Adhesives having a microreplicated topography and methods of making and using same

Abstract

Adhesives having a microreplicated topography are prepared from contacting a microembossed pattern to a layer of adhesive. When an adhesion interface is established between the layer of adhesive and a supporting substrate, the topography of the adhesive surface controls the performance of the adhesion interface. Articles having microreplicated adhesive surfaces are also disclosed that have an advantage of providing microchannels for fluid egress for an effective period of time. Multiple microembossed patterns produce microreplicated adhesive surfaces having both microchannels for fluid egress and pegs for improved adhesive properties.

1 . An adhesive article comprising a continuous pressure sensitive adhesive layer having a first major surface and a second major surface, said first major surface comprising: 
 (a) a plurality of lands that provide a bonding surface for bonding the article to a substrate; and    (b) a plurality of channels between the lands that extend below the lands to a depth of about 3 μm to about 45 μm, and enable fluid egress when the article is in contact with to the substrate,    wherein the channels occupy about 1% to about 65% of the total area of the first major surface of the adhesive layer.    
   
   
       2 . The article of  claim 1 , wherein the channels are interconnected.  
   
   
       3 . The article of  claim 1 , wherein the channels define a square grid.  
   
   
       4 . The article of  claim 1 , wherein the channels define a series of hexagons.  
   
   
       5 . The article of  claim 1 , wherein the channels define a series of diamonds.  
   
   
       6 . The article of  claim 1 , wherein the channels are substantially parallel to each other.  
   
   
       7 . The article of  claim 1 , wherein the channels occupy about 2% to about 50% of the total area of the first major surface of the adhesive layer.  
   
   
       8 . The article of  claim 1 , wherein the channels occupy about 3% to about 40% of the total area of the first major surface of the adhesive layer.  
   
   
       9 . The article of  claim 1 , wherein the channels occupy about 4% to about 30% of the total area of the first major surface of the adhesive layer.  
   
   
       10 . The article of  claim 1 , wherein the channels occupy about 5% to about 15% of the total area of the first major surface of the adhesive layer.  
   
   
       11 . The article of  claim 1 , wherein the channels have a cross sectional shape selected from the group consisting of curved, rectangular, trapezoidal, bimodal, and triangular.  
   
   
       12 . The article of  claim 11 , wherein the channels have a bimodal cross sectional shape.  
   
   
       13 . The article of  claim 1 , wherein the channels extend below the lands to a depth of about 3 μm to about 20 μm.  
   
   
       14 . The article of  claim 1 , wherein the channels extend below the lands to a depth of about 5 μm to about 30 μm.  
   
   
       15 . The article of  claim 1 , wherein the channels extend below the lands to a depth of about 6 μm to about 20 μm.  
   
   
       16 . The article of  claim 1 , wherein the channels have a width of up to about 500 μm.  
   
   
       17 . The article of  claim 1 , wherein the channels have a width of about 200 μm to about 250 μm.  
   
   
       18 . The article of  claim 1 , wherein the channels have a width up to about 200 μm.  
   
   
       19 . The article of  claim 1 , wherein the channels have a width of about 90 μm to about 190 μm.  
   
   
       20 . The article of  claim 1 , wherein the channels have a width of about 50 μm to about 120 μm.  
   
   
       21 . The article of  claim 1 , wherein the channels are arranged such that the spacing between the channels is about 0.77 mm to about 2.54 mm.  
   
   
       22 . The article of  claim 1 , wherein the channels are arranged such that the spacing between the channels is about 0.8 mm to about 1.3 mm.  
   
   
       23 . The article of  claim 1 , wherein the channels are arranged such that the spacing between the channels is about 1.3 to about 2.5 mm.  
   
   
       24 . The article of  claim 1 , wherein the pressure sensitive adhesive is tacky at room temperature.  
   
   
       25 . The article of  claim 1 , wherein the adhesive layer comprises an acrylic pressure sensitive adhesive.  
   
   
       26 . The article of  claim 25  wherein the acrylic pressure sensitive adhesive is tacky at room temperature.  
   
   
       27 . The article of  claim 1 , wherein the adhesive layer comprises a crosslinked pressure sensitive adhesive.  
   
   
       28 . The article of  claim 1 , wherein the adhesive layer has a thickness of at least about 5 μm.  
   
   
       29 . The article of  claim 1 , wherein the adhesive layer has a thickness of about 20 μm to about 50 μm.  
   
   
       30 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that when the article is applied to a substrate and a bond is established between the lands and the substrate, at least a portion of the channels remain open for a period of time sufficient to remove fluid from the interface between the article and the substrate.  
   
   
       31 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that at least a portion of the channels remain open during the period in which the article is applied to a substrate and a bond is established between the lands and the substrate.  
   
   
       32 . The article of  claim 31 , wherein the channels occupy about 2% to about 50% of the total area of the first major surface of the adhesive layer.  
   
   
       33 . The article of  claim 31 , wherein the channels occupy about 5% to about 15% of the total area of the first major surface of the adhesive layer.  
   
   
       34 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that at least a portion of the channels remain open (a) during the period in which the article is applied to a first substrate and a bond is established between the lands and the first substrate, and (b) thereafter when the article is removed from the first substrate and re-applied to a substrate that may be the same as, or different from, the first substrate.  
   
   
       35 . The article of  claim 34 , wherein the channels occupy about 2% to about 50% of the total area of the first major surface of the adhesive layer.  
   
   
       36 . The article of  claim 34 , wherein the channels occupy about 5% to about 15% of the total area of the first major surface of the adhesive layer.  
   
   
       37 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that following application of the article to a substrate and establishment of a bond between the lands and the substrate, at least a portion of the channels remain open for at least one hour at 22° C. and 50% relative humidity.  
   
   
       38 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that following application of the article to a substrate and establishment of a bond between the lands and the substrate, at least a portion of the channels remain open for at least 24 hours at 22° C. and 50% relative humidity.  
   
   
       39 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that following application of the article to a substrate and establishment of a bond between the lands and the substrate, at least a portion of the channels remain open for at least 8 days at 22° C. and 50% relative humidity.  
   
   
       40 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that following application of the article to a substrate and establishment of a bond between the lands and the substrate, at least a portion of the channels remain open for at least 24 hours in an oven maintained at 66° C.  
   
   
       41 . The article of  claim 1 , wherein the pressure sensitive adhesive and channel structure are selected such that following application of the article to a substrate and establishment of a bond between the lands and the substrate, at least a portion of the channels remain open for at least 8 days in an oven maintained at 66° C.  
   
   
       42 . The article of  claim 1 , further comprising a release liner having a first major surface contacting the first major surface of the adhesive layer.  
   
   
       43 . The article of  claim 42 , wherein the first major surface of the release liner comprises (a) a plurality of lands corresponding to the lands of the first major surface of the adhesive layer, and (b) a plurality of ridges corresponding to the channels of the first major surface of the adhesive layer.  
   
   
       44 . The article of  claim 1 , further comprising a backing on the second major surface of the adhesive layer.  
   
   
       45 . The article of  claim 44 , wherein the backing has (i) a first major surface on the second major surface of the adhesive layer and (ii) a second major surface, wherein the second major surface of the backing is capable of being graphically imaged.  
   
   
       46 . The article of  claim 44 , wherein the backing has (i) a first major surface on the second major surface of the adhesive layer and (ii) a second major surface, wherein the second major surface of the backing bears a graphic image.  
   
   
       47 . The article of  claim 45 , wherein the article is in the form of a large format image graphic film.  
   
   
       48 . The article of  claim 46 , wherein the article is in the form of a large format image graphic film.  
   
   
       49 . The article of  claim 44 , wherein the backing is selected from the group consisting of foils, metallic plates, ceramic plates, polymeric films, vibration damping materials, reflective sheeting, retroreflective sheeting, and combinations thereof.  
   
   
       50 . The article of  claim 49 , wherein the backing comprises a flexible polymeric film.  
   
   
       51 . The article of  claim 50 , wherein the flexible polymeric film is selected from the group consisting of polyesters, polyolefins, polyvinyl chloride, and combinations thereof.  
   
   
       52 . The article of  claim 51 , wherein the backing comprises polyvinyl chloride.