High strength broadband twisted nematic liquid crystal solar control laminates, processes to produce, and uses thereof

Abstract

Provided are multilayer laminates having one or more layers comprising twisted nematic liquid crystals and one or more layers of a polymeric sheet comprising a polymer with a modulus between 20,000 psi (138 MPa) and 100,000 psi (690 MPa). The twisted nematic liquid crystal layers reflect infrared radiation. Thus, the multilayer laminates are useful to reduce the transmission of infrared energy. For example, in some embodiments the multilayer laminates are useful as windows to reduce energy consumption necessary to cool the interior of a structure such as an automobile or building. Preferably, the multilayer laminates retain the beneficial properties of safety glass. The multilayer laminates may include additional layers such as infrared absorbing layers, half wave plates, and the like, to minimize the transmission of infrared energy. The multilayer laminates may also include further additional layers such as polymeric films, polymeric sheets, rigid sheets, and the like.

1 . A process for producing a multilayer laminate article for reflecting infrared radiation, said process comprising the steps of:
 (a) applying a cholesteric liquid crystal layer having infrared-reflecting properties to a first substrate;   (b) applying a liquid solvent-free chemical adhesive agent to a surface of the cholesteric liquid crystal layer;   (c) applying a second substrate to the surface of the cholesteric liquid crystal layer to which the liquid solvent-free chemical adhesive agent has been applied, to form a sandwich structure having an edge and two outer surfaces;   (d) applying pressure to the outer surfaces of the sandwich structure; and   (e) curing the sandwich structure; and   (f) optionally, removing the first substrate from the sandwich structure.   
     
     
         2 . A process according to  claim 1  wherein the method of applying the cholesteric liquid crystal layer is selected from the group consisting of knife-casting, bar casting, cast-film extrusion, stripper casting, and cascade casting. 
     
     
         3 . A process according to  claim 1  wherein the liquid solvent-free chemical adhesive agent is applied as a bead to the surface of the cholesteric liquid crystal layer. 
     
     
         4 . A process according to  claim 1  comprising processing the sandwich structure through a roll laminator to apply pressure. 
     
     
         5 . A process according to  claim 1  wherein the sandwich structure is thermally cured or photochemically cured. 
     
     
         6 . A process according to  claim 1  wherein two or more cholesteric liquid crystal layers are applied to the first substrate.