THERMOFORMABLE CONDUCTIVE LAMINATE AND PROCESS

A process for making a thermoformable conductive plastic laminate for use in making plastic parts adapted for electrostat- ic spray painting of a uniform high quality paint finish includes forming a matte release coated casting sheet (20), casting an elec- trically conductive polymer (24) in thin film form on the casting sheet, drying to form a conductive primer coat (24), and transfer- laminating the conductive coating to a thin, thermoformable plastic face she et (26). The matte release coat (20) has fine particu- late filler that transfer a micro-roughened matte surface to the conductive primer coat (24). The conductive primer (24) includes a polyester resin containing a fine particulate conductive material such as carbon black and, preferably, an anti-blocking agent such as fumed silica. The primer coated face sheet (26) can be thermoformed and bonded to an underlying plastic substrate panel (28). The conductive primer (24) has sufficient elongation and maintains uniform electrical surface conductivity and film thick- ness throughout the transfer-laminating, thermoforming and substrate panel- cladding process. The uniform surface resistivity of the conductive primer film (24) is sufficient to permit electrostatic spray painting of the finished contoured panel and in one em- bodiment of the finished contoured panel and in one embodiment produces a Class "A" quality, exterior-automatic paint finish on the resulting panel.