Phenolic epoxy polymer or polyester and charge transporting small molecule at interface between a charge generator layer and a charge transport layer

An imaging member comprising an electrophotographic imaging member comprising a substrate having an electrically conductive surface, a charge generator layer, a charge transport layer comprising a polycarbonate film forming binder and a charge transporting small molecule, and an interface layer comprising a polymer and a charge transporting between the charge generator layer and the charge transport layer, wherein the interface layer comprises a mixture of a charge transporting material and certain phenolic epoxy polymers of polyesters.

BACKGROUND OF THE INVENTION 
This invention relates in general to electrostatography and, more 
specifically, to an electrophotoconductive imaging member that is 
resistant to delamination. 
In the art of xerography, a xerographic plate comprising a photoconductive 
insulating layer is imaged by first uniformly depositing an electrostatic 
charge on the imaging surface of the xerographic plate and then exposing 
the plate to a pattern of activating electromagnetic radiation such as 
light which selectively dissipates the charge in the illuminated areas of 
the plate while leaving behind an electrostatic latent image in the 
nonilluminated areas. This electrostatic latent image may then be 
developed to form a visible image by depositing finely divided 
electroscopic marking particles on the imaging surface. 
A photoconductive layer for use in xerography may be a homogeneous layer of 
a single material such as vitreous selenium or it may be a composite layer 
containing a photoconductor and another material. One type of composite 
photoconductive layer used in electrophotography is illustrated in U.S. 
Pat. No. 4,265,990. A photosensitive member is described in this patent 
having at least two electrically operative layers. One layer comprises a 
photoconductive layer which is capable of photogenerating holes and 
injecting the photogenerated holes into a contiguous charge transport 
layer. Generally, where the two electrically operative layers are 
positioned on an electrically conductive layer with the photoconductive 
layer sandwiched between a contiguous charge transport layer and the 
conductive layer, the outer surface of the charge transport layer is 
normally charged with a uniform electrostatic charge and the conductive 
layer is utilized as an electrode. In flexible electrophotographic imaging 
members, the electrode is normally a thin conductive coating supported on 
a thermoplastic resin web. Obviously, the conductive layer may also 
function as an electrode when the charge transport layer is sandwiched 
between the conductive layer and a photoconductive layer which is capable 
of photogenerating holes and injecting the photogenerated holes into the 
charge transport layer. The charge transport layer in this embodiment, of 
course, must be capable of supporting the injection of photogenerated 
charges from the photoconductive layer and transporting the charges 
through the charge transport layer. 
Various combinations of materials for charge generating layers and charge 
transport layers have been investigated. For example, the photosensitive 
member described in U.S. Pat. No. 4,265,990 utilizes a charge generating 
layer in contiguous contact with a charge transport layer comprising a 
polycarbonate resin and one or more of certain aromatic amine compounds. 
Various generating layers comprising photoconductive layers exhibiting the 
capability of photogeneration of holes and injection of the holes into a 
charge transport layer have also been investigated. Typical 
photoconductive materials utilized in the generating layer include 
amorphous selenium, trigonal selenium, and selenium alloys such as 
selenium-tellurium, selenium-tellurium-arsenic, selenium-arsenic, and 
mixtures thereof. The charge generation layer may comprise a homogeneous 
photoconductive material or particulate photoconductive material dispersed 
in a binder. Other examples of homogeneous and binder charge generation 
layer are disclosed in U.S. Pat. No. 4,265,990. Additional examples of 
binder materials such as poly(hydroxyether) resins are taught in U.S. Pat. 
No. 4,439,507. The disclosures of the aforesaid U.S. Pat. No. 4,265,990 
and U.S. Pat. No. 4,439,507 are incorporated herein in their entirety. 
Photosensitive members having at least two electrically operative layers 
as disclosed above in, for example, U.S. Pat. No. 4,265,990 provide 
excellent images when charged with a uniform negative electrostatic 
charge, exposed to a light image and thereafter developed with finely 
developed electroscopic marking particles. 
When one or more photoconductive layers are applied to a flexible 
supporting substrate, it has been found that the resulting photoconductive 
member may delaminate during flexing, particularly when the charge 
generator layer is formed from a vacuum deposited or sublimated material. 
Delamination can be especially acute when the photoreceptor is led around 
small small diameter support rods or drive roller. For example, 
photoreceptor delamination can sometimes be encountered in as few as 1,000 
imaging cycles under the stressful conditions of being led around rollers 
having a diameter of about 2 cm. The use of adhesive interface layers 
containing an adhesive such as a phenoxy resin or certain polyesters 
causes surface potential to decline during cycling because the flow of 
charges is impeded. 
Further, it has been found that during cycling of photoconductive imaging 
members containing a vacuum deposited As.sub.2 Se.sub.3 charge generator 
layer, charge injection dark decay can reach unacceptable levels and 
render the photoconductive imaging member unsuitable for forming quality 
images. 
INVENTION DISCLOSURE STATEMENT 
U.S. Pat. No. 4,439,507 to Pan et al, issued Mar. 27, 1984--A photoreceptor 
is disclosed comprising a substrate, a conductive layer, a photogenerating 
layer and a charge transport layer. The photogenerating layer may comprise 
a resinous binder material of a poly(hydroxyether) material. The charge 
transport layer may contain a diamine charge transport molecule. The 
charge transport layer may also contain various resins including, for 
example, poly(hydroxyether) binders, polyesters, epoxies as well as block, 
random or alternating copolymers thereof. 
U.S. Pat. No. 4,515,882 to Mammino et al, issued Mar. 7, 1985--An 
electrophotographic imaging member is disclosed comprising at least one 
photoconductive layer and an overcoating layer comprising a film forming 
continuous phase comprising charge transport molecules and finely divided 
charge injection enabling particles dispersed in the continuous phase. The 
charge transport layer may also contain various resins including, for 
example, poly(hydroxyether) binders, polyesters, epoxy resins as well as 
block, random or alternating copolymers thereof. 
U.S. Pat. No. 4,150,987 to Anderson et al, issued Apr. 29, 1979--An 
electropotographic plate is disclosed comprising a conventional charge 
generation material and a p-type hydrazone containing charge transport 
layer. The charge transport layer may contain a polyester resin. Various 
brands of polyesters are described, for example, in Examples 2b-f and 
5a-e. 
U.S. Pat. No. 4,464,450 to L. Teuscher, issued Aug. 7, 1984--An amino 
silane blocking layer is disclosed for use in photoreceptors comprising a 
substrate, a conductive layer, a photogenerating layer and a charge 
transport layer. 
U.S. Pat. No. 4,637,971 to Takei et al, issued Jan. 20, 1987--A 
photoreceptor is disclosed in which various polycarbonate binders may be 
used in a photosensitive layer. 
U.S. Pat. No. 4,007,042 to Buckely et al, issued Feb. 8, 1977--A migration 
imaging member is disclosed comprising a substrate overcoated with a 
softenable layer and a migration marking material. The softenable layer 
may contain various resins listed, for example, in column 6, lines 15-28. 
Among the list are included phenolic resins; epoxy resins; and mixtures of 
copolymers thereof. 
U.S. Pat. No. 3,140,174 to Clark, issued July 7, 1967--An overcoated 
photoreceptor is disclosed in which the overcoating may contain various 
resins listed, for example, in column 3, lines 11-22. These resins include 
polyester resins and epoxides. 
U.S. Pat. No. 4,579,801 to Yashiki, issued Apr. 1, 1986--An 
electrophotographic imaging member is disclosed having a phenolic resin 
layer formed from a resol coat, between a substrate and a photosensitive 
layer. The photosensitive layer may be a single layer or a divided layer 
made up of a charge generating layer and a charge transport layer. The 
charge transport layer may contain various resins including, for example a 
polyester resin. 
U.S. Pat. No. 4,256,823 to Takahashi, issued Mar. 17, 1981--An 
electrophotographic imaging member is disclosed comprising a 
photoconductive insulating binder layer and an clearcoling layer formed by 
applying a dispersion of a organic high polymer on the photoconductive 
insulating binder layer. The clearcoling layer may contain, for example, 
an epoxy resin. 
Thus, the characteristics of electrostatographic imaging members comprising 
a supporting substrate, charge generator layer and charge transport layer 
exhibit deficiencies which are undesirable in automatic, cyclic 
electrostatographic copiers, duplicators, and printers. 
SUMMARY OF THE INVENTION 
It is an object of the invention to provide an electrophotographic imaging 
member which overcomes the above-noted disadvantages. 
It is an another object of this invention to provide an electrophotographic 
imaging member with improved resistance to delamination. 
It is another object of this invention to provide an electrophotographic 
imaging member which minimizes charge injection dark decay. 
It is still another object of this invention to provide an 
electrophotographic imaging member which provides stable image 
development. 
The foregoing objects and others are accomplished in accordance with this 
invention by providing an imaging member comprising an electrophotographic 
imaging member comprising a substrate having an electrically conductive 
surface, a charge generator layer, a charge transport layer comprising a 
polycarbonate film forming binder and a charge transporting small 
molecule, and an interface layer comprising a polymer and a charge 
transporting small molecule uniformly distributed along at least the 
interface between said charge generator layer and said charge transport 
layer, wherein said interface layer comprises a mixture of a charge 
transporting material and a polymer selected from the group consisting of 
a phenolic epoxy polymer represented by the following structure: 
##STR1## 
wherein R is hydrogen or an alkyl group containing from 1 to 8 carbon 
atoms and n.sub.1 is a number from 1 to 8 and a polyester represented by 
the following structure: 
##STR2## 
wherein R.sub.1 and R.sub.2 are an alkyl group having from 1 to/2 carbon 
atoms, a cycloalkyl group containing from 4 to 36 carbon atoms, an aryl 
group, or an alkylaryl group containing from 1 to 8 carbon atoms in the 
alkyl group, and n.sub.2 is a number from 4 to 1,000. The charge 
transporting material can be the same as that in the transport layer or, 
if it is different from that in the transport layer, the ionization 
potential (l.sub.p) should be equal to or larger than the l.sub.p of the 
transporting substance in the transport layer. For example, if the charge 
transporting molecule in the transport layer is a diamine, the charge 
transporting material in the interface layer can be a diamine. 
Although the supporting substrate layer having an electrically conductive 
surface may be a conventional rigid substrate, maximum benefit is derived 
from an increased resistance to delamination for flexible supporting 
substrate layers having an electrically conductive surface. The flexible 
supporting substrate layer having an electrically conductive surface may 
be opaque or substantially transparent and may comprise numerous suitable 
materials having the required mechanical properties. For example, it may 
comprise an underlying flexible insulating support layer coated with a 
flexible electrically conductive layer, or merely a flexible conductive 
layer having sufficient internal strength to support the 
electrophotoconductive layer. The flexible electrically conductive layer, 
which may comprise the entire supporting substrate or merely be present as 
a coating on an underlying flexible web member, may comprise any suitable 
electrically conductive material including, for example, aluminum, 
titanium, nickel, chromium, brass, gold, stainless steel, carbon black, 
graphite and the like. The flexible conductive layer may vary in thickness 
over substantially wide ranges depending on the desired use of the 
electrophotoconductive member. Accordingly, the conductive layer can 
generally range in thicknesses of from about 50 Angstrom units to many 
centimeters. When a highly flexible photoresponsive imaging device is 
desired, the thickness of the conductive layer may be between about 100 
Angstrom units to about 750 Angstrom units. Any underlying flexble support 
layer may be of any suitable material. Typical underlying flexible support 
layers of film forming polymers include insulating non-conducting 
materials comprising various resins such as polycarbonate resins, 
polyethylene terephthalate resin, polyimide resins, polyamide resin, and 
the like. The coated or uncoated flexible supporting substrate layer may 
have any number of different configurations such as, for example, a sheet, 
a scroll, an endless flexible belt, and the like. Preferably, the 
insulating web is in the form of an endless flexible belt and comprises a 
commercially available polyethylene terephthalate resin (Mylar, available 
from E.l. duPont de Nemous & Co.). 
Preferably, a suitable charge blocking layer may be interposed between the 
conductive layer and the electrophotographic imaging layer. Some materials 
can form a layer which functions as both an adhesive layer and charge 
blocking layer. Any suitable blocking layer material capable of trapping 
charge carriers may be utilized. Typical blocking layers include 
polyvinylbutyral, organosilanes, epoxy resins, polyesters, polyamides, 
polyurethanes, silicones and the like. If a resin is employed in the 
blocking layer, it should preferably have a molecular weight of between 
about 600 and about 200,000 and glass transition temperature of at least 
about 5.degree. C. The polyvinylbutyral, epoxy resins, polyesters, 
polyamides, and polyurethanes can also serve as an adhesive layer. Charge 
blocking layers preferably have a dry thickness between about 0.005 
micrometer and about 0.2 micrometers. Adhesive layers preferably have a 
dry thickness between about 0.01 micrometer and about 2 micrometers. 
It has been found that when charge generator layers are formed from vacuum 
deposited or sublimated photoconductive materials such as As.sub.2 
Se.sub.3, amorphous selenium containing tellurium, perylene, 
phthalocyanine, bisazo pigments, and the like, charge injection dark decay 
can reach unacceptable levels and render the photoconductive imaging 
member unsuitable for forming quality images. Such charge injection dark 
decay can be markedly reduced by the use of a blocking layer comprising an 
amino silane reaction product, a polyvinyl butyral or polyvinyl 
pyrrolidone and the like. 
The silane reaction product described in U.S. Pat. No. 4,464,450 is 
particularly preferred as a blocking layer material because cyclic 
stability is extended. The specific silanes employed to form the preferred 
blocking layer are identical to the preferred silanes employed to treat 
the crystalline particles of this invention. In other words, silanes 
having the following structural formula: 
##STR3## 
wherein R.sub.1 is an alkylidene group containing 1 to 20 carbon atoms, 
R.sub.2 and R.sub.3 are independently selected from the group consisting 
of H, a lower alkyl group containing 1 to 3 carbon atoms, a phenyl group 
and a poly(ethyleneamino) group, and R.sub.4, R.sub.5, and R.sub.6 are 
independently selected from a lower alkyl group containing 1 to 4 carbon 
atoms. Typical hydrolyzable silanes include 3-aminopropyltriethoxysilane, 
N-aminoethyl-3-aminopropyltrimethoxysilane, 
N-2-aminoethyl-3-aminopropyltrimethoxysilane, 
N-2-aminoethyl-3-aminopropyltris(ethylethoxy) silane, p-aminophenyl 
trimethoxysilane, 3-aminopropyldiethylmethylsilane, (N,N'-dimethyl 
3-amino)propyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 
3-aminopropyl trimethoxysilane, N-methylaminopropyltriethoxysilane, 
methyl[2-(3-trimethoxysilylpropylamino)ethylamino]-3-propanoate, 
(N,N'-dimethyl 3-amino)propyl triethoxysilane, 
N,N-dimethylaminophenyltriethoxy silane, 
trimethoxysilylpropyldiethylenetriamine and mixtures thereof. The blocking 
layer forming hydrolyzed silane solution may be prepared by adding 
sufficient water to hydrolyze the alkoxy groups attached to the silicon 
atom to form a solution. Insufficient water will normally cause the 
hydrolyzed silane to form an undesirable gel. Generally, dilute solutions 
are preferred for achieving thin coatings. Satisfactory reaction product 
layers may be achieved with solutions containing from about 0.1 percent by 
weight to about 1 percent by weight of the silane based on the total 
weight of solution. A solution containing from about 0.01 percent by 
weight to about 2.5 percent by weight silane based on the total weight of 
solution are preferred for stable solutions which form uniform reaction 
product layers. The pH of the solution of hydrolyzed silane is carefully 
controlled to obtain optimum electrical stability. A solution pH between 
about 4 and about 10 is preferred. Optimum blocking layers are achieved 
with hydrolyzed silane solutions having a pH between about 7 and about 8, 
because inhibition of cycling-up and cycling-down characteristics of the 
resulting treated photoreceptor maximized. Control of the pH of the 
hydrolyzed silane solution may be effected with any suitable organic or 
inorganic acid or acidic salt. Typical organic and inorganic acids and 
acidic salts include acetic acid, citric acid, formic acid, hydrogen 
iodide, phosphoric acid, ammonium chloride, hydrofluorosilicic acid, 
Bromocresol Green, Bromophenol Blue, p-toluene sulphonic acid and the 
like. 
Any suitable technique may be utilized to apply the hydrolyzed silane 
solution to the conductive layer. Typical application techniques include 
spraying, dip coating, roll coating, wire wound rod coating, and the like. 
Generally, satisfactory results may be achieved when the reaction product 
of the hydrolyzed silane forms a blocking layer having a thickness between 
about 20 Angstroms and about 2,000 Angstroms. This siloxane coating is 
described in U.S. Pat. No. 4,464,450, issued Aug. 7, 1984 to Leon A. 
Teuscher, the disclosure of this patent being incorporated herein in its 
entirety. 
Other preferred blocking layers materials are polyvinyl butyral and 
polyvinyl pyrrolidone. These film forming polymers polymers preferably 
have a weight average molecular weight of between about 2,000 and about 
200,000. 
In some cases, intermediate layers between the blocking layer and the 
adjacent charge generating or photogenerating material may be desired to 
improve adhesion or to act as an electrical barrier layer. If such layers 
are utilized, they preferably have a dry thickness between about 0.01 
micrometer to about 2 micrometers. Typical adhesive layers include 
film-forming polymers such as polyester, polyvinylbutyral, 
polyvinylpyrrolidone, polyurethane, polymethyl methacrylate and the like. 
Generally, the electrophotoconductive imaging member of this invention 
comprises a substrate having an electrically conductive surface, a charge 
generator layer, a charge transport layer and an interface layer 
containing a polymer mixed with a charge transporting small molecule 
uniformly distributed along at least the interface between the charge 
generator layer and the transport layer, wherein the interface polymer is 
selected from certain phenolic epoxy polymers and certain polyesters. 
The charge generating layer may contain homogeneous, heterogeneous, 
inorganic or organic photoconductive compositions. One example of 
photoconductive compositions containing a heterogeneous composition is 
described in U.S. Pat. No. 3,121,006 wherein finely divided particles of a 
photoconductive inorganic compound is dispersed in an electrically 
insulating organic resin binder. The entire disclosure of this patent is 
incorporated herein by reference. Other well known photoconductive 
compositions include amorphous selenium, halogen doped amorphous selenium, 
amorphous selenium alloys including selenium arsenic, selenium tellurium, 
selenium arsenic antimony, and halogen doped selenium alloys, cadmium 
sulfide and the like. Often, the inorganic selenium based photoconductive 
materials are deposited as a relatively homogeneous layer. Moreover, many 
of these inorganic materials may be deposited by vacuum deposition 
techniques, particularly the selenium, selenium alloy and arsenic 
triselenide materials. 
Other typical charge generating materials include metal free phthalocyanine 
described in U.S. Pat. No. 3,357,989, metal phthalocyanines such as copper 
phthalocyanine and vanadyl phthalocyanine, perylene, quinacridones 
available from DuPont under the tradename Monastral Red, Monastral Violet 
and Monastral Red Y, substituted 2,4-diamino-triazines disclosed in U.S. 
Pat. No. 3,442,781, polynuclear aromatic quinones available from Allied 
Chemical Corporation under the tradename Indofast Double Scarlet, Indofast 
Violet Lake B, Indofast Brilliant Scarlet and Indofast Orange; chlorodiane 
blue; dibromoanthanthrone; thiapyrilium, diazo compounds; triaszo 
compounds; squaraines; and the like. The disclosures of U.S. Pat. No. 
3,357,989 and U.S. Pat. No. 3,442,781 are incorporated herein by reference 
in their entirety. Some organic charge generating materials such as 
phthalocyanine, perylenes and like can be deposited by sublimation. 
Any suitable inactive resin binder material may be empolyed in the charge 
generator layer of photoreceptors having generator layers comprising a 
mixture of a resin binder and photoconductive material. Typical organic 
resinous binders include polycarbonates, acrylate polymers, vinyl 
polymers, cellulose polymers, polyesters, polysiloxanes, polyamides, 
polyurethanes, epoxies, and the like. Many organic resinous binders are 
disclosed, for example, in U.S. Pat. No. 3,121,006 and U.S. Pat. No. 
4,439,507, the entire disclosures of which are incorporated herein by 
reference. Organic resinous polymers may be block, random or alternating 
copolymers. The photogenerating composition or pigment is present in the 
resinous binder composition in various amounts in heterogeneous binder 
layers. When using an electrically inactive or insulating resin, it is 
essential that there be particle-to-particle contact between the 
photoconductive particles. This necessitates that the photoconductive 
material be present in an amount of at least about 15 percent by volume of 
the binder layer with no limit on the maximum amount of photoconductor in 
the binder layer. If the matrix or binder comprises an active material, 
e.g. poly-N-vinylcarbazole, a photoconductive material need only to 
comprise about 1 percent or less by volume of the binder layer with no 
limitation on the maximum amount of photoconductor in the binder layer. 
Generally for generator layers containing an electrically active matrix or 
binder such as polyvinyl carbazole or poly(methyl phenyl silylene), from 
about 5 percent by volume to about 60 percent by volume of the 
photogenerating pigment is dispersed in about 40 percent by volume to 
about 95 percent by volume of binder, and preferably from about 7 percent 
to about 30 percent by volume of the photogenerating pigment is dispersed 
in from about 70 percent by volume to about 93 percent by volume of the 
binder. The specific proportions selected also depends to some extent on 
the thickness of the generator layer. If desired, the charge generating 
layer may contain between about 0.5 percent by weight to about 5 percent 
by weight of phenoxy epoxy resin or a polyester, based on the total weight 
by layer. 
The thickness of the photogenerating binder layer is not particularly 
critical. Layer thicknesses from about 0.05 micrometer to about 40.0 
micrometers have been found to be satisfactory. The photogenerating binder 
layer containing photoconductive compositions and/or pigments, and the 
resinous binder material preferably ranges in thickness of from about 0.1 
micrometer to about 5.0 micrometers, and has an optimum thickness of from 
about 0.3 micrometer to about 3 micrometers for best light absorption and 
improved dark decay stability and mechanical properties. A layer thickness 
of between about 0.1 micrometer and about 1 micrometer is preferred for 
homogeneous vacuum deposited or sublimated photogenerator materials 
because almost complete absorption of incident radiation is achieved in 
these thicknesses. 
Other typical photoconductive layers include amorphous or alloys of 
selenium such as arsenic triselenide, selenium-arsenic, 
selenium-tellurium-arsenic, selenium-tellurium, trigonal selenium and the 
like dispersed in a film forming binder. 
The active charge transport layer should be capable of supporting the 
injection of photo-generated holes and electrons from the charge generator 
layer and allowing the transport of these holes or electrons through the 
charge transport layer to selectively discharge the surface charge. The 
active charge transport layer not only serves to transport holes or 
electrons, but also protects the photoconductive layer from abrasion or 
chemical attack and therefor extends the operating life of the 
photoreceptor imaging member. The charge transport layer should exhibit 
negligible, if any, discharge when exposed to a wavelength of light useful 
in xerography, e.g. 4000 Angstroms to 8000 Angstroms. Therefore, the 
charge transport layer is substantially transparent to radiation in a 
region in which the photoconductor is to be used. Thus, the active charge 
transport layer is a substantially non-photoconductive material which 
supports the injection of photogenerated holes from the generation layer. 
The active transport layer is normally transparent when exposure is 
effected through the active layer to ensure that most of the incident 
radiation is utilized by the underlying charge carrier generator layer for 
efficient photogenertion. When used with a transparent substrate, 
imagewise exposure may be accomplished through the substrate with all 
light passing through the substrate. In this case, the active transport 
material need not be absorbing in the wavelength region of use. The charge 
transport layer in conjunction with the generation layer in the instant 
invention is a material which is an insulator to the extent that an 
electrostatic charge placed on the transport layer is not conductive in 
the absence of illumination, i.e. a rate sufficient to prevent the 
formation and retention of an electrostatic latent image thereon. 
The active charge transport layer may comprise an activating compound 
useful as an additive dispersed in electrically inactive polymeric film 
forming binder materials making these materials electrically active. These 
charge transporting small molecule compounds are added to polymeric film 
forming binder component which are incapable of supporting the injection 
of photogenerated holes from the generation material and incapable of 
allowing the transport of these holes therethrough. This will convert the 
electrically inactive polymeric material to a material capable of 
supporting the injection of photogenerated holes from the generation 
material and capable of allowing the transport of these holes through the 
active layer in order to discharge the surface charge on the active layer. 
Preferred electrically active layers comprise an electrically inactive 
resin material, e.g. a polycarbonate made electrically active by the 
addition of one or more of the following compounds poly-N-vinylcarbazole; 
poly-1-vinylpyrene; poly-9-vinylanthracene; polyacenaphthalene; 
poly-9-(4-pentenyl)-carbazole; poly-9-(5-hexyl)-carbazole; polymethylene 
pyrene; poly-1-(pyrenyl)-butadiene; N-substituted polymeric acrylic acid 
amides of pyrene; chlorodiane blue; 
N,N'-diphenyl-N,N'-bis(phenylmethyl)-[1,1'-biphenyl]-4,4'-diamine; 
N,N'-diphenyl-N,N'-bis(3-methylphenyl)-2,2'-dimethyl-1,1'-biphenyl-4,4'-di 
amine and the like. 
Non-film forming charge transporting small molecule materials include 
following: 
Diamine transport molecules of the types described in U.S. Pat. Nos. 
4,306,008, 4,304,829, 4,233,384, 4,115,116, 4,299,897, 4,265,990 and 
4,081,274. Typical diamine transport molecules include 
N,N'-diphenyl-N,N'-bis(alkylphenyl)-[1,1'-biphenyl]-4,4'-diamine wherein 
the alkyl is, for example, methyl, ethyl, propyl, n-butyl, etc. such as 
N,N'-diphenyl-N,N'-bis(3"-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(4-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(2-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(3-ethylphenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(4-ethylphenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(4-n-butylphenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(3-chlorophenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(4-chlorophenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(phenylmethyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N,N',N'-tetraphenyl-[2,2'-dimethyl-1,1'-biphenyl]-4,4'-diamine, 
N,N,N',N'-tetra(4-methylphenyl)-[2,2'-dimethyl-1,1'-biphenyl]-4,4'-diamine 
, N,N' 
-diphenyl-N,N'-bis(4-methylphenyl)-[2,2'-dimethyl-1,1'-biphenyl]-4,4'-diam 
ine, 
N,N'-diphenyl-N,N'-bis(2-methylphenyl)-[2,2'-dimethyl-1,1'-biphenyl]-4,4'- 
diamine, 
N,N'-diphenyl-N,N'-bis(3-methylphenyl)-[2,2'-dimethyl-1,1'-biphenyl]-4,4'- 
diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-pyrenyl-1,6-diamine, and 
the like. Pyrazoline transport molecules as disclosed in U.S. Pat. Nos. 
4,315,982, 4,278,746, and 3,837,851. Typical pyrazoline transport 
molecules include 
1-[lepidyl-(2)]-3-(p-diethylaminophenyl)-5-(p-diethylaminophenyl)pyrazolin 
e, 
1-[quinolyl-(2)]-3-(p-diethylaminophenyl)-5-(p-diethylaminophenyl)pyrazoli 
ne, 
1-[pyridyl-(2)]-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazolin 
e, 
1-[6-methoxypyridyl-(2)]-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl) 
pyrazoline, 
1-phenyl-3-[p-dimethylaminostyryl]-5-(p-dimethylaminostyryl)pyrazoline, 
1-phenyl-3-[p-diethylaminostyryl]-5-(p-diethylaminostyryl)pyrazoline, and 
the like. Substituted fluorene charge transport molecules as described in 
U.S. Pat. No. 4,245,021. Typical fluorene charge transport molecules 
include 9-(4'-dimethylaminobenzylidene)fluorene, 
9-(4'-methoxybenzylidene)fluorene, 9-(2',4'-dimethoxybenzylidene)fluorne, 
2-nitro-9-benzylidene-fluorene, 
2-nitro-9-(4'-diethylaminobenzylidene)fluorene and the like. Oxadiazole 
transport molecules such as 
2,5-bis(4-diethylaminophenyl)-1,3,4-oxadiazole, pyrazoline, imidazole, 
triazole, and others described in German Pat. Nos. 1,058,836, 1,060,260 
and 1,120,875 and U.S. Pat. No. 3,895,944. Hydrazone transport molecules 
including p-diethylaminobenzaldehyde(diphenylhydrazone), 
o-ethoxy-p-diethylaminobenzaldehyde(diphenylhydrazone), 
o-methyl-p-diethylaminobenzaldehyde(diphenylhydrazone), 
o-methyl-p-dimethylaminobenzaldehyde(diphenylhydrazone), 
p-dipropylaminobenzaldehyde-(diphenylhydrazone), 
p-diethylaminobenzaldehyde-(benzylphenylhydrazone), 
p-dibutylaminobenzaldehyde-(diphenylhydrazone), 
p-dimethylaminobenzaldehyde-(diphenylhydrazone) and the like described, 
for example in U.S. Pat. No. 4,150,987. Other hydrazone transport 
molecules include compounds such as 1-naphthalenecarbaldehyde 
1-methyl-1-phenylhydrazone, 1-naphthalenecarbaldehyde 1,1-phenylhydrazone, 
4-methoxynaphthlene-1-carbaldehyde 1-methyl-1-phenylhydrazone and other 
hydrazone transport molecules described, for example in U.S. Pat. Nos. 
4,385,106, 4,338,388, 4,387,147, 4,399,208 and 4,399,207. Another charge 
transport molecule is a carbazole phenyl hydrazone such as 
9-methylcarbazole-3-carbaldehyde-1,1-diphenylhydrazone, 
9-ethylcarbazole-3-carbaldehyde-1-methyl-1-phenylhydrazone, 
9-ethylcarbazole-3-carbaldehyde-1-ethyl-1-phenylhydrazone, 
9-ethylcarbazole-3-carbaldehyde-1-ethyl-1-benzyl-1-phenylhydrazone, 
9-ethylcarbazole-3-carbaldehyde-1,1-diphenylhydrazone, and other suitable 
carbazole phenyl hydrazone transport molecules described, for example, in 
U.S. Pat. No. 4,256,821. Similar hydrazone transport molecules are 
described, for example, in U.S. Pat. No. 4,297,426. Tri-substituted 
methanes such as alkyl-bis(N,N-dialkylaminoaryl)methane, 
cycloalkyl-bis(N,N-dialkylaminoaryl)methane, and 
cycloalkenyl-bis(N,N-dialkylaminoaryl)methane as described, for example, 
in U.S. Pat. No. 3,820,989. 9-fluorenylidene methane derivatives including 
(4-n-butoxycarbonyl-9-fluorenylidene)malonontrile, 
(4-phenethoxycarbonyl-9-fluorenylidene)malonontrile, 
(4-carbitoxy-9-fluorenylidene)malonontrile, 
(4-n-butoxycarbonyl-2,7-dinitro-9-fluorenylidene)malonate, and the like. 
Other typical transport materials include the numerous transparent organic 
non-polymeric transport materials described in U.S. Pat. No. 3,870,516 and 
the nonionic compounds described in U.S. Pat. No. 4,346,157. The 
disclosures of each of the patents identified above pertaining to charge 
transport molecule which are soluble or dispersible on a molecular scale 
in a film forming binder are incorporated herein in their entirety. 
An especially preferred transport layer employed in one of the two 
electrically operative layers in the multilayer photoconductor of this 
invention comprises from about 25 to about 75 percent by weight of at 
least one charge transporting aromatic amine compound, and about 75 to 
about 15 percent by weight of a polymeric film forming resin in which the 
aromatic amine is soluble. 
The charge transport layer forming mixture preferably comprises an aromatic 
amine compound of one or more compounds having the general formula: 
##STR4## 
wherein R.sub.1 and R.sub.2 are an aromatic group selected from the group 
consisting of a substituted or unsubstituted phenyl group, naphthyl group, 
and polyphenyl group and R.sub.3 is selected from the group consisting of 
a substituted or unsubstituted aryl group, alkyl group having from 1 to 18 
carbon atoms and cycloaliphatic compounds having from 3 to 18 carbon 
atoms. The substituents should be free form electron withdrawing groups 
such as NO.sub.2 groups, CN groups, and the like. Typical aromatic amine 
compounds that are represented by this structural formula include: 
I. Triphenyl amines such as: 
##STR5## 
II. Bis and poly triarylamines such as: 
##STR6## 
III. Bis arylamine ether such as: 
##STR7## 
IV. Bis alkyl-arylamines such as: 
##STR8## 
A preferred aromatic amine compound has the general formula: 
##STR9## 
wherein R.sub.1, and R.sub.2 are defined above and R.sub.4 is selected 
from the group consisting of a substituted or unsubstituted biphenyl 
group, diphenyl ether group, alkyl group having from 1 to 18 carbon atoms, 
and cycloaliphatic group having from 3 to 12 carbon atoms. The 
substituents should be free form electron withdrawing groups such as 
NO.sub.2 groups, CN groups, and the like. 
Excellent results in controlling dark decay and background voltage effects 
have been achieved when the imaging members doped in accordance with this 
invention comprising a charge generation layer comprise a layer of 
photoconductive material and a contiguous charge transport layer of a 
polycarbonate resin material having a molecular weight of from about 
20,000 to about 250,000 having dispersed therein from about 25 to about 75 
percent by weight of one or more compounds having the general formula: 
##STR10## 
wherein R.sub.1, R.sub.2, and R.sub.4 are defined above and X is an aryl 
group substituted with a group selected from the group consisting of an 
alkyl group having from 1 to about 4 carbon atoms and chlorine, the 
photoconductive layer exhibiting the capability of photogeneration of 
holes and injection of the holes and the charge transport layer being 
substantially non-absorbing in the spectral region at which the 
photoconductive layer generates and injects photogenerated holes but being 
capable of supporting the injection of photogenerated holes from the 
photoconductive layer and transporting said holes through the charge 
transport layer. 
Examples of charge transporting aromatic amines represented by the 
structural formulae above for charge transport layers capable of 
supporting the injection of photogenerated holes of a charge generating 
layer and transporting the holes through the charge transport layer 
include triphenylmethane, bis(4-diethylamine-2-methylphenyl) 
phenylmethane; 4'-4"-bis(diethylamino)-2',2"-dimethyltriphenyl-methane, 
N,N'-bis(alkylphenyl)-[1,1'-biphenyl]-4,4'-diamine wherein the alkyl is, 
for example, methyl, ethyl, propyl, n-butyl, etc., 
N,N'-diphenyl-N,N'-bis(chlorophenyl)-[1,1'-biphenyl]-4,4'-diamine, 
N,N'-diphenyl-N,N'-bis(3"-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, and 
the like dispersed in an inactive resin binder. 
Any suitable inactive polycarbonate resin binder soluble in suitable 
solvent may be employed in the process of this invention. Generally, the 
polycarbonate film forming binders may be represented by the formula 
##STR11## 
wherein R is is a divalent group selected from the group consisting of 
alkylidene, phenylidene, or cycloalkylidene and n is a number from 10 to 
1,000. Typical R groups include, for example, isopropylidene, 
cyclohexylidene, ethylidene, isobutylidene, phenylethylidene, 
decahydronapthylidene, and the like. Typical inactive polycarbonate resin 
binders include poly(4,4'-isopropylidenediphenyl carbonate), 
poly[1,1-cyclohexylidenebis(4-phenyl)carbonate], poly(phenolphthalein 
carbonate), poly(diphenylmethane bis-4-phenyl carbonate), 
poly[2,2-(4-methylpentatne)bis-4-phenyl carbonate], and and the like. 
Molecular weights can vary from about 20,000 to about 250,000. Other 
specific examples of polycarbonate resins are described, for example, in 
U.S. Pat. No. 4,637,971, the entire disclosure thereof incorporated herein 
by reference. 
The preferred electrically inactive resin materials are polycarbonate 
resins have a molecular weight from about 20,000 to about 250,000 more 
preferably from about 50,000 to about 100,000. The materials most 
preferred as the electrically inactive resin material is 
poly(4,4'-dipropylidene-diphenylene carbonate) with a molecular weight of 
from about 35,000 to about 40,000, available as Lexan 145 from General 
Electric Company; poly(4,4'-isopropylidene-diphenylene carbonate) with a 
molecular weight of from about 40,000 to about 45,000, available as Lexan 
141 from the General Electric Company; a polycarbonate resin having a 
molecular weight of from about 50,000 to about 100,000, available as 
Makrolon from Farbenfabricken Bayer A. G.; a polycarbonate resin having a 
molecular weight of from about 20,000 to about 50,000 available as Merlon 
from Mobay Chemical Company and 
poly[1,1-cyclohexylidenebis(4-phenyl)carbonate]. 
In all of the above charge transport layers, the activating compound which 
renders the electrically inactive polymeric material electrically active 
should be present in amounts of from about 15 to about 75 percent by 
weight. The activating compound is preferably present in the range of 
between about 30 percent and about 60 percent because the presence of 
excessive transport material causes adversely affects the mechanical 
properties of the layers. 
The imaging member of this invention contains an interface layer containing 
a polymer and a charge transport molecule uniformly distributed along at 
least the interface between the charge generator layer and the transport 
layer. This interface polymer is selected from certain specific phenolic 
epoxy polymers or certain specific polyesters. The phenolic epoxy polymer 
is represented by the following structure: 
##STR12## 
wherein R is hydrogen or an alkyl group containing from 1 to 8 carbon 
atoms and n.sub.1 is a number from 1 to 8. Specific preferred phenolic 
epoxy polymers include ECN 1235, ECN 1299 and EPN 1138, available from 
CIBA Chemical & Dye Co. and DEN 438, available from Dow Chemical Co. 
The polyester is represented by the following structure: 
##STR13## 
wherein R.sub.1 and R.sub.2 are an alkyl group having from 1 to 12 carbon 
atoms or a cycloalkyl group containing from 4 to 36 carbon atoms or an 
aryl group, or an alkylaryl group containing from 1 to 8 carbon atoms in 
the alkyl group, and n.sub.2 is a number from 4 to 1000. Examples of 
aliphatic groups for the polyester include those containing from about 1 
carbon atom to about 30 carbon atoms, such as methyl, ethyl, propyl, 
butyl, pentyl, hexyl, heptyl, decyl, pentadecyl, eicodecyl, and the like. 
Preferred aliphatic groups include alkyl group containing from about 1 
carbon atom to about 6 carbon atoms, such as methyl, ethyl, propyl, and 
butyl. Illustrative examples of aromatic groups include those containing 
from about 6 carbon atoms to about 25 carbon atoms, such as phenyl, 
naphthyl, anthryl, and the like, with phenyl being preferred. The 
aliphatic and aromatic groups can be substituted with various known 
substituents, including for example, alkyl, halogen, nitro, sulfo and the 
like. Typical cycloalkyl groups include cyclohexyl, cyclobutyl, 
cyclooctyl, and the like. The aliphatic and aromatic groups can be 
substituted with various known substituents, including for example, alkyl, 
halogen, nitro, sulfo and the like. Specific preferred polyester resins 
include PE 200 and PE 100, available from Goodyear Tire & Rubber Co. and 
49000, available from E. I. duPont de Nemours & Co. 
Any suitable charge transport molecule may be utilized in the interface 
layer. Typical charge transport molecules include the diamine molecules of 
the type described in U.S. Pat. Nos. 4,306,008, 4,304,829, 4,233,384, 
4,115,116, 4,299,897, 4,265,990 and 4,081,274; pyrazoline transport 
molecules as described in U.S. Pat. Nos. 4,315,982; 4,278,746 and 
3,837,851; benzaldehydehydrazones as described in U.S. Pat. No. 4,150,987; 
and other hydrazone molecules described in U.S. Pat. Nos. 4,385,106, 
4,338,388, 4,387,147, 4,399,208 and 4,399,207, the entire disclosures of 
these charge transport molecule patents being incorporated herein by 
reference. It is preferred to employ the same charge transport molecule in 
both the transport layer and the interface layers. In the event that the 
charge transport molecules are different in these layers, the ionization 
potential (l.sub.p) of the molecule in the adhesion promoting interface 
layer should be greater than the l.sub.p of the molecule in the transport 
layer. 
When these phenolic epoxy polymers or polyesters are supplied to the 
interface between the charge generating layer and the charge transport 
layer as a component in the charge transport layer instead of as a 
separate interface layer, the phenolic epoxy polymer or polyester must be 
miscible with the film forming binder component, the charge transport 
material (which may be also be the film forming binder component) and any 
solvent employed to apply the transport layer as coating. The transport 
layer, after drying or curing, contains the phenolic epoxy polymer or 
polyester in the form of a solid solution or molecular dispersion in the 
film forming binder component. A solid solution is defined as a 
composition in which at least one component is dissolved in another 
component and which exists as a homogeneous solid phase. A molecular 
dispersion is defined as a composition in which particles of at least one 
component are dispersed in another component, the dispersion of the 
particles being on a molecular scale. A solid solution or molecular 
dispersion of the phenolic epoxy polymer or polyester of this invention in 
the film forming binder component of the charge transport layer is 
necessary to assure transparency of the transport layer. If the phenolic 
epoxy polymer or polyester is immiscible, phase separation results in an 
opaque transport layer and also results in unacceptable charge trapping. 
The phenolic epoxy polymers or polyesters should be present in small 
concentrations of less than about 10 percent by weight and more than about 
0.5 percent by weight, based on the total weight of the transport layer to 
increase adhesion between the generator and transport layers. 
The use of poly(hydroxyether) binders in charge transport layers have been 
disclosed, for example, in U.S. Pat. No. 4,439,507. This latter compound 
phase separates from polycarbonate charge transport binders whereas the 
phenolic epoxy compound of this invention forms a solid solution with 
polycarbonates. Phase separation of the poly(hydroxyether) binder from 
polycarbonate charge transport binder causes charge trapping in the 
transport layer resulting in residual potential build up with multiple 
cycle operation. This results in unacceptable background print out in the 
final copies. 
The use of polyester resins in charge transport layers have been disclosed, 
for example, in U.S. Pat. No. 4,439,507, U.S. Pat. No. 4,515,882, and U.S. 
Pat. No. 4,150,987. In U.S. Pat. No. 4,150,987, among the the specific 
polyesters disclosed in Examples 2b-f and 5a-e, it has been found that 
diamine charge transport molecules dissolve only in small concentrations 
in PE-200 polymer (available from Goodyear Tire & Rubber Co.) and 49,000 
polymer (available from E. I. duPont de Nemours & Co.). Nevertheless, 
these layers provide adequate charge transport when used as a thin 
interface film between the generator and transport layers but are not 
adequate when employed as thick transport layer films. Since preferred 
diamine charge transport molecules has limited solubility in PE-200 
(Goodyear) and 49,000 (duPont) in the presence of polycarbonate and 
diamine charge transport material, these materials impede the flow of 
charge during imagewise exposure when present in concentrations exceeding 
about 10 percent by weight, based on the total weight of the transport 
layer. 
Any suitable and conventional technique may be utilized to mix and 
thereafter apply the interface layer or charge transport layer coating 
mixture to the charge generating layer. Typical application techniques 
include spraying, dip coating, roll coating, wire wound rod coating, and 
the like. Drying of the deposited coating may be effected by any suitable 
conventional technique such as oven drying, infra red radiation drying, 
air drying and the like. Generally, the thickness of the transport layer 
is betweeen about 5 micrometers to about 100 micrometers, but thicknesses 
outside this range can also be used. A layer thickness of between about 5 
micrometers and about 35 micrometers is preferred because it provides 
adequate contrast potentials. If the phenolic epoxy polymers or polyesters 
mixed with charge transport molecule of this invention are supplied to the 
interface between the charge generating layer and the charge transport 
layer as a separate interface layer instead as of as an additive in the 
charge transport layer, the interface layer preferably has a thickness 
between about micrometer 0.005 and about 2.0 micrometer because the lower 
limit assures improved adhesion and the upper limit is set by the charge 
transport considerations. The amount of small molecule transport material 
that may be employed in the separate interface layer is preferably between 
about 1 and about 20 percent by weight small molecule transport material, 
based on the total weight of the interface layer. Unlike the charge 
transport layer, a larger proportion of the small molecule transport 
material can be added to the thin interface layer without significantly 
impeding the flow of charge during imagewise exposure. 
The charge transport layer should be an insulator to the extent that the 
electrostatic charge placed on the charge transport layer is not conducted 
in the absence of illumination at a rate sufficient to prevent formation 
and retention of an electrostatic latent image thereon. In general, the 
ratio of the thickness of the charge transport layer to the charge 
generator layer is preferably maintained from about 2:1 to 200:1 and in 
some instances as great as 400:1. 
Optionally, an overcoate layer may also be utilized to improve resistance 
to abrasion. These overcoating layers may comprise organic polymers or 
inorganic polymers that are electrically insulating or slightly 
semi-conductive. 
The photoreceptors of this invention provide an electrophotographic imaging 
member with improved resistance to delamination. In addition, markedly 
extends the cycling by reducing photoreceptor charge injection dark decay.

A number of examples are set forth hereinbelow and are illustrative of 
different compositions and conditions that can be utilized in practicing 
the invention. All proportions are by weight unless otherwise indicated. 
It will be apparent, however, that the invention can be practiced with 
many types of compositions and can have many different uses in accordance 
with the disclosure and as pointed out hereinafter. 
EXAMPLE I 
A photoconductive imaging member was prepared by providing an aluminized 
polyethylene terephthalate (Mylar available from E. l. duPont de Nemours & 
Co.) substrate having a thickness of 3 mils and applying thereto, using a 
Bird applicator, a solution containing 0.4 gm 
3-aminopropyltriethoxysilane, 90 gm of 200 proof alcohol and 10 gm water. 
This layer was then allowed to dry for 5 minutes at room temperature and 
10 minutes at 135.degree. C. in a forced air oven. The resulting blocking 
layer had a dry thickness of 0.02 micrometer. 
An adhesive interface layer was then prepared by applying to the blocking 
layer a coating having a wet thickness of 0.5 mil and containing 0.5 
percent by weight based on the total weight of the solution of polyester 
adhesive (DuPont 49,000, available from E. I. duPont de Nemours & Co.) in 
a 70:30 volume ratio mixture of tetrahydrofuran/cyclohexanone with a Bird 
applicator. The adhesive interface layer was allowed to dry for 1 minute 
at room temperature and 10 minutes at 100.degree. C. in a forced air oven. 
The resulting adhesive interface layer had a dry thickness of 0.05 
micrometer. 
The adhesive interface layer was thereafter coated with a photogenerating 
layer of As.sub.2 Se.sub.3. As.sub.2 Se.sub.3 was vacuum deposited by 
heating an alloy of selenium containing 40 percent by weight arsenic in a 
vacuum at 10.sup.-6 Torr to form a photogenerating layer having a 
thickness of 0.15 micron. 
This photogenerator layer was overcoated with a charge transport layer. The 
charge transport layer was prepared by introducing into an amber glass 
bottle in a weight ratio of 1:1 
N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and 
Makrolon R, a polycarbonate resin having a molecular weight of from about 
50,000 to 100,000 commercially available from Farbensabricken Bayer A. G. 
The resulting mixture was dissolved in methylene chloride to form a 
solution containing 15 percent by weight solids. This solution was applied 
on the photogenerator layer using a Bird applicator to form a coating 
which upon drying had a thickness of 25 microns. The resulting 
photoreceptor device containing all of the above layers was annealed at 
135.degree. C. in a forced air oven for 6 minutes. 
The coated photoreceptor was cycled in a Xerox Scanning machine for 10,000 
cycles. It was found that the photoinduced discharge characteristics 
remained stable for the 10,000 cycles. Also, when the coated photoreceptor 
was flexed around a 2 cm diameter roll 100 times, the transport layer 
delaminated from the generator layer. 
EXAMPLE II 
A photoconductive imaging member was prepared in the same manner and with 
the same proportions of materials as in Example I except that the 
transport layer solution used in Example I was modified by the addition of 
8 percent by weight phenolic epoxy (ECN 1299, available from CIBA Chemical 
& Dye Co.) based on the total weight of solids. This solution was applied 
on the photogenerator layer using a Bird applicator to form a coating 
which upon drying had a thickness of 25 microns. The resulting 
photoreceptor device containing all of the above layers was annealed at 
135.degree. C. in a forced air oven for 6 minutes. 
The coated photoreceptor was cycled in a Xerox Scanning machine for 10,000 
cycles. It was found that the photoinduced discharge characteristics 
remained stable for the 10,000 cycles. When the coated photoreceptor was 
flexed around a 2 cm diameter roll 1,000 times, the transport layer did 
not delaminate from the generator layer. A comparison of the results 
obtained in Examples I and II clearly indicate that the adhesion between 
the generator and transport layer of the photoreceptor of this invention 
was improved without any impact on the electrophotographic properties. 
EXAMPLE III 
A photoconductive imaging member was prepared in the same manner and with 
the same proportions of materials as in Example I except that an interface 
layer was coated between the generator and transport layers. The interface 
layer contained 1 gram of an epoxy novolac (DEN 438, available from Dow 
Chemical Co.), 100 m grams of 
N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and 99 
grams of tetrahydrofuran. This mixture was coated with a Bird applicator 
and dried for 10 minutes at 100.degree. C. in a forced dry air oven to 
form an interface layer having a dried thickness of 0.1 micrometer. 
The coated photoreceptor was cycled in a Xerox copying machine for 10,000 
cycles. It was found that the photoinduced discharge characteristics 
remained stable for the 10,000 cycles. Also, when the photoreceptor was 
flexed around a 2 cm diameter roll 1,000 times, the transport layer did 
not delaminate from the generator layer. Examples I and III clearly 
demonstrate that the adhesion between the generator layer and the 
transport layer is improved without any impact on the electrophotograhic 
properties. 
EXAMPLE IV 
A photoconductive imaging member was prepared in the same manner and with 
the same proportions of materials as in Example II except that the 
additive was 8 percent by weight of polyester (PE 200, Goodyear Tire & 
Rubber Co.). The resulting device showed excellent adhesion improvements 
compared to the device in Example I without any deterioration of 
electrophotographic properties. 
EXAMPLE V 
A photoconductive imaging member was prepared in the same manner and with 
the same proportions of materials as in Example III except that a 
polyester (49000, available from E. I. duPont de Nemours & Co.) was 
substituted for the epoxy novolac polymer. The solvent was methylene 
chloride instead of tetrahydrofuran. The proportions of polymer and 
solvent remained the same. The resulting device showed excellent adhesion 
improvements compared to the device in Example I without any deterioration 
of electrophotographic properties. 
EXAMPLE VI 
The devices of Examples I through V all contained a charge blocking layer 
of gamma amino propyltriethoxy silane. Identical photoreceptors were 
prepared using containing polyvinyl butyral as a blocking layer material 
instead of gamma amino propyltriethoxy silane. The blocking layer coating 
solution was prepared with 1 gram of polyvinyl butyral (B-72, available 
from Monsanto Co.) in 99 grams of ethanol/butanol in a ratio of 70:30. 
This coating mixture was applied with a Bird applicator and the resulting 
coating dried for 15 minutes at 100.degree. C. in a forced dry air oven to 
form a layer having a dried thickness of 0.08 micrometer. The substitution 
of polyvinyl butyral for gamma amino propyltriethoxy silane in the 
blocking layer gave photoreceptors that performed in the same way as the 
corresponding photoreceptors in Examples I through V. 
Although the invention has been described with reference to specific 
preferred embodiments, it is not intended to be limited thereto, rather 
those skilled in the art will recognize that variations and modifications 
may be made therein which are within the spirit of the invention and 
within the scope of the claims.