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Process for hardcoating polycarbonate sheet

  • US 4,946,531 A
  • Filed: 12/01/1988
  • Issued: 08/07/1990
  • Est. Priority Date: 12/01/1988
  • Status: Expired due to Term
First Claim
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1. A process for producing a hardcoated aromatic polycarbonate resin sheet, said process comprising the steps of:

  • (a) hardcoating a flexible aromatic polycarbonate film having a thickness selected from between about 0.5 mils and about 30 mils, the hardcoating of the film being a continuous procedure involving;

    (i) applying an uncured coating material to the film, the coating material comprising an amount of polyfunctional acrylate ester monomers and an amount of a photoinitiator,(ii) passing the film and applied uncured coating material through a constant pressure compression nip, the compression nip pressure being selected from between about 5 psi to about 50 psi to provide a substantially uniform layer of uncured coating material on the film,(iii) anaerobically contacting the uniform coating layer with a peripheral surface of a longitudinally rotateable, cylindrical casting drum,(iv) curing the coating layer by directing ultraviolet radiation through the film to the coating layer while the coating layer is in contact with the drum surface to provide a hardcoated film having a cured coating having surface characteristics determined by the casting surface, the cured coating having a thickness selected from between 0.1 mils and 1.0 mils; and

    (b) laminating the hardcoated film onto a rigid aromatic polycarbonate substrate, the substrate having a thickness selected from between about 35 mils to about 1000 mils, the laminating involving;

    (i) preparing an overlay by placing an amount of an acrylic adhesive between a surface of the substrate and an uncoated surface of the hardcoated film, and by bringing the uncoated surface of the film into a position adjacent to the surface of said substrate;

    (ii) passing the overlay through a laminating nip to eliminate diatomic oxygen from between the film and the substrate, and from the adhesive, said laminating nip pressing the overlay with a substantially constant pressure to create a substantially uniform layer of adhesive between the film and the substrate; and

    (iii) curing the adhesive layer by directing ultraviolet radiation through the film to the adhesive layer to cure the adhesive layer and bond the hardcoated film to the substrate, said cured adhesive layer having a thickness selected from between 0.2 mils and 2.0 mil.

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