US 12,228,755 B2
Retroreflective article comprising multiple locally-laminated layers
Kevin W. Gotrik, Hudson, WI (US); Kui Chen-Ho, Woodbury, MN (US); Graham M. Clarke, Woodbury, MN (US); Scott J. Jones, Woodbury, MN (US); Michael A. McCoy, St. Paul, MN (US); Shri Niwas, Maple Grove, MN (US); David J. Rowe, Roseville, MN (US); Tien Yi T. H. Whiting, St. Paul, MN (US); and Ying Xia, Woodbury, MN (US)
Assigned to 3M Innovative Properties Company, St. Paul, MN (US)
Appl. No. 17/605,654
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Apr. 24, 2020, PCT No. PCT/IB2020/053886
§ 371(c)(1), (2) Date Oct. 22, 2021,
PCT Pub. No. WO2020/217220, PCT Pub. Date Oct. 29, 2020.
Claims priority of provisional application 62/838,569, filed on Apr. 25, 2019.
Prior Publication US 2022/0214478 A1, Jul. 7, 2022
Int. Cl. G02B 5/128 (2006.01)
CPC G02B 5/128 (2013.01) 22 Claims
OG exemplary drawing
 
1. A retroreflective article comprising:
a binder layer; and,
a plurality of retroreflective elements spaced over a length and breadth of a front side of the binder layer, each retroreflective element comprising a transparent microsphere partially embedded in the binder layer so as to exhibit an embedded area of the transparent microsphere;
wherein at least some of the retroreflective elements each comprise a first locally-laminated layer that is embedded between the transparent microsphere and the binder layer; and, a second locally-laminated layer that is embedded between the transparent microsphere and the binder layer;
the first and second locally-laminated reflective layers being in the form of discontinuous, discrete reflective layers that exhibit one or more edges indicating that the reflective layer was locally broken off from a layer of reflective material that previously laterally surrounded the reflective layer, with at least some of the first and second locally-laminated reflective layers exhibiting discontinuities in the form of cracks, gaps or fracture lines;
wherein for at least some of the microspheres on which the first and second locally-laminated, embedded layers are present, at least a portion of the second locally-laminated, embedded layer is positioned in parallel to the first locally-laminated, embedded layer so that incoming light rays can reach the in-parallel portion of the second locally-laminated, embedded layer without having to pass through any portion of the first locally-laminated, embedded layer.