Process for attaching a modifying agent to a substrate

Abstract

Modifying agents, e.g., a poly(sulfonyl) azide, are attached to a substrate surface, e.g., the surface of a polyolefin particle, by a process comprising the steps of: A. Contacting in an open contact zone and under a flow of inert gas a substrate with a modifying agent, binding agent, e.g., a phenolic-based antioxidant, and a liquid mixing agent, e.g., methylene chloride, to form a substrate mixture; B. Closing the contact zone and stopping the flow of inert gas to the contact zone; C. Agitating the substrate mixture under the inert gas in the closed contact zone to commence evaporation of the liquid mixing agent; D. Reducing the temperature and pressure of the closed contact zone while continuing to agitate the substrate mixture; and E. Completing the substantial evaporation of the mixing agent from the substrate mixture by opening the contact zone and initiating an inert gas flow while continuing agitation of the substrate mixture and maintaining a reduced pressure.