EP2141546A1

EP2141546A1 - Photoconductors containing Tris and Bis(enylaryl)arylamine

Info

Publication number: EP2141546A1
Application number: EP09164060A
Authority: EP
Inventors: Jin Wu
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 2008-06-30
Filing date: 2009-06-29
Publication date: 2010-01-06
Anticipated expiration: 2029-06-29
Also published as: JP5544117B2; JP2010015147A; EP2141546B1

Abstract

A photoconductor that includes, for example, a photogenerating layer, and at least one charge transport layer wherein at least one of said charge transport layers is comprised of at least one charge transport component, and at least one of a tris(enylaryl)amine and a bis(enylaryl)arylamine.

Description

This disclosure is generally directed to photoreceptors, photoconductors, and the like. More specifically, the present disclosure is directed to rigid, multilayered flexible, belt imaging members, or devices comprised of an optional supporting medium like a substrate, at least one of a photogenerating layer and a charge transport layer containing an additive mixture comprised of a tris(enylaryl)amine and a bis(enylaryl)arylamine, or a tris(enylaryl)amine or a bis(enylaryl)arylamine including a plurality of charge transport layers, such as a first charge transport layer and a second charge transport layer, an optional adhesive layer, an optional hole blocking or undercoat layer, and an optional overcoating layer. At least one in embodiments refers, for example, to 1, to from 1 to about 10, to from 2 to about 7; to from 2 to about 4, to 2, and the like. Moreover, the mixture of the bis(enylaryl)arylamine and the tris(enylaryl)amine can be added to at least one of the charge transport layers and, for example, instead of being dissolved in the charge transport layer solution, the mixture of the bis(enylaryl)arylamine and the tris(enylaryl)amine can be added to the charge transport mixture as a dopant.
Yet more specifically, there is disclosed a photoconductor comprised of a supporting substrate, a photogenerating layer, and a mixture comprised of a tris(enylaryl)amine and a bis(enylaryl)arylamine, containing charge transport layer or charge transport layers, such as a first pass charge transport layer, a second pass charge transport layer, or both the first and second pass charge transport layers to primarily permit minimum crystallization of the charge transport component, and in embodiments permitting charge transport molecules that are free of crystallization; possess rapid or fast transport of charges; excellent ghosting characteristics; excellent photoconductor photosensitivities, and an acceptable, and in embodiments a low V_r; and minimization or prevention of V_r cycle up. Crystallization tends to render the charge transport component, like a number of aryl amine molecules, ineffective, and more specifically, crystallization can cause, subsequent to cycling, unacceptable print quality in, for example, a number of xerographic copying and printing apparatuses.
Also disclosed are methods of imaging and printing with the photoconductor devices illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additive, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto. In those environments wherein the device is to be used in a printing mode, the imaging method involves the same operation with the exception that exposure can be accomplished with a laser device or image bar. More specifically, flexible belts disclosed herein can be selected for the Xerox Corporation iGEN3^® machines that generate with some versions over 100 copies per minute. Processes of imaging, especially xerographic imaging and printing, including digital, and/or color printing, are thus encompassed by the present disclosure. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the imaging members of this disclosure are useful in high resolution color xerographic applications, particularly high speed color copying and printing processes.
Aspects of the present disclosure relate to a photoconductor comprising an optional supporting substrate, a photogenerating layer, and at least one charge transport layer wherein at least one of the charge transport layers is comprised of at least one charge transport component, and a mixture of a tris(enylaryl)amine and a bis(enylaryl)arylamine; a photoconductor comprising a supporting substrate, a photogenerating layer, and at least one charge transport layer, and wherein the charge transport layer is comprised of a charge transport component, a binder, and a mixture of a bis(enylaryl)arylamine and a tris(enylaryl)amine; and a photoconductor comprised in sequence of a supporting substrate, a photogenerating layer, and a charge transport layer, and wherein the charge transport layer comprises a hole transport compound, and a mixture of a bis(butadienylaryl)aryl amine and a tris(butadienylaryl)amine.
A number of additives can be included in the charge transport layer or charge transport layers in amounts, for example, that in embodiments may be dependant on the thickness of the charge transport layer or layers, noting, for example, that thicker charge transport layers may be subject to increased crystallization, thus the amount of the tris and bis compounds will vary accordingly as indicated herein.
Additive mixture amounts present in the charge transport layer are, for the trisamine, from about 99 to about 1 weight percent, and where the total thereof is about 100 weight percent. In embodiments, the additive mixture selected for the charge transport layer or layers is comprised of from about 20 to about 80 weight percent, about 25 to about 75 weight percent, and about 40 to about 60 weight percent of tris(enylaryl)amine, and about 80 to about 20 weight percent, about 75 to about 25 weight percent, and about 60 to about 40 weight percent of the bis(enylaryl)arylamine; also 50/50 mixtures of the tris and bis can be selected. In embodiments, from about 1 to about 20, from about 1 to about 15, from about 1 to about 10, and from about 2 to about 7 weight percent of the mixture of the bis and tris additive can be present in the charge transport layer.
Examples of bis(enylaryl)arylamines are, for example, are represented by or encompassed by the following formula/structure
wherein each R is hydrogen, alkyl, alkoxy, aryl, substituted derivatives thereof, such as alkylaryl, alkoxyaryl, haloaryl, halo, and the like; and m and n each independently represents the number of segments, such as 0 or 1. Alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl; alkoxy groups include methoxy, ethoxy, propoxy, and butoxy; and aryl groups include phenyl, p-tolyl, 2,4-dimethylphenyl, p-methoxyphenyl, and p-chlorophenyl.
Yet more specifically, examples of bis additives are bis(butadienylaryl)arylamines such as bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl] phenylamine (T-651 available from Takasago Chemical Corp., Tokyo, Japan), N,N-bis[4-[4,4-bis(4-methylphenyl)-1,3-butadienyl]phenyl]-4-methoxyphenylamine; (ethenylaryl)(butadienylaryl)arylamines such as [4-(2,2-diphenylethenyl)phenyl][4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine; bis(ethenylaryl)arylamines such as N,N-bis[4-(2,2-diphenylethenyl)phenyl]-4-methylphenylamine (T-736 available from Takasago Chemical Corp., Tokyo, Japan), N,N-bis[4-[2,2-bis(4-methylphenyl)ethenyl]phenyl]-4-methylphenylamine (T-925 available from Takasago Chemical Corp., Tokyo, Japan), and the like, and mixtures thereof.
In embodiments, the bis additive can be represented by the following formulas/structures

and
Examples of the tris additives include those compounds as represented by or encompassed by
wherein each R is hydrogen, alkyl, alkoxy, aryl, substituted derivatives, such as alkylaryl, alkoxyaryl, haloaryl, halo, and the like; and m, n, and p each represents the number of groups, and can be 0 or 1. Specific alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl; and specific alkoxy groups include methoxy, ethoxy, propoxy, and butoxy, and specific groups include phenyl, p-tolyl, 2,4-dimethylphenyl, p-methoxyphenyl, and p-chlorophenyl.
More specifically, examples of the tris additives are tris(butadienylaryl)amines such as tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine (T-693 available from Takasago Chemical Corp., Tokyo, Japan) and tris[4-(4,4-dimethylphenyl-1,3-butadienyl)phenyl]amine, (butadienylaryl)bis(ethylenylaryl)amines such as [4-(4,4-diphenyl-1,3-butadienyl)phenyl]bis[4-(2,2-diphenylethenyl)phenyl] amine, (ethylenylaryl)bis(butadienylaryl)amines such as [4-(2,2-diphenylethenyl) phenyl]bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine, tris(ethylenylaryl)amines such as tris[4-(2,2-diphenylethenyl)phenyl]amine, and the like, and mixtures thereof.
In embodiments, the tris additive can be represented by the following
Also, in embodiments the photoconductor charge transport layer or layers, such as for example from 1 to about 4 layers, contains a mixture of bis(butadienylaryl)arylamine and tris(butadienylaryl)amine, and more specifically, a mixture of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine and tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine, as represented by
There can be selected for the photoconductors disclosed herein a number of known layers, such as substrates, photogenerating layers, charge transport layers, hole blocking layers, adhesive layers, protective overcoat layers, and the like. Examples, thicknesses, specific components of many of these layers include the following.
A number of known supporting substrates can be selected for the photoconductors illustrated herein, such as those substrates that will permit the layers thereover to be effective. The thickness of the substrate layer depends on many factors, including economical considerations, electrical characteristics, and the like, thus this layer may be of a substantial thickness, for example over 3,000 µm, such as from about 1,000 to about 3,500, from about 1,000 to about 2,000, from about 300 to about 700 µm, or of a minimum thickness of, for example, about 100 to about 500 µm. In embodiments, the thickness of this layer is from about 75 to about 300 µm, or from about 100 to about 150 µm.
The substrate may be comprised of a number of different materials, such as those that are opaque or substantially transparent, and may comprise any suitable material. Accordingly, the substrate may comprise a layer of an electrically nonconductive or conductive material, such as an inorganic or an organic composition. As electrically nonconducting materials, there may be employed various resins known for this purpose including polyesters, polycarbonates, polyamides, polyurethanes, and the like, which are flexible as thin webs. An electrically conducting substrate may be any suitable metal of, for example, aluminum, nickel, steel, copper, and the like, or a polymeric material, as described above, filled with an electrically conducting substance, such as carbon, metallic powder, and the like, or an organic electrically conducting material. The electrically insulating or conductive substrate may be in the form of an endless flexible belt, a web, a rigid cylinder, a sheet, and the like. The thickness of the substrate layer depends on numerous factors, including strength desired and economical considerations. For a drum, this layer may be of substantial thickness of, for example, up to many centimeters, or of a minimum thickness of less than a millimeter. Similarly, a flexible belt may be of a substantial thickness of, for example, about 250 µm, or of a minimum thickness of less than about 50 µm, provided there are no adverse effects on the final electrophotographic device. In embodiments where the substrate layer is not conductive, the surface thereof may be rendered electrically conductive by an electrically conductive coating. The conductive coating may vary in thickness over substantially wide ranges depending upon the optical transparency, degree of flexibility desired, and economic factors.
Illustrative examples of substrates are as illustrated herein, and more specifically, layers selected for the imaging members of the present disclosure, and which substrates can be opaque or substantially transparent comprise a layer of insulating material including inorganic or organic polymeric materials, such as MYLAR^® a commercially available polymer, MYLAR^® containing titanium, a layer of an organic or inorganic material having a semiconductive surface layer, such as indium tin oxide or aluminum arranged thereon, or a conductive material inclusive of aluminum, chromium, nickel, brass, or the like.
The photogenerating layer in embodiments is comprised of an optional binder, and known photogenerating pigments, and more specifically, hydroxygallium phthalocyanine, titanyl phthalocyanine, and chlorogallium phthalocyanine, and a resin binder. Generally, the photogenerating layer can contain known photogenerating pigments, such as metal phthalocyanines, metal free phthalocyanines, alkylhydroxyl gallium phthalocyanines, hydroxygallium phthalocyanines, chlorogallium phthalocyanines, perylenes, especially bis(benzimidazo)perylene, titanyl phthalocyanines, and the like, and more specifically, vanadyl phthalocyanines, Type V hydroxygallium phthalocyanines, and inorganic components, such as selenium, selenium alloys, and trigonal selenium. The photogenerating pigment can be dispersed in a resin binder similar to the resin binders selected for the charge transport layer, or alternatively no resin binder need be present. Generally, the thickness of the photogenerating layer depends on a number of factors, including the thicknesses of the other layers, and the amount of photogenerating material contained in the photogenerating layer. Accordingly, this layer can be of a thickness of, for example, from about 0.05 to about 10 µm, and more specifically, from about 0.25 to about 2 µm when, for example, the photogenerating compositions are present in an amount of from about 30 to about 75 percent by volume. The maximum thickness of this layer in embodiments is dependent primarily upon factors, such as photosensitivity, electrical properties, and mechanical considerations. The photogenerating layer binder resin is present in various suitable amounts, for example from about 1 to about 50 weight percent, and more specifically, from about 1 to about 10 weight percent, and which resin may be selected from a number of known polymers, such as poly(vinyl butyral), poly(vinyl carbazole), polyesters, polycarbonates, polyarylates, poly(vinyl chloride), polyacrylates and methacrylates, copolymers of vinyl chloride and vinyl acetate, phenolic resins, polyurethanes, poly(vinyl alcohol), polyacrylonitrile, polystyrene, other known suitable binders, and the like. It is desirable to select a coating solvent that does not substantially disturb or adversely affect the previously coated layers of the device. Examples of coating solvents for the photogenerating layer are ketones, alcohols, aromatic hydrocarbons, halogenated aliphatic hydrocarbons, silanols, amines, amides, esters, and the like. Specific solvent examples are cyclohexanone, acetone, methyl ethyl ketone, methanol, ethanol, butanol, amyl alcohol, toluene, xylene, chlorobenzene, carbon tetrachloride, chloroform, methylene chloride, trichloroethylene, dichloroethane, tetrahydrofuran, dioxane, diethyl ether, dimethyl formamide, dimethyl acetamide, butyl acetate, ethyl acetate, methoxyethyl acetate, and the like.
Moreover, the photogenerating layer can be specifically comprised of a titanyl phthalocyanine component generated, for example, by the processes as illustrated in U.S. Publication No. 2006 0105254 .
In embodiments, the Type V phthalocyanine pigment included in the photogenerating layer can be generated by dissolving Type I titanyl phthalocyanine in a solution comprising a trihaloacetic acid and an alkylene halide; adding the resulting mixture comprising the dissolved Type I titanyl phthalocyanine to a solution comprising an alcohol, and an alkylene halide thereby precipitating a Type Y titanyl phthalocyanine; and treating the resulting Type Y titanyl phthalocyanine with monochlorobenzene.
The process illustrated herein further provides a titanyl phthalocyanine having a crystal phase distinguishable from other known titanyl phthalocyanines. The titanyl phthalocyanine Type V prepared by a process according to the present disclosure is distinguishable from, for example, Type IV titanyl phthalocyanines in that a Type V titanyl phthalocyanine exhibits an X-ray powder diffraction spectrum having four characteristic peaks at 9.0°, 9.6°, 24.0°, and 27.2°, while Type IV titanyl phthalocyanines typically exhibit only three characteristic peaks at 9.6°, 24.0°, and 27.2°.
In embodiments, examples of polymeric binder materials that can be selected as the matrix for the photogenerating layer are thermoplastic and thermosetting resins, such as polycarbonates, polyesters, polyamides, polyurethanes, polystyrenes, polyarylsilanols, polyarylsulfones, polybutadienes, polysulfones, polysilanolsulfones, polyethylenes, polypropylenes, polyimides, polymethylpentenes, poly(phenylene sulfides), poly(vinyl acetate), polysiloxanes, polyacrylates, polyvinyl acetals, polyamides, polyimides, amino resins, phenylene oxide resins, terephthalic acid resins, phenoxy resins, epoxy resins, phenolic resins, polystyrene and acrylonitrile copolymers, poly(vinyl chloride), vinyl chloride and vinyl acetate copolymers, acrylate copolymers, alkyd resins, cellulosic film formers, poly(amideimide), styrene butadiene copolymers, vinylidene chloride-vinyl chloride copolymers, vinyl acetate-vinylidene chloride copolymers, styrene-alkyd resins, poly(vinyl carbazole), and the like. These polymers may be block, random, or alternating copolymers.
The photogenerating composition or pigment is present in the resinous binder composition in various amounts. Generally, however, from about 5 percent by weight to about 90 percent by weight of the photogenerating pigment is dispersed in about 10 percent by weight to about 95 percent by weight of the resinous binder, or from about 20 percent by weight to about 50 percent by weight of the photogenerating pigment is dispersed in about 80 percent by weight to about 50 percent by weight of the resinous binder composition. In one embodiment, about 50 percent by weight of the photogenerating pigment is dispersed in about 50 percent by weight of the resinous binder composition. The total weight percent of components in the photogenerating layer is about 100.
In embodiments, a suitable known adhesive layer can be included in the photoconductor. Typical adhesive layer materials include, for example, polyesters, polyurethanes, and the like. The adhesive layer thickness can vary and in embodiments is, for example, from about 0.05 µm (500 Angstroms) to about 0.3 µm (3,000 Angstroms). The adhesive layer can be deposited on the hole blocking layer by spraying, dip coating, roll coating, wire wound rod coating, gravure coating, Bird applicator coating, and the like. Drying of the deposited coating may be effected by, for example, oven drying, infrared radiation drying, air drying and the like.
As an optional adhesive layer or layers usually in contact with or situated between the hole blocking layer and the photogenerating layer, there can be selected various known substances inclusive of copolyesters, polyamides, poly(vinyl butyral), poly(vinyl alcohol), polyurethane, and polyacrylonitrile. This layer is, for example, of a thickness of from about 0.001 to about 1 µm, or from about 0.1 to about 0.5 µm. Optionally, this layer may contain effective suitable amounts, for example from about 1 to about 10 weight percent, of conductive and nonconductive particles, such as zinc oxide, titanium dioxide, silicon nitride, carbon black, and the like, to provide, for example, in embodiments of the present disclosure further desirable electrical and optical properties.
The hole blocking or undercoat layer or layers for the photoconductors of the present disclosure can contain a number of components including known hole blocking components, such as amino silanes, doped metal oxides, a metal oxide like titanium, chromium, zinc, tin and the like; a mixture of phenolic compounds and a phenolic resin, or a mixture of two phenolic resins, and optionally a dopant such as SiO₂. The phenolic compounds usually contain at least two phenol groups, such as bisphenol A (4,4'-isopropylidenediphenol), E (4,4'-ethylidenebisphenol), F (bis(4-hydroxyphenyl)methane), M (4,4'-(1,3-phenylenediisopropylidene)bisphenol), P (4,4'-(1,4-phenylene diisopropylidene)bisphenol), S (4,4'-sulfonyldiphenol), and Z (4,4'-cyclohexylidenebisphenol); hexafluorobisphenol A (4,4'-(hexafluoro isopropylidene) diphenol), resorcinol, hydroxyquinone, catechin, and the like.
The hole blocking layer can be, for example, comprised of from about 20 weight percent to about 80 weight percent, and more specifically, from about 55 weight percent to about 65 weight percent of a suitable component like a metal oxide, such as TiO₂; from about 20 weight percent to about 70 weight percent, and more specifically, from about 25 weight percent to about 50 weight percent of a phenolic resin; from about 2 weight percent to about 20 weight percent, and more specifically, from about 5 weight percent to about 15 weight percent of a phenolic compound containing, for example, at least two phenolic groups, such as bisphenol S; and from about 2 weight percent to about 15 weight percent, and more specifically, from about 4 weight percent to about 10 weight percent of a plywood suppression dopant, such as SiO₂. Examples of phenolic resins include formaldehyde polymers with phenol, p-tert-butylphenol, cresol, such as VARCUM^® 29159 and 29101 (available from OxyChem Company), and DURITE^® 97 (available from Borden Chemical); formaldehyde polymers with ammonia, cresol and phenol, such as VARCUM^® 29112 (available from OxyChem Company); formaldehyde polymers with 4,4'-(1-methylethylidene)bisphenol, such as VARCUM^® 29108 and 29116 (available from OxyChem Company); formaldehyde polymers with cresol and phenol, such as VARCUM^® 29457 (available from OxyChem Company), DURITE^® SD-423A, SD-422A (available from Borden Chemical); or formaldehyde polymers with phenol and p-tert-butylphenol, such as DURITE^® ESD 556C (available from Borden Chemical).
Charge transport layer components and molecules include a number of known materials such as those illustrated herein, such as aryl amines, which layer is generally of a thickness of from about 5 to about 75 µm, and more specifically, of a thickness of from about 10 to about 40 µm. Examples of charge transport layer components include
and
wherein X is alkyl, alkoxy, aryl, a halogen, or mixtures thereof, and especially those substituents selected from the group consisting of Cl, OCH₃ and CH₃; and molecules of the following formula
wherein X and Y are independently alkyl, alkoxy, aryl, a halogen, or mixtures thereof.
Alkyl and alkoxy refer, for example, to those substituents containing from 1 to about 25 carbon atoms, and more specifically, from 1 to about 12 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, and the corresponding alkoxides. Aryl can contain from 6 to about 36 carbon atoms, such as phenyl, and the like. Halogen includes chloride, bromide, iodide and fluoride. Substituted alkyls, alkoxys, and aryls can also be selected in embodiments.
Examples of specific aryl amines include N,N'-diphenyl-N,N'-bis(alkylphenyl)-1,1-biphenyl-4,4'-diamine wherein alkyl is selected from the group consisting of methyl, ethyl, propyl, butyl, hexyl, and the like; N,N'-diphenyl-N,N'-bis(halophenyl)-1,1'-biphenyl-4,4'-diamine wherein the halo substituent is a chloro substituent; N,N'-bis(4-butylphenyl)-N,N'-di-p-tolyl-[p-terphenyl]-4,4"-diamine, N,N'-bis(4-butylphenyl)-N,N'-di-m-tolyl-[p-terphenyl]-4,4"-diamine, N,N'-bis(4-butylphenyl)-N,N'-di-o-tolyl-[p-terphenyl]-4,4"-diamine, N,N'-bis(4-butylphenyl)-N,N'-bis-(4-isopropylphenyl)-[p-terphenyl]-4,4"-diamine, N,N'-bis(4-butylphenyl)-N,N'-bis-(2-ethyl-6-methylphenyl)-[p-terphenyl]-4,4"-diamine, N,N'-bis(4-butylphenyl)-N,N'-bis-(2,5-dimethylphenyl)-[p-terphenyl]-4,4'-diamine, N,N'-diphenyl-N,N'-bis(3-chlorophenyl)-[p-terphenyl]-4,4"-diamine, tetra-p-tolyl-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-bis(4-methoxyphenyl)-1,1-biphenyl-4,4'-diamine, and the like. Other known charge transport layer molecules can be selected, reference for example, U.S. Patents 4,921,773 and 4,464,450 .
In embodiments, the charge transport component can be represented by the following formulas/structures

and
Examples of the binder materials selected for the charge transport layers include polycarbonates, polyarylates, acrylate polymers, vinyl polymers, cellulose polymers, polyesters, polysiloxanes, polyamides, polyurethanes, poly(cyclo olefins), epoxies, and random or alternating copolymers thereof; and more specifically, polycarbonates such as poly(4,4'-isopropylidene-diphenylene)carbonate (also referred to as bisphenol-A-polycarbonate), poly(4,4'-cyclohexylidine diphenylene)carbonate (also referred to as bisphenol-Z-polycarbonate), poly(4,4'-isopropylidene-3,3'-dimethyl-diphenyl)carbonate (also referred to as bisphenol-C-polycarbonate), and the like. In embodiments, the charge transport layer binders are comprised of polycarbonate resins with a weight average molecular weight of from about 20,000 to about 100,000, or with a molecular weight M_w of from about 50,000 to about 100,000 preferred. Generally, in embodiments the transport layer contains from about 10 to about 75 percent by weight of the charge transport material, and more specifically, from about 35 percent to about 50 percent of this material.
The thickness of each of the charge transport layers in embodiments is from about 5 to about 75 µm, but thicknesses outside this range may in embodiments also be selected.
The thickness of the continuous charge transport overcoat layer selected depends upon the abrasiveness of the charging (bias charging roll), cleaning (blade or web), development (brush), transfer (bias transfer roll), and the like in the system employed, and can be up to about 10 µm. In embodiments, this thickness for each layer is from about 1 to about 5 µm. Various suitable and conventional methods may be used to mix, and thereafter apply the overcoat layer coating mixture to the photoconductor. 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, infrared radiation drying, air drying, and the like. The dried overcoating layer of this disclosure should transport holes during imaging, and should not have too high a free carrier concentration.
Examples of components or materials optionally incorporated into the charge transport layers or at least one charge transport layer to, for example, enable improved lateral charge migration (LCM) resistance include hindered phenolic antioxidants, such as tetrakis methylene(3,5-di-tert-butyl-4-hydroxy hydrocinnamate) methane (IRGANOX^® 1010, available from Ciba Specialty Chemical), butylated hydroxytoluene (BHT), and other hindered phenolic antioxidants including SUMILIZER™ BHT-R, MDP-S, BBM-S, WX-R, NW, BP-76, BP-101, GA-80, GM and GS (available from Sumitomo Chemical Company, Ltd.), IRGANOX^® 1035, 1076, 1098, 1135, 1141, 1222, 1330, 1425WL, 1520L, 245, 259, 3114, 3790, 5057 and 565 (available from Ciba Specialties Chemicals), and ADEKA STAB™ AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, AO-80 and AO-330 (available from Asahi Denka Company, Ltd.); hindered amine antioxidants such as SANOL™ LS-2626, LS-765, LS-770 and LS-744 (available from SNKYO CO., Ltd.), TINUVIN^® 144 and 622LD (available from Ciba Specialties Chemicals), MARK™ LA57, LA67, LA62, LA68 and LA63 (available from Asahi Denka Co., Ltd.), and SUMILIZER™ TPS (available from Sumitomo Chemical Co., Ltd.); thioether antioxidants such as SUMILIZER™ TP-D (available from Sumitomo Chemical Co., Ltd); phosphite antioxidants such as MARK™ 2112, PEP-8, PEP-24G, PEP-36, 329K and HP-10 (available from Asahi Denka Co., Ltd.); other molecules, such as bis(4-diethylamino-2-methylphenyl) phenylmethane (BDETPM), bis-[2-methyl-4-(N-2-hydroxyethyl-N-ethyl-aminophenyl)]-phenylmethane (DHTPM), and the like. The weight percent of the antioxidant in at least one of the charge transport layers is from about 0 to about 20, from about 1 to about 10, or from about 3 to about 8 weight percent.
Primarily for purposes of brevity, the examples of each of the substituents, and each of the components/compounds/molecules, polymers, for each of the layers, specifically disclosed herein are not intended to be exhaustive. Thus, a number of components, polymers, formulas, structures, and R group or substituent examples, and carbon chain lengths not specifically disclosed or claimed are intended to be encompassed by the present disclosure and claims. Also, the carbon chain lengths are intended to include all numbers between those disclosed or claimed or envisioned, this from 1 to about 20 carbon atoms, and from 6 to about 36 carbon atoms includes 1, 2, 3, 4, 5, 6, 7, ,8, 9, 10, 11, 12, 13, 14, 15, up to 36, or more. At least one refers, for example , to from 1 to about 5, from 1 to about 2, 1, 2, and the like. Similarly the thickness of each of the layers, the examples of components in each of the layers, the amount ranges of each of the components disclosed and claimed is not exhaustive, and it is intended that the present disclosure and claims encompass other suitable parameters not disclosed or that may be envisioned.

EXAMPLE I

A Type I titanyl phthalocyanine (TiOPc) was prepared as follows. To a 300 milliliter three-necked flask fitted with mechanical stirrer, condenser and thermometer maintained under an argon atmosphere were added 3.6 grams (0.025 mole) of 1,3-diiminoisoindoline, 9.6 grams (0.075 mole) of o-phthalonitrile, 75 milliliters (80 weight percent) of tetrahydronaphthalene, and 7.11 grams (0.025 mole) of titanium tetrapropoxide (all obtained from Aldrich Chemical Company except phthalonitrile which was obtained from BASF). The resulting mixture (20 weight percent of solids) was stirred and warmed to reflux (about 198°C) for 2 hours. The resultant black suspension was cooled to about 150°C, and then was filtered by suction through a 350 milliliter, M-porosity sintered glass funnel, which had been preheated with boiling dimethyl formamide (DMF). The solid Type I TiOPc product resulting was washed with two 150 milliliter portions of boiling DMF, and the filtrate, initially black, became a light blue-green color. The solid was slurried in the funnel with 150 milliliters of boiling DMF, and the suspension was filtered. The resulting solid was washed in the funnel with 150 milliliters of DMF at 25°C, and then with 50 milliliters of methanol. The resultant shiny purple solid was dried at 70°C overnight to yield 10.9 grams (76 percent) of pigment, which were identified as Type I TiOPc on the basis of their X-ray powder diffraction trace. Elemental analysis of the product indicated C, 66.54; H, 2.60; N, 20.31; and Ash (TiO₂), 13.76. TiOPc requires (theory) C, 66.67; H, 2.80; N, 19.44; and Ash, 13.86.
A Type I titanyl phthalocyanine can also be prepared in 1 chloronaphthalene or N-methyl pyrrolidone as follows. A 250 milliliter three-necked flask fitted with mechanical stirrer, condenser, and thermometer maintained under an atmosphere of argon was charged with 1,3-diiminoisoindolene (14.5 grams), titanium tetrabutoxide (8.5 grams), and 75 milliliters of 1-chloronaphthalene (CINp) or N methyl pyrrolidone. The mixture was stirred and warmed. At 140°C the mixture turned dark green and began to reflux. At this time, the vapor (which was identified as n-butanol by gas chromatography) was allowed to escape to the atmosphere until the reflux temperature reached 200°C. The reaction was maintained at this temperature for two hours, then was cooled to 150°C. The product was filtered through a 150 milliliter M-porosity sintered glass funnel, which was preheated to approximately 150°C with boiling DMF, and then washed thoroughly with three portions of 150 milliliters of boiling DMF, followed by washing with three portions of 150 milliliters of DMF at room temperature, and then three portions of 50 milliliters of methanol, thus providing 10.3 grams (72 percent yield) of a shiny purple pigment, which were identified as Type I TiOPc by X-ray powder diffraction (XRPD).

EXAMPLE II

Fifty grams of TiOPc Type I were dissolved in 300 milliliters of a trifluoroacetic acid/methylene chloride (1/4, volume/volume) mixture for 1 hour in a 500 milliliter Erlenmeyer flask with magnetic stirrer. At the same time, 2,600 milliliters of methanol/methylene chloride (1/1, volume/volume) quenching mixture were cooled with a dry ice bath for 1 hour in a 3,000 milliliter beaker with magnetic stirrer, and the final temperature of the mixture was about -25°C. The resulting TiOPc solution was transferred to a 500 milliliter addition funnel with a pressure-equalization arm, and added into the cold quenching mixture over a period of 30 minutes. The mixture obtained was then allowed to stir for an additional 30 minutes, and subsequently hose vacuum filtered through a 2,000 milliliter Buchner funnel with fibrous glass frit of about 4 to about 8 millimeters in porosity. The pigment resulting was then well mixed with 1,500 milliliters of methanol in the funnel, and vacuum filtered. The pigment was then well mixed with 1,000 milliliters of hot water (>90°C), and vacuum filtered in the funnel four times. The pigment was then well mixed with 1,500 milliliters of cold water, and vacuum filtered in the funnel. The final water filtrate was measured for conductivity, which was below 10 µS. The resulting wet cake contained approximately 50 weight percent of water. A small portion of the wet cake was dried at 65°C under vacuum and a blue pigment was obtained. A representative XRPD of this pigment after quenching with methanonol/methylene chloride was identified by XRPD as Type Y titanyl phthalocyanine.
The remaining portion of the wet cake was redispersed in 700 grams of monochlorobenzene (MCB) in a 1,000 milliliter bottle, and rolled for an hour. The dispersion was vacuum filtered through a 2,000 milliliter Buchner funnel with a fibrous glass frit of about 4 to about 8 millimeters in porosity over a period of two hours. The pigment was then well mixed with 1,500 milliliters of methanol and filtered in the funnel twice. The final pigment was vacuum dried at 60°C to 65°C for two days. Approximately 45 grams of the pigment were obtained. The XRPD of the resulting pigment after the MCB conversion was designated as a Type V titanyl phthalocyanine. The Type V had an X ray diffraction pattern having characteristic diffraction peaks at a Bragg angle of 2Q ±0.2° at about 9.0°, 9.6°, 24.0°, and 27.2°.

COMPARATIVE EXAMPLE 1

On a 30 millimeter aluminum drum substrate, an undercoat layer was prepared as follows. Zirconium acetylacetonate tributoxide (35.5 parts), γ-aminopropyl triethoxysilane (4.8 parts), and poly(vinyl butyral) BM-S (2.5 parts) were dissolved in n-butanol (52.2 parts). The resulting coating solution was coated on the above drum substrate by a dip coater; the undercoat layer was pre-heated at 59°C for 13 minutes, humidified at 58°C (dew point = 54°C) for 17 minutes; and then was dried at 135°C for 8 minutes. The thickness of the resulting undercoat layer was approximately 1.3 µm.
A photogenerating layer at a thickness of about 0.2 µm comprising titanyl phthalocyanine Type V as prepared in Example II was deposited on the above hole blocking layer or undercoat layer. The photogenerating layer coating dispersion was prepared as follows. Three grams of the Type V pigment were mixed with 2 grams of polymeric binder (polyvinyl butyral, BM-S, Sekisui Chemicals, Japan), and 45 grams of n-butyl acetate. The mixture was milled in an Attritor mill with about 200 grams of 1 millimeter Hi-Bea borosilicate glass beads for about 3 hours. The dispersion was filtered through a 20 µm Nylon cloth filter, and the solid content of the dispersion was diluted to about 6 weight percent.
Subsequently, a charge transport layer was coated on top of the photogenerating layer from a solution prepared from tetra-p-tolyl-biphenyl-4,4'-diamine, TmTBD (5 grams),
and a film forming polymer binder PCZ-400 [poly(4,4'-dihydroxy-diphenyl-1-1-cyclohexane, M_w = 40,000)] available from Mitsubishi Gas Chemical Company, Ltd. (7.5 grams) in a solvent mixture of 28 grams of tetrahydrofuran (THF), and 12 grams of toluene by simple mixing. The charge transport layer (PCZ-400/TmTBD = 60/40) was dried at about 120°C for about 40 minutes.
A number of photoconductors were prepared by repeating the above process with the thickness of the charge transport layer being from about 16 µm in Comparative Example 1 (A) to about 20 µm in Comparative Example 1 (B), to about 24 µm in Comparative Example 1 (C), to about 28 µm in Comparative Example 1 (D), to about 32 µm in Comparative Example 1 (E).

COMPARATIVE EXAMPLE 2

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the charge transport layer N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (mTBD) as a replacement for the above TmTBD.

EXAMPLE III

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, about 2 weight percent of a mixture of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine, and tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine (which mixture was available as T-770 from Takasago Chemical Corp., Tokyo, Japan).
A number of photoconductors were prepared by repeating the above process, resulting in photoconductors each with a charge transport layer (PCZ-400/TmTBD/T-770 mixture ratio of 60/38/2) and of from about 16 to about 32 µm in thickness.
The above bis/tris mixture is represented by

EXAMPLE IV

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, a 5 weight percent mixture of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine and tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine (available as T-770 from Takasago Chemical Corp., Tokyo, Japan).
A number of photoconductors were prepared by repeating the above process, resulting in photoconductors each with a charge transport layer (PCZ-400/TmTBD/T-770 mixture ratio of 60/35/5) and of from about 16 to about 32 µm in thickness.

EXAMPLE V

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, a 10 weight percent mixture of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine and tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine (available as T-770 from Takasago Chemical Corp., Tokyo, Japan).
A number of photoconductors were prepared by repeating the above process, resulting in photoconductors each with a charge transport layer (PCZ-400/TmTBD/T-770 ratio 60/30/10) and of from about 16 to about 32 µm in thickness.

EXAMPLE VI

A number of photoconductors are prepared by repeating the process of Comparative Example 1 except that there is included in the single tetra-p-tolyl-biphenyl-4,4'-diamine or TmTBD charge transport layer 10 weight percent of at least a bis/tris mixtures, where the bis compound is selected from a group consisting of N,N-bis[4-[4,4-bis(4-methylphenyl)-1,3-butadienyl]phenyl]-4-methoxyphenylamine, [4-(2,2-diphenylethenyl)phenyl][4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine, N,N-bis[4-(2,2-diphenylethenyl)phenyl]-4-methylphenylamine (T-736 available from Takasago Chemical Corp., Tokyo, Japan), and N,N-bis[4-[2,2-bis(4-methylphenyl) ethenyl]phenyl]-4-methylphenylamine (T-925 available from Takasago Chemical Corp., Tokyo, Japan); and the tris compound is selected from a group consisting of tris[4-(4,4-dimethylphenyl-1,3-butadienyl)phenyl]amine, [4-(4,4-diphenyl-1,3-butadienyl)phenyl]bis[4-(2,2-diphenylethenyl)phenyl]amine, [4-(2,2-diphenylethenyl) phenyl]bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine, and tris[4-(2,2-diphenylethenyl)phenyl]amine.

CRYSTALLIZATION MEASUREMENTS

A number of the above prepared photoconductors of the Comparative Examples, and Examples III, IV, and V were visually inspected for the charge transport component crystallization. When a photoconductor charge transport layer of tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) without the additive is selected for the photoconductor of Comparative Example 1, it tends to crystallize to form visible crystal domains across the charge transport layer.
Visual inspections for photoconductor crystallization was rated "YES" or "NO". Whenever any crystal of any size is observed by human eyes, the rating is "YES" for crystallization. Otherwise, the rating is "NO".
For the photoconductor of Comparative Example 2 with the mTBD contained in the charge transport layer, substantially no crystallization was visually observed.

As illustrated in Table 1, that follows, the crystallization characteristics for a number of the above prepared photoconductors containing the tris(enylaryl)amine additive in the charge transport layer were excellent, especially for the photoconductors of Example V.

TABLE 1

TmTBD Crystallization (CTL Thickness)	Comparative Example 1 (PCZ-400/ TmTBD = 60/40)	Example III (PCZ-400/ TmTBD/T-770 = 60/38/2)	Example IV (PCZ-400/ TmTBD/T-770 = 60/35/5)	Example V (PCZ-400/ TmTBD/T-770 = 60/30/10)
A (16 µm)	YES	NO	NO	NO
B (20 µm)	YES	YES	NO	NO
C (24 µm)	YES	YES	NO	NO
D (28 µm)	YES	YES	YES	NO
E (32 µm)	YES	YES	YES	NO

ELECTRICAL PROPERTY TESTING

Three of the above prepared photoreceptors, each with 24 µm thick charge transport layers, of Comparative Example 2, and Examples IV (C) and V (C) were tested in a scanner set to obtain photoinduced discharge cycles, sequenced at one charge-erase cycle followed by one charge-expose-erase cycle, wherein the light intensity was incrementally increased with cycling to produce a series of photoinduced discharge characteristic curves from which the photosensitivity and surface potentials at various exposure intensities are measured. Additional electrical characteristics were obtained by a series of charge-erase cycles with incrementing surface potential to generate several voltage versus charge density curves. The scanner was equipped with a scorotron set to a constant voltage charging at various surface potentials. The photoconductors were tested at surface potentials of 700 volts with the exposure light intensity incrementally increased by means of regulating a series of neutral density filters; the exposure light source was a 780 nanometer light emitting diode. The xerographic simulation was completed in an environmentally controlled light tight chamber at ambient conditions (40 percent relative humidity and 22°C). The results are summarized in Table 2.

TABLE 2

	V (1 erg/cm²) (V)	V (2 ergs/cm²) (V)	V (4 ergs/cm²) (V)
Comparative Example 2 (mTBD Alone)	261	99	80
Example IV (C) (TmTBD/T-770 = 35/5)	261	57	24
Example V (C) (TmTBD/T-770 = 30/10)	260	56	23

There is illustrated by the above Table 2 data a number of improved characteristics, for example, fast or rapid transport of charges for the Example IV (C) and V (C) photoconductive members as determined by the generation of known PIDC curves. More specifically, V (1 ergs/cm²), V (2 ergs/cm²) and V (4 ergs/cm²) in Table 2 each represents the surface potential of the photoconductors when exposure is 1, 2 and 4 ergs/cm², and is used to characterize the PIDC.
Rapid transporting photoconductor devices were obtained with TmTBD/T-770 charge transport layers (Examples IV and V) when compared with the mTBD photoconductor (Comparable Example 2) since TmTBD intrinsically possesses higher hole transporting mobility than mTBD, however, TmTBD may not be as useful alone due to its tendency to crystallize. The incorporation of the additive mixture of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine and tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine substantially eliminated the TmTBD crystallization.
Rapid or fast transporting refers to, for example, fast discharge, for example, 42V lower at (2 ergs/cm²) and 56V lower at (4 ergs/cm²) for the Example IV (C) and V (C) photoconductive members, when compared with the Comparative Example 2 photoconductive member.

EXAMPLE VII

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, 2 weight percent of tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine additive (available as T-693 and obtained from Takasago Chemical Corp., Tokyo, Japan), and represented by
A number of photoconductors were prepared by repeating the above, and where each charge transport layer was comprised of PCZ-400/TmTBD/T-693, at a ratio of 60/38/2, and with a charge transport layer thickness of from about 16 to about 32 µm.

EXAMPLE VIII

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, 5 weight percent of tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine additive (available as T-693 and obtained from Takasago Chemical Corp., Tokyo, Japan). The charge transport layer of PCZ-400/TmTBD/T-693 ratio was 60/35/5.
A number of photoconductors were prepared by repeating the above, and where each of the charge transport layers were comprised of PCZ-400/TmTBD/T-693, at a ratio of 60/37/3, and with a charge transport layer thickness of from about 16 to about 32 µm.

EXAMPLE IX

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, a tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine additive (available as T-693 and obtained from Takasago Chemical Corp., Tokyo, Japan).
A number of photoconductors were prepared by repeating the above, and where each photoconductor charge transport layer was comprised of PCZ-400/TmTBD/T-693, at a ratio of 60/30/10, and with a charge transport layer thickness of from about 16 to about 32 µm.

EXAMPLE X

A number of photoconductors are prepared by repeating the process of Comparative Example 1 except that there is included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer 10 weight percent of at least one of tris[4-(4,4-dimethylphenyl-1,3-butadienyl)phenyl]amine, [4-(4,4-diphenyl-1,3-butadienyl)phenyl]bis[4-(2,2-diphenylethenyl)phenyl]amine, [4-(2,2-diphenylethenyl) phenyl]bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine, and tris[4-(2,2-diphenylethenyl)phenyl]amine.

CRYSTALLIZATION MEASUREMENTS

As illustrated in Table 3 that follows, the crystallization characteristics for a number of the above prepared photoconductors containing the tris(enylaryl)amine additive in the charge transport layer were excellent, especially for the photoconductors of Example IX.

TABLE 3

TmTBD Crystallization	Comparative Example 1 (TmTBD only)	Example VII (TmTBD/T-693 = 38/2)	Example VIII (TmTBD/T-693 = 35/5)	Example IX (TmTBD/T-693 = 30/10)
A (16 µm)	YES	NO	NO	NO
B (20 µm)	YES	YES	NO	NO
C (24 µm)	YES	YES	NO	NO
D (28 µm)	YES	YES	YES	NO
E (32 µm)	YES	YES	YES	NO

ELECTRICAL PROPERTY TESTING

The results are summarized in Table 4.

TABLE 4

	V (1 erg/cm²) (V)	V (2 ergs/cm²) (V)	V (4 ergs/cm²) (V)
Comparative Example 2 (mTBD Alone)	261	99	80
Example VIII (C) (TmTBD/T-693 = 35/5)	252	47	24
Example IX (C) (TmTBD/T-693 = 30/10)	246	45	23

There is illustrated by the above Table 4 data a number of excellent characteristics, for example, fast or rapid charge transport for the Example VIII (C) and IX (C) photoconductive members as determined by the generation of known PIDC curves. More specifically, V (1 ergs/cm²), V (2 ergs/cm²) and V (4 ergs/cm²) in Table 4 each represents the surface potential of the photoconductor when the exposure was 1, 2, and 4 ergs/cm², and this was used to characterize the PIDC.
Rapid charge transporting photoconductors were obtained with the TmTBD/T-693 charge transport layers (Examples VIII (C) and IX (C)) when compared with the mTBD photoconductor device (Comparative Example 2); and the incorporation of the T-693 tris(butadienylaryl)amine additive in the charge transport layer substantially eliminated the TmTBD crystallization.
Fast transporting refers to fast discharge, for example, 10 to 15V lower in V (1 ergs/cm²), about 50V lower in V (2 ergs/cm²), and about 60V lower in V (4 ergs/cm²) for the Example VIII (C) and IX (C) photoconductive members, when compared with the Comparative Example 2 photoconductive member.

EXAMPLE X

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, 2 weight percent of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine (T-651 available from Takasago Chemical Corp., Tokyo, Japan), and represented by
A number of photoconductors were prepared by repeating the above process, resulting in photoconductors each with a charge transport layer (PCZ-400/TmTBD/T-651 ratio of 60/38/2), and from about 16 to about 32 µm in thickness.

EXAMPLE XI

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, 5 weight percent of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine (T-651 available from Takasago Chemical Corp., Tokyo, Japan), represented by
A number of photoconductors were prepared by repeating the above process, resulting in photoconductors each with a charge transport layer (PCZ-400/TmTBD/T-651 ratio 60/35/5), and from about 16 to about 32 µm in thickness.

EXAMPLE XII

A photoconductive member was prepared by repeating the process of Comparative Example 1 except that there was included in the single tetra-p-tolyl-biphenyl-4,4'-diamine (TmTBD) charge transport layer, 10 weight percent of bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine (T-651 available from Takasago Chemical Corp., Tokyo, Japan), as represented by
A number of photoconductors was prepared by repeating the above process, resulting in photoconductors each with a charge transport layer (PCZ-400/TmTBD/T-651 ratio of 60/30/10), and from about 16 to about 32 µm in thickness.

EXAMPLE XIII

A number of photoconductors are prepared by repeating the process of Comparative Example 1 except that there is included in the single tetra-p-tolyl-biphenyl-4,4'-diamine or TmTBD charge transport layer 10 weight percent of at least one of N,N-bis[4-[4,4-bis(4-methylphenyl)-1,3-butadienyl]phenyl]-4-methoxy phenylamine, [4-(2,2-diphenylethenyl)phenyl][4-(4,4-diphenyl-1,3-butadienyl)phenyl] phenylamine, N,N-bis[4-(2,2-diphenylethenyl)phenyl]-4-methylphenylamine (T-736 available from Takasago Chemical Corp., Tokyo, Japan), and N,N-bis[4-[2,2-bis(4-methylphenyl)ethenyl]phenyl]-4-methylphenylamine (T-925 available from Takasago Chemical Corp., Tokyo, Japan).

CRYSTALLIZATION MEASUREMENTS

As illustrated in Table 5 that follows, the crystallization characteristics for a number of the above prepared photoconductors containing a bis(enylaryl)amine additive in the charge transport layer were excellent, especially for the photoconductors of Example XII.

TABLE 5

TmTBD Crystallization (CTL Thickness)	Comparative Example 1 (TmTBD only)	Example X (TmTBD/T-651 = 38/2)	Example XI (TmTBD/T-651 = 35/5)	Example XII (TmTBD/T-651 = 30/10)
A (16 µm)	YES	NO	NO	NO
B (20 µm)	YES	YES	NO	NO
C (24 µm)	YES	YES	NO	NO
D (28 µm)	YES	YES	YES	NO
E (32 µm)	YES	YES	YES	NO

ELECTRICAL PROPERTY TESTING

The results are summarized in Table 6.

TABLE 6

	V (1 erg/cm²) (V)	V (2 ergs/cm²) (V)	V (4 ergs/cm²) (V)
Comparative Example 2 (mTBD Alone)	261	99	80
Example XI (C) (TmTBD/T-651 = 35/5)	261	55	28
Example XII (C) (TmTBD/T-651 = 30/10)	260	52	26

There is illustrated by the above Table 6 data a number of improved characteristics, for example, fast transport for the Example XI (C) and XII (C) photoconductive members as determined by the generation of known PIDC curves. More specifically, V (1 ergs/cm²), V (2 ergs/cm²), and V (4 ergs/cm²) in Table 6 each represents the surface potential of the photoconductor when exposure is 1, 2 and 4 ergs/cm², and is used to characterize the PIDC.
Rapid charge transporting photoconductors were obtained with the TmTBD/T-651 charge transport layers (Examples XI and XII) as compared to the mTBD photoconductor (Comparable Example 2). The incorporation of the bis[4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine additive into the charge transport layer minimized or eliminated the TmTBD crystallization.
Rapid or fast transporting refers to fast discharge, for example, 44V lower (2 ergs/cm²) and 54V lower (4 ergs/cm²) for the Example XI (C) and XII (C) photoconductive members, as compared to the Comparative Example 2 photoconductive members of 99 and 80, respectively.

Claims

A photoconductor comprising, a photogenerating layer, and at least one charge transport layer wherein at least one of said charge transport layers is comprised of at least one charge transport component, and at least one of a tris(enylaryl)amine and a bis(enylaryl)arylamine.
A photoconductor according to claim 1 wherein said tris(enylaryl)amine and said bis(enylaryl)arylamine are present as a mixture comprised of from 1 to 99 weight percent of said tris(enylaryl)amine, and from 99 to 1 weight percent of said bis(enylaryl)arylamine, and wherein the total thereof is 100 weight percent.
A photoconductor according to any preceding claim, wherein said bis(enylaryl)arylamine is represented by
wherein each R is at least one of hydrogen, alkyl, alkoxy, aryl, and halo; and m and n each independently represents the number of segments.
A photoconductor according to any preceding claim wherein said tris(enylaryl)amine is represented by
wherein each R is at least one of hydrogen, alkyl, alkoxy, aryl, and halo; and m, n, and p each independently represents the number of segments.
A photoconductor according to any preceding claim, wherein said bis(enylaryl)arylamine and said tris(enylaryl)amine are selected from the group consisting of at least one of N,N-bis[4-[4,4-bis(4-methylphenyl)-1,3-butadienyl]phenyl]-4-methoxyphenylamine, [4-(2,2-diphenylethenyl)phenyl][4-(4,4-diphenyl-1,3-butadienyl)phenyl]phenylamine, N,N-bis[4-(2,2-diphenylethenyl)phenyl]-4-methylphenylamine, N,N-bis[4-[2,2-bis(4-methylphenyl)ethenyl]phenyl]-4-methylphenylamine tris[4-(4,4-diphenyl-1,3-butadienyl)phenyl]amine, tris[4-(4,4-dimethylphenyl-1,3-butadienyl) phenyl]amine, [4-(4,4-diphenyl-1,3-butadienyl)phenyl]bis[4-(2,2-diphenylethenyl) phenyl]amine, [4-(2,2-diphenylethenyl)phenyl]bis[4-(4,4-diphenyl-1,3-butadienyl) phenyl]amine, and tris[4-(2,2-diphenylethenyl)phenyl]amine.
A photoconductor according to any preceding claim, wherein said bis(enylaryl)arylamine is represented by at least one of

and
A photoconductor according to any preceding claim, wherein said tris(enylaryl)amine is represented by
A photoconductor according to any preceding claim wherein said charge transport component is comprised of aryl amine molecules, and which aryl amines are encompassed by the following alternative formulas
and
wherein X is selected from the group consisting of alkyl, alkoxy, aryl, and halogen, and mixtures thereof
A photoconductor according to claim 1, wherein said at least one charge transport layer is comprised of at least one charge transport component, and said tris(enylaryl)amine, and wherein at least one charge transport layer is from 1 to 2 layers.
A photoconductor according to any of claim 1, wherein said at least one charge transport layer is comprised of at least one charge transport component, and said bis(enylaryl)arylamine, and wherein at least one charge transport layer is from 1 to 2 layers.
A drum or belt imaging member or device comprising a photoconductor according to any preceding claim.
A method of imaging and printing which comprises forming an electrostatic latent image on the imaging member with the photoconductor according to any of claims 1-10, developing the image with a toner composition, transferring the image to a substrate, and permanently affixing the image thereto.