Patent ID: 11839681

Abstract:
The present invention includes: 1) dissolving a first binder in a first solvent; 2) dissolving a dispersing agent in a solution in which the first binder is dissolved; 3) adding charcoal powder to the solution obtained in 2) and performing homogenous mixing to produce a dispersion in which the charcoal powder is bound to the first binder; 4) spray drying the dispersion obtained in 3) to produce a primary capsule from which the first solvent is removed; 5) dissolving a second binder and a softening agent in a second solvent; 6) homogeneously mixing a coloring agent and the dispersing agent with a solution in which the second binder and the softening agent are dissolved; 7) mixing the primary capsule with the solution obtained in 6) to produce a double capsule dispersion in which the primary capsule is bound to the second binder; and 8) spray-drying the double capsule dispersion to product a double capsule from which the second solvent is removed.