Embossed polymer sheet

Abstract

A high frequency semi-isotropic embossed polymer interlayer sheet is disclosed. The embossed polymer interlayer sheet has a first side; a second side opposing the first side; and an embossed surface on at least one of the sides, and a surface texture ratio, Str, (as measured per ISO 25178) of between 0.1 and 0.99. The embossed polymer sheet may have at least 50 roughness peaks per centimeter (R PC, as measured per ASME B46.1 (1985)). The embossed polymer sheet may have a mottle value of less than or equal to 2.5 (as measured by a Clear Mottle Analyzer (CMA)). The embossed polymer sheet may be polyvinyl butyral.

1 . An embossed polymer interlayer sheet comprising: a first side; a second side opposing the first side; and an embossed surface on at least one of the sides, wherein the embossed polymer interlayer sheet has a high frequency semi-isotropic surface having a surface texture ratio, Str, (as measured per ISO 25178) of between 0.2 and 0.99, a surface roughness, Sz, of from greater than about 10 to less than about 85 microns, and at least 50 roughness peaks per centimeter (R PC, as measured per ASME B46.1 (1985)). 
     
     
         2 . The embossed polymer interlayer sheet of  claim 1 , wherein the Str value (as measured per ISO 25178) is greater than 0.5. 
     
     
         3 . The embossed polymer interlayer sheet of  claim 1 , wherein the Str value (as measured per ISO 25178) is between 0.2 and 0.8. 
     
     
         4 . The embossed polymer interlayer sheet of  claim 1 , wherein the embossed polymer interlayer sheet has at least 100 roughness peaks per centimeter (R PC, as measured per ASME B46.1 (1985)). 
     
     
         5 . The embossed polymer interlayer sheet of  claim 1 , wherein the embossed polymer interlayer sheet has a peak height distribution kurtosis, Sku, of greater than 3.0 (as measured per ISO 25178). 
     
     
         6 . The embossed polymer interlayer sheet of  claim 1 , wherein the embossed polymer interlayer sheet has uniform de-airing and an average light transmission of at least 70% when placed between two glass substrates and de-aired using a cold nip roll process. 
     
     
         7 . The embossed polymer interlayer sheet of  claim 1 , wherein the embossed polymer interlayer sheet has a mottle value of less than or equal to 2.5 (as measured by a Clear Mottle Analyzer (CMA)) when laminated between two glass substrates. 
     
     
         8 . The embossed polymer interlayer sheet of  claim 1 , wherein the embossed polymer interlayer sheet comprises a multi-layer sheet. 
     
     
         9 . The embossed polymer interlayer sheet of  claim 1 , wherein the embossed polymer interlayer sheet comprises poly(vinyl butyral). 
     
     
         10 . An embossed polymer interlayer sheet comprising: a first side; a second side opposing the first side; and an embossed surface on at least one of the sides, wherein the embossed polymer interlayer sheet has a semi-isotropic surface having a surface texture ratio, Str, (as measured per ISO 25178) of between 0.2 and 0.99 and wherein the embossed polymer interlayer sheet has at least 50 roughness peaks per centimeter (R PC, as measured per ASME B46.1 (1985)),
 wherein the polymer sheet is embossed by an embossing roller having a surface comprising blasted voids having a diameter of less than or equal to 0.02 inches and a depth of up to about 200 μm.   
     
     
         11 . The embossed polymer interlayer sheet of  claim 10 , wherein the polymer sheet is embossed by an embossing roller having a surface comprising blasted voids having a diameter of from 0.001 to about 0.01 inches and a depth of between about 10 and about 100 μm. 
     
     
         12 . The embossed polymer interlayer sheet of  claim 10 , wherein the embossed polymer interlayer sheet has uniform de-airing and an average light transmission of at least 70% when de-aired using a cold nip roll process. 
     
     
         13 . The embossed polymer interlayer sheet of  claim 10 , wherein the embossed polymer sheet is embossed by an embossing roller having a surface roughness, Rz, of about 20 to 200 microns. 
     
     
         14 . The embossed polymer interlayer sheet of  claim 10 , wherein the embossed polymer sheet is embossed by a method comprising the steps of: extruding a polymer melt sheet; after the extruding, embossing the polymer melt sheet in a single embossing stage and after the embossing, cooling the polymer melt sheet to form an embossed polymer interlayer sheet, wherein, after the cooling, the polymer interlayer sheet retains substantially all of the embossing applied to the polymer melt sheet. 
     
     
         15 . The embossed polymer interlayer sheet of  claim 10 , wherein the embossed polymer interlayer sheet comprises a multi-layer sheet. 
     
     
         16 . The embossed polymer interlayer sheet of  claim 10 , wherein the embossed polymer interlayer sheet comprises poly(vinyl butyral). 
     
     
         17 . An embossed polymer interlayer sheet comprising: a first side; a second side opposing the first side; and an embossed surface on at least one of the sides, wherein the embossed polymer interlayer sheet has a high frequency semi-isotropic surface having a surface texture ratio, Str, (as measured per ISO 25178) of between 0.2 and 0.99 and having at least 50 roughness peaks per centimeter (R PC, as measured per ASME B46.1 (1985)), and wherein the embossed polymer interlayer sheet has uniform de-airing and an average light transmission of at least 70% when de-aired using a cold nip roll process and a surface roughness, Sz, of from greater than about 10 to less than about 85 microns. 
     
     
         18 . The embossed polymer interlayer sheet of  claim 17 , wherein the embossed polymer interlayer sheet comprises a multi-layer sheet. 
     
     
         19 . The embossed polymer interlayer sheet of  claim 17 , wherein the polymer is polyvinyl butyral. 
     
     
         20 . The embossed polymer interlayer sheet of  claim 17 , wherein the embossed polymer interlayer sheet has a mottle value of less than or equal to 2.5 (as measured by a Clear Mottle Analyzer (CMA)).