Breathable film cover for window structures

[0002] This application claims benefit to U.S. provisional application Ser. No. 60/075,748, filed Feb. 23, 1998.

[0003] The invention herein resides in the art of film covers for window plates. More particularly, the invention relates to a light reflective and ultraviolet absorptive film cover for windows. Specifically, the invention pertains to a breathable film cover for polycarbonate or polyacrylate plate windows exhibiting light reflective and/or ultraviolet absorptive characteristics.

[0004] It is well known in the art to employ metalized polymeric films to cover glass plates in window structures. Typically, these films are employed to filter ultraviolet (UV) light and/or to reflect light from the window plate. Typically, the polymeric film is one of polyester, polyethylene, polypropylene or the like. While such film covers have proven to be effective in the past for covering and filtering/reflecting light from glass panels, there are materials other than glass which are presently being used for window panels and panes. Presently, plastic material such as polycarbonate and polyacrylate are being used as the primary window structure. These materials are strong, light weight, shatter proof and of high clarity, serving well for window structures, and particularly in skylights, verandas, sun rooms, and the like.

[0005] It has been found that when the prior art metalized polymeric films are attached to polycarbonate or polyacrylate plates, problems develop. Specifically, bubbles, craters, or tunneling appears when the metalized film is applied to such plastic plates. It has come to be found that plastic plates such as those of polycarbonate and polyacrylate contain moisture that creates such defects at the interface of the adhesive and the plate when the plate loses its inherent moisture. The moisture escape is termed degasification. These defects appear because the polymeric film used for such applications is impervious to moisture, providing an excellent barrier against moisture transfer. Being impermeable to the escaping moisture, the objectionable bubbles, craters and tunnels develop at the interface between the film and the plastic plate.

[0006] In view of the fact that it is desirable to employ polycarbonate and polyacrylate plates for certain window structures, and in further view of the fact that such window structures often require the implementation of reflective and/or filtering films, there is a need in the art for a metalized polymeric film which is breathable and capable of adhering to polycarbonate and polyacrylate plates without the development of bubbles, craters or tunnels as a result of degasification of the plate material.

[0007] In light of the foregoing, it is a first aspect of the invention to provide a breathable film cover for window structures.

[0008] It is another aspect of the invention to present a breathable film cover for window structures which is particularly adapted for implementation with polycarbonate and polyacrylate plates.

[0009] Still a further aspect of the invention is the provision of a breathable film cover for window structures having light reflective and filtering capabilities.

[0010] Yet an additional aspect of the invention is the provision of a breathable film cover for window structures which is efficient, effective, and conducive to implementation with state of the art materials.

[0011] The foregoing, and other aspects of the invention which will become apparent as the detailed description proceeds are attained by the implementation of a plasticized polyvinyl chloride film having a metalized coating thereon and adhesively attached to a polycarbonate or polyacrylate plate by means of an ultraviolet absorptive adhesive.

[0012] For a complete understanding of the objects, techniques and structure of the invention reference should be made to the following detailed description and accompanying drawing wherein a cross-sectional view of a window structure of polycarbonate or polyacrylate is shown with a breathable film cover adhered thereto in accordance with the invention

[0013] Referring now to the drawing, it can be seen that a window structure manufactured in accordance with the invention is designated generally by the numeral 10. The window 10 includes a plate 12 of polycarbonate or polyacrylate, defining the window pane or transparent portion. The plate 12 receives a metalized plasticized polyvinyl chloride (PVC) film thereover. As shown in the drawing, the plasticized PVC film 18 has a metalization coating 16 adhered to an inner surface thereof, which in turn receives an adhesive layer 14 adapted for securing engaging with the plate 12. According to the preferred embodiment of the invention, the adhesive 14 includes a UV absorber. An anti-scratch/anti-static coating 20 is provided over the plasticized PVC film 18.

[0014] It will be appreciated that in accordance with the invention, the composite 14-20 is adhesively secured to the plate 12 on the interior of the building for which the plate 12 serves as a window or transparent structure. Accordingly, the anti-scratch/anti-static coating 20 is at the innermost portion of the window structure 10 when employed in a building.

[0015] In accordance with the invention, the polymeric plasticized PVC film 18 is a clear stabilized film and the adhesive 14 is an acrylic adhesive which may be either permanent or removable, in either case containing a UV absorber. A suitable PVC film is MACal 9899 manufactured by Morgan Adhesives Company. A suitable removable adhesive is MR 983, both of which are solution acrylic pressure sensitive adhesives of Morgan Adhesives Company, and permanent adhesive is MP 319, each of which would be provided with 3 percent TINUVIN, manufactured by Ciba-Geigy, as a UV absorber. Those skilled in the art will understand that TINUVIN is a liquid benzotriazole type of ultraviolet absorber that imparts good light stability to a variety of polymers during use.

[0016] The plasticized PVC film 18, even with the metalization coating 16, is permeable with respect to water and, accordingly, any moisture escaping from the polycarbonate or polyacrylate plate 12 will simply pass through the adhesive 14, metalization coating 16, and coating 20 to the atmosphere. Accordingly, bubbles, craters, and tunnels are eliminated and the laminate 14-20 presents a light shield and filter for polycarbonate and polyacrylate plates which is as secure and attractive as the predecessor films of polyester, polyethylene and polypropylene for glass.

[0017] Thus it can be seen that the objects of the invention have been satisfied by the structure presented above. While it is contemplated that various modifications, enhancements and adaptations may be made of the invention, it is to be understood that the scope and breadth of the invention is that defined by the claims.