US 9,809,009 B2
Multiple layer interlayer having improved optical and sound insulation properties
Jun Lu, East Longmeadow, MA (US); Wenjie Chen, Amherst, MA (US); Curtis Schilling, III, Kingsport, TN (US); John D'Errico, Glastonbury, CT (US); Weihong Cui, Longmeadow, MA (US); Zhou Li, Northborough, MA (US); and Jeffrey B. Hurlbut, West Springfield, MA (US)
Assigned to Solutia Inc., St. Louis, MO (US)
Filed by Solutia Inc., St. Louis, MO (US)
Filed on Dec. 8, 2014, as Appl. No. 14/563,622.
Prior Publication US 2016/0159050 A1, Jun. 9, 2016
Int. Cl. B32B 27/08 (2006.01); B32B 27/22 (2006.01); B32B 7/02 (2006.01); B32B 27/30 (2006.01)
CPC B32B 27/08 (2013.01) [B32B 7/02 (2013.01); B32B 27/22 (2013.01); B32B 27/306 (2013.01); B32B 2250/246 (2013.01); B32B 2270/00 (2013.01); B32B 2307/102 (2013.01); B32B 2307/418 (2013.01); B32B 2307/558 (2013.01); B32B 2307/56 (2013.01); B32B 2419/00 (2013.01); B32B 2457/12 (2013.01); B32B 2605/00 (2013.01); B32B 2605/18 (2013.01)] 20 Claims
 
1. A polymer interlayer comprising:
at least one soft layer having a first refractive index, the soft layer comprising a first poly(vinyl acetal) resin having a first residual hydroxyl content and a first residual acetate content, and a first plasticizer;
at least one stiffer layer having a second refractive index, the stiffer layer comprising a second poly(vinyl acetal) resin having a second residual hydroxyl content and a second residual acetate content, and a second plasticizer;
wherein at least one of the first and second plasticizers is a high refractive index plasticizer having a refractive index of at least about 1.460;
wherein the absolute value of the difference between the first refractive index and the second refractive index (delta RI) is less than about 0.010;
wherein the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 2.0 weight percent; and
wherein the polymer interlayer has a damping loss factor (η) (as measured by ISO 16940) of at least about 0.15 at 20° C. and a sound transmission loss (STL) (as measured by ASTM E90 (2009) at 20° C.) of at least 37 decibels.