Method of Forming a Three-Dimensional Microstructure on a Surface, Uses Thereof, and Microstructured Products so Obtained

Abstract

A method of forming a three-dimensional microstructure on a flat surface of a support, comprising the application of a first flat and uniform layer of silicone on said surface of support and the application on the first layer of silicone of a second three dimensionally microstructured layer of silicone, said first layer and second layer of silicone become integrally connected to thus form a common three-dimensional microstructure ensuring anti-adhesive properties distributed regularly on the surface of the support, so that any flexible surface of substrate, in particular a surface of adhesive deposited on said layers of silicone will be microstructured by inverse replication of the three-dimensional microstructure formed by the two layers of silicone, where said layers of silicone are fixed by hardening by heating or by exposure to an ultraviolet or electronic radiation, or a combination thereof, applications thereof and films, notably self-adhesive films, such as those microstructured by said method.

1 . A method of forming a three-dimensional microstructure on a flat surface of a support, characterized in that the method comprises the application of a first flat and uniform layer of silicone on said surface of the support and the application on the first layer of silicone of a second three dimensionally microstructured layer of silicone, said first layer and second layer of silicone become integrally connected to thus form a common three-dimensional microstructure ensuring anti-adhesive properties distributed regularly on the surface of the support, so that any flexible surface of a substrate will be microstructured by inverse replication of the three-dimensional microstructure formed by the two layers of silicone, where said layers of silicone are fixed by hardening. 
     
     
         2 . (canceled) 
     
     
         3 . The method according to  claim 1 , characterized in that the three-dimensional microstructure formed by the first layer and second layer of silicone comprises micro-honeycombed motifs. 
     
     
         4 . The method according to  claim 1 , characterized in that a surface of adhesive is deposited on said second layer of silicone. 
     
     
         5 . The method according to  claim 1 , characterized in that the first layer of silicone comprises a functionalized polyorganosiloxane with groups 
       
         
           
           
               
               
           
         
         as a crosslinking agent, and at least one functionalized polyorganosiloxane which can react with the crosslinking agent. 
       
     
     
         6 . The method according to  claim 1 , characterized in that the first layer of silicone comprises a functionalized polyorganosiloxane with groups 
       
         
           
           
               
               
           
         
         as a crosslinking agent, and at least one functionalized polyorganosiloxane with groups 
       
       
         
           
           
               
               
           
         
         which can react with the crosslinking agent, where R comprises at least one ethylenic unsaturation. 
       
     
     
         7 . The method according to  claim 5 , characterized in that the first layer of silicone comprises a catalyst for the activation of said crosslinking reaction. 
     
     
         8 . The method according to  claim 7 , characterized in that the activation catalyst is selected from the group consisting of platinum, rhodium and tin based catalysts. 
     
     
         9 . The method according to  claim 1 , characterized in that the first layer of silicone comprises, in addition, one or more additives chosen from the group consisting of adhesion modulators, reaction accelerators and inhibitors, pigments, surfactants and fillers. 
     
     
         10 . The method according to  claim 1 , characterized in that the first layer of silicone is hardened by heating. 
     
     
         11 . The method according to  claim 10 , characterized in that the layer of silicone is hardened by heating at temperatures of 70-200° C. 
     
     
         12 . The method according to  claim 1 , characterized in that the first layer of silicone is hardened by exposure to electronic radiation. 
     
     
         13 . The method according to  claim 1 , characterized in that the first layer of silicone has a thickness of 0.4-1.6 μm. 
     
     
         14 . The method according to  claim 1 , characterized in that said second layer of silicone comprises at least a polydimethylsiloxane with acrylate function, and a ketone type catalyst wherein the second layer of silicone is hardened by exposure to ultraviolet radiation. 
     
     
         15 . The method according to  claim 1 , characterized in that said second layer of silicone comprises at least a polydimethylsiloxane with epoxy function, and an iodonium salt type catalyst, wherein the second layer of silicone is hardened by exposure to ultraviolet radiation. 
     
     
         16 . The method according to  claim 1 , characterized in that said second layer of silicone comprises at least a polydimethylsiloxane with acrylate function, wherein the second layer of silicone is hardened by exposure to one of ultraviolet radiation and electronic radiation. 
     
     
         17 . The method according to  claim 1 , characterized in that the three-dimensional microstructure formed by said first layer of silicone and said second layer of silicone consists of microembossed motifs, whose crest height varies from 3 to 50 μm. 
     
     
         18 . The method according to  claim 1 , characterized in that the second layer of silicone is applied to the first layer in a quantity in a range from 3 to 25 g/m 2 . 
     
     
         19 . The method according to  claim 1 , characterized in that the first layer of silicone and the second layer of silicone have surface tensions in a range from 15 to 25 mN/m. 
     
     
         20 . The method according to  claim 1 , characterized in that said support comprises one of the elements selected from the group consisting of paper, polyethylene film, polyester film, polypropylene film, polyvinyl chloride film, and polyamide film. 
     
     
         21 . The method according to  claim 4 , characterized in that said adhesive is deposited on said first layer and second layer of silicone by one of the steps consisting of coating directly on said layers and lamination. 
     
     
         22 . The method according to  claim 21 , characterized in that, in the case of direct coating, the adhesive is in one of a liquid form and a hot cast solid form. 
     
     
         23 . The method according to  claim 4 , characterized in that the adhesive is applied to a flexible plastic film. 
     
     
         24 . The method according to  claim 4 , characterized in that during the application of said adhesive surface on any surface, the adhesive surface contact with the latter is from 15 to 32%. 
     
     
         25 . A three dimensionally microstructured film comprising a substrate including a surface of adhesive which is three dimensionally microstructured by the method according to  claim 1  and comprises motifs on the surface opposite the surface which is in contact with the microstructure formed by said layers of silicone. 
     
     
         26 - 32 . (canceled) 
     
     
         33 . The method according to  claim 6 , characterized in that the first layer of silicone comprises a catalyst for the activation of said crosslinking reaction. 
     
     
         34 . The method according to  claim 1 , characterized in that the first layer of silicone is hardened by exposure to an ultraviolet radiation. 
     
     
         35 . The method according to  claim 1 , characterized in that said second layer of silicone comprises at least a polydimethylsiloxane with epoxy function, wherein the second layer of silicone is hardened by exposure to electronic radiation. 
     
     
         36 . The method according to  claim 22  wherein the adhesive in liquid form is one of an organic solvent and an emulsion in water.