JP2009058635A - Charging member, process cartridge, and electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging member in which a film itself hardly becomes uneven, toner, an external additive for use in the toner, and so forth hardly adhere on the surface even after repeated use for a long period of time, and the charging and image output can be performed stably for a long period of time, and to provide a process cartridge and an electrophotographic apparatus including the same. <P>SOLUTION: The surface layer includes polylsiloxane including a first unit expressed by SiO<SB>0.5</SB>R<SP>1</SP>(OR<SP>2</SP>)(OR<SP>3</SP>), a second unit expressed by SiO<SB>1.0</SB>R<SP>4</SP>(OR<SP>5</SP>), and a third unit expressed by SiO<SB>1.5</SB>R<SP>6</SP>and silicone oil. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  At present, a contact charging method has been put into practical use as one of methods for charging the surface of an electrophotographic photosensitive member.

  In the contact charging method, a voltage is applied to a charging member disposed in contact with the electrophotographic photosensitive member, and a slight discharge is caused in the vicinity of a contact portion between the charging member and the electrophotographic photosensitive member, thereby causing the electron In this method, the surface of the photographic photosensitive member is charged.

  As a charging member for charging the surface of the electrophotographic photosensitive member, from the viewpoint of sufficiently securing a contact nip between the electrophotographic photosensitive member and the charging member, a supporting member and an elastic layer provided on the supporting member ( A material having a conductive elastic layer) is generally used.

  Further, since the elastic layer (conductive elastic layer) often contains a relatively large amount of low molecular weight component, the low molecular weight component may bleed out and contaminate the surface of the electrophotographic photosensitive member. In order to suppress this contamination, a surface layer having a smaller elastic modulus than the conductive elastic layer is often provided on the conductive elastic layer.

  In addition, the shape of the charging member is generally a roller shape. Hereinafter, the roller-shaped charging member is also referred to as a “charging roller”.

  In addition, a widely used method among contact charging methods is a method in which a voltage obtained by superimposing an AC voltage on a DC voltage is applied to a charging member (hereinafter also referred to as “AC + DC contact charging method”). In the case of the AC + DC contact charging method, a voltage having a peak-to-peak voltage that is twice or more the charging start voltage is used as the AC voltage.

  The AC + DC contact charging system is a system that can perform stable charging with high charging uniformity by using an AC voltage. However, since the AC voltage source is used, the charging device and the electrophotographic apparatus are increased in size and cost compared to a method in which only a DC voltage is applied to the charging member (hereinafter also referred to as “DC contact charging method”). Will be invited.

  That is, the DC contact charging method is superior to the AC + DC contact charging method in terms of downsizing and cost reduction of the charging device and the electrophotographic apparatus.

  Patent Document 1 discloses that a non-reactive silicone oil having a molecular weight of 30000 or less is contained in a resin layer containing a fluororesin in an amount of 0.05 to 30 parts by weight with respect to 100 parts by weight of the fluororesin. A member is disclosed. By using this charging member, it is difficult to be in close contact with the photosensitive member, the friction can be reduced, and contamination of the surface of the member to be charged can be significantly reduced. Further, by using the charging member in a contact-type charging device, a good image can be obtained over a long period of time.

  Patent Document 2 discloses a charging member in which a coating layer of a charging member is formed from a urethane-modified acrylic resin containing a non-reactive silicone oil having a molecular weight of 30000 or less. By using this charging member, it is difficult to be in close contact with the member to be charged, the friction with the member to be charged can be reduced, and the contamination of the surface of the member to be charged can be remarkably reduced as described above. Further, by using the charging member in a contact-type charging device, a good image can be obtained over a long period of time.

Patent Document 3 discloses a low hardness conductive roll using a reactive silicone oil (B component) together with a silicone graft acrylic polymer (A component) as a resin composition forming the outermost layer of the low hardness conductive roll. ing. In this low hardness conductive roll, reactive silicone oil (B component) can be introduced between the silicone graft acrylic polymers (A component) to produce rubber elasticity, and the outermost layer can be made flexible. As a result, the roll rotation torque is reduced and no rubbing noise caused by stick-slip is generated, the image quality is improved and the scratches on the roll surface during durability can be suppressed, resulting in excellent toner filming resistance. The provided low hardness electroconductive roll can be obtained.
JP 2002-214883 A Japanese Patent Laid-Open No. 2002-214876 Japanese Patent No. 3608396

  However, since the DC contact charging method does not have an effect of improving the charging uniformity due to the AC voltage, the surface of the charging member is contaminated (toner, external additive used for the toner, etc.) and the electric resistance of the charging member itself is not uniform. Tends to appear in the output image.

  In addition, if a fluororesin, urethane-modified acrylic resin, silicone graft acrylic polymer or the like is used as the surface layer binder of the charging member, it is incompatible with the silicone oil to be added. It is easy to form (sea-island structure). Therefore, it becomes easy to become spotted unevenness along with solvent volatilization during drying at the time of forming the surface layer. In addition, during subsequent use, there will be parts that adhere to or difficult to adhere to the toner and external additives used in the toner, and in particular, the part that adheres grows during durability, resulting in image defects. May end up.

  In particular, in the case of the DC contact charging method, it may occur remarkably when a halftone image is output under a high temperature and high humidity (30 ° C./80% RH) environment.

An object of the present invention is to provide a charging member having the following characteristics, and a process cartridge and an electrophotographic apparatus having the charging member.
(1) Even if silicone oil is added, it is compatible with polysiloxane, which is a binder, so that the film itself is less likely to become uneven, and toners and external additives that are used in toners even after repeated use over a long period of time Is hard to stick to the surface.
(2) When the silicone oil is added, the effect of increasing the photoreceptor surface potential by -1.5 V to -4.0 V enables stable charging and image output for a long period of time even when used in the DC contact charging method.

The present invention is a charging member having a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, the surface layer comprising SiO _0.5 A polysiloxane having a first unit represented by R ¹ (OR ² ) (OR ³ ), a second unit represented by SiO _1.0 R ⁴ (OR ⁵ ), and a third unit represented by SiO _1.5 R ⁶ ; And a charging member containing silicone oil.
(The above R ¹ , R ⁴ and R ⁶ each independently represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group or oxyalkylene group. The above R ² , R ³ and R ⁵ represent And each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group.)
The present invention also provides a process cartridge and an electrophotographic apparatus having the above charging member.

According to the present invention, it is possible to provide a charging member having the following characteristics, and a process cartridge and an electrophotographic apparatus having the charging member.
(1) Even if silicone oil is added, it is compatible with polysiloxane, which is a binder, so that the film itself is less likely to become uneven, and toners and external additives that are used in toners even after repeated use over a long period of time Is hard to stick to the surface.
(2) When the silicone oil is added, the effect of increasing the photoreceptor surface potential by -1.5 V to -4.0 V enables stable charging and image output for a long period of time even when used in the DC contact charging method.

  The charging member of the present invention has a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer.

  The simplest configuration of the charging member of the present invention is a configuration in which two layers of a conductive elastic layer and a surface layer are provided on a support, but between the support and the conductive elastic layer or between the conductive elastic layer and One or more other layers may be provided between the surface layer and the surface layer.

  FIG. 1 shows an example of the configuration of the charging member of the present invention. In FIG. 1, 101 is a support, 102 is a conductive elastic layer, and 103 is a surface layer.

  The charging member support may be conductive (conductive support), for example, metallic (made of alloy) formed of iron, copper, stainless steel, aluminum, aluminum alloy, or nickel. A support can be used. In addition, for the purpose of imparting scratch resistance to these surfaces, surface treatment such as plating treatment may be performed within a range not impairing conductivity.

  As the conductive elastic layer, one type or two or more types of elastic bodies such as rubber and thermoplastic elastomer used in the conventional elastic layer (conductive elastic layer) of the charging member can be used.

  Examples of the rubber include the following. Urethane rubber, silicone rubber, butadiene rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, ethylene-propylene rubber, polynorbornene rubber, styrene-butadiene-styrene rubber, acrylonitrile rubber, epichlorohydrin rubber and alkyl ether rubber.

  Examples of the thermoplastic elastomer include styrene elastomers and olefin elastomers. As a commercial item of a styrene-type elastomer, the brand name "Lavalon" by Mitsubishi Chemical Corporation, the brand name "Septon Compound" by Kuraray Co., Ltd., etc. are mentioned, for example. Commercially available olefin elastomers include, for example, trade name “Thermo Run” manufactured by Mitsubishi Chemical Co., Ltd., trade name “Milastomer” manufactured by Mitsui Petrochemical Co., Ltd., trade name “Sumitomo Chemical Co., Ltd.” "Sumitomo TPE", trade name "Santplane" manufactured by Advanced Elastomer Systems, etc.

Moreover, the electroconductivity can be set to a predetermined value by appropriately using a conductive agent in the conductive elastic layer. The electrical resistance of the conductive elastic layer can be adjusted by appropriately selecting the type and amount of the conductive agent, and the preferred range of the electrical resistance is 10 ² Ω or more and 10 ⁸ Ω or less, more preferable. The range is from 10 ³ Ω to 10 ⁶ Ω.

  Examples of the conductive agent used in the conductive elastic layer include a cationic surfactant, an anionic surfactant, an amphoteric surfactant, an antistatic agent, and an electrolyte.

  Examples of the cationic surfactant include the following. Quaternary ammonium salts such as lauryltrimethylammonium, stearyltrimethylammonium, octadodecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium and modified fatty acid dimethylethylammonium. Examples of the quaternary ammonium salt include perchlorate, chlorate, borofluoride, ethosulphate and halogenated benzyl salts (such as benzyl bromide and benzyl chloride).

  Examples of the anionic surfactant include aliphatic sulfonate, higher alcohol sulfate ester salt, higher alcohol ethylene oxide addition sulfate ester salt, higher alcohol phosphate ester salt and higher alcohol ethylene oxide addition phosphate ester salt.

  Examples of the antistatic agent include nonionic antistatic agents such as higher alcohol ethylene oxide, polyethylene glycol fatty acid ester and polyhydric alcohol fatty acid ester.

Examples of the electrolyte include salts (such as quaternary ammonium salts) of metals (Li, Na, K, etc.) belonging to Group 1 of the periodic table. Specific examples of the metal salt of Group 1 of the periodic table include LiCF ₃ SO ₃ , NaClO ₄ , LiAsF ₆ , LiBF ₄ , NaSCN, KSCN, and NaCl.

In addition, as a conductive agent for the conductive elastic layer, a salt of a Group 2 metal (Ca, Ba, etc.) (Ca (ClO ₄ ) ₂ etc.) or an antistatic agent derived therefrom can be used. . Further, an ion conductive conductive agent such as a complex of these with a polyhydric alcohol or a derivative thereof or a complex of these with a monool can also be used. Examples of the polyhydric alcohol include 1,4-butanediol, ethylene glycol, polyethylene glycol, propylene glycol, and polyethylene glycol. Examples of monools include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether.

  In addition, as a conductive agent for the conductive elastic layer, conductive carbon such as ketjen black EC, acetylene black, carbon for rubber, carbon for color (ink) subjected to oxidation treatment, and pyrolytic carbon should be used. You can also. The following are mentioned as carbon for rubber | gum. Super Abrasion Furnace (SAF: Super Abrasion Resistance), Intermediate Super Abrasion Furnace (ISAF: Semi Super Abrasion Resistance), High Abrasion Furnace (HAF: High Abrasion Resistance), Fast Extrusion Purchase Furnace (GPF: general purpose), Semi Rein Forcing Furnace (SRF: medium reinforcement), Fine Thermal (FT: fine particle thermal decomposition) and Medium Thermal (MT: medium particle thermal decomposition).

  Also, graphite such as natural graphite and artificial graphite can be used as a conductive agent for the conductive elastic layer.

  In addition, as a conductive agent for the conductive elastic layer, metal oxides such as tin oxide, titanium oxide and zinc oxide, and metals such as nickel, copper, silver and germanium can be used.

  In addition, conductive polymers such as polyaniline, polypyrrole, and polyacetylene can be used as the conductive agent for the conductive elastic layer.

  In addition, an inorganic or organic filler or a crosslinking agent may be added to the conductive elastic layer. Examples of the filler include silica (white carbon), calcium carbonate, magnesium carbonate, clay, talc, zeolite, alumina, barium sulfate, and aluminum sulfate. Examples of the crosslinking agent include sulfur, peroxide, crosslinking aid, crosslinking accelerator, crosslinking promotion aid, and crosslinking retarder.

  The hardness of the conductive elastic layer is preferably 70 degrees or more with Asker C from the viewpoint of suppressing the deformation of the charging member when the charging member and the electrophotographic photosensitive member as the member to be charged are brought into contact with each other. In particular, it is more preferably 73 degrees or more.

  Moreover, it is preferable to use a so-called crown shape in which the thickness of the central portion is larger than the thickness of the end portion.

  From the viewpoint of sufficiently exerting the function of the conductive elastic layer provided for sufficiently securing the contact nip with the electrophotographic photosensitive member, the elastic modulus of the surface layer of the charging member is preferably 2000 MPa or less. On the other hand, in general, the crosslinking density tends to decrease as the elastic modulus of the layer decreases, so from the viewpoint of suppressing contamination of the surface of the electrophotographic photoreceptor due to the low molecular weight component bleed out on the surface of the charging member, The elastic modulus of the surface layer of the charging member is preferably 100 MPa or more.

  In addition, the thicker the surface layer, the greater the effect of suppressing the bleed out of the low molecular weight component, but the charging ability of the charging member is reduced. Therefore, specifically in the present invention, the thickness of the surface layer is preferably 0.01 μm or more and 1.00 μm or less, and more preferably 0.04 μm or more and 0.60 μm or less. When the layer thickness is in the above range, the solvent to be used is quickly volatilized, so that there is an effect that it is very difficult to cause unevenness after film formation. Furthermore, phase separation during drying is unlikely to occur in a mixture in an incompatible state that causes normal thick film formation.

  To confirm the thickness of the surface layer, the surface portion of the charging member is shaved with a razor, applied to liquid nitrogen and broken, and then the cross section is about 20000 times with a scanning electron microscope (SEM) (manufactured by JEOL Ltd.). The magnification was confirmed.

  Further, from the viewpoint of suppressing adhesion of toner and external additives to the surface of the charging member, the surface roughness (Rz) of the surface of the charging member (= surface of the surface layer) is preferably 10 μm or less, more preferably 7 μm or less in JIS94. Preferably, 5 μm or less is even more preferable.

  Next, the material constituting the surface layer that is the outermost layer of the charging member of the present invention will be described.

The surface layer of the charging member is represented by a first unit represented by SiO _0.5 R ¹ (OR ² ) (OR ³ ), a second unit represented by SiO _1.0 R ⁴ (OR ⁵ ), and SiO _1.5 R ^6. A polysiloxane having a third unit and silicone oil are contained.

R ¹ , R ⁴ and R ⁶ each independently represent a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group or oxyalkylene group. R ² , R ³ and R ⁵ each independently represent a hydrogen atom or a substituted or unsubstituted alkyl group.

  Here, the use of a polysiloxane skeleton as the binder has a good affinity with silicone oil and is easily dissolved uniformly.

The above “first unit represented by SiO _0.5 R ¹ (OR ² ) (OR ³ )” means a range A1 surrounded by a square of polysiloxane as shown in the following formula (i). To do. In the range A1, oxygen atoms other than OR ² and OR ³ (O of Si—O—Si) are bonded to two silicon atoms, and therefore, an oxygen atom bonded per silicon atom The number of (Si—O—Si O) is considered to be 0.5.

The “second unit represented by SiO _1.0 R ⁴ (OR ⁵ )” is the same as the “ ^first unit represented by SiO _0.5 R ¹ (OR ² ) (OR ³ )”, and specifically, The range A2 surrounded by a square of polysiloxane as shown in the following formula (ii) is meant.

The above “third unit represented by SiO _1.5 R ⁶ ” is also the same as “ ^first unit represented by SiO _0.5 R ¹ (OR ² ) (OR ³ )”. It means a range A3 surrounded by a square of polysiloxane as shown in iii).

  When the number of moles of the first unit in the polysiloxane is x [mol], the number of moles of the second unit is y [mol], and the number of moles of the third unit is z [mol], It is preferable that 0.60 ≦ {(x + y) / (x + y + z)} ≦ 0.80. If {(x + y) / (x + y + z)} <0.60, the electrical characteristics of the surface layer necessary for good image formation during continuous paper feeding may be insufficient. In addition, when 0.80 <{(x + y) / (x + y + z)}, the amount of silanol groups and alkoxide groups is excessively large, and therefore mechanical strength may be reduced due to moisture absorption in a high humidity environment. Increases sex. Therefore, the range of 0.60 ≦ {(x + y) / (x + y + z)} ≦ 0.80 is preferable, and the range of 0.62 ≦ {(x + y) / (x + y + z)} ≦ 0.78 is further satisfied. Is more preferable.

  Here, measurement of x, y, and z was performed by solid-state Si-NMR (manufactured by CMX-300 Chemicals). The measurement sample was produced as follows. First, a polysiloxane condensate was applied onto a Teflon (registered trademark) sheet using a spin coater (trade name: 1H-D7 type, manufactured by Mikasa Co., Ltd.) at a rotation speed of 300 rpm and a rotation time of 2 seconds. Subsequently, ultraviolet rays were appropriately irradiated, and the obtained film-like film was pulverized to obtain a measurement sample. The measurement conditions are as follows.

The resulting data was subjected to an exponential window and subjected to Fourier transform to obtain a spectrum. The trapezoidal windows were T1: 0, T2: 0, T3: 10, T4: 15, and the broadening factor was 50 Hz. Data processing was performed using Spinsight which is an application attached to the apparatus and Grams manufactured by Galactic. As observed spectra, there are three peaks in the vicinity of −49 ppm, −57 ppm, and −66 ppm, and RSi (OR ′) ₂ (OSi≡), RSi (OR ′) (OSi≡) ₂ , RSi (OSi≡) Attributed to ₃ . Where R is an alkyl, epoxy or fluorinated alkyl chain. OR ′ is OH or an alkoxy group. Further, when a phenyl group-containing silane compound is used, there are peaks in the vicinity of −63 ppm, −71 ppm, and −78 ppm, and PhSi (OR ′) ₂ (OSi≡) and PhSi (OR ′) (OSi≡) _{2 respectively.} , PhSi (OSi≡) ₃ . Waveform separation of the obtained spectrum was performed, the area ratio of each peak was calculated, and the abundance ratio was estimated.

  The polysiloxane is obtained by condensing a hydrolyzable silane compound having a cationic polymerizable group by hydrolysis to obtain a hydrolyzable condensate, and then cleaving the cationic polymerizable group. It can be obtained by crosslinking the condensate.

  As the hydrolyzable silane compound having a group capable of cationic polymerization, a hydrolyzable silane compound having a structure represented by the following formula (2) is preferable.

In the above formula (2), R ²¹ represents a saturated or unsaturated monovalent hydrocarbon group. R ²² represents a saturated or unsaturated monovalent hydrocarbon group. Z ²¹ represents a divalent organic group. Rc ²¹ represents a group capable of cationic polymerization. d is an integer from 0 to 2, e is an integer from 1 to 3, and d + e = 3.

The cationically polymerizable group Rc ²¹ in the formula (2), means a cationic polymerizable organic group which forms an oxyalkylene group by cleavage, for example, cyclic ether groups such as an epoxy group and an oxetane group, and And vinyl ether groups. Among these, an epoxy group is preferable from the viewpoint of availability and reaction control.

Examples of the saturated or unsaturated monovalent hydrocarbon group of R ²¹ and R ^{22 in} the above formula (2) include an alkyl group, an alkenyl group, and an aryl group. Among these, a linear or branched alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group and an ethyl group are more preferable.

Examples of the divalent organic group of Z ^{21 in} the above formula (2) include an alkylene group and an arylene group. Among these, an alkylene group having 1 to 6 carbon atoms is preferable, and an ethylene group is more preferable.

  E in the above formula (2) is preferably 3.

When d in the above formula (2) is 2, two R ²¹ may be the same or different.

When e in the above formula (2) is 2 or 3, two or three R ²² may be the same or different.

Specific examples of the hydrolyzable silane compound having the structure represented by the above formula (2) are shown below.
(2-1): Glycidoxypropyltrimethoxysilane (2-2): Glycidoxypropyltriethoxysilane (2-3): Epoxycyclohexylethyltrimethoxysilane (2-4): Epoxycyclohexylethyltriethoxysilane In producing the polysiloxane used in the charging member of the present invention, as described above, a hydrolyzable silane compound having a cationically polymerizable group is condensed by hydrolysis to obtain a hydrolyzable condensate. In particular, from the viewpoint of controlling the surface properties of the charging member, when obtaining a hydrolyzable condensate, in addition to the hydrolyzable silane compound having a group capable of cationic polymerization, it is further represented by the following formula (1). It is preferable to use a hydrolyzable silane compound having a structure in combination.

In the above formula (1), R ¹¹ represents a phenyl group-substituted alkyl group or an unsubstituted alkyl group, or an alkyl group-substituted aryl group or an unsubstituted aryl group. R ¹² represents a saturated or unsaturated monovalent hydrocarbon group. a is an integer of 0 or more and 3 or less, b is an integer of 1 or more and 4 or less, and a + b = 4.

As the alkyl group in the phenyl group-substituted alkyl group or unsubstituted alkyl group represented by R ¹¹ in the formula (1), a linear alkyl group having 1 to 21 carbon atoms is preferable.

The aryl group in the alkyl group-substituted aryl group or unsubstituted aryl group of R ^{11 in} the above formula (1) is preferably a phenyl group.

  In the above formula (1), a is preferably an integer of 1 or more and 3 or less, more preferably 1.

  B in the above formula (1) is preferably an integer of 1 or more and 3 or less, more preferably 3.

Examples of the saturated or unsaturated monovalent hydrocarbon group for R ^{12 in} the above formula (1) include an alkyl group, an alkenyl group, and an aryl group. Among these, a linear or branched alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group, an ethyl group, and an n-propyl group are more preferable.

When a in formula (1) is 2 or 3, two or three R ¹¹ may be the same or different.

When b in the above formula (1) is 2, 3 or 4, 2, 3 or 4 R ¹² may be the same or different.

Specific examples of the hydrolyzable silane compound having the structure represented by the above formula (1) are shown below.
(1-1): Tetramethoxysilane (1-2): Tetraethoxysilane (1-3): Tetrapropoxysilane (1-4): Methyltrimethoxysilane (1-5): Methyltriethoxysilane (1- 6): methyltripropoxysilane (1-7): ethyltrimethoxysilane (1-8): ethyltriethoxysilane (1-9): ethyltripropoxysilane (1-10): propyltrimethoxysilane (1- 11): propyltriethoxysilane (1-12): propyltripropoxysilane (1-13): hexyltrimethoxysilane (1-14): hexyltriethoxysilane (1-15): hexyltripropoxysilane (1- 16): Decyltrimethoxysilane (1-17): Decyltriethoxysilane (1-18): Decyltripro Xylsilane (1-19): Phenyltrimethoxysilane (1-20): Phenyltriethoxysilane (1-21): Phenyltripropoxysilane (1-22): Diphenyldimethoxysilane (1-23): Diphenyldiethoxysilane In the case of using a hydrolyzable silane compound having a structure represented by the above formula (1), a in the above formula (1) is preferably an integer of 1 to 3, and b is an integer of 1 to 3. It is preferable that Also, one R ¹¹ out of a R ¹¹ is preferably a linear alkyl group having 1 to 21 carbon atoms.

Only 1 type of hydrolysable silane compound which has a structure shown by the said Formula (1) may be used, and may be used 2 or more types. When using 2 or more types, it is preferable to use together that whose R < ¹¹ > in said Formula (1) is an alkyl group, and whose R < ¹¹ > in said Formula (1) is a phenyl group.

  Using a hydrolyzable silane compound containing a fluorinated alkyl group as the hydrolyzable silane compound having a structure other than the structure represented by the above formula (1) or (2) improves surface releasability. Preferred above. As the hydrolyzable silane compound containing a fluorinated alkyl group, an alkoxysilane having a structure represented by the following general formula (3) is preferably used in consideration of ease as a starting material.

In the above formula (1), p = 0, 1 or 2, q = 1, 2 or 3 and p + q = 3, and n is an integer of 0 or more and 30 or less. Z ₃₁ is a divalent organic group (for example, an alkylene group having 1 to 6 carbon atoms), and R ³² and R ³³ are each independently a saturated or unsaturated hydrocarbon group (for example, having 1 to 3 carbon atoms). 3 linear or branched alkyl groups and the like.

  In particular, in the general formula (3), a compound in which n is 5 or more is preferable from the viewpoint of processability.

Specific examples of the compounds (3-1) to (3-6) in the category of the above formula (3) are shown below, but of course the present invention is not limited to the following compounds.
(3-1): CF ₃ —C ₂ H ₄ —Si (OR) ₃
(3-2): CF ₃ —CF ₂ —C ₂ H ₄ —Si (OR) ₃
(3-3): CF ₃ — (CF ₂ ) ₃ —C ₂ H ₄ —Si (OR) ₃
(3-4): CF ₃ — (CF ₂ ) ₅ —C ₂ H ₄ —Si (OR) ₃
(3-5): CF ₃ — (CF ₂ ) ₇ —C ₂ H ₄ —Si (OR) ₃
(3-6): CF ₃ — (CF ₂ ) ₉ —C ₂ H ₄ —Si (OR) ₃
Here, R represents a methyl group or an ethyl group.

  Depending on the type and amount of addition of silicone oil, when the charging bias is constant as shown in FIG. 4, for example, when the photosensitive member potential is set to −400 V (corresponding to a halftone image), it is more sensitive than the non-added product. It has the effect of increasing the body surface potential by −1.5 to −4.0V. For this reason, there is an effect that it is possible to cover the influence that the toner and the external additive of the toner adhere and the potential decreases.

  The silicone oil is preferably a polyether-modified silicone oil or a phenol-modified silicone oil represented by the following general formula (S1).

  In the above formula, R is a substituted or unsubstituted monovalent hydrocarbon group, and specific examples include an alkyl group having 1 to 30 carbon atoms, an alkenyl group, an aryl group, and an arylalkyl group. Among these, a methyl group is representative. A or B is a phenol group-containing organic group or a polyoxyalkylene group-containing organic group, at least one of which is represented by the following formula (S2) or (S3).

(R ¹ is a divalent hydrocarbon group, R ² is a monovalent hydrocarbon group or an alkoxy group, R ³ is the same or different divalent hydrocarbon group having 1 to 4 carbon atoms. R ⁴ is a hydrogen atom, a monovalent hydrocarbon group or an acyl group, a is an integer of 0 or more and 4 or less, b is 0 or 1, and c is an integer of 1 or more and 100 or less. )
In addition, as said phenol group containing organic group, group represented by a following formula (S4) or (S5) is preferable.

m is 0 or more and 500 or less, y is 0 or more and 50 or less, and x + y is 5 or more and 500 or less.

  The addition amount of the silicone oil in the surface layer is preferably 0.5% by mass or more and 3.0% by mass or less with respect to 100% by mass of the polysiloxane. If it is less than 0.5 mass%, as shown in FIG. 4, the effect of improving the potential by adding silicone oil is small. On the other hand, if it is larger than 3.0% by mass, the photosensitive member is contaminated, and image defects are liable to occur.

  The weight average molecular weight of the silicone oil is preferably 300 or more and 5000 or less. If it is smaller than 300, the potential stabilizing effect is small, and if it is larger than 5000, the affinity with the coating liquid for surface coating tends to be low, and there is a tendency to become clouded, which tends to cause unevenness during coating. More preferably, it is 500 or more and 4000 or less.

  For measurement of the weight average molecular weight of silicone oil, HLC-8120GPC (trade name, manufactured by Tosoh Corporation) was used as a GPC apparatus. The column used was a guard column (TSK guardcolumn SuperH-L), TSKgel SuperH4000, TSKgel SuperH3000, TSKgel SuperH2000, and TSKgel SuperH1000. As the eluent, toluene for high performance liquid chromatography was used, and the temperature was set to INLET 40 ° C., OVEN 40 ° C., and RI 40 ° C. The detector was RI. Polystyrene (EasiCal PS-2) was used for the calibration curve.

  Specific examples of the silicone oil include polyether-modified silicone oils and phenol-modified silicone oils manufactured by Toray Dow Corning Silicone Co., Ltd., Shin-Etsu Chemical Co., Ltd., and GE Toshiba Silicone Co., Ltd.

  Hereinafter, a specific method for forming the surface layer in the charging member of the present invention will be described.

  First, a hydrolyzable condensate is obtained by hydrolyzing a hydrolyzable silane compound having a cationically polymerizable group and, if necessary, the other hydrolyzable silane compound in the presence of water.

  During the hydrolysis reaction, a hydrolyzable condensate having a desired degree of condensation can be obtained by controlling temperature, pH and the like.

  In the hydrolysis reaction, the degree of condensation may be controlled by using a metal alkoxide or the like as a catalyst for the hydrolysis reaction. Examples of the metal alkoxide include aluminum alkoxide, titanium alkoxide and zirconia alkoxide, and complexes thereof (acetylacetone complex and the like).

  Moreover, when the hydrolyzable condensate is obtained, the blending ratio of the hydrolyzable silane compound represented by the above formulas (1), (2) and (3) is such that a polysiloxane having a desired composition can be obtained. Can be adjusted appropriately. The content of aryl groups in the resulting polysiloxane is 5% by mass to 30% by mass, the content of alkylene ether groups is 5% by mass to 70% by mass, and the content of fluorinated alkyl groups is 5% by mass to 50% by mass. It is preferable that The content of the siloxane moiety is preferably 20% by mass to 85% by mass.

  Moreover, when using together the hydrolysable silane compound which has a structure shown by said Formula (1), it is preferable to satisfy | fill the following conditions. That is, the molar ratio (MC: M1) between the hydrolyzable silane compound (MC) having a group capable of cationic polymerization and the hydrolyzable silane compound (M1) having the structure represented by the above formula (1) is 10: 1. It is preferable to mix | blend so that it may become the range of 1:10.

  Next, silicone oil is added to the obtained hydrolyzable condensate to prepare a coating solution for the surface layer, and a member having a support and a conductive elastic layer formed on the support (hereinafter referred to as “conductive”). It is also referred to as an “elastic member.”) The prepared coating solution for the surface layer is applied thereon.

  The step of adding silicone oil separately from the step of condensing the silane compound by hydrolysis is that when silicone oil is added and synthesized, white turbidity is likely to occur, depending on the type or amount of silicone oil being synthesized. This is because of lack of stabilization. Moreover, it is because the film structure after ultraviolet curing may not satisfy 0.60 ≦ {(x + y) / (x + y + z)} ≦ 0.80.

  When preparing the coating solution for the surface layer, an appropriate solvent may be used in addition to the hydrolyzable condensate in order to improve the coating property. Suitable solvents include, for example, alcohols such as ethanol and 2-butanol, ethyl acetate, methyl ethyl ketone, or a mixture thereof. Moreover, when applying the surface layer coating liquid onto the conductive elastic member, coating using a roll coater, dip coating, ring coating, or the like can be employed.

  Next, the surface layer coating liquid applied on the conductive elastic member is irradiated with an active energy ray. Then, the cationically polymerizable group in the hydrolyzable condensate contained in the coating solution for the surface layer is cleaved, whereby the hydrolyzable condensate can be crosslinked. The hydrolyzable condensate is cured by crosslinking.

  As the active energy ray, ultraviolet rays are preferable.

  By curing the surface layer with ultraviolet rays, it is difficult for extra heat to be generated, and phase separation during volatilization of the solvent such as thermosetting hardly occurs, and a very uniform film state can be obtained. For this reason, uniform and potential stability to the photosensitive member can be obtained.

  When the conductive elastic layer of the conductive elastic member expands due to the heat generated during the ultraviolet irradiation and then contracts due to cooling, if the surface layer does not sufficiently follow this expansion / contraction, the surface layer has many wrinkles and cracks. It may become. However, when ultraviolet rays are used for the crosslinking reaction, the hydrolyzable condensate can be crosslinked in a short time (within 15 minutes), and heat generation is small, so that wrinkles and cracks on the surface layer are hardly generated.

  Also, when the charging member is placed in an environment where the temperature and humidity change is abrupt, the surface layer will not wrinkle or wrinkle unless the surface layer sufficiently follows the expansion and contraction of the conductive elastic layer due to the change in temperature and humidity. Cracks may occur. However, if the cross-linking reaction is performed by ultraviolet rays with less heat generation, the adhesion between the conductive elastic layer and the surface layer increases, and the surface layer can sufficiently follow the expansion / contraction of the conductive elastic layer. Wrinkles and cracks in the surface layer due to changes in environmental temperature and humidity can also be suppressed.

  In addition, if the crosslinking reaction is performed using ultraviolet rays, it is possible to suppress deterioration of the conductive elastic layer due to thermal history, and thus it is possible to suppress a decrease in electrical characteristics of the conductive elastic layer.

  For irradiation with ultraviolet rays, a high pressure mercury lamp, a metal halide lamp, a low pressure mercury lamp, an excimer UV lamp, or the like can be used. Among these, an ultraviolet ray source rich in light having an ultraviolet wavelength of 150 nm to 480 nm is used. .

  The integrated light quantity of ultraviolet rays is defined as follows.

UV integrated light quantity [mJ / cm ² ] = UV intensity [mW / cm ² ] × irradiation time [s]
The adjustment of the accumulated amount of ultraviolet light can be performed by the irradiation time, lamp output, distance between the lamp and the irradiated object, and the like. Moreover, you may give a gradient to integrated light quantity within irradiation time.

  In the case of using a low-pressure mercury lamp, the integrated light amount of ultraviolet rays can be measured using an ultraviolet integrated light amount meter UIT-150-A or UVD-S254 (both trade names) manufactured by USHIO INC. Moreover, when using an excimer UV lamp, the integrated light quantity of ultraviolet rays can be measured using an ultraviolet integrated light quantity meter UIT-150-A or VUV-S172 (both trade names) manufactured by Ushio Electric Co., Ltd.

  In the crosslinking reaction, it is preferable that a cationic polymerization catalyst (polymerization initiator) is allowed to coexist from the viewpoint of improving the crosslinking efficiency. For example, since an epoxy group exhibits high reactivity with respect to an onium salt of a Lewis acid activated by an active energy ray, the above cationic polymerizable group is an epoxy group. It is preferable to use an onium salt of an acid.

  Examples of other cationic polymerization catalysts include borate salts, compounds having an imide structure, compounds having a triazine structure, azo compounds, and peroxides.

  Among various cationic polymerization catalysts, aromatic sulfonium salts and aromatic iodonium salts are preferable from the viewpoints of sensitivity, stability, and reactivity. In particular, a bis (4-tert-butylphenyl) iodonium salt, a compound having a structure represented by the following formula (trade name: Adekaoptomer SP-150, manufactured by Asahi Denka Kogyo Co., Ltd.),

A compound having a structure represented by the following formula (trade name: Irgacure 261, manufactured by Ciba Specialty Chemicals)

Is preferred.

In the present invention, the volume resistivity of the surface layer of the charging member is preferably 10 ¹⁰ Ω · cm or more and 10 ¹⁶ Ω · cm or less. If the volume resistivity is too small, the electrical characteristics of the surface layer necessary for good image formation may be insufficient when used repeatedly. On the other hand, if the volume resistivity is too large, it takes too much time for discharge (a slight discharge in the vicinity of the contact portion between the electrophotographic photosensitive member and the charging member) and the image output speed is high. In some cases, the photoreceptor cannot be sufficiently charged.

  In the present invention, the volume resistivity of the surface layer means a value obtained by measurement as follows.

First, the coating solution for the surface layer used when forming the surface layer of the charging member to be measured is spin coated (trade name: 1H-D7 type, manufactured by Mikasa Co., Ltd.) on an aluminum sheet (thickness: 100 μm). Was applied at a rotation speed of 300 rpm and a rotation time of 2 seconds. In addition, as a surface layer coating solution here, the one before addition of silicone oil is used. This is cured and dried on the aluminum sheet under the same conditions as those for forming the surface layer of the charging member to be measured (irradiation with an ultraviolet ray having a wavelength of 254 nm so that the integrated light amount is 9000 mJ / cm ² ). A layer was formed. In addition, the coating amount at the time of apply | coating the surface layer coating liquid on an aluminum sheet was adjusted so that the layer thickness of the layer (layer after hardening and drying) formed on an aluminum sheet might be 10 micrometers.

  The aluminum sheet having the layer formed thereon was cut into a 4 cm × 4 cm square shape, and gold deposition was performed on the layer side surface of the sample piece.

  In a high-temperature and high-humidity environment (H / H: 40 ° C. × 95% RH), this gold-deposited sample piece was incorporated into a resistance measurement system having the configuration shown in FIG. 2, and resistance was measured under the condition of an applied DC voltage of 10V. . The resistance obtained by the measurement was converted from the sample area and thickness to the volume resistivity to obtain the volume resistivity of the surface layer of the charging member to be measured. In FIG. 2, 14 is a resistance measuring device (trade name: 4140B PA METER / DC VOLTAG SOURCE, manufactured by HEWLETT PACKARD), 15 is a contact electrode terminal, and 16 is a flat plate electrode.

  FIG. 3 shows an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the charging member of the present invention.

  In FIG. 3, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member, which is driven to rotate at a predetermined peripheral speed in the direction of the arrow about the shaft 2. As an electrophotographic photosensitive member, those having a support and an inorganic photosensitive layer or an organic photosensitive layer formed on the support are generally used. In addition, the electrophotographic photosensitive member may have a charge injection layer as a surface layer.

  The surface of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by the charging member 3 (roller-shaped charging member in FIG. 3) of the present invention. Next, by receiving exposure light (image exposure light) 4 output from an exposure means (not shown) such as slit exposure or laser beam scanning exposure, the surface of the electrophotographic photoreceptor 1 is subjected to static corresponding to the target image. Electro-latent images are sequentially formed.

  When the surface of the electrophotographic photosensitive member 1 is charged by the charging member 3, a voltage of only a DC voltage or a voltage obtained by superimposing an AC voltage on the DC voltage is applied to the charging member 3 from a voltage applying unit (not shown). In the examples described later, a voltage (−1000 V) of only DC voltage was applied to the charging member. In the examples described later, the dark portion potential was −470 V and the light portion potential was −125 V.

  The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed (reversal development or normal development) with toner contained in the developer of the developing unit 5 to become a toner image. Next, the toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred onto a transfer material (such as paper) P by a transfer bias from a transfer unit (such as a transfer roller) 6. The transfer material P is taken out from the transfer material supply means (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 (contact portion) in synchronization with the rotation of the electrophotographic photoreceptor 1 and fed. Is done.

  Examples of the developing means include a jumping developing means, a contact developing means, and a magnetic brush means. From the viewpoint of improving toner scattering properties, a contact developing means is preferable. Adopted.

  Moreover, as a transfer roller, what coat | covers the elastic resin layer adjusted to medium resistance on a support body is illustrated.

  The transfer material P that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member 1 and introduced into the fixing means 8 to receive the image fixing, and is printed out as an image formed product (print, copy). Is done. In the case of the double-sided image forming mode or the multiple image forming mode, this image formed product is introduced into a recirculation conveyance mechanism (not shown) and reintroduced into the transfer unit.

  The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by receiving a developer (toner) remaining after transfer by a cleaning means (cleaning blade or the like) 7. Further, after being subjected to charge removal processing by pre-exposure light (not shown) from pre-exposure means (not shown), it is repeatedly used for image formation. When the charging unit is a contact charging unit, pre-exposure is not always necessary.

  Among the above-described components such as the electrophotographic photosensitive member 1, the charging member 3, the developing unit 5, the transfer unit 6 and the cleaning unit 7, a plurality of components may be housed in a container and integrally combined as a process cartridge. it can. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. In FIG. 3, the electrophotographic photosensitive member 1, the charging member 3, the developing means 5 and the cleaning means 7 are integrally supported to form a cartridge, and the electrophotographic apparatus main body is mounted on the electrophotographic apparatus main body using the guide means 10 such as a rail of the electrophotographic apparatus main body. The process cartridge 9 is detachable.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the examples, “part” means “part by mass”.

(Example 1)
-Medium-high nitrile NBR 100 parts [Product name: Nipol DN219, bound acrylonitrile content median value 33.5%, Mooney viscosity median value 27, manufactured by Nippon Zeon Co., Ltd.]
Color Carbon black (filler) 48 parts [trade name: # 7360SB, particle size 28nm, specific surface area by nitrogen adsorption 77m ² / g, DBP absorption amount 87100cm ³ / 100g, Tokai Carbon Co., Ltd.]
・ 20 parts of calcium carbonate (filler) [trade name: Nanox # 30, manufactured by Maruo Calcium Co., Ltd.]
-5 parts of zinc oxide-1 part of stearic acid The above ingredients were mixed in a 6 L pressure kneader (product name: TD6-15MDX, manufactured by Toshin Co., Ltd.) for 24 minutes at a filling rate of 70 vol% and a blade rotation speed of 30 rpm. An unvulcanized rubber composition was obtained. Tetrabenzylthiuram disulfide [trade name: Sunseller TBZTD, manufactured by Sanshin Chemical Industry Co., Ltd.] 4.5 parts as a vulcanizing agent with respect to 174 parts by mass of this unvulcanized rubber composition 1.2 parts of sulfur was added. Then, with an open roll having a roll diameter of 12 inches, the left and right turn-over was performed 20 times in total with a front roll rotation speed of 8 rpm, a rear roll rotation speed of 10 rpm, and a roll gap of 2 mm. Thereafter, the roll gap was set to 0.5 mm, and thinning was performed 10 times to obtain a kneaded material I for the conductive elastic layer.

  Next, a cylindrical steel support (having a surface plated with nickel) having a diameter of 6 mm and a length of 252 mm was prepared. A thermosetting adhesive (trade name: METALOC U) containing metal and rubber in a region up to 115.5 mm on both sides across the center of the cylindrical surface in the axial direction (a region having an axial width of 231 mm). -20, manufactured by Toyo Chemical Laboratory Co., Ltd.). This was dried at a temperature of 80 ° C. for 30 minutes, and further dried at a temperature of 120 ° C. for 1 hour.

  The kneaded product I was extruded simultaneously into a cylindrical shape having an outer diameter of 8.85 mm coaxially around the core metal with an adhesive layer by extrusion molding using a cross head, and the end portion was cut to obtain the outer periphery of the core metal. The electroconductive elastic roller-1 which laminated | stacked the unvulcanized electroconductive elastic layer on this was produced. The extruder used was an extruder having a cylinder diameter of 70 mm (Φ70) and L / D = 20. The temperature during extrusion was 90 ° C., 90 ° C. cylinder, and 90 ° C. screw.

  Next, both ends of the conductive elastic layer portion (rubber portion) of the conductive elastic roller-1 before surface polishing were cut, and the axial width of the conductive elastic layer portion was set to 232 mm. Thereafter, the surface of the conductive elastic layer portion was polished with a rotating grindstone (work rotation speed 333 rpm, grindstone rotation speed 2080 rpm, polishing time 12 sec). In this way, a conductive elastic roller (surface polishing) having a crown shape with an end diameter of 8.26 mm and a center diameter of 8.50 mm, a surface ten-point average roughness (Rz) of 4.3 μm, and a runout of 15 μm. Later conductive elastic roller) -1 was obtained.

  Ten-point average roughness (Rz) was measured according to JISB6101.

  The shake was measured using a high-precision laser measuring machine LSM-430v (trade name) manufactured by Mitutoyo Corporation. Specifically, the outer diameter is measured using the measuring device, and the difference between the maximum outer diameter value and the minimum outer diameter value is defined as the outer diameter difference run. This measurement is performed at five points, and the average of the five outer diameter difference shakes is measured. The value was the runout of the object to be measured.

  The hardness of the obtained conductive elastic roller (conductive elastic roller after surface polishing) -1 was 73 degrees (Asker C). In the present invention, the Asker C hardness is measured in a measurement environment of 25 ° C. × 55% RH by bringing a pusher of an Asker C-type hardness meter (manufactured by Kobunshi Keiki Co., Ltd.) into contact with the surface to be measured. It was performed under the condition of weighting.

Next, as a surface layer treating agent, the following components were mixed in a 300 ml eggplant flask, stirred at room temperature for 30 minutes, and then heated and refluxed on an oil bath set at 120 ° C. for 20 hours. A hydrolyzable silane compound condensate I (solid content 28 wt%) was obtained.
・ Glycidoxypropyltriethoxysilane (GPTES) (hydrolyzable silane compound)
[Product name: KBE-403, manufactured by Shin-Etsu Chemical Co., Ltd.]
12.47 g (0.045 mol)
・ Phenyltriethoxysilane (PhTES) (hydrolyzable silane compound)
[Product name: KBE-103, manufactured by Shin-Etsu Chemical Co., Ltd.]
43.08 g (0.179 mol)
・ Hexyltrimethoxysilane (HeTMS) (hydrolyzable silane compound)
[Product name: KBM-3063, manufactured by Shin-Etsu Chemical Co., Ltd.]
13.18 g (0.064 mol)
Tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FTS-5, n = 5) (hydrolyzable silane compound)
[Product Name: SIT8175.0, Gelest, Inc. Made]
16.32 g (0.032 mol)
・ Water 25.93g
・ Ethanol 72.54g
Next, the above-described measurement sample was prepared using a 25 wt% mixed product of 10 g of 2-butanol / 65 g of ethanol added to 25 g of the above condensate, and the solid content was 7 wt%. x + y) / (x + y + z) was measured. The volume resistance was 1.5 × 10 ¹⁴ Ω · cm, (x + y) / (x + y + z) = 0.75.

  Next, a 5.0 wt% diluted product obtained by adding 1.5 g of polyether-modified silicone oil-1 [trade name: SF8427, manufactured by Toray Dow Corning Silicone Co., Ltd., weight average molecular weight Mw = 412] to 28.5 g of MEK— 1 was prepared. To 25 g of the above-mentioned condensate I (solid content 28 wt%), a mixed solvent of 2-butanol 10 g / ethanol 65 g (solid content 7 wt%) was added, and 1.0 g of diluted product-1 was added (100 parts by mass of polysiloxane). (0.71 part by mass of silicone oil). Furthermore, 2 g of an aromatic sulfonium salt [trade name: Adekaoptomer SP-150, manufactured by Asahi Denka Kogyo Co., Ltd.] as a photocationic polymerization initiator diluted to 10 wt% with methyl isobutyl ketone (MIBK) was added. . Furthermore, it diluted with ethanol so that solid content might be 1 wt%, and the coating liquid 1 for surface layers was prepared.

Next, the surface layer coating liquid-1 is applied on the conductive elastic layer of the conductive elastic roller (conductive elastic roller after surface polishing) -1 by ring application (discharge amount: 0.020 ml / s, Speed: 85 mm / s, total discharge amount: 0.065 ml). The surface layer was formed by irradiating ultraviolet rays having a wavelength of 254 nm so that the integrated light amount was 9000 mJ / cm ² , and curing (drying by a crosslinking reaction) and drying the surface layer coating solution-1. A low-pressure mercury lamp manufactured by Harrison Toshiba Lighting Co., Ltd. was used for ultraviolet irradiation.

  It is considered that the glycidoxy group of glycidoxypropyltriethoxysilane was cleaved by the irradiation of ultraviolet rays, and the crosslinking reaction of the surface layer coating solution-1 occurred.

  The charging roller produced as described above is designated as charging roller-I.

・ Evaluation of charging roller ・ Evaluation 1
The appearance state of the surface of the charging roller-I after coating was visually determined as follows. The evaluation results are shown in Table 2.
A: When there is no unevenness on the surface of the charging roller.
B: When some unevenness or streaks occur on the surface of the end of the charging roller.
C: When unevenness or streaks occur in the entire area of the surface of the charging roller.

・ Evaluation 2
The following output image evaluation was performed using the charging roller-I produced in the same manner as described above.

  The produced charging roller-I and the electrophotographic photosensitive member were assembled in a process cartridge that integrally supports them, and this process cartridge was mounted on a laser beam printer for A4 paper longitudinal output. The developing method of this laser beam printer (trade name: HP Color LaserJet 3600) is a reversal developing method, the output speed of the transfer material is 94 mm / s, and the image resolution is 600 dpi.

  The electrophotographic photosensitive member incorporated in the process cartridge together with the charging roller-I is an organic electrophotographic photosensitive member formed by forming an organic photosensitive layer having a layer thickness of 13.0 μm on a support. The organic photosensitive layer is a laminated photosensitive layer formed by laminating a charge generation layer and a charge transport layer containing a modified polycarbonate (binder resin) from the support side. The charge transport layer is an electrophotographic photoreceptor. It is a surface layer.

  The toner used in the laser beam printer is a so-called polymerized toner having a glass transition temperature of 63 ° C. and a volume average particle diameter of 6 μm. This polymerized toner is obtained by adding silica fine particles and titanium oxide fine particles to particles obtained by suspension polymerization of a polymerizable monomer system containing a wax, a charge control agent, a dye, styrene, butyl acrylate and an ester monomer in an aqueous medium. Including toner particles added externally.

  Image output is performed in a high-temperature and high-humidity environment (30 ° C / 80% RH), an E-character pattern with a printing rate of 1% is formed on A4 paper, and an intermittent output mode in which idle rotation is performed for 4 seconds every two sheets. Output. Image output in the intermittent output mode is more strict with respect to the evaluation of contamination on the surface of the charging member because the number of times of sliding between the charging member and the photosensitive member is increased even with the same number of sheets passing compared to continuous sheet passing. It is evaluation. 4000 sheets were output at a process speed of 94 mm / s.

  The output image was evaluated by visually observing the output image every 1000 sheets. The evaluation results are shown in Table 2.

The evaluation criteria are as follows.
AA: Unevenness in charging due to toner or external additive sticking to the surface of the charging roller cannot be confirmed on the output image.
A: Unevenness in coating due to unevenness during coating and toner or external additive adhering to streaks on the surface of the charging roller can hardly be confirmed on the output image.
B: Unevenness during coating and uneven charging due to adhesion of toner or external additive to streaks on the surface of the charging roller can be confirmed on the output image.
C: Unevenness during coating and uneven charging due to adhesion of toner and external additive to streaks on the surface of the charging roller can be confirmed on the output image, and the degree of the uneven charging is large. Specifically, it is possible to confirm white vertical stripe-shaped charging unevenness.

(Example 2)
About the electroconductive elastic roller, what was used in Example 1 was used.

  As the surface layer treating agent, the hydrolyzable silane compound condensate I used in Example 1 was used. Then, the surface layer coating solution-2 was prepared in the same manner as in Example 1 except that the addition amount of the diluted product-1 was 4.0 g (silicone oil 2.86 parts by mass with respect to 100 parts by mass of the polysiloxane). Obtained.

  Then, the surface layer was formed by the method similar to Example 1, and charging roller-II was produced. The charging roller-II was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

(Example 3)
About the electroconductive elastic roller, what was used in Example 1 was used.

  As the surface layer treating agent, the hydrolyzable silane compound condensate I used in Example 1 was used. On the other hand, 5.0 wt% dilution of polyether modified silicone oil-2 [trade name: FZ-2118, manufactured by Toray Dow Dow Corning Silicone Co., Ltd., weight average molecular weight Mw = 2065] added to 28.5 g of MEK. Article-2 was prepared. Then, a mixed solvent of 2-butanol 10 g / ethanol 65 g was added to 25 g of condensate I (solid content 28 wt%) (solid content 7 wt%), and 2.0 g of diluted product-2 was added (100 parts by mass of polysiloxane). (1.43 parts by mass of silicone oil). Thereafter, surface layer coating solution-3 was obtained in the same manner as in Example 1.

  Then, the surface layer was formed by the method similar to Example 1, and the charging roller-III was produced. Evaluation similar to Example 1 was performed on the charging roller-III. The evaluation results are shown in Table 2.

Example 4
About the electroconductive elastic roller, what was used in Example 1 was used.

  As the surface layer treating agent, the hydrolyzable silane compound condensate I used in Example 1 was used. On the other hand, 5.0 wt% dilution of polyether modified silicone oil-3 [trade name: FZ-77, manufactured by Toray Dow Dow Corning Silicone Co., Ltd., weight average molecular weight Mw = 2332] added to 28.5 g of MEK. Article 3 was prepared. Then, a mixed solvent of 2-butanol 10 g / ethanol 65 g was added to 25 g of the condensate I (solid content 28 wt%) (solid content 7 wt%), and 2.0 g of the diluted product-3 was added (100 parts by mass of polysiloxane). (1.43 parts by mass with respect to silicone oil). Thereafter, surface layer coating solution-4 was obtained in the same manner as in Example 1.

  Then, the surface layer was formed by the method similar to Example 1, and charging roller-IV was produced. The charging roller-IV was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

(Example 5)
About the electroconductive elastic roller, what was used in Example 1 was used.

Next, as a surface layer treatment agent, the following components were mixed in a 300 ml eggplant flask, stirred at room temperature for 30 minutes, and then heated and refluxed on an oil bath set at 120 ° C. for 24 hours. A hydrolyzable silane compound condensate II (solid content 28 wt%) was obtained.
・ Glycidoxypropyltriethoxysilane (GPTES) (hydrolyzable silane compound)
[Product name: KBE-403, manufactured by Shin-Etsu Chemical Co., Ltd.]
27.62 g (0.099 mol)
・ Phenyltriethoxysilane (PhTES) (hydrolyzable silane compound)
[Product name: KBE-103, manufactured by Shin-Etsu Chemical Co., Ltd.]
47.70 g (0.198 mol)
Tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FTS-5, n = 5) (hydrolyzable silane compound)
[Product Name: SIT8175.0, Gelest, Inc. Made]
11.42 g (0.022 mol)
・ Water 25.93g
・ Ethanol 69.88g
Next, the above-described measurement sample was prepared using 25 g of the above condensate II and a mixed solvent of 10 g of 2-butanol / 65 g of ethanol added to a solid content of 7 wt%, and resistance measurement and solid Si-NMR ( x + y) / (x + y + z) was measured. The volume resistance was 5.7 × 10 ¹³ Ω · cm, (x + y) / (x + y + z) = 0.61.

  Next, 5.0 wt% diluted product-4 in which 1.5 g of polyether-modified silicone oil-4 [trade name: TSF4452, manufactured by GE Toshiba Silicones Co., Ltd., weight average molecular weight Mw = 9500] was added to 28.5 g of MEK. Prepared. A mixed solvent of 10 g of 2-butanol / 65 g of ethanol was added to 25 g of the above-mentioned condensate II (solid content: 28 wt%) (solid content: 7 wt%), and 2.0 g of diluted product-4 was added (to 100 parts by mass of polysiloxane). (1.43 parts by mass of silicone oil). Thereafter, a surface layer coating solution-5 was obtained in the same manner as in Example 1.

  Then, the surface layer was formed by the method similar to Example 1, and the charging roller-V was produced. Evaluation similar to Example 1 was performed on the charging roller-V. The evaluation results are shown in Table 2.

(Example 6)
About the electroconductive elastic roller, what was used in Example 1 was used.

  As a treating agent for the surface layer, the hydrolyzable silane compound condensate II used in Example 5 was used. On the other hand, a 5 wt% diluted product obtained by adding 1.5 g of polyether-modified silicone oil-5 [trade name: SILWET-7280, manufactured by GE Toshiba Silicone Co., Ltd., weight average molecular weight Mw = 340] to 28.5 g of MEK-5 Was prepared. Then, a mixed solvent of 2-butanol 10 g / ethanol 65 g was added to 25 g of condensate II (solid content 28 wt%) (solid content 7 wt%), and 2.0 g of diluted product-5 was added (to 100 parts by mass of polysiloxane). (1.43 parts by mass of silicone oil). Thereafter, a surface layer coating solution-6 was obtained in the same manner as in Example 1.

  Then, the surface layer was formed by the method similar to Example 1, and the charging roller-VI was produced. Evaluation similar to Example 1 was performed about the charging roller-VI. The evaluation results are shown in Table 2.

(Example 7)
About the electroconductive elastic roller, what was used in Example 1 was used.

  As a treating agent for the surface layer, the hydrolyzable silane compound condensate II used in Example 5 was used. On the other hand, a 5.0 wt% diluted product obtained by adding 1.5 g of phenol-modified silicone oil-6 [trade name: BY16-799, manufactured by Toray Dow Dow Corning Silicone Co., Ltd., weight average molecular weight Mw = 3150] to MEK 28.5 g. -6 was prepared. Then, a mixed solvent of 2-butanol 10 g / ethanol 65 g was added to 25 g of condensate II (solid content 28 wt%) (solid content 7 wt%), and 2.0 g of diluted product-6 was added (to 100 parts by mass of polysiloxane). (1.43 parts by mass of silicone oil). Thereafter, a surface layer coating solution-7 was obtained in the same manner as in Example 1.

  Then, the surface layer was formed by the method similar to Example 1, and the charging roller-VII was produced. The charging roller-VII was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

(Example 8)
About the electroconductive elastic roller, what was used in Example 1 was used.

Next, as a surface layer treatment agent, the following components were mixed in a 300 ml eggplant flask, stirred at room temperature for 30 minutes, and then heated and refluxed on an oil bath set at 120 ° C. for 24 hours. A condensate III (solid content 28 wt%) of a hydrolyzable silane compound was obtained.
・ Glycidoxypropyltriethoxysilane (GPTES) (hydrolyzable silane compound)
[Product name: KBE-403, manufactured by Shin-Etsu Chemical Co., Ltd.]
27.62 g (0.099 mol)
・ Methyltriethoxysilane (MTES) (hydrolyzable silane compound)
[Product name: KBE-13, manufactured by Shin-Etsu Chemical Co., Ltd.]
35.37 g (0.198 mol)
Tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FTS-5, n = 5) (hydrolyzable silane compound)
[Product Name: SIT8175.0, Gelest, Inc. Made]
11.42 g (0.022 mol)
・ Water 25.93g
・ Ethanol 41.82g
Next, the above-described measurement sample was prepared using 25 g of the above condensate III and a mixed solvent of 10 g of 2-butanol / 65 g of ethanol added to a solid content of 7 wt%, and resistance measurement and solid Si-NMR ( x + y) / (x + y + z) was measured. The volume resistance was 1.2 × 10 ¹⁰ Ω · cm, (x + y) / (x + y + z) = 0.52.

  A surface layer coating solution-8 was obtained in the same manner as in Example 2 except that this condensate III was used (2.86 parts by mass of silicone oil with respect to 100 parts by mass of polysiloxane).

  Then, the surface layer was formed by the method similar to Example 1, and the charging roller-VIII was produced. The charging roller-VIII was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 9
About the electroconductive elastic roller, what was used in Example 1 was used.

Next, as a surface layer treatment agent, the following components were mixed in a 300 ml eggplant flask, stirred at room temperature for 30 minutes, and then heated and refluxed on an oil bath set at 120 ° C. for 24 hours. A hydrolyzable silane compound condensate IV (solid content 28 wt%) was obtained.
・ Glycidoxypropyltriethoxysilane (GPTES) (hydrolyzable silane compound)
[Product name: KBE-403, manufactured by Shin-Etsu Chemical Co., Ltd.]
17.82 g (0.064 mol)
・ Methyltriethoxysilane (MTES) (hydrolyzable silane compound)
[Product name: KBE-13, manufactured by Shin-Etsu Chemical Co., Ltd.]
5.71 g (0.032 mol)
・ Phenyltriethoxysilane (PhTES) (hydrolyzable silane compound)
[Product name: KBE-103, manufactured by Shin-Etsu Chemical Co., Ltd.]
53.85 g (0.224 mol)
・ Water 25.93g
・ Ethanol 48.09g
Next, the above-described measurement sample was prepared using 25 g of the above condensate IV and a mixed solvent of 10 g of 2-butanol / 65 g of ethanol to make the solid content 7 wt%, and resistance measurement and solid Si-NMR ( x + y) / (x + y + z) was measured. The volume resistance was 4.3 × 10 ¹⁵ Ω · cm, (x + y) / (x + y + z) = 0.85.

  A surface layer coating solution-9 was prepared in the same manner as in Example 2 except that this condensate IV was used (2.86 parts by mass of silicone oil with respect to 100 parts by mass of polysiloxane).

  Thereafter, a surface layer was formed in the same manner as in Example 1 to prepare a charging roller-IX. The charging roller-IX was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

(Comparative Example 1)
About the electroconductive elastic roller, what was used in Example 1 was used.

  As the surface layer treating agent, the hydrolyzable silane compound condensate I used in Example 1 was used. And the coating liquid -10 for surface layers was prepared by the method similar to Example 1 except having added the diluted product-1 (0 mass part of silicone oil with respect to 100 mass parts of polysiloxane).

  Then, the surface layer was formed by the method similar to Example 1, and the charging roller-X was produced. The charging roller-X was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

(Comparative Example 2)
About the electroconductive elastic roller, what was used in Example 1 was used.

  Next, a fluororesin [trade name: LF200, manufactured by Asahi Glass Co., Ltd.] (Binder 1) was dissolved in a MEK / toluene mixed solvent, and carbon and an isocyanate curing agent were added. Thereafter, an alkyl-modified silicone oil [trade name: SH230, manufactured by Toray Dow Corning Silicone Co., Ltd.] added to 3 parts by mass with respect to 100 parts by mass of the fluororesin was used as a surface layer coating solution-11.

At this time, the volume resistance of the fluororesin was 5.7 × 10 ⁷ Ω · cm.

  Then, the surface layer was formed by the method similar to Example 1, and charging roller-XI was produced. Evaluation similar to Example 1 was performed about the charging roller-XI. The evaluation results are shown in Table 3.

(Comparative Example 3)
About the electroconductive elastic roller, what was used in Example 1 was used.

  Next, urethane-modified acrylic resin [trade name: EAU65B, manufactured by Asia Kogyo Co., Ltd.] (Binder 2) was dissolved in MEK solvent, and an isocyanate curing agent was added. Then, 1 part by mass of dimethyl silicone oil [trade name: L-45, manufactured by Nippon Unicar Co., Ltd.] with respect to 100 parts by mass of the urethane-modified acrylic resin was used as the surface layer coating solution-12.

The volume resistance of the urethane-modified acrylic resin at this time was 5.2 × 10 ⁷ Ω · cm.

  Then, the surface layer was formed by the method similar to Example 1, and charging roller-XII was produced. Evaluation similar to Example 1 was performed about the charging roller-XII. The evaluation results are shown in Table 3.

  As described above, even if silicone oil is added, it is compatible with the polysiloxane as a binder, so that the film itself does not become uneven, and the toner and the external additive used for the toner even after repeated use over a long period of time. Etc. are difficult to stick to the surface. Therefore, it is possible to provide a charging member that can stably charge and output an image for a long period of time even when used in a DC contact charging method, and a process cartridge and an electrophotographic apparatus having the charging member.

It is a figure which shows an example of a structure of the charging member of this invention. It is a figure which shows the structure of the resistance measurement system used for the resistance measurement of a surface layer. FIG. 2 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having a charging member of the present invention. It is a figure which shows an example of the photoreceptor electric potential change of a silicone oil addition type | system | group.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Support body 102 Conductive elastic layer 103 Surface layer 14 Resistance measuring device 15 Contact electrode terminal 16 Flat plate electrode 1 Electrophotographic photosensitive member 2 Axis 3 Charging member 4 Exposure light 5 Developing means 6 Transfer means 7 Cleaning means 8 Fixing means 9 Process cartridge 10 Guide means P Transfer material

Claims (8)

A charging member having a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, the surface layer comprising SiO _0.5 R ¹ (OR ² ) a polysiloxane having a first unit represented by (OR ³ ), a second unit represented by SiO _1.0 R ⁴ (OR ⁵ ), and a third unit represented by SiO _1.5 R ⁶ ; A charging member comprising:
(The above R ¹ , R ⁴ and R ⁶ each independently represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group or oxyalkylene group. The above R ² , R ³ and R ⁵ represent And each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group.)   In the polysiloxane, the number of moles of the first unit is x [mol], the number of moles of the second unit is y [mol], and the number of moles of the third unit is z [mol]. The charging member according to claim 1, wherein 0.60 ≦ {(x + y) / (x + y + z)} ≦ 0.80. The charging member according to claim 1 or 2, wherein the silicone oil is a polyether-modified silicone oil or a phenol-modified silicone oil represented by the following general formula (S1).

(In the above formula, R is a substituted or unsubstituted monovalent hydrocarbon group. A or B is a phenol group-containing organic group, polyoxyalkylene, at least one of which is represented by the following formula (S2) or (S3): A group-containing organic group, m is from 0 to 500, y is from 0 to 50, and x + y is from 5 to 500.)

(R ¹ is a divalent hydrocarbon group, R ² is a monovalent hydrocarbon group or an alkoxy group, R ³ is the same or different divalent hydrocarbon group having 1 to 4 carbon atoms. R ⁴ is a hydrogen atom, a monovalent hydrocarbon group or an acyl group, a is an integer of 0 or more and 4 or less, b is 0 or 1, and c is an integer of 1 or more and 100 or less. )   The content of the silicone oil in the surface layer is 0.5% by mass or more and 3.0% by mass or less with respect to 100% by mass of the polysiloxane. The charging member described.   The charging member according to claim 1, wherein the silicone oil has a weight average molecular weight Mw of 300 or more and 5000 or less. The surface layer is
(I) a condensation step in which a hydrolyzable silane compound having a group capable of cationic polymerization is condensed by hydrolysis;
(II) a step of adding silicone oil to the hydrolyzable condensate obtained in step (I), and (III) a condensation obtained in step (II) by cleaving the cationically polymerizable group. Cross-linking step of cross-linking a compound having a product
The charging member according to claim 1, wherein the charging member is formed by:   A process cartridge comprising the charging member according to claim 1.   An electrophotographic apparatus comprising the charging member according to claim 1.

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