JP2010026349A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus using a trickle development method, in which a loaded electrostatic latent image carrier has high wear resistance, exhibits excellent durability, can stably perform high-quality image formation over a long period of time, and achieves substantially maintenance-free image formation, and an image forming method. <P>SOLUTION: In the image forming apparatus including a developing means to perform development with a developer of a trickle development method using a two-component developer including toner and a carrier, the electrostatic latent image carrier has a support and at least a photosensitive layer on the support, and the outermost surface layer of the electrostatic latent image carrier contains a crosslinked resin formed by crosslinking a reactive charge transport material having at least two hydroxyl groups and an isocyanate compound, and at least one kind of tertiary amines represented by general formula (I). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention comprises an electrophotographic photosensitive member that realizes high abrasion resistance and stabilization of electric characteristics over a long period of time, and contains a two-component developer composed of a toner and a carrier, and a new carrier or the developer The present invention relates to an image forming apparatus and an image forming method using an electrophotographic system such as a copying machine, a printer, a facsimile, and a composite machine including a developing unit that is appropriately replenished and a developer is replaced.

In an image forming apparatus such as a copying machine, a facsimile, a printer, or a printing machine, a two-component developer composed of a carrier and toner is used. This two-component developer is used for development again by stirring only the toner consumed by development and stirring the recovered carrier. This carrier is deteriorated due to wear of the coating layer of the carrier due to long-term stirring. Recently, in order to suppress this, the two-component developer is replenished as needed, and the two-component developer which has become excessive due to this replenishment. A trickle development method for forming an image while collecting the agent has been proposed.
In this trickle system, inventions of the following systems are known. :
A method of replenishing a developing device with a toner and carrier mixture called a premix developer (see, for example, Patent Documents 1 to 4)
A system in which toner and carrier are independently replenished to the developing device, and excess developer in the developing tank is recovered (see Patent Documents 5 to 7)
A system for controlling toner replenishment corresponding to toner consumption, carrier replenishment corresponding to replenished toner amount, and developer discharge (see Patent Documents 8 and 9).
A system in which a carrier replenishment unit is shared by a plurality of developing devices (see Patent Documents 10 and 11)
A system in which toner and carrier arranged at a different location from the developing means are mixed in a mixing ratio and supplied into the developing tank (see Patent Documents 12 and 13).

  On the other hand, as a problem in electrophotography, there is known a so-called carrier adhesion phenomenon in which carriers adhere to a photoreceptor. When this phenomenon occurs, the carrier attached to the photoconductor is pressed against the surface of the photoconductor by a member in contact with the photoconductor such as a cleaning member or a transfer member, or stays on the edge of the cleaning blade, etc. There are problems that cause scratches and wear on the surface of the photoreceptor. Therefore, when manufacturing carriers, not only electrical characteristics, but generally, physical properties such as weight average particle diameter, volume resistivity, and magnetization are manufactured in a suitable range to suppress carrier adhesion. Have been to.

  However, the above physical property values are average values of the entire carrier particle group, and each has a certain width. Therefore, even when the physical property values are manufactured in a suitable range, particles that are likely to cause carrier adhesion, for example, particles having a small particle diameter and those having a small volume resistivity value are included in a certain ratio in the manufacturing stage. It will be.

  In the trickle development type image forming apparatus, when toner is consumed by image formation, a new carrier is supplied accordingly, so that particles that easily adhere to the carrier are also supplied. Further, even if such particles that easily adhere to the carrier adhere to the carrier and are released to the outside of the developing device, they are not collected by the developer discharging means provided in the developing device, but are adhered to the photoconductor. It is carried to the contact member, and the amount attached to the contact member increases. In order to reduce the particles that are likely to adhere to the carrier, for example, a countermeasure such as using a core material from which fine powder has been cut can be considered so as to reduce the variation in the physical property values described above, but this involves an increase in manufacturing cost. In addition, it is technically very difficult to select particles that are likely to adhere due to volume resistivity or magnetization, and even if these technologies are used, the removal is sufficient for an increase in cost. Not. Therefore, in the trickle developing type image forming apparatus, even if the necessity of replacing the carrier that suppresses carrier deterioration is eliminated, there is a problem that the photosensitive layer is worn, and the frequency of replacement due to a decrease in the life due to wear of the photosensitive member is high. There is concern that it will increase.

In such a trickle development type image forming apparatus, use of a highly durable photoconductor has been proposed. Examples of the highly durable photoconductor include the following.
(1) An inorganic photoconductor and a high hardness amorphous silicon photoconductor, a photoconductor having a protective layer made of colloidal silica-containing curable silicone resin on the surface layer (Patent Document 14),
(2) a photoreceptor (Patent Documents 15 and 16) having on its surface a resin layer in which an organosilicon-modified hole transporting compound is bonded in a curable organosilicon polymer;
(3) A photoreceptor (Patent Document 17) having, in a protective layer, a urethane resin obtained by crosslinking and polymerizing a plurality of polyols and polyisocyanates.
(4) a photoreceptor having a surface layer composed of a crosslinked layer obtained by curing a radical polymerizable monomer and a radical polymerizable compound having a charge transporting structure (Patent Documents 18 to 20);
(5) For example, an image forming apparatus combining an amorphous silicon photoconductor and a trickle developing method (Patent Document 21),
(6) Combination with a photoreceptor having a curable silicone resin in the surface layer (Patent Document 22).

The amorphous silicon photoconductor, which is the inorganic photoconductor (1) or (5), exhibits high durability against scratches and abrasion, but has the following problems.
1. 1. Optical characteristics such as the light absorption wavelength range and the amount of absorption of the organic photoreceptor; 2. Electrical characteristics such as high sensitivity and stable charging characteristics; 3. Wide selection range of materials; 4. ease of manufacture; Cost, 6. Non-toxic, etc.
Specifically, regarding the charging characteristics, since the relative permittivity is large and the volume resistivity is small, the charging ability is small and the dark attenuation characteristic is large. Therefore, the contrast potential at the time of image formation that takes into account the residual potential and the development bias potential cannot be kept small without obtaining a charging potential. Further, voltage development with a small contrast potential does not provide a sufficient image density, and it is also disadvantageous for tone reproduction. Further, it is considered that the image forming environment is further deteriorated in the photoconductor in which the charging characteristics are repeatedly deteriorated, and maintenance of stabilization of the charging potential and the contrast potential becomes a big problem. In addition, the amorphous silicon photoreceptor is formed of SiH _{4 as} a raw material for forming a photoconductive layer at the time of charging, leaving some Si—H bonds, so that Si—H and Si—Si are formed during discharge. An oxidizing gas such as ozone acts on the dangling bond formed by breaking the bond to form a low resistance material SiOx film. For this reason, there is a problem in that image flow is likely to occur, and NOx adheres to the surface layer, causing image flow more and more. This image flow is greatly influenced by the amount of moisture in the atmosphere, and particularly when a SiOx film is formed, the image flow occurs at a humidity of about 50% RH.

  In order to avoid such a problem of image flow, a photosensitive member heating means such as a heater (drum heater) for heating the photosensitive member is necessary, which involves an increase in size and complexity of the image forming apparatus. Furthermore, it is not preferable for environmental load such as energy saving and resource saving.

  In addition, a photoconductor having a resin layer on the surface of the colloidal silica-containing curable silicone resin (1) or the organosilicon-modified hole transporting compound (2) bonded in a curable organosilicon polymer, Repeated electrophotographic characteristics and environmental characteristics are insufficient, and fog and image blur are likely to occur. In the photoconductor using these, it is necessary to mount a drum heater or the like to suppress the occurrence of image blurring, which leads to an increase in the size and cost of the apparatus as described above. Further, when the trickle developing method is combined with an image forming apparatus having these photoconductors, the abrasion resistance is insufficient and the durability is inferior.

  On the other hand, in (3), (4) and the like, specifically, in the case of a photoreceptor having a surface layer composed of a crosslinked layer obtained by curing a radically polymerizable compound and having an elastic displacement rate of 35% or more, a trickle developing method. A photoconductor that employs a material having an elastic power that is considered to be a conventional index of wear resistance cannot predict wear resistance. This is what has been found as a result of extensive studies by the inventor. That is, in the trickle development method, scratches due to carrier adhesion are considered to be the main factor of photoconductor wear, and innumerable scratches in the circumferential direction of the photoconductor actually occur. Moreover, it can be said that this scratch wear does not have a good correlation with the elastic displacement rate. That is, when trying to obtain a highly durable photoreceptor in the trickle development system, it is inappropriate (irrational) that the photoreceptor desires high durability against scratch wear even if the photoreceptor is manufactured using the elastic displacement rate as an index. I must say.

On the other hand, a photoreceptor having a protective layer made of a urethane resin obtained by crosslinking and polymerizing a plurality of polyols and polyisocyanates exhibits a relatively high durability. This may be because the durability against scratching due to carrier adhesion, which is considered to be the main factor of photoconductor wear in the trickle development system, is high. However, when the surface of these protective layers made of urethane resin is exposed to an oxidizing gas such as ozone or NOx, an electrostatic latent image flows and image blurring occurs. For this reason, the present inventor's research reveals that the oxidizing gas generated from the charger is insufficiently durable even though there is a margin in wear resistance due to repeated use over a long period of time. Yes.
Further, in the past examination of the present inventors, an electrophotographic photosensitive member having a charge transporting urethane resin layer obtained by heat-crosslinking a reactive charge transporting substance having a specific structure and an isocyanate compound as the outermost surface layer was considered. is there. And this thing achieves the reduction of the residual potential, and the wear resistance is remarkably improved. When the surface of this electrophotographic photosensitive member is exposed to an oxidizing gas, an electrostatic latent image flows, It has also been clarified by the present inventor's research that image blurring occurs.

  From the above considerations, even if these highly durable photoconductors in the prior art are mounted on a trickle development type image forming apparatus, stable and high-quality images can be formed over a long period of time, and maintenance-free image formation is possible. The current situation is that no device is available.

Japanese Patent Publication No. 2-21591 JP-A-9-166912 JP 9-218575 A Japanese Patent Laid-Open No. 9-244376 JP-A-9-204105 Japanese Patent Laid-Open No. 9-251235 JP-A-9-269644 Japanese Patent Laid-Open No. 10-63074 Japanese Patent Laid-Open No. 10-63075 JP-A-7-234575 JP 2001-194860 A JP-A-11-143196 JP-A-11-272075 Japanese Patent Laid-Open No. 6-118681 Japanese Patent Laid-Open No. 9-124943 JP-A-9-190004 JP 2004-117766 A Japanese Patent No. 3194392 JP 2000-66425 A JP 2004-302450 A JP 2007-233300 A JP 2005-3838 A

  An object of the present invention is to solve the above problems in the prior art and achieve the following objects. That is, according to the present invention, in a trickle developing type image forming apparatus, an organic photoconductor having high wear resistance can stably form an image with high durability and high quality over a long period of time and is maintenance-free. It is an object of the present invention to provide an image forming apparatus that can perform the above-described process and to provide an image forming method that uses such a trickle-developing image forming apparatus.

  In an image forming apparatus having a developing unit that develops with a trickle developing developer using a two-component developer containing a toner and a carrier, the electrostatic latent image carrier includes a support, In the electrostatic latent image carrier having at least a photosensitive layer on the support, the outermost surface layer of the electrostatic latent image carrier comprises a reactive charge transport material having at least two hydroxyl groups and an isocyanate compound. The present inventors have found that the above problems can be achieved by containing a crosslinkable resin formed by crosslinking and at least one selected from tertiary amines represented by the following general formula, and have reached the present invention.

That is, the present invention has the following solutions.
(1) In an image forming apparatus having a developing means for developing with a developer of a trickle developing method using an electrostatic latent image bearing member, and a two-component developer containing a toner and a carrier,
The electrostatic latent image carrier has a support and at least a photosensitive layer on the support, and the outermost surface layer of the electrostatic latent image carrier has at least two hydroxyl groups. An image forming apparatus comprising: a crosslinkable resin formed by crosslinking a substance and an isocyanate compound; and at least one selected from tertiary amines represented by the following general formula (I).

（式（Ｉ）中、R1、R2は置換又は無置換のアルキル基であり、R1、R2は同一であっても異なっても良い。また、R3は少なくとも水酸基を１つ有するアルキル基またはアリール基を表す。）

(In the formula (I), R1 and R2 are substituted or unsubstituted alkyl groups, and R1 and R2 may be the same or different. R3 is an alkyl group or aryl group having at least one hydroxyl group. Represents.)

(2) The image forming apparatus according to (1), wherein the outermost surface layer is a protective layer on a photosensitive layer of the electrostatic latent image carrier.
(3) The outermost surface layer contains conductive fine particles, and the conductive fine particles are M _x Sb _y O _z (where M represents a metal element other than Sb. _X , y, and z represent each The image forming apparatus according to (1) or (2) above, wherein the image forming apparatus is at least one kind represented by a molar ratio of elements.
(4) The image forming apparatus according to (3), wherein the conductive fine particles include zinc antimonate (ZnSb ₂ O ₆ ).
(5) The image forming apparatus according to any one of (1) to (4), wherein the isocyanate compound has an aromatic ring and has at least two isocyanate groups.
(6) The image forming apparatus according to (5), wherein the isocyanate compound having an aromatic ring uses an adduct type compound of a diisocyanate compound and a polyol in combination.
(7) The image forming apparatus according to any one of (1) to (6), wherein NCO% of the isocyanate compound is 3 to 50.
(8) The image forming apparatus according to any one of (1) to (7), wherein the content of the reactive charge transporting substance is 5 to 45 wt% in the outermost surface layer.
(9) The reactive charge transporting substance having at least two hydroxyl groups has a molecular structure represented by the following general formula (1), according to any one of (1) to (8), Image forming apparatus.

（式（１）中、Ｙは、少なくとも２個の水酸基を有する炭素数１〜６のアルキル基又はアルコキシ基を表し、Ｘは電荷輸送性化合物基を表す。前記アルキル基又はアルコキシ基は水酸基以外の置換基を有していても良い。また、ｎは１〜４の整数を表す。）

(In Formula (1), Y represents a C1-C6 alkyl group or alkoxy group having at least two hydroxyl groups, and X represents a charge transporting compound group. The alkyl group or alkoxy group is other than a hydroxyl group. And n represents an integer of 1 to 4.)

(10) The image forming apparatus according to (9), wherein the group X in the formula (1) has a molecular structure represented by the following general formula (2).

（式（２）中、Ａｒ_１〜Ａｒ_３は置換又は無置換のアリール基またはアリーレン基を表し、これらは同一であっても異なっていても良い。また、Ａｒは２価の芳香族基を表す。また、前記一般式（１）中の置換基Ｙの数ｎは前記式（２）中のＡｒ_１〜Ａｒ_３のアリーレン基の数と、前記Ａｒ_３を置換基とする炭素原子（不飽和炭素原子）が有する結合の手の合計と同一であり、少なくともＡｒ_１、〜Ａｒ_３及び前記Ａｒ_３を置換基とする炭素原子のいずれかが、前記一般式（１）中の置換基Ｙを有する。ただし前記Ａｒは前記Ａｒ_３を置換基とする炭素原子の隣の不飽和炭素原子と結合している基である。）

(In formula (2), Ar _{1 to} Ar ₃ represent a substituted or unsubstituted aryl group or arylene group, which may be the same or different. Ar represents a divalent aromatic group. In addition, the number n of the substituent Y in the general formula (1) represents the number of the arylene groups Ar _{1 to} Ar ₃ in the formula (2) and the carbon atom (non-determined) having the Ar ₃ as a substituent. Saturated carbon atom) is the same as the total number of bonds, and at least any _one of Ar ₁ , Ar ₃ and Ar ₃ as a substituent is a substituent Y in the general formula (1). However, Ar is a group bonded to an unsaturated carbon atom adjacent to the carbon atom having Ar ₃ as a substituent.)

(11) The image forming apparatus according to (9), wherein the group X in the formula (1) has a molecular structure represented by the following general formula (3).

（式（３）中、Ａｒ_１〜Ａｒ_４は置換又は無置換のアリール基またはアリーレン基を表し、これらは同一でも異なっていても良い。また、Ａｒはアリーレン基を表す。前記一般式（１）中の置換基Ｙの数ｎは前記Ａｒ_１〜Ａｒ_４のアリーレン基の合計の数と同一であり、少なくともＡｒ_１〜Ａｒ_４のいずれか１つが、前記一般式（１）中の置換基Ｙを有する。ただし前記Ａｒは前記Ａｒ_３及びＡｒ_４を置換基とする炭素原子の隣の不飽和炭素原子と結合している基である。）

(In Formula (3), Ar _{1 to} Ar ₄ represent a substituted or unsubstituted aryl group or an arylene group, which may be the same or different. Ar represents an arylene group. ) the number n of substituents Y in the same as the total number of the arylene group of said _Ar 1 to Ar _4, any one of at least _Ar 1 to Ar _4, substituents in the general formula (1) Y, provided that Ar is a group bonded to an unsaturated carbon atom adjacent to the carbon atom having Ar ₃ and Ar ₄ as substituents.

(12) The image forming apparatus according to any one of (9) to (11), wherein the reactive charge transporting substance has a structure in which a hydroxyl group is bonded to at least two adjacent carbon atoms. .
(13) The image forming apparatus according to (12), wherein the reactive charge transport material (1) has at least a molecular structure represented by the following general formula (4).

（式（４）中、Ｒは炭素数１〜４の置換又は無置換のアルキレン基、又はアルコキシレン基を表わし、Xは前記式（１）のＸと同じ基を表す。また、ｎは１〜４の整数を表す。）

(In Formula (4), R represents a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms or an alkoxylene group, X represents the same group as X in Formula (1), and n represents 1) Represents an integer of ~ 4.)

(14) The outermost surface layer contains a crosslinkable resin formed by cross-linking the polyol compound and an isocyanate compound using at least one polyol compound having no charge transporting compound group. The image forming apparatus according to any one of (1) to (13).
(15) The image forming apparatus according to (14), wherein at least one of the polyol compounds has an OH equivalent which is a ratio of molecular weight to molecular number (molecular weight / number of hydroxyl groups) of less than 150.
(16) The image forming apparatus according to any one of (1) to (15), wherein the image forming apparatus forms a color image by sequentially superposing a plurality of color toners.
(17) The toner is a toner containing at least a binder resin, a colorant, and an external additive. The external additive has a charge amount of −40 to −80 μC / g and a hydrophobicity of 60% or more. The image forming apparatus according to any one of (1) to (16), wherein the image forming apparatus is titanium oxide.
(18) The external additive of the toner contains hydrophobic silica, and the content ratio (Si / Ti) of the silica to the titanium oxide is 1.0 to 2.0. The image forming apparatus according to (17).
(19) The image forming apparatus according to any one of (1) to (18), wherein the toner has a volume average particle diameter of 5 to 9 μm.
(20) A toner solution is prepared by dissolving or dispersing a toner material containing at least an active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound in an organic solvent. A solution is emulsified or dispersed in an aqueous medium to prepare a dispersion, and the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound are reacted in the aqueous medium to cause adhesion. The image forming apparatus according to any one of (17) to (19), which is obtained by generating a base material in a particulate form and removing the organic solvent.
(21) The image forming apparatus according to any one of (17) to (20), wherein the toner has an average circularity of 0.93 to 1.00.
(22) The carrier according to (1) to (21), wherein the carrier comprises a core material and a coating layer covering the surface of the core material, and the volume specific resistance of the carrier is 7 to 13 [Log Ω · cm]. The image forming apparatus according to any one of the above.
(23) The image forming apparatus according to (22), wherein the carrier has a volume average particle diameter of 30 μm to 60 μm.
(24) The above (1) to (1), wherein the image forming apparatus is a tandem type in which a plurality of image forming elements each having at least the electrostatic latent image carrier and further having a charging unit, a developing unit, a transfer unit, and a fixing unit are provided. 23) The image forming apparatus according to any one of 23).
(25) The image forming apparatus further includes an intermediate transfer member on which the toner image formed on the electrostatic latent image carrier is primarily transferred, and a toner image carried on the intermediate transfer member as a secondary on the recording medium. (1) to (1), wherein a plurality of color toner images are sequentially superimposed on an intermediate transfer member to form a color image, and the color image is secondarily transferred collectively onto a recording medium. (24) The image forming apparatus according to any one of (24).
(26) a charging step of charging the surface of the electrostatic latent image carrier, an exposure step of exposing the charged electrostatic latent image carrier surface to form an electrostatic latent image, and the electrostatic latent image as a toner A development step of forming a visible image by developing using a two-component developer containing a carrier, and at least an image forming method comprising:
Reactive charge transport wherein the electrostatic latent image carrier has a support and at least a photosensitive layer on the support, and the outermost surface layer of the electrostatic latent image carrier has at least two hydroxyl groups Containing at least one selected from a cross-linkable resin formed by cross-linking a functional substance and an isocyanate compound, and a tertiary amine represented by the following general formula. A developing unit having a supply unit for supplying any one of the component developers to the inside of the developing unit; and a discharging unit for discharging either the carrier or the two-component developer contained in the developing unit to the outside of the developing unit. An image forming method which is performed.

  According to the present invention, the electrostatic latent image carrier is a support and an electrostatic latent image carrier having at least a photosensitive layer on the support, and the outermost surface layer of the electrostatic latent image carrier is at least 2 A crosslinkable resin formed by crosslinking a reactive charge transporting substance having one hydroxyl group and an isocyanate compound, and at least one selected from tertiary amines represented by the general formula (I) In addition, it is equipped with an organic photoconductor that has excellent wear resistance and suppresses the occurrence of abnormal images due to oxidizing gas. Thus, it is possible to provide an image forming apparatus that can suppress rubbing scratches, has high electrostatic property stability, can stably output a good image for a long period of time, and is almost maintenance-free.

Hereinafter, an image forming apparatus and an image forming method according to the present invention will be described with reference to embodiments.
The image forming apparatus of the present invention has developing means for developing with a trickle developing type developer using a two-component developer containing toner and carrier, and the electrostatic latent image carrier of the image forming apparatus has a unique configuration have. Such a trickle developing type developing means includes a supplying means for supplying carrier or carrier and toner to the developing means, and a discharging means for discharging the carrier or carrier and toner contained in the developing means to the outside of the developing means. It is comprised.

(Electrostatic latent image carrier)
The electrostatic latent image carrier used in the image forming apparatus of the present invention includes a support in the image forming apparatus having a trickle developing type developing unit using a two-component developer containing a toner and a carrier. A crosslinkable resin having at least a photosensitive layer on the body, and wherein the outermost surface layer of the electrostatic latent image carrier is formed by crosslinking a reactive charge transporting substance having at least two hydroxyl groups and an isocyanate compound And a tertiary amine represented by the following general formula (I).

In formula (I), R1 and R2 are substituted or unsubstituted alkyl groups, and R1 and R2 may be the same or different. R3 represents an alkyl group or an aryl group having at least one hydroxyl group.
In the first embodiment, the electrostatic latent image carrier is provided with a single-layer type photosensitive layer on a support, and further includes a protective layer, an intermediate layer, and other layers as necessary.
Further, in the second embodiment, the electrostatic latent image carrier is further provided with a support, and a laminated photosensitive layer having a charge generation layer and a charge transport layer at least in this order on the support. Depending on the case, it has a protective layer, an intermediate layer, and other layers. In the second embodiment, the charge generation layer and the charge transport layer may be laminated in reverse.
In the single-layer type photosensitive layer according to the first embodiment, the outermost surface layer corresponds to a photosensitive layer or a protective layer formed on the photosensitive layer. In the multilayer photosensitive layer according to the second embodiment, a charge transport layer or a protective layer formed on the charge transport layer corresponds to the outermost surface layer. In the trickle developing system used in the image forming apparatus of the present invention, a carrier or a carrier and a toner and a supply unit for supplying the toner to the developing unit, and a part of the two-component developer contained in the developing unit are disposed outside the developing unit. Developer discharging means for discharging is provided.

  FIG. 1 is a schematic cross-sectional view of an electrostatic latent image carrier that can be used in the present invention, in which a photosensitive layer 202 is provided on a support 201. 2, 3 and 4 show examples of the layer structure of another electrostatic latent image carrier that can be used in the present invention. FIG. 2 shows that the photosensitive layer is a charge generation layer (CGL). It is a function separation type composed of a charge generation layer (CTL) 203 and a charge transfer layer (CTL) 204. FIG. 3 shows a structure in which an undercoat layer 205 is provided between a support 201, a charge generation layer (CGL) 203 of a function separation type photosensitive layer, and a charge transport layer (CTL) 204. Further, an intermediate layer 207 may be provided between the undercoat layer 205 and the charge generation layer 203. FIG. 4 shows a type in which a protective layer 206 is further laminated on the charge transport layer 204. FIG. 5 shows a type in which an intermediate layer 207 is provided between the undercoat layer 205 and the charge generation layer 203. As long as the electrostatic latent image carrier of the present invention has at least the photosensitive layer 202 on the support 201, the other layers and the types of the photosensitive layers may be arbitrarily combined. The electrostatic latent image carrier that can be used in the image forming apparatus of the present invention only needs to have at least the photosensitive layer 202 on the support 201, and the other layers as described above, and the types of the photosensitive layers. May be combined arbitrarily.

<Outermost surface layer>
An image forming apparatus having a developing means using a trickle developing type developer of the present invention has an electrostatic latent image carrier, and an outermost surface layer is provided on the electrostatic latent image carrier. The outermost surface layer is selected from a crosslinkable resin formed by crosslinking a reactive charge transporting substance having at least two hydroxyl groups and an isocyanate compound, and a tertiary amine represented by the following general formula (I) It contains at least one kind.

  In formula (I), R1 and R2 are substituted or unsubstituted alkyl groups, and R1 and R2 may be the same or different. R3 represents an alkyl group or an aryl group having at least one hydroxyl group.

By including such a tertiary amine, the influence of the oxidizing gas can be greatly reduced in the outermost surface layer, and the gas resistance against the oxidizing gas is remarkably improved.
The reason for this is not clearly understood, but is thought to be as follows. That is, it is presumed that the tertiary amine skeleton contained in the reactive charge transporting substance effectively suppresses the generation of radical substances against oxidizing gases such as ozone and NOx produced under the use conditions. In addition, when one of the three substituents R1 to R3 of the amino group is an aryl group, the reason why the deterioration of the electrical characteristics such as the increase in residual potential due to the addition is small is probably a charge. It is thought that this is because it has a transport capability and has a small side effect as a trap for charge carriers. Furthermore, when the hydroxyl group of this amine compound is an alcoholic hydroxyl group, it can be presumed to be more preferable because it is considered that the influence of the oxidizing gas is further reduced.

  Specific examples of the substituted or unsubstituted alkyl group of the tertiary amine represented by the formula (1) include 1 to 50 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and an undecanyl group. For example, an alkyl group of 1 to 20). In addition, examples of the substituent of the alkyl group having a substituent include those mentioned in the specific examples of the alkyl group described above, alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group, or fluorine atom, chlorine atom, bromine Examples include atoms, halogen atoms of iodine atoms, aromatic hydrocarbon groups, and heterocyclic groups such as pyrrolidine, piperidine and piperazine.

[Conductive fine particles]
The outermost surface layer of the electrostatic latent image carrier contains conductive fine particles. The conductive fine particles are at least 1 represented by M _x Sb _y O _z (where M represents a metal element other than Sb, and x, y, and z represent the molar ratio of each element). Contains seeds. Preferably, zinc antimonate (ZnSb ₂ O ₆ ) is contained as conductive fine particles.

The outermost surface layer containing conductive fine particles represented by M _x Sb _y O _z not only adjusts the resistance of the outermost surface layer but also assists charge transport by the reactive charge transport material. Therefore, what is contained in the outermost surface layer is closely related to the type and content of the reactive charge transport material, and it is difficult to specify only the volume resistance value. Optimum design needs to be made each time, such as the allowable amount for exposure, the residual potential increase at that time, and the content of conductive fine particles. Thus, the inclusion of conductive fine particles can greatly reduce the increase in residual potential.

Examples of the conductive fine particles include metals, metal oxides, carbon black, and the like, and it is particularly preferable that at least one kind represented by the formula M _x Sb _y O _z is included. In the formula represented by the above formula usable for such conductive fine particles, examples of the metal element M include Zn, In, Sn, Ti, and Zr. Of these, Zn and In are particularly preferred in the present invention.
As the conductive fine particles represented by the above formula, x, y, and z represent the molar ratio of each element. Zn _x Sb _y O _z in which M is Zn in the above formula is 1: 1.6 to 2.4: 5 to 7 in terms of a ratio (x: y: z) based on x. In the case of In _x Sb _y O _z where M is In in the above formula, the ratio based on x (x: y: z) is 1: 0.02 to 1.25: 1. 55 to 4.63.
Examples of the metal M include aluminum, copper, chromium, nickel, silver, and stainless steel in addition to the above-described Zn and In, and those obtained by depositing these metals on the surface of the resin particles. As the metal oxide, ultrafine particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, tin-doped indium oxide, antimony-doped tin oxide, and zirconium oxide can be used.
Examples of the conductive fine particles represented by the formula M _x Sb _y O _z (where M represents a metal element other than Sb. _X , y, and z represent the molar ratio of each element) include, for example, Examples thereof include zinc antimonate (ZnSb ₂ O ₆ ) disclosed in Japanese Patent No. 3221132, indium antimonate (InSbO ₄ ) disclosed in Japanese Patent No. 3198494, and the like.

  The zinc antimonate is marketed, for example, as a conductive sol (trade name Celnax series, manufactured by Nissan Chemical Industries, Ltd.), and can be easily obtained in a state of being colloidally dispersed in a solvent. In addition, as a method for dispersing conductive fine particles obtained as a powder, an existing dispersion method can be used. For example, as a device for performing the dispersion method, a high-speed liquid collision dispersion method using a microfluidizer (manufactured by MFI), an optimizer (manufactured by Sugino Machine), or the like is suitable.

In general, when conductive fine particles are contained in the outermost surface layer of the electrostatic latent image carrier, the bulk resistance of the outermost surface layer is reduced, which is disadvantageous for maintaining the electrostatic charge on the surface of the electrophotographic photosensitive member. As a result, there is a concern that it may work against image blur caused by oxidizing gas. Therefore, the content of the conductive fine particles is limited in order to reduce the residual potential and not cause image blurring. However, the conductive fine particles represented by the formula M _x Sb _y O _z exhibit the effect of suppressing image blur while exhibiting the residual potential reduction effect of the exposed portion, and therefore the allowable amount of the amount that can be contained is Become very wide. Therefore, it can be said that this material is a very preferable material for reducing the residual potential. The reason why the conductive fine particles represented by M _x Sb _y O _z exhibit the effect of suppressing image blur while expressing the residual potential reducing effect is not clear, but the conductive fine particles are not capable of ion conduction. In addition, it is considered that the charge transfer is performed by the mechanism of electron conduction, so that it is not easily affected by the oxidizing gas. In addition, since the residual potential reduction effect per content is high, a large exposure area potential reduction effect can be obtained even with a small content, so that the desired exposure area potential can be reached without significantly reducing the bulk resistance of the outermost surface layer. It can be considered that it works very effectively.

These conductive fine particles may be used alone or in combination of two or more.
The volume average particle diameter of the conductive fine particles is preferably 0.01 to 1 μm, and more preferably 0.01 to 0.5 μm. When the volume average particle size is less than 0.01 μm, the distance between the particles of the conductive fine particles contained in the outermost surface layer becomes small, which may be disadvantageous for maintaining the electrostatic charge on the surface. In addition, it becomes easy to form secondary particles with non-uniform particle sizes by agglomerating in the coating liquid, and as a result, localized in the layer as larger particles, resulting in abnormal images due to a decrease in the charged potential of the non-exposed area. That is, in the exposed area development method (negative positive method), granular background stains may occur, and in the non-exposed area development method (positive positive method), an abnormal image of white spots may occur. On the other hand, when the volume average particle diameter of the conductive fine particles exceeds 1 μm, the conductive fine particles with respect to the coating film are too large, resulting in insufficient leveling of the surface, and the surface roughness of the electrophotographic photosensitive member increases. For example, the followability of the blade to the surface of the electrophotographic photosensitive member in the blade cleaning method may be reduced, and cleaning failure may occur due to toner slipping. In particular, it is very disadvantageous for cleaning spherical toner, which is relatively difficult to clean with a blade. Moreover, there is a possibility of causing an abnormal image due to localization of large particles in the protective layer.
The conductive particles may be subjected to surface treatment with a known material or means as necessary.
0.5-65 mass% is preferable and, as for content in the outermost surface layer of electroconductive fine particles, 5-45 mass% is more preferable. When the content is less than 0.5% by mass, the residual potential reduction effect may be insufficient or the effect of improving wear resistance may not be exhibited. When the content exceeds 65% by mass, the bulk of the outermost surface layer The resistance becomes too low and image blurring may occur, the coating film may become brittle, and wear resistance may be reduced.

Fine particles other than the conductive fine particles represented by the formula M _x Sb _y O _z may be contained in the outermost surface layer of the electrostatic latent image carrier.
Examples of such fine particles include organic resin fine particles such as fluorine resin fine particles (for example, polytetrafluoroethylene), silicone resin fine particles, guanamine formaldehyde resin fine particles; metal powders such as copper, tin, aluminum, and indium. Metal oxides such as silica, tin oxide, zinc oxide, titanium oxide, alumina, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide, tin-doped indium oxide; tin fluoride, fluorine Metal fluorides such as calcium fluoride and aluminum fluoride; inorganic fine particles such as potassium titanate and boron nitride; and the like. Among these, silica, alumina, titanium oxide, and tin oxide are particularly preferable because they have little influence on the electric characteristics of the electrophotographic photosensitive member and can significantly improve the wear resistance.

When the fine particles other than the conductive fine particles are used in combination, the content of the conductive fine particles represented by M _x Sb _y O _z in the outermost surface layer is preferably 10 to 100% by mass with respect to the total amount of fine particles. If the content of the conductive fine particles is less than 10% by mass, the residual potential reduction effect and the image blur suppression effect by the conductive fine particles may be insufficient.

(Isocyanate compound)
It is also a preferred aspect of the present invention that the isocyanate compound used for the outermost surface layer has an aromatic ring and has at least 2, preferably 3 or more isocyanate groups.

The crosslinkable resin formed by crosslinking the reactive charge transporting substance having at least two hydroxyl groups and an isocyanate compound is a kind of polyurethane resin that forms a urethane bond. The polyurethane resin forms a three-dimensional network structure by cross-linking a polyfunctional isocyanate compound and a polyol compound. For this reason, it is suitably used as a binder resin having high wear resistance. When a reactive charge transport material is used as the polyol compound, a considerable amount of at least an isocyanate compound is required. For this reason, the characteristics of the isocyanate compound greatly affect the electrophotographic characteristics of the electrostatic latent image carrier. As a result of investigations by the inventors, those using an isocyanate compound (aliphatic isocyanate) that does not have an aromatic ring represented by HDI (hexamethylene diisocyanate) are practical for low-speed or short-term electrophotographic characteristics. There was no problem above. However, in an image forming apparatus that performs an electrophotographic process (a process in which charging, exposure, development, transfer, and static elimination are repeated) continuously at high speed for a long period of time, an increase in the potential of the exposed area occurs, and an abnormal image such as a decrease in image density eventually occurs. It turns out that it will generate.
This was clarified by continuous electrostatic fatigue addition evaluation using a drum-shaped electrostatic latent image carrier single unit test apparatus. In the electrostatic latent image carrier using the aliphatic isocyanate compound described above, the exposed portion residual potential is remarkably increased immediately after electrostatic fatigue is applied for 120 minutes under predetermined conditions. If this is the case, it can be said that it is difficult or impossible to deploy to high-speed machines.

In contrast, in the present invention, by using an isocyanate compound having an aromatic ring (aromatic isocyanate), it is clear that the increase in the residual potential of the exposed portion immediately after the addition of electrostatic fatigue can be greatly reduced. It was. Although the reason for this is not clearly understood, it is thought that it may have the following effects.
That is, the polyurethane resin theoretically crosslinks without excess or deficiency due to the presence of the same number of hydroxyl groups and isocyanate groups. Therefore, when a reactive charge transporting substance having a hydroxyl group is used, at least an isocyanate compound having an isocyanate group equivalent to the number of hydroxyl groups is required. Here, for example, when considering that the reactive charge transporting substance is contained in an amount of 25 wt% of the entire resin, the OH equivalent of the reactive charge transporting substance (value obtained by dividing the molecular weight by the number of hydroxyl groups in the molecule) and isocyanate Depending on the NCO% of the compound, at least the same amount of isocyanate compound is required. That is, 25 wt% of the isocyanate compound is also contained. At this time, when an aliphatic isocyanate compound is used, the isocyanate compound occupying the protective layer has almost no π electrons and hardly contributes to charge transport, so the charge transport ability as a bulk is low. it is conceivable that. Therefore, it is considered that when electrostatic fatigue is repeatedly applied to repeat the electrophotographic process, charge transfer is hindered due to the low charge transporting ability and accumulated as a residual potential.
On the other hand, the aromatic isocyanate compound has an aromatic ring and a large number of π electrons. Since π electrons exhibit charge transporting ability due to the spread of the charge transporting compound, it is considered that the charge transporting property is greatly affected. The outermost layer employed in the present invention having an aromatic isocyanate compound is considered to have a very high π electron density in the resin film. If this π electron density is high, it is considered that the charge transport property in the film is enhanced and the accumulation of residual potential is suppressed.

  When this isocyanate compound has only one isocyanate group, the isocyanate compound becomes a terminal portion bonded in a pendant form to the polyol. In order to obtain a network structure as a polyurethane resin, it is necessary to separately include a polyfunctional polyisocyanate compound. When the polyfunctional polyisocyanate compound is an aliphatic isocyanate, the π electron density in the resin film is lowered, and thus the charge transport ability is lowered. Accordingly, the isocyanate compound that can be used in the present invention preferably has an aromatic ring and has two or more isocyanate groups in the molecule. Moreover, since it has three or more isocyanate groups, it forms a three-dimensional network structure, so that it becomes a binder resin with high wear resistance and is more preferably used.

Moreover, it is also a preferred embodiment of the present invention that the isocyanate group of the isocyanate compound having an aromatic ring is bonded to the aromatic ring via an alkyl group.
Furthermore, it is a preferable aspect of the present invention that the isocyanate compound having an aromatic ring is an adduct type of a diisocyanate compound and a polyol.

  The aromatic ring has a substantially planar steric structure due to a conjugated double bond, and the degree of freedom of molecular conformation is small. Therefore, when forming a three-dimensional network structure, it is thought that the movement which approaches the distance which can perform a crosslinking reaction with respect to a hydroxyl group is restricted. As a result, the possibility that the hydroxyl group and the isocyanate group remain uncrosslinked is increased, and the abrasion resistance and electrostatic characteristics of the photoconductor are reduced due to a decrease in the crosslink density and electrostatic side effects caused by unreacted functional groups. It is thought that. On the other hand, for example, when the isocyanate group of an isocyanate compound having an aromatic ring has a structure in which the aromatic group is bonded to the aromatic ring via an alkyl group, the alkyl group is a σ bond, and the σ bond alkyl chain rotates freely. Because it is possible, the degree of freedom of conformation of the molecule is high and the restriction of movement is small. For this reason, it is thought that the said malfunction is hard to generate | occur | produce and it is easy to form a crosslinked structure. Similarly, in the case of an adduct type of a diisocyanate compound and a polyol, it is considered that the polyol portion has a high degree of freedom of molecular conformation and a cross-linked structure is easily formed. Therefore, if these isocyanate compounds are used, it is considered that the photoconductor is excellent in wear resistance and electrostatic characteristics.

  In general, substances called aromatic isocyanate compounds are used as a general term for compounds in which an isocyanate group is directly bonded to an aromatic ring. The aromatic isocyanate compound in the present invention is an aromatic ring in a molecule. As described above, it is used to include a substance having an alkyl group between an aromatic ring and an isocyanate group.

Examples of the aromatic isocyanate used in the present invention include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymer MDI and xylene diisocyanate (XDI), and TDI, MDI, and XDI. And an adduct type of polyol such as trimethylolpropane.
A commercial item can be used as such an aromatic isocyanate. For example, Cosmonate T series, Cosmonate M series, Cosmonate ND, Takenate 500 and its adduct type Takenate D-110N manufactured by Mitsui Takeda Chemical Company, Dainippon Ink Chemical Industries, Ltd., an adduct type of tolylene diisocyanate Barnock D750, Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.
Among these, the adduct type of xylene diisocyanate (XDI) or xylene diisocyanate has the following structure in which an aromatic ring and an isocyanate group are bonded by a methylene group, and thus it is easy to form a crosslinked structure for the reasons described above. Are preferably used.

Moreover, it is also a suitable aspect of this invention that NCO% of the isocyanate compound which has the said aromatic ring is 3-50, More preferably, it is 10%-40%. NCO% means the content of isocyanate group, and is the weight percent of the isocyanate functional group (NCO, its molecular weight is calculated as 42) contained in 100 g of the compound having an isocyanate group. Calculated by:
NCO% = (weight of isocyanate functional group g / 100 g) × 100.

  It is conceivable that the higher the NCO%, the more crosslink points are formed, that is, the crosslink density is increased, so that the wear resistance is improved. If NCO% is less than 3, the content of the isocyanate compound relative to the polyol when the hydroxyl group / isocyanate group is equivalent is relatively increased, the crosslinking density is lowered, and the wear resistance is insufficient. there is a possibility. If the NCO% is greater than 50, the reactivity of the isocyanate compound becomes too high, and the reaction proceeds in the coating solution. For example, the life of the coating solution is shortened. In addition, there is a risk of causing an environmental burden such as an increase in organic waste liquid.

Furthermore, in the present invention, an aliphatic polyisocyanate compound may be used in combination with an aromatic isocyanate compound. Aliphatic polyisocyanates include, for example, chain isocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, alicyclic polyisocyanates such as isophorone diisocyanate, cyclohexylmethane diisocyanate, and isocyanurates. And those obtained by blocking the polyisocyanate with a phenol derivative, oxime, caprolactam, or the like, or trimers composed of isocyanate compounds (for example, hexamethylene diisocyanate trimer).
Further, adducts of trimethylolpropane and aliphatic polyisocyanate (for example, hexamethylene diisocyanate) or alicyclic polyisocyanate (for example, isophorone diisocyanate) are preferably used. An example of an adduct composed of trimethylolpropane and hexamethylene diisocyanate is shown in the following structural formula (II).

A commercial item can be used as aliphatic polyisocyanate used together with such aromatic polyisocyanate. For example, Sumijoule HT (manufactured by Sumika Bayern) can be mentioned as an adduct composed of the above-mentioned trimethylolpropane and hexamethylene diisocyanate.
As the polyisocyanate, polyisocyanate having a charge generating molecular skeleton or polyisocyanate having a charge transporting molecular skeleton may be used.

(Reactive charge transporting substance having a hydroxyl group)
Next, the reactive charge transporting material having a hydroxyl group that is preferably used in the present invention will be described.
The outermost surface layer of the electrostatic latent image carrier used in the present invention is formed by crosslinking a reactive charge transporting substance having at least two hydroxyl groups and an isocyanate compound having an aromatic ring. It contains a resin, and the reactive charge transport material has a molecular structure represented by the following general formula (1).

In the formula (1), n represents an integer of 1 to 4, when n is 1, Y is an organic group having 1 to 6 carbon atoms having at least two hydroxyl groups, and when n is 2 or more, Y Is a hydroxyl group or an organic group having 1 to 50 carbon atoms, and X represents a charge transporting compound group.
In the reactive charge transport material (1), the charge transport compound group X has a molecular structure represented by the above general formulas (2), (3) and (IV).

In the general formula (1) of the reactive charge transport material described above, the charge transport compound group X preferably has a diarylamino group (—NAr ₁ Ar ₂ ).
However diarylamino group: In _{-NAr 1 Ar 2, Ar 1 ~Ar} 2 each independently represent a substituted or unsubstituted aromatic group.

The charge transporting compound group X has a molecular structure of a diarylamino group (—NAr ₁ Ar ₂ ) represented by the general formula (2). Preferred examples of the X group include groups represented by the following formula (i).

In the above formula, Ar _{1 to} Ar ₂ are the same groups as described above, Ar ₃ represents a substituted or unsubstituted aromatic group similar to Ar _{1 to} Ar _2, and at least one of Ar _{1 to} Ar ₃ is It has a hand bonded to the Y group. The number of bonds is the same as the number n of Y groups.
The charge transporting compound group X may have a molecular structure of a diarylamino group (—NAr ₁ Ar ₂ ) represented by the following general formula (iii).

In the formula (iii), Ar _{1 to} Ar ₂ are the same groups as described above, Ar ₃ is the same group as Ar _{1 to} Ar _2, and Ar _{1 to} Ar ₃ are each independently substituted or unsubstituted. represents an aromatic group, Ar represents a substituted or unsubstituted arylene group, R1 represents a hydrogen atom or Ar _4, which may be the same or different. Further, at least one of Ar _{1 to} Ar ₃ and R 1 has the substituent Y in the general formula (1) (when R 1 is a hydrogen atom, a single bond is formed when this R 1 has the substituent Y) Become). In addition, the total amount of the number of bond hands that Ar _{1 to} Ar ₃ and R1 (when R1 is an alkyl group or a single bond) has the same number as n in the above (1).
When the group R1 in the formula (iii) is a hydrogen group, it has a molecular structure represented by the following general formula (2).

In formula (2), Ar _{1 to} Ar ₃ and Ar have the same meaning as in formula (iii), Ar _{1 to} Ar ₃ represent a substituted or unsubstituted aryl group or arylene group, and these are the same. May be different. Ar represents a divalent aromatic group. The number n of the substituent Y in the general formula (1) is the number of Ar _{1 to} Ar ₃ arylene groups in the formula (2) and the carbon atom (unsaturated carbon) having the Ar ₃ as a substituent. atom) is the same as the sum of the coupling hand having has at least Ar _1, any of the carbon atoms with a substituent to Ar ₃ and the Ar ₃ is a substituted group Y in the general formula (1) . However, Ar is a group bonded to an unsaturated carbon atom adjacent to the carbon atom having Ar ₃ as a substituent.

  In the formula (iii), when the group R1 is not a hydrogen atom, it has a molecular structure represented by the following general formula (3).

In formula (3), Ar _{1 to} Ar ₃ and Ar have the same meaning as in formula (iii), Ar _{1 to} Ar ₃ represent a substituted or unsubstituted aryl group or arylene group, and these are the same or different. Ar may represent an arylene group. Ar ₄ represents the same group (substituted or unsubstituted aryl group or arylene group) as Ar _{1 to} Ar _3, and these may be the same or different. The number n of the substituents Y in the general formula (1) is identical to the total number of the arylene group of said _Ar 1 to Ar _4, any one of at least _Ar 1 to Ar _4, the general formula (1 ) In the substituent Y. However, Ar is a group bonded to an unsaturated carbon atom adjacent to the carbon atom having Ar ₃ and Ar ₄ as a substituent.

  The reactive charge transport material (1) may have a molecular structure represented by the following general formula (4), which is a structure in which a hydroxyl group is bonded to at least two adjacent carbon atoms.

  In said formula (4), R represents a C1-C50 bivalent organic group, n represents the integer of 1-4. In the formula, X is as described above. For example, examples of the divalent organic group include an alkylene group having 1 to 50 carbon atoms, more preferably an alkylene group having 1 to 20 carbon atoms.

  In addition, as the reactive charge transport material (1), [Y] n in the formula may be a group represented by the following general formula (6).

  In the formula (6), Z represents a single bond or an organic group having 1 to 50 carbon atoms, and n represents an integer of 2 to 4. In addition, when Z is an organic group, it has the same meaning as R in the formula (4).

  The cross-linked resin formed by cross-linking the reactive charge transporting substance having at least two or more hydroxyl groups and the isocyanate compound is a polyurethane resin in which a urethane bond is formed. This polyurethane resin is suitably used as a binder resin having high wear resistance because a polyfunctional isocyanate compound and a polyol compound form a three-dimensional network structure by a crosslinking reaction. When a reactive charge transport material is used as such a polyol compound, there is a possibility that the structure may be disadvantageous for the formation of a three-dimensional network structure. For example, when a case where a charge transport material having a structure other than the reactive charge transport material used in the present invention is used is considered, a pendant structure in which a charge transport compound group hangs at the end of the resin skeleton is obtained. Such a structure is a terminal molecule without a polyol component in the charge transport compound group or the like, cannot form a polymer structure, and cannot form a resin layer. For this reason, such a pendant structure cannot form a three-dimensional network structure, and the formation of a three-dimensional network structure of polyurethane is hindered. As a result, the wear resistance is greatly deteriorated. If the reactive charge transport material content is reduced and the polyurethane resin component is increased as a countermeasure, the charge mobility of the outermost layer decreases, and there is a high possibility of problems such as a decrease in photosensitivity and an increase in residual potential. It becomes. That is, the wear resistance and electrical characteristics of the outermost layer are in a trade-off relationship.

(Reactive charge transporting substance having a hydroxyl group)
Next, the reactive charge transporting substance having a hydroxyl group that is preferably used in the present invention will be described. The charge transporting substance having a hydroxyl group used in the present invention is represented by the general formula (1): [Y] _n -X. Among the compounds represented by the general formula (1), the Y group has two hydroxyl groups at least on adjacent carbon atoms, or X directly through an organic group having 1 to 50 carbon atoms. A charge transporting substance bonded to a group. As a more preferred charge transporting substance when the Y group has two hydroxyl groups at least on adjacent carbon atoms, a compound represented by the general formula (4) can be mentioned. Moreover, as a preferable charge transporting substance bonded to the X group in the general formula (1) directly or through an organic group having 1 to 50 carbon atoms, a compound represented by the general formula (6) can be given. . In particular, the X group in the general formulas (4) and (6) is preferably an X group represented by the general formula (2), (3) or (IV).

In the present invention, such a charge transporting substance having an X group has at least two hydroxyl groups, and these hydroxyl groups are preferably one of the following two types.
As a 1st thing, what has a hydroxyl group in two adjacent carbon atoms can be mentioned. In particular, as the first one, in the general formula (1), the Y group may be a group represented by the general formula (4).
Moreover, as a 2nd thing, Y group can mention the group represented by the said General formula (6) in the said General formula (1).
In these combinations, in the formula (2), (3) or (IV), Ar _{1 to} Ar ₄ each independently represents a substituted or unsubstituted aromatic group. However, when Ar _{1 to} Ar ₄ are bonded to the Y group, these substituted or unsubstituted aromatic groups include divalent aromatic groups.

Specifically, the unsubstituted aromatic group includes a phenyl group, a phenoxyphenyl group (o-, m or p-phenoxyphenyl group), a biphenyl group, a phenylalkylenephenyl group ((the alkylene group includes a methylene group, Ethylene group, propylene group, butylene group, pentene group (cyclopentene group), hexylene group (cyclohexylene group, etc.), for example, phenylethylphenyl group (-φ (CH ₂ ) ₂ -φ-: φ is a C ₆ H ₄ group ) Phenylcyclohexylenephenylphenyl group), phenylalkoxylphenyl group ((alkoxylene group is methoxylene group (—CH ₂ O—), ethoxylene group (— (CH ₂ ) ₂ O—), propoxyxylene group (—CH _{2 CH (CH 3) O-)} , etc. Butokishiren group) such as phenyl ethoxyphenyl ), Terphenyl group, naphthalene group, and the like pyrene group.

Examples of the substituent of the substituted aromatic group, an alkyl group (methyl group, ethyl group, propyl group, butyl group, pentyl group, C ₁ -C ₁₀ about an alkyl group such as hexyl group), an alkoxy group (methoxy group, ethoxy group, a propoxy group, a butoxy group, pentoxy group, C ₁ -C ₁₀ about alkyl group), alkoxyalkyl groups such hexoxy group, a halogen (fluorine group, chlorine group, a bromine group, etc. iodine group) group, a cyano group , A nitro group, an alkoxycarbonyl group, and the like, and a substituted aromatic group such as a mono- to tetra-substituted phenyl group selected from these substituents, a phenoxyphenyl group, and a biphenyl group.
The R1 group in the formula (iii) is the same as the Ar _{1 to} Ar ₄ or a hydrogen group. However, when the R1 group is a hydrogen group, as a matter of course, there is no hand to bond with the Y group. In this case, R1 group becomes a single bond.
Ar in the formulas (iii) and (IV) is a divalent substituted or unsubstituted aromatic group which is the same group as that in the case of bonding to the Y group in the aforementioned Ar _{1 to} Ar ₄ . is there.

The X group represented by the formula (2), (3) or (IV) has n Y groups represented by the formula (1).
Such a Y group is a group having a hydroxyl group at two adjacent carbon atoms, or a group represented by the formula (6). The group having a hydroxyl group at two adjacent carbon atoms is a group represented by the formula (4).

  In said Formula (4), R is a C1-C50 bivalent organic group or a single bond, and n is an integer of 1-4. More specifically, the divalent organic group having 1 to 50 carbon atoms is an alkylene group having 1 to 50 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentene group, or a hexylene group. , A methoxylene group, an ethoxylene group, a propoxyxylene group, a butoxyxylene group, a pentoxylene group, a hexoxyxylene group, etc., a divalent alkoxylene group having 1 to 50 carbon atoms, a divalent alkylenecarbonyloxy group having 1 to 50 carbon atoms, etc. Can be mentioned. These can be appropriately selected from one kind alone (for example, methyleneoxy group), one kind, or a plurality of kinds or two or more kinds. For example, one type includes a plurality of examples such as a methyleneoxypropoxyxylene group, and two or more types include a divalent alkoxyalkylene group (for example, methoxyethylene group), an alkoxyalkylenecarbonyloxy group (methoxypentenecarbonyl group). Oxy group, etc.).

The above formula (1) comprising the substituent X selected from the above formula (2), (3) or (IV) and the substituent Y selected from the above formula (4) or (6) More specifically, examples of the charge transporting substance represented by the formula include compounds having substituents represented by Tables 1 to 38.
Tables 1 to 7 show the compounds of the formula (1) in which the substituent X corresponds to the structure shown in the compound (i) and the substituent Y is a substituent corresponding to the structure represented by the general formula (6). An example is shown.

  Tables 8 to 22 show the compounds of the formula (1) in which the substituent X corresponds to the structure shown in the compound (i) and the substituent Y is a substituent corresponding to the structure represented by the general formula (6). An example is shown.

  Tables 23 to 30 show the compounds of the formula (2) in which the substituent X corresponds to the structure shown in the compound (iii) and the substituent Y is a substituent corresponding to the structure represented by the general formula (6). An example is shown.

  Tables 31 and 32 show compounds of the formula (1) in which the substituent X corresponds to the structure shown in the compound (iii) and the substituent Y is a substituent corresponding to the structure represented by the general formula (6). An example is shown.

  Tables 33 to 34 show the compounds of the formula (1) in which the substituent X corresponds to the structure shown in the compound (IV) and the substituent Y is a substituent corresponding to the structure represented by the general formula (6). An example is shown.

  Tables 35 to 36 show compounds of the formula (1) in which the substituent X corresponds to the structure shown in the compound (IV) and the substituent Y is a substituent corresponding to the structure represented by the general formula (6). An example is shown.

The said compound can be arranged | categorized for every "compound No." in the following Table 37-Table 42.
First, the reactive charge transport material in the present invention, that is, the charge transport material having two or more hydroxyl groups will be described. First, a compound in which two or more hydroxyl groups are present at different ends of the charge transport compound group is considered. Among such compounds, examples of charge transport materials in which a hydroxyl group is bonded directly or via a methylene chain are shown below.

Since these reactive charge transport materials form a network structure by reaction with a polyfunctional isocyanate compound, they are much more abrasion resistant than polyurethane resin films using reactive charge transport materials having only one hydroxyl group. Will improve. When these reactive charge transport materials are used, the charge transport compound group is incorporated as the main chain of the polyurethane chain.
In the present invention, the following compounds can be exemplified as more preferred reactive charge transporting substances.

In the present invention, when a specific reactive charge transport material is used, the occurrence of the above-mentioned problems is small and high wear resistance can be achieved. This is considered to be as follows. That is, the reactive charge transport material (1) used in the present invention has a structure in which an alkylene group having at least two hydroxyl groups or a divalent alkoxy group and a charge transport compound group are bonded to each other, and is attached to the polyurethane chain. It is thought that it has a pendant type while having two or more cross-linking points. Therefore, the structure is less affected by the secondary structure of the polyurethane chain, and is less likely to cause steric distortion in the charge transporting compound group. In addition, it is considered that high wear resistance is achieved.
Examples of preferred reactive charge transport materials in the present invention are shown below.

In the present invention, when the reactive charge transporting material described above is used, the occurrence of the above-described problems can be reduced and high wear resistance can be achieved. This is because of the following reasons. That is, in the present invention, the reactive charge transporting substance (4) has a structure in which at least 2 to 6 alkyl groups or alkoxy groups having a hydroxyl group are bonded to a charge transporting compound group. It is incorporated into the main chain with two or more cross-linking points in the chain. Here, since the hydroxyl group is bonded to the charge transporting compound group via an alkylene group having 2 to 6 carbon atoms or a (divalent) alkoxy group, it has 2 to 2 carbon atoms between the charge transporting compound group and the urethane bond. The structure has 6 alkylene groups or (divalent) alkoxy groups. Since the alkylene group having 2 to 6 carbon atoms or the (divalent) alkoxy group has a very high degree of freedom in conformation of the carbon chain, even if it is incorporated into the main chain, the secondary structure of the resulting polyurethane chain Less susceptible to steric distortion in the charge transport compound group, resulting in reduced charge mobility, reduced sensitivity and increased residual potential, and high wear resistance. .
In the present invention, in the reactive charge transporting substances (1) and (4), the charge transporting compound group X has a molecular structure represented by the following general formulas (2) and (3), thereby further increasing the residual potential. Suppression is achieved. In this invention, since the three-dimensional distortion at the time of urethane bond formation does not arise easily in this invention, the charge transport property derived from a charge transportable compound structure can be exhibited. For example, the stilbene group of the general formula (2) and the α-phenyl stilbene type compound group of the general formula (3) have a very good charge transporting ability as a non-reactive charge transporting substance having no hydroxyl group. Even when the structure of a reactive charge transporting material into which an alkyl group having two hydroxyl groups or an alkoxy group is introduced, it is considered that the structure exhibits a very good charge transporting ability.

  In addition, it has been found that the reactive charge transport material having a hydroxyl group at each of two adjacent carbon atoms preferably used in the present invention has improved wear resistance. The following reasons can be considered for this. That is, since two hydroxyl groups are bonded to adjacent carbon atoms, when both are cross-linked with isocyanate, a structure in which two polyurethane bonds are connected by a carbon-carbon bond is obtained. There is a structure in which the charge transport compound group is suspended in a pendant shape, so that there is almost no steric strain on the reactive charge transport material, and the structure has the smallest number of carbon atoms in the main chain of the polyurethane chain. Since the structure is formed more densely and wear resistance is improved, it is possible to achieve improved wear resistance while maintaining good electrophotographic characteristics with almost no decrease in charge transport capability. Conceivable.

  Furthermore, the charge transport material of the following structural formula (4) that is preferably used in the present invention exhibits even better wear resistance, and the reason is considered as follows. In the charge transport material of the following structural formula (4), the adjacent carbon atom to which the hydroxyl group is bonded is located at the molecular end. In other words, these two hydroxyl groups can exist in a conformation with the least steric hindrance, and therefore it can be said that both hydroxyl groups are very easily reacted. Therefore, it is considered that the number of hydroxyl groups remaining unreacted after the crosslinking reaction is very small, which makes it easy to form a coating film having a high crosslinking density, and the adverse effect on the electrophotographic characteristics due to the residual functional group is also very small. It seems that an electrostatic latent image carrier having high wear resistance and good electrophotographic characteristics can be obtained.

The outermost surface layer of the present invention can contain a polyol compound as required. As this polyol, the number of functional groups should just be 2 or more, and diol and a trivalent or more polyol are used. Although a polyol is illustrated below, the polyol used for this invention is not limited to this.
Examples of the diol include alkylene glycol (for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (for example, diethylene glycol, Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (eg, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (eg, bisphenol) A, bisphenol F, bisphenol S, etc.); alkylene oxides of the above alicyclic diols (for example, ethylene oxide, propylene oxide, butyleneo) Side etc.) adducts, alkylene oxide of the bisphenols (e.g., ethylene oxide, propylene oxide, and the like butylene oxide, etc.) adducts.

Examples of the trihydric or higher polyol include polyhydric aliphatic alcohols (eg, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (eg, phenol novolac, cresol novolac, etc.); Examples include alkylene oxide adducts of the above trivalent or higher polyphenols.
Preferred examples include trimethylolpropane or a styrene-acrylic copolymer having a hydroxyethyl group introduced, and a polyol represented by the following structural formula (II) (for example, in the formula, l = 28, m = 42). , N = 30 (number average molecular weight 1000 or more, weight average molecular weight about 31000)). Examples of such polyols include, for example, styrene-acrylic copolymer LZR-170 (manufactured by Fujikura Kasei Co., Ltd.).

  Also, a polyol having a polyether skeleton, a polyol having a polyester skeleton, a polyol having an acrylic skeleton, a polyol having an epoxy skeleton, a polycarbonate, a polyol having a skeleton, a polyol having a charge generating molecular skeleton, or a charge transporting molecular skeleton Polyols are also used.

In the present invention, various polyols can be used in combination.
In this case, the ratio of the molecular weight to the number of hydroxyl groups (molecular weight / number of hydroxyl groups = OH equivalent) of at least one of the plurality of polyols is preferably 30 or more and less than 150, and more preferably 40 or more and less than 120.
By combining polyols having an OH equivalent of 30 or more and less than 150, an outermost surface layer having high wear resistance can be formed. That is, it is considered that when the content of the polyol having a small OH equivalent is increased, the crosslinking density is increased, and a finer three-dimensional network structure is formed to improve the wear resistance.

Here, the content of the polyol having an OH equivalent of 30 or more and less than 150 is preferably 10 to 90% by mass ratio with respect to the total amount of the plurality of polyols.
When the content of the polyol that is 30 or more and less than 150 is less than 10%, the effect of improving the wear resistance is not so much exhibited. On the other hand, if it is greater than 90%, the crosslink density increases, so the wear resistance of the protective layer increases, but the reactivity increases because the number of functional groups increases, resulting in a coating solution. The storage stability is lowered and the life is shortened. Therefore, problems in the manufacturing process are likely to occur, and a large amount of organic waste liquid may be generated. In addition, since the number of cross-linking points increases, volume shrinkage during cross-linking increases, and cracks in the coating film and defects due to repelling may occur.

Moreover, it is preferable that at least one of the plurality of polyols is a polyol having an OH equivalent of 150 or more and less than 1500.
When at least one of a plurality of polyols is a polyol having an OH equivalent of 150 or more and less than 1500, the film-forming property is good and the formed outermost layer has high wear resistance, and the outermost layer-forming coating is formed. Storage stability when used as a working solution is high and exhibits very good storage stability.
The reason for this is that the polyol having the above defined OH equivalent has a relatively large molecular weight, so that the coating liquid has an appropriate viscosity, and the polyol or polyisocyanate having a low OH equivalent has the reactivity used in the present invention. This is presumably because the uniform mixing state of the charge transport material is maintained and the leveling property and uniformity of the wet coating film are improved.

The content of the reactive charge transporting substance in the outermost layer is preferably 5 to 45 wt%, and more preferably 10 to 35 wt%.
If it is less than 5 wt%, even in the embodiment of the present invention containing conductive fine particles, the charge transport ability may be insufficient, and the residual potential may increase. When exposed, the image density was remarkably lowered, which sometimes caused problems. For example, if the oxidizing gas concentration in the device tends to be high, such as an image forming device using a corotron or scorotron charging method, or an image forming device installed in a room using a blue heater, a normal image There is a concern that the phenomenon that the film cannot be formed occurs. Furthermore, since an image forming apparatus using the trickle developing method, such as the image forming apparatus of the present invention, is used for a long period of time almost maintenance-free, the replacement interval of the charger and the like becomes long. In general, it is known that a charger that has been used for a long time is likely to cause an abnormal image in a charger, particularly a corotron or scorotron charging method. An electrostatic latent image carrier having resistance to an oxidizing gas as in the present invention is very effective.

In addition, various additives may be added to the outermost surface layer as necessary for the purpose of improving smoothness and chemical stability.
The outermost surface layer is formed on the photosensitive layer using a conventional coating method such as dip coating, spray coating, blade coating or knife coating. Among these, dip coating and spray coating are particularly preferable in terms of mass productivity and coating film quality.

In the present invention, the thickness of the outermost surface layer is preferably 0.5 to 50 μm, more preferably 1 to 40 μm, and further preferably 2 to 20 μm.
If it is thinner than 0.5 μm, the margin for disappearance or scratches due to wear is too small, and sufficient durability cannot be ensured in many cases. On the other hand, if it is thicker than 50 μm, it may cause problems such as an increase in residual potential. Therefore, it is necessary to form the outermost layer with a suitable film thickness so as to secure a margin for wear and scratches and to reduce the occurrence of residual potential.

[Photosensitive layer]
Next, the multilayer type photosensitive layer and the single layer type photosensitive layer constituting the electrostatic latent image carrier of the present invention will be described.
<Multi-layer type photosensitive layer>
The multilayer photosensitive layer is usually formed by laminating a charge generation layer (CGL) and a charge transport layer (CTL) in this order on a support.

(Charge generation layer)
The charge generation layer contains at least a charge generation material, and includes a binder resin and, if necessary, other components.
There is no restriction | limiting in particular as a charge generation substance, Although it can select suitably according to the objective, Either an inorganic material and an organic material can be used.
Examples of the inorganic material include, but are not limited to, crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic compounds.

  Examples of the organic material include, but are not limited to, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, and triphenylamine skeletons. Azo pigments, azo pigments having a diphenylamine skeleton, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bisstilbene skeleton, having a distyryl oxadiazole skeleton Azo pigments, azo pigments having a distyrylcarbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane or triphenylmethane pigments, benzoquinone or naphthalene Tokinon pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, and the like. These may be used individually by 1 type and may use 2 or more types together.

The binder resin for the charge generation layer is not particularly limited and may be appropriately selected depending on the purpose. For example, polyamide resin, polyurethane resin, epoxy resin, polyketone resin, polycarbonate resin, silicone resin, acrylic resin, polyvinyl butyral resin , Polyvinyl formal resin, polyvinyl ketone resin, polystyrene resin, poly-N-vinyl carbazole resin, polyacrylamide resin, and the like. These may be used individually by 1 type and may use 2 or more types together.
Note that a charge transport material may be added as necessary. In addition to the binder resin described above, a polymer charge transport material can be added as the binder resin for the charge generation layer.

As a method for forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system can be mentioned.
Examples of the former method include a glow discharge polymerization method, a vacuum deposition method, a CVD method, a sputtering method, a reactive sputtering method, an ion plating method, and an accelerated ion injection method. This vacuum thin film manufacturing method can satisfactorily form the inorganic material or organic material described above.
In order to provide the charge generation layer by the latter casting method, a charge generation layer forming coating solution is used, and a conventional method such as dip coating, spray coating, or bead coating is used. it can.

Examples of the organic solvent used in the charge generation layer forming coating solution include acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, dichloroethane, dichloropropane, trichloroethane, trichloroethylene, tetrachloroethane, Tetrahydrofuran, dioxolane, dioxane, methanol, ethanol, isopropyl alcohol, butanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve, ethyl cellosolve, propyl cellosolve and the like can be mentioned. These may be used individually by 1 type and may use 2 or more types together.
Among these, tetrahydrofuran, methyl ethyl ketone, dichloromethane, methanol, and ethanol having a boiling point of 40 ° C. to 80 ° C. are particularly preferable because they can be easily dried after coating.

  The coating solution for forming a charge generation layer can be produced by dispersing and dissolving the charge generation material and a binder resin in the organic solvent. Examples of the method for dispersing the organic pigment in the organic solvent include a dispersion method using a dispersion medium such as a ball mill, a bead mill, a sand mill, and a vibration mill, and a high-speed liquid collision dispersion method.

  Depending on the thickness of the charge generation layer, the electrophotographic characteristics, particularly the photosensitivity, change. Generally, the thicker the thickness, the higher the photosensitivity. Therefore, the thickness of the charge generation layer is preferably set in a suitable range according to the required specification of the image forming apparatus. In order to obtain the sensitivity required for the electrophotographic photosensitive member. Usually, 0.01 to 5 μm is preferable, and 0.05 to 2 μm is more preferable.

(Charge transport layer)
In the present invention, when the charge transport layer is the outermost layer, as described above, in the electrostatic latent image carrier having at least the photosensitive layer, the outermost surface layer of the electrostatic latent image carrier has at least two or more. It contains a crosslinkable resin formed by crosslinking a reactive charge transporting substance having a hydroxyl group and an isocyanate compound, and conductive fine particles.

  However, when the outermost surface layer is a protective layer formed on the charge transport layer, the wear resistance of the charge transport layer may be low. The charge transport layer is a layer intended to hold a charged charge and to couple the charge generated and separated in the charge generation layer by exposure to the charged charge held by movement. In order to achieve the purpose of holding the charged charge, it is required that the electric resistance is high. Further, in order to achieve the purpose of obtaining a high surface potential with the charged charge that has been held, it is required that the dielectric constant is small and the charge mobility is good.

Examples of the hole transport material (electron donating material) include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4- Dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, etc. . These may be used individually by 1 type and may use 2 or more types together.
On the other hand, examples of the polymer charge transport material include those having the following structure.

(A) Polymer having carbazole ring For example, poly-N-vinylcarbazole, JP-A-50-82056, JP-A-54-9632, JP-A-54-11737, JP-A-4-175337 And the compounds described in JP-A-4-183719 and JP-A-6-234841.

(B) Polymer having hydrazone structure For example, JP-A-57-78402, JP-A-61-20953, JP-A-61-296358, JP-A-1-134456, JP-A-1-134456 179164, JP-A-3-180851, JP-A-3-180852, JP-A-3-50555, JP-A-5-310904, JP-A-6-234840, etc. Is done.

(C) Polysilylene polymer For example, JP-A-63-285552, JP-A-1-88461, JP-A-4-264130, JP-A-4-264131, JP-A-4-264132, Examples thereof include compounds described in Kaihei 4-264133 and JP-A-4-289867.

(D) Polymer having a triarylamine structure For example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-134457, JP-A-2-282264, JP-A-2- Examples thereof include compounds described in JP-A-304456, JP-A-4-133305, JP-A-4-133066, JP-A-5-40350, and JP-A-5-202135.

(E) Other polymers For example, formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-150749, JP-A-6-234836, JP-A-6-234837 The described compounds and the like are exemplified.

  In addition to the above, the polymer charge transport material includes, for example, a polycarbonate resin having a triarylamine structure, a polyurethane resin having a triarylamine structure, a polyester resin having a triarylamine structure, and a polyarylamine structure having a polyarylamine structure. And ether resins. Examples of the polymer charge transporting material include JP-A 64-1728, JP-A 64-13061, JP-A 64-19049, JP-A-4-11627, JP-A 4-116627. JP 2225014, JP 4-230767, JP 4-320420, JP 5-232727, JP 7-56374, JP 9-127713, JP 9-222740. And compounds described in JP-A-9-265197, JP-A-9-211877, JP-A-9-30495, and the like.

  Examples of the polymer having an electron donating group include not only the above-mentioned polymers but also copolymers with known monomers, block polymers, graft polymers, star polymers, and further, for example, A cross-linked polymer having an electron donating group as disclosed in Japanese Patent No. 109406 can also be used.

Examples of the binder resin for the charge transport layer include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyvinyl acetate resin, polystyrene resin, phenol resin, epoxy resin, polyurethane resin, and polychlorinated resin. Vinylidene resin, alkyd resin, silicone resin, polyvinyl carbazole resin, polyvinyl butyral resin, polyvinyl formal resin, polyacrylate resin, polyacrylamide resin, phenoxy resin, and the like are used. These may be used individually by 1 type and may use 2 or more types together.
The charge transport layer may also contain a copolymer of a crosslinkable binder resin and a crosslinkable charge transport material.

  The charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer. If necessary, an appropriate amount of additives such as a plasticizer, an antioxidant, and a leveling agent can be added to the charge transport layer in addition to the charge transport material and the binder resin.

  The thickness of the charge transport layer is preferably 5 to 100 μm, and in recent years, the charge transport layer has been made thinner to meet the demand for higher image quality. In order to achieve higher image quality of 1200 dpi or more, 5 More preferably, it is ˜30 μm.

Next, the single layer type photosensitive layer will be described.
<Single layer type photosensitive layer>
The single-layer type photosensitive layer contains a charge generation material, a charge transport material, a binder resin, and other components as necessary.
When a single-layer photosensitive layer is provided by a casting method, such a single-layer photosensitive layer can be prepared by, for example, dissolving at least a charge generation material, a thermosetting binder resin, and a charge transport material having a crosslinkable functional group in an appropriate solvent. It can be formed by dispersing, coating and drying. In addition, a plasticizer can be added to the single-layer photosensitive layer as necessary.

  The thickness of the single-layer type photosensitive layer is preferably 5 to 100 μm, and more preferably 5 to 50 μm. When the film thickness is less than 5 μm, the chargeability may decrease, and when it exceeds 100 μm, the sensitivity may decrease.

[Support]
The support in the electrostatic latent image carrier of the present invention is not particularly limited as long as it has conductivity, and can be appropriately selected according to the purpose.
As the support, a conductor or an insulator subjected to a conductive treatment is suitable, for example, a metal such as Al, Ni, Fe, Cu, or Au, or an alloy thereof; insulating properties such as polyester, polycarbonate, polyimide, and glass A metal such as Al, Ag, Au, or a thin film made of a conductive material such as In ₂ O ₃ or SnO ₂ formed on a substrate; carbon black, graphite, metal powder such as Al, Cu, Ni, etc. Examples thereof include a resin substrate obtained by uniformly dispersing a conductive glass powder and imparting conductivity to a resin, and paper subjected to a conductive treatment.

  There is no restriction | limiting in particular as a shape and a magnitude | size of a support body, Any of plate shape, drum shape, or belt shape can be used. When a belt-like support is used, there is an advantage that the apparatus becomes complicated and the size is increased while it is necessary to provide a driving roller and a driven roller inside, but the degree of freedom in layout is increased. However, when the protective layer is formed, the protective layer is not flexible enough to cause a crack called a crack on the surface, which may cause a granular background stain. . For this reason, a drum-like thing with high rigidity is suitable as a support.

  An undercoat layer may be provided between the support and the photosensitive layer as necessary. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and reducing the residual potential.

  The undercoat layer generally contains a resin as a main component, but these resins are resins having high resistance to dissolution in general organic solvents in consideration of applying a photosensitive layer thereon with a solvent. It is preferable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resins, alkyd-melamine resins, and epoxy resins. And a curable resin that forms a three-dimensional network structure.

  Further, fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like, or metal sulfides and metal nitrides may be added. These undercoat layers can be formed by a conventional coating method using an appropriate solvent.

As the undercoat layer, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is used, for example, a metal oxide layer formed by a sol-gel method or the like, and Al ₂ O ₃ is anodized. In addition, an organic material such as polyparaxylylene (parylene), an inorganic material such as SnO ₂ , TiO ₂ , ITO, or CeO ₂ provided by a vacuum thin film manufacturing method can be used.
There is no restriction | limiting in particular in the thickness of an undercoat layer, According to the objective, it can select suitably, 0.1-10 micrometers is preferable and 1-5 micrometers is more preferable.

In the electrostatic latent image carrier of the present invention, a so-called photoreceptor, an intermediate layer may be provided on the support, if necessary, in order to improve adhesion and charge blocking properties. In general, the intermediate layer is mainly composed of a resin. However, considering that the photosensitive layer is applied and formed using a solution containing a solvent on the resin, a resin having a high solvent resistance with respect to a general organic solvent. It is desirable that
Examples of the intermediate layer resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane resins, melamine resins, phenol resins, and alkyd-melamines. Examples thereof include curable resins that form a three-dimensional network structure, such as resins and epoxy resins.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention has a developing means for developing with a developer of a trickle developing system using a two-component developer containing an electrostatic latent image carrier and a toner and a carrier. Means, exposure means, and developing means, transfer means, fixing means, cleaning means, and other means appropriately selected as necessary, for example, static elimination means, recycling means, control means, etc. Become. In such an image forming apparatus of the present invention, the supply means for supplying the carrier or carrier and toner to the developing means, and the discharge means for discharging the carrier or carrier and toner contained in the developing means to the outside of the developing means. And is configured. The charging unit and the exposure unit may be collectively referred to as an electrostatic latent image forming unit.
The image forming method of the present invention includes at least a charging step, an exposure step, and a development step, and includes a transfer step, a fixing step, a cleaning step, and other steps appropriately selected as necessary, for example, a static elimination step, a recycling step. Process, control process and the like. The charging process and the exposure process may be collectively referred to as an electrostatic latent image forming process.
The image forming apparatus is preferably a tandem type including a plurality of image forming elements each having at least an electrostatic latent image carrier, a charging unit, a developing unit, a transfer unit, and a fixing unit.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the charging step can be performed by the charging unit, the exposure step can be performed by the exposing unit, The developing step can be performed by the developing unit, the transferring step can be performed by the transferring unit, the fixing step can be performed by the fixing unit, and the cleaning step can be performed by the cleaning unit. The other steps can be performed by the other means.

-Charging process and charging means-
The charging step is a step of charging the surface of the electrostatic latent image carrier, and is performed by the charging unit.
The charging means is not particularly limited as long as it can apply a voltage to the surface of the latent electrostatic image bearing member to be uniformly charged, and can be appropriately selected according to the purpose. A non-contact charging means for charging in a non-contact manner with the electrostatic latent image carrier is used.
Examples of the non-contact charging means include a non-contact charger and a needle electrode device using a corona discharge, a solid discharge element; conductive or semi-conductive disposed with a minute gap with respect to the electrophotographic photosensitive member. And a charging roller. Among these, corona discharge is particularly preferable.

The corona discharge is a non-contact charging method that gives positive or negative ions generated by corona discharge in the air to the surface of the electrophotographic photosensitive member, and has a characteristic of giving a certain amount of charge to the electrophotographic photosensitive member. There are a charger and a scorotron charger having a characteristic of giving a constant potential.
The coroton charger is composed of a casing electrode that occupies a half space around the discharge wire, and a discharge wire placed almost at the center thereof.
The scorotron charger is obtained by adding a grid electrode to the corotron charger, and the grid electrode is provided at a position 1.0 mm to 2.0 mm away from the surface of the electrophotographic photosensitive member.

-Exposure process and exposure means-
The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure unit.
The optical system in the exposure is roughly classified into an analog optical system and a digital optical system. The analog optical system is an optical system that projects an original directly onto an electrostatic latent image carrier by the optical system. The digital optical system receives image information as an electrical signal, converts it into an optical signal, and converts it into an optical signal. It is an optical system that exposes and forms an electrostatic latent image carrier.
The exposure means is not particularly limited as long as the surface of the latent electrostatic image bearing member charged by the charging means can be exposed like an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using a toner or a developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing means supplies either the carrier or the two-component developer to the inside of the developing means, and either the carrier or the two-component developer accommodated in the developing means is outside the developing means. It is preferable to have discharging means for discharging.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrophotographic photosensitive member (photosensitive member), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is caused by an electric attractive force. It moves to the surface of the electrophotographic photoreceptor. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrophotographic photosensitive member.

  The developer accommodated in the developing device is a developer containing the toner. As the developer, a two-component developer composed of a toner and a carrier is used.

<Toner>
The toner contains at least a binder resin, a colorant, and an external additive, preferably contains a release agent and a charge control agent, and further contains other components as necessary.

-Binder resin-
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, styrene, such as polystyrene, polychlorostyrene, polyvinyltoluene, or its substitution polymer; Styrene / p-chlorostyrene Copolymer, Styrene / propylene copolymer, Styrene / vinyl toluene copolymer, Styrene / vinyl naphthalene copolymer, Styrene / methyl acrylate copolymer, Styrene / ethyl acrylate copolymer, Styrene / butyl acrylate Copolymer, styrene / octyl acrylate copolymer, styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer Polymer, styrene / acrylonitrile copolymer, styrene / Vinyl methyl ether copolymer, styrene / vinyl ethyl ether copolymer, styrene / vinyl methyl ketone copolymer, styrene / butadiene copolymer, styrene / isoprene copolymer, styrene / acrylonitrile / indene copolymer, styrene / Styrene copolymers such as styrene / maleic acid copolymer and styrene / maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyl butyral, poly Examples thereof include acrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, and paraffin wax. These may be used individually by 1 type and may use 2 or more types together.

-Colorant-
The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Degreen Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc Hana, Lithbon, etc. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as a color of the said coloring agent, According to the objective, it can select suitably, For example, the thing for black, the thing for color, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Examples of the black material include carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black, copper, iron (CI pigment black 11), and titanium oxide. And organic pigments such as aniline black (CI Pigment Black 1).
Examples of the magenta color pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48: 1, 49, 50, 51, 52, 53, 53: 1, 54, 55, 57, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 177, 179, 202, 206, 207, 209, 211; C.I. I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.
Examples of the color pigment for cyan include C.I. I. Pigment Blue 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 60; I. Bat Blue 6; C.I. I. Acid Blue 45, copper phthalocyanine pigments having 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton, green 7 and green 36, and the like.
Examples of the color pigment for yellow include C.I. I. Pigment Yellow 0-16, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 55, 65, 73, 74, 83, 97, 110, 151, 154, 180; C.I. I. Bat yellow 1, 3, 20, orange 36 and the like.

  The content of the colorant in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass. When the content is less than 1% by mass, a reduction in the coloring power of the toner is observed. When the content exceeds 15% by mass, poor dispersion of the pigment in the toner occurs, the coloring power decreases, and the electrical characteristics of the toner. May be reduced.

  The colorant may be used as a master batch combined with a resin. The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, styrene copolymer, polymethyl methacrylate resin, polybutyl Methacrylate resin, polyvinyl chloride resin, polyvinyl acetate resin, polyethylene resin, polypropylene resin, polyester resin, epoxy resin, epoxy polyol resin, polyurethane resin, polyamide resin, polyvinyl butyral resin, polyacrylic acid resin, rosin, modified rosin, terpene Examples thereof include resins, aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffins. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the styrene or substituted polymer thereof include polyester resin, polystyrene resin, poly p-chlorostyrene resin, and polyvinyl toluene resin. Examples of the styrene copolymer include a styrene-p-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, and a styrene-methyl acrylate copolymer. Polymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene- Butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene An acrylonitrile-indene copolymer, Styrene - maleic acid copolymer, styrene - like maleic acid ester copolymer.

  The masterbatch can be produced by mixing or kneading the masterbatch resin and the colorant under high shear. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. The flushing method is a method of mixing or kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, and transferring the colorant to the resin side to remove moisture and the organic solvent component. For the mixing or kneading, for example, a high shear dispersion device such as a three-roll mill is preferably used.

-Release agent-
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes, such as carbonyl group containing wax, polyolefin wax, and long-chain hydrocarbon, are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, a carbonyl group-containing wax is preferable.

Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, dialkyl ketones, and the like. Examples of the polyalkanoic acid ester include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecane. Examples thereof include diol distearate. Examples of the polyalkanol ester include tristearyl trimellitic acid and distearyl maleate. Examples of the polyalkanoic acid amide include dibehenyl amide. Examples of the polyalkylamide include trimellitic acid tristearylamide. Examples of the dialkyl ketone include distearyl ketone. Of these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred.
Examples of the polyolefin wax include polyethylene wax and polypropylene wax.
Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40 to 160 degreeC is preferable, 50 to 120 degreeC is more preferable, and 60 to 90 degreeC is especially preferable. . When the melting point is less than 40 ° C., the heat resistant storage stability may be adversely affected. When the melting point exceeds 160 ° C., cold offset may easily occur during fixing at a low temperature.
The melt viscosity of the release agent is preferably 5 to 1000 cps, more preferably 10 to 100 cps, as a measured value at a temperature 20 ° C. higher than the melting point of the wax. If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.

There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 40 mass% or less is preferable and 3-30 mass% is more preferable.
When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

-Charge control agent-
The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored material is used, a colorless or nearly white material may be used. Preferably, for example, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten Examples thereof include a single substance or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, and a metal salt of a salicylic acid derivative. These may be used individually by 1 type and may use 2 or more types together.

Commercially available products may be used as the charge control agent. Examples of the commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, phenolic condensate E-89 (all manufactured by Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (all manufactured by Hodogaya Chemical Co., Ltd.), No. Quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (both manufactured by Hoechst); LRA-901, boron complex LR-147 (Nippon Carlit Co., Ltd.); quinacridone, azo pigment; sulfone Group, a carboxyl group, and the like and polymeric compounds having a functional group such as a quaternary ammonium salt.
The charge control agent may be melted and kneaded with the master batch and then dissolved or dispersed, or may be added together with the toner components when directly dissolving or dispersing in the organic solvent, or the toner. You may fix to the toner surface after particle manufacture.

  The content of the charge control agent in the toner varies depending on the type of the binder resin, the presence / absence of an additive, a dispersion method, and the like, and cannot be generally specified. On the other hand, 0.1-10 mass parts is preferable, and 0.2-5 mass parts is more preferable. When the content is less than 0.1 parts by mass, the charge controllability may not be obtained. When the content exceeds 10 parts by mass, the chargeability of the toner becomes too large, and the effect of the main charge control agent is reduced. As a result, the electrostatic attractive force with the developing roller increases, which may lead to a decrease in developer fluidity and a decrease in image density.

-External additive-
The external additive is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, Strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate Barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like can be used. Among these, when two types of silica and titanium oxide are used, the effect of suppressing the burying of the additive in the toner and the effect of stabilizing the charging of the toner are particularly exhibited.
In the present invention, a premix developer containing a carrier has excellent fluidity and a premix developer containing a carrier having a charge amount of −40 μC / g to −80 μC / g and a hydrophobization degree of 60% or more. It is extremely important to obtain a toner with no or few aggregates.
Moreover, it is preferable that the said external additive contains hydrophobic silica and the containing mass ratio (Si / Ti) of this silica and titanium oxide is 1.0-2.0. Hydrophobic titanium oxide is excellent in environmental stability and image density stability. On the other hand, since the charge rising property tends to deteriorate, it is considered that this side effect is increased only with titanium oxide fine particles. Therefore, by using the silica and titanium oxide in combination and setting the above-mentioned content ratio, it is possible to ensure environmental stability and image density stability while suppressing deterioration of the charge rising characteristics.
The amount of the external additive added is preferably 0.1% by mass to 5% by mass and more preferably 0.3% by mass to 3% by mass with respect to the toner.

As the hydrophobic titanium oxide particles, titanium oxide particles surface-treated with an organosilicon compound can be used. Examples of the organosilicon compound include silane coupling agents and silicone oils. Among these, silane coupling agents are suitable for obtaining the hydrophobic titanium oxide particles of the present invention.
As the silane coupling agent, for example, any type of organoalkoxysilane, organoacyloxysilane, organochlorosilane, organosilane, organosilazane, and special silylating agent can be used. Of these, organoalkoxysilane and organoacyloxysilane are preferably used, and hydrophobic titanium oxide particles having a hydrophobization degree of 50 to 80% can be advantageously obtained.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a fluidity improver, a cleaning property improver, a magnetic material, a metal soap, etc. are mentioned.

The fluidity improver can be surface-treated to increase hydrophobicity and prevent deterioration of fluidity and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, and a fluoride can be used. Examples thereof include silane coupling agents having an alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils.
The cleaning improver is added to the toner to remove the developer after transfer remaining on the electrostatic latent image carrier or the intermediate transfer member. For example, fatty acid such as zinc stearate, calcium stearate, stearic acid Metal salts; polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.
There is no restriction | limiting in particular as said magnetic material, According to the objective, it can select suitably from well-known things, For example, iron powder, a magnetite, a ferrite, etc. are mentioned. Among these, white is preferable in terms of color tone.

-Toner production method-
The method for producing the toner is not particularly limited and can be appropriately selected according to the purpose from conventionally known toner production methods. For example, a kneading / pulverizing method, a polymerization method, a dissolution suspension method, The spray granulation method etc. are mentioned.

--Kneading and grinding method--
The kneading and pulverizing method is, for example, a method of producing the toner base particles by melt-kneading a toner material containing at least a binder resin and a colorant, pulverizing and classifying the obtained kneaded material. is there.
In the melt kneading, the toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Casey Kay Co., Ltd. Used. This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt-kneading temperature is determined with reference to the softening point of the binder resin. If the temperature is higher than the softening point, cutting is severe, and if the temperature is too low, dispersion may not proceed.

  In the pulverization, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.

In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed, for example, by removing the fine particle portion with a cyclone, a decanter, a centrifuge, or the like.
After the pulverization and classification are completed, the pulverized product is classified into an air stream by centrifugal force or the like, and toner base particles having a predetermined particle diameter can be produced.

  Next, the external additive is externally added to the toner base particles. By mixing and stirring the toner base particles and the external additive using a mixer, the surface of the toner base particles is coated while being crushed. At this time, it is important from the viewpoint of durability that the external additives such as inorganic fine particles and resin fine particles are uniformly and firmly attached to the toner base particles.

--- Polymerization method--
As a method for producing a toner by the polymerization method, for example, a toner solution containing at least an active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound is dissolved or dispersed in an organic solvent to prepare a toner solution. After the preparation, the toner solution is emulsified or dispersed in an aqueous medium to prepare a dispersion, and the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound in the aqueous medium are prepared. Is preferably produced by removing the organic solvent, specifically, a modified polyester capable of at least urea or urethane bonding in the organic solvent. A toner material containing a resin, a colorant, and a release agent is dissolved or dispersed. Then, the solution or dispersion is dispersed in an aqueous medium, subjected to a polyaddition reaction, the solvent of this dispersion is removed and washed.

  Examples of the modified polyester resin capable of being bonded with urea or urethane include, for example, polyester prepolymer having an isocyanate group obtained by reacting a carboxyl group or a hydroxyl group at a terminal of a polyester with a polyvalent isocyanate compound (PIC). Can be mentioned. The modified polyester resin obtained by crosslinking and / or extending the molecular chain by the reaction of this polyester prepolymer and amines can improve the hot offset property while maintaining the low temperature fixability.

Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane). Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; And those blocked with oxime, caprolactam, and the like. These may be used individually by 1 type and may use 2 or more types together.
The ratio of the polyvalent isocyanate compound (PIC) is preferably 5/1 to 1/1 as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group, 4/1 to 1.2 / 1 is more preferable, and 2.5 / 1 to 1.5 / 1 is still more preferable.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having the isocyanate group is preferably 1 or more, more preferably 1.5 to 3 on average, and 1.8 to 2.5 on average. Is more preferable.

Examples of amines (B) to be reacted with the polyester prepolymer include a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4), an amino acid (B5). ), B1 to B5 amino groups blocked (B6), and the like.
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-). Dimethyl dicyclohexyl methane, diamine cyclohexane, isophorone diamine, etc.); aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like.
Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of the blocked B1-B5 amino group (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). . Among these amines (B), B1 and a mixture of B1 and a small amount of B2 are particularly preferable.

  The ratio of the amines (B) is equivalent to the equivalent ratio [NCO] / [NHx of the isocyanate group [NCO] in the polyester prepolymer (A) having an isocyanate group and the amino group [NHx] in the amine (B). ] Is preferably 1/2 to 2/1, more preferably 1.5 / 1 to 1 / 1.5, and still more preferably 1.2 / 1 to 1 / 1.2.

  According to the method for producing a toner by the polymerization method as described above, a toner having a small particle diameter and a spherical shape can be produced at low cost with little environmental load.

  The toner used in the present invention is not particularly limited in its shape, size, etc., and can be appropriately selected according to the purpose. The average circularity, volume average particle diameter, volume average, etc. are as follows. It is preferable to have a ratio of the particle size to the number average particle size (volume average particle size / number average particle size).

The average circularity is a value obtained by dividing the circumference of an equivalent circle having the same projected area as the shape of the toner by the circumference of the actual particles. For example, 0.93 to 1.000 is preferable, and 0.940 to 0 is preferable. .99 is more preferred.
When the average circularity is less than 0.930, the toner is in an irregular shape separated from the sphere, and a satisfactory transferability and a high-quality image free from dust may not be obtained. In an image forming system that employs blade cleaning or the like, poor cleaning occurs on the photosensitive member and the transfer belt, and in the case of image formation with a high image area ratio such as dirt on the image, for example, a photographic image. The toner on which an untransferred image is formed due to a paper feed failure or the like may become a transfer residual toner on the photosensitive member, resulting in background smearing of the image, or the charging roller for contact charging the photosensitive member Etc., and the original charging ability may not be exhibited.

Here, the average circularity can be measured by using a flow particle image analyzer (Flow Particle Image Analyzer). For example, it can be measured using a flow type particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd.
In the measurement, fine dust is removed through a filter, and as a result, in 10 ml of water having 10 or less particles within a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) in 10 ⁻³ cm ³ of water. Add a few drops of a nonionic surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.), add 5 mg of a measurement sample, and use an ultrasonic disperser (manufactured by SMT, UH-50) at 20 kHz, 50 W / Dispersion treatment is performed for 1 minute under the conditions of 10 cm ³ , and further, dispersion treatment is performed for a total of 5 minutes, and the particle concentration of the measurement sample is 4,000 to 8,000 particles / 10 ⁻³ cm ³ The particle size distribution of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm is measured using the sample dispersion liquid.

The sample dispersion liquid is passed through a flow path (expanded along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). In order to form an optical path that passes across the thickness of the flow cell, the strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell 2. Taken as a dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.
In about 1 minute, the equivalent circle diameter of 1,200 or more particles can be measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter can be measured. The results (frequency% and cumulative%) can be obtained by dividing the range of 0.06 to 400 μm into 226 channels (divided into 30 channels per octave). In actual measurement, particles are measured in a range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

  There is no restriction | limiting in particular as a volume average particle diameter of the said toner, Although it can select suitably according to the objective, 5 micrometers-9 micrometers are preferable. In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning properties. is there. Further, when the volume average particle diameter is smaller than the range of the present invention, in the case of the two-component developer, the toner is fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier is reduced, When used as an agent, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. Further, these phenomena are the same for the toner having a fine powder content larger than the range of the present invention.

  On the contrary, when the particle diameter of the toner is larger than the range of the present invention, it becomes difficult to obtain a high resolution and high quality image, and when the balance of the toner in the developer is performed, In many cases, the variation of the particle size becomes large. The volume average particle diameter (Dv) is measured automatically based on the value of the volume average particle diameter (Dv) measured with an aperture diameter of 100 μm using a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics. Measured.

  When the mass average particle size is less than 5 μm, transferability and cleaning properties are deteriorated, which causes abnormal images, and the toner tends to be fused to the surface of the carrier, so that the carrier life in the premix toner is increased. If it exceeds 9 μm, it may be difficult to obtain a high-resolution and high-quality image.

The ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, and more preferably 1.00 to 1.10.
When the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) exceeds 1.25, the two-component developer causes the surface of the carrier to be agitated for a long period of time in the developing device. The toner may be fused to reduce the charging ability of the carrier. In the case of a one-component developer, the toner filming on the developing roller or the toner is thinned to fuse the toner to a member such as a blade. May occur, and it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the variation in the toner particle size may increase. is there.

  The volume average particle diameter and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) are, for example, a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd. Can be measured.

  The coloration of the toner is not particularly limited and may be appropriately selected according to the purpose, and may be at least one selected from black toner, cyan toner, magenta toner, and yellow toner. Can be obtained by appropriately selecting the type of the colorant, and is preferably a color toner.

(Developer)
In the present invention, a two-component developer comprising the toner and a carrier is used as the developer.

-Career-
There is no restriction | limiting in particular as a carrier used for a two-component developer, Although it can select suitably according to the objective, What has a core material and the resin layer which coat | covers this core material is preferable.

  There is no restriction | limiting in particular as a material of the said core material, It can select suitably from well-known things, For example, 50-90 emu / g manganese-strontium (Mn-Sr) type material, manganese-magnesium (Mn-) Mg) -based materials and the like are preferable, and highly magnetized materials such as iron powder (100 emu / g or more) and magnetite (75 to 120 emu / g) are preferable in terms of securing image density. In addition, the copper-zinc (Cu-Zn) system (30 to 80 emu / g) or the like is advantageous in that it can weaken the contact with the electrostatic latent image carrier in which the toner is in a spiked state, and is advantageous in improving the image quality. The weakly magnetized material is preferred. These may be used alone or in combination of two or more.

  The material of the resin layer is not particularly limited and can be appropriately selected from known resins according to the purpose. For example, amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, Polyester resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride And fluorinated terpolymers (triple fluorinated (multiple) copolymers) such as terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers, silicone resins, etc. It is done. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is particularly preferable.

  The silicone resin is not particularly limited and can be appropriately selected according to the purpose from generally known silicone resins. For example, a straight silicone resin consisting only of an organosilosan bond; an alkyd resin; Examples thereof include polyester resins, epoxy resins, acrylic resins, silicone resins modified with urethane resins, and the like.

Commercially available products can be used as the silicone resin. Examples of straight silicone resins include KR271, KR255, and KR152 manufactured by Shin-Etsu Chemical Co., Ltd .; SR2400, SR2406, and SR2410 manufactured by Toray Dow Corning Silicone Co., Ltd. Etc.
Commercially available products can be used as the modified silicone resin. For example, KR206 (alkyd modified), KR5208 (acryl modified), ES1001N (epoxy modified), KR305 (urethane modified) manufactured by Shin-Etsu Chemical Co., Ltd .; SR2115 (epoxy-modified), SR2110 (alkyd-modified) manufactured by Dow Corning Silicone Co., Ltd., and the like.
In addition, although a silicone resin can be used alone, it is also possible to simultaneously use a component that undergoes a crosslinking reaction, a charge amount adjusting component, and the like.

  The resin layer may contain conductive powder or the like as necessary. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle diameter of these conductive powders is preferably 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.

For example, the resin layer is prepared by dissolving the silicone resin or the like in a solvent to prepare a coating solution, and then uniformly coating the coating solution on the surface of the core material by a known coating method, drying, and baking. It can be formed by doing. Examples of the application method include an immersion method, a spray method, and a brush coating method.
There is no restriction | limiting in particular as said solvent, Although it can select suitably according to the objective, For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cellosolve, butyl acetate, etc. are mentioned.
The baking is not particularly limited, and may be an external heating method or an internal heating method. For example, a stationary electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, etc. The method of using, the method of using a microwave, etc. are mentioned.

  The amount of the resin layer in the carrier is preferably 0.01 to 5.0% by mass. When the amount is less than 0.01% by mass, the uniform resin layer may not be formed on the surface of the core material. When the amount exceeds 5.0% by mass, the resin layer becomes thick. In some cases, granulation of carriers occurs, and uniform carrier particles may not be obtained.

  The volume resistivity of the carrier is preferably 7 to 13 [Log Ω · cm] (volume resistivity obtained by logarithm (Log): Log (Ω · cm)). When the volume resistivity is less than 7 [Log Ω · cm], carrier adhesion tends to occur. Furthermore, since the image forming apparatus of the present invention is a trickle developing system, the carrier particles contained in the premix toner are also replenished according to the amount of toner consumed. The specific resistance of the carrier particles has a certain width, and the content of particles having a specific resistance of 7 [Log Ω · cm] or less increases. For this reason, the number of particles adhering to the carrier increases, which causes wear of the photoreceptor. On the other hand, if it exceeds 13 [Log Ω · cm], an image having a large edge effect and a large roughness is obtained. There is no particular problem with character copying. However, with color copying, the above problem occurs when a picture is copied. In addition, the edges of the carrier become hard during development, and stripes and unevenness are likely to occur.

The volume average particle size of the carrier is preferably 30 to 60 μm, more preferably 40 to 55 μm. When the volume average particle size is less than 30 μm, the volume average particle size is less than 30 μm, so that granulation is easily performed at the time of forming the coating layer, and a large amount of mass-shaped carriers are formed, resulting in trouble during production. Further, carrier scattering from the developing sleeve becomes significant. Furthermore, since the image forming apparatus of the present invention is a trickle developing system, the carrier particles contained in the premix toner are also replenished according to the amount of toner consumed. Carrier particles have a certain range of particle diameters, and carriers having an average particle diameter of less than 30 μm include carrier particles having smaller particle diameters, which tend to cause carrier adhesion and wear of the photoreceptor. It becomes the factor of.
On the other hand, when the thickness exceeds 60 μm, the solid uniformity is poor, and a carrier scratch may occur in the solid portion. In addition, when copying a picture document, the edge of the image (relative to the paper discharge direction) produces an edge effect, poor dot reproducibility, and poor graininess. May be.

There is no restriction | limiting in particular as content in this two-component developer of the said carrier, According to the objective, it can select suitably, For example, 90 mass%-98 mass% are preferable, and 93 mass%-97 mass% are preferable. More preferred.
In general, the mixing ratio of the toner and the carrier of the two-component developer is preferably 1 part by mass to 10.0 parts by mass of the toner with respect to 100 parts by mass of the carrier.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the visible image with the electrophotographic photosensitive member using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) includes at least a transfer unit that peels and charges the visible image formed on the electrophotographic photosensitive member toward the recording medium. preferable. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

-Fixing Step and Fixing Unit The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium. Alternatively, it may be performed at the same time in a state in which the toner of each color is laminated.

The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose. A fixing unit and a heat source for heating the fixing member are used.
Examples of the fixing member include a combination of an endless belt and a roller, a combination of a roller and a roller, etc., but the warm-up time can be shortened, and in terms of realizing energy saving, A combination of an endless belt and a roller having a small heat capacity is preferable in terms of expansion of the fixable width.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrophotographic photosensitive member, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrophotographic photosensitive member. For example, a neutralization lamp is preferably used. Can be mentioned.

The cleaning step is a step of removing the toner remaining on the electrophotographic photosensitive member, and can be suitably performed by a cleaning unit. It is also possible to employ a method in which the residual toner charges are made uniform by the rubbing member and collected by the developing roller without using the cleaning means.
The cleaning means is not particularly limited, and may be selected from known cleaners as long as the electrophotographic toner remaining on the electrophotographic photosensitive member can be removed. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

  The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit. There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  The image forming apparatus of the present invention comprises the electrostatic latent image carrier and components such as a charging unit, a developing unit, a transfer unit, and a cleaning unit which are integrally coupled as a process cartridge, and this unit is composed of a main body of the apparatus. It may be configured to be detachable.

Here, the configuration and operation of the entire image forming apparatus will be described with reference to FIG. 6 for one aspect of carrying out the image forming method of the present invention by the image forming apparatus of the present invention.
In FIG. 6, 1 is a main body of a color copying machine as an image forming apparatus, 2 is a writing unit that emits laser light based on input image information, and 20Y, 20M, 20C, and 20BK are colors (yellow, magenta, cyan, black). ), A photosensitive drum 21 as an electrostatic latent image carrier of the present invention housed in each of the process cartridges 20Y, 20M, 20C, and 20BK, and 22 for charging the surface of the photosensitive drum 21, respectively. , 23Y, 23M, 23C, and 23BK are developing units (developing devices) that develop an electrostatic latent image formed on the photosensitive drum 21, and 24 is a toner image formed on the photosensitive drum 21, and an intermediate transfer belt. A transfer bias roller 25 for transferring to 27, and a cleaning unit 25 for collecting untransferred toner on the photosensitive drum 21.

  27 is an intermediate transfer belt on which toner images of a plurality of colors are transferred in an overlapping manner, 28 is a second transfer bias roller for transferring the toner image formed on the intermediate transfer belt 27 to the recording medium P, and 29 is on the intermediate transfer belt 27 An intermediate transfer belt cleaning unit that collects untransferred toner, 30 is a conveyance belt that conveys a recording medium P on which a four-color toner image is transferred, and 32Y, 32M, 32C, and 32BK are developing units 23Y, 23M, and 23C. , 23BK, a toner replenishing unit that replenishes toner of each color, 47Y, 47M, 47C, 47BK are carrier replenishing units that newly replenish carriers to each developing unit 23Y, 23M, 23C, 23BK, and 51 is a document reading unit. 55 is a document conveying section for conveying to 55, 55 is a document reading section (scanner) for reading image information of document D, and 61 is for storing a recording medium P such as transfer paper. Paper feed unit that, 66 denotes a fixing unit for fixing the unfixed image on the recording medium P.

  Here, each of the process cartridges 20Y, 20M, 20C, and 20BK is obtained by integrating the photosensitive drum 21, the charging unit 22, and the cleaning unit 25, respectively. Image formation of each color (yellow, magenta, cyan, black) is performed on the photosensitive drum 21 in each of the process cartridges 20Y, 20M, 20C, and 20BK.

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the document D is transported from the document table in the direction of the arrow in FIG. 6 by the transport roller of the document transport unit 51 and placed on the contact glass 53 of the document reading unit 55. Then, the document reading unit 55 optically reads the image information of the document D placed on the contact glass 53.

  Specifically, the document reading unit 55 scans the image of the document D on the contact glass 53 while irradiating light emitted from the illumination lamp. Then, the light reflected by the document D is imaged on the color sensor via the mirror group and the lens. The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Furthermore, processing such as color conversion processing, color correction processing, and spatial frequency correction processing is performed by an image processing unit (not shown) based on RGB color separation image signals, and yellow, magenta, cyan, and black are processed. Get color image information.

On the other hand, the four photosensitive drums 21 rotate in the clockwise direction of FIG. First, the surface of the photosensitive drum 21 is uniformly charged at a position facing the charging unit 22 (a charging step). Thus, a charged potential is formed on the photosensitive drum 21.
The charging device is not particularly limited and can be appropriately selected according to the purpose. For example, a known contact charging device including a conductive or semiconductive roller, brush, film, rubber blade, corotron, A non-contact charger using a corona discharge such as a scorotron, a means for providing a gap such as a gap tape at the end of the roller, and a charge placed close to the electrostatic latent image carrier in a non-contact manner via the gap tape For example.

  The shape of the charging member may take any form such as a magnetic brush or a fur brush in addition to the roller, and can be selected according to the specifications and form of the electrophotographic apparatus. In the case of a magnetic brush, for example, various ferrite particles such as Zn-Cu ferrite are used as a charging member, a non-magnetic conductive sleeve for supporting the charging member, and a magnetic roll included in the charging member, To do. Alternatively, in the case of a brush, for example, a fur treated with carbon, copper sulfide, metal or metal oxide is used as the material of the fur brush, and this is wound around a metal or other conductive cored bar. A charging member is obtained by pasting.

In addition, it is preferable to use a contact-type charger or a charger that is disposed in a non-contact manner by means for providing a gap from the viewpoint that an image forming apparatus with reduced ozone generation from the charger can be obtained. In particular, it is preferable that the charger is arranged in contact with or not in contact with the electrostatic latent image carrier and configured to charge the surface of the electrostatic latent image carrier by applying a DC and AC voltage in a superimposed manner.
Among them, the charger charges the surface of the electrostatic latent image carrier by applying a direct current and an alternating voltage to a charging roller arranged in a non-contact proximity via a means for providing a gap to the electrostatic latent image carrier. This is particularly preferable because it has a great merit that charging unevenness can be reduced and a margin for charging failure caused by contamination of the charging roller is large and it can be used without maintenance.

Thereafter, the surface of the charged photosensitive drum 21 reaches the irradiation position of each laser beam.
In the writing unit 2, laser light corresponding to the image signal is emitted from the light source corresponding to each color. The laser light is incident on the polygon mirror 3 and reflected, and then passes through the lenses 4 and 5. The laser light that has passed through the lenses 4 and 5 passes through different optical paths for each of the yellow, magenta, cyan, and black color components (exposure process).
The laser beam corresponding to the yellow component is reflected by the mirrors 6 to 8 and then irradiated to the surface of the photosensitive drum 21 of the first process cartridge 20Y from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotational axis direction (main scanning direction) of the photosensitive drum 21 by the polygon mirror 3 that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 21 charged by the charging unit 22.

  Similarly, the laser beam corresponding to the magenta component is reflected by the mirrors 9 to 11 and then irradiated to the surface of the photosensitive drum 21 of the second process cartridge 20M from the left side of the paper, thereby causing an electrostatic latent image corresponding to the magenta component. An image is formed. The cyan component laser light is reflected by the mirrors 12 to 14 and then irradiated to the surface of the photosensitive drum 12 of the third process cartridge 20C from the left side of the drawing to form a cyan component electrostatic latent image. The black component laser light is reflected by the mirror 15 and then irradiated on the surface of the photosensitive drum 21 of the fourth process cartridge 20BK from the left side of the paper, thereby forming an electrostatic latent image of black component.

Writing to the electrostatic latent image carrier can be performed, for example, by exposing the surface of the electrostatic latent image carrier imagewise using an exposure device. The exposure device is not particularly limited as long as the surface of the electrostatic latent image carrier charged by the charger can be exposed like an image to be formed, and can be appropriately selected according to the purpose.
Examples include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.

Thereafter, the surface of the photosensitive drum 21 on which the electrostatic latent images of the respective colors are formed reaches positions facing the developing units 23Y, 23M, 23C, and 23BK, respectively. Then, each color toner is supplied from the developing units 23Y, 23M, 23C, and 23BK onto the photosensitive drum 21, and the latent image on the photosensitive drum 21 is developed (developing step).
Thereafter, the surface of the photosensitive drum 21 after the development process reaches a position facing the intermediate transfer belt 27. Here, the transfer bias roller 24 is installed at each facing position so as to contact the inner peripheral surface of the intermediate transfer belt 27. Then, at the position of the transfer bias roller 24, the images of the respective colors formed on the photosensitive drum 21 are sequentially superimposed and transferred onto the intermediate transfer belt 27 (first transfer step).
Then, the surface of the photosensitive drum 21 after the first transfer process reaches a position facing the cleaning unit 25. The untransferred toner remaining on the photosensitive drum 21 is collected by the cleaning unit 25 (this is a cleaning process).
Thereafter, the surface of the photosensitive drum 21 passes through a static elimination unit (not shown), and a series of image forming processes on the photosensitive drum 21 is completed.
On the other hand, the surface of the intermediate transfer belt 27 on which the images of the respective colors on the photosensitive drum 21 are transferred in a superimposed manner travels in the direction of the arrow in FIG. Then, the full color image on the intermediate transfer belt 27 is secondarily transferred onto the recording medium P at the position of the second transfer bias roller 28 (this is a second transfer step).

Thereafter, the surface of the intermediate transfer belt 27 reaches the position of the intermediate transfer belt cleaning unit 29. Then, the untransferred toner on the intermediate transfer belt 27 is collected by the intermediate transfer belt cleaning unit 29, and a series of transfer processes on the intermediate transfer belt 27 is completed.
Here, the recording medium P at the position of the second transfer bias roller 28 is transported from the paper feeding unit 61 via the transport guide 63, the registration roller 64, and the like.
Specifically, the recording medium P fed by the paper feeding roller 62 from the paper feeding unit 61 that stores the recording medium P passes through the conveyance guide 63 and is guided to the registration roller 64. The recording medium P that has reached the registration roller 64 is conveyed toward the position of the second transfer bias roller 28 in synchronization with the toner image on the intermediate transfer belt 27.
Thereafter, the recording medium P on which the full-color image is transferred is guided to the fixing unit 66 by the conveyance belt 30. In the fixing unit 66, the color image is fixed on the recording medium P at the nip between the heating roller 67 and the pressure roller 68.
Then, the recording medium P after the fixing process is discharged as an output image outside the apparatus main body 1 by the paper discharge roller 69, and a series of image forming processes is completed.

Next, the image forming unit of the image forming apparatus will be described in detail with reference to FIGS.
FIG. 7 is a cross-sectional view showing the image forming unit, and FIG. 8 is a cross-sectional view in the longitudinal direction (the direction perpendicular to the paper surface of FIG. 2) showing the developing device.
The four image forming units installed in the apparatus main body 1 have substantially the same structure except that the color of the toner T used in the image forming process is different. , M, C, BK) are not shown.

As shown in FIG. 7, the process cartridge 20 mainly contains a photosensitive drum 21 as an image carrier, a charging unit 22, and a cleaning unit 25 integrally in a case 26. The cleaning unit 25 is provided with a cleaning blade 25 a and a cleaning roller 25 b that are in contact with the photosensitive drum 21.
The developing device 23 mainly includes a developing roller 23a as a developer carrying member facing the photosensitive drum 21, a first conveying screw 23b as a first conveying member facing the developing roller 23a, and a partition member 23e. The second conveying screw 23c as the second conveying member facing the first conveying screw 23b, the doctor blade 23d as the developer carrying member facing the developing roller 23a, and the developer G accommodated in the developing device 23 A developer discharging means 23k for discharging a part of the developing device 23 to the outside.

  Further, the developing device 23 is provided with a first developer containing portion 23g and a second developer containing portion 23h separated by a partition member 23e. Referring to FIG. 8, the first developer accommodating portion 23g and the second developer accommodating portion 23h communicate with each other at both ends in the longitudinal direction (the range in which the partition member 23e is not interposed), and the developer circulation path is formed. Forming. In the first developer accommodating portion 23g, a developing roller 23a, a first conveying screw 23b, a doctor blade 23d, and the like are disposed. A second conveying screw 23c, a magnetic sensor 40, and the like are disposed in the second developer accommodating portion 23h. In addition, referring to FIG. 7, the distance between the developing roller 23a and the photosensitive drum 21 facing position (first facing position) and the developing roller 23a and doctor blade 23d facing position (second facing position). Is provided with a cover member 23m for covering the developer carried on the developing roller 23a.

  Referring to FIG. 8, the developing roller 23a includes a magnet 23a1 fixed inside to form a magnetic pole on the circumferential surface of the roller, and a sleeve 23a2 made of a nonmagnetic material such as aluminum and rotating around the magnet 23a1. Composed. A plurality of magnetic poles (main pole, transport pole, pumping pole, agent cutting pole, etc.) are formed on the developing roller 23a (sleeve 23a2) by the magnet 23a1.

  The developing roller 23a (sleeve 23a2) is connected to a drive motor (not shown) installed in the apparatus main body 1 and is rotationally driven by the drive motor. Although not shown, the developing roller 23a, the first conveying screw 23b, and the second conveying screw 23c are drivingly connected by a gear train. As a result, as the developing roller 23a is driven to rotate by the drive motor, the first conveying screw 23b and the second conveying screw 23c are also driven to rotate.

In addition, the 1st conveyance screw 23b and the 2nd conveyance screw 23c are mainly comprised by the axial part and the screw part (it is a single screw).
In the developing device 23, a two-component developer G composed of toner T and carrier C is accommodated.
The toner T in the first embodiment (the toner in the developer G and the toner in the toner replenishing unit 32) contains toner base particles and additives made of a resin and a colorant. The particle size of the toner T is 5 μm to 9 μm.
In addition, the toner T according to the first embodiment is synthesized by a polymerization reaction such as emulsion polymerization or suspension polymerization using a monomer, or a method in which the resin itself is melted and sprayed to form fine particles by heat or the like. Alternatively, it can be produced by a method in which an additive is mixed and adhered to a base particle obtained by dispersing in water or the like to a predetermined particle size using a Henschel mixer or the like.

  The carrier C in the developer G is obtained by forming a coating layer on magnetic core material particles. The particle size of the carrier C is 30 μm to 60 μm.

The image forming process described above will be described in more detail with a focus on the developing process.
The developing roller 23a rotates in the direction of the arrow in FIG. As shown in FIG. 8, the developer G in the developing device 23 is generated by the rotation of the first conveying screw 23 b and the second conveying screw 23 c arranged so as to interpose the partition member 23 e therebetween in the arrow direction. It circulates in the longitudinal direction while being mixed and agitated together with toner T (supplemented toner) replenished from the replenishing section 32 through the toner replenishing port 23f (circulation in the direction of the broken arrow in FIG. 8). The first conveying screw 23b (first conveying member) conveys the developer G to the right side in FIG. 8, and the second conveying screw 23c (second conveying member) conveys the developer G to the left side in FIG. It is conveyed in the direction opposite to the conveying direction of the conveying screw 023b.

In the first embodiment, the toner replenishing port 23f is disposed on the upstream side (see the right side in FIG. 8) of the developer circulation path (conveyance path) by the second conveyance screw 23c. Further, a supply port 23p for supplying the collected detached toner into the developing device 23 is provided adjacent to the toner supply port 23f (see FIG. 9).
The toner T frictionally charged in the circulation path and adsorbed on the carrier C is carried on the developing roller 23a together with the carrier C. The developer G carried on the developing roller 23a then reaches the position of the doctor blade 23d (second opposing position). The developer G on the developing roller 23a is adjusted to an appropriate amount at the position of the doctor blade 23d. At this time, the developer G is rubbed by the gap (the doctor gap D1 shown in FIG. 10) between the doctor blade 23d and the developing roller 23a, and the toner T is further charged. Thereafter, the developer G on the developing roller 23a reaches a position facing the photosensitive drum 21 (a first facing position and a developing region).

  Thereafter, in the development area, the toner T in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive drum 21. Specifically, the toner T is latently exposed by the electric field formed by the potential difference (development potential) between the latent image potential (exposure potential) of the image area irradiated with the laser light L and the development bias applied to the development roller 23a. Adhere to the image.

  Thereafter, most of the toner T adhering to the photosensitive drum 21 in the developing process is transferred onto the intermediate transfer belt 27. The untransferred toner T remaining on the photosensitive drum 21 is collected in the cleaning unit 25 by the cleaning blade 25a and the cleaning roller 25b.

  Here, the toner replenishing unit 32 provided in the apparatus main body 1 has a toner cartridge 33 configured to be replaceable and a toner replenishing path for guiding new toner (supplementary toner) T discharged from the toner cartridge 33 to the developing device 23. 34. Since the image forming apparatus of the present invention is a trickle developing system, a new toner used for replenishment is a premix toner in which a toner and a carrier are mixed in advance at a certain ratio. In the toner cartridge 33, a new premixed toner T (any one of yellow, magenta, cyan, and black) is accommodated.

  Referring to FIG. 9, an air pump 35 (powder pump) is installed in the toner replenishment path 34 (however, in FIG. 9, a part of the carrier is discharged to the developing device 23 floor and discharged to the developing device 23k. The collecting device for collecting the developer is omitted). When the air pump 35 is driven, the replenishing toner in the toner cartridge 33 moves through the toner replenishing path 34 formed of a flexible and excellent toner resistance tube, and enters the developing device 23 through the toner replenishing port 23f. Will be replenished. The tube of the toner supply path 34 is formed of a rubber material such as polyurethane, nitrile, EPDM, or silicone, or a resin material such as polyethylene or nylon.

  The toner cartridge 33 is provided with air supply paths 36 a and 36 b that communicate with the bottom and top of the toner cartridge 33 via the air pump 36. Then, by driving the air pump 36, air is supplied to the toner cartridge 33, and aggregation of toner in the toner cartridge 33 is suppressed. The tubes of the air supply paths 36a and 36b are made of a rubber material such as polyurethane, nitrile, EPDM, or silicone, or a resin material such as polyethylene or nylon, and have an inner diameter of 2 mm to 7 mm.

The toner T in the toner cartridge 33 is appropriately replenished into the developing device 23 from the toner replenishing port 23f as the toner T in the developing device 23 is consumed. The toner T in the developing device 23 is consumed by a magnetic sensor 40 (toner concentration detecting means) installed below the second conveying screw 23c of the developing device 23 and a photo sensor (not shown) facing the photosensitive drum 21. Detected by. Then, the toner replenishment port 32f provides the toner replenishment port 23f so that the detection result of the magnetic sensor 40 or the photosensor has an output value corresponding to the target toner density (the ratio of the toner T in the developer G). Then, the toner is supplied to the developing device 23.
The toner replenishment amount to be replenished to the developing device 23 is adjusted by controlling the drive time of the air pump 35 disposed in the toner replenishment path 34. In addition to the pump mechanism described above, a screw mechanism can also be used as the conveying means in the toner supply path 34.

  On the other hand, a developer discharge port 23k as a developer discharge means is provided near the upper end of the wall surface of the second developer storage portion 23h and downstream of the toner supply port 23f. When the new carrier C is supplied from the carrier supply unit 47 into the developing device 23 and the amount of developer in the developing device 23 exceeds a predetermined amount, the excess developer G is discharged from the developer discharge port 23k. 23 is discharged outside. The developer G discharged from the developer discharge port 23k is conveyed to the developer recovery unit 44 via the developer recovery path 43.

In this way, as the new carrier C is replenished, the developer surface (height) rises, and the developer G exceeding the height of the developer discharge port 23k is discharged out of the developing device 23. The amount of developer in the developing device 23 is always kept constant.
In the fourth embodiment, the overflow method is used as the developer discharging means for discharging the developer from the developing device 23. However, the developer discharging port 23k is provided with an openable / closable shutter, and the developer is opened and closed by opening and closing the shutter. Can also be discharged.

FIG. 10 shows a trickle-type developing device 23 provided with a new toner supply means 32 and a carrier supply means 47 separately. Specifically, a carrier replenishing unit 47 as a carrier replenishing unit is provided above the second developer containing unit 23h, in addition to the toner replenishing unit 32 (toner replenishing unit). The carrier replenishment unit 47 is configured to be replaceable, a carrier replenishment path 49 for guiding the new carrier C discharged from the carrier cartridge 48 to the developing device 23 via the toner replenishment port 23f (replenishment port), It consists of A new carrier C is accommodated in the carrier cartridge 48. Then, the carrier is appropriately supplied from the carrier supply unit 47 into the developing device 23 at a predetermined timing.
Although not shown, the adjustment of the carrier replenishment amount to be replenished to the developing device 23 is performed by controlling the driving time of the air pump disposed in the carrier replenishment path 49. In addition, as a conveyance means in the carrier replenishment path 49, a screw mechanism can be used in addition to the pump mechanism described above.

  In the image forming apparatus and the image forming method of the present invention, the mounted electrostatic latent image carrier has high wear resistance, and stably performs excellent durability and high-quality image formation over a long period of time. In addition, it is suitable for a trickle developing system that can perform image formation almost maintenance-free.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to the following Example.

-Preparation example of reactive charge transport material-
Next, a charge transporting polyol (reactive charge transporting substance) used for forming a protective layer in the production of the electrostatic latent image carrier according to the present invention described later is disclosed in, for example, Japanese Patent Publication No. 3540056. Can be obtained by other synthesis methods.
The specific synthesis method is shown below.

[Synthesis Example of Charge Transporting Polyol (CTP-2)]
[Synthesis of diethyl 4-methoxybenzylphosphonate]
4-Methoxybenzyl chloride and triethyl phosphite were reacted at 150 ° C. for 5 hours. Thereafter, excess triethyl phosphite and by-product ethyl chloride were removed by distillation under reduced pressure to obtain diethyl 4-methoxybenzylphosphonate.

[Synthesis of 4-methoxy-4 ′-(di-p-tolylamino) stilbene]
Equimolar diethyl 4-methoxybenzylphosphonate and 4- (di-p-tolylamino) benzaldehyde were dissolved in N, N-dimethylformamide, and tert-butoxypotassium was added little by little with stirring under water cooling. After stirring at room temperature for 5 hours, water was added to make it acidic, and a crude product of the target product was obtained. Further, purification was performed by column chromatography on silica gel to obtain 4-methoxy-4 ′-(di-p-tolylamino) stilbene as a target product.

[Synthesis of 4-hydroxy-4 ′-(di-p-tolylamino) stilbene]
The obtained 4-methoxy-4 ′-(di-p-tolylamino) stilbene and double equivalent sodium ethanethiolate were dissolved in N, N-dimethylformamide and reacted at 130 ° C. for 5 hours. Thereafter, the mixture was cooled, opened in water, neutralized with hydrochloric acid, and the target product was extracted with ethyl acetate. The extract was washed with water, dried and evaporated to give a crude product. Further, purification by column chromatography on silica gel gave 4-hydroxy-4 ′-(di-p-tolylamino) stilbene (CTP-1) as a target product.

[Synthesis of 1,2-dihydroxy-3- [4 ′-(di-p-tolylamino) stilben-4-yloxy] propane]
A reaction vessel equipped with a stirrer, thermometer, condenser, and dropping funnel was charged with 11.75 g of 4-hydroxy-4 ′-(di-p-tolylamino) stilbene, 4.35 g of glycidyl methacrylate, and 8 ml of toluene at 90 ° C. Then, 0.16 g of triethylamine was added, and the mixture was heated and stirred at 95 ° C. for 8 hours. Thereafter, 16 ml of toluene and 20 ml of a 10% aqueous sodium hydroxide solution were added, and the mixture was further stirred with heating at 95 ° C. for 8 hours.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate, washed with acid and washed with water, and then the solvent was distilled off to obtain 19 g of a crude product. Furthermore, the desired product 1,2-dihydroxy-3- [4 ′-(di-p-tolylamino) stilbene-4- (1) having the following structural formula (CTP-2) was analyzed by column chromatography using silica gel (solvent: ethyl acetate). [Iloxy] propane was obtained. (Yield 9.85 g, yellow crystals, melting point 127-128.7 ° C., OH equivalent 2332.80)

The IR measurement data of (CTP-2) is shown in FIG. 11 (IR data No. 1).
As described above, a triphenylamine derivative having a methoxy group can be synthesized, and thereafter a charge transporting polyol having another 1,2-dihydroxypropyloxy group can be synthesized through the same reaction route as described above.
In the above reaction pathway, 1,2-dihydroxypropyloxy group can be introduced by reacting a charge transporting substance having a hydroxyl group with glycidyl methacrylate and then undergoing alkaline hydrolysis, so that charge transportability and abrasion resistance The number of hydroxyl groups can be arbitrarily determined while balancing the sex. The number of hydroxyl groups in the charge transport material having a hydroxyl group can be arbitrarily increased (theoretically infinite) by designing the molecular structure. In the present invention, the 1,2-dihydroxypropyloxy group is preferably 1 to 4.

[Synthesis Example of Charge Transporting Polyol (CTP-4)]
Using the derivatives necessary for the structure of the target compound, the reaction pathway similar to that in the above synthesis example is used to produce a hydroxy α-phenylstilbene derivative ({4- [2,2-bis- (4- Hydroxyphenyl) -vinyl] -phenyl} -di-p-toluyl-amine).

  33.9 g of the amine and 35 g of potassium carbonate were placed in a reaction vessel equipped with a stirrer, and 120 ml of DMAc and 3 ml of nitrobenzene were added and dissolved. Subsequently, 70.5 g of 2-bromoethanol was dropped and reacted at 100 ° C. for 18 hours. Then, it cooled to room temperature, the insoluble matter was removed, and it diluted with toluene. Thereafter, the toluene solution was washed with brine and water, and magnesium sulfate was added for dehydration. Thereafter, filtration was performed and toluene was distilled off to obtain 39.6 g of a target crude product. Then, it is purified by column chromatography using a column filled with silica gel with a mixed solvent of dichloromethane / ethyl acetate (20/1 to 3/1) as a developing solvent, and further with a mixed solvent of toluene / cyclohexane (2/1). Recrystallized and purified twice, and the target product of the following structural formula (CTP-4) (2- (4- {2- [4- (di-p-toluyl-amino) phenyl-]-1- [4- (2 -Hydroxy-ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol) (yield 22.3 g, yellow crystals, melting point 178.5-179.0 ° C., OH equivalent: 285.86).

  As described above, a 2-hydroxyethoxy group can be introduced by reacting a charge transport material having a hydroxyl group with 2-bromoethanol. In the above reaction, by controlling the number of carbon atoms in bromoalcohol, hydroxyl alkoxy groups with any number of carbon atoms can be introduced, and the number of hydroxyl groups can be determined arbitrarily while balancing charge transport and wear resistance. can do.

Synthesis Example of p-Diethylaminophenethyl Alcohol 9.6 g (70 mmol) of p-aminophenethyl alcohol, 38.7 g (280 mmol) of potassium carbonate, and 100 ml of monochlorobenzene were heated and stirred at 120 ° C. in an argon atmosphere in a four-necked flask. . To this, 32.8 g (210 mmol) of ethyl iodide was added dropwise over 5 hours. After the addition, the mixture was further heated and stirred for 5 hours. The reaction solution was cooled to room temperature, diluted with dichloromethane, and washed with water three times. The dichloromethane solution was dried over anhydrous magnesium sulfate, the solvent was distilled off, and the residue was purified by silica gel chromatography using a toluene / ethyl acetate (2/1) mixed solvent as an eluent to give 12.1 g of p-diethylaminophenethyl alcohol (yield). : 89% by mass).
As described above, a desired tertiary amine can be easily obtained by reacting a primary or secondary amine having a hydroxyl group with an alkyl halide.

The image forming apparatus of the present invention replenishes the electrostatic latent image carrier, the charging unit, the exposure unit, and the two-component developer as needed, and forms an image while collecting the excess two-component developer. An electrostatic latent image carrier described below as an example is mounted as an image forming apparatus of the present invention having a trickle developing type developing means. Hereinafter, these will be described as examples.
Example 1
[Preparation of electrostatic latent image carrier 1]
The electrostatic latent image carrier 1 was produced by the following procedure.
<Formation of undercoat layer>
15 parts by mass of alkyd resin (Beckolite M6401-50, manufactured by Dainippon Ink & Chemicals, Inc.) and 10 parts by mass of melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.), 150 parts by mass of methyl ethyl ketone Dissolved in the part. To this, 90 parts by mass of titanium oxide powder (Taipere CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) was added and dispersed for 12 hours with a ball mill to prepare an undercoat layer coating solution.
Next, the obtained undercoat layer coating solution is applied to a cylindrical aluminum substrate having a diameter of 30 mm by a dip coating method and dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of 3.5 μm. did.

<Formation of charge generation layer>
Next, 4 parts by mass of polyvinyl butyral resin (XYHL, manufactured by UCC) was dissolved in 150 parts by mass of cyclohexanone. To this, 10 parts by mass of a bisazo pigment represented by the following structural formula (A) was added and dispersed for 48 hours by a ball mill, and then 210 parts by mass of cyclohexanone was added and dispersed for 3 hours. This was taken out into a container and diluted with cyclohexanone so that the solid content was 1.5% by mass to prepare a coating solution for charge generation layer.

  The obtained charge generation layer coating solution was applied onto the undercoat layer and dried at 130 ° C. for 20 minutes to form a charge generation layer having a thickness of 0.2 μm.

<Formation of charge transport layer>
Next, 100 parts by mass of tetrahydrofuran, 10 parts by mass of bisphenol Z-type polycarbonate resin, 0.002 parts by mass of silicone oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.), and charge transport represented by the following structural formula (B) 7 parts by mass of the substance was added and dissolved to prepare a charge transport layer coating solution.

  The obtained charge transport layer coating solution was applied onto the charge generation layer by a dip coating method and dried at 110 ° C. for 20 minutes to form a charge transport layer having a thickness of 22 μm.

<Formation of protective layer>
Polyol [styrene-acrylic copolymer LZR-170 consisting of styrene, methyl methacrylate and hydroxyethyl methacrylate (OH equivalent: about 367), (solid content: 41% by mass): manufactured by Fujikura Kasei Co., Ltd.] 20 parts by mass, 2- (4- {2- [4- (Di-p-toluyl-amino) phenyl-]-1- [4- (2-hydroxy-ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol [Structural Formula (CTP-4) 20 parts by mass, 5 parts by mass of p-diethylaminophenethyl alcohol were dissolved in 50 parts by mass of cyclohexanone and 200 parts by mass of tetrahydrofuran, and a polyol adduct of tolylene diisocyanate [Coronate L: NCO% = 13%, solid content 75%. Manufactured by Nippon Polyurethane Industry Co., Ltd.] 38 parts by mass were dissolved to prepare a coating solution for forming a protective layer.
The obtained coating solution for forming a protective layer was applied onto the charge transport layer by a spray coating method and heated at 150 ° C. for 30 minutes to form a protective layer having a thickness of 8 μm.
As described above, the electrostatic latent image carrier 1 in which the undercoat layer, the charge generation layer, the charge transport layer, and the protective layer were formed in this order on the aluminum substrate was produced.

(Example 2)
[Preparation of electrostatic latent image carrier 2]
The charge transport layer was formed in the same manner as in Example 1.
<Formation of protective layer>
To 100 parts by mass of tetrahydrofuran, 16 parts by mass of zinc antimonate sol (trade name: Celnax CX-Z210, manufactured by Nissan Chemical Industries, solid content 20% by mass, volume average particle size 0.04 μm) was added for 10 minutes. Dispersion treatment was carried out by ultrasonic irradiation to prepare Dispersion I.
Next, polyol [styrene-acrylic copolymer LZR-170 (OH equivalent: about 367) consisting of styrene, methyl methacrylate, hydroxyethyl methacrylate, (solid content: 41 mass%): manufactured by Fujikura Kasei Co., Ltd.], 21 parts by mass, 2- (4- {2- [4- (Di-p-toluyl-amino) phenyl-]-1- [4- (2-hydroxy-ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol [Structural Formula (CTP -4)] 20 parts by mass, 5.3 parts by mass of p-diethylaminophenethyl alcohol were dissolved in 51 parts by mass of cyclohexanone and 80 parts by mass of tetrahydrofuran, and further a polyol adduct of hexamethylene diisocyanate [Sumijoule HT: NCO% = 13. %, Solid content 75%; manufactured by Sumika Bayern Co., Ltd.] 39 parts by mass were dissolved, and in addition to Dispersion I, a protective layer-forming coating solution was prepared.
The obtained coating solution for forming a protective layer was applied onto the charge transport layer by a spray coating method and heated at 150 ° C. for 30 minutes to form a protective layer having a thickness of 8 μm.
In this way, an electrostatic latent image carrier 2 in which an undercoat layer, a charge generation layer, a charge transport layer, and a protective layer were formed in this order on an aluminum substrate was produced.

(Example 3)
[Preparation of electrostatic latent image carrier 3]
The charge transport layer was formed in the same manner as in Example 1.
<Formation of protective layer>
To 100 parts by mass of tetrahydrofuran, 17 parts by mass of zinc antimonate sol (trade name: Celnax CX-Z210, manufactured by Nissan Chemical Industries, solid content 20% by mass, volume average particle size 0.04 μm) was added for 10 minutes. Dispersion treatment was performed by ultrasonic irradiation to prepare Dispersion II.
Next, 27.5 parts by mass of a polyol [styrene-acrylic copolymer LZR-170 (OH equivalent: about 367) comprising styrene, methyl methacrylate, hydroxyethyl methacrylate] (solid content: 41% by mass): manufactured by Fujikura Kasei Co., Ltd.] 2- (4- {2- [4- (Di-p-toluyl-amino) phenyl-]-1- [4- (2-hydroxy-ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol [Structural Formula (CTP-4)] 20 parts by mass, 5.7 parts by weight of p-diethylaminophenethyl alcohol were dissolved in 55 parts by mass of cyclohexanone and 90 parts by mass of tetrahydrofuran, and a polyol adduct of tolylene diisocyanate [Coronate L: NCO% = 13%, solid content 75%; manufactured by Nippon Polyurethane Industry Co., Ltd.] 42 parts by mass were dissolved, and in addition to Dispersion II, a protective layer forming coating solution was prepared.
The obtained coating solution for forming a protective layer was applied onto the charge transport layer by a spray coating method and heated at 150 ° C. for 30 minutes to form a protective layer having a thickness of 8 μm.
As described above, the electrostatic latent image carrier 3 in which the undercoat layer, the charge generation layer, the charge transport layer, and the protective layer were formed in this order on the aluminum substrate was produced.

Example 4
[Preparation of electrostatic latent image carrier 4]
In Example 3, benzylmethylethanolamine (manufactured by Aldrich) was used in place of p-diethylaminophenethyl alcohol, and 16 parts by mass of polyol (LZR-170), 2- (4- {2- [4- ( 23.6 parts by mass of di-p-toluyl-amino) phenyl-]-1- [4- (2-hydroxy-ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol [Structural Formula (CTP-4)] An electrostatic latent image carrier 4 was produced in the same manner as in Example 3 except that 43 parts by mass of isocyanate (Coronate L) was used.

(Example 5)
[Preparation of electrostatic latent image carrier 5]
In Example 3, 4-diethylaminophenol (manufactured by Aldrich) was used in place of p-diethylaminophenethyl alcohol, and 16 parts by mass of polyol (LZR-170), 2- (4- {2- [4- ( 23.6 parts by mass of di-p-toluyl-amino) phenyl-]-1- [4- (2-hydroxy-ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol [Structural Formula (CTP-4)] An electrostatic latent image carrier 5 was produced in the same manner as in Example 3 except that 43 parts by mass of isocyanate (Coronate L) was used.

(Example 6)
[Preparation of electrostatic latent image carrier 6]
In Example 3, p-dibenzylaminophenethyl alcohol was used instead of p-diethylaminophenethyl alcohol, and 22 parts by mass of polyol (LZR-170), 2- (4- {2- [4- (di- 23.6 parts by mass of p-toluyl-amino) phenyl-]-1- [4- (2-hydroxy-ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol [structural formula (CTP-4)], isocyanate An electrostatic latent image carrier 6 was produced in the same manner as in Example 3 except that (Coronate L) was 40 parts by mass.

(Example 7)
[Preparation of electrostatic latent image carrier 7]
In Example 3, 23 parts by mass of polyol (LZR-170), 2- (4- {2- [4- (di-p-toluyl-amino) phenyl-]-1- [4- (2-hydroxy-) (Ethoxy) -phenyl] -vinyl} -phenoxy) -ethanol [Structural Formula (CTP-4)] instead of {4- [2,2-bis- (4-hydroxyphenyl) -vinyl] -phenyl} -di -p-toluyl-amine [Structural Formula (CTP-3)] 20 parts by weight and isocyanate (Coronate L) was added in an amount of 44 parts by weight. Was made.

(Example 8)
[Preparation of electrostatic latent image carrier 8]
In Example 3, 32 parts by mass of polyol (LZR-170), 20 parts by mass of charge transport material (CTP-5) having the following structural formula instead of CTP-4, and 40 parts by mass of isocyanate (Coronate L) were used. Except for the above, an electrostatic latent image carrier 8 was produced in the same manner as in Example 1.

Example 9
[Preparation of electrostatic latent image carrier 9]
In Example 3, 7.5 parts by mass of polyol (LZR-170), 20 parts by mass of charge transport material (CTP-6) having the following structural formula instead of CTP-4, and 53 parts by mass of isocyanate (Coronate L) An electrostatic latent image carrier 9 was produced in the same manner as in Example 1 except that.

(Example 10)
[Preparation of electrostatic latent image carrier 10]
In Example 3, 22 parts by mass of polyol (LZR-170), 20 parts by mass of charge transporting material (CTP-2) having the above structural formula instead of CTP-4, and 45 parts by mass of isocyanate (Coronate L) were used. An electrostatic latent image carrier 10 was produced in the same manner as Example 3 except for the above.

(Example 11)
[Preparation of electrostatic latent image carrier 11]
In Example 3, 20 parts by mass of polyol (LZR-170), 20 parts by mass of charge transport material (CTP-7) having the following structural formula instead of CTP-4, and 46 parts by mass of isocyanate (Coronate L) were used. Except for the above, an electrostatic latent image carrier 11 was produced in the same manner as in Example 3.

Example 12
[Preparation of electrostatic latent image carrier 12]
In Example 3, 27 parts by mass of polyol (LZR-170), 20 parts by mass of charge transport material (CTP-8) having the following structural formula instead of CTP-4, and 42 parts by mass of isocyanate (Coronate L) were used. Except for the above, an electrostatic latent image carrier 12 was produced in the same manner as in Example 3.

(Example 13)
[Preparation of electrostatic latent image carrier 13]
In Example 3, 29 parts by mass of polyol (LZR-170), 20 parts by mass of charge transport material (CTP-9) having the following structural formula instead of CTP-4, and 41 parts by mass of isocyanate (Coronate L) were used. Except for the above, an electrostatic latent image carrier 13 was produced in the same manner as in Example 3.

(Example 14)
[Preparation of electrostatic latent image carrier 14]
In Example 3, 12 parts by mass of polyol (LZR-170), 20 parts by mass of charge transport material (CTP-10) having the following structural formula instead of CTP-4, and 50 parts by mass of isocyanate (Coronate L) were used. An electrostatic latent image carrier 14 was produced in the same manner as Example 3 except for the above.

(Example 15)
[Preparation of electrostatic latent image carrier 15]
In Example 3, electrostatic latent image support was carried out in the same manner as in Example 3 except that 66 parts by mass of polyol (LZR-170), 6 parts by mass of CTP-4, and 39 parts by mass of isocyanate (Coronate L) were used. A body 15 was produced.

(Example 16)
[Preparation of electrostatic latent image carrier 16]
In Example 3, an electrostatic latent was obtained in the same manner as in Example 3 except that 74 parts by mass of polyol (LZR-170), 2.5 parts by mass of CTP-4, and 39 parts by mass of isocyanate (Coronate L) were used. An image carrier 16 was produced.

(Example 17)
[Preparation of electrostatic latent image carrier 17]
In Example 3, electrostatic latent image support was carried out in the same manner as in Example 3, except that 12 parts by mass of polyol (LZR-170), 26 parts by mass of CTP-4, and 42 parts by mass of isocyanate (Coronate L) were used. A body 17 was produced.

(Example 18)
[Fabrication of electrostatic latent image carrier 18]
In Example 13, 0.1 part by weight of polyol (LZR-170), 33 parts by weight of CTP-9, 44 parts by weight of isocyanate (Coronate L), and Example 13 were used except that zinc antimonate was not added. Similarly, an electrostatic latent image carrier 18 was produced.

(Example 19)
[Preparation of electrostatic latent image carrier 19]
In Example 3, 59 parts by mass of polyol (LZR-170), 22 parts by mass of xylene diisocyanate [Takenate 500: NCO% = 45%; manufactured by Mitsui Takeda Chemical Co., Ltd.] as the isocyanate, and 7.2 of p-diethylaminophenethyl alcohol An electrostatic latent image carrier 19 was produced in the same manner as in Example 3 except that the mass part was used.

(Example 20)
[Preparation of electrostatic latent image carrier 20]
In Example 19, except that 62 parts by mass of polyol (LZR-170) and isocyanate were used, and tolylene diisocyanate [Cosmonate T-80: NCO% = 48%; manufactured by Mitsui Takeda Chemical Co., Ltd.] was 21 parts by mass. In the same manner as in Example 19, an electrostatic latent image carrier 20 was produced.

(Example 21)
[Preparation of electrostatic latent image carrier 21]
In Example 19, except that the polyol (LZR-170) was 56 parts by mass and the isocyanate was naphthalene diisocyanate [Cosmonate ND: NCO% = 40%; manufactured by Mitsui Takeda Chemical Co.], 7.2 parts by mass. In the same manner as in Example 19, an electrostatic latent image carrier 21 was produced.

(Example 22)
[Preparation of electrostatic latent image carrier 17]
Example 19 Example 19 except that polyol (LZR-170) was used as 47 parts by mass, isocyanate, and polymer MDI [Cosmonate M-100: NCO% = 30%; manufactured by Mitsui Takeda Chemical Co.] was used as 29 parts by mass. In the same manner as in Example 19, an electrostatic latent image carrier 22 was produced.

(Example 23)
[Preparation of electrostatic latent image carrier 23]
In Example 3, in place of polyol (LZR-170), trimethylolpropane (OH equivalent 45) was 7 parts by mass and isocyanate (Coronate L) was 53 parts by mass. A latent image carrier 23 was produced.

(Example 24)
[Preparation of electrostatic latent image carrier 24]
In Example 23, 6 parts by mass of trimethylolpropane, 49 parts by mass of isocyanate (Coronate L), and tin oxide colloid (trade name; Sun Colloid HIT301M1, manufactured by Nissan Chemical Industries, solid content 30 masses instead of zinc antimonate) %, Volume average particle size 0.01 μm) was changed to 24 parts by mass, and an electrostatic latent image carrier 24 was produced in the same manner as in Example 23.

(Example 25)
[Preparation of electrostatic latent image carrier 25]
In Example 23, 7 parts by mass of trimethylolpropane, 53 parts by mass of isocyanate (Coronate L), and conductive titanium oxide fine particles (trade name; ET-500W, manufactured by Ishihara Sangyo Co., Ltd., volume average) instead of zinc antimonate An electrostatic latent image carrier 25 was produced in the same manner as in Example 23 except that the particle diameter was 0.25 μm.

(Example 26)
[Preparation of electrostatic latent image carrier 26]
In Example 3, in place of zinc antimonate sol, a methanol sol of indium antimonate (solid content 18% by mass, volume average particle size 0 based on the method disclosed in Example 2 of JP-A-7-144717. 0.026 μm) was prepared, and an electrostatic latent image carrier 26 was prepared in the same manner as in Example 3 except that 20 parts by mass was added instead of the zinc antimonate sol.

(Comparative Example 1)
[Preparation of electrostatic latent image carrier 27]
In Example 3, without adding p-diethylaminophenethyl alcohol, in addition to 46 parts by mass of polyol (LZR-170) and 39 parts by mass of isocyanate (Coronate L), electrostatic latent An image carrier 27 was produced.

(Comparative Example 2)
[Production of electrostatic latent image carrier 28]
In Example 3, instead of p-diethylaminophenethyl alcohol, benzylethanolamine (manufactured by Aldrich) was used, and polyol (LZR-170) was 11 parts by mass and isocyanate (Coronate L) was 50 parts by mass. In the same manner as in Example 3, an electrostatic latent image carrier 28 was produced.

(Comparative Example 3)
[Preparation of electrostatic latent image carrier 29]
In Example 3, in place of p-diethylaminophenethyl alcohol, dibenzylamine (manufactured by Aldrich) was used, and polyol (LZR-170) was 28 parts by mass, and isocyanate (coronate L) was 42 parts by mass. In the same manner as in Example 3, an electrostatic latent image carrier 29 was produced.

(Comparative Example 4)
[Fabrication of electrostatic latent image carrier 30]
In Example 3, N-benzyl-N-ethylaniline (manufactured by Aldrich) was used instead of p-diethylaminophenethyl alcohol, and 38 parts by mass of polyol (LZR-170) and 36 parts by mass of isocyanate (Coronate L) were used. A latent electrostatic image bearing member 30 was produced in the same manner as in Example 3 except that the above-described parts were used.

(Comparative Example 5)
[Preparation of electrostatic latent image carrier 31]
In Example 3, 34 parts by mass of polyol (LZR-170), 38 parts by mass of isocyanate (Coronate L), and 20 parts by mass of charge transport material (CTP-11) having the following structural formula instead of CTP-4 An electrostatic latent image carrier 31 was produced in the same manner as in Example 3 except that.

(Comparative Example 6)
[Preparation of electrostatic latent image carrier 32]
In Example 3, 34 parts by mass of polyol (LZR-170), 38 parts by mass of isocyanate (Coronate L), and 20 parts by mass of charge transport material (CTP-1) having the following structural formula instead of CTP-4 An electrostatic latent image carrier 32 was produced in the same manner as in Example 3 except that.

(Toner Production Example 1)
-Synthesis of polyol resin 1-
In a separable flask equipped with a stirrer, a thermometer, an N ₂ inlet, and a cooling tube, 1000 g of low-molecular bisphenol A type epoxy resin (number average molecular weight 1000), 50 g of terephthalic acid, 10 g of benzoic acid, and 300 g of xylene. added. The temperature was raised to 70-100 ° C. in an N ₂ atmosphere, 0.183 g of lithium chloride was added, the temperature was further raised to 160 ° C., xylene was distilled off under reduced pressure, and polymerization was performed at a reaction temperature of 180 ° C. for 6-9 hours. The polyol resin 1 was synthesized.
The obtained polyol resin 1 had a number average molecular weight of 2,800, a weight average molecular weight of 16,500, and a glass transition temperature (Tg) of 61 ° C.

-Preparation of toner-
Next, toner materials having the following formulation were mixed using a Henschel mixer (manufactured by Mitsui Miike Co., Ltd.), and then kneaded for 30 minutes with two rolls having a roll surface set at 60 ° C. Then, after rolling and cooling and coarse pulverization, a jet mill type pulverizer (I-2 type mill, manufactured by Nippon Pneumatic Industrial Co., Ltd.) and a wind classifier (DS classifier, manufactured by Nippon Pneumatic Industrial Co., Ltd.) by swirling flow are performed. Toner base particles 1 were prepared.
-Toner prescription-
Binder resin: Polyol resin 1 ... 100 parts by mass Colorant: Cyan pigment (copper phthalocyanine) 5 parts by mass Charge control agent: Bontron E-84 (manufactured by Orient Chemical Co., Ltd.) 2 Parts by mass

  With respect to 100 parts by mass of the obtained “toner base particle 1”, 1.2 parts by mass of hydrophobic silica (HDK2000H, manufactured by Clariant Japan Co., Ltd.) as an external additive, and titanium oxide (JMT-150IB, manufactured by Teika Co., Ltd.) Toner 1 was prepared by adding 0.9 part by mass (charge amount: −45 μC / g, hydrophobicity: 67%) and mixing with a Henschel mixer.

Here, the charge amount and the degree of hydrophobicity of titanium oxide were measured as follows.
<Titanium oxide charge>
The amount of charge of titanium oxide was measured by weighing 96 g of carrier (manufactured by Powdertech, non-coated ferrite; F-150) and 0.4 g of titanium oxide, placing them in a 100 ml polypropylene container, placing them horizontally on a rotating roller, and at 100 rpm. Rotate mix for 15 minutes. 0.2 g of the mixed sample was measured using a blow-off coulometer. It calculated from the measured value by the following formula.
Charge amount (μc / g) = − Q (A + B) / XA
In the above equation, X represents the mass (g) of the mixed sample, A represents the mass (g) of the measurement sample, B represents the mass (g) of the carrier, and Q represents the measurement value (C: Coulomb).

<Titanium oxide hydrophobicity>
The hydrophobization degree of titanium oxide was measured by adding 0.03 g of titanium oxide to a 200 ml beaker, adding 70 ml of ion exchange dyed with edible blue No. 1, and stirring with a magnetic stirrer at 300 rpm. Drip at a rate of 2.5 ml / min. The liquid transmittance was measured, a graph of methanol concentration and transmittance was prepared, and the methanol concentration when the transmittance was minimized was measured.

  With respect to the obtained toner 1, the volume average particle diameter of the toner measured as follows was 7.0 μm, and the average circularity was 0.92.

<Measurement of Volume Average Particle Size (Dv) of Toner>
The volume average particle diameter (Dv) of the toner can be measured by a Coulter counter method. Examples of the measuring device for the particle size distribution of toner particles by the Coulter counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of an electrolytic aqueous solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as the aperture. Volume distribution and number distribution are calculated. From the obtained distribution, the mass average particle diameter (D4) and the number average particle diameter of the toner can be obtained.

  As a channel, it is 2.00 micrometers or more and less than 2.52 micrometers; 2.52 micrometers or more and less than 3.17 micrometers; 3.17 micrometers or more and less than 4.00 micrometers; 4.00 micrometers or more and less than 5.04 micrometers; 5.04 micrometers or more and less than 6.35 micrometers; .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; Less than 40 μm; 25.40 μm or more and less than 32.00 μm; 3 channels of 32.00 μm or more and less than 40.30 μm are used, and particles having a particle size of 2.00 μm or more and less than 40.30 μm are targeted. Further, (Dv / Dn) was automatically calculated from the above value.

<Measurement of average circularity of toner>
The average circularity can be measured using a flow type particle image analyzer (Flow Particle Image Analyzer). A measurement method using a flow particle image analyzer (Flow Particle Image Analyzer) will be described below.
The measurement of toner, toner particles and external additives using a flow particle image analyzer can be performed using, for example, a flow particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd.

The measurement is performed by removing fine dust through a filter, and as a result, in ^10-3 water of 10 ⁻³ cm ³ of water having a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) of 20 particles or less. A few drops of nonionic surfactant (Contaminone N, manufactured by Wako Pure Chemical Industries, Ltd.) are added, and 5 mg of a measurement sample is further added, and 20 kHz, 50 W / 10 cm ^{3 with an} ultrasonic disperser (STM, UH-50). The sample is dispersed for 1 minute under the above conditions, and further dispersed for 5 minutes in total, and the sample concentration of the measurement sample is 4000 to 8000 particles / 10 ⁻³ cm ³ (for particles in the equivalent circle diameter range). Using the dispersion, the particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm is measured.

  The sample dispersion is passed through a flow path (expanded along the flow direction) of a flat and flat transparent flow cell (thickness: 200 μm). In order to form an optical path that passes across the thickness of the flow cell, the strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell 2. Taken as a dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area was calculated as the equivalent circle diameter.

  In about 1 minute, the equivalent circle diameter of 1200 or more particles can be measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter can be measured. As shown in Table 1, the results (frequency% and cumulative%) can be obtained by dividing the range of 0.06 μm to 400 μm into 226 channels (divided into 30 channels for one octave). In actual measurement, particles are measured in the range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

(Carrier production example 1)
The following composition was dispersed with a homomixer for 10 minutes to prepare a coating layer forming solution.
-Composition of coating layer forming solution-
・ Acrylic resin solution (solid content concentration: 50 mass%): 1500 mass parts ・ Guanamine solution (solid content concentration: 70 mass%): 450 mass parts ・ Acid catalyst (solid content concentration: 40 mass%) ·· 9 parts by mass · Alumina particles (volume average particle size: 0.35 µm, volume resistivity: 1.0 × 10 ¹⁴ Ω · cm) · · 1500 parts by mass · Titanium oxide particles (volume average particle size: 0. 015 μm, volume resistivity: 1.0 × 10 ⁶ Ω · cm) 500 parts by weight Toluene 6000 parts by mass Next, a magnetite powder having a volume average particle size of 52 μm is used as the core material, and the above coating is applied. The layer forming solution was applied to the surface of the core material with a Spira coater (Okada Seiko Co., Ltd.) at a coater internal temperature of 40 ° C. so that the thickness of the coating layer was 0.15 μm, and dried. The obtained carrier was left to stand in an electric furnace at 180 ° C. for 1 hour and fired. After cooling, the magnetite-coated powder bulk was pulverized using a sieve having an opening of 90 μm to prepare Carrier 1.
With respect to the obtained carrier 1, the volume resistivity measured as follows was 13.0 [Log Ω · cm]. The volume average particle size of the carrier 1 measured as follows was 52 μm.

<Volume average particle diameter of carrier>
The volume average particle diameter of the carrier was measured using a SRA type of a Microtrac particle size analyzer (Nikkiso Co., Ltd.) with a range setting of 0.7 μm or more and 200 μm or less.

<Volume specific resistance>
The volume resistivity is obtained by putting a carrier between the electrodes of the resistance measurement parallel electrode (gap 2 mm), applying DC 1000 V, and converting the resistance value measured after 30 sec with a high resist meter into volume resistivity. It was.

<Two-component developer production example 1>
7 parts by mass of “Toner 1” and 93 parts by mass of “Carrier 1” are uniformly mixed using a tumbler mixer and charged to form a two-component developer having a toner concentration of 7% by mass (hereinafter referred to as “Developer 1”). Was made.

<Premix toner production example 1>
90 parts by mass of “Toner 1” and 10 parts by mass of “Carrier 1” were mixed to prepare a premix toner having a toner concentration of 90% by mass (hereinafter referred to as “Premix Toner 1”).

<Evaluation of abrasion resistance and paper passing test>
Using each of the electrostatic latent image carriers 1 to 32 of Examples 1 to 26 and Comparative Examples 1 to 6 obtained above, a paper passing test of 100,000 sheets of A4 size was performed. First, the electrostatic latent image carrier is mounted on a process cartridge, and an imagio Neo C600 remodeling machine manufactured by Ricoh Co., Ltd. using a 655 nm semiconductor laser as an image exposure light source (developer supply mechanism and developer discharge to each color development unit) The developer was modified to operate in a trickle development system, “Developer 1” was used as the developer, “Premix Toner 1” was used as the replenishing toner, and the initial dark portion potential was set to −700V. Thereafter, a paper passing test for 50,000 sheets was started, and the dark part and exposed part potentials at the initial stage and after copying 50,000 sheets, images after the paper passing test, and film thickness reduction after copying 50,000 sheets were measured. The amount of film thickness reduction was determined by measuring the thickness of the photosensitive layer before and after the paper passing test at 30 points in 1 cm intervals using an eddy current film thickness meter (Fisherscope MMS, manufactured by Fischer), and calculating the average value. The difference between the average values of the two was taken as the film thickness reduction amount.

<Evaluation of potential of exposed area after deterioration acceleration test and deterioration acceleration test>
Each electrostatic latent image carrier obtained above was subjected to a surface potential of −800 V, a drum passing current of −35 μA, and a test time of 4 hours using a photoconductor deterioration acceleration test apparatus disclosed in JP-A-2002-139958. After carrying out the deterioration acceleration test, it was installed in the above-mentioned modified printer equipped with the development unit modified so that the probe of the surface potential meter (Model 344 manufactured by Trek) was installed on the developing sleeve, After adjusting the voltage of the charger so that the potential (VD) becomes −600 V, the surface potential at the developing sleeve portion when writing equivalent to a 1200 dpi full face image is measured, and the residual potential of the exposed portion potential is measured. Evaluated.

<Evaluation of gas resistance>
Each electrostatic latent image carrier obtained above is allowed to stand for 4 days in a desiccator adjusted to a nitrogen oxide gas concentration of 50 ppm, and the resolution of the image in an environment of 27 ° C. and 80% RH before and after is compared. Was evaluated. The results are shown in Table 61.

From the results shown in Table 61, the electrostatic latent image carrier having the crosslinked surface layer used in Examples 1 to 26 has high wear resistance and good electrical characteristics and gas resistance characteristics. In some cases, a slightly abnormal image was observed after the test, but it was not problematic for practical use.
In contrast, the electrostatic latent image carriers used in Comparative Examples 1 to 4 have good wear resistance and electrical characteristics, but have low gas resistance and are thought to be caused by surface deterioration due to oxidizing gas. The resolution was reduced. Also, in the actual paper passing test, thin line blurring occurred.
In Comparative Examples 5 and 6, although the electrical characteristics were good, the abrasion resistance was low, and the protective layer disappeared due to abrasion when 20,000 sheets were passed through.

  Further, in the paper passing test of Example 1, after carrying out a paper passing test of 50,000 sheets with an unused carrier, the charge amount and volume resistivity of the carrier taken out from the developer remaining in the developing device. The amount of charge decrease and the amount of resistance change were calculated from the difference, and the amount of charge decrease was 3.6 μc / g and the amount of resistance change was 1.0 [Log Ω · cm]. It was confirmed that the carrier characteristics were maintained without maintenance work for agent replacement.

Here, the amount of decrease in charge is a general blow-off method (TB-200, manufactured by Toshiba Chemical Co., Ltd.) obtained by friction charging with a mixture of 7% by mass of toner with respect to 93% by mass of the initial carrier. The amount obtained by subtracting the amount of charge (Q2) measured by the same method as the above method from the amount of charge (Q1) measured in step 1 from the carrier obtained by removing the toner in the developer after running by the blow-off device. Means. The target value is within 10.0 μc / g.
The resistance change amount was measured by a high resist meter after 30 seconds after applying initial 1,000 carriers between the electrodes of the resistance measurement parallel electrodes (gap 2 mm), applying DC 1,000V. The value obtained by converting the obtained value into the volume resistivity (R1), and measuring the carrier obtained by removing the toner in the developer after running with the blow-off device by the same method as the resistance measuring method. It means the amount obtained by subtracting (R2). The target value is within 3.0 [Log (Ω · cm)] in absolute value.

(Toner Production Example 2)
1.1 parts by mass of hydrophobic silica (HDK2000H, manufactured by Clariant Japan) as an external additive and titanium oxide (JMT-150IB, Taker) with respect to 100 parts by mass of “toner base particle 1” obtained in Toner Production Example 1 0.9 part by mass of a charge of −78 μC / g, manufactured by a company, and a hydrophobicity of 68%) was added and mixed with a Henschel mixer to prepare toner 2.

(Toner Production Example 3)
To 100 parts by mass of “Toner Base Particle 1” obtained in Toner Production Example 1, 1.2 parts by mass of hydrophobic silica (HDK2000H, manufactured by Clariant Japan Co.) as an external additive, titanium oxide (SMT-150AI, Taca) 0.9 parts by mass of a charge amount of −35 μC / g, a hydrophobization degree of 65%) was added and mixed with a Henschel mixer to prepare toner 3.

(Toner Production Example 4)
To 100 parts by mass of “toner base particle 1” obtained in Toner Production Example 1, 1.2 parts by mass of hydrophobic silica (HDK2000H, manufactured by Clariant Japan) as an external additive, titanium oxide (MT-150AFM, Taca) 0.9 part by mass (manufactured by Co., Ltd., charge amount -30 μC / g, hydrophobicity 30%) was added and mixed with a Henschel mixer to prepare toner 4.

(Toner Production Example 5)
Into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 724 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 276 parts by mass of isophthalic acid, and 2 parts by mass of dibutyltin oxide were placed at 230 ° C. under normal pressure. For 8 hours and further under reduced pressure of 10 mmHg to 15 mmHg for 5 hours, cooled to 160 ° C., 32 parts by mass of phthalic anhydride was added thereto, and reacted for 2 hours.
Subsequently, it cooled to 80 degreeC and reacted with 188 mass parts of isophorone diisocyanate in ethyl acetate for 2 hours, and the isocyanate containing prepolymer (P1) was obtained.
Subsequently, 267 parts by mass of the prepolymer (P1) and 14 parts by mass of isophoronediamine were reacted at 50 ° C. for 2 hours to obtain a urea-modified polyester (U1) having a mass average molecular weight of 64,000.
In the same manner as above, 724 parts by mass of bisphenol A ethylene oxide 2-mole adduct and 276 parts by mass of terephthalic acid were subjected to polycondensation at 230 ° C. for 8 hours under normal pressure, and then reacted for 5 hours at a reduced pressure of 10 mmHg to 15 mmHg. 5,000 unmodified polyester (E1) was obtained.
200 parts by mass of urea-modified polyester (U1) and 800 parts by mass of unmodified polyester (E1) are dissolved in 2,000 parts by mass of a mixed solvent of ethyl acetate / MEK (1/1) and mixed to obtain a binder resin ( An ethyl acetate / MEK solution of B1) was obtained.
A part was dried under reduced pressure, and the binder resin (B1) was isolated. The glass transition temperature (Tg) was 62 ° C.

(Synthesis example A of polyester resin)
・ Terephthalic acid: 60 parts by mass • Dodecenyl succinic anhydride: 25 parts by mass • Trimellitic anhydride: 15 parts by mass • Bisphenol A (2,2) propylene oxide: 70 parts by mass • Bisphenol A (2,2) Ethylene oxide: 50 parts by mass

  The above composition was placed in a 1 L four-necked round bottom flask equipped with a thermometer, a stirrer, a condenser, and a nitrogen gas introduction tube. The flask was set in a mantle heater, and nitrogen gas was introduced from the nitrogen gas introduction tube. Was added to the flask, and the temperature in the flask was maintained in an inert atmosphere. Then, 0.05 g of dibutyltin oxide was added and the reaction was performed while maintaining the temperature at 200 ° C. to obtain polyester A. This polyester A had a peak molecular weight of 4,200 and a glass transition temperature (Tg) of 59.4 ° C.

(Example of master batch production)
・ C. I. Pigment Yellow 155 ... 40 parts by mass-Polyester resin A as a binder resin ... 60 parts by mass-Water ... 30 parts by mass

The raw materials were mixed with a Henschel mixer to obtain a mixture in which water was soaked into the pigment aggregate. This was kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C., and pulverized to a size of 1 mm in diameter with a pulverizer to prepare a master batch (M1).
In a beaker, 240 parts by mass of the binder resin (B1) in ethyl acetate / MEK solution, 20 parts by mass of pentaerythritol tetrabehenate (melting point 81 ° C., melt viscosity 25 cps), 8 parts by mass of the master batch (M1) were placed. The mixture was stirred at 12,000 rpm with a TK homomixer at 60 ° C., uniformly dissolved, and dispersed to prepare a toner material liquid.
706 parts by mass of ion-exchanged water, 294 parts by mass of hydroxyapatite suspension (Nippon Chemical Industry Co., Ltd., Superite 10) and 0.2 part by mass of sodium dodecylbenzenesulfonate were placed in a beaker and dissolved uniformly. .
Next, the temperature was raised to 60 ° C., and the toner material liquid was added while stirring at 12,000 rpm with a TK homomixer, followed by stirring for 10 minutes.
Next, this mixed liquid is transferred into a Kolben equipped with a stir bar and a thermometer, heated to 98 ° C. to remove the solvent, filtered, washed and dried, and then subjected to air classification, “toner base particle 2 Was made.
To 100 parts by mass of the obtained “toner base particles 2”, 1.0 part by mass of hydrophobic silica (HDK2000H, manufactured by Clariant Japan Co., Ltd.), a charge amount: −45 μC / g, a degree of hydrophobicity: 67% of titanium oxide ( Toner 5 was prepared by adding 1.0 part by mass of JMT-150IB (manufactured by Teika Co., Ltd.) and mixing with a Henschel mixer.

(Toner Production Example 6)
850 parts by mass of the urea-modified polyester resin (U1) produced in Toner Production Example 5 and 150 parts by mass of the unmodified polyester resin (E1) were dissolved in 2000 parts by mass of an ethyl acetate / MEK (1/1) mixed solvent. To obtain an ethyl acetate / MEK (1/1) solution of the binder resin (B2). A part of this was dried under reduced pressure to isolate the binder resin (B2).
Next, a toner 6 was produced in the same manner as in the toner production example 5 except that the binder resin (B2) was used instead of the binder resin (B1) used in the toner production example 5.

  Next, the volume average particle diameter and average circularity of the obtained toners 2 to 6 were measured in the same manner as in the toner 1. The results are shown in Table 62.

(Carrier production example 2)
In Carrier Production Example 1, “Carrier 2” was produced in the same manner as Carrier Production Example 1, except that a coating layer forming solution having the following composition was used.
-Composition of coating layer forming solution-
・ Acrylic resin solution (solid content concentration: 50 mass%): 1500 mass parts ・ Guanamine solution (solid content concentration: 70 mass%): 450 mass parts ・ Acid catalyst (solid content concentration: 40 mass%) ·· 9 parts by mass · Alumina particles (volume average particle size: 0.35 µm, volume resistivity: 1.0 x 10 ¹⁴ Ω · cm) ··· 1500 parts by mass · Carbon black (BP-2000, manufactured by Cabot Corporation) ... 1000 parts by massToluene ... 6000 parts by mass

(Carrier production example 3)
The following composition was dispersed with a homomixer for 10 minutes to prepare a coating layer forming solution.
-Composition of coating layer forming solution-
・ Acrylic resin solution (solid content concentration: 50 mass%): 1500 mass parts ・ Guanamine solution (solid content concentration: 70 mass%): 450 mass parts ・ Acid catalyst (solid content concentration: 40 mass%) ·· 9 parts by mass · Alumina particles (volume average particle size: 0.35 µm, volume resistivity: 1.0 × 10 ¹⁴ Ω · cm) ··· 1500 parts by mass · Titanium oxide particles (volume average particle size: 0. 015 μm, volume resistivity: 1.0 × 10 ⁶ Ω · cm) 500 parts by mass Toluene 6000 parts by mass Next, a magnetite powder having a volume average particle size of 35 μm is used as the core material, and the above coating is applied. The layer forming solution was applied to the surface of the core material with a Spira coater (Okada Seiko Co., Ltd.) at a coater internal temperature of 40 ° C. and dried.
The obtained carrier was baked in an electric furnace at 180 ° C. for 1 hour. After cooling, the magnetite-coated powder bulk was pulverized using a sieve having an opening of 90 μm to prepare “Carrier 3”.

  The volume average particle diameter and volume resistivity of the obtained carriers 2 to 3 were measured in the same manner as the carrier 1. The results are shown in Table 63.

(Examples 27 to 33, Comparative Examples 7 to 13)
Next, the toners 1 to 6 and the carriers 1 to 3 prepared above are combined as shown in Table 4 to prepare a two-component developer, and using the electrostatic latent image carriers 3 and 27, the same as described above. A paper passing test was performed, and the amount of film thickness reduction after copying 50,000 sheets, image evaluation, and image definition were evaluated. The results are shown in Table 64.

<Image definition>
The image definition was evaluated by the reproducibility of the character image portion. In the evaluation method, a character chart having an image area of 5% (the size of one character is about 2 mm × 2 mm) was output, and the character reproducibility was evaluated by an image.

  From the results of Table 64, in Examples 27 to 33, when the electrostatic latent image carrier 6 having a crosslinked surface layer and a developer in which various toners and carriers are combined, the electrostatic latent image carrier is High abrasion resistance was exhibited, and the image after the paper passing test was also good. In some cases, a slightly abnormal image was observed after the test, but it was not problematic for practical use. On the other hand, in Comparative Examples 7 to 13, the abrasion resistance was relatively good, but the image after the paper passing test had the image density of the halftone portion decreased, and the characters were crushed due to the further decrease in resolution. The result is an abnormal image that cannot be identified. As described above, in the trickle development system, the use of the electrostatic latent image carrier 3 having the cross-linked surface layer as in the configuration of the present invention widens the tolerance for toner and carrier design, and has high image quality and high durability. The carrier design was found to be easy.

(Example 34)
(Production Example 33 of Electrostatic Latent Image Carrier)
A dispersion (25-1) was prepared by dispersing 0.4 parts by mass of the bisazo pigment of the above structural formula (A) together with 40 parts by mass of methyl ethyl ketone for 24 hours using a ball mill. Next, 60 parts by mass of tetrahydrofuran, 5 parts by mass of the charge transport material of the above structural formula (B), 5 parts by weight of the electron transport material represented by the following structural formula (C), 10 parts by mass of bisphenol Z-type polycarbonate, silicone A solution (25-2) in which 0.002 parts by mass of oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved was added to the dispersion (25-1) to prepare a single-layer photosensitive layer coating solution.

The resulting single-layer photosensitive layer coating solution was applied to a cylindrical aluminum substrate having an outer diameter of 60 mm by a dip coating method and dried at 130 ° C. for 20 minutes to form a photosensitive layer having a thickness of 25 μm.
Here, the coating solution for the crosslinked surface layer of Production Example 3 of the latent electrostatic image bearing member was spray-coated, dried at 15 ° C. for 30 minutes to provide a surface crosslinked layer having a thickness of 8 μm. Thus, an electrostatic latent image carrier 33 was produced. Using this, the same test as in Example 1 was performed. As a result, the initial exposure portion potential was 120 (−V), the exposure portion potential after output of 50,000 sheets was 220 (−V), and the film reduction amount was 2.6 μm. Yes, the output image was good.

  In the image forming apparatus and the image forming method of the present invention, since the mounted electrostatic latent image carrier has high wear resistance and high resistance to oxidizing gas, it has excellent durability and high quality image formation. Can be stably performed over a long period of time, and image formation can be performed almost maintenance-free. Therefore, it can be widely applied to trickle developing type full-color copying machines, full-color laser printers, full-color plain paper fax machines, and the like.

FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of an electrostatic latent image carrier used in the image forming apparatus of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier used in the image forming apparatus of the present invention. FIG. 3 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier used in the image forming apparatus of the present invention. FIG. 4 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier used in the image forming apparatus of the present invention. FIG. 5 is a schematic cross-sectional view showing another example of the layer structure of the electrostatic latent image carrier used in the image forming apparatus of the present invention. FIG. 6 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 7 is a schematic diagram illustrating an example of an image forming unit of the image forming apparatus of the present invention. FIG. 8 is a schematic view showing another example of the image forming unit of the image forming apparatus of the present invention. FIG. 9 is a diagram showing an example of a developing device used in the image forming apparatus of the present invention. FIG. 10 is a diagram showing an example of a trickle developing device used in the image forming apparatus of the present invention. It is IR chart which shows the measurement result of IR of (CTP-2), a horizontal axis represents wave number (cm ^<-1> ), and a vertical axis | shaft represents the transmittance | permeability (T%).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Writing part 3 Polygon mirror 4, 5 Lens 6, 7, 8, 9, 10, 11 Mirror 20Y, 20M, 20C, 20B Process cartridge 21 Electrostatic latent image carrier (photoreceptor)
22 Charging unit 23Y, 23M, 23C, 23B Developing unit (developing device)
24 transfer bias roller 25 cleaning unit 26 case 27 intermediate transfer belt 28 second transfer bias roller 29 intermediate transfer belt cleaning unit 30 transport belt 32Y, 32M, 32C, 32B toner supply unit 47Y, 47M, 47C, 47K carrier supply unit 51 document Conveying section 53 Contact glass 55 Document reading section 61 Paper feeding section 66 Fixing section 201 Support body 202 Photosensitive layer 203 Charge generation layer 204 Charge transport layer 205 Undercoat layer 206 Crosslinked surface layer 207 Intermediate layer P Recording medium D Document

Claims (26)

In an image forming apparatus comprising: an electrostatic latent image bearing member; and a developing unit that develops with a developer of a trickle developing method using a two-component developer including a toner and a carrier.
The electrostatic latent image carrier has a support and at least a photosensitive layer on the support, and the outermost surface layer of the electrostatic latent image carrier has at least two hydroxyl groups. An image forming apparatus comprising: a crosslinkable resin formed by crosslinking a substance and an isocyanate compound; and at least one selected from tertiary amines represented by the following general formula (I).

(In the formula (I), R1 and R2 are substituted or unsubstituted alkyl groups, and R1 and R2 may be the same or different. R3 is an alkyl group or aryl group having at least one hydroxyl group. Represents.)   2. The image forming apparatus according to claim 1, wherein the outermost surface layer is a protective layer on a photosensitive layer of the electrostatic latent image carrier. The outermost surface layer contains conductive fine particles, and the conductive fine particles are M _x Sb _y O _z (where M represents a metal element other than Sb. _X , y, and z are moles of each element. The image forming apparatus according to claim 1, wherein the image forming apparatus is at least one kind represented by: The image forming apparatus according to claim 3, wherein the conductive fine particles include zinc antimonate (ZnSb ₂ O ₆ ).   The image forming apparatus according to claim 1, wherein the isocyanate compound has an aromatic ring and has at least two isocyanate groups.   The image forming apparatus according to claim 5, wherein the isocyanate compound having an aromatic ring uses an adduct type compound of a diisocyanate compound and a polyol in combination.   The image forming apparatus according to claim 1, wherein NCO% of the isocyanate compound is 3 to 50.   The image forming apparatus according to claim 1, wherein the content of the reactive charge transporting substance is 5 to 45 wt% in the outermost surface layer. The image forming apparatus according to claim 1, wherein the reactive charge transporting substance having at least two hydroxyl groups has a molecular structure represented by the following general formula (1).

(In Formula (1), Y represents a C1-C6 alkyl group or alkoxy group having at least two hydroxyl groups, and X represents a charge transporting compound group. The alkyl group or alkoxy group is other than a hydroxyl group. And n represents an integer of 1 to 4.) The image forming apparatus according to claim 9, wherein the group X in the formula (1) has a molecular structure represented by the following general formula (2).

(In formula (2), Ar _{1 to} Ar ₃ represent a substituted or unsubstituted aryl group or arylene group, which may be the same or different. Ar represents a divalent aromatic group. In addition, the number n of the substituent Y in the general formula (1) represents the number of the arylene groups Ar _{1 to} Ar ₃ in the formula (2) and the carbon atom (non-determined) having the Ar ₃ as a substituent. Saturated carbon atom) is the same as the total number of bonds, and at least any _one of Ar ₁ , Ar ₃ and Ar ₃ as a substituent is a substituent Y in the general formula (1). However, Ar is a group bonded to an unsaturated carbon atom adjacent to the carbon atom having Ar ₃ as a substituent.) The image forming apparatus according to claim 9, wherein the group X in the formula (1) has a molecular structure represented by the following general formula (3).

(In Formula (3), Ar _{1 to} Ar ₄ represent a substituted or unsubstituted aryl group or an arylene group, which may be the same or different. Ar represents an arylene group. ) the number n of substituents Y in the same as the total number of the arylene group of said _Ar 1 to Ar _4, any one of at least _Ar 1 to Ar _4, substituents in the general formula (1) Y, provided that Ar is a group bonded to an unsaturated carbon atom adjacent to the carbon atom having Ar ₃ and Ar ₄ as substituents.   The image forming apparatus according to claim 9, wherein the reactive charge transporting substance has a structure in which a hydroxyl group is bonded to at least two adjacent carbon atoms. 13. The image forming apparatus according to claim 12, wherein the reactive charge transport material (1) has at least a molecular structure represented by the following general formula (4).

(In the formula, R represents a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms or an alkoxylene group, X represents the same group as X in the formula (1), and n represents 1 to 4). Represents an integer.)   2. The outermost surface layer contains a crosslinkable resin formed by using at least one polyol compound having no charge transporting compound group and crosslinking the polyol compound and an isocyanate compound. 14. The image forming apparatus according to any one of.   The image forming apparatus according to claim 14, wherein at least one of the polyol compounds has an OH equivalent that is a ratio of molecular weight to the number of hydroxyl groups (molecular weight / number of hydroxyl groups) of less than 150.   The image forming apparatus according to claim 1, wherein the image forming apparatus forms a color image by sequentially superposing a plurality of colors of toner.   The toner is a toner containing at least a binder resin, a colorant, and an external additive. The external additive has a charge amount of −40 to −80 μC / g and a titanium oxide having a hydrophobicity of 60% or more. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   18. The toner according to claim 17, further comprising hydrophobic silica as an external additive of the toner, wherein a content ratio (Si / Ti) between the silica and the titanium oxide is 1.0 to 2.0. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein the toner has a volume average particle diameter of 5 to 9 μm.   The toner is prepared by dissolving or dispersing a toner material containing at least an active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound in an organic solvent. A dispersion is prepared by emulsifying or dispersing in a medium, and the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound are reacted in the aqueous medium to form an adhesive substrate. The image forming apparatus according to claim 17, wherein the image forming apparatus is obtained by generating the particles in a particulate form and removing the organic solvent.   The image forming apparatus according to claim 17, wherein the toner has an average circularity of 0.93 to 1.00.   The said carrier consists of a core material and the coating layer which coat | covers the surface of this core material, The volume specific resistance of this carrier is 7-13 [Log (ohm) * cm], The any one of Claims 1-21 characterized by the above-mentioned. An image forming apparatus according to claim 1.   23. The image forming apparatus according to claim 22, wherein the carrier has a volume average particle diameter of 30 [mu] m to 60 [mu] m.   The image forming apparatus is a tandem type in which at least the electrostatic latent image carrier is further provided with a plurality of image forming elements each having a charging unit, a developing unit, a transfer unit, and a fixing unit. 24. The image forming apparatus according to any one of 23.   An image forming apparatus further transfers an intermediate transfer member on which a toner image formed on the electrostatic latent image carrier is primarily transferred, and a secondary transfer of the toner image carried on the intermediate transfer member to a recording medium. A plurality of color toner images are sequentially superimposed on the intermediate transfer member to form a color image, and the color image is secondarily transferred collectively onto a recording medium. The image forming apparatus described in 1. A charging step for charging the surface of the electrostatic latent image carrier, an exposure step for exposing the charged electrostatic latent image carrier surface to form an electrostatic latent image, and the electrostatic latent image with toner and a carrier. An image forming method including at least a development step of forming a visible image by developing using the two-component developer.
Reactive charge transport wherein the electrostatic latent image carrier has a support and at least a photosensitive layer on the support, and the outermost surface layer of the electrostatic latent image carrier has at least two hydroxyl groups Containing at least one selected from a cross-linkable resin formed by cross-linking a functional substance and an isocyanate compound, and a tertiary amine represented by the following general formula. A developing unit having a supply unit for supplying any one of the component developers to the inside of the developing unit; and a discharging unit for discharging either the carrier or the two-component developer contained in the developing unit to the outside of the developing unit. An image forming method which is performed.

Images