 +23
13 13 No 2.0 5.0 +13 +30
14 14 No 3.0 7.0 +13 +27
15 15 No 2.2 5.2 +13 +28
16 16 No 3.4 7.4 +12 +24
17 17 No 2.9 5.9 +12 +23
18 18 No 2.7 5.7 +12 +24
19 19 No 2.4 5.4 +13 +25
20 20 No 2.2 5.2 +13 +28
21 21 No 2.0 5.0 +14 +29
22 22 No 2.7 5.7 +12 +27
23 23 No 2.4 5.4 +12 +28
24 24 No 2.0 5.0 +13 +30
25 25 No 1.9 4.9 +13 +32
26 26 No 1.9 4.9 +14 +33
27 27 No 3.8 7.9 +12 +21
28 28 No 2.2 5.3 +13 +30
29 29 No 2.8 6.3 +13 +28
30 30 No 2.9 6.4 +13 +27
31 31 No 2.3 5.8 +14 +31
32 32 No 2.7 6.2 +14 +30
33 33 No 2.7 6.2 +14 +30
34 34 No 2.8 6.3 +13 +28
35 35 No 2.9 6.4 +13 +27 able 5 (cont'd)
Potential
Electro- Dark attenuation
variation photo- . Cracks rate (%)
level (V) graphic in
ExamAfter
photoconducple Before finish of
sensitive
running 500-sheet Avd AVI tive layer
test image
member
reprod .
36 36 No 2.9 6.4 +13 +27
37 37 No 2.5 6.0 +14 +31
38 38 No 2.7 6.2 +14 +30
39 39 No 2.7 6.2 +14 +30
40 40 No 4.1 8.6 +13 +26
41 41 No 2.3 5.8 +14 +33
42 42 No 3.3 7.8 +14 +30
43 43 No 2.5 6.0 +14 +31
44 44 No 3.7 8.2 +13 +27
45 45 No 3.2 6.7 +13 +26
46 46 No 3.0 6.5 +13 +27
47 47 No 2.7 6.2 +14 +28
48 48 No 2.5 6.0 +14 +31
49 49 No 2.3 5.8 +15 +32
50 50 No 3.0 6.5 +13 +30
51 51 No 2.7 6.2 +13 +31
52 52 No 2.3 5.8 +14 +33
53 53 No 2.2 5.7 +14 +35
54 54 No 2.2 5.7 +15 +36
55 55 No 4.1 8.7 +13 +24
56 56 No 2.5 6.1 +14 +33
57 57 No 2.0 5.0 +13 +30
58 58 No 3.5 7.2 +13 +25
59 59 No 4.8 8.8 +11 +20
60 60 No 1.8 4.8 +14 +35
61 61 No 2.9 6.2 +13 +28
62 62 No 3.9 7.2 +11 +23
63 63 No 2.3 5.8 +14 +33
64 64 No 3.8 8.0 +14 +28
65 65 No 5.1 9.6 +12 +23
66 66 No 2.1 5.6 +15 +38
67 67 No 3.2 7.0 +14 +31
68 68 No 4.2 8.0 +12 +26 able 6
Potential
ElectroDark attenuation
variation
ComphotoCracks rate (%)
level (V) paragraphic in
After
tive photo¬ conduc¬
Before finish of
Examsensitive
running 500-sheet AVd AVI ple tive layer
test image
member
reprod .
1 CI No 2.4 5.4 +15 +50
2 C2 , No 7.0 10.5 +14 +27
3 C3 No 8.5 13.5 +13 +23
4 C4 No 10.0 15.0 +13 +23
5 C5 No 7.5 12.5 +14 +27
6 C6 No 3.0 6.0 +16 +51
7 C7 No 2.0 5.0 +17 +61
8 C8 No 2.0 5.0 +18 +63
9 C9 No 7.5 12.5 +13 +24
10 CIO No 8.5 13.5 +13 +24
11 Cll No 8.0 13.0 +13 +22
12 C12 No 2.0 5.0 +15 +46
13 C13 Yes 6.5 11.5 +13 +25
14 C14 No 1.9 4.9 +16 +48
15 C15 Yes 6.0 11.0 +14 +25
16 C16 No 2.0 5.0 +14 +45
17 C17 No 2.7 6.2 +16 +53
18 C18 No 7.3 11.3 +15 +30
19 C19 No 8.8 14.3 +14 +26
20 C20 No 10.3 15.8 +14 +26
21 C21 No 7.8 13.3 +15 +30
22 C22 No 3.3 6.8 +17 +54
23 C23 No 2.3 5.8 +18 +64
24 C24 No 2.3 5.8 +19 +66
25 C25 No 7.8 13.3 +14 +27
26 C26 No 8.8 14.3 +14 +27
27 C27 No 8.3 13.8 +14 +25
28 C28 No 2.3 5.8 +16 +49
29 C29 Yes 6.8 12.3 +14 +28
30 C30 No 2.2 5.7 +17 +51 able 6 (cont'd)
Potential
ElectroDark attenuation
variation
ComphotoCracks rate (%)
level (V) paragraphic in
After
tive photoconduc¬
Before finish of
Examsensitive
running 500-sheet AVd AVI ple tive layer
test image
member
reprod .
31 C31 Yes 6.3 11.8 +15 +28
32 C32 No 2.3 5.8 +15 +48
33 C33 No 6.0 11.0 +16 +35
34 C34 No 5.0 10.0 +17 +40
35 C35 No 12.0 20.0 +12 +22
36 C36 No 2.0 5.0 +20 +90
37 C37 No 5.0 10.0 +15 +45
38 C38 No 1.8 4.8 +14 +55
39 C39 Yes 9.0 12.0 +13 +25
40 C40 No 3.6 7.6 +13 +50
41 C41 Yes 10.0 14.0 +11 +20
42 C42 No 1.8 4.6 +14 +66
43 C43 No 11.0 16.0 +12 +22
44 C44 No 3.0 7.0 +15 +47
45 C45 No 13.0 18.0 +11 +20
46 C46 No 1.6. 4.6 +15 +66
47 C47 No 2.8 6.0 +13 +53
48 C48 Yes 9.0 13.0 +11 +23
49 C49 No 1.5 4.0 +15 +72
50 C50 No 7.3 12.0, +13 +28
51 C51 No 2.5 5.5 +18 +60
52 C52 No 12.0 16.5 +11 +23
53 C53 No 6.5 10.2 +13 +29
54 C54 No 1.6 4.6 +17 +71
55 C55 No 8.5 11.0 +13 +25
56 C56 No 2.5 5.5 +17 +58
57 C57 No 10.5 15.5 +12 +22
58 C58 No 2.6 5.8 +15 +58
59 C58 No 11.5 16.0 +11 +20
60 C60 No 3.7 7.0 +13 +48 able 6 (cont'd)
Potential
ElectroDark attenuation
variation
ComphotoCracks rate (%)
level (V) paragraphic in
After
tive photo¬ conduc¬
Before finish of
Examsensitive
running 500-sheet AVd AVI ple tive layer
test image
member
reprod .
61 C61 No 2.1 5.6 +15 +58
62 C62 Yes 9.3 12.8 +14 +28
63 C63 No 3.9 8.4 +14 +53
64 C64 Yes 10.3 14.8 +12 +23
65 C65 No 2.1 5.4 +15 +69
66 C66 No 11.3 16.8 +13 +25
67 C67 No 3.3 7.8 +16 +50
68 C68 No 13.3 18.8 +12 +23
69 C69 No 1.9 5.4 +16 +69
70 C70 No 3.1 6.8 +14 +56
71 C71 Yes 9.3 13.8 +12 +26
72 C72 No 1.8 4.8 +16 +75
73 C73 No 7.6 12.8 +14 +31
74 C74 No 2.8 6.3 +19 +63
75 C75 No 12.3 17.3 +12 +26
76 C76 No 6.8 11.0 +14 +32
77 C77 No 1.9 5.4 +18 +74
78 C78 No 8.8 11.8 +14 +28
79 C79 No 2.8 6.3 +18 +60
80 C80 No 10.8 16.3 +13 +25
81 C81 No 2.9 6.6 +16 +61
82 C82 No 11.8 16.8 +12 +23
83 C83 No 4.0 7.8 +14 +51
[ 0134 ] Production Example of
Electrophotographic Photosensitive Member 69
[0135] he procedure of Production Example of
Electrophotographic Photosensitive Member 1 was
repeated to form the conductive layer, the undercoat layer and the charge generation layer on the support in this order.
[0136] Next, 5.6 parts of the amine compound (charge- transporting material) represented by the formula (CT- 1) and 2.4 parts of the amine compound represented by the formula (CT-2) , 10 parts of polycarbonate (trade name: Z200; available from Mitsubishi Engineering- Plastics Corporation) and 0.36 part of a siloxane modified polycarbonate having a repeating structural unit represented by the following formula (B-1) and a repeating structural unit represented by the following formula (B-2) and having a terminal structure unit represented by the following formula (B-3) [(B-1): (B-2) = 95:5 (molar ratio)]
Figure imgf000053_0001
were dissolved in a mixed solvent of 60 parts of o- xylene, 40 parts of dimethoxymethane and 2.7 parts of methyl benzoate to prepare a coating liquid for charge transport layer. This coating liquid for charge transport layer was dip-coated on the charge generation layer, and then the wet coating formed was dried at 120°C for 30 minutes to form a charge transport layer with a layer thickness of 7.0 m.
[0137] Thus, an electrophotographic photosensitive member 69 was produced the charge transport layer of which was a surface layer .
[0138] Example 69
[0139]About the electrophotographic photosensitive member 69, measurement was made in the same way as Examples 1 to 68 and Comparative Examples 1 to 83 to find the value of dark attenuation rate before the sheet feeding durability test and that after the finish of the image reproduction on 500 sheets.
[0140]As the result, the dark attenuation rate before the
sheet feeding durability test was 2.5%, and the dark attenuation rate after the finish of the image
reproduction on 500 sheets was 5.5%. The dark area potential variation level AVd was +12 V, and the light area potential variation level AVI was +25 V.
[0141]While the present invention has been described with
reference to exemplary embodiments, it is to be
understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the . following claims is to be accorded the broadest
interpretation so as to encompass all such
modifications and equivalent structures and functions.
[0142] This application claims the benefit of Japanese Patent Application No. 2011-046518, filed March 3, 2011,
Japanese Patent Application No. 2011-215135, filed September 29, 2011 and Japanese Patent Application No. 2012-039026, filed February 24, 2012 which are hereby incorporated by reference herein in their entirety.

Claims

[1] A process for producing an electrophotographic
photosensitive member; the process comprising:
the step of forming on a support a conductive layer having a volume resistivity of from 1.0*108 Ω -cm or more to 5.0χ1012 Ω-cm or less, and
the step of forming a photosensitive layer on the conductive layer,
wherein;
the step of forming the conductive layer comprises: the step of preparing a coating liquid for the. conductive layer by use of a- solvent, a binder material and a metal oxide particle, and
the step of forming the conductive layer by use of the coating liquid for the conductive layer;
the metal oxide particle (P) and the binder material (B) in the coating liquid for the conductive layer are in a mass ratio (P/B) of from 1.5/1.0 to 3.5/1.0;
the metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus or a titanium oxide particle coated with tin oxide doped with tungsten; and
where powder resistivity of the metal oxide particle is represented by x (Ω -cm) and powder resistivity of the titanium oxide particle as a core particle constituting the metal oxide particle is represented by y (Ω -cm) , the y and the x satisfy the following relations (i) and (ii) :
5.0*107 < y < 5.0xl09 (i)
Ι.ΟχΙΟ2 < y/x < 1.0x10s (ii) .
[2] The process for producing an electrophotographic
photosensitive member according to claim 1, wherein the metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus.
[3] The process for producing an electrophotographic
photosensitive member according to claim 1, wherein the metal oxide particle is a titanium oxide particle coated with tin oxide doped with tungsten.
The process for producing an electrophotographic photosensitive member according to any one of claims to 3, wherein the y and the x satisfy the following relation (iii) :
l.OxlO3 < y/x < l.OxlO5 (iii).
PCT/JP2012/055885 2011-03-03 2012-03-01 Process for producing electrophotographic photosensitive member Ceased WO2012118229A1 (en)

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Families Citing this family (37)

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Publication number Priority date Publication date Assignee Title
JP4743921B1 (en) 2009-09-04 2011-08-10 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06208238A (en) 1992-11-06 1994-07-26 Canon Inc Electrophotographic receptor and electrophotographic device using the same
JPH06207118A (en) * 1993-01-12 1994-07-26 Titan Kogyo Kk White conductive titanium dioxide powder and its production
JPH06222600A (en) 1992-12-01 1994-08-12 Canon Inc Electrophotographic photoreceptor and electrophotographic apparatus using the electrophotographic photoreceptor
JPH10186702A (en) * 1996-12-26 1998-07-14 Canon Inc Electrophotographic photoreceptor, process cartridge and electrophotographic apparatus
JP2003316059A (en) 2002-04-19 2003-11-06 Canon Inc Electrophotographic photosensitive member, process cartridge having electrophotographic photosensitive member, and electrophotographic apparatus
WO2005008685A1 (en) * 2003-07-23 2005-01-27 Ishihara Sangyo Kaisha, Ltd. Electroconductive powder and method for production thereof
JP2007047736A (en) 2005-03-28 2007-02-22 Canon Inc Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus, and method for manufacturing electrophotographic photosensitive member

Family Cites Families (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5422210A (en) 1991-03-18 1995-06-06 Canon Kabushiki Kaisha Electrophotographic photosensitive member and electrophotographic apparatus, device unit and facsimile machine using the same
US5385797A (en) 1991-09-24 1995-01-31 Canon Kabushiki Kaisha Electrophotographic photosensitive member, and electrophotographic apparatus, device unit, and facsimile machine employing the same
US5357320A (en) 1992-09-04 1994-10-18 Canon Kabushiki Kaisha Electrophotographic apparatus
ES2106940T3 (en) 1992-11-06 1997-11-16 Canon Kk ELECTROPHOTOGRAPHIC PHOTOSENSITIVE ELEMENT AND ELECTROPHOTOGRAPHIC APPARATUS USING THE SAME.
EP0609511B1 (en) 1992-12-01 1998-03-11 Canon Kabushiki Kaisha Electrophotographic photosensitive member and electrophotographic apparatus employing the same
US5455135A (en) 1992-12-18 1995-10-03 Canon Kabushiki Kaisha Electrophotographic photosensitive member with overlayer and electrophotographic apparatus employing same
JP3667024B2 (en) 1996-03-08 2005-07-06 キヤノン株式会社 Electrophotographic photoreceptor
US6156472A (en) 1997-11-06 2000-12-05 Canon Kabushiki Kaisha Method of manufacturing electrophotographic photosensitive member
US6773856B2 (en) 2001-11-09 2004-08-10 Canon Kabushiki Kaisha Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
JP4712288B2 (en) 2003-05-23 2011-06-29 チタン工業株式会社 White conductive powder and its application
JP2005062846A (en) 2003-07-31 2005-03-10 Canon Inc Electrophotographic photoreceptor
US7245851B2 (en) 2003-11-26 2007-07-17 Canon Kabushiki Kaisha Electrophotographic apparatus
US7276318B2 (en) 2003-11-26 2007-10-02 Canon Kabushiki Kaisha Electrophotographic photosensitive member, and electrophotographic apparatus and process cartridge which make use of the same
CN100559290C (en) * 2005-03-28 2009-11-11 佳能株式会社 Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus, and method for producing an electrophotographic photosensitive member
EP1870774B1 (en) 2005-04-08 2012-07-18 Canon Kabushiki Kaisha Electrophotographic apparatus
WO2007066790A2 (en) 2005-12-07 2007-06-14 Canon Kabushiki Kaisha Polyvinyl acetal resin, electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
JP2008052105A (en) * 2006-08-25 2008-03-06 Kyocera Mita Corp Electrophotographic photoreceptor and image forming apparatus
JP4041921B1 (en) * 2007-01-26 2008-02-06 キヤノン株式会社 Electrophotographic photoreceptor manufacturing method
KR20080076604A (en) * 2007-02-16 2008-08-20 삼성전자주식회사 An electrophotographic photosensitive member having excellent electrical characteristics, image quality, and high stability thereof, and an electrophotographic image forming apparatus using the same
JP4840271B2 (en) * 2007-07-02 2011-12-21 富士ゼロックス株式会社 Image forming apparatus
EP2221671B1 (en) 2007-12-04 2013-11-20 Canon Kabushiki Kaisha Electrophotographic photoreceptor, process for producing electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus
JP4743921B1 (en) 2009-09-04 2011-08-10 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
JP4956654B2 (en) 2009-09-04 2012-06-20 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member
CN103109236B (en) 2010-09-14 2015-03-25 佳能株式会社 Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member
JP4948670B2 (en) 2010-10-14 2012-06-06 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member
JP5036901B1 (en) 2010-10-29 2012-09-26 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member
JP4959022B2 (en) 2010-10-29 2012-06-20 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
JP4959024B1 (en) 2010-12-02 2012-06-20 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member
JP5079153B1 (en) 2011-03-03 2012-11-21 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus, and method for manufacturing electrophotographic photosensitive member
JP5755162B2 (en) 2011-03-03 2015-07-29 キヤノン株式会社 Method for producing electrophotographic photosensitive member
JP5089816B2 (en) 2011-04-12 2012-12-05 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member
JP5089815B2 (en) 2011-04-12 2012-12-05 キヤノン株式会社 Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member
CN103529663B (en) 2012-06-29 2016-04-20 佳能株式会社 Electrophotographic photosensitive element, handle box and electronic photographing device
US9029054B2 (en) 2012-06-29 2015-05-12 Canon Kabushiki Kaisha Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
CN103529662B (en) 2012-06-29 2016-05-18 佳能株式会社 Electrophotographic photosensitive element, handle box and electronic photographing device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06208238A (en) 1992-11-06 1994-07-26 Canon Inc Electrophotographic receptor and electrophotographic device using the same
JPH06222600A (en) 1992-12-01 1994-08-12 Canon Inc Electrophotographic photoreceptor and electrophotographic apparatus using the electrophotographic photoreceptor
JPH06207118A (en) * 1993-01-12 1994-07-26 Titan Kogyo Kk White conductive titanium dioxide powder and its production
JPH10186702A (en) * 1996-12-26 1998-07-14 Canon Inc Electrophotographic photoreceptor, process cartridge and electrophotographic apparatus
JP2003316059A (en) 2002-04-19 2003-11-06 Canon Inc Electrophotographic photosensitive member, process cartridge having electrophotographic photosensitive member, and electrophotographic apparatus
WO2005008685A1 (en) * 2003-07-23 2005-01-27 Ishihara Sangyo Kaisha, Ltd. Electroconductive powder and method for production thereof
JP2007047736A (en) 2005-03-28 2007-02-22 Canon Inc Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus, and method for manufacturing electrophotographic photosensitive member

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2681627A4 *

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