Retroreflective article
AssigneeMinnesota Mining and Manufacturing Company
InventorsTzu-Li J. Huang, Walton J. Hammar, James C. Coderre, Mirian D. Nave
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Abstract
The present invention provides improved, flexible retroreflective articles based upon an optically clear, aliphatic polyurethane polymer. The aliphatic polymer has a plurality of hard chain segments of the formula --C(O)N(H)--C.sub.6 H.sub.10 --N(H)C(O)--.
Claims27
A flexible, retroreflective article, comprising a land and an array of retroreflective elements on the land, wherein the retroreflective elements comprise an optically clear, flexible, aliphatic polyurethane polymer wherein the aliphatic polyurethane polymer comprises a first plurality of hard chain segments having the formula
- --C(O)N(H)--C.sub.6 H.sub.10 --N(H)C(O)--
- which are incorporated into the polyurethane polymer.
A flexible, retroreflective article, comprising a land and an array of retroreflective elements on the land, wherein the retroreflective elements comprise an optically clear, flexible aliphatic polyurethane polymer having a softening temperature of at least 110.degree. C.
Dependencies are inferred from the claim text.