JP5556052B2 - Electrophotographic photosensitive member, image forming apparatus, and cartridge - Google Patents

Description

  The present invention relates to an image forming apparatus (electrophotographic apparatus) such as a copying machine, a printer, a facsimile, and a plate making system that employs an electrophotographic system.

  Conventionally, inorganic photoconductive substances such as selenium, cadmium sulfide, and zinc oxide have been widely used as materials for electrophotographic photoreceptors (hereinafter, simply referred to as “photoreceptors” as appropriate). On the other hand, since the organic photoconductive substance is excellent in film formability, for example, a photoreceptor can be easily produced by coating it on a conductive support or the like. Therefore, since a photoconductor using an organic photoconductive substance is excellent in productivity, the organic photoconductive substance is very useful as an inexpensive photoconductor material. Furthermore, a photoreceptor using an organic photoconductive substance has an advantage that color sensitivity can be freely controlled, for example, by selecting dyes and pigments to be used. In view of this, a wide range of studies have been made on photoreceptors using organic photoconductive substances (organic photoreceptors).

  In recent years, a layered type (functional separation) in which a charge generation layer containing, for example, an organic photoconductive dye or a pigment, and a charge transport layer containing, for example, an organic photoconductive substance such as a photoconductive polymer or a low molecular weight compound are laminated. Type) photoreceptors have been developed. In the multilayer type photoreceptor, significant improvement has been made to the sensitivity and durability, which have been the problems of conventional organic photoreceptors. Among them, the azo pigment preferably contained in the charge generation layer exhibits excellent photoconductivity with respect to a white light source such as a halogen lamp. Therefore, organic photoconductive substances having various characteristics can be easily obtained depending on the combination of the amine component and the coupler component, and many have been proposed so far (see, for example, Patent Document 1).

  Furthermore, recently, there is a growing need for ultra-high quality output images. Therefore, blue to purple (specifically, the emission wavelength is usually 380 nm to 500 nm, hereinafter referred to as “blue (purple)” as appropriate), a beam formed on the photoreceptor using a semiconductor laser as an exposure light source. It has been proposed to reduce the spot diameter (see, for example, Patent Document 2). However, this technique usually requires a photoreceptor having a certain sensitivity or more with respect to a blue (purple) light source. In order to effectively use the irradiated light, the photoconductor is usually required to have high spectral sensitivity in the wavelength range of the exposure light source.

  As an azo pigment corresponding to such a blue (purple) light source, a technique using an anthraquinone azo pigment (for example, see Patent Document 3), a technique using an azo pigment (for example, Patent Document 4, Patent Document 5, and Patent Document) 6) has been proposed.

  In addition, image forming apparatuses such as copiers and printers are required to have higher image quality such as higher resolution and higher gradation performance in addition to stability in image formation in which there are few image defects. Therefore, in these image forming apparatuses, a toner having a narrow particle size distribution with an average particle size of about 3 to 8 μm is usually used to improve the image quality.

  Conventionally, the toner has been produced mainly by a melt kneading and pulverizing method in which a binder resin and a colorant are melt-kneaded until uniform and then pulverized. However, in the melt-kneading pulverization method, it has been difficult to efficiently produce toner that can cope with high image quality.

  Therefore, for example, a technique for producing a toner by a polymerization method that generates toner particles in an aqueous medium has been proposed. For example, Patent Document 3 describes a toner manufactured by a suspension polymerization method. For example, Patent Document 4 describes a toner produced by an emulsion polymerization aggregation method. Among them, the emulsion polymerization aggregation method is a method for producing a toner by aggregating polymer resin fine particles and a colorant in a liquid medium. In this method, the particle size and the circularity of the toner can be adjusted by controlling the aggregation conditions, and thus there is an advantage that various performances of the toner can be easily optimized.

  For example, in order to improve releasability, low-temperature fixability, high-temperature offset property, filming resistance, etc., a method of incorporating a low softening point substance (wax) into the toner has been proposed. When a toner is manufactured using a conventional melt-kneading pulverization method, the amount of the low softening point substance contained in the toner is usually about 5% by weight or less with respect to the binder resin. On the other hand, it is described that a toner produced using a polymerization method can contain a low softening point substance in a large amount (specifically, 5 wt% to 30 wt% or less) (for example, Patent Document 7 and Patent Document 8).

JP-A-3-68953 Japanese Patent Laid-Open No. 9-240051 Japanese Patent Laid-Open No. 10-239956 JP 2002-14482 A JP 2002-131951 A JP 2000-105478 A Japanese Patent Laid-Open No. 5-88409 Japanese Patent Laid-Open No. 11-143125

  However, the photoreceptors described in Patent Documents 3 to 6 do not necessarily have sufficient sensitivity to a blue (purple) light source such as a blue (violet) semiconductor laser.

Therefore, in order to ensure sufficient sensitivity with respect to a blue (purple) light source, it is conceivable to output an image with the light amount extremely increased. However, in such a case, the endurance potential fluctuation tends to increase. For this reason, in order to output a stable super high-quality image, it is desired that the photoreceptor has sufficient durability.
In addition, the conventional photoconductors sometimes have various problems with respect to the output stability of the light source, such as a decrease in reliability, an increase in cost, and a decrease in the life of the light source. Furthermore, there is a limit to the power of the light source, and the photoconductor cannot always ensure proper sensitivity.

  In addition, when an image is formed using the toner described in Patent Documents 7 and 8, high image quality is usually obtained. However, since the fogging phenomenon of the obtained image is also likely to occur, it has been difficult to achieve high resolution, high gradation, and low fog at a high level in the conventional technique.

  The present invention was devised in view of the above-described problems. When an image is formed using monochromatic light having a wavelength of 380 nm or more and 500 nm or less, the exposure is high sensitivity, low residual potential, and high resolution. An object of the present invention is to provide an electrophotographic photosensitive member capable of faithfully forming an electrostatic latent image, and an image forming apparatus and a cartridge including the same.

  The inventor of the present invention has intensively studied to solve the above problems, and as a result, the spectral sensitivity at a wavelength of 380 nm to 500 nm is improved by containing a structural isomer of an azo compound having a predetermined structure in the photosensitive layer in a predetermined ratio. The present inventors have found that an electrophotographic photoreceptor capable of forming an electrostatic latent image with high sensitivity and low residual potential and faithful to high-resolution exposure can be realized during image formation using monochromatic light of this wavelength, The present invention has been completed.

That is, the gist of the present invention includes a conductive support and a photosensitive layer formed on the conductive support, and an electrostatic latent image is formed by exposure with monochromatic light having a wavelength of 380 nm to 500 nm. An electrophotographic photoreceptor to be formed, wherein the photosensitive layer contains an azo compound composition composed of a plurality of structural isomers represented by the following formula (1), and the azo compound composition contains Cp ₁ And Cp ₂ has both a group represented by the following formula (2) and a group represented by the following formula (3) in the molecule, and contains an azo compound represented by the following formula (1) as a main component. The present invention resides in an electrophotographic photosensitive member.
(In formula (1), each X independently represents a linking group having 2 to 30 atoms, Ar represents each independently an arylene group which may have a substituent, and n represents 0 to 4) The following integers are represented, and Cp ₁ and Cp ₂ have the same molecular weight and each independently represent a group represented by the following formula (2) or (3).
(In the formulas (2) and (3), R ¹ and R ² each independently represents a substituent, Z represents a divalent aromatic hydrocarbon group or a nitrogen-containing heterocyclic group, and k and l represent Independently represents an integer of 0 or more and 4 or less.)

At this time, it is preferable that X in the formula (1) has a structure represented by the following formula (4).

Moreover, it is preferable that said Formula (1) is represented by following formula (5) (Claim 3).
(In the formula (5), R each independently represents a substituent, Cp ₁ and Cp ₂ have the same molecular weight, and each independently represents a group represented by the formula (2) or (3); Each independently represents an integer from 0 to 4.

  Furthermore, the electrophotographic photoreceptor of the present invention has an undercoat layer containing metal oxide particles between the conductive support and the photosensitive layer, and is accumulated from the small particle size side of the metal oxide particles. The accumulated 90% particle size is preferably 0.3 μm or less.

  Another gist of the present invention is that the electrophotographic photosensitive member of the present invention, a charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member are exposed to monochromatic light having a wavelength of 380 nm to 500 nm. An exposure unit that forms an electrostatic latent image, a developing unit that has toner and develops the formed electrostatic latent image with the toner, and a transfer unit that transfers the toner to a transfer target. The present invention resides in a characteristic image forming apparatus.

  At this time, it is preferable that the average circularity measured by the flow type particle image analyzer of the toner is 0.940 or more and 1.000 or less.

The toner preferably satisfies all of the following (i) to (iii) (Claim 7).
(I) The volume median diameter (Dv50) is 4.0 μm or more and 7.0 μm or less.
(Ii) The average circularity is 0.93 or more.
(Iii) The relationship between the volume median diameter (Dv50) of the toner and the number% (Dns) of the toner having a particle diameter of 2.00 μm to 3.56 μm satisfies Dns ≦ 0.233EXP (17.3 / Dv50). Fulfill.

  Further, in the toner, the relationship between the volume median diameter (Dv50) and the number% (Dns) of toner having a particle diameter of 2.00 μm or more and 3.56 μm or less satisfies Dns ≦ 0.110EXP (19.9 / Dv50). It is more preferable to satisfy | fill (Claim 8), and it is also more preferable to satisfy | fill 0.0517EXP (22.4 / Dv50) <= Dns (Claim 9).

The toner is preferably a toner produced in an aqueous medium.
Furthermore, it is preferable that the toner has a resin coating layer.

Still another subject matter of the present invention is that at least the electrophotographic photosensitive member of the present invention, a charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member are exposed to monochromatic light having a wavelength of 380 nm to 500 nm. And an image forming apparatus comprising: an exposure unit that forms an electrostatic latent image, a developing unit that includes toner, and that develops the formed electrostatic latent image with toner; and a transfer unit that transfers the toner to a transfer target And a cartridge case for detachably supporting the electrophotographic photosensitive member. (Claim 12)
At this time, it is preferable that the toner satisfies all of the above (i) to (iii).

According to the present invention, high spectral sensitivity at a wavelength of 380 nm to 500 nm, high sensitivity, low residual potential, and high resolution when performing image formation using monochromatic light having a wavelength of 380 nm to 500 nm. It is possible to realize an electrophotographic photosensitive member capable of forming an electrostatic latent image faithfully with respect to exposure, and an image forming apparatus and a cartridge including the same.
In particular, in these image forming apparatuses and cartridges, by using a toner that satisfies specific requirements, it is possible to achieve high quality represented by high resolution, high gradation, etc., and for high-resolution exposure. Therefore, it is possible to form an image that is faithfully developed and has few defects.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus including an electrophotographic photoreceptor and toner according to the present invention. It is a 1000 times SEM photograph showing the adhesion state of the toner on the cleaning blade after evaluation of the actual image of the toner.

  Hereinafter, although an embodiment of the present invention is described in detail, the present invention is not limited to the following embodiment, and can be arbitrarily changed without departing from the gist of the present invention.

[1. Electrophotographic photoreceptor]
The electrophotographic photoreceptor of the present invention (that is, the photoreceptor) has a conductive support and a photosensitive layer formed on the conductive support, and is exposed to monochromatic light having a wavelength of 380 nm to 500 nm. Thus, the photosensitive member forms an electrostatic latent image. As the constitution of the photosensitive layer, any known constitution can be used. For example, a layer containing a charge generation material (charge generation layer) and a layer containing a charge transport material (charge transport layer) are laminated. Multilayer photoreceptors; single layer photoreceptors in which a charge generating material is dispersed in a layer containing a charge transport material. Further, in the laminated type photoconductor, there are a normal laminated type photoconductor in which the charge generation layer and the charge transport layer are laminated in this order from the conductive support side, and a reverse laminated type photoconductor in which the photoconductive layer is reversely laminated. A layer configuration can also be used. Among these, a sequentially laminated type photoreceptor that can exhibit a particularly well-balanced photoconductivity is preferable.

In any case, the photoreceptor of the present invention contains an azo compound composition comprising a plurality of structural isomers represented by the following formula (1) in the photosensitive layer. Further, this azo compound composition has both a group represented by the following formula (2) and a group represented by the following formula (3) as Cp ₁ and Cp ₂ in the molecule, and the following formula (1 ) As a main component. In addition, any structural isomer of the azo compound represented by the following formula (1) usually functions as a charge generating substance.
(In formula (1), each X independently represents a linking group having 2 to 30 atoms, Ar represents each independently an arylene group which may have a substituent, and n represents 0 or more and 4 or less. Represents an integer, and Cp ₁ and Cp ₂ have the same molecular weight and each independently represent a group represented by the following formula (2) or (3).

(In the formulas (2) and (3), R ¹ and R ² each independently represents a substituent, Z represents a divalent aromatic hydrocarbon group or a nitrogen-containing heterocyclic group, and k and l represent Independently represents an integer of 0 or more and 4 or less.)

[1-1. Azo compound composition]
The azo compound composition according to the present invention is a composition comprising a plurality of types of azo compounds represented by the formula (1). That is, the azo compound represented by the formula (1) has a plurality of types of structural isomers, and a composition comprising these structural isomers, in which the ratio of structural isomers constituting the isomer is a specific ratio. The azo compound composition according to the present invention.

[Arylene Ar]
In formula (1), Ar independently represents an arylene group which may have a substituent. In addition, although two Ar which exists in Formula (1) may differ, since manufacture is easy, it is preferable that they are the same.

  The number of carbon atoms in Ar is arbitrary as long as the effects of the present invention are not significantly impaired, but are each independently usually 6 or more, usually 20 or less, preferably 16 or less, more preferably 10 or less. When Ar has too many carbon atoms, the stability of the azo compound according to the present invention may be lowered. In addition, when Ar is substituted by the substituent mentioned later, it is preferable that all the carbon numbers including the carbon number which a substituent has satisfy | fill the said range.

  The molecular weight of Ar is arbitrary as long as the effects of the present invention are not significantly impaired, but each is usually 76 or more, usually 350 or less, preferably 250 or less, more preferably 150 or less. When the molecular weight of Ar is too large, the stability of the azo compound according to the present invention may be reduced. In addition, when Ar is substituted with the substituent mentioned later, it is preferable that the whole molecular weight including the molecular weight of a substituent satisfy | fills the said range.

  Examples of the arylene group include a phenylene group, a naphthylene group, a pyrenylene group, and a phenanthrene group. Among them, a phenylene group is preferable, and among the phenylene groups, a p-phenylene group is more preferable from the viewpoint of electrical characteristics.

As described above, Ar may have a substituent. At this time, the substituents of each Ar in the same molecule may be different, but are preferably the same. It is because manufacture is easy.
The number of atoms of the substituent is arbitrary as long as the effects of the present invention are not significantly impaired. However, if the substituent has too many atoms, the electrical properties of the azo compound according to the present invention may be affected. For this reason, the number of atoms of the substituent is preferably 20 or less, and more preferably 10 or less.

Examples of the substituent that Ar may have include a hydroxyl group, an alkyl group, an alkoxy group, an aralkyloxy group, an aryloxy group, an aryl group, an arylthio group, and a halogen atom.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a tertiary butyl group, and a cyclohexylmethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group.
Examples of the aralkyloxy group include a benzyloxy group.
Examples of the aryloxy group include phenoxy group and 1-naphthoxy group.
Examples of the aryl group include a phenyl group and a naphthyl group.
Examples of the arylthio group include a phenylthio group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

Moreover, when Ar has an alkyl group, the alkyl group may be each independently linear or branched. Further, it may be a chain or a ring. Furthermore, it may have only a saturated bond or may have an unsaturated bond.
Further, the substituent may be further substituted with, for example, an alkyl group such as a methyl group; a halogen atom such as a fluorine atom or a chlorine atom.
In addition, 1 type may be substituted for single type or multiple types, and 2 or more types may be substituted by arbitrary ratios and combinations.

  In the formula (1), the nitrogen atom constituting the azo moiety (that is, the bonding site represented by —N═N—) can be bonded to any carbon atom of Ar. However, the carbon atom on Ar bonded to the nitrogen atom constituting the azo moiety and the carbon atom on Ar bonded to X (the other Ar in the case of n = 0) described later are adjacent positions. Preferably not. This is from the viewpoint of the characteristics of the electrophotographic photosensitive member.

In addition to X, two Ar atoms in the molecule may be bridged with each other to form a ring structure. In addition, when n = 0, Ars in the molecule are directly bonded to each other, but apart from the bond, they may be cross-linked to form a ring structure.
In the case where Ars are bonded to each other and are crosslinked to form a ring structure, the newly formed bond may directly bond Ars to each other or may include a linking group. Especially, it is preferable that the newly formed bond includes a linking group. That is, when Ar forms a ring structure, it is preferable that they are bonded via a linking group and then cross-linked to form a ring structure.

  This linking group is arbitrary as long as the effects of the present invention are not significantly impaired. Among them, those having an atom number of usually 10 or less, preferably 8 or less, more preferably 6 or less are desirable. When the linking group has too many atoms, the stability of the azo compound according to the present invention may be lowered. The number of carbon atoms of the linking group is usually 0 or more, preferably 1 or more, and usually 8 or less, preferably 6 or less, more preferably 4 or less. When there are too many carbon numbers, the stability of the azo compound concerning this invention may fall.

Specific examples of the linking group include a carbonyl group (representing a divalent —C (═O) —), a sulfinyl group, a sulfonyl group, a sulfinato group, an alkylene group, an alkylidene group, an oxy group, a seleno group, a thio group, and the like. Is mentioned. Of these, a carbonyl group and an alkylene group are preferred. In addition, a connection group may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.
Furthermore, the linking group may have a substituent. The type of the substituent is arbitrary as long as the effects of the present invention are not significantly impaired, and examples thereof include the same substituents that can be substituted for Ar.

[Linking group X]
In the formula (1), X represents a linking group for linking Ar.
The number of atoms of the linking group X is usually 2 or more, preferably 3 or more, more preferably 4 or more, particularly preferably 5 or more, and usually 30 or less, preferably 25 or less, more preferably 15 or less, and particularly preferably 10 The range is as follows. If the linking group X has too many atoms, the electrical characteristics may be affected. When the linking group X is substituted with a substituent described later, the total number of atoms including the number of atoms of the substituent preferably satisfies the above range.

  The molecular weight of the linking group X is usually 25 or more, preferably 50 or more, more preferably 65 or more, and usually 400 or less, preferably 250 or less, more preferably 150 or less. If the molecular weight of the linking group X is too large, the electrical characteristics may be affected. When the linking group X is substituted with a substituent described later, it is preferable that the entire molecular weight including the molecular weight of the substituent satisfies the above range.

Specific examples of the linking group X include a group having a heterocyclic ring, a group having an aromatic ring (hereinafter referred to as “aromatic ring” as appropriate), a group having a condensed polycycle, and an aliphatic hydrocarbon group. group _{having, -S (O) 2 -,} - N (CH 3) -, - N (O) -, - C (= O) - , and the like.

  When the linking group X is a group having a heterocyclic ring, the linking group X preferably has at least one selected from the group consisting of nitrogen, oxygen and sulfur, and more preferably has nitrogen and oxygen. Examples of the linking group X in this case include a divalent group having an indole ring, a divalent group having an oxazole ring, a divalent group having an isoxazole ring, a divalent group having an oxadiazole ring, and a thiophene ring. A divalent group having a heteroaryl ring such as a divalent group is preferred. Among these, as the linking group X, a divalent group having an oxadiazole ring is more preferable.

  When the linking group X is a group having an aromatic ring, for example, an arylene group is preferable, and among the arylene groups, a phenylene group, a naphthylene group, an anthrylene group, and a phenanthrylene group are preferable. Of these, a phenylene group and a naphthylene group are more preferable.

  When the linking group X is a group having a condensed polycycle, the condensed polycycle is preferably, for example, a tetralin ring, an azulene ring or a fluorene ring, more preferably a tetralin ring or a fluorene ring.

When the linking group X is a group having an aliphatic hydrocarbon group, the aliphatic hydrocarbon group is preferably, for example, an alkylene group, an alkenylene group, an alkynylene group or an alkylidene group.
When the linking group X is an alkylene group, an alkylene group having usually 1 or more, preferably 2 or more, and usually 9 or less, preferably 6 or less is desirable.
When the linking group X is an alkenylene group, an alkenylene group having 2 or more carbon atoms and usually 9 or less, preferably 6 or less, more preferably 4 or less is desirable.
When the linking group X is an alkynylene group, an alkynylene group having 2 or more carbon atoms and usually 9 or less, preferably 6 or less, more preferably 4 or less is desirable.
When the linking group X is an alkylidene group, an alkylidene group whose carbon number is usually 2 or more, preferably 3 or more, and usually 9 or less, preferably 6 or less is desirable.

The linking group X may be linear or branched. Further, it may be a chain or a ring. Furthermore, it may have only a saturated bond or may have an unsaturated bond.
Moreover, the coupling group X may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations. When there are a plurality of Xs, Xs may be the same or different.

  The linking group X may have a substituent. As for this substituent, 1 type may be substituted by single or multiple, and 2 or more types may be substituted by arbitrary combinations and ratios. The type of the substituent is not limited. For example, the alkyl group which may have a substituent, the aryl group which may have a substituent, the alkoxy group which may have a substituent, a halogen atom, A cyano group, a nitro group, etc. are mentioned. Among these, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, and a halogen atom are preferable.

Among the linking groups X, a linking group having an oxadiazole ring is preferable from the viewpoint of electrical characteristics, and an oxadiazole ring having a structure represented by the following formula (4) is particularly preferable.

[Integer n]
In the formula (1), n represents an integer of 0 or more and 4 or less. When n = 0, it represents that Ars are directly bonded. Further, n is preferably 1 from the viewpoint of the electrical characteristics of the azo compound according to the present invention.

[Example of structure combining X and Ar]
Examples of the combination of X and Ar suitable for the present invention are shown below. However, the following structure is illustrated for more specifically explaining the present invention, and the present invention is not limited to the following structure unless departing from the gist thereof. Me represents a methyl group.

Among these exemplified structures, the following structures are more preferable from the viewpoint of photoreceptor characteristics with respect to exposure with monochromatic light having a wavelength of 380 nm to 500 nm. In this structure, a substituent may be bonded to the phenylene group.

Therefore, similarly, from the viewpoint of the photoreceptor characteristics with respect to exposure with monochromatic light having a wavelength of 380 nm to 500 nm, the formula (1) is preferably expressed by the following formula (5).
In the formula (5), each R independently represents the same substituent as that which Ar may have.
M independently represents an integer of 0 or more and 4 or less. In addition, when m = 0, it represents that the substituent R is not substituted to the phenylene group specified in Formula (5).
Cp ₁ and Cp ₂ are the same as those in the formula (1).

[Couplers Cp ₁ and Cp ₂ ]
In the formula (1), Cp ₁ and Cp ₂ each independently represent a coupler residue represented by the following formula (2) or the following formula (3). However, Cp ₁ and Cp ₂ have the same molecular weight.

(Atomic group Z)
In formulas (2) and (3), Z represents a divalent aromatic hydrocarbon group or a nitrogen-containing heterocyclic group, and has a ring structure in which two bonds of Z are bonded to separate nitrogen atoms. doing.

  The carbon number of the divalent aromatic hydrocarbon group is usually 6 or more, and usually 16 or less, preferably 10 or less, more preferably 8 or less. If the number of carbon atoms is too large, the electrical characteristics may be affected. In addition, when a bivalent aromatic hydrocarbon group is substituted by the substituent mentioned later, it is preferable that the total carbon number including the carbon number of a substituent satisfy | fills the said range.

  The molecular weight of the divalent aromatic hydrocarbon group is usually 76 or more, and usually 250 or less, preferably 180 or less, more preferably 150 or less. If the molecular weight is too large, the electrical properties may be affected. In addition, when a bivalent aromatic hydrocarbon group is substituted by the substituent mentioned later, it is preferable that the whole molecular weight including the molecular weight of a substituent satisfy | fills the said range.

  Specific examples of the divalent aromatic hydrocarbon group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.

  The carbon number of the divalent nitrogen-containing heterocyclic group is usually 4 or more, preferably 5 or more, and usually 12 or less, preferably 9 or less. If the number of carbon atoms is too large, the electrical characteristics may be affected. In addition, when a bivalent nitrogen-containing heterocyclic group is substituted with the substituent mentioned later, it is preferable that the whole carbon number including carbon number of a substituent satisfy | fills the said range.

  The molecular weight of the divalent nitrogen-containing heterocyclic group is usually 77 or more, and usually 200 or less, preferably 180 or less, more preferably 150 or less. If the molecular weight is too large, the electrical properties may be affected. In addition, when a bivalent nitrogen-containing heterocyclic group is substituted with the substituent mentioned later, it is preferable that the whole molecular weight including the molecular weight of a substituent satisfy | fills the said range.

  Specific examples of the divalent nitrogen-containing heterocyclic group include a pyridineyl group, a quinolinediyl group, and a pyrimidinediyl group, and a pyridinediyl group is particularly preferable.

(Substituent R ² )
Z may have a substituent R ² at an arbitrary position. The number of substituents R ² is represented by 1 in formulas (2) and (3), and the range of 1 is 0 or more and 4 or less. Note that when l is 0 indicates that the substituent R ² is not substituted with Z.

The type of the substituent R ² is arbitrary as long as the effects of the present invention are not significantly impaired. For example, an alkyl group, an alkoxy group, an aralkyloxy group, an aryloxy group, an alkylthio group, an aralkylthio group, a halogen atom, and an alkyl halide. Group, amino group, nitro group, thiol group, nitrile group and the like. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example. Examples of the halogenated alkyl group include a trifluoromethyl group.
Incidentally, the substituent R ² may be only one kind substituted, or two or more of these may be substituted in any combination and in any ratio.

Moreover, these substituents R ² may be further substituted. Examples of the substituent that can be further substituted include those similar to the substituent R ² itself that can be substituted for Z. Among them, preferred are a fluorine atom, a chlorine atom, a methyl group, a methoxy group, a nitro group, A trifluoromethyl group, more preferably a fluorine atom, a methyl group, or a methoxy group.

(Substituent R ¹ )
In Formula (2) and Formula (3), R ¹ represents a substituent that substitutes for the naphthalene skeleton of each of Formula (2) and Formula (3). The number of the substituent R ¹ is represented by k in the formulas (2) and (3), and the range of k is 0 or more and 4 or less. In addition, when k is 0, it represents that the substituent R ¹ is not substituted on the naphthalene skeleton.

The number of atoms of the substituent R ¹ is usually 1 or more, preferably 2 or more, more preferably 5 or more, and usually 30 or less, preferably 25 or less, more preferably 20 or less. If the number of atoms is too large, the electrical characteristics may be affected. In the case where the substituent R ¹ is substituted with a substituent which will be described later, it is preferable that the number of atoms total atom number is also included in the substituents meet the scope of the.

The carbon number of the substituent R ¹ is usually 0 or more, preferably 1 or more, and usually 15 or less, preferably 10 or less, more preferably 8 or less. If the number of carbon atoms is too large, the electrical characteristics may be affected. In the case where the substituent R ¹ is substituted with a substituent which will be described later, it is preferable that the carbon number of the total number was also included carbon atoms of the substituent satisfies the scope of the.

The molecular weight of the substituent R ¹ is usually 15 or more, preferably 17 or more, more preferably 30 or more, and usually 250 or less, preferably 200 or less, more preferably 150 or less. If the molecular weight is too large, the electrical properties may be affected. In the case where the substituent R ¹ is substituted with a substituent which will be described later, it is preferable that the molecular weight of the whole, including the molecular weight of the substituent groups meet the scope of the.

The type of the substituent R ¹ is arbitrary as long as the effects of the present invention are not significantly impaired, and examples thereof include an organic group containing a carbon atom and an inorganic group containing no carbon atom.
Examples of the organic group containing a carbon atom include hydrocarbon groups such as aliphatic hydrocarbon groups (for example, alkyl groups and alkenyl groups) and aromatic hydrocarbon groups (for example, aryl groups); alkoxy groups, aralkyloxy groups, Oxygen-containing hydrocarbon groups such as aryloxy groups; halogenated hydrocarbon groups containing halogen atoms such as halogenated alkyl groups and halogenated aryl groups; nitrile groups, primary to tertiary amino groups substituted with organic groups, etc. Is mentioned.
In this case, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a normal butoxy group, a tertiary riboxy group, a pentoxy group, an octyloxy group, and a cyclohexylmethyloxy group. Examples of the alkenyl group include allyl group, methylallyl group, chloroallyl group and the like. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the halogenated alkyl group include a trifluoromethyl group.

On the other hand, examples of the inorganic group containing no carbon atom include an unsubstituted amino group, thiol group, nitro group, hydroxyl group, and halogen atom.
In this case, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In addition, these substituents R ¹ may be further substituted. Further, examples of the substituent that can be substituted include an alkyl group, an alkoxy group, and a halogen atom.

Among those described above, preferable examples of the substituent R ¹ include an alkyl group, an alkoxy group, a hydroxyl group, and a halogen atom. Among these, an alkoxy group having 1 to 8 carbon atoms, a cycloalkyloxy group, and an aralkyloxy group are more preferable, and an alkoxy group having 1 to 8 carbon atoms is particularly preferable.
Incidentally, the substituent R ¹ may be only one kind substituted, or two or more of these may be substituted in any combination and in any ratio.

(For binding position of ^{R 1)}
In the formula (2) and the formula (3), the bonding position of the substituent R ¹ can be four bonding positions of the aromatic ring. Among them, the bonding positions represented by the following formulas are preferable. This is because of the characteristics of the electrophotographic photosensitive member.

(Examples of couplers Cp ₁ and Cp ₂ )
Examples of the structures of Cp ₁ and Cp ₂ that can be suitably used in the present invention are shown below. However, the following structures are illustrated for more specifically explaining the present invention, and the present invention is not limited to the following structures unless departing from the gist thereof. Bun or nBu represents an n-butyl group.

[Structural isomers of azo compounds]
The azo compound according to the present invention is a compound represented by the above formula (1), and the following three azo compounds exist as structural isomers depending on the combination of the structures of Cp ₁ and Cp ₂ . The azo compound composition according to the present invention is a composition comprising two or more (usually three) of these three azo compounds.
Isomer 1. Cp ₁ Equation (2) Cp ₂ Equation (2)
Isomer 2. Cp Formula ₁ (2) Cp Formula ₂ (3)
Isomer 3. Cp Formula ₁ (3) Cp Formula ₂ (3)

The azo compound composition according to the present invention contains the isomer 2 as a main component among the azo compounds represented by the isomers 1 to 3. Here, the main component means that it is usually the largest among the abundance ratios of the isomers 1 to 3. That is, the azo compound composition according to the present invention includes a coupler residue represented by the formula (2) and a coupler residue represented by the formula (3) as Cp ₁ and Cp ₂ among the azo compounds according to the present invention. An isomer having both of the groups in the molecule is represented by Cp ₁ and Cp ₂ in which only one of the coupler residue represented by the formula (2) and the coupler residue represented by the formula (3) is contained in the molecule. It contains more than the isomer it has.

  Specifically, when the total amount of the isomers 1 to 3 is 100%, the abundance ratio of the isomer 2 is usually 44% or more, which is judged from the productivity during the production of the azo compound. Then, 45% or more is preferable, considering the dispersibility of the azo compound composition, 46% or more is more preferable, 47% judging from the characteristics of the photoreceptor is more preferable, and considering the image quality obtained from the image forming apparatus. Then, 48% or more is particularly preferable.

The effect of the present invention includes an azo compound composition comprising a plurality of structural isomers represented by the formula (1), and Cp ₁ and Cp _{2 in the} azo compound composition are represented by the formula (2). It is obtained by having both a coupler residue represented by the formula (3) and a coupler residue represented by the formula (3) in the molecule, and containing the azo compound represented by the formula (1) as a main component. . The reason for the effect is not clear, but according to the inventor's study, it is presumed as follows.
That is, the isomer 2 (that is, both the coupler residue represented by the formula (2) and the coupler residue represented by the formula (3) as Cp ₁ and Cp ₂ in the molecule, The azo compound represented by the formula (1) is another isomer 1,3 (that is, Cp ₁ and Cp ₂ are coupler residues having the same structure, and the azo compound represented by the formula (1) ), The molecular structure is asymmetric and has a large dipole moment. For this reason, when the photoreceptor of the present invention is exposed to monochromatic light having a wavelength of 380 nm or more and 500 nm and the azo compound composition, which is a charge generation material, is excited to generate charges, the isomer 2 is excited by excitation. When a child separates charge in a molecule and generates a transport carrier, the charge separated + charge and −charge can be used widely in the molecule. As a result, the charge separated + charge and −charge Recombination is suppressed. For this reason, the isomer 2 undergoes charge separation with higher efficiency when exposed to light than other isomers, and the separated charge is injected into the charge transport material. Therefore, Cp ₁ and Cp ₂ contain, as a main component, isomer 2 having in the molecule both the coupler residue represented by the formula (2) and the coupler residue represented by the formula (3). Thus, it is assumed that the photosensitive member can be made highly sensitive and have a low residual potential.
In addition, the excitons generated by the exposure in this way are separated into charges with high efficiency without any loss such as deactivation due to recombination, and are injected into the charge transport material. It is presumed that a faithful electrostatic latent image can be formed. Furthermore, a high-quality image can be formed at high speed by further using a specific toner that can effectively visualize this high-resolution electrostatic latent image.

  The photoreceptor of the present invention may contain two or more azo compound compositions in the photosensitive layer. For example, the case where two or more azo compound groups having different types of Ar and X and different values of n are present. Even in such a case, it is sufficient that at least one azo compound composition satisfies the above-described requirements. This is because the effects of the present invention can be obtained at least as much as the azo compound composition.

[1-2. Charge generating material that can be used in combination with the azo compound composition of the present invention]
In addition to the azo compound composition according to the present invention, the photoreceptor of the present invention may be used in combination with a charge generating material having another structure, as long as at least the azo compound composition according to the present invention is contained in the photosensitive layer. it can. In addition, the charge generation substance used together may be used individually by 1 type, and may be used 2 or more types by arbitrary combinations and ratios. Alternatively, two or more types can be used in combination. However, the amount of the charge generating material used in combination is not limited, but it is preferable not to exceed the weight of the azo compound composition satisfying the above conditions in order to sufficiently obtain the effects of the present invention.

Examples of the charge generating material that can be used in combination include inorganic photoconductive materials and organic photoconductive materials.
Examples of the inorganic photoconductive material include selenium and its alloys, cadmium sulfide and the like.
Examples of organic photoconductive materials include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, benzimidazole pigments, Examples include thioindigo pigments, anthraquinone pigments, cyanine pigments, pyrylium pigments, and thiopyrylium pigments. Of these, organic pigments are preferable, and phthalocyanine pigments and azo pigments are particularly preferable.

  Specific examples of phthalocyanine pigments include metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, and other metals or their oxides, halides, hydroxides, alkoxides, etc. And various crystal forms of phthalocyanines. Among them, X-type or τ-type metal-free phthalocyanine which is a highly sensitive crystal form; titanyl phthalocyanine such as A-type (also known as β-type), B-type (also known as α-type) and D-type (also known as Y-type); vanadyl phthalocyanine; Chloroindium phthalocyanine; Chlorogallium phthalocyanine such as type II; Hydroxygallium phthalocyanine such as V type; μ-oxo-gallium phthalocyanine dimer such as G type and I; μ-oxo-aluminum phthalocyanine dimer such as type II Etc. are preferable. Further, among these phthalocyanines, A-type, B-type or D-type titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type hydroxygallium phthalocyanine, G-type μ-oxo-gallium phthalocyanine dimer and the like are particularly preferable.

In particular, oxytitanium phthalocyanine preferably has a clear diffraction peak mainly at a Bragg angle (2θ ± 0.2 °) of 27.3 ° in a powder X-ray diffraction spectrum by CuKα characteristic X-ray.
Further, oxytitanium phthalocyanine preferably has a clear diffraction peak at a Bragg angle (2θ ± 0.2 °) of 9.0 ° to 9.7 ° in a powder X-ray diffraction spectrum by CuKα characteristic X-ray.
Specific examples of the azo pigments include bisazo pigments, trisazo pigments, tetrakis pigments and the like.

[1-3. Configuration of electrophotographic photosensitive member]
The photoreceptor of the present invention has a conductive support and a photosensitive layer formed on the conductive support, and if the photosensitive layer contains the above-mentioned azo compound composition, the details thereof will be described. The configuration is not limited. A typical configuration will be described below.

[1-3-1. Conductive support)
The conductive support is not particularly limited, and for example, metal materials such as aluminum, aluminum alloy, stainless steel, copper, and nickel; conductive powders such as metal, carbon, and tin oxide are included to impart conductivity. Resin material: Resin, glass, paper, etc., on which a conductive material such as aluminum, nickel, ITO (indium tin oxide alloy) or the like is deposited or applied on its surface are mainly used, unless the effect of the present invention is remarkably limited. However, the present invention is not limited to this. Among them, the material for the conductive support is preferably a material having a specific resistance of 10 ³ Ωcm or less at normal temperature (usually 25 ° C.).
In addition, the material of an electroconductive support body may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

  Examples of the shape of the conductive support include a drum shape, a sheet shape, and a belt shape. In addition, as a conductive support, a conductive material having an appropriate resistance value is applied on a substrate formed of a metal material for controlling conductivity and surface properties and for covering defects. You may have done.

When a metal material such as an aluminum alloy is used as the conductive support, it may be used after, for example, a treatment for applying an anodized film. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method.
The anodized film is formed, for example, by anodizing in an acidic bath. Specific examples of the acidic solution used at this time include chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, and the like. Among them, sulfuric acid is preferable. When anodizing using sulfuric acid, the sulfuric acid concentration is 100 g / L or more and 300 g / L or less, the dissolved aluminum concentration is 2 g / L or more and 15 g / L or less, the reaction temperature is 15 ° C. or more and 30 ° C. or less, and the electrolysis voltage is The current density is preferably set within the range of 0.5 A / dm ² or more and 2 A / dm ² or less, but is not limited to the above conditions. In addition, an acidic solution may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  The average film thickness of the anodized film is usually 3 μm or more, preferably 5 μm or more, and usually 20 μm or less, preferably 7 μm or less. When the average film thickness of the anodic oxide coating is thick, in the sealing treatment described later, it is processed under strong conditions such as high concentration of the sealing agent, high processing temperature, and long processing time. There is a case. Therefore, there is a possibility that the productivity of the photosensitive member may be deteriorated, or that a surface defect such as a stain, a stain or a dusting may be easily generated on the surface of the coating.

  The formed anodized film is preferably sealed. The sealing treatment can be performed by any known method. For example, a low temperature sealing treatment in which a conductive support is immersed in an aqueous solution containing nickel fluoride as a main component, or a conductive support in an aqueous solution containing a sealant such as nickel acetate as a main component. It is preferably applied by high-temperature sealing treatment to be immersed.

The concentration of the nickel fluoride aqueous solution used when the low-temperature sealing treatment is performed is arbitrary as long as the effects of the present invention are not significantly impaired, but a range of 3 g / L or more and 6 g / L or less is preferable. The treatment temperature is usually 25 ° C. or higher, preferably 30 ° C. or higher, and usually 40 ° C. or lower, preferably 35 ° C. or lower. The nickel fluoride aqueous solution is desirably treated at a pH of usually 4.5 or higher, preferably pH 5.5 or higher, and usually pH 6.5 or lower, preferably pH 6.0 or lower. At this time, any known pH adjusting agent can be used as the pH adjusting agent. For example, oxalic acid, boric acid, formic acid, acetic acid, sodium hydroxide, sodium acetate, aqueous ammonia and the like are preferably used. This is because the low-temperature sealing process proceeds smoothly. In addition, a pH adjuster may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations. The treatment time is preferably in the range of 1 minute to 3 minutes per 1 μm of film thickness. In order to further improve the physical properties of the coating, for example, cobalt fluoride, cobalt acetate, nickel sulfate, a surfactant and the like may be contained in the nickel fluoride aqueous solution.
Further, after the low temperature sealing treatment, usually washing and drying are performed.

On the other hand, when performing the above-mentioned high-temperature sealing treatment, it is preferable to use, for example, nickel acetate, cobalt acetate, lead acetate, nickel acetate-cobalt, barium nitrate, etc., and more preferably nickel acetate. preferable. When nickel acetate aqueous solution is used as the sealing agent, the concentration of the solution can be any concentration, but is preferably used at a concentration in the range of 5 g / L to 20 g / L. The treatment temperature is usually 80 ° C. or higher, preferably 90 ° C. or higher, and usually 100 ° C. or lower, preferably 98 ° C. or lower. The pH of the aqueous nickel acetate solution is usually pH 4.0 or higher, preferably pH 5.0 or higher, and usually pH 8.0 or lower, preferably pH 6.0 or lower. At this time, any known pH adjusting agent can be used as the pH adjusting agent. For example, aqueous ammonia, sodium acetate, or the like is preferably used. This is because the high temperature sealing treatment proceeds smoothly. In addition, a pH adjuster may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations. Furthermore, the treatment time is usually 10 minutes or longer, preferably 20 minutes or longer, and usually 100 minutes or shorter, preferably 60 minutes or shorter. In order to further improve the physical properties of the coating, for example, sodium acetate, an organic carboxylic acid, an anionic surfactant, a nonionic surfactant, or the like may be contained in the nickel acetate aqueous solution.
Further, after the high temperature sealing treatment, it is preferable to further carry out treatment with high temperature water and / or high temperature steam substantially free of salts. After the high temperature sealing treatment, it is usually washed and dried.

  The surface of the conductive support may be smooth, or may be roughened by using a special cutting method or polishing. In addition, the surface of the conductive support may be roughened by mixing particles having an appropriate particle diameter with the material constituting the conductive support. In order to reduce the cost, the drawing tube can be used as it is as a conductive support without cutting. Especially when non-cutting aluminum support such as drawing, impact processing, ironing, etc. is used as a conductive support, the above processing eliminates dirt, foreign matter, etc. on the surface, small scratches, etc. This is preferable because a clean conductive support can be obtained. In the present specification, mixing means that the components to be mixed are not necessarily mixed uniformly in the system unless otherwise specified, and means that the components to be mixed are combined in the same system. To do.

The surface roughness Ra of the conductive support is preferably 0.01 μm or more, preferably 0.3 μm or less, and more preferably 0.20 μm or less. If the surface roughness Ra is too small, the adhesion of the photosensitive layer or the like to the conductive support may be deteriorated. If the surface roughness Ra is too large, image defects such as black spots are likely to occur.
As a method for processing the surface roughness of the conductive support within the above range, for example, a method of cutting and roughening the surface of the conductive support with a cutting tool or the like; collision of fine particles with the surface of the conductive support Sand blasting method by performing; Processing method by ice particle cleaning device described in JP-A-4-204538; Honing method described in JP-A-9-236937; Anodizing method; Anodizing method; Buffing method; method by laser ablation described in JP-A-4-233546; method using polishing tape described in JP-A-8-001502; roller burnishing processing described in JP-A-8-001510 Methods and the like. However, the method for roughening the surface of the conductive support is not limited thereto.

(Definition and measurement method of surface roughness)
The surface roughness Ra means arithmetic average roughness and represents an average value of absolute value deviations from the average line. Specifically, a reference length is extracted from the roughness curve in the direction of the average line, and the absolute values of deviations from the average line of the extracted portion to the measurement curve are summed and averaged.
The surface roughness Ra can be measured by, for example, a surface roughness meter (Tokyo Seimitsu Surfcom 570A). However, other measuring instruments may be used as long as the measuring instrument produces the same result within the error range.

[1-3-2. (Undercoat layer)
An undercoat layer may be provided between the conductive support and the photosensitive layer in order to improve adhesiveness, blocking property and the like. This undercoat layer may be a single layer or a plurality of layers. The thickness of the undercoat layer is arbitrary as long as the effects of the present invention are not significantly impaired. However, from the viewpoint of the photoreceptor characteristics and applicability, 0.1 μm or more is preferable, and 20 μm or less is preferable. In addition, an undercoat layer may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  Examples of the undercoat layer include those containing metal oxide particles such as those formed of a resin and those obtained by dispersing particles of a metal oxide or the like in a resin. Among these, those formed by dispersing metal oxide particles in a resin (hereinafter, appropriately referred to as “binder resin”) are preferable. Hereinafter, this type of undercoat layer will be described. However, the content described below is an example of the undercoat layer, and the undercoat layer is not limited to the one described below.

(Metal oxide particles)
・ Types of metal oxide particles:
As the metal oxide particles contained in the undercoat layer, any metal oxide particles that can be used for the photoreceptor can be used as long as the effects of the present invention are not significantly limited. Specific examples thereof include metal oxide particles containing one kind of metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide; calcium titanate, strontium titanate, barium titanate, etc. Examples thereof include metal oxide particles containing a plurality of metal elements. Among these, metal oxide particles made of a metal oxide having a band gap of 2 eV or more and 4 eV or less are preferable. If the band gap is too small, carrier injection from the conductive support tends to occur, and defects such as black spots and color spots tend to occur when an image is formed. On the other hand, if the band gap is too large, the charge transfer is hindered by the trapping of electrons, and the electrical characteristics may be deteriorated.
Among these metal oxide particles, titanium oxide, aluminum oxide, silicon oxide and zinc oxide are preferable, titanium oxide and aluminum oxide are more preferable, and titanium oxide is particularly preferable.

  As the metal oxide particles, only one type of particles may be used, or a plurality of types of particles may be mixed and used in an arbitrary combination and ratio. Further, the metal oxide particles may be formed from only one kind of metal oxide, or may be formed by using two or more kinds of metal oxides in an arbitrary combination and ratio.

・ Crystal form of metal oxide particles:
The crystal form of the metal oxide particles is arbitrary as long as the effects of the present invention are not significantly impaired. For example, there is no restriction | limiting in the crystal form of the metal oxide particle (namely, titanium oxide particle) which used the titanium oxide as a metal oxide, For example, any of a rutile, anatase, brookite, and an amorphous | non-crystalline substance can be used. The crystal form of the titanium oxide particles may be in a single crystal state or in a plurality of crystal states.

・ Surface treatment of metal oxide particles:
Various surface treatments may be performed on the surface of the metal oxide particles. For example, treatment with a treating agent such as an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or organic silicon compound may be performed. One of these treatment agents may be used alone, or two or more thereof may be used in any ratio and combination.

  In particular, when titanium oxide particles are used as the metal oxide particles, the surface treatment is preferably performed with an organosilicon compound. Examples of the organosilicon compound include silicone oils such as dimethylpolysiloxane and methylhydrogenpolysiloxane; organosilanes such as methyldimethoxysilane and diphenyldimethoxysilane; silazanes such as hexamethyldisilazane; vinyltrimethoxysilane and γ-mercaptopropyl. Examples thereof include silane coupling agents such as trimethoxysilane and γ-aminopropyltriethoxysilane.

The metal oxide particles are particularly preferably those treated with a silane treating agent having a structure represented by the following formula (6). This silane treatment agent has good reactivity with metal oxide particles and is a good treatment agent.

In the formula (6), R ^u1 and R ^u2 each independently represent an alkyl group. The carbon number of R ^u1 and R ^u2 is not limited, but is usually 1 or more and usually 18 or less, preferably 10 or less, more preferably 6 or less, and particularly preferably 3 or less. Thereby, the reactivity with a metal oxide particle becomes suitable for a silane processing agent. If the number of carbons is too large, the reactivity between the silane treating agent and the metal oxide particles will decrease, or the treated metal oxide particle coating solution (coating solution for forming the undercoat layer, which will be described later). There is a possibility that the dispersion stability of the resin is lowered. Preferable specific examples of R ^u1 and R ^u2 include methyl group, ethyl group, propyl group and the like.

In the formula (6), R ^u3 represents an alkyl group or an alkoxy group. Although there is no restriction ^| limiting in carbon number of ^Ru3 , Usually, it is 1 or more, and usually 18 or less, Preferably it is 10 or less, More preferably, it is 6 or less, Most preferably, it is 3 or less. Thereby, the reactivity with a metal oxide particle becomes suitable for a silane processing agent. If the number of carbons is too large, the reactivity between the silane treatment agent and the metal oxide particles may decrease, or the dispersion stability of the metal oxide particles after the treatment in the coating solution may decrease. . Specific examples of suitable R ^u3 include a methyl group, an ethyl group, a methoxy group, and an ethoxy group.

  In addition, when processing with the above processing agents, the outermost surface of a metal oxide particle is normally processed with the silane processing agent represented by the structure of said Formula (6). At this time, the surface treatment mentioned above may perform only one surface treatment, and may perform two or more surface treatments by arbitrary combinations. For example, the metal oxide particles may be treated with a treating agent such as aluminum oxide, silicon oxide or zirconium oxide before the surface treatment with the silane treating agent represented by the formula (6). Moreover, you may use together the metal oxide particle which performed different surface treatment in arbitrary combinations and a ratio.

-Volume average particle size of metal oxide particles:
The volume average particle size of the metal oxide particles is usually 0.1 μm or less, preferably 95 nm or less, more preferably 90 nm or less, and the lower limit is usually 20 nm or more. This is because the exposure-charge repetition characteristics under low temperature and low humidity are stable, and image defects such as black spots and color spots can be suppressed from occurring in the obtained image.
The volume average particle size of the metal oxide particles is measured by dispersing the undercoat layer in a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3, so that the metal oxide particles are dispersed in the solvent. Measurement is performed by preparing a dispersed dispersion and performing a dynamic light scattering method on the dispersion. The dynamic light scattering method will be described later.

-Cumulative 90% particle size accumulated from the small particle size side of the metal oxide particles:
The cumulative 90% particle size accumulated from the small particle size side of the metal oxide particles is usually 0.3 μm or less, preferably 0.2 μm or less, more preferably 0.15 μm or less, and there is no limit on the lower limit. .05 μm or more. If the cumulative 90% particle size is too large, image defects such as black spots and color spots may occur during image formation. On the other hand, if the cumulative 90% particle size is too small, the storage stability of the coating liquid may be lowered when the undercoat layer forming coating liquid described below is applied and dried to form the undercoat layer. Because.

  In conventional photoreceptors, the undercoat layer may contain metal oxide particles that are large enough to penetrate the front and back of the undercoat layer, and the large metal oxide particles may cause defects during image formation. there were. In addition, when a contact type is used as the charging means, when the photosensitive layer is charged, the charge moves from the conductive support to the photosensitive layer through the metal oxide particles, and the charging is appropriately performed. There was also a possibility that it could not be done. However, when the accumulated 90% particle diameter accumulated from the small particle diameter side of the metal oxide particles is within the above-described range, the large metal oxide particles are very few. Therefore, the photoconductor of the present invention can suppress the occurrence of defects and the inability to charge properly, and enables high-quality image formation.

・ Evaluation of particle size distribution of metal oxide particles by dynamic light scattering method:
The metal oxide particles in the undercoat layer are preferably present as primary particles. However, there are few such cases in general, and there are many cases where they are aggregated and exist as aggregate secondary particles, or both are mixed. Therefore, it is preferable to evaluate the state of the metal oxide particles by measuring the particle size distribution of the metal oxide particles in the undercoat layer. Although it is very difficult to directly evaluate the particle size distribution of the metal oxide particles in the undercoat layer, by dispersing the undercoat layer in a specific solvent and evaluating the dispersion, The particle size distribution of the metal oxide particles can be known.

  Specifically, a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3 is prepared, and a dispersion in which an undercoat layer is dispersed in this solvent is prepared, and the particle size distribution in the dispersion is determined. Ask. At this time, the volume average particle size of the metal oxide particles and the cumulative 90% particle size accumulated from the small particle size side are measured by the dynamic light scattering method regardless of the form of the metal oxide particles. Values can be used.

  In the dynamic light scattering method, the speed of Brownian motion of finely dispersed particles is detected, and the particle size distribution is detected by irradiating the particles with laser light and detecting light scattering (Doppler shift) with different phases according to the speed. Is what you want. The value of the volume average particle diameter of the metal oxide particles in the undercoat layer is a value when the metal oxide particles are stably dispersed in a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3. It does not mean the particle size of metal oxide particles or the like as powder before dispersion. In actual measurement, it is preferable to use a dynamic light scattering type particle size analyzer (manufactured by Nikkiso Co., Ltd., MICROTRAC UPA model: 9340-UPA, hereinafter referred to as “UPA” as appropriate) with the following settings. The specific measurement operation is preferably performed based on an instruction manual for the particle size analyzer (manufactured by Nikkiso Co., Ltd., Document No. T15-490A00, revised No. E).

・ Setting of dynamic light scattering particle size analyzer:
Measurement upper limit: 5.9978 μm
Measurement lower limit: 0.0035 μm
Number of channels: 44
Measurement time: 300 sec.
Measurement temperature: 25 ° C
Particle permeability: Absorption Particle refractive index: N / A (not applicable)
Particle shape: non-spherical density: 4.20 (g / cm ³ ) (The value of density is for titanium dioxide particles. In the case of other particles, it is preferable to use the values described in the instruction manual. )
Dispersion medium type: Mixed solvent of methanol and 1-propanol (weight ratio: methanol / 1-propanol = 7/3)
Dispersion medium refractive index: 1.35

In addition, when the dispersion liquid which disperse | distributed the undercoat layer to the solvent which mixed methanol and 1-propanol by the weight ratio of 7: 3 is too thick, and the density | concentration is outside the measurable range of a measuring device. The dispersion is diluted with a mixed solvent of methanol and 1-propanol (methanol / 1-propanol = 7/3 (weight ratio); refractive index = 1.35), and the concentration can be measured by the measuring device. It is preferable to fit in. For example, in the case of UPA, it is preferable to dilute with a mixed solvent of methanol and 1-propanol so that the sample concentration index (SIGNAL LEVEL) suitable for measurement is usually 0.6 or more and 0.8 or less. .
Even if the dilution is performed in this manner, it is considered that the particle diameter of the metal oxide particles in the liquid in which the undercoat layer is dispersed does not change. Therefore, the volume average particle diameter measured as a result of the dilution described above and Cumulative 90% particle size is treated as volume average particle size and cumulative 90% particle size measured in a liquid in which the undercoat layer is dispersed in a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3. To do.

-Average primary particle size of metal oxide particles:
There is no restriction | limiting in the average primary particle diameter of metal oxide particle, and it is arbitrary unless the effect of this invention is impaired remarkably. However, the average primary particle size of the metal oxide particles is determined by the arithmetic average value of the particle diameters directly observed by a transmission electron microscope (hereinafter referred to as “TEM” as appropriate). Is usually 1 nm or more, preferably 5 nm or more, and usually 100 nm or less, preferably 70 nm or less, more preferably 50 nm or less.

-Refractive index of metal oxide particles:
There is no restriction | limiting in the refractive index of a metal oxide particle, What kind of thing can be used if it can be used for a photoreceptor. The refractive index of the metal oxide particles is usually 1.3 or more, preferably 1.4 or more, more preferably 1.5 or more, and usually 3.0 or less, preferably 2.9 or less, more preferably 2. 8 or less.

(Binder resin)
・ Binder resin type:
As the binder resin contained in the undercoat layer, any binder resin can be used as long as the effects of the present invention are not significantly impaired, and any binder resin that can be used for a photoreceptor is usually used. Usually, it is soluble in a solvent such as an organic solvent, and the undercoat layer after formation is insoluble or low in solubility in a solvent such as an organic solvent used in a coating solution for forming a photosensitive layer. Use a material that does not substantially mix.

  Examples of the binder resin used in the undercoat layer include phenoxy resin, epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, and polycarbonate resin. , Polyurethane resin, polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacrylic acid resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble Polyester resins, cellulose esters such as nitrocellulose and celluloses such as cellulose ether resins, casein, gelatin, polyglutamic acid, starch, starch acetate , Amino starch, zirconium chelate compound, an organic zirconium compound such as zirconium alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanyl alkoxide compound, silane coupling agent, and the like. Of these, polyamide resins such as alcohol-soluble copolymerized polyamides and modified polyamides are preferable because they exhibit good dispersibility and coating properties. However, the present invention is not limited to these unless the effects of the present invention are significantly limited.

  As the polyamide resin, for example, so-called copolymer nylon obtained by copolymerizing 6-nylon, 66-nylon, 610-nylon, 11-nylon, 12-nylon, etc .; N-alkoxymethyl-modified nylon, N-alkoxyethyl-modified Examples thereof include alcohol-soluble nylon resins such as a type obtained by chemically modifying nylon such as nylon.

  Among these polyamide resins, a copolymerized polyamide resin containing a diamine component corresponding to the diamine represented by the following formula (7) (hereinafter, appropriately referred to as “diamine component corresponding to formula (7)”) as a constituent component is particularly preferable. .

In the formula ^{(7), R} u4 ~R ^u7 each independently represent a hydrogen atom or an organic substituent. a and b each independently represent an integer of usually 0 or more and usually 4 or less. In addition, when there are a plurality of the organic substituents, these substituents may be the same as or different from each other.

Examples of suitable ones as organic substituent represented by R ^u4 to R ^u7, like hydrocarbon group which may contain a hetero atom. Among these, preferred examples include alkyl groups such as methyl group, ethyl group, n-propyl group, and isopropyl group; alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, and isopropoxy group; phenyl group, naphthyl group, Examples include an aryl group such as an anthryl group and a pyrenyl group, and an alkyl group or an alkoxy group is more preferable. Particularly preferred are a methyl group and an ethyl group.

Although the carbon number of the organic substituent represented by R ^u4 to R ^u7 is optional unless significantly impairing the effects of the present invention, usually 1 or more and usually 20 or less, preferably 18 or less, more preferably 12 or less. If the number of carbon atoms is too large, the solubility in the solvent may deteriorate and the coating solution may gel, or even if temporarily dissolved, the coating solution may become cloudy or gel with the passage of time.

  The copolymerized polyamide resin containing a diamine component corresponding to the formula (7) as a constituent component constitutes a constituent component other than the diamine component corresponding to the formula (7) (hereinafter simply referred to as “other polyamide constituent components”). It may be included as a unit. Examples of other polyamide constituents include lactams such as γ-butyrolactam, ε-caprolactam, lauryllactam; 1,4-butanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,20-eicosanedicarboxylic acid, and the like. Dicarboxylic acids; diamines such as 1,4-butanediamine, 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,12-dodecanediamine; piperazine and the like. At this time, examples of the copolymerized polyamide resin include those obtained by copolymerizing the constituent components into, for example, binary, ternary, and quaternary. Other polyamide components may be used alone or in combination of two or more in any ratio and combination.

  When the copolymerized polyamide resin containing the diamine component corresponding to the formula (7) as a constituent component contains other polyamide constituent components as constituent units, the proportion of the diamine component corresponding to the formula (7) in all the constituent components Although there is no limitation, it is usually 5 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, and usually 40 mol% or less, preferably 30 mol% or less. If the diamine component corresponding to the formula (7) is too much, the stability of the coating solution may be deteriorated, and if it is too little, the change in electrical characteristics under high temperature and high humidity conditions becomes large, and the electrical characteristics against environmental changes Stability may be degraded.

Specific examples of the copolymerized polyamide resin are shown below. However, in specific examples, the copolymerization ratio represents the monomer charge ratio (molar ratio).

  There is no restriction | limiting in particular in the manufacturing method of said copolyamide, The normal polycondensation method of polyamide is applied suitably. For example, a polycondensation method such as a melt polymerization method, a solution polymerization method, and an interfacial polymerization method can be appropriately applied. In the polymerization, for example, a monobasic acid such as acetic acid or benzoic acid; a monoacid base such as hexylamine or aniline may be contained in the polymerization system as a molecular weight regulator. In addition, these binder resin may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Moreover, you may use in the form hardened | cured with the hardening | curing agent. Among these, alcohol-soluble copolymerized polyamide, modified polyamide, and the like are preferable because they exhibit good dispersibility and coating properties.

-Number average molecular weight of binder resin:
There is no limitation on the number average molecular weight of the binder resin. For example, when a copolymerized polyamide is used as the binder resin, the number average molecular weight of the copolymerized polyamide is usually 10,000 or more, preferably 15000 or more, and usually 50000 or less, preferably 35000 or less. If the number average molecular weight is too small or too large, it is difficult to maintain the uniformity of the undercoat layer.

-Use ratio of metal oxide particles and binder resin:
The use ratio of the metal oxide particles and the binder resin is arbitrary as long as the effects of the present invention are not significantly impaired. However, the metal oxide particles are usually 0.5 parts by weight or more, preferably 0.7 parts by weight or more, more preferably 1.0 parts by weight or more, and usually 4 parts by weight with respect to 1 part by weight of the binder resin. The amount is preferably 3.8 parts by weight or less, more preferably 3.5 parts by weight or less. If the metal oxide particles are too small relative to the binder resin, the electrical characteristics of the photoreceptor may be deteriorated, and in particular, the residual potential may be increased. Moreover, when there are too many metal oxide particles with respect to binder resin, there exists a possibility that image defects, such as the black spot of a picture formed using the said photoreceptor and a color point, may increase.

(Additives that may be included in the undercoat layer)
The undercoat layer may contain components other than the metal oxide particles and the binder resin described above. Such components include, for example, antioxidants; heat stabilizers such as sodium phosphite, sodium hypophosphite, phosphorous acid, hypophosphorous acid, hindered phenols; additives such as polymerization additives; Is mentioned.
In addition, an additive may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Formation method of undercoat layer)
The undercoat layer is usually obtained by forming a coating solution for forming the undercoat layer. The film formation is usually performed by a coating method, and the undercoat layer is formed by drying the coating film of the applied coating solution. Usually, various physical properties of the undercoat layer are affected by physical properties of the coating solution for forming the undercoat layer.

  The content of the binder resin in the coating solution is arbitrary as long as the effects of the present invention are not significantly impaired. However, the content of the binder resin in the coating solution for forming the undercoat layer is usually 0.5% by weight or more, preferably 1% by weight or more, and usually 20% by weight or less, preferably 10% by weight or less. is there.

  Usually, the coating liquid for forming the undercoat layer is obtained by dissolving or dispersing the components constituting the undercoat layer in a solvent. As a solvent (undercoat layer solvent) used in the coating solution for forming the undercoat layer, any solvent can be used as long as it can dissolve the binder resin. As this solvent, an organic solvent is usually used. Examples of the solvent include alcohols having 5 or less carbon atoms such as methanol, ethanol, 1-propanol or 2-propanol; chloroform, 1,2-dichloroethane, dichloromethane, trichrene, carbon tetrachloride, 1,2-dichloropropane. Halogenated hydrocarbons such as: Nitrogen-containing organic solvents such as dimethylformamide; Aromatic hydrocarbons such as toluene and xylene.

  The said solvent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, even a solvent that does not dissolve the binder resin alone can be used as long as the binder resin can be dissolved by using a mixed solvent with another solvent (for example, the organic solvent exemplified above). . Usually, the use of a mixed solvent can reduce coating unevenness.

  In the coating liquid for forming the undercoat layer, the amount ratio between the solvent and the solid content of the metal oxide particles, binder resin, etc. varies depending on the coating method of the coating liquid for forming the undercoat layer, and is uniform in the applied coating method. So that a proper coating film can be formed.

  The coating liquid for forming the undercoat layer may contain components other than the metal oxide particles, the binder resin, and the solvent described above as long as the effects of the present invention are not significantly impaired. When the example of such a component is given, the thing similar to the additive which the undercoat layer may contain is mentioned.

  There is no restriction | limiting in particular in the manufacturing method of a coating liquid. However, the coating solution for forming the undercoat layer contains the metal oxide particles as described above, and the metal oxide particles are dispersed in the coating solution for forming the undercoat layer. Therefore, the method for producing the coating liquid for forming the undercoat layer usually has a dispersion step of dispersing the metal oxide particles.

[1-3-3. Photosensitive layer]
The photosensitive layer is formed on the above-described conductive support (when the above-described undercoat layer is provided, on the layer of the undercoat layer, that is, on the conductive support via the undercoat layer). As the structure of the photosensitive layer, any known structure can be used. As an example of a specific configuration, a laminated structure comprising two or more layers including a charge generation layer in which a charge generation material is dispersed in a binder resin and a charge transport layer in which a charge transport material is dispersed in a binder resin A single layer type photosensitive layer having a single phase structure in which a charge transport material and a charge generation material are both dispersed in a binder resin. In addition, in the laminated type photosensitive layer, there are a normal laminated type photoreceptor in which the charge generation layer and the charge transport layer are laminated in this order from the conductive support side, and a reverse laminated type photoreceptor in which the reverse order is laminated.

  In general, it is known that the charge generating material exhibits an equivalent function as a function of generating charge regardless of whether it is used for a single layer type photoreceptor or a laminated type photoreceptor. Therefore, in the present invention, the present invention can be applied to any type of photosensitive layer, but in particular, a sequentially laminated type photoreceptor capable of exhibiting balanced photoconductivity is preferable.

(Charge generating material)
As the charge generation material, as described above, at least one azo compound composition according to the present invention is used. Moreover, only 1 type may be used for the azo compound composition concerning this invention, and it may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, as long as the effects of the present invention are not significantly hindered, known charge generating substances can be used in any combination and ratio as described above.

(Laminated photosensitive layer)
When the photoreceptor of the present invention is a so-called multilayer photoreceptor, the layer containing the charge generation material is usually a charge generation layer. However, in the multilayer photoconductor, a charge generating material may be contained in the charge transport layer as long as the effects of the present invention are not significantly impaired.

-Charge generation layer:
The charge generation layer of the laminated photosensitive layer is formed containing a charge generation material. The charge generation layer may be configured as a vapor deposition film or the like formed of the above-described charge generation material alone, but is usually configured as a film in which the charge generation material is bound with a binder resin. In particular, when an organic pigment is used as the charge generation material, it is preferable to form a film in which the fine particles of the organic pigment are bound with a binder resin. Such a charge generation layer is prepared, for example, by dissolving or dispersing a charge generation material and a binder resin in a solvent or dispersion medium to prepare a coating solution, and this coating solution is a conductive support in the case of a sequentially laminated photosensitive layer. It can be obtained by coating and drying on the body (on the undercoat layer when an undercoat layer is provided) and on the charge transport layer in the case of a reverse lamination type photosensitive layer.

  There is no limitation on the binder resin used in the charge generation layer of the multilayer photosensitive layer, for example, polyvinyl acetal such as polyvinyl butyral resin, polyvinyl formal resin, partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal, acetal, or the like. Resin, polyarylate resin, polycarbonate resin, polyester resin, modified ether polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, Polyamide resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, vinyl chloride Vinyl chloride-vinyl acetate, such as ru-vinyl acetate copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer Copolymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, silicone-alkyd resin, insulating resin such as phenol-formaldehyde resin, poly-N-vinylcarbazole, polyvinylanthracene, polyvinyl Mention may be made of organic photoconductive polymers such as perylene. Also, for example, polyvinyl acetate, polyacrylic acid ester, polymethacrylic acid ester, polyvinyl acetoacetal, polyvinyl propional, cellulose ester, cellulose ether, butadiene, styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinyl Examples thereof include polymers and copolymers of vinyl compounds such as alcohol and ethyl vinyl ether, polyamides, silicon resins, and the like, but are not limited thereto as long as the effects of the present invention are not significantly impaired. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  Moreover, there is no restriction | limiting in the solvent and dispersion medium which melt | dissolve binder resin and are used for preparation of a coating liquid, Arbitrary solvents and dispersion media can be used. Specific examples thereof include cyclic saturated aliphatic, aromatic, halogenated aromatic, amide, alcohol, aliphatic polyhydric alcohol, chain and cyclic ketone, ester, halogenated hydrocarbon, chain and cyclic. Examples include ethers, aprotic polar substances, nitrogen-containing compounds, mineral oils such as ligroin, water, and the like. In addition, a solvent and / or a dispersion medium may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  Examples of the cyclic saturated aliphatic solvent or dispersion medium include pentane, hexane, octane, nonane, methylcyclohexane, ethylcyclohexane, and the like. Examples of the aromatic solvent or dispersion medium include toluene, xylene, anisole, and the like. Examples of the halogenated aromatic solvent or dispersion medium include chlorobenzene, dichlorobenzene, chloronaphthalene, and the like. Examples of the amide solvent or dispersion medium include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like. Examples of the alcohol solvent or dispersion medium include methanol, ethanol, isopropanol, n-butanol, and benzyl alcohol. Examples of the solvent or dispersion medium for aliphatic polyhydric alcohols include ethylene glycol, glycerin, polyethylene glycol, and the like. Examples of the solvent or dispersion medium for the chain and cyclic ketones include acetone, cyclohexanone, methyl ethyl ketone, and the like. Examples of the ester solvent or dispersion medium include methyl formate, ethyl acetate, and n-butyl acetate. Examples of the halogenated hydrocarbon solvent or dispersion medium include methylene chloride, chloroform, 1,2-dichloroethane, and the like. Examples of the chain or cyclic ether solvent or dispersion medium include diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, and ethylene glycol monomethyl ether. Examples of the aprotic polar solvent or dispersion medium include acetonitrile, N, N-dimethylformamide, 1,3-dimethyl-2-imidazolinone, N-methyl-2-pyrrolidone, γ-butyrolactone, dimethyl sulfoxide, sulfolane. , Hexamethylphosphoric triamide, and the like. Examples of the nitrogen-containing compound solvent or dispersion medium include n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, and triethylamine.

  Among the solvents or dispersion media, those that do not dissolve the undercoat layer are preferable. In addition, the said substance is an illustration, and unless the effect of this invention is impaired remarkably, it is not limited to these.

  The content ratio (weight ratio) between the binder resin and the charge generation material in the charge generation layer of the multilayer photosensitive layer is usually 30 parts by weight or more, preferably 50 parts by weight of the charge generation material with respect to 100 parts by weight of the binder resin. Part or more, and usually 500 parts by weight or less, preferably 300 parts by weight or less. When the ratio of the charge generation material is too high, the stability of the coating solution is reduced due to aggregation of the charge generation material, and when it is too low, the sensitivity as a photoreceptor may be reduced. Is preferably used. When a plurality of types of charge generation materials are used in combination, it is preferable that the total of these charge generation materials be within the above range.

  The thickness of the charge generation layer of the multilayer photosensitive layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.1 μm or more, preferably 0.15 μm or more, and usually 2 μm or less, preferably 0. 8 μm or less. Even if the film thickness is too thin or too thick, the electrical characteristics may be affected.

When dissolving or dispersing the charge generation material in a solvent or dispersion medium, the charge generation material is ground in a paint shaker, sand grind mill, ball mill, ultrasonic treatment, stirring, ball mill dispersion method, attritor dispersion method, sand mill. You may make it melt | dissolve or disperse | distribute arbitrarily using well-known refinement | miniaturization methods, such as a dispersion method, a planetary mill dispersion method, a roll mill dispersion method, and an ultrasonic dispersion method. At the time of dispersion, it is preferable that the volume average particle size of the charge generation material is reduced to a particle size of usually 1 μm or less, preferably 0.5 μm or less.
The volume average particle size of the charge generation material can be measured in the same manner as the volume average particle size of the metal oxide particles contained in the undercoat layer, or a particle size analysis by a known laser diffraction scattering method. It can also be measured by an apparatus, a particle size analyzer using a light transmission centrifugal sedimentation method, or the like.

-Charge transport layer:
As long as the charge transport layer of the multilayer photosensitive layer is a layer formed containing a charge transport material, it may be a single layer, or a stack of a plurality of layers having different components or composition ratios of components. It may be. The charge transport layer of the multilayer photosensitive layer preferably has a structure in which a charge transport material is bound with a binder resin. Such a charge transport layer is prepared by, for example, dissolving or dispersing a charge transport material and a binder resin in a solvent or a dispersion medium to prepare a coating solution. In the case of an inversely laminated photosensitive layer, it can be obtained by applying and drying in the form of a conductive support (on the undercoat layer when an undercoat layer is provided).

As long as the charge transporting substance is a substance that transports charges, any known compound can be used in any combination and ratio as long as the effect of the present invention is not significantly impaired.
However, since the forward-stacking type photosensitive layer functions when the light passing through the charge transport layer or the photosensitive layer reaches the charge generation material, these layers have excellent exposure light transmittance that does not block the exposure light. It is preferable. Therefore, it is preferable that the charge transport material and the binder resin have high compatibility and do not cause the constituent materials to precipitate or turbidity.

  Further, in the case of the charge transport layer of the sequential lamination type photosensitive layer, in order to form a good image, the transmittance of the exposure light wavelength in the charge transport layer is preferably 87% or more, more preferably 90% or more, and further preferably. Is preferably 93% or more, particularly preferably 95% or more. In particular, when the exposure light is monochromatic light having a wavelength of 380 nm or more and 500 nm or less, the transmittance of the exposure light in the charge transport layer is preferably in the above range.

The exposure light transmittance of the charge transport layer can be achieved, for example, by using the azo compound composition according to the present invention as a charge generation material and selecting an appropriate charge transport material. It can also be achieved by adjusting the thickness of the charge transport layer.
Any known method can be used for measuring the transmittance of exposure light. For example, the layer is formed on a transparent plate (for example, a quartz glass plate) at a measurement wavelength, and is commercially available. It can be measured with a spectrophotometer.

  Specific examples of such charge transport materials include diphenoquinone derivatives, aromatic nitro compounds such as 2,4,7-trinitrofluorenone, carbazole derivatives, indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, oxadi Heterocyclic compounds such as azole derivatives, pyrazoline derivatives, thiodiazole derivatives, nitrogen-containing compounds such as aniline derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine compounds, or a combination of these compounds, or Examples thereof include a polymer having a group consisting of these compounds in the main chain or side chain.

  Furthermore, as a charge transport material, the ionization potential is usually 4.8 eV or more, preferably 4.9 eV or more, more preferably 5.0 eV or more, usually 5.8 eV or less, preferably 5.7 eV or less, more preferably 5.6 eV or less is desirable. If the ionization potential of the charge transport material is too small, it tends to be weakened by ozone or the like, and if it is too large, the charge injection efficiency from the charge generation material tends to be poor. The ionization potential can be easily measured using a photoelectron spectrometer AC-1 (manufactured by Riken Keiki Co., Ltd.) in the atmosphere using a powder or a film.

Examples of the charge transport material having such an ionization potential include compounds represented by the following formula (8). Note that in the structure represented by the formula (8), an alkyl group, an alkoxy group, an aryl group, or the like may be substituted as a substituent in the skeleton.
(In the formula (8), Ar ^t1 to Ar ^t6 each independently represents an aromatic residue which may have a substituent, or an aliphatic residue which may have a substituent, and X ^t represents Independently represents an organic residue, R ^t1 to R ^t4 each independently represents an organic group, and n1 to n6 each independently represents an integer of 0 to 2.

In formula (8), Ar ^t1 to Ar ^t6 each independently represent an aromatic residue that may have a substituent or an aliphatic residue that may have a substituent.
The carbon number of the aromatic residue is usually 5 or more, preferably 6 or more, and usually 20 or less, preferably 16 or less, more preferably 10 or less, from the viewpoint of electrical characteristics. Examples of aromatic compounds corresponding to the aromatic residues include aromatic hydrocarbons such as benzene, naphthalene, anthracene, pyrene, perylene, phenanthrene, and fluorene; aromatic heterocycles such as thiophene, pyrrole, carbazole, and imidazole. And so on. Among the aromatic residues, an aromatic hydrocarbon residue is preferable, and a benzene residue is particularly preferable.

  On the other hand, the carbon number of the aliphatic residue is usually 1 or more, usually 20 or less, preferably 16 or less, more preferably 10 or less. Especially, when it is a saturated aliphatic residue, 6 or less carbon atoms are preferable, and when it is an unsaturated aliphatic residue, 2 or more carbon atoms are preferable. Examples of aliphatic compounds corresponding to the above aliphatic residues include saturated aliphatic compounds such as branched or straight-chain alkanes such as methane, ethane, propane, isopropane, isobutane, and unsaturated aliphatic compounds. Examples thereof include alkenes such as ethylene and butylene.

In addition, the aromatic residue or aliphatic residue that becomes Ar ^t1 to Ar ^t6 may be substituted with a substituent.
These substituents have the effect of adjusting the intramolecular charge and increasing the charge mobility when introduced, but if the bulk becomes too large, the substitution is caused by distortion of the conjugate plane in the molecule and intermolecular steric repulsion. There is a possibility of lowering the charge mobility. For this reason, the number of carbon atoms of the substituent is preferably 1 or more, preferably 6 or less, more preferably 4 or less, and particularly preferably 2 or less.

These substituents which may be substituted are not particularly limited, but examples include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group and allyl group; methoxy group, ethoxy group, propoxy An alkoxy group such as a group; an aryl group such as a phenyl group, an indenyl group, a naphthyl group, an acenaphthyl group, a phenanthryl group, and a pyrenyl group; and a heterocyclic group such as an indolyl group, a quinolyl group, and a carbazolyl group. In addition, these substituents may be linked to each other to form a ring.
Among these, a substituent that is not sterically bulky is preferable in terms of improving the stability of the charge transport material in the photosensitive layer and improving the electrical characteristics. Examples of such a suitable substituent include a methyl group, an ethyl group, a butyl group, an isopropyl group, and a methoxy group.

In particular, when Ar ^t1 to Ar ^t4 are benzene residues, it is preferable to have a substituent. In this case, preferable substituents are an alkyl group and an alkoxy group, and among them, a methyl group, an ethyl group, and a methoxy group are preferable. More preferably, it is a methyl group. Further, when Ar ^t5 to Ar ^t6 are benzene residues, preferred substituents are a methyl group and a methoxy group, and more preferably a methyl group.

In addition, when Ar ^t1 to Ar ^t6 have a substituent, it is preferable to have a plurality of substituents because crystal precipitation can be suppressed. However, if the amount is too large, charge transfer is rather caused by distortion of the conjugate plane in the molecule and intermolecular steric repulsion. There is a tendency to lower the degree. For this reason, when the aromatic residue or aliphatic residue which becomes Ar ^t1 to Ar ^t6 has a ring structure, the number of substituents per ring is preferably 2 or less.

In formula (8), ^Xt each independently represents an organic residue. Examples of this organic residue include an aromatic residue, a saturated aliphatic residue, a heterocyclic residue, an organic residue having an ether structure, and an organic residue having a divinyl structure, which may have a substituent. Etc. Among these, organic residues having 1 to 15 carbon atoms are preferable, and aromatic residues, saturated aliphatic residues, and organic residues having an ether structure are preferable. In the case of an aromatic residue, the number of carbon atoms is preferably 6 or more, preferably 14 or less, and more preferably 10 or less. In the case of a saturated aliphatic residue, the number of carbon atoms is preferably 1 or more, preferably 10 or less, more preferably 8 or less. In the case of an organic residue having an ether structure, the number of carbon atoms is preferably 1 or more, preferably 10 or less, and more preferably 6 or less.

The organic residue ^Xt may have a substituent in the structure exemplified above. The substituent is not particularly limited, but is an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or an allyl group; an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group; a phenyl group, an indenyl group, Examples thereof include aryl groups such as naphthyl group, acenaphthyl group, phenanthryl group and pyrenyl group; and heterocyclic groups such as indolyl group, quinolyl group and carbazolyl group. In addition, these substituents may be linked to each other to form a ring. Furthermore, the carbon number of these substituents is preferably 1 or more, preferably 10 or less, more preferably 6 or less, and particularly preferably 3 or less. Accordingly, examples of particularly suitable substituents include a methyl group, an ethyl group, a butyl group, an isopropyl group, and a methoxy group.

In addition, when the organic residue ^Xt has a substituent as described above, it is preferable that the organic residue ^Xt has a plurality of substituents because crystal precipitation can be suppressed. In some cases, the charge mobility tends to be lowered. Therefore, per one X ^t, the number of the substituents is preferably 2 or less.

  In formula (8), n1 to n4 each independently represents an integer of 0 or more and 2 or less. n1 is preferably 0 or 1, and n2 is preferably 0 or 1.

In formula (8), R ^t1 to R ^t4 each independently represents an organic group. The carbon number of R ^t1 to R ^t4 is preferably 30 or less, and more preferably 20 or less.
Further, those having a hydrazone structure in which a hydrogen atom is not directly conjugated to a nitrogen atom of the hydrazone and a stilbene structure are preferable. When R ^t1 to R ^t4 have a hydrazone structure, it is particularly preferable that carbon is bonded to a nitrogen atom.

In formula (8), n5 and n6 each independently represent an integer of 0 or more and 2 or less.
When n5 is 0, it represents that Ar ^t5 and Ar ^t6 are directly bonded, and when n6 is 0, n5 is preferably 0.
For n5 and n6 are both 1, X ^t is an alkylidene group, an arylene group, or preferably an organic residue having an ether structure. As the structure of the alkylidene group, a phenylmethylidene group, a 2-methylpropylidene group, a 2-methylbutylidene group, a cyclohexylidene group, and the like are preferable. Moreover, as a structure of an arylene group, a phenylene group, a naphthylene group, etc. are preferable. Moreover, as a structure of the organic residue having an ether structure, —O— (CH ₂ ) _n —O— (where n is an integer of 1 to 6) and the like are preferable. Among these, an organic residue having an alkylidene group or an ether structure is more preferable from the viewpoint of transmittance with respect to exposure light having a wavelength of 380 nm to 500 nm.
If n5 and n6 are both 0, ^{Ar t5} is preferably a benzene residue or a fluorene residue. When it is a benzene residue, the benzene residue is preferably substituted with an alkyl group and / or an alkoxy group, more preferably a methyl group and / or a methoxy group, and these substituents are represented by the formula It is particularly preferable to substitute at the p-position of the nitrogen atom specified in (8).
If n6 is 2, ^{X t} is preferably a benzene residue.

Examples of specific combinations of n1 to n6 include combinations shown in Table 1 below.

Specific examples of suitable structures of formula (8) are shown below. However, the charge transport material is not limited to the following exemplary structures. In the following exemplary structures, R ^t represents a hydrogen atom or a substituent. Here, as a substituent, an alkyl group, an alkoxy group, an aryl group or the like is preferable, and a methyl group or a phenyl group is more preferable. N7 is an integer of 0 to 2. Further, R ^t may be the same or different.

Among these, a compound having the following structure is particularly preferable because of its good effect.

Moreover, the compound represented by the following formula (9) is more preferable from the viewpoint of the electric characteristics of the electrophotographic photosensitive member.

In formula (9), R ^t7 and R ^t8 each independently represent a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or the like. R ^t9 and R ^t10 each independently represent an alkylene group which may have a substituent, or an arylene group which may have a substituent. R ^t11 , R ^t12 , R ^t13 and R ^t14 each independently represents an alkyl group which may have a substituent or an aryl group which may have a substituent. However, at least one of R ^{t11 to} R ^t14 is an aryl group having a substituent. In addition, the above-mentioned substituent may have one and may have two or more. When it has two or more, each may be the same substituent or different substituents. Moreover, when it is a different substituent, it can be used by arbitrary combinations and a ratio.

In formula (9), R ^t7 is preferably a group having a chiral center, and more preferably the chiral center is a carbon atom. The group bonded to the chiral center of R ^t7 is not particularly limited as long as it is not a substituent that deteriorates electrical properties such as a carbonyl group, an alkoxycarbonyl group, or a nitro group. The group bonded to the chiral center of R ^t7 is a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, And an aryl group which may have a substituent is preferred. Among these, a hydrogen atom, an alkyl group which may have a substituent, and an alkenyl group which may have a substituent are more preferable. Furthermore, a hydrogen atom or an alkyl group which may have a substituent is particularly preferable. The alkyl group for R ^t7 has usually 1 or more, preferably 2 or more, particularly preferably 3 or more, and is usually 20 or less, preferably 15 or less, particularly preferably 10 or less.

Examples of the substituent that the alkyl group, alkenyl group, alkynyl group, and aryl group may have as R ^t7 include a hydroxyl group, an optionally substituted methyl group, an ethyl group, and a propyl group. And an aryl group such as an optionally substituted phenyl group and an aryl group such as a naphthyl group, and an optionally substituted arylthio group such as a phenylthio group. Examples of the group that further substitutes the above substituent include an alkyl group such as a methyl group and a halogen atom such as a fluorine atom.

Examples of R ^t7 which is a group having at least one chiral center include a group represented by the following formula (10).

In formula (10), R ^t15 , R ^t16 , and R ^t17 are different from each other, and are a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent. Represents. Among them, two of R ^{t15 to} R ^t17 are alkyl groups that may have a substituent, and one is particularly preferably a hydrogen atom.

Examples of the alkyl group that may have a substituent of R ^{t15 to} R ^{t17 and} the substituent that the alkenyl group has include a hydroxyl group, a methyl group that may be further substituted, an ethyl group, and a propyl group. And an alkyl group such as a group, an aryl group such as an optionally substituted phenyl group and an naphthyl group, an arylthio group such as an optionally substituted phenylthio group, and the like.

  Examples of the group that further substitutes the above substituent include an alkyl group such as a methyl group and a halogen atom such as a fluorine atom.

In formula (9), R ^t8 represents, for example, a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. Among them, R ^t8 is preferably a hydrogen atom or an alkyl group which may have a substituent, and particularly preferably a hydrogen atom.

Moreover, as an example of the substituent which said alkyl group and an aryl group have, the substituent etc. which were mentioned in said ^{Rt15- Rt17} , etc. are mentioned, for example.

In formula (9), R ^t9 and R ^t10 each independently represent, for example, an alkylene group which may have a substituent or an arylene group which may have a substituent. Among them, as R ^t9 and R ^t10 , each independently preferably an arylene group which may have a substituent, more preferably a phenylene group, and a 1,4-phenylene group. Is particularly preferred.

Moreover, as an example of the substituent which said alkylene group and arylene group have, the substituent etc. which were mentioned in description of said ^{Rt15- Rt17} , etc. are mentioned, for example.

In formula (9), R ^t11 , R ^t12 , R ^t13 , and R ^t14 each independently represent an alkyl group that may have a substituent, or an aryl group that may have a substituent. Represent. However, at least one group of R ^{t11 to} R ^t14 is an aryl group having a substituent. That is, the other three groups may be an alkyl group which may have a substituent or an aryl group which may have a substituent. Above ^all, of R t11 ^{to R t14,} 2 or more groups, is preferably an aryl group which may have a substituent. Furthermore, it is particularly preferable that all groups are aryl groups which may have a substituent.

Specific examples of the aryl group include a phenyl group and a naphthyl group. ^Examples of the substituent include those similar to the substituents listed for R ^{t15 to} R ^t17 , and among them, an alkyl group is preferable, and 3-position or / and 4 with respect to the carbon atom bonded to the nitrogen atom. A tolyl group and a xylyl group having a substituted methyl group at the position are particularly preferred.

As the charge transport material, any known charge transport material may be used in place of the compound represented by the formula (8) or in combination with the compound represented by the formula (8). Examples of known charge transport materials include aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, electron withdrawing materials such as quinone compounds such as diphenoquinone, and carbazole derivatives. , Indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, benzofuran derivatives and other heterocyclic compounds, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives and multiple types of these compounds Or an electron donating substance such as a polymer having a group composed of these compounds in the main chain or side chain. Among these, carbazole derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of these compounds are bonded are preferable.
In addition, any one kind of charge transport materials may be used alone, or two or more kinds may be used in any combination.

  Examples of the binder resin used in the charge transport layer of the multilayer photoreceptor and the photosensitive layer of a single-layer photoreceptor described later include vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymers thereof. , Polycarbonate, polyester, polyester carbonate, polysulfone, polyimide, phenoxy resin, epoxy resin, silicone resin and the like. Moreover, although these partially crosslinked hardened | cured materials, what mixed these, etc. are mentioned, unless the effect of this invention is restrict | limited remarkably, it is not limited to this.

  Among them, preferred binder resins include polycarbonate resins and polyarylate resins. Polycarbonate resins and polyarylate resins usually have a partial structure of a diol component. Examples of the diol component forming these structures include bisphenol residues and biphenol residues.

  Specific examples of the compound having a bisphenol residue as a diol component include bis- (4-hydroxy-3,5-dimethylphenyl) methane, bis- (4-hydroxyphenyl) methane, and bis- (4-hydroxy-3- Methylphenyl) methane, 1,1-bis- (4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxyphenyl) propane, 2,2 -Bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxyphenyl) butane, 2,2-bis- (4-hydroxyphenyl) pentane, 2,2-bis- ( 4-hydroxyphenyl) -3-methylbutane, 2,2-bis- (4-hydroxyphenyl) hexane, 2,2-bis- (4-hydroxyphenyl) ) -4-methylpentane, 1,1-bis- (4-hydroxyphenyl) cyclopentane, 1,1-bis- (4-hydroxyphenyl) cyclohexane, bis- (3-phenyl-4-hydroxyphenyl) methane, 1,1-bis- (3-phenyl-4-hydroxyphenyl) ethane, 1,1-bis- (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis- (3-phenyl-4-hydroxy) Phenyl) propane, 1,1-bis- (4-hydroxy-3-methylphenyl) ethane, 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxy) -3-ethylphenyl) propane, 2,2-bis- (4-hydroxy-3-isopropylphenyl) propane, 2,2-bis- (4-hydroxy-) -Sec-butylphenyl) propane, 1,1-bis- (4-hydroxy-3,5-dimethylphenyl) ethane, 2,2-bis- (4-hydroxy-3,5-dimethylphenyl) propane, 1, 1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane, 1,1-bis- (4-hydroxy-3,6-dimethylphenyl) ethane, bis- (4-hydroxy-2,3,5- Trimethylphenyl) methane, 1,1-bis- (4-hydroxy-2,3,5-trimethylphenyl) ethane, 2,2-bis- (4-hydroxy-2,3,5-trimethylphenyl) propane, bis -(4-hydroxy-2,3,5-trimethylphenyl) phenylmethane, 1,1-bis- (4-hydroxy-2,3,5-trimethylphenyl) phenylethane 1,1-bis- (4-hydroxy-2,3,5-trimethylphenyl) cyclohexane, bis- (4-hydroxyphenyl) phenylmethane, 1,1-bis- (4-hydroxyphenyl) -1- Phenylethane, 1,1-bis- (4-hydroxyphenyl) -1-phenylpropane, bis- (4-hydroxyphenyl) diphenylmethane, bis- (4-hydroxyphenyl) dibenzylmethane, 4,4 ′-[1 , 4-phenylenebis (1-methylethylidene)] bis- [phenol], 4,4 ′-[1,4-phenylenebismethylene] bis- [phenol], 4,4 ′-[1,4-phenylenebis (1-Methylethylidene)] bis- [2,6-dimethylphenol], 4,4 ′-[1,4-phenylenebismethylene] bis- [2,6-di Tylphenol], 4,4 ′-[1,4-phenylenebismethylene] bis- [2,3,6-trimethylphenol], 4,4 ′-[1,4-phenylenebis (1-methylethylidene)] Bis- [2,3,6-trimethylphenol], 4,4 ′-[1,3-phenylenebis (1-methylethylidene)] bis- [2,3,6-trimethylphenol], 4,4′- Dihydroxydiphenyl ether, 4,4-bis (4-hydroxyphenyl) valeric acid stearyl ester, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenyl sulfide, 3,3 ′, 5,5′-tetramethyl- 4,4′-dihydroxydiphenyl ether, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenylsulfone, 3,3 , 5,5′-tetramethyl-4,4′-dihydroxydiphenyl sulfide, phenolphthalein, 4,4 ′-[1,4-phenylenebis (1-methylvinylidene)] bisphenol, 4,4 ′-[1 , 4-phenylenebis (1-methylvinylidene)] bis [2-methylphenol], (2-hydroxyphenyl) (4-hydroxyphenyl) methane, (2-hydroxy-5-methylphenyl) (4-hydroxy-3 -Methylphenyl) methane, 1,1- (2-hydroxyphenyl) (4-hydroxyphenyl) ethane, 2,2- (2-hydroxyphenyl) (4-hydroxyphenyl) propane, 1,1- (2-hydroxy) Phenyl) (4-hydroxyphenyl) propane, and the like.

  Specific examples of the compound having a biphenol residue as a diol component include 4,4′-biphenol, 2,4′-biphenol, 3,3′-dimethyl-4,4′-dihydroxy-1,1′-. Biphenyl, 3,3′-dimethyl-2,4′-dihydroxy-1,1′-biphenyl, 3,3′-di- (t-butyl) -4,4′-dihydroxy-1,1′-biphenyl, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxy-1,1′-biphenyl, 3,3 ′, 5,5′-tetra- (t-butyl) -4,4′- And dihydroxy-1,1′-biphenyl, 2,2 ′, 3,3 ′, 5,5′-hexamethyl-4,4′-dihydroxy-1,1′-biphenyl, and the like.

  Among these, particularly preferred compounds include bis- (4-hydroxy-3,5-dimethylphenyl) methane, bis- (4-hydroxyphenyl) methane, bis- (4-hydroxy-3-methylphenyl) methane, 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 1,1-bis- (4-hydroxyphenyl) ethane, 2,2-bis- (4-hydroxyphenyl) propane, 2-hydroxyphenyl Examples of the compound include bisphenol residues such as (4-hydroxyphenyl) methane and 2,2- (2-hydroxyphenyl) (4-hydroxyphenyl) propane.

Hereinafter, although the diol component (bisphenol residue, biphenol residue, etc.) of a preferable polycarbonate resin is illustrated, a diol component is not limited to the following.

In particular, in order to exert the effect of the present invention greatly, a diol component having the following structure is preferable.

In order to improve mechanical properties, it is preferable to use polyarylate. In this case, it is preferable to use a compound having the following structure as the diol component.

Furthermore, it is preferable to use a compound having the following structure as the dicarboxylic acid component.

Among these, a dicarboxylic acid component having the following structure is particularly preferable.

These dicarboxylic acid components and diol components may be used alone or in combination of two or more in any combination and ratio.
Moreover, binder resin may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  If the molecular weight of the binder resin in the charge transport layer of the laminated photosensitive layer is too low, the mechanical strength may be insufficient. Conversely, if the molecular weight is too high, the viscosity of the coating solution for forming the photosensitive layer is too high. Productivity may be reduced. Therefore, for example, in the case of polycarbonate resin and polyarylate resin, the viscosity average molecular weight is usually 10,000 or more, preferably 20,000 or more, and usually 100,000 or less, more preferably 70,000 or less.

  The content ratio (weight ratio) between the binder resin and the charge transport material in the charge transport layer of the multilayer photoconductor is usually 30 parts by weight or more, preferably 40 parts by weight or more with respect to 100 parts by weight of the binder resin. The amount is usually 200 parts by weight or less, preferably 150 parts by weight or less. This is because if the ratio of the charge transport material is too high, the mechanical strength of the charge transport layer may decrease, whereas if the ratio of the charge transport material is too low, the electrical characteristics may deteriorate. . When a plurality of types of charge generation materials are used in combination, it is preferable that the total of these charge generation materials be within the above range.

  The thickness of the charge transport layer of the multilayer photosensitive layer is usually 5 μm or more, preferably 8 μm or more, and usually 45 μm or less, preferably 35 μm or less. This is because if the film thickness is too thin, the life of the photoconductor tends to be shortened due to wear, and if the film thickness is too thick, the resolution of the image tends to deteriorate due to diffusion of exposure light and charges. That is, by adjusting the film thickness of the charge transport layer, the degree of exposure light reaching the charge generation material can also be adjusted.

(Single layer type photosensitive layer)
The single-layer type photosensitive layer preferably has a configuration in which the charge generating substance is dispersed in a layer having the same configuration as the charge transport layer of the multilayer photoconductor. Specifically, the single-layer type photosensitive layer is dissolved or dispersed in the solvent or dispersion medium using the charge generation material, the charge transport material, and the binder resin used for the charge transport layer in the multilayer type photosensitive layer. Then, a coating solution is prepared, and can be obtained by applying and drying on a conductive support (on the undercoat layer when an undercoat layer is provided).

  The kind of the charge transport material and the binder resin, the ratio of use (weight ratio), and the like are the same as those described for the charge transport layer of the laminated photosensitive layer. A charge generating material is further dispersed in the layer comprising these charge transporting material and binder resin.

As the charge generation material, the same materials as those described for the charge generation layer of the laminated photosensitive layer can be used. However, in the case of a single-layer type photosensitive layer, it is preferable to make the particle size of the charge generating material sufficiently small. Specifically, it is usually 1 μm or less, preferably 0.5 μm or less. The particle size can be measured by, for example, a laser diffraction scattering method.
If the amount of the charge generating material dispersed in the single-layer type photosensitive layer is too small, sufficient sensitivity may not be obtained. On the other hand, if the amount is too large, chargeability and sensitivity may be lowered. is there. Therefore, the charge generating material is used in an amount of usually 0.5% by weight or more, preferably 1% by weight or more, and usually 50% by weight or less, preferably 20% by weight or less based on the entire monolayer type photosensitive layer.

  The thickness of the photosensitive layer of the single-layer type photoreceptor is arbitrary as long as the effects of the present invention are not significantly impaired, but are usually 5 μm or more, preferably 10 μm or more, and usually 50 μm or less, preferably 45 μm or less. This is because if the film thickness is too thin, the life of the photoconductor tends to be shortened due to wear, and if the film thickness is too thick, the resolution of the image tends to deteriorate due to diffusion of exposure light and charges.

  The content ratio (weight ratio) between the binder resin and the charge generating material in the single-layer type photosensitive layer is usually 1 part by weight or more, preferably 2 parts by weight or more, and usually 10 parts by weight or more with respect to 100 parts by weight of the binder resin. The amount is not more than parts by weight, preferably not more than 8 parts by weight.

  Since the single-layer type photosensitive layer functions when the light passing through the photosensitive layer reaches the charge generation material, it is preferable that these layers have excellent exposure light transmittance so as not to block exposure light. . Therefore, it is preferable that the charge transport material and the binder resin have high compatibility and do not cause the constituent materials to precipitate or turbidity.

The exposure light transmittance of the charge transport layer and the charge transport material is achieved by selecting an appropriate charge transport material, for example, using a compound represented by the above-described preferred specific example of the charge transport material as the charge transport material. Is possible. It can also be achieved by adjusting the thickness of the charge transport layer.
Any known method can be used for measuring the transmittance of exposure light. For example, the layer is formed on a transparent plate (for example, a quartz glass plate) at a measurement wavelength, and is commercially available. It can be measured with a spectrophotometer.

(Additive)
The multilayer type photosensitive layer and the single layer type photosensitive layer are used for the purpose of improving, for example, film forming property, flexibility, coating property, stain resistance, gas resistance, light resistance, etc. in the photosensitive layer or each layer constituting the photosensitive layer. For example, additives such as known plasticizers, antioxidants, ultraviolet absorbers, electron-withdrawing compounds, leveling agents, and surfactants may be contained.

  For example, examples of additives used in the charge transport layer include well-known plasticizers and cross-linking agents, antioxidants, stabilizers used to improve film formability, flexibility, and mechanical strength. Examples include sensitizers, various leveling agents for improving coating properties, and additives such as dispersion aids. Examples of the plasticizer include aromatic compounds such as phthalic acid esters, phosphoric acid esters, epoxy compounds, chlorinated paraffins, chlorinated fatty acid esters, and methylnaphthalene. Examples of the antioxidant include hindered phenol compounds and hindered amine compounds. Examples of the leveling agent include silicone oil and fluorine oil. In addition, an additive may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Surface layer)
In both the laminated type photosensitive layer and the single layer type photosensitive layer, the photosensitive layer formed by the above procedure may be the uppermost layer, that is, the surface layer, but another layer may be provided on the photosensitive layer, and this may be used as the surface layer. .
For example, a protective layer may be provided for the purpose of preventing or reducing mechanical deterioration such as wear of the photosensitive layer and electrical deterioration of the photosensitive layer due to discharge products generated from a charger or the like. The protective layer is formed, for example, by containing a conductive material in a suitable binder resin, or a co-polymer using a compound having a charge transporting ability such as a triphenylamine skeleton described in JP-A-9-190004. Coalescence can be used.

  Examples of the conductive material used for the protective layer include aromatic amino compounds such as TPD (N, N′-diphenyl-N, N′-bis- (m-tolyl) benzidine), antimony oxide, indium oxide, tin oxide, Metal oxides such as titanium oxide, tin oxide-antimony oxide, aluminum oxide, and zinc oxide can be used, but are not limited thereto. In addition, these electroconductive materials may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

  As the binder resin used for the protective layer, for example, a known resin such as polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, or siloxane resin may be used. it can. Also, a copolymer of the resin and a skeleton having a charge transporting ability such as a triphenylamine skeleton as described in JP-A-9-190004 can be used. In addition, these binder resin may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

The electrical resistance of the protective layer is preferably in the range of usually 10 ⁹ Ω · cm or more and 10 ¹⁴ Ω · cm or less. If the electric resistance is higher than the above range, the residual potential tends to increase and an image with a lot of fog tends to be formed. On the other hand, if the electric resistance is lower than the above range, the image tends to be blurred or the resolution is lowered. Further, the protective layer is usually configured so as not to substantially prevent the transmission of light irradiated during image exposure.

  In addition, for the purpose of reducing the frictional resistance and wear on the surface of the photoconductor, and increasing the transfer efficiency of the toner from the photoconductor to the transfer belt and paper, the surface layer is made of, for example, a fluorine resin, silicone resin, polyethylene, etc. Resin or the like, particles made of these resins, or particles of an inorganic compound may be contained in the surface layer. Moreover, you may form the layer containing these resin and particle | grains newly as a surface layer. In addition, these resin and particle | grains may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

(Method for forming each layer)
The photosensitive layer of the photoreceptor of the present invention is usually formed by repeating the steps of sequentially applying and drying the coating solution obtained by dissolving or dispersing the substance to be contained in a solvent or dispersion medium for each layer. Is done. The kind of the solvent or dispersion medium used in this case is not limited, and one kind may be used alone, or two or more kinds may be used in any composition ratio. In consideration of the purpose of each layer and the properties of the selected solvent and dispersion medium, it is preferable to appropriately adjust the physical properties such as solid content concentration and viscosity of the coating solution within a desired range.

  As the solvent or dispersion medium used for preparing the coating solution for coating and forming each layer constituting the photoreceptor, for example, the same solvent or dispersion medium as described in the section of the charge generation layer can be used.

  These solvents and dispersion media may be used alone or in combination of two or more in any combination and ratio. Moreover, the said solvent and a dispersion medium are examples, and if it does not restrict | limit the effect of this invention remarkably, it will not be limited to the above.

  As a coating method of the photosensitive layer, for example, a spray coating method, a spiral coating method, a ring coating method, a dip coating method, or the like can be used. As the spray coating method, any known spray method can be used. For example, a method using air spray, airless spray, electrostatic air spray, electrostatic airless spray, rotary atomizing electrostatic spray, hot spray, hot airless spray, or the like can be used. In addition, the application | coating method may be performed individually by 1 type, and may be performed combining 2 or more types arbitrarily.

  Among them, in order to obtain the atomization degree and adhesion efficiency for obtaining a uniform film thickness, in the rotary atomizing electrostatic spray, the conveying method disclosed in the republication No. 1-805198, that is, cylindrical It is preferable that the workpiece is continuously conveyed without being spaced apart in the axial direction while rotating the workpiece. As a result, an electrophotographic photoreceptor excellent in film thickness uniformity with high overall adhesion efficiency can be obtained.

  As the spiral coating method, any known spiral coating method can be used. For example, a method using an injection coating machine or a curtain coating machine disclosed in Japanese Patent Application Laid-Open No. 52-119651, a paint from a minute opening disclosed in Japanese Patent Application Laid-Open No. A method of flying continuously, a method using a multi-nozzle body disclosed in JP-A-3-193161, and the like can be used.

As the dip coating method, any method can be used as long as it is a known dip coating method.
At this time, in the case of applying a coating solution for a single layer type photosensitive layer and a charge transport layer of a laminated type photosensitive layer, the solid content concentration of the coating solution is usually 5% by weight or more, preferably 10% by weight or more, More preferably, it is 15% by weight or more, usually 60% by weight or less, preferably 50% by weight or less, more preferably 35% by weight or less. The viscosity of the coating solution is usually 30 mPa · s or higher, preferably 50 mPa · s or higher, more preferably 100 mPa · s or higher, and usually 800 mPa · s or lower, preferably 700 mPa · s or lower, more preferably 500 mPa · s. The following range.

  When applying a coating solution for the charge generation layer of the laminated photosensitive layer, the solid content concentration of the coating solution is usually 0.5% by weight or more, preferably 1% by weight or more, and usually 20% by weight or less. , Preferably 15% by weight or less, more preferably 10% by weight or less. The viscosity of the coating solution is preferably in the range of 0.1 mPa · s or more, more preferably 0.5 mPa · s or more, and usually 20 mPa · s or less, preferably 10 mPa · s or less, more preferably 5 mPa · s or less. And

  As a drying method, for example, a hot air dryer, a steam dryer, an infrared dryer, a far-infrared dryer, or the like can be used, but the drying method is not limited thereto. The coating film may be dried at room temperature or the drying temperature may be adjusted as appropriate. The drying temperature may be a constant temperature or may be varied during the drying process. When adjusting the drying temperature, it is usually 100 ° C or higher, preferably 110 ° C or higher, more preferably 120 ° C or higher, and usually 250 ° C or lower, preferably 170 ° C or lower, more preferably 140 ° C or lower. If the drying temperature is too high, bubbles may be mixed into the photosensitive layer. If the drying temperature is too low, it takes time to dry, and the amount of residual solvent increases, which may adversely affect electrical characteristics. . Also, the drying time is not limited, and can be arbitrarily set within a range that does not significantly limit the effect of the present invention. In addition, also as a drying method, 1 type may be performed independently and 2 or more types may be performed by arbitrary ratios and combinations.

[1-4. Advantages of electrophotographic photosensitive member of the present invention]
The photoreceptor of the present invention has high spectral sensitivity at a wavelength of 380 nm to 500 nm. Therefore, when image formation is performed using monochromatic light having a wavelength of 380 nm to 500 nm, the photoconductor of the present invention has high sensitivity, low residual potential, and faithfully electrostatic exposure to high resolution exposure. It is possible to form a latent image.
Furthermore, the photoconductor of the present invention is usually a highly sensitive photoconductor that matches well with a toner whose particle size is controlled, such as the toner according to the present invention described later.

[2. toner]
In the case of forming an image using the photoreceptor of the present invention, any toner can be used. In particular, the use of the first toner and / or the second toner described below has a specific effect. Is preferable. The first toner and the second toner are suitable for use as an electrostatic image developing toner.

[2-1. First toner]
The first toner according to the present invention has an average circularity measured by a flow type particle image analyzer of the first toner of 0.940 or more, preferably 0.942 or more, and usually 1.000 or less. When the degree of circularity is high, the cleaning property may be deteriorated, so that it is preferably 0.990 or less, more preferably 0.980 or less, and still more preferably 0.970 or less. Since the spherical toner having a high degree of circularity is less likely to get caught between toners or various members, the mechanical share at the charging roller is small, and the surface shape change is slight. Further, since the fluidity of the toner base itself is high, even if the amount of the externally added inorganic powder changes, the fluidity hardly changes greatly. As described above, a toner having a high degree of circularity has a form factor with less toner deterioration. Furthermore, toner having a high degree of circularity is excellent in releasability from the photosensitive member, and therefore has an excellent transfer efficiency, a sufficient image density can be ensured, and a residual toner can be reduced.

  However, toner having a high average circularity tends to increase the weakly charged toner ratio WST [%] measured by the E-SPART analyzer, which indicates that the toner scattering tends to deteriorate. Further, a toner having a high average circularity tends to pass through the cleaning blade when the transfer residual toner is scraped off with a cleaning blade, and tends to cause an image to be stained. In addition, the above phenomenon becomes more remarkable when performing high-speed printing. Therefore, the average circularity of the first toner according to the present invention is preferably 0.97 or less, more preferably 0.96 or less. Further, toner having a small particle size and high circularity is difficult to scrape off with a cleaning blade, and the toner easily passes through the cleaning blade. Therefore, the particle size distribution can be controlled particularly according to the circularity. preferable.

[Measurement method and definition of average circularity]
The “average circularity” in the present invention is measured as follows and is defined as follows. That is, the toner base particles are dispersed in a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) in a range of 5720 / μL or more and 7140 / μL or less, and a flow type particle image analyzer (Sysmex Corporation (formerly Toa) Using FPIA 2100) manufactured by Medical Electronics Co., Ltd., measurement is performed under the following apparatus conditions, and the value is defined as “average circularity”. In the case where the toner is obtained by fixing or adhering an external additive to the surface of the toner base particles, it is measured as a measurement sample.
・ Mode: HPF
-HPF analysis amount: 0.35 μL
-HPF detection number: 2000-2500

The following is measured by the apparatus and automatically calculated and displayed in the apparatus. The “circularity” is defined by the following equation.
[Circularity] = [Perimeter of a circle with the same area as the projected particle area] / [Perimeter of projected particle image]
Then, 2000 or more and 2500 or less, which is the number of HPF detected, is measured, and the arithmetic average (arithmetic mean) of the circularity of each particle is displayed on the apparatus as “average circularity”.

[2-2. Second toner]
The second toner according to the present invention satisfies all of the following (i) to (iii).
(I) The volume median diameter (Dv50) is 4.0 μm or more and 7.0 μm or less.
(Ii) The average circularity is 0.93 or more.
(Iii) The relationship between the volume median diameter (Dv50) of the toner and the number% (Dns) of the toner having a particle diameter of 2.00 μm to 3.56 μm satisfies Dns ≦ 0.233EXP (17.3 / Dv50). Fulfill.

About (i) The volume median diameter (Dv50) of the second toner according to the present invention is 4.0 μm or more and 7.0 μm or less. Within this range, a high-quality image can be sufficiently provided. Among them, from the viewpoint of enabling high-quality image formation, it is preferable that the thickness is preferably 6.8 μm or less, more preferably 6.5 μm or less. Further, from the viewpoint of reducing the amount of very fine toner powder (hereinafter sometimes referred to as “fine powder” as appropriate), it is preferably 4.5 μm or more, more preferably 5.0 μm or more, and particularly preferably 5 μm. .3 μm or more.

[Measurement method and definition of volume median diameter (Dv50)]
The “volume median diameter (Dv50)” in the present invention is measured as follows and is defined as follows.
That is, in a cylindrical polyethylene (PE) beaker having an inner diameter of 47 mm and a height of 51 mm, 0.100 g of toner using a spatula and 20 wt% sodium dodecylbenzenesulfonate aqueous solution (hereinafter referred to as “DBS aqueous solution” as appropriate) using a dropper. Is added 0.15 g. At this time, the toner and the 20% DBS aqueous solution are added only to the bottom of the beaker so that the toner does not scatter on the edge of the beaker.
Next, the mixture is stirred for 3 minutes using a spatula until the toner and 20% DBS aqueous solution become a paste. At this time, the toner should be prevented from being scattered on the edge of the beaker.

  Subsequently, 30 g of a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) is added, and the mixture is stirred for 2 minutes using a spatula, and the whole is made into a uniform solution visually. Next, a fluororesin-coated rotor having a length of 31 mm and a diameter of 6 mm is placed in a beaker and dispersed using a stirrer at 400 rpm for 20 minutes. At this time, macroscopic particles visually observed at the gas-liquid interface and the edge of the beaker are dropped into the beaker at a rate of once every 3 minutes so as to form a uniform dispersion. Subsequently, this is filtered through a mesh having a mesh size of 63 μm, and the obtained filtrate is defined as a “toner dispersion”.

The volume median diameter (Dv50) of toner is Multisizer III (aperture diameter 100 μm; hereinafter abbreviated as “Multisizer”) manufactured by Beckman Coulter, and Isoton II manufactured by the same company is used as a dispersion medium. The “toner dispersion liquid” is diluted to a dispersoid concentration of 0.03% by weight and measured with Multisizer III analysis software with a KD value of 118.5. The measurement particle size range is from 2.00 to 64.00 μm, and this range is discretized into 256 divisions at equal intervals on a logarithmic scale, and the volume calculated based on the statistical values on the basis of the volume The median diameter (Dv50).
In the case where the toner is obtained by fixing or adhering an external additive to the surface of the toner base particles, it is measured as a measurement sample.

Regarding (ii) The second toner according to the present invention has an average circularity of 0.93 or more and preferably 0.94 or more. Furthermore, it is more preferable to have the same average circularity as the first toner. This is for the same reason as the first toner.
In the second toner according to the present invention, the definition and measurement method of the average circularity is the same as that of the first toner according to the present invention.

Regarding (iii) In the second toner according to the present invention, the relationship between the volume median diameter (Dv50) of the toner and the number% (Dns) of toner having a particle diameter of 2.00 μm to 3.56 μm is
Dns ≦ 0.233EXP (17.3 / Dv50)
Meet. In the present specification, “EXP” indicates “Exponential”. That is, the base of the natural logarithm, and the right side is the exponent. This formula is sometimes referred to as “requirement (iii) formula”.

  The expression of requirement (iii) is intended to indicate that fine powder increases as the volume median diameter (Dv) of the second toner decreases, and the volume median diameter (Dv) is 4 In the region of .5 μm or less, the volume median diameter (Dv) approaches the region of particle size of 2.00 μm or more and 3.56 μm or less, so that the value of Dns increases exponentially. Such an area of 2.00 μm or more and 3.56 μm or less is an area expressed by a specified channel of Multisizer III manufactured by Coulter Counter.

  In the second toner according to the present invention, the toner particles included in the particle diameter range of 2.00 μm to 3.56 μm have a volume median diameter (Dv) of 4.0 μm to 7.0 μm. This is the particle size range that should be specifically excluded in the region (see requirement (i)), the basis of which follows experimental results.

  The second toner according to the present invention in which the particle size distribution satisfies the requirement (iii) provides high image quality, and is less contaminated even when a high-speed printing machine is used. (Following flatness) is suppressed and the cleaning property is excellent. In addition, since the charge amount distribution is very sharp because the particle size distribution is sharp, toner particles with a small charge amount do not cause smearing of the white background portion of the image or scattering to contaminate the inside of the apparatus. In addition, toner particles having a large charge amount do not develop and adhere to members such as a layer regulating blade and a roller to cause image defects such as streaks and blurring, and “selective development” hardly occurs. Note that “selective development” is a phenomenon in which only toner having a charge amount necessary for development is developed and consumed when the toner charge amount distribution is broad.

  That is, the amount of fine powder affects the image with the formula of the requirement (iii) as a boundary. When the value of Dns exceeds the right side in the expression of requirement (iii), fine powder tends to cause defects in the image. For example, as shown in FIG. 2, fine powder may accumulate on the cleaning blade, and afterimages, blurring, dirt, and the like may occur as image defects. FIG. 2 is a 1000 × magnification scanning electron microscope (SEM) photograph showing an example of the state of toner adhesion on the cleaning blade after evaluation of the actual image of the toner.

  An image forming apparatus is usually designed to transfer toner particles having a specific charge amount. For this reason, first, toner particles having such a specific charge amount are preferentially transferred to the photoreceptor during electrostatic development. The toner particles exceeding the specific charge amount may adhere to the member or the like and may be contaminated or fluidity may be deteriorated. On the other hand, toner particles that are less than the specific charge amount may accumulate in the cartridge and contaminate members and the like.

  Here, the toner charge amount correlates with the toner particle size when the toner composition is the same. Generally, the smaller the particle size, the higher the charge amount per unit weight, and the larger the particle amount, the smaller the charge amount per unit weight. Become. That is, when a large amount of toner having a small particle size is present, the charge amount becomes too high, and thus tends to cause adhesion to a member or the like and deterioration of toner fluidity. When the second toner according to the present invention is used, the above-described “selective development” is suppressed. The requirement (iii) is defined by the toner of 3.56 μm or less.

This 3.56 μm is a value defined for the channel of the measuring apparatus. On the other hand, the lower limit value was set to 2.00 μm because of the measurement limit of the measuring apparatus.
That is, the reason why the particle number% (Dns) is specified to be 2.00 μm or more and 3.56 μm or less is used for measuring the particle size of the second toner according to the present invention. It is a measurement limit of the apparatus, and the upper limit value is a critical value of the effect obtained from the results described in the examples. Accordingly, if the number% of the toner having a particle size larger than 3.56 μm is adopted, it becomes difficult to clearly separate the toner that exhibits the effect of the present invention from the toner that does not perform the effect according to the formula.

Further, in the second toner according to the present invention, the relationship between the volume median diameter (Dv50) and the number% (Dns) of the toner having a particle diameter of 2.00 μm to 3.56 μm is expressed by the following formula (iii-1). Satisfying is preferable from the viewpoint of the effect.
Dns ≦ 0.110EXP (19.9 / Dv50) (iii-1)

On the other hand, in the second toner according to the present invention, the relationship between the volume median diameter (Dv50) and the number% (Dns) of toner having a particle diameter of 2.00 μm or more and 3.56 μm or less is represented by the following formula (iii-2). It is preferable from the viewpoint of producing with good yield.
0.0517EXP (22.4 / Dv50) ≦ Dns (iii-2)

In addition, it is preferable that the second toner according to the present invention has a Dns of 6% by number or less because it can provide a higher quality image or hardly contaminate the image forming apparatus.
Further, the above-described preferred particle diameter ranges of the volume median diameter (Dv50) and Dns, for example, the conditions such as “Dv50 is 4.5 μm or more” and “Dns is 6% by number or less” are satisfied in combination. More preferably. As a result, it is possible to provide a high-quality image without deteriorating the yield from the viewpoint of production, and to realize a toner that hardly contaminates the image forming apparatus and hardly causes “selective development”.

[Measurement Method and Definition of Number% (Dns) of Toner with Particle Size of 2.00 μm to 3.56 μm]
The “number% (Dns) of toner having a particle size of 2.00 μm to 3.56 μm” in the present invention is measured as follows and is defined as follows.
That is, 0.100 g of toner is added to a cylindrical polyethylene (PE) beaker having an inner diameter of 47 mm and a height of 51 mm using a spatula and 0.15 g of a 20 wt% DBS aqueous solution using a dropper. At this time, the toner and the 20% DBS aqueous solution are added only to the bottom of the beaker so that the toner does not scatter on the edge of the beaker.
Next, the mixture is stirred for 3 minutes using a spatula until the toner and 20% DBS aqueous solution become a paste. At this time, the toner should be prevented from being scattered on the edge of the beaker.

  Subsequently, 30 g of dispersion medium Isoton II is added, and the mixture is stirred for 2 minutes using a spatula to make the whole visually uniform solution. Next, a fluororesin-coated rotor having a length of 31 mm and a diameter of 6 mm is placed in a beaker and dispersed using a stirrer at 400 rpm for 20 minutes. At this time, macroscopic particles visually observed at the gas-liquid interface and the edge of the beaker are dropped into the beaker at a rate of once every 3 minutes so as to form a uniform dispersion. Subsequently, this is filtered through a mesh having a mesh size of 63 μm, and the obtained filtrate is defined as a “toner dispersion”.

  For the number% (Dns) of the toner having a particle size of 2.00 μm or more and 3.56 μm or less, Multisizer (aperture diameter 100 μm) is used, Isoton II made by the same company is used as a dispersion medium, and the above “toner dispersion liquid” is used. The dispersion is diluted to a concentration of 0.03% by weight and measured with Multisizer III analysis software with a KD value of 118.5. The lower limit particle size of 2.00 μm is the detection limit of the measuring device multisizer, and the upper limit particle size of 3.56 μm is a prescribed channel value in the measuring device multisizer. In the second toner according to the present invention, an area having a particle diameter of 2.00 μm or more and 3.56 μm or less is recognized as a fine powder area.

The measurement particle size range is from 2.00 μm to 64.00 μm, and this range is discretized into 256 divisions at equal intervals on a logarithmic scale, and 2.00 μm based on the statistical values on the basis of their number. The ratio of the particle size component from 3 to 3.56 μm is calculated on the basis of the number and is defined as “Dns”.
In the case where the toner is obtained by fixing or adhering an external additive to the surface of the toner base particles, it is measured as a measurement sample.

[Advantages of the second toner according to the present invention]
Hereinafter, the advantages of the second toner according to the present invention will be described in comparison with the prior art.
In recent years, the use of image forming apparatuses such as electrophotographic copying machines has been expanded, and the market demand for image quality has been increasing. Particularly in office documents, in addition to the development of mapping technology and latent image forming technology for input, the types of character hieroglyphics are becoming more abundant and finer at the time of output. In addition, with the spread and development of presentation software, the reproducibility of an electrostatic latent image with extremely high image quality, which has few defects and unclearness in printed images, is required. In particular, as a toner used when the electrostatic latent image on the electrostatic latent image carrier (here, the photosensitive member) constituting the image forming apparatus is a line image of 100 μm or less (approximately 300 dpi or more), a conventional particle size is used. With a large toner, fine line reproducibility is generally poor, and the sharpness of the line image is still not sufficient.

  In particular, in an image forming apparatus such as an electrophotographic printer using a digital image signal, an electrostatic latent image is formed by gathering a certain number of dot units, and a solid portion, a halftone portion, and a light portion have a dot density. It is expressed by changing. However, if the toner is not arranged faithfully in the dot unit and the mismatch between the position of the dot unit and the position of the actually placed toner occurs, this corresponds to the ratio of the dot density of the black portion and the white portion of the digital latent image. There is a possibility that the gradation of the toner image cannot be obtained. Further, when the resolution is improved by reducing the dot size in order to improve the image quality, it tends to become more difficult to be faithful to an electrostatic latent image formed from minute dots. For this reason, although the resolution is high, there is an undeniable tendency for the image to have poor gradation and lack sharpness.

In view of this, a technique has been proposed in which the toner particle size distribution is regulated to improve the reproducibility of minute dots and improve the image quality.
For example, JP-A-2-284158 proposes a toner having an average particle diameter of 6 to 8 μm. This technique has attempted to form an electrostatic latent image of fine dots with high reproducibility by reducing the particle size.

Further, for example, Japanese Patent Laid-Open No. 5-119530 discloses a toner mother particle having a toner having a weight average particle diameter of 4 to 8 μm and further containing 17 to 60% by number of toner mother particles having a particle diameter of 5 μm or less. Is described.
Further, for example, JP-A-1-221755 describes a magnetic toner containing 17 to 60 number% of magnetic toner base particles having a particle size of 5 μm or less.

For example, Japanese Patent Laid-Open No. 6-289648 describes toner base particles in which the content of toner base particles having a particle size of 2.0 to 4.0 μm is 15 to 40% by number in the toner particle size distribution. ing.
Furthermore, for example, Japanese Patent Application Laid-Open No. 2001-134005 describes a toner having about 15 to 65% by number of particles of 5 μm or less. Similar toners are also disclosed in JP-A-11-147331 and JP-A-11-362389.

For example, JP-A-2-000877 contains 17 to 60% by number of toner base particles having a particle size of 5 μm or less, and 1 to 30 toner base particles having a particle size of 8 to 12.7 μm. Toner having a specific particle size distribution in a toner having a volume average particle diameter of 4 to 10 μm and a toner having a specific particle size distribution is described. ing.
Further, Japanese Patent Application Laid-Open No. 2004-045948 discloses that in a toner particle having a 50% volume particle diameter of 2 to 8 μm, the number of toner particles having a particle diameter of “0.7 × 50% number particle diameter” or less is 10 number%. It is described that:

  However, all of these toners contain a large number of particles having a particle size of 3.56 μm or less exceeding the upper limit of the right side in the formula of requirement (iii) of the present invention. Is a toner in which a relatively large amount of fine powder remains with respect to toner having a predetermined particle size. In such a toner, since the proportion of fine powder is still large, particularly in a developing method that requires a momentary frictional charging, such as a non-magnetic one-component developing method, a toner that has a fast charge rising is required, toner particles that are not sufficiently charged are generated. Therefore, the toner drops from the developing roller and blows out the toner, the printing history of the first round remains after the second round of the developing roller, and the image density selectively increases and decreases (ghost), the drum cleaning failure, the developing roller Contamination of the printed image may occur due to poor toner layer formation.

  Further, in recent years, along with market demand for image quality, there has been a demand for toner having a long life and high-speed printing. However, these required characteristics have not been sufficiently satisfied with the conventional toner. If there is a lot of fine powder like conventional toner, the fine powder will contaminate the member with continuous printing, the charge imparting ability to the toner will be reduced and the image will be distorted, and if it is introduced into a high speed printer, toner scattering will be noticeable was there.

  Also, in order to provide high image printing, it is desirable that the toner particle size distribution be sharp. This is because, when coarse powder (that is, very large toner particles) is contained, the toner charge amount distribution becomes broad and “selective development” occurs. When the selection phenomenon occurs, a good image can be obtained at the initial stage of image formation. However, as the image formation continues, the density may gradually decrease or the particle size of the toner may increase, resulting in a sticky image. . Such a phenomenon is said to be inferior in selective developability. Furthermore, the coarse powder having a low charge amount tends to significantly reduce the guaranteed life number. Japanese Patent Application Laid-Open No. 2003-255567 discloses a toner having a large number of coarse powders with a number variation coefficient of 24.2%. Such a toner is not suitable for stably providing a high-resolution image. In addition, International Publication No. 2004-088431 pamphlet does not indicate that the particle size distribution is sharp.

  Further, it is desirable to pay attention to toner transfer characteristics in order to realize high-quality image formation. The toner having high transfer characteristics refers to toner having high transfer efficiency of toner particles developed on the photoreceptor to the intermediate transfer drum or paper, or high transfer efficiency from the intermediate transfer drum to paper. However, JP-A-7-098521, JP-A-2006-091175, and JP-A-2006-119616 describe pulverized toner having a high average circularity from the viewpoint of the manufacturing process, and have high transfer characteristics. Insufficient to provide quality printing.

  As described above, the toner used in the conventional image forming apparatus does not satisfy any of the above requirements (i) to (iii). The reason for this is that if the amount of fine powder is reduced as much as possible (that is, if the requirement (iii) is satisfied), the generation of coarse powder tends to occur. Further, trying to round the toner by physical impact (that is, satisfying the requirement (ii)) promotes the generation of fine powder (that is, the requirement (iii) is not satisfied). This is because the. Furthermore, if the toner is intended to be circularized by thermal fusion (that is, if the requirement (ii) is satisfied), toner particles tend to be fused with each other and coarse powder tends to be generated.

  On the other hand, the second toner according to the present invention satisfies all of the above (i) to (iii). The second toner that satisfies all the requirements (i), (ii), and (iii) according to the present invention can obtain high image quality, and has little stains even when used in a high-speed printing machine, resulting in an afterimage (ghost). In addition, it suppresses blurring (solid followability) and is excellent in cleaning properties. In addition, since the charge amount distribution is very sharp because the particle size distribution is sharp, particles with a small charge amount do not cause the white background portion of the image to be smeared or scattered to stain the inside of the apparatus, The toner particles having a large charge amount do not develop and adhere to members such as a layer regulating blade and a roller, thereby causing image defects such as streaks and blurring. That is, the “selective development” described above is unlikely to occur.

  In particular, the second toner according to the present invention has a very sharp charge amount distribution as compared with the conventional toner. The charge amount distribution has a correlation with the particle size distribution of the toner. When the toner has a broad particle size distribution like a conventional toner, the charge amount distribution is also broad. When the charge amount distribution becomes broad, the ratio of particles with low charge or particles with high charge that cannot be controlled by the developing conditions of the image forming apparatus for the toner increases, causing various image defects. . For example, toner particles with a small charge amount cause smearing of the white background of the image or scattering in the apparatus, causing smearing. In addition, toner particles having a large charge amount accumulate on members such as a layer regulating blade and a roller in a developing tank without being developed, and cause image defects such as streaks and blurring due to fusion.

  This is because the development process conditions are set so as to match the average value of the toner charge amount in the design of the development process in the image forming apparatus. This is because the image forming apparatus tends to cause image defects such as scattering and streaks. Therefore, the toner having a broad particle size distribution does not match well with the image forming apparatus. On the other hand, if the charge amount distribution is sharp as in the second toner according to the present invention, the developability can be controlled by bias adjustment or the like, and the image forming apparatus member is not contaminated. An image can be given.

  The “standard deviation of charge amount”, which is one of the values indicating the “charge amount distribution” of the second toner according to the present invention, is preferably 1.0 or more, more preferably 1.3 or more, and 2. 0 or less is preferable, 1.8 or less is more preferable, and 1.5 or less is particularly preferable. When the upper limit is exceeded, toner adheres to the layer regulation blade and is difficult to be transported, and the adhered toner may further block the transported toner and contaminate members in the image forming apparatus. On the other hand, when the value falls below the lower limit, it may not be preferable from an industrial viewpoint.

  As described above, since the second toner according to the present invention has a sharp charge amount distribution, the contamination (toner scattering) in the image forming apparatus caused by the poorly charged toner is very small. This effect is remarkably exhibited particularly in a high-speed type image forming apparatus in which the developing process speed to the photosensitive member is 100 mm / second or more.

In addition, the second toner according to the present invention has a sharp charge amount distribution, so that the developability is very good, and toner particles that accumulate without being developed are very few. This is particularly effective in an image forming apparatus having a high toner consumption speed. Specifically, a toner used in an image forming apparatus that satisfies the following formula (iv) is preferable in order to sufficiently exhibit the effects of the present invention.
Warranty life sheet number (sheets) x printing rate ≧ 400 (sheets) of toner filling machine (iv)
In the formula (iv), the “printing rate” is represented by a value obtained by dividing the sum of the printed portion areas by the total area of the printing medium in the printed matter for determining the guaranteed lifetime number that is the performance of the image forming apparatus. The “print rate” of the print% of “5%” is “0.05”.

  Furthermore, since the second toner according to the present invention has a very sharp particle size distribution, the reproducibility of the electrostatic latent image is very good. Therefore, the effect of the second toner according to the present invention is sufficiently exhibited particularly when used in an image forming apparatus having a resolution of 600 dpi or more on the photosensitive member. Further, by using such toner, the image forming apparatus can provide a high-resolution image with a resolution of 600 dpi or more on the photosensitive member. “Resolution to photoconductor” is the same as “resolution of device”.

[2-3. Other physical properties of toner according to the present invention]
The toner according to the present invention, such as the first toner and the second toner according to the present invention, preferably has the physical properties described below in addition to the physical properties described above.

  Among the peak molecular weights of the toner according to the present invention in gel permeation chromatography (hereinafter sometimes abbreviated as “GPC”) of a soluble content in tetrahydrofuran (hereinafter sometimes abbreviated as “THF” where appropriate), at least One is preferably 30,000 or more, more preferably 40,000 or more, still more preferably 50,000 or more, preferably 200,000 or less, more preferably 150,000 or less, and even more preferably 100,000 or less. When the peak molecular weight is lower than the above range, the mechanical durability in the non-magnetic one-component development method may be deteriorated. When the peak molecular weight is higher than the above range, the low temperature fixability and the fixing strength are deteriorated. There is a case.

  Further, the chargeability of the toner according to the present invention may be positively charged or negatively charged, but is preferably used as a negatively chargeable toner. Control of the chargeability of the toner can be adjusted by selection and content of the charge control agent, selection and blending amount of the external additive, and the like.

[2-4. Configuration of Toner According to the Present Invention]
Each of the toners according to the present invention, such as the first toner and the second toner according to the present invention, is configured by appropriately selecting a binder resin, a colorant, a wax, an external additive, and the like.
The binder resin may be appropriately selected from those known to be used for toner. For example, styrene resin, vinyl chloride resin, rosin modified maleic acid resin, phenol resin, epoxy resin, saturated or unsaturated polyester resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, Ethylene-acrylate copolymer, xylene resin, polyvinyl butyral resin, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-anhydrous malein An acid copolymer etc. can be mentioned. These resins may be used alone or in combination of two or more in any combination and ratio.

  The colorant constituting the toner according to the present invention may be appropriately selected from those known to be usable for toner. For example, yellow pigments, magenta pigments, and cyan pigments shown below can be used. As black pigments, carbon black or a mixture of the following yellow pigments / magenta pigments / cyan pigments toned to black is used. .

  Among these, carbon black as a black pigment exists as an aggregate of very fine primary particles, and when dispersed as a pigment dispersion, particle coarsening due to reaggregation tends to occur. The degree of reagglomeration of carbon black particles correlates with the amount of impurities contained in carbon black (the degree of residual undecomposed organic matter). If there are many impurities, coarsening due to reaggregation after dispersion tends to be severe. Indicates. As a quantitative evaluation of the amount of impurities, the ultraviolet absorbance of the toluene extract of carbon black measured by the following method is preferably 0.05 or less, and more preferably 0.03 or less. Generally, carbon black produced by the channel method tends to have a large amount of impurities, so that carbon black produced by the furnace method is preferred.

  The ultraviolet absorbance (λc) of carbon black is measured by the following method. First, 3 g of carbon black was sufficiently dispersed and mixed in 30 mL of toluene. Filter using 5C filter paper. Thereafter, the filtrate was put in a quartz cell having a 1 cm square light absorption part, and the value (λs) measured for absorbance at a wavelength of 336 nm using a commercially available ultraviolet spectrophotometer, and the value obtained by measuring the absorbance of toluene alone as a reference using the same method. From (λo), the ultraviolet absorbance is obtained by λc = λs−λo. Examples of commercially available spectrophotometers include an ultraviolet-visible spectrophotometer (UV-3100PC) manufactured by Shimadzu Corporation.

  As the yellow pigment, for example, a compound represented by a condensed azo compound, an isoindolinone compound or the like is used. As a specific example, C.I. I. CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 150, 155, 168, 180, 194, etc. are preferably used. It is done.

  Examples of magenta pigments include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. As a specific example, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 17.3, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, C.I. I. Pigment Violet 19 or the like is preferably used. Among them, C.I. I. Pigment red 122, 202, 207, 209, C.I. I. A quinacridone pigment represented by pigment violet 19 is particularly preferred. Among the quinacridone pigments, C.I. I. A compound represented by CI Pigment Red 122 is particularly preferable.

Examples of cyan pigments that can be used include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like. As a specific example, C.I. I. Pigment blue 1, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like; I. Pigment Green 7, 36, etc. can be used particularly preferably.
In addition, a colorant may be used individually by 1 type and may be used 2 or more types by arbitrary combinations and ratios.

  The toner according to the present invention preferably contains a wax for imparting releasability. Any wax can be used as long as it has releasability, and is not particularly limited. Specific examples include olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene and copolymer polyethylene; paraffin wax; ester waxes having a long-chain aliphatic group such as behenyl behenate, montanate ester, stearyl stearate; Plant waxes such as hydrogenated castor oil and carnauba wax; ketones having long chain alkyl groups such as distearyl ketone; silicones having alkyl groups; higher fatty acids such as stearic acid; long chain aliphatic alcohols such as eicosanol; glycerin and penta Examples include carboxylic acid esters or partial esters of polyhydric alcohols obtained from polyhydric alcohols such as erythritol and long chain fatty acids; higher fatty acid amides such as oleic acid amide and stearic acid amide; low molecular weight polyesters and the like.

  In order to improve the fixability among these waxes, the melting point of the wax is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher. Moreover, 100 degrees C or less is preferable, 90 degrees C or less is still more preferable, and 80 degrees C or less is especially preferable. If the melting point is too low, the wax tends to be exposed and sticky after fixing, and if the melting point is too high, the fixability at low temperatures tends to be poor. Furthermore, as the wax compound species, ester waxes obtained from aliphatic carboxylic acids and mono- or polyhydric alcohols are preferred, and ester waxes having 20 to 100 carbon atoms are preferred.

  The said wax may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Further, the melting point of the wax compound can be appropriately selected depending on the fixing temperature for fixing the toner. The amount of the wax used is preferably 4 parts by weight or more, more preferably 6 parts by weight or more, particularly preferably 8 parts by weight or more, preferably 20 parts by weight or less, more preferably 18 parts by weight with respect to 100 parts by weight of the toner. Or less, particularly preferably 15 parts by weight or less.

  When the volume median diameter (Dv50) of the toner is 7 μm or less, that is, when the toner has a small particle size, the exposure of the wax to the toner surface becomes extremely intense as the amount of wax used increases. The storage stability of the toner tends to deteriorate. The second toner according to the present invention has a sharp particle size distribution that does not cause deterioration of the toner characteristics as compared with the conventional toner even when the amount of wax used is large as in the above range. The toner has a particle size.

  The toner according to the present invention may be one in which a known external additive is blended on the surface of the toner base particles in order to control fluidity and developability. Examples of the external additive include metal oxides and hydroxides such as alumina, silica, titania, zinc oxide, zirconium oxide, cerium oxide, talc, hydrotalcite; calcium titanate, strontium titanate, barium titanate, etc. Metal nitrides such as titanium nitride and silicon nitride; carbides such as titanium carbide and silicon carbide; organic particles such as acrylic resins and melamine resins; Among these, silica, titania, and alumina are preferable, and those that have been surface-treated with, for example, a silane coupling agent or silicone oil are more preferable. In addition, only 1 type may be used for an external additive, and it may combine 2 or more types by arbitrary combinations and a ratio.

The average primary particle size of the external additive is usually 1 nm or more, preferably 5 nm or more, and usually 500 nm or less, preferably 100 nm or less. It is also preferable to use a combination of a small particle size and a large particle size in the particle size range.
The total amount of the external additive is usually 0.05 parts by weight or more, preferably 0.1 parts by weight or more, and usually 10 parts by weight or less, preferably 5 parts by weight with respect to 100 parts by weight of the toner base particles. It is as follows.

  By the way, the toner according to the present invention can be used for a magnetic two-component development system in which a carrier for conveying the toner to the electrostatic latent image portion by a magnetic force coexists, or a magnetic one-component development in which magnetic powder is contained in the toner. It may be used for either a non-magnetic one-component development method that does not use magnetic powder in the toner, but in order to exhibit the effects of the present invention remarkably, it is particularly suitable for a non-magnetic one-component development method. It is preferably used as a toner.

When used as a toner for the magnetic two-component development system, the carrier that can be mixed with the toner is a known magnetic substance such as an iron powder type, ferrite type, or magnetite type carrier; A magnetic resin carrier or the like can be used. As the carrier coating resin, for example, generally known styrene resins, acrylic resins, styrene acrylic copolymer resins, silicone resins, modified silicone resins, fluorine resins, and the like can be used. Is not to be done. In addition, a carrier may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
The average particle size of the carrier is not particularly limited, but those having an average particle size of 10 μm or more and 200 μm or less are preferable.
These carriers are preferably used in an amount of 5 to 100 parts by weight per 1 part by weight of the toner.

[2-5. Toner production method]
The method for producing the toner according to the present invention is not particularly limited. For example, the toner is produced by a pulverization method or a method of forming particles in an aqueous medium (hereinafter sometimes abbreviated as “wet method”). Can do. As the wet method, a method of performing radical polymerization in an aqueous medium such as a suspension polymerization method or an emulsion polymerization aggregation method (hereinafter abbreviated as “polymerization method”, and the obtained toner may be abbreviated as “polymerization toner” in some cases. And a chemical pulverization method typified by a melt suspension method can be preferably used.
Further, there is no particular limitation on the method for making the toner have a particle size in a specific range according to the present invention. For example, in the production process of the polymerized toner, in the case of the suspension polymerization method, a method in which a high shearing force is applied in the process in which polymerizable monomer droplets are generated, or a dispersion stabilizer or the like is increased.

  When toner is produced by a pulverization method, it is generally desirable to perform a classification step because fine powder is likely to be generated. In particular, in order to satisfy the toner particle size requirement according to the present invention, an excessive classification operation may be necessary in the pulverization method, and the yield may be significantly reduced. However, the pulverized toner is not excluded as the toner used in the image forming apparatus of the present invention. On the other hand, the toner according to the present invention is preferably obtained by a wet method in which particles are formed in an aqueous medium from the viewpoint that fine powder is hardly generated and a classification step is not essential.

  As a method for obtaining a toner having a specific particle size distribution according to the present invention, any of a pulverization method; a polymerization method such as a suspension polymerization method and an emulsion polymerization aggregation method; a chemical pulverization method typified by a melt suspension method, etc. Manufacturing methods can also be used. However, in the “pulverization method”, “suspension polymerization method”, and “chemical pulverization method represented by the melt suspension method”, in order to adjust the particle diameter of the toner from a larger size to a smaller size, When trying to reduce the particle size, the proportion of the particles on the small particle side tends to increase, and an excessive burden is imposed on the classification step and the like. In contrast, the emulsion polymerization agglomeration method has a relatively sharp particle size distribution and is adjusted from a size smaller than the diameter of the toner base particles to a larger size. A toner having a diameter distribution is obtained. Therefore, it is particularly preferable to produce the toner according to the present invention by the emulsion polymerization aggregation method for the above reasons.

[Method for producing toner by emulsion polymerization aggregation method]
The following is a method for producing particles by performing polymerization in an aqueous medium from the viewpoint of hardly generating fine powder among methods for forming particles in an aqueous medium, and further a method for producing particles by an emulsion polymerization aggregation method. Will be described. When a toner is produced by an emulsion polymerization aggregation method, a polymerization process, a mixing process, an aggregation process, an aging process (rounding process), and a washing / drying process are usually performed. That is, generally, a dispersion liquid containing primary polymer particles obtained by emulsion polymerization is mixed with a dispersion liquid such as a colorant, a charge control agent, and wax, and the primary particles in the dispersion liquid are aggregated to form core particles. Then, if necessary, the toner base particles can be obtained by washing and drying the particles obtained by fusing and adhering the resin fine particles or the like as necessary.

(Polymerization process)
In this production method, usually, a polymerization step for producing polymer primary particles by emulsion polymerization is performed. Usually, a raw material polymerizable monomer is polymerized by emulsion polymerization to produce polymer primary particles containing a desired binder resin.
As the binder resin constituting the polymer primary particles used in the emulsion polymerization aggregation method, one or two or more polymerizable monomers that can be polymerized by the emulsion polymerization method are appropriately used, and those obtained by emulsion polymerization of the polymerizable monomer are used. What is necessary is just to use. Examples of the polymerizable monomer include “a polymerizable monomer having an acidic group” (hereinafter sometimes simply referred to as “acidic monomer”), “a polymerizable monomer having a basic group” (hereinafter simply referred to as “basic monomer”). "Polymerizable monomer having a polar group" (hereinafter sometimes referred to simply as "polar monomer") and "polymerizability having neither an acidic group nor a basic group" It is preferable to use “monomer” (hereinafter sometimes referred to as “other monomer”) as a raw material polymerizable monomer. At this time, each polymerizable monomer may be mixed separately, or a plurality of polymerizable monomers may be mixed in advance and then mixed simultaneously. Further, it is possible to change the composition of the polymerizable monomer during the mixing of the polymerizable monomer. The polymerizable monomer may be mixed as it is, or may be mixed as an emulsion prepared by mixing with water or an emulsifier in advance.

  Examples of the “acidic monomer” include polymerizable monomers having a carboxyl group such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and cinnamic acid; polymerizable monomers having a sulfonic acid group such as sulfonated styrene A polymerizable monomer having a sulfonamide group such as vinylbenzenesulfonamide; Examples of the “basic monomer” include aromatic vinyl compounds having an amino group such as aminostyrene; nitrogen-containing heterocyclic ring-containing polymerizable monomers such as vinylpyridine and vinylpyrrolidone; These polar monomers may be used alone or in combination of two or more in any combination and ratio. Furthermore, it may exist as a salt with a counter ion. Among these, it is preferable to use an acidic monomer, and (meth) acrylic acid is more preferable.

  The proportion of the total amount of polar monomers in 100% by weight of all polymerizable monomers constituting the binder resin as the polymer primary particles is preferably 0.05% by weight or more, more preferably 0.3% by weight or more, The content is preferably 0.5% by weight or more, particularly preferably 1% by weight or more, preferably 10% by weight or less, more preferably 5% by weight or less, and still more preferably 2% by weight or less. When it is within the above range, the dispersion stability of the obtained polymer primary particles is improved, and the particle shape and particle size can be easily adjusted in the aggregation process.

Examples of the “other monomer” include styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, pn-nonylstyrene; methyl acrylate, Acrylic esters such as ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate , Methacrylates such as isobutyl methacrylate, hydroxyethyl methacrylate, ethylhexyl methacrylate; acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylic acid De, N, N-dibutyl acrylamide, acrylic acid amides such as acrylamide; and the like.
In addition, a polymerizable monomer may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  Among the above-described polymerizable monomers used in combination, as a preferred embodiment, an acidic monomer and other monomers may be used in combination. More preferably, (meth) acrylic acid is used as the acidic monomer, and a polymerizable monomer selected from styrenes and (meth) acrylic acid esters is used as the other monomer. It is preferable to use (meth) acrylic acid as the monomer, and use a combination of styrene and (meth) acrylic acid esters as the other monomer, and particularly preferably use (meth) acrylic acid as the acidic monomer. As a combination of styrene and n-butyl acrylate.

  Furthermore, it is also preferable to use a crosslinked resin as the binder resin constituting the polymer primary particles. In that case, as a crosslinking agent shared with the above-mentioned polymerizable monomer, for example, a polyfunctional monomer having radical polymerization is used. Examples of the multifunctional monomer include divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol acrylate, diallyl phthalate, and the like. Is mentioned. In addition, a polymerizable monomer having a reactive group in a pendant group such as glycidyl methacrylate, methylol acrylamide, acrolein or the like can be used as a crosslinking agent. Among them, radically polymerizable bifunctional monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable.

These crosslinking agents such as multifunctional monomers may be used alone or in combination of two or more in any combination and ratio.
When a crosslinked resin is used as the binder resin constituting the polymer primary particles, the blending ratio of the crosslinking agent such as a polyfunctional monomer in the total polymerizable monomer constituting the binder resin is preferably 0.005% by weight or more. More preferably, it is 0.1% by weight or more, more preferably 0.3% by weight or more, preferably 5% by weight or less, more preferably 3% by weight or less, still more preferably 1% by weight or less.

  Known emulsifiers can be used for the emulsion polymerization. For example, one or more emulsifiers selected from cationic surfactants, anionic surfactants and nonionic surfactants are used in combination. Can be used.

  Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide and the like.

  Examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium lauryl sulfate.

  Nonionic surfactants include, for example, polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc. Is mentioned.

  The amount of the emulsifier used is usually 1 part by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the polymerizable monomer. Moreover, 1 type, or 2 or more types, such as cellulose derivatives, such as polyvinyl alcohols, such as a partial or complete saponified polyvinyl alcohol, and hydroxyethyl cellulose, can be used together with these emulsifiers as a protective colloid.

Examples of the polymerization initiator include hydrogen peroxide; persulfates such as potassium persulfate; organic peroxides such as benzoyl peroxide and lauroyl peroxide; 2,2′-azobisisobutyronitrile; Azo compounds such as 2′-azobis (2,4-dimethylvaleronitrile); redox initiators and the like are used. In addition, a polymerization initiator may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The polymerization initiator is usually used in an amount of 0.1 to 3 parts by weight based on 100 parts by weight of the polymerizable monomer. Especially, as a polymerization initiator, it is preferable that at least one part or all is hydrogen peroxide or organic peroxides.

  Any of the polymerization initiators may be mixed into the polymerization system at any time before, simultaneously with, and after mixing of the polymerizable monomers, and these mixing methods may be combined as necessary.

In the emulsion polymerization, a known chain transfer agent can be used as necessary. Specific examples of the chain transfer agent include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropyl xanthogen, carbon tetrachloride, trichlorobromomethane and the like. A chain transfer agent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. The amount used is usually in the range of 5% by weight or less based on the total polymerizable monomer.
Moreover, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, etc. can be further mix | blended with a reaction system suitably.

  In the emulsion polymerization, the polymerizable monomer is polymerized in the presence of a polymerization initiator. The polymerization temperature is usually 50 ° C. or higher, preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and usually 120 ° C. or lower. Preferably it is 100 degrees C or less, More preferably, it is 90 degrees C or less.

  The volume average diameter (Mv) of the polymer primary particles obtained by emulsion polymerization is usually 0.02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and usually 3 μm or less, preferably 2 μm or less. More preferably, it is 1 μm or less. When the particle size is less than the above range, it may be difficult to control the aggregation rate. When the particle size exceeds the above range, the particle size of the toner obtained by aggregation tends to be large, and a toner having a target particle size can be obtained. It can be difficult.

  The glass transition temperature by DSC method (differential scanning calorimetry) of the binder resin as the polymer primary particles is preferably 40 ° C. or higher, more preferably 55 ° C. or higher, preferably 80 ° C. or lower, more preferably 65 ° C. It is as follows. Within this range, the storage stability is good and, in addition, the cohesiveness is not impaired. If the glass transition temperature is too high, the cohesiveness of the polymer primary particles is poor, and there is a tendency to use an aggregating agent excessively or to increase the agglomerating temperature excessively, resulting in generation of fine powder. May be easier to do. Here, if the glass transition temperature of the binder resin overlaps with the heat amount change based on other components, for example, the melting peak of polylactone or wax, and cannot be clearly determined, the toner is removed in a state where such other components are excluded. It shall mean the glass transition temperature when produced.

  The acid value of the binder resin constituting the polymer primary particles is preferably 3 mgKOH / g or more, more preferably 5 mgKOH / g or more, preferably 50 mgKOH / g or less, more preferably as a value measured by the method of JIS K0070. Is 30 mgKOH / g or less.

  The lower limit of the solid content concentration of the polymer primary particles in the “polymer primary particle dispersion” is preferably 14% by weight or more, more preferably 21% by weight or more, while the upper limit thereof. The value is preferably 30% by weight or less, and more preferably 25% by weight or less. When it is within the above range, it is easy to adjust the aggregation rate of the polymer primary particles empirically in the aggregation process, and as a result, it is easy to adjust the particle size, particle shape, and particle size distribution of the core particles to an arbitrary range. It becomes.

(Mixing process)
In this production method, after the polymerization step, it is preferable to perform a mixing step of mixing a dispersion liquid containing primary particles of polymer obtained by emulsion polymerization with a dispersion liquid containing a colorant, a charge control agent, a wax and the like. . As a result, the primary particles in the dispersion liquid are agglomerated to form core particles (preferably after a shell coating step for fixing or adhering resin fine particles or the like), and the obtained particles are washed and dried. By doing so, toner mother particles can be obtained.

  The colorant is not particularly limited as long as it is a commonly used colorant. Examples thereof include the pigments described above, carbon black such as furnace black and lamp black, and magnetic colorants. The content ratio of the colorant may be an amount sufficient for the obtained toner to form a visible image by development, and is preferably 1 part by weight or more, more preferably 3 parts by weight or more in the toner, Moreover, 25 weight part or less is preferable, 15 weight part or less is more preferable, and 12 weight part or less is especially preferable.

The colorant may be a magnetic colorant having magnetism. Examples of the magnetic colorant include a ferromagnetic material exhibiting ferrimagnetism or ferromagnetism in the vicinity of 0 ° C. to 60 ° C., which is a use environment temperature of a printer, a copying machine, and the like, specifically, for example, magnetite (Fe ₃ O ₄ ), Maghematite (γ-Fe ₂ O ₃ ), intermediates and mixtures of magnetite and maghemite, M _x Fe _3-x O ₄ , where M is Mg, Mn, Fe, Co, Ni, Cu, Zn represents Cd or the like.) spinel _{ferrite, BaO · 6Fe 2 O 3,} 6 -cubic ferrite such as _{SrO · 6Fe 2 O 3, Y} 3 Fe 5 O 12, Sm 3 Fe 5 O garnet-type oxides such as ₁₂ , rutile-type oxide such as CrO _2, and, Cr, Mn, Fe, Co, include those exhibiting magnetism in the vicinity of 0 ° C. to 60 ° C. of such metal or their ferromagnetic alloys such as Ni, But, magnetite, intermediates maghemite or magnetite and maghemite are preferred.
In addition, a coloring agent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  When it is contained from the viewpoint of preventing scattering and charging control while having the characteristics as a non-magnetic toner, the content of the magnetic powder in the toner is usually 0.2% by weight or more, preferably 0.5% by weight. % Or more, more preferably 1% by weight or more, and usually 10% by weight or less, preferably 8% by weight or less, more preferably 5% by weight or less. When used as a magnetic toner, the content of the magnetic powder in the toner is usually 15% by weight or more, preferably 20% by weight or more, and usually 70% by weight or less, preferably 60% by weight or less. . If the content of the magnetic powder is less than the above range, the magnetic force required for the magnetic toner may not be obtained, and if it exceeds the above range, it may cause poor fixing properties.

  As a blending method of the colorant in the emulsion polymerization aggregation method, usually, a polymer primary particle dispersion and a colorant dispersion are mixed to form a mixed dispersion, and then aggregated to obtain a particle aggregate. The colorant is preferably used in the state of being emulsified in water by a mechanical means such as a sand mill or a bead mill in the presence of an emulsifier. In this case, it is preferable that the colorant dispersion is added in an amount of 10 to 30 parts by weight, and 1 to 15 parts by weight of an emulsifier with respect to 100 parts by weight of water. In addition, mixing is performed while monitoring the particle size of the colorant in the dispersion during the dispersion, and finally the volume average diameter (Mv) is preferably 0.01 μm or more, more preferably 0.05 μm or more, It is preferable to control within a range of preferably 3 μm or less, more preferably 0.5 μm or less. The blending of the colorant dispersion at the time of emulsion aggregation is usually used by calculating so as to be 2 wt% or more and 10 wt% or less in the finished toner mother particles after aggregation.

  The toner preferably contains a wax in order to improve the fixing property. The wax may be contained in the polymer primary particles or in the resin fine particles. However, as the amount of wax used increases, the aggregation control tends to deteriorate and the particle size distribution tends to become broader. Therefore, as a method of blending the wax in the emulsion polymerization aggregation method, a wax dispersion in which the volume average diameter (Mv) is usually 0.01 μm or more in water and usually emulsified and dispersed to 2.0 μm or less, preferably 0.5 μm or less. It is preferable that the liquid is mixed at the time of emulsion polymerization or mixed in the aggregation process. In order to disperse the wax with a suitable dispersed particle size in the toner, it is preferable to mix the wax as a seed during emulsion polymerization. By mixing as a seed, polymer primary particles in which wax is encapsulated are obtained, so that a large amount of wax does not exist on the surface of the toner, and deterioration of chargeability and heat resistance of the toner can be suppressed. The wax content in the polymer primary particles is preferably 4% by weight or more, more preferably 5% by weight or more, particularly preferably 7% by weight or more, preferably 30% by weight or less, more preferably 20% by weight or less. Particularly preferably, it is 15% by weight or less.

  Further, wax may be included in the resin fine particles. In this case as well, as in the case of obtaining polymer primary particles, it is preferable to mix with wax as a seed during emulsion polymerization. The content ratio of the wax in the entire resin fine particles is preferably smaller than the content ratio of the wax in the entire polymer primary particles. Generally, when wax is contained in resin fine particles, the fixability is improved, but on the other hand, the generation amount of fine powder tends to increase. The reason for this is that the fixability is improved because the speed of movement of the wax to the toner surface is increased when heat is applied, but the inclusion of the wax in the resin fine particles broadens the particle size distribution of the resin fine particles. It is considered that the aggregation control becomes difficult, and as a result, an increase in fine powder is caused.

The toner according to the present invention may be blended with a charge control agent in order to impart charge amount and charge stability. As the charge control agent, conventionally known compounds are usually used. Examples thereof include hydroxycarboxylic acid metal complexes, azo compound metal complexes, naphthol compounds, naphthol compound metal compounds, nigrosine dyes, quaternary ammonium salts, and mixtures thereof. In addition, a charge control agent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
The blending amount of the charge control agent is preferably in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin.

  When a charge control agent is contained in the toner in the emulsion polymerization aggregation method, the charge control agent is blended with a polymerizable monomer or the like at the time of emulsion polymerization, or is blended in the aggregation process with the polymer primary particles and the colorant. The blended primary particles, the colorant, and the like can be blended by a method such as blending after agglomeration to obtain an appropriate particle size as a toner. Among these, the charge control agent is preferably emulsified and dispersed in water using an emulsifier, and used as an emulsified dispersion having a volume average diameter (Mv) of 0.01 μm to 3 μm. The blend of the charge control agent dispersion at the time of emulsion aggregation is calculated and used so as to be 0.1 wt% or more and 5 wt% or less in the finished toner base particles after aggregation.

  The volume average diameter (Mv) of the polymer primary particles, resin fine particles, colorant particles, wax particles, charge control agent particles, etc. in the dispersion is measured using a nanotrack by the method described in Examples. , Defined as its measured value.

(Aggregation process)
After the mixing step, an aggregating step for aggregating primary particles in the dispersion liquid obtained in the mixing step is usually performed.
In the aggregation step in the emulsion polymerization aggregation method, the above-described primary polymer particles, resin fine particles, colorant particles, and charge components such as a charge control agent and wax are mixed at the same time or sequentially. It is possible to prepare a dispersion of the above components, that is, a polymer primary particle dispersion, a resin fine particle dispersion, a colorant particle dispersion, a charge control agent dispersion, and a wax fine particle dispersion. It is preferable from the viewpoint of uniformity.

  Also, when mixing these different types of dispersions, the components contained in each dispersion have different aggregation rates, and in order to achieve uniform aggregation, mix them over a certain period of time, either continuously or intermittently. It is preferable to do. The suitable time required for mixing varies depending on the amount of the dispersion to be mixed, the solid concentration, and the like. For example, when the colorant particle dispersion is mixed with the polymer primary particle dispersion, it is preferable to mix for 3 minutes or more. Further, when mixing the resin fine particle dispersion with the core particles, it is preferable to mix them over 3 minutes.

  The agglomeration treatment includes a method of mixing an electrolyte, a method of heating, a method of reducing the concentration of an emulsifier in the system, a method of combining these, etc. When primary particles are agglomerated under stirring to obtain particle agglomerates that are approximately the size of the toner, the particle size of the particle agglomerates is controlled from the balance between the agglomeration force between the particles and the shearing force due to agitation. However, the cohesive force can be increased by the above method.

The electrolyte in the case of aggregating by mixing the electrolyte may be either an organic salt or an inorganic salt. For example, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , CH ₃ Inorganic salt having a monovalent metal cation such as COONa, C ₆ H ₅ SO ₃ Na; Inorganic salt having a divalent metal cation such as MgCl ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ ; Al ₂ ( And inorganic salts having a trivalent metal cation such as SO ₄ ) ₃ and Fe ₂ (SO ₄ ) ₃ . Among these, when an inorganic salt having a divalent or higher polyvalent metal cation is used, it is preferable from the viewpoint of productivity because the aggregation rate is increased. As a result, fine powder that does not reach the desired toner particle size is likely to be generated. Therefore, it is preferable to use an inorganic salt having a monovalent metal cation that does not have a strong aggregating action, because the amount of fine powder generated can be suppressed.
In addition, an electrolyte may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  The amount of the electrolyte used varies depending on the type of electrolyte, the target particle size, etc., but is usually 0.05 parts by weight or more, preferably 0.1 parts by weight or more with respect to 100 parts by weight of the solid component of the mixed dispersion. It is usually 25 parts by weight or less, preferably 15 parts by weight or less, more preferably 10 parts by weight or less. If the amount used is less than the above range, the progress of the agglomeration reaction may be delayed, and a fine powder of 1 μm or less may remain after the agglomeration reaction, or the average particle size of the obtained particle aggregate may not reach the target particle size. When the amount exceeds the above range, rapid agglomeration tends to occur and it becomes difficult to control the particle size, and the obtained core particles may contain coarse powder or irregular shapes.

  In addition, it is preferable that the electrolyte is mixed not intermittently but intermittently or continuously over a certain period of time. The mixing time varies depending on the amount used, but it is more preferable to mix for 0.5 minutes or more. Usually, when the electrolyte is mixed, abrupt aggregation starts as soon as the electrolyte is mixed. Therefore, a large amount of polymer primary particles, colorant particles, or aggregates left behind in the aggregation tend to remain. These are considered to be one of the sources of fine powder. According to the said operation, since uniform agglomeration can be performed without abrupt agglomeration, generation of fine powder can be prevented.

  Further, the final temperature of the aggregation step when the electrolyte is mixed to perform aggregation is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, preferably 70 ° C. or lower, more preferably 60 ° C. or lower. Here, controlling the temperature before the aggregation step is one of the methods for controlling the particle diameter of the toner to a specific range of particle diameter according to the present invention. Some colorants added to the aggregating step induce aggregation, such as the electrolyte, and sometimes aggregate without adding electrolyte. This aggregation causes fine powder to be generated. Therefore, the aggregation can be prevented by cooling the temperature of the polymer primary particle dispersion in advance when mixing the colorant dispersion. In this production method, the polymer primary particles are cooled in advance in a range of preferably 0 ° C. or higher, more preferably 2 ° C. or higher, preferably 15 ° C. or lower, more preferably 12 ° C. or lower, and particularly preferably 10 ° C. or lower. It is good to keep. Note that this method is not effective only when the electrolyte is added to perform agglomeration, and the agglomeration is performed without mixing the electrolyte, such as a method of agglomeration by mixing a polar organic solvent such as pH control or alcohol. And is not particularly limited to the aggregation method.

  When the aggregation is performed by heating, the final temperature of the aggregation step is usually (Tg-20 ° C) or higher, preferably (Tg-10 ° C) or higher, when the polymer primary particle glass transition temperature is represented by Tg. It is Tg or less, preferably (Tg-5 ° C.) or less.

  In addition, as a method for preventing sudden aggregation in order to prevent the generation of fine powder, there is a method of mixing demineralized water or the like. The method of mixing demineralized water or the like has a less cohesive action than the method of mixing the electrolyte, so it is not a method that is actively adopted in terms of production efficiency in the general manufacturing method. A large amount of filtrate tends to be obtained. However, it is very effective when fine aggregation control is required as in the present invention. Moreover, in this invention, it is preferable to employ | adopt combining combining the method of heating, the method of mixing electrolyte, etc. At this time, the method of mixing the desalted water after mixing the electrolyte is particularly preferable in that the aggregation is easily controlled.

  The time required for agglomeration is optimized by the shape of the apparatus and the processing scale. In order to reach the target particle size of the toner base particles, the temperature at which the aggregation process is completed, for example, the emulsifier The time from the temperature 8 ° C. lower than the temperature during the operation of stopping the growth of the core particles by mixing, pH control, etc. (hereinafter sometimes abbreviated as “aggregation final temperature”) to the aggregation final temperature is 30 minutes or more. Preferably, it is more preferably 1 hour or longer. The polymer primary particles, colorant particles, or aggregates thereof remaining by extending the time are not left behind, but are taken into the target core particles or agglomerate with each other so that the target core is obtained. Become particles.

In order to obtain a toner that satisfies all of the requirements (i) to (iii), it is preferable to employ an operation in which the aggregation speed is not high compared with the operation that is normally performed in the aggregation process. Examples of the operation in which the speed of aggregation is not high include, for example, cooling the dispersion to be used in advance, mixing the dispersion over time, employing an electrolyte that does not have a large aggregation action, There are methods such as intermittent mixing, slowing the rate of temperature rise, and lengthening the aggregation time.

In the aging step, it is preferable to employ an operation in which the aggregated particles are difficult to redisperse. Examples of operations in which the aggregated particles are difficult to finely disperse include, for example, a method of lowering the number of rotations of stirring, a method of mixing the dispersion stabilizer continuously or intermittently, a method of mixing the dispersion stabilizer and water in advance. is there.
In addition, the toner satisfying all the requirements (i) to (iii) is obtained by converting the finally obtained toner or toner base particles into particles having a volume median diameter (Dv50) or less by an operation such as classification. It is preferable to be obtained without going through the removing step.

(Shell coating process)
In this production method, toner primary particles are obtained by aggregating polymer primary particles to form core particles, and washing and drying the particles obtained by fusing after a shell coating step for fixing or adhering resin fine particles and the like. Is preferably obtained. In this case, since the obtained toner base particles have a resin coating layer, there is an advantage that the toner is excellent in stability, storage stability and environmental resistance.

  The ratio of the resin fine particles to the whole core particles is usually 0.5 parts by weight or more, preferably 5 parts by weight or more, and usually 30 parts by weight or less, preferably 20 parts by weight or less with respect to 100 parts by weight of the core particles. .

  The resin fine particles may be produced by the same method as the polymer primary particles, and the configuration thereof is not particularly limited. However, the ratio of the total amount of polar monomers in 100% by weight of the total polymerizable monomer constituting the binder resin as the resin fine particles is preferably 0.05% by weight or more, more preferably 0.1% by weight or more, and further Preferably it is 0.2 weight% or more, Preferably it is 3 weight% or less, More preferably, it is 1.5 weight% or less. When it is within the above range, the dispersion stability of the obtained resin fine particles is improved, and the particle shape and particle size can be easily adjusted in the aggregation process.

  Further, the proportion of the total amount of polar monomers in 100% by weight of the total polymerizable monomer constituting the binder resin as the resin fine particles is 100% by weight of the total polymerizable monomer constituting the binder resin as the polymer primary particle. It is preferable that the ratio is smaller than the ratio of the total amount of polar monomers to be used because the particle shape and particle size can be easily adjusted in the aggregation process, the generation of fine powder can be suppressed, and the charging characteristics are excellent.

  In addition, the glass transition temperature of the binder resin as the resin fine particles is preferably higher than the glass transition temperature of the binder resin as the polymer primary particles from the viewpoint of storage stability and the like.

  In this production method, the toner base particles can be formed by coating (adhering or fixing) resin fine particles on the surface of the core particles as necessary. The volume average diameter (Mv) of the resin fine particles is preferably 0.02 μm or more, more preferably 0.05 μm or more, preferably 3 μm or less, more preferably 1.5 μm or less. In general, the use of the resin fine particles tends to promote the generation of fine powder that does not reach a predetermined toner particle size. Therefore, the conventional toner coated with resin fine particles tends to increase the amount of fine powder that does not satisfy a predetermined toner particle size.

  In this production method, when the amount of the wax is increased, the high temperature fixability is improved, but the wax is likely to be exposed on the toner surface, so that the chargeability and heat resistance may be deteriorated. However, the deterioration of performance can be prevented by coating the surface of the core particles with resin fine particles not containing wax.

  However, when the resin fine particles contain wax for the purpose of improving the high-temperature fixability, the resin fine particles once attached to the surface of the core particles are easily peeled off. This is presumably because the resin fine particles described above have a wide particle size distribution, so that there are large-sized resin fine particles with weak adhesion. Therefore, in order to reduce the peeling off, it is preferable to raise the temperature while mixing an aqueous solution in which a dispersion stabilizer and water are mixed in advance in a liquid in which particles having resin fine particles attached to the surface are dispersed. .

  In addition, when adopting the “step of starting the temperature rise after mixing the emulsifier” as described later, that is, when the aging step is performed after abruptly reducing the cohesive force, the cohesive force is rapidly reduced. In some cases, the fine resin particles once adhered may be easily detached. Therefore, it is preferable to fuse the resin fine particles after adhering them without significantly reducing the cohesive force and suppressing the particle diameter growth.

(Aging process)
In the emulsion polymerization aggregation method, in order to increase the stability of the particle aggregate obtained by aggregation, an emulsifier and a pH adjuster are mixed as a dispersion stabilizer to reduce the cohesive force between the particles and grow toner base particles. It is preferable to add an aging step for causing fusion between the agglomerated particles after stopping.

  The amount of the emulsifier to be mixed is not limited, but is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, still more preferably 3 parts by weight or more with respect to 100 parts by weight of the solid component of the mixed dispersion. Further, it is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, and still more preferably 10 parts by weight or less. After the aggregation process, before the completion of the ripening process, by mixing an emulsifier or increasing the pH value of the flocculation liquid, aggregation of the particle aggregates aggregated in the aggregation process can be suppressed. The generation of coarse particles in the toner can be suppressed.

  Here, as a method of controlling the particle size within a specific range which means that the particle size distribution is sharp in the second toner according to the present invention, for example, the number of stirring rotations before the step of mixing the emulsifier and the pH adjuster is performed. A method of reducing the shearing force, that is, a method of reducing the shearing force by stirring. This method is preferably employed when a system having a weak aggregating action, for example, an emulsifier or a pH adjuster is mixed at a time and rapidly transferred to a stable (dispersed) system. As described above, if the method of raising the temperature while mixing an aqueous solution in which a dispersion stabilizer and water are mixed in advance is adopted, if the stirring rotational speed is decreased, the system is too inclined to agglomeration, so the particle size May lead to hypertrophy.

As an example, a toner having a specific particle size distribution used in the image forming apparatus of the present invention, that is, the second toner according to the present invention satisfying all the requirements (i) to (iii) can be obtained by the above method. Yes, but I will tell you more. The content of fine powder can be adjusted according to the degree to which the rotational speed is reduced. For example, when the stirring rotation speed is reduced from 250 rpm to 150 rpm, a toner having a smaller particle diameter with a sharper particle size distribution than that of a known toner can be provided, and the second toner according to the present invention can be obtained. However, this value is
(A) The diameter of the stirring vessel (as a so-called general cylindrical shape) and the maximum diameter of the stirring blade (and its relative ratio),
(B) The height of the stirring vessel,
(C) The peripheral speed at the tip of the stirring blade,
(D) The shape of the stirring blade,
(E) the position of the blade in the stirring vessel,
It depends on the conditions.
In particular, (c) is preferably 1.0 m / second or more, more preferably 1.2 m / second or more, particularly preferably 1.5 m / second, and preferably 2.5 m / second or less, and 2.3 m. / Second or less is more preferable, and 2.2 m / second or less is particularly preferable. This is because, within the above range, a suitable shear rate that does not peel off and does not enlarge is given to the particles.

The temperature of the ripening step is preferably Tg or higher, more preferably 5 ° C higher than Tg, and preferably 80 ° C higher than Tg, when the glass transition temperature Tg of the binder resin as the polymer primary particles is used. Below the temperature, more preferably below 50 ° C. above the Tg.
The time required for the aging step varies depending on the shape of the target toner, but after reaching the glass transition temperature of the polymer constituting the polymer primary particles, usually 0.1 hour or more, preferably 1 hour or more. In addition, it is usually desirable to hold for 5 hours or less, preferably 3 hours or less.

  By such a heat treatment, the polymer primary particles in the aggregate are fused and integrated, and the shape of the toner base particles as the aggregate becomes close to a sphere. The particle aggregate before the aging step is considered to be an aggregate due to electrostatic or physical aggregation of the polymer primary particles, but after the aging step, the polymer primary particles constituting the particle aggregate are fused to each other. In addition, the shape of the toner base particles can be made nearly spherical. According to such a ripening step, by controlling the temperature and time of the ripening step, the shape of the polymer primary particles is agglomerated, the potato type with advanced fusion, the spherical shape with further fusion For example, various shapes of toner can be manufactured according to the purpose.

(Washing / drying process)
The particle aggregate obtained through each of the above steps is subjected to solid / liquid separation according to a known method, the particle aggregate is recovered, then washed as necessary, and then dried. Toner mother particles can be obtained.

  Further, resin fine particles mainly composed of a polymer are further formed on the surface of the particles obtained by the emulsion polymerization aggregation method by a method such as a spray drying method, an in-situ method, or a submerged particle coating method. The outer layer is preferably formed with a thickness of 0.01 μm or more and 0.5 μm or less to provide encapsulated toner base particles.

(Other matters regarding the emulsion polymerization aggregation method)
By devising the manufacturing method as described above, toner base particles that can satisfy all the requirements (i) to (iii) can be manufactured. The toner base particles may be used as they are as the toner according to the present invention, but usually, a toner satisfying all the requirements (i) to (iii) is obtained by performing an external addition process described later.

  The toner of the present invention may be one in which a known external additive is blended on the surface of the toner base particles in order to control fluidity and developability (external addition treatment). Examples of the external additive include metal oxides and hydroxides such as alumina, silica, titania, zinc oxide, zirconium oxide, cerium oxide, talc, hydrotalcite, calcium titanate, strontium titanate, barium titanate, etc. Metal titanates, nitrides such as titanium nitride and silicon nitride, carbides such as titanium carbide and silicon carbide, and organic particles such as acrylic resins and melamine resins. In addition, an external additive may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Among these, silica, titania, and alumina are preferable, and those that have been surface-treated with, for example, a silane coupling agent or silicone oil are more preferable. The average primary particle diameter is preferably 1 nm or more, more preferably 5 nm or more, preferably 500 nm or less, more preferably 100 nm or less. It is also preferable to use a combination of a small particle size and a large particle size in the particle size range. The total amount of the external additive is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, preferably 10 parts by weight or less, more preferably 100 parts by weight of the toner base particles. Is 5 parts by weight or less.

  The toner according to the present invention obtained by the emulsion polymerization aggregation method preferably has an average circularity measured using a flow particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation (formerly Toa Medical Electronics)). 0.90 or more, more preferably 0.92 or more, still more preferably 0.94 or more. It is considered that the closer to a sphere, the less the amount of charge is localized in the particle, and the developability tends to be uniform. However, since the perfect spherical toner deteriorates the cleaning property, the average circle The degree is preferably 0.99 or less, more preferably 0.98 or less, and still more preferably 0.97 or less.

[Production method of toner by pulverization method]
The toner according to the present invention can also be produced, for example, by a pulverization method. In the pulverization method, a toner is manufactured by pulverizing a resin. In this case, since the particle size distribution of the toner obtained by the pulverization method (hereinafter referred to as “pulverized toner” as appropriate) is often not desired, the pulverized toner is usually classified.

  The resin used for producing the pulverized toner may be appropriately selected from those known to be usable for toner. For example, styrene resin, vinyl chloride resin, rosin modified maleic acid resin, phenol resin, epoxy resin, saturated or unsaturated polyester resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-acrylate copolymer, xylene Resin, polyvinyl butyral resin, etc. are used. Of these, polyester resins are preferred. In addition, these resin may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

The polyester resin is composed of a polyhydric alcohol and a polybasic acid, and if necessary, a polymerizable monomer composition containing at least one of these polyhydric alcohol and polybasic acid containing a trifunctional or higher polyfunctional component (crosslinking component). Obtained by polymerization.
In the above, among the polyhydric alcohols used for the synthesis of the polyester resin, examples of the divalent alcohol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4. -Butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol and other diols, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxy Examples thereof include bisphenol A alkylene oxide adducts such as propylene bisphenol A and the like. Among these monomers, it is particularly preferable to use a bisphenol A alkylene oxide adduct as the main component monomer, and among them, an adduct having an average number of alkylene oxide additions per molecule of 2 to 7 is preferable.

Examples of the trihydric or higher polyhydric alcohol involved in the crosslinking of polyester include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripenta. Erythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane 1,3,5-trihydroxymethylbenzene, and the like.
In addition, a polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  On the other hand, as the polybasic acid, for example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, Mention may be made of divalent organic acids such as malonic acid, anhydrides of these acids, lower alkyl esters, alkenyl succinic acids such as n-dodecenyl succinic acid and n-dodecyl succinic acid, or alkyl succinic acids.

Examples of the tribasic or higher polybasic acid involved in the crosslinking of polyester include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, and 1,2,4-cyclohexanetricarboxylic acid. 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra ( Methylene carboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, and anhydrides thereof.
In addition, a polybasic acid may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

These polyester resins can be synthesized by a usual method. For example, conditions such as reaction temperature (170 ° C. or higher and 250 ° C. or lower), reaction pressure (5 mmHg or higher and normal pressure or lower) are determined according to the reactivity of the monomer, and the reaction may be terminated when predetermined physical properties are obtained. .
The softening point of the polyester resin is preferably 90 ° C. or higher, more preferably 95 ° C. or higher, 135 ° C. or lower, more preferably 133 ° C. or lower. The range of the glass transition temperature is, for example, from 50 ° C. to 65 ° C. when the softening point is 90 ° C., and from 60 ° C. to 75 ° C. when the softening point is 135 ° C. In this case, if the softening point is lower than the above range, an offset phenomenon at the time of fixing tends to occur. If the softening point is higher than the above range, the fixing energy increases, and the color toner tends to deteriorate glossiness and transparency. Further, if the glass transition temperature is lower than the above range, toner agglomerates and sticking are likely to occur, and if it is higher than the above range, the fixing strength at the time of thermal fixing tends to decrease.

  The softening point of the polyester resin can be adjusted mainly by the molecular weight of the resin. When the tetrahydrofuran soluble content of the resin is measured by the GPC method, the number average molecular weight is preferably 2000 or more, more preferably 3000 or more, preferably 20000 or less, More preferably, it should be 12000 or less. The glass transition temperature can be adjusted mainly by selecting the monomer component constituting the resin. For example, the glass transition temperature can be increased by using an aromatic polybasic acid as a main component as the acid component. That is, among the polybasic acids described above, for example, phthalic acid, isophthalic acid, terephthalic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid and the like, anhydrides thereof, lower alkyl esters, etc. It is desirable to use as the main component.

Here, the softening point is defined as a value measured using a flow tester described in JIS K7210 and K6719. Specifically, using a flow tester (CFT-500, manufactured by Shimadzu Corporation), a plunger having an area of 1 cm ² while heating a sample of about 1 g at a preheating time of 50 ° C. for 5 minutes and a heating rate of 3 ° C./min. A load of 30 kg / cm ² is applied by pushing through a die having a hole diameter of 1 mm and a length of 10 mm. Thus, a plunger stroke-temperature curve is drawn, and when the height of the S-shaped curve is “h”, the temperature corresponding to “h / 2” is defined as the softening point. Moreover, the measurement of a glass transition temperature is defined as what was measured in accordance with the conventional method using the differential scanning calorimeter (DSC7 by Perkin-Elmer company, or DSC120 by Seiko Electronics Co., Ltd.).

  In general, when the acid value of the polyester resin is too high, it is difficult to obtain a stable high charge amount, and the charge stability at high temperature and high humidity tends to deteriorate. Therefore, the acid value of the polyester resin is preferably adjusted to 50 KOH mg / g or less, more preferably 30 KOH mg / g or less, and particularly preferably 15 KOH mg / g or less. The lower limit is usually 3 KOHmg / g or more.

  Examples of a method for adjusting the acid value of the polyester resin within the above range include, for example, a method of controlling the blending ratio of alcohol-based and acid-based monomers used at the time of resin synthesis, and a lower acid monomer component in advance by transesterification Examples thereof include a method of synthesizing using an alkyl ester, a method of neutralizing residual acid groups by blending a basic component such as an amino group-containing glycol in the composition, and the like. However, these methods are merely examples, and any known method can be employed without being limited thereto. Here, the acid value of the polyester resin is measured according to the method of JIS K0070. However, when the resin is difficult to dissolve in the solvent, a good solvent such as dioxane is used.

The polyester resin is represented by the following formulas (a) to (d) when the glass transition temperature (Tg) is plotted as an x-axis variable and the softening point (Sp) is plotted as a y-axis variable on the xy coordinates. Those having physical properties within a range surrounded by a straight line are preferred. The unit of Tg and Sp is “° C.”.
Formula (a) Sp = 4 * Tg-110
Formula (b) Sp = 4 * Tg-170
Formula (c) Sp = 90
Formula (d) Sp = 135

  When a polyester resin having physical properties surrounded by straight lines represented by the formulas (a) to (d) is used for the pulverized toner, the pulverized toner has extremely high resistance to mechanical stress. In addition, the toner can be prevented from aggregating and solidifying due to frictional heat generated during continuous use, and appropriate chargeability can be maintained over a long period of time.

The pulverized toner may contain components other than the resin. For example, a colorant may be included. The colorant used in the pulverization method is not particularly limited as long as it is a commonly used colorant. For example, the colorant used for the above-described polymerized toner can be used.
The content ratio of the colorant may be an amount sufficient for the obtained toner to form a visible image by development, for example, usually 1 part by weight or more, preferably 3 parts by weight in 100 parts by weight of the resin. These are usually 25 parts by weight or less, preferably 15 parts by weight or less, more preferably 12 parts by weight or less.

The pulverized toner may contain, for example, a charge control agent. Any known charge control agent can be used. For example, examples of the charge control agent for positive charge include nigrosine dyes, amino group-containing vinyl copolymers, quaternary ammonium salt compounds, and polyamine resins. Examples of the charge control agent for negative charge include metal-containing azo dyes containing metals such as chromium, zinc, iron, cobalt, and aluminum, salts of salicylic acid or alkylsalicylic acid with the aforementioned metals, metal complexes, and the like. Can be mentioned. In addition, only 1 type may be used for a charge control agent and it may use 2 or more types together by arbitrary combinations and a ratio.
The amount of the charge control agent used is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, preferably 25 parts by weight or less, more preferably 15 parts by weight or less with respect to 100 parts by weight of the resin. is there. In this case, the charge control agent may be blended in the resin, or may be used in a form adhered to the surface of the toner base particles.

  Among these charge control agents, taking into account the ability to impart charge to the toner and color toner adaptability (the charge control agent itself is colorless or light and has no color disturbance to the toner), A group-containing vinyl copolymer and / or a quaternary ammonium salt compound is preferable, and for negative chargeability, metal salts and metal complexes of salicylic acid or alkylsalicylic acid with chromium, zinc, aluminum, boron and the like are preferable.

Among these, examples of the amino group-containing vinyl copolymer include copolymer resins of amino acrylates such as N, N-dimethylaminomethyl acrylate and N, N-diethylaminomethyl acrylate with styrene and methyl methacrylate. . Examples of the quaternary ammonium salt compound include tetraethylammonium chloride, a salt-forming compound of benzyltributylammonium chloride and naphtholsulfonic acid, and the like. For positively chargeable toners, the above amino group-containing vinyl copolymers and quaternary ammonium salt compounds may be blended alone or in combination.
As the metal salt and metal complex of salicylic acid or alkyl salicylic acid, among various known substances, chromium, zinc or boron complex of 3,5-ditertiary butyl salicylic acid is particularly preferable.

  The above colorant and charge control agent may be subjected to preliminary dispersion treatment, so-called master batch treatment, by pre-kneading with a resin or the like in advance in order to improve dispersibility and compatibility in the toner.

  In the pulverized toner, any other known component such as a low molecular weight polyalkylene, a low melting point release agent such as a paraffin wax, an ester wax, or the like can be contained as other constituent components.

Examples of specific operations for producing the toner according to the present invention by a pulverization method include the following.
1. The resin and the charge control substance, colorant, and additive contained as necessary are uniformly dispersed by a dispersing device such as a Henschel mixer.
2. The obtained dispersion is melt-kneaded by a melt-kneader such as a kneader, an extruder, or a roll mill.
3. The obtained kneaded material is coarsely pulverized by a coarse pulverizer such as a hammer mill or a cutter mill, and then finely pulverized by a fine pulverizer such as a jet mill or an I-type mill.
4). The obtained finely pulverized product is classified by a classifier such as a dispersion classifier or a zigzag classifier.
5. In the obtained classified product, an external additive such as silica is dispersed with a Henschel mixer or the like, if necessary.

  In particular, the toner according to the present invention can be produced by the pulverization method by performing classification until the specific particle size distribution according to the present invention is obtained in the above operation 4.

(Suspension polymerization method)
A method for producing the toner according to the present invention by the suspension polymerization method is not particularly limited. For example, an additive that improves the chemical structure such as the number of polar groups of the binder polymer, the molecular weight distribution, and the suspension state (dispersion stability). And the like, the stirring strength during suspension polymerization, the mixing method of the polymerizable monomers, the types and amounts of the polymerization initiator and the chain transfer agent, the polymerization temperature, and the degree of classification. . Particularly preferable methods include a method in which a high shearing force is applied in a process in which polymerizable monomer droplets are generated, or a dispersion stabilizer or the like is increased.

  Examples of the raw material such as resin used when producing the toner according to the present invention by the suspension polymerization method include those described in the section of the emulsion polymerization aggregation method.

[Chemical grinding method typified by melt suspension method]
A method for producing the toner according to the present invention by a chemical pulverization method typified by a melt suspension method is not particularly limited. For example, the type of binder polymer, chemical structure, molecular weight distribution, etc .; It is carried out by adjusting the kind and amount of the underwater additive; stirring intensity at the time of adding the polymer solution, mixing method, temperature, etc .;

  Examples of the resin used when the toner is manufactured by a chemical pulverization method such as a melt suspension method include those described in the section of the pulverization method. Other materials include those described in the emulsion polymerization aggregation method.

[3. Image forming apparatus]
An embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

  As shown in FIG. 1, an image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2 as a charging unit, an exposure device 3 as an exposure unit, a developing device 4 as a developing unit (with toner T inside), In addition, the image forming apparatus includes a transfer device 5 as a transfer unit, and further includes a cleaning device (cleaning unit) 6 and a fixing device (fixing unit) 7 as necessary.

  The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention (hereinafter also simply referred to as a photoreceptor). In FIG. 1, as an example, a cylindrical conductive support is used. A drum-shaped photoreceptor having the above-described photosensitive layer formed on the surface is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged along the outer peripheral surface of the electrophotographic photoreceptor 1.

The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential.
Specific examples of the charging device include a corona charging device such as a corotron and a scorotron, a direct charging device (contact type charging device) that charges a surface of a photosensitive member with a direct charging member to which a voltage is applied, and the like. . Examples of the direct charging member (contact charger) include a charging roller and a charging brush.

As the direct charging means by the direct charging device, there are a contact charging means with air discharge and an injection charging means without air discharge, and any method can be applied in the present invention.
Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose alternating current on direct current. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2.

  The exposure apparatus 3 is not limited in the number or type as long as it can expose the charged photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the photoreceptor 1. Therefore, the number of exposure apparatuses may be one, or two or more. Specific examples of the exposure apparatus 3 include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. However, the wavelength of light used for exposure is usually a short wavelength monochromatic light having a wavelength of 380 nm or more and a wavelength of 500 nm or less, preferably a wavelength of 480 nm or less, more preferably 430 nm or less. The photoconductor of the present invention exhibits excellent effects peculiar to the present invention by combining with such blue (purple) monochromatic light.

  The developing device 4 is not particularly limited as long as it has toner and develops the formed electrostatic latent image with toner. For example, cascade development, one-component conductive toner development, two-component magnetic brush development, etc. Any apparatus such as a dry development system or a wet development system can be used. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. This replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

  The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicone resin, a urethane resin, a fluororesin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.

  The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43, and is in contact with the photoreceptor 1 and the supply roller 43. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The restricting member 45 is formed of, for example, a resin blade such as a silicone resin or a urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with a resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g weight / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

  The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.

  As the toner T, it is preferable to use the toner according to the present invention described above. As an example, FIG. 1 shows a toner storage form, but the storage method, storage location, replenishment method, and the like are arbitrary as long as the effects of the present invention are not significantly limited. Only one type of toner may be used, or two or more types of toner may be used in any combination and ratio.

  The type of the transfer device 5 is not limited as long as it transfers toner, and an arbitrary method such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method is used. The device can be used. Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like disposed so as to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers a toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium, transfer target). Transfer to P.

  There is no restriction | limiting about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (pressure roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. Each of the upper and lower fixing members 71 and 72 includes a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, a fixing sheet, or the like. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.
The type of the fixing device is not particularly limited, and a fixing device of an arbitrary method such as heat roller fixing, flash fixing, oven fixing, pressure fixing, or the like can be provided.

In the electrophotographic apparatus configured as described above, an image is recorded by the following method.
That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed with a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.
When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.

After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.
In addition to the above-described configuration, the image forming apparatus may be configured to perform, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

  The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.

According to the image forming apparatus of the present embodiment as described above, it is possible to form an electrostatic latent image with high sensitivity, low residual potential, and faithful to high resolution exposure. The image forming apparatus of the present invention can reduce the beam spot diameter on the electrophotographic photosensitive member by using an exposure light source having a wavelength of 380 nm or more and 500 nm or less, and can obtain a high resolution image.
In particular, in this embodiment, since the toner according to the present invention satisfying specific requirements is used as the toner, high quality represented by high resolution, high gradation, etc. can be realized very well, and exposure with high resolution is possible. Therefore, it is possible to form an image that is faithfully developed and has few defects.

  The electrophotographic photosensitive member 1 and the toner T are combined to form an integrated cartridge (this is appropriately referred to as an “electrophotographic photosensitive member cartridge”), and the electrophotographic photosensitive member cartridge is used as an image in a copying machine, a laser beam printer, or the like. You may make it the structure which can be attached or detached with respect to a forming apparatus main body. In this case, the cartridge is usually configured to include at least the photoconductor of the present invention and a cartridge case that detachably supports the photoconductor of the present invention with respect to the image forming apparatus.

  Further, the electrophotographic photosensitive member cartridge includes one or more of a charging device (charging means) 2, an exposure device (exposure means) 3, a developing device (developing means) 4 and a transfer device (transfer means) 5. May be combined with elements. Further, in addition to these elements, a cleaning device 6 and a fixing device 7 may be provided. In this case, an electrophotographic photosensitive member cartridge can be obtained by using a cartridge case configured to be detachable with respect to the image forming apparatus and storing and supporting it in combination with the above-described elements.

With this configuration, for example, when the electrophotographic photosensitive member 1 or other member deteriorates, the electrophotographic photosensitive member cartridge is removed from the image forming apparatus main body, and another new electrophotographic photosensitive member cartridge is mounted on the image forming apparatus main body. can do.
Further, when the toner T has run out of the toner cartridge, the toner cartridge can be taken out from the main body of the image forming apparatus, and the toner can be easily filled or another new toner cartridge can be mounted. . Accordingly, maintenance and management of the image forming apparatus are facilitated.

The toner in the electrophotographic photosensitive member cartridge preferably satisfies all of the following (i) to (iii).
(I) The volume median diameter (Dv50) is 4.0 μm or more and 7.0 μm or less.
(Ii) The average circularity is 0.93 or more.
(Iii) The relationship between the volume median diameter (Dv50) of the toner and the number% (Dns) of the toner having a particle diameter of 2.00 μm to 3.56 μm satisfies Dns ≦ 0.233EXP (17.3 / Dv50). Fulfill.
The details of (i) to (iii) are the same as those described in the section of toner.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited to the following examples, and can be implemented with appropriate modifications without departing from the gist thereof. In the following, “part” means “part by weight”.

[I. Examples relating to evaluation of photoreceptors]
[I-1. Measuring method]
[Measurement method of viscosity average molecular weight]
The viscosity average molecular weight of the resin used for the charge transport layer was measured as follows.
The resin was dissolved in dichloromethane to prepare a solution having a concentration C of 6.00 [g / L]. The flow time t [s] of the sample solution was measured in a constant temperature water bath set to 20.0 ° C. using an Ubbelohde capillary viscometer with a flow time t ₀ [s] of the solvent (dichloromethane) of 136.16 seconds. . And the viscosity average molecular weight Mv was computed according to the following formula | equation.
a = 0.438 × η _sp +1
η _sp = t / t ₀ −1
t ₀ = 136.16 [s]
b = 100 × η _sp / C
C = 6.00 [g / L]
η = b / a
Mv = 3207 × η ^1.205

[I-2. Production of Azo Compound Composition]
[Production Example 1]
26.8 g of 3-hydroxynaphthalic anhydride and 14.1 g of o-phenylenediamine were suspended in a mixed solvent of 50 mL of glacial acetic acid and 300 mL of nitrobenzene, and reacted with heating under reflux for 8 hours. After the reaction, the solid was collected by filtration, washed with 400 mL of methanol, and dried to obtain 30.4 g of a yellow solid. From the measurement result of liquid chromatography, the obtained yellow solid is clearly a mixture of structural isomers including both the compound represented by the following structural formula (1a) and the compound represented by the structural formula (1b). became.

The obtained yellow solid was subjected to separation operation by liquid chromatography, whereby the compound represented by the structural formula (1a) and the compound represented by the structural formula (1b) were fractionated.
0.8 g of the compound represented by the structural formula (1a) and 0.8 g of the compound represented by the structural formula (1b) were dissolved in 245 mL of dimethyl sulfoxide, and 2,5-bis ( A solution of 1.1 g of tetrazonium borofluoride salt of p-aminophenyl) -1,3,4-oxadiazole in 15 mL of dimethyl sulfoxide was added dropwise. Next, a solution prepared by dissolving 2.3 g of sodium acetate in 7 mL of water was dropped, and the mixture was stirred for 3 hours to carry out a coupling reaction. The precipitated solid was collected by filtration, washed successively with 10% aqueous acetic acid, water, and THF, dried, and expressed as one of the following structural formulas (A1), (A2), and (A3) as the target composition. 1.7 g of an azo compound composition comprising the above compound was obtained. Analyze this composition by liquid chromatography and calculate the composition ratio (Create a calibration curve for each component contained in the azo composition, and determine the weight of each component contained from the liquid chromatography measurement results of the composition. And the composition ratio was calculated by weight ratio). Compound represented by Structural Formula (A1): Compound represented by Structural Formula (A2): Compound represented by Structural Formula (A3) = 24 .6: 50.5: 24.9.

[Production Example 2]
By performing the same coupling reaction as in Production Example 1 except that 1.0 g of the compound represented by the structural formula (1a) and 0.6 g of the compound represented by the structural formula (1b) were used. As a composition, 1.8 g of an azo compound composition composed of the compound represented by any one of the structural formulas (A1), (A2), and (A3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (A1): the compound represented by the structural formula (A2): the compound represented by the structural formula (A3) = It was 39.0: 47.2: 13.8.

[Production Example 3]
By performing the same coupling reaction as in Production Example 1 except that 0.64 g of the compound represented by the structural formula (1a) and 0.96 g of the compound represented by the structural formula (1b) were used. As a composition, 1.7 g of an azo compound composition composed of the compound represented by any one of the structural formulas (A1), (A2) and (A3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (A1): the compound represented by the structural formula (A2): the compound represented by the structural formula (A3) = It was 16.2: 48.1: 35.7.

[Comparative Production Example 1]
By carrying out the same coupling reaction as in Production Example 1 except that 1.2 g of the compound represented by the structural formula (1a) and 0.4 g of the compound represented by the structural formula (1b) were used. As a composition, 1.7 g of an azo compound composition composed of the compound represented by any one of the structural formulas (A1), (A2) and (A3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (A1): the compound represented by the structural formula (A2): the compound represented by the structural formula (A3) = It was 56.0: 37.6: 6.4.

[Comparative Production Example 2]
The target composition was obtained by carrying out the same coupling as in Production Example 1 except that 0.48 g of the compound represented by structural formula (1a) and 1.12 g of compound represented by structural formula (1b) were used. As a product, 1.7 g of an azo compound composition comprising the compound represented by any one of the structural formulas (A1), (A2) and (A3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (A1): the compound represented by the structural formula (A2): the compound represented by the structural formula (A3) = 9.3: 41.6: 49.1.

[Production Example 4]
26.8 g of 3-hydroxynaphthalic anhydride and 16.0 g of 3,4-diaminotoluene were suspended in a mixed solvent of 50 mL of glacial acetic acid and 300 mL of nitrobenzene, and reacted with heating under reflux for 8 hours. After the reaction, the solid was collected by filtration, washed with 400 mL of methanol, and dried to obtain 26.4 g of a yellow solid. From the measurement results of liquid chromatography, the obtained yellow solid is clearly a mixture of structural isomers including both the compound represented by the following structural formula (2a) and the compound represented by the structural formula (2b). became.

The obtained yellow solid was subjected to separation operation by liquid chromatography, whereby the compound represented by the structural formula (2a) and the compound represented by the structural formula (2b) were fractionated.
0.76 g of the compound represented by the structural formula (2a) and 0.84 g of the compound represented by the structural formula (2b) were dissolved in 245 mL of dimethyl sulfoxide, and 2,5-bis ( A solution of 1.1 g of tetrazonium borofluoride salt of p-aminophenyl) -1,3,4-oxadiazole in 15 mL of dimethyl sulfoxide was added dropwise. Next, a solution prepared by dissolving 2.3 g of sodium acetate in 7 mL of water was dropped, and the mixture was stirred for 3 hours to carry out a coupling reaction. The precipitated solid was collected by filtration, washed successively with 10% aqueous acetic acid, water, and THF, dried, and expressed as one of the following structural formulas (B1), (B2), and (B3) as the target composition. 1.7 g of an azo compound composition comprising the above compound was obtained. Analyze this composition by liquid chromatography and calculate the composition ratio (Create a calibration curve for each component contained in the azo composition, and determine the weight of each component contained from the liquid chromatography measurement results of the composition. And the composition ratio was calculated by weight ratio). The compound represented by the structural formula (B1): the compound represented by the structural formula (B2): the compound represented by the structural formula (B3) = 22. 6: 49.9: 27.5.

[Production Example 5]
By carrying out the same coupling reaction as in Production Example 4 except that 0.88 g of the compound represented by the structural formula (2a) and 0.72 g of the compound represented by the structural formula (2b) were used. As a composition, 1.6 g of an azo compound composition composed of the compound represented by any one of the structural formulas (B1), (B2), and (B3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (B1): the compound represented by the structural formula (B2): the compound represented by the structural formula (B3) = 30.0: 49.3: 20.7.

[Production Example 6]
By carrying out the same coupling reaction as in Production Example 4 except that 0.72 g of the compound represented by structural formula (2a) and 0.88 g of compound represented by structural formula (2b) were used. As a composition, 1.7 g of an azo compound composition composed of the compound represented by any one of the structural formulas (B1), (B2), and (B3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (B1): the compound represented by the structural formula (B2): the compound represented by the structural formula (B3) = 21.1: 48.9.1: 29.8.

[Comparative Production Example 4]
By carrying out the same coupling reaction as in Production Example 4 except that 1.16 g of the compound represented by structural formula (2a) and 0.44 g of compound represented by structural formula (2b) were used. As a composition, 1.8 g of an azo compound composition composed of the compound represented by any one of the structural formulas (B1), (B2), and (B3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (B1): the compound represented by the structural formula (B2): the compound represented by the structural formula (B3) = It was 52.3: 40.1: 7.7.

[Comparative Production Example 5]
By performing the same coupling as in Production Example 4 except that 0.4 g of the compound represented by the structural formula (2a) and 1.2 g of the compound represented by the structural formula (2b) were used, the target composition was obtained. As a product, 1.7 g of an azo compound composition comprising the compound represented by any one of the structural formulas (B1), (B2), and (B3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (B1): the compound represented by the structural formula (B2): the compound represented by the structural formula (B3) = 6.7: 38.1: 55.2.

[Production Example 7]
26.8 g of 3-hydroxynaphthalic anhydride and 16.1 g of 4-fluoro-o-phenylenediamine were suspended in a mixed solvent of 50 mL of glacial acetic acid and 300 mL of nitrobenzene, and reacted with heating under reflux for 8 hours. . After the reaction, the solid was collected by filtration, washed with 400 mL of methanol, and dried to obtain 32.1 g of a yellow solid. From the measurement result of liquid chromatography, the obtained yellow solid is clearly a mixture of structural isomers including both the compound represented by the following structural formula (3a) and the compound represented by the structural formula (3b). became.

The obtained yellow solid was subjected to separation operation by liquid chromatography, whereby the compound represented by the structural formula (3a) and the compound represented by the structural formula (3b) were fractionated.
0.8 g of the compound represented by structural formula (3a) and 0.8 g of compound represented by structural formula (3b) were dissolved in 245 mL of dimethyl sulfoxide, and 2,5-bis ( A solution of 1.1 g of tetrazonium borofluoride salt of p-aminophenyl) -1,3,4-oxadiazole in 15 mL of dimethyl sulfoxide was added dropwise. Next, a solution prepared by dissolving 2.3 g of sodium acetate in 7 mL of water was dropped, and the mixture was stirred for 3 hours to carry out a coupling reaction. The precipitated solid was collected by filtration, washed successively with 10% aqueous acetic acid, water, and THF, dried, and expressed as one of the following structural formulas (C1), (C2), and (C3) as the target composition. 1.6 g of an azo compound composition comprising the above compound was obtained. Analyze this composition by liquid chromatography and calculate the composition ratio (Create a calibration curve for each component contained in the azo composition, and determine the weight of each component contained from the liquid chromatography measurement results of the composition. And the composition ratio was calculated by weight ratio). Compound represented by Structural Formula (C1): Compound represented by Structural Formula (C2): Compound represented by Structural Formula (C3) = 24 .8: 49.9: 25.3.

[Production Example 8]
By carrying out the same coupling reaction as in Production Example 7 except that 0.96 g of the compound represented by the structural formula (3a) and 0.64 g of the compound represented by the structural formula (3b) were used. As a composition, 1.6 g of an azo compound composition composed of the compound represented by any one of the structural formulas (C1), (C2), and (C3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (C1): the compound represented by the structural formula (C2): the compound represented by the structural formula (C3) = 35.9: 47.8: 16.3.

[Production Example 9]
By carrying out the same coupling reaction as in Production Example 7 except that 0.56 g of the compound represented by structural formula (3a) and 1.04 g of compound represented by structural formula (3b) were used. As a composition, 1.5 g of an azo compound composition composed of the compound represented by any one of the structural formulas (C1), (C2), and (C3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (C1): the compound represented by the structural formula (C2): the compound represented by the structural formula (C3) = 12.4: 45.6: 42.0.

[Comparative Production Example 5]
By carrying out the same coupling reaction as in Production Example 7 except that 1.2 g of the compound represented by the structural formula (3a) and 0.4 g of the compound represented by the structural formula (3b) were used. As a composition, 1.7 g of an azo compound composition composed of the compound represented by any one of the structural formulas (C1), (C2), and (C3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (C1): the compound represented by the structural formula (C2): the compound represented by the structural formula (C3) = It was 56.5: 37.7: 5.7.

[Comparative Production Example 6]
The target composition was obtained by performing the same coupling as in Production Example 7 except that 0.32 g of the compound represented by the structural formula (3a) and 1.28 g of the compound represented by the structural formula (3b) were used. As a product, 1.6 g of an azo compound composition composed of the compound represented by any one of the structural formulas (C1), (C2), and (C3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (C1): the compound represented by the structural formula (C2): the compound represented by the structural formula (C3) = It was 4.2: 32.4: 63.4.

[Production Example 10]
2,8.8 g of 3,6-dihydroxynaphthalic anhydride and 16.0 g of 3,4-diaminotoluene were suspended in a mixed solvent of 86 mL of glacial acetic acid and 430 mL of nitrobenzene, and reacted with heating under reflux for 8 hours. . After the reaction, the solid was collected by filtration, washed with 520 mL of methanol, and dried to obtain 37.5 g of a yellow solid. 23.0 g of the obtained yellow solid was suspended in 1000 mL of DMF (N, N-dimethylformamide), and 69 g of potassium carbonate and 14 g of tosyl chloride were added. After stirring at 80 ° C. for 2 hours, the temperature was lowered to room temperature, 31 g of methyl iodide was added dropwise, and the mixture was further stirred for 2 hours. The reaction solution was filtered while hot at 80 ° C., and the filtrate was recrystallized using DMF and water to obtain 25.2 g of a yellow solid. This yellow solid was suspended in 750 mL of ethanol, heated to reflux, and 750 mL of 1N potassium hydroxide was added dropwise. Thereafter, the same treatment as in Production Example 3 was carried out to obtain 15 g of a yellow solid. From the measurement result of liquid chromatography, the obtained yellow solid is clearly a mixture of structural isomers including both the compound represented by the following structural formula (4a) and the compound represented by the structural formula (4b). became.

The obtained yellow solid was separated by liquid chromatography, whereby the compound represented by the structural formula (4a) and the compound represented by the structural formula (4b) were fractionated.
0.8 g of the compound represented by the structural formula (4a) and 0.8 g of the compound represented by the structural formula (4b) are dissolved in 245 mL of dimethyl sulfoxide, and 2,5-bis ( A solution of 1.1 g of tetrazonium borofluoride salt of p-aminophenyl) -1,3,4-oxadiazole in 15 mL of dimethyl sulfoxide was added dropwise. Next, a solution prepared by dissolving 2.3 g of sodium acetate in 7 mL of water was dropped, and the mixture was stirred for 3 hours to carry out a coupling reaction. The precipitated solid was collected by filtration, washed successively with 10% aqueous acetic acid, water, and THF, dried, and expressed as one of the following structural formulas (D1), (D2), and (D3) as the target composition. 1.8 g of an azo compound composition comprising the above compound was obtained. Analyze this composition by liquid chromatography and calculate the composition ratio (Create a calibration curve for each component contained in the azo composition, and determine the weight of each component contained from the liquid chromatography measurement results of the composition. And the composition ratio was calculated by weight ratio). Compound represented by Structural Formula (D1): Compound represented by Structural Formula (D2): Compound represented by Structural Formula (D3) = 25 3: 49.8: 24.9.

[Production Example 11]
By carrying out the same coupling reaction as in Production Example 10 except that 0.88 g of the compound represented by structural formula (4a) and 0.72 g of compound represented by structural formula (4b) were used. As a composition, 1.5 g of an azo compound composition composed of the compound represented by any one of the structural formulas (D1), (D2), and (D3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (D1): the compound represented by the structural formula (D2): the compound represented by the structural formula (D3) = 30.9: 49.3: 19.8.

[Production Example 12]
By carrying out the same coupling reaction as in Production Example 10 except that 0.60 g of the compound represented by the structural formula (4a) and 1.00 g of the compound represented by the structural formula (4b) were used. As a composition, 1.5 g of an azo compound composition composed of the compound represented by any one of the structural formulas (D1), (D2), and (D3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (D1): the compound represented by the structural formula (D2): the compound represented by the structural formula (D3) = 14.7: 46.3: 39.0.

[Comparative Production Example 7]
By carrying out the same coupling reaction as in Production Example 10 except that 1.12 g of the compound represented by structural formula (4a) and 0.48 g of compound represented by structural formula (4b) were used. As a composition, 1.6 g of an azo compound composition composed of the compound represented by any one of the structural formulas (D1), (D2), and (D3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (D1): the compound represented by the structural formula (D2): the compound represented by the structural formula (D3) = 49.3: 42.2: 8.5.

[Comparative Production Example 8]
By performing the same coupling as in Production Example 10 except that 0.4 g of the compound represented by the structural formula (4a) and 1.2 g of the compound represented by the structural formula (4b) were used, the target composition was obtained. As a product, 1.6 g of an azo compound composition composed of the compound represented by any one of the structural formulas (D1), (D2), and (D3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (D1): the compound represented by the structural formula (D2): the compound represented by the structural formula (D3) = It was 6.2: 38.8: 55.0.

[Production Example 13]
2,8.8 g of 3,6-dihydroxynaphthalic anhydride and 14.1 g of o-phenylenediamine were suspended in a mixed solvent of 86 mL of glacial acetic acid and 430 mL of nitrobenzene, and reacted with heating under reflux for 8 hours. After the reaction, the solid was collected by filtration, washed with 520 mL of methanol, and dried to obtain 35.6 g of a yellow solid. 9.1 g of the obtained yellow solid was suspended in 396 mL of DMF, and 29.0 g of potassium carbonate and 5.7 g of tosyl chloride were added. After stirring at 80 ° C. for 2 hours, 12.4 g of potassium carbonate and 16.7 g of butyl iodide (n) were added, and the mixture was further stirred for 2 hours. The reaction solution was filtered while hot and then recrystallized using DMF and water to obtain 9.5 g of a yellow solid. This yellow solid was suspended in 333 mL of ethanol, heated to reflux, and 333 mL of 1N aqueous potassium hydroxide solution was added dropwise. After stirring for 4.5 hours, the temperature was lowered, neutralized with acetic acid, and the precipitated solid was collected by filtration. This was washed with methanol to obtain 5.8 g of a yellow solid. From the measurement result of liquid chromatography, the obtained yellow solid is clearly a structural isomer mixture containing both the compound represented by the following structural formula (5a) and the compound represented by the structural formula (5b). became.

The obtained yellow solid was subjected to a separation operation by liquid chromatography to fractionate the compound represented by the structural formula (5a) and the compound represented by the structural formula (5b).
0.8 g of the compound represented by structural formula (5a) and 0.8 g of compound represented by structural formula (5b) were dissolved in 245 mL of dimethyl sulfoxide, and 2,5-bis ( A solution of 1.1 g of tetrazonium borofluoride salt of p-aminophenyl) -1,3,4-oxadiazole in 15 mL of dimethyl sulfoxide was added dropwise. Next, a solution prepared by dissolving 2.3 g of sodium acetate in 7 mL of water was dropped, and the mixture was stirred for 3 hours to carry out a coupling reaction. The precipitated solid was collected by filtration, washed successively with 10% aqueous acetic acid, water, and THF, dried, and expressed as one of the following structural formulas (E1), (E2), and (E3) as the target composition. 1.5 g of an azo compound composition comprising the above compound was obtained. Analyze this composition by liquid chromatography and calculate the composition ratio (Create a calibration curve for each component contained in the azo composition, and determine the weight of each component contained from the liquid chromatography measurement results of the composition. And the composition ratio was calculated by weight ratio). Compound represented by Structural Formula (E1): Compound represented by Structural Formula (E2): Compound represented by Structural Formula (E3) = 25 5: 49.6: 24.9.

[Production Example 14]
By performing the same coupling reaction as in Production Example 13 except that 0.72 g of the compound represented by the structural formula (5a) and 0.88 g of the compound represented by the structural formula (5b) were used. As a product, 1.5 g of an azo compound composition comprising the compound represented by any one of the structural formulas (E1), (E2) and (E3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (E1): the compound represented by the structural formula (E2): the compound represented by the structural formula (E3) = 21.0: 49.0: 30.0.

[Production Example 15]
By carrying out the same coupling reaction as in Production Example 13 except that 1.04 g of the compound represented by structural formula (5a) and 0.56 g of compound represented by structural formula (5b) were used. As a composition, 1.5 g of an azo compound composition composed of the compound represented by any one of the structural formulas (E1), (E2) and (E3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (E1): the compound represented by the structural formula (E2): the compound represented by the structural formula (E3) = 11.1: 46.1: 42.8.

[Comparative Production Example 9]
By performing the same coupling reaction as in Production Example 13 except that 1.16 g of the compound represented by the structural formula (5a) and 0.44 g of the compound represented by the structural formula (5b) were used. As a composition, 1.8 g of an azo compound composition composed of the compound represented by any one of the structural formulas (E1), (E2), and (E3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (E1): the compound represented by the structural formula (E2): the compound represented by the structural formula (E3) = It was 54.0: 39.1: 6.9.

[Comparative Production Example 10]
By performing the same coupling as in Production Example 13 except that 0.36 g of the compound represented by the structural formula (5a) and 1.24 g of the compound represented by the structural formula (5b) were used, the target composition was obtained. As a product, 1.7 g of an azo compound composition comprising the compound represented by any one of the structural formulas (E1), (E2), and (E3) was obtained. When this composition was analyzed by liquid chromatography and the composition ratio was calculated, the compound represented by the structural formula (E1): the compound represented by the structural formula (E2): the compound represented by the structural formula (E3) = 5.4: 35.6: 59.0.

[I-3. Production and Evaluation of Photoconductor]
Examples relating to a photoreceptor using an azo compound composition within the range defined in the present invention as a charge generating material will be described below using Examples 1 to 15. In addition, Comparative Examples 1 to 10 are used to compare with the case where an azo compound composition having a composition ratio outside the specified range of the present invention is used as the charge generation material.

[Example 1]
-Preparation of dispersion for forming undercoat layer Rutile titanium oxide ("TTO55N" manufactured by Ishihara Sangyo Co., Ltd.) having an average primary particle size of 40 nm and 3% by weight of methyldimethoxysilane (Toshiba Silicone Co., Ltd.) “TSL8117”) was mixed with a Henschel mixer to obtain surface-treated titanium oxide. 1 kg of a raw material slurry obtained by mixing 50 parts of the surface-treated titanium oxide and 120 parts of methanol, with a zirconia bead (YTZ manufactured by Nikkato Co., Ltd.) having a diameter of about 100 μm as a dispersion medium, a mill volume of about 0.15 L. Using an ultra apex mill (UAM-015 type) manufactured by Kotobuki Kogyo Co., Ltd., a dispersion treatment was performed for 1 hour in a liquid circulation state with a rotor peripheral speed of 10 m / second and a liquid flow rate of 10 kg / hour to prepare a titanium oxide dispersion.

  The titanium oxide dispersion, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (4) described in Examples of JP-A-4-31870 -Amino-3-methylcyclohexyl) methane [compound represented by the following formula (B)] / hexamethylenediamine [compound represented by the following formula (C)] / decamethylene dicarboxylic acid [compound represented by the following formula (D) ] / Octadecamethylene dicarboxylic acid [compound represented by the following formula (E)] having a composition molar ratio of 75% / 9.5% / 3% / 9.5% / 3% The mixture was stirred and mixed while heating to dissolve the polyamide pellets. Thereafter, ultrasonic dispersion treatment with an ultrasonic transmitter having an output of 1200 W was performed for 1 hour, and further filtered through a PTFE membrane filter (Advantech Mytex LC) having a pore diameter of 5 μm. According to the above procedure, the surface-treated titanium oxide / copolymerized polyamide has a weight ratio of 3/1, a mixed solvent of methanol / 1-propanol / toluene has a weight ratio of 7/1/2, and contains solid content. A dispersion for forming an undercoat layer having a concentration of 18.0% by weight was obtained.

-Preparation of charge generation layer coating solution 0.75 part of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "Denkabutyral"# 6000C) and 0.75 part of phenoxy resin (product of Union Carbide, PKHH) A binder solution was prepared by dissolving in 28.5 parts of 1,2-dimethoxyethane.
Subsequently, 30 parts of 1,2-dimethoxyethane was added to 1.5 parts of the azo compound composition produced in Production Example 1, and the mixture was pulverized with a sand grind mill for 8 hours for atomization and dispersion treatment. Mixed.
The binder solution was further mixed with 13.5 parts of a 9: 1 (weight ratio) mixture of 1,2-dimethoxyethane and 4-methoxy-4-methyl-2-pentanone. By the above procedure, a charge generation layer coating solution having a solid content concentration of 4.0% by weight was prepared.

-Preparation of charge transport layer coating solution 35 parts of a compound represented by the following formula (CT1), 35 parts of a compound represented by the following formula (CT2), and a polycarbonate resin represented by the following formula (BB1) (m: 100 parts of n = 51: 49, viscosity average molecular weight 30,000) were dissolved in 480 parts of tetrahydrofuran and 120 parts of toluene to prepare a charge transport layer coating solution.

-Production of a forward laminated type electrophotographic photoreceptor A material obtained by vapor-depositing aluminum on a 75 μm thick polyester film was used as a conductive support. On this, the undercoat layer-forming dispersion was applied with a wire bar so that the film thickness after drying was 1.25 μm. Furthermore, the charge generation layer coating solution was coated on the undercoat layer with a wire bar so that the film thickness after drying was 0.4 μm. This was air-dried to form a charge generation layer.
On the charge generation layer, the charge transport layer coating solution was applied with an applicator and dried at room temperature for 30 minutes and then at 125 ° C. for 20 minutes to form a charge transport layer having a thickness of 25 μm. Through the above steps, a photoreceptor E1 was obtained.

Measurement of transmittance of charge transport layer at desired wavelength The charge transport layer coating solution (charge transport layer coating solution used to obtain the photoreceptor E1) used at this time was coated on quartz glass with an applicator. The sample was dried at room temperature for 30 minutes and then at 125 ° C. for 20 minutes to form a charge transport layer sample having a thickness of 25 μm.
In order to measure the transmittance of the sample of the charge transport layer with respect to light having a wavelength of 405 nm, measurement was performed using a spectrophotometer UV1650PC manufactured by Shimadzu Corporation with an equivalent quartz glass as a background. As a result of the measurement, the transmittance was 99.9%.

[Examples 2 to 15 and Comparative Examples 1 to 10]
The same operation as in Example 1 was performed except that the azo compound compositions of Production Examples 2 to 15 and Comparative Production Examples 1 to 10 were used when preparing the charge generation layer coating solutions in the Examples and Comparative Examples. As a result, Example photoreceptors E2 to E15 and Comparative photoreceptors CE1 to CE10 were obtained.

[Comparison evaluation of the produced electrophotographic photoreceptor]
The photoreceptor obtained above is attached to an electrophotographic characteristic evaluation apparatus (basic and applied electrophotographic technology, edited by Electrophotographic Society, Corona, pages 404 to 405) prepared according to the Electrophotographic Society measurement standard. The electrical characteristics were evaluated by a cycle of charging, exposure, potential measurement, and static elimination.

Each photoconductor was wound around an aluminum drum having an outer diameter of 80 mm, the aluminum drum and the aluminum vapor deposition layer of the photoconductor were electrically connected, and the photoconductor was rotated at a constant rotational speed of 60 rpm. In an environment of a temperature of 25 ° C. and a humidity of 50%, the photosensitive member is charged so that the initial surface potential is −700 V, and exposure is performed using a laser beam having an oscillation wavelength of 405 nm, and an exposure amount (hereinafter referred to as “surface potential” of −350 V). and sometimes the sensitivity _{E 1/2),} the surface potential (hereinafter when exposed at a light quantity 1.0μJ / cm ^2, was determined) and that VL. The time from exposure to potential measurement was 389 milliseconds. 75 lux white light was used as the static elimination light, and the exposure width was 2 mm. Residual potential (hereinafter referred to as Vr) after irradiation with static elimination light was measured.

Sensitivity E1 _{/ 2} is an exposure amount required for the surface potential to be ½ of the initial potential, and the smaller the value, the higher the sensitivity. In addition, VL is a potential after exposure, and Vr is a potential after irradiation with static elimination light. In either case, a smaller value is excellent in electrical characteristics.
The measurement results are shown in Table 2 below.

[Reference Examples 1 to 25]
The photoconductor obtained above is mounted on an electrophotographic characteristic evaluation apparatus (in accordance with the electrophotographic society measurement standard, the basic and applied electrophotographic technology, edited by the Electrophotographic Society, Corona, pages 404 to 405), Evaluation of electrical characteristics by charging, exposure, potential measurement, and static elimination cycle was performed as follows, and the results are shown below.

  Irradiation energy (lux · sec) when the surface potential becomes −350 V by charging the photoreceptor so that the initial surface potential becomes −700 V under the conditions of 25 ° C. and humidity 50%, and irradiating light from a halogen lamp. ) As the sensitivity. Further, the residual potential after irradiation (hereinafter sometimes referred to as Vr) was measured using white static elimination light. The results are shown in Table 3.

  From the above results, only the electrophotographic photosensitive member containing the azo compound composition defined in the present invention is highly sensitive to monochromatic light exposure with a wavelength of 380 nm to 500 nm and exhibits a low residual potential, which is very useful. It became clear that there was.

Example 16
Implementation was performed except that a polycarbonate resin having a viscosity average molecular weight of 39,200 represented by the following formula (BB2) was used instead of the polycarbonate resin having a repeating structure represented by the formula (BB1) used in Example 1. In the same manner as in Example 1, a photoreceptor E16 was obtained. When the charge transport layer coating solution used in this example was subjected to the same operation and measurement as in “Measurement of transmittance at desired wavelength of charge transport layer” in Example 1, the transmittance was 99.9. %Met.

Example 17
The same procedure as in Example 1 was carried out except that a polycarbonate resin having a viscosity average molecular weight of 28,800 represented by the following formula (BB3) was used instead of the polycarbonate resin having a repeating structure represented by the formula (BB1). In the same manner as in Example 1, a photoconductor E17 was obtained. When the charge transport layer coating solution used in this example was subjected to the same operation and measurement as in “Measurement of transmittance at desired wavelength of charge transport layer” in Example 1, the transmittance was 99.9. %Met.

Example 18
Except for using a polycarbonate resin having a viscosity average molecular weight of 39,000 represented by the following formula (BB4) instead of the polycarbonate resin having a repeating structure represented by the formula (BB1) used in Example 10, the present invention was carried out. In the same manner as in Example 10, a photoconductor E18 was obtained. When the charge transport layer coating solution used in this example was subjected to the same operation and measurement as in “Measurement of transmittance at desired wavelength of charge transport layer” in Example 1, the transmittance was 99.9. %Met.

Example 19
Instead of the polycarbonate resin having a repeating structure represented by the formula (BB1) used in Example 4, a polyarylate resin having a viscosity average molecular weight of 41,000 having a repeating structure represented by the following formula (BB5) is used. A photoconductor E19 was obtained in the same manner as in Example 4 except for the above. When the charge transport layer coating solution used in this example was subjected to the same operation and measurement as in “Measurement of transmittance at desired wavelength of charge transport layer” in Example 1, the transmittance was 99.9. %Met.

Example 20
Instead of the polycarbonate resin having a repeating structure represented by the formula (BB1) used in Example 13, a polycarbonate resin having a viscosity average molecular weight of 41,000 having a repeating structure represented by the following formula (BB6) was used. A photoconductor E20 was obtained in the same manner as in Example 13 except for the above. When the charge transport layer coating solution used in this example was subjected to the same operation and measurement as in “Measurement of transmittance at desired wavelength of charge transport layer” in Example 1, the transmittance was 99.9. %Met.

[Evaluation of the produced electrophotographic photoreceptor]
The electrophotographic photoreceptors obtained in Examples 16 to 20 were evaluated in the same manner as in Examples 1 to 15 and Comparative Examples 1 to 10 described above. The evaluation results are as shown in Table 4 below.

  From the above results, it can be seen that the electrophotographic photosensitive member of the present invention exhibits good electrical characteristics even in various binders for charge transport layers.

[II. Examples relating to image quality evaluation when images are formed]
[II-1. Preparation of photoconductor]
Example 21
-Preparation of undercoat layer Rutile type titanium oxide having an average primary particle size of 40 nm ("TTO55N" manufactured by Ishihara Sangyo Co., Ltd.) and 3% by weight of methyldimethoxysilane ("TSL8117" manufactured by Toshiba Silicone Co., Ltd.) )) Was mixed with a Henschel mixer to obtain surface-treated titanium oxide. 1 kg of a raw material slurry obtained by mixing 50 parts of the surface-treated titanium oxide and 120 parts of methanol, with a zirconia bead (YTZ manufactured by Nikkato Co., Ltd.) having a diameter of about 100 μm as a dispersion medium, a mill volume of about 0.15 L. Using an ultra apex mill (UAM-015 type) manufactured by Kotobuki Kogyo Co., Ltd., a titanium oxide dispersion was prepared by performing a dispersion treatment for 1 hour in a liquid circulation state with a rotor peripheral speed of 10 m / second and a liquid flow rate of 10 kg / hour.

  The titanium oxide dispersion, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (described in Examples of JP-A-4-31870) 4-amino-3-methylcyclohexyl) methane [compound represented by the following formula (B)] / hexamethylenediamine [compound represented by the following formula (C)] / decamethylene dicarboxylic acid [represented by the following formula (D) Compound] / octadecamethylenedicarboxylic acid [compound represented by the following formula (E)] having a composition molar ratio of 75% / 9.5% / 3% / 9.5% / 3, The mixture was stirred and mixed while heating to dissolve the polyamide pellets. Thereafter, ultrasonic dispersion treatment with an ultrasonic transmitter having an output of 1200 W was performed for 1 hour, and further filtered through a PTFE membrane filter (Advantech Mytex LC) having a pore diameter of 5 μm. According to the above procedure, the surface-treated titanium oxide / copolymerized polyamide has a weight ratio of 3/1, a mixed solvent of methanol / 1-propanol / toluene has a weight ratio of 7/1/2, and contains solid content. A dispersion for forming an undercoat layer having a concentration of 18.0% by weight was obtained.

  This undercoat layer forming dispersion A is dip-coated on an anodized aluminum cylinder (outer diameter 30 mm, length 375.8 mm, thickness 0.75 mm), and the film thickness after drying is 1.5 μm. An undercoat layer was provided so as to be.

Preparation of charge generation layer 0.75 part of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “Denkabutyral” # 6000C) and 0.75 part of phenoxy resin (product of Union Carbide, PKHH) A binder solution was prepared by dissolving in 28.5 parts of 2-dimethoxyethane.
Subsequently, 30 parts of 1,2-dimethoxyethane was added to 1.5 parts of the azo compound composition produced in Production Example 1, and the mixture was pulverized with a sand grind mill for 8 hours for atomization and dispersion treatment. Mixed.
The binder solution was further mixed with 13.5 parts of a 9: 1 (weight ratio) mixture of 1,2-dimethoxyethane and 4-methoxy-4-methyl-2-pentanone. By the above procedure, a charge generation layer coating solution having a solid content concentration of 4.0% by weight was prepared.
On the undercoat layer formed using the dispersion A for forming the undercoat layer, the charge generation layer coating solution was dip-coated so that the film thickness after drying was 0.4 μm. This was air-dried to form a charge generation layer.

Preparation of charge transport layer 35 parts of the compound represented by the formula (CT1), 35 parts of the compound represented by the formula (CT2), 8 parts of the antioxidant represented by the following formula (AO1), and a leveling agent 0.05 part of silicone oil (KF96 manufactured by Shin-Etsu Chemical Co., Ltd.), 100 parts of a polycarbonate resin (m: n = 51: 49, viscosity average molecular weight 30,000) represented by the above formula (BB1) were added to 480 tetrahydrofuran. Part and 120 parts of toluene to prepare a charge transport layer coating solution.

  On the above-described charge generation layer, a charge transport layer coating solution was dip-coated so that the film thickness after drying was 18 μm, to obtain a photoreceptor drum E21 having a laminated photosensitive layer.

[Example 22]
The azo compound composition used in Example 21 is changed to that obtained in Production Example 3, and an aluminum cylinder is subjected to anodizing treatment, and thereafter sealing treatment is performed with a sealing agent mainly composed of nickel acetate. The photosensitive drum E22 was obtained in the same manner as in Example 21 except that an anodic oxide coating (alumite coating) of about 6 μm was formed and the undercoat layer was not applied.

Example 23
A photoconductor drum E23 was obtained in the same manner as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Production Example 4.

Example 24
A photoconductor drum E24 was obtained in the same manner as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Production Example 5.

Example 25
A photoconductor drum E25 was obtained in the same manner as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Production Example 7.

Example 26
A photoconductor drum E26 was obtained in the same manner as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Production Example 9.

Example 27
A photoconductor drum E27 was obtained in the same manner as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Production Example 10.

Example 28
The azo compound composition used in Example 21 was changed to that obtained in Production Example 11, an aluminum cylinder was subjected to anodizing treatment, and then sealing treatment was performed with a sealing agent mainly composed of nickel acetate. Thus, an anodized film (alumite film) of about 6 μm was formed, and a photosensitive drum E28 was obtained by carrying out the same operations as in Example 21 except that the undercoat layer was not applied.

Example 29
A photoconductor drum E29 was obtained in the same manner as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Production Example 13.

Example 30
A photoconductor drum E30 was obtained in the same manner as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Production Example 15.

[Comparative Example 11]
A photosensitive drum CE11 was obtained by the same operation as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Comparative Production Example 1.

[Comparative Example 12]
Photosensitive drum CE12 was obtained by performing the same operation as in Example 21 except that the azo compound composition used in Example 21 was changed to that obtained in Comparative Production Example 4.

[Comparative Example 13]
A photoconductive drum CE13 was obtained by carrying out the same operations as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Comparative Production Example 6.

[Comparative Example 14]
A photosensitive drum CE14 was obtained by the same operation as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Comparative Production Example 8.

[Comparative Example 15]
A photosensitive drum CE15 was obtained by the same operation as in Example 21, except that the azo compound composition used in Example 21 was changed to that obtained in Comparative Production Example 10.

[II-2. Preparation of toner]
[Measurement method and definition of volume average diameter (Mv)]
The volume average diameter (Mv) of the particles having a volume average diameter (Mv) of less than 1 μm is determined by the handling of nanotracks using Nikkiso Co., Ltd., model: Microtrac Nanotrac 150 (hereinafter abbreviated as “nanotrack”). According to the instructions, the company's analysis software Microtrac Particle Analyzer Ver10.1.2. Using −019EE, ion-exchanged water having an electric conductivity of 0.5 μS / cm was used as a dispersion medium, and measurement was performed by the method described in the instruction manual under the following conditions or the following conditions, respectively.

The following conditions were used for the wax dispersion and the polymer primary particle dispersion.
Solvent refractive index: 1.333
-Measurement time: 100 seconds-Number of measurements: 1 time-Particle refractive index: 1.59
-Permeability: Transmission-Shape: True spherical shape-Density: 1.04

The following conditions were used for the pigment premix solution and the colorant dispersion.
Solvent refractive index: 1.333
-Measurement time: 100 seconds-Number of measurements: 1 time-Particle refractive index: 1.59
・ Transparency: Absorption ・ Shape: Non-spherical shape ・ Density: 1.00

[Measurement method and definition of volume median diameter (Dv50)]
As a pre-measurement treatment of the toner finally obtained through the external addition step, the following was performed. In a cylindrical polyethylene (PE) beaker having an inner diameter of 47 mm and a height of 51 mm, 0.100 g of toner using a spatula, and 20 wt% DBS aqueous solution using a syringe (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S-20A) 0.15 g was added. At this time, toner and a 20% DBS aqueous solution were added only to the bottom of the beaker so that the toner would not scatter on the edge of the beaker. Next, the mixture was stirred for 3 minutes using a spatula until the toner and 20% DBS aqueous solution became a paste. At this time, the toner was prevented from being scattered on the edge of the beaker.

  Subsequently, 30 g of dispersion medium Isoton II (manufactured by Beckman Coulter, Inc.) was added, and the mixture was stirred for 2 minutes using a spatula to make a uniform solution visually. Next, a fluororesin-coated rotor having a length of 31 mm and a diameter of 6 mm was placed in a beaker and dispersed using a stirrer at 400 rpm for 20 minutes. At this time, using a spatula at a rate of once every 3 minutes, macroscopic particles visually observed at the gas-liquid interface and the edge of the beaker were dropped into the beaker so as to form a uniform dispersion. Subsequently, this was filtered through a mesh having an opening of 63 μm, and the obtained filtrate was designated as “toner dispersion”.

  Regarding the measurement of the particle diameter during the production process of the toner base particles, the filtrate obtained by filtering the agglomerated slurry with a 63 μm mesh was used as the “slurry liquid”.

  The volume median diameter (Dv50) of the particles is Bocman Coulter's Multisizer III (aperture diameter 100 μm) (hereinafter abbreviated as “Multisizer”), the dispersion medium is Isoton II, and the above-mentioned “ The “toner dispersion” or “slurry” was diluted to a dispersoid concentration of 0.03% by weight and measured with Multisizer III analysis software with a KD value of 118.5. The measurement particle size range is from 2.00 μm to 64.00 μm, and this range is discretized into 256 divisions so as to be equally spaced on a logarithmic scale, and the volume calculated based on the statistical values on the basis of the volume is the volume. The median diameter (Dv50) was used.

[Measurement Method and Definition of Number% (Dns) of Toner with Particle Size of 2.00 μm to 3.56 μm]
As a pre-measurement process for the toner after the external addition step, the following procedure was performed. In a cylindrical polyethylene (PE) beaker having an inner diameter of 47 mm and a height of 51 mm, 0.100 g of toner using a spatula, and 20 wt% DBS aqueous solution using a syringe (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S-20A) 0.15 g was added. At this time, toner and a 20% DBS aqueous solution were added only to the bottom of the beaker so that the toner would not scatter on the edge of the beaker. Next, the mixture was stirred for 3 minutes using a spatula until the toner and 20% DBS aqueous solution became a paste. At this time, the toner was prevented from being scattered on the edge of the beaker.

  Subsequently, 30 g of dispersion medium Isoton II was added, and the mixture was stirred for 2 minutes using a spatula, and the whole was made into a uniform solution visually. Next, a fluororesin-coated rotor having a length of 31 mm and a diameter of 6 mm was placed in a beaker and dispersed using a stirrer at 400 rpm for 20 minutes. At this time, macroscopic particles visually observed at the gas-liquid interface and the edge of the beaker were dropped into the beaker at a rate of once every 3 minutes so as to form a uniform dispersion. Subsequently, this was filtered with a mesh having an opening of 63 μm, and the obtained filtrate was used as a toner dispersion.

  For the number% (Dns) of toner having a particle size of 2.00 μm or more and 3.56 μm or less, a multisizer (aperture diameter 100 μm) is used, and Isoton II manufactured by the same company is used as a dispersion medium. The “slurry liquid” was diluted to a dispersoid concentration of 0.03% by weight and measured with Multisizer III analysis software with a KD value of 118.5.

  The lower limit particle size of 2.00 μm is the detection limit of the measuring device multisizer, and the upper limit particle size of 3.56 μm is a prescribed channel value in the measuring device multisizer. In the present invention, an area having a particle size of 2.00 μm or more and 3.56 μm or less is recognized as a fine powder area.

  The measurement particle size range is from 2.00 μm to 64.00 μm, and this range is discretized into 256 divisions at equal intervals on a logarithmic scale, and 2.00 μm based on the statistical values on the basis of their number. To 3.56 μm, the ratio of the particle size component was calculated on the basis of the number and was defined as “Dns”. In the case where the toner is one obtained by fixing or adhering an external additive to the surface of the toner base particles, it was measured as a measurement sample.

[Measurement method and definition of average circularity]
“Average circularity” was measured as follows and defined as follows. That is, the toner base particles are dispersed in a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) in a range of 5720 / μL or more and 7140 / μL or less, and a flow type particle image analyzer (Sysmex Corporation (formerly Toa) Using FPIA2100) manufactured by Medical Electronics Co., Ltd., measurement was performed under the following apparatus conditions, and the value was defined as “average circularity”. In the following examples and the like, the same measurement was performed three times, and an arithmetic average value of three “average circularity” was adopted as the “average circularity”. In the case where the toner is one obtained by fixing or adhering an external additive to the surface of the toner base particles, it was measured as a measurement sample.
・ Mode: HPF
-HPF analysis amount: 0.35 μL
-HPF detection number: 2000-2500

The following is measured by the apparatus and automatically calculated and displayed in the apparatus. The “circularity” is defined by the following equation.
[Circularity] = [Perimeter of a circle with the same area as the projected particle area] / [Perimeter of projected particle image]
Then, 2000 or more and 2500 or less, which is the number of HPF detected, is measured, and the arithmetic average (arithmetic mean) of the circularity of each particle is displayed on the apparatus as “average circularity”.

[Method and definition of number variation coefficient]
The “number variation coefficient” is defined as follows.
[Number variation coefficient] = 100 × [standard deviation of particle distribution based on number] / [number average particle diameter]

  The standard deviation of the number-based particle distribution and the number average particle diameter were measured using Multisizer III according to the method of measuring the volume median diameter (Dv50). The measurement particle range is from 2.00 μm to 64.00 μm, and this range is discretized into 256 divisions at equal intervals in the logarithmic memory, and the number-based particle distribution based on the statistical values based on the number-based number. And the number variation coefficient was calculated from the above formula.

[Measurement method of electrical conductivity]
The electrical conductivity was measured using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation) according to an ordinary method according to the instruction manual.

[Measuring method of melting point peak temperature, melting peak half width, crystallization temperature, crystallization peak half width]
From the endothermic curve when the temperature is raised from 10 ° C. to 110 ° C. at a rate of 10 ° C./min using the method described in the company's instruction manual using Seiko Instruments Inc. model: SSC5200, the melting point peak temperature The half-width of the melting peak was measured, and then the crystallization temperature and the half-width of the crystallization peak were measured from the exothermic curve when the temperature was lowered from 110 ° C. to 10 ° C. at a rate of 10 ° C./min.

[Measurement method of solid content concentration]
Using a solid content concentration measuring instrument INFRARED MOISTURE DETERMINATION BALANCE model FD-100, manufactured by Kett Science Laboratory, weighed 1.00 g of a sample containing solid content on a balance, and the conditions of a heater temperature of 300 ° C. and a heating time of 90 minutes The solid content concentration was measured.

[Measurement method of charge amount distribution (standard deviation of charge amount)]
0.8 g of toner / carrier (19.2 g of ferrite carrier manufactured by Powdertech Co., Ltd.) was placed in a glass sample bottle and stirred for 30 minutes at 250 rpm using a reciprocating shaker NR-1 (manufactured by Taitec Corporation). The stirred toner / carrier mixture was subjected to charge amount distribution measurement using an E-Spart charge amount distribution measuring apparatus (manufactured by Hosokawa Micron Corporation). The value obtained by dividing the charge amount of each particle by the particle diameter is obtained from the obtained data (the range from −16.197 C / μm to +16.197 C / μm is discretized into 128 divisions every 0.2551 C / μm). The standard deviation of the 3000 particle measurement results was obtained and used as the standard deviation of the charge amount.

[Toner Production Example 1]
(Preparation of wax / long-chain polymerizable monomer dispersion A1)
Paraffin wax (Nihon Seiki Co., Ltd. HNP-9, surface tension 23.5 mN / m, thermal characteristics: melting point peak temperature 82 ° C., melting heat 220 J / g, melting peak half width 8.2 ° C., crystallization temperature 66 ° C., Crystallization peak half width 13.0 ° C.) 27 parts (540 g), stearyl acrylate (Tokyo Kasei Co., Ltd.) 2.8 parts, 20 wt% sodium dodecylbenzenesulfonate aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20A) ( (Hereinafter abbreviated as “20% DBS aqueous solution”) 1.9 parts and 68.3 parts of demineralized water are heated to 90 ° C. and stirred for 10 minutes using a homomixer (Mark II f model, manufactured by Tokushu Kika Kogyo Co., Ltd.). did.

  Next, this dispersion was heated to 90 ° C., and circulation emulsification was started under a pressure condition of 25 MPa using a homogenizer (manufactured by Gorin, 15-M-8PA type). Dispersion was carried out until (Mv) reached 250 nm to prepare a wax / long-chain polymerizable monomer dispersion A1 (emulsion solid content concentration = 30.2 wt%).

(Preparation of polymer primary particle dispersion A1)
In a reactor (inner volume 21 L, inner diameter 250 mm, height 420 mm) equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device, the wax / long-chain polymerizable unit The monomer dispersion A1 (35.6 parts, 712.12 g) and 259 parts of demineralized water were charged, and the temperature was raised to 90 ° C. under a nitrogen stream while stirring.

  Then, the mixture of the following “polymerizable monomers etc.” and “emulsifier aqueous solution” was added to the solution over 5 hours while stirring the liquid. The point at which this mixture was started to be dropped was designated as “polymerization start”, and the following “initiator aqueous solution” was added over 4.5 hours from 30 minutes after the start of polymerization. Further, after 5 hours from the start of polymerization, the following “addition start” The agent aqueous solution ”was added over 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Polymerizable monomers, etc.]
Styrene 76.8 parts (1535.0 g)
Butyl acrylate 23.2 parts Acrylic acid 1.5 parts Hexanediol diacrylate 0.7 parts Trichlorobromomethane 1.0 part

[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Demineralized water 67.1 parts

[Initiator aqueous solution]
8% by weight aqueous hydrogen peroxide solution 15.5 parts 8% by weight L (+)-ascorbic acid aqueous solution 15.5 parts

[Additive initiator aqueous solution]
8 wt% L (+)-ascorbic acid aqueous solution 14.2 parts

  After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion A1. The volume average diameter (Mv) measured using Nanotrac was 280 nm, and the solid content concentration was 21.1% by weight.

(Preparation of polymer primary particle dispersion A2)
A 20 wt% DBS aqueous solution 1.0 was added to a reactor (inner volume 21 L, inner diameter 250 mm, height 420 mm) equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device. And 312 parts of demineralized water, heated to 90 ° C. under a nitrogen stream, and stirred with stirring, 3.2 parts of 8% by weight aqueous hydrogen peroxide solution and 3.2 parts of 8% by weight L (+)-ascorbic acid aqueous solution Were added all at once. The time point 5 minutes after the batch addition of these is defined as “polymerization start”.

  Thereafter, a mixture of the following “polymerizable monomers etc.” and “emulsifier aqueous solution” was added over 5 hours from the start of polymerization, and the following “initiator aqueous solution” was added over 6 hours from the start of polymerization. The inner temperature was maintained at 90 ° C. for 1 hour with further stirring.

[Polymerizable monomers, etc.]
92.5 parts of styrene (1850.0 g)
Butyl acrylate 7.5 parts Acrylic acid 0.5 parts Trichlorobromomethane 0.5 parts

[Emulsifier aqueous solution]
20% DBS aqueous solution 1.5 parts Demineralized water 66.0 parts

[Initiator aqueous solution]
8 wt% aqueous hydrogen peroxide solution 18.9 parts 8 wt% L (+)-ascorbic acid aqueous solution 18.9 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion A2. The volume average diameter (Mv) measured using Nanotrac was 290 nm, and the solid content concentration was 19.0% by weight.

(Preparation of colorant dispersion A)
Carbon black (Mitsubishi Chemical Co., Ltd.) manufactured by a furnace method with a 300 L internal volume equipped with a stirrer (propeller blade) and a toluene extract having an ultraviolet absorbance of 0.02 and a true density of 1.8 g / cm ³ Mitsubishi Carbon Black MA100S) 20 parts (40 kg), 20% DBS aqueous solution 1 part, nonionic surfactant (manufactured by Kao Corp., Emulgen 120) 4 parts, ion-exchanged water 75 parts with an electric conductivity of 2 μS / cm In addition, it was predispersed to obtain a pigment premix solution. The volume average diameter (Mv) of carbon black in the dispersion after pigment premixing measured with Nanotrac was 90 μm.

The pigment premix solution was supplied as a raw material slurry to a wet bead mill and subjected to one-pass dispersion. The inner diameter of the stator was φ75 mm, the separator diameter was φ60 mm, the distance between the separator and the disk was 15 mm, and zirconia beads having a diameter of 100 μm (true density of 6.0 g / cm ³ ) were used as a dispersion medium. Since the effective internal volume of the stator is 0.5 L and the filling volume of the media is 0.35 L, the media filling rate is 70% by weight. The pigment premix liquid is continuously supplied from the supply port at a supply speed of 50 L / hr by a non-pulsating metering pump, and the rotor rotation speed is constant (peripheral speed at the rotor tip is 11 m / sec), and continuously from the discharge port. To obtain a black colorant dispersion A. The volume average diameter (Mv) of the colorant dispersion A measured with Nanotrac was 150 nm, and the solid content concentration was 24.2% by weight.

(Production of toner mother particle A)
By using the following components, toner base particles A were produced by performing the following aggregation processes (core material aggregation process, shell coating process), circularization process, washing process, and drying process.
Polymer primary particle dispersion A1 95 parts as solid content (998.2 g as solid content)
Polymer primary particle dispersion A2 5 parts as solid content Colorant dispersion A 6 parts as colorant solid content 20% DBS aqueous solution In the core material agglomeration step, 0.2 parts 20% DBS aqueous solution as solid content In the circularization step, 6 parts solids

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device The liquid A1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 7 ° C. for 5 minutes. Subsequently, with stirring at 250 ° C. at an internal temperature of 7 ° C., 0.52 part of a 5 wt% aqueous solution of ferrous sulfate as FeSO ₄ .7H ₂ O was added over 5 minutes, and then the colorant dispersion A Was added uniformly over 5 minutes, and the mixture was uniformly mixed at an internal temperature of 7 ° C., and a 0.5 wt% aqueous solution of aluminum sulfate was added dropwise over 8 minutes under the same conditions (solid content relative to resin solid content). 0.10 parts). Thereafter, the internal temperature was raised to 54.0 ° C. while maintaining the rotational speed of 250 rpm, the volume median diameter (Dv50) was measured using a multisizer, and grown to 5.32 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion A2 was added over 3 minutes while maintaining the internal temperature of 54.0 ° C and the rotation speed of 250 rpm, and the state was maintained for 60 minutes.

○ Circularization process Subsequently, the rotational speed was reduced to 150 rpm (a peripheral speed of 1.56 m / second at the tip of the stirring blade, a stirring speed reduced by 40% with respect to the rotational speed of the aggregation process), and then a 20% DBS aqueous solution (solid content) 6 parts) was added over 10 minutes, and then the temperature was raised to 81 ° C. over 30 minutes, and heating and stirring were continued under these conditions until the average circularity reached 0.943. Thereafter, the mixture was cooled to 30 ° C. over 20 minutes to obtain a slurry.

Washing step The obtained slurry was extracted and suction filtered with an aspirator using 5 types C (Toyo Filter Paper No. 5C) filter paper. The cake remaining on the filter paper is transferred to a stainless steel container having an internal volume of 10 L equipped with a stirrer (propeller blade), and 8 kg of ion exchange water having an electric conductivity of 1 μS / cm is added and stirred uniformly at 50 rpm. Thereafter, stirring was continued for 30 minutes.

  Thereafter, the filter paper was suction filtered with an aspirator again using Type 5 C (Toyo Filter Paper No. 5C) filter paper, and the solid matter remaining on the filter paper was again equipped with a stirrer (propeller blade) and had an electrical conductivity of 1 μS / cm. It was transferred to a container with an internal volume of 10 L containing 8 kg of ion-exchanged water, and uniformly dispersed by stirring at 50 rpm and kept stirring for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm.

○ Drying step The solid material obtained here was spread on a stainless steel bat so that the height was 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain toner mother particles A.

(Manufacture of toner A)
External Addition Step To 250 g of the obtained toner base particles A, 1.55 g of H2000 silica manufactured by Clariant and 0.62 g of SMT150IB titania fine powder manufactured by Teika are mixed as an external additive, and a sample mill (manufactured by Kyoritsu Riko) is used. The toner A was obtained by mixing at 6000 rpm for 1 minute and sieving with 150 mesh.

Analyzing Step The “volume median diameter (Dv50)” measured using the toner A multisizer obtained here is 5.54 μm, and “number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 3.83%, the average circularity was 0.943, and the number variation coefficient was 18.6%.

[Toner Production Example 2]
(Production of toner mother particle B)
In the agglomeration step (core material agglomeration step, shell coating step), rounding step, washing step and drying step of “manufacturing toner mother particle A”, “core material agglomeration step”, “shell coating step” and “circularization step” The toner mother particles B were obtained in the same manner as in “Production of toner mother particles A” in Toner Production Example 1 except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device The liquid A1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 7 ° C. for 5 minutes. Subsequently, while maintaining the internal temperature at 7 ° C. and continuing stirring at 250 rpm, 0.52 part of 5 wt% aqueous solution of ferrous sulfate as FeSO ₄ · 7H ₂ O was added over 5 minutes, and then the colorant Dispersion A was added over 5 minutes, mixed uniformly at an internal temperature of 7 ° C., and a 0.5 wt% aqueous solution of aluminum sulfate was added dropwise over 8 minutes under the same conditions (based on the resin solid content). Solid content is 0.10 parts). Thereafter, the internal temperature was raised to 55.0 ° C. while maintaining the rotational speed of 250 rpm, the volume median diameter (Dv50) was measured using a multisizer, and grown to 5.86 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion A2 was added over 3 minutes while maintaining the internal temperature at 55.0 ° C. and the rotation speed at 250 rpm, and held as it was for 60 minutes.

○ Circularization process Subsequently, the rotation speed was reduced to 150 rpm (a peripheral speed of 1.56 m / second at the tip of the stirring blade, a stirring speed reduced by 40% with respect to the rotation speed of the aggregation process), and then a 20% DBS aqueous solution (as solid content) 6 parts) was added over 10 minutes, and then the temperature was raised to 84 ° C. over 30 minutes, and heating and stirring were continued until the average circularity reached 0.942. Thereafter, it was cooled to 30 ° C. over 20 minutes to obtain a slurry.

(Manufacture of toner B)
Thereafter, the toner B was prepared in the same manner as in “Production of Toner A” except that the amount of H2000 silica as an external additive was changed to 1.41 g and the amount of SMT150IB titania fine powder was changed to 0.56 g. Got.

Analyzing Step The volume median diameter (Dv50) measured by using the multisizer of toner B obtained here is 5.97 μm, and “the number% of toner having a particle diameter of 2.00 μm to 3.56 μm (Dns ) ”Was 2.53%, the average circularity was 0.943, and the number variation coefficient was 18.4%.

[Toner Production Example 3]
(Production of toner mother particles C)
In the agglomeration step (core material agglomeration step, shell coating step), rounding step, washing step and drying step of “manufacturing toner mother particle A”, “core material agglomeration step”, “shell coating step” and “circularization step” The toner mother particles C were obtained in the same manner as in “Production of toner mother particles A” in Toner Production Example 1 except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device The liquid A1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 7 ° C. for 5 minutes. Subsequently, while maintaining the internal temperature at 7 ° C. and adding stirring at 250 rpm, 0.52 parts of FeSO ₄ · 7H ₂ O as a 5 wt% aqueous solution of ferrous sulfate was added over 5 minutes, and then the colorant was dispersed. Liquid A was added over 5 minutes, mixed uniformly at an internal temperature of 7 ° C., and a 0.5 wt% aqueous solution of aluminum sulfate was added dropwise over 8 minutes under the same conditions (solid to resin solids). Min is 0.10 parts). Thereafter, the internal temperature was raised to 57.0 ° C. while maintaining the rotational speed of 250 rpm, and the volume median diameter (Dv50) was measured using a multisizer to grow it to 6.72 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion A2 was added over 3 minutes while maintaining the internal temperature at 57.0 ° C and the rotation speed at 250 rpm, and held as it was for 60 minutes.

○ Circularization process Subsequently, the rotational speed was reduced to 150 rpm (a peripheral speed of 1.56 m / second at the tip of the stirring blade, a stirring speed reduced by 40% with respect to the rotational speed of the aggregation process), and then a 20% DBS aqueous solution (solid content) 6 parts) was added over 10 minutes, and then heated to 87 ° C. over 30 minutes, and heating and stirring were continued until the average circularity reached 0.941. Thereafter, it was cooled to 30 ° C. over 20 minutes to obtain a slurry.

(Manufacture of toner C)
Thereafter, the toner C was prepared in the same manner as in “Production of toner A” except that the amount of H2000 silica as an external additive was changed to 1.25 g and the amount of SMT150IB titania fine powder was changed to 0.50 g. Got.

Analyzing Step The volume median diameter (Dv50) measured by using the multisizer of toner C obtained here is 6.75 μm, and “the number% of toner having a particle diameter of 2.00 μm to 3.56 μm (Dns ) ”Was 1.83%, the average circularity was 0.942, and the number variation coefficient was 18.7%.

[Toner Production Example 4]
(Manufacture of toner mother particles D)
In the agglomeration step (core material agglomeration step, shell coating step), rounding step, washing step and drying step of “manufacturing toner mother particle A”, “core material agglomeration step”, “shell coating step” and “circularization step” The toner mother particles D were obtained in the same manner as in “Production of toner mother particles A” in Toner Production Example 1 except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device The liquid A1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 7 ° C. for 5 minutes. Subsequently, while maintaining the internal temperature at 21 ° C. and adding stirring at 250 rpm, 0.52 parts of FeSO ₄ · 7H ₂ O as a 5 wt% aqueous solution of ferrous sulfate was added over 5 minutes, and then the colorant was dispersed. Liquid A was added over 5 minutes, mixed uniformly at an internal temperature of 7 ° C., and a 0.5 wt% aqueous solution of aluminum sulfate was added dropwise over 8 minutes under the same conditions (solid to resin solids). Min is 0.10 parts). Thereafter, the internal temperature was raised to 54.0 ° C. while maintaining the rotational speed of 250 rpm, the volume median diameter (Dv50) was measured using a multisizer, and grown to 5.34 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion A2 was added over 3 minutes while maintaining the internal temperature of 54.0 ° C and the rotation speed of 250 rpm, and the state was maintained for 60 minutes.

○ Circularization process Subsequently, the rotation speed was reduced to 220 rpm (circumferential speed 2.28 m / sec at the tip of the stirring blade, stirring speed reduced by 12% with respect to the aggregation process rotation speed), and then 20% DBS aqueous solution (as solid content) 6 parts) was added over 10 minutes, then the temperature was raised to 81 ° C. over 30 minutes, and heating and stirring were continued until the average circularity reached 0.942. Then, it cooled to 30 degreeC over 20 minutes, and obtained the slurry.

(Manufacture of toner D)
Thereafter, a toner D was obtained by the same operation of the external addition process as in “Production of Toner A” in Toner Production Example 1.

Analyzing Step The volume median diameter (Dv50) of the toner D obtained here measured using a multisizer is 5.48 μm, and “the number% of toner having a particle size of 2.00 μm to 3.56 μm (Dns ) "Was 4.51%, the average circularity was 0.943, and the number variation coefficient was 20.4%.

[Toner Production Example 5]
(Manufacture of toner mother particles E)
In the agglomeration step (core material agglomeration step, shell coating step), rounding step, washing step and drying step of “manufacturing toner mother particle A”, “core material agglomeration step”, “shell coating step” and “circularization step” The toner mother particles E were obtained in the same manner as in “Production of toner mother particles A” in Toner Production Example 1 except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device The liquid A1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 7 ° C. for 5 minutes. Subsequently, while maintaining the internal temperature at 21 ° C. and adding stirring at 250 rpm, 0.52 parts of FeSO ₄ · 7H ₂ O as a 5 wt% aqueous solution of ferrous sulfate was added over 5 minutes, and then the colorant was dispersed. Liquid A was added over 5 minutes, mixed uniformly at an internal temperature of 7 ° C., and a 0.5 wt% aqueous solution of aluminum sulfate was added dropwise over 8 minutes under the same conditions (solid to resin solids). Min is 0.10 parts). Thereafter, the internal temperature was raised to 55.0 ° C. while maintaining the rotational speed of 250 rpm, the volume median diameter (Dv50) was measured using a multisizer, and grown to 5.86 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion A2 was added over 3 minutes while maintaining the internal temperature at 55.0 ° C. and the rotation speed at 250 rpm, and held as it was for 60 minutes.

○ Circularization process Subsequently, the rotational speed was reduced to 220 rpm (a peripheral speed of 2.28 m / second at the tip of the stirring blade, a stirring speed reduced by 12% with respect to the rotational speed of the aggregation process), and then a 20% DBS aqueous solution (solid content) 6 parts) was added over 10 minutes, and then the temperature was raised to 84 ° C. over 30 minutes, and heating and stirring were continued until the average circularity reached 0.941. Thereafter, it was cooled to 30 ° C. over 20 minutes to obtain a slurry.

(Manufacture of toner E)
Thereafter, the toner E was changed in the same manner as in “Production of Toner A” except that the amount of H2000 silica as an external additive was changed to 1.41 g and the amount of SMT150IB titania fine powder was changed to 0.56 g. Got.

Analyzing Step The volume median diameter (Dv50) measured using a multisizer of the developing toner E obtained here is 5.93 μm, and “the number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 3.62%, the average circularity was 0.942, and the number variation coefficient was 20.1%.

[Toner Production Example 6]
(Manufacture of toner mother particles F)
In the agglomeration step (core material agglomeration step, shell coating step), rounding step, washing step and drying step of “manufacturing toner mother particle A”, “core material agglomeration step”, “shell coating step” and “circularization step” The toner mother particles F were obtained in the same manner as in “Production of toner mother particles A” in Toner Production Example 1 except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device The liquid A1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 7 ° C. for 5 minutes. Subsequently, while maintaining the internal temperature at 21 ° C. and adding stirring at 250 rpm, 0.52 parts of FeSO ₄ · 7H ₂ O as a 5 wt% aqueous solution of ferrous sulfate was added over 5 minutes, and then the colorant was dispersed. Liquid A was added over 5 minutes, mixed uniformly at an internal temperature of 7 ° C., and a 0.5 wt% aqueous solution of aluminum sulfate was added dropwise over 8 minutes under the same conditions (solid to resin solids). Min is 0.10 parts). Thereafter, the internal temperature was raised to 57.0 ° C. while maintaining the rotational speed of 250 rpm, and the volume median diameter (Dv50) was measured using a multisizer to grow it to 6.76 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion A2 was added over 3 minutes while maintaining the internal temperature at 57.0 ° C and the rotation speed at 250 rpm, and held as it was for 60 minutes.

○ Circularization process Subsequently, the rotational speed was reduced to 220 rpm (a peripheral speed of 2.28 m / second at the tip of the stirring blade, a stirring speed reduced by 12% with respect to the rotational speed of the aggregation process), and then a 20% DBS aqueous solution (solid content) 6 parts) was added over 10 minutes, and then heated to 87 ° C. over 30 minutes, and heating and stirring were continued until the average circularity reached 0.941. Thereafter, it was cooled to 30 ° C. over 20 minutes to obtain a slurry.

(Manufacture of toner F)
Thereafter, the amount of H2000 silica as an external additive was changed to 1.25 g, and the amount of SMT150IB titania fine powder was changed to 0.50 g. Got.

Analyzing Step The volume median diameter (Dv50) measured by using the multisizer of toner F obtained here is 6.77 μm, and “the number% of toner having a particle size of 2.00 μm to 3.56 μm (Dns ) ”Was 2.48%, the average circularity was 0.942, and the number variation coefficient was 21.1%.

[Toner Comparative Production Example 1]
(Manufacture of toner mother particles G)
In the agglomeration step (core material agglomeration step, shell coating step), rounding step, washing step and drying step of “manufacturing toner mother particle A”, “core material agglomeration step”, “shell coating step” and “circularization step” The toner mother particles G were obtained in the same manner as in “Production of toner mother particles A” in Toner Production Example 1 except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device The liquid A1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 7 ° C. for 5 minutes. Subsequently, while maintaining the internal temperature at 21 ° C. and continuously stirring at 250 rpm, 0.52 parts of FeSO ₄ · 7H ₂ O as a 5 wt% aqueous solution of ferrous sulfate was added all at once in 5 minutes, and then the colorant was dispersed. Liquid A was added all at once in 5 minutes, mixed uniformly at an internal temperature of 7 ° C., and 0.5 wt% aqueous aluminum sulfate solution was added all at once in 8 seconds under the same conditions (solid to resin solids). Min is 0.10 parts). Thereafter, the internal temperature was raised to 57.0 ° C. while maintaining the rotational speed of 250 rpm, and the volume median diameter (Dv50) was measured using a multisizer to grow to 6.85 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion A2 was added all at once in 3 minutes while maintaining the internal temperature at 57.0 ° C. and the rotational speed of 250 rpm, and held as it was for 60 minutes.

○ Circularization process Subsequently, 20% DBS aqueous solution (6 parts as solid content) was maintained for 10 minutes while maintaining the rotational speed at 250 rpm (peripheral speed 2.59 m / sec at the tip of the stirring blade, the same stirring speed as the aggregation process rotational speed). Then, the temperature was raised to 87 ° C. over 30 minutes, and heating and stirring were continued until the average circularity became 0.942. Thereafter, the mixture was cooled to 30 ° C. over 20 minutes to obtain a slurry.

(Manufacture of toner G)
Thereafter, the toner G was prepared in the same manner as in “Production of Toner A” except that the amount of H2000 silica as an external additive was changed to 1.25 g and the amount of SMT150IB titania fine powder was changed to 0.50 g. Got.

○ Analyzing step The volume median diameter (Dv50) measured using a multisizer of the developing toner G obtained here is 6.79 μm, and “number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 4.52%, the average circularity was 0.943, and the number variation coefficient was 24.5%.

[Toner Production Example 7]
(Preparation of wax / long-chain polymerizable monomer dispersion H1)
Paraffin wax (Nihon Seiki Co., Ltd. HNP-9, surface tension 23.5 mN / m, thermal characteristics: melting point peak temperature 82 ° C., melting heat 220 J / g, melting peak half width 8.2 ° C., crystallization temperature 66 ° C., 27 parts (540 g) of crystallization peak half-value width of 13.0 ° C., 2.8 parts of stearyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.9 parts of 20% DBS aqueous solution, and 68.3 parts of demineralized water were heated to 90 ° C. Then, the mixture was stirred for 10 minutes using a homomixer (Mark II f model, manufactured by Tokushu Kaika Co., Ltd.).

  Next, this dispersion was heated to 90 ° C., and circulation emulsification was started under a pressure condition of 25 MPa using a homogenizer (manufactured by Gorin, 15-M-8PA type). Dispersion was carried out until (Mv) reached 250 nm to prepare a wax / long-chain polymerizable monomer dispersion H1 (emulsion solid content concentration = 30.2 wt%).

(Preparation of polymer primary particle dispersion H1)
The wax / long-chain polymerizable monomer dispersion is added to a reactor (inner volume 21 L, inner diameter 250 mm, height 420 mm) equipped with a stirrer (three blades), a heating / cooling device, and raw material / auxiliary charging devices. 35.6 parts (712.12 g) of H1 and 259 parts of demineralized water were charged, and the temperature was raised to 90 ° C. under a nitrogen stream while stirring.

  Then, the mixture of the following “polymerizable monomers etc.” and “emulsifier aqueous solution” was added to the solution over 5 hours while stirring the liquid. The point at which this mixture was started to be dropped was designated as “polymerization start”, and the following “initiator aqueous solution” was added over 4.5 hours from 30 minutes after the start of polymerization. Further, after 5 hours from the start of polymerization, the following “addition start” The agent aqueous solution ”was added over 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Polymerizable monomers, etc.]
Styrene 76.8 parts (1535.0 g)
Butyl acrylate 23.2 parts Acrylic acid 1.5 parts Hexanediol diacrylate 0.7 parts Trichlorobromomethane 1.0 part

[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Demineralized water 67.1 parts

[Initiator aqueous solution]
8% by weight aqueous hydrogen peroxide solution 15.5 parts 8% by weight L (+)-ascorbic acid aqueous solution 15.5 parts

[Additive initiator aqueous solution]
8 wt% L (+)-ascorbic acid aqueous solution 14.2 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion H1. The volume average diameter (Mv) measured using Nanotrac was 265 nm, and the solid content concentration was 22.3% by weight.

(Preparation of silicone wax dispersion H2)
Alkyl-modified silicone wax (thermal characteristics: melting point peak temperature 77 ° C., heat of fusion 97 J / g, melting peak half width 10.9 ° C., crystallization temperature 61 ° C., crystallization peak half width 17.0 ° C.) 27 parts (540 g) Then, 1.9 parts of a 20% DBS aqueous solution and 71.1 parts of demineralized water were placed in a 3 L stainless steel container, heated to 90 ° C., and stirred for 10 minutes with a homomixer (Mark II f model manufactured by Tokushu Kika Kogyo Co., Ltd.). Next, this dispersion was heated to 99 ° C., and circulation emulsification was started under a pressure of 45 MPa using a homogenizer (manufactured by Gorin Co., Ltd., 15-M-8PA type). ) To 240 nm to prepare a silicone wax dispersion H2 (emulsion solid content concentration = 27.3%).

(Preparation of polymer primary particle dispersion H2)
23.3 parts (466 g) of silicone wax dispersion H2 was added to a reactor (inner volume 21 L, inner diameter 250 mm, height 420 mm) equipped with a stirrer (three blades), a heating / cooling device, and each raw material / auxiliary charging device. ), 1.0 part of 20% DBS aqueous solution and 324 parts of demineralized water were added, the temperature was raised to 90 ° C. under a nitrogen stream, and 3.2 parts of 8% aqueous hydrogen peroxide solution, 8% L (+) − with stirring. 3.2 parts of ascorbic acid aqueous solution was added all at once. The time point 5 minutes after the batch addition of these is defined as “polymerization start”.

  A mixture of the following “polymerizable monomers etc.” and “emulsifier aqueous solution” was added over 5 hours from the start of polymerization, and the following “initiator aqueous solution” was added over 6 hours from the start of polymerization. While stirring, the internal temperature was maintained at 90 ° C. for 1 hour.

[Polymerizable monomers, etc.]
92.5 parts of styrene (1850.0 g)
Butyl acrylate 7.5 parts Acrylic acid 1.5 parts Trichlorobromomethane 0.6 parts

[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Demineralized water 67.0 parts

[Initiator aqueous solution]
8 wt% aqueous hydrogen peroxide solution 18.9 parts 8 wt% L (+)-ascorbic acid aqueous solution 18.9 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion H2. The volume average diameter (Mv) measured using Nanotrac was 290 nm, and the solid content concentration was 19.0% by weight.

(Preparation of colorant dispersion H)
Carbon black (Mitsubishi Chemical Co., Ltd.) manufactured by a furnace method with a 300 L internal volume equipped with a stirrer (propeller blade) and a toluene extract having an ultraviolet absorbance of 0.02 and a true density of 1.8 g / cm ³ Mitsubishi Carbon Black MA100S) 20 parts (40 kg), 20% DBS aqueous solution 1 part, nonionic surfactant (manufactured by Kao Corp., Emulgen 120) 4 parts, ion-exchanged water 75 parts with an electric conductivity of 2 μS / cm In addition, it was predispersed to obtain a pigment premix solution. The volume average diameter (Mv) of carbon black in the dispersion after pigment premixing measured with Nanotrac was 90 μm.

The pigment premix solution was supplied as a raw material slurry to a wet bead mill and subjected to one-pass dispersion. The stator inner diameter was 75 mmφ, the separator diameter was 60 mmφ, the distance between the separator and the disk was 15 mm, and zirconia beads having a diameter of 100 μm (true density 6.0 g / cm ³ ) were used as the dispersing medium. Since the effective internal volume of the stator is 0.5 L and the filling volume of the media is 0.35 L, the media filling rate is 70% by weight. The pigment premix liquid is continuously supplied from the supply port at a supply speed of 50 L / hr by a non-pulsating metering pump, and the rotor rotation speed is constant (peripheral speed at the rotor tip is 11 m / sec), and continuously from the discharge port. To obtain a black colorant dispersion H. The volume average diameter (Mv) of the colorant dispersion H measured with Nanotrac was 150 nm, and the solid content concentration was 24.2% by weight.

(Production of toner mother particles H)
Using the following components, toner base particles H were produced by carrying out the following aggregation processes (core material aggregation process, shell coating process), circularization process, washing process and drying process.
Polymer primary particle dispersion H1 90 parts as solids (958.9 g as solids)
Polymer primary particle dispersion H2 10 parts as solid content Colorant dispersion H 4.4 parts as colorant solids 20% DBS aqueous solution In the core material agglomeration step, 0.15 parts 20% DBS aqueous solution as solids Circularization step Then, 6 parts as solid content

○ Core material agglomeration step Polymer primary particle dispersion H1 and a mixer (volume 12 L, inner diameter 208 mm, height 355 mm) equipped with a stirrer (double helical blade), heating / cooling device, and each raw material / auxiliary charging device A 20% DBS aqueous solution was charged and uniformly mixed at an internal temperature of 10 ° C. for 10 minutes. Subsequently, the mixture was stirred at an internal temperature of 10 ° C. at 280 rpm, and 0.12 part of a 5 wt% aqueous solution of potassium sulfate as K ₂ SO ₄ was continuously added over 1 minute. The mixture was continuously added over a minute and mixed uniformly at an internal temperature of 10 ° C.

  Thereafter, 100 parts of demineralized water was continuously added over 30 minutes, and then the internal temperature was raised to 48.0 ° C. over 67 minutes (0.5 ° C./min) while maintaining the rotational speed of 280 rpm. Next, after raising the temperature by 1 ° C. every 30 minutes (0.03 ° C./min), hold at 54.0 ° C., measure the volume median diameter (Dv50) using a multisizer, and grow to 5.15 μm. It was.

The stirring conditions at this time are as follows.
(A) Diameter of the stirring vessel (as a so-called general cylindrical shape): 208 mm
(B) Height of stirring container: 355 mm
(C) Peripheral speed at the tip of the stirring blade: 280 rpm, that is, 2.78 m / sec.
(D) Shape of stirring blade: Double helical blade (diameter 190mm, height 270mm, width 20mm)
(E) Position of the blade in the stirring vessel: 5 mm above the bottom of the vessel.

○ Shell coating step Thereafter, the polymer primary particle dispersion H2 was continuously added over 6 minutes with the internal temperature of 54.0 ° C. and the rotation speed of 280 rpm, and held as it was for 60 minutes. At this time, the Dv50 of the particles was 5.34 μm.

○ Circularization Step Subsequently, the mixture was heated to 83 ° C. while adding a mixed aqueous solution of 20% DBS aqueous solution (6 parts as a solid content) and 0.04 part of water over 30 minutes, and thereafter 1 every 30 minutes. The temperature was raised to 88 ° C., and heating and stirring were continued under these conditions until the average circularity reached 0.939 over 3.5 hours. Then, it cooled to 20 degreeC over 10 minutes, and obtained the slurry. At this time, the Dv50 of the particles was 5.33 μm and the average circularity was 0.937.

Washing step The obtained slurry was extracted and suction filtered with an aspirator using 5 types C (Toyo Filter Paper No. 5C) filter paper. The cake remaining on the filter paper is transferred to a stainless steel container having an internal volume of 10 L equipped with a stirrer (propeller blade), and 8 kg of ion exchange water having an electric conductivity of 1 μS / cm is added and stirred uniformly at 50 rpm. Thereafter, stirring was continued for 30 minutes.

  Thereafter, the filter paper was suction filtered with an aspirator again using Type 5 C (Toyo Filter Paper No. 5C) filter paper, and the solid matter remaining on the filter paper was again equipped with a stirrer (propeller blade) and had an electrical conductivity of 1 μS / cm. It was transferred to a container with an internal volume of 10 L containing 8 kg of ion-exchanged water, and uniformly dispersed by stirring at 50 rpm and kept stirring for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm.

○ Drying step The solid material obtained here was spread on a stainless steel vat so as to have a height of 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain toner mother particles H.

(Manufacture of toner H)
External Addition Step To the obtained toner base particle H500 g, 8.75 g of Clariant H30TD silica as an external additive is mixed and mixed with a 9 L Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) at 3000 rpm for 30 minutes. 1.4 g of HAP-05NP calcium phosphate manufactured by Calcium Co., Ltd. was mixed, mixed at 3000 rpm for 10 minutes, and sieved with 200 mesh to obtain toner H.

Analyzing Step The “volume median diameter (Dv50)” measured using a multisizer of the toner H obtained here is 5.26 μm, and “number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 5.87%, the average circularity was 0.948, and the number variation coefficient was 18.0%.

[Toner Production Example 8]
(Production of toner mother particle I)
In the aggregation process (core material aggregation process, shell coating process), rounding process, washing process and drying process of “manufacturing toner mother particles H”, “core material aggregation process”, “shell coating process” and “rounding process” The toner mother particles I were obtained in the same manner as in “Production of toner mother particles H” in Toner Production Example 7 except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device Liquid H1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 10 ° C. for 5 minutes. Subsequently, the mixture was stirred at 280 rpm at an internal temperature of 10 ° C. and 0.12 part of a 5 wt% aqueous solution of potassium sulfate was continuously added over 1 minute, and then the colorant dispersion H was continuously added over 5 minutes. Mix evenly at a temperature of 10 ° C. Thereafter, 100 parts of demineralized water was continuously added over 26 minutes, and then the internal temperature was raised to 52.0 ° C. over 64 minutes (0.5 ° C./min) while maintaining the rotational speed of 280 rpm. Subsequently, after raising the temperature by 1 ° C. over 30 minutes (0.03 ° C./min), the temperature was maintained for 110 minutes, and the volume median diameter (Dv50) was measured using a multisizer to grow to 5.93 μm. The stirring conditions at this time were the same as those in Toner Production Example 7.

○ Shell coating step Thereafter, the polymer primary particle dispersion H2 was continuously added over 6 minutes while maintaining the internal temperature at 53.0 ° C and the rotation speed at 280 rpm, and held as it was for 90 minutes. At this time, the Dv50 of the particles was 6.23 μm.

○ Circularization Step Subsequently, the temperature was raised to 85 ° C. while adding a mixed aqueous solution of 20% DBS aqueous solution (6 parts as a solid content) and 0.04 part of water over 30 minutes, and then 92 minutes over 130 minutes. The temperature was raised to 0 ° C., and heating and stirring were continued under these conditions until the average circularity reached 0.943. Then, it cooled to 20 degreeC over 10 minutes, and obtained the slurry. At this time, Dv50 of the particles was 6.17 μm, and the average circularity was 0.945. The washing process and the drying process were performed in the same manner as in Toner Production Example 7.

External Addition Step After adding 7.5 g of Clariant H30TD silica as an external additive to 500 g of the obtained toner base particles I, and mixing with a 9 L Henschel mixer (Mitsui Mining Co., Ltd.) at 3000 rpm for 30 minutes, Maruo Calcium Toner I was obtained by mixing 1.2 g of HAP-05NP calcium phosphate manufactured by Co., Ltd., mixing at 3000 rpm for 10 minutes, and sieving with 200 mesh.

Analyzing Step The “volume median diameter (Dv50)” measured by using the toner I multisizer obtained here is 6.16 μm, and “number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 2.79%, the average circularity was 0.946, and the number variation coefficient was 19.2%.

[Toner Production Example 9]
(Manufacture of toner mother particles J)
In the aggregation process (core material aggregation process, shell coating process), rounding process, washing process and drying process of “manufacturing toner mother particles H”, “core material aggregation process”, “shell coating process” and “rounding process” The toner mother particles J were obtained in the same manner as in “Production of toner mother particles H” in Toner Production Example 7, except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device Liquid H1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 10 ° C. for 10 minutes. Subsequently, the mixture was stirred at 280 rpm at an internal temperature of 10 ° C. and 0.12 part of a 5 wt% aqueous solution of potassium sulfate was continuously added over 1 minute, and then the colorant dispersion H was continuously added over 5 minutes. Mix evenly at a temperature of 10 ° C. Thereafter, 0.5 part of demineralized water was continuously added over 26 minutes, and then the internal temperature was raised to 52.0 ° C. over 64 minutes (0.5 ° C./minute) with the rotation speed being 280 rpm. Subsequently, after raising the temperature by 1 ° C. over 30 minutes (0.03 ° C./min), the temperature was maintained for 130 minutes, and the volume median diameter (Dv50) was measured using a multisizer to grow to 6.60 μm. The stirring conditions at this time were the same as those in Toner Production Example 7.

○ Shell coating step Thereafter, the polymer primary particle dispersion H2 was continuously added over 6 minutes while maintaining the internal temperature at 53.0 ° C and the rotation speed at 280 rpm, and held as it was for 60 minutes. At this time, the Dv50 of the particles was 6.93 μm.

○ Circularization Step Subsequently, the temperature was raised to 90 ° C. while adding a mixed aqueous solution of 20% DBS aqueous solution (6 parts as a solid content) and 0.04 part of water over 30 minutes, and then 97 minutes over 60 minutes. The temperature was raised to 0 ° C. and heating and stirring were continued under these conditions until the average circularity reached 0.945. Then, it cooled to 20 degreeC over 10 minutes, and obtained the slurry. At this time, the Dv50 of the particles was 6.93 μm and the average circularity was 0.945. The washing process and the drying process were performed in the same manner as in Toner Production Example 7.

External Addition Step To the obtained toner base particles J500 g, 6.25 g of Clariant H30TD silica as an external additive is mixed and mixed with a 9 L Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) for 30 minutes at 3000 rpm. Toner J was obtained by mixing 1.0 g of HAP-05NP calcium phosphate manufactured by Calcium Co., Ltd., mixing at 3000 rpm for 10 minutes, and sieving with 200 mesh.

Analyzing Step The “volume median diameter (Dv50)” measured using the toner J multisizer obtained here is 6.97 μm, and “number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 1.85%, the average circularity was 0.946, and the number variation coefficient was 19.5%.

[Toner Comparative Production Example 2]
(Production of toner mother particles K)
In the aggregation process (core material aggregation process, shell coating process), rounding process, washing process and drying process of “manufacturing toner mother particles H”, “core material aggregation process”, “shell coating process” and “rounding process” The toner mother particles K were obtained in the same manner as in “Production of toner mother particles H” in Toner Production Example 7, except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device Liquid H1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 10 ° C. for 10 minutes. Subsequently, the mixture was stirred at 280 rpm at an internal temperature of 10 ° C. and 0.12 part of a 5 wt% aqueous solution of potassium sulfate was continuously added over 1 minute, and then the colorant dispersion H was continuously added over 5 minutes. Mix evenly at a temperature of 10 ° C. Thereafter, 100 parts of demineralized water was continuously added over 30 minutes, and the internal temperature was raised to 34.0 ° C. over 40 minutes (0.6 ° C./min) with the rotation speed being 280 rpm. Subsequently, it hold | maintained for 20 minutes, the volume median diameter (Dv50) was measured using the multisizer, and it was made to grow to 3.81 micrometers.

○ Shell coating step Thereafter, the polymer primary particle dispersion H2 was added over 6 minutes while maintaining the internal temperature of 34.0 ° C and the rotation speed of 280 rpm, and the state was maintained for 90 minutes.

○ Circularization process Subsequently, 20% DBS aqueous solution (6 parts as solid content) was added over 10 minutes while maintaining the rotation speed at 280 rpm (the same stirring speed as the aggregation process rotation speed), and then 76 ° C over 30 minutes. The mixture was heated and stirred until the average circularity reached 0.962. Then, it cooled to 20 degreeC over 10 minutes, and obtained the slurry.

(Manufacture of toner K)
Thereafter, 100 parts of the toner base particles H of toner production example 7 and 1 part of the toner base particles K are mixed, and 500 ml of the toner base particle mixture K is mixed with 8.75 g of Clariant H30TD silica as an external additive. After mixing for 30 minutes at 3000 rpm with a 9 L Henschel mixer (Mitsui Mining Co., Ltd.), 1.4 g of HAP-05NP calcium phosphate manufactured by Maruo Calcium Co., Ltd. is mixed, mixed for 10 minutes at 3000 rpm, and sieved with 200 mesh. Toner K was obtained.

Analyzing Step The “volume median diameter (Dv50)” measured using the toner K multisizer obtained here is 5.31 μm, and “number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 7.22%, the average circularity was 0.949, and the number variation coefficient was 19.2%.

[Toner Comparative Production Example 3]
(Manufacture of toner mother particles L)
In the aggregation process (core material aggregation process, shell coating process), rounding process, washing process and drying process of “manufacturing toner mother particles H”, “core material aggregation process”, “shell coating process” and “rounding process” The toner base particles L were obtained in the same manner as in “Production of toner base particles H” in Toner Production Example 7, except that “A” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device Liquid H1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 10 ° C. for 10 minutes. Subsequently, the mixture was stirred at 310 rpm at an internal temperature of 10 ° C., and 0.12 part of potassium sulfate 5 wt% aqueous solution as K ₂ SO ₄ was continuously added over 1 minute, and then the colorant dispersion H was added for 5 minutes. The mixture was continuously added over time and mixed uniformly at an internal temperature of 10 ° C.

  Thereafter, 100 parts of demineralized water was continuously added over 30 minutes, and the internal temperature was raised to 48.0 ° C. over 67 minutes (0.5 ° C./minute) while maintaining the rotation speed at 310 rpm. Next, after raising the temperature by 1 ° C. every 30 minutes (0.03 ° C./min), the temperature was maintained at 53.0 ° C., and the volume median diameter (Dv50) was measured using a multisizer and grown to 5.08 μm. .

The stirring conditions at this time were the same as in Toner Production Example 7 except for the following (c).
(C) The peripheral speed at the tip of the stirring blade: 310 rpm, that is, 3.08 m / sec.

○ Shell coating step Thereafter, the polymer primary particle dispersion H2 was continuously added over 6 minutes while maintaining the internal temperature of 54.0 ° C and the rotation speed of 310 rpm, and held as it was for 60 minutes. At this time, the Dv50 of the particles was 5.19 μm.

○ Circularization Step Subsequently, the mixture was heated to 83 ° C. while adding a mixed aqueous solution of 20% DBS aqueous solution (6 parts as a solid content) and 0.04 part of water over 30 minutes, and thereafter 1 every 30 minutes. The temperature was raised to 90 ° C., and heating and stirring were continued under these conditions until the average circularity reached 0.939 over 2.5 hours. Then, it cooled to 20 degreeC over 10 minutes, and obtained the slurry. At this time, the Dv50 of the particles was 5.18 μm and the average circularity was 0.940. The washing process and the drying process were performed in the same manner as in Toner Production Example 7.

External Addition Step To the obtained toner base particle L500 g, 8.75 g of Clariant H30TD silica as an external additive is mixed and mixed with a 9 L Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) at 3000 rpm for 30 minutes. Toner L was obtained by mixing 1.4 g of HAP-05NP calcium phosphate manufactured by Calcium Co., Ltd., mixing at 3000 rpm for 10 minutes, and sieving with 200 mesh.

Analyzing Step The “volume median diameter (Dv50)” measured using the multi-sizer of toner L obtained here is 5.18 μm, and “the number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 9.94%, the average circularity was 0.940, and the number variation coefficient was 20.4%.

[Toner Comparative Production Example 4]
(Manufacture of toner mother particles M)
In the aggregation process (core material aggregation process, shell coating process), rounding process, washing process and drying process of “manufacturing toner mother particles H”, “core material aggregation process”, “shell coating process” and “rounding process” The toner mother particles M were obtained in the same manner as in “Production of toner mother particles H” in Toner Production Example 7, except that “” was changed as follows.

○ Core material agglomeration process Dispersion of primary polymer particles in a mixer (volume 12L, inner diameter 208mm, height 355mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device Liquid H1 and 20% DBS aqueous solution were charged and mixed uniformly at an internal temperature of 10 ° C. for 10 minutes. Then at an internal temperature of 10 ° C., allowed to stir for 5 wt% aqueous solution of potassium sulfate from continuously added over 1 minute 0.12 parts as _K 2 SO ₄ at 310 rpm, over a period of 5 minutes colorant dispersion H Were added continuously and mixed uniformly at an internal temperature of 10 ° C.

  Thereafter, 100 parts of demineralized water was continuously added over 30 minutes, and the internal temperature was raised to 52.0 ° C. over 56 minutes (0.8 ° C./minute) while maintaining the rotation speed at 310 rpm. Next, after raising the temperature by 1 ° C. every 30 minutes (0.03 ° C./min), hold at 54.0 ° C., measure the volume median diameter (Dv50) using a multisizer, and grow it to 5.96 μm. It was.

The stirring conditions at this time were the same as in Toner Production Example 7 except for the following (c).
(C) The peripheral speed at the tip of the stirring blade: 310 rpm, that is, 3.08 m / sec.

○ Shell coating step Thereafter, the polymer primary particle dispersion H2 was continuously added over 6 minutes while maintaining the internal temperature of 54.0 ° C and the rotation speed of 310 rpm, and held as it was for 60 minutes. At this time, Dv50 of the particles was 5.94 μm.

○ Circularization Step Subsequently, the mixture was heated to 88 ° C. while adding a mixed aqueous solution of 20% DBS aqueous solution (6 parts as a solid content) and 0.04 part of water over 30 minutes, and thereafter 1 every 30 minutes. The temperature was raised to 90 ° C., and heating and stirring were continued under these conditions until the average circularity reached 0.940 over 2 hours. Then, it cooled to 20 degreeC over 10 minutes, and obtained the slurry. At this time, the Dv50 of the particles was 5.88 μm and the average circularity was 0.943. The washing process and the drying process were performed in the same manner as in Toner Production Example 7.

External Addition Step To the obtained toner base particles M500 g, 7.5 g of Clariant H30TD silica as an external additive is mixed and mixed with a 9 L Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) for 30 minutes at 3000 rpm. Toner M was obtained by mixing 1.2 g of HAP-05NP calcium phosphate manufactured by Calcium Co., Ltd., mixing at 3000 rpm for 10 minutes, and sieving with 200 mesh.

Analyzing Step The “volume median diameter (Dv50)” measured using a multisizer of the toner M obtained here is 5.92 μm, and “number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 5.22%, the average circularity was 0.945, and the number variation coefficient was 21.2%.

[Toner Comparative Production Example 5]
3 parts of toner base particles K are mixed with 100 parts of toner base particles J of toner production example 9, 500 g of this toner base particle mixture is mixed with 6.25 g of H30TD silica manufactured by Clariant as an external additive, and a 9 L Henschel mixer is mixed. (Mitsui Mining Co., Ltd.) was mixed at 3000 rpm for 30 minutes, Maruo Calcium Co., Ltd. HAP-05NP calcium phosphate 1.0 g was mixed, mixed at 3000 rpm for 10 minutes, and sieved with 200 mesh to obtain toner N. .

Analyzing Step The “volume median diameter (Dv50)” measured using the toner N multisizer obtained here is 6.88 μm, and “the number% of toner having a particle size of 2.00 μm to 3.56 μm”. (Dns) "was 9.08%, the average circularity was 0.952, and the number variation coefficient was 25.6%.

(Live-action evaluation)
A small spot irradiation type blue LED (Nisshin Denshi, B3MP-8: 470 nm) is used as a photoconductor for the exposure part of a commercial tandem LED color printer MICROLINE Pro 9800PS-E (Oki Data Co., Ltd.) that supports A3 printing. It was modified so that it could be irradiated. The photosensitive drums E21 to E30 and CE11 to 15 and the toners A to M are mounted on the black drum cartridge and the black toner cartridge of the modified machine in the combinations shown in Tables 5 to 16, respectively. Mounted on the printer.

Specifications of MICROLINE Pro 9800PS-E:
Quadruple tandem color 36ppm, monochrome 40ppm
Contact roller charging (DC voltage applied)
With static elimination light

A strobe illumination power source LPS-203K was connected to the small spot irradiation type blue LED of this image forming apparatus, and black dots having a diameter of 8 mm were written at intervals of 8 mm to form an image.
The obtained point image was enlarged, and the image quality was evaluated in five stages by combining the sharpness of the developed point image outline and the degree of toner scattering around the point image. The results are shown in Tables 5 to 16.

The criteria for comprehensive evaluation of image quality based on the sharpness of the outline of the point image and the degree of scattering around the point image were as follows.
1: The dot outline is clear and a good dot image is obtained without toner scattering. 2: The dot image is good without toner scattering.
3: A good dot image is obtained although the toner is slightly scattered.
4: There is toner scattering and the sharpness of the outline of the point image is low.
5: Toner scattering is large and the contour of the dot image is uneven.

For toners L and N, the toner ejected from the developing tank, and the actual image evaluation could not be performed.
From the above results, it has been clarified that, when the photoconductor of the present invention is used and monochromatic light having a wavelength of 380 to 500 nm is used, a high-quality image faithful to the electrostatic latent image can be obtained.

  Since the photoconductor of the present invention has high sensitivity and high image quality with respect to a light source having a wavelength of 380 nm or more and 500 nm or less, an electrophotographic system is used for an image forming apparatus and an electrophotographic photoconductor cartridge on which the photoconductor is mounted. It can be used in any field, and in particular, it can be suitably used for printers, facsimiles, copiers and the like.

1 Photoconductor 2 Charging device (charging roller)
DESCRIPTION OF SYMBOLS 3 Exposure apparatus 4 Developing apparatus 5 Transfer apparatus 6 Cleaning apparatus 7 Fixing apparatus 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Control member 71 Upper fixing member (pressure roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (13)

An electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, and forming an electrostatic latent image by being exposed to monochromatic light having a wavelength of 380 nm to 500 nm. And
The photosensitive layer contains an azo compound composition composed of a plurality of structural isomers represented by the following formula (1),
The azo compound composition has both a group represented by the following formula (2) and a group represented by the following formula (3) as Cp ₁ and Cp ₂ in the molecule, and the following formula (1) An electrophotographic photoreceptor comprising an azo compound represented as a main component.
(In the formula (1),
Each X independently represents a linking group having 2 to 30 atoms,
Ar represents an arylene group which may each independently have a substituent,
n represents an integer of 0 or more and 4 or less,
Cp ₁ and Cp ₂ have the same molecular weight and each independently represent a group represented by the following formula (2) or (3). )
(In the formulas (2) and (3),
R ¹ and R ² each independently represents a substituent,
Z represents a divalent aromatic hydrocarbon group or a nitrogen-containing heterocyclic group,
k and l each independently represent an integer of 0 or more and 4 or less. ) 2. The electrophotographic photosensitive member according to claim 1, wherein X in the formula (1) has a structure represented by the following formula (4).
The electrophotographic photosensitive member according to claim 1, wherein the formula (1) is represented by the following formula (5).
(In Formula (5),
Each R independently represents a substituent;
Cp ₁ and Cp ₂ have the same molecular weight and each independently represent a group represented by the formula (2) or (3),
m independently represents an integer of 0 or more and 4 or less. ) Having an undercoat layer containing metal oxide particles between the conductive support and the photosensitive layer;
The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein a cumulative 90% particle size accumulated from the small particle size side of the metal oxide particles is 0.3 µm or less. An electrophotographic photosensitive member according to any one of claims 1 to 4,
Charging means for charging the electrophotographic photosensitive member;
Exposing the charged electrophotographic photosensitive member with monochromatic light having a wavelength of 380 nm to 500 nm to form an electrostatic latent image; and
A developing means having toner and developing the formed electrostatic latent image with the toner;
An image forming apparatus comprising: a transfer unit that transfers the toner to a transfer target. 6. The image forming apparatus according to claim 5, wherein an average circularity measured by the toner flow type particle image analyzer is 0.940 or more and 1.000 or less. The image forming apparatus according to claim 5, wherein the toner satisfies all of the following (i) to (iii).
(I) The volume median diameter (Dv50) is 4.0 μm or more and 7.0 μm or less.
(Ii) The average circularity is 0.93 or more.
(Iii) The relationship between the volume median diameter (Dv50) of the toner and the number% (Dns) of the toner having a particle diameter of 2.00 μm to 3.56 μm satisfies Dns ≦ 0.233EXP (17.3 / Dv50). Fulfill. In the toner, the relationship between the volume median diameter (Dv50) and the number% (Dns) of the toner having a particle diameter of 2.00 μm to 3.56 μm satisfies Dns ≦ 0.110EXP (19.9 / Dv50). The image forming apparatus according to claim 7. In the toner, the relationship between the volume median diameter (Dv50) and the number% (Dns) of toner having a particle diameter of 2.00 μm to 3.56 μm satisfies 0.0517EXP (22.4 / Dv50) ≦ Dns. The image forming apparatus according to claim 7, wherein the image forming apparatus is an image forming apparatus. The image forming apparatus according to claim 5, wherein the toner is a toner manufactured in an aqueous medium. The image forming apparatus according to claim 5, wherein the toner has a resin coating layer. At least the electrophotographic photoreceptor according to any one of claims 1 to 4,
A charging unit for charging the electrophotographic photosensitive member, an exposure unit for exposing the charged electrophotographic photosensitive member to monochromatic light having a wavelength of 380 nm to 500 nm to form an electrostatic latent image, and a toner. A developing unit that develops the electrostatic latent image with toner, and a cartridge case that detachably supports the electrophotographic photosensitive member with respect to an image forming apparatus that includes a transfer unit that transfers the toner to a transfer target. A cartridge characterized by that. The cartridge according to claim 12, wherein the toner satisfies all of the following (i) to (iii).
(I) The volume median diameter (Dv50) is 4.0 μm or more and 7.0 μm or less.
(Ii) The average circularity is 0.93 or more.
(Iii) The relationship between the volume median diameter (Dv50) of the toner and the number% (Dns) of the toner having a particle diameter of 2.00 μm to 3.56 μm satisfies Dns ≦ 0.233EXP (17.3 / Dv50). Fulfill.