A process for the preparation of diaminophenothiazinium compounds is described, which allows achieving quickly and effectively a high degree of purity of the same.

An object of the present invention is to provide a method for removing geniposide or genipin or both from a material containing geniposide or genipin or both. The present invention is a method for removing geniposide or genipin or both from a material containing geniposide or genipin or both, the method comprising treating the material containing geniposide or genipin or both using an activated carbon having (a) a methylene blue adsorption ability of 50 ml/g or more; and (b) an iodine adsorption ability of 750 mg/g or more, thereby removing geniposide or genipin or both.

Method of making an aqueous aniline-free or aniline-free and N-methylaniline-free leucoindigo solution from an aqueous leucoindigo solution comprising aniline or aniline and N-methylaniline, the concentration of aniline or aniline and N-methylaniline being determined according to ISO 14362-1:2017(E), wherein said leucoindigo is in the form of an alkali metal salt, the method comprising at least steps (A) to (C): (A) providing a liquid stream comprising said aqueous leucoindigo solution comprising said amine(s); (B) providing a purification stream; (C) bringing into contact said liquid stream with said purification stream.

Aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt;

wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); and
wherein the concentration of the leucoindigo salt is in a concentration range of from 15 to 45% by weight based on the total weight of the solution, and wherein the solution is stable at a temperature of 23 C.; or
wherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the solution is stable at a temperature of 60 C.

This application discloses the approach of synthesizing cellulose acetate nanoparticles and rods which may have a chemically functionalized surface and an encapsulated cargo load. Functionalization and/or loading of the cargo are made through a physical mixing of the functionalizing and/or cargo components in the synthesizing bath. This can result in particles with functionalized surfaces with various functional groups, as well as active cargo load encapsulated in the particles. The encapsulated cargo includes but is not limited to biologically, chemically, and optically active substances.

An object of the present invention is to provide a method for removing geniposide or genipin or both from a material containing geniposide or genipin or both. The present invention is a method for removing geniposide or genipin or both from a material containing geniposide or genipin or both, the method comprising treating the material containing geniposide or genipin or both using an activated carbon having (a) a methylene blue adsorption ability of 50 ml/g or more; and (b) an iodine adsorption ability of 750 mg/g or more, thereby removing geniposide or genipin or both.

A method of producing organic pigment microparticles includes: Step 1 of precipitating organic pigment microparticles by mixing an organic pigment raw material liquid in which an organic pigment raw material is mixed with a solvent, and a precipitation solvent for precipitating the organic pigment microparticles from the organic pigment raw material liquid in a thin film fluid formed by introducing the organic pigment raw material liquid and the precipitation solvent in a space between at least two processing surfaces which are disposed so as to face each other, being capable of approaching to and separating from each other, at least one of which rotates relatively to the other; and Step 2 of coating at least a part of the organic pigment microparticles with an oxide coating; wherein the oxide coating is optically colorless and transparent, and Step 1 and Step 2 are performed out continuously in the thin film fluid.

The present specification relates to a method for preparing a colorant composition comprising dissolving a first xanthene-based dye having the same number of positive charges and negative charges and a second xanthene-based dye having more negative charges than positive charges by one or more in a first solvent; and precipitating the dissolved first xanthene-based dye and the dissolved second xanthene-based dye in a second solvent, and a colorant composition, a colorant dispersion, a photosensitive resin composition, a color filter and a liquid crystal display device.

The present invention relates to [1] a process for producing a fine organic pigment, including step 1 of kneading a mixture prepared by compounding a raw material organic pigment, a water-soluble inorganic salt and a water-soluble organic solvent; and step 2 of subjecting the kneaded mixture obtained in the step 1 to cleaning treatment with an aqueous solvent and then to filtration treatment, in which before or after kneading the mixture in the step 1 and before subjecting the kneaded mixture to filtration treatment in the step 2, a sulfonic acid salt dispersant is compounded in an amount of not less than 0.8 part by mass and not more than 8.0 parts by mass on the basis of 100 parts by mass of the raw material organic pigment; [2] a process for producing a dispersion, including step 3 of subjecting a pigment mixture containing the fine organic pigment obtained by the production process according to the above [1], an organic solvent and water to dispersion treatment; and [3] a process for producing an ink, including step 4 of mixing the dispersion obtained by the production process according to the above [2] with at least one medium selected from the group consisting of water and an organic solvent.

The present invention relates to methods for obtaining natural colorants from materials of plant origin. The method comprises a mixing step, a co-pigmentation step, an enzymatic hydrolysis step and various filtration steps carried out under specific conditions.