JPH04234763A - Method of covering laminated type photosensitive body - Google Patents

Abstract

PURPOSE: To make it possible to form layers of single turn paths and to use a material which is not formed via a solvent soln., for example, a photoforming material. CONSTITUTION: This method includes vacuum vapor deposition of a conductive layer 3 on a substrate, vacuum vapor deposition of a charge blocking layer 4 on this conductive layer 3 and vacuum vapor deposition of a charge generating layer 6 on this charge blocking layer 4 in a process for producing an electrophotographic image forming member.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to electrophotography and, more particularly, to electrophotographic imaging members and methods for forming imaging members.

0002

BACKGROUND OF THE INVENTION In electrophotography, an electrophotographic plate containing a photoconductive insulating layer on a conductive layer is first imaged by uniformly charging its surface. The plate is then exposed to a pattern of activated electromagnetic radiation, such as light. The radiation selectively dissipates the charge in the illuminated areas of the photoconductive insulating layer and leaves an electrostatic latent image in the non-illuminated areas. This electrostatic latent image is then developed to form a visible image by depositing finely divided electroscopically visible particles on the surface of the photoconductive insulating layer. The resulting visible image is then transferred from the electrophotographic plate to a support such as paper. This imaging process is repeated many times with a reusable photoconductive insulating layer.

Electrophotographic imaging members can come in many forms. For example, the imaging member may be a homogeneous layer of a single material such as vitreous selenium, or it may be a composite layer including a photoconductor and another material. One type of composite imaging member includes a layer of finely divided particles of a photoconductive inorganic compound dispersed in an electrically insulating organic resin binder. U.S. Pat. No. 4,265,990 discloses a stacked photoreceptor having separate photogenerating and charge transport layers. The photogenerating layer is capable of photogenerating holes and injecting the photogenerated holes into the charge transport layer. Laminated photoreceptors consisting of a thin charge generating layer and a thick charge transport layer have many advantages over single layer structures.

The key to the function of layered photoreceptors is that they are very thin, reducing the distance that photogenerated charge must travel, and reducing the amount of photogenerated charge that can be captured in the charge generation layer. Located in the charge generation layer. However, to function as a good generating layer, the charge generating layer must also be optically thick to absorb most of the light during imagewise exposure. These two parameters are
Requires charge generating layer materials that are highly light absorbing and favor pigments in crystalline form.

One type of multilayer photoreceptor used as a belt in electrophotographic imaging systems consists of a substrate,
It includes a conductive layer, a blocking layer, an adhesive layer, a charge generating layer, a charge transport layer, and a conductive ground strip layer adjacent one end of the imaging layer. The photoreceptor may also include additional layers such as an anti-curl layer and an optional protective coating layer. Assembling such multilayer photoreceptors requires forming various layers on top of each other. Depositing the material in various layers requires various methods to form the layers.

For example, one method for forming charge generating layers from organic materials is solution casting. However, photogenerated pigments such as phthalocyanines and perylene amides are primarily insoluble and require dispersion in solvent-soluble binders. U.S. Pat. No. 4,587 to Hor et al.
, 189 discloses a layered photosensitive imaging member comprising an electrically conductive support substrate, an adhesive layer of a polymeric material, a vacuum evaporated photogenerating layer comprising a perylene diimide pigment, and a hole transport layer of an arylamine. are doing. The photoconductive layer is formed by vacuum deposition of perylene pigment, followed by a solvent coated layer of polyaryldiimide material in a resin binder.

[0007] Borsenben
U.S. Pat. No. 4,578,334 and U.S. Pat. No. 4,618,560 to Ger) et al. disclose multilayer photoconductive elements and methods of making the same that exhibit very high electrophotographic speeds. A charge generation layer of N,N'-bis(2-phenethyl) perylene-3,4:9,10 bis(dicarboximide) and a charge transport layer consisting of an arylamine substance in a polymeric binder are in a laminated structure. established in A layer of perylene pigment may be obtained by vacuum deposition of the pigment and protective coating it with a solution of an organic solvent, a polymeric binder and an arylamine, and curing the layer to remove the solvent. U.S. Pat. No. 4,57 to Staudenmaier et al.
No. 8,333 further discloses the above multilayer photoreceptor having an adhesive interlayer of acrylonitrile copolymer between the conductive support and the charge generating layer.

US Pat. No. 4,780,386 to Hordon et al. discloses a selenium alloy process to control tellurium fractionation during vacuum deposition of a charge generating layer. The process involves polishing the surface of the alloy prior to vacuum deposition. A charge transport layer containing selenium or a selenium alloy may be provided between the charge generation layer containing selenium-tellurium-arsenic and the substrate. The charge generation layer and charge transport layer may be vacuum deposited.

US Pat. No. 4,770,965 to Fender et al. discloses a method in which a selenium alloy is vacuum deposited onto a substrate to form a glassy photoconductive insulating layer. This insulating layer is then heated until the selenium in the layer adjacent to the substrate crystallizes. An aluminum oxide layer may be formed on the substrate by glow discharge treatment of the substrate in a vacuum coater.

US Pat. No. 4,842,973 to Badesha et al. discloses at least one first layer crucible containing particles of selenium or a selenium alloy in a vacuum vessel; A method of vacuum depositing a plurality of selenium alloy layers by providing a crucible with at least one second layer containing the alloy is disclosed. The particles in the crucible of the first layer are heated to deposit the first layer on the substrate while the particles in the crucible of the second layer are maintained below the deposition temperature. The particles in the second layer crucible are then rapidly heated and deposited into a second layer on the substrate.

Another example of a multilayer photoreceptor includes a vacuum deposited phthalocyanine as a charge generation layer with a solvent coated charge transport layer. Borsenbenger
U.S. Pat. No. 4,471,039 to Benger et al., U.S. Pat.
No. 55,463 and Kato et al., US Pat. No. 4,731,312, disclose a number of vacuum deposited phthalocyanines. In particular, these patents disclose indium phthalocyanine photoconductors that are vacuum deposited onto a substrate.

The manufacturing methods described above provide imaging members with a number of disadvantages. In particular, the methods described above utilize other coating techniques, such as solvent coating, to coat the adhesion and blocking layers of the photoreceptor. Since the conductive metal layer on the polymeric substrate is vacuum deposited, such additive coating techniques involve the transfer of the formed layer or layers from the vacuum deposition vessel to another coating facility, and the vacuum deposition. Requires return to container. These movements not only increase manufacturing time, but also increase the likelihood of photoreceptor damage or defects due to increased handling. Accordingly, it is desirable to reduce the time required to manufacture electrophotographic imaging members while simultaneously manufacturing imaging members that have fewer defects.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the drawbacks of the prior art by providing a method of manufacturing a laminated photoreceptor. It is an object of the present invention to provide a coating method for assembling photoreceptors that produces fewer printout defects.

Yet another object of the present invention is to provide a multilayer photoreceptor with fewer drawbacks. Another object of the invention is to provide an efficient coating method for assembling electrophotographic imaging members. It is also an object of the present invention to provide a conductive metal layer on the surface of the electrophotographic imaging member.
It is an object of the present invention to provide a method of coating an oxide layer and a photogenerating layer.

It is also an object of the present invention to improve layer adhesion in multilayer electrophotographic imaging members.

[0016]

Means for Solving the Problems The present invention includes placing a substrate in a reduced pressure environment, forming a conductive layer on the substrate, forming a blocking layer on the conductive layer, and forming a charge generation layer on the blocking layer. The shortcomings of the prior art are overcome by providing a coating method that includes forming a coating and continuously maintaining a reduced pressure environment during the coating process. Layers deposited in a reduced pressure environment can be formed in a single pass, eliminating many drawbacks. Additionally, materials that are not formed via solvent solutions, such as photogenerating materials, can be used according to the invention.

A more complete understanding of the present invention may be obtained by reference to the accompanying FIG. 1, which is a cross-sectional view of a multilayer photoreceptor of the present invention. The electrophotographic imaging members of the present invention include at least a conductive layer, a blocking layer, and a charge generating layer, all of which are formed in a continuously maintained vacuum environment. These layers are formed by placing the substrate in a reduced pressure environment and then subsequently vacuum depositing the respective layer.

[0018] The first layer coated onto the substrate in a reduced pressure environment comprises:
It is a conductive layer. Vapor deposition is performed to provide a substrate/conductive layer web or drum with a suitable conductive layer thickness. This conductive layer may, for example, be formed from a metal that is vacuum deposited onto the substrate. After deposition of the conductive layer, a blocking layer is formed on the conductive layer while the substrate/conductive layer web or drum remains in a reduced pressure environment. The blocking layer may be a metal oxide layer deposited directly by evaporation, by reactive evaporation of the metal in a partial pressure of oxygen, or by oxidation of a previously applied conductive layer. It may be. A substrate/conductive layer/blocking layer web is obtained.

The charge generating layer is then applied to the substrate/conductive layer/blocking layer web, still in a vacuum environment. The charge generating layer is vacuum deposited onto the blocking layer to obtain a substrate/conductive layer/blocking layer/charge generating layer web. Vapor deposition is carried out until the desired thickness is obtained. Subsequently, if desired, other layers may be applied to the substrate/conductive layer/blocking layer/charge generating layer in a vacuum environment or other coating equipment. For example, a charge transport layer may be applied, for example it may be applied by melt extrusion in a vacuum environment, or elsewhere by other coating methods.

A description of suitable materials for forming the layers of the electrophotographic imaging members of the invention is provided below with reference to the representative structure of the electrophotographic imaging members of the invention shown in FIG. It will be done. This image forming member has an anti-curl layer 1
, a supporting substrate 2, an electrically conductive layer 3, a blocking layer 4,
Optional adhesive layer 5, charge generating layer 6, charge transport layer 7 and protective coating layer 8 are provided.

Support substrate 2 may be opaque or substantially transparent and may include any number of materials with sufficient mechanical properties. Thus, the substrate may include a layer of electrically non-conducting or electrically conductive material, such as an inorganic or organic composition. Any of a variety of resins may be used as electrically non-conductive materials, including polyesters, polycarbonates, polyamides, polyurethanes, and the like. The electrically insulating or conductive substrate is flexible and may be in any of a number of different shapes, such as sheets, scrolls, flexible endless belts, cylinders, and the like. Preferably, the substrate is in the form of a flexible endless belt and is E. I. du Pont de Nemours
& Co. Mylar available from
, or ICI Americas Inc. including a commercially available biaxially oriented polyester known as Melinex available from Amazon. Alternatively, the preferred substrate may be in the form of a rigid cylinder formed by molding or extrusion.

The selection of substrate thickness depends on a large number of factors, including mechanical function and economic considerations and whether the final configuration is a flexible belt or a rigid drum. The thickness of the flexible layer is preferably from about 25 μm to about 150 μm
and preferably from about 75 μm to about 125 μm for good flexibility and minimally reduced surface bending stress when circulating around small diameter rollers, e.g. 19 mm diameter rollers. . The substrate of the flexible belt may have a substantial thickness, such as greater than 200 μm, or a minimum thickness, such as less than 50 μm, as long as there are no adverse effects on the photoconductive device. The thickness of the rigid drum substrate may range from about 1 mm to about several centimeters, depending on the diameter of the drum and its composition. The surface of the substrate layer is preferably cleaned before coating to promote better adhesion of the deposited coating. Cleaning is performed by exposing the surface of the substrate to plasma discharge, ion bombardment, or the like.

An electrically conductive layer 3 is provided adjacent to the substrate 2 . The electrically conductive layer 3 preferably comprises an electrically conductive metal layer formed on the substrate 2 in a reduced pressure environment. The conductive layer can be applied by any vacuum deposition technique. Vacuum deposition techniques include thermal evaporation, electron-beam bombardment, and RF and DC sputtering. Typical metals that may be vacuum deposited are aluminum, zirconium,
Niobium, tantalum, vanadium, hafnium, titanium,
Including nickel, stainless steel, chromium, tungsten, molybdenum, brass and gold, etc., and mixtures thereof. Semiconductors, such as silicon, or certain metal oxides, such as antimony-tin-oxide, are conductive and may also be vacuum deposited.

The conductive layer preferably has a thickness within a wide range depending on the optical clarity and flexibility desired in the electrophotographic imaging member. Therefore, the conductive layer thickness for flexible photoreceptor imaging devices is about 2 nm and about 100 nm.
nm, more preferably from about 5 nm to about 30 nm for optimum electrical conductivity, flexibility and optical transparency.

[0025] After the deposition of the electrically conductive layer 3, a blocking layer 4 is applied thereto. Electron blocking layers for positively charged photoreceptors allow holes from the imaging surface of the photoreceptor to migrate toward the conductive layer. For negatively charged photoreceptors, any suitable hole blocking layer capable of forming a barrier to prevent hole injection from the conductive layer to the opposite photoconductive layer may be utilized. The hole blocking layer may include any material that can be vacuum deposited. For example, the blocking layer is preferably a metal oxide or nitride. Aluminum oxide makes a good blocking layer, and other oxides are suitable and provide a better surface for adhesion of the charge generating layer. Other oxides that can be used to form the blocking layer 4 are, for example, oxides of silicon, both stoichiometric and non-stoichiometric SiOx, stoichiometric and non-stoichiometric SiOx. oxides of titanium and zirconium.

The blocking layer of the present invention can be formed in any of a number of ways while the substrate/conductive layer web or drum remains in a vacuum environment. According to one method, after a conductive layer of metal has been deposited in the aforementioned process, a metal oxide layer is formed by exposing the previously deposited metal layer to oxygen, thus forming a thin layer of metal oxide. A layer forms on the outer surface of the metal layer upon exposure to oxygen. Exposure to oxygen is carried out by introducing a partial pressure of oxygen into the reduced pressure environment.

Alternatively, the blocking layer of the invention may be evaporated directly onto the conductive layer, for example from a metal oxide, by electron beam evaporation or sputtering. Sputtering may include direct sputtering of preferred oxides or nitrides, or reactive sputtering of metals in partial pressures of oxygen or nitrogen, which result in deposition of the compound. Alternatively, reactive sputtering may be combined with direct sputtering of the metal, first depositing a metal conductive layer and then the metal oxide or nitride.

The blocking layer is preferably continuous and has a thickness of less than about 0.5 μm. Larger thicknesses lead to undesirably high residual potentials. Approximately 0.00
A hole blocking layer thickness between 5 μm and about 0.3 μm is preferred to achieve optimal electrical function. A thickness between about 0.03 μm and about 0.06 μm is most preferred for optimal electrical properties. The choice of material, deposition technique and thickness of the blocking layer also affects the conductive layer,
Influenced by the requirement to have good adhesion between the blocking layer and the photogenerating layer.

In some cases, for example, the blocking layer 4
An intermediate layer such as adhesive layer 5 between charge generating layer 6 and charge generating layer 6 is desirable for stronger adhesion. Optional adhesive layer
An optional adhesive layer is not necessary as long as appropriate choices are made in the materials of the blocking layer and charge generating layer. Vacuum deposition methods are believed to provide stronger adhesion between adjacent layers than is provided, for example, when the layers are solvent coated. If an adhesive layer is utilized, it preferably has a thickness of between about 0.001 μm and about 0.2 μm and is preferably removed in a vacuum environment, i.e. from coating the conductive layer to the charge generating layer. applied without breaking the vacuum during coating. To apply such a layer, an adhesive material must be used that can be vacuum deposited. Alternatively, the adhesive layer may be solvent coated. In such cases, the web material containing the substrate, conductive layer and blocking layer is isolated to prevent solvent evaporation from interacting with the web. The adhesive is, for example, polyester (
For example, E. I. du Pont de Nemo
urs&co. du Pont available from
49,000 resin; Goodyear Rubber
& Tire Co. Vitel P available from
E-100 and Vitel PE-200), polyvinyl butyral, polyvinylpyrrolidone, polyurethane, polymethyl methacrylate, 2-vinylpylidene, 4
- Contains film-forming polymers such as vinylpylidene, polyvinyl alcohol and polyvinyl chloride.

For web coating, the electrically conductive layer 3 and the blocking layer 4 are generally easily coated in a single evaporation reaction. It is possible, but not necessary, that the generator layer 5 is deposited in the same evaporation reaction. The charge generation layer 6 is a substrate/
The conductive layer/blocking layer is deposited while maintaining a reduced pressure environment. Charge generation applied by vacuum evaporation (
(photogenerating) layer may be utilized according to the present invention. Examples of materials for the photogenerating layer include inorganic and organic photoconductive pigment materials and dyes that are stable at the temperatures required for vacuum deposition, including inorganic and organic pigments such as chalcogenides, II-VI and III- V compounds, including diamines and other polycyclic pigment molecules of phthalocyanine, perylene and perinone anhydrides. Thus, the photogenerating layer is described in U.S. Pat.
816,118; metal phthalocyanines such as magnesium, zinc and copper phthalocyanines; oxidized metal phthalocyanines such as vanadyl, titanyl, zirconyl phthalocyanines; chloro-indium and bromo-indium. metal halide phthalocyanines such as phthalocyanines; and e.g.
Other and substitute variations of the phthalocyanines described in US Pat. No. 816,118 may also be included. ”Ph
thalocyanine compounds” (F
．． H. Moser and A. L. Written by Thomas, Reinhold Co. (1963) publication) is
Contains a detailed description of phthalocyanines and their synthesis. Other materials include polycyclic molecules such as dibromoanthanthrone, Monastra from du Pont.
Quinacridone, Vat orange 1 and V, available under the trade names Monastral Red, Monastral Violet and Monastral Red Y
Dibromoanthanthrone pigment available under the trade name at orange 3, benzimidazole perylene, Allied Chemical Corporation
ion to Indofast Double Sca
rlet, Indofast Violet Lak
e B, Indofast Brilliant Sc
These include polynuclear aromatic quinones available under the tradenames arlet and Indofast Orange, and amorphous selenium, tricrystalline selenium, and selenium alloys such as selenium-tellurium, selenium-tellurium-arsenic, selenium arsenide, and the like. Multiple photogenerating layer compositions may be utilized where the photoconductive layer enhances or diminishes the properties of the photogenerating layer. An example of a mold of this shape is U.S. Pat.
No. 5,639. Other suitable light-generating materials known in the art may also be utilized, if desired. Vanadyl phthalocyanine, chloro-indium phthalocyanine, titanyl phthalocyanine, metal-free phthalocyanine, benzimidazole perylene, phenethyldiimide perylene, N-butyl and N-propyldiimide perylene, tricrystalline selenium, such as selenium-tellurium, selenium-tellurium-arsenic and Charge generating layers comprising photoconductive materials such as selenium alloys, such as selenium arsenide, and mixtures thereof, are particularly preferred because of their sensitivity to white light. Vanadyl phthalocyanine, chloro-indium phthalocyanine, titanyl phthalocyanine, bromo-indium phthalocyanine, zirconium phthalocyanine, magnesium phthalocyanine, metal-free phthalocyanine and tellurium alloys also offer the added advantage that these materials are sensitive to infrared light. Therefore, it is preferable.

The photogenerating layer of the present invention generally has a thickness in the range of about 0.1 to about 2 μm, preferably about 0.2 to about 0 μm.
．． It has a thickness of 7 μm. Thicknesses outside this range can also be selected so long as the objectives of the invention are achieved. After completion of coating the conductive layer, blocking layer, optional adhesive layer, and photogenerating layer in a maintained vacuum environment, the charge transport layer is applied. The charge transport layer is relatively thick and the formation of this layer may be done outside the vacuum deposition vessel by other than vacuum deposition, for example by solvent coating techniques.

The charge transport layer 7 is capable of supporting the injection of photogenerated holes or electrons from the charge generation layer 6 and allows the transport of these holes or electrons through the layer, and has a selective surface charge. It may include any suitable transparent organic polymeric or non-polymeric material that can be electrically discharged. The charge transport layer not only transports holes or electrons, but also serves to protect the photoconductive layer from abrasion or chemical attack.
Therefore, the working life of the photoreceptor imaging member is extended. The charge transport layer must exhibit little, if any, discharge when exposed to light at wavelengths useful in xerography, such as from 400 nm to 900 nm. The charge transport layer is preferably substantially transparent to radiation in the areas where the photoconductor is used. It includes a material that supports injection of photogenerated holes or electrons from the charge generating layer. The charge transport layer is usually transparent to ensure that when exposure is performed therethrough, the majority of the incident light is utilized by the underlying charge generation layer. When a transparent substrate is used,
Imagewise exposure or erasure may be done through the substrate with all light passing through the substrate. In this case, the charge transport material does not need to be transparent to light in the wavelength range used. The charge transport layer associated with the charge generation layer is an insulator to the extent that electrostatic charges placed on the charge transport layer are not conductive in the absence of illumination.

The charge transport layer may include active compounds or charge transport molecules that are dispersed in normally electrically inactive film-forming polymeric materials to render those materials electrically active. has been done. These charge transport molecules may be added to polymeric materials that cannot support the injection of photogenerated holes or electrons and cannot allow the transport of these holes or electrons. Particularly preferred transport layers for use in multilayer photoconductors include from about 25% to about 75% by weight of at least one charge transport compound, and from about 75% to about 25% in which the charge transport compound is soluble.
Contains weight of polymeric film-forming resin. Alternatively, the charge transport moiety may be incorporated either into the backbone of the polymer or as a pendant group on the polymer.

The hole charge transport layer is preferably formed from a mixture containing at least one aromatic amine compound represented by the general formula below.

[0035]

[Chemical formula 1]

In the above formula, R1 and R2 are each an aromatic group selected from the group consisting of substituted or unsubstituted phenyl group, naphthyl group, and polyphenyl group, and R3 is substituted or unsubstituted phenyl group, naphthyl group, and polyphenyl group. aryl groups, alkyl groups having 1 to 18 carbon atoms, and alicyclic groups having 3 to 18 carbon atoms. Substituents should not have electron-withdrawing groups such as NO2 groups and CN groups. A typical aromatic amine compound represented by this structural formula is I. Triphenylamines such as:

[0037]

[Case 2]

II. Polytriarylamines such as:

[0039]

[Chemical formula 3]

III. Bisarylamine ethers such as:

[0041]

[C4]

[0042] and IV. Bisalkyl-arylamines such as:

[
0043

[C5]

[0044] In the above formula, R is hydrogen or CH3
, C2 H5 and the like. Preferred aromatic amine compounds have the general formula below.

[0045]

[C6]

In the above formula, R1 and R2 are as defined above, and R4 is a substituted or unsubstituted biphenol group, a diphenyl ether group, an alkyl group having 1 to 18 carbon atoms, and a group having 3 to 18 carbon atoms.
selected from the group consisting of alicyclic groups having 12 alicyclic groups. Substituents should not have electron-withdrawing groups such as NO2 groups and CN groups.

The charge transporting aromatic amine represented by the above structural formula includes triphenylmethane, bis(4-diethylamine-2-methylphenyl)phenylmethane; 4',
4"-bis(diethylamino)-2',2"-dimethyl-triphenylmethane;N,N'-bis(alkylphenyl)-(1,1'-biphenyl)-4,4'-diamine (in the formula, Alkyl is, for example, methyl, ethyl, propyl, n-butyl, etc.); and N,N'-diphenyl-N,N'-bis(3''-methylphenyl)-(1,
Including those dispersed in an inert resin binder such as 1'-biphenyl)-4,4'-diamine.

Any suitable inert resin binder dissolved in methylene chloride or other suitable solvent may be used. Typical inert resin binders that dissolve in methylene chloride include polycarbonate resins, polystyrene, polyphenylene, polyesters, polyarylates, polyacrylates, polyethers, polysulfones, and the like. The molecular weight is about 20,000 to about 1,500,000. Other solvents that dissolve these binders include tetrahydrofuran, toluene, trichloroethylene, 1,1,2-trichloroethane and 1,1,1,-trichloroethane, and the like.

Preferred electrically inert resin materials are polycarbonate resins having a molecular weight of about 20,000 to about 120,000, more preferably about 50,000 to about 100,000. The most preferable electrically inactive resin material is Gener
Lexa from al Electric Company
Poly(4,4'-dipropylidene-diphenylene carbonate) of molecular weight from about 35,000 to about 40,000 available as
Le from ral Electric Company
Poly(4,4'-isopropylidene-diphenylene carbonate) of molecular weight from about 40,000 to about 45,000, available as xan 141;
arbenfabricken Bayer A. G.
Approximately 50,0, available as Makrolon from
Polycarbonate resin having a molecular weight of 00 to about 100,000; Mobay Chemical Com
About 20, available as Merlon from pany.
a polycarbonate resin having a molecular weight of from 000 to about 50,000; a polyether carbonate; and 4
, 4'-cyclohexylidene diphenyl carbonate. Methylene chloride solvent is a desirable component of the charge transport layer coating mixture because of its ability to dissolve all components well and its low boiling point.

Particularly preferred multilayer photoconductors include a charge generating layer containing a binder layer of photoconductive material and from about 25% to about 75% by weight of one or more compounds having the formula: from about 20,000 to about 1
It includes a hole transport layer of polycarbonate resin material having a molecular weight of 20,000.

[0051]

[C7]

In the above formula, X and Y are selected from the group consisting of alkyl groups having 0 to 4 carbon atoms, and chlorine, and the photoconductive layer has the ability to photogenerate and inject holes. , the hole transport layer is substantially non-absorbing in the spectral region where the photoconductive layer generates and injects photogenerated holes, but is substantially non-absorbing in the region of the spectrum where the photoconductive layer generates and injects photogenerated holes; It is possible to support and transport the holes through the hole transport layer.

The thickness of the charge transport layer is preferably about 5 μm.
to about 100 μm, preferably about 2
The range is from 0 μm to about 50 μm. The optimum thickness depends on the specific application requirements of electrical stability, lifetime, and xerographic speed. For example, optional layers such as subbing layers, anti-curl layers, or protective coating layers may be applied to the electrophotographic devices described above.

The invention is further illustrated by the following non-limiting examples, which are merely illustrative:
It will be understood that this invention is not limited to the materials, conditions, process parameters, etc. listed herein.

[0055]

EXAMPLES Example 1 Benzimidazole perylene (BZP), which is formed by condensation of perylene dianhydride and O-phenylene diamine described in U.S. Pat. No. 4,587,189, was used as a charge generating material, and A multilayer imaging member was manufactured using triaryldiamine of the following formula as a hole transport layer.

[0056]

[Chemical formula 8] The substrate is a poly(ethylene terephthalate) film (IC
(available as Merinex from I) and placed in a vacuum vessel at a pressure of 1 x 10-5 Torr. An electron beam source is used to deposit a conductive layer of titanium approximately 10 nm thick. This is followed by a silicon dioxide layer approximately 10 nm thick. Finally, without breaking the vacuum, approximately 0.
A 2 μm thick layer was deposited from a tantalum board resistively heated to 500°C.

The vacuum deposited layer is then protectively coated with a solution containing a triaryldiamine hole transport material in a polycarbonate polymer. The ratio of triaryldiamine to polymer is 1:1 and the solvent is a mixture of 65% dichloromethane and 35% 1,1,2-trichloroethane. The ratio of solids to solvent is adjusted to obtain a dry thickness of 15 μm. The solvent is cast using a draw bar applicator and the resulting film is dried at 60° C. for 1 hour.

The production of the metal-oxide-pigment multilayer described above results in a high degree of adhesion between the metal and pigment layers of about 400 g/cm and higher. Adhesion was achieved by attaching adhesive coated tape to the pigment layer and using Instron Model #60
22 Measured by using an adhesion tester. Electrophotographic characteristics include negative voltage corona charging, 650 nm
It is measured by observing dark discharge and light discharge in the light of . The charging characteristics are obtained by plotting the initial potential measured 190 msec after charging for an applied negative charge varying from 10 to 250 nanoclones/cm2. Multilayer imaging members prepared in the above manner charge capacitively to more than 2000 volts and exhibit less than 10% dark discharge in 2 seconds even at electric fields greater than 70 volts/μm. The light sensitivity is excellent, with a discharge slope of 150 volts/erg/cm2, and from 1000 volts to 100 volts/erg/cm2.
It takes less than 7 erg/cm2 of energy to discharge to volts with a residual potential of less than 20 volts.

Example 2 Another oxide multilayer imaging member is prepared in the same manner as in Example 1 except that zirconium, aluminum and titanium oxides are used in place of silicon dioxide. In addition, oxide thicknesses of nominally 30 nm and 100 nm are made in addition to 10 nm. The resulting imaging member is substantially identical in function to that of Example 1.

Example 3 Another substrate multilayer imaging member was made of poly(ethylene terephthalate).
It is produced in the same manner as in Example 1 except that poly(vinylidene chloride) and poly(ether sulfone) substrates are used instead of the substrate. The obtained image forming member is Example 1
It is substantially the same in function as that of .

Example 4 A long web 18 inches wide was placed in a large roll vacuum coater and coated with a 10 nm layer of titanium followed by a 10 nm layer of titanium.
A layer of zirconium oxide is applied by one sputtering. The oxide layer is formed by reactive sputtering in a partial pressure of oxygen. The web is wound up and transferred to a second vacuum roll coater where a layer of BZP pigment with a thickness corresponding to an optical density of 1.0 at a wavelength of 650 nm is thermally evaporated out of the stainless steel crucible. The crucible temperature is controlled at 550° C. and the web speed is adjusted to provide the desired light density uniformly across the width and length of the web. After the pigment charge generating layer is deposited,
The wound web is transferred to a web solvent coater where a charge transport layer of the same composition as in Example 1 is applied using an extrusion die. The dry thickness obtained is 25 μm. The electrical properties of the resulting multilayer imaging member were the same as those of Example 1, as evaluated by the capacitive difference in charge transport layer thickness.

The Xerox 4050 laser printer has a discharge area corresponding to -100 volts on the imaging member that develops black toner, while a -500 volts discharge area on the imaging member develops black toner.
The charged area corresponding to the bolt is specially modified to not develop toner. The paper print thus obtained has a black image formed by the laser discharging the imaging member;
It consists of other white parts. This imaging mechanism is very sensitive to defects in the imaging member that cause localized lack of charge acceptance or high levels of dark discharge. Even the smallest defects are printed as black dots and are easily detected. Sections from the imaging member produced by the method described above are cut and bonded to a belt of the size required by the Xerox 4050 printer. improved 4
Prints made on the 050 printer showed that the imaging members produced by the method described above were free of defects.

Example 5 Another pigmented multilayer imaging member using zirconium oxide in place of silicon oxide and chloro-indium phthalocyanine, bisN-propylimidoperylene and bisN-methylimideperylene in place of BZP pigments. It is manufactured in the same manner as in Example 1 except for the above. The chloro-indium phthalocyanine was prepared as described in U.S. Pat. No. 4,555,465, while propyl and methylperylene were prepared as perylene as described in U.S. Pat. No. 4,587,189. Prepared by condensation of a 3,4,9,10-tetracarboxylic acid or its corresponding anhydride with the appropriate amine in quinoline.

Multilayer imaging members prepared by the method described above exhibited excellent capacitive charging characteristics with low dark discharge. Chloro-indium phthalocyanine imaging members exhibit high sensitivity from 550 nm to 800 nm; n-propylperylene diamine exhibits high sensitivity from 420 nm to 660 nm, and n-methylperylene diamine exhibits high sensitivity from 450 nm.
It showed slightly low sensitivity at 580 nm.

Example 6 A multilayer imaging member is prepared on a molded 84 mm diameter polypropylene cylinder substrate. The cylinder was placed in a vacuum vessel and rotated about its axis, while a 20 nm thick layer of aluminum and a 10 nm thick layer of aluminum oxide were deposited by an electron beam source. This is followed by a 0.2 μm thick layer of thermally sublimated BZP pigment as described in Example 1. The cylinder was removed from the vacuum vessel and the 1,1, 40/60 ratio
4 in a mixture of 2-trichloroethane and dichloromethane
A solution of bis-triarylamine and polycarbonate in a 0/60 ratio was sprayed onto it while the cylinder was rotating. The solid-liquid ratio is adjusted to obtain a smooth film and the number of reactions is chosen to obtain a dry thickness of 20 μm. After spray coating, the charge transport layer was dried overnight at 60°C.

[0066] The resulting imaging member was
12 copier and after reducing the exposure using the copier's "copy darker" slide switch, excellent copies were obtained. Although the invention has been described with reference to certain preferred embodiments, it is not intended to be limited thereto; rather, those skilled in the art will understand that the invention is within the spirit of the invention and as set forth in the claims. It will be recognized that changes and improvements can be made within the organization.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a multilayer photoreceptor of the present invention.

[Explanation of symbols]

1. Anti-curl layer 2 Support base 3 Conductive layer 4 Blocking layer 5 Adhesive layer 6 Charge generation layer 7 Charge transport layer 8 Protective film layer

Claims (1)

[Claims] 1. A method of manufacturing an electrophotographic imaging member, comprising: vacuum depositing a conductive layer on a substrate; vacuum depositing a charge blocking layer on the conductive layer; and charge generation on the charge blocking layer. A method comprising vacuum depositing a layer.