Translucent gasket comprising a watermark that is not visible in reflected light

Abstract

The invention relates to a light-transmitting gasket intended to be positioned on the base of a stopper or cap, in the form of a support having a light-transmitting coating applied to at least one of the surfaces thereof. The gasket is characterised in that the coating contains a watermark, i.e. an image visible in transmitted light, but not visible in reflected light.

1 . A light-transmitting gasket intended in particular to be inserted at the bottom of a stopper or cap, in the form of a support on at least one of the faces of which a light-transmitting coating is applied, characterized in that the coating contains a watermark, that is to say an image visible in transmitted light and not visible in reflection. 
     
     
         2 . The gasket according to  claim 1 , characterized in that the light-transmitting coating comprises a paper sheet and/or at least one polymeric film. 
     
     
         3 . The gasket according to  claim 1 , characterized in that the support is made of a foamed material and is advantageously chosen from the group comprising low density polyethylene (PE), polypropylene (PP), PET, and polystyrene (PS). 
     
     
         4 . The gasket according to  claim 3 , characterized in that a density of the foamed material is between 30 and 500 kg/m 3 . 
     
     
         5 . The gasket according to  claim 3 , characterized in that thickness of the foamed material is between 1 and 3 mm. 
     
     
         6 . The gasket according to  claim 1 , characterized in that the support is made of a non-foamed material and is advantageously chosen from the group comprising polyethylene, polyethylene copolymers, thermoplastic elastomers, PP, PET, and PS. 
     
     
         7 . The gasket according to  claim 6 , characterized in that the material has a density between 800 and 1500 kg/m 3 . 
     
     
         8 . The gasket according to  claim 1 , characterized in that the support is made of a non-foamed, non-extruded material. 
     
     
         9 . The gasket according to  claim 8 , characterized in that the paper has a density between 40 and 600 kg/m 3 . 
     
     
         10 . The gasket according to  claim 2 , characterized in that the polymer film is selected from the group comprising PET, PVDC, polyester, PP, PA, and PE. 
     
     
         11 . The gasket according to  claim 2 , characterized in that the polymeric film is white in color. 
     
     
         12 . The gasket according to  claim 2 , characterized in that the watermark is in the form of a white-colored printing. 
     
     
         13 . The gasket according to  claim 1 , characterized in that the watermark is in the form of a printing applied between the support and the light-transmitting coating. 
     
     
         14 . The gasket according to  claim 1 , characterized in that the watermark is applied to the back of the light-transmitting coating. 
     
     
         15 . The gasket according to  claim 8 , wherein the material comprises paper.