Film material for forming blackboards

摘要

Disclosed is a plastics film material for forming blackboards, which comprises a film of polyethylene or polypropylene covered on one surface with a layer of paint. The layer of paint is made of polyurethane resin composed of polyol and polyisocyanate and containing a coloring pigment, a bulking agent, such as powdered alumina and powdered calcium carbonate, and in some cases, silicone oil or polyethylene wax. The film material is attached to a base board with the layer of paint exposed on the outside to form a blackboard.