Coating PVC film etc. with PVA - by plasma treatment and application of aq. PVA soln., gives reduced gas permeability and improved antistatic properties

摘要

PVC articles are provided with a coating layer of polyvinyl alcohol (PVA) applied directly without an intermediate adhesive layer. Pref. the surface of the PVC is subjected to an atmos. of low temp. plasma of a gas which does not polymerise in the plasma state, and the treated article is coated with aq. PVA soln. and allowed to dry. coating is carried out e.g. within 24 hours of the plasma exposure and the PVA coating is dried e.g. at 50-70 deg.C. The process is esp. useful for treating vinyl chloride (co)polymer films to give reduced gas permeability, improved antistatic properties, improved mechanical strength, improved chemical resistance and improved scratch resistance. The treatment is relatively cheap and is simpler to carry out than e.g. laminating PVC film to polyethylene, polypropylene, polyesters, etc. using polyurethane bonding agents as carried out previously.