Patent ID: 8719964

Claim:
An article comprising a polymer coating on at least a portion of said article's surface, wherein said polymer coating comprises a polyurethane dispersion comprising the reaction product of: (1) an isocyanate functional prepolymer comprising the reaction product of: (i) a polyol; (ii) an isocyanate; and, (iii) a stabilizing ingredient; (2) a chain extender; and, (3) a chain terminator, and wherein said polymer coating further comprises a two-zone structure comprising: (1) an inner zone, comprising: (i) a volume within the interstitial spaces of the constituent material of said article that is approximately 600 micron to 1100 micron thick; and, (ii) a plurality of large polymer cavities, said polymer cavities ranging in size from 50 micron to 900 micron and comprising approximately 20% to 80% of said volume of said inner zone; (2) a porous and translucent outer zone capable of transmitting light, said outer zone comprising: (i) a contiguous polymer layer approximately 40 micron to 120 micron thick, said contiguous polymer layer being bounded on an internal aspect by said inner zone and bounded on an external aspect by an external surface; (ii) a plurality of fine polymer cavities, said polymer cavities being smaller than 50 micron in size and being vertically oriented in relation to one another such that said fine polymer cavities form stomas and/or capillaries throughout the full thickness of said outer zone; and, (iii) an external surface comprising a plurality of up to 5 micron thick asperities positioned randomly thereon.