JP2012058305A - Image forming method and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus and image forming apparatus, able to obtain a satisfactory digital image without causing image blur and image irregularity even in an image forming apparatus using an organic photoreceptor having a curable protective layer.SOLUTION: The organic photoreceptor has a charge generating layer, a charge transport layer, and a cross-linking protective layer on its conductive support, the charge generating layer containing 2.3-butanediol-added-titanyl phthalocyanine pigment and being 0.8 to 1.3 in the ratio (R700/R780) of the 700 nm-reflectance (R700) of reflection spectrum to the 780 nm-reflectance (R780) of the reflection spectrum. In the image forming method, the developing means contains toner containing antioxidant.

Description

  The present invention relates to an image forming apparatus and an image forming method used for electrophotographic image formation.

  Electrophotographic photoconductors move from inorganic photoconductors such as Se, arsenic, arsenic / Se alloys, CdS, ZnO, etc. to organic photoconductors with excellent advantages such as pollution and ease of manufacture, and various materials are used. Organic photoreceptors (hereinafter also simply referred to as photoreceptors) have been developed.

  However, the organophotoreceptor does not have sufficient wear resistance, and the active material such as ozone and NOx generated from the charging process deteriorates the charge transport material, resulting in image density due to deterioration of sensitivity and increase in residual potential. Deterioration and image blur are likely to occur.

  In order to improve the abrasion resistance characteristics of the organic photoreceptor, a photosensitive body improved by improving the abrasion resistance characteristics by installing a curable protective layer cross-linked to the organic photoreceptor has been proposed (for example, Patent Document 1). reference). However, if the crosslink density is increased and the wear resistance of the protective layer is improved, the refresh function of the surface will be reduced, and during repeated use, image blurring in a high temperature environment or image unevenness in a low temperature and low humidity environment will occur. It tends to be easier.

  In order to prevent the image blur, an attempt has been made to solve both wear resistance and image blur by using an antioxidant together with the protective layer (see, for example, Patent Document 2). However, in the curable protective layer having high wear resistance, the antioxidant effect (deactivation effect of active gas such as ozone and NOx) by the antioxidant in the protective layer does not last long, and again When used, image blurring easily occurs in a high-temperature environment.

  On the other hand, the improvement in the image unevenness is 2.3% in place of the highly sensitive Y-type titanyl phthalocyanine pigment in view of the fact that the image unevenness is related to the humidity dependency of the photoreceptor. A photoreceptor using a butanediol adduct titanyl phthalocyanine pigment as a charge generating substance has been proposed (Patent Document 3).

  However, when a curable protective layer with greatly improved abrasion resistance is provided on the photosensitive layer of 2.3-butanediol adduct titanyl phthalocyanine pigment, the image unevenness is improved, but the occurrence of image blur is improved. And a good digital image cannot be obtained.

JP-A-8-179541 JP 2008-587779 A JP 2004-125818 A

  The present invention has been made in view of the above-described problems, and the object thereof is to prevent both image blur and image unevenness even in an image forming apparatus using an organic photoreceptor having a curable protective layer. Another object of the present invention is to provide an image forming apparatus and an image forming method capable of obtaining a good digital image.

  In order to solve the above-mentioned problems, the present inventors have improved the characteristics of an organic photoreceptor having a curable protective layer, developed an organic photoreceptor having high sensitivity and low humidity dependency, and As a result of the investigation, the present invention has been achieved based on the idea that it is necessary to supply the surface of the body with a continuous antioxidant that maintains the deactivation effect of ozone and NOx.

  The object of the present invention can be achieved by having the following configuration.

  1. A charging potential is applied on the organic photoconductor by a charging unit, an electrostatic latent image is formed on the organic photoconductor on which the charging potential is applied by an exposure unit, and the electrostatic latent image is visualized as a toner image by a developing unit. In the image forming method in which the toner image is transferred to a transfer medium by a transfer unit and then the toner remaining on the organic photoconductor is removed by a cleaning unit, the organic photoconductor is placed on a conductive support. .3-butanediol adduct titanyl phthalocyanine pigment, and the ratio (R700 / R780) of the reflectance (R700) at 700 nm to the reflectance (R780) at 780 nm of the reflection spectrum is 0.8 to 1.3. An image forming method comprising a charge generation layer, a charge transport layer, and a cross-linkable curable protective layer, wherein the developing means contains a toner containing an antioxidant.

  2. 2. The image forming method as described in 1 above, wherein an antioxidant of the developing unit is added to the toner as an external additive.

  3. 3. The image forming method as described in 1 or 2 above, wherein the antioxidant is a hindered phenol compound.

  4). 4. The image forming method according to any one of 1 to 3, wherein the protective layer contains metal oxide particles surface-treated with a compound having a polymerizable functional group.

  5. Organic photoreceptor, charging means for charging the organic photoreceptor, exposure means for forming an electrostatic latent image on the organic photoreceptor by image exposure, developing means for developing the electrostatic latent image into a toner image, the toner In an image forming apparatus having transfer means for transferring an image to a transfer medium and cleaning means for removing toner remaining on the organic photoreceptor after the transfer, the organic photoreceptor is placed on a conductive support and 2.3-butanediol A charge generation layer containing an adduct titanyl phthalocyanine pigment and having a ratio (R700 / R780) of a reflectance (R700) at 700 nm and a reflectance (R780) at 780 nm of a reflection spectrum of 0.8 to 1.3; An image forming apparatus comprising a transport layer and a cross-linking curable protective layer, wherein the developing means contains a toner containing an antioxidant.

  By using the image forming method of the present invention, a photoconductor provided with a curable protective layer does not cause both image blur and image unevenness, improves the wear resistance of the photoconductor, and causes no fogging. Further, it is possible to achieve both improvement in image blur and image unevenness and wear resistance characteristics of the photoreceptor.

An example of the reflection spectrum of the photosensitive layer containing the pigment of this invention. An example of a reflection spectrum of a photosensitive layer using a pigment containing a 2,3-butanediol adduct titanyl phthalocyanine, which has a characteristic peak at a Bragg angle 2θ (± 0.2 °) of 9.5 ° (9.5 ° And a spectrum diagram of phthalocyanine having a characteristic peak at 8.3 ° (8.3 ° type). 1 is a cross-sectional configuration diagram of a color image forming apparatus using an electrophotographic photosensitive member of the present invention. A spectrum diagram of Y-type titanyl phthalocyanine having a characteristic peak at a Bragg angle 2θ (± 0.2 °) of 27.2 ° in an X-ray diffraction spectrum.

  In the image forming method of the present invention, a charging potential is applied on an organic photoconductor by a charging unit, an electrostatic latent image is formed on the organic photoconductor provided with the charging potential by an exposure unit, and the electrostatic latent image is formed. In an image forming method in which a toner image is visualized by a developing means, and then the toner image is transferred to a transfer medium by a transfer means, and then the toner remaining on the organic photoreceptor is removed by a cleaning means. A 2.3-butanediol adduct titanyl phthalocyanine pigment is contained on a conductive support, and the ratio (R700 / R780) of the reflectance (R700) at 700 nm and the reflectance (R780) at 780 nm of the reflection spectrum is 0. A charge generation layer, a charge transport layer, and a cross-linkable curable protective layer, each of which has a toner containing an antioxidant. To.

  Since the image forming method of the present invention has the above structure, image blur and image unevenness do not occur even when it is repeatedly used in a high temperature and high humidity or low temperature and low humidity environment, and the wear resistance of the photoreceptor is improved. Occurrence can be prevented, and both improvement in image blur and image unevenness and wear resistance of the photoreceptor can be achieved.

  First, the organic photoreceptor according to the present invention will be described.

  In the present invention, the organic photoconductor means an electrophotographic photoconductor constituted by providing an organic compound with at least one of a charge generation function and a charge transport function essential to the configuration of the electrophotographic photoconductor. All known organic electrophotographic photoreceptors such as a photoreceptor composed of the above organic charge generating substance or organic charge transporting substance, a photoreceptor composed of a polymer complex with a charge generating function and a charge transporting function are contained.

  The organic photoreceptor has a photosensitive layer (charge generation layer, charge transport layer) and a protective layer via an intermediate layer on a conductive support.

  The specific constitution of the organic photoreceptor used in the present invention will be described below.

(Conductive support)
As the conductive support used in the photoreceptor of the present invention, a sheet-like or cylindrical conductive support is used.

  The cylindrical conductive support of the present invention means a cylindrical support necessary for forming an endless image by rotating, and the straightness is in the range of 0.1 mm or less and the deflection is 0.1 mm or less. Certain conductive supports are preferred. Exceeding the range of straightness and shake makes it difficult to form a good image.

As a material for the conductive support, 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 conductive support preferably has a specific resistance of 10 ³ Ω · cm or less at room temperature.

  As the conductive support used in the present invention, one having an alumite film that has been sealed on the surface thereof may be used. The alumite treatment is usually performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid, etc., but anodizing treatment in sulfuric acid gives the most preferable result. In the case of anodizing in sulfuric acid, the sulfuric acid concentration is preferably 100 to 200 g / l, the aluminum ion concentration is 1 to 10 g / l, the liquid temperature is about 20 ° C., and the applied voltage is preferably about 20 V. It is not limited. The average film thickness of the anodized film is usually 20 μm or less, particularly preferably 10 μm or less.

(Middle layer)
In the present invention, an intermediate layer having a barrier function is preferably provided between the conductive support and the photosensitive layer, and in particular, an intermediate layer in which titanium oxide fine particles are dispersed and contained in a binder resin such as polyamide is preferable. The average particle diameter of the titanium oxide particles is preferably in the range of 10 nm to 400 nm in terms of number average primary particle diameter, and is preferably 15 nm to 200 nm. If it is less than 10 nm, the effect of preventing the occurrence of moire by the intermediate layer is small. On the other hand, if it is larger than 400 nm, the titanium oxide particles in the intermediate layer coating solution are likely to settle, and as a result, the uniform dispersibility of the titanium oxide particles in the intermediate layer is poor, and the black spots are likely to increase. An intermediate layer coating liquid using titanium oxide particles having a number average primary particle size in the above range has good dispersion stability, and the intermediate layer formed from such a coating liquid has an environmental characteristic in addition to the function of preventing the occurrence of black spots. Is good and has cracking resistance.

  The shape of the titanium oxide particles used in the present invention includes a dendritic shape, a needle shape, a granular shape, and the like. The titanium oxide particles having such a shape are, for example, titanium oxide particles, anatase type, rutile as crystal types. There are types, amorphous types, and the like. Any crystal type may be used, or two or more crystal types may be mixed and used. Among them, the rutile type and granular type are the best.

  The titanium oxide particles of the present invention are preferably surface-treated. Among these, it is preferable to perform a plurality of surface treatments, and among the plurality of surface treatments, the last surface treatment is a surface treatment using a reactive organosilicon compound. In addition, at least one of the surface treatments is at least one surface treatment selected from alumina, silica, and zirconia, and finally a surface treatment using a reactive organosilicon compound. It is preferable to carry out.

  Alumina treatment, silica treatment and zirconia treatment are treatments for precipitating alumina, silica or zirconia on the surface of the titanium oxide particles. The alumina, silica and zirconia deposited on these surfaces are water of alumina, silica and zirconia. Japanese products are also included. The surface treatment of the reactive organosilicon compound means using a reactive organosilicon compound in the treatment liquid.

  In this way, when the surface treatment of the titanium oxide particles is performed at least twice, the surface of the titanium oxide particles is uniformly coated (treated), and when the surface-treated titanium oxide particles are used for the intermediate layer, the intermediate layer It is possible to obtain a good photoconductor having good dispersibility of the titanium oxide particles therein and causing no image defects such as black spots.

  Preferable reactive organosilicon compounds used for the surface treatment include various alkoxysilanes such as methyltrimethoxysilane, n-butyltrimethoxysilane, n-hexycyltrimethoxysilane, dimethyldimethoxysilane, and methylhydrogenpolysiloxane.

(Photosensitive layer)
The photosensitive layer structure of the photoreceptor of the present invention has a structure in which a charge generation layer (CGL) and a charge transport layer (CTL) are separated on the intermediate layer, and further has a protective layer thereon.

  The structure of the photosensitive layer of the function-separated negatively charged photoreceptor will be described below.

(Charge generation layer)
The charge generation layer contains a charge generation material (CGM). Other substances may contain a binder resin and other additives as necessary.

  The charge generation layer of the organophotoreceptor of the present invention contains a 2.3-butanediol adduct titanyl phthalocyanine pigment, and the ratio of the reflectance (R700) at 700 nm to the reflectance (R780) at 780 nm (R700). / R780) is 0.8 to 1.3. The structure of the charge generation layer is formed as follows.

  That is, generally, the photosensitive layer of an organic photoreceptor is formed by applying and drying a coating solution in which a charge generating material is dispersed in a solution in which a binder resin is dissolved in an organic solvent. In order to enhance the electrical characteristics and image characteristics of the photoreceptor, it is considered important to uniformly disperse the charge generating material in the photosensitive layer. When the dispersion is insufficient, coarse particles are contained in the coating solution, and as a result, the photosensitive layer formed using the coating solution also contains coarse particles of the charge generating material, Image characteristics are degraded. Therefore, in the process of preparing the charge generation layer coating solution, it is important to sufficiently disperse the charge generation material so that the coating solution does not contain secondary agglomerated particles or coarse particles.

  On the other hand, when the dispersibility of the charge generation material is increased by a high dispersion share, a uniformly dispersed coating film can be formed, but the crystal structure of the charge generation material is changed by the dispersion share and its characteristics are impaired, and sensitivity and potential stability are stabilized. May cause problems with sex.

  The present inventors have found that the pigment containing titanyl phthalocyanine of the present invention and 2,3-butanediol adduct titanyl phthalocyanine (hereinafter also referred to as the pigment of the present invention) has a high fracture surface activity when pulverized. I wondered if it was stable. In other words, butanediol desorption or phthalocyanine ring decomposition due to hydrolysis or the like is likely to occur at crystal defects that occur on the fracture surface, etc. that occur when pulverized, and the decomposition products inhibit charge generation or become charge traps. Inferred that it may adversely affect sensitivity and repeatability.

  In accordance with this reasoning, the present invention has attempted to increase dispersibility without putting too much stress on the pigment crystal. As a result, we can synthesize small particle size pigment particles, and we can solve the problem by carrying out low share dispersion that only loosens the secondary agglomeration without crushing while maintaining the crystals at the time of pigment synthesis. As a result of continuous investigation, as a guide, the ratio (R700 / R780) of the reflectance (R700) at 700 nm and the reflectance (R780) at 780 nm of the reflection spectrum of the photosensitive layer containing the pigment of the present invention is dispersibility. It has been found that it can be an index indicating the degree of compatibility between crystallinity and maintenance of crystallinity.

  According to the results of the study by the present inventors, when the ratio (R700 / R780) of the charge generation layer is 0.8 to 1.3, the sensitivity does not depend on humidity, but the sensitivity is high. It was found that an organic photoreceptor having a high potential stability repeatedly can be obtained.

  FIG. 1 is an example of the reflection spectrum of a photosensitive layer containing the pigment of the present invention.

  FIG. 1A shows a characteristic in which the ratio of reflection spectrum (R700 / R780) is within the scope of the present invention.

  FIG. 1B shows a characteristic in which the ratio of reflection spectrum (R700 / R780) is outside the range of the present invention.

  The pigment containing the titanyl phthalocyanine of the present invention and the 2,3-butanediol adduct titanyl phthalocyanine (the pigment of the present invention) is at least titanyl phthalocyanine and the 2,3-butanediol adduct titanyl in one pigment particle. It means a pigment containing phthalocyanine.

  In the dispersion of the pigment of the present invention, the reflectance near 780 nm increases and the ratio (R700 / R780) decreases as the dispersion of secondary aggregation and the crushing of crystals progress.

  When the ratio (R700 / R780) is less than 0.8, it indicates that the pigment crystal was crushed due to excessive dispersion share, and the 2,3-butanediol adduct titanyl phthalocyanine tends to be decomposed at the defective portion of the crystal. As a result, image blur tends to occur.

  On the other hand, when the ratio (R700 / R780) exceeds 1.3, it indicates the presence of secondary agglomerated particles and coarse particles with poor dispersion, and fogging and image unevenness increase.

  In the present invention, the reflection spectrum of the photosensitive layer is measured with a sample in which a charge generation layer is formed on an aluminum support with a dry film thickness of 0.3 μm. The reflection spectrum is measured as a relative reflectance when the reflectance of the aluminum support is 100%. In order to remove irregularities due to interference fringes in the obtained reflection spectrum, the measurement data is approximated by a second order polynomial in the range of 685 to 715 nm and 765 to 795 nm, and the reflectance (R700) and reflectance (R780) are calculated. The ratio (R700 / R780) is calculated.

  The reflection spectrum was measured by using an optical film thickness measuring device Solid Lambda Thickness (Spectra Corp.).

  The 2,3-butanediol adduct titanyl phthalocyanine pigment is synthesized as shown by the following chemical reaction.

  The 2,3-butanediol adduct titanyl phthalocyanine pigment has its specific crystal form due to the difference in the addition ratio of butanediol.

  The crystal types described below are shown as an example of the reflection spectrum of the photosensitive layer using a pigment containing the 2,3-butanediol adduct titanyl phthalocyanine in FIG.

  When an excess of titanyl phthalocyanine and at least one of (2R, 3R) -2,3-butanediol or (2S, 3S) -2,3-butanediol (hereinafter also referred to as butanediol) is reacted, In the diffraction spectrum, a pigment having a characteristic peak at a Bragg angle 2θ (± 0.2 °): 9.5 ° (hereinafter abbreviated as 9.5 ° type) is obtained as shown in FIG. The 9.5 type butanediol-added titanyl phthalocyanine pigment has peaks at 16.4 °, 19.1 °, 24.7 °, and 26.5 ° in addition to 9.5.

Structure of the pigment Ti = O absorption near 970 cm ^-1 in the IR spectrum disappeared, 630 cm ^-1 of the absorption of the O-Ti-O appears in the vicinity about the 390 to 410 ° C. in a thermal analysis (TG) 11 % Mass loss (possibly due to the elimination of butylene oxide by thermal decomposition), and from the results of mass spectrometry, titanyl phthalocyanine and (2R, 3R) -2,3-butanediol or (2S, 3S ) -2,3-butanediol is considered to have a dehydrated condensation structure at 1/1.

On the other hand, when a butanediol compound is reacted at 1 mol or less with respect to 1 mol of titanyl phthalocyanine, the powder X-ray diffraction spectrum has a characteristic peak at a Bragg angle 2θ: 8.3 ° (± 0.2 °) ( Hereinafter, the pigment shown in FIG. 2 (2) is obtained. The 8.3 ° butanediol-added titanyl phthalocyanine pigment has peaks at 24.7 °, 25.1 °, and 26.5 ° in addition to 8.3 °. The pigment shows both absorption of Ti = O near 970 cm ⁻¹ and O—Ti—O near 630 cm ⁻¹ in the IR spectrum. In addition, from the result of mass analysis that the mass loss is less than 11% at 390 to 410 ° C. by thermal analysis and from the result of mass analysis, butanediol / titanyl phthalocyanine = 1/1 adduct and titanyl phthalocyanine are mixed at a certain ratio ( It is presumed that two or more compounds are mixed in one pigment particle to form a pigment having a specific crystal type. The butanediol addition ratio is estimated to be 40 to 70 mol% from the mass loss of 390 to 410 ° C. in the thermal analysis.

  In the X-ray diffraction spectrum, the characteristic peak means a clearly different peak exceeding the background variation.

  In the present invention, the pigment of the present invention is characterized by at least a Bragg angle (2θ ± 0.2 °) of 8.3 ° in the X-ray diffraction spectrum in that good sensitivity and repeated potential stability can be obtained. More preferably, it has a peak.

  In the present invention, for synthesis of 2,3-butanediol adduct titanyl phthalocyanine, the optical material of (2R, 3R) -2,3-butanediol or (2S, 3S) -2,3-butanediol is used as a raw material. The isomeric 2,3-butanediol is preferably used, but a racemate that does not exhibit optical isomerism may be used.

The pigment of the present invention is a pigment at the time of synthesis and desirably has a BET specific surface area of 20 m ² / g or more.

  Thus, when the coating solution of the charge generation layer containing a pigment having a large BET specific surface area and a small particle size is dispersed in a low shear to maintain the dispersibility of the pigment during synthesis, good sensitivity and repeated potential are obtained. A photosensitive member having stability can be produced.

[Method for producing 2,3-butanediol adduct titanyl phthalocyanine]
2,3-butanediol adduct titanyl phthalocyanine, for example, an adduct of titanyl phthalocyanine and at least one of (2R, 3R) -2,3-butanediol or (2S, 3S) -2,3-butanediol, Titanyl phthalocyanine and (2R, 3R) -2,3-butanediol or (2S, 3S) -2,3-butanediol (hereinafter sometimes referred to as butanediol compound) in various solvents at room temperature or under heating It can be synthesized by reacting. The raw material titanyl phthalocyanine can be synthesized from phthalonitrile and titanium tetrachloride, synthesized from diiminoisoindoline and alkoxy titanium, or synthesized from phthalonitrile, urea and alkoxy titanium. The method can also be used, but high purity titanyl phthalocyanine with a low chlorine content obtained from diiminoisoindoline and alkoxytitanium is particularly preferred. The titanyl phthalocyanine is preferably made amorphous by a method such as acid paste treatment and then reacted with a butanediol compound. For the addition reaction between amorphous titanyl phthalocyanine and a butanediol compound, usually 5 to 30 times the solvent is used. The solvent is not particularly limited, and aromatic solvents such as chlorobenzene, dichlorobenzene, anisole, chloronaphthalene and quinoline to ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and acetophenone, ether solvents such as tetrahydrofuran, dioxolane and diglyme, Furthermore, there can be mentioned a large number of aprotic polar solvents such as dimethylformamide, dimethylacetamide and dimethylsulfoxide, other halogen-based solvents and ester-based solvents.

The reaction between titanyl phthalocyanine and a butanediol compound is shown below. The reaction can be carried out under a wide range of temperature conditions, the reaction temperature is preferably in the range of 25 to 300 ° C., and a pigment having a BET specific surface area of 20 m ² / g or more. In order to synthesize | combine, it is more preferable that it is the range of 30-100 degreeC.

  The butanediol compound is usually added at a ratio of 0.2 to 2.0 mol with respect to 1 mol of titanyl phthalocyanine. In order to be an equimolar adduct, the diol compound must be used in an amount of 1.0 mol or more. When the diol compound is added in an amount of 1.0 mol or less in the above ratio, the obtained adduct becomes a mixed crystal with titanyl phthalocyanine.

[Dispersion of the pigment of the present invention]
In order to make a dispersion liquid such as a charge generation layer using the pigment of the present invention (a pigment containing titanyl phthalocyanine and 2,3-butanediol adduct titanyl phthalocyanine), these pigments are dispersed in a solvent. There are no particular restrictions on the solvent, and ketone solvents such as methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, and acetophenone, ether solvents such as tetrahydrofuran, dioxolane, and diglyme, and alcohol solvents such as methyl cellosolve, ethyl cellosolve, and butanol There may be mentioned a large number of solvents, ester solvents such as ethyl acetate and t-butyl acetate, aromatic solvents such as toluene and chlorobenzene, and halogen solvents such as dichloroethane and trichloroethane.

  A binder can be added to the dispersion. The binder can be selected widely as long as it is soluble in the solvent used. Examples include polyvinyl butyral, polyvinyl formal, polyvinyl acetate, polyvinyl chloride, polyamide, polycarbonate, polyester, and copolymers thereof. The ratio of the binder and the pigment is not particularly limited, but is usually 1/10 to 10/1. When the amount of the binder is small, the dispersion becomes unstable, and when the amount is too large, the electric resistance is increased, and when the electrophotographic photosensitive member is formed, the residual potential tends to increase repeatedly.

  The dispersion means preferably used in the present invention is the above-described low shear dispersion (low shear dispersion). As the low shear dispersion, ultrasonic dispersion or a medium having a small specific gravity (glass (specific gravity: 2.5)). Media dispersion using beads or the like is preferred.

  As an indicator of the dispersion state, the ratio of the reflection spectrum of the charge generation layer (R700 / R750) needs to be in the range of 0.8 to 1.3. Control of the ratio of these reflection spectra (R700 / R750) can be performed by adjusting the share applied to the dispersion during dispersion. Specifically, it can be controlled by the dispersion method, the diameter and amount of media used during dispersion, the dispersion time, and the like.

  In the organophotoreceptor of the present invention, the above-mentioned butanediol adduct titanyl phthalocyanine pigment is used as the charge generating material, but other phthalocyanine pigments, azo pigments, perylene pigments, azulium pigments and the like can be used in combination. The thickness of the charge generation layer is preferably 0.1 μm to 2 μm.

(Charge transport layer)
The charge transport layer contains a charge transport material (CTM) and a binder resin that disperses and forms a CTM. Other substances may contain additives such as antioxidants as necessary.

  A known charge transport material (CTM) can be used as the charge transport material (CTM). For example, a triphenylamine derivative, a hydrazone compound, a styryl compound, a benzidine compound, a butadiene compound, or the like can be used. These charge transport materials are usually dissolved in a suitable binder resin to form a layer.

  The binder resin used for the charge transport layer (CTL) may be either a thermoplastic resin or a thermosetting resin. For example, polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, and these resins A copolymer resin containing two or more of the repeating unit structures. In addition to these insulating resins, high molecular organic semiconductors such as poly-N-vinylcarbazole can be used. Of these, polycarbonate resins are most preferred because of their low water absorption and good CTM dispersibility and electrophotographic characteristics.

  The ratio of the binder resin to the charge transport material is preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin. The thickness of the charge transport layer is preferably 10 to 40 μm.

  Solvents or dispersion media used for layer formation of the charge transport layer include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone. , Benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxolane, dioxane , Methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve and the like. The present invention is not limited to these, but toluene, tetrahydrofuran, dioxolane and the like are preferably used. These solvents may be used alone or as a mixed solvent of two or more.

(Protective layer)
The protective layer of the organic photoreceptor of the present invention is a cross-linking curable protective layer. The crosslinkable protective layer is formed by coating and curing a coating solution containing a crosslinkable polymerizable compound to form a protective layer having a crosslinked structure.

  The polymerizable compound is an unsaturated polymerizable functional group that causes the chain polymerization reaction to proceed in the former chain polymerization reaction mode, when the polymer formation reaction is largely divided into chain polymerization and sequential polymerization. A compound having a functional group or an isomerizable polymerizable functional group. On the other hand, the latter sequential polymerization reaction form refers to a compound having a hydroxyl group or an organosilicon compound having a hydrolyzable group that can cause a condensation reaction to proceed.

  The protective layer according to the present invention is formed by polymerizing a polymerizable compound. As the polymerizable compound, a monomer that is polymerized (cured) by irradiation with active rays such as ultraviolet rays and electron beams, and becomes a resin generally used as a binder resin of a photoreceptor, such as polystyrene and polyacrylate, is particularly preferable. Styrene monomers, acrylic monomers, methacrylic monomers, vinyl toluene monomers, vinyl acetate monomers, and N-vinyl pyrrolidone monomers are preferred.

Among them, a curable compound having an acryloyl group (CH ₂ ═CHCO—) or a methacryloyl group (CH ₂ ═CCH ₃ CO—) is particularly preferable because it can be polymerized (cured) in a small amount of light or in a short time.

  In the present invention, these polymerizable compounds may be used alone or in combination.

  Moreover, although an epoxy compound, a vinyl ether compound, an oxetane compound etc. are mentioned especially in a cationic polymerizable compound, an oxetane compound is preferable.

  Examples of the polymerizable compound are shown below. The number of Ac groups (the number of acryloyl groups) or the number of Mc groups (the number of methacryloyl groups) described below represents the number of acryloyl groups or methacryloyl groups.

  However, in the above, R is shown below.

  However, in the above, R 'is shown below.

  Moreover, although the specific example of a preferable oxetane compound is shown below, this invention is not limited to these.

  Examples of the epoxy compound include aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.

  In the present invention, the polymerizable compound is preferably a compound having a functional group (reactive group) of 3 or more. In addition, two or more kinds of polymerizable compounds may be used in combination, but even in this case, it is preferable to use 50% by mass or more of the compound having three or more functional groups as the polymerizable compound.

  The protective layer according to the present invention preferably contains inorganic fine particles. As the inorganic fine particles, the following are preferable.

(Inorganic fine particles)
The inorganic fine particles are preferably metal oxide particles including transition metals. For example, silica (silicon oxide), magnesium oxide, zinc oxide, lead oxide, aluminum oxide, tantalum oxide, indium oxide, bismuth oxide, yttrium oxide, cobalt oxide, copper oxide, manganese oxide, selenium oxide, iron oxide, zirconium oxide, Examples include metal oxide particles such as germanium oxide, tin oxide, titanium oxide, niobium oxide, molybdenum oxide, and vanadium oxide. Among these, particles such as titanium oxide, alumina, zinc oxide, and tin oxide are preferable.

  The metal oxide particles are preferably prepared by a known production method, for example, a general production method such as a gas phase method, a chlorine method, a sulfuric acid method, a plasma method, or an electrolytic method.

  The number average primary particle size of the metal oxide is preferably in the range of 1 to 300 nm. Especially preferably, it is 3-100 nm.

  The number average primary particle size of the metal oxide particles is a photographic image (excluding aggregated particles) taken with a scanning electron microscope (manufactured by JEOL Ltd.) with a magnification of 10000 times, and 300 particles randomly taken by a scanner. A) automatic image processing analyzer LUZEX AP (Nireco Corp.) software version Ver. The number average primary particle size was calculated using 1.32.

  The inorganic fine particles are preferably surface-treated with a surface treatment agent such as a silane coupling agent or a titanium coupling agent. Examples of the surface treatment agent include well-known silane cups such as t-butylphenyldichlorosilane, 3-methacryloxypropyldimethoxymethylsilane, 3- (3-cyanopropylthiopropyl) dimethoxymethylsilane, and hydrogenpolysiloxane compounds. A ring agent, a titanium coupling agent, or the like is used.

  It is also preferable to use metal oxide particles that have been surface treated with a chain polymerizable compound having a surface treatment group.

  That is, by reacting a chain-polymerizable compound having a surface treatment group with metal oxide particles having a hydroxyl group on the surface (generally, metal oxide particles not subjected to surface treatment have a hydroxyl group on the surface). The metal oxide particles surface-treated with a chain polymerizable compound having a surface treatment group can be obtained.

  Examples of the compound having a surface treatment group include the following compounds.

_{S-1 CH 2 = CHSi (} CH 3) (OCH 3) 2
_{S-2 CH 2 = CHSi (} OCH 3) 3
S-3 CH ₂ = CHSiCl _{3
S-4 CH 2 = CHCOO (} CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-5 CH 2 = CHCOO (} CH 2) 2 Si (OCH 3) 3
_{S-6 CH 2 = CHCOO (} CH 2) 3 Si (CH 3) (OCH 3) 2
_{S-7 CH 2 = CHCOO (} CH 2) 3 Si (OCH 3) 3
_{S-8 CH 2 = CHCOO (} CH 2) 2 Si (CH 3) Cl 2
_{S-9 CH 2 = CHCOO (} CH 2) 2 SiCl 3
_{S-10 CH 2 = CHCOO (} CH 2) 3 Si (CH 3) Cl 2
S-11 CH ₂ = CHCOO (CH ₂ ) ₃ SiCl _{3
S-12 CH 2 = C (} CH 3) COO (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-13 CH 2 = C (} CH 3) COO (CH 2) 2 Si (OCH 3) 3
_{S-14 CH 2 = C (} CH 3) COO (CH 2) 3 Si (CH 3) (OCH 3) 2
_{S-15 CH 2 = C (} CH 3) COO (CH 2) 3 Si (OCH 3) 3
_{S-16 CH 2 = C (} CH 3) COO (CH 2) 2 Si (CH 3) Cl 2
_{S-17 CH 2 = C (} CH 3) COO (CH 2) 2 SiCl 3
_{S-18 CH 2 = C (} CH 3) COO (CH 2) 3 Si (CH 3) Cl 2
_{S-19 CH 2 = C (} CH 3) COO (CH 2) 3 SiCl 3
_{S-20 CH 2 = CHSi (} C 2 H 5) (OCH 3) 2
S-21 CH ₂ ═C (CH ₃ ) Si (OCH ₃ ) _{3
S-22 CH 2 = C (} CH 3) Si (OC 2 H 5) 3
_{S-23 CH 2 = CHSi (} OCH 3) 3
_{S-24 CH 2 = C (} CH 3) Si (CH 3) (OCH 3) 2
_{S-25 CH 2 = CHSi (} CH 3) Cl 2
_{S-26 CH 2 = CHCOOSi (} OCH 3) 3
_{S-27 CH 2 = CHCOOSi (} OC 2 H 5) 3
_{S-28 CH 2 = C (} CH 3) COOSi (OCH 3) 3
_{S-29 CH 2 = C (} CH 3) COOSi (OC 2 H 5) 3
_{S-30 CH 2 = C (} CH 3) COO (CH 2) 3 Si (OC 2 H 5) 3
When the polymerizable compound according to the present invention is reacted, a method of reacting by electron beam cleavage, a method of reacting with light or heat by adding a radical polymerization initiator or a cationic polymerizable initiator, and the like are used. As the polymerization initiator, either a photopolymerization initiator or a thermal polymerization initiator can be used. Further, both light and heat initiators can be used in combination.

As a radical polymerization initiator of these photocurable compounds, a photopolymerization initiator is preferable, and among them, an alkylphenone compound or a phosphine oxide compound is preferable. In particular, a compound having an α-hydroxyacetophenone structure or an acylphosphine oxide structure is preferable. The compound that initiates cationic polymerization, e.g., diazonium, ammonium, iodonium, sulfonium, aromatic onium compounds such as phosphonium ^{_{B (C 6 F 5) 4}} -, PF 6 -, AsF 6 -, SbF 6 - , CF ₃ SO ₃ ^- ionic polymerization initiator or sulfonic acid sulfonated materials that generate a such as salts, halides or generates hydrogen halide, can be mentioned nonionic polymerization initiator such as iron arene complex. In particular, a sulfonate that generates a sulfonic acid that is a nonionic polymerization initiator and a halide that generates a hydrogen halide are preferable.

The photoinitiator used preferably below is illustrated.
Examples of α-aminoacetophenone series

Examples of α-hydroxyacetophenone compounds

Examples of acylphosphine oxide compounds

Examples of other radical polymerization initiators

Nonionic polymerization initiator

Ionic polymerization initiator

  In order to form a protective layer by polymerizing the photopolymerizable compound, a coating solution for the protective layer (a composition containing a polymerizable compound or surface-treated inorganic fine particles) is applied on the photosensitive layer, and then the coating film is formed. After the primary drying to such an extent that the fluidity of the film disappears, the protective layer is cured by irradiating with ultraviolet rays, and further, the secondary drying is performed to make the amount of volatile substances in the coating film a specified amount. preferable.

  As a device for irradiating ultraviolet rays, a known device used for curing an ultraviolet curable resin can be used.

The amount of ultraviolet rays (mJ / cm ² ) for curing the resin with ultraviolet rays is preferably controlled by the ultraviolet irradiation intensity and irradiation time.

  On the other hand, as the thermal polymerization initiator, ketone peroxide compounds, peroxyketal compounds, hydroperoxide compounds, dialkyl peroxide compounds, diacyl peroxide compounds, peroxydicarbonate compounds, peroxyester compounds Compounds and the like are used, and these thermal polymerization initiators are disclosed in company product catalogs.

  In the present invention, similar to the photopolymerization initiator, these thermal polymerization initiators are mixed with a composition containing a polymerizable compound, surface-treated inorganic fine particles, etc., and a coating liquid for the protective layer is prepared. The protective layer according to the present invention is formed by preparing and coating the coating solution on the photosensitive layer and then drying by heating. As the thermal polymerization initiator, the above-mentioned other radical polymerization initiators can be used.

  Also, as for the coating method of the protective layer, the dip coating in which the entire photoreceptor is immersed in the protective layer coating solution increases the diffusion of the polymerization initiator to the lower layer, so that the photosensitive layer film under the protective layer is not dissolved as much as possible. Therefore, it is preferable to use a coating processing method such as a volume regulation type (a circular slide hopper type is a typical example). The circular amount regulation type coating is described in detail in, for example, Japanese Patent Application Laid-Open No. 58-189061.

  These polymerization initiators may be used alone or in combination of two or more. Content of a polymerization initiator is 0.1-20 mass parts with respect to 100 mass parts of an acryl-type compound, Preferably it is 0.5-10 mass parts.

  The protective layer of the present invention can further contain various charge transport materials and antioxidants, and various lubricant particles can be added. For example, fluorine atom-containing resin particles can be added. Fluorine atom-containing resin particles include tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluorochloroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and these One or two or more types are preferably selected from the copolymers, but tetrafluoroethylene resin and vinylidene fluoride resin are particularly preferable. The ratio of the lubricant particles in the protective layer is preferably 5 to 70 parts by mass, more preferably 10 to 60% by mass with respect to 100 parts by mass of the acrylic resin. The average particle size of the lubricant particles is preferably 0.01 μm to 1 μm. Particularly preferably, it is 0.05 μm to 0.5 μm. The molecular weight of the resin can be appropriately selected and is not particularly limited.

  Solvents for forming the protective layer include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, sec-butanol, benzyl alcohol, toluene, xylene, methylene chloride, methyl ethyl ketone, cyclohexane, acetic acid. Examples thereof include, but are not limited to, ethyl, butyl acetate, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, 1-dioxane, 1,3-dioxolane, pyridine and diethylamine.

  The protective layer of the present invention is preferably subjected to reaction by irradiation with actinic radiation after natural drying or heat drying after coating.

  As the coating method, a known method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, and a slide hopper method can be used as in the case of the intermediate layer and the photosensitive layer. .

  The photoreceptor of the present invention is capable of generating a cured resin by irradiating actinic rays on the coating to generate radicals and polymerizing, and curing by forming a cross-linking bond between molecules and within the molecule. preferable. As the active ray, ultraviolet rays and electron beams are particularly preferable.

As the ultraviolet light source, any light source that generates ultraviolet light can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a flash (pulse) xenon, or the like can be used. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 100 mJ / cm ² . The power of the lamp is preferably 0.1 kW to 5 kW, particularly preferably 0.5 kW to 3 kW.

  As an electron beam source, there is no particular limitation on the electron beam irradiation apparatus, and generally, an electron beam accelerator for electron beam irradiation is a curtain beam type that is relatively inexpensive and can provide a large output. Used. The acceleration voltage during electron beam irradiation is preferably 100 to 300 kV. The absorbed dose is preferably 0.5 to 10 Mrad.

  The irradiation time for obtaining the necessary irradiation amount of active rays is preferably 0.1 second to 10 minutes, and more preferably 0.1 second to 5 minutes from the viewpoint of work efficiency.

  As the actinic radiation, ultraviolet rays are easy to use and are particularly preferable.

  The photoreceptor of the present invention can be dried before and after irradiating active rays and during irradiation with active rays, and the timing of drying can be appropriately selected by combining them.

  Drying conditions can be appropriately selected depending on the type of solvent, film thickness, and the like. The drying temperature is preferably room temperature to 180 ° C, particularly preferably 80 ° C to 140 ° C. The drying time is preferably 1 minute to 200 minutes, and particularly preferably 5 minutes to 100 minutes.

  The thickness of the protective layer is preferably 0.2 to 10 μm, more preferably 0.5 to 6 μm.

  Although the protective layer formed by polymerization using a chain polymerizable compound as the polymerizable compound has been described above, the protective layer formed by the following sequential reaction is also included in the protective layer according to the present invention.

  The protective layer according to the present invention includes a protective layer of a polyurethane resin layer formed by a reaction between a polyhydroxy compound and a polyisocyanate compound.

  The protective layer according to the present invention includes a protective layer of a siloxane-based resin layer formed by a polycondensation reaction of a hydrolyzable organosilicon compound.

  Next, as a coating processing method for manufacturing the organic photoreceptor, a coating processing method such as dip coating, spray coating, circular amount regulation type coating, etc. is used. In order to prevent dissolution as much as possible, and in order to achieve uniform coating processing, it is preferable to use a coating processing method such as spray coating or circular amount regulation type (circular slide hopper type is a typical example). It is most preferable to use the circular amount regulation type coating method for the protective layer. The circular amount regulation type coating is described in detail in, for example, Japanese Patent Application Laid-Open No. 58-189061.

  Next, a toner containing an antioxidant for developing means according to the present invention will be described.

  The developing means according to the present invention has a developer containing toner. As the toner, a so-called electrostatic image developing toner is used, and the toner according to the present invention contains an antioxidant. The antioxidant may be dispersed and contained in the toner particles, but is preferably contained as an external additive.

  The toner according to the present invention contains an antioxidant. The antioxidant may be added internally to the toner particles, but is preferably added as an external additive. When the toner is internally added, the toner content is preferably 0.1% by mass to 20% by mass. On the other hand, when adding as an external additive, 0.005 mass%-10 mass parts are preferable with respect to 100 mass parts of toner before external additive addition, and 0.01 mass%-5 mass parts are more preferable.

〔Antioxidant〕
The antioxidant suppresses fading caused by light irradiation and fading caused by various oxidizing gases such as ozone, active oxygen, NOx, and SOx. Examples of such antioxidants include antioxidants described in JP-A-57-74192, JP-A-57-87989, and JP-A-60-72785, and JP-A-61-154989. Hydrazides disclosed in JP-A No. 61-14659, hindered amine antioxidants disclosed in JP-A No. 61-146591, nitrogen-containing heterocyclic mercapto compounds disclosed in JP-A No. 61-177279, No. -1156777 and JP-A-1-36479, thioether-based antioxidants, JP-A-1-36480, JP-A-1-118137, hindered phenolic antioxidants having specific structures Agents, ascorbic acids disclosed in JP-A-7-195824 and JP-A-8-150773, JP-A-7-1 No. 9037, such as zinc sulfate, thiocyanate disclosed in JP-A-7-314882, thiourea derivatives disclosed in JP-A-7-314883, JP-A-7-276790 and Sugars disclosed in JP-A-8-108617, phosphoric acid antioxidants disclosed in JP-A-8-118791, nitrites, sulfites and thiosulfates disclosed in JP-A-8-300807 Moreover, the hydroxylamine derivative etc. which are disclosed by Unexamined-Japanese-Patent No. 9-267544 can be mentioned. Furthermore, polycondensates of dicyandiamide and polyalkylene polyamine disclosed in JP-A No. 2000-266928 can be suitably used as an antioxidant.

  The antioxidant used in the present invention is preferably a hindered phenol compound.

  Here, the hindered phenol refers to compounds having a branched alkyl group at the ortho position relative to the hydroxyl group of the phenol compound and derivatives thereof (however, the hydroxyl group may be converted to alkoxy).

  The following are examples of typical antioxidant compounds.

  Examples of the antioxidants that have been commercialized include the following compounds such as “Irganox 1076”, “Irganox 1010”, “Irganox 1098”, “Irganox 245”, “Irganox 1330”, “ "Irganox 3114", "Irganox 1076", "3,5-di-tert-butyl-4-hydroxybiphenyl" or more hindered phenols, "Sanol LS2626", "Sanol LS765", "Sanol LS2626", "Sanol LS770, Sanol LS744, Tinuvin 144, Tinuvin 622LD, Mark LA57, Mark LA67, Mark LA62, Mark LA68, Mark LA63 and higher hindered amines , ”Smilizer P-D or higher thioether type, “Mark 2112”, “Mark PEP-8”, “Mark PEP-24G”, “Mark PEP-36”, “Mark 329K”, “Mark HP-10” or higher phosphite type Can be mentioned. Of these, hindered phenol compounds are particularly preferred.

  Next, the configuration of the toner other than the antioxidant will be described in detail.

  The toner according to the present invention is generally referred to as an electrostatic image developing toner, and the toner includes toner particles and an external additive.

  The toner particles basically have a configuration in which pigments or dyes are dispersed in a toner binder resin, but may additionally contain an anti-offset agent, a charge control agent, or the like.

  On the other hand, as an external additive of the toner, a fluidizing agent, a cleaning aid, an antioxidant according to the present invention, and the like can be contained.

  The toner according to the present invention may be produced by kneading and pulverizing the constituents of toner particles, but may also be produced by a polymerization method (so-called polymerized toner). In the production of the polymerized toner, a surfactant, a polymerization initiator, a chain transfer agent, an aggregating agent, and the like are further used during the polymerization of the toner.

[Toner binder resin]
As the toner binder resin, it is preferable to use a thermoplastic resin capable of obtaining sufficient adhesion with the coloring fine particles, and particularly preferable is a solvent-soluble one. Moreover, if the precursor is a solvent-soluble one, even a curable resin that forms a three-dimensional structure can be used.

  As such a toner binder resin, those generally used as a toner binder resin can be used without particular limitation. Specifically, for example, acrylic resins such as styrene resins, alkyl acrylates, and alkyl methacrylates can be used. Resin, styrene-acrylic copolymer resin, polyester resin, silicone resin, olefin resin, amide resin, epoxy resin, etc., especially in order to improve transparency and color reproducibility of superimposed images Preferred examples include styrene resins, acrylic resins, styrene-acrylic copolymer resins, and polyester resins, which have high properties, low melting properties, and high sharp melt properties. These can be used alone or in combination of two or more.

  Further, when the toner particles constituting the toner of the present invention are produced by suspension polymerization, emulsion polymerization, emulsion polymerization aggregation, etc., as a polymerizable monomer for obtaining a toner binder resin, for example, Styrene monomers such as styrene, methylstyrene, methoxystyrene, butylstyrene, phenylstyrene, chlorostyrene; methyl acrylate, ethyl acrylate, butyl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid (Meth) acrylic acid ester monomers such as butyl and ethylhexyl methacrylate; carboxylic acid monomers such as acrylic acid, methacrylic acid, and fumaric acid can be used. These can be used alone or in combination of two or more.

  As such a toner binder resin, the glass transition point (Tg) is preferably 20 to 70 ° C., more preferably 30 to 60 ° C., and the softening point is preferably 80 to 110 ° C., more preferably 90 to 105. ° C.

[Colorant]
Examples of the colorant constituting the toner of the present invention include inorganic pigments, organic pigments, and dyes.

  A conventionally well-known thing can be used as an inorganic pigment. Specific inorganic pigments are exemplified below.

  Examples of the black pigment include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and magnetic powder such as magnetite and ferrite.

  These inorganic pigments can be used alone or in combination as required. The amount of the pigment added is preferably 2 to 20 parts by mass, more preferably 3 to 15 parts by mass with respect to 100 parts by mass of the toner binder resin.

  When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, it is preferable to add 20 to 60% by mass in the toner from the viewpoint of imparting predetermined magnetic properties.

  Conventionally known organic pigments and dyes can also be used. Specific organic pigments and dyes are exemplified below.

  Examples of pigments for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 4, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the orange or yellow pigment include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 155, C.I. I. And CI Pigment Yellow 156.

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

  As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 etc. can be used, and a mixture thereof can also be used.

  These organic pigments and dyes can be used alone or in combination as desired. The amount of the pigment added is preferably 2 to 20 parts by mass, more preferably 3 to 15 parts by mass with respect to 100 parts by mass of the toner binder resin.

  The colorant can also be used after surface modification. As the surface modifier, conventionally known ones can be used, and specifically, silane coupling agents, titanium coupling agents, aluminum coupling agents and the like can be preferably used.

[Offset inhibitor]
The toner particles constituting the toner of the present invention may contain an offset preventive agent that contributes to the suppression of the offset phenomenon. Here, the offset preventing agent is not particularly limited. For example, polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax, fatty acid ester wax, paraffin wax, carnauba wax, sazol wax, Examples thereof include rice wax, candelilla wax, jojoba oil wax, and beeswax wax.

  When the toner particles are produced by an emulsion polymerization aggregation method, a method of incorporating an offset inhibitor into the toner particles is to use a dispersion (wax emulsion) of the offset inhibitor particles in the aggregation and fusion process for forming the toner particles. Addition of toner binder resin fine particles, coloring fine particles, and offset preventive agent particles to agglomerate and fuse, and toner binder resin fine particles containing an offset preventive agent in agglomeration and fusing steps to form toner particles And colorant fine particles can be aggregated and fused, and these methods may be combined.

  The content ratio of the offset preventing agent in the toner particles is preferably 0.5 to 20 parts by mass, more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the toner binder resin.

[Charge control agent]
The toner particles constituting the toner of the present invention may contain a charge control agent. Here, the charge control agent is not particularly limited, and various substances that give a positive or negative charge by frictional charging can be exemplified. For example, a negatively chargeable charge control used for toner particles constituting a color toner. Examples of the agent include colorless, white, or light color charge control agents so as not to adversely affect the color tone and translucency of the color toner. Preferred examples of such a charge control agent include metal complexes of salicylic acid derivatives such as zinc and aluminum (salicylic acid metal complexes), calixarene compounds, organoboron compounds, and fluorine-containing quaternary ammonium salt compounds. . Specifically, examples of the salicylic acid metal complex include those disclosed in JP-A-53-127726 and JP-A-62-145255, and examples of calixarene compounds include, for example, JP-A-2-201378. What is disclosed in Japanese Patent Laid-Open No. 2002-221967, for example, as disclosed in JP-A-2-221967, and as a fluorine-containing quaternary ammonium salt compound, for example, disclosed in JP-A-3-1162. Can be mentioned.

  The content ratio of the charge control agent in the toner particles is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the toner binder resin.

  Examples of the method of incorporating an internal additive such as a charge control agent in the toner particles include the same method as the method of incorporating the offset preventing agent described above.

[Chain transfer agent]
When the toner particles constituting the toner of the present invention are produced by an emulsion polymerization aggregation method, a chain transfer agent generally used can be used for the purpose of adjusting the molecular weight of the toner binder resin. The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as 2-chloroethanol, octyl mercaptan, dodecyl mercaptan, and t-dodecyl mercaptan, and styrene dimers.

(Polymerization initiator)
When the toner particles constituting the toner of the present invention are produced by suspension polymerization, emulsion polymerization or emulsion polymerization aggregation, the polymerization initiator for obtaining the toner binder resin may be a water-soluble polymerization initiator. Any appropriate one can be used. Specific examples of the polymerization initiator include persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2 -Amidinopropane) salts), peroxide compounds and the like.

[Surfactant]
As the surfactant used when the toner particles constituting the toner of the present invention are produced by suspension polymerization, emulsion polymerization or emulsion polymerization aggregation method, various conventionally known ionic surfactants and nonionic surfactants are used. An agent or the like can be used.

[Flocculant]
Examples of the aggregating agent used when the toner particles constituting the toner of the present invention are produced by an emulsion polymerization aggregating method include alkali metal salts and alkaline earth metal salts. Examples of the alkali metal constituting the flocculant include lithium, potassium, and sodium, and examples of the alkaline earth metal constituting the flocculant include magnesium, calcium, strontium, and barium. Of these, potassium, sodium, magnesium, calcium, and barium are preferable. Examples of the counter ion (anion constituting the salt) of the alkali metal or alkaline earth metal include chloride ion, bromide ion, iodide ion, carbonate ion and sulfate ion.

<Toner particle size>
The particle diameter of the toner of the present invention is preferably 3 to 10 μm, and more preferably 4 to 7 μm, for example, on a volume basis median diameter. When the toner production method is, for example, an emulsion polymerization aggregation method, the median diameter can be controlled by the concentration of the aggregating agent used, the amount of organic solvent added, the fusing time, and the polymer composition.

  When the volume-based median diameter is in the above range, the transfer efficiency is increased, the image quality of halftone is improved, and the image quality of fine lines and dots is improved.

  The volume-based median diameter of the toner is measured and calculated using a measuring apparatus in which a computer system for data processing (manufactured by Beckman Coulter) is connected to “Multisizer 3” (manufactured by Beckman Coulter). Specifically, 0.02 g of toner is added to 20 ml of a surfactant solution (for example, a surfactant solution in which a neutral detergent containing a surfactant component is diluted 10 times with pure water for the purpose of dispersing the toner). Then, ultrasonic dispersion was performed for 1 minute to prepare a toner dispersion, and this toner dispersion was placed in a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand. Pipette until the indicated concentration is between 5% and 10%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the measurement particle count is 25000, the aperture diameter is 50 μm, the frequency value is calculated by dividing the measurement range of 1 to 30 μm into 256, and the volume integrated fraction is 50 % Particle diameter was defined as the volume-based median diameter.

(External additive)
The above toner particles can constitute the toner of the present invention as they are, but in order to improve fluidity, chargeability, cleaning properties, etc., a fluidizing agent that is a so-called post-treatment agent is added to the toner particles. An external additive such as a cleaning aid may be added to constitute the toner of the present invention.

  As the post-treatment agent, for example, inorganic oxide fine particles composed of silica fine particles, alumina fine particles, titanium oxide fine particles, etc., inorganic stearate compound fine particles such as aluminum stearate fine particles, zinc stearate fine particles, or calcium titanate, titanium Inorganic titanic acid compound fine particles such as zinc acid are listed. These can be used individually by 1 type or in combination of 2 or more types.

  These inorganic fine particles are preferably subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil or the like in order to improve heat-resistant storage stability and environmental stability.

  The total addition amount of these various external additives is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner particles. In addition, various external additives may be used in combination.

<Toner production method>
Examples of the method for producing the toner of the present invention include a kneading / pulverizing method, a suspension polymerization method, an emulsion polymerization method, an emulsion polymerization aggregation method, an encapsulation method, and other known methods. In consideration of the necessity of obtaining a toner having a reduced particle size in order to achieve high image quality, an emulsion polymerization aggregation method is used from the viewpoint of manufacturing cost and manufacturing stability. Is preferred.

  In the emulsion polymerization aggregation method, a dispersion of fine particles (hereinafter referred to as “toner binder resin fine particles”) made of a toner binder resin produced by the emulsion polymerization method is used as a component of toner particle constituents such as other coloring fine particles. Mix with the dispersion, and slowly aggregate while balancing the repulsive force on the surface of the fine particles by adjusting the pH and the cohesive force by adding an aggregating agent made of an electrolyte, and perform association while controlling the average particle size and particle size distribution At the same time, it is a method for producing toner particles by controlling the shape by fusing fine particles by heating and stirring.

  As for the method for producing the polymerized toner, in addition to those described in JP-A No. 2000-214629, a known production method can be applied for producing the toner of the present invention.

(Developer)
The toner of the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer. When the toner of the present invention is used as a two-component developer, the carrier is made of a conventionally known material such as a metal such as iron, ferrite, or magnetite, or an alloy of such a metal with a metal such as aluminum or lead. Magnetic particles can be used, and ferrite particles are particularly preferable. Further, as the carrier, a coat carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, a binder type carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used.

  The coating resin constituting the coat carrier is not particularly limited, and examples thereof include olefin resins, styrene resins, styrene-acrylic resins, acrylic resins, silicone resins, ester resins, and fluorine resins. Moreover, it does not specifically limit as resin which comprises a resin dispersion type carrier, A well-known thing can be used, For example, a styrene-acrylic-type resin, a polyester resin, a fluororesin, a phenol resin etc. can be used.

  The volume-based median diameter of the carrier is preferably 20 to 100 μm, and more preferably 20 to 60 μm. The volume-based median diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

[Image forming apparatus]
FIG. 3 is a cross-sectional configuration diagram of a color image forming apparatus showing an embodiment of the present invention.

  In the image forming apparatus of the present invention, it is desirable to use a semiconductor laser or light emitting diode having an oscillation wavelength of 350 to 850 nm as an image exposure light source when an electrostatic latent image is formed on a photoreceptor. By using these image exposure light sources, the exposure dot diameter in the writing principal direction is narrowed down to 10 to 100 μm, and digital exposure is performed on the organic photoreceptor, so that 600 dpi (dpi: number of dots per 2.54 cm) to 2400 dpi. Or higher-resolution electrophotographic images can be obtained.

The exposure dot diameter refers to the length of the exposure beam along the main scanning direction (Ld: measured at the maximum length) in a region where the intensity of the exposure beam is 1 / e ² or more of the peak intensity.

The light beams used have a scanning optical system and LED solid scanner such as a semiconductor laser, there is a Gaussian distribution and Lorentz distribution, etc. also the light intensity distribution is in each 1 / e ² or more regions of peak intensity The exposure dot diameter according to the present invention is used.

  This color image forming apparatus is called a tandem type color image forming apparatus, and includes four sets of image forming units (image forming units) 10Y, 10M, 10C, and 10Bk, an endless belt-shaped intermediate transfer body unit 7, and a feeding unit. It comprises a paper conveying means 21 and a fixing means 24. A document image reading device SC is disposed on the upper part of the main body A of the image forming apparatus.

  The image forming unit 10Y that forms a yellow image includes a charging unit (charging step) 2Y, an exposure unit (exposure step) 3Y, and a developing unit disposed around a drum-shaped photoconductor 1Y as a first image carrier. A unit (developing step) 4Y, a primary transfer roller 5Y as a primary transfer unit (primary transfer step), and a cleaning unit 6Y. An image forming unit 10M that forms a magenta image includes a drum-shaped photosensitive member 1M as a first image carrier, a charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roller 5M as a primary transfer unit, It has a cleaning means 6M. An image forming unit 10C for forming a cyan image includes a drum-shaped photoreceptor 1C as a first image carrier, a charging unit 2C, an exposure unit 3C, a developing unit 4C, and a primary transfer roller 5C as a primary transfer unit. It has cleaning means 6C. The image forming unit 10Bk that forms a black image includes a drum-shaped photoreceptor 1Bk as a first image carrier, a charging unit 2Bk, an exposure unit 3Bk, a developing unit 4Bk, a primary transfer roller 5Bk as a primary transfer unit, and a cleaning unit. 6Bk.

  The four sets of image forming units 10Y, 10M, 10C, and 10Bk include charging means 2Y, 2M, 2C, and 2Bk that rotate around the photosensitive drums 1Y, 1M, 1C, and 1Bk, and image exposure means 3Y, 3M, 3C and 3Bk, rotating developing means 4Y, 4M, 4C and 4Bk, and cleaning means 6Y, 6M, 6C and 6Bk for cleaning the photosensitive drums 1Y, 1M, 1C and 1Bk.

  The image forming units 10Y, 10M, 10C, and 10Bk have the same configuration except that the colors of toner images formed on the photoreceptors 1Y, 1M, 1C, and 1Bk are different, and the image forming unit 10Y is taken as an example in detail. explain.

  The image forming unit 10Y has a charging unit 2Y (hereinafter simply referred to as a charging unit 2Y or a charger 2Y), an exposure unit 3Y, a developing unit 4Y, and a cleaning unit 6Y (around a photosensitive drum 1Y as an image forming body). Hereinafter, the cleaning unit 6Y or the cleaning blade 6Y) is simply disposed, and a yellow (Y) toner image is formed on the photosensitive drum 1Y. In the present embodiment, in the image forming unit 10Y, at least the photosensitive drum 1Y, the charging unit 2Y, the developing unit 4Y, and the cleaning unit 6Y are provided so as to be integrated.

  The charging unit 2Y is a unit that applies a uniform potential to the photosensitive drum 1Y. In the present embodiment, a corona discharge type charger 2Y is used for the photosensitive drum 1Y.

  The image exposure means 3Y performs exposure based on the image signal (yellow) on the photosensitive drum 1Y given a uniform potential by the charger 2Y, and forms an electrostatic latent image corresponding to the yellow image. As the exposure unit 3Y, a unit composed of LEDs and light-emitting elements in which light emitting elements are arranged in an array in the axial direction of the photosensitive drum 1Y, a laser optical system, or the like is used.

  The image forming apparatus of the present invention is configured by integrally combining the above-described photosensitive member and components such as a developing device and a cleaning device as a process cartridge (image forming unit), and this image forming unit is connected to the apparatus main body. It may be configured to be detachable. In addition, at least one of a charging device, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally supported together with a photosensitive member to form a process cartridge (image forming unit), which is detachable from the apparatus main body. A single image forming unit may be detachable using guide means such as a rail of the apparatus main body.

  The endless belt-like intermediate transfer body unit 7 includes an endless belt-like intermediate transfer body 70 as a second image carrier having a semiconductive endless belt shape that is wound around a plurality of rollers and is rotatably supported.

  Each color image formed by the image forming units 10Y, 10M, 10C, and 10Bk is sequentially transferred onto a rotating endless belt-shaped intermediate transfer body 70 by primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means. Thus, a synthesized color image is formed. An image support P as an image support (support for supporting a fixed final image: for example, plain paper, transparent sheet, etc.) housed in the paper feed cassette 20 is fed by a paper feed means 21 and is supplied to a plurality of image supports P. The intermediate rollers 22A, 22B, 22C, 22D, and the registration roller 23 are conveyed to a secondary transfer roller 5b as a secondary transfer unit, and are secondarily transferred onto the image support P to collectively transfer color images. . The image support P to which the color image has been transferred is subjected to fixing processing by the fixing means 24, is sandwiched between the paper discharge rollers 25, and is placed on a paper discharge tray 26 outside the apparatus. Here, a toner image transfer support formed on a photosensitive member such as an intermediate transfer member or an image support is generally referred to as a transfer medium.

  On the other hand, the endless belt-shaped intermediate transfer body 70 obtained by transferring the color image to the image support P by the secondary transfer roller 5b as the secondary transfer means and then separating the curvature of the image support P is subjected to residual toner by the cleaning means 6b. Removed.

  During the image forming process, the primary transfer roller 5Bk is always in contact with the photoreceptor 1Bk. The other primary transfer rollers 5Y, 5M, and 5C are in contact with the corresponding photoreceptors 1Y, 1M, and 1C, respectively, only during color image formation.

  The secondary transfer roller 5b contacts the endless belt-shaped intermediate transfer body 70 only when the image support P passes through the secondary transfer roller 5b and the secondary transfer is performed.

  Further, the housing 8 can be pulled out from the apparatus main body A through the support rails 82L and 82R.

  The housing 8 includes image forming units 10Y, 10M, 10C, and 10Bk and an endless belt-shaped intermediate transfer body unit 7.

  The image forming units 10Y, 10M, 10C, and 10Bk are arranged in tandem in the vertical direction. An endless belt-shaped intermediate transfer body unit 7 is disposed on the left side of the photoreceptors 1Y, 1M, 1C, and 1Bk in the drawing. The endless belt-shaped intermediate transfer body unit 7 includes an endless belt-shaped intermediate transfer body 70 that can be rotated by winding rollers 71, 72, 73, 74, primary transfer rollers 5Y, 5M, 5C, 5Bk, and cleaning means 6b. Consists of.

  The image forming apparatus of the present invention is generally applicable to electrophotographic apparatuses such as electrophotographic copying machines, laser printers, LED printers, and liquid crystal shutter printers. The present invention can be widely applied to such devices.

  In the following, the configuration and effects of the present invention are shown in the embodiments, but of course, the embodiments of the present invention are not limited to these. In addition, “part” in the sentence represents “part by mass”.

Synthesis example 1
(Synthesis of amorphous titanyl phthalocyanine)
1,3-diiminoisoindoline; 29.2 g was dispersed in 200 ml of orthodichlorobenzene, titanium tetra-n-butoxide; 20.4 g was added, and the mixture was heated at 150 to 160 ° C. for 5 hours in a nitrogen atmosphere. After allowing to cool, the precipitated crystals were filtered, washed with chloroform, washed with 2% aqueous hydrochloric acid, washed with water, washed with methanol, and dried to obtain 26.2 g (yield 91%) of crude titanyl phthalocyanine. Next, the crude titanyl phthalocyanine was dissolved by stirring in 250 ml of concentrated sulfuric acid at 5 ° C. or lower for 1 hour, and this was poured into 5 L of water at 20 ° C. The precipitated crystals were filtered and sufficiently washed with water to obtain 225 g of a wet paste product. The wet paste product was then frozen in a freezer, thawed again, filtered and dried to obtain 24.8 g of amorphous titanyl phthalocyanine (yield 86%).

(Synthesis of pigment (CG-1) of the present invention)
The above-mentioned amorphous titanyl phthalocyanine (10.0 g) and (2R, 3R) -2,3-butanediol (0.94 g, 0.6 equivalent ratio) (equivalent ratio is equivalent ratio to titanyl phthalocyanine, hereinafter the same) are combined with orthodichlorobenzene ( ODB) was mixed in 200 ml, and the mixture was heated and stirred at 60 to 70 ° C. for 6.0 hours. After standing overnight, methanol was added to the reaction solution, and the resulting crystals were filtered. The crystals after filtration were washed with methanol (a pigment containing (2R, 3R) -2,3-butanediol adduct titanyl phthalocyanine). CG-1: 10.3 g was obtained. The X-ray diffraction spectrum of CG-1 is shown in FIG. There are distinct peaks at 8.3 °, 24.7 °, 25.1 ° and 26.5 °. There is a peak in the 576 and 648 in the mass spectra, O-Ti-O both absorption appears Ti = O near 970 cm ^-1, around 630 cm ^-1 in the IR spectrum. In addition, since thermal analysis (TG) has a mass loss of about 7% at 390 to 410 ° C., a 1: 1 adduct of titanyl phthalocyanine and (2R, 3R) -2,3-butanediol (shown in Chemical Formula 1 above) A dehydrated condensation structure) and a non-adduct (not added) titanyl phthalocyanine mixed crystal.

It was 31.2 m < ² > / g when the BET specific surface area of the obtained CG-1 was measured with the flow type specific surface area automatic measuring device (Micrometrics flow soap type: Shimadzu Corporation).

Synthesis Example 2 (Synthesis of pigment (CG-2) of the present invention)
(2S, 3S) -2,3 in the same manner as in Synthesis Example 1 except that (2S, 3S) -2,3-butanediol was used instead of (2R, 3R) -2,3-butanediol. -Pigment CG-2 containing butanediol-titanyl phthalocyanine adduct was obtained: 10.5 g. In the X-ray diffraction spectrum of CG-2, clear peaks are observed at 8.3 °, 24.7 °, 25.1 °, and 26.5 °, and in the IR spectrum, Ti = O around 970 cm ⁻¹ , 630 cm. Both absorptions of O—Ti—O appear in the vicinity of ⁻¹ . The BET specific surface area of CG-2 was 30.5 m ² / g.

Synthesis Example 3 (Synthesis of pigment (CG-3) of the present invention)
In the reaction of amorphous titanyl phthalocyanine of Synthesis Example 1 and (2R, 3R) -2,3-butanediol, the reaction temperature was changed to 90 to 100 ° C. instead of 60 to 70 ° C. (2R , 3R) -2,3-butanediol adduct, pigment CG-3 containing titanyl phthalocyanine: 10.6 g was obtained. In the X-ray diffraction spectrum of CG-3, clear peaks are observed at 8.3 °, 24.7 °, 25.1 °, and 26.5 °, and in the IR spectrum, Ti = O around 970 cm ⁻¹ , 630 cm. Both absorptions of O—Ti—O appear in the vicinity of ⁻¹ . The BET specific surface area of CG-3 was 20.5 m ² / g.

Synthesis Example 4 (Synthesis of pigment (CG-4) of the present invention)
In the reaction of the amorphous titanyl phthalocyanine of Synthesis Example 1 and (2R, 3R) -2,3-butanediol, the reaction temperature was changed to 130 to 140 ° C. instead of 60 to 70 ° C. (2R , 3R) -2,3-butanediol adduct titanyl phthalocyanine pigment CG-4: 10.6 g was obtained. In the X-ray diffraction spectrum of CG-4, clear peaks are observed at 8.3 °, 24.7 °, 25.1 °, and 26.5 °, and in the IR spectrum, Ti = O around 970 cm ⁻¹ , 630 cm. Both absorptions of O—Ti—O appear in the vicinity of ⁻¹ . The BET specific surface area of CG-4 was 13.5 m ² / g.

Synthesis Example 5 (Synthesis of pigment (CG-5) of the present invention)
In the reaction of amorphous titanyl phthalocyanine of Synthesis Example 1 with (2R, 3R) -2,3-butanediol, (2R, 3R) -2,3-butanediol is converted into a racemic 2,3- Pigment CG-5: 11.5 g containing (racemic) -2,3-butanediol adduct titanyl phthalocyanine was obtained in the same manner except that butanediol was used. Appear both absorption of O-Ti-O Ti = O near 970 cm ^-1, around 630 cm ^-1 in the IR spectrum of CG-5, BET specific surface area was 28.6m ² / g.

Synthesis Example 6 (Synthesis of Pigment (CG-6) of Comparative Example)
In the reaction of amorphous titanyl phthalocyanine of Synthesis Example 1 and (2R, 3R) -2,3-butanediol, 2.35 g (1.5 equivalent ratio) of (2R, 3R) -2,3-butanediol was used, Except that the reaction temperature was 130 to 140 ° C., 12.0 g of pigment CG-6 containing (2R, 3R) -2,3-butanediol adduct titanyl phthalocyanine was obtained. In the X-ray diffraction spectrum of CG-6 (FIG. 2 (1)), clear peaks are observed at 9.5 °, 16.4 °, 19.1 °, 24.7 °, 26.5 °, and IR disappeared Ti = O absorption near 970 cm ^-1 in the spectrum, the absorption of O-Ti-O appears in the vicinity of 630 cm ^-1. The BET specific surface area of CG-6 was 10.2 m ² / g.

Production of Photoreceptor 1 An intermediate layer coating solution having the following composition was dip coated on a cylindrical aluminum substrate to form an intermediate layer having a thickness of 4.0 μm.

<Intermediate layer coating solution>
The following composition was dispersed using a circulating wet disperser.

Polyamide resin “CM8000” (manufactured by Toray Industries, Inc.) 10 parts Titanium oxide (number average primary particle size 35 nm, primary surface treatment; silica / alumina treatment,
Secondary surface treatment; methyl hydrogen polysiloxane treatment) 30 parts Methanol 100 parts The following charge generation layer coating solution was dip coated thereon to form a charge generation layer having a thickness of 0.3 μm.

<Charge generation layer coating solution>
The following composition was mixed and dispersed with a circulating ultrasonic homogenizer RUS-600TCVP (manufactured by Nippon Seiki Seisakusho, 19.5 kHz, 600 W) (abbreviation: circulating homogenizer) at a circulating flow rate of 40 L / H for 0.5 hour.

Charge generation material: CG-1 of Synthesis Example 1 24 parts Polyvinyl butyral resin “ESREC BL-1” (manufactured by Sekisui Chemical Co., Ltd.) 12 parts 3-methyl-2-butanone / cyclohexanone = 4/1 (V / V) 400 parts A charge transport layer coating solution in which the following composition was mixed was applied thereon and dried by heating at 110 ° C. for 60 minutes to form a charge transport layer having a thickness of 20 μm.

<Charge transport layer coating solution>
Charge transport material: (Compound A below) 200 parts Polycarbonate “Iupilon Z300” (manufactured by Mitsubishi Gas Chemical Company) 300 parts 2,6-di-tert-butyl-4-phenylphenol 5 parts Toluene / tetrahydrofuran = 1/9 (v / V) 2000 copies

  The following protective layer was formed on the charge transport layer.

<Protective layer>
Surface-treated titanium oxide particles (titanium oxide particles having a number average primary particle size of 6 nm and surface-treated with the same mass of S-15)
100 parts Polymerizable compound (Exemplary compound Mc-31) 100 parts Isopropyl alcohol 500 parts After dispersing the above components for 10 hours using a sand mill,
30 parts of a polymerization initiator 1-6 was added, mixed and stirred under light shielding to dissolve, and a protective layer coating solution was prepared (light shielding during storage). A protective layer was applied using a circular slide hopper applicator on the photoreceptor on which the coating solution had been prepared up to the charge transport layer. After coating, after drying for 20 minutes at room temperature (solvent drying process), using a metal halide lamp (500 W), irradiation is performed for 1 minute while rotating the photoconductor at a position of 100 mm (ultraviolet curing process), and crosslinking curing with a film thickness of 3 μm. Protective layer 1 was formed to obtain photoreceptor 1.

  The charge generation layer is dried on an aluminum support, coated and dried at a film thickness of 0.3 μm, a sample for reflection spectrum measurement is prepared, and an optical film thickness measurement device Solid Lambda Thickness (Spectra Corp.) is used. The reflection spectrum was measured. The measured data is shown in FIG. The reflection spectrum was measured as a relative reflectance when the reflectance of the aluminum support was 100%. In order to remove irregularities due to interference fringes in the obtained reflection spectrum, the measurement data is approximated by a second order polynomial in the range of 685 to 715 nm and 765 to 795 nm, and the reflectance (R700) and reflectance (R780) are calculated. The ratio (R700 / R780) was calculated.

  Moreover, the data which measured the X-ray-diffraction spectrum using the sample which apply | coated and dried the said charge generation layer on the transparent glass plate are shown in FIG. 2 (2).

Production of Photoreceptor 2 Photoreceptor 2 was produced in the same manner as in Photoreceptor 1 except that the dispersion time of the charge generation material coating solution was changed to 2.5 hours.

Production of Photoreceptor 3 Photoreceptor 3 was produced in the same manner as in Photoreceptor 1 except that CG-2 obtained in Synthesis Example 2 was used as the charge generation material.

Production of Photoreceptor 4 Photoreceptor 4 was produced in the same manner as in Photoreceptor 1 except that the charge generation layer coating solution was changed to ultrasonic dispersion under the following conditions.

<Charge generation layer coating solution>
The following compositions were mixed and subjected to ultrasonic dispersion for 1.5 hours in an ultrasonic cleaning tank (abbreviation: US bath) of 28 kHz and 500 W.

Charge generation material: CG-1 of Synthesis Example 1 24 parts Polyvinyl butyral resin “ESREC BL-1” (manufactured by Sekisui Chemical Co., Ltd.) 12 parts 3-methyl-2-butanone / cyclohexanone = 4/1 (V / V) 400 parts Production of Photoreceptor 5 Photoreceptor 5 was produced in the same manner as in Photoreceptor 4, except that the dispersion time of the charge generation material coating solution was changed to 4 hours.

Production of Photoreceptor 6 Photoreceptor 6 was produced in the same manner as in Photoreceptor 1 except that the charge generation layer coating solution was changed to sand mill (abbreviation: SM) dispersion under the following conditions.

<Charge generation layer coating solution>
The following compositions were mixed, and glass beads having an outer diameter of 1 mm were used as a dispersion medium, and dispersion was performed for 1 hour in a sand mill under conditions of a bead filling rate of 80% by volume and a rotation speed of 800 rpm.

Charge generation material: CG-1 of Synthesis Example 1 24 parts Polyvinyl butyral resin “ESREC BL-1” (manufactured by Sekisui Chemical Co., Ltd.) 12 parts 3-methyl-2-butanone / cyclohexanone = 4/1 (V / V) 400 parts Production of Photoreceptor 7 Photoreceptor 7 was produced in the same manner as in Photoreceptor 6, except that CG-3 obtained in Synthesis Example 3 was used as the charge generation material.

Production of Photoreceptor 8 Photoreceptor 8 was produced in the same manner as in Photoreceptor 6, except that CG-4 obtained in Synthesis Example 4 was used as the charge generation material.

Production of Photoreceptor 9 Photoreceptor 9 was produced in the same manner as in Photoreceptor 1 except that CG-5 obtained in Synthesis Example 5 was used as the charge generation material.

Production of Photoreceptor 10 (Comparative Example) Photoreceptor 10 was produced in the same manner as in Photoreceptor 6, except that the dispersion time of the charge generation layer coating solution was changed to 10 hours.

Production of Photoreceptor 11 (Comparative Example) Photoreceptor 11 was produced in the same manner as Photoreceptor 1 except that CG-4 obtained in Synthesis Example 4 was used as the charge generation material.

Production of Photoreceptor 12 (Comparative Example) Photoreceptor 12 was produced in the same manner as Photoreceptor 6, except that CG-6 obtained in Synthesis Example 6 was used as the charge generation material.

  For the photoconductors 2 to 12, the reflection spectrum was measured in the same manner as the photoconductor 1. The results are shown in Table 1. The values of the reflection spectrum in Table 1 are values measured in the charge generation layer, but almost the same values are obtained even if the charge transport layer is measured after coating.

Production of photoconductors 13 to 20 Photoconductors 13 to 20 were produced in the same manner except that the materials used for the protective layer 1 of the photoconductor 1 and the curing conditions were changed as shown in the list of Table 2.
Curing conditions (light): A metal halide lamp (500 W) was irradiated for 1 minute while rotating the photoreceptor at a position of 100 mm to obtain a protective layer having a thickness of 3 μm.
Curing conditions (heat): Heated at 140 ° C. for 30 minutes to obtain a protective layer having a thickness of 3 μm.

Photoconductor 21 (polycarbonate was used as a binder for the protective layer)
Photoreceptor 21 was produced in the same manner as Photoreceptor 1 except that the protective layer was formed as follows in the production of Photoreceptor 1.

<Protective layer>
Titanium oxide particles surface-treated with a hole transporting compound (titanium oxide particles having a number average primary particle size of 6 nm and surface-treated with the same mass of S-15)
100 parts Binder (Polycarbonate having the following structure: weight average molecular weight 20,000) 100 parts Isopropyl alcohol 500 parts The above components were dispersed for 10 hours using a sand mill to prepare a protective layer coating solution. A protective layer was applied using a circular slide hopper applicator on the photoreceptor on which the coating solution had been prepared up to the charge transport layer. After coating, the film was dried at 100 ° C. for 50 minutes to obtain a protective layer having a thickness of 3 μm.

Production of Photoreceptor 22 (Comparative Example) Photoreceptor 22 was produced in the same manner as in Photoreceptor 1 except that CG-1 of the charge generation layer was replaced with Y-type titanyl phthalocyanine (Y-Ti). Y-type titanyl phthalocyanine is a titanyl phthalocyanine pigment having a maximum peak at 27.2 ° in an X-ray diffraction spectrum (FIG. 4), and is a pigment synthesized by the following synthesis example.

Synthesis example of Y-type titanyl phthalocyanine A titanyl phthalocyanine crude product was synthesized from diiminoisoindoline and titanium tetrabutoxide, dissolved in sulfuric acid, poured into water, filtered, washed thoroughly with water, and containing amorphous titanyl phthalocyanine pigment in water. A paste was obtained. This pigment hydrous paste (about 10 g in terms of solid content) was dispersed in a mixture of 100 ml of orthodichlorobenzene and 100 ml of water (the water layer was separated), heated at 70 ° C. for 6 hours, and then poured into methanol to form crystals. Was filtered and dried to obtain Y-type titanyl phthalocyanine.

  Table 1 below summarizes the structures of the charge generation layer and the protective layer of the photoreceptors 1 to 22.

In Table 1,
Mixed crystal (R, R form) is a pigment containing titanyl phthalocyanine and (2R, 3R) -2,3-butanediol titanyl phthalocyanine adduct. Mixed crystal (S, S form) is titanyl phthalocyanine and (2S , 3S) -2,3-Butanediol titanyl phthalocyanine adduct A mixed crystal (racemic) is a pigment containing titanyl phthalocyanine and (racemic) -2,3-butanediol titanyl phthalocyanine adduct The simple substance means a pigment containing only the (2R, 3R) -2,3-butanediol titanyl phthalocyanine adduct Y-Ti represents a Y-type titanyl phthalocyanine pigment.

  In Table 1, Protective Layer 1 to Protective Layer 10 are Protective Layer 1 to Protective Layer 10 shown in Table 2 below.

Preparation of Toner and Developer A toner for adding an antioxidant external additive and a developer using the toner were prepared.

(Latex preparation)
Add a solution prepared by dissolving 7.08 g of an anionic active agent (sodium dodecyl sulfate: SDS) in ion-exchanged water (2760 g) to a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet. To do. The internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. On the other hand, 72.0 g of behenyl behenate was added to a monomer composed of 115.1 g of styrene, 42.0 g of n-butyl acrylate, and 10.9 g of methacrylic acid, and heated to 80 ° C. and dissolved to prepare a monomer solution. did.

  Here, the above heated solution was mixed and dispersed by a mechanical disperser having a circulation path to produce emulsified particles having a uniform dispersed particle size. Subsequently, a solution in which 0.84 g of a polymerization initiator (potassium persulfate: KPS) was dissolved in 200 g of ion-exchanged water was added, and the mixture was heated and stirred at 80 ° C. for 3 hours to prepare latex particles.

  Subsequently, a solution obtained by further dissolving 7.73 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water was added, and after 15 minutes, 383.6 g of styrene, 140.0 g of n-butyl acrylate, 36. A mixed solution of 4 g and 14.0 g of n-octyl-3-mercaptopropionic acid ester was dropped over 120 minutes. After completion of dropping, the mixture was heated and stirred for 60 minutes and then cooled to 30 ° C. to obtain latex particles. This latex particle is designated as Latex 1.

(Toner preparation example)
Preparation of Toner Bk (Black) 9.2 g of sodium n-dodecyl sulfate is dissolved in 160 ml of ion-exchanged water with stirring. Under stirring, 20 g of Legal 330R (carbon black manufactured by Cabot Corporation) was gradually added, and then dispersed using CLEARMIX. As a result of measuring the particle diameter of the dispersion using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., the weight average diameter was 112 nm. This dispersion is referred to as “colorant dispersion 1”.

  1250 g of the above-mentioned “Latex 1”, 2000 ml of ion-exchanged water and “Colorant Dispersion 1” are placed in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube and a stirring device and stirred. After adjusting to 30 ° C., a 5 mol / liter aqueous sodium hydroxide solution was added to this solution to adjust the pH to 10.0.

  Subsequently, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added at 30 ° C. over 5 minutes with stirring. Thereafter, after standing for 2 minutes, temperature increase is started and the temperature is increased to 90 ° C. in 60 minutes (temperature increase rate: 1 ° C./min). In that state, the particle size was measured with Multisizer 3, and when the volume-based median diameter (Dv50) reached 6.6 μm, an aqueous solution in which 115 g of sodium chloride was dissolved in 700 ml of ion-exchanged water was added to stop particle growth. The mixture is further heated and stirred at a liquid temperature of 85 ° C. for 4 hours to be fused.

  Then, it cooled to 30 degreeC on the conditions of 6 degreeC / min, hydrochloric acid was added, pH was adjusted to 4.0, and stirring was stopped. The produced colored particles were filtered / washed under the following conditions, and then dried with hot air at 40 ° C. to obtain colored particles. This is referred to as “toner Bk”. The volume-based median diameter (Dv50) of the toner Bk was 6.5 μm.

Production of Toner Y, Toner M, and Toner C In the production of Toner Bk, C.I. I. Toner Y was obtained in the same manner except that CI Pigment Yellow 74 was used. The volume-based median diameter (Dv50) of Toner Y was 6.6 μm.

  In the production of toner Bk, C.I. I. Toner M was obtained in the same manner except that CI Pigment Red 122 was used. The volume-based median diameter (Dv50) of Toner M was 6.6 μm.

  In the production of toner Bk, C.I. I. Toner C was obtained in the same manner except that CI Pigment Blue 15: 3 was used. The volume-based median diameter (Dv50) of Toner C was 6.5 μm.

  Next, toner Bk, toner Y, toner M, and toner C are subjected to the following external additive treatment, and toner Bk-1 to toner Bk-11, toner Y-1, toner Y-2, toner M-1, and toner M-2, Toner C-1 and Toner C-2 were produced.

(External additive treatment)
Preparation of Toner Bk-1 To 100 parts of toner particles constituting the toner Bk, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, hydrophobization degree = 63) was added at a ratio of 1.2 parts, and antioxidant (AO-1) was further added to 0.1 parts, and “Henschel Mixer” (Mitsui Mining Co., Ltd.) was added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare toner Bk-1.

Preparation of Toner Bk-2 Toner Bk-2 was prepared in the same manner as toner Bk-1, except that the antioxidant was changed to AO-3.

Preparation of toner Bk-3 Toner Bk-1 was prepared by performing the same external additive treatment as toner Bk-1 except that the amount of antioxidant AO-1 added was changed to 0.05% by mass. Bk-3 was adjusted.

Preparation of toner Bk-4 In preparation of toner Bk-1, the same external additive treatment as toner Bk-1 was performed except that the antioxidant was changed to AO-6 and the addition amount was changed to 0.2 parts. Toner Bk-4 was adjusted.

Preparation of toner Bk-5 In preparation of toner Bk-1, the same external additive treatment as toner Bk-1 was performed except that the antioxidant was changed to AO-6 and the addition amount was changed to 2.0 parts. Toner Bk-5 was adjusted.

Preparation of Toner Bk-6 In preparation of Toner Bk-1, the same external additive treatment as that of Toner Bk-1 was performed except that the antioxidant was changed to AO-8 and the addition amount was changed to 0.4 part. Toner Bk-6 was adjusted.

Preparation of Toner Bk-7 Toner Bk-7 was prepared by performing the same external additive treatment as toner Bk-1 except that the antioxidant was changed to AO-15 in the preparation of toner Bk-1.

Preparation of Toner Bk-8 In preparation of Toner Bk-1, the same external additive treatment as that of Toner Bk-1 was performed except that the antioxidant was changed to AO-18 and the addition amount was 0.5 parts. Toner Bk-5 was prepared.

Preparation of toner Bk-9 In preparation of toner Bk-1, the same external additive treatment as that of toner Bk-1 was performed except that the antioxidant was changed to ascorbic acid and the addition amount was changed to 0.4 parts. Toner Bk-9 was prepared.

Preparation of toner Bk-10 In preparation of toner Bk-1, the same external additive treatment as that of toner Bk-1 was performed except that the antioxidant was changed to tocopherol and the addition amount was changed to 0.4 part. Bk-10 was adjusted.

Preparation of toner Bk-11 (comparative toner)
In the production of the toner Bk-1, the same external additive treatment was carried out except that the antioxidant was removed to prepare the toner Bk-11.

Preparation of Toner Y-1 To 100 parts of toner particles constituting the toner Y, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, hydrophobization degree = 63) was added at a ratio of 1.2 parts, and antioxidant (AO-1) was further added to 0.1 parts, and “Henschel Mixer” (Mitsui Mining Co., Ltd.) was added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare toner Y-1.

Preparation of Toner M-1 To 100 parts of toner particles constituting the toner M, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter) = 20 nm, hydrophobization degree = 63) is added at a ratio of 1.2 parts, and an antioxidant (AO-1) is added to 0.1 parts, and "Henschel mixer" (Mitsui Mine) is added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare toner M-1.

Preparation of Toner C-1 To 100 parts of toner particles constituting the toner C, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, hydrophobization degree = 63) was added at a ratio of 1.2 parts, and antioxidant (AO-1) was further added to 0.1 parts, and “Henschel Mixer” (Mitsui Mining Co., Ltd.) was added. After that, coarse particles were removed using a sieve having an opening of 45 μm to prepare toner C-1.

Preparation of Toner Y-2 Toner Y-2 was prepared in the same manner as in preparation of toner Y-1, except that the antioxidant (AO-1) was removed.

Preparation of Toner M-2 Toner M-2 was prepared in the same manner as in Preparation of Toner M-1, except that the antioxidant (AO-1) was removed.

Preparation of Toner C-2 Toner C-2 was prepared in the same manner as in the preparation of toner C-1, except that the antioxidant (AO-1) was removed.

  Regarding the volume-based median diameter (Dv50) of the toner, it was confirmed that there was no substantial difference in the value between the toner before and after the external additive treatment.

  Table 3 summarizes the external additive treatment of each toner.

[Manufacture of developer]
7 parts each of the toner Bk-1 to toner Bk-11, toner Y-1, toner M-1, toner C-1, toner Y-2, toner M-2 and toner C-2 and styrene-methacrylate By mixing 93 parts of a 35 μm ferrite carrier with a volume-based median diameter (Dv50) coated with a polymer, developer Bk-1 for evaluation, developer Bk-11, developer Y-1, developer M -1, Developer C-1, Developer Y-2, Developer M-2, and Developer C-2 were produced.

[Evaluation]
The photoreceptors and developers obtained as described above are combined as shown in Table 4 (combination Nos. 1 to 28). Basically, a commercially available full-color multifunction apparatus bizhub PRO C6500 (Konica Minolta Business Technologies) having the configuration shown in FIG. Manufactured by Co., Ltd .; using an exposure light of a semiconductor laser of 600 dpi and 780 nm). Since the full-color multifunction peripheral has four image forming units, the photosensitive members of each image forming unit are the same type of photosensitive member (for example, in the case of the photosensitive member 1, four photosensitive members 1 are provided. Prepared) and unified and evaluated. Each evaluation was performed under the conditions of 30 ° C. and 80% RH, and an A4 image with a YMCBk color printing ratio of 2.5% was printed on a neutral A4 sheet and subjected to a printing durability test. The environmental conditions were evaluated.

Fog (evaluated with black and white image)
Evaluation was conducted after the printing durability test for 500,000 sheets under the above environmental conditions of 30 ° C. and 80% RH. The fog density was measured by reflection density of a solid white image using RD-918 manufactured by Macbeth. The reflection density was evaluated by a relative density (the density of A4 paper not printed is 0.000).

A: Density is less than 0.010 (good)
○: Concentration is 0.010 or more and 0.020 or less (a level that causes no problem in practical use)
X: The density is higher than 0.020 (a level causing a problem in practical use).

(Image blur)
Immediately after the printing endurance test for 500,000 sheets under environmental conditions of 30 ° C. and 80% RH, the main power supply of the actual machine was stopped. Immediately after the stop, the power was turned on and the image was ready for printing. Immediately after that, a halftone image (relative reflection density of 0.4 with a Macbeth densitometer) and a 6-dot lattice image of the entire A3 were printed on the entire A3 neutral paper. The state of the printed image was observed and the following evaluation was performed.

◎: No blurring in halftone and grid images (good)
○: A thin strip-like density decrease in the longitudinal direction of the photoreceptor is observed only in the halftone image (no problem in practical use)
X: Lattice image loss or line width narrowing due to image blurring (practical problem).

(Evaluation of image unevenness)
After printing and printing durability test for 500,000 sheets at 30 ° C. and 80% RH, it was allowed to stand for 1 hour at 10 ° C. and 10% RH, and four sets of the full-color multifunction machine bizhub PRO C6500 were used. The image forming unit was activated, and a halftone image including a human face photograph was printed on A4 paper, and evaluated according to the following criteria.

A: Halftone color image is reproduced smoothly and no noticeable image unevenness is found (good)
○: Half-tone color image has partially uneven image density, but is not conspicuous and is reproduced smoothly as a whole (no problem in practical use)
×: Clear image unevenness occurs in the halftone color image (there is a problem in practical use).

(Amount of photoconductor wear)
Evaluation was made based on the difference in film thickness before and after the printing and printing durability test for 500,000 sheets under the environmental conditions of 30 ° C. and 80% RH. The photosensitive layer thickness is measured at 10 points at random on the uniform film thickness portion (the film thickness tends to be non-uniform at both ends of the photoreceptor, so at least 3 cm at both ends), and the average value is measured as the film thickness of the photosensitive layer. Thickness. The film thickness measuring device is an eddy current type film thickness measuring device EDDY560C (manufactured by HELMUT FISCHER GMBTE CO), and the difference in the photosensitive layer thickness before and after the printing test is defined as the film thickness depletion amount.

A: The amount of wear is less than 0.7 μm (good)
○: Amount of wear is 0.7 μm or more and 2 μm or less (no problem in practical use)
X: The amount of wear is larger than 2 μm (there is a practical problem)
The evaluation results are summarized in Tables 4 and 5 below.

  As is apparent from Tables 4 and 5, the combination Nos. The photoreceptors 1 to 9, 13 to 20, and 23 to 27 have practical results or more in each evaluation item, but the charge generation layer of the photoreceptor is a 2.3-butanediol adduct titanyl phthalocyanine. Even if a pigment is contained, the combination No. 1 using the photoreceptors 10 and 12 having a ratio (R700 / R780) of less than 0.8 is used. 10 and 12, image blurring occurred, and the combination No. 10 using the photoconductor 11 having a ratio (R700 / R780) larger than 1.3. 11, the occurrence of image unevenness is remarkable. In addition, combination No. using a photosensitive member 21 whose protective layer is polycarbonate is used. No. 21 has a large amount of depletion, and the combination No. 21 using the photoreceptor 22 in which the charge generation material of the photoreceptor is a Y-type titanyl phthalocyanine pigment is used. In FIG. 22, the occurrence of image unevenness is remarkable. Further, combination No. 1 using a developer containing no antioxidant in the toner is used. In 28, image blurring and fogging are remarkable.

Production of Photoreceptor 23 Photoreceptor 23 was produced in the same manner as in production of Photoreceptor 1 except that the protective layer was changed to the following protective layer.

  59 g of γ-glycidoxypropyltrimethoxysilane and 32 g of dimethoxysilane were dissolved in 35 g of ethanol to obtain a uniform solution. 26 g of dihydroxymethyltriphenylamine (T-1 below), 1 g of an antioxidant (antioxidant AO-1) and 1 g of an aluminum chelate (aluminum chelate A (W) manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied on the charge transport layer of the photoreceptor 1 as a protective layer for a siloxane-based resin layer having a dry film thickness of 3 μm, and was cured by heating at 120 ° C. for 1 hour to prepare a photoreceptor 23.

  The photosensitive member 23 is combined with Bk-1, toner Y-1, toner M-1, and toner C-1 (combination No. 29). Evaluation was performed in the same manner as in Example 1. The evaluation results are shown in Table 5 below.

  As is apparent from Table 6, the effect of the present invention is remarkably exhibited even in the photosensitive member of the protective layer of the siloxane-based resin layer in which the photosensitive member is formed by a condensation reaction.

Production of Photoreceptor 24 Photoreceptor 24 was produced in the same manner as in production of Photoreceptor 1 except that the protective layer was changed to the following protective layer.

  228 parts of polyol having a number average molecular weight of 800 obtained by ring-opening polymerization of ε-caprolactone to bishydroxyethyl terephthalate, 8.1 parts of 1,4-butanediol, 15.0 parts of trimethylolpropane, 1012.8 parts of cyclohexanone, After adding 0.034 parts of dibutyltin dioctoate and mixing and dissolving uniformly, 160 parts of 4,4'-diphenylmethane diisocyanate and 20 parts of titanium oxide treated with dimethoxysilane are mixed and dispersed, and then the solution is dried to a thickness of 3 μm. As a protective layer for the polyurethane-based resin layer, it was applied on the charge transport layer of the photoreceptor 1 and cured by heating at 120 ° C. for 3 hours to prepare a photoreceptor 24.

  The photosensitive member 24 is combined with Bk-1, toner Y-1, toner M-1, and toner C-1 (combination No. 30). Evaluation was performed in the same manner as in 1. The evaluation results are shown in Table 6 below.

  As is apparent from Table 7, the effect of the present invention is remarkably exhibited even in the photosensitive member of the protective layer of the polyurethane resin layer formed by the condensation reaction of the photosensitive member.

  Next, a toner in which an antioxidant was internally added and a developer using the toner were prepared.

Preparation of Toner BkN (Black) 9.2 g of sodium n-dodecyl sulfate is dissolved by stirring in 160 ml of ion-exchanged water. Under stirring, 20 g of Legal 330R (Carbot Black manufactured by Cabot) and 2 g of antioxidant (AO-1) were gradually added, and then dispersed using CLEARMIX. As a result of measuring the particle diameter of the dispersion using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., the weight average diameter was 112 nm. This dispersion is referred to as “colorant dispersion 2”.

  1250 g of the above-mentioned “Latex 1”, 2000 ml of ion-exchanged water, and “Colorant dispersion 2” are placed in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube, and a stirring device and stirred. After adjusting to 30 ° C., a 5 mol / liter aqueous sodium hydroxide solution was added to this solution to adjust the pH to 10.0.

  Subsequently, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added at 30 ° C. over 5 minutes with stirring. Thereafter, after standing for 2 minutes, temperature increase is started and the temperature is increased to 90 ° C. in 60 minutes (temperature increase rate: 1 ° C./min). In that state, the particle size was measured with Multisizer 3, and when the volume-based median diameter (Dv50) reached 6.6 μm, an aqueous solution in which 115 g of sodium chloride was dissolved in 700 ml of ion-exchanged water was added to stop particle growth. The mixture is further heated and stirred at a liquid temperature of 85 ° C. for 4 hours to be fused.

  Then, it cooled to 30 degreeC on the conditions of 6 degreeC / min, hydrochloric acid was added, pH was adjusted to 4.0, and stirring was stopped. The produced colored particles were filtered / washed under the following conditions, and then dried with hot air at 40 ° C. to obtain colored particles. This is referred to as “toner BkN”. The volume-based median diameter (Dv50) of the toner BkN was 6.5 μm.

Production of toner YN, toner MN, and toner CN In production of toner BkN, C.I. I. Toner YN was obtained in the same manner except that CI Pigment Yellow 74 was used. The volume-based median diameter (Dv50) of Toner YN was 6.6 μm.

  In the production of toner BkN, C.I. I. Toner MN was obtained in the same manner except that CI Pigment Red 122 was used. The volume-based median diameter (Dv50) of the toner MN was 6.6 μm.

  In the production of toner BkN, C.I. I. Toner CN was obtained in the same manner except that CI Pigment Blue 15: 3 was used. The volume-based median diameter (Dv50) of the toner CN was 6.5 μm.

  Next, the toner BkN, toner YN, toner MN, and toner CN are subjected to the following external additive processing, and toner BkN-50, toner YN-50, toner MN-50, and toner CN-50 external additive processing toner are applied. Produced.

(External additive treatment)
Preparation of Toner BkN-50 To 100 parts of toner particles constituting toner BkN, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, hydrophobization degree = 63) is added at a ratio of 1.2 parts, mixed by “Henschel mixer” (manufactured by Mitsui Mining Co., Ltd.), and then coarse particles are removed using a 45 μm aperture sieve. Toner BkN-50 was produced.

Preparation of Toner YN-50 To 100 parts of toner particles constituting toner YN, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, hydrophobization degree = 63) is added at a ratio of 1.2 parts, mixed by “Henschel mixer” (manufactured by Mitsui Mining Co., Ltd.), and then coarse particles are removed using a 45 μm aperture sieve. Toner YN-50 was produced.

Preparation of Toner MN-50 To 100 parts of toner particles constituting the toner MN, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, hydrophobization degree = 63) is added at a ratio of 1.2 parts, mixed by “Henschel mixer” (manufactured by Mitsui Mining Co., Ltd.), and then coarse particles are removed using a 45 μm aperture sieve. Toner MN-50 was prepared.

Preparation of Toner CN-50 To 100 parts of toner particles constituting the toner CN, 1 part of hydrophobic silica (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, hydrophobization degree = 63) is added at a ratio of 1.2 parts, mixed by “Henschel mixer” (manufactured by Mitsui Mining Co., Ltd.), and then coarse particles are removed using a 45 μm aperture sieve. Toner CN-50 was produced.

[Manufacture of developer]
7 parts each of the toner BkN-50, toner YN-50, toner MN-50, and toner CN-50, and 93 parts of a ferrite carrier having a volume-based median diameter (Dv50) of 35 μm coated with a styrene-methacrylate copolymer Were mixed to produce developer BkN-50, developer YN-50, developer MN-50, and developer CN-50 for evaluation.

  The developer BkN-50, developer YN-50, developer MN-50, and developer CN-50 are combined with the photoreceptor 1 (combination No. 31). Evaluation was performed in the same manner as in 1. The evaluation results are shown in Table 8 below.

  As is apparent from Table 8, even when the antioxidant is internally added to the toner particles, the effect of the present invention is obtained.

1Y, 1M, 1C, 1Bk photoconductor 2Y, 2M, 2C, 2Bk charging unit 3Y, 3M, 3C, 3Bk exposure unit 4Y, 4M, 4C, 4Bk developing unit 10Y, 10M, 10C, 10Bk image forming unit

Claims (5)

  A charging potential is applied on the organic photoconductor by a charging unit, an electrostatic latent image is formed on the organic photoconductor on which the charging potential is applied by an exposure unit, and the electrostatic latent image is visualized as a toner image by a developing unit. In the image forming method in which the toner image is transferred to a transfer medium by a transfer unit and then the toner remaining on the organic photoconductor is removed by a cleaning unit, the organic photoconductor is placed on a conductive support. .3-butanediol adduct titanyl phthalocyanine pigment, and the ratio (R700 / R780) of the reflectance (R700) at 700 nm to the reflectance (R780) at 780 nm of the reflection spectrum is 0.8 to 1.3. An image forming method comprising a charge generation layer, a charge transport layer, and a cross-linkable curable protective layer, wherein the developing means contains a toner containing an antioxidant.   The image forming method according to claim 1, wherein an antioxidant of the developing unit is added as an external additive to the toner.   The image forming method according to claim 1, wherein the antioxidant is a hindered phenol compound.   The image forming method according to claim 1, wherein the protective layer contains metal oxide particles surface-treated with a compound having a polymerizable functional group.   Organic photoreceptor, charging means for charging the organic photoreceptor, exposure means for forming an electrostatic latent image on the organic photoreceptor by image exposure, developing means for developing the electrostatic latent image into a toner image, the toner In an image forming apparatus having transfer means for transferring an image to a transfer medium and cleaning means for removing toner remaining on the organic photoreceptor after the transfer, the organic photoreceptor is placed on a conductive support and 2.3-butanediol A charge generation layer containing an adduct titanyl phthalocyanine pigment and having a ratio (R700 / R780) of a reflectance (R700) at 700 nm and a reflectance (R780) at 780 nm of a reflection spectrum of 0.8 to 1.3; An image forming apparatus comprising a transport layer and a cross-linking curable protective layer, wherein the developing means contains a toner containing an antioxidant.

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