Process for preparing granules of pigments by means of double extrusion

Abstract From the Canadian patent

A process for the production of a particle composition containing at least , one resin and at least one pigment is described, said process comprising the following steps : .cndot. extrusion of a mixture containing said at least one resin and said at least one pigment without induced heating; .cndot. subsequent extrusion with , induced heating, of the mixture obtained from the preceding extrusion; .cndot. granulation of the mixture thus obtained. With the abovementioned process it is possible to obtain a composition having granules with an average diameter less than 2 microns and a greater homogeneity than the known processes.