Abstract: The present invention provides an electrophotographic photoreceptor which has high light resistance, has high durability in exposure to oxidizing gases such as ozone and NOx, is excellent in mechanical properties such as printing durability, wearing resistance, marring resistance, and slip properties in repetitions of use, and further has excellent electrical properties. Specifically, the present invention provides an electrophotographic photoreceptor having an electroconductive substrate and provided thereon at least a photosensitive layer having a charge generation material, a charge transport material, and a binder resin.

Abstract: A method for preparing a coating solution containing a cocrystallized titanyl phthalocyanine-titanyl fluorophthalocyanine, the method comprising: dry milling a charge-generation pigment or mixtures of charge-generation pigments; increasing the amorphousness of the pigment mixture as determined by X-ray crystallography using X-radiation characteristic of Cu K? at a wavelength of 1.

Abstract: An electrophotographic photoconductor including an electroconductive support and a photoconductive layer formed thereon, which contains a phthalocyanine pigment and a disazo pigment of formula (I): wherein A and B are coupler radicals having different structures.

Abstract: An improved organophotoreceptor includes an electrically conductive substrate and a photoconductive element on the electrically conductive substrate where the photoconductive element comprises: a) a charge transport material having the following formula: where X is a linking group; Y1 and Y2 are, each independently, a phenothiazine group, a phenoxazine group, or a phenazine group; R1, R2, R3, and R4 are, each independently, an alkyl group, an alkenyl group, a heterocyclic group, or an aromatic group; and R5 and R6 are, each independently, a hydrogen, an alkyl group, an alkenyl group, a heterocyclic group, or an aromatic group; and (b) a charge generating compound. Corresponding electrophotographic apparatuses and imaging methods are described.

Abstract: A titanyl phthalocyanine crystal having an X-ray diffraction spectrum having a plurality of diffraction peaks in which a maximum diffraction peak is observed at a Bragg (2 ?) angle of 27.2°±0.2° and a diffraction peak is observed at a lowest Bragg (2?) angle of 7.3°±0.2° when a specific X-ray of Cu—K? having a wavelength of 1.514 ? irradiates the titanyl phthalocyanine crystal. A photoreceptor having a photosensitive layer including the titanyl phthalocyanine crystal is also provided.

Abstract: Improved organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising: (a) a charge transport material having the formula where R1, R2, R3, R4, R5, R6, R7, and R8, are, each independently, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; R9 and R10 are, each independently, H, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group; Ar1 and Ar2 are, each independently, an aromatic group; Y is an arylamine group; and X1 and X2 are, each independently, a linking group; and (b) a charge generating compound. Corresponding electrophotographic apparatuses and imaging methods are described.

Abstract: The invention is to provide an organic photoconductive material capable of realizing electrophotographic photoreceptors of high reliability that have high charge potential, high sensitivity, good responsiveness to light and good durability, of which the characteristics do not lower even when they are driven at low temperatures or at high speed and even when they are exposed to light, and to provide an electrophotographic photoreceptor that comprises the material and an image-forming apparatus. An organic photoconductive material of the following general formula (1), for example, an enamine compound of the following structural formula (1-1) is produced.

Abstract: An electrophotographic photoconductor contains a conductive support; and a photoconductive layer disposed on the photoconductive support; wherein the photoconductive layer contains an azo compound expressed by a general formula <<1>> ArN?N—Cp)n,??(<<1>>) wherein in the general formula <<1>>, Ar is a substituted or non-substituted aromatic series hydrocarbon group or an aromatic series heterocyclic ring group which can be bonded by way of a bonding group; Cp is a coupler residual group; n represents an integer of 1, 2, 3, or 4, at least one of the Cp is a coupler residual group selected from the group consisting of general formulae <<2>>, <<3>>, and <<4>> wherein in the general formulae <<2>>, <<3>>, and <<4>>, all substituents are as defined in the specification.

Abstract: An electrophotographic photoreceptor comprising a support and a photosensitive layer is disclosed. The photosensitive layer contains a mixture of compounds represented by Formula (1) having different n and (Rp+Rs) is not more than 99%, wherein Rp is a ratio of a component having the maximum content in the mixture and Rs is a ratio of a component having the content next to the maximum content in percent. X—(CTM-group)n—Y??(1) In the formula, CTM-group is a charge transfer group; X and Y are each a hydrogen atom, a halogen atom or a mono-valent organic group; and n is an integer of from 0 to 10, provided that n is an integer of from 1 to 10 when both X and Y are hydrogen atom or a halogen atom. A processing cartridge comprising the electrophotographic photoreceptor is also disclosed.

Abstract: Improved organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising: (a) a charge transport material having the formula ?where R1 and R2 are, each independently, an alkyl group, an alkenyl group, an alkynyl group, an aromatic group, or a heterocyclic group; R3 and R4 are, each independently, H, an alkyl group, an alkenyl group, an alkynyl group, an aromatic group, or a heterocyclic group; X1 and X2 are, each independently, a linking group; Y1 and Y2, each independently, comprise an arylamine group; and Z is a bridging group; and (b) a charge generating compound. Corresponding electrophotographic apparatuses and imaging methods are described.

Abstract: The present invention provides an organic electrophotographic photo-receptor having a conductive substrate and a photosensitive layer laid on the conductive substrate, wherein the photosensitive layer contains at least one ?-oxo bridged heterometal compound as a charge generating material. The organic electrophotographic photo-receptor has high photo-sensitivity, high stability, excellent durability on sensitivity and on electric potential, and has excellent organic photo-conductive property.

Abstract: Naphthalenetetracarboxylic acid diimide derivatives include a structure represented by the following formula: in which, R1, R2, and R3 are each independently any one selected from the group consisting of hydrogen; halogen; substituted or unsubstituted alkyl of C1 to C20; substituted or unsubstituted alkoxy of C1 to C20; substituted or unsubstituted aryl of C6 to C30; and substituted or unsubstituted aralkyl of C7 to C30. An electrophotographic photoconductive material includes the naphthalenetetracarboxylic acid diimide derivatives as an electron transferring material.

Abstract: Improved organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising: (a) a charge transport material having the formula where R1, R2, R3, and R4 are, independently, H, an alkyl group, an alkaryl group, or an aryl group; X1 and X2 are, independently, a linking group having the formula —(CH2)m—, branched or linear, where m is an integer between 1 and 20, inclusive, and one or more of the methylene groups is optionally replaced by O, S, C?O, O?S?O, a heterocyclic group, an aromatic group, urethane, urea, an ester group, a NR5 group, a CHR6 group, or a CR7R8 group where R4, R5, R6, and R7 are, independently, H, hydroxyl group, thiol group, an alkyl group, an alkaryl group, a heterocyclic group, or an aryl group; and Y1, Y2, and Y3 are, independently, an arylamine group; and (b) a charge generating compound.

Abstract: Improved organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising: (a) a charge transport material having the formula where n is an integer between 3 and 6; R1 and R2 are, each independently, H, an alkyl group, an alkenyl group, an aromatic group, or a heterocyclic group; R3, R4, and R5 are, each independently, H, thiol, hydroxyl, carboxyl, an amino group, a halogen, nitro, cyano, an alkyl group, an alkenyl group, an aromatic group, a heterocyclic group, or a part of a ring group; X1 and X2 are, each independently, a linking group; Y comprises an arylamine group; and Z is a bridging group; and (b) a charge generating compound. Corresponding electrophotographic apparatuses and imaging methods are described.

Abstract: The present invention provides an electrophotosensitive material which realizes uniform dispersion of phthalocyanines in a photosensitive layer and has high sensitivity to a digital light source, and also excellent in charge stability under the high temperature atmosphere, weatherability and NOx resistance.

Abstract: A single layered electrophotographic photoreceptor includes a photosensitive layer having having at least a charge generating material, a charge transport material and a binder on a conductive support, wherein the charge generating material is amorphous titanylphthalocyanine, and the photosensitive layer is a hindered phenol compound and/or hindered amine compound.

Abstract: An organic optoelectronic device includes a solution coatable thin film having a hole transporting material, an electron transporting material, and a photogenerating component uniformly dispersed therein. The thin film is about 0.2 microns or less, and can be spin-coated onto a substrate and further coated with electrodes.

Abstract: A photoconductive imaging member comprised of a supporting substrate, and thereover a single photoactive layer comprised of a mixture of a photogenerator component, an electron transport component, a transport component, and a polymeric binder; and wherein said photogenerating component is comprised of a mixture of a metal free phthalocyanine and a hydroxygallium phthalocyanine.

Abstract: An amorphous mixture consisting essentially of TiOFPc and TiOPc and containing more than 75 weight percent of substantially chlorine-free TiOPc is produced by forming a mixture of crude crystalline TiOFPc and crude crystalline, substantially chlorine-free TiOPc that contains less than 80 weight percent TiOPc, treating the mixture under conditions effective to form a substantially amorphous mixture of TiOFPc and TiOPc containing less than 75 weight percent TiOPc, which is then treated with water, and dried. A further amount of crude crystalline, substantially chlorine-free TiOPc sufficient to form a new mixture containing more than 75 weight percent of substantially chlorine-free TiOPc is added, and the new mixture is converted to a substantially amorphous mixture of TiOFPc and TiOPc. A nanoparticulate cocrystalline composition is obtained by forming a slurry in an organic solvent of the dried substantially amorphous mixture, and wet milling the slurry to form the cocrystalline composition.

Abstract: An electrophotographic image forming apparatus comprising: an electrophotographic photoreceptor comprising: an electroconductive substrate; a charge generation layer; and a charge transport layer in this order, a charger; an irradiator; an image developer; and a transferer applying an electric current not less than 65 ?A to the electrophotographic photoreceptor, wherein the charge generation layer comprises titanylphthalocyanine crystals having a CuK? 1.542 ? X-ray diffraction spectrum having plural diffraction peaks, wherein a maximum diffraction peak is observed at a Bragg (2 ?) angle of 27.2°; main peaks are observed at 9.4°, 9.6° and 24.0°; and a minimum diffraction peak is observed at 7.3°; and no diffraction peak is observed at an angle greater than 7.3° and less than 9.4°, wherein said angles may vary by ±0.2° and the minimum interval where no peak is observed between required peaks at 7.3 and 9.4 is 2.0 degrees absolute or more.

Abstract: In a process for forming an amorphous TiOPc/TiOFPc pigment mixture containing a low concentration of TiOFPc, a mixture containing phthalonitrile and titanium tetrachloride is subjected to reaction conditions effective to form lightly chlorine-substituted crude crystalline Cl—TiOPc. The lightly chlorine-substituted crude crystalline Cl—TiOPc is combined with crude crystalline TiOFPc in a weight ratio from about 75:25 Cl—TiOPc:TiOFPc to about 99.5:0.5 Cl—TiOPc:TiOFPC to form a crude crystalline pigment mixture, which is treated under conditions effective to form a substantially amorphous pigment mixture of Cl—TiOPc and TiOFPc. The substantially amorphous mixture can subsequently be converted to a nanocrystalline Cl—TiOPc/TiOFPc pigment composition containing a low concentration of TiOFPc.

Abstract: An electrophotographic article having a complex of charge generating material and at least one transfer material selected from the group consisting of electron transfer material and hole transfer material is formed by admixing the charge generating material, at least one transfer material, and an organic binder in a solvent to form a coatable dispersion comprising a complex of charge generating material and said at least one transfer material; and coating said coatable dispersion onto a conductive substrate to form a charge transfer layer on the electrophotoconductive article. A novel S-form titanyl oxyphthalocyanine is also preferred, the novel form displaying major peaks of Bragg's 2theta angle to the CuK-alpha characteristic X-ray (wavelength 1.541 Angstrom) at least at 9.5±0.2 degrees, 9.7±0.2 degrees, 11.7±0.2 degrees, 13.5±0.2 degrees, (optionally at 21±0.2 degrees and/or 23.5±0.2 degrees,) 24.1±0.2 degrees, 26.4±0.2 degrees, and 27.3±0.2 degrees group.

Abstract: In a process for forming a self-dispersing crystalline phthalocyanine pigment composition of monodisperse nanoparticles, a mixture containing titanyl fluorophthalocyanines, unsubstituted titanyl phthalocyanine, and an organic monomeric dispersant but substantially free of organic solvents or inorganic salts is dry milled, thereby forming a substantially amorphous phthalocyanine pigment composition. The substantially amorphous composition is contacted with an organic solvent having a hydrogen bonding parameter gammac lower than about 8, thereby forming a self-dispersing cocrystalline phthalocyanine pigment composition of monodisperse nanoparticles containing titanyl fluorophthalocyanines and titanyl phthalocyanine, which can be used to form the charge generation layer of an electrophotographic element.

Abstract: This invention relates to a novel organophotoreceptor that includes a photoconductive layer having a) a novel charge transport compound having the formula ?where R1 is a carbazole group, a julolidine group, or a p-(N,N-disubstituted)arylamine, R2, R3, R4, R5 and R6 are, independently, an alkyl group or an aryl group, R7 and R8 are, independently, hydrogen, an alkyl group, or an aryl group, X is oxygen, sulfur, or a NR? group where R? is hydrogen, an alkyl, or an aryl group, and Y is a trivalent aryl group; (b) a charge generating compound; and wherein the at least one photoconductive layer is carried on an electrically conductive substrate.

Abstract: An electrophotographic photoconductor includes a photosensitive layer on a conductive substrate. The photosensitive layer contains a pigment that consists of crystallites composed of molecules having a titanylphthalocyanine structure, wherein a crystallite diameter of the pigment is not smaller than 20 nm and a primary particle diameter of the pigment is not larger than 500 nm.

Abstract: An electrophotographic photoconductor including an electroconductive support and a photoconductive layer formed thereon, which contains a phthalocyanine pigment and a disazo pigment of formula (I): wherein A and B are coupler radicals having different structures.

Abstract: A photoconductive imaging member containers of a supporting substrate, and thereover a single layer comprised of a mixture of a photogenerator component, a charge transport component, an electron transport component, and a polymer binder, and wherein the photogenerating component is a pigment.

Abstract: Improved organophotoreceptors have: (a) a charge transport compound having the formula where R1 and R2 are, independently, an (N,N-disubstituted) arylamine group, such as a julolidine group, a triphenyl amine group, or an N-substituted carbazole group; R3 and R4 are, independently, an alkylsulfonylphenyl group; and X is a linking group having the formula —(CH2)m—, branched or linear, where m is an integer between 0 and 20, inclusive, and one or more of the methylene groups is optionally replaced by an oxygen atom, a carbonyl group, urethane, urea, an ester group, a —NR5 group, a CHR6 group, or a CR7R8 group where R5, R6, R7, and R8 are, independently, H, an alkyl group, or aryl group; (b) a charge generating compound; and (c) an electrically conductive substrate over which the charge transport compound and the charge generating compound are located.

Abstract: The subject application provides for a composition crystal comprising a phthalocyanine compound and an asymmetric phthalocyanine wherein a part of benzene ring in phthalocyanine structure is substituted with naphthalene ring, pyridine or pyrazine ring, is stable against crystal transfer such as agglomeration, precipitation, crystal growth, crystal habit transfer and crystal electric potential, and has good electric properties such as good sensitivity. When this composition crystal is used as a charge generation material in an electrophotographic receptor, the electrophotographic photoreceptor shows good sensitivity and good image quality without noise.

Abstract: Providing an electrophotographic photoconductor comprising a conductive support and a photoconductive layer disposed on the photoconductive support; wherein the photoconductive layer contains an azo compound expressed by a general formula <<1>>. Ar?N?N—Cp)n??general formula <<1>> (in the general formula <<1>>, Ar expresses one of a substituted or non-substituted aromatic carbon hydride group and heterocyclic ring aromatic series group which can be combined by way of a bond group; Cp expresses a coupler residual group; n expresses an integer of one of 1, 2, 3, and 4; at least one of the Cp is a coupler residual group selected from one of the following general formulae <<2>>, <<3>>, and <<4>>.

Abstract: An electrophotographic photosensitive member having a sensitivity to a short semiconductor laser light in a wavelength range of 380-500 nm is provided by incorporating a specific porphyrin compound in a photosensitive layer. The porphyrin compound is characterized by having a heterocyclic substituent, preferably 4 heterocyclic substituents each of a pyridyl group. The porphyrin compound includes a 5,10,15,20-tetrapyridyl-21H,23H-porphyrinato-zinc compound having a novel crystal form characterized by certain peaks in a CuK&agr;-characteristic X-ray diffraction pattern.

Abstract: An improved organophotoreceptor includes an electrically conductive substrate and a photoconductive element on the electrically conductive substrate where the photoconductive element comprises:

Abstract: An electrophotographic photoconductor including an electroconductive support and a photoconductive layer formed thereon, which contains a phthalocyanine pigment and a disazo pigment of formula (I): 1

Abstract: Perylene-3,4:9,10-tetracarboxylic diimides of the general formula I where R1, R2, R3 and R4 are independently hydrogen, chlorine, bromine or substituted or unsubstituted aryloxy, arylthio, arylamino, hetaryloxy or hetarylthio; R5, R6, R7, R8, R9 and R10 are independently hydrogen or long-chain alkyl, alkoxy or alkylthio whose carbon chain may in each case contain up to four double bonds, with the proviso that at least four of these radicals are not hydrogen are prepared and used as liquid-crystalline materials for electronic, optoelectronic and photonic applications, for coloration of macromolecular organic and of inorganic materials, as fluorescent dyes and as laser dyes and also as organic materials for solar collectors and electroluminescence applications.

Abstract: An electrophotographic photoreceptor containing a charge generation material composition comprising a sandwich-type metal bisphthalocyanine compound represented by the general formula (I), having a primary particle diameter of 1 micron or less, and a phthalocyanine-based charge generation material represented by the general formula (II): Pc═M1═Pc  (I) M2═Pc  (II) wherein Pc is a phthalocyanine residue of the general formula (III); R1˜R16 are each a hydrogen atom, a halogen atom, a nitro group, an alkyl group or an alkoxy group; and M1 and M2 each represent hydrogen or metal atom bonded to the center of a phthalocyanine residue, M1 being an atom selected from the group consisting of Ti, Zr, Sn, Ge and lanthanides, and M2 being an atom selected from the group consisting of hydrogen (H2), Cu and Al, and Ti, V, Zr, Ge, Ga and In to which oxygen, halogen atom, hydroxyl group or the like is bonded.

Abstract: The invention provides an image forming apparatus comprising: an electrophotographic photoreceptor having a conductive substrate and a photosensitive layer provided on the conductive substrate; a charging unit for charging the electrophotographic photoreceptor; an exposure unit for exposing the charged electrophotographic photoreceptor to light thereby forming an electrostatic latent image; a developing unit for developing the electrostatic latent image with toner thereby forming a toner image; and a transfer unit for transferring the toner image from the electrophotographic photoreceptor to a transferred image-receiving medium, wherein said exposure unit is a multi beam exposure unit which has a surface emitting laser array and which carries out the electrostatic latent image formation by scanning the electrophotographic photoreceptor with eight or more light beams; and wherein said electrophotographic photoreceptor gives a quantum efficiency of 0.

Abstract: In a process for forming a self-dispersing crystalline phthalocyanine pigment composition of monodisperse nanoparticles, a mixture containing titanyl fluorophthalocyanines, unsubstituted titanyl phthalocyanine, and an organic monomeric dispersant but substantially free of organic solvents or inorganic salts is dry milled, thereby forming a substantially amorphous phthalocyanine pigment composition. The substantially amorphous composition is contacted with an organic solvent having a hydrogen bonding parameter gammac lower than about 8, thereby forming a self-dispersing cocrystalline phthalocyanine pigment composition of monodisperse nanoparticles containing titanyl fluorophthalocyanines and titanyl phthalocyanine, which can be used to form the charge generation layer of an electrophotographic element.

Abstract: An electrophotographic article having a complex of charge generating material and at least one transfer material selected from the group consisting of electron transfer material and hole transfer material is formed by admixing the charge generating material, at least one transfer material, and an organic binder in a solvent to form a coatable dispersion comprising a complex of charge generating material and said at least one transfer material; and coating said coatable dispersion onto a conductive substrate to form a charge transfer layer on the electrophotoconductive article. A novel S-form titanyl oxyphthalocyanine is also preferred, the novel form displaying major peaks of Bragg's 2theta angle to the CuK-alpha characteristic X-ray (wavelength 1.541 Angstrom) at least at 9.5±0.2 degrees, 9.7±0.2 degrees, 11.7±0.2 degrees, 13.5±0.2 degrees, (optionally at 21±0.2 degrees and/or 23.5±0.2 degrees,) 24.1±0.2 degrees, 26.4±0.2 degrees, and 27.3±0.

Abstract: A photoconductive imaging member comprised of a supporting substrate, and thereover a single photoactive layer comprised of a mixture of a photogenerator component, an electron transport component, a transport component, and a polymeric binder; and wherein said photogenerating component is comprised of a mixture of a metal free phthalocyanine and a hydroxygallium phthalocyanine.

Abstract: The present invention provides an organic electrophotographic photo-receptor having a conductive substrate and a photosensitive layer laid on the conductive substrate, wherein the photosensitive layer contains at least one &mgr;-oxo bridged heterometal compound as a charge generating material. The organic electrophotographic photo-receptor has high photo-sensitivity, high stability, excellent durability on sensitivity and on electric potential, and has excellent organic photo-conductive property.

Abstract: Organophotoreceptors comprise an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising: a) a charge transport compound having the formula where R1 and R2 are, independently, hydrogen, an alkyl group, a heterocyclic group, an alkaryl group or an aryl group; X is an aromatic group; Y is an (N,N-disubstituted) arylamine group, such as a (N,N-disubstituted) arylamine group, a carbazole group or a julolidine group; Z is (CH2)m group where m is an integer between 1 and 30 where one or more of the methylene groups is optionally replaced by O, S, C═O, O═C—O, O═C—NR3, sulfoxide, sulfate, phosphate, an aryl group, urethane, urea, a NR4 group, a CHR5 group, or a CR6R7 group where R3, R4, R5, R6, and R7 are, independently, H, hydroxyl, thiol, an amine group, an alkyl group, a heterocyclic group, an alkaryl group, or an aryl group; and E is an epoxy group; and (b) a charge generating co

Abstract: An electrophotographic photosensitive member exhibiting a high sensitivity and a potential stability on repetitive use and capable of suppressing image defects, such as black spots in a reversal development scheme, is provided. The photosensitive member includes a support, and a phthalocyanine layer formed on the support and a novel phthalocyanine crystal, which comprises a phthalocyanine compound and a substituted or unsubstituted condensed polycyclic hydrocarbon compound.

Abstract: An organic optoelectronic device includes a solution coatable thin film having a hole transporting material, an electron transporting material, and a photogenerating component uniformly dispersed therein. The thin film is about 0.2 microns or less, and can be spin-coated onto a substrate and further coated with electrodes.

Abstract: An electrophotographic image forming apparatus comprising:

Abstract: A member including for example, a supporting layer and a single photogenerating layer, the photogenerating layer comprising particles including hydroxygallium phthalocyanine phthalocyanine Type V, x polymorph metal free phthalocyanine, or chlorogallium phthalocyanine dispersed in a matrix comprising an arylamine hole transporter and an electron transporter selected from the group consisting of N,N′bis(1,2-dimethylpropyl)-1,4,5,8-naphthalenetetracarboxylic diimide, 1,1′-dioxo-2-(4-methylphenyl)-6-phenyl-4-(dicyanomethylidene)thiopyran, and a quinone selected from the group consisting of carboxybenzylhaphthaquinone, and tetra (t-butyl) diphenoquinone, and mixtures thereof, and a film forming binder.

Abstract: A single layered electrophotographic photoreceptor includes a photosensitive layer having having at least a charge generating material, a charge transport material and a binder on a conductive support, wherein the charge generating material is amorphous titanylphthalocyanine, and the photosensitive layer is a hindered phenol compound and/or hindered amine compound.

Abstract: An electrophotography photosensitive body has a single layer photosensitive layer on top of a conductive substrate, directly or via an undercoat layer. The single layer photosensitive layer contains at least a resin binder, a charge generating substance, and a charge transport substance, wherein at least one of the charge generating substances is a titanyl phthalocyanine, which, in a x-ray powder diffraction spectrum having a radiation source of CuK &agr; and within a range of a Bragg angle 2&thgr;=5˜35°, a ratio, R, of a value, P, of a diffraction intensity of a highest peak and a value, B, of a diffraction intensity of the background satisfies the equation R=(P−B)/B≦7.0. The resulting electrophotographic photosensitive layer shows excellent electrical properties with positive charging as well as excellent stability when repeatedly used.

Abstract: In a process for forming an amorphous TiOPc/TiOFPc pigment mixture containing a low concentration of TiOFPc, a mixture containing phthalonitrile and titanium tetrachloride is subjected to reaction conditions effective to form lightly chlorine-substituted crude crystalline Cl—TiOPc. The lightly chlorine-substituted crude crystalline Cl—TiOPc is combined with crude crystalline TiOFPc in a weight ratio from about 75:25 Cl—TiOPc:TiOFPc to about 99.5:0.5 Cl—TiOPc:TiOFPC to form a crude crystalline pigment mixture, which is treated under conditions effective to form a substantially amorphous pigment mixture of Cl—TiOPc and TiOFPc. The substantially amorphous mixture can subsequently be converted to a nanocrystalline Cl—TiOPc/TiOFPc pigment composition containing a low concentration of TiOFPc.

Abstract: In a process for forming an amorphous pigment mixture consisting essentially of TiOPc and TiOFPc and containing more than about 75 weight percent of TiOPc, a mixture of crude crystalline TiOPc and TiOFPc pigments in a weight ratio of at least 75:25 TiOPc:TiOFPc is combined with at least about 5 wt. %, based on the total weight of TiOPc and TiOFPc, of an organic milling aid. The mixture is treated under conditions effective to form a substantially amorphous pigment mixture of TiOPc and TiOFPc. The organic milling aid can be separated from the substantially amorphous pigment mixture, which can be converted to a nanoparticulate cocrystalline TiOPc/TiOFPc composition.

Abstract: An amorphous mixture consisting essentially of TiOFPc and TiOPc and containing more than 75 weight percent of substantially chlorine-free TiOPc is produced by forming a mixture of crude crystalline TiOFPc and crude crystalline, substantially chlorine-free TiOPc that contains less than 80 weight percent TiOPc, treating the mixture under conditions effective to form a substantially amorphous mixture of TiOFPc and TiOPc containing less than 75 weight percent TiOPc, which is then treated with water, and dried. A further amount of crude crystalline, substantially chlorine-free TiOPc sufficient to form a new mixture containing more than 75 weight percent of substantially chlorine-free TiOPc is added, and the new mixture is converted to a substantially amorphous mixture of TiOFPc and TiOPc. A nanoparticulate cocrystalline composition is obtained by forming a slurry in an organic solvent of the dried substantially amorphous mixture, and wet milling the slurry to form the cocrystalline composition.