Continuous media recirculation milling process

Abstract

A continuous method of preparing submicron particles of a compound useful in imaging elements (or other materials, such as pigments, etc.) comprises the steps of continuously introducing the compound and rigid milling media into a milling chamber, contacting the compound with the milling media while in the chamber to reduce the particle size of the compound, continuously removing the compound and the milling media from the milling chamber, and thereafter separating the compound from the milling media. In a preferred embodiment, the milling media is a polymeric resin having a mean particles size of less than 300 .mu.m. The method enables the use of fine milling media in a continuous milling process which provides extremely fine particles of the compound useful in imaging elements while avoiding problems, e.g., separator screen plugging associated with prior art processes requiring the separation of compound from the milling media in the milling chamber.

Dependencies are inferred from the claim text.