公开(公告)号：US10954673B2

公开(公告)日：2021-03-23

申请号：US16365369

申请日：2019-03-26

申请人： CertainTeed LLC

发明人： David Gomes ,  Tracy H. Panzarella ,  Rachel Z. Pytel ,  Colleen McDowell

IPC分类号： E04D1/20 ,  E04D1/00 ,  B01J2/16

摘要： Provided are roofing granules, such as solar-reflective roofing granules, methods for making them and their use in roofing products. In one aspect, the disclosure provides a collection of solar-reflective roofing granules having a solar reflectivity of at least 70%, wherein substantially each roofing granule comprises an inner layer, an outer layer disposed on an outer surface of the inner layer and substantially surrounding the inner layer, wherein the inner layer and the outer layer are formed from substantially the same composition but have substantially different porosities, the outer layer having a porosity substantially lower than the porosity of the outer layer. Methods for making such roofing granules can include forming layers of substantially the same first and second compositions, wherein the forming of the layer of the second composition is performed under substantially different conditions from the forming of the layer of the first composition.