JP2008145567A - Functional member, developing roller and developing method using the same and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a functional member produced by mixing conductive or semi-conductive particles in a polymeric material layer, to vary the resistance value of the polymeric material layer in proportion to the added quantity, while having high durability and causing no defect in a formed image when using the polymeric material layer as a covering layer, and to provide a developing method using this developing roller, and an image forming apparatus. <P>SOLUTION: The functional member has a covering layer formed on a conductive member, wherein the covering layer contains the conductive or semi-conductive particles having a hydrophilic or hydrophobic group dispersed in non-conductive polymeric material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic functional member, a developing roller, a developing method using the same, and an image forming apparatus.

  Conventionally, in an electrophotographic image forming method, control of conductivity in a functional member such as a developing roller has been an important issue, and technical studies have been repeated.

As a material constituting the functional member, a resin (polymer material) is often used, which is basically non-conductive. However, when it is used in an electrophotographic image forming method, there are many types having a certain resistance value with a resistance value range of about 10 ² to 10 ¹¹ Ω · cm.

Therefore, in order to set the resistance value of the functional member to an appropriate value, the resistance value is adjusted by mixing conductive fine particles such as carbon black with a polymer material and changing the type and mixing ratio of the conductive fine particles. ing. However, at this time, the mixing ratio of the conductive fine particles and the magnitude of the resistance value fluctuated thereby are not proportional, and in many conductive fine particles, particularly in the semiconductive region (around 10 ⁴ to 10 ¹⁰ Ω · cm), There is a tendency that the resistance value changes rapidly with respect to the added amount.

  For this reason, in the electrophotographic image forming apparatus, when used as a functional member such as a developing roller, it is necessary to select a region where stable image formation is possible even if there is a slight variation in resistance value. When such measures are taken, there is a problem that variations in characteristics and defects such as image fog and insufficient density tend to occur.

In order to improve the above problem as much as possible, attempts have been made to form a resin layer on the surface of carbon black particles by graft polymerization, but a sufficient effect for practical use has not been obtained (Patent Document 1).
JP 7-295367 A

  The present invention has been made in view of the above circumstances.

  That is, an object of the present invention is to produce a functional member in which the resistance value of the polymer material layer changes in proportion to the amount added by mixing conductive or semiconductive particles in the polymer material layer. The developing roller in which the polymer material layer is applied to the coating layer has a high durability and is a functional member capable of producing a developing roller that does not cause defects in the formed image. Development method and image using the developing roller A forming apparatus is provided.

  As a result of intensive studies, the inventors have added a semiconductive or conductive particle having a specific functional group, so that the resistance value varies in proportion to the added amount of the conductive particle over a wide range. As a result, the present invention has been achieved.

  That is, the object of the present invention is achieved by adopting the following configuration.

1.
In a functional member in which a coating layer is formed on a conductive member, the coating layer is formed by dispersing conductive or semiconductive particles having a hydrophilic group or a hydrophobic group in a non-conductive polymer material. The functional member characterized by the above-mentioned.

2.
2. The functional member according to 1, wherein the hydrophilic group is any one of a hydroxyl group, a carboxyl group, a sulfonic acid group, and an ethylene oxide group.

3.
2. The functional member according to 1, wherein the hydrophobic group is either an alkyl group or an aryl group.

4).
The functional member according to any one of claims 1 to 3, wherein the functional member is a developing roller, and the conductive member is a conductive shaft.

5.
5. The developing roller according to claim 4, wherein the developing roller does not have an elastic layer, and the coating layer is formed directly on the conductive shaft.

6).
A developing method comprising performing non-magnetic one-component development using the developing roller according to claim 5.

7).
A non-contact development using the developing method according to claim 6.

  Conventionally commonly used carbon black (may be abbreviated as CB) is difficult to disperse, and in a desired resistance region, a resistance with a large fluctuation range of resistance value with respect to the added amount is stable. Adjustment becomes difficult. In addition, there is a case where an image defect occurs due to a difference in micro resistance value in the functional member, and stabilization has been a problem.

  As described above, in the past, in order to improve the dispersibility of conductive fine particles such as carbon black, the surface of the fine particles was treated with a coupling agent, and the particle surface was resinized by graft polymerization. . However, the performance was not improved as expected, but the cost was increased due to a decrease in productivity, restrictions on the usable polymer material, etc., and only a very insufficient effect was obtained.

  However, by using conductive or semiconductive particles having a hydrophilic group or a hydrophobic group according to the present invention, a very remarkable effect was obtained.

  The reason is estimated as follows.

  The conductivity development mechanism of carbon black is explained by the percolation theory. When a certain critical filling rate is exceeded, the electric resistance rapidly decreases. However, when it is used in an electrophotographic image forming method as in the present invention, it is necessary to use it in a semiconductive region, and its control is difficult.

  On the other hand, as exemplified here, improvement can be achieved even if graft CB is used as a means of improving the dispersibility of CB, but there are restrictions on the monomer component formed by graft polymerization with the CB surface, and the resin (filler) to be used in the functional layer It is difficult to select a low surface energy resin having good releasability for the purpose of improving ming. In addition, if a resin formed by graft polymerization and a resin formed by a functional layer are selected separately, even if a compatible resin system is selected, a stable desired resistance can be obtained due to problems such as compatibility between the resins. Is difficult.

  On the other hand, by the method of the present invention, the dispersibility is remarkably improved from the dispersion state that can be achieved by ordinary CB, so that the percolation transition does not occur up to the CB high filling amount region, and the resistance control to the desired region can be achieved. It becomes possible. This is considered to be caused by the dispersion exceeding the dispersion at the normal structure level, so that an isolated state of each CB is formed, and the resistance does not decrease so rapidly but stably decreases (see FIG. 5).

  Thus, by using CB in an appropriate dispersion state in the present invention, it becomes possible to control within a desired resistance range.

  According to the present invention, by mixing conductive or semiconductive particles in the polymer material layer, a functional member in which the resistance value of the polymer material layer changes in proportion to the amount of the additive is produced. A developing roller in which a layer is applied to a coating layer is a functional member capable of producing a developing roller that has high durability and does not cause defects in the formed image, and provides a developing method and an image forming apparatus using the developing roller can do.

  In particular, the development roller without a base rubber is subject to variations in the conventional resistance control due to environmental conditions, etc., and the charge imparting function to the toner and developability are likely to change greatly, and leakage in a high humidity environment becomes a problem. This is a particularly effective technique.

  Next, the compound, image forming material, developing method, and image forming apparatus used in the present invention will be described below.

  The present invention relates to a functional member for electrophotography, and is particularly effective when used in the form of a roller, but for a developing roller that requires high-precision resistance adjustment in that it is directly related to image noise. It is particularly effective when applied. Accordingly, the following description will be focused on the developing roller, particularly the developing roller for non-magnetic one-component development.

[Functional member with coating layer formed on conductive member]
As described above, the functional member is mainly various electrophotographic rollers, particularly a developing roller, particularly a developing roller for non-magnetic one-component development.

[Configuration of roller]
The configuration of the functional member (roller) of the present invention is, for example, formed along a shaft body (axial center, conductive shaft) 1 and the outer peripheral surface of the shaft body 1 as shown in the schematic cross-sectional view of FIG. The elastic layer (base rubber layer) 2 is provided, and the adhesive layer 3 and the surface layer 4 formed on the outer peripheral surface of the elastic layer 2 are provided. Then, the outer peripheral surface of the adhesive layer 3 may be subjected to an activation process such as a normal plasma discharge process in order to improve the adhesiveness with the surface layer 4 formed on the outer peripheral surface.

Conductive member It is often called a shaft body (axial center), and in the case of a developing roller, it is a conductive shaft, but the material is not particularly limited. For example, a metal core bar having a diameter of about 5.0 to 30 mm, a metal rod-like body, or a hollow cylinder body is used. Examples of the metal material include aluminum, stainless steel, and iron obtained by plating the surface. Also, a conductive resin may be used.

Covering layer Elastic layer (base rubber layer) 2 formed along the outer peripheral surface of the conductive shaft which is the conductive member (shaft body) 1, and adhesive layer 3 and surface formed on the outer peripheral surface of the elastic layer 2 Layer 4 etc. However, the elastic layer (base rubber layer) 2 shown in FIG. 1 does not have to be provided, and the configuration may be extremely thin and substantially free. Rather, the cost can be reduced, and this is a preferable mode. Therefore, the adhesive layer 3 is not essential, but it is of course possible to provide it for adhesion to the conductive shaft without the elastic layer.

  A material for forming the elastic layer 2 formed on the outer peripheral surface of the shaft 1 is preferably silicone rubber, urethane rubber, styrene-butadiene rubber or the like as a main component. Further, the silicone rubber is not particularly limited, but it is preferable to use a dimethyl silicone polymer having a vinyl group added as a crosslinking site and a dimethyl silicone oil added thereto.

  In the present invention, the main component includes the case where the elastic layer (base rubber layer) 2 is made of only silicone rubber.

In addition to the silicone rubber, the base rubber layer 2 includes metal oxides such as carbon black (furnace black, acetylene black), TiO ₂ , ZnO, SnO ₂ , iron oxide, graphite, potassium titanate, 4 It is also possible to add a conductive agent such as a quaternary ammonium salt, a borate salt, or a lithium salt.

The material for forming the adhesive layer 3 formed on the outer peripheral surface of the elastic layer 2 is not particularly limited, and any conventionally known material may be used. For example, hydrogenated acrylonitrile-butadiene copolymer rubber (hydrogenated nitrile rubber: H-NBR), ethylene-propylene diene rubber (EPDM), styrene-butadiene rubber (SBR), nitrile rubber, polyurethane elastomer, polyester, N-methoxy Methylated nylon, etc., carbon black (furnace black, acetylene black), TiO ₂ , ZnO, SnO ₂ , metal oxides such as iron oxide, graphite, potassium titanate, quaternary ammonium salt, borate, lithium salt, etc. The thing which mix | blended these electrically conductive agents is mention | raise | lifted. Among these, it is preferable to select from the viewpoint of good adhesiveness with the surface layer 4 forming material.

  In addition to the above materials, a vulcanization accelerator and a vulcanizing agent can be appropriately blended in the adhesive layer 3 forming material as necessary. Examples of the vulcanization accelerator include tetramethylthiuram disulfide (TMTD), ortho-tolyl-biguanidine, and zinc dibutyldithiocarbamate. These may be used alone or in combination of two or more. Moreover, sulfur etc. are mention | raise | lifted as said vulcanizing agent.

  The material for forming the surface layer 4 formed on the outer peripheral surface of the adhesive layer 3 is not particularly limited as long as it is generally used conventionally. For example, a mixture of urethane and acrylic urethane, an acrylic silicone copolymer, etc. Can be given. And when using the mixture of the said urethane and acrylic urethane, it is preferable to set the mixing ratio of both in the range of urethane / acryl urethane = 10 / 90-90 / 10 by mass ratio.

The surface layer 4 forming material is further appropriately added with the conductive or semiconductive particles of the present invention as a conductive agent. Examples of the conductive agent include carbon black (furnace black, acetylene black), TiO ₂ , ZnO, SnO ₂ , metal oxides such as iron oxide, graphite, potassium titanate, quaternary ammonium salt, borate, lithium salt, etc. Is given. These may be used alone or in combination of two or more.

  The surface layer 4 is desirably set to have a thickness of 25 μm or less, preferably 10 to 20 μm, and more preferably 3 to 10 μm. That is, when the thickness of the surface layer 4 exceeds 25 μm, toner releasability and wear resistance are improved. However, this is because the contact portion with the layer forming blade is likely to be deformed and the restoration of the deformed portion may be delayed. Furthermore, it is generally difficult to form a uniform film by coating and to form a film having surface smoothness.

  The adhesive layer 3 and the surface layer forming material can be applied by various application methods such as a dipping application method and a roller application method.

  In the application, the activation treatment can be performed by application of a siloxane compound, corona discharge treatment, or plasma discharge treatment.

  When the electrophotographic apparatus roller thus obtained has a configuration having an elastic layer, the thickness of the elastic layer 2 is preferably 10 to 1000 μm, more preferably 100 to 600 μm. The thickness of the adhesive layer 3 is preferably in the range of 1 to 100 μm, particularly preferably 3 to 30 μm.

  The roller for electrophotographic equipment of the present invention is not limited to the above three-layer structure, and for example, a plurality of layers may be formed as the surface layer.

Non-conductive polymer material The non-conductive polymer material in the present invention is a non-conductive polymer material necessary for film formation of a layer containing conductive or semiconductive particles having a hydrophilic group or a hydrophobic group. Examples of the molecular material (resin) include a mixture of urethane and acrylic urethane, an acrylic silicone copolymer, a urethane silicone copolymer, and the like.

[Conductive or semiconductive particles having a hydrophilic group or a hydrophobic group]
Conductive or semiconductive particles As the conductive or semiconductive particles into which hydrophilic groups or hydrophobic groups are introduced, known ones conventionally used as conductive materials for various rollers in the electrophotographic technical field. Any of inorganic compounds and organic compounds may be used.

  Examples of materials that have been most widely used as the semiconductive or conductive particles include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and titanium black.

  The average particle size of the semiconductive / conductive particles used in the present invention is generally less than 1.0 μm, preferably in the range of 0.005 to 0.3 μm. Incidentally, the measurement of the particle size of the dispersion in which carbon black was dispersed with a surfactant was performed using MASTERSIZER 2000 (manufactured by Malvern Instruments Ltd.).

  Further, the amount of conductive or semiconductive particles used for adjusting the resistance is usually 5 to 60 parts by weight, preferably 10 to 50 parts by weight, more preferably 15 to 100 parts by weight of the resin for forming a coating film. -40 mass parts.

Hydrophobic group and hydrophilic group In the present invention, the dispersibility of the semiconductive / conductive particles can ensure dispersibility in an aqueous medium by chemically introducing a hydrophilic group into the particle surface. On the other hand, dispersibility in an organic medium can be improved by introducing a hydrophobic functional group. Therefore, the dispersion of the semiconductive / conductive particles has an extremely high dispersion level and remarkably excellent long-term dispersion stability as compared with dispersion by mere physical adsorption of the dispersant.

  Here, the “aqueous medium” means that the main component (50% by mass or more) is made of water. Examples of components other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Among these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin, are particularly preferable.

  The “organic medium” refers to a solvent that is hardly soluble in water. Such as, for example, toluene, xylene, tetrahydrofuran, 1,3-dioxolane, cyclohexanone, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, Monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, etc. are used alone or in combination of two or more.

  In addition, the resin that forms the surface coating layer is also included in the case where the coating solution is formed in a molten state, and water-soluble various alcohols, dioxane, THF, DMSO, DMF, DMAc, acetone, etc. are used together to some extent as auxiliary solvents. What you did is fine.

  From the viewpoint of environmental friendliness, a dehalogenated solvent is desired. Further, from the viewpoint of drying temperature and drying time, it is usually preferable that the temperature can be set within a range of 180 ° C. or less, particularly 80 to 150 ° C.

The hydrophilic group is not particularly limited as long as it is a group that expresses the self-dispersibility of the pigment in the aqueous solvent by being introduced on the surface of the colored pigment. For example, -O-L ₁ ⁺ , -N ^{+ _{R 1 R 2 R 3 X -}} , -COO - M 1 +, -SO 3 - M 2 +, - (CH 2 CH 2 O) m R 4, -Y 1 O - L 2 +, -Y 2 COO - ^{_{M 3 +, -Y 3 SO 3}} - M 4 +, is _{-Y 4 (CH 2 CH 2 O} ) n R 5, at least one organic group selected from the group consisting of quinone skeleton-containing group and a lactone group .

In the organic group, L ₁ ⁺ and L ₂ ⁺ represent H ⁺ , Na ⁺ or K ⁺ . R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group. The alkyl group is an alkyl group having 1 to 4 carbon atoms, preferably 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. The aralkyl group is an aralkyl group having 7 to 10 carbon atoms, preferably 7 to 9 carbon atoms, and examples thereof include a benzyl group. The aryl group is an aryl group having 6 to 18 carbon atoms, preferably 6 to 12 carbon atoms, and examples thereof include a phenyl group, a biphenyl group, and a naphthyl group.

Further, X ^- is ^{Br -, Cl -, I -} , R 6 COO - or R ₆ SO ₃ ^- represents a. R ₆ represents an alkyl group, an aralkyl group or an aryl group. The alkyl group is an alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. The aralkyl group is an aralkyl group having 7 to 10 carbon atoms, preferably 7 to 9 carbon atoms, and examples thereof include a benzyl group. The aryl group is an aryl group having 6 to 18 carbon atoms, preferably 6 to 12 carbon atoms, and examples thereof include a phenyl group, a biphenyl group, and a naphthyl group.

M ₁ ⁺ , M ₂ ⁺ , M ₃ ⁺ and M ₄ ⁺ represent H ⁺ , Na ⁺ , K ⁺ or —N ⁺ HR ₇ R ₈ . R ₇ and R ₈ each independently represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group. The alkyl group, aralkyl group and aryl group are the same as those in R ₁ , R ₂ and R ₃ .

  N represents an integer of 1 or more, preferably 1 to 10.

R ₄ and R ₅ represent a hydrogen atom, an alkyl group, an aralkyl group or an aryl group. The alkyl group, aralkyl group and aryl group are the same as those in R ₁ , R ₂ and R ₃ .

Y ₁ , Y ₂ , Y ₃ and Y _{4 each} represents an alkylene group, an aralkylene group or an arylene group. The alkylene group is an alkylene group having 1 to 4 carbon atoms, preferably 1 to 3 carbon atoms, and examples thereof include a methylene group, a dimethylene group, a trimethylene group, and a tetramethylene group. The aralkylene group includes an aralkylene group having 7 to 10 carbon atoms, preferably 7 to 9 carbon atoms. A benzyl group etc. are mentioned. The arylene group is an arylene group having 6 to 18 carbon atoms, preferably 6 to 12 carbon atoms, and examples thereof include a phenylene group, a biphenylene group, and a naphthylene group.

Preferable specific examples of —O—L ₁ ⁺ include, for example, a hydroxyl group, —O ⁻ Na ^{+ and the} like.

^{_{-N + R 1 R 2 R 3}} X - as a preferred embodiment, for example, ^{_{-N + H 3 Cl -, -N}} + (CH 3) 3 Cl - , and the like.

Preferable specific examples of —COO ⁻ M ₁ ⁺ include, for example, —COOH, —COO ⁻ Na ^{+ and the} like.

Preferable specific examples of —SO ₃ ⁻ M ₂ ⁺ include, for example, —SO ₃ H, —SO ₃ ⁻ Na ^{+ and the} like.

Preferable specific examples of — (CH ₂ CH ₂ O) _m R ₄ include — (CH ₂ CH ₂ O) —H, — (CH ₂ CH ₂ O) ₂ —H, and the like.

Specific preferred examples of -Y ₁ O ^- L ₂ ⁺ include -C ₆ H ₄ OH, -C ₆ H ₄ O ^- Na ^{+ and the} like.

As M ₃ ⁺ a preferred embodiment, for _{example, -C 6 H 4 COOH, -C} 6 H 4 COO - - -Y 2 COO Na + and the like.

As M ₄ ⁺ preferred embodiment, for _{example, -C 6 H 4 SO 3 H} , -C 6 H 4 SO 3 - - -Y 3 SO 3 Na + and the like.

Preferred specific examples of —Y ₄ (CH ₂ CH ₂ O) _n R ₅ include, for example, —C ₆ H ₄ (CH ₂ CH ₂ O) —H, —C ₆ H ₄ (CH ₂ CH ₂ O) ₂ — H etc. are mentioned.

  The quinone skeleton-containing group is a group containing a quinone skeleton such as p-benzoquinone, o-benzoquinone, and 1,4-naphthoquinone.

Further, the lactone group is a —COO 2 ^— group that forms a ring.

Of the above-mentioned groups, the hydrophilic group is preferably —O ⁻ L ₁ ⁺ , —COO ⁻ M ₁ ⁺ , —SO ₃ ⁻ M ₂ ⁺ , —Y ₁ O from the viewpoint of ease of introduction treatment and production cost. _{^{- L 2 +, -Y 2 COO}} - M 3 + and -Y ₃ SO ₃ ^- M ₄ group consisting ^+, especially _{^{-O - L 1 +, -COO -}} M 1 +, -SO 3 - M 2 +, It is at least one group selected from the group consisting of —Y ₂ COO ⁻ M ₃ ⁺ and —Y ₃ SO ₃ ⁻ M ₄ ⁺ .

  Chemical introduction of the hydrophilic group may be accomplished by chemically bonding the compound containing the hydrophilic group and the pigment surface, or oxidizing the pigment surface itself to generate the hydrophilic group. May be achieved.

  The introduction method is not particularly limited as long as the above-described chemical introduction can be achieved. For example, JP 2000-513396 A, JP 10-120958 A, JP 2000-512670 A The methods described in JP-A-7-41689, JP-A-2002-265833, and JP-T-2001-511543 can be used. In the present invention, it is preferable to use a diazotization reaction method, a surface oxidation method, or the like from the viewpoint of ease of introduction treatment, production cost, and production stability.

When using the diazotization reaction method, a hydrophilic group or a group having a group capable of deriving the group (hereinafter referred to as a hydrophilic group) and an amino group are reacted with an aqueous solution of sodium nitrite in hydrochloric acid to form a hydrophilic group. A diazonium salt containing a functional group or the like is generated, and the diazonium salt is reacted with a pigment. Specifically, for example, a hydrophilic group is introduced according to the method described in JP-T-2000-513396. Specifically, for example, pigments mixed with sulfanilic acid was added aqueous sodium nitrite solution while heating the mixture, adding hydrochloric acid to the mixed ^{_{solution, -C 6 H 4 S0 3 -}} Na + A pigment with introduced groups is obtained. At this time, when 4-aminobenzoic acid is used instead of sulfanilic acid, a pigment having a —C ₆ H ₄ COO ⁻ Na ⁺ group introduced therein can be obtained. The hydrophilic group of carbon black is preferably any one of a hydroxyl group, a carboxyl group, a sulfonic acid group, and an ethylene oxide group.

  When the surface oxidation method is used, the surface of the pigment is oxidized using ozone, nitric acid, nitrous acid, hypochlorous acid, sodium hypochlorite, potassium hypochlorite, or the like. Specifically, for example, a hydrophilic group is introduced according to the method described in JP-A-10-120958. Specifically, for example, when sodium hypochlorite is dropped into a dispersion in which the pigment is dispersed in water as it is and stirring is continued while heating, a pigment in which the surface itself is oxidized and a hydrophilic group is generated is obtained. It is done.

  The degree of introduction (amount) of the hydrophilic group is not limited as long as the obtained colorant particles have the self-dispersibility.

  On the other hand, imparting a hydrophobic group to carbon black can be performed by using the diazotization reaction method described above using a diazonium salt having a substituent at the 4-position of the benzene ring.

Examples of the group substituted at the 4-position of the benzene ring of the diazonium salt include R ₁ , OR ₁ , COR ₁ , COOR ₁ , OCOR _{1 and the} like, and R ₁ is an alkyl group having about 1 to 20 carbon atoms or An aryl group. Suitable examples are -C ₁₁ H _23, include -C ₁₇ H _35.

[Roller resistance measurement]
The conductivity of the developing roller or the like can be evaluated by volume resistivity (volume resistance, volume resistance value). As a method for measuring the volume resistivity, it can be measured by a known method.

In the present invention, when the volume resistivity of the developing roller measured by the following method is 1 × 10 ² to 1 × 10 ⁹ Ω · cm, it is determined that the conductive roller exhibits appropriate conductivity. Particularly preferably, it is 1 × 10 ³ to 1 × 10 ⁸ Ω · cm. This is because, when the volume resistivity of the developing roller is in the above range, the charge generated on the surface of the developing roller leaks moderately and the leakage is moderately suppressed.

  The volume resistivity of the developing roller can be typically measured by a metal roller electrode method using an apparatus as shown in FIG.

  That is, the electrode roller 101 made of stainless steel is brought into contact with the developing roller 1 and pressed with 9.8 N together with the weight of the electrode roller 101, and a voltage of +100 V is applied to one end of the developing roller 1 while rotating the roller in this state. The current value was measured by applying the voltage, and the volume resistivity of the developing roller was calculated from the following formula (1).

R = V / I Formula (1)
(Measurement condition)
Measurement environment: 23 ° C, 57RH%
Applied voltage: + 100V
Roller rotation speed: 27rpm
Electrode roller load: 9.8 N (including electrode roller weight)
Effective width of electrode roller: 230 mm (diameter 30 mm)
Measurement item: Current value (average value after 5 seconds of voltage application)
[Developer, image forming method and image forming apparatus]
(Developer)
An example of a non-magnetic one-component developing method using the toner of the present invention will be described, but it is not necessarily limited thereto.

  FIG. 2 is a schematic cross-sectional view for explaining a developing device for developing non-magnetic one-component toner.

  A latent image holding member (photosensitive drum) 10 is formed by an electrophotographic process means or an electrostatic recording means (not shown). Reference numeral 32 denotes a developing roller, and an elastic layer such as silicone rubber is applied to a shaft body made of aluminum, iron, stainless steel or the like.

  The toner T is stored in the hopper 6 and is supplied onto the developing roller by a supply roll. The supply roll is made of a foam material such as polyurethane foam, and rotates with a relative speed in the forward or reverse direction with respect to the developing roller 32. Together with the toner supply, the developed toner on the developing roller (undeveloped toner) We are also stripping off. The toner supplied onto the developing roller 32 is uniformly and thinly applied by a toner regulating blade 5 which is a kind of member that performs toner thinning and charging.

  The contact pressure between the toner regulating blade and the developing roller is 3 to 250 N / m, preferably 10 to 30 N / m, as the linear pressure in the developing roller bus direction. When the contact pressure is less than 3 N / m, it is difficult to uniformly apply the toner, and the toner charge amount distribution becomes broad, which may cause fogging or scattering. On the other hand, if the contact pressure exceeds 250 N / m, a large pressure is applied to the toner and the toner deteriorates, which is not preferable because toner aggregation occurs. Further, it is not preferable because a large torque is required to drive the developing roller. That is, by adjusting the contact pressure to 3 to 250 N / m, it is possible to effectively loosen the toner and to instantly increase the toner charge amount.

  As a material of the member for thinning and charging the toner, it is formed of a material capable of charging the toner to a desired polarity by frictional charging. Specific examples include metal elastic materials such as stainless steel, aluminum, and phosphor bronze, and rubber elastic materials such as silicone rubber, urethane rubber, and styrene-butadiene rubber. Alternatively, a composite layer in which a polyamide resin, a polyimide resin, a melamine resin, a phenol resin, a fluorine resin, a silicone resin, a polyester resin, a urethane resin, a styrene resin, or the like is laminated on the above-described material layer may be formed. Furthermore, by adding conductive rubber, conductive resin, fillers such as metal oxides, carbon black, inorganic whiskers, inorganic fibers, and charge control agents to the elastic material described above, it is possible to improve the charge imparting property. It is. As a member for thinning and charging the toner, an elastic roller can be used in addition to the elastic blade.

  In the present invention, silicone rubber, urethane rubber, styrene-butadiene rubber and the like are suitable. Furthermore, an organic resin layer such as polyamide, polyimide, nylon, melamine, melamine cross-linked nylon, phenol resin, fluorine resin, silicone resin, polyester resin, urethane resin, styrene resin may be provided. In addition, conductive rubber, conductive resin, etc. are used, or fillers such as metal oxides, carbon black, inorganic whiskers, inorganic fibers, and charge control agents are dispersed in blade rubber and resin. It is preferable because it imparts charge imparting properties and can charge the toner appropriately.

  In non-magnetic one-component development in which a thin layer of toner is coated on the developing roller with a blade, the thickness of the toner layer on the developing roller is set to be opposite between the developing roller and the photosensitive drum in order to obtain a sufficient image density. It is preferable that the gap length is smaller than that of the so-called non-contact development method, and an alternating electric field is applied to the gap. A gap of 40 to 300 μm, more preferably 60 to 170 μm, is provided between the photoreceptor surface and the developing roller surface. On the other hand, the toner layer provided on the developing roller overlaps with about 1 to 3 toner particles. A toner layer of ˜30 μm is preferable. The film thickness of the toner layer on the developing roller can be obtained by microscopic observation.

  That is, the developing cartridge loaded in the actual image forming apparatus is irradiated with parallel light from the cross-sectional direction of the developing process, and a high-speed, high-resolution camera (for example, Phototron: FASTCAM MAX, photographing speed 100,000 (FPS)) It can measure from what image | photographed by and visualized the behavior of the image development part.

  The film thickness (a) of the toner layer on the developing roller is determined by the gap (b) between the toner layer on the developing roller and the photosensitive member in the area close to the photosensitive member, and the center of the developing nip sandwiched between the developing roller and the photosensitive member. Is obtained from the difference (a = c−b).

  2 is applied between the developing roller 32 and the photosensitive drum 10 by applying a developing bias in which an alternating electric field or a DC electric field is superimposed on the alternating electric field, from the developing roller to the photosensitive drum. Therefore, it is possible to easily move the toner and to obtain a high-quality image.

(Image forming method and image forming apparatus)
An example of a full-color image forming apparatus that forms a full-color image using each color toner will be specifically described with reference to FIG.

  In the full-color image forming apparatus shown in FIG. 3, a charging brush 111 that uniformly charges the surface of the photosensitive drum 10 to a predetermined potential around the photosensitive drum 10 that is rotationally driven, and the photosensitive drum 10 A cleaner 112 for scraping off the remaining toner is provided.

  Further, a laser scanning optical system 20 for scanning and exposing the photosensitive drum 10 charged by the charging brush 111 with a laser beam is provided. The laser scanning optical system 20 includes a laser diode, a polygon mirror, and an fθ optical element. As is well known, print data for each of yellow, magenta, cyan, and black is transferred from the host computer to the control unit. The laser scanning optical system 20 sequentially outputs the laser beam as a laser beam based on the print data for each color, scans and exposes the photosensitive drum 10, and thereby the static image for each color is formed on the photosensitive drum 10. Electro latent images are sequentially formed.

  In addition, the full-color developing device 30 that supplies full-color development to the photosensitive drum 10 on which the electrostatic latent image is formed in this manner, performs yellow, magenta, cyan, and black around the support shaft 33. Four color-developing units 31Y, 31M, 31C, and 31Bk each containing non-magnetic one-component toner are provided. The developing units 31Y, 31M, 31C, and 31Bk rotate around the support shaft 33, and the developing units 31Y, 31M, 31C, and 31Bk are rotated. It is guided to a position facing the photosensitive drum 10.

  Further, in each of the developing devices 31Y, 31M, 31C, and 31Bk in the full-color developing device 30, as shown in FIG. 4, the toner is formed on the outer peripheral surface of the developer carrier (developing roller) 32 that rotates and conveys the toner. A regulating member is in pressure contact, and the toner regulating member regulates the amount of toner conveyed by the developing roller 32 and charges the conveyed toner. In the full-color developing device 30, two toner regulating members may be provided in order to appropriately regulate and charge the toner conveyed by the developing roller.

  Then, whenever the electrostatic latent image of each color is formed on the photosensitive drum 10 by the laser scanning optical system 20 as described above, the full-color developing device 30 is rotated around the support shaft 33 as described above. Then, the developing devices 31Y, 31M, 31C, and 31Bk containing toner of the corresponding colors are sequentially guided to positions facing the photosensitive drum 10, and the developing rollers 32 in the developing devices 31Y, 31M, 31C, and 31Bk are moved. Development is performed by sequentially supplying charged toner of each color onto the photosensitive drum 10 in which the electrostatic latent images of each color are sequentially formed as described above in contact with the photosensitive drum 10. It has become.

  Further, an endless intermediate transfer belt 40 that is rotationally driven is provided as an intermediate transfer body at a position downstream of the full-color developing device 30 in the rotation direction of the photosensitive drum 10. The photosensitive drum 10 is rotated in synchronization with the photosensitive drum 10. The intermediate transfer belt 40 is pressed by a rotatable primary transfer roller 41 so as to come into contact with the photosensitive drum 10, and a portion of a support roller 42 that supports the intermediate transfer belt 40 includes: A secondary transfer roller 43 is rotatably provided, and the recording material S such as recording paper is pressed against the intermediate transfer belt 40 by the secondary transfer roller 43.

  Further, a cleaner 50 that scrapes off the toner remaining on the intermediate transfer belt 40 is provided in a space between the full-color developing device 30 and the intermediate transfer belt 40 so as to be able to contact with and separate from the intermediate transfer belt 40. ing.

  Further, the paper feeding means 60 that guides the recording material S such as plain paper to the intermediate transfer belt 40 includes a paper feeding tray 61 that accommodates the recording material S and the recording material S that is accommodated in the paper feeding tray 61 one by one. The recording material S fed in synchronization with the paper feed roller 62 for feeding paper and the image formed on the intermediate transfer belt 40 is sent between the intermediate transfer belt 40 and the secondary transfer roller 43. The recording material S sent between the intermediate transfer belt 40 and the secondary transfer roller 43 in this way is pressed against the intermediate transfer belt 40 by the secondary transfer roller 43. The toner image is pressed and transferred from the intermediate transfer belt 40 to the recording material S.

  On the other hand, the recording material S on which the toner image is pressed and transferred as described above is guided to the fixing device 70 by the conveying means 66 constituted by an air suction belt or the like, and is transferred by the fixing device 70. The toner image is fixed on the recording material S, and then the recording material S is discharged onto the upper surface of the apparatus main body 100 through the vertical conveyance path 80.

  Next, the operation of forming a full color image using this full color image forming apparatus will be specifically described.

  First, the photosensitive drum 10 and the intermediate transfer belt 40 are rotationally driven in the respective directions at the same peripheral speed, and the photosensitive drum 10 is charged to a predetermined potential by the charging brush 11.

  The photosensitive drum 10 thus charged is exposed to a yellow image by the laser scanning optical system 20 to form an electrostatic latent image of the yellow image on the photosensitive drum 10. The yellow image is developed by supplying the yellow toner charged by the toner regulating member as described above from the developing device 31Y in which the yellow toner is accommodated in the photosensitive drum 10, and the yellow toner image is thus formed. The intermediate transfer belt 40 is pressed against the body drum 10 by the primary transfer roller 41, and the yellow toner image formed on the photosensitive drum 10 is primarily transferred to the intermediate transfer belt 40.

  After the yellow toner image is transferred to the intermediate transfer belt 40 in this way, the full-color developing device 30 is rotated around the support shaft 33 as described above, and the developing device 31M containing magenta toner is exposed to light. As in the case of the yellow image described above, the magenta image is exposed to the photosensitive drum 10 charged by the laser scanning optical system 20 to form an electrostatic latent image. The electrostatic latent image is developed by a developing device 31M containing magenta toner, and the developed magenta toner image is primarily transferred from the photosensitive drum 10 to the intermediate transfer belt 40. Black image exposure, development and primary transfer are sequentially performed, and yellow, magenta, cyan, and black toner images are sequentially superimposed on the intermediate transfer belt 40. To form a toner image of Rukara.

  When the final black toner image is primarily transferred onto the intermediate transfer belt 40, the recording material S is fed between the secondary transfer roller 43 and the intermediate transfer belt 40 by the timing roller 63, and the secondary transfer roller. The recording material S is pressed against the intermediate transfer belt 40 by 43, and the full color toner image formed on the intermediate transfer belt 40 is secondarily transferred onto the recording material S.

  When the full-color toner image is secondarily transferred onto the recording material S in this way, the recording material S is guided to the fixing device 70 by the conveying means 66, and the full-color toner transferred by the fixing device 70 is transferred. The image is fixed on the recording material S, and then the recording material S is discharged onto the upper surface of the apparatus main body 100 through the vertical conveyance path 80.

[Non-magnetic one-component developer (toner)]
The toner according to the present invention is not particularly limited in its production method, composition and the like. Here, an example is shown as a representative example.

  The developer that can be used in the present invention is preferably a non-magnetic one-component developer. As the toner constituting the non-magnetic one-component developer, a chemical toner typified by a polymerized toner obtained through a step of polymerizing a polymerizable monomer in an aqueous medium to form resin particles is preferably used.

  The particle diameter of the developer (toner) used in the present invention is preferably 3 to 9 μm in terms of volume-based median diameter (volume D50% diameter). The ratio of the developer (toner) having a volume-based median diameter of 4 μm or less is preferably 25% or less, and the ratio of the developer (toner) having a volume of 12 μm or more is preferably 1% or less.

  The volume-based median diameter, the ratio of the developer (toner) whose volume-based median diameter is 4 μm or less, and the ratio of the developer (toner) whose volume is 12 μm or more are the same as those of Coulter Multisizer II (manufactured by Beckman Coulter). It can be measured and calculated using a device connected to a computer system for data processing (manufactured by Beckman Coulter).

  As a measurement procedure, 0.02 g of toner is blended with 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is poured into a beaker containing ISOTON II (manufactured by Beckman Coulter) in a sample stand with a pipette until the measured concentration reaches 5% to 10%, and the measurement is performed with a measuring machine count of 30000. To do. The aperture diameter of the Coulter Multisizer is 100 μm.

  In the present invention, a developer (toner) having a particle size and a particle size distribution within the above range is filled in a developing device or a process cartridge by a known filling method, and when these units are used to form an image. A good toner image without image unevenness can be stably obtained.

[Method for producing developer (toner)]
Next, a method for producing a developer (toner) that can be used in the present invention will be described.

  Here, as a preferred toner for the present invention, a polymerized toner formed through a process of aggregating resin particles in an aqueous medium is taken as an example.

  Resin particles having a mass average particle diameter of 20 to 500 nm can be used. Resin particles having such a size can be prepared by emulsion polymerization to be obtained.

  The step of agglomerating the resin particles in the aqueous medium is performed by adding a salting-out agent having an alkali metal salt, an alkaline earth metal salt, or the like in water in which at least the resin particles, the colorant particles, and the wax particles are dispersed at a critical aggregation concentration or more. Then, it is a step of performing fusion at the same time as agglomeration (hereinafter also referred to as salting out) is advanced by heating to a temperature higher than the glass transition point of the resin particles. This aggregation process is hereinafter referred to as a salting out / fusion process.

  Unlike the method in which the toner used in the present invention is fused after forming aggregated primary particles of resin particles, colorant particles and wax particles, the formation of particles by salting out and the fusion proceed simultaneously, and the toner Since the particles can be prepared, it is presumed that the uniformity of the toner particles is not impaired, and a toner having a uniform chargeability can be stably obtained.

  Here, examples of alkali metal atoms of alkali metal salts and alkaline earth metal salts that are salting-out agents include metal atoms such as lithium, potassium, and sodium, and examples of alkaline earth metal atoms include magnesium, calcium, strontium, and barium. And metal atoms such as Of these, metal atoms such as potassium, sodium, magnesium, calcium, and barium are preferable.

  Examples of constituents of alkali metal salts and alkaline earth metal salts include chlorine salts, bromine salts, iodine salts, carbonates, sulfates, and the like.

  Furthermore, examples of the organic solvent that is infinitely soluble in water include methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, glycerin, acetone, and the like, but preferably methanol having 3 or less carbon atoms, ethanol, 1- Alcohols such as propanol and 2-propanol are preferable, and 2-propanol is more preferable.

  When performing salting-out / fusion, it is preferable to make the time allowed to stand after adding the salting-out agent as short as possible. The reason for this is not clear, but if it is left for a long time after salting out, the aggregation state of the particles may change, the particle size distribution may become unstable, or the surface properties of the fused toner may change. appear.

  The temperature for adding the salting-out agent needs to be at least the glass transition temperature of the resin particles. The reason for this is that if the temperature at which the salting-out agent is added is equal to or higher than the glass transition temperature of the resin particles, the salting-out / fusion of the resin particles proceeds rapidly, but it becomes difficult to control the particle size. There arises a problem that particles having a particle size are generated. The range of the addition temperature may be not higher than the glass transition temperature of the resin particles, but is generally 5 to 55 ° C, preferably 10 to 45 ° C.

  It is also possible to add a salting-out agent below the glass transition temperature of the resin particles, then raise the temperature as quickly as possible, and heat it above the glass transition temperature of the resin particles.

  The time until this temperature rise is preferably less than 1 hour. Furthermore, it is necessary to quickly raise the temperature, and the rate of temperature rise is preferably 0.25 ° C./min or more and 5 ° C./min or less. The upper limit of the temperature rising rate is not particularly clear, but by setting the temperature rising rate within the above range, the progress of salting out and the control of the particle size can be appropriately performed.

<Polymerizable monomer>
Resin particles prepared by emulsion polymerization can be used as the resin particles. As the polymerizable monomer for preparing the resin particles, the radical polymerizable monomer (1) is an essential constituent, and a crosslinking agent (2) can be used as necessary. Further, it is necessary to contain at least one radical polymerizable monomer (3) having the following acidic group. Furthermore, you may contain the radically polymerizable monomer which has a basic group (4).

(1) Radical polymerizable monomer The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used.

  For example, aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers, etc. are used. I can do it.

  Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples thereof include styrene monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof.

  Examples of (meth) acrylic acid ester monomers include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, and methacrylic acid. Methyl, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate Etc.

  Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate.

  Examples of vinyl ether monomers include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether, and the like.

  Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

  Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

(2) Crosslinking agent A radical polymerizable crosslinking agent may be used as a crosslinking agent in order to improve the properties of the resin particles.

  Examples of the radical polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diaryl phthalate.

  The radical polymerizable crosslinking agent is preferably used in the range of 0.1 to 10 parts with respect to 100 parts of the total radical polymerizable monomer, although it depends on the characteristics.

(3) Radical polymerizable monomer having an acidic group As the radical polymerizable monomer having an acidic group, for example, a carboxyl group or a sulfone group-containing monomer can be used.

  Examples of the carboxylic acid group-containing monomer include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester and the like.

  Examples of the sulfonic acid-containing monomer include styrene sulfonic acid, arylsulfosuccinic acid, octyl arylsulfosuccinate, and the like.

  These may have a structure of an alkali metal salt such as sodium or potassium, or an alkaline earth metal salt such as calcium.

(4) Radical polymerizable monomer having a basic group Examples of the radical polymerizable monomer having a basic group include primary amines, secondary amines, tertiary amines, and quaternary ammonium salts. An amine compound such as can be used.

  Examples of amine compounds include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above four compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacrylic acid. Oxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide, vinylpyridine, vinylpyrrolidone, vinyl N-methylpyridinium chloride, Vinyl N-ethylpyridinium chloride, N, N-diarylmethylammonium chloride, N, N-dia Lumpur ethyl chloride and the like.

<Radical polymerization initiator>
The radical polymerization initiator used for emulsion polymerization can be used as appropriate as long as it is water-soluble. Peroxide compounds such as potassium persulfate persulfate, ammonium persulfate, etc., 4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salt, etc. Etc.

  Further, the radical polymerization initiator can be combined with a reducing agent and used as a redox initiator, if necessary. By using a redox initiator, the polymerization activity increases, the polymerization temperature can be lowered, and the polymerization time can be further shortened.

  Any temperature may be selected as long as the polymerization temperature is equal to or higher than the lowest radical generation temperature of the polymerization initiator, but a range of 50 to 90 ° C is preferable. However, it is also possible to perform polymerization at room temperature or higher by using a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid or the like).

<Surfactant>
A surfactant is preferably used for the emulsion polymerization of the radically polymerizable monomer. The surfactant that can be used in this case is not particularly limited, but the following anionic or nonionic surfactants can be mentioned as preferable ones.

  As an anionic surfactant, for example, sodium dodecyl benzene sulfonate sulfonate, sodium arylalkyl polyether sulfonate, etc., sodium sulfate dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc. Examples of the fatty acid salts include sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate and the like.

  Examples of the nonionic surfactant include polyethylene oxide, polypropylene oxide, a combination of polyethylene oxide and polypropylene oxide, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester, and the like. I can list them.

  These are mainly used as emulsifiers during emulsion polymerization, but may be used in other steps or for other purposes.

<Colorant>
As the colorant, it is preferable to use an inorganic pigment or an organic pigment.

  Examples of inorganic pigments include conventionally known black pigments and magnetic pigments.

  As the black pigment, for example, carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black can be used.

  These inorganic pigments can be used alone or in combination as required. The amount of the inorganic pigment added is preferably 2 to 20 parts, more preferably 3 to 100 parts by weight of toner (parts by mass, and “parts” means “parts by mass” unless otherwise specified). 15 parts.

  A conventionally well-known organic pigment can be used as an organic pigment. Any organic pigment can be used, but specific organic pigments are listed below.

  Examples of the magenta or red pigment include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the pigment for orange or yellow include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. And CI Pigment Yellow 138.

  Examples of the pigment for cyan or green include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  These organic pigments can be used alone or in combination as required. The addition amount of the pigment is preferably 2 to 20 parts, more preferably 3 to 15 parts with respect to 100 parts of the toner.

<wax>
The wax that can be used for the toner includes conventionally known waxes. Specifically, polyolefin waxes such as polyethylene wax and polypropylene wax, long-chain hydrocarbon waxes such as paraffin wax and sazol wax, dialkyl ketone waxes such as distearyl ketone, carnauba wax, montan wax, and trimethylolpropane. Tribehenate, pentaerythritol tetramyristate, pentaerythritol tetrastearate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol distearate, trimellit Ester waxes such as acid tristearyl and distearyl maleate, ethylenediamine dibehenyl amide, trimellitic acid tristearyl amide, etc. Such as amide waxes.

<Additive>
In addition to the colorant and wax, the toner usable in the present invention can be added with additives such as a known charge control agent that imparts various functions.

<Filtration and washing process>
Toner particles formed by agglomerating resin particles in the salting-out / fusion process are filtered from an aqueous medium, washed with washing water, and impurities such as surfactant and salting-out agent adhering to the toner particles are removed. Remove. The filtration and washing machine used in this step is not particularly limited, and for example, a centrifuge, a Nutsche, a filter press or the like is used.

<Drying process>
The toner particles after filtration and washing are dried. The dryer used in this step is not particularly limited. For example, spray dryer, vacuum dryer, vacuum dryer, stationary shelf dryer, mobile shelf dryer, fluidized bed dryer, rotary dryer, stirring A type dryer or the like is used. The water content in the toner after drying is preferably 5% by mass or less, and more preferably 2% by mass or less.

<Crushing process>
This process may not be particularly necessary, but the toner particles may become weakly aggregated after drying. In this case, for example, a crushing device such as a jet mill, a Henschel mixer, or a coffee mill may be used. Aggregation may be crushed.

<Tonerization process>
In the toner forming step, the toner particles obtained above may be used as they are, but it is preferable to add an external additive described later for the purpose of improving fluidity, chargeability, and cleaning properties, for example.

  The equipment for adding the external additive is not particularly limited. For example, a known mixer such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, or a V-type mixer can be used.

  The toner of the present invention is preferably used as a non-magnetic one-component developer, but may be used as a magnetic one-component developer in some cases.

<External additive>
The external additive is not particularly limited, and various inorganic fine particles, organic fine particles and lubricants can be used.

  A conventionally well-known thing can be used as an inorganic fine particle. Specifically, fine particles such as silica, titania, alumina, strontium titanate, magnesium titanate, calcium titanate, and barium titanate are preferable, and these can be used alone or in combination. Further, these fine particles are more preferably subjected to a hydrophobic treatment.

  Examples of the silica fine particles include commercially available products R-805, R-809, R-812, R-972, R-974, R-976, NX-90, RX-50, manufactured by Nippon Aerosil Co., Ltd., manufactured by Clariant. Commercial products HVK-2150, H-200, commercially available products TS-530, TS-610, TS-720, H-5, MS-5 manufactured by Cabot Corporation, and the like can be given.

  Examples of the titanium fine particles include commercial products T-604 and T-805 manufactured by Nippon Aerosil Co., Ltd., commercial products MT-100B, MT-100S, MT-500BS, MT-600, MT-600SS, and JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC, TG-811F, etc. are mentioned.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm are preferably used. Specific examples include homopolymers such as styrene and methyl methacrylate, and copolymers thereof.

  As the lubricant, for example, a metal salt of a higher fatty acid is preferably used. Specific examples include zinc stearate, such as zinc, aluminum, copper, magnesium, calcium, zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. Salts, salts of zinc linoleic acid, calcium and the like can be mentioned.

  The amount of these external additives added is preferably about 0.1 to 5 parts with respect to 100 parts of toner.

  Next, representative embodiments of the present invention and their performance will be shown, and the present invention will be further described. Of course, the present invention is not limited to these examples.

  In the text, “part” means “part by mass”.

[Example 1]
(Hydrophilic treated carbon black: Compound 1)
A hydrophilic treated carbon black aqueous dispersion was obtained by the following method.

Carbon black “Regal 330” 100 g and sulfanilic acid 20 g were mixed. This mixture was placed in a beaker in a 70 ° C. water bath. A solution consisting of 8.4 g sodium nitrite dissolved in 371.6 g distilled water was added to the beaker with rapid mixing to form a pigmented slurry. Hydrochloric acid was added to this solution and the pH of the slurry was adjusted to 2. The slurry was rapidly mixed at 70 ° C. for 1 hour using a magnetic stirrer and then dried in the oven at 70 ° C. -C ₆ resulting material was dried H ₄ S0 ₃ ^- was colored pigment modified with a Na ⁺ groups. A sample, which was a surface-modified color pigment, was extracted with methanol in a Soxhlet extractor for 10 hours to remove any reaction product and re-dried to obtain Compound 1. Compound 1 aqueous dispersion was obtained by dissolving Compound 1 in ion-exchanged water while stirring.

(Preparation of emulsion 1)
In a glass three-necked flask equipped with a stirrer, 80 g of isophorone diisocyanate (IPDI), 252 g of polyoxytetramethylene glycol (PTMG) with a molecular weight of 2000, and 14.4 g of dimethylolpropionic acid (DMPA) In addition, 100 g of ethyl acetate as a solvent and 0.02 g of dibutyltin dilaurate as a catalyst were added at a rate, heated to 80 ° C. using an oil bath and allowed to react for 6 hours. A prepolymer solution was obtained.

  Next, the polyurethane prepolymer solution was dispersed in 500 g of water containing 9 g of triethylamine and emulsified, and then 11.9 g of piperazine hexahydrate and 2 of bis (aminopropyl) amine were added to 180 g of water. An aqueous solution in which 0.4 g was dissolved was added, and the mixture was reacted at 30 ° C. for 3 hours to be polymerized. Then, ethyl acetate was recovered under reduced pressure from the dispersion liquid in which the polymerized resin particles were dispersed in this manner, to obtain an emulsion 1 in which urethane resin particles were dispersed in an aqueous system. The particle size of the resin particles in the emulsion 1 thus obtained was 0.1 μm.

(Preparation of Developing Roller A1) Within the Present Invention With respect to 100 parts of solid content in emulsion 1 prepared as described above, 40 parts of compound 1 (in terms of solid content) and polymethylmethacrylate cross-linking having a volume average particle size of 13 μm Resin fine particles (manufactured by Nippon Shokubai Co., Ltd .: Eposta MA1013) were added at a ratio of 10 parts, and these were mixed with a commercially available mixer (manufactured by Keyence Co., Ltd .: hybrid mixer HM-500), and coating for coating layer using emulsion 1 was performed. Liquid A was prepared.

  The coating solution A for coating layer is applied to the surface of a conductive substrate made of an aluminum roller having a diameter of 16 mm, and this is dried with hot air at 120 ° C. for 10 minutes, so that the coating layer having a thickness of about 30 μm Thus, a developing roller A1 was formed.

(Preparation of developing roller A2) Within the present invention In preparation of developing roller A1, except that compound 1 (in terms of solid content) was 30 parts and carbon black (manufactured by Cabot: XC-72R) was 10 parts. A developing roller A2 was obtained in the same manner.

(Preparation of developing roller A3) Outside of the present invention In the preparation of developing roller A1, the developing roller was prepared in the same manner except that 25 parts of conductive agent carbon black (XC-72R) was used instead of compound 1. A3 was obtained.

(Preparation of developing roller A1-2) Within the present invention In the preparation of developing roller A1, a functional group obtained by the same method except that the sulfonic acid group of p-aminobenzenesulfonic acid was changed to a hydroxyl group in the production method of Compound 1. Developing roller A1-2 was obtained in the same manner except that 40 parts of compound 1-2 (in terms of solid content) obtained by the above treatment was used.

(Preparation of developing roller A1-3) Within the present invention In the preparation of developing roller A1, the same applies except that the sulfonic acid group of p-aminobenzenesulfonic acid was changed to a carboxyl group in the production method of Compound 1 (p-aminobenzoic acid) Developing roller A1-3 was obtained by the same method except that the amount of compound 1-3 (solid content conversion) obtained by the above method was 40 parts.

(Preparation of developing roller A1-4) Within the present invention In the preparation of developing roller A1, a compound obtained by the same method except that the sulfonic acid group of p-aminobenzenesulfonic acid was changed to an ethylene oxide group in the production method of Compound 1 Developing roller A1-4 was obtained in the same manner except that the amount of 1-4 (in terms of solid content) was 40 parts.

(Preparation of developing roller A1-5) Within the present invention In the preparation of developing roller A1, compound 1 obtained by the same method except that the sulfonic acid group of p-aminobenzenesulfonic acid was changed to an amino group in the production method of compound 1. Developing roller A1-5 was obtained in the same manner except that -5 (in terms of solid content) was 40 parts.

(Hydrophobic treated carbon black: Compound 2)
Carbon black was produced by treating the surface of carbon black with the following diazonium salt. This is designated Compound 2.

(Preparation of base rubber layer forming material 1) Within the present invention X-34-424: A / B (silicone rubber, manufactured by Shin-Etsu Chemical Co., Ltd.) 100 parts, X-34-387: A / B (silicone rubber, Shin-Etsu Chemical) A base rubber layer forming material 1 was prepared by mixing and dispersing with 100 parts of Kogyo Co., Ltd. and further adding 100 parts of Compound 2.

(Preparation of base rubber layer forming material 2) In the present invention, the base rubber layer forming material 2 was prepared in the same manner as in the preparation of the base rubber layer forming material 1, except that the compound 2 was changed to 70 parts and 20 parts of ketjen black. Was prepared.

(Preparation of base rubber layer forming material 3) Outside the present invention In preparing base rubber layer forming material 1, base rubber layer forming material 3 was prepared in the same manner except that compound 2 was changed from 100 parts to 80 parts of ketjen black. Prepared.

(Preparation of intermediate layer forming material 1) In the present invention, a reactor equipped with a stirrer, a thermometer, and a nitrogen gas introduction tube was charged with 1000 g of polycarbonate diol (manufactured by Daicel Chemical Industries, "Placcel CD220", number average molecular weight 2000) and isophorone. 278 g of diisocyanate was charged and reacted at 100 ° C. for 6 hours under a nitrogen stream to obtain a prepolymer having a free isocyanate value of 3.44%, and 548 g of methyl ethyl ketone was added thereto to obtain a uniform solution of urethane prepolymer.

  Subsequently, 1000 g of the urethane prepolymer solution was added in the presence of a mixture consisting of 71.8 g of isophoronediamine, 4.0 g of di-n-butylamine, 906 g of methyl ethyl ketone and 603 g of isopropyl alcohol, and reacted at 50 ° C. for 3 hours. The polyurethane resin solution thus obtained had a resin solid content concentration of 30% and an amine value of 1.2 KOH (mg / g).

  On the other hand, a reactor equipped with a stirrer, a water separator, a thermometer, and a nitrogen gas introduction pipe was charged with 1400 g of glycidol (manufactured by NOF Corporation, Epiol OH) and a tetramethoxysilane partial condensate (average number of Si, 4, Tama). Chemical Co., Ltd., methyl silicate 51) 8957.9 g was charged, and the mixture was heated to 90 ° C. with stirring under a nitrogen stream, and then reacted with 2.0 g of dibutyltin dilaurate as a catalyst.

  During the reaction, methanol in the water separator was distilled off, and the reaction was cooled when the amount reached about 630 g. It took 5 hours to cool after raising the temperature. Subsequently, about 80 g of methanol remaining in the system was removed under reduced pressure at 13 kPa for about 10 minutes. In this way, an epoxy group-containing alkoxysilane partial condensate was obtained.

  Furthermore, after heating 500 g of the above-mentioned polyurethane resin to 50 ° C. in the same reaction apparatus, 10.95 g of the epoxy group-containing alkoxysilane partial condensate was added and reacted at 60 ° C. for 4 hours under a nitrogen stream. An alkoxy group-containing silane-modified polyurethane resin was obtained.

  100 parts of the alkoxy group-containing silane-modified polyurethane resin thus obtained and 40 parts of Compound 2 were added and mixed and dispersed to prepare an intermediate layer forming material 1 as an intermediate layer forming material immediately below the surface layer.

(Preparation of Intermediate Layer Forming Material 2) Within Preparation of Intermediate Layer Forming Material 1 In the preparation of the intermediate layer forming material 1, the intermediate layer forming material 2 was prepared in the same manner except that the compound 2 was changed to 30 parts and 15 parts of ketjen black.

(Preparation of intermediate layer forming material 3) Outside of the present invention In preparing intermediate layer forming material 1, intermediate layer forming material 3 was prepared in the same manner except that compound 2 was changed to 35 parts of ketjen black.

(Preparation of surface layer forming material 1) Within the present invention In a reactor equipped with a stirrer, thermometer, nitrogen gas inlet tube, and reflux condenser, 310 parts of ε-caprolactone, 150 parts of alcohol-modified siloxane oil and tetrabutyl titanate 0 .05 parts was charged and reacted at a temperature of 180 ° C. for 10 hours under a nitrogen stream to obtain a polysiloxane-polyester copolymer having a hydroxyl value of 37, an acid value of 0.40, and a number average molecular weight of 3,030.

  150 parts of the above copolymer and 27 parts of 1,4-butanediol are dissolved in a mixed solvent of 200 parts of methyl ethyl ketone and 100 parts of dimethylformamide, and 91 parts of hydrogenated diphenylmethane with good stirring at 60 ° C. A solution obtained by dissolving diisocyanate (which may be abbreviated as hydrogenated MDI or H12MDI) in 188 parts of dimethylformamide was gradually added dropwise and reacted at 80 ° C. for 6 hours to obtain a silicone copolymer polyurethane resin solution. . This solution was very transparent and had a viscosity of 35.5 Pa · s (25 ° C.) at a solid content of 35%.

  100 parts of the silicone copolymer polyurethane resin thus obtained and 40 parts of Compound Example 2 are added, and 40 parts of particles made of a crosslinked urethane resin having a number average primary particle diameter of 20 μm are mixed and dispersed to form a surface layer forming material. A rubber composition (surface layer forming material 1) was prepared.

(Preparation of surface layer forming material 2) Within the present invention In preparing surface layer forming material 1, surface layer forming material 2 was prepared in the same manner except that compound 2 was changed to 30 parts and 15 parts of ketjen black.

(Preparation of surface layer forming material 3) Outside the present invention In preparing the surface layer forming material 1, the surface layer forming material 3 was prepared in the same manner except that the compound 2 was changed to 35 parts of ketjen black.

(Preparation of developing roller B1) Within the present invention Next, a SUS303 metal core (diameter: 10 mm) is set as the shaft body 2 in the roller mold, and the gap between the shaft body and the inner peripheral surface of the roller mold is set as described above. The obtained base rubber layer forming material 1 is cast, heat vulcanized (180 ° C. × 1 hour), demolded, and further subjected to secondary vulcanization treatment (200 ° C. × 4 hours) to obtain a shaft body A base rubber layer (thickness 5 mm) was formed on the outer periphery of 2.

  The shaft body with the base rubber layer thus obtained is removed from the mold, and the intermediate layer forming material 1 is formed with a thickness of 15 μm on the outer peripheral surface of the base rubber layer and heated at 100 ° C. for 1 hour. It processed and the layer which consists of a polyurethane resin-silica hybrid body was formed. Further, the surface layer forming material 1 was applied to a thickness of 15 μm and treated at 100 ° C. for 1 hour to form a surface layer made of a silicone copolymer polyurethane resin, to obtain a developing roller B1 of the present invention. This is referred to as a developing roller B1.

(Preparation of the developing roller B2) Within the present invention In the preparation of the developing roller B1, the base rubber layer forming material 2, the intermediate layer forming material, and the surface layer forming material are replaced with the base rubber layer forming material 2 and the intermediate layer, respectively. Using the forming material 2 and the surface layer forming material 2, a similar developing roller B2 was obtained.

(Preparation of developing roller B3) Outside of the present invention In the preparation of developing roller B1, instead of combining the base rubber layer forming material, the intermediate layer forming material, and the surface layer forming material into one, the base rubber layer forming material 3 and the intermediate layer, respectively. Using the forming material 3 and the surface layer forming material 3, a similar developing roller B3 was obtained.

(Preparation of surface layer forming material 4) Outside of the present invention: Example using graft carbon Deionized with 0.1 part of polyvinyl alcohol dissolved in a flask equipped with a stirrer, inert gas introduction tube, reflux condenser and thermometer 200 parts of water was charged. Then, 48 parts of styrene and 12 parts of carbon black MA-600 prepared in advance were charged, heated to 140 ° C. while blowing nitrogen gas, and stirred at this temperature for 5 hours to conduct a polymerization reaction, followed by cooling. did. After the reaction, 300 parts of toluene was added to the reactive organism, and then 7000 parts of methanol was added and reprecipitated to obtain grafted carbon black. Surface layer forming material 4 was prepared in the same manner except that compound 2 in surface layer forming material 1 was changed to 35 parts with the grafted carbon black obtained here as an actual carbon black addition amount.

(Preparation of developing roller B4) Outside of the present invention In developing roller B1, surface layer forming material 4 was used instead of surface layer forming material 1, and similar developing roller B4 was obtained.

(Preparation of developing roller B1-2) Within the present invention: Base rubber-less 40 parts by mass of compound 2 is added to a solution in which 100 parts by mass of polyamide resin “CM8000” (manufactured by Toray Industries, Inc.) is dissolved in 500 parts by mass of methanol. Then, a coating solution for forming a coating layer was prepared by dispersing for 2 hours using a sand mill.

  After spraying this coating solution on the surface of a conductive substrate made of an aluminum roller having a diameter of 16 mm, drying is performed at 120 ° C. for 30 minutes to form a coating layer having a total film thickness of 15 μm after drying, Developing roller B1-2 was obtained.

(Characteristic evaluation)
Next, the developing roller obtained as described above was mounted on a commercially available printer (manufactured by Konica Minolta: Magiccolor 2300DL non-magnetic one-component development), and the following evaluation was performed. The linear pressure of the regulating member pressed against the surfaces of the developing rollers A1 to A3 and A1-2 to 1-5, B1 to B4 and B1-2 was changed to 70 mN / mm, and the system speed was changed to 160 mm. The developing bias potential conditions were the same as the developer regulating member potential, and two conditions of regulating member potential of −300V were implemented.

  Then, using the printers equipped with the developing rollers A1 to A3 and A1-2 to 1-5, B1 to B4 and B1-2 as described above, the temperature is 32.5 ° C. and the humidity is 85%. In a humidity environment (H / H) and a low-temperature, low-humidity environment (L / L) at a temperature of 10 ° C. and a humidity of 10% (L / L), after performing a printing durability test on 5000 sheets, the toner fill to each developing roller The ming state was evaluated. In addition, it obtains the initial image density (ID) after high-temperature / high-humidity environment (H / H) and low-temperature / low-humidity environment (L / L), and after the 5000 printing test, and can also change the environment. The image density difference ΔTDa based on this was obtained, and the image density difference ΔTDb after the initial printing under the respective environments and after the 5000 printing test was obtained. The results are shown below.

  In each evaluation, “O” indicates no problem, “Δ” indicates a practically acceptable level, and “X” indicates a practical problem.

Image Density The evaluation was based on how much the color of the solid image density is the transmission density on paper.

○: Yellow (Y), magenta (M), and cyan (C) have a transmission density on paper of 1.0 or more, black (Bk) is 1.4 or more, and ΔTDa and ΔTDb are both 0.2 or less. Δ: Transmission density on paper of yellow (Y), magenta (M), cyan (C) is 1.0 or more and black (Bk) is 1.4 or more, but either ΔTDa or ΔTDb is 0.2 Large x: At least one of the colors has a transmission density on paper of yellow (Y), magenta (M), cyan (C) of 1.0 or more, and black (Bk) of 1.4 or more, or ΔTDa and ΔTDb In each case, the density unevenness was evaluated based on the degree of on-paper transmission density unevenness synchronized with the rotation of the developing roller in a solid image.

○: There is no density unevenness in the naked eye observation, or it does not matter. Δ: There is some density unevenness in the naked eye observation, but the density difference is less than 0.2. ×: The density unevenness (density difference) is 0.2 or more. Image loss Judgment was made based on the reproducibility of 2-ON and 2-OFF dot lines in a solid black image.

○: Dot reproducibility is secured △: White line is recognized but partially broken ×: White line is not recognized Leakage noise For solid images in a high-temperature and high-humidity environment, evaluate the following: went.

○: No white spots and no traces of charge leakage are detected. Δ: Slight white spots (diameter of 0.5 mm or less) are recognized, but it is judged that there is no practical problem. X: White spots larger than 0.5 mm. Fog with spots The fog (fine spots) on the white background of the image was evaluated based on the result of visual observation and observation with a magnifying glass (× 10).

○: No fog is observed in both the naked eye observation and the magnifying glass. Δ: No fog is observed in the naked eye observation, but is observed in the loupe observation.

  When the developing rollers A1, A2, B1, B2, and A1-2 to A1-5, B1-2 in the present invention are used, good results are obtained, but the rollers A3, B3, and B4 outside the present invention are obtained. It can be seen that there is a problem with at least one of the characteristics when using.

[Example 2]
In the surface layer forming material 1 described in Example 1, 20 to 50 parts of carbon black (CB) was added to 100 parts of resin, and then a 10 μm coating film was formed on an aluminum plate.

  By measuring the volume specific resistance of the obtained CB-containing resin film at 10 points, variation of the average value and the resistance value in the coating film was confirmed.

  In the case of Compound 1 (in terms of solid content) used in Example 1, the volume resistivity can be stably controlled from the 14th power to the 7th power depending on the amount added, and the variation range of 10-point measurement is 1 / It is within 3 digits. The results are shown in FIG. 5 as an example.

  On the other hand, when untreated carbon black (Cabot Corp .: XC-72R) is used, the volume resistivity is increased from the 14th power to the second power by setting the CB amount to 20 to 40 parts as shown as a comparative example. In the case where 25 parts of CB amount is added, the resistance value varies by 1 to 3/2 digits in 10-point measurement, and when used as a surface layer of the developing roller, It is estimated that

  Further, the same resistance value when adding 30 parts of the grafted carbon black used to produce the developing roller B4 is a fourth power level, but there is a variation in resistance of about one digit. Further, this coating film is poor in uniformity in appearance observation, and it is assumed that the coating film peels off when it is configured as a roller.

FIG. 3 is a schematic cross-sectional view showing a configuration of a roller of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a developing device for developing non-magnetic single component toner. 1 is a configuration cross-sectional view of an example of a full-color image forming apparatus. Resistance value measurement method. Relationship between added amount of carbon black and resistance value.

Explanation of symbols

1 Shaft (Rotating shaft)
2 Elastic layer (base rubber layer)
3 Adhesive layer (intermediate layer)
4 Surface layer 10 Photosensitive drum 20 Laser scanning optical system 30 Full-color developing device 31, 31Y, 31M, 31C, 31Bk Developing device 32 Developer carrier (developing roller)
33 Support shaft 40 Intermediate transfer belt 50 Cleaner 60 Paper feed means 70 Fixing device 80 Vertical conveyance path S Recording material

Claims (7)

In a functional member in which a coating layer is formed on a conductive member, the coating layer is formed by dispersing conductive or semiconductive particles having a hydrophilic group or a hydrophobic group in a non-conductive polymer material. The functional member characterized by the above-mentioned. The functional member according to claim 1, wherein the hydrophilic group is any one of a hydroxyl group, a carboxyl group, a sulfonic acid group, and an ethylene oxide group. The functional member according to claim 1, wherein the hydrophobic group is an alkyl group or an aryl group. The functional member according to claim 1, wherein the functional member is a developing roller, and the conductive member is a conductive shaft. The developing roller according to claim 4, wherein the developing roller does not have an elastic layer, and the coating layer is formed directly on the conductive shaft. A developing method comprising performing non-magnetic one-component development using the developing roller according to claim 5. An image forming apparatus, wherein non-contact development is performed using the developing method according to claim 6.

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