Hollow containers with inert or impermeable inner surface through plasma-assisted surface reaction or on-surface polymerization

Abstract

Plasma assisted polymerization and deposition of a very thin inner surface coating in a plastic or metal container without an undesirable increase in container surface temperature is provided to change the surface properties of the internal plastic surface of a container by reaction of the surface with a reactive gas which has been energized to produce a plasma or the surface is activated by a plasma of reactive gas so that it becomes receptive to a further surface reaction. It involves locating the container in an enclosure, inserting means for feeding a reactant gas into the container, selectively controlling the pressure inside the enclosure and inside of the container, cleaning a surface of the container to be coated in situ, pretreating the surface to be coated for enabling a polymer coating subsequently deposited thereon to secure proper adhesion between the coating material and the container material, feeding a reactant gas of predetermined constituency and having barrier properties into the container, generating a plasma of said reactant gas and depositing a relatively thin polymer coating on the surface to be coated, and performing a post polymerization treatment on said polymer coating for eliminating residual monomers and other polymer extractables in situ following deposition of said polymer coating.