Surface functionalization of metallized polymer webs via vacuum deposited radiation cured polymer coatings

摘要

The surface of most polymer films is treated prior to metallization to promote metal nucleation and adhesion. Surface treatments such as corona discharge, flame and low pressure plasmas are used to add functional groups to the polymer surface, that influence the growth and structure of the metal films. The functionalization of the polymer, although limited to the film surface, provides a cost-effective means for improving film handing and metallization quality. Recently a new low cost vacuum deposition method has been developed for depositing radiation curable acrylate polymers inline with the metallization process. This work shows that thin highly cross linked polymers deposited prior to metallization, can be used to functionallize the film surface resulting in metal coatings of exceptional quality. The composite polymer films have chemical and physical properties that extend beyond surface functionalization. The data show that acrylate coated polypropylene films have superior thermal and mechanical properties, which allow processing at higher temperature conditions. Aluminum, silicon oxide and aluminum oxide coatings deposited on the highly cross linked acrylate polymer have greater chemical and mechanical stability resulting in superior barrier properties. The chemistry of the acrylate coatings can be customized to produce surfaces that have variable, surface tension, erfractive index, dielectric constant, color, infrared absorption and electrical conductivity. Post metallization coatings can also be used to protect the metal surface from abrasion, environmental damage and microcracking of the metal deposit during film stretching.