JP3496083B2 - Electrostatic latent image transfer type image forming method and image forming apparatus used therefor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image transfer type image forming method, and more particularly to an electrostatic latent image transfer type image forming method using a single-layer type organic electrophotographic photosensitive member, and an electrostatic latent image transfer used therefor. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art Many photoconductor systems and constituent materials are known as organic electrophotographic photoconductors used in the Carlson process which is one of electrophotographic processes. In order to achieve the desired quality requirements, the so-called function separation method, in which the functions of the photoconductor are separated and the functions are shared by several layers with different compositions and components, is the mainstay of current organic electrophotographic photoconductors. It is a method. As such an organic electrophotographic photosensitive member, a laminated organic electrophotographic photosensitive member in which a charge generating layer containing a charge generating pigment and a charge transporting layer containing an organic hole transporting material are laminated is a mainstream in practice. However, various single-layer organic electrophotographic photoreceptors have been proposed in order to simplify the manufacturing process, reduce costs, and the like. For example, JP-A-5
Japanese Patent Laid-Open No. 4-1633 discloses a single-layer type organic electrophotographic photosensitive member in which a charge-generating pigment is dispersed in a resin together with a donor and an acceptor which are charge-transporting substances, and JP-A-3-256050. Discloses a single-layer type organic electrophotographic photosensitive member having the same constitution as above using a diphenoquinone derivative as an acceptor. On the other hand, a visible image transfer method and an electrostatic latent image transfer method are known as one type of electrophotography. The former is a system in which an electrostatic latent image formed on an electrophotographic photosensitive member is developed with toner or the like to be visualized, and the visualized image on the photosensitive member is transferred to plain paper or the like, and the latter is
The electrostatic latent image is formed on the electrostatic recording medium by bringing the electrophotographic photosensitive member on which the electrostatic latent image is formed into contact with the electrostatic recording medium capable of holding the electrostatic latent image and applying a voltage therebetween. Is transferred, and then the electrostatic latent image transferred on the electrostatic recording body is developed and visualized.

The electrostatic latent image transfer system has a drawback in that plain paper cannot be used because an electrostatic recording medium having a conductive layer and a dielectric layer is required, but the electrostatic latent image on the electrophotographic photoreceptor is used. Since there is no need to develop the image directly, there is a merit that there is a high margin in the device design of arranging various units necessary for the electrophotographic process around the electrophotographic photosensitive member, and a toner image is formed directly on the electrophotographic photosensitive member. Not because
There is an advantage that a cleaning device for the photoconductor is not required and the mechanical stress on the surface of the photoconductor is very small. Furthermore, in particular, in the electrostatic latent image transfer system, since it is not necessary to transfer the developed image after development, there is a possibility that a high-definition and high-quality recorded image can be obtained as compared with the developed image transfer system. In particular, the study is being conducted as a method adapted to output a high quality electrophotographic recorded image.

In order to form a high-definition, high-quality recorded image on an electrostatic recording medium by such an electrostatic latent image transfer system,
It is necessary that an electrostatic latent image having a large potential contrast between the image portion and the non-image portion and having a high potential is transferred onto the electrostatic recording body. Therefore, the characteristics required for the organic electrophotographic photosensitive member are that it has good chargeability and high sensitivity, and that it does not change with time.

[0005]

However, when an organic electrophotographic photosensitive member is used in the electrostatic latent image transfer system, particularly when a single-layer type organic electrophotographic photosensitive member is used, the charging potential decreases with time. The dark contrast is increased and the potential contrast between the image portion and the non-image portion is large on the electrostatic recording material, and the electrostatic latent image having a high potential cannot be transferred, so that it is formed on the electrostatic recording material. There is a problem that the density of the formed image is lowered and the background is stained. Then, the subject of this invention is solving such a problem. That is, an object of the present invention is to stably produce an electrostatic latent image for a long period of time without causing a decrease in charging potential or an increase in dark decay over time when a single-layer organic electrophotographic photoreceptor is used. An object of the present invention is to provide an electrostatic latent image transfer type image forming method capable of transferring, and an electrostatic latent image transfer type image forming apparatus used therefor.

[0006]

The above objects of the present invention can be achieved by the inventions described in the claims. That is, the invention of claim 1 forms an electrostatic latent image on a single-layer type organic electrophotographic photosensitive member, and then contacts the electrostatic recording member with the surface of the photosensitive member, and the photosensitive member and the electrostatic recording member. A voltage is applied between the two to transfer the electrostatic latent image on the electrostatic recording medium, and the electrostatic latent image on the electrostatic recording medium is developed using a developer capable of generating solvent vapor. > In an electrostatic latent image transfer type image forming method of developing and visualizing with an image device, forming an electrostatic latent image on the photoconductor in an atmosphere isolated from the atmosphere in the developing device and its peripheral portion. This is a characteristic electrostatic latent image transfer type image forming method. The invention of claim 2 is the same as the invention of claim 1,
The electrostatic latent image transfer type image forming method is characterized in that the ambient atmosphere of the single-layer organic electrophotographic photosensitive member is filled with the outside air of the image forming apparatus. A third aspect of the present invention is the electrostatic latent image transfer type image forming method according to the second aspect, wherein the single layer type organic electrophotographic photosensitive member is heated by heated outside air.

According to the present invention described above, there is no decrease in charging potential or increase in dark decay of a single-layer type organic electrophotographic photosensitive member due to repeated use, and the electrostatic latent image is stably maintained for a long period of time. Image transfer can be performed. The reason for this is not clear, but it is possible that the electrostatic latent image is formed on the single-layer organic electrophotographic photosensitive member in an atmosphere isolated from the atmosphere in the developing device and its peripheral portion. The contact between the electrophotographic photoreceptor and the deterioration gas of the photoreceptor such as the solvent vapor of the developer is suppressed, and the ambient atmosphere of the single-layer organic electrophotographic photoreceptor is filled with the outside air of the image forming apparatus to form an image. Ozone, nitrogen oxides (NOx), and other oxidizing gases generated in the device are suppressed from coming into contact with the single-layer organic electrophotographic photosensitive member, and thus the single-layer organic electrophotographic photosensitive member can be stored with time. It is possible to better prevent the decrease of the charging potential and the increase of dark decay of
It is considered that the electrostatic latent image can be stably transferred over a long period of time.

Further, by heating the single-layer type organic electrophotographic photosensitive member by the heated outside air, the deteriorating gas and its derivatives adhering to the surface of the single-layer type organic electrophotographic photosensitive member are removed from the surface of the photosensitive member. Since the photoconductor that has been separated or decomposed and slightly deteriorated is recovered, the charge potential of the single-layer organic electrophotographic photoconductor does not decrease and the dark decay does not increase even when it is repeatedly used, and it is stable over a long period of time. It is considered that the electrostatic latent image can be transferred by using this method.

In the single-layer type organic electrophotographic photosensitive member used in the present invention, the charge generating pigment and the organic hole transporting substance are dispersed in a binder directly or through an undercoat layer on a conductive substrate. An electrophotographic photosensitive member having a single photosensitive layer, a single photosensitive layer in which a charge generating pigment and an organic acceptor compound are dispersed in a binder directly or through an undercoat layer on a conductive substrate. An electrophotographic photosensitive member having, or
An electrophotographic photoreceptor having a single photosensitive layer in which a charge generating pigment, an organic hole transporting substance and an organic acceptor compound are dispersed in a binder directly or through an undercoat layer on a conductive substrate is preferable. . Such a single-layer type organic electrophotographic photosensitive member has good chargeability and high sensitivity, and has a large potential contrast between an image portion and a non-image portion on the photosensitive member and is capable of forming an electrostatic latent image having a high potential. You can Therefore, by transferring the electrostatic latent image onto the electrostatic recording medium, it is possible to form an electrostatic latent image on the electrostatic recording medium having a high potential contrast between the image portion and the non-image portion and having a high potential. Therefore, a high-definition, high-quality recorded image can be obtained.

As the charge generating pigment, it is preferable to use a phthalocyanine pigment, a bisazo pigment or the like, especially X
Type metal-free phthalocyanine pigment, or the following general formula (1)
Alternatively, it is preferable to use the compound represented by (2).

[Chemical 1] (In the formula, Cp represents a coupler residue.)

[Chemical 2] (In the formula, R represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a nitro group, and Cp represents a coupler residue.) Specific examples of R include a methyl group, an ethyl group, a methoxy group, and an ethoxy group. , Chlorine atom and the like. Specific examples of the coupler residue in the compound represented by the general formula (1) or (2) include those shown in Table 1- (1) to (20). Examples of the coupler residue in the compound represented by the general formula (1) include No. 1, 14, 2
Nos. 6 and 44 are particularly preferable, and as the coupler residue in the compound represented by the general formula (2), No. Those designated 1, 14, 18, 26, 44 or 62 are particularly preferred.

[0011]

[Table 1- (1)]

[0012]

[Table 1- (2)]

[0013]

[Table 1- (3)]

[0014]

[Table 1- (4)]

[0015]

[Table 1- (5)]

[0016]

[Table 1- (6)]

[0017]

[Table 1- (7)]

[0018]

[Table 1- (8)]

[0019]

[Table 1- (9)]

[0020]

[Table 1- (10)]

[0021]

[Table 1- (11)]

[0022]

[Table 1- (12)]

[0023]

[Table 1- (13)]

[0024]

[Table 1- (14)]

[0025]

[Table 1- (15)]

[0026]

[Table 1- (16)]

[0027]

[Table 1- (17)]

[0028]

[Table 1- (18)]

[0029]

[Table 1- (19)]

[0030]

[Table 1- (20)]

As the organic hole transporting substance of the single-layer type organic electrophotographic photoreceptor of the present invention, known substances can be used, for example, compounds having a triphenylamine moiety in the molecule, hydrazone compounds, triphenyl. Methane compounds, oxadiazole compounds, carbazole group-containing compounds, bipisoline compounds, styryl compounds,
Examples thereof include a butadiene-based compound, a polysilane-based compound having a linear main chain made of Si, and a polymer donor compound such as polyvinylcarbazole.

Specific examples include, for example, 4'-diphenylamino-α-phenylstilbene, 4'-bis (4-methylphenyl) amino-α-phenylstilbene, N,
N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine, 4'-methoxy-N, N'-diphenyl- [1,
1'-biphenyl] -4-amine, 9-ethylcarbazole-3-aldehyde-1-methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-
1,1-diphenylhydrazone, 4-diethylaminostyryl-3-aldehyde-1-methyl-1-phenylhydrazone, 4-methoxybenzaldehyde-1-methyl-1-phenylhydrazone, 4-diphenylaminobenzaldehyde-1-benzyl-1 -Phenylhydrazone, 1,1-bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane, 1,1-bis (4-dibenzylaminophenyl) propane, 2,2'-dimethyl- 4,4'-bis (diethylamino) -triphenylmethane, 2,5-bis (4-
Diethylaminophenyl) -1,3,4-oxadiazole, 2-N, N-diphenylamino-5- (4-diethylaminophenyl) -1,3,4-oxadiazole, 2-N, N-diphenylamino-5- ( N-ethylcarbazol-3-yl) -1,3,4-oxadiazole, 3-styryl-9-ethylcarbazole, 3-
(4-methoxystyryl) -9-ethylcarbazole,
4-diphenylaminostilbene, 4-dibenzylaminostilbene, 1,4-bis (4-diphenylaminostyryl) benzene, 1,4-bis [4-di (p-tolyl) aminostyryl] benzene, 1-phenyl- 3-
(4-Diethylaminostyryl) -5- (4-diethylaminophenyl) pyrazoline, 1-phenyl-3- (4
-Dimethylaminostyryl) -5- (4-dimethylaminophenyl) pyrazoline and the like.

As the organic acceptor compound,
It is preferable to use a compound represented by the following general formula (3) or (4).

[Chemical 3] (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each is at least one selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyano group and a nitro group. Represents a group, X is ═O, the following formulas (I) and (I
At least 1 selected from the group consisting of groups represented by I)
Represents a species group. ) = C (A1) (B1 ) (I) = N-R 5 (II)

In the above (I), A1 and B1 are the same or different and each is at least one selected from the group consisting of a hydrogen atom, a halogen atom, a cyano group, a substituted or unsubstituted aromatic group, and -COOR ₆ . Represents a group. Above (II)
In, R ₅ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic group, or a cyano group. R ₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic group. )

[Chemical 4] (In the formula, X represents at least one group selected from the group consisting of = 0, groups represented by the following formulas (III) and (IV).) = C (A2) (B2) (III ) = N-R ₇ (IV)

In the above (III), A2 and B2 are the same or different and each is a hydrogen atom, a cyano group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, and -COOR. Represents at least one group selected from the group consisting of ₈ . Above (I
In V), R ₇ is a substituted or unsubstituted phenyl group,
It represents a substituted or unsubstituted naphthyl group or a cyano group. R ₈ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted phenyl group. W represents at least one group selected from the group consisting of an alkyl group, a halogen atom, an alkoxycarbonyl group, a phenyl group, a cyano group, or a nitro group. n represents an integer of 0 to 4. )

The content of the charge generating pigment in the photosensitive layer of the single-layer type organic electrophotographic photosensitive member is 0.3 to 10 relative to the photosensitive layer.
Weight percent is suitable. If it is more than this, the charging potential is lowered, and if it is less than this, the light absorption property of the photoreceptor is deteriorated and the sensitivity is lowered. Further, the content of the organic acceptor compound is appropriately 6 to 60% by weight, and the weight composition ratio of the hole transport material and the organic acceptor compound is 50/1.
~ 1/5 is suitable. When the content of the organic acceptor compound is less than this, the residual potential is increased and the sensitivity is decreased, and when it is more than this, the electron injection amount from the substrate is increased and the charging property is decreased. .

As the binder in the photosensitive layer of the single-layer type organic electrophotographic photoreceptor, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin is used. , Addition resin of alkyd resin, polycarbonate resin, silicone resin, melamine resin, polyaddition resin, polycondensation resin, and copolymer resin containing two or more of these repeating units,
For example, vinyl chloride-vinyl acetate copolymer, vinyl chloride-
Examples thereof include vinyl acetate-maleic anhydride copolymer resin.

The role of the binder in the photoconductor is not only good dispersion of the charge generation pigment and molecular dispersion of the organic hole transporting substance or the organic acceptor compound, but also the photoconductor required in the image forming process. Is also responsible for the mechanical strength of. However, in the electrostatic latent image transfer type image forming method of the present invention, since development on the photoconductor is not required, cleaning of the photoconductor may be much weaker than that of the image transfer process of the visible image transfer system. Therefore, in the electrostatic latent image transfer type image forming method of the present invention, the content of the binder in the photosensitive layer can be reduced.

The amount of the binder in the photosensitive layer is 20 to 90% by weight, preferably 30 to 70% by weight. The thickness of the photosensitive layer is preferably 5 to 30 μm, and if it is thinner than this, the charging property is lowered, and if it is thick, the electrostatic capacity of the photoconductor is lowered and the transfer potential is lowered.

As the conductive substrate in the single-layer type organic electrophotographic photosensitive member, a metal plate such as aluminum, nickel, copper or stainless steel, a metal drum or a metal foil, a thin film of aluminum, tin oxide or copper iodide is applied. Examples thereof include plastic films and glass. Further, for the purpose of improving the charging property, an undercoat layer can be provided between the photosensitive layer and the conductive substrate. As these materials, in addition to the binder material, polyamide resin, polyvinyl alcohol, casein, polyvinyl can be used. Pyrrolidone or the like can be used.

To prepare a single-layer type organic electrophotographic photoreceptor,
The photosensitive layer forming liquid prepared by dissolving or dispersing the above materials in an organic solvent or ball mill, ultrasonic wave or the like is applied onto a conductive substrate by a dipping method, blade coating, spray coating or the like and dried to form a photosensitive layer. It may be formed.

Next, the electrostatic latent image transfer type image forming apparatus of the present invention will be described. For the electrostatic latent image transfer type image forming method of the present invention, it is preferable to use the following electrostatic latent image transfer type image forming apparatus. That is, after forming an electrostatic latent image on a single-layer organic electrophotographic photosensitive member, an electrostatic recording material is brought into contact with the surface of the photosensitive material, and a voltage is applied between the photosensitive material and the electrostatic recording material. A developer capable of transferring the electrostatic latent image onto the electrostatic recording medium and generating the solvent vapor from the electrostatic latent image on the electrostatic recording medium.
In an electrostatic latent image transfer type image forming apparatus which is developed and visualized by a developing device, at least the photoconductor is housed in a housing isolated from the atmosphere in the developing device and its peripheral portion. It is preferable to use an electrostatic latent image transfer type image forming apparatus. In addition, the housing is provided with a pair of air ports for inflowing and outflowing gas, and at least one of the air ports is filled with the ambient atmosphere of the single-layer organic electrophotographic photosensitive member by the outside air of the image forming apparatus. It is preferable to provide the ventilation means having the blower mechanism, and it is preferable to further provide the gas heating means to the ventilation means having the blower mechanism. Further, it is preferable that the housing in which the single-layer organic electrophotographic photosensitive member is housed can be attached to and detached from the image forming apparatus.

According to the electrostatic latent image transfer type image forming apparatus of the present invention, the single layer type organic electrophotographic photosensitive member is housed in the housing and is isolated from the atmosphere in the developing device and its peripheral portion, thereby repeating. Even when an image is formed, the electrostatic latent image is stably transferred for a long period without lowering the charging potential or increasing the dark decay of the single-layer organic electrophotographic photoreceptor over time. be able to.

Further, in order to fill the ambient atmosphere of the single-layer type organic electrophotographic photosensitive member with the outside air of the image forming apparatus, at least one pair of air openings for letting gas in and out are provided in the housing. By ventilating the outside air into the housing by providing a ventilation means having an air blowing mechanism, it is possible to better prevent a decrease in charging potential and an increase in dark decay of the single-layer organic electrophotographic photosensitive member, and for a long period of time. The electrostatic latent image can be transferred stably.

Further, by providing a gas heating means in the ventilation means having a blowing mechanism and heating the single-layer type organic electrophotographic photosensitive member with hot air, the single-layer type organic electrophotographic photosensitive member is restored to almost the same state as the initial state. Therefore, the electrostatic latent image can be stably transferred over a long period of time. Further, by making the housing in which the single-layer type organic electrophotographic photosensitive member is housed in the image forming apparatus removable, the photosensitive member can be replaced together with the housing when the photosensitive member is replaced. The operability of the device can be easily and simply made. As the single-layer organic electrophotographic photosensitive member in this electrostatic latent image transfer type image forming apparatus, it is preferable to use the single-layer organic electrophotographic photosensitive member described in detail above.

An example of the electrostatic latent image transfer type image forming apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view schematically showing an example of the electrostatic latent image transfer type image forming apparatus of the present invention. As shown in FIG. 1, a single-layer organic electrophotographic photosensitive member 1 provided on a drum-shaped conductive substrate is housed in a housing 6. The housing 6 is provided with air holes 7A and 7B, and the air holes 7A are provided with ventilation means having a blowing mechanism. Further, the gas heating means 13 is provided in the ventilation means having a blowing mechanism. Further, the casing 6 houses the static elimination lamp 5, the casing 6 is set with the charger 2, and the opening or window through which the laser writing light 3 passes or transmits is provided. The single-layer type organic electrophotographic photosensitive member 1 housed in the housing 6 is in contact with the electrostatic recording body 10 that is conveyed while being in close contact with the conductive transfer drum 9 at the opening of the housing 6, and the transfer voltage is applied. A power source 8 applies a voltage between the photoconductor and the electrostatic recording body. To form an image using this electrostatic latent image transfer type image forming apparatus, the single layer type organic electrophotographic photosensitive member 1 housed in the housing 6 is uniformly charged by the charger 2 and laser writing light is applied. 3 is irradiated onto the photoconductor to form an electrostatic latent image on the photoconductor surface, and then the electrostatic recording body 10 is formed on the photoconductor surface.
And a voltage is applied between the photoconductor and the electrostatic recording body by the transfer voltage power source 8 to transfer the electrostatic latent image to the electrostatic recording body 10, and electrostatic charges on the electrostatic recording body are transferred. The latent image may be developed by the developing unit 12 and visualized. Reference numerals 4 and 11 in the figure denote electrometers used for measuring potentials in the following examples, where 4 is a photoconductor surface electrometer and 11 is an electrostatic recording surface electrometer.

Examples of the material constituting the housing in the present invention include metals or alloys such as aluminum, nickel, steel, and stainless steel, and various known materials such as various plastics or glass and wood boards, quartz boards, and the like. It is preferable to use a plastic material in terms of weight and processability.

[0048]

EXAMPLES The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited thereby.

Example 1 Phthalocyanine pigment represented by the following formula (A) / polycarbonate represented by the following formula (B) / organic hole-transporting substance represented by the following formula (C) 2/50 by weight
A coating liquid having a composition of / 48 was prepared by adding it to tetrahydrofuran. This coating solution was coated on a drum-shaped aluminum substrate by a dipping coating method and dried by heating to prepare an electrophotographic photosensitive member having a single photosensitive layer of about 14 μm.

[Chemical 5]

[Chemical 6]

[Chemical 7] The electrostatic latent image transfer characteristic was evaluated by the electrostatic latent image transfer type electrophotographic apparatus of the embodiment shown in FIG. The photosensitive drum is covered with a polypropylene casing. + 800V about the photoconductor
After corona charging, the entire surface is exposed with a laser beam having a wavelength of 670 nm to attenuate the surface potential of the photoconductor to about 10 V,
An electrostatic latent image pattern was formed on the photoreceptor. The nip width at the contact portion between the photoconductor and the electrostatic recording paper was set to about 5 mm, the moving speed was set to about 20 mm / sec, and the applied voltage between the photoconductor and the electrostatic recording paper was set to -750 V and static electricity was applied to the photoconductor. When the electrostatic latent image pattern was transferred onto the electrostatic recording paper, the initial electrostatic recording paper transfer potential Vp was -95V. 1000 operations above
The charging potential Vs, the post-exposure potential Vr, and the electrostatic recording paper transfer potential Vp of the photoconductor after repeating the measurement were measured. as a result,
The potential of the exposed area is about 3 due to the increase of Vr after 1000 times.
Although it became 0V, Vs was 775V. Also, 10
Vp after repeating 00 times was -90V. 100
Change rate of electrostatic recording paper transfer potential within ± 10% before and after repeated 0 times continuously, change amount of charged potential of photoconductor is ± 10%
Within that, there was no practical problem.

Comparative Example 1 The electrostatic latent image transfer characteristics were measured in the same manner as in Example 1 except that the polypropylene casing covering the photosensitive drum was removed during the repeated test. As a result, 1000
After repeating V times, Vr rises to about 100 V and Vs is 7
50V, Vp after repeating 1000 times is -75V
Fell to.

Example 2 A repeated test was conducted under the same conditions as in Example 1 except that a fan blows outside air at an amount of about 1 liter / minute from one of a pair of air holes provided in the housing. As a result, the potential of the exposed portion became about 20V due to the rise of Vr after 1000 times, but Vs was 785V. Moreover, Vp after repeating 1000 times was -93V.

Example 3 In Example 2, outside air heated by a heater provided outside the fan was blown to the photoconductor at an amount of about 1 liter / min for 30 minutes to heat the photoconductor to about 90 ° C. After the heat treatment and after standing to cool, Vr became about 10V and Vs recovered to 800V.

Example 4 The composition ratio of the photoreceptor is pigment / Pc-Z / organic hole transport material /
4/50/2 by weight ratio of organic acceptor compounds in order
A disazo pigment of the following structural formula (D), a polycarbonate (Pc-Z) of the above structural formula (B), and an organic hole transporting substance of the above structural formula (C) in tetrahydrofuran so as to have a composition of 4/24. An appropriate amount of each organic acceptor compound represented by the following structural formula (E) was added to prepare a coating solution. This liquid was coated on a drum-shaped aluminum substrate by a dipping coating method and dried by heating to prepare an electrophotographic photosensitive member having a single photosensitive layer of about 14 μm.

[Chemical 8]

[Chemical 9] In the same manner as in Example 1, without charging the outside air, the initial charging potential Vs of the photoconductor, the post-exposure potential Vr, the initial electrostatic recording paper transfer potential Vp, and the charging of the photoconductor after repeating 1000 times. The potential Vs, the post-exposure potential Vr, and the electrostatic recording paper transfer potential Vp after repeating 1000 times were measured. The results are shown in Table 2.

Example 5 The compound of the following structural formula (F) was used as the organic acceptor compound, and the weight composition of pigment / Pc-Z / organic hole transport material / organic acceptor compound was set to 4/50/28/18. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the above was carried out, and the outside air was blown in the same manner as in Example 2 to obtain the initial charging potential Vs of the photosensitive member, the post-exposure potential Vr, and the initial electrostatic recording paper. The transfer potential Vp, the charging potential Vs and the post-exposure potential Vr of the photoconductor after 1000 times of repetition, and the electrostatic recording paper transfer potential Vp after 1000 times of repetition were measured.

[Chemical 10]

Example 6 The phthalocyanine pigment represented by the structural formula (A) of Example 1 was used as the charge generation pigment, and the weight composition ratio of the photosensitive layer was pigment / Pc-Z / organic hole transport material / organic acceptor compound. Example 5 except that the order was 2/50/30/18
An electrophotographic photosensitive member was produced in the same manner as in, and the charging potential Vs, the post-exposure potential Vr, and the electrostatic recording paper transfer potential Vp were measured in the same manner as in Example 5. The results are shown in Table 2.

Example 7 A disazo pigment having the following structural formula (G) was used as the charge generating pigment, and the weight composition ratio of the photosensitive layer was 4 / in the order of pigment / Pc-Z / organic hole transporting material / organic acceptor compound. 50 /
An electrophotographic photosensitive member was produced in the same manner as in Example 5 except that the charging potential was Vs, the post-exposure potential Vr, and the electrostatic recording paper transfer potential Vp.
Was measured. The results are shown in Table 2.

[Chemical 11]

Example 8 The phthalocyanine pigment represented by the structural formula (A) of Example 1 was used as the charge generating pigment, and the compound of the following structural formula (H) was used as the organic acceptor compound. An electrophotographic photoreceptor was prepared in the same manner as in Example 5, except that the order of pigment / Pc-Z / organic hole transporting material / organic acceptor compound was changed to 2/50/24/24, and the same as in Example 5. Then, the charging potential Vs of the photoconductor, the post-exposure potential Vr, and the electrostatic recording paper transfer potential Vp were measured. The results are shown in Table 2.

[Chemical 12]

[0058]

[Table 2]

[0059]

According to the electrostatic latent image transfer type image forming method of the present invention, an electrostatic latent image is formed on the photoconductor in an atmosphere isolated from the atmosphere in the developing device and its peripheral portion. As a result, the electrostatic latent image can be stably transferred for a long period of time without a decrease in charging potential or an increase in dark decay of the single-layer organic electrophotographic photosensitive member due to repeated use. By filling the ambient atmosphere of the single-layer organic electrophotographic photosensitive member with the outside air of the image forming apparatus, it is possible to better prevent the decrease of the charging potential and the increase of dark decay of the single-layer organic electrophotographic photosensitive member over time. Therefore, the electrostatic latent image can be stably transferred over a long period of time. In addition, by heating the single-layer organic electrophotographic photosensitive member by the heated outside air, the deteriorated photosensitive member is recovered, and even when repeatedly used, the charging potential of the single-layer organic electrophotographic photosensitive member is lowered and dark decay is prevented. Without causing an increase,
The electrostatic latent image can be transferred stably over a long period of time. Furthermore, by using a single-layer type organic electrophotographic photosensitive member containing an organic acceptor compound, the electrophotographic photosensitive member has good chargeability and high sensitivity. An electrostatic latent image having a large potential contrast and a high potential can be formed, and there is no decrease in the charging potential or increase in dark decay over time of the photoconductor due to repeated use. An electrostatic latent image having a large potential contrast with the non-image portion and a high potential can be stably transferred onto the electrostatic recording medium for a long period of time. By using an X-type metal-free phthalocyanine pigment or a specific disazo pigment or a specific acceptor compound as the charge generation pigment, the above effect can be more effectively exhibited. According to the electrostatic latent image transfer type image forming method of the present invention,
When the single-layer organic electrophotographic photosensitive member is housed in a housing and isolated from the atmosphere in the developing device and its peripheral portion, the single-layer organic electrophotographic photosensitive member is aged even when repeated image formation is performed. It is possible to stably transfer the electrostatic latent image for a long period of time without lowering the charging potential or increasing the dark decay in the above. Further, a pair of air inlets for letting gas in and out is provided in the housing, and at least one of the air inlets is a blowing mechanism for filling the ambient atmosphere of the single-layer organic electrophotographic photosensitive member with the outside air of the image forming apparatus. By ventilating the outside air into the housing by providing a ventilation means having, it is possible to better prevent a decrease in the charging potential and an increase in dark decay of the single-layer organic electrophotographic photosensitive member, and stably for a long period of time. An electrostatic latent image can be transferred. Further, by providing a gas heating means in the ventilation means having a blowing mechanism and heating the single-layer organic electrophotographic photoreceptor with hot air, the single-layer organic electrophotographic photoreceptor can be recovered to almost the same state as the initial state. Therefore, the electrostatic latent image can be stably transferred over a long period of time. Further, by making the housing in which the single-layer type organic electrophotographic photosensitive member is housed in the image forming apparatus removable, the photosensitive member can be replaced together with the housing when the photosensitive member is replaced. The operability of the device can be easily and simply made.

[Brief description of drawings]

FIG. 1 is a schematic sectional view schematically showing an example of an electrostatic latent image transfer type image forming apparatus of the present invention.

[Explanation of symbols]

1 Single-layer organic electrophotographic photoreceptor 2 charger 3 Laser writing light 4 Photoconductor surface potential meter 5 Static elimination lamp 6 housing 7A air hole 7B air hole 8 Transfer voltage power supply 9 Conductive transfer drum 10 Electrostatic recording 11 Electrostatic recording surface electrometer 12 Development Department 13 Heating means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI G03G 5/06 346 G03G 5/06 346A 370 370 15/18 15/18 (56) Reference JP-A-6-175516 (JP, A) JP-A-6-202359 (JP, A) JP-A-6-266136 (JP, A) JP-A-6-161280 (JP, A) JP-A-5-11566 (JP, A) JP-A-5 -27488 (JP, A) JP-A-6-35251 (JP, A) JP-A-50-39552 (JP, A) Actual development 3-29943 (JP, U) (58) Fields investigated (Int.Cl) . ^7, DB name) G03G 21/00 370 - 540 G03G 21/20 G03G 15/18 G03G 15/10 G03G 15/00 550 G03G 21/16 - 21/18

Claims (13)

(57) [Claims] 1. An electrostatic latent image is formed on a single-layer type organic electrophotographic photoreceptor, and then an electrostatic recording body is brought into contact with the surface of the photoreceptor,
A voltage may be applied between the photoconductor and the electrostatic recording medium to transfer the electrostatic latent image on the electrostatic recording medium, and the electrostatic latent image on the electrostatic recording medium may generate solvent vapor. In an electrostatic latent image transfer type image forming method of developing and visualizing with a developing device using a developer, an electrostatic latent image is formed on the photoconductor in an atmosphere isolated from the atmosphere in the developing device and its peripheral portion. An electrostatic latent image transfer type image forming method characterized by forming the image. 2. The electrostatic latent image transfer type image forming method according to claim 1, wherein the ambient atmosphere of the single-layer organic electrophotographic photosensitive member is filled with the outside air of the image forming apparatus. 3. The electrostatic latent image transfer type image forming method according to claim 2, wherein the single-layer organic electrophotographic photosensitive member is heated by heated outside air. 4. A single-layer type organic electrophotographic photosensitive member is obtained by binding a charge generation pigment to an electroconductive substrate directly or via an undercoat layer and at least one of an organic hole transporting substance and an organic acceptor compound. 4. The electrostatic latent image transfer type image forming method according to claim 1, which is an electrophotographic photosensitive member having a single photosensitive layer dispersed in the agent. 5. The electrostatic latent image transfer type image forming method according to claim 4, wherein in the single-layer type organic electrophotographic photosensitive member, the charge generating pigment is an X type metal-free phthalocyanine pigment. 6. The electrostatic latent image transfer type image formation according to claim 4, wherein in the single-layer type organic electrophotographic photoreceptor, the charge generating pigment is a compound represented by the following general formula (1). Method. [Chemical 1] (In the formula, Cp represents a coupler residue.) 7. The electrostatic latent image transfer type image formation according to claim 4, wherein in the single-layer type organic electrophotographic photoreceptor, the charge generating pigment is a compound represented by the following general formula (2). Method. [Chemical 2] (In the formula, R represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen or a nitro group, and Cp represents a coupler residue.) 8. The electrostatic latent image transfer image according to claim 4, wherein in the single-layer organic electrophotographic photoreceptor, the organic acceptor compound is a compound represented by the following general formula (3). Forming method. [Chemical 3] (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each is at least one selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyano group and a nitro group. Represents a group, X is ═O, the following formulas (I) and (I
At least 1 selected from the group consisting of groups represented by I)
Represents a species group. = In C (A1) (B1) ( I) = N-R 5 (II) above (I), A1, B1 are the same or different, a hydrogen atom, a halogen atom, a cyano group, a substituted or unsubstituted aromatic group , And at least one group selected from the group consisting of —COOR ₆ . In the above (II), R
₅ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic group, or a cyano group. R ₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic group. ) 9. The electrostatic latent image transfer image according to claim 4, wherein in the single-layer organic electrophotographic photoreceptor, the organic acceptor compound is a compound represented by the following general formula (4). Forming method. [Chemical 4] (In the formula, X represents at least one group selected from the group consisting of = 0, groups represented by the following formulas (III) and (IV).) = C (A2) (B2) (III ) = N−R ₇ (IV) In the above (III), A2 and B2 are the same or different,
It represents at least one group selected from the group consisting of a hydrogen atom, a cyano group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, and -COOR ₈ . In the above (IV), R ₇ represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or a cyano group. R ₈ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted phenyl group. W is at least 1 selected from the group consisting of an alkyl group, a halogen atom, an alkoxycarbonyl group, a phenyl group, a cyano group, or a nitro group.
Represents a species group. n represents an integer of 0 to 4. ) 10. An electrostatic latent image is formed on a single-layer type organic electrophotographic photoreceptor, and then an electrostatic recording body is brought into contact with the surface of the photoreceptor,
A voltage may be applied between the photoconductor and the electrostatic recording medium to transfer the electrostatic latent image on the electrostatic recording medium, and the electrostatic latent image on the electrostatic recording medium may generate solvent vapor. In an electrostatic latent image transfer type image forming apparatus which develops and visualizes with a developing device using a developer, at least the photoconductor is housed in a housing that isolates the atmosphere in the developing device and its surroundings. An electrostatic latent image transfer type image forming apparatus characterized by being provided. 11. The housing has a pair of air ports through which gas flows in and out, and at least one of the air ports is filled with the ambient atmosphere of the single-layer organic electrophotographic photosensitive member by the outside air of the image forming apparatus. 11. An electrostatic latent image transfer type image forming apparatus according to claim 10, further comprising ventilation means having a blowing mechanism for controlling the electrostatic latent image. 12. The electrostatic latent image transfer type image forming apparatus according to claim 11, wherein a ventilation means having a blowing mechanism is provided with a heating means for gas. 13. The electrostatic latent image transfer type image forming apparatus according to claim 10, wherein the housing containing the single-layer type organic electrophotographic photosensitive member is detachable from the image forming apparatus.