Secure envelope and method for securing information

Abstract

A windowed envelope is disclosed comprising: a first panel with an interior and an exterior side; a second panel attached to the first panel to define an interior portion having opposite side edges, a closed edge portion and an opening portion opposite the closed edge portion to provide access to the interior portion of the envelope; and a flap for sealingly adhering to an exterior surface of the first panel. The flap has an interior and an exterior side and is attached to the second panel at an edge of the second panel opposite the closed edge portion. The envelope comprises thereon an adhesive layer on the interior side of the flap comprising an adhesive; wherein a non-transparent window is located on the first panel or the second panel. The window comprises a reducible dye and a microencapsulated reducing agent, which is adapted to irreversibly change to a transparent window upon heating the non-transparent window to a temperature above room temperature.

1 . A windowed envelope comprising:
 a first panel with an interior and an exterior side;   a second panel attached to the first panel to define an interior portion having opposite side edges, a closed edge portion and an opening portion opposite the closed edge portion to provide access to the interior portion of the envelope; and   a flap for sealingly adhering to an exterior surface of the first panel, the flap having an interior and an exterior side and attached to the second panel at an edge of the second panel opposite the closed edge portion, the envelope comprising thereon an adhesive layer on the interior side of the flap comprising an adhesive;   wherein a non-transparent window is located on the first panel or the second panel, the window comprising a reducible dye and a microencapsulated reducing agent, which is adapted to irreversibly change to a transparent window upon heating the non-transparent window to a temperature above room temperature.   
   
   
       2 . The envelope of  claim 1 , wherein the dye and the reducing agent are included in an ink vehicle overcoated on the window. 
   
   
       3 . The envelope of  claim 1 , wherein the dye and the reducing agent are included in a polymeric matrix of the window. 
   
   
       4 . The envelope of  claim 1 , wherein the dye is selected from the group consisting of methylene green, methylene blue and rezasurin. 
   
   
       5 . The envelope of  claim 1 , wherein the reducing agent is bleach. 
   
   
       6 . The envelope of  claim 1 , wherein the reducing agent is a chemical base. 
   
   
       7 . The envelope of  claim 1 , wherein printed or written information is located inside the envelope behind the window. 
   
   
       8 . The envelope of  claim 1 , wherein the window is located on the second panel. 
   
   
       9 . The envelope of  claim 1 , wherein the window comprises two heat insulating layers with the window located therebetween and adjacent each heat insulating layer. 
   
   
       10 . The envelope of  claim 3 , wherein the polymeric matrix comprises at least one substance selected from the group consisting of IR absorbents, microwave absorbents, nano ceramics and air bubbles in the polymeric matrix. 
   
   
       11 . A method of detecting information located inside a closed envelope without opening the envelop comprising:
 providing a windowed envelope comprising: a first panel with an interior and an exterior side; a second panel attached to the first panel to define an interior portion having opposite side edges, a closed edge portion and an opening portion opposite the closed edge portion to provide access to the interior portion of the envelope; and a flap for sealingly adhering to an exterior surface of the first panel, the flap having an interior and an exterior side and attached to the second panel at an edge of the second panel opposite the closed edge portion, the envelope comprising thereon an adhesive layer on the interior side of the flap comprising an adhesive; wherein a non-transparent window is located on the first panel or the second panel, the window comprising a reducible dye and a microencapsulated reducing agent, which is adapted to irreversibly change to transparent upon heating the window to a temperature above room temperature; wherein information is located in the envelope behind the window;   heating the window to a temperature above room temperature, wherein the window irreversibly changes from non-transparent to transparent thereby exposing the information located in the envelope behind the window.   
   
   
       12 . The method of  claim 11  further comprising reading the information located in the envelope behind the window after the heating step. 
   
   
       13 . The method of  claim 12 , wherein the reading step comprises optically reading the information. 
   
   
       14 . The method of  claim 12 , further comprising transferring the read information to a database for storage. 
   
   
       15 . The method of  claim 11 , wherein the heating step comprises heating the window using a heat lamp. 
   
   
       16 . A windowed envelope comprising:
 a first panel with an interior and an exterior side;   a second panel attached to the first panel to define an interior portion having opposite side edges, a closed edge portion and an opening portion opposite the closed edge portion to provide access to the interior portion of the envelope; and   a flap for sealingly adhering to an exterior surface of the first panel, the flap having an interior and an exterior side and attached to the second panel at an edge of the second panel opposite the closed edge portion, the envelope comprising thereon an adhesive layer on the interior side of the flap comprising an adhesive;   wherein a non-transparent window is located on the first panel or the second panel, the window comprising a thermochromic material, which is adapted to change to a transparent window upon heating the non-transparent window to a temperature above room temperature.   
   
   
       17 . The envelope of  claim 16 , wherein the window comprises two heat insulating layers with the window located therebetween and adjacent each heat insulating layer. 
   
   
       18 . The envelope of  claim 16 , wherein the window comprises a polymeric matrix with the thermochromic material located in the polymeric matrix, the polymeric matrix further comprising at least one substance selected from the group consisting of IR absorbents, microwave absorbents, nano ceramics and air bubbles. 
   
   
       19 . A method of detecting information located inside a closed envelope without opening the envelop comprising:
 providing a windowed envelope comprising: a first panel with an interior and an exterior side; a second panel attached to the first panel to define an interior portion having opposite side edges, a closed edge portion and an opening portion opposite the closed edge portion to provide access to the interior portion of the envelope; and a flap for sealingly adhering to an exterior surface of the first panel, the flap having an interior and an exterior side and attached to the second panel at an edge of the second panel opposite the closed edge portion, the envelope comprising thereon an adhesive layer on the interior side of the flap comprising an adhesive; wherein a non-transparent window is located on the first panel or the second panel, the window comprising a thermochromic material, which is adapted to irreversibly or reversibly change to transparent upon heating the window to a temperature above room temperature; wherein information is located in the envelope behind the window;   heating the window to a temperature above room temperature, wherein the window changes from non-transparent to transparent thereby exposing the information located in the envelope behind the window.   
   
   
       20 . The method of  claim 19 , wherein the window comprises two heat insulating layers with the window located therebetween and adjacent each heat insulating layer. 
   
   
       21 . The method of  claim 19 , further comprising reading the information located in the envelope behind the window after the heating step. 
   
   
       22 . The method of  claim 21 , wherein the reading step comprises optically reading the information. 
   
   
       23 . The method of  claim 21 , further comprising transferring the read information to a database for storage. 
   
   
       24 . A method of detecting whether contents of a closed envelope have been read or tampered with comprising the steps of:
 providing a sealed, windowed envelope comprising: a first panel with an interior and an exterior side; a second panel attached to the first panel to define an interior portion having opposite side edges, a closed edge portion and an opening portion opposite the closed edge portion to provide access to the interior portion of the envelope; and a flap for sealingly adhering to an exterior surface of the first panel, the flap having an interior and an exterior side and attached to the second panel at an edge of the second panel opposite the closed edge portion, the envelope comprising thereon an adhesive layer on the interior side of the flap comprising an adhesive; wherein a window is located on the first panel or the second panel, the window comprising at least two layers each comprising a thermochromic material, wherein one of the layers is transparent at room temperature and another layer is non-transparent at room temperature; and then sequentially,   heating the layers to a temperature above about 50 C and less than about 100 C, wherein both layers become transparent; and   heating the layers to a temperature above about 100 C, wherein one of the layers is non-transparent and the other layer is transparent.   
   
   
       25 . The method of  claim 24 , further sequentially comprising:
 allowing the layers to reach about room temperature wherein both layers become non-transparent;   heating the layers to between about 50 C and less than about 100 C; and   
     heating the layers to a temperature above about 100 C wherein one of the layers is non-transparent and the other layer is transparent.