JPH01211769A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve chargeability of an electrophotographic sensitive body, to reduce relative humidity at high temp. and under high humidity, and to prevent dewing of the photosensitive body at low temp. by imparting absorptivity for infrared rays to an electroconductive substrate and/or a photosensitive layer. CONSTITUTION:A compd. having absorptivity for infrared rays is incorporated into an electroconductive substrate 11 and/or a photosensitive layer 15 of a photosensitive layer. Suitable electroconductive substrate 11 having absorptivity for infrared rays is a metal such as Al coated with CuO, etc. by vapor deposition or sputtering, etc. Suitable absorbent for infrared rays to be incorporated into a photosensitive layer 15 is CuO, etc. Thus, chargeability of an org. photosensitive body is improved, relative humidity of atmosphere of a photosensitive body is reduced even at high temp. and under high humidity, and dewing of the photosensitive body at low temp. is prevented.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to an electrophotographic photoreceptor.

[Prior art]

The photosensitive layer of a photoreceptor used in electrophotographic copying machines, printers, etc. is made of inorganic materials such as dye-sensitized zinc oxide, cadmium sulfide, selenium, and selenium-arsenic and selenium-tellurium compounds containing selenium. It is divided into a photosensitive layer and a variety of organic photosensitive layers.

Incidentally, in recent years, photoreceptors used in electrophotographic copying machines have begun to be made of organic photosensitive materials, which have the advantages of being inexpensive, productive, and non-polluting.

Organic electrophotographic photoreceptors include photoconductive resins such as polyvinylcarbazole (PVK), and PVK-TNF.
(2,4,7 trini-1-rofluorenone), pigment dispersion type as typified by phthalocyanine nosinder, and functionally separated type using a combination of a charge-generating substance and a charge-transporting substance. It is known that the body etc.
In particular, functionally separated photoreceptors are attracting attention.

When such an organic photoreceptor is applied to the Carlson process, it has low chargeability and poor charge retention (high dark decay), and these characteristics deteriorate significantly with repeated use, causing problems such as It has the drawbacks of density unevenness, fog, and background smearing in the case of reverse development.

That is, the chargeability of organic photoreceptors decreases due to pre-exposure fatigue. This pre-exposure fatigue is mainly caused by light absorbed by the heavy-generating material, so the longer the charges generated by light absorption remain in the photoreceptor in a mobile state, the more the number of charges increases. It is thought that the higher the amount, the more significant the deterioration in chargeability due to pre-exposure fatigue becomes. In other words, even if a charging operation is performed while the charge generated by light absorption remains, the surface charge will be neutralized by the movement of the remaining carriers, so the surface potential will increase until the residual charge is consumed. do not. Therefore, the increase in surface potential is delayed by the amount of pre-exposure fatigue, and the apparent charge level 4 becomes lower.

As a method to improve these drawbacks, a method is known in which an inorganic material such as 5iO5AΩ203 is provided between the support and the charge generation layer by a method such as vapor deposition, sputtering, or anodization. (Japanese Unexamined Patent Publication No. 55-142354), and it is also known to include metal powder in the charge generation layer (Japanese Unexamined Patent Publication No. 60-214364).

In addition, polyamide resin (Japanese Unexamined Patent Publication No. 58-30
No. 757, JP-A-58-987:39), alcohol-soluble nylon resin (JP-A-60-19676)
Resin layers such as water-soluble polyvinyl butyral resin (Japanese Patent Application Laid-Open No. 60-232553), polyvinyl butyral resin (Japanese Patent Application Laid-Open No. 58-106549) have been proposed.

However, with regard to the deterioration of chargeability and charge retention due to repeated use, improvement measures on the photoreceptor side have not been sufficient to provide a photoreceptor.

JP-A No. 51-111338 discloses that when an As2Se3 photoreceptor is maintained at a temperature 10 to 30% higher than room temperature and not exceeding 40°C, the rate of fatigue (dark decay) is slowed down. I'm there.

On the other hand, in the operating environment of a copying apparatus, under high temperature and high humidity conditions, image blurring and image distortion occur, and at low temperatures, there are problems such as dew condensation on the photoreceptor and scumming.

Regarding this environmental dependence, JP-A-61-7843 discloses that the relative humidity of the photoreceptor under high temperature and high humidity can be reduced by heating the support of the photoreceptor layer at a relatively low temperature using a planar heating element. , JP-A-62-121483 discloses a method of blowing hot or cold air onto a photoreceptor, which is a method that can prevent dew condensation on the photoreceptor at low temperatures and prevent deterioration of the photoreceptor at high temperatures. has been disclosed, but the method was not necessarily satisfactory.

〔the purpose〕

An object of the present invention is to provide an electrophotographic photoreceptor that can improve the charging property of the photoreceptor, reduce relative humidity under high temperature and high humidity conditions, and prevent dew condensation on the photoreceptor at low temperatures. Another object of the present invention is to provide an electrophotographic photoreceptor that can be efficiently heated by infrared irradiation.

〔composition〕

According to the present invention, an electrophotographic photoreceptor comprising at least a photosensitive layer formed on a conductive support is characterized in that the conductive support and/or the photosensitive layer have infrared absorbing properties. provided.

The present inventors have developed an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, which prevents image blurring and image distortion due to a decrease in surface potential under high humidity, and also prevents dew condensation on the photoreceptor at low temperatures. As a result of intensive studies on methods for preventing and suppressing background smearing of images under low temperature and low humidity conditions, we found that when a compound having infrared absorbing properties is contained in the conductive support and/or photosensitive layer of the photoreceptor, The inventors have found that the above object can be achieved and have completed the present invention.

Next, the electrophotographic photoreceptor of the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view showing an example of the structure of a photoreceptor according to the present invention, in which a photoreceptor layer 15 is provided on a conductive support 11. As shown in FIG.

FIGS. 2A and 2A are cross-sectional views showing another example of the structure, in which the photosensitive layer is composed of a stack of a charge generation layer 21 and a charge transport layer 23. FIG.

3 and 4 are cross-sectional views showing still other structural examples, in which FIG. 3 has an intermediate layer 13 provided between the conductive support 11 and the photosensitive layer 15, and FIG. In this example, a protective layer 17 is provided on a photosensitive layer 15.

The conductive substrate 11 having infrared absorbing properties may be one having conductivity with a volume resistance of 1010 Ωcm or less, or a metal surface such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, etc. with copper oxide, manganese dioxide, or oxide. Coated with cobalt, iron oxide, chromium oxide, lead sulfide, nickel sulfide, etc. by vapor deposition, sputtering, etc., or
Copper, iron, chromium, etc. whose surface has been oxidized, film-like or cylindrical plastic in which the above metal oxides or sulfides are dispersed, aluminum, nickel, chromium, nichrome, copper, silver, gold on paper. , a material coated with a metal such as platinum, a metal oxide such as tin oxide or indium oxide, or a plastic in which carbon black or the like is dispersed can be used.

In addition, those exhibiting conductivity with a volume resistance of 1010 Ω or less,
For example, aluminum, nickel, chromium, nichrome,
Film or cylindrical plastic or paper coated with metals such as copper, silver, gold, platinum, or metal oxides such as tin oxide or indium oxide by vapor deposition or sputtering, or aluminum, aluminum alloy, or nickel. , plates made of stainless steel, etc., and their adhesives, 1
．． 1. Also used are pipes that have been made into blank pipes using extrusion, drawing, etc., and then surface-treated by cutting, superfinishing, polishing, etc., and then coated with a resin solution containing the metal oxides and sulfides dispersed above. be able to.

In the present invention, both inorganic and organic types can be used as the photosensitive layer, and examples of the inorganic type photosensitive layer include amorphous Se,
5e-Te compound, 5e-As compound, 5e-Te-C
Q compounds, Cds, ZnO, etc. are used.

Next, the organic photosensitive layer 15 will be explained, but first, the laminated photosensitive layer will be described.

The charge generation layer 21 is a layer mainly made of a charge generation substance,
A binder resin may be used if necessary.

Binder resins include polyamide, polyurethane,
Polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone,
Polystyrene, poly-N-vinylcarbazole, polyacrylamide, etc. are used.

Examples of charge-generating substances include C.I.Pig-7=Mend Blue 25 [Color Index (CI) 211]
80], CI Pigment Red 41 (CI 212
00), Sea Eye Acid Red 52 (CI 4510
0), CI Basic Red 3 (CI 45210
), furthermore, phthalocyanine pigments having a porphyrin skeleton, and azo pigments having a carbazole skeleton (Japanese Patent Laid-Open No. 5
3-95033), azo pigments having a distyrylbenzene skeleton (described in JP-A-53-133455), azo pigments having a triphenylamine skeleton (described in JP-A-53-133455),
(described in JP-A-53-132547), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-2172)
8), an azo pigment having an oxadiazole skeleton (described in JP-A No. 54-12742), an azo pigment having a fluorenone skeleton (described in JP-A-54-22834)
Azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), azo pigments having a distyryloxadiazole skeleton (described in JP-A-54-17733),
2129), an azo pigment having a distyrylcarbazole skeleton (described in JP-A-54-17734), and CI Pigment Blue 16 (CI
74100), indigo pigments such as C.I. Butt Brown 5 (CI 73410) and C.I. Butt Dye (CI 73030), Argo Scarlet B (manufactured by Violet), Indanthrene Scarlet R (manufactured by Bayer), etc. Examples include perylene pigments.

Among these charge generating substances, azo pigments are preferred.

These charge generating substances may be used alone or in combination of two or more.

The binder resin is suitably used in an amount of 0 to 100 parts by weight, preferably 0 to 100 parts by weight, based on 100 parts by weight of the charge generating substance.
~50 parts by weight.

The charge generation layer is prepared by dispersing a charge generation substance together with a binder resin if necessary using a ball mill, attritor, santomill, etc. using a solvent such as tetrahydrofuran, cyclohexane, dioxane, dichloroethane, etc., diluting the dispersion liquid appropriately and applying it. It can be formed by Application can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.

The thickness of the charge generation layer is suitably about 0.01 to 5 .mu.m, preferably 0.1 to 2 .mu.m.

The charge transport layer 23 can be formed by dissolving or dispersing a charge transport substance and a binder resin in a suitable solvent, coating the solution on the charge generation layer, and drying the solution. Moreover, a plasticizer, a leveling agent, etc. can also be added if necessary.

Charge transport materials include hole transport materials and electron transport materials.

Examples of the hole transport substance include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamic acid 1 and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, polyvinylpyrene, Oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9-(P-diethylaminostyryl)anthracene, 1,1-bis-(4-dibenzylaminophenyl)propane, styrylanthracene, styrylpyrazoline, phenyl Hydrazones, α-
Examples include electron-donating substances such as phenylstilbene derivatives and benzidine derivatives.

Examples of the electron transport substance include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinone dimethane, 2,4,7-dolinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone,
2,4,5.7-titranitroxanthone, 2.4.8
-)-linitrothioxanthone, 2,6.8-trinitro-4H-indeno(1,2-b)thiophene-4-
1.3.7-trinitrodibenzothiophene-5
, 5-dioxide and other electron-accepting substances.

These charge transport substances may be used alone or in a mixture of two or more.

Binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester,
Polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N- vinylcal) <sol, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin,
Examples include thermoplastic or thermosetting resins such as phenol resins and alkyd W resins.

As the solvent, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, etc. are used.

The appropriate thickness of the charge transport N23 is about 5 to 50 μm.

Next, the case where the photosensitive layer M15 has a single layer structure will be described.

In this case as well, most of the materials are of a functionally separated type consisting of a charge generating substance and a charge transporting substance.

That is, the compounds shown above can be used as the charge generating substance and the charge transporting substance.

A single-layer photosensitive layer can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance and a binder resin in a suitable solvent, coating the solution and drying the solution. Moreover, a plasticizer, a leveling agent, etc. can also be added if necessary.

As the binder resin, in addition to using the binder resin mentioned above for charge transport N23 as is, charge generation N2
The binder resins listed in 1 may be used in combination.

The single-layer photosensitive layer is formed by dipping coating, spray coating, bead coating, etc. using a coating solution in which a charge generating substance, a charge transporting substance, and a binder resin are dispersed using a dispersion machine using a solvent such as tetrahydrofuran, dioxane, dichloroethane, or cyclohexanone. Can be formed by coating.

The thickness of the single photosensitive layer is suitably about 5 to 50 tones.

Note that in the present invention, it is also possible to further provide an insulating layer on the photosensitive layer 15.

Further, in the present invention, as shown in FIG. 3, by providing an intermediate layer 13 between the conductive support and the photosensitive layer, the first effect of the present invention can be further improved. and can also improve adhesion.

For the intermediate layer 13, an inorganic material such as 5iO1A 203 is formed by vapor deposition, sputtering, anodization, etc., or a polyamide resin (Japanese Unexamined Patent Publication No. 58-30757,
JP-A-58-98739), alcohol-soluble nylon resin (JP-A-60-196766), water-soluble polyvinyl butyral resin (JP-A-60-23255)
3), polyvinyl butyral resin (JP-A-58-
106549), a resin layer made of polyvinyl alcohol, etc. can be used.

Furthermore, a resin intermediate layer in which pigment particles such as ZnO1Tie2 and ZnS are dispersed can also be used as the intermediate layer.

Furthermore, as the intermediate layer 13 of the present invention, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, etc. can also be used.

The thickness of the intermediate layer N13 is suitably 0 to 5 μm.

As the resin used for the protective layer 17, ABS resin, A
C3 resin, olefin vinyl copolymer resin, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyarylate,
Polyaryl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, methacrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene resin, polyurethane, poly Examples include vinyl chloride, polyvinylidene chloride, and epoxy resin.

In addition, from the viewpoint of wear resistance, polytetrafluoroethylene resin, fluorine resin, and silicone resin can be added as additives to lower the wear coefficient and improve wear resistance and scratch resistance. The wear resistance can also be improved by dispersing inorganic compounds such as , tin oxide, and potassium titanate into the resin.

The thickness of this surface protective layer is 0.5 to 10R1, preferably 1
~5 μm.

Examples of the infrared absorbing agent to be contained in the photosensitive layer include copper oxide, manganese dioxide, cobalt oxide, iron oxide, chromium oxide, lead sulfide, and nickel sulfide.

The present invention is constructed by containing the above-mentioned infrared absorbers in the photosensitive layer of the photoreceptor, but since infrared absorbers are generally black or green-blue in color, charges are generated in the photosensitive layer. Since there is a risk that the substance will not be exposed to light, it is usually contained in a place such as the intermediate layer shown in FIG. 3, 13.

Incidentally, as a method of heating the photoreceptor of the present invention, a method of irradiating infrared rays is preferably used, but as a light source, an infrared lamp (an ordinary tungsten lamp, halogen lamp, etc. with a filter attached to extract only infrared rays) is used. ) and semiconductor lasers, the schematic diagrams of which are shown in FIG. 5 and FIGS. 6a and 6b.

FIG. 5 shows a method in which a light source is irradiated from the inside of the photoreceptor, and is used when the inside of the conductive support is subjected to infrared absorption treatment or when the support itself is an infrared absorber.

FIG. 6a is a diagram showing irradiation from the outside (photosensitive layer side) of the photoreceptor, and FIG. 6b is a detailed depiction of the light source section.

-16= In Figure 6, infrared rays are irradiated from the outside of the photoreceptor, but in this case, there is not much of a problem if the photosensitive layer absorbs only visible light, but for example, for laser printers, When a photoreceptor has the ability to absorb near infrared rays, it is necessary to provide a filter as shown at 33 in Figure 6 in order to accelerate fatigue of the photoreceptor. Furthermore, since infrared rays only need to be irradiated onto the photoreceptor, it is advisable to attach a cover or the like around the lamp.

Moreover, the mirror in the figure is for condensing light, and it is preferable to use it. When using a semiconductor laser, a Selfox lens array or the like may be used to condense the light linearly over the entire length of the photoreceptor.

Regarding the timing of irradiation with infrared rays, it is possible to continue irradiating the infrared rays when the photoreceptor is in use, or to use it only when the photoreceptor is not in use.

Furthermore, by heating the photoreceptor at a temperature higher than the atmosphere of the photoreceptor, preferably 40° C. or higher, and more preferably 50° C. or higher, significantly better characteristics of the photoreceptor can be obtained than at lower temperatures.

Further, the upper limit of the temperature is not particularly limited, but is naturally limited by the melting point, glass transition point, decomposition point, etc. of the substance constituting the photoreceptor.

Also, for the upper limit limited in this way, overheat
It is also effective to use a cooling device to prevent this.

〔Example〕

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples.

Example 1 A charge generation layer coating liquid and a charge transport layer coating liquid having the following compositions were applied to the outer surface of an aluminum drum with an outer diameter of 40 mm and a length of 250 mm coated with carbon black dispersed in polycarbonate. was coated and dried to form a charge generation layer (0.3Izm) and a charge transport layer (18ρ).

[Charge generation layer coating liquid]

Trisazo pigment with the following structural formula: 1-layer cyclohexanone 150#2-butanone
50 no! [Charge transport layer coating liquid] Charge transport substance having the following structural formula 5 parts by weight Tetrahydrofuran 40 Monochlorobenzene 40 The organic photoreceptor prepared as above was coated with a laser printer (Ricoh PC Laser 6000).
), and a surface electrometer probe was set at a position where the surface potential of the photoreceptor could be measured immediately after charging. Also the fifth
A tungsten lamp was set inside the photoreceptor as shown in Figure 2, and a temperature sensor was set inside the drum so that the temperature of the photoreceptor was 50±5°C, and the temperature was adjusted by turning the lamp on and off. This was done with 3000 consecutive prints.

The environmental conditions at this time are as follows.

15°C-75% 25°C-60% 30°C-90% Comparative Example 1 A photoreceptor was prepared in the same manner as in Example 1 except that the conductive support was made of Afl, and then a lamp was prepared. was turned on and off at the same timing as in Example 1.

Table 1 shows the results of Example 1 and Comparative Example 1.

Table 1 Example 2 A 0.2 μm thick charge generation layer and a 25 μm thick charge transport layer having the following composition were coated on a support made of a polyester film in which oxidized network powder was dispersed and aluminum was vapor-deposited.

[Charge generation layer coating liquid]

X-type metal-free phthalocyanine 10 parts by weight Polyvinyl butyral 5 parts by weight (Denka Kagaku Kogyo: Denka Butyral #4000-1) Cyclohexanone 100 parts by weight Cyclohexane
85 parts by weight [Charge transport layer coating liquid] Charge transport material having the following structural formula 10 parts by weight Methylene chloride 80 parts by weight This was used as a photoreceptor for mounting.

This was placed on a laser printer (Ricoh LP4080) equipped with the same heating device and surface electrometer as in Example 1. When the laser printer was started, it was heated to 80°C, and when it reached 80°C, it was cooled down to 35°C using a separately provided fan, and when the temperature reached 35°C, printing was started. After printing 500 sheets in a row, heat the temperature at 80℃ again as above.
A cycle of heating to 35° C. and cooling to 35° C. was repeated, and 500 prints were made again.

This operation was repeated 6 times in succession: 3000 sheets were printed.

Comparative Example 2 The same operations as in Example 2 were performed except that a polyester film in which copper oxide powder was not dispersed was used. However, lamp irradiation was performed for the same time as the time required to reach 80° C. in Example 1.

FIG. 7 shows profiles of surface potentials measured in Example 2 and Comparative Example 2.

Example 3 An intermediate layer (o, 3rd grade) consisting of the following composition was formed on a substrate in which iron oxide was vapor-deposited on the outer surface of an aluminum drum with a diameter of 80 mm.
A charge generation layer (0.3 μs) and a charge transport layer (22 μm) were sequentially applied.

[Intermediate J side coating liquid]

Methanol 96 parts by weight [Charge generation layer coating liquid] Charge generating substance with the following structural formula Type 2 dish part Cyclohexanone 100 parts by weight [Charge transport layer coating liquid] Charge transporting substance having the following structural formula 10 parts by weight Tetrahydrofuran 80 parts by weight or more The photoreceptor prepared as described above was mounted on a copying machine (Recopy FT5510) modified to be negatively charged, and a surface electrometer probe was set so that the surface potential of the photoreceptor could be measured immediately before development. A sharp cut filter was used to cut out light of 760 nm or less.

In addition, the drum temperature is 25℃ (room temperature), 40℃, 50℃, 6
0℃.

The temperature was controlled by turning the lamp on and off so that the temperature was 80'C and 100C. After setting each condition, the copying machine was used repeatedly, and the surface potential of the unexposed area immediately before development was measured.

=24- Figure 8 shows the relationship between the surface potential and the photoreceptor temperature when 5000 sheets were printed. Incidentally, under each condition, the potential at the time of the first sheet before the running test was about -900V.

Example 4 An intermediate layer coating solution having the following composition and a charge generation layer coating were applied to an aluminum cylinder having an outer diameter of 40 mm and a length of 250 mm, on which a coating solution in which copper oxide was dispersed in polyamide was coated in 5 tones. A coating liquid and a charge transport layer coating liquid were sequentially applied and dried to form an intermediate layer (3 patterns), charge generation 7m (0,2 tiles), and charge transport N (21 tiles).

[Intermediate layer coating liquid]

Titanium dioxide 10 parts by weight Toluylene-2,4-diisocyanate 0.2 parts by weight 2-butanone 100 parts by weight 4-methyl-2-pentanone 60 parts by weight [Charge generation layer coating liquid] Trisazo pigment having the following structural formula 2 parts by weight Polyvinyl butyral (manufactured by Denki Kagaku Kogyo ■, Denka Butyra 0.5 parts by weight)
4000-1) Cyclohexanone 150 parts by weight 2-butanone [Charge transport layer coating liquid] Charge transport substance with the following structural formula 100 parts by weight Tetrahydrofuran 800 parts by weight or more 6000), and a surface electrometer probe was set so that the surface potential of the photoreceptor could be measured immediately after charging. Also, set a tungsten lamp outside the photoreceptor as shown in Figure 5, set a temperature sensor inside the drum so that the temperature of the photoreceptor is 40±5℃, and turn on the lamp.
Adjustment was made by turning off the printer, and 3,000 sheets were printed continuously.

The filter used was IR-90 manufactured by Fuji Photo. The environmental conditions at this time are as follows.

25°C-50% 10°C-70% 30°C-90% Comparative Example 3 The same evaluation as in Example 1 was performed except that the coating liquid in which copper oxide was dispersed was not applied.

However, since lamp irradiation was performed at the same timing as in Example 1, the temperature did not reach 40°C. Example 1 and comparative example 1
The results are shown in Table-2.

Table 2 Example 5 A charge generation layer (0,1 μII+) having the following composition and a charge transport layer ( 20 μm) was applied.

[Charge generation) ~ Coating liquid]

Same as Example 4 [Charge generation layer coating liquid] Charge transport material having the following structural formula: 90 parts by weight Methylene chloride 800 parts by weight Comparative Example 4 Everything was carried out in the same manner as in Example 5 except that the surface coating of the aluminum drum was not performed. .

The photoreceptors prepared in Example 5 and Comparative Example 4 were mounted on a laser printer (Recopy PC Laser 6000), set so that the drum surface temperature could be measured, and the increase in the photoreceptor surface temperature after irradiation with a heating lamp was performed. A temperature curve and a temperature drop curve were measured. The results are shown in Figure 9.

Example 6 A charge generation layer (0,:bs+) and a charge transport N (17 μm) having the following composition were sequentially coated on a polyester film whose surface was coated with a polyamide resin layer containing carbon black (10 μm), and dried to form a photoreceptor. It was created.

[Charge generation layer coating liquid]

Charge generating substance having the following structural formula: 5 parts by weight Cyclohexanone 200 parts by weight Methyl isobutyl ketone 100 parts by weight [Charge transport layer coating liquid] Charge transporting substance having the following structural formula: 10 parts by weight Tetrahydrofuran 80 parts by weight or more Photoreceptor prepared as follows conductive coating and belt joining,
It was used as a photoreceptor for mounting. This was set in a copying machine (Recopy FT2070) equipped with a sharp cut filter (Fuji Photo: 5C-72) attached to a halogen lamp from the inside of the photoreceptor as shown in FIG.

This is heated to 75℃ at startup, cooled down to room temperature using another fan, starts copying when it reaches room temperature, and heated to 75℃ again when it reaches 500 sheets → room temperature. The cooling cycle was repeated 8 times and 4000 copies were made continuously. At this time, the surface potential was measured in the same manner as in Example 1.

Comparative Example 5 The same evaluation as in Example 6 was performed except that the polyamide resin layer containing the carbon blank was not coated.

However, since the lamp irradiation time was set only for the time when the photoreceptor of Example 6 reached 75°C, the temperature did not reach 75°C.

FIG. 10 shows the profile of the surface potential of the photoreceptor in the running test of Example 6 and Comparative Example 5.

〔effect〕

Since the electrophotographic photoreceptor of the present invention has the above structure, it exhibits the following remarkable effects.

(1) The photoreceptor can be efficiently heated by infrared irradiation.

3l- (2) It is possible to lower the relative humidity of the photoreceptor atmosphere under high temperature and humidity conditions, and prevent image blurring and image distortion.

(3) It is possible to prevent dew condensation on the photoreceptor at low temperatures and background smearing of images at low temperatures and humidity.

(4) In organic photoreceptors, the charging properties of the photoreceptors can be improved.

[Brief explanation of the drawing]

FIG. 1, FIG. 2a, FIG. 2b, FIG. 3, and FIG. 4 are schematic cross-sectional views of the electrophotographic photoreceptor according to the present invention, and FIG.
FIGS. 6a and 6 are explanatory diagrams of the method of heating an electrophotographic photoreceptor of the present invention, and FIGS. 7, 9, and 10 are diagrams showing the electron 2 is a graph showing the relationship between the number of prints and the surface potential when printing using a photographic photoreceptor. FIG. 8 is a graph showing the relationship between surface potential and photoreceptor temperature when 5,000 copies were made using the electrophotographic photoreceptor of the present invention. 11. Conductive support, 13. Intermediate layer, 15.. Photosensitive layer, 17. Protective layer, 21. Charge generation layer, 23.. Charge transport layer, 31.. Photoreceptor, 32.. Lamp or lens array. , =32-33...filter, 34...cover, 35...mirror.

Claims (1)

[Claims] (1) An electrophotographic photoreceptor comprising at least a photosensitive layer formed on a conductive support, characterized in that the conductive support and/or the photosensitive layer have infrared absorbing properties.