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Timestamp: 2015-07-31 07:31:23
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Matched Legal Cases: ['Application No. 52', 'Application No. 52', 'Application No. 52', 'Application No. 52', 'Application No. 52', 'Application No. 52', 'Application No. 52', 'Application No. 52']

Patent US4365014 - Electrophotographic photoconductor - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsAn electrophotographic photoconductor is prepared by forming a photoconductive layer containing a hydrazone compound therein on an electroconductive support member. The hydrazone compounds represented by the following general formula, are useful as photoconductive materials and as charge transport materials...http://www.google.com/patents/US4365014?utm_source=gb-gplus-sharePatent US4365014 - Electrophotographic photoconductorAdvanced Patent SearchPublication numberUS4365014 APublication typeGrantApplication numberUS 06/079,406Publication dateDec 21, 1982Filing dateSep 27, 1979Priority dateSep 29, 1978Also published asCA1139598A1, DE2939483A1, DE2939483C2, DE2954414C2, US4454212Publication number06079406, 079406, US 4365014 A, US 4365014A, US-A-4365014, US4365014 A, US4365014AInventorsKiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Masaomi SasakiOriginal AssigneeRicoh Company, LimitedExport CitationBiBTeX, EndNote, RefManPatent Citations (5), Referenced by (14), Classifications (5) External Links: USPTO, USPTO Assignment, EspacenetElectrophotographic photoconductor
US 4365014 AAbstract
An electrophotographic photoconductor is prepared by forming a photoconductive layer containing a hydrazone compound therein on an electroconductive support member. The hydrazone compounds represented by the following general formula, are useful as photoconductive materials and as charge transport materials for use in electrophotography: ##STR1## wherein R1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group.
1. An electrophotographic element comprising:an electroconductive support member; a charge carrier producing layer comprising an azo pigment having a styrylstilbene group, as a photoconductive material effective for producing charge carriers; and a charge transport layer adjacent said charge carrier producing layer, which consists essentially of a hydrazone having the formula ##STR32## wherein R1 is methyl, ethyl,2-hydroxyethyl, or 2-chloroethyl, and R2 is methyl, ethyl, benzyl or phenyl, and a binder resin selected from the group consisting of polyamide, polyurethane, polyester, epoxy resin, polyketone, polyvinyl ketone, polystyrene, poly-N-vinyl carbazole and polyacrylamide. 2. An electrophotographic element as claimed in claim 1, wherein said charge transport layer comprises a hydrazone selected from the group consisting of:9-Methylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-Methylcarbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-Methylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone; 9-Ethylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-Ethylcarbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-Ethylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone; 9-(β-Hydroxyethyl)carbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-(β-Hydroxyethyl)carbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-(β-Hydroxyethyl)carbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone; 9-(β-Chloroethyl)carbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-(β-Chloroethyl)carbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-(β-Chloroethyl)carbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone. 3. An electrophotographic element as claimed in claim 1, wherein said charge transport layer comprises a hydrazone selected from the group consisting of 9-Ethylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone, 9-Ethylcarbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone and 9-Ethylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone.
4. An electrophotographic element as claimed in claim 1, wherein said photoconductive material is 1,4-bis[4-{2-hydroxy-3-(2,4-dimethylphenyl)carbamoylnaphthyl-1} azostyryl-1]benzene.
5. An electrophotographic element as claimed in claim 1, wherein said charge transport layer comprises a hydrazole selected from the group consisting of:9-Methylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-Methylcarbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-Methylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone; 9-Ethylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-Ethylcarbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-Ethylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone; 9-(β-Hydroxyethyl)carbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-(β-Hydroxyethyl)carbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-(β-Hydroxyethyl)carbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone; 9-(β-Chloroethyl)carbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone; 9-(β-Chloroethyl)carbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone; 9-(β-Chloroethyl)carbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone;and said photoconductive material is 1,4-bis[4-{2-hydroxy-3-(2,4-dimethylphenyl)carbamoylnaphthyl-1} azostyryl-1]benzene. 6. An electrophotographic element as claimed in claim 1, wherein said charge transport layer comprises a hydrazone selected from the group consisting of 9-Ethylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone, 9-Ethylcarbazole-3-carbaldehyde 1-ethyl-1-phenylhydrazone and 9-Ethylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone, and said photoconductive material is 1,4-bis[4-{2-hydroxy-3-(2,4-dimethylphenyl)carbamoylnaphthyl-1} azostyryl-1]benzene.
The present invention relates to an electrophotographic photoconductor and more particularly to an electrophotographic photoconductor comprising an electroconductive support member and a photoconductive layer containing a hydrazone compound represented by the following general formula (1) therein, which is formed on the electroconductive support member: ##STR2## wherein R1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group.
Recently, a variety of electrophotographic photoconductors containing various organic materials have been proposed to eliminate the above-mentioned shortcomings of the inorganic materials. As a matter of fact, some of them are practically used. For instance, the following photoconductors are used in practice: a photoconductor comprising poly-N-vinylcarbazole and 2,4,7-trinitrofluorene-9-one (U.S. Pat. No. 3,484,237); a photoconductor consisting essentially of azo pigments (U.S. Pat. No. 3,775,105); and a photoconductor consisting essentially of an eutectic cacrystalline substance comprising a dye and a resin (U.S. Pat. No. 3,684,502 and U.S. Pat. No. 3,732,180). These photoconductors have excellent characteristics and high practical value in fact. However, they still have their own shortcomings in view of the requirements for use in electrophotography.
It is therefore an object of the present invention to provide an electrophotographic photoconductor, eliminating the above-mentioned shortcomings of the conventional electrophotographic photoconductors.
The hydrazone compounds represented by the previously mentioned general formula (1) can be prepared by the following ordinary procedure by condensing equal moles of 3-formylcarbazole compound and N-alkylphenylhydrazine compound in alcohol, and, if necessary, a small amount of a condensing agent, such as glacial acetic acid or inorganic acid, is added thereto.
The following are the specific examples of the hydrazone compounds represented by the general formula (1): ##STR4## The photoconductive materials for use in the present invention contain any of the above hydrazone compounds. By use of any of the photoconductive materials, the photoconductors according to the present invention are prepared as shown in FIG. 1 through FIG. 3. Referring to FIG. 1, there is shown one embodiment of a photoconductor according to the present invention, in which a photoconductive layer 2 comprising a hydrazone compound, a sensitizer dye and a binder agent (resin), is formed on an electroconductive support member 1. Referring to FIG. 2, there is shown another embodiment of a photoconductor according to the present invention, in which, on the electroconductive support member 1, there is formed a photoconductive layer 2' wherein a charge carrier producing material 3 is dispersed in a charge transport medium 4 comprising a hydrazone compound and a binder agent. Referring to FIG. 3, there is shown a further embodiment of a photoconductor according to the present invention, in which on the electroconductive support member 1, there is formed a photoconductive layer 2" comprising a charge carrier producing layer 5 consisting essentially of the charge carrier producing material 3, and the charge transport layer 4.
As the binder agents for use in the present invention, the following can be employed: polyamide, polyurethane, polyester, epoxy resin, condensed resins, such as polyketone and polycarbonate, and vinyl polymers such as polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and polyacrylamide, and any other electrically insulating and adhesive resins.
As the sensitizers for use in the photoconductive layer 2 of the photoconductor in FIG. 1, the following can be employed: triarylmethane dye, such as Brilliant Green, Victoria Blue B, Methyl Violet, Crystal Violet and Acid Violet 6 B, and xanthene dye, such as Rhodamine B, Rhodamine 6G, Rhodamine G Extra, Eosine S, erythrosine, Rose Bengale and Fluorescein, and thiazine dye, such as Methylene Blue, and cyanine dye, such as cyanin, and pyrylium dye, such as 2,6-diphenyl-4-(N,N-dimethylaminophenyl) thiapyrylium-perchlorate and benzopyrylium salt.
3. Azo pigments having a carbazole group as represented by the general formula: ##STR5## (U.S. Patent Application Ser. No. 872,679 and Corresponding Japanese Patent Application No. 52-8740)
4. Azo pigments having a styrylstilbene group as represented by the general formula: ##STR6## (U.S. Patent Application Ser. No. 898,130 and Corresponding Japanese Patent Application No. 52-48859)
5. Azo pigments having a triphenylamine group as represented by the general formula: ##STR7## (U.S. Patent Application Ser. No. 897,508 and Corresponding Japanese Patent Application No. B 52-45812)
6. Azo pigments having a dibenzothiophene group as represented by the general formula: ##STR8## (U.S. Patent Application Ser. No. 925,157 and Corresponding Japanese Patent Application No. 52-86255)
7. Azo pigments having an oxadiazole group as represented by the general formula: ##STR9## (U.S. Patent Application Ser. No. 908,116 and Corresponding Japanese Patent Application No. 52-77155)
8. Azo pigments having a fluorenone group as represented by the general formula: ##STR10## (U.S. Patent Application Ser. No. 925,157 and Corresponding Japanese Patent Application No. 52-87351)
9. Azo pigments having bis-stilbene groups as represented by the general formula: ##STR11## (U.S. Patent Application Ser. No. 922,526 and Corresponding Japanese Patent Application No. 52-81790)
10. Azo pigments having distyryloxadiazole group as represented by the general formula: ##STR12## (U.S. Patent Application Ser. No. 908,116 and Corresponding Japanese Patent Application No. 52-66711)
11. Azo pigments having a distyrylcarbazole group as represented by the general formula: ##STR13## (U.S. Patent Application Ser. No. 921,086 and Corresponding Japanese Patent Application No. 52-81791)
14. Perylene pigments, such as A190 Scarlet B (commercially available from Bayer A.G.) and Indanthren Scarlet R (commercially available from Bayer A.G.).
To two parts by weight of Diane Blue (C.I. Pigment Blue 25 C.I. 21180) were added 98 parts by weight of tetrahydrofuran. The mixture of Diane Blue and tetrahydrofuran was ground in a ball mill so that a charge carrier producing pigment dispersion was prepared. This dispersion was coated on an aluminum evaporated polyester film by a doctor blade and was then air-dried at room temperature, so that a 1 μm thick charge carrier producing layer was formed on the aluminum evaporated polyester film.
Two parts by weight of 9-(ethylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone which is represented by the formula (5), ##STR14## 3 parts by weight of polycarbonate (Panlite L commercially available from Teijin Co., Ltd.) and 45 parts of tetrahydrofuran were mixed so that a charge transporting layer formation liquid was prepared. The thus prepared charge transporting layer formation liquid was coated on the charge carrier producing layer by a doctor blade and was then dried at 100� C. for 10 minutes so that an approximately 10 μm thick charge transporting layer was formed on the charge carrier producing layer. Thus, an electrophotographic photoconductor No. 1 according to the present invention was prepared.
The electrophotographic photoconductor was charged negatively in the dark under application of -6 kV of corona charge for 20 seconds and was then allowed to stand in the dark for 20 seconds without applying any charge thereto. At this moment, the surface potential Vpo (V) of the photoconductor was measured by Paper Analyzer (Kawaguchi Electro Works, Model SP-428). The photoconductor was then illuminated by a tungsten lamp in such a manner that the illuminance on the illuminated surface of the photoconductor was 20 lux, so that the exposure E1/2(lux. second) required to reduce the initial surface potential Vpo (V) to 1/2 the initial surface potential Vpo (V) was measured. The results showed that Vpo=-870 V and E1/2=3.7 lux.second.
__________________________________________________________________________ ##STR15##
__________________________________________________________________________     Charge carrier producing pigment                                3 parts by weight     Polyester resin (Polyester     Adhesive 49000 commercially     available from Dupont)     1 part by weight     Tetrahydrofuran            96 parts by weight__________________________________________________________________________
Then, two parts by weight of 9-ethylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone, which is represented by the formula, ##STR16## 3 parts by weight of polycarbonate (Panlite L commercially available from Teijin Co., Ltd.) and 45 parts by weight of tetrahydrofuran were mixed so that a charge transporting layer formation liquid was prepared.
As in the case of Example 1, the electrophotographic photoconductor was charged negatively in the dark under application of -6 kV of corona charge for 20 seconds, and was then allowed to stand in the dark for 20 seconds without applying any charge thereto, and as in the case of Example 1, Vpo and E1/2 were measured. The results showed that Vpo=-690 V and E1/2=9.9 lux. second.
In Example 2, ##STR17## was employed as the charge carrier producing pigment, and 9-ethylcarbazole-3-carbaldehyde-1,1-diphenylhydrazone represented by the formula (8) ##STR18## was employed as the charge transport material. Under the same conditions as in Example 2, a 1.0 μm thick charger carrier producing layer was formed on an aluminum evaporated polyester film, and a 12 μm thick charge transport layer was formed on the charge carrier producing layer. Thus, an electrophotographic photoconductor No. 3 was prepared, and Vpo and E1/2 were measured likewise. The results showed that Vpo=-1210 V and E1/2=7.5 lux. second.
In Example 2, ##STR19## was employed as the charge carrier producing pigment, and 9-ethylcarbazole-3-carbaldehyde-1-methyl-1-phenylhydrazone represented by formula ##STR20## was employed as the charge transport material. Under the same conditions as in Example 2, a 0.5 μm thick charge carrier producing layer was formed on an aluminum evaporated polyester film, and a 10 μm thick charge transport layer was formed on the charge carrrier producing layer. Thus, an electrophotographic photoconductor No. 4 was prepared, and Vpo and E1/2 were measured likewise. The results showed that Vpo=-830 V and E1/2=1.3 lux. second.
A 1 μm thick charge carrier producing layer consisting of selenium was formed on an approximately 300 μm thick aluminum plate by vacuum evaporation. Then, two parts by weight of 9-methycarbazole-3-carbaldehyde-1-methyl-1-phenylhydrazone represented by the formula (1) ##STR21## 3 parts by weight of polyester resin (Polyester Adhesive 49000 commercially available from Dupont) and 45 parts by weight of tetrahydrofuran were mixed so that a charge transport layer formation liquid was prepared. The thus prepared charge transport formation liquid was coated on the charge carrier producing layer consisting of selenium by a doctor blade and was then air-dried at room temperature, and was further dried under reduced pressure so that a 10 μm thick charge transport layer was formed on the charge carrier producing layer. Thus, an electrophotographic photoconductor No. 5 according to the present invention was prepared. By the same procedure as in the case of Example 1, Vpo and E1/2 were measured. The results showed that Vpo=-1210 V and E1/2=3.1 lux. second.
In Example 5, instead of selenium, a perylene pigment C. I. Vat Red 23 (C. I. 71130) represented by the formula ##STR22## was vacuum-evaporated with the thickness of 0.3 μm on an approximately 300 μm thick aluminum plate so that a charge carrier producing layer was formed. As the charge transport material, 9-(β-hydroxylethyl) carbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone represented by the formula (9) was employed so that a 12 μm thick charge transport layer was formed. ##STR23##
Under the same condition as in Example 5, except the above-mentioned charge carrier producing layer and charge transport layer, an electrophotographic photoconductor No. 6 according to the present invention was prepared. By the same procedure as in the case of Example 1, Vpo and E1/2 were measured. The results showed that Vpo=-1430 V and E1/2=7.7 lux. second.
A mixture of one part by weight of Chloro Diane Blue and 158 parts by weight of tetrahydrofuran was ground and mixed in a ball mill. To the mixture were added 12 parts by weight of 9-ethylcarbazole-3-carbaldehyde-1-methyl-1-phenylhydrazone represented by the formula (5) ##STR24## 18 parts by weight of polyester resin (Polyester Adhesive 49000 commercially available from Dupont). The mixture was further mixed so that a photoconductive layer formation liquid was prepared. The thus prepared photoconductor layer formation liquid was coated on an aluminum evaporated polyester film by a doctor blade and was then dried at 100� C. for 30 minutes so that a 16 μm thick photoconductive layer was formed on the aluminum evaporated polyester film. Thus, an electrophotographic photoconductor No. 7 according to the present invention was prepared. The photoconductor was positively charged under application of +6 kV of corona charge. Under the same conditions and by use of the same paper analyzer as in Example 1, Vpo and E1/2 were measured. The results showed that Vpo=1430 V and E1/2=8.7 lux. second.
In Example 7, instead of Chloro Diane Blue and 9-ethylcarbazole-3-carbaldehyde-1-methyl-1-phenylhydrazone represented by the formula (5), ##STR25## was employed as the charge carrier producing pigment, and 9-(β-hydroxylethyl) carbazole-3-carbaldehyde 1-benzyl-1-phenyhydrazone represented by the formula (11) was employed as the charge transport material. ##STR26##
Under the same conditions as in Example 7, a 12 μm thick photoconductive layer was formed on an aluminum evaporated polyester film, so that an electrophotographic photoconductor No. 8 according to the present invention was prepared. By the same procedure as in the case of Example 1, Vpo and E1/2 were measured. The results showed that Vpo=1030 V and E1/2=6.7 lux. Second.
In Example 7, instead of Chloro Diane Blue and 9-ethylcarbazole-3-carbaldehyde-1-methyl-1-phenylhydrazone represented by the formula (5), ##STR27## was employed as the charge carrier producing pigment, and 9-(β-chloroethyl) carbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone represented by the formula (13) was employed as the charge transport material. ##STR28##
Under the same conditions as in Example 7, a 12 μm thick photoconductive layer was formed on an aluminum evaporated polyester film, so that an electrophotographic photoconductor No. 9 according to the present invention was prepared. By the same procedure as in the case of Example 1, Vpo and E1/2 were measured. The results showed that Vpo=1090 V and E1/2=7.3 lux. second.
In Example 7, instead of Chloro Diane Blue and 9-ethylcarbazole-3-carbaldehyde-1-methyl-1-phenylhydrazone represented by the formula (5), ##STR29## was employed as the charge carrier producing pigment, and 9-(β-chloroethyl) carbazole-3-carbaldehyde 1,1-diphenylhydrazone represented by the formula (16) was employed as the charge transport material. ##STR30##
Under the same conditions as in Example 7, a 12 μm thick photoconductive layer was formed on an aluminum evaporated polyester film so that an electrophotographic photoconductor No. 10 according to the present invention was prepared. By the same procedure as in the case of Example 1, Vpo and E1/2 were measured. The results showed that Vpo=650 V and E1/2=7.5 lux. second.
Each of the electrophotographic photoconductors prepared in Examples 7 to 10 was positively charged by a commercially available copying machine and a latent image was formed on each photoconductor and was developed with a negatively charged dry type toner. The thus developed toner image was transferred electrostatically to a high quality transfer sheet and was fixed to the transfer sheet. As a result, a clear toner image was obtained from each electrophotographic photoconductor. In the case where a wet type developer was used instead of the dry type toner, a clear image was also obtained from each photoconductor.
One part by weight of 9-(ethylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone which is represented by the formula (5), ##STR31## one part by weight of polycarbonate (Panlite L commercially available from Teijin Co., Ltd.) and 0.001 part by weight Crystal Violet were dissolved in 9 parts by weight of 1,2-dichloroethane. The thus prepared photoconductive layer formation liquid was coated on a paper, whose surface was treated so as to be electroconductive, by a wire bar and was then dried at 100� C. for 5 minutes so that an approximately 6 μm thick photoconductive layer was formed on the paper. Thus, an electrophotographic photoconductor No. 11 according to the present invention was prepared.
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