Abstract: An ammonia-modified titanyl phthalocyanine for use in preparing charge generating layer of a photoreceptor is disclosed. The ammonia-modified titanyl phthalocyanine is obtained by a process comprising the following steps: (a) reacting titanium tetrachloride with halogen-containing naphthalene to obtain an unmodified titanyl phthalocyanine; (b) dispersing the unmodified titanyl phthalocyanine in an organic solvent; and (c) subjecting the unmodified titanyl phthalocyanine to an ammonia-induced complexation-mediated crystal transformation so as to obtain the ammonia-modified titanyl phthalocyanine. The ammonia-induced complexation-mediated crystal transformation step can be achieved by either bubbling ammonia gas through the titanyl phthalocyanine-containing organic solution or by adding an ammonia-saturated aqueous solution to the titanyl phthalocyanine-containing organic solution. The ammonia-modified titanyl phthalocyanine is characterized by having Bragg diffraction angles of 7.5, 9.3, 13.6, 14.3, 17.9, 24.

Abstract: A process for the preparation of hydroxygallium phthalocyanines which comprises hydrolyzing a gallium phthalocyanine precursor pigment by dissolving said hydroxygallium phthalocyanine in a strong acid and then reprecipitating the resulting dissolved pigment in basic aqueous media; removing any ionic species formed by washing with water, concentrating the resulting aqueous slurry comprised of water and hydroxygallium phthalocyanine to a wet cake; removing water from said slurry by azeotropic distillation with an organic solvent, and subjecting said resulting pigment slurry to mixing with the addition of a second solvent to cause the formation of said hydroxygallium phthalocyanine polymorphs.

Abstract: A method for preparing hydroxygallium phthalocyanine crystals wherein hydroxygallium phthalocyanine crystals having distinct diffraction peaks at 7.0.degree., 13.4.degree., 16.6.degree., 26.0.degree. and 26.7.degree. of the Bragg angle (2.theta..+-.0.2.degree.) with respect to CuK.alpha. characteristics X-ray in the X-ray diffraction spectrum are crystal-transferred by solvent treatment. The crystals after crystal-transfer have distinct diffraction peaks at (i) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree., (ii) 7.9.degree., 16.5.degree., 24.4.degree. and 27.6.degree., (iii) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 18.1.degree., 24.5.degree., 26.2.degree. and 27.1, (iv) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.8.degree. or (v) 6.8.degree., 12.8.degree., 15.8.degree. and 26.0.degree. of the Bragg angle (2.theta..+-.0.2.degree. C.) with respect to CuK.alpha. characteristics X-ray in the X-ray diffraction spectrum.

Abstract: This invention relates to a process for preparing alpha-phase metal phthalocyanine pigments from crude metal phthalocyanine pigments comprising(a) acid pasting or acid swelling a crude metal phthalocyanine pigment;(b) dry milling the acid-pasted or acid-swelled metal phthalocyanine pigment in the presence of 5 to 50 parts by weight of a stabilizer per 100 parts by weight of the crude metal phthalocyanine pigment until the average particle size is reduced to less than about 0.5 .mu.m;(c) finishing the milled metal phthalocyanine pigment by thoroughly mixing said milled metal phthalocyanine pigment with a finishing solvent mixture comprising 3 to 6 parts by weight, relative to the crude metal phthalocyanine pigment, of water and 0.4 to 1.

Abstract: The present invention relates to a process for producing a crystalline I-type oxytitanium phthalocyanine having strong peaks in CuK.alpha. characteristic X-ray diffraction at Bragg angles (2.theta..+-.0.2.degree.) of 9.0.degree., 14.2.degree., 23.9.degree., and 27.1.degree., comprising milling-treatment of oxytitanium phthalocyanine or an aqueous paste thereof with a solvent containing a saturated hydrocarbon solvent.

Abstract: An electrophotographic imaging member is characterized by a halogenindium phthalocyanine produced by dry milling and treating with an organic amine solvent.

Abstract: A process for the preparation of Type V hydroxygallium phthalocyanine which comprises the in situ formation of an alkoxy-bridged gallium phthalocyanine dimer, hydrolyzing said alkoxy-bridged gallium phthalocyanine dimer to hydroxygallium phthalocyanine, and subsequently converting the hydroxygallium phthalocyanine product obtained to Type V hydroxygallium phthalocyanine.

Abstract: A process for preparing a titanyl phthalocyanine crystal showing at least one diffraction peak at a Bragg angle (2.theta..+-.0.2) of 27.3.degree. is disclosed, which comprises dissolving or suspending titanyl phthalocyanine in concentrated sulfuric acid to form a solution or a slurry and diluting the solution or slurry with an alcohol solvent, an aromatic solvent, a mixed solvent of an alcohol solvent and water, a mixed solvent of an aromatic solvent and water, or a mixed solvent of an alcohol solvent and an aromatic solvent with or without water thereby to precipitate a crystal, and, if desired, treating the precipitated crystal with an alcohol solvent, an aromatic solvent, a mixed solvent of an alcohol solvent and an aromatic solvent or a mixed solvent of an alcohol solvent and/or an aromatic solvent and water. The resulting titanyl phthalocyanine crystal exhibits high photosensitivity and excellent durability as a photoconductive material of an electrophotographic photoreceptor.

Abstract: Naphthalocyanines of the general formula I ##STR1## where the variables have the following meanings: R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are each independently of the others hydrogen, hydroxyl or C.sub.1 -C.sub.20 -alkyl or C.sub.1 -C.sub.20 -alkoxy, whose carbon chains may each be interrupted by from 1 to 4 oxygen atoms in ether function and which may be phenyl-substituted,R.sup.9, R.sup.10, R.sup.11 and R.sup.12 are each independently of the others hydrogen, halogen or C.sub.1 -C.sub.20 -alkyl or C.sub.1 -C.sub.20 -alkoxy, whose carbon chains may each be interrupted by from 1 to 4 oxygen atoms in ether function,Me is two hydrogen atoms, two univalent metal atoms or a bivalent metal atom with or without further substituents for valence saturation,are pigments with isometric particles and a particle size distribution from 10 to 300 nm.

Abstract: Gallium phthalocyanine halide crystals wherein a part of the crystals are changed into hydroxygallium phthalocyanine is disclosed. A method for preparing gallium phthalocyanine halide crystals wherein gallium phthalocyanine halide crystals are brought into contact with water and a part of the crystals are changed into hydroxygallium phthalocyanine is also disclosed. An electrophotographic photoreceptor formed by laminating at least a charge generating layer and a charge transporting layer successively on a conductive support wherein the charge generating layer contains gallium phthalocyanine halide crystals An which a part of the crystals are changed into hydroxygallium phthalocyanine is also disclosed.

Abstract: A hydroxygallium phthalocyanine crystal, having distinct diffraction peaks at Bragg angles (2.theta.+/-0.2.degree.) of 7.0.degree., 13.4.degree., 16.6.degree., 26.0.degree. and 26.7.degree. to CuK.alpha. characteristic X-ray-in X-ray diffraction spectrum; a process for preparing the hydroxygallium phthalocyanine crystal; and a electrophotographic photoreceptor comprising the hydroxygallium phthalocyanine crystal.

Abstract: Disclosed are a phthalocyanine composition which comprises having main diffraction peaks at 7.5.degree., 22.5.degree., 24.3.degree., 25.3.degree. and 28.6.degree. of Bragg angles (2.theta..+-.0.2.degree.) in an X-ray diffraction spectrum with Cu K.alpha., a process for preparing the same, an electrophotographic photoreceptor using the same and a coating solution for a charge generation layer containing the same.

Abstract: A process for the preparation of hydroxygallium phthalocyanines which comprises hydrolyzing a gallium phthalocyanine precursor pigment by dissolving said hydroxygallium phthalocyanine in a strong acid and then reprecipitating the resulting dissolved pigment in basic aqueous media; removing any ionic species formed by washing with water, concentrating the resulting aqueous slurry comprised of water and hydroxygallium phthalocyanine to a wet cake; removing water from said slurry by azeotropic distillation with an organic solvent, and subjecting said resulting pigment slurry to mixing with the addition of a second solvent to cause the formation of said hydroxygallium phthalocyanine polymorphs.

Abstract: A halogen-containing hydroxygallium phthalocyanine crystal showing intense diffraction peaks at Bragg angles (2.theta..degree..+-.0.2.degree.) of (1) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree.; (2) 7.9.degree., 16.5.degree., 24.4.degree., and 27.6.degree.; (3) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 18.1.degree., 24.5.degree., 26.2.degree., and 27.1.degree.; 4) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree., and 28.3.degree.; or (5) 6.8.degree., 12.8.degree., 15.8.degree., and 26.0.degree. and an electrophotographic photoreceptor containing the halogen-containing hydroxygallium phthalocyanine crystal as a charge generating material are disclosed.

Abstract: A process for the preparation of hydroxygallium phthalocyanine which comprises hydrolysis of halogallium phthalocyanine precursor to a hydroxygallium phthalocyanine, and conversion of said resulting hydroxygallium phthalocyanine to Type V hydroxygallium phthalocyanine by contacting said resulting hydroxygallium phthalocyanine with an organic solvent; and wherein said precursor halogallium phthalocyanine is obtained by the reaction of gallium halide with diiminoisoindolene in an organic solvent.

Abstract: A novel dichlorotin phthalocyanine crystal having distinct diffraction peaks at 8.5.degree., 11.2.degree., 14.5.degree., and 27.2.degree. of the Bragg angles (2.theta..+-.0.2) in the X-ray diffraction spectrum; a process for producing the dichlorotin phthalocyanine crystal, comprising mechanically grinding a known dichlorotin phthalocyanine crystal together with an inorganic salt, followed by, if desired, a solvent treatment; an electrophotographic photoreceptor containing, in the photosensitive layer thereof, the dichlorotin phthalocyanine crystal; and a coating composition for producing an electrophotographic photoreceptor, comprising the dichlorotin phthalocyanine crystal, a binder resin, and an acetic ester solvent. The photoreceptor exhibits high sensitivity and excellent durability. The coating composition maintains the dichlorotin phthalocyanine crystal in its desired form either while being prepared or after being coated.

Abstract: A process for preparing chlorogallium phthalocyanine comprising the steps of: reacting gallium trichloride and phthalonitrile or diiminoisoindoline in an aromatic hydrocarbon solvent; and treating the resulting chlorogallium phthalocyanine with a second solvent different from the aromatic hydrocarbon solvent.

Abstract: The present invention provides a process for producing beta-form pigmentary copper phthalocyanine comprising a) producing crude copper phthalocyanine by charging phthalic anhydride or phthalimide, urea, a copper compound and a catalyst, at a substantially continuous and uniform rate, into a reaction chamber containing dry, granular, pre-formed copper phthalocyanine, and removing the reaction product from the reaction chamber; and b) convening the crude copper phthalocyanine produced in step a) into pigmentary form, by milling it either in the dry state or in an aqueous medium; mixing the milled material with an aqueous emulsion comprising i) a liquid C.sub.6 -C.sub.20 amine which is insoluble in water or alkali but is soluble in acid and ii) a surfactant capable of emulsifying the liquid amine; rendering the resulting mixture acidic to thereby dissolve the amine; and finally separating the desired pigmentary copper phthalocyanine from the treatment mixture.

Abstract: A novel titanyl phthalocyanine crystal, a photoconductive material comprising the same, and an electrophotographic photoreceptor using the same are disclosed. The titanyl phthalocyanine crystal has a primary particle diameter ranging from 0.03 to 0.15 .mu.m, shows a maximum X-ray diffraction peak at a Bragg angle (2.theta..+-.0.2.degree.) of 27.3.degree., has a ellipsoidal tabular form, and has a BET specific surface area of not less than 35 m.sup.2 /g. The crystal has improved crystal form stability against solvents and holds its crystal form for an extended period of time in a dispersed and coated state. An electrophotographic photoreceptor using the crystal as a photoconductive material is excellent in sensitivity, stability, and durability.

Abstract: A process for producing crystalline oxytitanium phthalocyanine showing strong peaks in CuK.alpha. characteristic X-ray diffraction at Bragg angles 2.theta..+-.0.2.degree. of 9.0.degree., 14.2.degree., 23.9.degree., and 27.1.degree., which comprises a dispersion treatment of the aqueous paste of oxytitanium phthalocyanine in an ether type compound.

Abstract: A process for the production of a copper phthalocyanine pigment composition from 70 to 99% by weight of a crude copper phthalocyanine and 30 to 1% by weight of a phthalocyanine derivative,the crude copper phthalocyanine being converted to a pigment without a large amount of energy and the treatment of exhaust water,the copper phthalocyanine pigment composition having excellent fluidity, tinting strength and stability with time when used in a coating composition or a printing ink,the copper phthalocyanine pigment composition showing almost no "strike-through" when used for gravure printing on low-quality paper,the process comprising dry milling the entirety of the crude copper phthalocyanine and the phthalocyanine derivative in an amount of 0.5 to 10% by weight of a final composition in the absence of a milling auxiliary until the content of an .alpha.

Abstract: A layered photoconductive imaging member comprised of a supporting substrate, a photogenerating layer and a charge transport layer, and wherein the photogenerating layer contains Type IV oxytitanium phthalocyanine obtained by a process which comprises the hydrolysis of a dihalotitanium phthalocyanine in a strong acid.

Abstract: A dichlorotin phthalocyanine crystal showing, in the X-ray diffractometry using a CuK.sub..alpha. ray, a peak at a Bragg angle (2.theta..+-.0.2.degree.) of 28.2.degree. with any other peak(s) observed at a Bragg angle(s) between 25.degree. and 30.degree. having an intensity of not more than 30% of that of the peak at 28.2.degree.. The crystal is useful as a photoconductive material having sensitivity in the longer wavelength region. The electrophotographic photoreceptor containing the crystal exhibits high sensitivity and excellent durability.

Abstract: A halogenated hydroxygallium phthalocyanine crystal shows intense diffraction peaks at Bragg angles (2.THETA..+-.0.2.degree.) of (1) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree.; (2) 7.9.degree., 16.5.degree., 24.4.degree., and 27.6.degree.; (3) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 18.1.degree., 24.5.degree., 26.2.degree., and 27.1.degree.; (4) 7.5.degree., 9.9.degree., 12.5.degree., 16,3.degree., 18.6.degree., 25.1.degree., and 28.3.degree. or (5) 6.8.degree., 12.8.degree., 15.8.degree., and 26.0.degree. and is suited for use in an electrophotographic photoreceptor is disclosed.

Abstract: A process for the preparation of Type II dihydroxygermanium phthalocyanine which comprises treating dihalogermanium phthalocyanine or dialkoxygermanium phthalocyanine with a strong acid, followed by treatment with water, and subsequent optional washing with an organic base and an aprotic organic solvent.

Abstract: A process for the preparation of titanyl phthalocyanine Type 1a which comprises admixing Type I titanyl phthalocyanine with a component that enables dissolution thereof; adding the resulting dissolved titanyl phthalocyanine pigment to a solvent mixture thereby enabling reprecipitation of said pigment; and subsequently contacting the Type X titanyl phthalocyanine formed with hot halobenzene.

Abstract: A process for preparing a hydroxymetal phthalocyanine pigment containing a central metal atom selected from aluminum, gallium, indium, silicon, germanium and tin and having a novel crystal form is disclosed, comprising treating a precursor of a hydroxymetal phthalocyanine pigment with an acid and treating the precipitated hydroxymetal phthalocyanine pigment with a solvent under an acidic condition. The resulting hydroxymetal phthalocyanine pigment includes hydroxygallium crystals showing distinct diffraction peaks at Bragg angles (2.theta..+-.0.2.degree.) of (1) 8.2.degree., 12.4.degree., 16.5.degree. and 26.3.degree. or (2) 6.8.degree., 12.5.degree. and 26.4.degree.. The resulting hydroxymetal phthalocyanine pigment exhibits high photosensitivity and excellent stability as a charge generating material of an electrophotographic photoreceptor.

Abstract: Crystals of chlorogallium phthalocyanine, having distinct diffraction peaks at (i) 7.4.degree., 16.6.degree., 25.5.degree. and 28.3.degree., (ii) 6.8.degree., 17.3.degree., 23.6.degree. and 26.9.degree., or (iii) 8.7.degree. to 9.2.degree., 17.6.degree., 24.0.degree., 27.4.degree. and 28.8.degree. of the Bragg angle (2.theta..+-.0.2) to a CuK.alpha. characteristic X-ray; a photoconductive material for electrophotographic photoreceptor comprising the chlorogallium phthalocyanine; and an electrophotographic photoreceptor comprising an electroconductive support having thereon a light-sensitive layer containing at least one or more of chlorogallium phthalocyanine crystals. The electrophotographic photoreceptor has excellent sensitivity and durability.

Abstract: There are here disclosed an amorphous alkoxyphthalocyanine which is a compound or a mixture of compounds represented by the formula (1) shown in claim 1; and a method for preparing this amorphous alkoxyphthalocyanine which comprises the step of heating a crystalline phthalocyanine compound or a mixture of crystalline phthalocyanine compounds in an organic solvent.

Abstract: A process for the preparation of a more perfect crystalline form of the Type I polymorph of titanyl phthalocyanine which comprises dissolving a precursor titanyl phthalocyanine Type I in a solution of trihaloacetic acid and alkylene chloride; adding the resultant solution to a solvent thereby enabling precipitation of Type X titanyl phthalocyanine; separating the titanyl phthalocyanine Type X from the solution; followed by a first washing with an organic solvent and a second washing with water; slurrying the resulting Type X titanyl phthalocyanine in an organic solvent enabling conversion of said Type X to Type IV titanyl phthalocyanine; and thereafter, subjecting the Type IV titanyl phthalocyanine obtained to treatment with an organic solvent to enable said crystalline form of titanyl phthalocyanine Type I.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor comprises a conductive substrate and a photosensitive layer provided on the substrate. The photosensitive layer comprises titanylphthalocyanine having a peak at a Bragg angle 2.theta. of 27.2.degree..+-.2.degree. in the Cu-K.alpha. X ray-diffraction spectrum thereof and an alkyldiol which has 3 to 12 carbon atoms and the two hydroxyl group is bonded to carbon atoms arranged at different position in the molecular thereof. The amount of the diol is 0.1 to 1000 parts by weight per 100 parts by weight of the titanyl-phthalocyanine.

Abstract: A novel dichlorotin phthalocyanine crystal having distinct diffraction peaks at 8.5.degree., 11.2.degree., 14.5.degree., and 27.2.degree. of the Bragg angles (2.theta..+-.0.2) in the X-ray diffraction spectrum; process for producing the dichlorotin phthalocyanine crystal, comprising mechanically grinding a known dichlorotin phthalocyanine crystal together with an inorganic salt, followed by, if desired, a solvent treatment; an electrophotographic photoreceptor containing, in the photosensitive layer thereof, the dichlorotin phthalocyanine crystal; and a coating composition for producing an electrophotographic photoreceptor, comprising the dichlorotin phthalocyanine crystal, a binder resin, and an acetic ester solvent. The photoreceptor exhibits high sensitivity and excellent durability. The coating composition maintains the dichlorotin phthalocyanine crystal in its desired form either while being prepared or after being coated.

Abstract: A novel phthalocyanine mixed crystal comprising a dihalogenotin phthalocyanine and a halogenogallium phthalocyanine and an electrophotographic photoreceptor containing the same are disclosed. The phthalocyanine mixed crystal preferably has an intense X-ray diffraction peak at a Bragg angle (2.theta..+-.0.2.degree.) of 26.9. The phthalocyanine mixed crystal is useful as a charge generating material which provides an electrophotographic photoreceptor excellent in sensitivity, stability on repeated use, and environmental stability.

Abstract: A layered photoconductive imaging member comprised of a supporting substrate, a photogenerating layer and a charge transport layer, and wherein the photogenerating layer contains Type IV titanyl phthalocyanine obtained by a process which comprises the addition of an oxytitanium phthalocyanine containing a mixture of Type I and Type II titanyl phthalocyanine polymorphs, or a substantially pure Type II titanyl phthalocyanine polymorph to a solvent comprised of a trihaloacetic acid and an alkylene halide; adding the resultant solution to a mixture which enables precipitation of Type X oxytitanium phthalocyanine; separating the Type X oxytitanium phthalocyanine from the solution; and thereafter subjecting the Type X oxytitanium phthalocyanine obtained to treatment with a halobenzene, followed by the separation of the said Type IV oxytitanium phthalocyanine.

Abstract: Disclosed is the X polymorphic form of titanyl phthalocyanine.

Abstract: A phthalocyanine mixed crystal comprising a halogenated indium phthalocyanine and a halogenated gallium phthalocyanine and an electrophotographic photoreceptor containing the phthalocyanine mixed crystal. The phthalocyanine mixed crystal is a charge generating material which provides an electrophotographic photoreceptor excellent in sensitivity, stability on repeated use, and environmental stability.

Abstract: Oxytitanium phthalocyanine hydrate crystal and an electrophotographic photoreceptor using said crystal are disclosed. The structural formula of the crystal is TiOPc(H.sub.2 O).sub.n wherein Pc represents a phthalocyanine residual group, and n represents from 0.15 to 1; and the elemental analysis values of C, H and N are as follows: C: 65.0 to 66.3%; H: 2.5 to 3.1%; and N: 18.5 to 19.3%.

Abstract: A process for preparing an oxytitanium phthalocyanine hydrate crystal which, when dried at 100.degree. C. and 0.1 mmHg for 8 hours and then allowed to stand in air at room temperature for 12 hours, has a structural formula of TiOPc.multidot.(H.sub.2 O).sub.n, wherein Pc represents a phthalocyanine nucleus, and n represents a number of from 0.15 to 1, and elemental analysis values of C: 65.0 to 66.3%, H: 2.5 to 3.1%, and N: 18.5 to 19.3% is disclosed, which process comprises the steps of: mechanically grinding a mixture of oxytitanium phthalocyanine and an inorganic salt to convert the crystal form of the oxytitanium phthalocyanine to a crystal form showing a distinct peak in its X-ray diffraction pattern at a Bragg angle (2.theta..+-.0.2.degree. ) of 27.3.degree. and treating the resulting oxytitanium phthalocyanine crystal with a mixed solvent of water and a water-insoluble organic solvent.

Abstract: A layered photoconductive imaging member comprised of a supporting substrate, a photogenerating layer comprised of titanyl phthalocyanine photogenerating pigments and thereover a charge transport layer, and wherein said photogenerating pigments are prepared by a process which comprises the formation of a slurry comprised of dihalotitanium phthalocyanine in a mixture comprised of a trihaloacetic acid and an alkylene chloride; adding the resultant slurry to a mixture of an aliphatic alcohol and water enabling hydrolysis whereby Type X oxytitanium phthalocyanine is obtained; separating the Type X oxytitanium phthalocyanine from the slurry; and thereafter subjecting the Type X oxytitanium phthalocyanine obtained to treatment with a halobenzene, followed by the separation of Type IV oxytitanium phthalocyanine photogenerating pigments.

Abstract: The present invention relates to a process for preparing a beta-phase metal phthalocyanine pigments in which(a) a crude metal phthalocyanine having an average particle size of about 10 to about 200 .mu.M is dry milled until the average particle size is reduced to about 0.01 to about 0.5 .mu.m;(b) the milled metal phthalocyanine is finished by thoroughly mixing said metal phthalocyanine with at least about 4 parts by weight, relative to the metal phthalocyanine, of a finishing solvent containing a mixture of(i) about 5 to 100 percent by weight, based on the total amount of finishing solvent, of a monocarboxylic acid monoester, dicarboxylic acid diester, diol diester, lactone, or cyclic carbonate, or a mixture thereof, and(ii) 0 to about 95 percent by weight, based on the total amount of finishing solvent, of water;(c) the ester used in step (b) is hydrolyzed; and(d) the beta-phase metal phthalocyanine pigment is collected.

Abstract: Dichlorotin phthalocyanine crystals having distinct diffraction peaks at (i) 8.7.degree., 9.9.degree., 10.9.degree., 13.1.degree., 15.2.degree., 16.3.degree., 17.4.degree., 21.9.degree. and 25.5.degree., or (ii) 9.2.degree., 12.2.degree., 13.4.degree., 14.6.degree., 17.0.degree. and 25.3.degree. of the Bragg angle (2.theta..+-.0.2) to a CuK.alpha. characteristic X-ray; a method of preparing dichlorotin phthalocyanine crystals having the strongest diffraction peak at 28.2.degree. in the range of from 25.degree. to 30.degree. of the Bragg angle (2.theta..+-.0.2) in an X-ray diffraction spectrum; and an electrophotographic photoreceptor comprising an electroconductive support having thereon a light-sensitive layer containing the dichlorotin phthalocyanine crystals having distinct diffraction peaks at the particular angles or the dichlorotin phthalocyanine crystals prepared by the method.

Abstract: A process for the production of a .beta.-form copper phthalocyanine having a particle size of 0.005 to 0.2 .mu.m and an aspect ratio of 1 to 3, which comprises the following steps:a. dry-milling a crude copper phthalocyanine in a milling apparatus until the resultant dry-milled product has an .alpha.-crystal content of more than 45% by weight,wet-milling the resultant dry-milled product in the presence of a water-soluble inorganic salt and at least one organic liquid selected from the group consisting of water-soluble alkylene glycols having 2 to 3 carbon atoms and polyoxyalkylene glycols, wherein the inorganic salt is used in an amount that is 2 to 10 times, by weight, as large as that of the dry-milled copper phthalocyanine, and wherein the organic liquid is used in an amount that is 0.1 to 2 times, by weight, as large as that of the dry-milled copper phthalocyanine, andc. removing the inorganic salt and the organic liquid from the resultant wet-milled product.

Abstract: A process for the preparation of crystalline oxytitanium phthalocyanine showing D-type crystalline form comprising contacting dichlorotitanium phthalocyanine, dibromotitanium phthalocyanine or a mixture of them with at least one organic solvent selected from the group consisting of aromatic nitro compounds, nitrogen-containing cyclic ethers, aromatic amines, alcohols containing not less than 4 carbon atoms, aldehydes, ketones, lactones, lactams, acid amides, nitriles, alkyl sulfoxides, substituted phenols and non-substituted phenols in association with water.

Abstract: A process for the preparation of a copper phthalocyanine pigment, which comprises dry grinding crude copper phthalocyanine, treating the dry ground crude copper phthalocyanine with an aqueous solution of a mineral acid under such conditions of acid concentration and temperature as not to transform the .beta. form contained in the ground crude copper phthalocyanine into the .alpha. one to thereby carry out the pigmentation and removing the mineral acid from the resulting mixture.

Abstract: An electrophotographic photosensitive member, comprising: an electroconductive support and a photosensitive layer disposed on the electroconductive support, wherein the photosensitive layer comprises (i) oxytitanium phthalocyanine having a crystal form characterized by main peaks specified by Bragg angles (2.theta..+-.0.2 degree) of 9.0 degrees, 14.2 degrees, 23.9 degrees and 27.1 degrees in X-ray diffraction pattern based on CuK.alpha. characteristic X-rays, and (ii) a fluorene compound represented by the following formula (I): ##STR1## wherein Ar.sup.1 and Ar.sup.2 independently denote aryl group optionally having a substituent; R.sup.1 and R.sup.2 independently denote alkyl group optionally having a substituent, aralkyl group optionally having a substituent or aryl group optionally having a substituent; and R.sup.3 denotes hydrogen atom, alkyl group optionally having a substituent, alkoxy group optionally having a substituent, hydroxyl group or halogen atom.

Abstract: An imaging member comprised of a supporting substrate, a photogenerating layer comprised of a titanyl phthalocyanine of the type selected from the group consisting of Type IV, Type X, Type Z-1, and Type Z-2, prepared by the process which comprises dissolving a titanyl phthalocyanine in a solution of trifluoroacetic acid and methylene chloride; adding the resultant solution to a solvent or solvent mixture that will enable precipitation; and separating the product titanyl phthalocyanine from the solution followed by an optional washing, and a charge transport layer.

Abstract: A new composition of titanyl phthalocyanine is provided. This composition has in its infrared absorption spectrum characteristically strong absorptions at absorption wavenumbers (in unit of cm.sup.-1) of 1490.+-.2, 1415.+-.2, 1332.+-.2, 1119.+-.2, 1072.+-.2, 1060.+-.2, 961.+-.2, 893.+-.2, 780.+-.2, 751.+-.2 and 730.+-.2, and has an extremely high solvent stability and dispersibility, and a large photoelectric conversion efficiency. The new form of composition can be obtained by adding to titanyl phthalocyanine, compounds of other phthalocyanines or naphthalocyanines as additives, and treating the amorphous composition of the mixture to crystallize the composition. By applying an appropriate binder, with the novel composition crystals as a charge generation agent, on a substrate, it is possible to obtain an electrophotographic photosensitive material that has a charge generation layer with an extremely high dispersibility and an extremely large photoelectric conversion efficiency.

Abstract: A process for the preparation of titanyl phthalocyanine which comprises the treatment of titanyl phthalocyanine Type X with a halobenzene.

Abstract: There are disclosed low crystalline oxytitanium phthalocyanines which have characteristic strong peaks at specific angles of Bragg angle 2.theta..+-.0.2.degree.. Using the low crystalline oxytitanium phthalocyanines, it is easy to obtain oxytitanium phthalocyanines having novel crystal forms. Electrophotographic photosensitive member containing the oxytitanium phthalocyanines having novel crystal forms have a very high photosensitivity to beams of long wavelength, a ver high potential stability as well as excellent durability in repetitive use.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor contains in a light sensitive layer thereof a titanylphthalocyanine having specific crystalline characteristics as defined in the specification and a polycyclic quinone pigment or a bisazo pigment as defined in the specification. The photoreceptor has a high sensitivity over a broad wavelength region, especially near-infrared range. It is suitably used for a laser printer.