Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

An object of the present invention is to provide a method of efficiently producing a colorant that can be used for production of a pigment composition or an aqueous pigment dispersion with a small volume-average particle size of a dispersed substance and with fewer coarse particles. The inventor of the present invention has achieved the object by a method of producing a colorant that includes: step 1 of kneading a composition containing a pigment having a primary particle size of 100 nm or more, a liquid medium, and a water-soluble inorganic salt with a processing machine to produce a kneaded product containing a pigment having a primary particle size in a range of 10 nm or more and less than 100 nm; and step 2-1 of mixing the kneaded product, a resin having an anionic group, and a basic compound.

A dye ink composition includes: a compound A represented by the general formula (I-1) as defined herein; a compound B represented by the general formula (I-2) as defined herein; at least one of a compound C-I represented by the general formula (I-3-1) as defined herein or a compound C-II represented by the general formula (I-3-2) as defined herein; a compound D represented by the general formula (I-4) as defined herein; and water.

It is an object of the present technology to overcome the disadvantages of conventional chlorination of a copper phthalocyanine which produces copper phthalocyanine, wherein the number of chlorines is less than than or equal to 4. The pigments described herein contain less chlorine than standard commercial grades of tetrachlorinated (or greater) copper phthalocyanine pigments while achieving similar color space, chromaticity, fastness properties, and color travel in automotive waterborne and solvent borne systems. The inventive pigments are more advantageous from a toxicity and environmental perspective, and allow the manufacturer to produce pigments in a safe and economical manner.

It is an object of the present technology to overcome the disadvantages of conventional chlorination of a copper phthalocyanine which produces copper phthalocyanine, wherein the number of chlorines is less than than or equal to 4. The pigments described herein contain less chlorine than standard commercial grades of tetrachlorinated (or greater) copper phthalocyanine pigments while achieving similar color space, chromaticity, fastness properties, and color travel in automotive waterborne and solvent borne systems. The inventive pigments are more advantageous from a toxicity and environmental perspective, and allow the manufacturer to produce pigments in a safe and economical manner.

An electrophotographic photoreceptor includes a conductive support, a charge generation layer disposed on the conductive support, and a charge transport layer disposed on the charge generation layer. The charge generation layer includes a charge generating material and a vinyl copolymer. The vinyl copolymer includes a structural unit including a chlorine atom, a structural unit including an acyloxy group, and a structural unit including two or more carboxyl groups. The proportion of the structural unit including an acyloxy group to all of the structural units is 13.4 mol % or more and 20.0 mol % or less. The charge transport layer includes a charge transporting material and a binder resin.

Provided is an organic pigment composition for color filters, which can be used preferably for a color filter that allows to produce a liquid crystal display device which has excellent heat resistance, a brighter display screen, and accordingly higher brightness; a method for producing the same; and a color filter which includes the organic pigment composition for color filters. The color filter has higher heat resistance by using the organic pigment composition for color filters which includes a phthalocyanine pigment and a pigment derivative in which the ratio of a multi-substituted phthalimide alkyl group to the whole amount of the pigment derivative is limited.

Provided is an organic pigment composition for color filters, which can be used preferably for a color filter that allows to produce a liquid crystal display device which has excellent heat resistance, a brighter display screen, and accordingly higher brightness; a method for producing the same; and a color filter which includes the organic pigment composition for color filters. The color filter has higher heat resistance by using the organic pigment composition for color filters which includes a phthalocyanine pigment and a pigment derivative in which the ratio of a multi-substituted phthalimide alkyl group to the whole amount of the pigment derivative is limited.

Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

A dye ink composition includes: a compound A represented by the general formula (I-1) as defined herein; a compound B represented by the general formula (I-2) as defined herein; at least one of a compound C-I represented by the general formula (I-3-1) as defined herein or a compound C-II represented by the general formula (I-3-2) as defined herein; a compound D represented by the general formula (I-4) as defined herein; and water.