초록 ▼

A process for modifying colorants which comprise an active ingredient of solid primary particles in the submicron range by an encapsulation with polymer starting materials that are not substantially altered during the process. Writing fluids, textile colorants and cosmetic inks are disclosed wherein

A process for modifying colorants which comprise an active ingredient of solid primary particles in the submicron range by an encapsulation with polymer starting materials that are not substantially altered during the process. Writing fluids, textile colorants and cosmetic inks are disclosed wherein the intrinsic physical qualities of a solid active material are modified to create a stable aqueous dispersion with performance and rheology characteristic of the polymer, and not of the active ingredient.

대표청구항 ▼

A process for producing a colorant comprising a stable aqueous suspension of submicron sized particles of polymer encapsulated active ingredient, wherein a polymer matrix surrounds a core of solid active ingredient, said process comprising the steps of: A. Mixing together an organic solvent, a polym

A process for producing a colorant comprising a stable aqueous suspension of submicron sized particles of polymer encapsulated active ingredient, wherein a polymer matrix surrounds a core of solid active ingredient, said process comprising the steps of: A. Mixing together an organic solvent, a polymer soluble in said solvent but substantially insoluble in water and an active ingredient which substantially is insoluble in water to form a homogeneous mixture, wherein said solvent is characterized by a vapor pressure higher than water and said mixing is continued until said active ingredient has dispersed in said solvent without appreciable agglomeration; and B. Adding said solvent/polymer/active ingredient mixture to water, in a concentration range of 1.0% to 50.0%, by weight, and dispersing until an emulsion results wherein solvent/polymer/active ingredient comprises a discontinuous phase, having a size less than 4 microns with water as the continuous phase, werein said dispersing step is done under conditions where interfacial tension between the organic solvent and the water is less than approximately 10 dynes/cm.; and C. Removing substantially all of said solvent to define an aqueous suspension of said particles.