CA2067011A1 - Electrophotographic photoreceptor - Google Patents
Electrophotographic photoreceptorInfo
- Publication number
- CA2067011A1 CA2067011A1 CA 2067011 CA2067011A CA2067011A1 CA 2067011 A1 CA2067011 A1 CA 2067011A1 CA 2067011 CA2067011 CA 2067011 CA 2067011 A CA2067011 A CA 2067011A CA 2067011 A1 CA2067011 A1 CA 2067011A1
- Authority
- CA
- Canada
- Prior art keywords
- acid
- electrophotographic photoreceptor
- photoreceptor according
- layer
- charge transport
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
- G03G5/02—Charge-receiving layers
- G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
- G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
- G03G5/0503—Inert supplements
- G03G5/051—Organic non-macromolecular compounds
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
- G03G5/02—Charge-receiving layers
- G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
- G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
- G03G5/0503—Inert supplements
- G03G5/051—Organic non-macromolecular compounds
- G03G5/0514—Organic non-macromolecular compounds not comprising cyclic groups
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- General Physics & Mathematics (AREA)
- Photoreceptors In Electrophotography (AREA)
Abstract
ABSTRACT
An electrophotographic photoreceptor disclosed herein has on a conductive base, a photoconductive layer containing at least a charge generation material and a charge transport material, the photoconductive layer further containing an organic acid, whose acid dissociation constant pKa in its aqueous solution is in a range of 2.1 to 4.3, in an amount of 0.001 to 10 parts by weight per 100 parts by weight of the charge transport material. The photoconductive layer may be the laminated-type photoconductive layer or the dispersion-type photoconductive layer. The electrophotographic photoreceptor according to the invention is excellent in durability.
An electrophotographic photoreceptor disclosed herein has on a conductive base, a photoconductive layer containing at least a charge generation material and a charge transport material, the photoconductive layer further containing an organic acid, whose acid dissociation constant pKa in its aqueous solution is in a range of 2.1 to 4.3, in an amount of 0.001 to 10 parts by weight per 100 parts by weight of the charge transport material. The photoconductive layer may be the laminated-type photoconductive layer or the dispersion-type photoconductive layer. The electrophotographic photoreceptor according to the invention is excellent in durability.
Description
~67~ ~
ELECTROP~OTOGRAPHIC P~OTOR~CEPTOR
E~IE~ OF THE INVENTION
The invention relates to an electrophotographic photoreceptor. More particularly, it relates to the electro-photographic photoreceptor having an excellent durability.
BA~KGOUND OF THE INVENTION
In recent years, the electrophotography has been applied to copying machines as well as various printers, because they can give images with high qualities without delay. As a photoreceptor which plays an important role in the electrophotography, the photoreceptor comprising an inorganic photoconductive substance such as selenium, arsenic-selenium alloy, cadmium sulfide, zinc oxide and the like has been used.
More recently, the photoreceptor comprising an organic photoconductive substance was proposed. The latter has advantages, i.e. it is not a pollutant and it has a film-formability and a shapability.
As one of the organic photoreceptors, the so-called "laminated-type photoreceptor" in which a charge generation layer and a charge transport layer are successively laminated was developed. The laminated-type photoreceptor is increasingly interested in and is expected to be widely used in the near future because it has the following advantages:
(1) the photoreceptor having a high sensitivity can be obtained by suitably selecting and combining a charge generation material and a charge transport material;
ELECTROP~OTOGRAPHIC P~OTOR~CEPTOR
E~IE~ OF THE INVENTION
The invention relates to an electrophotographic photoreceptor. More particularly, it relates to the electro-photographic photoreceptor having an excellent durability.
BA~KGOUND OF THE INVENTION
In recent years, the electrophotography has been applied to copying machines as well as various printers, because they can give images with high qualities without delay. As a photoreceptor which plays an important role in the electrophotography, the photoreceptor comprising an inorganic photoconductive substance such as selenium, arsenic-selenium alloy, cadmium sulfide, zinc oxide and the like has been used.
More recently, the photoreceptor comprising an organic photoconductive substance was proposed. The latter has advantages, i.e. it is not a pollutant and it has a film-formability and a shapability.
As one of the organic photoreceptors, the so-called "laminated-type photoreceptor" in which a charge generation layer and a charge transport layer are successively laminated was developed. The laminated-type photoreceptor is increasingly interested in and is expected to be widely used in the near future because it has the following advantages:
(1) the photoreceptor having a high sensitivity can be obtained by suitably selecting and combining a charge generation material and a charge transport material;
(2) the photoreceptor having a high safety can be obtained because the charge generation material and the charge transport material can be selected from a wide range of the materials; and (3) the photoreceptor can be prepared by a simple coating and thus, it can be prepared with low costs.
,' ~.: ' ', :: ~ ~ .;
. : : :
.
~7~1~
;owever, tr.e ?rior laminated-type pho.oreceptors nave poor durabllities. '~ en they are repeatedly used, electric problems such as a lowerins in charyed potential, an accumulation of a residual potential and a change in sensitivity are caused. The problem as to the accumulation of the residual potential is especially serious because if the residual potential 1s accumulated, much copies could not be obtained. Such an accumulation of the residual potential is considered to arise from some causes, among which impurities present in the charge transport layer are important. The impurities include impurities originally present in a composition used for forming the charge transport layer, impurities produced after the charge transport layer is subjected to a corona discharge and impuritles produced by decomposing after the charge transport layer is exposed repeatedly during an exposure step and an erasing step and after the charge transport layer is subjected to an outside light during a maintenance operation. These impurities trap carriers, thereby unmovable space charges which remain as the residual charges in the charge transport layer are produced.
As an other cause of lowering the durability of the laminated-type photoreceptor, the reduction in thickness of the charge transport layer due to mechanical stresses, for example an abrasion such as a blade cleaning, leading to the lowering in electric properties is mentioned.
An increase in thickness of the charge transport layer is effective for preventing the reduction in thickness of the charge transport layer and increasing the sensitivity of the photoreceptor, but it is accompanied with the increase of amounts of the impurities, thereby the accumulation of the residual potential makes more remarkable.
For preventing the accumulation of the residual potential caused by the impurities present in the charge transport layer, an addition or a specific com?ound in the charge transport layer is attempted. However, the prior known compounds are not satisfactory because they prevent the accumulation of the residual potential insufficiently and they affect the electric properties including the charge-ability and the sensitivity.
The present inventors have been investigated the specific compound which can prevent the accumulation of the residual potential sufficiently without affecting the electric properties and now they found that specific organic acids satisfy the above requirements.
SUMMARY OF THE INVENTION
According to the invention, an electrophotographic photoreceptor has on a conductive base a photoconductive layer containing at least a charge generation material and a charge transport material, the photoconductive layer further containing an organic acid, whose acid dissociation constant pKa in its aqueous solution is in a range of 2.1 to 4.3, in an amount of 0.001 to 10 parts by weight per 100 parts by weight of the charge transport material.
pE~ EXPLANATION OF THE INVENTION
The photoreceptor according to the invention has the conductive base, on which the photoconductive layer is provided.
The photoconductive layer is a laminated-type photoconductive layer in which the charge transport layer and the charge generation layer are successively laminated, or a dispersion-type photoconductive layer in which the particulate charge generation material is dispersed in a medium containing the charge transport material.
As the conductive base, any of the known conductive base can be used. Examples of the conductive base include a base comprising a metallic material such as aluminium, stainless steel, copper and nickel as well as a base comprising an .
~06~ 3 ~
insulating mate~ial such as polyester film or paper on which a conductive laver such as a layer of aluminium, copper, palladium, tin oxide or indium oxide is provided.
The organic acid contained in the photoconductive layer in the photoreceptor of the invention should have the acid dissociation constant pKa in its aqueous solution in the range of 2.1 to 4.3. As the usable organic acid, aromatic carboxylic acids, saturated or unsaturated aliphatic carboxylic acids, sulfur-containing organic acids and phosphorus-containing organic acids, which may have any substituents such as halogen atom, and hydroxy, thiol, alkyl, aryl, nitro, amino, dialkylamino, alkoxy and aryloxy groups, are exemplified.
Especially, the aromatic carboxylic acid which may be substituted as well as the saturated or unsaturated aliphatic carboxylic acid which may be substituted are preferable.
Typical examples of the organic acids include acrylic acid, adipic acid, adenosine-2'-phosphate, valeric acid, 3-chloropropionic acid, acetic acid, cyanoacetic acid, phenylacetic acid, phenoxyacetic acid, bromoacetic acid, butyric acid, cyclohexanecarboxylic acid, o-anisic acid, 1-anilinesulfonic acid, p-aminobenzoic acid, benzoic acid, p-chlorobenzoic acid, m-hydroxybenzoic acid, o-nitrobenzoic acid, salicylic acid, 1-naphthoic acid, oxalacetic acid, succinic acid, tartaric acid, lactic acid, malic acid, phthalic acid, terephthalic acid, mandelic acid and crotonic acid.
In the laminated-type photoconductive layer, the organic acid can be contained in the charge generation layer and/or the charge transport layer. When it is contained in the charge generation layer, its amount is generally 0.001 to 10 parts by weight, preferably 0.01 to 2 parts by weight per 100 parts by weight of the charge transport material in the charge transport ; layer. On the other hand, when it is contained in the charge transport layer, its amount is generally 0.001 to 10 parts by weight, preferably 0.01 to 2 parts by weight per 100 parts by ' ~6 ~
weight or ~he charge transport material in the charge tr~nsport layer. ~h- inc1usion of the organic acid in the charge transport layer is more preferable.
.
The charge generation layer in the laminated-type photoconducti.ve layer contains the charge generation material.
As the charge generation material used in the charge generation layer, various inorganic photoconductive substances such as selen um or its alloys, arsenic-selenium alloy, cadmium sulfide and zinc oxide as well as various organic photoconductive substances such as phthalocyanine, azo pigment, quinacridone, polycyclic quinone, pyrylium salt, thiapyrylium salt, indigo, thioindigo, anthoanthrone, pyranthrone and cyanine can be used.
Among them, the phthalocyanine without a metal; the phthalocyanine coordinated with the metal or its compound such as tin, zinc, vanadium, oxytitanium, tin chloride, copper indium chloride and gallium chloride; and the azo pigment such as monoazo, bisazo, trisazo and polyazo are preferable.
The charge generation material can be used in the charge generation layer together with at least one of binder resins such as polyester resin, polyvinyl acetate, polyacrylate, polymethacrylate, polycarbonate, polyvinyl acetacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy resin, urethane resin, cellulose ester and cellulose ether.
The charge generation material is preferably used in an amount of 30 to 500 parts by weight per 100 parts by weight of the binder resin.
If necessary, the charge generation layer may contain various additives such as a leveling agent, an antioxidant and a sensitizer.
The charge generation layer is usually formed on the conductive base according to any one of the known methods, ~ Q 6 ~ ~ J ~
preferably a coating method wherein a coating solution containing the charge generation material and the binder resin together with any optional additives in a suitable solvent is coated. Alternatively, the charge generation layer may be formed by directly depositing the charge generation material on the conductive base.
The thickness of the charge generation layer is generally 0.1 to 2 ~Im~ preferably 0.15 to 0.8 ~m.
The charge transport layer contains the charge transport material and the binder resin. The charge transport material used in the charge transport layer is an electron donative material, the examples of which include heterocyclic compounds such as carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole, pyrazoline and thiadiazole; aniline derivatives;
hydrazone compounds; arornatic amine derivatives; stilbene derivatives and polymers having the above compound in their main chain or their side chain.
As the binder resin used together with the charge transport material in the charge transport layer, a vinyl polymer such as polymethyl methacrylate, polystyrene and polyvinyl chloride and its copolymer, polycarbonate, polyester, polyester carbonate, polysulfone, polyimide, phenoxy resin, epoxy resin and silicone resin can be used. Their partially crosslinked products may be used.
The charge transport material is generally used in an amount of 30 to 200 parts by weight, preferably ~0 to 150 parts by weight per 100 parts by weight of the binder resin.
If necessary, the charge transport layer may contain various additives such as the antioxidant and the sensitizer.
~670 ~ ~i The charge transport layer is usually formed on the charge generation layer according to any of the known methods, preferably the coating method wherein the coating solution containing the charge transport material and the binder res~in together with any optional additives in a suitable solvent is coated.
.The thickness of the charge transport layer is generally 10 to 60 ~m, preferably 10 to 45 ~m.
The laminated-type photoconductive layer described in the above has the charge generation layer on which the charge transport layer is provided, but the order of laminating the charge generation layer and the charge transport layer may be changed, if necessary.
As an outer layer, a known overcoat layer, for example. a layer mainly composed of a thermoplastic or thermosetting polymer can be provided.
As mentioned in the above, the dispersion-type photoconductive layer comprises the particulate charge generation material dispersed in the medium containing the charge transport material and the binder resin. The ratio of the charge transport material to the binder resin is the same as that in the laminated-type photoconductive layer.
In the dispersion-type photoconductive layer, the charge generation material should have a small particle size. Its particle size is preferably 1 ~m or less, more preferably 0~5 ~m or less.
-The charge generation material dispersed in the medium ispreferably in an amount of 0.5 to 50 % by weight, more preferably in an amount of 1 to 20 % by weight based on the medium.
, ---~7~
When the organic acid is contained in the dispersion-type phot:oconductive layer, its amount is generally 0.001 to 10 parts by weight, preferably 0.01 to 2 parts by weight per 100 parts by weight of the charge transport material in the photoconductive layer.
If necessary, the dispersion-type photoconductive layer may contain various additives such as a plasticizer, a dispersion assistant, a leveling agent and a surfactant.
The thickness of the dispersion-type photoconductive layer is generally 5 to 50 um, preferably 10 to 45 ~m.
EFFECT OF THE I~y~TION
The electrophotographic photoreceptor containing the specific organic acid in the photoconductive layer according to the invention shows very high sensitivity and low residual potential. It hardly shows the accumulation of the residual potential and the change in charge-ability and sensitivity, even if its repeated use. Therefore, it is excellent in the durability.
FXa~PT~
The invention will be better understood by reference to certain examples, which are included herein for the purpose of illustration only and are not intended to limit the invention.
Example 1 10 Parts by weight of a bisazo compound having the following formula:
~6~1~1.L
o ~ o , o ~ O
were added to 150 parts by weight of 4-methoxy-4-methyl-pentanone-2 and they were subjected to the grinding and dispersion treatment using a sand grind mill. The thus obtained dispersion was added to 100 parts by weight of a S % solution of polyvinyl butyral (~6000-C ~trade name), ex DENKI KAGAKU KOGYO
K.K.) in 1,2-dimethoxyethane so as to prepare a dispersion with a solid concentration of 4.0 %.
The above dispersion was coated using a wire bar on a surface of a polyethylene terephthalate film having an aluminium deposited layer followed by drying, thereby the charge generation layer with a thickness of 0,4 g/m2 was formed.
On the charge generation layer, a solution of 95 parts by weight of a hydrazone compound having the following formula:
CH=~y_N
.
.
.
' ' . . .
. . - : .
..
1.5 parts by weight of 4~(2,2'-dicyanovinyl)phenyl 2,4,5-trichlorobenzene sulfonate, 0.2 part by weight of p- -hydroxybenzoic acid ~pKa 4.58) and lOO parts by weight of a polycarbonate resin having the following formula: ~
C~3 C~3 C~30 to~l ~oll ~
in a mixed solvent of 1,4-dioxane and tetrahydrofuran (volume ratio of 50:50) was coated using an applicator followed by drying at room temperature for 30 minutes and 125C for 30 minutes, thereby the charge transport layer with a thickness of 35 ~m was formed.
In this way, a laminated-type electrophotographic photoreceptor (sample A) was prepared.
~xa~ples 2 to 6 The procedures in Example 1 were repeated, except that p-hydroxybenzoic acid was replaced with other organic acids, o-nitrobenzoic acid of pKa 2.17 (Example 2, sample B), o-chlorobenzoic acid of pKa 2.92 (Example 3, sample C), 2-bromovaleric acid of pKa 2.7 (Example 4, sample D), 3-.
phenylsalicylic acid of pKa 2.8 (Example 5, sample E) and p-tert-butylbenzoic acid of pKa ~.2 (Example 6, sample F).
Comparative Example 1 The procedure in Example 1 was repeated, except that p-hydroxybenzoic acid was omitted so as to prepare the photoreceptor (sample G).
Comparative Example 2 , 7~1 ~
The procedure in Example 1 was repeated, except that p-hydroxybenzoic acid was replaced with trichloroacetic acid (pKa 0.66) so as to prepare the photoreceptor (sample H).
am~le 7 10 Parts by weight of a bisazo compound having the following formula:
O ~ ~, O O
~0 C~H
~ ~N=N ,~0O~
and 0.2 part by weight of 2-bromovaleric acid (pKa 2.7) were added to 150 parts by weight of 9-methoxy-4-methyl-pentanone-2 and they were subjected to the grinding and dispersion treatment using a sand grind mill. The thus obtained dispersion was added to 100 parts by weight of a 5 % solution of polyvinyl butyral (~6000-C (trade name), ex DENKI KAGAKU KOGYO K.K.) in 1,2-dimethoxyethane so as to prepare a dispersion with a solid concentration of 4.0 %.
.~
The above dispersion was coated on a surface of a polyethylene terephthalate film having an aluminium deposited layer using a wire bar followed by drying, thereby the charge generation layer with a thickness of 0.4 g/m2 was formed.
.
On the charge generation layer, a solution of 95 parts by weight of a hydrazone compound having the following formula:
", ~
- ~ , .
~ " .
2~67~
~ CH=II-N~
1.5 parts by weight of 4-(2,2'-dicyanovinyl)phenyl 2,4,5-trichlorobenzene sulfonate and 100 parts by weight of a polycarbonate resin having the following formula:
\ CH3 /
i 0~1 ~OC J
in a mixed solvent of 1,4-dioxane and tetrahydrofuran (volume ratio of 50:50) was coated using an applicator followed by drying at room temperature for 30 minutes and 125C for 30 minutes, thereby the charge transport layer with a thickness of 35 ~m was formed.
In this way, a laminated-type electrophotographic photoreceptor (sample I) was prepared.
F.~amRle 8 ~' , .~
.~
The procedure in Example 7 was repeated, except that 2-bromovaleric acid was replaced with o-nitrobenzoic acid of pKa 2.17 so as to prepare the photoreceptor (sample J).
Comparative Example 3 The procedure in Example 7 was repeated, except that 2-bromovaleric acid was omitted so as to prepare the photoreceptor (sample K).
Test Example The characteristics of the photoreceptors A to K prepared in Examples and Comparative Examples were tested.
Each photoreceptor was placed in an apparatus for determining the characteristics of the photoreceptor (Model EPA-8100, ex KAWAGUCHI DENKI K.K.) and charged so that the current flowing into the aluminium layer was 72 ~A, followed by exposing and erasing. Then, the charge-ability (Vo), the dark decay (DD, the rate of decaying of the electrical potential in the dark after 2 seconds from the charging), the sensitivity of half decay exposure (E1/2, reference potential 500 V) and the residual potential (Vr) were determined.
The results are shown in Table 1.
Table 1 _ .
photo- Vo DD ' Vr E1/2 92~ ~
A 1299 '~ I 0.65 B 1347 32 E _ 9 , O . 64 _~ _ _ C l330 27 ~ 0.63 _ D _ 1352 31 I 7 0.65 E 1369 _ 33 5 0.63 300 ~ 0 64 G 1290 33 E 17 0.67 _ _ _ _ _ ~eclse H 641 125 I 4 determination (comparative) ~ conducted . . _ __ ~_ _ _ I 1156 33 ,~ ~0 ~ 0.65 ~ 1122 ~ 0.60 K 1151 26 ~Ej 35 0.68 (com~arative) . _ As clear from the results in Table 1, the electro-photographic photoreceptor according to the invention has the excellent properties.
Example 9 The procedure in Example 1 was repeated, except that an-~ aluminium cylinder having a diameter of 80 mm, a length of 340 `~ mm and a thickness of 1 mm was used as the conductive base so as ~ to prepare the cylindrical photoreceptor.
,,'; .
.~ : This photoreceptor was set in a commercial copying machine.
The images with high qualities could be obtained.
' .:
i - 14 -`~
;','"
:i .
,' ~.: ' ', :: ~ ~ .;
. : : :
.
~7~1~
;owever, tr.e ?rior laminated-type pho.oreceptors nave poor durabllities. '~ en they are repeatedly used, electric problems such as a lowerins in charyed potential, an accumulation of a residual potential and a change in sensitivity are caused. The problem as to the accumulation of the residual potential is especially serious because if the residual potential 1s accumulated, much copies could not be obtained. Such an accumulation of the residual potential is considered to arise from some causes, among which impurities present in the charge transport layer are important. The impurities include impurities originally present in a composition used for forming the charge transport layer, impurities produced after the charge transport layer is subjected to a corona discharge and impuritles produced by decomposing after the charge transport layer is exposed repeatedly during an exposure step and an erasing step and after the charge transport layer is subjected to an outside light during a maintenance operation. These impurities trap carriers, thereby unmovable space charges which remain as the residual charges in the charge transport layer are produced.
As an other cause of lowering the durability of the laminated-type photoreceptor, the reduction in thickness of the charge transport layer due to mechanical stresses, for example an abrasion such as a blade cleaning, leading to the lowering in electric properties is mentioned.
An increase in thickness of the charge transport layer is effective for preventing the reduction in thickness of the charge transport layer and increasing the sensitivity of the photoreceptor, but it is accompanied with the increase of amounts of the impurities, thereby the accumulation of the residual potential makes more remarkable.
For preventing the accumulation of the residual potential caused by the impurities present in the charge transport layer, an addition or a specific com?ound in the charge transport layer is attempted. However, the prior known compounds are not satisfactory because they prevent the accumulation of the residual potential insufficiently and they affect the electric properties including the charge-ability and the sensitivity.
The present inventors have been investigated the specific compound which can prevent the accumulation of the residual potential sufficiently without affecting the electric properties and now they found that specific organic acids satisfy the above requirements.
SUMMARY OF THE INVENTION
According to the invention, an electrophotographic photoreceptor has on a conductive base a photoconductive layer containing at least a charge generation material and a charge transport material, the photoconductive layer further containing an organic acid, whose acid dissociation constant pKa in its aqueous solution is in a range of 2.1 to 4.3, in an amount of 0.001 to 10 parts by weight per 100 parts by weight of the charge transport material.
pE~ EXPLANATION OF THE INVENTION
The photoreceptor according to the invention has the conductive base, on which the photoconductive layer is provided.
The photoconductive layer is a laminated-type photoconductive layer in which the charge transport layer and the charge generation layer are successively laminated, or a dispersion-type photoconductive layer in which the particulate charge generation material is dispersed in a medium containing the charge transport material.
As the conductive base, any of the known conductive base can be used. Examples of the conductive base include a base comprising a metallic material such as aluminium, stainless steel, copper and nickel as well as a base comprising an .
~06~ 3 ~
insulating mate~ial such as polyester film or paper on which a conductive laver such as a layer of aluminium, copper, palladium, tin oxide or indium oxide is provided.
The organic acid contained in the photoconductive layer in the photoreceptor of the invention should have the acid dissociation constant pKa in its aqueous solution in the range of 2.1 to 4.3. As the usable organic acid, aromatic carboxylic acids, saturated or unsaturated aliphatic carboxylic acids, sulfur-containing organic acids and phosphorus-containing organic acids, which may have any substituents such as halogen atom, and hydroxy, thiol, alkyl, aryl, nitro, amino, dialkylamino, alkoxy and aryloxy groups, are exemplified.
Especially, the aromatic carboxylic acid which may be substituted as well as the saturated or unsaturated aliphatic carboxylic acid which may be substituted are preferable.
Typical examples of the organic acids include acrylic acid, adipic acid, adenosine-2'-phosphate, valeric acid, 3-chloropropionic acid, acetic acid, cyanoacetic acid, phenylacetic acid, phenoxyacetic acid, bromoacetic acid, butyric acid, cyclohexanecarboxylic acid, o-anisic acid, 1-anilinesulfonic acid, p-aminobenzoic acid, benzoic acid, p-chlorobenzoic acid, m-hydroxybenzoic acid, o-nitrobenzoic acid, salicylic acid, 1-naphthoic acid, oxalacetic acid, succinic acid, tartaric acid, lactic acid, malic acid, phthalic acid, terephthalic acid, mandelic acid and crotonic acid.
In the laminated-type photoconductive layer, the organic acid can be contained in the charge generation layer and/or the charge transport layer. When it is contained in the charge generation layer, its amount is generally 0.001 to 10 parts by weight, preferably 0.01 to 2 parts by weight per 100 parts by weight of the charge transport material in the charge transport ; layer. On the other hand, when it is contained in the charge transport layer, its amount is generally 0.001 to 10 parts by weight, preferably 0.01 to 2 parts by weight per 100 parts by ' ~6 ~
weight or ~he charge transport material in the charge tr~nsport layer. ~h- inc1usion of the organic acid in the charge transport layer is more preferable.
.
The charge generation layer in the laminated-type photoconducti.ve layer contains the charge generation material.
As the charge generation material used in the charge generation layer, various inorganic photoconductive substances such as selen um or its alloys, arsenic-selenium alloy, cadmium sulfide and zinc oxide as well as various organic photoconductive substances such as phthalocyanine, azo pigment, quinacridone, polycyclic quinone, pyrylium salt, thiapyrylium salt, indigo, thioindigo, anthoanthrone, pyranthrone and cyanine can be used.
Among them, the phthalocyanine without a metal; the phthalocyanine coordinated with the metal or its compound such as tin, zinc, vanadium, oxytitanium, tin chloride, copper indium chloride and gallium chloride; and the azo pigment such as monoazo, bisazo, trisazo and polyazo are preferable.
The charge generation material can be used in the charge generation layer together with at least one of binder resins such as polyester resin, polyvinyl acetate, polyacrylate, polymethacrylate, polycarbonate, polyvinyl acetacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy resin, urethane resin, cellulose ester and cellulose ether.
The charge generation material is preferably used in an amount of 30 to 500 parts by weight per 100 parts by weight of the binder resin.
If necessary, the charge generation layer may contain various additives such as a leveling agent, an antioxidant and a sensitizer.
The charge generation layer is usually formed on the conductive base according to any one of the known methods, ~ Q 6 ~ ~ J ~
preferably a coating method wherein a coating solution containing the charge generation material and the binder resin together with any optional additives in a suitable solvent is coated. Alternatively, the charge generation layer may be formed by directly depositing the charge generation material on the conductive base.
The thickness of the charge generation layer is generally 0.1 to 2 ~Im~ preferably 0.15 to 0.8 ~m.
The charge transport layer contains the charge transport material and the binder resin. The charge transport material used in the charge transport layer is an electron donative material, the examples of which include heterocyclic compounds such as carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole, pyrazoline and thiadiazole; aniline derivatives;
hydrazone compounds; arornatic amine derivatives; stilbene derivatives and polymers having the above compound in their main chain or their side chain.
As the binder resin used together with the charge transport material in the charge transport layer, a vinyl polymer such as polymethyl methacrylate, polystyrene and polyvinyl chloride and its copolymer, polycarbonate, polyester, polyester carbonate, polysulfone, polyimide, phenoxy resin, epoxy resin and silicone resin can be used. Their partially crosslinked products may be used.
The charge transport material is generally used in an amount of 30 to 200 parts by weight, preferably ~0 to 150 parts by weight per 100 parts by weight of the binder resin.
If necessary, the charge transport layer may contain various additives such as the antioxidant and the sensitizer.
~670 ~ ~i The charge transport layer is usually formed on the charge generation layer according to any of the known methods, preferably the coating method wherein the coating solution containing the charge transport material and the binder res~in together with any optional additives in a suitable solvent is coated.
.The thickness of the charge transport layer is generally 10 to 60 ~m, preferably 10 to 45 ~m.
The laminated-type photoconductive layer described in the above has the charge generation layer on which the charge transport layer is provided, but the order of laminating the charge generation layer and the charge transport layer may be changed, if necessary.
As an outer layer, a known overcoat layer, for example. a layer mainly composed of a thermoplastic or thermosetting polymer can be provided.
As mentioned in the above, the dispersion-type photoconductive layer comprises the particulate charge generation material dispersed in the medium containing the charge transport material and the binder resin. The ratio of the charge transport material to the binder resin is the same as that in the laminated-type photoconductive layer.
In the dispersion-type photoconductive layer, the charge generation material should have a small particle size. Its particle size is preferably 1 ~m or less, more preferably 0~5 ~m or less.
-The charge generation material dispersed in the medium ispreferably in an amount of 0.5 to 50 % by weight, more preferably in an amount of 1 to 20 % by weight based on the medium.
, ---~7~
When the organic acid is contained in the dispersion-type phot:oconductive layer, its amount is generally 0.001 to 10 parts by weight, preferably 0.01 to 2 parts by weight per 100 parts by weight of the charge transport material in the photoconductive layer.
If necessary, the dispersion-type photoconductive layer may contain various additives such as a plasticizer, a dispersion assistant, a leveling agent and a surfactant.
The thickness of the dispersion-type photoconductive layer is generally 5 to 50 um, preferably 10 to 45 ~m.
EFFECT OF THE I~y~TION
The electrophotographic photoreceptor containing the specific organic acid in the photoconductive layer according to the invention shows very high sensitivity and low residual potential. It hardly shows the accumulation of the residual potential and the change in charge-ability and sensitivity, even if its repeated use. Therefore, it is excellent in the durability.
FXa~PT~
The invention will be better understood by reference to certain examples, which are included herein for the purpose of illustration only and are not intended to limit the invention.
Example 1 10 Parts by weight of a bisazo compound having the following formula:
~6~1~1.L
o ~ o , o ~ O
were added to 150 parts by weight of 4-methoxy-4-methyl-pentanone-2 and they were subjected to the grinding and dispersion treatment using a sand grind mill. The thus obtained dispersion was added to 100 parts by weight of a S % solution of polyvinyl butyral (~6000-C ~trade name), ex DENKI KAGAKU KOGYO
K.K.) in 1,2-dimethoxyethane so as to prepare a dispersion with a solid concentration of 4.0 %.
The above dispersion was coated using a wire bar on a surface of a polyethylene terephthalate film having an aluminium deposited layer followed by drying, thereby the charge generation layer with a thickness of 0,4 g/m2 was formed.
On the charge generation layer, a solution of 95 parts by weight of a hydrazone compound having the following formula:
CH=~y_N
.
.
.
' ' . . .
. . - : .
..
1.5 parts by weight of 4~(2,2'-dicyanovinyl)phenyl 2,4,5-trichlorobenzene sulfonate, 0.2 part by weight of p- -hydroxybenzoic acid ~pKa 4.58) and lOO parts by weight of a polycarbonate resin having the following formula: ~
C~3 C~3 C~30 to~l ~oll ~
in a mixed solvent of 1,4-dioxane and tetrahydrofuran (volume ratio of 50:50) was coated using an applicator followed by drying at room temperature for 30 minutes and 125C for 30 minutes, thereby the charge transport layer with a thickness of 35 ~m was formed.
In this way, a laminated-type electrophotographic photoreceptor (sample A) was prepared.
~xa~ples 2 to 6 The procedures in Example 1 were repeated, except that p-hydroxybenzoic acid was replaced with other organic acids, o-nitrobenzoic acid of pKa 2.17 (Example 2, sample B), o-chlorobenzoic acid of pKa 2.92 (Example 3, sample C), 2-bromovaleric acid of pKa 2.7 (Example 4, sample D), 3-.
phenylsalicylic acid of pKa 2.8 (Example 5, sample E) and p-tert-butylbenzoic acid of pKa ~.2 (Example 6, sample F).
Comparative Example 1 The procedure in Example 1 was repeated, except that p-hydroxybenzoic acid was omitted so as to prepare the photoreceptor (sample G).
Comparative Example 2 , 7~1 ~
The procedure in Example 1 was repeated, except that p-hydroxybenzoic acid was replaced with trichloroacetic acid (pKa 0.66) so as to prepare the photoreceptor (sample H).
am~le 7 10 Parts by weight of a bisazo compound having the following formula:
O ~ ~, O O
~0 C~H
~ ~N=N ,~0O~
and 0.2 part by weight of 2-bromovaleric acid (pKa 2.7) were added to 150 parts by weight of 9-methoxy-4-methyl-pentanone-2 and they were subjected to the grinding and dispersion treatment using a sand grind mill. The thus obtained dispersion was added to 100 parts by weight of a 5 % solution of polyvinyl butyral (~6000-C (trade name), ex DENKI KAGAKU KOGYO K.K.) in 1,2-dimethoxyethane so as to prepare a dispersion with a solid concentration of 4.0 %.
.~
The above dispersion was coated on a surface of a polyethylene terephthalate film having an aluminium deposited layer using a wire bar followed by drying, thereby the charge generation layer with a thickness of 0.4 g/m2 was formed.
.
On the charge generation layer, a solution of 95 parts by weight of a hydrazone compound having the following formula:
", ~
- ~ , .
~ " .
2~67~
~ CH=II-N~
1.5 parts by weight of 4-(2,2'-dicyanovinyl)phenyl 2,4,5-trichlorobenzene sulfonate and 100 parts by weight of a polycarbonate resin having the following formula:
\ CH3 /
i 0~1 ~OC J
in a mixed solvent of 1,4-dioxane and tetrahydrofuran (volume ratio of 50:50) was coated using an applicator followed by drying at room temperature for 30 minutes and 125C for 30 minutes, thereby the charge transport layer with a thickness of 35 ~m was formed.
In this way, a laminated-type electrophotographic photoreceptor (sample I) was prepared.
F.~amRle 8 ~' , .~
.~
The procedure in Example 7 was repeated, except that 2-bromovaleric acid was replaced with o-nitrobenzoic acid of pKa 2.17 so as to prepare the photoreceptor (sample J).
Comparative Example 3 The procedure in Example 7 was repeated, except that 2-bromovaleric acid was omitted so as to prepare the photoreceptor (sample K).
Test Example The characteristics of the photoreceptors A to K prepared in Examples and Comparative Examples were tested.
Each photoreceptor was placed in an apparatus for determining the characteristics of the photoreceptor (Model EPA-8100, ex KAWAGUCHI DENKI K.K.) and charged so that the current flowing into the aluminium layer was 72 ~A, followed by exposing and erasing. Then, the charge-ability (Vo), the dark decay (DD, the rate of decaying of the electrical potential in the dark after 2 seconds from the charging), the sensitivity of half decay exposure (E1/2, reference potential 500 V) and the residual potential (Vr) were determined.
The results are shown in Table 1.
Table 1 _ .
photo- Vo DD ' Vr E1/2 92~ ~
A 1299 '~ I 0.65 B 1347 32 E _ 9 , O . 64 _~ _ _ C l330 27 ~ 0.63 _ D _ 1352 31 I 7 0.65 E 1369 _ 33 5 0.63 300 ~ 0 64 G 1290 33 E 17 0.67 _ _ _ _ _ ~eclse H 641 125 I 4 determination (comparative) ~ conducted . . _ __ ~_ _ _ I 1156 33 ,~ ~0 ~ 0.65 ~ 1122 ~ 0.60 K 1151 26 ~Ej 35 0.68 (com~arative) . _ As clear from the results in Table 1, the electro-photographic photoreceptor according to the invention has the excellent properties.
Example 9 The procedure in Example 1 was repeated, except that an-~ aluminium cylinder having a diameter of 80 mm, a length of 340 `~ mm and a thickness of 1 mm was used as the conductive base so as ~ to prepare the cylindrical photoreceptor.
,,'; .
.~ : This photoreceptor was set in a commercial copying machine.
The images with high qualities could be obtained.
' .:
i - 14 -`~
;','"
:i .
Claims (34)
1. An electrophotographic photoreceptor having on a conductive base, a photoconductive layer containing at least a charge generation material and a charge transport material, the photoconductive layer further containing an organic acid, whose acid dissociation constant pKa in its aqueous solution is in a range of 2.1 to 4.3, in an amount of 0.001 to 10 parts by weight per 100 parts by weight of the charge transport material.
2. An electrophotographic photoreceptor according to claim 1, wherein the photoconductive layer is a laminated-type photoconductive layer comprising at least a charge generation layer and a charge transport layer.
3. An electrophotographic photoreceptor according to claim 1, wherein the photoconductive layer is a dispersion-type photoconductive layer wherein the charge generation material is dispersed in a medium containing the charge transport material and a binder resin.
4. An electrophotographic photoreceptor according to claim 1, 2 or 3, wherein the organic acid is at least one selected from the group consisting of aromatic carboxylic acids which may be substituted, saturated or unsaturated aliphatic carboxylic acids which may be substituted, sulfur-containing organic acids which may be substituted and phosphorus-containing organic acids which may be substituted.
5. An electrophotographic photoreceptor according to claim 4, wherein the organic acid is the aromatic carboxylic acid which may be substituted or the aliphatic carboxylic acid which may be substituted.
6. An electrophotographic photoreceptor according to claim 4, wherein the organic acid is at least one selected from the group consisting of acrylic acid, adipic acid, adenosine-2'-phosphate, valeric acid, 3-chloropropionic acid, acetic acid, cyanoacetic acid, phenylacetic acid, phenoxyacetic acid, bromoacetic acid, butyric acid, cyclohexanecarboxylic acid, o-anisic acid, 1-anilinesulfonic acid, p-aminobenzoic acid, benzoic acid, p-chlorobenzoic acid, m-hydroxybenzoic acid, o-nitrobenzoic acid, salicylic acid, 1-naphthoic acid, oxalacetic acid, succinic acid, tartaric acid, lactic acid, malic acid, phthalic acid, terephthalic acid, mandelic acid and crotonic acid.
7. An electrophotographic photoreceptor according to claim 1, 2 or 3, wherein the organic acid is contained in an amount of 0.01 to 2 parts by weight per 100 parts by weight of the charge transport material.
8. An electrophotographic photoreceptor having on a conductive base, a laminated-type photoconductive layer comprising at least a charge generation layer which contains a charge generation material and a binder resin and a charge transport layer which contains a charge transport material and a binder resin, the laminated-type photoconductive layer further containing an organic acid, whose acid dissociation constant pKa in its aqueous solution is in a range of 2.1 to 4.3, in an amount of 0.001 to 10 parts by weight per 100 parts by weight of the charge transport material.
9. An electrophotographic photoreceptor according to claim 1, 2, 3 or 8, wherein the conductive base comprises a metallic material or an insulating substrate having a conductive layer on its surface.
10. An electrophotographic photoreceptor according to claim 9, wherein the metallic material is at least one selected from the group consisting of aluminium, stainless steel, copper and nickel.
11. An electrophotographic photoreceptor according to claim 9, wherein the insulating substrate having the conductive layer on its surface comprises a polyester film having the conductive layer on its surface or a paper having the conductive layer on its surface.
12. An electrophotographic photoreceptor according to claim 11, wherein the conductive layer which is provided on the surface of the polyester film or the paper is a layer comprising aluminium, copper, palladium, tin oxide or indium oxide.
13. An electrophotograhic photoreceptor according to claim 1, 2, 3 or 8, wherein the charge generation material is an inorganic photoconductive substance.
14. An electrophotographic photoreceptor according to claim 13, wherein the inorganic photoconductive substance is at least one selected from the group consisting of selenium or its alloys, arsenic-selenium alloy, cadmium sulfide and zinc oxide.
15. An electrophotographic photoreceptor according to claim 1, 2, 3 or 8, wherein the charge generation material is an organic photoconductive substance.
16. An electrophotographic photoreceptor according to claim 15, wherein the organic photoconductive substance is at least one selected from the group consisting of phthalocyanine, azo pigment, quinacridone, polycyclic quinone, pyrylium salt, thiapyrylium salt, indigo, thioindigo, anthoanthrone, pyranthrone and cyanine.
17. An electrophotographic photoreceptor according to claim 16, wherein the phthalocyanine is at least one selected from the group consisting of phthalocyanine without a metal, phthalocyanine coordinated with a metal, phthalocyanine coordinated with a metal oxide and phthalocyanine coordinated with a metal chloride.
18. An electrophotographic photoreceptor according to claim 17, wherein the metal is at least one selected from the group consisting of tin, zinc and vanadium.
19. An electrophotographic photoreceptor according to claim 17, wherein the metal oxide is oxytitanium.
20. An electrophotographic photoreceptor according to claim 17, wherein the metal chloride is tin chloride, copper indium chloride or gallium chloride.
21. An electrophotographic photoreceptor according to claim 16, wherein the azo pigment is at least one selected from the group consisting of monoazo, bisazo, trisazo and polyazo.
22. An electrophotographic photoreceptor according to claim 1, 2, 3 or 8, wherein the charge transport material is an electron donative material which is at least one selected from the group consisting of heterocyclic compounds, aniline derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives and polymers having the above compound in their main chain or their side chain.
23. An electrophotographic photoreceptor according to claim 22, wherein the heterocyclic compound is at least one selected from the group consisting of carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole, pyrazoline and thiadiazole.
24. An electrophotographic photoreceptor according to claim 2 or 8, wherein the organic acid is contained in the charge transport layer.
25. An electrophotographic photoreceptor according to claim 2 or 8, wherein the organic acid is contained in the charge generation layer.
26. An electrophotographic photoreceptor according to claim 2 or 8, wherein the organic acid is contained in both the charge transport layer and the charge generation layer.
27. An electrophotographic photoreceptor according to claim 2 or 8, wherein the charge generation layer has a thickness of 0.1 to 2 µm.
28. An electrophotographic photoreceptor according to claim 2 or 8, wherein the charge generation layer has a thickness of 0.15 to 0.8 µm.
29. An electrophotographic photoreceptor according to claim 2 or 8, wherein the charge transport layer has a thickness of 10 to 60 µm.
30. An electrophotographic photoreceptor according to claim 2 or 8, wherein the charge transport layer has a thickness of 10 to 45 µm.
31. An electrophotographic photoreceptor according to claim 3, wherein the dispersion-type photoconductive layer has a thickness of 5 to 50 µm.
32. An electrophotographic photoreceptor according to claim 3, wherein the dispersion-type photoconductive layer has a thickness of 10 to 45 µm.
33. An electrophotographic photoreceptor according to claim 8, wherein the binder resin included in the charge generation layer is at least one selected from the group consisting of polyester resin, polyvinyl acetate, polyacrylate ester, polymethacrylate ester, polycarbonate, polyvinyl acetacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy resin, urethane resin, cellulose ester and cellulose ether.
39. An electrophotographic photoreceptor according to claim 8, wherein the binder resin included in the charge transport layer is at least one selected from the group consisting of vinyl homopolymer and copolymer, polycarbonate, polyester, polyester carbonate, polysulfone, polyimide, phenoxy resin, epoxy resin and silicone resin as well as their partially crosslinked products.
35. An electrophotographic photoreceptor according to claim 3, wherein the binder resin is at least one selected from the group consisting of vinyl homopolymer and copolymer, polycarbonate, polyester, polyester carbonate, polysulfone, polyimide, phenoxy resin, epoxy resin and silicone resin as well as their partially crosslinked products.
36. An electrophotographic photoreceptor according to claim
39. An electrophotographic photoreceptor according to claim 8, wherein the binder resin included in the charge transport layer is at least one selected from the group consisting of vinyl homopolymer and copolymer, polycarbonate, polyester, polyester carbonate, polysulfone, polyimide, phenoxy resin, epoxy resin and silicone resin as well as their partially crosslinked products.
35. An electrophotographic photoreceptor according to claim 3, wherein the binder resin is at least one selected from the group consisting of vinyl homopolymer and copolymer, polycarbonate, polyester, polyester carbonate, polysulfone, polyimide, phenoxy resin, epoxy resin and silicone resin as well as their partially crosslinked products.
36. An electrophotographic photoreceptor according to claim
34 or 35, wherein the vinyl polymer is at least one selected from the group consisting of polymethyl methacrylate, polystyrene and polyvinyl chloride.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9730191 | 1991-04-26 | ||
| JP97301/91 | 1991-04-26 | ||
| JP8693892A JPH05100452A (en) | 1991-04-26 | 1992-04-08 | Electrophotographic sensitive body |
| JP86938/92 | 1992-04-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2067011A1 true CA2067011A1 (en) | 1992-10-27 |
Family
ID=26428008
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2067011 Abandoned CA2067011A1 (en) | 1991-04-26 | 1992-04-24 | Electrophotographic photoreceptor |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0511018A1 (en) |
| JP (1) | JPH05100452A (en) |
| CA (1) | CA2067011A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2021096343A (en) * | 2019-12-17 | 2021-06-24 | 富士フイルムビジネスイノベーション株式会社 | Electrophotographic photoreceptor, process cartridge, and image forming apparatus |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60243660A (en) * | 1984-05-18 | 1985-12-03 | Minolta Camera Co Ltd | Photosensitive body |
| JPS6242162A (en) * | 1985-08-19 | 1987-02-24 | Minolta Camera Co Ltd | Lamination type photosensitive body |
| JPH02148043A (en) * | 1988-11-30 | 1990-06-06 | Mita Ind Co Ltd | Electrophotographic sensitive body |
-
1992
- 1992-04-08 JP JP8693892A patent/JPH05100452A/en active Pending
- 1992-04-24 CA CA 2067011 patent/CA2067011A1/en not_active Abandoned
- 1992-04-24 EP EP19920303745 patent/EP0511018A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05100452A (en) | 1993-04-23 |
| EP0511018A1 (en) | 1992-10-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0224738B1 (en) | Electrophotographic photoreceptor | |
| EP0221487B1 (en) | Electrophotographic photoreceptor | |
| JPH05158258A (en) | Electrophotographic sensitive body | |
| CA2023623C (en) | Electrophotographic photoreceptor | |
| JPH0572753A (en) | Electrophotographic sensitive body | |
| CA2067011A1 (en) | Electrophotographic photoreceptor | |
| JP3184741B2 (en) | Electrophotographic photoreceptor | |
| EP0409145B1 (en) | Electrophotographic photoreceptor | |
| JP2976441B2 (en) | Electrophotographic photoreceptor | |
| JP3141171B2 (en) | Manufacturing method of electrophotographic photoreceptor | |
| JP3010808B2 (en) | Electrophotographic photoreceptor | |
| JPH05232718A (en) | Electrophotographic sensitive member | |
| JP2811107B2 (en) | Electrophotographic photoreceptor | |
| EP0708374B1 (en) | Electrophotographic photoreceptor | |
| JP2858152B2 (en) | Electrophotographic photoreceptor | |
| US5024913A (en) | Electrophotographic photosensitive material | |
| JP3228657B2 (en) | Electrophotographic photoreceptor, process cartridge having the electrophotographic photoreceptor, and electrophotographic apparatus | |
| JPH0545899A (en) | Electrrophotographic sensitive body, electrophotographic device, device unit and facsimile constituted by using this body | |
| JP2852787B2 (en) | Electrophotographic photoreceptor | |
| JP3146635B2 (en) | Electrophotographic photoreceptor and electrophotographic apparatus provided with the electrophotographic photoreceptor | |
| JP2607120B2 (en) | Electrophotographic photoreceptor | |
| JP2791497B2 (en) | Electrophotographic photoreceptor | |
| JP2601299B2 (en) | Electrophotographic photoreceptor | |
| JP2607122B2 (en) | Electrophotographic photoreceptor | |
| JP3295305B2 (en) | Electrophotographic photoreceptor, process cartridge having the electrophotographic photoreceptor, and electrophotographic apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |