A process incorporating a chlorine dioxide generating compound such as sodium chlorite into a polymer or oligomer film is coated onto various substrates. Controlled release is accomplished by absorption of moisture from the environment. The chlorine dioxide so released acts as a biocide and a fumigant. The chlorite is dissolved into a hydrogen bonded phase containing a monomeric, or polymeric amide or a monomeric or polymeric alcohol. This hydrogen bonded phase is then mixed with an incompatible apolar phase consisting of anhydride containing such as polymers such as maleic anhydride copolymers with olefins, grafted maleic anhydride-polypropylene polymers. Chlorine dioxide is released by direct reaction of the anhydride or hydrolyzed anhydride with the chlorite anion across the phase boundary. Increasing the molecular weight of the phases, increasing the phase incompatibility and decreasing the concentration of anhydride will all decrease the chlorine dioxide release rate.
Stephen T. Wellinghoff