Method of producing organic-particles-dispersion liquid
AssigneeFUJIFILM Corporation
InventorsTakayuki Kusano, Yousuke Miyashita
Life of this patent
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Abstract
A method of producing an organic particle dispersion, which has: dissolving an organic material into a good solvent to form a solution, mixing the solution with a poor solvent for the organic material in which the poor solvent is compatible with the good solvent, to form organic particles of the organic material in a mixed liquid, and thereby preparing a dispersion in which the organic particles are dispersed, in which a polymer compound having a weight average molecular weight of 1,000 or more is contained when preparing the dispersion.
Claims13
A method of producing an organic pigment particle dispersion, for use in production of a color filter, which comprises:
- dissolving an organic pigment comprising a diketopyrrolopyrrole compound into a good solvent to form a solution,
- mixing the solution with a poor solvent for the organic pigment, the poor solvent being compatible with the good solvent, to prepare a first aqueous dispersion in which organic pigment particles having a number average particle diameter of 1 μm or less are dispersed,
- concentrating the first aqueous dispersion by at least one of the following (a) to (d):
- (a) adding an extraction solvent to the first aqueous dispersion to extract the organic pigment particles into an extraction solvent phase;
- (b) filtering the first aqueous dispersion through a filter;
- (c) sedimenting the organic pigment particles of the first aqueous dispersion by centrifugal separation;
- and
- (d) drying a solvent of the first aqueous dispersion under heat or reduced pressure;
- to form a concentrated liquid containing the organic pigment particles, wherein the concentrated liquid has a pigment concentration 100 to 1000 times higher than the pigment concentration in the first aqueous dispersion, and
- mixing the concentrated liquid with an organic medium and a polymer dispersant having a weight average molecular weight of 1,000 or more and having an acidic group, to form a second organic dispersion, suitable for a color filter coating liquid, which contains the organic medium and the organic pigment particles therein.
Dependencies are inferred from the claim text.