Patent ID: 7172712

Claim:
A method of making a multichromal sphere, comprising: preparing a composition comprising at least (1) a matrix material and (2) at least two sets of particles, each of the sets of particles having a color different from at least one of another of the sets of particles and a segregation property different from at least one of another of the sets of particles; encapsulating the composition within a shell to form an encapsulated sphere; immobilizing the encapsulated sphere in a manner to restrict at least rotation of the encapsulated sphere; subjecting the immobilized encapsulated sphere to an external field associated with the segregation property different among the sets of particles, under conditions in which particles of the sets of particles migrate within the matrix material, thereby producing color segregation in the immobilized encapsulated sphere; and following producing the color segregation, solidifying the matrix material while substantially maintaining the color segregation, wherein the matrix material comprises at least one polymerizable monomer or oligomer that polymerizes into a polymer having a melting temperature below a melting temperature of the shell, wherein the at least one polymerizable monomer or oligomer is polymerized into the polymer having a melting temperature below a melting temperature of the shell prior to or during subjecting the immobilized encapsulated sphere to the external field associated with the segregation property different among the sets of particles, wherein the conditions in which the particles of the sets of particles migrate within the matrix material comprise a temperature above the melting temperature of the polymerized matrix material and below the melting temperature of the shell, and wherein the solidifying of the polymerized matrix material comprises cooling the polymerized matrix material from the temperature above the melting temperature of the polymerized matrix material to a temperature below the melting temperature of the polymerized matrix material.