JP5663835B2 - Electrophotographic photosensitive member, electrophotographic cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, an electrophotographic cartridge, and an image forming apparatus used for a copying machine, a printer, and the like.

  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. In particular, in office documents, in addition to the development of mapping technology and latent image forming technology for input, the types of character hieroglyphics are more abundant and finer at the time of output. Due to the spread and development, the reproducibility of a latent image with extremely high image quality that has few defects and unclearness in printed images is required. In particular, as a developer used in the case where the electrostatic latent image on the latent image carrier constituting the image forming apparatus is a line image of 100 μm or less (approximately 300 dpi or more), a conventional toner having a large particle diameter has fine line reproducibility. In general, the line image is not clear enough.

  To cope with high image quality, it is effective to reduce the particle size of the toner. This technology is good at chemical toners, and various toners have been developed (Patent Documents 1 to 11). In particular, in the case of a chemical toner, it is possible to produce a toner having a narrow particle size distribution, and it is possible to make the charging characteristics uniform, which is advantageous in the electrophotographic process.

On the other hand, as a problem in the case of using a chemical toner, it is mentioned that when the toner shape is close to a sphere, the toner slips between the photosensitive member and the blade, resulting in poor cleaning. Therefore, when chemical toner is used, a method of increasing the contact pressure of the cleaning blade and suppressing defective cleaning is often used. However, in this case, other problems such as generation of rubbing noise are liable to occur during image printing. This problem is particularly remarkable when a suspension polymerization toner having a high degree of circularity is used.
As described above, the current state of the art is that the potential of the chemical toner has not been sufficiently extracted.
JP-A-2-284158 JP-A-5-119530 JP-A-1-221755 JP-A-6-289648 JP 2001-134005 A Japanese Patent Laid-Open No. 11-147331 Japanese Patent Laid-Open No. 2001-175024 JP-A-2-000877 JP 2004-045948 A JP 2003-255567 A WO2004-088431

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described background art, and its problem is that an electrophotographic photosensitive member and an electrophotographic device that do not have poor cleaning even when toner having a high degree of circularity is used and that generate no abnormal noise such as frictional noise during printing. An object is to provide a cartridge and an image forming apparatus. Another object of the present invention is to provide an electrophotographic cartridge and an image forming apparatus that do not generate abnormal noise such as rubbing noise during image printing.

  As a result of intensive investigations in view of these current situations, the present inventors have used a charge transport material having a specific structure in the photosensitive layer, so that there is no cleaning failure in images, rubbing noise during image printing, etc. As a result, it was found that no abnormal noise was generated.

  The first aspect of the present invention is an electrophotographic photosensitive member used for an image forming apparatus provided with an electrostatic charge image developing toner having an average circularity of 0.940 or more and 1.000 or less as measured by a flow type particle image analyzer. The electrophotographic photosensitive member is an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, and the photosensitive layer contains an enamine compound represented by the following general formula (1).

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５は、それぞれ独立して水素原子、分子量１００以下の置換基を有していても良いアリール基、または、分子量１００以下の置換基を有していても良いアルキル基を表し、Ｒ^１とＲ^２のうちのいずれか一つと、Ｒ^４とＲ^５のうちのいずれか一つが少なくとも分子量１００以下の置換基を有していても良いアリール基である。）

(In the formula (1), R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom, an aryl group which may have a substituent having a molecular weight of 100 or less, or a molecular weight of 100 It represents an alkyl group which may have the following substituents, and any one of R ¹ and R ² and any one of R ⁴ and R ⁵ has a substituent having a molecular weight of 100 or less. An aryl group that may be

  In the first aspect of the present invention, the electrostatic image developing toner is preferably a toner produced in an aqueous medium. The electrostatic image developing toner preferably has a resin coating layer. The electrostatic image developing toner contains a wax, and the wax is preferably contained in an amount of 4 to 20 parts by mass with respect to 100 parts by mass of the electrostatic charge developing toner.

  In the first invention, the enamine compound preferably has a molecular weight of 500 or less.

  According to a second aspect of the present invention, there is provided an electrophotographic photosensitive member according to the first aspect of the present invention, a charging unit for charging the electrophotographic photosensitive member, and an exposure for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image. And an at least one selected from the group consisting of a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member.

  In the second invention, the electrophotographic photosensitive member cartridge may further have a blade cleaning mechanism. The blade cleaning mechanism is preferably a counter contact system.

  According to a third aspect of the present invention, there is provided an electrophotographic photosensitive member according to the first aspect of the present invention, a charging device for charging the electrophotographic photosensitive member, and an exposure device for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image. And a developing device that develops the electrostatic latent image formed on the electrophotographic photosensitive member.

  In the third aspect of the present invention, the charging device is preferably disposed in contact with the electrophotographic photosensitive member at least when the electrophotographic photosensitive member is charged. Further, it is preferable that the developing device is disposed in contact with the electrophotographic photosensitive member at least when developing the latent image formed on the electrophotographic photosensitive member.

  According to the present invention, in the photosensitive layer of the electrophotographic photosensitive member, a charge transport material having a specific structure is used, and the electrophotographic photosensitive member is used in combination with a toner that satisfies a specific condition. A good image with no decrease in density is obtained, and no noise is generated during image formation.

Hereinafter, although an embodiment of the present invention is described in detail, the present invention is not limited to the following description, and can be appropriately implemented without departing from the gist of the present invention.
In the electrophotographic photoreceptor of the present invention, it is essential to use an enamine compound described later as a charge transport material in the photosensitive layer.

<Enamine compound>
The enamine compound that can be used in the present invention may be any enamine compound having a structure represented by the following formula (1).

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５は、それぞれ独立して、水素原子、分子量１００以下の置換基を有していても良いアリール基、分子量１００以下の置換基を有していても良いアルキル基を表し、Ｒ^１とＲ^２のうちのいずれか一つと、Ｒ^４とＲ^５のうちのいずれか一つが少なくとも分子量１００以下の置換基を有していても良いアリール基である。）

(In formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ are each independently a hydrogen atom, an aryl group optionally having a substituent having a molecular weight of 100 or less, and a molecular weight of 100 or less. And any one of R ¹ and R ² and any one of R ⁴ and R ⁵ has a substituent having a molecular weight of 100 or less. An aryl group that may be present.)

R ¹ , R ² , R ³ , R ⁴ , and R ⁵ each independently have a hydrogen atom, an aryl group that may have a substituent with a molecular weight of 100 or less, or a substituent with a molecular weight of 100 or less. Represents an optionally substituted alkyl group. In addition, when an aryl group or an alkyl group has a substituent, the molecular weight of the substituent needs to be 100 or less.

  Examples of the aryl group that may have a substituent having a molecular weight of 100 or less include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a fluorenyl group, and a biphenyl group. Among these, in consideration of the characteristics of the electrophotographic photoreceptor, a phenyl group, a naphthyl group, and a fluorenyl group are preferable, a phenyl group and a naphthyl group are more preferable, and a phenyl group is still more preferable.

  The aryl group and alkyl group may have a substituent having a molecular weight of 100 or less. In order to obtain the effects of the present invention, the molecular weight of the substituent is usually 100 or less, more preferably 80 or less, still more preferably 60 or less, and even more preferably 40 or less. Specific examples of preferred substituents include alkyl groups having linear, branched, and cyclic structures such as methyl, ethyl, propyl, butyl, and cyclohexyl groups, alkoxy groups such as methoxy, ethoxy, and propoxy groups, Examples include alkylamino groups such as dimethylamino group, diethylamino group and methylethylamino group, and halogen atoms such as fluorine atom, chlorine atom and bromine atom. Among these, alkyl group, alkoxy group, Alkylamino groups are preferred, and among these, alkyl groups and alkoxy groups having 5 or less carbon atoms are more preferred, alkyl groups and alkoxy groups having 3 or less carbon atoms are more preferred, and methyl groups and methoxy groups are particularly preferred.

In addition, the substituents of R ¹ to R ⁵ can also form a cyclic structure in which the substituents are directly bonded to each other or via a linking group.
The number of substituents is arbitrary as possible substitutions, since the number of substitution molecular weight increases the number comes to enamine compound, or faded effects of the present invention, the solubility may decrease, usually R ¹ When R ⁵ has a substituent, the number of substituents is usually 4 or less, more preferably 3 or less, and still more preferably 2 or less with respect to one R ¹ to R ⁵ .

  In addition, since the enamine compound that can be used in the present invention has a molecular weight increased as described above, the effect of the present invention may be diminished or the solubility may be lowered. Below, more preferably 485 or less, still more preferably 470 or less, particularly preferably 455 or less. In addition, if the molecular weight is too small, the enamine compound may bleed out from the photosensitive layer and the desired electrophotographic photosensitive member characteristics may not be obtained. Therefore, it is usually 200 or more, more preferably 225 or more, and still more preferably. Is 250 or more, particularly preferably 275 or more.

Usually, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently have a hydrogen atom, an aryl group which may have a substituent having a molecular weight of 100 or less, and a substituent having a molecular weight of 100 or less. An aryl group that may have a substituent having at least a molecular weight of 100 or less, and any one of R ¹ and R ² and any one of R ⁴ and R ⁵ However, in consideration of the charge transport ability of the enamine compound, R ¹ , R ⁴ , and R ⁵ are preferably aryl groups that may have a substituent having a molecular weight of 100 or less, and the productivity of the enamine compound is improved. In consideration, R ¹ , R ⁴ , and R ⁵ are preferably an aryl group that may have a substituent having a molecular weight of 100 or less, and R ³ is preferably a hydrogen atom. In consideration of the stability of the enamine compound, R ¹ , ^R 4, ^{R 5} Molecular weight of 100 or less which may have a substituent aryl group, an aryl group optionally R ² optionally has a molecular weight of 100 or less substituents, or may have a molecular weight of 100 or less substituents More preferably, it is an alkyl group, and R ³ is a hydrogen atom, more preferably, R ¹ , R ² , R ⁴ , and R ⁵ are aryl groups that may have a substituent having a molecular weight of 100 or less, and R ³ is It is a hydrogen atom.

R ¹ and R ² , or R ⁴ and R ⁵ can form a cyclic structure via a direct bond or a linking group. Specific examples of the linking group include a carbonyl group (representing divalent —C (═O) —), a sulfinyl group, a sulfonyl group, a sulfinato group, an alkylene group, an alkenylene group, an alkylidene group, an oxy group, a seleno group, Examples thereof include a thio group, and an alkylene group and an alkenylene group are preferable. One linking group may be used alone, or two or more linking groups may be used in any ratio and combination.

  The structure of an enamine compound suitable for the present invention is exemplified below. The following structures are illustrated to make the present invention more concrete, and are not limited to the following structures unless departing from the concept of the present invention.

（Ｒは、水素原子又は上記した分子量１００以下の置換基を表し、それぞれ同一でも異なっていても構わない。具体的には、水素原子又は、置換基；置換基としては、アルキル基、アルコキシ基等が好ましい。特に好ましくは、メチル基、メトキシ基である。）

(R represents a hydrogen atom or a substituent having a molecular weight of 100 or less, and may be the same or different. Specifically, a hydrogen atom or a substituent; examples of the substituent include an alkyl group and an alkoxy group. (Methyl group and methoxy group are particularly preferable.)

<Configuration of electrophotographic photoreceptor>
The electrophotographic photoreceptor of the present invention has a photosensitive layer containing the above-mentioned enamine compound on a conductive support.
<Conductive support>
As the conductive support used for the photoreceptor, for example, metal materials such as aluminum, aluminum alloy, stainless steel, copper, nickel, and conductive powders such as metal, carbon, tin oxide are added to provide conductivity. Mainly used are resin, glass, paper, or the like obtained by depositing or applying a conductive material such as aluminum, nickel, or ITO (indium tin oxide) to the surface. As a form, a drum shape, a sheet shape, a belt shape or the like is used. A conductive material having an appropriate resistance value may be applied to a conductive support made of a metal material in order to control conductivity, surface properties, etc., or to cover defects.

  When a metal material such as an aluminum alloy is used as the conductive support, it is preferably used after an anodized film is applied. When the anodized film is applied, it is preferable to perform a sealing treatment by a known method.

For example, an anodic oxidation film is formed by anodizing in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, etc. give. In the case of anodic oxidation in sulfuric acid, the sulfuric acid concentration is 100 to 300 g / L, the dissolved aluminum concentration is 2 to 15 g / L, the liquid temperature is 15 to 30 ° C., the electrolysis voltage is 10 to 20 V, and the current density is 0.5 to it is preferably in the range of 2A / dm ^2, but not limited to the above conditions.

  It is preferable to perform a sealing treatment on the anodic oxide film thus formed. The sealing treatment may be performed by a known method, for example, a low-temperature sealing treatment in which it is immersed in an aqueous solution containing nickel fluoride as a main component, or a high temperature in which it is immersed in an aqueous solution containing nickel acetate as a main component. A sealing treatment is preferably performed.

  The concentration of the nickel fluoride aqueous solution used in the case of the low-temperature sealing treatment can be appropriately selected, but more preferable results are obtained when it is used in the range of 3 to 6 g / L. Moreover, in order to advance a sealing process smoothly, as processing temperature, it is 25-40 degreeC, Preferably it is 30-35 degreeC, Moreover, nickel fluoride aqueous solution pH is 4.5-6.5, Preferably it is 5. It is preferable to process in the range of 5 to 6.0. As the pH adjuster, oxalic acid, boric acid, formic acid, acetic acid, sodium hydroxide, sodium acetate, aqueous ammonia and the like can be used. The treatment time is preferably in the range of 1 to 3 minutes per 1 μm of film thickness. In order to further improve the physical properties of the film, cobalt fluoride, cobalt acetate, nickel sulfate, a surfactant or the like may be added to the nickel fluoride aqueous solution. Subsequently, it is washed with water and dried to finish the low temperature sealing treatment.

  As the sealing agent in the case of the high-temperature sealing treatment, an aqueous solution of a metal salt such as nickel acetate, cobalt acetate, lead acetate, nickel acetate-cobalt, and barium nitrate can be used, and it is particularly preferable to use nickel acetate. . The concentration in the case of using an aqueous nickel acetate solution is preferably 5 to 20 g / L. The treatment temperature is 80 to 100 ° C., preferably 90 to 98 ° C., and the pH of the nickel acetate aqueous solution is preferably 5.0 to 6.0. Here, ammonia water, sodium acetate, or the like can be used as the pH adjuster. The treatment time is 10 minutes or longer, preferably 20 minutes or longer. In this case, sodium acetate, organic carboxylic acid, anionic surfactant, nonionic surfactant, etc. may be added to the nickel acetate aqueous solution in order to improve the film properties. Subsequently, it is washed with water and dried to finish the high temperature sealing treatment.

  When the average film thickness is thick, stronger sealing conditions are required due to the higher concentration of the sealing liquid and high temperature / long-time treatment. Accordingly, productivity is deteriorated and surface defects such as spots, dirt, and dusting are likely to occur on the coating surface. From such a point, it is preferable that the average film thickness of the anodic oxide coating is usually 20 μm or less, particularly 7 μm or less.

  The support surface may be smooth, or may be roughened by using a special cutting method or polishing. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without cutting. Especially when using non-cutting aluminum supports such as drawing, impact processing, ironing, etc., the process eliminates dirt, foreign matter, etc. on the surface, small scratches, etc., and a uniform and clean support can be obtained. Therefore, it is preferable. Specifically, the conductive support preferably has a surface roughness Ra of 0.01 μm or more and 0.3 μm or less. If Ra is less than 0.01 μm, the adhesion may be deteriorated, and if it exceeds 0.3 μm, image defects such as black spots may occur. The most preferable range of Ra is 0.01 to 0.20 μm.

[Measurement method and definition of surface roughness Ra]
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 Ra is a value measured with 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.

  In order to process the surface roughness of the conductive support within the above range, a method of grinding the support surface with a cutting tool or the like, or a method of sandblasting by causing fine particles to collide with the support surface There are a processing method using an ice particle cleaning device described in JP-A-4-204538 and a honing processing method described in JP-A-9-236937. Further, an anodizing method, an alumite treatment method, a buffing method, a laser ablation method described in JP-A-4-233546, a method using a polishing tape described in JP-A-8-1502, Examples thereof include a roller burnishing method described in Kaihei 8-1510. However, the method for roughening the surface of the support is not limited thereto.

As the conductive material, a metal drum such as aluminum or nickel, a plastic drum deposited with aluminum, tin oxide, indium oxide or the like, or a paper / plastic drum coated with a conductive substance can be used. The material for the conductive support is preferably a material having a specific resistance of 10 ³ Ωcm or less at room temperature.

<Underlayer>
The photoreceptor of the present invention preferably contains an undercoat layer. This undercoat layer preferably contains a binder resin and metal oxide particles having a refractive index of 2.0 or less. Further, the volume average particle diameter of the metal oxide aggregate secondary particles in a liquid in which the undercoat layer is dispersed in a solvent in which methanol and 1-propanol are mixed at a mass ratio of 7: 3 is 0.1 μm or less. In addition, it is preferable that the cumulative 90% particle size is 0.3 μm or less, the volume average particle size is 0.09 μm or less, and the cumulative 90% particle size is 0.2 μm or less. preferable. If the volume average particle size is too small, defective cleaning and device contamination may be caused. The volume average particle size is preferably 0.01 μm or more, and the cumulative 90% particle size is also preferably 0.05 μm or more.

<Metal oxide>
In the present invention, it is preferable to use metal oxide particles for the undercoat layer. As the metal oxide particles, any metal oxide particles that can be generally used for an electrophotographic photoreceptor can be used. More specifically, as metal oxide particles, 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 And metal oxide particles containing a plurality of metal elements such as barium titanate. Among these, metal oxide particles having a band gap of 2 to 4 eV are 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. 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 crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. In addition, those having a plurality of crystal states from those having different crystal states may be included.

  The metal oxide particles may be subjected to various surface treatments on the surface. For example, treatment with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, a polyol, or an organic silicon compound may be performed. In particular, when titanium oxide particles are used, surface treatment with an organosilicon compound is preferable. Examples of organosilicon compounds include silicone oils such as dimethylpolysiloxane or methylhydrogenpolysiloxane, organosilanes such as methyldimethoxysilane and diphenyldidimethoxysilane, silazanes such as hexamethyldisilazane, vinyltrimethoxysilane, and γ-mercaptopropyltrimethyl. Silane coupling agents such as methoxysilane and γ-aminopropyltriethoxysilane are common, but the silane treatment agent represented by the structure of the following general formula (C) has the best reactivity with metal oxide particles. It is a good treatment agent.

In formula (C), R ^1u and R ^2u each independently represent an alkyl group, more specifically a methyl group or an ethyl group. R ^3u is an alkyl group or an alkoxy group, and more specifically represents a group selected from the group consisting of a methyl group, an ethyl group, a methoxy group, and an ethoxy group. In addition, although the outermost surface of these surface-treated particles is treated with such a treatment agent, it may be treated with a treatment agent such as aluminum oxide, silicon oxide or zirconium oxide before the treatment. I do not care. As the titanium oxide particles, only one type of particles may be used, or a plurality of types of particles may be mixed and used.

  As the metal oxide particles to be used, those having an average primary particle diameter of 500 nm or less are usually used, those having an average primary particle diameter of 1 nm to 100 nm are preferably used, and those having an average primary particle diameter of 5 to 50 nm are more preferably used. The average primary particle diameter is obtained by an arithmetic average value of the particle diameters directly observed by a transmission electron microscope (hereinafter abbreviated as “TEM”).

  In addition, as the metal oxide particles to be used, those having various refractive indexes can be used, but any particles can be used as long as they can be usually used for an electrophotographic photoreceptor. Preferably, those having a refractive index of 1.4 or more and a refractive index of 3.0 or less are used. The refractive index of the metal oxide particles is described in various publications. For example, according to the filler utilization dictionary (edited by Filler Research Society, Taiseisha, 1994), it is as shown in Table 1 below.

Among the metal oxide particles according to the present invention, as specific trade names of titanium oxide particles, ultrafine titanium oxide “TTO-55 (N)” that has not been subjected to surface treatment, Al ₂ O ₃ coating was applied. Ultrafine titanium oxide “TTO-55 (A)”, “TTO-55 (B)”, ultrafine titanium oxide “TTO-55 (C)” surface-treated with stearic acid, Al ₂ O ₃ and organosiloxane Ultra-fine titanium oxide “TTO-55 (S)” surface-treated with high purity titanium oxide “CR-EL”, sulfuric acid method titanium oxide “R-550”, “R-580”, “R-630” , “R-670”, “R-680”, “R-780”, “A-100”, “A-220”, “W-10”, chlorinated titanium oxide “CR-50”, “CR-” 58 "," CR-60 "," CR-60-2 ", CR-67 ", conductive titanium oxide" SN-100P "," SN-100D "," ET-300W "(above, manufactured by Ishihara Sangyo Co., Ltd.)," R-60 "," A-110 "," including titanium oxide a-0.99 ", etc., it was subjected to _Al 2 _{O 3} coating" SR-1 "," R-GL "," R-5N "," R-5N-2 "," R-52N " , "RK-1", _"a-SP", was subjected to SiO 2, _Al 2 _{O 3} coating "R-GX", "R-7E", was subjected _ZnO, the SiO 2, _Al 2 _{O 3} coating " “R-650”, “R-61N” coated with ZrO ₂ and Al ₂ O ₃ (manufactured by Sakai Chemical Industry Co., Ltd.), and “TR-700” surface-treated with SiO ₂ and Al ₂ O ₃ ", _ZnO," TR-840 surface-treated with SiO 2, _Al 2 _{O 3} "," TA-500 " Other, "TA-100", "TA-200", titanium oxide "TA-300", etc. surface-untreated, "TA-400" was subjected to a surface treatment with _Al 2 _{O 3} (or more, manufactured by Fuji Titanium Industry Co., Ltd. ), “MT-150W”, “MT-500B” without surface treatment, “MT-100SA”, “MT-500SA”, SiO ₂ , Al ₂ O surface-treated with SiO ₂ , Al ₂ O _{3 3} and “MT-100SAS”, “MT-500SAS” (manufactured by Teika), etc. surface-treated with organosiloxane.

  Moreover, as a specific brand name of aluminum oxide particles, “Aluminium Oxide C” (manufactured by Nippon Aerosil Co., Ltd.) and the like can be mentioned.

  Moreover, as a concrete brand name of a silicon oxide particle, "200CF", "R972" (made by Nippon Aerosil Co., Ltd.), "KEP-30" (made by Nippon Shokubai Co., Ltd.), etc. are mentioned. Moreover, "SN-100P" (made by Ishihara Sangyo Co., Ltd.) etc. are mentioned as a specific brand name of a tin oxide particle. And as a specific brand name of zinc oxide particles, “MZ-305S” (manufactured by Teika Co., Ltd.) can be mentioned, but the metal oxide particles usable in the present invention are not limited to these.

  In the coating solution for forming the undercoat layer of the electrophotographic photosensitive member in the present invention, the metal oxide particles are preferably used in the range of 0.5 to 4 parts by mass with respect to 1 part by mass of the binder resin.

<Binder resin>
As the binder resin used in the undercoat layer, it is usually used in a coating solution for forming an undercoat layer of an electrophotographic photosensitive member, is soluble in an organic solvent, and the formed undercoat layer forms a photosensitive layer. It is not particularly limited as long as it is insoluble in the organic solvent used in the coating liquid for use, or has low solubility and does not substantially mix.

  As such a binder resin, for example, phenoxy, epoxy, polyvinyl pyrrolidone, polyvinyl alcohol, casein, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide, etc. are used alone or in a cured form together with a curing agent. Among these, polyamide resins, particularly polyamide resins such as alcohol-soluble copolymer polyamides and modified polyamides, are preferable because they exhibit good dispersibility and coating properties.

  Examples of the polyamide resin include so-called copolymer nylon obtained by copolymerizing 6-nylon, 66-nylon, 610-nylon, 11-nylon, 12-nylon, N-alkoxymethyl-modified nylon, N-alkoxyethyl, and the like. Examples thereof include alcohol-soluble nylon resins of a type in which nylon is chemically modified, such as modified nylon. Specific product names include, for example, “CM4000” “CM8000” (manufactured by Toray Industries, Inc.), “F-30K”, “MF-30”, “EF-30T” (manufactured by Nagase Chemtech). It is done.

  Among these polyamide resins, a copolymerized polyamide resin containing a diamine represented by the following formula (D) as a constituent component is particularly preferably used.

In formula (D), R ^{4 to} R ⁷ each independently represent a hydrogen atom or an organic substituent. m and n each independently represents an integer of 0 to 4, and when there are a plurality of substituents, these substituents may be different from each other. The organic substituent represented by R ^{4 to} R ⁷ is preferably a hydrocarbon group having 20 or less carbon atoms, which may contain a hetero atom, and more preferably a methyl group, an ethyl group, or an n-propyl group. Alkyl groups such as isopropyl group; alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group; aryl groups such as phenyl group, naphthyl group, anthryl group, pyrenyl group, etc., more preferably alkyl group A group or an alkoxy group, particularly preferably a methyl group or an ethyl group.

  The copolymerized polyamide resin containing the diamine represented by the formula (D) as a constituent component is, for example, lactams such as γ-butyrolactam, ε-caprolactam, lauryllactam; 1,4-butanedicarboxylic acid, 1 , 12-dodecanedicarboxylic acid, 1,20-eicosanedicarboxylic acid and other dicarboxylic acids; 1,4-butanediamine, 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,12-dodecanediamine, etc. Diamines: those obtained by combining piperazine and the like and copolymerized in binary, ternary, quaternary and the like. Although there is no limitation in particular about this copolymerization ratio, Usually, the diamine component represented by the said general formula (D) is 5-40 mol%, Preferably it is 5-30 mol%.

  The number average molecular weight of the copolymerized polyamide is preferably 10,000 to 50,000, particularly preferably 15,000 to 35,000. Even if the number average molecular weight is too small or too large, it is difficult to maintain the uniformity of the film. There is no particular limitation on the method for producing the copolymerized polyamide, and a normal polyamide polycondensation method is appropriately applied, and a melt polymerization method, a solution polymerization method, an interfacial polymerization method, or the like is used. In the polymerization, monobasic acids such as acetic acid and benzoic acid, or monoacid bases such as hexylamine and aniline can be added as a molecular weight regulator.

  It is also possible to add a heat stabilizer represented by sodium phosphite, sodium hypophosphite, phosphorous acid, hypophosphorous acid and hindered phenol, and other polymerization additives. Specific examples of the copolymerized polyamide suitable for use in the present invention are shown below. However, in specific examples, the copolymerization ratio represents the charging ratio (molar ratio) of the monomer.

  In addition, the electrophotographic photoreceptor of the present invention preferably contains one or more curable resins. In particular, it is preferably used for the undercoat layer, and it is preferable that a thermosetting resin, a photocurable resin, an EB curable resin, or the like is used for the curable resin. In any case, after application, a reaction occurs between the polymers and the like, crosslinking occurs, and the polymer is cured.

  Here, specific examples of the curable resin will be described. The thermosetting resin is a general term for a type of resin that is cured by a chemical reaction caused by heat. Specifically, there are phenol resin, urea resin, melamine resin, cured epoxy resin, urethane resin, unsaturated polyester resin, and the like. In addition, it is possible to impart curability by introducing a curable substituent into a normal thermoplastic polymer. Generally, it is a polymer having a cross-linked structure three-dimensionally, which may be called a condensation-type cross-linking polymer or an addition-type cross-linking polymer. Usually, in the production, the reaction proceeds with time and the reaction rate and the molecular weight increase. As a result, the elastic modulus increases, the specific volume decreases, and the solubility in the solvent greatly decreases.

  Next, a general thermosetting resin will be described. A phenolic resin is a synthetic resin made from phenols and formaldehyde, and has the advantage of being inexpensive and capable of forming a beautiful shape. In general, in the reaction of phenols (P) and formaldehyde (F), those having an F / P molar ratio of about 0.6 to 1 are obtained under acidic conditions, and resins having a base catalyst of about 1 to 3 are obtained. Produces.

  The urea resin is a synthetic resin formed by reacting urea with formalin, and has an advantage that it can be freely colored with a colorless and transparent solid. In general, in the reaction between urea and formaldehyde, polymethylene urea having no methylol group is produced under acidic conditions, and a mixture of methylol ureas is obtained under basic conditions.

  Melamine resin is a thermosetting resin obtained by the reaction of melamine derivative and formaldehyde, and is more expensive than urea resin, but it is excellent in hardness, water resistance and heat resistance, and is colorless and transparent and free to color. It has the advantage that it can be made, and is excellent for lamination and adhesion.

  Epoxy resin is a general term for thermosetting resins that can be cured by graft polymerization with epoxy groups remaining in the polymer. When a prepolymer before graft polymerization and a curing agent are mixed and heat-cured, the product is completed, but both the prepolymer and the commercialized resin are called epoxy resins. The prepolymer is mainly a liquid compound having two or more epoxy groups in one molecule. By reaction (mainly polyaddition) of this polymer and various curing agents, a three-dimensional polymer is produced and becomes a cured epoxy resin. The cured epoxy resin has good adhesion and adhesion, and is excellent in heat resistance, chemical resistance, and electrical stability. General-purpose epoxy resins are bisphenol A diglycyl ether-based resins, but there are glycidyl ester-based resins, glycidyl amine-based resins, and cyclic aliphatic epoxy resins. Typical examples of the curing agent include aliphatic and aromatic polyamines, acid anhydrides, and polyphenols, which react with an epoxy group by polyaddition to be polymerized and three-dimensionalized. Other examples include tertiary amines and Lewis acids.

  The urethane resin is a polymer compound obtained by copolymerizing a monomer with a urethane bond usually formed by condensation of an isocyanate group and an alcohol group. Usually, it is divided into a liquid main agent and a curing agent at room temperature, and the two liquids are polymerized by stirring and mixing to form a solid.

  The unsaturated polyester resin is divided into a resin and a curing agent that are liquid at room temperature, and the two liquids are polymerized by stirring and mixing to form a solid. Although it has the feature of high transparency, there is a problem with respect to dimensional stability and the like due to large shrinkage during polymerization and curing. Since it is often sold in the form of a volatile solvent, it gradually deforms as the solvent evaporates after curing.

  A photocurable resin consists of what mixed oligomers (low polymer), such as epoxy acrylate and urethane acrylate, a reactive diluent (monomer), and a photoinitiator (benzoin type, acetophenone type, etc.). In addition to these, there are addition type footing polymers that use a copolymer of polyfunctional monomers such as divinylbenzene and ethylene glycol dimethacrylate. In addition, it is preferable to use a polymer other than a so-called curable resin in combination, and in particular, a polyamide resin such as an alcohol-soluble copolymer polyamide or the modified polyamide is preferable because it exhibits good dispersibility and coatability.

  Any organic solvent that can dissolve the binder resin for the undercoat layer can be used as the organic solvent for the coating solution for forming the undercoat layer. Specifically, alcohols having 5 or less carbon atoms such as methanol, ethanol, isopropyl alcohol, or normal propyl alcohol; halogens such as chloroform, 1,2-dichloroethane, dichloromethane, trichrene, carbon tetrachloride, 1,2-dichloropropane, etc. Hydrocarbons: Nitrogen-containing organic solvents such as dimethylformamide; aromatic hydrocarbons such as toluene and xylene, and the like. Among these, an arbitrary combination and a mixed solvent in an arbitrary ratio can be used. Moreover, even if it is an organic solvent which does not dissolve the binder resin for the undercoat layer alone, it can be used as long as it can be dissolved, for example, by using a mixed solvent with the above organic solvent. . In general, coating unevenness can be reduced by using a mixed solvent.

  The amount ratio of the organic solvent used in the coating solution for forming the undercoat layer and the solid content of the binder resin, titanium oxide particles, etc. varies depending on the coating method of the coating solution for forming the undercoat layer, and a uniform coating film in the applied coating method May be used with appropriate modification so that the above is formed.

  The layer forming coating solution preferably contains metal oxide particles. In this case, the metal oxide particles are dispersed in the coating solution. In order to disperse the metal oxide particles in the coating solution, for example, it can be produced by wet dispersion in an organic solvent with a known mechanical grinding device such as a ball mill, a sand grind mill, a planetary mill, or a roll mill. However, it is preferable to disperse using a dispersion medium.

  As a dispersing device for dispersing using a dispersion medium, any known dispersing device may be used. Pebble mill, ball mill, sand mill, screen mill, gap mill, vibration mill, paint shaker, atomizer Examples include lighters. Among these, those that can be dispersed by circulating the coating liquid are preferable, and wet stirring ball mills such as a sand mill, a screen mill, and a gap mill are used from the viewpoints of dispersion efficiency, fineness of the final particle size, ease of continuous operation, and the like. . These mills may be either vertical or horizontal. The disc shape of the mill can be any plate type, vertical pin type, horizontal pin type or the like. Preferably, a liquid circulation type sand mill is used.

  The wet stirring ball mill is supplied from a cylindrical stator, a slurry supply port provided at one end of the stator, a slurry discharge port provided at the other end of the stator, a medium filled in the stator, and a supply port. A rotor of a pin, disk or annular type that stirs and mixes the prepared slurry, and is connected to the discharge port and rotates integrally with the rotor, or rotates independently of the rotor, and rotates with centrifugal force. In a wet stirring ball mill consisting of an impeller type separator that separates media and slurry by action and discharges the slurry from the discharge port, the shaft center for driving the separator to rotate is made a hollow discharge port that communicates with the discharge port. Those are particularly preferred.

  According to such a wet stirring ball mill, the slurry from which the media is separated by the separator is discharged through the shaft center, but since the centrifugal force does not act on the shaft center, the slurry is discharged without kinetic energy. Is done. For this reason, kinetic energy is not wasted and useless power is not consumed.

  Such a wet stirring ball mill may be horizontally oriented, but is preferably vertically oriented in order to increase the media filling rate, and a discharge port is provided at the upper end of the mill. It is also desirable to provide a separator above the media filling level. When the discharge port is provided at the upper end of the mill, the supply port is provided at the bottom of the mill. In a preferred embodiment, the supply port is composed of a valve seat and a V-shaped, trapezoidal, or cone-shaped valve body that is fitted to the valve seat so as to be movable up and down and can be in line contact with the edge of the valve seat. By forming an annular slit that prevents the passage of media between the V-shaped, trapezoidal, or cone-shaped valve body, the raw slurry is supplied, but the fall of the media can be prevented. . Further, it is possible to widen the slit to raise the valve body and discharge the media, or to lower the valve body to close the slit and seal the mill. Further, since the slit is formed by the edge of the valve body and the valve seat, the coarse particles in the raw material slurry are difficult to bite, and even if it is bitten, it is easy to come out vertically and clogging is difficult to occur.

  Such a wet stirring ball mill is also preferably provided with a screen for separating the media at the bottom and a product slurry outlet, so that the product slurry remaining in the mill can be removed after pulverization.

  In the present invention, the wet stirring ball mill applied to disperse the coating solution for forming the undercoat layer, which is preferably used, may be a separator or a screen or slit mechanism, but is preferably an impeller type, A mold is preferred. It is desirable to place the wet stirring ball mill in a vertical orientation and to provide a separator at the top of the mill. Especially when the media filling rate is set to 80 to 90%, the grinding is most efficiently performed, and the separator is more than the media filling level. It is possible to position it above, and there is an effect that it is possible to prevent the medium from being ejected on the separator.

  Specific examples of the wet stirring ball mill having such a structure include an ultra apex mill manufactured by Kotobuki Kogyo Co., Ltd.

  The metal oxide is preferably dispersed in the presence of a dispersion solvent in a wet manner, but a binder resin and various additives may be mixed at the same time. Although it does not restrict | limit especially as this solvent, If it uses the organic solvent used for the said coating liquid for undercoat layer formation, it will become unnecessary to go through processes, such as solvent exchange, after dispersion | distribution, and is suitable. Any one of these solvents may be used alone, or two or more thereof may be used in combination as a mixed solvent.

  From the viewpoint of productivity, the amount of the solvent used is usually 0.1 parts by mass or more, preferably 1 part by mass or more, and usually 500 parts by mass or less, preferably 1 part by mass of the metal oxide to be dispersed. The range is 100 parts by mass or less. The temperature at the time of mechanical dispersion can be from the freezing point of the solvent (or mixed solvent) to the boiling point or less, but is usually in the range of 10 ° C. or more and 200 ° C. or less from the viewpoint of safety during production. Done in

  After the dispersion treatment using the dispersion medium, it is preferable that the dispersion medium is separated and removed and further subjected to ultrasonic treatment. In the ultrasonic treatment, ultrasonic vibration is applied to the coating solution for forming the undercoat layer, but there is no particular limitation on the vibration frequency and the like. Usually, ultrasonic waves are generated by an oscillator having a frequency of 10 kHz to 40 kHz, preferably 15 kHz to 35 kHz. Add vibration.

  Although there is no restriction | limiting in particular in the output of an ultrasonic oscillator, Usually 100W-5kW thing is used. Usually, it is better to disperse a small amount of coating liquid with ultrasonic waves with a small output ultrasonic oscillator than to process a large amount of coating liquid with ultrasonic waves with a high output ultrasonic oscillator. The amount of the undercoat layer-forming coating solution to be processed is preferably 1 to 50 L, more preferably 5 to 30 L, and particularly preferably 10 to 20 L. In this case, the output of the ultrasonic oscillator is preferably 200 W to 3 kW, more preferably 300 W to 2 kW, and particularly preferably 500 W to 1.5 kW.

  The method of applying ultrasonic vibration to the coating solution for forming the undercoat layer is not particularly limited, but the method of directly immersing the ultrasonic oscillator in the container containing the coating solution for forming the undercoat layer, the coating for forming the undercoat layer Examples thereof include a method in which an ultrasonic oscillator is brought into contact with the outer wall of the container in which the liquid is stored, and a method in which a solution containing the coating liquid for forming the undercoat layer is immersed in a liquid that has been vibrated by the ultrasonic transmitter. Among these methods, a method of immersing a solution containing the coating solution for forming the undercoat layer in a liquid that has been vibrated by an ultrasonic transmitter is preferably used. In this case, the liquid to be vibrated by the ultrasonic transmitter includes water; alcohols such as methanol; aromatic hydrocarbons such as toluene; and fats and oils such as silicone oil. In view of cleaning properties, it is preferable to use water. In the method of immersing a solution containing a coating liquid for forming an undercoat layer in a liquid that has been vibrated by an ultrasonic transmitter, the efficiency of ultrasonic treatment changes depending on the temperature of the liquid. It is preferable to keep it constant. The temperature of the liquid to which vibration is applied may increase due to the applied ultrasonic vibration. The temperature of the liquid is usually 5 to 60 ° C, preferably 10 to 50 ° C, and more preferably 15 to 40 ° C.

  The container for storing the coating solution for forming the undercoat layer during the ultrasonic treatment is a container that is usually used for containing the coating solution for forming the undercoat layer used for forming the photosensitive layer for the electrophotographic photoreceptor. Any container may be used as long as it is a resin container such as polyethylene and polypropylene, a glass container, and a metal can. Among these, metal cans are preferable, and in particular, 18 liter metal cans as defined in JIS Z 1602 are preferably used. This is because it is hardly affected by organic solvents and is strong against impact.

The coating solution for forming the undercoat layer is used after being filtered as necessary in order to remove coarse particles. As the filtration media in this case, any filtration media such as cellulose fiber, resin fiber, glass fiber, etc., which are usually used for filtration may be used. As a form of the filtration media, a so-called wind filter in which various fibers are wound around a core material is preferable due to a large filtration area and high efficiency. As the core material, any conventionally known core material can be used, and examples thereof include a stainless steel core material and a resin-made core material that does not dissolve in an undercoat layer forming coating solution such as polypropylene.
The coating solution for forming the undercoat layer thus produced is used for forming the undercoat layer by further adding a binder or various auxiliary agents if desired.

In order to disperse metal oxide particles such as titanium oxide particles in the coating solution for the undercoat layer, it is preferable to use a dispersion medium having an average particle diameter of 5 μm to 200 μm.
Since the dispersion medium is generally in the shape of a perfect sphere, the average particle diameter can be obtained by a method of sieving with a sieve described in, for example, JIS Z 8801: 2000 or by image analysis. The density can be measured by the method. Specifically, it is possible to measure the average particle diameter and the sphericity with an image analysis apparatus typified by LUZEX50 manufactured by Nireco. The average particle diameter of the dispersion medium is usually 5 μm to 200 μm, and more preferably 10 μm to 100 μm. In general, a dispersion medium having a small particle diameter tends to give a uniform dispersion in a short time. However, if the particle diameter is excessively small, the mass of the dispersion medium becomes too small to perform efficient dispersion.

The density of the dispersion medium is usually 5.5 g / cm ³ or more, preferably 5.9 g / cm ³ or more, more preferably 6.0 g / cm ³ or more. Generally, dispersion using a higher density dispersion medium tends to give a uniform dispersion in a shorter time. The sphericity of the dispersion medium is preferably 1.08 or less, more preferably a dispersion medium having a sphericity of 1.07 or less.

  The material of the dispersion medium is insoluble in the coating solution for forming the undercoat layer and has a specific gravity larger than that of the coating solution for forming the undercoat layer and reacts with the coating solution for forming the undercoat layer, Any known dispersion medium can be used as long as it does not alter the forming coating solution. Steel balls such as chrome balls (ball bearing steel balls) and carbon balls (carbon steel balls); stainless steel Spheres: Ceramic spheres such as silicon nitride spheres, silicon carbide, zirconia, and alumina; spheres coated with a film of titanium nitride, titanium carbonitride, and the like. Among these, ceramic spheres are preferable, and zirconia fired balls are particularly preferable. Is preferred. More specifically, it is particularly preferable to use zirconia fired beads described in Japanese Patent No. 3400836.

<Undercoat layer forming method>
In the present invention, the preferred undercoat layer is a dip coating, spray coating, nozzle coating, spiral coating, ring coating, bar coating coating, roll coating coating, blade coating, etc., on the support. It forms by apply | coating by the well-known coating method of this, and drying.

  Spray coating methods include air spray, airless spray, electrostatic air spray, electrostatic airless spray, rotary atomizing electrostatic spray, hot spray, and hot airless spray. Considering the degree of conversion, adhesion efficiency, etc., in the rotary atomizing electrostatic spray, the conveying method disclosed in the republished Japanese Patent Publication No. 1-805198, that is, the cylindrical workpiece is rotated while the axial direction is spaced. By continuously transporting the electrophotographic photosensitive member, an electrophotographic photosensitive member excellent in film thickness uniformity can be obtained with a comprehensively high adhesion efficiency.

Examples of the spiral coating method include a method using a liquid injection coating machine or a curtain coating machine disclosed in Japanese Patent Laid-Open No. 52-119651, and a coating liquid from a minute opening disclosed in Japanese Patent Laid-Open No. 1-2231966. And a method using a multi-nozzle body disclosed in JP-A-3-193161.
In the case of the dip coating method, the total solid concentration of the coating solution for forming the undercoat layer is usually 1% by mass or more, preferably 10% by mass or more, and usually 50% by mass or less, preferably 35% by mass or less. The viscosity is preferably 0.1 mPa · s or more, and preferably 100 mPa · s or less.

  Thereafter, the coating film is dried, and the drying temperature and time are adjusted so that necessary and sufficient drying is performed. The drying temperature is usually 100 to 250 ° C, preferably 110 ° C to 170 ° C, more preferably 115 ° C to 140 ° C. As a drying method, a hot air dryer, a steam dryer, an infrared dryer, and a far infrared dryer can be used.

<Charge generating material>
The photosensitive layer formed on the conductive support may have a single layer structure in which the charge generation material and the charge transport material are present in the same layer and dispersed in the binder resin, or the charge generation material may be Any of a layered structure in which the charge generation layer dispersed in the binder resin and the charge transport material dispersed in the binder resin are functionally separated may be used.

  In the present invention, it is preferable to use a dye / pigment as a charge generating substance, if necessary. For example, selenium and its alloys, cadmium sulfide, other inorganic photoconductive materials, phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, ant Various photoconductive materials such as organic pigments such as anthrone pigments and benzimidazole pigments can be used, and organic pigments, phthalocyanine pigments, and azo pigments are particularly preferable.

Specific examples of the phthalocyanine used include metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, and other metals, or oxides, halides, hydroxides, and alkoxides thereof. Various crystal forms of such coordinated phthalocyanines are used. Particularly, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), and D-type (also known as Y-type), which are highly sensitive crystalline Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and I, μ-oxo such as type II -Aluminum phthalocyanine dimer is preferred. Of these phthalocyanines, A-type (β-type), B-type (α-type), D-type (Y-type) oxytitanium phthalocyanine, II-type chlorogallium phthalocyanine, V-type hydroxygallium phthalocyanine, G-type μ-oxo- Gallium phthalocyanine dimer and the like are particularly preferable.
In particular, it is preferable that oxytitanium phthalocyanine has a clear diffraction peak mainly at a Bragg angle (2θ ± 0.2 °) of 27.2 ° in a powder X-ray diffraction spectrum by CuKα characteristic X-ray.

  Further, the 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. . In the oxytitanium phthalocyanine, the chlorine content in the crystal is preferably 1.5% by mass or less. The chlorine content is determined from elemental analysis.

  In the oxytitanium phthalocyanine crystal, the ratio of the chlorinated oxytitanium phthalocyanine represented by the following formula (E) is higher than the unsubstituted oxytitanium phthalocyanine represented by the following formula (F). The ratio is 0.070 or less. The mass spectral intensity ratio is preferably 0.060 or less, more preferably 0.055 or less. In the production, when the dry grinding method is used for amorphization, 0.02 or more is preferable, and when the acid paste method is used for amorphization, 0.03 or more is preferable. The amount of chloro substitution can be measured based on the technique disclosed in JP-A No. 2001-115054.

  The particle size of these oxytitanyl phthalocyanines varies greatly depending on the production method and the crystal conversion method, but considering the dispersibility, the primary particle size is preferably 500 nm or less, and from the viewpoint of coating film formability, it is preferably 300 nm or less. . In addition to the chlorinated oxytitanium phthalocyanine, the oxytitanium phthalocyanine may be substituted with, for example, a fluorine atom, a nitro group, or a cyano group. Alternatively, various oxytitanium phthalocyanine derivatives substituted with a substituent such as a sulfone group may be contained.

  In the present invention, the oxytitanium phthalocyanine suitable for use is, for example, a composition of oxytitanium phthalocyanine by synthesizing dichlorotitanium phthalocyanine from phthalonitrile and titanium halide as raw materials and then hydrolyzing and purifying the dichlorotitanium phthalocyanine. Can be produced by crystallizing an amorphous oxytitanium phthalocyanine composition obtained by producing a product intermediate and amorphizing the resulting oxytitanium phthalocyanine composition intermediate in a solvent. .

  Titanium chloride is preferred as the titanium halide. Examples of titanium chloride include titanium tetrachloride, titanium trichloride, and the like, and titanium tetrachloride is particularly preferable. When titanium tetrachloride is used, the content of chlorinated oxytitanium phthalocyanine contained in the resulting oxytitanium phthalocyanine composition can be easily controlled.

  The reaction temperature is usually 150 ° C. or higher, preferably 180 ° C. or higher. In order to control the content of chlorinated oxytitanium phthalocyanine, more preferably 190 ° C. or higher, usually 300 ° C. or lower, preferably 250 ° C. or lower, more Preferably it is performed at 230 degrees C or less. Usually, titanium chloride is added to a mixture of phthalonitrile and a reaction solvent. The titanium chloride at this time may be added directly as long as it has a boiling point or less, or may be added in combination with the high boiling point solvent.

  In the present invention, for example, when dioxyalkane is used as a reaction solvent and oxytitanium phthalocyanine is produced using phthalonitrile and titanium tetrachloride, titanium tetrachloride is divided at a low temperature of 100 ° C. or lower and a high temperature of 180 ° C. or higher. In this invention, oxytitanium phthalocyanine suitable for use in the present invention can be produced.

  The obtained dichlorotitanium phthalocyanine is heated and hydrolyzed, and then pulverized by a known mechanical pulverizer such as a paint shaker, ball mill, sand grind mill, or so-called acid obtained as a solid in cold water after being dissolved in concentrated sulfuric acid. Amorphized by a paste method or the like. In view of dark decay, mechanical pulverization is preferable, and the acid paste method is preferable from the viewpoint of sensitivity and environment dependence.

  The obtained amorphous oxytitanium phthalocyanine composition is crystallized with a known solvent to obtain an oxytitanium phthalocyanine composition suitable for use in the present invention. More specifically, as the solvent, halogenated aromatic hydrocarbon solvents such as orthodichlorobenzene, chlorobenzene and chloronaphthalene; halogenated hydrocarbon solvents such as chloroform and dichloroethane; aromatics such as methylnaphthalene, toluene and xylene Group hydrocarbon solvents; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as methyl ethyl ketone and acetone; alcohols such as methanol, ethanol, butanol and propanol; ethers such as ethyl ether, propyl ether, butyl ether and ethylene glycol Solvents: Monoterpene hydrocarbon solvents such as terpinolene and pinene, liquid paraffin, etc. are preferably used. Among them, orthodichlorobenzene, toluene, methylnaphthalene, ethyl acetate, butyl ether, pine Etc. are preferred.

The powder X-ray diffraction spectrum by CuKα characteristic X-ray of oxytitanium phthalocyanine can be measured according to the method usually used for powder X-ray diffraction measurement of solids.
In the present invention, oxytitanium phthalocyanine, which is preferably used, has a clear diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° in a powder X-ray diffraction spectrum by CuKα characteristic X-ray. Further, those having a clear diffraction peak at 9.0 ° to 9.8 ° are preferable. In particular, those having a peak at 9.0 °, 9.6 °, 9.5 ° and 9.7 ° or the like are preferable. Among them, those having no clear diffraction peak are preferable at a Bragg angle (2θ ± 0.2 °) of 26.3 °.

  The phthalocyanine compound may be in a mixed crystal state. As the mixed state that can be placed in the phthalocyanine compound or crystal state here, the respective constituent elements may be mixed and used later, or in a mixed state in the manufacturing and processing steps of the phthalocyanine compound such as synthesis, pigmentation, and crystallization. It may be the one that gave rise to. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

When using an azo pigment, various known bisazo pigments and trisazo pigments are preferably used. Examples of preferred azo pigments are shown below. In the following general formula, Cp ¹ to Cp ³ represent couplers.

The Cp ¹ to Cp ³ coupler preferably has the following structure.

  Examples of the binder resin used for the charge generation layer in the multilayer photoreceptor include polyvinyl butyral resin, polyvinyl formal resin, polyvinyl such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal or acetal. Acetal 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 acetate-vinyl acetate copolymers such as vinyl acetate copolymers, hydroxy-modified vinyl chloride-vinyl acetate copolymers, carboxyl-modified vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, etc. Insulating resins such as polymers, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, styrene-alkyd resins, silicone alkyd resins, phenol-formaldehyde resins, poly-N-vinylcarbazole, polyvinyl anthracene, polyvinyl perylene It can be selected from organic photoconductive polymers such as, but not limited to these polymers. These binder resins may be used alone or in combination of two or more.

  Solvents and dispersion media used to dissolve the binder resin and prepare the coating solution include, for example, saturated aliphatic solvents such as pentane, hexane, octane, and nonane, aromatic solvents such as toluene, xylene, and anisole, chlorobenzene Halogenated aromatic solvents such as dichlorobenzene and chloronaphthalene, amide solvents such as dimethylformamide and N-methyl-2-pyrrolidone, alcohol solvents such as methanol, ethanol, isopropanol, n-butanol and benzyl alcohol, glycerin , Aliphatic polyhydric alcohols such as polyethylene glycol, chain, branched, and cyclic ketone solvents such as acetone, cyclohexanone, methyl ethyl ketone, 4-methoxy-4-methyl-2-pentanone, methyl formate, ethyl acetate, n-acetate -Ester solvents such as butyl, Halogenated hydrocarbon solvents such as methylene chloride, chloroform, 1,2-dichloroethane, chained and cyclic ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve , Aprotic polar solvents such as acetonitrile, dimethyl sulfoxide, sulfolane, hexamethylphosphoric triamide, n-butylamine, isopropanolamine, diethylamine, triethanolamine, nitrogen-containing compounds such as ethylenediamine, triethylenediamine, triethylamine, and mineral oils such as ligroin Water, etc. are mentioned, and those that do not dissolve the undercoat layer described later are preferably used. These can be used alone or in combination of two or more.

  In the charge generation layer of the multilayer photoreceptor, the blending ratio (mass ratio) of the binder resin and the charge generation material is 10 to 1000 parts by weight, preferably 30 to 500 parts by weight with respect to 100 parts by weight of the binder resin. The film thickness is usually 0.1 μm to 4 μm, preferably 0.15 μm to 0.6 μm. If the ratio of the charge generation material is too high, the stability of the coating solution is lowered due to problems such as aggregation of the charge generation material. On the other hand, if it is too low, the sensitivity as a photoreceptor is reduced. It is preferable. As a method for dispersing the charge generating substance, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. In this case, it is effective to refine the particles to a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

<Charge transport material>
As the charge transport material, the enamine compound is used. The enamine compound may be used alone or in combination with other charge transporting substances. The charge transporting substance used in combination is not particularly limited as long as it is a known substance. For example, aromatic nitro compounds such as 2,4,7-trinitrofluorenone, and cyano compounds such as tetracyanoquinodimethane , Electron withdrawing substances such as quinone compounds such as diphenoquinone, carbazole derivatives, indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, heterocyclic compounds such as benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, Examples thereof include electron donating substances such as stilbene derivatives, butadiene derivatives, enamine derivatives and those obtained by bonding a plurality of these compounds, or polymers having a group consisting 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.
The structure of a suitable charge transport material that can be used in the present invention is exemplified below.

In the above formula, R ′ may be the same or different (intramolecular). Specifically, it is a hydrogen atom or a substituent, and the substituent is preferably an alkyl group, an alkoxy group, an aryl group or the like. Particularly preferred are a methyl group and a phenyl group. N ′ is an integer of 0 to 2.
In the electrophotographic photoreceptor of the present invention, since the effect of the present invention may be diminished if the amount of the charge transport material used in combination with the enamine compound is too large, the amount of the total charge transport material in the photosensitive layer may be reduced. When the amount is 100 parts by mass, the amount of the enamine compound used is usually 50 parts by mass or more, more preferably 60 parts by mass or more, still more preferably 70 parts by mass or more, and particularly preferably 80 parts by mass or more.

<Binder resin>
In forming a charge transport layer of a function-separated type photoreceptor having a charge generation layer and a charge transport layer, and a photosensitive layer of a single layer type photoreceptor, a binder resin is used to disperse the compound in order to ensure film strength. . In the case of the charge transport layer of the functional separation type photoreceptor, a coating solution obtained by dissolving or dispersing the charge transport material and various binder resins in a solvent, and in the case of a single layer type photoreceptor, the charge generation material and the charge transport. It can be obtained by applying and drying a coating solution obtained by dissolving or dispersing the substance and various binder resins in a solvent. Examples of the binder resin include polymers and copolymers of vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylic acid ester resin, methacrylic acid ester resin, vinyl alcohol resin, ethyl vinyl ether, polyvinyl Butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicone resin, silicone-alkyd resin, poly-N-vinylcarbazole resin Etc. These resins may be modified with a silicon reagent or the like.

  In particular, in the present invention, it is preferable to contain one or more kinds of polymers obtained by interfacial polymerization. Interfacial polymerization is a polymerization method that utilizes a polycondensation reaction that proceeds at the interface of two or more solvents (mostly organic solvents-water systems) that do not mix with each other. For example, a dicarboxylic acid chloride is dissolved in an organic solvent, a glycol component is dissolved in alkaline water, etc., and both liquids are mixed at room temperature to be separated into two phases. At the interface, a polycondensation reaction proceeds to produce a polymer. Let Examples of other two components include phosgene and an aqueous glycol solution. Further, as in the case of condensing a polycarbonate oligomer by interfacial polymerization, the two components may not be divided into two phases, but the interface may be used as a polymerization field.

  As the reaction solvent, it is preferable to use two layers of an organic phase and an aqueous phase. The organic phase is preferably methylene chloride, and the aqueous phase is preferably an alkaline aqueous solution. During the reaction, it is preferable to use a catalyst, and the amount of the condensation catalyst used in the reaction is about 0.005 to 0.1 mol%, preferably 0.03 to 0.08 mol% with respect to the diol as the glycol component. It is. If it exceeds 0.1 mol%, a great deal of labor may be required for extraction and removal of the catalyst in the washing step after polycondensation.

  The reaction temperature is 80 ° C. or less, preferably 60 ° C. or less, more preferably 10 ° C. to 50 ° C., and the reaction time depends on the reaction temperature, but usually 0.5 minutes to 10 minutes. Time, preferably 1 minute to 2 hours. If the reaction temperature is too high, the side reaction cannot be controlled. On the other hand, if the reaction temperature is too low, the reaction control is preferable, but the refrigeration load may increase and the cost may increase accordingly.

  Moreover, the density | concentration in an organic phase should just be a range with which the composition obtained is soluble, Specifically, it is about 10-40 mass%. The proportion of the organic phase is preferably a volume ratio of 0.2 to 1.0 with respect to the aqueous alkali metal hydroxide solution of diol, that is, the aqueous phase.

  Moreover, it is preferable that the quantity of a solvent is adjusted so that the density | concentration of the production | generation resin in the organic phase obtained by polycondensation may be 5-30 mass%. Thereafter, an aqueous phase containing water and alkali metal hydroxide is newly added, and in order to further adjust the polycondensation conditions, a condensation catalyst is preferably added and the desired polycondensation is completed according to the interfacial polycondensation method. The ratio of the organic phase to the aqueous phase during polycondensation is preferably about 1: 0.2 to 1 in terms of volume ratio.

  The polymer produced by interfacial polymerization is particularly preferably a polycarbonate resin or a polyester resin (particularly a polyarylate resin is preferred). The polymer is preferably a polymer using an aromatic diol as a raw material, and a preferable aromatic diol structure is represented by the following formula (A).

［式（Ａ）中、Ｘ^２は単結合又は連結基を示し、Ｙ^１ないしＹ^８は各々独立に、水素原子又は原子数２０以下の置換基を示す。］

[In Formula (A), X ² represents a single bond or a linking group, and Y ¹ to Y ⁸ each independently represent a hydrogen atom or a substituent having 20 or less atoms. ]

In formula (A), X ² is preferably a single bond or a group represented by the following structure. The “single bond” refers to a state in which there are no atoms “X ² ” and the two left and right benzene rings in the formula (A) are simply bonded by a single bond.

上記構造中、Ｒ^１ａ及びＲ^２ａは、それぞれ独立に、水素原子、炭素数１〜２０のアルキル基、置換されていてもよいアリール基、又は、ハロゲン化アルキル基を示し、Ｚは、炭素数４〜２０の置換されていてもよい炭化水素基を示す。

In the above structure, R ^1a and R ^2a each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a halogenated alkyl group, and Z represents the number of carbon atoms. 4 to 20 optionally substituted hydrocarbon groups are shown.

  In particular, polycarbonate resins and polyarylate resins containing a bisphenol or biphenol component having the following structural formula are preferable from the viewpoints of sensitivity, residual potential, and the like.

  Examples of structures of bisphenol and biphenol that can be suitably used for polycarbonate resin and polyarylate resin are shown below. This illustration is made for the sake of clarity, and is not limited to the illustrated structure unless it is contrary to the spirit of the present invention.

  In particular, in order to maximize the effects of the present invention, a polycarbonate resin containing a bisphenol or biphenol component having the following structure is preferable.

  In order to improve mechanical properties, it is preferable to use polyester, particularly polyarylate, and in this case, it is preferable to use the following structure as a bisphenol component,

酸成分としては、以下構造を用いることが好ましい。

As the acid component, the following structure is preferably used.

  Further, when terephthalic acid and isophthalic acid are used, it is preferable that the molar ratio of terephthalic acid is large.

  The ratio of the binder resin and the charge transport material used in the charge transport layer of the multilayer photoreceptor and the photosensitive layer of the single photoreceptor is usually 100 parts by weight of the binder resin in both the single layer and multilayer. The charge transport material is 20 parts by mass or more, preferably 30 parts by mass or more from the viewpoint of residual potential reduction, and more preferably 40 parts by mass or more from the viewpoint of stability during repeated use and charge mobility. Preferably it is 50 mass parts or more. On the other hand, from the viewpoint of thermal stability of the photosensitive layer, it is usually 150 parts by mass or less, preferably 120 parts by mass or less from the viewpoint of compatibility between the charge transport material and the binder resin, and from the viewpoint of printing durability. 100 parts by mass or less is more preferable.

  In the case of a single-layer type photoreceptor, the charge generating substance is further dispersed in the charge transport medium having the above-described blending ratio. In this case, the particle size of the charge generating material needs to be sufficiently small, preferably 1 μm or less, more preferably 0.5 μm or less. If the amount of the charge generating material dispersed in the photosensitive layer is too small, sufficient sensitivity cannot be obtained. If the amount is too large, there is an adverse effect of chargeability and sensitivity, for example, preferably 0.1 to 50% by mass. It is used in the range, preferably in the range of 1 to 20% by mass.

  The film thickness of the photosensitive layer of the single-layer type photoreceptor is usually 5 to 100 μm, preferably 10 to 50 μm. The film thickness of the charge transport layer of the forward laminated photoreceptor is usually 5 to 50 μm. Although used, it is preferably 10 to 45 μm from the viewpoint of long life and image stability, and more preferably 10 to 30 μm from the viewpoint of high resolution.

  The photosensitive layer has well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds to improve film-forming properties, flexibility, coating properties, stain resistance, gas resistance, light resistance, etc. Further, additives such as a leveling agent and a visible light shielding agent may be contained. In addition, the photosensitive layer may contain various additives such as a leveling agent, an antioxidant, and a sensitizer for improving the coating property as necessary. Examples of the antioxidant include hindered phenol compounds and hindered amine compounds. Examples of the light shielding agent include various dye compounds, azo compounds, and the like, and examples of the leveling agent include silicone oil and fluorine-based oil.

<Antioxidant>
The antioxidant is a kind of stabilizer added to prevent oxidation of members included in the photoreceptor. Antioxidants function as radical scavengers, and specific examples include phenol derivatives, amine compounds, phosphonic acid esters, sulfur compounds, vitamins, vitamin derivatives, and the like.

  Of these, phenol derivatives, amine compounds, vitamins and the like are preferable. Among these, a hindered phenol or a trialkylamine derivative having a bulky substituent in the vicinity of the hydroxy group is more preferable. Furthermore, an aryl compound derivative having a t-butyl group at the o position of the hydroxy group is preferable, and an aryl compound derivative having two t-butyl groups at the o position of the hydroxy group is more preferable.

  In addition, when the molecular weight of the antioxidant is too large, a problem may occur in the antioxidant ability. The molecular weight is preferably 1500 or less, and more preferably a compound having a molecular weight of 1000 or less. The lower limit is preferably 100 or more, more preferably 150 or more, and even more preferably 200 or more.

  Hereinafter, the antioxidant which can be used for this invention is shown. As the antioxidant that can be used in the present invention, all known materials can be used as antioxidants for plastics, rubber, petroleum, oils and fats, ultraviolet absorbers, and light stabilizers. The selected material can be preferably used.

(1) Phenols described in JP-A-57-122444, phenol derivatives described in JP-A-60-188756, and binderd phenols described in JP-A-63-18356.
(2) Paraphenylenediamines described in JP-A-57-122444, paraphenylenediamine derivatives described in JP-A-60-188756, and paraphenylenediamines described in JP-A-63-18356 .
(3) Hydroquinones described in JP-A-57-122444, hydroquinone derivatives described in JP-A-60-188756, and hydroquinones described in JP-A-63-18356.
(4) Organic sulfur compounds described in JP-A-63-18356.
(5) Organophosphorus compounds described in JP-A-57-122444 and organophosphorus compounds described in JP-A-63-18356.
(6) Hydroxyanisoles described in JP-A-57-122444.
(7) Piperidine derivatives and oxopiperazine derivatives having a specific skeleton structure described in JP-A-63-018355.
(8) Carotenes, amines, tocopherols, Ni (II) complexes, sulfides and the like described in JP-A-60-188956.

  Of these, hindered phenols shown below are preferred. “Hindered phenol” refers to phenols having a bulky substituent near the hydroxy group. Dibutylhydroxytoluene, 2,2′-methylenebis (6-tert-butyl-4-methylphenol), 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 4,4′-thiobis (6 -T-butyl-3-methylphenol), 2,2′-butylidenebis (6-t-butyl-4-methylphenol), α-tocophenol, β-tocophenol, 2,2,4-trimethyl-6- Hydroxy-7-t-butylchroman, pentaerythryltetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2′-thiodiethylenebis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate], 1,6-hexanediol bis [3- (3,5-di-t-butyl-4-hydroxyphene) Nyl) propionate], butylhydroxyanisole, dibutylhydroxyanisole, octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate (Octadecyl-3,5-di-tert-butyl-4-hydroxycinnamate) 1, 3,5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -benzene (1,3,5-trimethyl-2,4,6-tris- ( 3,5-di-tert-butyl-4-hydroxybenzyl) -benzene)

  Among the above hindered phenols, the following compounds are particularly preferable. Octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate 1,3,5-trimethyl-2,4,6-tris (octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate) 1,3,5-trimethyl-2,4,6-tris -(3,5-di-tert-butyl-4-hydroxybenzyl) -benzene (1,3,5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzoyl) ) -Benzene).

  These compounds are known as antioxidants for rubbers, plastics, oils and the like, and some are available as commercial products.

  In the photoreceptor used in the image forming apparatus of the present invention, the amount of the antioxidant in the photosensitive layer is not particularly limited, but is preferably 0.1 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the binder resin. In other cases, good electrical characteristics cannot be obtained. Particularly preferably, it is 1 part by mass or more. Moreover, since it may cause not only an electrical property but a problem with printing durability when too large, it is preferably 15 parts by mass or less, and more preferably 10 parts by mass or less.

<Electron withdrawing compound>
The photoreceptor preferably has an electron-withdrawing compound, and specifically, a sulfonic acid ester compound, a carboxylic acid ester compound, an organic cyano compound, a nitro compound, an aromatic halogen derivative, and the like are preferable. An ester compound and an organic cyano compound are more preferable, and a sulfonic acid ester compound is particularly preferable. One or more sulfonic acid ester structures are preferably contained in the molecule, more preferably two or more, and still more preferably three or more. The upper limit is preferably 10 or less, and more preferably 5 or less.

  The electron withdrawing ability can be predicted by the value of the LUMO energy level. In particular, the value of the LUMO energy level is −1 by structural optimization using semi-empirical molecular orbital calculation using PM3 parameters (hereinafter simply referred to as “semi-empirical molecular orbital calculation”). Compounds that are 0 eV to -3.0 eV are preferred. When the absolute value of the LUMO energy level is smaller than 1.0 eV, the effect of electron withdrawing cannot be expected so much, and when it exceeds 3.0 eV, charging may be deteriorated. The absolute value of the LUMO energy level is more preferably 1.5 eV or more, still more preferably 1.7 eV or more, and particularly preferably 1.9 eV or more. The upper limit is more preferably 2.7 eV or less, and even more preferably 2.5 eV or less.

  Specific examples of the electron-withdrawing compound include the following compounds.

<Outermost surface layer>
The charge generation material and the charge transport material may be in any layer, but the outermost surface layer contains fluorine atoms and silicon atoms from the viewpoint of toner transfer, improved cleaning properties, and the like. preferable. These atoms may be contained in any material including additives, charge generation materials, charge transport materials, and binder resins.

In particular, a protective layer may be provided on the outermost surface layer of the photoreceptor in order to prevent the photosensitive layer from being worn out or to prevent or reduce deterioration of the photosensitive layer due to a discharge substance generated from a charger or the like. The protective layer is formed 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 as described in JP-A-9-190004. Coalescence can be used. Examples of the conductive material include aromatic amino compounds such as TPD (N, N′-diphenyl-N, N′-bis- (m-tolyl) benzidine), antimony oxide, indium oxide, tin oxide, titanium oxide, and tin oxide. -Metal oxides such as antimony oxide, aluminum oxide, and zinc oxide can be used, but are not limited thereto. As the binder resin used for the protective layer, 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. In addition, a copolymer of the above resin and a skeleton having a charge transporting ability such as a triphenylamine skeleton as described in JP-A-9-190004 can also be used. The protective layer is preferably configured to have an electric resistance of 10 ⁹ to 10 ¹⁴ Ω · cm. When the electric resistance is higher than 10 ¹⁴ Ω · cm, the residual potential is increased and an image with much fogging is formed. On the other hand, when the electric resistance is lower than 10 ⁹ Ω · cm, the image is blurred and the resolution is lowered. In addition, the protective layer must be configured so as not to substantially impede transmission of light irradiated for image exposure.

  In addition, fluorine resin, silicone resin, polyethylene resin, polystyrene resin, etc. are used for the surface layer for the purpose of reducing frictional resistance and abrasion on the surface of the photoconductor and increasing the transfer efficiency of the toner from the photoconductor to the transfer belt and paper. May be included. Moreover, the particle | grains which consist of these resin, and the particle | grains of an inorganic compound may be included.

<Layer formation method>
Each layer constituting the photoreceptor is formed by sequentially applying a coating solution containing the material constituting each layer on the support using a known coating method and repeating the coating and drying process for each layer. The

  In the case of the charge transport layer of the single layer type photoreceptor and the multilayer type photoreceptor, the coating solution for forming the layer is usually used in a solid content concentration of 5 to 40% by mass, but 10 to 35% by mass. It is preferable to use in the range. Moreover, although the viscosity of this coating liquid is normally used in the range of 10-500 mPa * s, it is preferable to set it as the range of 50-400 mPa * s.

  In the case of the charge generation layer of the multilayer photoreceptor, the solid concentration is usually used in the range of 0.1 to 15% by mass, but is preferably used in the range of 1 to 10%. The viscosity of the coating solution is usually used in the range of 0.01 to 20 mPa · s, but is preferably used in the range of 0.1 to 10 mPa · s.

  Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.

  The coating solution is preferably dried by touching at room temperature and then heating and drying in a temperature range of 30 to 200 ° C. for 1 minute to 2 hours with no air or air. The heating temperature may be constant or may be changed while drying.

<Toner according to the present invention>
When an image is formed using the electrophotographic photosensitive member of the present invention, a toner that is a developer for developing a latent image is a toner having a specific circularity (hereinafter referred to as “the toner of the present invention” as appropriate). ) Is used. By using the toner having a specific circularity as described above, the image forming apparatus of the present invention can form a high-quality image.

<Toner circularity>
The shape of the toner of the present invention is such that the shape of each particle included in the particle group constituting the toner is closer to each other, and the closer to a sphere, the less likely the localization of the charge amount in the toner particles occurs. The developability tends to be uniform, which is preferable for improving the image quality. In particular, if the toner has a shape close to a perfect sphere, the contact area with the electrophotographic photosensitive member may be reduced, the toner transfer rate may be increased, and the toner consumption may be reduced. . On the other hand, it is difficult to manufacture a perfect spherical toner, and the cost of the toner increases. Therefore, it is sufficient that the toner is close to a sphere under a certain condition, and it is not necessary to be a perfect sphere.

  Therefore, specifically, the toner of the present invention has an average circularity measured by a flow particle image analyzer of usually 0.940 or more, preferably 0.945 or more, more preferably 0.950 or more, and further Preferably it is 0.955 or more, Most preferably, it is 0.960 or more. The upper limit of the average circularity is not limited as long as it is 1.000 or less, but is preferably 0.998 or less, more preferably 0.995 or less from the viewpoint of ease of production.

The average circularity is used as a simple method for quantitatively expressing the shape of toner particles. In the present invention, the average circularity is measured using a flow type particle image analyzer FPIA-2000 manufactured by Sysmex Corporation. Then, the circularity [a] of the measured particle is obtained by the following formula (X).
Circularity a = L0 / L (X)
(In Formula (X), L0 represents the perimeter of a circle having the same projected area as the particle image, and L represents the perimeter of the particle image when image processing is performed.)
The circularity is an index of the degree of unevenness of toner particles, and indicates 1.000 when the toner is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated.

  A specific method for measuring the average circularity is as follows. That is, a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 20 mL of water from which impurities in the container have been removed in advance, and about 0.05 g of a measurement sample (toner) is further added. The suspension in which this sample is dispersed is irradiated with ultrasonic waves for 30 seconds, and the dispersion concentration is set to 3.0 to 8.0 thousand pieces / μL (microliter). The circularity distribution of particles having an equivalent circle diameter of 60 μm or more and less than 160 μm is measured.

<Toner type>
The toner of the present invention is not limited as long as it has the above average circularity. Various types of toner are usually obtained depending on the production method, and any of the toners of the present invention can be used.
Hereinafter, the toner manufacturing method and the type of toner will be described.

The toner of the present invention may be produced by any conventionally known method, for example, a toner produced by a polymerization method or a melt suspension method, and further, a so-called pulverized toner is treated with heat or the like. Although a spheroidized toner can be used, a toner produced by a so-called polymerization method that generates toner particles in an aqueous medium is preferable.
As a method for producing a toner by a so-called polymerization method, a direct toner is used by using a suspension polymerization method described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842. To form a toner, a dispersion polymerization method in which a monomer is soluble in a water-based organic solvent insoluble in a polymer, or a direct polymerization in the presence of a water-soluble polar polymerization initiator to produce a toner. The toner can be produced using an emulsion polymerization method represented by a soap-free polymerization method.

Examples of the polymerization toner include suspension polymerization toner and emulsion polymerization aggregation toner.
In order to improve the releasability, low-temperature fixing property, high-temperature offset property, filming resistance and the like of the toner, a method of incorporating a low softening point substance (so-called wax) into the toner has been proposed. In the melt-kneading pulverization method, it is difficult to increase the amount of wax contained in the toner, and the limit is about 5% by mass with respect to the polymer (binder resin). In contrast, the polymerized toner can contain a low softening point substance in a large amount (5 to 30% by mass). The polymer here is one of the materials constituting the toner. For example, in the case of a toner manufactured by an emulsion polymerization aggregation method described later, the polymer is obtained by polymerizing a polymerizable monomer.

As a method for obtaining a toner having a fine particle size of 3 to 8 μm with a sharp particle size distribution that can control the average circularity of the toner to 0.940 or more, for example, suspension under normal pressure or under pressure is used. Examples thereof include a turbid polymerization method and an emulsion polymerization aggregation method.
When the toner according to the present invention is produced using the suspension polymerization method, as a specific method for encapsulating the low softening point substance, the polarity of the substance in the aqueous medium may be lower than that of the main monomer. The toner having a so-called core / shell structure in which a low softening point substance is coated with an outer shell resin can be obtained by setting the direction smaller and adding a small amount of a resin or monomer having a large polarity. Toner particle size distribution control and particle size control can be done by changing the type and amount of a poorly water-soluble inorganic salt or dispersant that acts as a protective colloid, as well as mechanical equipment conditions, such as rotor speed, number of passes, A predetermined toner of the present invention can be obtained by controlling the stirring conditions such as the shape of the stirring blade, the container shape, or the solid content concentration in the aqueous solution.

As the outer shell resin of the toner used in the present invention, generally used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins, and styrene-butadiene copolymers can be used. Those monomers are preferably used in a method for directly obtaining a toner by a polymerization method.
Specifically, styrene monomers such as styrene, o (m-, p-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, ( Meth) propyl acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (Meth) acrylic acid ester monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide Is preferably used.

  These monomers are used alone or generally so that the theoretical glass transition temperature (Tg) described in the publication polymer handbook 2nd edition III-P139-192 (John Wiley & Sons) is 40-75 ° C. It is used by mixing appropriately. When the theoretical glass transition temperature is less than 40 ° C., there are problems in terms of storage stability of the toner and durability of the developer. On the other hand, when it exceeds 75 ° C., the fixing point is increased. In some cases, the color toners are not sufficiently mixed, resulting in poor color reproducibility. Further, the transparency of the OHP image is remarkably lowered, which is not preferable from the viewpoint of high image quality.

  The molecular weight of the outer shell resin is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, a toner is previously extracted with a toluene solvent using a Soxhlet extractor for 20 hours, and then toluene is distilled off with a rotary evaporator. Further, the low softening point substance is dissolved, but the shell resin is used. After washing thoroughly with an organic solvent that cannot be dissolved, such as chloroform, a sample obtained by filtering a solution soluble in THF (tetrahydrofuran) with a solvent-resistant membrane filter having a pore size of 0.3 μm was manufactured by Waters. Using 150C, the column configuration can be measured by using A-801, 802, 803, 804, 805, 806, and 807 manufactured by Showa Denko and using a standard polystyrene resin calibration curve to measure the molecular weight distribution.

The number average molecular weight (Mn) of the obtained resin component is 5000 to 1000000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 100. Is preferred for the present invention.
In the present invention, when a toner having a core / shell structure is produced, it is particularly preferable to add a polar resin in addition to the outer shell resin in order to encapsulate the low softening point substance with the outer shell resin. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin are preferably used. The polar resin is particularly preferably one containing no unsaturated group capable of reacting with the shell resin or monomer in the molecule. If a polar resin having an unsaturated group is included, a crosslinking reaction occurs with the monomer that forms the shell resin layer. Particularly, as a full-color toner, it is extremely high in molecular weight, which is disadvantageous for the color mixture of four-color toners. It is not preferable.

In the present invention, the outermost resin layer may be provided by superposition on the surface of the toner having an outer shell structure by a polymerization method.
The glass transition temperature of the outermost shell resin layer is designed to be higher than the glass transition temperature of the outer shell resin layer for further improvement of block king resistance, and is further crosslinked to such an extent that the fixing property is not impaired. Is preferred. Further, the outermost resin layer preferably contains a polar resin or a charge control agent in order to improve chargeability.

Further, the method for providing the outermost shell resin layer is not particularly limited, and examples thereof include the following methods.
1. In the latter half of the polymerization reaction or after completion, if necessary, add a monomer in which a polar resin, charge control agent, cross-linking agent, etc. are dissolved and dispersed in the reaction system and adsorb to the polymer particles, and then add a polymerization initiator to perform polymerization. How to do.
2. If necessary, emulsion-polymerized particles or soap-free polymerized particles consisting of monomers containing a polar resin, a charge control agent, a crosslinking agent, etc. are added to the reaction system and aggregated on the surface of the polymerized particles. How to fix.
3. A method in which emulsion-polymerized particles or soap-free polymerized particles comprising monomers containing a polar resin, a charge control agent, a crosslinking agent, etc. are mechanically fixed to the toner particle surface in a dry manner as required.

  As the colorant used in the present invention, carbon black, a magnetic material, and a black colorant that is toned in black using the following yellow / magenta / cyan colorant are used. As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, etc. are preferably used.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigmentlets 2,3,5,6,7,23,48; 2,48; 3,48; 4,57; 1,81; 1,144,146,166,169,177,184,185,202, 206, 220, 221, 254 are particularly preferred.

  As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15; 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably. These colorants can be used alone or mixed and further used in the form of a solid solution.

In the case of a color toner, the colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin. When a magnetic material is used as the black colorant, 40 to 150 parts by mass are added to 100 parts by mass of the resin, unlike other colorants.
As the charge control agent used in the present invention, known ones can be used. In the case of a color toner, in particular, a charge control agent that is colorless and has a high toner charging speed and can stably maintain a constant charge amount. preferable. Further, when the direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibition and no solubilized product in an aqueous system is particularly preferable.

  Specific examples of the negative compounds include salicylic acid, naphthoic acid, dicarboxylic acid metal compounds, sulfonic acid, polymer compounds having carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene, and the like. As a positive system, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, and the like are preferably used. The charge control agent is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin. However, the addition of a charge control agent is not essential in the present invention.

  When the direct polymerization method is used in the present invention, examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, , 1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, Peroxide polymerization initiators such as methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide are used.

The addition amount of the polymerization initiator varies depending on the target degree of polymerization, but generally 0.5 to 20% by mass is added to the monomer. The kind of the initiator is slightly different depending on the polymerization method, but can be used alone or mixed with reference to the 10-hour half-life temperature. In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like can be further added and used.
When suspension polymerization is used as a toner production method used in the present invention, as a dispersant to be used, for example, as an inorganic oxide, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate , Magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic substance, ferrite and the like. As the organic compound, for example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, sodium salt of ethyl cellulose C carboxymethyl cellulose, starch and the like are used by dispersing in an aqueous phase. These dispersants are preferably used in an amount of 0.2 to 10.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Commercially available dispersants may be used as they are, but in order to obtain dispersed particles having a fine and uniform particle size, the inorganic compound can be produced in a dispersion medium under high-speed stirring. For example, in the case of tricalcium phosphate, a dispersant preferable for the suspension polymerization method can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring. Moreover, you may use together 0.001-0.1 mass part surfactant for refinement | miniaturization of these dispersing agents. Specifically, commercially available nonionic, anionic and cationic surfactants can be used, for example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, Calcium oleate is preferably used.

  When the direct polymerization method is used as the toner production method used in the present invention, the toner can be specifically produced by the following production method. Monomer composition in which a release agent, colorant, charge control agent, polymerization initiator and other additives consisting of a low softening substance are added to the monomer and dissolved or dispersed uniformly by a homogenizer, ultrasonic disperser, etc. The product is dispersed in an aqueous phase containing a dispersion stabilizer by a usual stirrer, homomixer, homogenizer or the like. Preferably, granulation is performed by adjusting the stirring speed and time so that droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. Polymerization is carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction, and for the purpose of improving durability characteristics, in order to remove unreacted polymerizable monomers, by-products, etc. The aqueous medium may be distilled off. After completion of the reaction, the produced toner particles are recovered by washing and filtration and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.

Further, the toner in the present invention may be classified to control the particle size distribution, and as a method therefor, a multi-division classifying device using inertial force is preferably used. By using this apparatus, the toner having the particle size distribution of the present invention can be produced efficiently.
When a toner is produced by an emulsion polymerization aggregation method, the production process usually includes a polymerization process, a mixing process, an aggregation process, a fusion process, and a washing / drying process. That is, generally, polymer primary particles are obtained by emulsion polymerization (polymerization step), and if necessary, a colorant (pigment), wax, charge control agent, etc. are dispersed in a dispersion containing the polymer primary particles. The body is mixed (mixing step), and a coagulant is added to the dispersion to agglomerate the primary particles to form a particle aggregate (aggregation step). Thus, particles are obtained (fusion process), and the obtained particles are washed and dried (washing / drying process) to obtain mother particles.

<Polymerization process>
The polymer fine particles (polymer primary particles) are not particularly limited. Therefore, either a fine particle obtained by polymerizing a polymerizable monomer in a liquid medium by a suspension polymerization method, an emulsion polymerization method or the like, or a fine particle obtained by pulverizing a lump of a polymer such as a resin is a polymer. It may be used as primary particles. However, a polymerization method, particularly an emulsion polymerization method, in particular, a method using wax as a seed in emulsion polymerization is preferable. When wax is used as a seed in emulsion polymerization, fine particles having a structure in which the polymer wraps the wax can be produced as polymer primary particles. According to this method, the wax can be contained in the toner without being exposed on the surface of the toner. For this reason, there is no contamination of the apparatus member by the wax, the chargeability of the toner is not impaired, and the low temperature fixing property, high temperature offset property, filming resistance, releasability, etc. of the toner can be improved. it can.

Hereinafter, a method of performing emulsion polymerization using wax as a seed, thereby obtaining polymer primary particles will be described.
The emulsion polymerization method may be performed according to a conventionally known method. Usually, a wax is dispersed in a liquid medium in the presence of an emulsifier to form wax fine particles, and a polymerization initiator that gives a polymer by polymerization (that is, a polymerizable carbon-carbon double bond). And a chain transfer agent, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, a protective colloid, an internal additive, and the like, if necessary, and polymerized by stirring. As a result, an emulsion is obtained in which polymer fine particles (that is, polymer primary particles) having a structure in which the polymer wraps the wax are dispersed in the liquid medium. Examples of the structure in which the polymer wraps the wax include a core-shell type, a phase separation type, and an occlusion type, and the core-shell type is preferable.

(I. Wax)
As the wax, any known wax that can be used for this purpose can be used. For example, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene and copolymer polyethylene; paraffin wax; silicone wax having an alkyl group; fluororesin wax such as low molecular weight polytetrafluoroethylene; higher fatty acids such as stearic acid; eicosanol Long-chain aliphatic alcohols such as behenate behenate, montanic acid ester, stearic acid ester ester wax having a long-chain aliphatic group; distearyl ketone and other long-chain alkyl group ketones; hydrogenated castor oil, Plant waxes such as carnauba wax; esters or partial esters obtained from polyhydric alcohols such as glycerin and pentaerythritol and long chain fatty acids; higher fatty acid amides such as oleic acid amide and stearic acid amide; Ester and the like. Especially, what has at least 1 the endothermic peak by a differential thermal analysis (DSC) in 50-100 degreeC is preferable.

  Among the waxes, for example, ester waxes, paraffin waxes, olefin waxes such as low molecular weight polypropylene and copolymer polyethylene, silicone waxes, and the like are preferable because a release effect can be obtained in a small amount. Paraffin wax is particularly preferable. In addition, 1 type may be used for wax and it may use 2 or more types together by arbitrary combinations and a ratio.

  When using wax, the amount used is arbitrary. However, it is desirable that the wax is usually 3 parts by mass or more, preferably 5 parts by mass or more, and usually 40 parts by mass or less, preferably 30 parts by mass or less with respect to 100 parts by mass of the polymer. If the amount of wax is too small, the fixing temperature range may be insufficient. If the amount is too large, the apparatus member may be contaminated and image quality may be deteriorated.

(Ii. Emulsifier)
There is no restriction | limiting in an emulsifier, Arbitrary things can be used in the range which does not impair the effect of this invention remarkably. For example, any of nonionic, anionic, cationic and amphoteric surfactants can be used.
Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyalkylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether, and sorbitan fatty acid esters such as sorbitan monolaurate. And the like.

Examples of the anionic surfactant include fatty acid salts such as sodium stearate and sodium oleate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, and alkyl sulfate salts such as sodium lauryl sulfate. .
Furthermore, examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of amphoteric surfactants include alkylbetaines such as lauryl betaine.
Among these, nonionic surfactants and anionic surfactants are preferable. In addition, 1 type may be used for an emulsifier and it may use 2 or more types together by arbitrary combinations and a ratio.

Furthermore, the blending amount of the emulsifier is arbitrary as long as the effects of the present invention are not significantly impaired.
(Iii. Liquid medium)
As the liquid medium, an aqueous medium is usually used, and water is particularly preferably used. However, the quality of the liquid medium is also related to the coarsening due to reaggregation of particles in the liquid medium. When the conductivity of the liquid medium is high, the dispersion stability with time tends to deteriorate. Therefore, when an aqueous medium such as water is used as the liquid medium, it is preferable to use ion-exchanged water or distilled water that has been desalted so that the electrical conductivity is usually 10 μS / cm or less, preferably 5 μS / cm or less. preferable. The conductivity is measured at 25 ° C. using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

Moreover, there is no restriction | limiting in the usage-amount of a liquid medium, However, The quantity of about 1-20 mass times is normally used with respect to a polymerizable monomer.
By dispersing the wax in the liquid medium in the presence of an emulsifier, fine wax particles are obtained. The order of blending the emulsifier and the wax in the liquid medium is arbitrary, but usually the emulsifier is first blended in the liquid medium and then the wax is mixed. Moreover, you may mix | blend an emulsifier with a liquid medium continuously.

(Iv. Polymerization initiator)
After preparing the wax fine particles, a polymerization initiator is blended in the liquid medium. Any polymerization initiator can be used as long as the effects of the present invention are not significantly impaired. For example, persulfates such as sodium persulfate and ammonium persulfate; organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide and p-menthane hydroperoxide; inorganics such as hydrogen peroxide Examples include peroxides. Of these, inorganic peroxides are preferable. In addition, 1 type may be used for a polymerization initiator and it may use 2 or more types together by arbitrary combinations and a ratio.

  In addition, other examples of the polymerization initiator include persulfates, organic or inorganic peroxides, and reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, sodium thiosulfate, sodium bisulfite, metabisulfate. A redox initiator can also be used in combination with reducing inorganic compounds such as sodium sulfite. In this case, reducing inorganic compounds may be used alone or in combination of two or more in any combination and ratio.

  Moreover, there is no restriction | limiting in the usage-amount of a polymerization initiator, It is arbitrary. However, a polymerization initiator is normally used in the ratio of 0.05-2 mass parts with respect to 100 mass parts of polymerizable monomers.

(V. Polymerizable monomer)
After the wax fine particles are prepared, a polymerizable monomer is blended in the liquid medium in addition to the polymerization initiator. There is no particular limitation on the polymerizable monomer, but for example, styrenes, (meth) acrylic acid esters, acrylamides, monomers having Bronsted acidic groups (hereinafter simply referred to as “acidic monomers”) ), Monofunctional monomers such as monomers having Bronsted basic groups (hereinafter sometimes simply referred to as “basic monomers”) are mainly used. Further, a monofunctional monomer can be used in combination with a polyfunctional monomer.

Examples of styrenes include styrene, methyl styrene, chlorostyrene, dichlorostyrene, p-tert-butyl styrene, pn-butyl styrene, pn-nonyl styrene, and the like.
Examples of the (meth) acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate. , Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxyethyl methacrylate, and 2-ethylhexyl methacrylate.

Examples of acrylamides include acrylamide, N-propyl acrylamide, N, N-dimethyl acrylamide, N, N-dipropyl acrylamide, N, N-dibutyl acrylamide, and the like.
Furthermore, examples of the acidic monomer include monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid; monomers having a sulfonic acid group such as sulfonated styrene; vinylbenzenesulfonamide and the like. Examples thereof include a monomer having a sulfonamide group.

Examples of the basic monomer include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocycle-containing monomers such as vinylpyridine and vinylpyrrolidone; amino groups such as dimethylaminoethyl acrylate and diethylaminoethyl methacrylate. Examples include (meth) acrylic acid esters.
In addition, the acidic monomer and the basic monomer may exist as a salt with a counter ion.

  Furthermore, as the polyfunctional monomer, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, Examples include diallyl phthalate. It is also possible to use a monomer having a reactive group such as glycidyl methacrylate, N-methylolacrylamide, or acrolein. Among these, radically polymerizable bifunctional monomers, particularly divinylbenzene and hexanediol diacrylate are preferable.

  Among these, the polymerizable monomer is preferably composed of at least styrenes, (meth) acrylic acid esters, and acidic monomers having a carboxyl group. In particular, styrene is preferred as the styrene, butyl acrylate is preferred as the (meth) acrylic acid ester, and acrylic acid is preferred as the acidic monomer having a carboxyl group.

In addition, 1 type may be used for a polymerizable monomer and it may use 2 or more types together by arbitrary combinations and a ratio.
When emulsion polymerization is performed using wax as a seed, it is preferable to use an acidic monomer or a basic monomer and a monomer other than these in combination. This is because the dispersion stability of the polymer primary particles can be improved by using an acidic monomer or a basic monomer in combination.

  At this time, the compounding amount of the acidic monomer or basic monomer is arbitrary, but the amount of the acidic monomer or basic monomer used is usually 0.05 parts by mass or more, preferably 0 with respect to 100 parts by mass of the total polymerizable monomer. It is desirable that the amount be 5 parts by mass or more, more preferably 1 part by mass or more, and usually 10 parts by mass or less, preferably 5 parts by mass or less. If the blending amount of the acidic monomer or basic monomer is below the above range, the dispersion stability of the polymer primary particles may be deteriorated, and if it exceeds the upper limit, the chargeability of the toner may be adversely affected.

  Moreover, when using a polyfunctional monomer together, the compounding quantity is arbitrary, However, The compounding quantity of the polyfunctional monomer with respect to 100 mass parts of polymerizable monomers is 0.005 mass part or more normally, Preferably it is 0.00. 1 part by mass or more, more preferably 0.3 part by mass or more, and usually 5 parts by mass or less, preferably 3 parts by mass or less, more preferably 1 part by mass or less. By using a polyfunctional monomer, the fixability of the toner can be improved. At this time, if the blending amount of the polyfunctional monomer is below the above range, the high temperature offset resistance may be inferior, and if it exceeds the upper limit, the low temperature fixability may be inferior.

  The method for blending the polymerizable monomer into the liquid medium is not particularly limited. For example, any of batch addition, continuous addition, and intermittent addition may be used, but it is preferable to blend continuously from the viewpoint of reaction control. Moreover, when using several polymerizable monomer together, each polymerizable monomer may be mix | blended separately, and may be mix | blended after mixing beforehand. Furthermore, you may mix | blend, changing the composition of a monomer mixture.

(Vi. Chain transfer agent, etc.)
After preparing the above wax fine particles, the liquid medium includes, in addition to the polymerization initiator and the polymerizable monomer, a chain transfer agent, a pH adjuster, a polymerization degree adjuster, and an antifoaming agent as necessary. Additives such as protective colloids and internal additives. Any of these additives can be used as long as the effects of the present invention are not significantly impaired. Moreover, these additives may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

Any known chain transfer agent can be used. Specific examples include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, carbon tetrachloride, trichlorobromomethane and the like. Moreover, a chain transfer agent is normally used in the ratio of 5 mass parts or less with respect to 100 mass parts of polymerizable monomers.
Further, any known colloid that can be used for this purpose can be used. Specific examples include partially or completely saponified polyvinyl alcohols such as polyvinyl alcohol, cellulose derivatives such as hydroxyethyl cellulose, and the like.

  Examples of the internal additive include those for modifying the adhesiveness, cohesiveness, fluidity, chargeability, surface resistance and the like of toners such as silicone oil, silicone varnish, and fluorine oil.

(Vii. Polymer primary particles)
Polymer initiators, polymerizable monomers, and additives as necessary are mixed in a liquid medium containing wax fine particles, stirred, and polymerized to obtain polymer primary particles. The polymer primary particles can be obtained in the form of an emulsion in a liquid medium.

There is no restriction | limiting in the order which mixes a polymerization initiator, a polymerizable monomer, an additive, etc. with a liquid medium. Further, there are no restrictions on the method of mixing and stirring, and the method is arbitrary.
Furthermore, the reaction temperature of the polymerization (emulsion polymerization reaction) is arbitrary as long as the reaction proceeds. However, 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 100 ° C. or lower, more preferably 90 ° C. or lower.

  The volume average particle diameter of the polymer primary particles is not particularly limited, but 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 Is 1 μm or less. If the volume average particle size is too small, it may be difficult to control the aggregation rate. If the volume average particle size is too large, the particle size of the toner obtained by aggregation tends to be large, and the target particles It may be difficult to obtain a toner having a diameter. The volume average particle diameter can be measured with a particle size analyzer using a dynamic light scattering method described later.

  In the present invention, the volume particle size distribution is measured by a dynamic light scattering method. This method obtains the particle size distribution by detecting the speed of Brownian motion of finely dispersed particles, irradiating the particles with laser light, and detecting light scattering (Doppler shift) with different phases according to the speed. It is. In the actual measurement, the above volume particle size is measured using the following ultrafine particle size distribution measuring apparatus using a dynamic light scattering method (manufactured by Nikkiso Co., Ltd., UPA-EX150, hereinafter abbreviated as UPA-EX). Perform by setting.

Measurement upper limit: 6.54 μm
Measurement lower limit: 0.0008 μm
Number of channels: 52
Measurement time: 100 sec.
Measurement temperature: 25 ° C
Particle permeability: Absorption Particle refractive index: N / A (not applicable)
Particle shape: non-spherical density: 1 g / cm ³
Dispersion medium type: WATER
Dispersion medium refractive index: 1.333
At the time of measurement, measurement is performed with a sample in which a dispersion of particles is diluted with a liquid medium so that the sample concentration index is in the range of 0.01 to 0.1 and is dispersed with an ultrasonic cleaner. The volume average particle diameter according to the present invention is measured by using the result of the volume particle size distribution as an arithmetic average value.

  The polymer constituting the polymer primary particles has at least one of peak molecular weights in gel permeation chromatography, usually 3000 or more, preferably 10,000 or more, more preferably 30,000 or more, and usually 100,000 or less. , Preferably it is 70,000 or less, more preferably 60,000 or less. When the peak molecular weight is in the above range, the durability, storage stability, and fixability of the toner tend to be good. Here, as the peak molecular weight, a value converted to polystyrene is used, and components insoluble in a solvent are excluded in measurement. The peak molecular weight can be measured in the same manner as the toner described later.

  In particular, when the polymer is a styrene resin, the lower limit of the number average molecular weight of the polymer in gel permeation chromatography is usually 2000 or more, preferably 2500 or more, more preferably 3000 or more, and the upper limit is Usually, it is 50,000 or less, preferably 40,000 or less, more preferably 35,000 or less. Furthermore, the lower limit of the weight average molecular weight of the polymer is usually 20,000 or more, preferably 30,000 or more, more preferably 50,000 or more, and the upper limit is usually 1,000,000 or less, preferably 500,000 or less. When a styrene resin in which at least one of the number average molecular weight and the weight average molecular weight, preferably both falls within the above ranges, is used as the polymer, the resulting toner has good durability, storage stability and fixability. is there. Further, the molecular weight distribution may have two main peaks. In addition, styrene resin refers to what styrene occupies normally 50 mass% or more in the whole polymer, Preferably 65 mass% or more is occupied.

  Further, the softening point of the polymer (hereinafter sometimes abbreviated as “Sp”) is usually 150 ° C. or less, preferably 140 ° C. or less from the viewpoint of low energy fixing, and usually 80 ° C. or more. The temperature is preferably 100 ° C. or higher in view of high temperature offset resistance and durability. Here, the softening point of the polymer is determined by measuring 1.0 g of a sample in a flow tester under conditions of a nozzle 1 mm × 10 mm, a load 30 kg, a preheating time of 50 ° C. for 5 minutes, and a heating rate of 3 ° C./min. The temperature at the midpoint of the strand from the start to the end of the flow can be obtained.

  Furthermore, the glass transition temperature [Tg] of the polymer is usually 80 ° C. or lower, preferably 70 ° C. or lower. If the glass transition temperature [Tg] of the polymer is too high, there is a possibility that low energy fixing cannot be performed. The lower limit of the glass transition temperature [Tg] of the polymer is usually 40 ° C. or higher, preferably 50 ° C. or higher. If the glass transition temperature [Tg] of the polymer is too low, the blocking resistance may be lowered. Here, the glass transition temperature [Tg] of the polymer is the intersection of the two tangent lines by drawing a tangent line at the start of the transition (inflection) of the curve measured at a heating rate of 10 ° C./min in a differential scanning calorimeter. It can be calculated as the temperature.

  The softening point and glass transition temperature [Tg] of the polymer can be adjusted to the above ranges by adjusting the kind of the polymer, the monomer composition ratio, the molecular weight, and the like.

<Mixing process and aggregation process>
By mixing and aggregating pigment particles in the emulsion in which the polymer primary particles are dispersed, an emulsion of aggregates (aggregated particles) containing a polymer and a pigment is obtained. In this case, it is preferable to prepare a pigment particle dispersion in which the pigment is uniformly dispersed in advance in a liquid medium using a surfactant or the like, and mix this with an emulsion of polymer primary particles. At this time, an aqueous solvent such as water is usually used as the liquid medium of the pigment particle dispersion, and the pigment particle dispersion is prepared as an aqueous dispersion. At that time, if necessary, a wax, a charge control agent, a release agent, an internal additive and the like may be mixed into the emulsion. Moreover, in order to maintain the stability of the pigment particle dispersion, the above-described emulsifier may be added.

As the polymer primary particles, the polymer primary particles obtained by emulsion polymerization can be used. At this time, the polymer primary particles may be used alone or in combination of two or more in any combination and ratio. Furthermore, polymer primary particles (hereinafter, referred to as “combined polymer particles” as appropriate) produced with raw materials and reaction conditions different from those of the emulsion polymerization described above may be used in combination.
Examples of the combined polymer particles include fine particles obtained by suspension polymerization or pulverization. Resin can be used as the material for such combined polymer particles. As this resin, for example, vinyl acetate, vinyl chloride, vinyl, in addition to the monomer (co) polymer used for the emulsion polymerization described above. Thermoplastics such as homopolymers or copolymers of vinyl monomers such as alcohol, vinyl butyral, vinyl pyrrolidone, saturated polyester resins, polycarbonate resins, polyamide resins, polyolefin resins, polyarylate resins, polysulfone resins, polyphenylene ether resins Examples thereof include thermosetting resins such as resins and unsaturated polyester resins, phenol resins, epoxy resins, urethane resins, and rosin-modified maleic resins. These combined polymer particles may be used alone or in combination of two or more in any combination and ratio. However, the ratio of the combination polymer particles is usually 5% by mass or less, preferably 4% by mass or less, more preferably 3% by mass or less, based on the total of the polymer primary particles and the polymer of the combination polymer particles. .

Moreover, there is no restriction | limiting in a pigment, According to the use, arbitrary things can be used. However, although the pigment is usually present in the form of particles as colorant particles, it is preferable that the pigment particles have a smaller density difference from the polymer primary particles in the emulsion polymerization aggregation method. This is because when the density difference is smaller, a uniform aggregated state is obtained when the polymer temporary particles and the pigment are aggregated, and thus the performance of the obtained toner is improved. The density of the polymer primary particles is usually 1.1 to 1.3 g / cm ³ .

From the above viewpoint, the true density of the pigment particles measured by the pycnometer method specified in JIS K 5101-11-1: 2004 is usually 1.2 g / cm ³ or more, preferably 1.3 g / cm ³ or more. Also, it is usually less than 2.0 g / cm ³ , preferably 1.9 g / cm ³ or less, more preferably 1.8 g / cm ³ or less. When the true density of the pigment is too large, the sedimentation property in a liquid medium tends to deteriorate. In addition, considering issues such as storage stability and sublimation, the pigment is preferably carbon black or an organic pigment.

Examples of pigments that satisfy the above conditions include yellow pigments, magenta pigments, and cyan pigments shown below. Further, as the black pigment, carbon black or a mixture of the following yellow pigment / magenta pigment / cyan pigment mixed with black is used.
Among these, carbon black used as a black pigment exists as an aggregate of very fine primary particles, and when dispersed as a pigment particle dispersion, the carbon black particles are likely to become coarse due to reaggregation. . The degree of reagglomeration of carbon black particles is correlated with the amount of impurities contained in carbon black (the degree of residual undecomposed organic matter), and if there are many impurities, coarsening due to reaggregation after dispersion is significant. Show the trend.

For quantitative evaluation of the amount of impurities, the ultraviolet absorbance of the toluene extract of carbon black measured by the following measurement method is usually 0.05 or less, preferably 0.03 or less. In general, since carbon black of the channel method tends to have a large amount of impurities, carbon black produced by the furnace method is preferred as the toner of the present invention.
The ultraviolet absorbance (λc) of carbon black is determined by the following method. That is, 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 yellow pigments, for example, compounds typified by condensed azo compounds and isoindolinone compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180, 185 and the like are preferably used.

  Further, 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. Specifically, 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, 177, 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. This quinacridone pigment is suitable as a magenta pigment because of its clear hue and high light resistance. 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. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.
In addition, 1 type may be used for a pigment and it may use 2 or more types together by arbitrary combinations and a ratio.

  The above-mentioned pigment is dispersed in a liquid medium and mixed with an emulsion containing polymer primary particles after forming a pigment particle dispersion. Under the present circumstances, the usage-amount of the pigment particle in a pigment particle dispersion is 3 mass parts or more normally with respect to 100 mass parts of liquid media, Preferably it is 5 mass parts or more, Moreover, normally 50 mass parts or less, Preferably it is 40 masses. Or less. When the blending amount of the colorant exceeds the above range, the pigment concentration is high, so the probability that the pigment particles are re-aggregated during the dispersion is increased. When the blending amount is less than the above range, the dispersion is excessive and an appropriate particle size distribution is obtained. Can be difficult.

Further, the ratio of the amount of the pigment used relative to the polymer contained in the polymer primary particles is usually 1% by mass or more, preferably 3% by mass or more, and usually 20% by mass or less, preferably 15% by mass or less. If the amount of the pigment used is too small, the image density may become thin, and if it is too large, the aggregation control may be difficult.
Further, the pigment particle dispersion may contain a surfactant. Although there is no restriction | limiting in particular in this surfactant, For example, the thing similar to the surfactant illustrated as an emulsifier in description of an emulsion polymerization method is mentioned. Of these, nonionic surfactants, anionic surfactants such as alkylaryl sulfonates such as sodium dodecylbenzenesulfonate, and polymer surfactants are preferably used. Moreover, 1 type of surfactant may be used in this case, and 2 or more types may be used together by arbitrary combinations and a ratio.

In addition, the ratio of the pigment to a pigment particle dispersion is 10-50 mass% normally.
Further, as the liquid medium of the pigment particle dispersion, an aqueous medium is usually used, and preferably water is used. At this time, the water quality of the polymer primary particles and the pigment particle dispersion is also related to the coarsening due to reaggregation of each particle, and when the conductivity is high, the dispersion stability with time tends to deteriorate. Therefore, it is preferable to use ion-exchanged water or distilled water that has been desalted so that the electrical conductivity is usually 10 μS / cm or less, preferably 5 μS / cm or less. The conductivity is measured at 25 ° C. using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

Moreover, when mixing a pigment with the emulsion containing a polymer primary particle, you may mix a wax with an emulsion. As the wax, the same waxes described in the explanation of the emulsion polymerization method can be used. The wax may be mixed before, during or after mixing the pigment with the emulsion containing the polymer primary particles.
Moreover, when mixing a pigment with the emulsion containing a polymer primary particle, you may mix a charge control agent with an emulsion.

  As the charge control agent, any known charge control agent can be used. Examples of the positively chargeable charge control agent include nigrosine dyes, quaternary ammonium salts, triphenylmethane compounds, imidazole compounds, polyamine resins, and the like. Examples of negative charge control agents include azo complex compound dyes containing atoms such as Cr, Co, Al, Fe, and B; metal salts or metal complexes of salicylic acid or alkylsalicylic acid; curixarene compounds, benzyl Examples include metal salts or metal complexes of acids, amide compounds, phenol compounds, naphthol compounds, and phenol amide compounds. Among these, colorless or light-colored ones are preferably selected in order to avoid color tone problems as toners, and quaternary ammonium salts and imidazole compounds are particularly preferable as positively chargeable charge control agents, and negatively chargeable charge control agents. As these, alkyl salicylic acid complex compounds and curixarene compounds containing atoms such as Cr, Co, Al, Fe and B are preferred. In addition, 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.

Although there is no restriction | limiting in the usage-amount of a charge control agent, 0.01 mass part or more normally with respect to 100 mass parts of polymers, Preferably it is 0.1 mass part or more, Moreover, 10 mass parts or less, Preferably it is 5 mass parts or less. It is. If the amount of the charge control agent used is too small or too large, the desired charge amount may not be obtained.
The charge control agent may be mixed before, during or after mixing the pigment with the emulsion containing the polymer primary particles.

Moreover, it is desirable that the charge control agent is mixed at the time of aggregation in the state of being emulsified in a liquid medium (usually an aqueous medium) in the same manner as the pigment particles.
After the pigment is mixed in the emulsion containing the polymer primary particles, the polymer primary particles and the pigment are aggregated. As described above, at the time of mixing, the pigment is usually mixed in the state of a pigment particle dispersion.

The aggregation method is not limited and is arbitrary, and examples thereof include heating, electrolyte mixing, pH adjustment, and the like. Among these, a method of mixing an electrolyte is preferable.
Examples of the electrolyte when the aggregation is performed by mixing the electrolyte include chlorides such as NaCl, KCl, LiCl, MgCl ₂ , and CaCl ₂ ; Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgSO ₄ , Examples include inorganic salts such as sulfates such as CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , and Fe ₂ (SO ₄ ) ₃ ; organic salts such as CH ₃ COONa and C ₆ H ₅ SO ₃ Na. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred.

In addition, 1 type may be used for electrolyte and it may use 2 or more types together by arbitrary combinations and a ratio.
The amount of electrolyte used varies depending on the type of electrolyte, but is usually 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and usually 25 parts by mass or less, based on 100 parts by mass of the solid component in the emulsion. Preferably it is 15 mass parts or less, More preferably, it is 10 mass parts or less. In the case of agglomerating by mixing electrolytes, if the amount of electrolyte used is too small, the progress of the agglutination reaction slows down, and fine particles of 1 μm or less remain after the agglomeration reaction, or the average particle size of the obtained agglomerates is the target There is a possibility that the particle size will not be reached, and if the amount of electrolyte used is too large, the agglomeration reaction will occur rapidly, making it difficult to control the particle size. May be included.

The obtained agglomerates are preferably subsequently spheroidized by heating in a liquid medium, similarly to the secondary agglomerates (agglomerates that have undergone the melting step) described later. Heating may be performed under the same conditions as in the case of the secondary aggregate (same conditions as described in the description of the fusion process).
On the other hand, when the aggregation is performed by heating, the temperature condition is arbitrary as long as the aggregation proceeds. Specific temperature conditions are usually 15 ° C. or higher, preferably 20 ° C. or higher, and aggregation is performed under a temperature condition of a polymer primary particle polymer glass transition temperature [Tg] or lower, preferably 55 ° C. or lower. . Although the time for agglomeration is also arbitrary, it is usually 10 minutes or longer, preferably 60 minutes or longer, and usually 300 minutes or shorter, preferably 180 minutes or shorter.

Moreover, it is preferable to stir when aggregating. Although the apparatus used for stirring is not specifically limited, What has a double helical blade is preferable.
The obtained agglomerates may proceed directly to the next step of forming a resin coating layer (encapsulation step), or may proceed to the encapsulation step after subsequent fusion treatment by heating in a liquid medium. . Desirably, after the aggregation step, the encapsulation step is performed, and the fusion step is performed by heating at a temperature equal to or higher than the glass transition temperature [Tg] of the encapsulated resin fine particles. It is preferable because it does not cause deterioration (such as heat deterioration).

<Encapsulation process>
After obtaining the aggregate, it is preferable to form a resin coating layer on the aggregate as necessary. The encapsulation process for forming a resin coating layer on the aggregate is a process for coating the aggregate with a resin by forming a resin coating layer on the surface of the aggregate. Thereby, the manufactured toner is provided with the resin coating layer. In the encapsulation process, the entire toner may not be completely covered, but the pigment makes it possible to obtain a toner that is not substantially exposed on the surface of the toner particles. Although there is no restriction | limiting in the thickness of the resin coating layer in this case, Usually, it is the range of 0.01-0.5 micrometer.

The method for forming the resin coating layer is not particularly limited, and examples thereof include a spray drying method, a mechanical particle composite method, an in-situ polymerization method, and a submerged particle coating method.
As a method for forming the resin coating layer by the spray drying method, for example, an aggregate forming an inner layer and resin fine particles forming a resin coating layer are dispersed in an aqueous medium to prepare a dispersion, A resin coating layer can be formed on the surface of the aggregate by spraying and drying.

  In addition, as a method for forming a resin coating layer by the mechanical particle composite method, for example, an aggregate that forms an inner layer and resin fine particles that form a resin coating layer are dispersed in a gas phase and mechanically formed in a narrow gap. In this method, resin fine particles are formed into a film on the surface of the aggregate by applying a strong force. For example, an apparatus such as a hybridization system (manufactured by Nara Machinery Co., Ltd.) or a mechanofusion system (manufactured by Hosokawa Micron Corporation) can be used.

Further, as the in-situ polymerization method, for example, the aggregate is dispersed in water, the monomer and the polymerization initiator are mixed, adsorbed on the surface of the aggregate, and heated to polymerize the monomer. Thus, a resin coating layer is formed on the surface of the aggregate that is the inner layer.
The submerged particle coating method includes, for example, reacting or bonding an aggregate forming an inner layer and resin fine particles forming an outer layer in an aqueous medium to form a resin coating layer on the surface of the aggregate forming the inner layer. Is a method of forming

  The resin fine particles used for forming the outer layer are particles mainly having a resin component smaller than the aggregate. The resin fine particles are not particularly limited as long as they are particles composed of a polymer. However, from the viewpoint that the thickness of the outer layer can be controlled, it is preferable to use resin fine particles similar to the polymer primary particles, the aggregates, or the fused particles obtained by fusing the aggregates. Resin fine particles similar to these polymer primary particles can be produced in the same manner as the polymer primary particles in the aggregate used for the inner layer.

The amount of resin fine particles used is arbitrary, but is usually 1% by mass or more, preferably 5% by mass or more, and usually 50% by mass or less, preferably 25% by mass or less based on the toner particles. Is desirable.
Furthermore, in order to effectively fix or fuse the resin fine particles to the aggregate, the resin fine particles usually have a particle size of about 0.04 to 1 μm.

  The glass transition temperature [Tg] of the polymer component (resin component) used in the resin coating layer is usually 60 ° C. or higher, preferably 70 ° C. or higher, and usually 110 ° C. or lower. Further, the glass transition temperature [Tg] of the polymer component used in the resin coating layer is preferably higher by 5 ° C. or higher than the glass transition temperature [Tg] of the polymer primary particles, and is higher by 10 ° C. or higher. It is more preferable. If the glass transition temperature [Tg] is too low, storage in a general environment is difficult, and if it is too high, sufficient meltability cannot be obtained.

Furthermore, it is preferable to contain polysiloxane wax in the resin coating layer. Thereby, the advantage of improvement in high temperature offset resistance can be obtained. Examples of the polysiloxane wax include silicone wax having an alkyl group.
The content of the polysiloxane wax is not limited, but is usually 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.08% by mass or more, and usually 2% by mass or less in the toner. Preferably it is 1 mass% or less, More preferably, you may be 0.5 mass% or less. If the amount of the polysiloxane wax in the resin coating layer is too small, the high temperature offset resistance may be insufficient, and if it is too large, the blocking resistance may be lowered.

  The method for containing the polysiloxane wax in the resin coating phase is arbitrary. For example, emulsion polymerization is performed using the polysiloxane wax as a seed, and the obtained resin fine particles and the aggregates forming the inner layer are mixed in an aqueous medium. And a resin coating layer containing polysiloxane wax on the surface of the agglomerate forming the inner layer.

<Fusion process>
In the fusing process, the aggregates are melt-integrated by heat-treating the aggregates.
In addition, when encapsulating resin fine particles are formed by forming a resin coating layer on the aggregate, the polymer constituting the aggregate and the resin coating layer on the surface thereof are integrated by heat treatment. It will be. Thereby, the pigment particles are obtained in a form that is not substantially exposed on the surface.

  The temperature of the heat treatment in the fusion step is set to a temperature equal to or higher than the glass transition temperature [Tg] of the polymer primary particles constituting the aggregate. Moreover, when a resin coating layer is formed, it is set as the temperature more than the glass transition temperature [Tg] of the polymer component which forms a resin coating layer. Although specific temperature conditions are arbitrary, it is preferable that it is 5 degreeC or more normally higher than the glass transition temperature [Tg] of the polymer component which forms a resin coating layer. Although there is no restriction | limiting in the upper limit, below 50 degreeC higher than the glass transition temperature [Tg] of the polymer component which forms a resin coating layer is preferable.

  The heat treatment time is usually 0.5 to 6 hours, although it depends on the treatment capacity and the production amount.

<Washing and drying process>
When the above-described steps are performed in a liquid medium, the toner can be obtained by washing the encapsulated resin particles obtained after the fusing step and drying to remove the liquid medium. There are no restrictions on the washing and drying methods, and they are arbitrary.

<Physical properties relating to toner particle size>
There is no restriction on the volume average particle size [Dv] of the toner of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired, but it is usually 4 μm or more, preferably 5 μm or more, and usually 10 μm or less, preferably 8 μm or less. It is. If the volume average particle diameter [Dv] of the toner is too small, the stability of the image quality may be lowered, and if it is too large, the resolution may be lowered.

  In the toner of the present invention, the value [Dv / Dn] obtained by dividing the volume average particle diameter [Dv] by the number average particle diameter [Dn] is usually 1.0 or more, and usually 1.25 or less, preferably It is desirable that it is 1.20 or less, more preferably 1.15 or less. The value of [Dv / Dn] represents the state of the particle size distribution, and the closer this value is to 1.0, the sharper the particle size distribution. A sharper particle size distribution is desirable because the chargeability of the toner becomes uniform.

  Further, the toner of the present invention has a volume fraction having a particle diameter of 25 μm or more, usually 1% or less, preferably 0.5% or less, more preferably 0.1% or less, and further preferably 0.05% or less. . The smaller this value, the better. This means that the ratio of the coarse powder contained in the toner is small. If the coarse powder is small, the amount of toner consumed during continuous development is small and the image quality is stable. Although it is most preferable that there is no coarse powder having a particle size of 25 μm or more, it is difficult in actual production, and usually it may not be 0.005% or less.

In the toner of the present invention, the volume fraction having a particle size of 15 μm or more is usually 2% or less, preferably 1% or less, more preferably 0.1% or less. Although it is most preferable that there is no coarse powder having a particle size of 15 μm or more, it is difficult in actual production, and it is usually not necessary to make it 0.01% or less.
Further, in the toner of the present invention, it is desirable that the number fraction having a particle size of 5 μm or less is usually 15% or less, preferably 10% or less, since this is effective in improving image fog.

  Here, the volume average particle diameter [Dv], the number average particle diameter [Dn], the volume fraction, the number fraction, and the like of the toner can be measured as follows. That is, as a toner particle size measuring device, a multisizer type II or type III (manufactured by Beckman Coulter, Inc.) of a Coulter counter is used, and an interface for outputting the number distribution / volume distribution and a general personal computer are connected. To use. In addition, Isoton II is used as the electrolytic solution. As a measuring method, 0.1 to 5 mL of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 mL of the electrolytic solution, and 2 to 20 mg of a measurement sample (toner) is further added. Then, the electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measured using a multisizer type II or type III of the Coulter counter using a 100 μm aperture. Thus, the number and volume of the toner are measured to calculate the number distribution and the volume distribution, respectively, and the volume average particle diameter [Dv] and the number average particle diameter [Dn] are obtained, respectively.

<Physical properties related to the molecular weight of the toner>
At least one of the peak molecular weights in the gel permeation chromatography (hereinafter sometimes abbreviated as GPC) of the THF soluble content of the toner of the present invention is usually 10,000 or more, preferably 20,000 or more, more preferably 3 It is 10,000 or more, and is usually 150,000 or less, preferably 100,000 or less, more preferably 70,000 or less. THF refers to tetrahydrofuran. 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 THF-insoluble content of the toner is usually 10% or more, preferably 20% or more, and usually 60% or less, preferably 50% or less, as measured by a weight method by Celite filtration described later. If it is not within the above range, it may be difficult to achieve both mechanical durability and low-temperature fixability.
The peak molecular weight of the toner of the present invention is measured under the following conditions using a measuring apparatus: HLC-8120GPC (manufactured by Tosoh Corporation).

That is, the column is stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 mL (milliliter) per minute. Next, the toner is dissolved in THF and filtered through a 0.2 μm filter, and the filtrate is used as a sample.
The measurement is performed by injecting 50 to 200 μL of a THF solution of a resin whose sample concentration (resin concentration) is adjusted to 0.05 to 0.6 mass%. In measuring the molecular weight of the sample (resin component in the toner), the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve created by several monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Manufactured by Toyo Soda Kogyo Co., Ltd., with molecular weights of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , It is appropriate to use 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

Furthermore, as a column used in the measurement method, in order to accurately measure a molecular weight region of 10 ³ to 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns, for example, manufactured by Waters A combination of μ-styrel 500, 103, 104, 105 and a combination of shodex KA801, 802, 803, 804, 805, 806, 807 manufactured by Showa Denko KK are preferable.

  The measurement of the insoluble content of tetrahydrofuran (THF) in the toner can be performed as follows. That is, 1 g of a sample (toner) was added to 100 g of THF, and allowed to stand still at 25 ° C. for 24 hours. After filtration using 10 g of Celite, the solvent of the filtrate was distilled off to determine the THF-soluble matter, and subtracted from 1 g. Insoluble matter can be calculated.

<Softening point and glass transition temperature of toner>
There is no restriction on the softening point [Sp] of the toner of the present invention, and it is optional as long as the effects of the present invention are not significantly impaired. From the viewpoint of fixing with low energy, it is usually 150 ° C. or lower, preferably 140 ° C. or lower. Further, from the viewpoint of high temperature offset resistance and durability, the softening point is usually 80 ° C. or higher, preferably 100 ° C. or higher.

The toner softening point [Sp] was measured with a flow tester under the conditions of 1.0 g of a sample of 1 mm × 10 mm nozzle, a load of 30 kg, a preheating time of 50 ° C. for 5 minutes, and a heating rate of 3 ° C./min. The temperature at the midpoint of the strand from the start to the end of the flow can be obtained.
Further, the glass transition temperature [Tg] of the toner of the present invention is not limited, and may be arbitrary as long as the effects of the present invention are not significantly impaired. Usually, the fixing temperature is 80 ° C. or lower, preferably 70 ° C. or lower. It is desirable because it is possible. The glass transition temperature [Tg] is usually 40 ° C. or higher, preferably 50 ° C. or higher, from the viewpoint of blocking resistance.

The glass transition temperature [Tg] of the toner is obtained by drawing a tangent line at the start of the transition (inflection) of the curve measured with a differential scanning calorimeter at a temperature rising rate of 10 ° C./min. It can be determined as temperature.
The softening point [Sp] and glass transition temperature [Tg] of the toner are greatly influenced by the type and composition ratio of the polymer contained in the toner. Therefore, the softening point [Sp] and the glass transition temperature [Tg] of the toner can be adjusted by appropriately optimizing the type and composition of the polymer. It can also be adjusted by the molecular weight of the polymer, the gel content, the type of low melting point components such as wax, and the blending amount.

<Wax in toner>
When the toner of the present invention contains a wax, the dispersed particle diameter of the wax in the toner particles is usually 0.1 μm or more, preferably 0.3 μm or more as an average particle diameter, and the upper limit is usually 3 μm or less. Preferably it is 1 micrometer or less. If the dispersed particle size is too small, the effect of improving the filming resistance of the toner may not be obtained. If the dispersed particle size is too large, the wax will be easily exposed on the surface of the toner, and the chargeability and heat resistance will be reduced. May be reduced.

The dispersed particle diameter of the wax may be determined by observing an electron microscope after slicing the toner, or wax particles remaining on the filter after elution of the toner polymer with an organic solvent or the like in which the wax does not dissolve. Can be confirmed by a method of measuring with a microscope.
Further, the proportion of the wax in the toner is arbitrary as long as the effects of the present invention are not significantly impaired, but usually 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, Further preferably, it is 4% by mass or more, usually 20% by mass or less, preferably 15% by mass or less. If the amount of wax is too small, the fixing temperature range may be insufficient. If the amount is too large, the apparatus member may be contaminated and the image quality may deteriorate.

<Externally added fine particles>
In order to improve toner fluidity, charging stability, anti-blocking property at high temperatures, and the like, external additive fine particles may be added to the surface of the toner particles.
As a method for attaching the externally added fine particles to the toner particle surface, for example, in the above-described toner manufacturing method, the secondary aggregate and the externally added fine particles are mixed in a liquid medium and then heated to externally add the toner particles onto the toner particles. Examples include a method of fixing fine particles; a method of mixing or fixing externally added fine particles to toner particles obtained by separating, washing, and drying secondary aggregates from a liquid medium.

  Examples of the mixer used when the toner particles and the externally added fine particles are mixed in a dry type include a Henschel mixer, a super mixer, a nauter mixer, a V-type mixer, a Redige mixer, a double cone mixer, and a drum type mixer. Can be mentioned. In particular, it is preferable to use a high-speed agitation type mixer such as a Henschel mixer or a super mixer, and appropriately mix and mix by stirring and mixing uniformly by appropriately setting the blade shape, the number of revolutions, the time, the number of times of driving and stopping.

In addition, as a device used for fixing toner particles and externally added fine particles in a dry method, a compression shearing device capable of applying compressive shear stress, a particle surface melting processing device capable of melting the particle surface, etc. Is mentioned.
A compression shearing apparatus generally has a narrow gap portion composed of a head surface and a head surface, a head surface and a wall surface, or a wall surface and a wall surface that move relatively while maintaining a gap, and particles to be processed are disposed in the gap. By being forced to pass through the portion, compressive stress and shear stress are applied to the particle surface without substantial pulverization. An example of such a compression shearing apparatus is a mechanofusion apparatus manufactured by Hosokawa Micron.

On the other hand, the particle surface melting treatment apparatus is generally configured so as to fix the externally added fine particles by using a hot air stream or the like and instantaneously heating the mixture of the basic fine particles and the externally added fine particles to a temperature higher than the melting start temperature of the basic fine particles. The Examples of such a particle surface melting apparatus include a surfing system manufactured by Nippon Pneumatic Co., Ltd.
As the externally added fine particles, known fine particles that can be used for this purpose can be used. Examples thereof include inorganic fine particles and organic fine particles.

  Examples of the inorganic fine particles include silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide and the like, boron nitride, nitriding Nitride such as titanium, zirconium nitride, silicon nitride, boride such as zirconium boride, silica, colloidal silica, titanium oxide, aluminum oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, zirconium oxide, cerium oxide, talc , Oxides and hydroxides such as hydrotalcite, various titanate compounds such as calcium titanate, magnesium titanate, strontium titanate, barium titanate, tricalcium phosphate, calcium dihydrogen phosphate, monohydrogen phosphate calcium Phosphoric compounds such as substituted calcium phosphates in which a portion of the phosphate ions is replaced by anions, sulfides such as molybdenum disulfide, fluorides such as magnesium fluoride and fluorocarbon, aluminum stearate, calcium stearate, stearic acid Various carbon blacks including metal soaps such as zinc and magnesium stearate, talc, bentonite, and conductive carbon black can be used. Furthermore, magnetic substances such as magnetite, maghematite, and an intermediate between magnetite and maghematite may be used.

On the other hand, as the organic fine particles, for example, styrene resin, acrylic resin such as polymethyl acrylate and polymethyl methacrylate, epoxy resin, melamine resin, tetrafluoroethylene resin, trifluoroethylene resin, polyvinyl chloride, Fine particles such as polyethylene and polyacrylonitrile can be used.
Among these externally added fine particles, silica, titanium oxide, alumina, zinc oxide, carbon black and the like are particularly preferably used.

In addition, 1 type may be used for an external addition fine particle, and 2 or more types may be used together by arbitrary combinations and a ratio.
In addition, the surface of these inorganic or organic fine particles may be a silane coupling agent, titanate coupling agent, silicone oil, modified silicone oil, silicone varnish, fluorine silane coupling agent, fluorine silicone oil, amino group or fourth group. Surface treatment such as hydrophobization may be performed by a treatment agent such as a coupling agent having a secondary ammonium base. In addition, 1 type may be used for a processing agent and it may use 2 or more types together by arbitrary combinations and a ratio.

  Further, the number average particle diameter of the externally added fine particles is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.001 μm or more, preferably 0.005 μm or more, and usually 3 μm or less, preferably 1 μm or less. A plurality of those having different average particle diameters may be blended. The average particle diameter of the externally added fine particles can be determined by observation with an electron microscope, conversion from the value of the BET specific surface area, or the like.

  The ratio of the externally added fine particles to the toner is arbitrary as long as the effects of the present invention are not significantly impaired. However, the ratio of the externally added fine particles to the total mass of the toner and the externally added fine particles is usually 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and usually 10%. Desirably, it is not more than mass%, preferably not more than 6 mass%, more preferably not more than 4 mass%. If the amount of the externally added fine particles is too small, the fluidity and the charging stability may be insufficient, and if the amount is too large, the fixability may be deteriorated.

<Toner and others>
The charging characteristics of the toner of the present invention may be negatively charged or positively charged, and can be set according to the type of image forming apparatus used. The charging characteristics of the toner can be adjusted by the selection and composition ratio of toner base particle components such as a charge control agent, the selection and composition ratio of externally added fine particles, and the like.

Further, the toner of the present invention can be used as a one-component developer, or mixed with a carrier and used as a two-component developer.
When used as a two-component developer, the carrier that is mixed with the toner to form the developer may be, for example, a known magnetic substance such as an iron powder, ferrite, or magnetite carrier, or a resin on the surface thereof. A coated one or a magnetic resin carrier 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.
The average particle diameter of the carrier is not particularly limited, but those having an average particle diameter of 10 to 200 μm are preferable. These carriers are preferably used at a ratio of 5 to 100 parts by mass with respect to 1 part by mass of the toner.

  The formation of a full color image by electrophotography can be carried out by a conventional method using magenta, cyan and yellow color toners and, if necessary, black toner.

[Image forming apparatus and electrophotographic cartridge]
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (an image forming apparatus 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, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.
The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor 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. 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 direct charging member to which a voltage is applied by contacting the photosensitive member surface, and a contact type charging device such as a charging brush. Often used. Examples of direct charging means include contact chargers such as charging rollers and charging brushes. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. In addition, as a voltage applied at the time of charging, in the case of only a direct current voltage, an alternating current can be superimposed on a direct current.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples 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. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light having a wavelength of 780 nm, monochromatic light having a wavelength of 600 nm to 700 nm, slightly short wavelength, or monochromatic light having a wavelength of 380 nm to 500 nm. . Moreover, the writing resolution is mainly 600 dpi or more at present, but there is a high-performance model having 1200 dpi. The resolution of the electrostatic latent image and the toner image is determined depending on the writing resolution, and the higher the resolution, the clearer the image is obtained. Therefore, a resolution of 1200 dpi or higher is preferable. For example, when writing is performed with an LED having a resolution of 600 dpi and 1200 dpi, the minimum dot formation interval is 42 μm and 21 μm, respectively.

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. 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 is configured to store toner T 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. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge. In the present embodiment, the toner of the present invention described above is preferably used as the toner T.

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 fluorine resin, 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 photosensitive member 1 and the supply roller 43 and is in contact with the electrophotographic photosensitive member 1 and the supply roller 43, respectively. 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 regulating member 45 is formed of a resin blade such as silicone resin or 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 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 / 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.
The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method 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 the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

There is no restriction | limiting in particular 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. If there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.
Among these, the blade cleaning method is preferable because of its simple structure, small size, low cost, and excellent cleaning performance and reliability. The blade cleaning method can be classified into a contact method and a pressurization method (57th Annual Meeting of the Imaging Society of Japan P196-211). The contact method is classified into counter contact and forward contact, and the pressurization method is classified into a low displacement method and a low load method.
In the present invention, a blade cleaning method is preferable for effectively removing the toner. In particular, when a toner having a high degree of circularity is used, the counter contact method is preferable because the toner easily slips between the blade and the photoreceptor. . The linear pressure of the blade against the photoreceptor is preferably set to 20 to 60 g / cm.
If the blade is set under the above conditions, there is a tendency that a rubbing sound is generated between the photosensitive member and the blade, but this can be avoided by using the photosensitive member of the present invention.

  The fixing device 7 includes an upper fixing member (fixing 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. The upper and lower fixing members 71 and 72 include 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 fixing 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 any type such as heat roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided including those used here.

In the electrophotographic apparatus configured as described above, an image is recorded as follows. 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 by 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.

Further, the image forming apparatus may be further modified and configured, for example, a configuration capable of performing processes such as a pre-exposure process and an auxiliary charging process, a structure performing offset printing, and a plurality of types. A full-color tandem system configuration using toner may be used.
The electrophotographic photosensitive member 1 is combined with one or more of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7 to form an integrated cartridge ( Hereinafter, it may be configured as an “electrophotographic cartridge” as appropriate, and the electrophotographic cartridge may be configured to be detachable from the main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In this case, for example, when the electrophotographic photosensitive member 1 or other member is deteriorated, this electrophotographic cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic cartridge is mounted on the main body of the image forming apparatus. Equipment maintenance and management are easy.

Hereinafter, the present invention will be described in more detail with reference to production examples, examples and comparative examples. In addition, the following examples are shown in order to explain the present invention in detail, and the present invention is not limited to the following examples unless it is contrary to the gist thereof. Note that “parts” used in the present examples indicate “parts by mass” unless otherwise specified. The viscosity average molecular weight of the resin used for the charge transport layer was calculated as follows. The resin is dissolved in dichloromethane to prepare a solution having a concentration C of 6.00 g / L. The flow time t of the sample solution is measured in a constant temperature water bath set to 20.0 ° C. using an Ubbelohde capillary viscometer with a flow time t ₀ of the solvent (dichloromethane) of 136.16 seconds. The viscosity average molecular weight was calculated according to the following formula.
a = 0.438 × η _sp +1 η _sp = t / t ₀ −1
b = 100 × η _sp / C C = 6.00 (g / L)
η = b / a
Mv = 3207 × η ^1.205
Further, the measurement method and definition of the average circularity of the toner are as follows.

<Measuring 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 to 7140 particles / μL, and a flow type particle image analyzer (Sysmex Corporation (formerly Toa Medical Electronics)). (Manufactured by FPIA 2100), measurement is performed under the following apparatus conditions, and the value is defined as “average circularity”. In the present invention, the same measurement is performed three times, and an arithmetic average value of three “average circularity” is adopted as the “average circularity”.
・ Mode: HPF
-HPF analysis amount: 0.35 μL
-HPF detection number: 2000-2500

The following is measured by the above device and automatically calculated and displayed in the above device, and “circularity” is defined by the following formula.
[Circularity] = [Perimeter of a circle with the same area as the projected particle area] / [Perimeter of projected particle image]
And 2000-2500 which is the number of HPF detection is measured, and the arithmetic average (arithmetic mean) of the circularity of each individual particle is displayed on the apparatus as “average circularity”.

<Photoconductor Preparation Example 1>
The following undercoat layer forming coating solution, charge generation layer forming coating solution, and charge transport layer forming coating solution are sequentially applied on an aluminum cylinder having a mirror-finished surface by a dip coating method. An undercoat layer, a charge generation layer, and a charge transport layer were formed so that the film thicknesses were 1.3 μm, 0.4 μm, and 25 μm, respectively, to obtain a photoreceptor drum A1.
The undercoat layer forming coating solution was prepared as follows. Rutile type titanium oxide having an average primary particle diameter of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by mass of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were mixed using a Henschel mixer. The surface-treated titanium oxide obtained by mixing was dispersed by a ball mill in a mixed solvent having a mass ratio of methanol / 1-propanol of 7/3 to obtain a surface-treated titanium oxide dispersed slurry. The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (4-amino-3-methylcyclohexyl) methane [following formula (B) Compound represented by the following formula] / hexamethylenediamine [compound represented by the following formula (C)] / decamethylene dicarboxylic acid [compound represented by the following formula (D)] / octadecamethylene dicarboxylic acid [represented by the following formula (E) The composition is made up of 60% / 15% / 5% / 15% / 5% of the copolymerized polyamide pellets with heating and stirring and mixing to dissolve the polyamide pellets. By performing the dispersion treatment, the mass ratio of methanol / 1-propanol / toluene is 7/1/2, and the surface treated titanium oxide / copolymerization Containing an amide in a weight ratio 3/1, to prepare a coating liquid for forming an undercoat layer having a solid concentration of 18.0%.

  As a charge generation material, 20 parts of oxytitanium phthalocyanine (D-type) shown in the X-ray diffraction spectrum of FIG. 2 and 280 parts of 1,2-dimethoxyethane are mixed and pulverized in a sand grind mill for 2 hours for atomization dispersion treatment Went. Subsequently, 10 parts of polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) were added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-methyl-2. -A binder solution obtained by dissolving in 85 parts of a mixed solution of pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a coating solution for forming a charge generation layer.

  Further, 80 parts by mass of a charge transport material having an enamine structure having the structure of the following formula (A) and a binder resin, a polyarylate resin represented by the repeating structure of the following formula (B) (viscosity average molecular weight = 40500) 50 parts by mass, 50 parts by mass of a polycarbonate resin (viscosity average molecular weight = 32000) represented by a repeating structure of the following formula (C), 2 parts of an antioxidant having the structure of the following formula (D), and silicone oil ( A charge transport layer coating solution was prepared by dissolving 0.03 parts by mass of KF96 Shin-Etsu Chemical Co., Ltd.) in 640 parts by mass of a tetrahydrofuran / toluene (mass ratio 8/2) mixed solvent.

<Photoreceptor Preparation Examples 2 to 6>
Photoconductor Preparation Example 1 except that the charge transport material having an enamine structure having the structure of the structural formula (A) is changed to a charge transport material having an enamine structure having the structures of the following structural formulas (E) to (I): By performing the same operation, electrophotographic photoreceptors A2 to A6 having a laminated photosensitive layer were produced.

<Photoconductor Preparation Example 7>
A laminated photosensitive layer is obtained by performing the same operation as in Photoconductor Preparation Example 1 except that 100 parts by mass of a polyarylate resin (viscosity average molecular weight = 40500) represented by the repeating structure of the above formula (B) is used as the binder resin. An electrophotographic photoreceptor A7 having the following structure was prepared.

<Photoreceptor Preparation Example 8>
The laminated photosensitive layer is formed by performing the same operation as in Photoconductor Preparation Example 1 except that 100 parts by mass of the polycarbonate resin (viscosity average molecular weight = 32000) represented by the repeating structure of the above formula (C) is used as the binder resin. An electrophotographic photosensitive member A8 was prepared.

<Photoreceptor Preparation Example 9>
The laminated photosensitive layer is formed by performing the same operation as in Photoconductor Preparation Example 1 except that 100 parts by mass of a polycarbonate resin (viscosity average molecular weight = 28000) represented by the repeating structure of the following formula (J) is used as the binder resin. An electrophotographic photosensitive member A9 was prepared.

<Comparative Photoconductor Preparation Examples 1-2>
The same operation as in Photoconductor Preparation Example 1 was performed except that the charge transport material having the enamine structure having the structure of the structural formula (A) was changed to the charge transport material having the structures of the following structural formulas (K) and (L). By doing so, electrophotographic photoreceptors AE1 to AE2 having a laminated photosensitive layer were produced.

<Image characteristic test (Examples 1-9, Comparative Examples 1-2)>
The image characteristic test was performed using a modified machine of a color printer HP Color LaserJet 4700dn (cleaning blade, counter contact type) manufactured by Hewlett-Packard Company.
The produced photosensitive drum and toner were mounted on a cyan process cartridge, and this cartridge was mounted on a printer. 10,000 images were formed under an environment of a temperature of 25 ° C. and a humidity of 50%, and ghost, fog, density reduction, filming, and poor cleaning were evaluated. The toner used for image characteristic evaluation had an average circularity = 0.990.
The evaluation results for each photoconductor are as follows.

<Photoconductor Preparation Examples 10-13, Comparative Photoconductor Preparation Examples 3-4>
Photoconductor preparation examples 1, 7, 8, and 9 and comparative photoconductor preparation examples 1 and 2 except that the support of the photoconductor was changed to an anodized aluminum cylinder and the thickness of the charge transport layer was changed to 18 μm. Photoreceptors B1, B2, B3, B4, BE1, and BE2 were produced by performing the same operation as described above.

<Image Characteristic Test (Reference Example 1-6)>
The previously prepared photoreceptors B1 to B4 and comparative photoreceptors BE1 to B2 were mounted on a black drum cartridge of a color printer MICROLINE 3050c manufactured by Oki Data Corporation, and mounted on the following printer.
Specifications of MICROLINE 3050c · Quad tandem · Color 21ppm, Monochrome 26ppm
・ 1200 dpi
-DC contact roller charging-Writing with LED-No static elimination light Toner was used for the printer. This toner was produced by a melt-kneading pulverization method, and the average circularity was 0.935.
The evaluation results for each photoconductor are as follows.

  As can be seen from the comparison between the image characteristic test and the comparative image characteristic, by using a charge transport material having a specific structure in the photosensitive layer, the image has no cleaning failure and abnormal noise such as rubbing noise. It was found that a good image can be obtained without occurrence.

  While the present invention has been described in connection with embodiments that are presently the most practical and preferred, the present invention is not limited to the embodiments disclosed herein. The electrophotographic photosensitive member, the electrophotographic photosensitive member cartridge, and the image forming apparatus can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Should also be understood as being included within the scope of the present invention.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. 3 is an X-ray analysis spectrum of oxytitanium phthalocyanine used in Photoconductor Preparation Example 1. FIG.

Explanation of symbols

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
DESCRIPTION OF SYMBOLS 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 (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (11)

An electrophotographic photosensitive member for use in an image forming apparatus provided with an electrostatic image developing toner having an average circularity of 0.940 or more and 1.000 or less measured by a flow type particle image analyzer, Has an at least photosensitive layer on a conductive support, and the photosensitive layer contains an enamine compound represented by the following general formula (1).

(In the formula ^{(1), R 1, R} 2, R 3, R 4, R 5 are each independently a hydrogen atom, the molecular weight 6 0 an alkyl group, molecular weight 60 an alkoxy group, or the molecular weight 60 or less which may have an alkyl amino, an aryl group, or represents a molecular weight 6 0 an alkyl group, molecular weight 60 an alkoxy group, or a molecular weight of 60 or less of an alkyl group which may have an alkyl amino group, and any one of R ¹ and R ^2, any one of R ⁴ and R ^5, at least, the molecular weight 6 0 an alkyl group, molecular weight 60 an alkoxy group, or a molecular weight of 60 or less alkylamino An aryl group which may have a group.) The electrophotographic photosensitive member according to claim 1, wherein the electrostatic image developing toner is a toner produced in an aqueous medium. The electrophotographic photosensitive member according to claim 1, wherein the electrostatic image developing toner has a resin coating layer. The toner for developing an electrostatic charge image contains a wax, and the wax is contained in an amount of 4 to 20 parts by weight with respect to 100 parts by weight of the toner for electrostatic charge development. An electrophotographic photoreceptor according to any one of the above. The electrophotographic photosensitive member according to claim 1, wherein the enamine compound has a molecular weight of 500 or less. The electrophotographic photosensitive member according to any one of claims 1 to 5, a charging unit that charges the electrophotographic photosensitive member, an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, And an electrophotographic photosensitive member cartridge comprising: at least one selected from the group consisting of a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member. The electrophotographic cartridge according to claim 6, further comprising a blade cleaning mechanism. The electrophotographic cartridge according to claim 7, wherein the blade cleaning mechanism is a counter contact type. 6. The electrophotographic photosensitive member according to claim 1, a charging device for charging the electrophotographic photosensitive member, an exposure device for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image, and An image forming apparatus comprising: a developing device that develops an electrostatic latent image formed on the electrophotographic photosensitive member. The image forming apparatus according to claim 9, wherein the charging device is disposed in contact with the electrophotographic photosensitive member when charging the electrophotographic photosensitive member at least. The image forming apparatus according to claim 9, wherein the developing device is disposed in contact with the electrophotographic photosensitive member when developing at least a latent image formed on the electrophotographic photosensitive member.

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