JPS58193549A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To improve suitability to coating and to obtain the titled receptor preventing the occurrence of unevenness in an image due to uneven coating by forming a charge generating layer contg. specified resins and a charge transferring layer on a support. CONSTITUTION:A charge generating layer having 001-1mum thickness and contg. a charge generating substance such as pyrylium dispersed in a resin mixture and a charge transferring layer having 5-30mum thickness and contg. a charge transferring substance such as N-ethylcarbazole are formed on a support. The resin mixture consists of acrylic resin having 15-70 deg.C glass transition point, 10-40 acid value and 10,000-50,000mol.wt. and of a resin having >=75 deg.C glass transition point such as polystyrene in 30/1-1/1 weight ratio. Thus, an electrophotographic receptor producing a slight memory effect owing to repeated electrostatic charging and having stable potential at all times is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor. As a typical electrophotographic photoreceptor, K[
lA photoreceptor in which a photoconductive layer is formed as a holding layer? There are photoreceptors which are widely used and have a lamination of a photoconductive layer and an insulating layer thereon as a photoconductive layer and a photoreceptor layer.

Conventionally, inorganic photoconductive materials such as sulfuric acid, sulfidicum, and zinc oxide have been known as photoconductive materials used in electrophotographic photoreceptors.

On the other hand, various organic photoconductive polymers including polyvinylcarbazole have been proposed, but these polymers are superior to the aforementioned inorganic photoconductive materials in terms of film-forming properties, lightweight properties, etc. Despite this, it has been difficult to put it into practical use to date because sufficient film formation properties have not yet been achieved, and inorganic photoconductive materials have been lacking in sensitivity, durability, and stability against environmental changes. In addition, hydrazone compounds disclosed in U.S. Pat. No. 4,150,987, triarylpyrazoline compounds disclosed in U.S. Pat. No. 3,837,851, etc., and JP-A-51 -94828 Publication, JP-A-51-94829
Organic photoconductors of low molecular weight 1 such as D9-styrylanthracene compounds have been proposed in Japanese Patent Publication No. 2003-100003. In this way, by appropriately selecting the binder to be used, it is possible to solve the problem of poor film-forming properties in the field of organic photoconductive polymers. However, it cannot be said to be as good as 7 minutes in terms of sensitivity.

For these reasons, a laminated structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed in recent years. Electrophotographic photoreceptors using this laminated structure as a photosensitive layer can now be improved in terms of sensitivity to visible light, charge retention, surface strength, etc.

Such an electrophotographic photoreceptor is disclosed in US Pat. No. 3,837, for example.
851, No. 3871882, and the like.

However, in a photoreceptor having such a laminated structure, the dark potential, halftone potential, and bright potential cannot be kept constant during repeated periods or pause times, and the image intensity i1. (D...
-,) tended to change easily.

The cause of this is that photomemory, @electronic memory, etc. are generated in the charge generation layer, and the effect on this trap is caused by the binding resin that binds the charge generation substance and forms a barrier layer. Thick (・.

In addition, if the binder resin lacks resistance and stability to light, moisture, and heat, it may cause problems when used as a binder material for charge-generating substances. It adversely affects the stability as a fi generation layer,
During the manufacture of the charge generation layer, restrictions are easily imposed on the use of the photosensitive layer, and the photoreceptor is often unstable.

In particular, when charging is repeated under humidified conditions, the charge generation layer deteriorates, causing problems with durability and stability under humid conditions, and furthermore, the binding In other words, suitability for IE charge generation material dispersion, coating performance to obtain a predetermined film thickness, adhesion to the support, etc. are also desired.3 The charge generation layer of conventional photoreceptors is characterized by its electrophotographic properties and binding properties. There were few products whose suitability as a resin was sufficiently satisfied overall.

In addition, temperature is a variable factor due to the environment, and the charging characteristics are easily affected by changes from low to high temperatures (or vice versa).

The main object of the present invention is to provide an electrophotographic photoreceptor that improves the coating properties of the coating solution during the formation of the chrysanthemum generation layer, thereby eliminating the occurrence of uneven coating caused by uneven coating. Furthermore, the present invention provides an electrophotographic photoreceptor having a charge generation layer consisting of a charge generation substance and a binder resin, which has excellent durability, is unaffected by changes in the environment, and can always provide stable images. The purpose is to provide the following.

The present invention provides an electrophotographic photoreceptor having a charge generation layer formed by binding a charge generation substance with a binder resin, in which the charge generation layer contains a resin having a glass transition point of 70°C or lower and a resin having a glass transition point of 75°C or higher. It is characterized by the fact that

The binder resin combined according to the present invention reduces the memory effect caused by repeated charging as a charge generation layer, and provides a photoreceptor in which a stable potential can always be obtained.

In addition, the binder resin in combination used in the present invention can be
Stable to humidity 1. The resin used in the present invention, which has a glass transition point of 15°C to 70°C, is effective for the production of the charge generation layer and the environmental customization of the photosensitive layer, and greatly contributes to its stability.
For example, a resin having a polar group such as a nitro group, an ester group, a carbonyl group, a carboxyl group, or a nitrile group, preferably an acrylic acid such as acrylic acid, acrylic ester, acrylamide, acrylonitrile, methacrylic acid, or methacrylic ester as a monomer component. Resins having an acid value of lO to 40 are suitable.The number average molecular weight of these resins is preferably 10,000 or more.

These acrylic resins may also be made of copolymers with other monomer components, such as styrene, vinyl acetate, vinyl chloride, butadiene, etc. Acrylic resins can be used to freely incorporate polar groups (e.g. Since the C0OH group) can be introduced and its content can be freely controlled, the dispersion state of the charge generating substance can be sufficiently satisfied, and its film forming and coating properties are also good.

Since it is an electropolymer obtained by such acrylic resin solution polymerization, it has a high molecular weight that can be used as a one-component product, and its stability and handling properties are sufficiently satisfactory for practical use. be.

The photosensitive layer of the present invention shows little deterioration due to repeated charging under moisture absorption, and has excellent durability under humid conditions. this is,
This is affected by the content of carboxyl groups in the molecule of the acrylic resin, and those with less carboxyl groups have poor dispersion with the charge generating substance and tend to be incompletely and unevenly coated with the binder resin. On the other hand, those with a large number of carboxyl groups have good dispersibility, but the resin itself is easily susceptible to changes in its insulation performance (such as a decrease in resistance) under humid conditions, and its y1% properties are poor.

The charge generation layer of the present invention shows little deterioration due to repeated charging under moisture absorption, and has excellent durability under humid conditions.

The polar groups of the acrylic resin used in the present invention are preferably arranged as free acids in the molecule so that the acid value ranges from 10 to 40 (KOHf required to neutralize 1 kg of resin).・.

What is the glass transition point of acrylic resin? , is 15℃~70℃
Therefore, the effects of environmental temperature changes on the characteristics of the photoconductive layer are small, and a photoreceptor that is stable against temperature changes can be provided.

Since the Tg of the acrylic resin is low, the influence of temperature on the charge generation layer is reduced.

The acrylic resin used in the present invention (acrylic resin used in the present invention) has a monomer component which is a noalkyl group having 4 or more carbon atoms, such as acrylic acid butyl ester, acrylic acid isobutyl ester, acrylic acid 2-ethylhexyl ester, methacrylic acid methacrylic acid oxdel ester, etc. Acrylic ester, acrylamide, acrylonitrile with a group-containing component, and the glass transition point of the copolymer or homopolymer is 15
℃~70''CK.In order to adjust the Tg, copolymerization with acrylic ester, methacrylic ester, styrene, etc. must be considered (.

When the glass transition point is 60° C. or lower, the characteristics of the charge generation layer include, for example, less accumulation of memory due to repeated charging, which is preferable. Also, if you use a material with a glass transition point of 70°C or higher, the memory of repeated charging will be large.
The stability of the photoreceptor due to charging is poor, resulting in unstable images each time it is copied.

On the other hand, in order to avoid corrosion by the solvent of the charge transport layer applied when the charge transport layer is provided on the charge generation layer, the glass transition point is particularly preferably 15° C. or higher.

In order to maintain adhesion with the acrylic resin support,
%, the glass transition point is preferably 60°C or lower.

The molecular structure of the acrylic resin is such that its glass transition point is preferably in the range of 15°C to 60°C.

The molecular structure of the polar groups contained in acrylic resin is
Carboxyl group is effective, and as a monomer material,
Examples include fumaric acid, itaconic acid, maleic acid or their monoester derivatives, acrylic acid or methacrylic acid.

Acrylic resins can be easily synthesized by conventional methods. That is, a polymerization initiator such as benzoyl peroxide, azoinobutyronitrile, or cumene hydroperoxide is used in a solvent such as toluene, methyl isobutyl ketone, or xylene, and the polymerization temperature is 40°C to 1.
It is sufficient to polymerize at 50°C.

In the polymerization of acrylic resin, the molecular weight can be adjusted by selecting and adjusting the amount of polymerization initiator and reaction conditions, but it is preferably in the range of 10,000 to 5000.

When a resin used in the present invention has a glass transition point of 75° C. or higher, it is possible to improve the coating properties of the coating solution, and therefore, as described above, it is possible to improve the coating properties of the coating solution. Image unevenness cannot be eliminated. Coating unevenness appears in response to sensitivity unevenness in the photosensitive layer, which reduces the commercial value of the photoreceptor. Examples of resins with a glass transition point of 75°C or higher include polystyrene and polyester. , epoxy/resin, chlorinated polyethylene, phenolic resin, etc.

The charge generation layer of the present invention (glass transition point c or lower, single K
Tg and (・5) Resin at 70°C or higher and T "The blending ratio of resin at 75°C or higher is 7g Resin at 70°C or lower (weight) 77
The ratio of the resin (weight) at g75°C or higher is 30/1 to 1/1, preferably 20/1 to 3/1.

The charge generation layer contains the charge generation material described above at an appropriate Tg as described above.
It can be formed by dispersing it in a resin consisting of a combination of a resin having a Tt of 70° C. or lower and a resin having a Tt of 75° C. or higher and coating it on a substrate.

The resin contained in the charge generation layer is suitably 80% by weight or less, preferably 40% by weight or less.

Organic solvents used during coating include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and amides such as N,N-dimethylformamide and N,N-dimethylacetamide. , sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, ethylene glycol methyl ether, esters such as methyl acetate, ethyl acetate,
Aliphatic and halogenated hydrocarbons such as chloroform, ethylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene (benzene, toluene, xylene,
Aromatics such as ligroin, monochlorobenzene, dichlorobenzene, etc. can be used.

Coating methods include dip coating method, spray coating method, spinner coach ink method, heat coating method,
This can be carried out using a coating method such as a Mayer bar coating method, a blade coating method, a roller coating method, or a curtain coating method.

For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying can be carried out at temperatures ranging from 30°C to 200°C for times ranging from 5 minutes to 2 hours, either stationary or under blowing air. Containing the organic photoconductor, and in order to shorten the range of the generated charge carriers, form a thin film layer, for example 48 layers, with a thickness of 5 microns or less, preferably 0.001 micron to 1 micron. is preferable. This means that
Most of the incident light is absorbed by the charge generation layer, generating many charge carriers, and the generated charge carriers must be injected into the charge transport layer without being deactivated by recombination or trapping. It is caused by

The charge generating layer used in the present invention includes pyridine, thiopyrylium dye, phthalocyanine pigment, anthorone pigment, dibenzpyrenequinone pigment, pyranthrone pigment, trisazo pigment, disazo pigment, azo pigment, indigo pigment, and quinacridone pigment. , asymmetric quinocyanin,
It can contain a charge generating substance such as quinocyanine.

The charge generating substance used in the electrophotographic photoreceptor of the present invention may be, for example, the inorganic compounds shown below (* indicates an organic compound).

′1 as a substitute for the proboscis ′i +11 (11) Thioindigo dye (C, 1,478800) (
12) β-11w/4 phthalocyanine l]3) (14) (15) Next, a synthesis example of the acrylic resin used in the present invention will be described.

Synthesis Example 1 150 parts of toluene was charged into a 500cc four flask equipped with a cooling tube, a stirring bar, and a temperature **1, and the temperature was raised to 110°C, and then 40 parts of styrene and 4 parts of n-butyl methacrylate were added.
0 parts, 120 parts of ethylene methacrylate, 12 parts of methacrylic acid, 4 parts of benzoyl peroxide, and 60 parts of toluene were added over 3 hours in the presence of an inert gas, and the resulting copolymer was heated for an additional 6 hours, with a nonvolatile content of 49. 5%, t: 52°0, polymer acid value 15 number average molecule - @ 28000. This is used as an acrylic resin film.

Synthesis Example 2 As in Synthesis Example 1, 200 parts of toluene, 70 parts of ethyl methacrylate, 116 parts of -1butyl methacrylate, 10 parts of acrylic acid, and 5 parts of 2.2'-azobisinobutyronitrile were used. , the obtained copolymer has a nonvolatile content of 52
! , 2%, Tf: 41”O, acid value of polymer 22
, the number average molecular weight was 42,000. This is designated as acrylic yoso-B.

Synthesis Example 3 Acrylic resin was polymerized in the same manner as in Synthesis Examples 1 and 2 to obtain the following product.

Seven-dimensional abbreviation SL ・Styrene n-BMA... Methacrylic acid i-butyl ester A... Methacrylic iron ethyl ester intestinal Buddha...
The methacrylic acid methyl ester charge transport layer is electrically connected to the charge generation layer described above, and receives and receives charge carriers injected from the charge carrier (generating charge in the presence of an electric field). It has the function of transporting charge carriers to the surface. At this time, this charge transport layer is &I! 1
The load generator 1- may be placed horizontally on top of the load generator 1-, or may be stacked below the load generator 1-. However, the III transport castle is
Preferably, it is laminated on the charge generation layer.

Since the photoconductor generally has the function of transporting charge carriers, the charge transport layer can be formed by the photoconductor.

Things that transport charge carriers in the charge transport layer'! (hereinafter simply referred to as a charge transport material) is preferably substantially insensitive to the wavelength range of electromagnetic waves to which the charge generation layer is sensitive. line,
Includes a broad definition of "light rays" that includes ultraviolet rays, visible light, near-infrared to 1-infrared rays, far-infrared rays, and the like. When the photosensitive wavelength range of the charge transport layer is -1 or overlaps with that of the charge generation layer, charge carriers generated in both will mutually guide each other, resulting in a decrease in degree IIIA.

Kamehira's transport fs substances include Fi electron-transporting substances and hole-transporting substances, and electron-transporting substances include chloranyl,
Bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-dolinitro-9-fluorenone, 2,4.5.7-titranito-o-9-fluorenone, 2,4.7-)dinitro-9-dicyano Examples include electron-withdrawing substances such as methylene fluorenone, 2,4.5.7-titranitroxanthone, and 2,4.8-trinidrothioxanthone, and polymerized versions of these electron-withdrawing substances.

Examples of hole-transporting substances include pyrene, N-xflucarpazole, N-isopropylcarbasol, N-methyl-N
-Phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10-ethylphenop Azi7,N,N-diphenylhydrazino-3-methyIJ
Thene-10-ethylphenoxazine, P-diethylaminobenzaldehyde-N, N-diphenylhydrazone,
P-diethylaminopene, ll'fuldehyde N-α-
Naphthyl-N-phenylhydrazone, P-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone, l,
3.3-) Hydrazones such as dimethylindolenine-ω-aldehyde-N,N-diphenylhydrazone, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis(P-diethylamino phenyl)-1,3,4-oxadiazole, 1
-Phenyl-3-(P-diethylaminostyryl)-5
-(P-diethylaminophenyl)pyrazoline, l-[
Quinolyl+21) -3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl]pyrazoline, l-C pyridyl+21) -3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1 -C6-Medoxyviridyl+i+
1-3- (P-diethylaminostyryl L)-5-(
p-diethylaminophenyl)pyrazoline, 1-[pyridyl+s+ 3-3- (p-diethylaminostyryl)-5-(P-diethylaminophenyl]pyrazoline, l-C revidyl+2+]-3-(P-diethylaminostyryl) = 5 -(P-diethylaminophenyl)pyrazolino, s-(pyridyl(animo)-3-(P-diethylaminostyryl)-4-methyl-5-(P-diethylaminophenyl)pyrazoline, 1-C pyridyl nl
) -3-(α-methyl-p-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazolino,
1-phenyl-3-(P-diethylaminostyryl)-
Pyrazolines such as 4-methyl-5-(P-diethylaminophenyl)pyrazoline, l-phenyl-3-(α-benzyl-p-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, spiropyrazoline, 2-( P-diethylaminostyryl)-6-ethylaminobenzoxazole, 2-(p-diethylaminophenyl)-4-(P-dimethylaminophenyl)-
Oxazole compounds such as 5-(2-chloronoenyl)oxazole, 2-(P-diethylaminostyryl)-
azole-based compounds such as 6-dinithylaminobenzothiazole, triarylmethane-based compounds such as bis(4-diethyl7mi/-2-methylphenyl)-phenylmethane, 1,1-bis(4-N, N-diethylamino-2-
polyarylalkane such as methylphenyl)hebutane, l,l,2,2-tetrakis(4-N,N-dimethylamino-2-methylphenyl)ethane, triphenylamine, poly-N-vinylcarbasol, poly and nylpyrene, polyvinylanthracene, polyvinylacridine,
Examples include poly-9-vinylphenylanthracene, hylene-formaldehyde)''m III, ethylcarbazole formaldehyde resin, and the like.

In addition to these organic charge transport materials, inorganic materials such as selenium, selenium-tellurium, amorphous silicon, and cadmium sulfide can also be used.

Further, these charge transport substances can be used alone or in combination of two or more.

When the charge transporting substance has the ability to imitate, it can be imitated by selecting an appropriate binder. Examples of resins that can be used as binders include acrylic resin,
polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer,
Insulating materials such as acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, borislupo/, polyacrylamide, polyamide, chlorinated rubber, organic photoconductive materials such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, etc. Polymers can be mentioned.

Since the charge transport layer has a limit in its ability to transport charge carriers, it cannot be made thicker than necessary. Generally, the range is 5 microns to 30 microns, with a preferred range being 8 microns to 20 microns. When forming the charge transport layer by coating, an appropriate coating method as described above can be used.

A photosensitive material comprising such a layered structure of a ridge generation layer and a charge transport layer is provided on a substrate having a conductive layer. Guide II
Examples of the substrate having a layer include those whose substrate itself is conductive, such as aluminum, aluminum alloy, steel, salivary lead,
Materials such as stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold and platinum can be used, and in addition, aluminum, aluminum alloys, indium oxide, tin oxide, indium oxide-tin oxide alloys, etc. can be used for air deposition. plastics (e.g. polyethylene, polypropylene,
A substrate in which conductive particles (e.g., carbon black, complex particles, etc.) are coated on plastic together with a suitable binder, and conductive particles are coated on plastic or paper. Substrates immersed in water, plastics containing conductive polymers, etc. can be used.

A sublayer 1- having a barrier function and adhesion function can also be provided between the conductive layer 1- and the photosensitive layer. Subbing layer C, casein, polyvinyl alcohol, nitrocellulose, ethylenenoacrylic acid coholyl-, polyamide (nylon 6,
Nylon 66, thick iron 610. It can be formed from copolymerized nylon, alkoxymenalized nylon 7, etc.), polyurethane, gelatin, aluminum oxide, etc.

The appropriate thickness of the film is 0.1 to 5 microns, preferably 0.5 to 3 microns.

When using a photoreceptor in which the Denran J-1 charge generation layer and charge transport layer are formed in this order, the wIL cargo transport reality is Atsuko+m.
Sensitivity'+! When made of A material, the charge transport surface must be positively charged, and when exposed after charging, electrons generated in the charge generation layer are injected into the charge transport layer in the exposed area.
After that, it reaches the surface and neutralizes the positive charges, resulting in attenuation of the surface potential and an electrostatic contrast between it and the unexposed area.

A visible image can be obtained by developing the thus obtained static image with a negatively charged toner. Either fix this directly, or transfer the toner image to paper or plastic film, etc.
It can be developed and fixed.

Alternatively, a method may be used in which the electrostatic latent scratches on the photoreceptor are transferred and fixed onto an insulating layer of transfer paper. The first type of developer, the developing method, and the dipping method may be any known method or methods, and are not limited to specific ones.

On the other hand, when the charge transport material consists of a hole transport substance, the surface of the charge transport layer must be negatively charged, and when exposed to foggy light after charging, the holes generated in the charge generation layer are transferred to the charge transport layer. After that, it reaches the surface and neutralizes the negative charges, resulting in attenuation of the surface potential and an electrostatic contrast between it and the unexposed area. In the case of existing trenches, it is necessary to use positively charged toner, contrary to the case where electron transport materials are used. It can also be widely used in electrophotographic applications.

Hereinafter, the present invention will be explained according to examples.

Example 1 Ammonia aqueous solution of casein (casein 1
1. SM, 28% ammonia water IF, water 222.1/)
Apply with a T-wire bar so that the film thickness after drying is 10 microns, and dry.

Next, a disazo pigment 5f having the structural formula was added to a solution in which acrylic resin A3* and polystyrene 2f were dissolved in 100 aa/ of toluene, and dispersed with an attritor for 2 hours.

This dispersion was applied onto the previously formed casein shield using a Mayer bar so that the film thickness after drying was 0.5 microns.
It was dried to form a charge generator.

5 of the hydrazone compound and 5 f of the styrene-acrylonitrile copolymer were dissolved in 70 m/m of monochlorobenzene, and this was applied onto the % load generation layer using a Mayer parr so that the film thickness after drying was 12 microns. It was dried to form a charge transport layer.

The electrophotographic photoreceptor thus prepared was held in the dark for 10 seconds using a corona charger at 15 KV using the static ivy method using an electrostatic copying paper tester Model 8P 42g manufactured by Kawaguchi Denki ■, and then at an illuminance of 5/1111. The photoless zone tL characteristics are also subbed.

The charging characteristics are the surface potential (v6) and the exposure t (
El/2) was measured. The results are shown in Table wJ1.

Furthermore, in order to measure the fluctuations in the bright area potential and dark area potential when used repeatedly, the pressure photoreceptor prepared in this example was
, No. 6, a corona charger (2), a lightless optical system having an exposure amount of 15 tux t, a developing device, a transfer charger, a static eliminating exposure optical system, and a cleaner.

This II transfer machine is configured to obtain tjk+ill on the transfer paper as the cylinder is driven. Using this copy m, the initial bright area potential (VL) and dark area potential (Vo
) and the light area [muscle VL) and dark area potential (Vo) after 5000 uses were measured. The results are shown in Table 2.

wJ1 table v, knee 600 volts El/2: 81 ux-sex (the unit in the table is -lt) Also, the photomemory property (PM) of the photoreceptor of this example
After holding the photoreceptor under 1000 jux for 5 seconds,
Evaluation was made by measuring the time required to recover the original charging characteristics. The results are shown in table m3.

m3 table sample PM (photo memory test) A
O, 5 minutes Also, as shown in Table 4, high temperature environment, low humidity environment, 1000
Durability such as repeated charging 0 times or more, and fluctuations such as changes in density during continuous copying from the first sheet after stopping repeated charging, were small, and stable copies were obtained.

Example 2 Photoreceptors B, C, D, Σ, F
, G, H, I, J, and K were created.

Separately, a comparative photoreceptor was prepared in the same manner as the photoreceptor described above, except that the resin shown in Table 5 was used as a binder for the charge generation layer.

Table 5 These photosensitivity) A B, C, D, E, F,
X, Y.

Continuation from the 1st sheet after the repeated charging of 2 is stopped Table 6 B -6159, 0-600-110-610-120
0,5C-6059,5-5,95-105-600-
1100,6o -6008,5-605-110-6
t5-11506 Tobi-65010, 5-670-140
-660-1500,9F -6108,5-600-
105-615-1100,6G-64010,5-
660-140-670-1500, 958-5958
,0-600-105-615-1100,61-60
08,5-595-100-605-1050,5J
-6058,0-610-105-615-11006
K-5707, 0-575-90-565-850,
95x -6159,0-600-210-510-3
200,5Y-6008,5-605-210-51
5-3150, 6Z-6108, 5-600-205
-515-3100,6 On the other hand, when the image quality of photosensitive drum B-K was evaluated, it was as shown in Table 7.

Table 7 Photosensitive tram J G, has a small acid value, K is min-f-
Because the violet is small, the dispersion state of the charge-generating substance becomes rapid, which tends to cause uneven coating, resulting in m degree non-uniformity on the 1llIi image.
This results in local changes in the properties and packing density of the charge-generating material.

Example 3 When a photoreceptor is prepared by coating a charge transport layer on the charge-generating layer as in Sample A of Example 1, if there is insufficient drying time, solvent may remain, which may cause problems during humidification. Since durability may be deteriorated, the drying temperature was increased to test for stable longitudinal alignment due to heat. Sample X of Example 2 was used as a comparative example. The results are shown in Table 8.

Table 8 8 Example = Repeated charging 60 times under the same process as 1
0 times, 25°0. Performed under 100% humidity, initial 10%
The retention rate at each heat treatment temperature as a coefficient of 0 is shown.

Sample A of Example 1 suffers little from thermal deterioration and exhibits good stability during drum manufacturing. Comparative sample X was unstable.

Example 4 Film j51 for aluminum improvement of aluminum vapor-deposited polyethylene terephthalate film! A 1.1 micron film of polyvinyl alcohol was formed.

Next, on the polyvinyl alcohol layer on which a dispersion of polystyrene and acrylic resin containing the disazo pigment used in Example 1 was previously formed, 11Ii was applied, so that the film thickness of the dried bale was 0.5 microns. A charge generating layer was formed by applying the same coating using Mayer Per and drying.

Next, a solution of pyrazoline compound 5t of the structural formula and polyarylate resin (at association of bisphenol A and terephthalic acid-isophthalic acid 5f) in putrahydrofuran mml K *f
It was applied onto the i-generating layer to a dry film thickness of 10 microns, and dried to form a 'llc#J transport pigeon.

The charging characteristics and durability characteristics of the photoreceptor were thus measured in the same manner as in Example 1. This result is the 6th
Shown in the table.

Table 6 ■.　　　　　　-615 El/2: 9.0 Initial dark potential VD: -610 Initial light area vL: -100 Patent applicant: Canon Co., Ltd.

Claims (1)

[Claims] An electrophotographic photoreceptor having a charge generation layer and a charge transport layer, wherein the charge generation layer contains a resin having a glass transition point of 70°C or lower and a resin having a glass transition point of 75°C or higher.