JP5383843B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus using an electrophotographic photosensitive member using a specific titanyl phthalocyanine crystal and an additive having a predetermined structure.

In general, organic photoconductors are often used as electrophotographic photoconductors used in electrophotographic equipment such as copying machines and laser printers due to demands for low price and low environmental pollution. As a charge generating agent used in such an organic photoreceptor, phthalocyanine pigments that are sensitive to light of infrared or near-infrared wavelength irradiated from a semiconductor laser or an infrared LED are widely used.
Such phthalocyanine pigments include metal-free phthalocyanine compounds, copper phthalocyanine compounds, titanyl phthalocyanine compounds, etc., depending on their chemical structures, and each phthalocyanine compound has various crystal forms depending on the production conditions. It is known to get.
In the presence of a large number of phthalocyanine compound crystals having different crystal types as described above, when a photoreceptor using a titanyl phthalocyanine having a Y-type crystal structure as a charge generator is manufactured, other crystal types of titanyl phthalocyanine are used. It is known that the electrical characteristics of the photoreceptor are improved as compared with the case where it is used.
For example, titanyl phthalocyanine having a maximum diffraction peak at a Bragg angle (2θ ± 0.2 °) = 27.3 ° with respect to Cu—Kα ray in an X-ray diffraction spectrum, and an organic compound capable of forming a phthalocyanine ring; A method for producing a Y-type crystal obtained by reacting a compound with dialkylamino alcohol to which urea or ammonia is added under conditions of 130 ° C. for about 4 hours is disclosed (for example, Patent Document 1).

In addition, a method for producing a Y-type crystal titanyl phthalocyanine compound obtained by reacting o-phthalonitrile and titanium tetrabutoxide directly without using a urea compound and reacting them at 215 ° C. for about 2 hours. Is disclosed (for example, Patent Documents 2 and 3).
More specifically, a method for producing a titanyl phthalocyanine crystal having a peak in a CuKα characteristic X-ray diffraction spectrum in a predetermined range and having no temperature change peak in a range of 50 to 400 ° C. in differential scanning calorimetry is disclosed. Has been.
JP-A-8-176456 (Example) Patent No. 3463032 (Claims) JP 2004-145284 (Claims)

  However, in the case of Patent Document 1, there has been a problem that the produced titanyl phthalocyanine crystal having a Y-type crystal structure easily causes a crystal transition in a β-type or α-type crystal in a coating solution for a photosensitive layer. For this reason, the storage stability of the photosensitive layer coating solution is poor, and as a result, there has been a problem that a photosensitive layer having good electrical characteristics cannot be formed stably.

  On the other hand, when the titanyl phthalocyanine crystal described in Patent Document 2 or Patent Document 3 is used, the crystal transition from the Y-type crystal in the coating solution for the photosensitive layer to the β-type crystal inferior in sensitivity characteristics can be suppressed. In the image forming apparatus using the photoconductor using the titanyl phthalocyanine crystal described in Patent Document 2 and Patent Document 3, fog is generated under high temperature and high humidity, and a good image cannot be obtained.

Therefore, the present inventors have conducted intensive studies in view of the above-mentioned problems, and as a result, using an additive having a predetermined structure and using a specific titanyl phthalocyanine crystal as a charge generator, storage stability in an organic solvent is achieved. As a result, it was found that stable production and good durability and image characteristics can be obtained.
That is, an object of the present invention is to provide an image forming apparatus using an electrophotographic photosensitive member that can be easily manufactured and has excellent crack resistance characteristics and electrical characteristics.

According to the present invention, an electrophotographic photosensitive member including a photosensitive layer containing at least a charge generating agent, a charge transporting agent, and a binder resin is provided on a substrate, and around the electrophotographic photosensitive member. , A charging unit, an exposure unit, a developing unit, and a transfer unit, wherein the charge generating agent has a Bragg angle 2θ ± 0.2 ° = 27 in a CuKα characteristic X-ray diffraction spectrum. .2 ° with the largest or second largest peak , 26.2 ° with no peak, and in differential scanning calorimetry, 270-400 ° C. other than the peak accompanying vaporization of adsorbed water In the CuKα characteristic X-ray diffraction spectrum of the titanyl phthalocyanine crystal having one peak within the range, the titanyl phthalocyanine crystal was measured after being immersed in an organic solvent for 7 days. And has a large peak at the maximum or second-Kutomo Bragg angle 2θ ± 0.2 ° = 27.2 °, no peak at 26.2 °, and the photosensitive layer, the following general formula as an additive ( An image forming apparatus including an electrophotographic photosensitive member containing the compound represented by 1) is provided, and the above-described problems can be solved.

(In general formula (1), R ^{1 to} R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group-substituted phenyl group having 1 to 4 carbon atoms, or an unsubstituted phenyl group. R represents a methylene group, and n represents an integer of 0 to 1.)

That is, if it is a titanyl phthalocyanine crystal having such optical characteristics and thermal characteristics, even if it is immersed in an organic solvent for a long period of, for example, 7 days or longer, crystals into α-type crystals and β-type crystals Metastasis can be effectively suppressed. Therefore, it is possible to obtain a photosensitive layer coating solution that is further excellent in storage stability, and it is possible to stably produce an electrophotographic photoreceptor excellent in electrical characteristics, image characteristics, and the like.
In addition, since an additive having a predetermined structure is included, an electrophotographic photoreceptor excellent in crack resistance can be provided regardless of the amount of titanyl phthalocyanine crystal added. Furthermore, since it contains a specific titanyl phthalocyanine crystal, the occurrence of fog can be effectively suppressed even when a large amount of additive is used.
Further, with this configuration, the crystal transition in the organic solvent can be more reliably controlled, and as a result, the quality of the titanyl phthalocyanine crystal having excellent storage stability can be determined quantitatively. .
That is, with such an image forming apparatus, it is possible to obtain good durability and image characteristics even in the image forming apparatus by including an electrophotographic photosensitive member that is stable and excellent in durability.

In constituting an image forming apparatus provided with the electrophotographic photosensitive member of the present invention, the organic solvent is at least one selected from the group consisting of tetrahydrofuran, dichloromethane, toluene, 1,4-dioxane, and 1-methoxy-2-propanol. Preferably it is a seed.
By comprising in this way, when this organic solvent is used as an organic solvent in the coating liquid for photosensitive layers, the stability of a specific titanyl phthalocyanine crystal can be judged more reliably.

In constituting an image forming apparatus provided with the electrophotographic photosensitive member of the present invention, the additive content is within the range of 3 to 55 parts by weight with respect to 100 parts by weight of the binder resin forming the photosensitive layer. It is preferable to use a value.
By configuring in this way, the balance among manufacturability, crack resistance characteristics, and electrical characteristics is further improved.

In constituting an image forming apparatus provided with the electrophotographic photosensitive member of the present invention, the additive is preferably a compound represented by the following formulas (2) to (6) or a derivative thereof.
By comprising in this way, the outstanding compatibility with binder resin is acquired, and the balance between a crack-proof characteristic and an electrical property becomes further favorable.

In constructing an image forming apparatus provided with the electrophotographic photosensitive member of the present invention, the photosensitive layer contains a charge generation layer containing a titanyl phthalocyanine crystal and either a hole transporting agent or an electron transporting agent. A multilayer electrophotographic photosensitive member in which a charge transport layer is laminated is preferable.
By comprising in this way, the usage-amount of a specific titanyl phthalocyanine crystal | crystallization can further be reduced.

[First Reference Embodiment]
A first reference embodiment of the present invention is an electrophotographic photoreceptor comprising a photosensitive layer containing at least a charge generating agent, a charge transporting agent, and a binder resin on a substrate, the charge generating agent Has a maximum or second largest peak at a Bragg angle 2θ ± 0.2 ° = 27.2 ° and no peak at 26.2 ° in a CuKα characteristic X-ray diffraction spectrum . Differential scanning calorimetry In addition to the peak accompanying vaporization of adsorbed water, it was a titanyl phthalocyanine crystal having one peak within a range of 270 to 400 ° C., and the titanyl phthalocyanine crystal was measured after being immersed in an organic solvent for 7 days. In the CuKα characteristic X-ray diffraction spectrum, at least the Bragg angle 2θ ± 0.2 ° = 27.2 ° has a maximum or second largest peak and a peak at 26.2 °. And the photosensitive layer contains an electrophotographic photosensitive member containing a compound represented by the following general formula (1) as an additive.

(In general formula (1), R ^{1 to} R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group-substituted phenyl group having 1 to 4 carbon atoms, or an unsubstituted phenyl group. R represents a methylene group, and n represents an integer of 0 to 1.)
Hereinafter, the types of electrophotographic photoreceptors will be described separately for a multilayer photoreceptor and a single-layer photoreceptor.

1. Laminated Photoreceptor (1) Basic Configuration As shown in FIG. 1, the laminated photoreceptor 20 contains a specific titanyl phthalocyanine crystal as a charge generating agent on a substrate 12 by means such as vapor deposition or coating. The charge generation layer 24 is formed, and then a charge transporting agent or the like and a coating solution for a photosensitive layer containing a binder resin are applied on the charge generation layer 24 and dried to form the charge transport layer 22. Can be created.
In contrast to the above structure, as shown in FIG. 1, the charge transport layer 22 may be formed on the substrate 12 and the charge generation layer 24 may be formed thereon.
However, since the charge generation layer 24 is much thinner than the charge transport layer 22, the charge transport layer 22 is formed on the charge generation layer 24 as shown in FIG. It is more preferable.

The charge transport layer 22 preferably contains either a hole transport agent or an electron transport agent.
By comprising in this way, it is not necessary to consider especially the compatibility etc. of the above-mentioned titanyl phthalocyanine crystal and the charge transfer agent, etc., and the binder resin having good compatibility with the titanyl phthalocyanine crystal, and the solvent Etc. can be used to constitute the photosensitive layer. Therefore, the characteristics of the titanyl phthalocyanine crystal can be exhibited more effectively, and an electrophotographic photoreceptor excellent in electrical characteristics and image characteristics can be stably obtained.

  Further, the positive or negative charge type is selected for the laminated photoreceptor depending on the order of formation of the charge generation layer and the charge transport layer and the kind of the charge transport agent used in the charge transport layer. For example, as shown in FIG. 1, when a charge generation layer 24 is formed on a substrate 12 and a charge transport layer 22 is formed thereon, an amine compound derivative or a stilbene derivative is used as a charge transport agent in the charge transport layer 22. When a positive hole transport agent is used, the photoreceptor becomes a negatively charged type. In this case, the charge generation layer 24 may contain an electron transport agent. In such a laminated electrophotographic photosensitive member, the residual potential of the photosensitive member is greatly reduced, and the sensitivity can be improved.

  As shown in FIG. 1, it is also preferable to previously form the intermediate layer 25 on the substrate 12 before forming the photosensitive layer. The reason for this is that by providing such an intermediate layer 25, it is possible to prevent the charge on the substrate side from being easily injected into the photoreceptor layer, and to firmly bond the photoreceptor layer onto the substrate 12, thereby This is because the above defects can be covered and smoothed.

(2) Substrate As the conductive substrate on which the multilayer photosensitive layer is formed, various materials having conductivity can be used. For example, conductive substrates formed of metals such as iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass, and the metals described above And a glass substrate coated with aluminum iodide, tin oxide, indium oxide, or the like.
That is, it is only necessary that the substrate itself has conductivity or the surface of the substrate has conductivity. The conductive substrate is preferably one having sufficient mechanical strength when used.
The shape of the conductive substrate may be any of a sheet shape and a drum shape according to the structure of the image forming apparatus to be used.

(3) Charge generation layer (3) -1 Charge generation agent The charge generation agent used in the photoreceptor of the present invention is a Bragg angle 2θ ± 0.2 ° = 27.2 ° in a CuKα characteristic X-ray diffraction spectrum. to have a maximum or the second largest peak, and the differential scanning calorimetry, within the vaporization of accompanying 270 to 400 ° C. in addition to peaks of adsorbed water, using a titanyl phthalocyanine crystal having a single peak It is characterized by that.
Hereinafter, the content of the titanyl phthalocyanine crystal will be described in detail.

(optical properties)
The titanyl phthalocyanine crystal as a charge generating agent is characterized by having a maximum or second largest peak at a Bragg angle 2θ ± 0.2 ° = 27.2 ° in a CuKα characteristic X-ray diffraction spectrum as an optical characteristic. (First optical characteristic).
Further, the CuKα characteristic X-ray diffraction spectrum is characterized by having no peak at a Bragg angle 2θ ± 0.2 ° = 26.2 ° (second optical characteristic).
Furthermore, in the CuKα characteristic X-ray diffraction spectrum, it is preferable that there is no peak at a Bragg angle 2θ ± 0.2 ° = 7.4 ° (third optical characteristic).
This is because when the first optical characteristic is not provided, the stability in the organic solvent tends to be significantly reduced as compared with the titanyl phthalocyanine crystal having such an optical characteristic. In other words, the storage stability in the organic solvent can be improved by providing the first optical characteristic, more preferably the second optical characteristic and the third optical characteristic.
Further, the titanyl phthalocyanine crystal collected after being immersed in an organic solvent for 7 days has a maximum or second largest peak at least at a Bragg angle 2θ ± 0.2 ° = 27.2 ° in a CuKα characteristic X-ray diffraction spectrum. In addition, there is no peak at 26.2 °.
The reason for this is that even when immersed in an organic solvent for 7 days, the crystal transition of the titanyl phthalocyanine crystal in the organic solvent can be more reliably controlled by maintaining the above-mentioned characteristics. This is because it can.
In addition, the immersion experiment evaluation in the organic solvent used as the reference | standard which evaluates the storage stability of a titanyl phthalocyanine crystal | crystallization is the coating liquid for charge generation layers (henceforth, application | coating for charge generation layers) for producing the electrophotographic photoreceptor, for example. It is preferable to carry out under the same conditions as the conditions for actually storing the liquid). Therefore, for example, it is preferable to evaluate the storage stability of titanyl phthalocyanine crystals in a closed system under conditions of a temperature of 23 ± 1 ° C. and a relative humidity of 50 to 60% RH.

The organic solvent for evaluating the storage stability of the titanyl phthalocyanine crystal is at least one member selected from the group consisting of tetrahydrofuran, dichloromethane, toluene, 1,4-dioxane, and 1-methoxy-2-propanol. preferable.
The reason for this is that when such an organic solvent is used as the organic solvent in the coating solution for the charge generation layer, the stability of the specific titanyl phthalocyanine crystal can be determined more reliably, and the specific titanyl phthalocyanine crystal, charge transport can be determined. This is because the compatibility in the agent, the binder resin, and the like is improved. Therefore, it is possible to form a photoconductor that exhibits the characteristics of specific titanyl phthalocyanine crystals and charge transfer agents more effectively, and to stably produce an electrophotographic photoconductor excellent in electrical characteristics and image characteristics. Because it can.

(Thermal characteristics)
In addition, the titanyl phthalocyanine crystal as a charge generating agent has, as a thermal characteristic, a single peak within a range of 270 to 400 ° C. in the differential scanning calorimetry, in addition to the peak accompanying vaporization of adsorbed water. And
The reason for this is that if the titanyl phthalocyani crystal having such optical characteristics and thermal characteristics is added to an organic solvent and allowed to stand for a long time, the crystal structure becomes an α-type crystal and a β-type crystal. This is because it is possible to effectively suppress the crystal transition. Therefore, by using such a titanyl phthalocyanine crystal, it is possible to obtain a coating solution for a charge generation layer excellent in storage stability. As a result, an electrophotographic photoreceptor excellent in electrical characteristics and image characteristics can be stably obtained. Can be manufactured.
A specific method for measuring the Bragg angle in the CuKα characteristic X-ray diffraction spectrum and a specific method for differential scanning calorimetry will be described in detail in Examples described later.

(Titanyl phthalocyanine compound)
Moreover, it is preferable that the structure of a titanyl phthalocyanine compound is a compound represented by following General formula (7).
This is because not only the stability of a specific titanyl phthalocyanine crystal can be further improved by using a titanyl phthalocyanine compound having such a structure, but also the specific titanyl phthalocyanine crystal can be stably produced. This is because it can.
Among the compounds represented by the general formula (7), an unsubstituted titanyl phthalocyanine compound represented by the following formula (8) is particularly preferable.
This is because a specific titanyl phthalocyanine crystal having more stable properties can be more easily produced by using a titanyl phthalocyanine compound having such a structure.

(In the general formula (7), X represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a cyano group, or a nitro group, and the repeating number e represents an integer of 1 to 4.)

(Production method)
In the CuKα characteristic X-ray diffraction spectrum, it has the largest or second largest peak at the Bragg angle 2θ ± 0.2 ° = 27.2 °, and in the differential scanning calorimetry, the peak accompanying vaporization of adsorbed water In addition, a titanyl phthalocyanine crystal having one peak in the range of 270 to 400 ° C. can be produced by the following steps (a) to (b).
(A) With respect to 1 mol of o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof, titanium alkoxide or titanium tetrachloride has a value within a range of 0.40 to 0.53 mol. And a urea compound is added at a value in the range of 0.1 to 0.95 mole per mole of o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof. Steps of reacting and producing titanyl phthalocyanine compound (b) Step of producing titanyl phthalocyanine crystal by subjecting the titanyl phthalocyanine compound produced in steps (b) and (a) to acid treatment Hereinafter, the production method of titanyl phthalocyanine crystal is described in detail. Explained.

(Production process of titanyl phthalocyanine compound)
As a method for producing a titanyl phthalocyanine compound, o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof, and titanium alkoxide or titanium tetrachloride as a material for producing such a molecule are combined with a urea compound. It is preferable to react in the presence to produce a titanyl phthalocyanine compound.
Here, the production method thereof will be specifically described taking the titanyl phthalocyanine compound represented by the formula (8) as an example.
That is, when manufacturing the titanyl phthalocyanine compound represented by Formula (8), it is preferable to implement according to following Reaction Formula (1) or following Reaction Formula (2). In the reaction formulas (1) and (2), as an example, titanium tetrabutoxide represented by the formula (10) is used as the titanium alkoxide.

Therefore, as shown in the reaction formula (1), the o-phthalonitrile represented by the formula (9) is reacted with titanium tetrabutoxide as the titanium alkoxide represented by the formula (10), or the reaction formula ( As shown in 2), 1,3-diiminoisoindoline represented by the formula (11) is reacted with a titanium alkoxide such as titanium tetrabutoxide represented by the formula (10) to obtain the formula (8) It is preferable to manufacture the titanyl phthalocyanine compound represented by these.
Titanium tetrachloride may be used instead of titanium alkoxide such as titanium tetrabutoxide represented by the formula (10).

The addition amount of titanium alkoxide such as titanium tetrabutoxide represented by formula (10) or titanium tetrachloride is represented by o-phthalonitrile represented by formula (9) or a derivative thereof, or formula (11). It is preferable to make it a value within the range of 0.40-0.53 mol with respect to 1 mol of 1,3-diiminoisoindoline or its derivative.
This is because the addition amount of titanium alkoxide such as titanium tetrabutoxide represented by the formula (10) or titanium tetrachloride is changed to o-phthalonitrile represented by the formula (9) or a derivative thereof, or the formula (11). By adding an excess amount exceeding 1/4 molar equivalent to the 1,3-diiminoisoindoline represented or its derivative, interaction with the urea compound described later is effectively exhibited. It is. Such interaction will be described in detail in the section of the urea compound.
Therefore, the addition amount of titanium alkoxide such as titanium tetrabutoxide represented by the formula (10) or titanium tetrachloride is changed to the o-phthalonitrile represented by the formula (9) or 1,3 represented by the formula (11). -It is more preferable to set it as the value within the range of 0.43-0.50 mol with respect to 1 mol of diiminoisoindoline etc., and it is further set as the value within the range of 0.45-0.47 mol. preferable.

Moreover, it is preferable to perform a process (a) in presence of a urea compound. The reason for this is that by using a titanyl phthalocyanine compound produced in the presence of a urea compound, the interaction between the urea compound and titanium alkoxide or titanium tetrachloride is exerted, so that specific titanyl phthalocyanine crystals can be efficiently obtained. It is because it can do.
That is, such an interaction means that ammonia produced by the reaction between a urea compound and titanium alkoxide or titanium tetrachloride further forms a complex with titanium alkoxide or titanium tetrachloride, and these substances are represented by reaction formulas (1) and (2 ) Is a function that further promotes the reaction represented by. Then, by reacting the raw material under such a promoting action, a titanyl phthalocyanine crystal that hardly undergoes crystal transition can be efficiently produced even in an organic solvent.

Further, the urea compound used in the step (a) is at least one member selected from the group consisting of urea, thiourea, O-methylisourea sulfate, O-methylisourea carbonate, and O-methylisourea hydrochloride. Is preferred.
The reason for this is that by using such a urea compound as the urea compound in the reaction formulas (1) and (2), ammonia generated in the course of the reaction more efficiently forms a complex with titanium alkoxide or titanium tetrachloride. This is because such a substance further promotes the reactions represented by the reaction formulas (1) and (2).
That is, this is because the ammonia produced by the reaction of titanium alkoxide or titanium tetrachloride as a raw material with a urea compound forms a complex compound with titanium alkoxide or the like more efficiently. Therefore, this complex compound further promotes the reactions represented by the reaction formulas (1) and (2).
It has been found that such a complex compound is likely to be produced specifically when reacted under a high temperature condition of 180 ° C. or higher. Therefore, among nitrogen-containing compounds having a boiling point of 180 ° C. or higher, for example, quinoline (boiling point: 237.1 ° C.), isoquinoline (boiling point: 242.5 ° C.), or a mixture thereof (weight ratio 10:90 to 90:10). ) Is more effective to implement in.
Therefore, it is more preferable to use urea among the above-described urea compounds because ammonia as a reaction accelerator and a complex compound resulting therefrom are more easily generated.

In addition, the amount of urea compound used in step (a) is 0.1 to 0.95 mol relative to 1 mol of o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof. It is preferable to set the value within the range.
This is because the above-described action of the urea compound can be more efficiently exhibited by setting the addition amount of the urea compound within the range.
Therefore, the addition amount of the urea compound is set to a value within a range of 0.3 to 0.8 mol with respect to 1 mol of o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof. It is more preferable to set the value within the range of 0.4 to 0.7 mol.

Examples of the solvent used in the step (a) include hydrocarbon solvents such as xylene, naphthalene, methylnaphthalene, tetralin, and nitrobenzene, and halogenated carbonization such as dichlorobenzene, trichlorobenzene, dibromobenzene, and chloronaphthalene. Hydrogen solvents, alcohol solvents such as hexanol, octanol, decanol, benzyl alcohol, ethylene glycol, and diethylene glycol, cyclohexanone, acetophenone, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc. Examples thereof include one or two or more arbitrary combinations of the group consisting of ketone solvents, amide solvents such as formamide, and acetamide, and nitrogen-containing solvents such as picoline, quinoline, and isoquinoline.
In particular, in the case of a nitrogen-containing compound having a boiling point of 180 ° C. or higher, for example, quinoline or isoquinoline, ammonia produced by the reaction of titanium alkoxide or titanium tetrachloride as a raw material with a urea compound is more efficiently produced by titanium. This is a suitable solvent because it easily forms a complex compound with an alkoxide or the like.

Moreover, it is preferable to make reaction temperature in a process (a) high temperature 150 degreeC or more. This is because when the reaction temperature is less than 150 ° C., particularly 135 ° C. or less, titanium alkoxide or titanium tetrachloride as a raw material reacts with a urea compound, and it becomes difficult to form a complex compound. Therefore, it becomes difficult for such a complex compound to further promote the reaction represented by the reaction formulas (1) and (2), and the titanyl phthalocyanine crystal which is difficult to undergo crystal transition even in an organic solvent is efficiently produced. This is because it becomes difficult to manufacture.
Therefore, the reaction temperature in the step (a) is more preferably set to a value within the range of 180 to 250 ° C, and further preferably set to a value within the range of 200 to 240 ° C.

Moreover, although the reaction time in a process (a) depends on reaction temperature, it is preferable to set it as the range of 0.5 to 10 hours. This is because when the reaction time is less than 0.5 hours, titanium alkoxide or titanium tetrachloride as a raw material reacts with a urea compound, and it becomes difficult to form a complex compound. Therefore, it becomes difficult for such a complex compound to further promote the reaction represented by the reaction formulas (1) and (2), and the titanyl phthalocyanine crystal which is difficult to undergo crystal transition even in an organic solvent is efficiently produced. This is because it becomes difficult to manufacture. On the other hand, when the reaction time exceeds 10 hours, it is economically disadvantageous or the produced complex compound may be reduced.
Therefore, the reaction time in step (a) is more preferably set to a value within the range of 0.6 to 3.5 hours, and further preferably set to a value within the range of 0.8 to 3 hours.

(Production process of titanyl phthalocyanine crystal)
Subsequently, it is preferable to perform an acid treatment as a post-treatment on the titanyl phthalocyanine compound produced in the above-described process to obtain a titanyl phthalocyanine crystal.
That is, as a step before carrying out the acid treatment, the titanyl phthalocyanine compound obtained by the above-mentioned reaction is added to a water-soluble organic solvent, stirred for a certain time under heating, and then at a temperature condition lower than that of the stirring treatment. It is preferable to perform a pre-acid treatment step in which the solution is allowed to stand for a certain period of time for stabilization.
Examples of the water-soluble organic solvent used in the pre-acid treatment step include alcohols such as methanol, ethanol, and isopropanol, N, N-dimethylformamide, N, N-dimethylacetamide, propionic acid, acetic acid, and N-methyl. One type or two or more types such as pyrrolidone and ethylene glycol may be mentioned. Note that a water-insoluble organic solvent may be added to the water-soluble organic solvent in a small amount.

Moreover, although the conditions of a stirring process are not specifically limited among the processes before an acid treatment, It is preferable to perform the stirring process for about 1 to 3 hours on the fixed temperature conditions of about 70-200 degreeC temperature range.
Furthermore, the conditions for the stabilization treatment after the stirring treatment are not particularly limited, but are about 10 to 50 ° C., particularly preferably about 5 to 15 hours under a constant temperature condition of about 23 ± 1 ° C. It is preferable to stabilize by standing.

Subsequently, it is preferable to implement an acid treatment process as follows.
That is, after dissolving the titanyl phthalocyanine crystal obtained in the acid treatment pre-process described above in an acid, the solution is dropped into water and recrystallized, and then the obtained titanyl phthalocyanine crystal is dissolved in an alkaline aqueous solution. It is preferable to wash. Specifically, the obtained crude crystals are dissolved in an acid, this solution is dropped into water under ice cooling, stirred for a certain period of time, and allowed to stand again at a temperature within the range of 10 to 30 ° C. Crystallization is preferred. Next, it is preferable to stir at 30 to 70 ° C. for 2 to 8 hours in a non-aqueous solvent without drying and in the presence of water.

In addition, as an acid used for acid treatment, it is preferable to use concentrated sulfuric acid, trifluoroacetic acid, sulfonic acid, etc., for example.
This is because, by using such a strong acid for acid treatment, impurities can be sufficiently decomposed, while decomposition of specific titanyl phthalocyanine crystals can be suppressed. Therefore, a titanyl phthalocyanine crystal having higher purity and excellent crystal characteristics can be obtained.
Further, as the alkaline aqueous solution used for the cleaning treatment, it is preferable to use a general alkaline aqueous solution such as an aqueous ammonia solution or an aqueous sodium hydroxide solution.
This is because the environment of the crystal can be changed from acidic to neutral by washing the specific titanyl phthalocyanine crystal after the acid treatment with the aqueous alkali solution. As a result, the crystal can be easily handled in the next step, and the stability of the crystal can be improved.
Examples of the non-aqueous solvent for the stirring treatment include halogen solvents such as chlorobenzene and dichloromethane.

(Addition amount)
Further, the amount of the charge generating agent added is preferably a value within the range of 5 to 1000 parts by weight with respect to 100 parts by weight of the binder resin described later.
This is because the charge generating agent can efficiently generate charges when the photosensitive member is exposed by setting the amount of the charge generating agent within the above range.
That is, when the amount of the charge generating agent added is less than 5 parts by weight with respect to 100 parts by weight of the binder resin, the amount of charge generated may be insufficient to form an electrostatic latent image on the photoreceptor. Because. On the other hand, when the added amount of the charge generator exceeds 1000 parts by weight with respect to 100 parts by weight of the binder resin, it may be difficult to uniformly disperse in the photosensitive layer coating solution.
Therefore, it is more preferable that the amount of the charge generator added to 100 parts by weight of the binder resin is a value within the range of 30 to 500 parts by weight.
The amount of the charge generator added is the amount of the titanyl phthalocyanine crystal when the titanyl phthalocyanine crystal of the present invention is used as the charge generator, and the titanyl phthalocyanine crystal is used in combination with another charge generator. Is the total addition amount of both.

  In addition, when the titanyl phthalocyanine crystal according to the present invention is used in combination with another charge generating agent, it is preferable to add a small amount of the other charge generating agent within a range that does not interfere with the effect of the titanyl phthalocyanine crystal described above. Specifically, it is preferable to add another charge generating agent in a proportion within the range of 100 parts by weight or less with respect to 100 parts by weight of the titanyl phthalocyanine crystal.

(3) -2 Binder Resin Examples of the binder resin include styrene polymers, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, acrylic polymers, styrene-acrylic. Copolymer, polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, polypropylene, vinyl chloride-vinyl acetate copolymer, polyester, alkyd resin, polyamide, polyurethane, polycarbonate, polyarylate, polysulfone, Thermoplastic resins such as diallyl phthalate resin, ketone resin, polyvinyl butyral resin, and polyether resin, silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, other crosslinkable thermosetting resins, and epoxy- Acry Over DOO, and urethane - like photocurable resin such as acrylate. These binder resins can be used alone or in combination of two or more.

(3) -3 Thickness Further, the thickness of the charge generation layer is preferably set to a value within the range of 0.01 to 5 μm, and more preferably set to a value within the range of 0.1 to 3 μm.

(4) Charge Transport Layer (4) -1 Hole Transport Agent As the hole transport agent, any of various conventionally known hole transport compounds can be used. In particular, benzidine compounds, phenylenediamine compounds, naphthylenediamine compounds, phenanthrylenediamine compounds, oxadiazole compounds [for example, 2,5-di (4-methylaminophenyl) -1,3,4-oxa Diazole etc.], styryl compounds [eg 9- (4-diethylaminostyryl) anthracene etc.], carbazole compounds [eg poly-N-vinylcarbazole etc.], organic polysilane compounds, pyrazoline compounds [eg 1-phenyl-3 -(P-dimethylaminophenyl) pyrazoline etc.], hydrazone compounds, triphenylamine compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazols Compounds, triazole compounds, butadiene compounds, pyrene-hydrazone compounds, acrolein compounds, carbazole-hydrazone compounds, quinoline-hydrazone compounds, stilbene compounds, stilbene-hydrazone compounds, diphenylenediamine compounds, etc. Are preferably used. These may be used alone or in combination of two or more.
Among these, hole transport agents (HTM-1 to 25) represented by the following formulas (12) to (36) are particularly preferably used as hole transport agents having excellent hole transport ability.

  The amount of the hole transport agent added is preferably 20 to 500 parts by weight with respect to 100 parts by weight of the binder resin, and preferably 30 to 200 parts by weight. Is more preferable. In addition, when using together a positive hole transport agent and the above-mentioned electron transport agent, it is preferable to make the total amount into the value within the range of 20-500 weight part with respect to 100 weight part of binder resin. More preferably, the value is within the range of 30 to 200 parts by weight.

(4) -2 Electron Transfer Agent As the electron transfer agent, any of various conventionally known electron transport compounds can be used. In particular, benzoquinone compounds, diphenoquinone compounds, naphthoquinone compounds, malononitrile, thiopyran compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, fluorenone compounds [for example, 2,4,7-trinitro-9-fluorenone, etc. ], Dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, succinic anhydride, maleic anhydride, dibromomaleic anhydride, 2,4,7-trinitrofluorenone imine compound, ethylated nitrofluorenone imine compound, tryptoan Thrin compound, tryptoanthrin imine compound, azafluorenone compound, dinitropyridoquinazoline compound, thioxanthene compound, 2-phenyl-1,4-benzoquinone compound, 2- Electrons such as anion radical and cation salts of phenyl-1,4-naphthoquinone compounds, 5,12-naphthacenequinone compounds, α-cyanostilbene compounds, 4, '-nitrostilbene compounds, and benzoquinone compounds Inhalable compounds are preferably used. These may be used alone or in combination of two or more.
Among these, electron transport agents (ETM-1 to 15) represented by the following formulas (37) to (51) are particularly preferably used as electron transport agents having excellent electron transport ability.

Further, the addition amount of the electron transport agent is preferably set to a value within the range of 20 to 500 parts by weight, and preferably within a range of 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. More preferred. In addition, when using together an electron transport agent and the below-mentioned hole transport agent, it is preferable to make the total amount into the value within the range of 20-500 weight part with respect to 100 weight part of binder resin. More preferably, the value is within the range of 30 to 200 parts by weight.
Moreover, when using together an electron transport agent and the hole transport agent mentioned later, the addition amount of an electron transport agent is the value within the range of 10-100 weight part with respect to 100 weight part of hole transport agents, It is preferable to do.

(4) -3 Additive In addition, the charge transport layer contains the following additive.

(In general formula (1), R ^{1 to} R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group-substituted phenyl group having 1 to 4 carbon atoms, or an unsubstituted phenyl group. R represents a methylene group, and n represents an integer of 0 to 1.)

Specific examples of the additive are preferably compounds represented by the following formulas (2) to (6) or derivatives thereof.
The reason for this is that, in this way, excellent compatibility with the binder resin can be obtained, and the balance between crack resistance and electrical characteristics can be further improved.

The content of the additive is preferably 3 to 55 parts by weight, preferably 5 to 50 parts by weight with respect to 100 parts by weight of the binder resin forming the photosensitive layer. It is more preferable that the value be within a range of 10 to 40 parts by weight.
The reason for this is that this configuration further improves the balance among manufacturability, crack resistance characteristics, and electrical characteristics.

(4) -4 Thickness Further, the thickness of the charge transport layer is preferably set to a value within the range of 0.1 to 50 μm, and more preferably set to a value within the range of 1 to 30 μm.

(5) Manufacturing Method Regarding the manufacturing method of the laminated photoreceptor layer of the present invention, after preparing a charge transport layer coating solution and a charge generation layer coating solution as follows, and coating each on a substrate, It is preferable to produce by drying.

(5) -1 Coating liquid preparation process The coating liquid preparation process includes, for example, a coating liquid for a charge transport layer composed of a binder resin, a hole transport agent, and a solvent, a binder resin, and a charge generator. And a charge generation layer coating solution comprising a solvent and a solvent. For example, it is preferable to disperse and mix using a roll mill, a ball mill, an attritor, a paint shaker, an ultrasonic disperser or the like to obtain a coating solution.
More specifically, the solid content concentration of the charge transport layer coating solution is within the range of 10 to 30% by weight, and the solid content concentration of the charge generation layer coating solution is within the range of 1 to 10% by weight. It is preferable to prepare a coating solution. The reason for this is that if the solid content concentration of the coating solution for the charge transport layer is less than 10% by weight, a coating defect may occur, whereas the solid content concentration of the coating solution exceeds 30% by weight. This is because unevenness of layers is likely to occur, and it may be difficult to form a thin film having a uniform thickness as a photoreceptor. Similarly, if the solid content concentration of the coating solution for the charge generation layer is less than 1% by weight, film defects may occur. If the solid content concentration exceeds 10% by weight, unevenness of the layer is likely to occur. It may be difficult to form a thin film having a uniform thickness as a body.
Various organic solvents can be used as the solvent for preparing the charge transport layer coating solution and the charge generation layer coating solution. For example, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene, dichloromethane, dichloroethane, chloroform and tetrachloride Halogenated hydrocarbons such as carbon and chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane and dioxolane; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate Class, dimethylformaldehyde, dimethylformamide, dimethylsulfoxide, etc., alone or in combination of two or more. That.
Furthermore, in order to improve the dispersibility of the charge transport agent, the charge generator, etc. and the smoothness on the surface of the photoreceptor layer, it is also preferable to add a surfactant, a leveling agent or the like when preparing the coating solution.

(5) -2 Application Step and Drying Step The first application step and the first drying step, the second application step and the second drying step are provided to form a photoreceptor layer composed of a charge transport layer and a charge generation layer. It is preferable. For example, as shown in FIG. 1A, the charge generation layer 24 is formed on the substrate 12 by the first coating process and the first drying process, and then, by the second coating process and the second drying process, It is preferable to form the charge transport layer 22 on the charge generation layer 24.

(Coating process)
In carrying out the coating step, it is also preferable to apply the coating solution directly on the substrate, or it is also preferable to apply it indirectly via an intermediate layer.
As a coating method, it is preferable to use, for example, a spin coater, an applicator, a spray coater, a bar coater, a dip coater, a doctor blade, etc., in order to form a photoreceptor layer having a uniform thickness.
The charge generation layer preferably has a thinner coating than the charge transport layer in order to reduce the residual potential.

(Drying process)
Moreover, after an application | coating process, it is preferable to make it dry at the drying temperature of 60 degreeC-150 degreeC, for example using a high temperature dryer, a vacuum dryer, etc. in a drying process. This is because when the drying temperature is less than 60 ° C., the drying time becomes excessively long, and it may be difficult to efficiently form a photoreceptor layer having a uniform thickness. is there. On the other hand, if the drying temperature exceeds 150 ° C., the photoconductor may be thermally decomposed.

2. Single Layer Type Photoreceptor (1) Basic Configuration As shown in FIG. 2A, the single layer type photoreceptor 10 has a single photoreceptor layer 14 provided on a conductive substrate 12. The photosensitive layer 14 contains a specific titanyl phthalocyanine crystal as a charge generating agent, a charge transport agent and a binder resin in the same layer.
In addition, the thickness of the photosensitive layer is preferably set to a value within the range of 5 to 100 μm, and more preferably set to a value within the range of 10 to 50 μm.
Further, as shown in FIG. 2B, a photosensitive member 10 ′ in which a barrier layer 16 is formed between the conductive substrate 12 and the photosensitive layer 14 within a range not impairing the characteristics of the photosensitive member may be used. Further, as shown in FIG. 2C, a photosensitive member 10 ″ having a protective layer 18 formed on the surface of the photosensitive layer 14 may be used.

The charge transporting agent contained in the photosensitive layer is preferably a single-layered photosensitive layer containing either a hole transporting agent or an electron transporting agent.
This is because the production of the titanyl phthalocyanine crystal can be performed stably and economically as compared with a laminated photoreceptor described later, while sufficiently exhibiting the characteristics of the titanyl phthalocyanine crystal. That is, it is because an electrophotographic photosensitive member having good electrical characteristics and image characteristics that sufficiently exhibit the characteristics of a specific titanyl phthalocyanine crystal as a charge generating agent can be produced stably and economically. .
Moreover, it is also preferable to contain both a hole transport agent and an electron transport agent as a charge transport agent.
This is because the charges generated from the titanyl phthalocyanine crystal in the exposure process can be transported more efficiently while fully exhibiting the characteristics of the specific titanyl phthalocyanine crystal. As a result, an electrophotographic photosensitive member having even better electrical characteristics and image characteristics can be obtained.

(2) Manufacturing method In manufacturing a single-layer type photoreceptor, a binder resin, a charge generator, a hole transport agent, and, if necessary, an electron transport agent are added to a solvent and dispersed and mixed. And a photosensitive layer coating solution. That is, when a single layer type photoreceptor is formed by a coating method, a titanyl phthalocyanine crystal as a charge generating agent, a charge transport agent, a binder resin and the like together with a suitable solvent, a known method such as a roll mill, a ball mill, What is necessary is just to disperse and mix using an attritor, a paint shaker, an ultrasonic disperser, etc., adjust a dispersion liquid, apply | coat this by a well-known means, and to dry.
Moreover, as a solvent for making the coating liquid for photosensitive layers, 1 type (s) or 2 or more types, such as tetrahydrofuran, a dichloromethane, toluene, 1, 4- dioxane, and 1-methoxy-2-propanol, are mentioned.
Furthermore, in order to improve the dispersibility of the charge transport agent and the charge generator and the smoothness of the surface of the photoreceptor layer, a surfactant, a leveling agent, and the like may be added to the photosensitive layer coating solution. .

[Second Embodiment]
The second embodiment is characterized in that it includes the multilayer electrophotographic photosensitive member of the first reference embodiment, and a charging unit, an exposing unit, a developing unit, and a transfer unit are arranged around the electrophotographic photosensitive member. The image forming apparatus.
In this example of the image forming apparatus, the case where the multilayer electrophotographic photosensitive member of the present invention is used as the multilayer electrophotographic photosensitive member will be described.

(1) Configuration In carrying out the image forming method of the second embodiment, a copying machine 40 which is an image forming apparatus as shown in FIG. 3 can be preferably used. The copying machine 40 includes an image forming unit 41, a paper discharge unit 42, an image reading unit 43, and a document feeding unit 44. The image forming unit 41 further includes an image forming unit 41a and a paper feeding unit 41b. In the illustrated example, the document feeding unit 44 includes a document placing tray 44a, a document feeding mechanism 44b, and a document discharge tray 44c, and the document placed on the document placing tray 44a. Is sent to the image reading position P by the document feeding mechanism 44b and then discharged to the document discharge tray 44c.

Then, when the document is sent to the document reading position P, the image reading unit 43 reads the image on the document using the light from the light source 43a. That is, an image signal corresponding to the image on the document is formed using an optical element 43b such as a CCD.
On the other hand, recording sheets (hereinafter simply referred to as “sheets”) S stacked on the sheet feeding unit 41b are sent one by one to the image forming unit 41a. The image forming unit 41a is provided with a photosensitive drum 51 as an image carrier, and around the photosensitive drum 51, a charger 52, an exposure unit 53, a developing unit 54, and a transfer roller. 55 and a cleaning device 56 are arranged along the rotation direction of the photosensitive drum 51.

  Among these components, the photosensitive drum 51 is rotationally driven in the direction indicated by the solid line arrow in the drawing, and the surface thereof is uniformly charged by the charger 52. Thereafter, an exposure process is performed on the photosensitive drum 51 by the exposure device 53 based on the above-described image signal, and an electrostatic latent image is formed on the surface of the photosensitive drum 51. Based on the electrostatic latent image, the developing device 54 attaches toner and develops it, thereby forming a toner image on the surface of the photosensitive drum 51. The toner image is transferred as a transfer image onto the sheet S conveyed to the nip portion between the photosensitive drum 51 and the transfer roller 55. Next, the sheet S on which the transferred image is transferred is conveyed to the fixing unit 57 and a fixing process is performed.

Here, the paper S after fixing is sent to the paper discharge unit 42. However, when performing post-processing (for example, stapling processing), the paper S is sent to the intermediate tray 42a and then back. Processing is performed. Thereafter, the sheet S is discharged to a discharge tray portion (not shown) provided on the side surface of the image forming apparatus. On the other hand, when no post-processing is performed, the sheet S is discharged to a discharge tray 42b provided below the intermediate tray 42a.
The intermediate tray 42a and the paper discharge tray 42b are configured as a so-called in-body paper discharge unit.
After the transfer is performed as described above, the residual toner (and paper dust) remaining on the photosensitive drum 51 is removed by the cleaning device 56. That is, while the photosensitive drum 51 is cleaned, residual toner is collected in a waste toner container (not shown).

  In the image forming apparatus of the present invention, by providing an electrophotographic photosensitive member that is stable and excellent in durability, good durability and image characteristics can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these description content.

1. Production of titanyl phthalocyanine crystal (1) Production of titanyl phthalocyanine crystal A (TiOPc-A) (1) -1 Production of titanyl phthalocyanine compound In an argon-substituted flask, 22 g (0.17 mol) of o-phthalonitrile and titanium tetra Butoxide 25g (0.073mol) and quinoline 300g were added, and it heated up to 150 degreeC, stirring.
Next, the temperature of the system was raised to 215 ° C. while distilling off the vapor generated from the reaction system, and the mixture was further stirred for 2 hours while maintaining this temperature.
Then, after the reaction is completed, when the reaction mixture is cooled to 150 ° C., the reaction mixture is taken out of the flask, filtered through a glass filter, and the resulting solid is washed successively with N, N-dimethylformamide and methanol and then vacuum-dried. 24 g of a blue-violet solid was obtained.

(1) -2 Pigmentation pretreatment 10 g of the blue-purple solid obtained in the production of the above-mentioned titanyl phthalocyanine compound is added to 100 ml of N, N-dimethylformamide and heated to 130 ° C. with stirring for 2 hours. The stirring process was performed.
Next, the heating was stopped when 2 hours passed, and further the stirring was stopped when the temperature was cooled to 23 ± 1 ° C. In this state, the liquid was allowed to stand for 12 hours for stabilization treatment. The stabilized supernatant was filtered off with a glass filter, and the resulting solid was washed with methanol and then vacuum dried to obtain 9.83 g of a crude crystal of a titanyl phthalocyanine compound.

(1) -3 Pigmentation treatment 5 g of crude crystals of titanyl phthalocyanine obtained by the above-mentioned pigmentation pretreatment were added to 100 ml of concentrated sulfuric acid and dissolved.
Next, this solution was dropped into water under ice cooling, stirred at room temperature for 15 minutes, and further allowed to stand at 23 ± 1 ° C. for 30 minutes to recrystallize and separate from the supernatant.
Next, the supernatant is filtered off with a glass filter, and the resulting solid is washed with water until the washing solution becomes neutral. Then, without drying, it is dispersed in 200 ml of chlorobenzene and heated to 50 ° C. And stirred for 10 hours. The supernatant was filtered off with a glass filter, and the obtained crystals were vacuum dried at 50 ° C. for 5 hours to obtain 4.1 g of unsubstituted titanyl phthalocyanine crystals (blue powder) represented by the formula (7). Obtained.

(2) Production of titanyl phthalocyanine crystal B (TiOPc-B) In the production of titanyl phthalocyanine crystal B (TiOPc-B), the pigmentation pretreatment produced in the same manner as the titanyl phthalocyanine crystal A (TiOPc-A) described above was carried out. 2 g of amorphous titanyl phthalocyanine in the previous stage was placed in a glass beaker and diethylene glycol dimethyl ether was added until the total volume was 200 ml.
Next, this was stirred at 23 ± 1 ° C. for 24 hours to obtain 1.8 g of titanyl phthalocyanine crystals.

(3) Production of titanyl phthalocyanine crystal C (TiOPc-C) In the production of titanyl phthalocyanine crystal C (TiOPc-C), after the pigmentation pretreatment produced in the same manner as the titanyl phthalocyanine crystal A (TiOPc-A) described above. 5 g of the crude crystal of titanyl phthalocyanine in the above step was dissolved in 100 ml of a mixed solvent of dichloromethane and trifluoroacetic acid (volume ratio 4: 1).
Next, this solution was dropped into a mixed poor solvent of methanol and water (volume ratio of 1: 1), stirred at room temperature for 15 minutes, and then allowed to stand at about 23 ± 1 ° C. for 30 minutes for recrystallization. And separated from the supernatant.
Next, the supernatant is filtered off with a glass filter, and the obtained crystals are washed with water until the washing solution becomes neutral, and then dispersed in 200 ml of chlorobenzene in the presence of water without being dried, and at room temperature for 1 hour. , Stirred. The supernatant was filtered off with a glass filter, and the obtained crystals were vacuum-dried at 50 ° C. for 5 hours to obtain 4.2 g of unsubstituted titanyl phthalocyanine crystals (blue powder) represented by the formula (7). Obtained.

(4) Production of titanyl phthalocyanine crystal D (TiOPc-D) In the production of titanyl phthalocyanine D (TiOPc-D), when producing a titanyl phthalocyanine compound, 22 g of o-phthalonitrile ( 0.17 mol), titanium tetrabutoxide 25 g (0.073 mol), and quinoline 300 g, except that urea 2.28 g (0.038 mol) was added, titanyl phthalocyanine crystal A (TiOPc-A), and titanyl phthalocyanine Crystals were produced to obtain 4.1 g of unsubstituted titanyl phthalocyanine crystals (blue powder).

(5) Production of titanyl phthalocyanine crystal E (TiOPc-E) In production of titanyl phthalocyanine crystal E (TiOPc-E), the amount of urea added when producing the titanyl phthalocyanine compound was 5.70 g (0.095 mol). The titanyl phthalocyanine crystal was produced in the same manner as the titanyl phthalocyanine crystal D (TiOPc-D) except that 4.1 g of unsubstituted titanyl phthalocyanine crystal (blue powder) was obtained.

(6) Production of titanyl phthalocyanine crystal F (TiOPc-F) In the production of titanyl phthalocyanine crystal F (TiOPc-F), the amount of urea added when the titanyl phthalocyanine compound was produced was 8.40 g (0. 14 mol) except that the titanyl phthalocyanine crystal was produced in the same manner as the titanyl phthalocyanine crystal D (TiOPc-D) to obtain 4.1 g of an unsubstituted titanyl phthalocyanine crystal (blue powder).

(7) Production of titanyl phthalocyanine crystal G (TiOPc-G) In the production of titanyl phthalocyanine crystal G (TiOPc-G), the amount of titanium tetrabutoxide added when producing the titanyl phthalocyanine compound was 15.0 g (0 0.044 mol) except that the titanyl phthalocyanine crystal was produced in the same manner as the titanyl phthalocyanine crystal E (TiOPc-E) to obtain 4.1 g of an unsubstituted titanyl phthalocyanine crystal (blue powder).

(8) Production of titanyl phthalocyanine crystal H (TiOPc-H) In the production of titanyl phthalocyanine crystal H, the amount of urea added when producing the titanyl phthalocyanine compound was 20.25 g (0.342 mol). A titanyl phthalocyanine crystal was produced in the same manner as the titanyl phthalocyanine crystal D (TiOPc-D) to obtain 4.1 g of an unsubstituted titanyl phthalocyanine crystal (blue powder).

2. Evaluation of titanyl phthalocyanine crystal (1) Measurement of CuKα characteristic X-ray diffraction spectrum 0.3 g of titanyl phthalocyanine crystal obtained in each of the above-described production examples within 60 minutes after production was applied to the coating liquid in the examples described later. Disperse in 5 g of the tetrahydrofuran used and store in a closed system for 7 days under conditions of a temperature of 23 ± 1 ° C. and a relative humidity of 50-60%. Then, the tetrahydrofuran is removed, and an X-ray diffractometer [Rigaku Corporation Measurement was performed by filling a sample holder of RINT1100]. The obtained spectrum charts are shown in FIGS.
The measurement conditions were as follows.
X-ray tube: Cu
Tube voltage: 40 kV
Tube current: 30 mA
Start angle: 3.0 °
Stop angle: 40.0 °
Scanning speed: 10 ° / min

Further, the obtained measurement results were evaluated according to the following criteria. The obtained results are shown in Table 1.
◯: Bragg angle 2θ ± 0.2 ° = 27.2 ° has the largest or second largest peak and no peak at 26.2 °.
X: It has a peak at a Bragg angle 2θ ± 0.2 ° = 26.2 °.

(2) Differential scanning calorimetry Differential scanning calorimetry of the titanyl phthalocyanine crystals obtained in the respective production examples was performed using a differential scanning calorimeter [manufactured by Rigaku Corporation, TAS-200, DSC8230D]. The obtained differential scanning Natsu amount analysis charts are shown in FIGS. Table 1 shows the peak temperature and the number of peaks in each chart.
Measurement conditions were as follows.
Sample pan: Al
Temperature increase rate: 20 ° C / min

  Hereinafter, a multilayer photoreceptor using each of the obtained titanyl phthalocyanine crystals as a charge generating agent was produced and evaluated as examples and the like.

[Example 1]
1. Manufacture of laminated photoreceptor (1) Formation of intermediate layer Using a paint shaker, 2.5 g of titanium oxide (MT-02, alumina, silica, silicone, surface-treated number average primary particle size is 10 nm (manufactured by Teika)) In addition, 1 g of quaternary copolymerized polyamide resin CM8000 (manufactured by Toray), 10 g of methanol as a solvent, and 2.5 g of n-butanol are mixed and dispersed for 10 hours, and further filtered through a 5 micron filter to obtain an intermediate layer A coating solution was prepared.
Next, one end of an aluminum substrate (supporting substrate) having a diameter of 30 mmφ and a length of 238.5 mm was placed on the upper side, and was applied by being immersed in the obtained intermediate layer coating solution at a rate of 5 mm / sec. Then, the hardening process was performed on 130 degreeC and the conditions for 30 minutes, and the intermediate | middle layer with a film thickness of 2 micrometers was formed.

(2) Formation of Charge Generation Layer Next, using a ball mill, 1 part by weight of titanyl phthalocyanine crystal D (TiOPc-D) produced as described above as the charge generation agent and polyvinyl acetal resin (ESREC KS-) as the binder resin are used. 5 Sekisui Chemical Co., Ltd.) 1 part by weight, 20 parts by weight of propylene glycol monomethyl ether as a dispersion medium, and 60 parts by weight of tetrahydrofuran were mixed and dispersed for 48 hours to obtain a coating solution for a charge generation layer. The obtained coating solution is filtered through a 3 micron filter, and then applied onto the above-described intermediate layer by dip coating, and dried at 80 ° C. for 5 minutes to form a charge generation layer having a thickness of 0.3 μm. did.

(3) Formation of charge transport layer Next, in an ultrasonic disperser, 70 parts by weight of a stilbene compound (HTM-1) represented by the formula (12) as a hole transport agent and a polycarbonate resin (Teijin Kasei) as a binder resin TS2020) After containing 100 parts by weight, 2 parts by weight of terphenyl (BP-1) represented by the formula (2) as an additive, and 460 parts by weight of tetrahydrofuran as a solvent, it was dispersed for 10 minutes with an ultrasonic disperser. Thus, a coating solution for a charge transport layer was obtained.
The obtained charge transport layer coating solution was applied onto the charge generation layer in the same manner as the charge generation layer coating solution, and dried at 130 ° C. for 30 minutes to form a charge transport layer having a thickness of 20 μm. A photographic photoreceptor was prepared.
The photoreceptor was produced in two ways: one formed using a coating solution for charge generation layer immediately after production and one formed using a coating solution for charge generation layer after storage for 7 days after production. .

2. Evaluation (1) Evaluation of change in light potential Further, the light potential Vr1 (V) of the photoreceptor formed using the charge generation layer coating solution immediately after production and the charge generation layer coating solution after storage for 7 days are used. The light potential Vr2 (V) of the formed photoreceptor was measured under the following conditions.
That is, the produced electrophotographic photosensitive member was charged to a surface potential of −700 V by corona discharge using a drum sensitivity tester under normal temperature and normal humidity (temperature: 20 ° C., humidity: 60%).
Next, light having a light intensity of 8 μW / cm ² monochromatized to a wavelength of 780 nm and a half-value width of 20 nm using a band-pass filter is exposed to the surface of the electrophotographic photosensitive member for 1.5 seconds, and 0.5 seconds from the start of exposure. The surface potential after 2 seconds was measured as a bright potential. Then, ΔVr (V) (= Vr2−Vr1) was calculated, and the electrical characteristics of the photosensitive layer were evaluated according to the following criteria from the absolute value of the change in the bright potential. The obtained results are shown in Table 1.
○: The absolute value of the change in bright potential is a value less than 10V.
(Triangle | delta): The absolute value of a bright potential change is a value below 10-30V.
X: The absolute value of the change in bright potential is a value of 30 V or more.

(2) Fog image evaluation In addition, using a printer Microline 22N (manufactured by Kyocera Mita Co., Ltd.) equipped with an electrophotographic photosensitive member formed using a coating solution for a charge generation layer after storage for 7 days, high temperature and high humidity (Temperature: 35 ° C, humidity: 85%) Image formation is performed, and an ISO standard 5% density image pattern is continuously printed on 200,000 sheets. An ISO standard 2% density image pattern is printed on an intermittent 50,000 sheets. did.
Next, with a spectrophotometer SpectroEye (manufactured by Gretag Macbeth Co., Ltd.), the non-printing area at the time of continuous printing of 200,000 sheets of ISO 5 standard 5% density image pattern and intermittent 50,000 sheets of ISO standard 2% density image pattern The image fog was evaluated according to the following criteria. The obtained results are shown in Table 1.
A: The density of the non-printing area is less than 0.008, and no fogging defect is observed at all.
(Triangle | delta): The density | concentration of a non-printing area is 0.008 or more and less than 0.015, and a fogging defect is observed a little.
X: The density of the non-printing area is 0.15 or more, and a remarkable fogging defect is observed.

(3) Evaluation of crack resistance About the manufactured photoreceptor, 45 g of olive oil (manufactured by BOSCO) was placed in a 50 ml beaker and partially immersed. Observation after 30 hours and 50 hours with a microscope confirmed whether cracks (cracks) had occurred, and evaluated according to the following criteria. The obtained results are shown in Table 2.
○: No crack is generated.
X: A crack has occurred.

[Examples 2 to 60]
In Examples 2 to 60, Example 1 except that the type of titanyl phthalocyanine crystal, the type of additive, and the content of the additive used when producing the photoreceptor were changed as shown in Table 2. A multilayer photoreceptor was manufactured and evaluated in the same manner as described above. The obtained results are shown in Table 2.

[Comparative Examples 1 to 66]
In Comparative Examples 1 to 66, Example 1 was used except that the type of titanyl phthalocyanine crystal, the type of additive, and the content of the additive used when producing the photoreceptor were changed as shown in Table 3. A multilayer photoreceptor was manufactured and evaluated in the same manner as described above. The obtained results are shown in Table 3.

[Comparative Examples 67-108]
In Comparative Examples 67 to 108, Example 1 except that the type of titanyl phthalocyanine crystal, the type of additive, and the content of the additive used in producing the photoreceptor were changed as shown in Table 4. A multilayer photoreceptor was manufactured and evaluated in the same manner as described above. Table 4 shows the obtained results.

According to the image forming apparatus using the electrophotographic photoreceptor according to the present invention, in the photosensitive layer, a specific titanyl phthalocyanine crystal is used as a charge generating agent together with an additive having a predetermined structure, so that storage in an organic solvent is possible. In addition to improved stability and ease of manufacture, good durability and image characteristics can be obtained.
Therefore, the image forming apparatus using the electrophotographic photosensitive member of the present invention makes not only the electrical characteristics and image characteristics in various image forming apparatuses such as copying machines and printers, but also facilitates production management, and further contributes significantly to economic effects. Is expected to do.

(A)-(c) is a figure provided in order to demonstrate the structure of a laminated type photoreceptor. (A)-(c) is a figure provided in order to demonstrate the structure of a single layer type photoreceptor. It is a figure provided in order to demonstrate the image forming apparatus provided with the lamination type electrophotographic photosensitive member. It is a CuKα characteristic X-ray diffraction spectrum in titanyl phthalocyanine crystal A. It is a CuKα characteristic X-ray diffraction spectrum in titanyl phthalocyanine crystal B. 2 is a CuKα characteristic X-ray diffraction spectrum of titanyl phthalocyanine crystal C. FIG. 2 is a CuKα characteristic X-ray diffraction spectrum of titanyl phthalocyanine crystal D. FIG. 2 is a CuKα characteristic X-ray diffraction spectrum of titanyl phthalocyanine crystal E. 2 is a CuKα characteristic X-ray diffraction spectrum of titanyl phthalocyanine crystal F. FIG. 3 is a CuKα characteristic X-ray diffraction spectrum of titanyl phthalocyanine crystal G. FIG. It is a CuKα characteristic X-ray diffraction spectrum in titanyl phthalocyanine crystal H. 3 is a differential scanning calorimetry chart in titanyl phthalocyanine crystal A. 3 is a differential scanning calorimetry chart in titanyl phthalocyanine crystal B. 2 is a differential scanning calorimetry chart in titanyl phthalocyanine crystal C. FIG. 2 is a differential scanning calorimetry chart in titanyl phthalocyanine crystal D. FIG. 2 is a differential scanning calorimetry chart in titanyl phthalocyanine crystal E. 2 is a differential scanning calorimetry chart in titanyl phthalocyanine crystal F. FIG. 2 is a differential scanning calorimetry chart in a titanyl phthalocyanine crystal G. 2 is a differential scanning calorimetry chart in titanyl phthalocyanine crystal H.

10: Single layer type photoreceptor 10 ': Single layer type photoreceptor 10 ": Single layer type photoreceptor 12: Conductive substrate 14: Photosensitive layer 16: Barrier layer 18: Protective layer 20: Multilayer type photoreceptor 20': Laminated photoreceptor 20 ″: Laminated photoreceptor 22: Charge transport layer 24: Charge generation layer 25: Intermediate layer 40: Copier 41: Image forming unit 41a: Image forming unit 41b: Paper feeding unit 42: Paper discharge unit 43: Image reading unit 43a: Light source 43b: Optical element 44: Document feeding unit 44a: Document loading tray 44b: Document feeding mechanism 44c: Document discharge tray 51: Photoconductor drum 52: Charger 53: Exposure unit 54: Developing unit 55: Transfer roller 56: Cleaning device 57: Fixing unit

Claims (5)

An electrophotographic photosensitive member provided with a photosensitive layer containing at least a charge generating agent, a charge transporting agent, and a binder resin is provided on a substrate, and charging means and exposure means are provided around the electrophotographic photosensitive member. An image forming apparatus comprising a developing unit and a transfer unit,
In the CuKα characteristic X-ray diffraction spectrum, the charge generator has a maximum or second largest peak at a Bragg angle 2θ ± 0.2 ° = 27.2 °, and no peak at 26.2 °, And in the differential scanning calorimetry, it is a titanyl phthalocyanine crystal having one peak in the range of 270 to 400 ° C. other than the peak accompanying vaporization of adsorbed water,
In the CuKα characteristic X-ray diffraction spectrum measured after the titanyl phthalocyanine crystal was immersed in an organic solvent for 7 days, it had a maximum or second largest peak at least at a Bragg angle 2θ ± 0.2 ° = 27.2 °. An image forming apparatus provided with an electrophotographic photosensitive member, having no peak at 26.2 °, and wherein the photosensitive layer contains a compound represented by the following general formula (1) as an additive: .

(In general formula (1), R ^{1 to} R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group-substituted phenyl group having 1 to 4 carbon atoms, or an unsubstituted phenyl group. R represents a methylene group, and n represents an integer of 0 to 1.)   The image forming apparatus according to claim 1, wherein the organic solvent is at least one member selected from the group consisting of tetrahydrofuran, dichloromethane, toluene, 1,4-dioxane, and 1-methoxy-2-propanol.   3. The image formation according to claim 1, wherein the content of the additive is set to a value within a range of 3 to 55 parts by weight with respect to 100 parts by weight of the binder resin forming the photosensitive layer. apparatus. The image forming apparatus according to claim 1, wherein the additive is a compound represented by the following formulas (2) to (6) or a derivative thereof.




  The photosensitive layer is a multilayer electrophotographic photoreceptor in which a charge generation layer containing the titanyl phthalocyanine crystal and a charge transport layer containing either a hole transport agent or an electron transport agent are laminated. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.