Three-dimensional microstructured multilayer products
View Patent ↗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 multilayer sheet including:
a. a first flexible support layer;
b. a second layer comprising a flat and uniform layer of silicone containing material positioned on said first layer;
c. a third layer comprising a three dimensionally microstructured layer of silicone containing material formed as a plurality of ridges, wherein said third layer is in direct contact with and permanently adhered to said second layer;
d. a fourth layer comprising a flexible adhesive substrate having a proximate first surface and a distal second surface, said first surface of said fourth layer being in direct contact with and releaseably secured to said third layer and having formed on said first surface a three dimensional topography which is matingly inversely replicated to conform to said microstructured layer of silicone containing material of said third layer.
2. A multilayer sheet, as defined in claim 1 , wherein said distal second surface of said fourth layer is visually free from any ridge pattern corresponding to said plurality of ridges of said flexible support.
3. A multilayer sheet, as defined in claim 1 , wherein said distal second surface of said fourth layer has an additional exterior layer applied thereto.
4. A multilayer sheet, as defined in claim 1 , wherein said distal second surface of said additional exterior layer is printed with at least one image.
5. A multilayer sheet, as defined in claim 3 , wherein the percentage of initial contact surface between the adhesive layer and the additional exterior layer is from about 15% to 32% of the total covering surface.
6. A multilayer sheet, as defined in claim 3 , wherein said additional exterior layer has a thickness of about 60 microns or less.
7. A multilayer sheet, as defined in claim 3 , wherein said additional exterior layer is facestock.
8. A multilayer sheet, as defined in claim 1 , wherein said ridges are rounded.
9. A multilayer sheet, as defined in claim 1 , wherein said second layer has a thickness of 0.4-1.6 μm.
10. A multilayer sheet, as defined in claim 1 , wherein said ridges have a height of about 3-50 μm.
11. A multilayer sheet, as defined in claim 10 , wherein said ridges have a generally truncated pyramidal cross-sectional shape.
12. A multilayer sheet, as defined in claim 1 , wherein said third layer ridges have a volume of about 15 cm 3 /m 2 .