Method of direct manufacture of pigmented polyurethane powder.

摘要

The present invention is directed to a process for the direct production of a pigmented thermoplastic polyurethane powder in finely divided form by a) reacting with agitation at an overall equivalent ratio of isocyanate groups to isocyanate reactive groups of about 0.5 to 1.1 (i) a surfactant-stabilized emulsion of fine droplets of a first reactant which has an average of about two isocyanate or isocyanate reactive groups in admixture with at least one pigment with (ii) a second reactant which contain an average of about two isocyanate or isocyanate reactive groups, in an inert organic liquid in which the first reactant, the pigment and the powder are substantially insoluble or immiscible to form particles of the powder which are protected from agglomeration by the surfactant, and b) separating the particles of the powder from the inert organic liquid. The present invention is also directed to the pigmented thermoplastic polyurethane powders obtained by this process.