Conformable Preconditioned Adhesive Sealing Tape

Abstract

An improved pressure sensitive flashing tape that is conformable over uneven or irregular surfaces for use in the construction industry, where a moisture and air seal having full adhesive contact to the adherend is required. The subject tape includes a topsheet layer and an adhesive underlayer. The topsheet is stabilized dimensionally as to tape length and width for ease in application, but is preconditioned with a plurality of diaphragm elements embossed into the topsheet and compacted under pressure so as to enable the tape to conform to raised and indented features, including lap joints, protruding screw heads, dents, holes, cracks and the like, in surfaces associated with flashing and associated building surfaces; thus improving weathertight sealing. The topsheet may also have fold lines disposed relative to the diaphragm elements so as to be complementary in function, the fold lines serving to further enhance conformability and adaptability during and after application.

What is claimed is: 
     
         1 . A flashing tape for weatherproofing, said flashing tape comprising a topsheet overlayer and an adhesive underlayer, the topsheet overlayer having a regular array of embossed and compacted unit diaphragm cells formed from a feedstock film, said compacted unit diaphragm cells having pliant and irresilient walls such that the release tension of the adhesive is greater than the elastic memory tension of the unit diaphragm cells or clusters thereof. 
     
     
         2 . The flashing tape of  claim 1 , wherein said unit diaphragm cells are dimensioned for pliantly sealing over construction fasteners, lap joints and defects, said unit diaphragm cells having a size ranging from 5 diaphragm cells per linear inch to 20 diaphragm cells per linear inch, and more preferably about 25 to 200 diaphragm cells per square inch. 
     
     
         3 . The flashing tape of  claim 16 , wherein said unit diaphragm cells are embossments of said topsheet and are characterized by a stretched dimension that is a multiple of the original thickness of said feedstock web and a compacted dimension that is fractionally 20 to 70% of the peak-to-peak height of the embossments of said array. 
     
     
         4 . The flashing tape of  claim 3 , wherein said unit diaphragm cells are embossments having a triangular base or a hexagonal base. 
     
     
         5 . The flashing tape of  claim 1 , wherein said flashing tape is a component of a building sealing system or fenestration unit. 
     
     
         6 . A roll-to-roll process for manufacturing a flashing tape, which comprises
 (a) embossing a precursor web of a polymeric material on a roller surface of an embossing roller, said precursor web having a first face, a second face, a thickness, a mid-thickness reference point centered therein, a width, and a linear dimension in the machine direction, said polymeric material having a yield point, said embossing roller surface having a regular pattern of adjoining three-dimensional pyramidal polyhedrons having a density of 25 to 200 polyhedra per square inch, said polyhedra each having at least one positive or negative radial dimension greater than said thickness of said precursor web, said at least one radial dimension having a radius relative to a rotational center of said embossing roller such that said yield point of said material is exceeded when pressingly contacted with said roller surface, thereby forming a topsheet web having a first side, a second side, and an array of adjoining diaphragm elements thereon, said array of diaphragm elements having an uncompacted height measured peak-to-peak thereof that is greater than said thickness of said precursor web and said diaphragm elements having an irreversibly stretched film wall thereof having a thickness that is less than said thickness of said precursor web;   (b) extruding an uninterruptedly coating layer of a pressure-sensitive glue onto a release liner layer;   (c) using a pinch roller having a pinch roller pressure adjusted so as to enable simultaneously:
 i) contacting said second side of said topsheet web with said continuous layer of said pressure-sensitive glue on said release liner; 
 ii) compacting each said diaphragm element and film wall thereof to a compacted fractional height that is less than said uncompacted height; 
   thereby forming a conditioned flashing tape rollstock having a topsheet layer, a glue layer, and a release liner layer, said glue layer having a generally smooth external surface when said release liner is removed, said topsheet layer having diaphragm elements characterized by irreversibly stretched and compacted film walls that are generally flattened, crinkled, pliant and irresilient; and,   (d) forming smaller rolls from said rollstock by division thereof.   
     
     
         7 . The process of  claim 6 , wherein said compacted fractional height measured peak-to-peak is 20 to 70% of said uncompacted height. 
     
     
         8 . The process of  claim 6 , further wherein said regular pattern of adjoining three-dimensional pyramidal polyhedrons on said roller surface defines a pattern of fold lines therebetween. 
     
     
         9 . The process of  claim 8 , further comprising configuring said embossing roller to align said fold lines in the machine direction, the cross direction, or to intersect at an angle intermediate to the machine direction and the cross direction. 
     
     
         10 . The process of  claim 9 , further comprising aligning said fold lines at intersecting angles defining the base of a triangle or a hexagon. 
     
     
         11 . The process of  claim 6 , wherein said pyramidal polyhedrons are selected from concave pyramidal polyhedron, convex pyramidal polyhedron, or concavoconvex pyramidal polyhedron. 
     
     
         12 . The process of  claim 11 , wherein said regular pattern comprises an array of alternatingly concave and convex pyramidal polyhedrons. 
     
     
         13 . The process of  claim 6 , wherein said pyramidal polyhedrons are selected from:
 i) a concave or convex pyramidal frustum defining an isosceles triangular base;   ii) a concave or convex pyramidal frustum defining an equilateral triangular base;   iii) a concave or convex pyramidal frustum defining a right angle triangular base;   iv) a concave or convex pyramidal frustum defining a diamond-shaped base;   v) a concave or convex pyramidal frustum defining a square-shaped base;   iv) a concave or convex pyramidal frustum defining a rectangle-shaped base;   or,   v) a concave or convex pyramidal frustum defining a hexagonal base.   
     
     
         14 . A flashing tape product by process, produced by a method comprising:
 (a) irreversibly yielding a precursor web to form an array of unit diaphragm cells at a density of 10 to 400 diaphragm cells per square inch of web, more preferably 25 to 200 diaphragm cells per square inch of web, said array having a peak-to-peak height that is a multiple of the thickness of the precursor web and said diaphragm cells of said array having a film wall thickness that is a fraction of the thickness of the precursor web; thereby defining a topsheet intermediate;   (b) compacting said diaphragm cells of said topsheet intermediate, thereby forming a conditioned topsheet intermediate having a peak-to-peak height that is 20 to 70% of the peak-to-peak height of the topsheet intermediate of step (a);   (c) coating a bottom side of said conditioned topsheet intermediate with an uninterrupted glue layer; and,   thereby forming a flashing tape having a topsheet embossed with conditioned diaphragms and a glue layer coated thereunder.   
     
     
         15 . The product by process of  claim 14 , further comprising sandwiching said glue layer between said conditioned topsheet intermediate and a release liner. 
     
     
         16 . The product by process of  claim 14 , further comprising applying a release formula so that said glue layer will not bond to a top side of said conditioned topsheet intermediate when said tape is rolled up, thereby eliminating the need for a release liner. 
     
     
         17 . The product by process of  claim 14 , wherein said array comprises fold lines disposed between said unit diaphragm cells. 
     
     
         18 . The product by process of  claim 17 , wherein said fold lines are disposed in a machine direction, a cross direction, or a crisscross direction. 
     
     
         19 . The product by process of  claim 17 , wherein said fold lines are disposed to intersect at angles defining a triangular, hexagonal, square, rectangular, diamond, or circular unit cell. 
     
     
         20 . The product by process of  claim 17 , wherein said fold lines define a reticulum of unyielded precursor web between said unit diaphragm cells.