PRODUCTION METHOD FOR FINE ORGANIC PIGMENT

摘要

The present invention provides the following process for producing a fine organic pigment which is capable of producing the fine organic pigment that has a very small primary particle size and is excellent in filtering property even in a cleaning step, and a fine organic pigment produced by the process; a process for producing a dispersion using the fine organic pigment, and a dispersion produced by the process; and a process for producing an ink using the dispersion. The present invention relates to [1] a process for producing a fine organic pigment, including steps 1 and 2: step 1: kneading a mixture prepared by compounding a raw material organic pigment, a water-soluble inorganic salt, a water-soluble organic solvent and a compound represented by the following formula (1) with each other, the compound being compounded in an amount of not less than 0.8 part by mass and not more than 18.0 parts by mass on the basis of 100 parts by mass of the raw material organic pigment: R1O(PO)m(EO)nA (1); and step 2: subjecting the mixture obtained in the step 1 to cleaning treatment with an aqueous solvent and then to filtration, [2] a fine organic pigment produced by the process according to the above aspect [1], [3] a dispersion produced using the fine organic pigment according to the above aspect [2], [4] a process for producing a paste of a fine organic pigment, including the above step 1 and 2, [5] a process for producing a dispersion, including step 3 of subjecting the paste of the fine organic pigment produced by the process according to the above aspect [4], an organic solvent and water to dispersing treatment, and [6] a process for producing an ink, including step 4 of mixing the dispersion produced by the process according to the above aspect [5] with at least one material selected from the group consisting of water and an organic solvent.

主权项

1. A process for producing a fine organic pigment, comprising the following steps 1 and 2:
step 1: kneading a mixture prepared by compounding a raw material organic pigment, a water-soluble inorganic salt, a water-soluble organic solvent and a compound represented by the following formula (1) with each other, the compound being compounded in an amount of not less than 0.8 part by mass and not more than 18.0 parts by mass, on the basis of 100 parts by mass of the raw material organic pigment:
R1O(PO)m(EO)nA  (1)wherein R1 is a hydrocarbon group having not less than 8 and not more than 24 carbon atoms; PO is propyleneoxide; EO is ethyleneoxide; m represents an average molar number of addition of propyleneoxide and is a number of not less than 0 and not more than 30, and n represents an average molar number of addition of ethyleneoxide and is a number of not less than 10 and not more than 70, with the proviso that a sum of m and n (m+n) is not less than 10 and not more than 70; and A is a hydrogen atom, —SO3−X+, —PO3H−X+ or —CH2COO−X+ wherein X+ is a monovalent cation, in which when both PO and EO are present, these constituents may be arranged in any optional order; and
step 2: subjecting the mixture obtained in the step 1 to cleaning treatment with an aqueous solvent and then to filtration.