Retroreflective sheeting with improved topcoat
AssigneeAvery Dennison Corporation
InventorsSusan L. Pohto, Richard J. Katona, George H. Wise, Robert K. Rega
Life of this patent
Estimating the term…
Abstract
Retroreflective sheeting having an aliphatic polyurethane topcoat is described. The aliphatic polyurethane topcoat is obtainable from a mixture comprising (A) an aliphatic polyurethane derived from an aliphatic polyisocyanate and a polyester polyol prepared from a mixture comprising (A-1) a dicarboxylic acid component comprising isophthalic acid as the major dicarboxylic acid; and (A-2) a polyol component; and (B) cellulose acetate butyrate. The mixture also may contain (C) at least one non-reactive solvent, and optionally, (D) one or more surfactants including, for example, hydroxy-containing non-silicone surfactants.
Claims32
Retroreflective sheeting having an aliphatic polyurethane topcoat obtained from a film-forming mixture comprising
- (A) an aliphatic polyurethane derived from an aliphatic polyisocyanate and a polyester polyol prepared from a mixture comprising
- (A-1) a dicarboxylic acid component comprising isophthalic acid as the major dicarboxylic acid;
- and
- (A-2) a polyol component;
- and
- (B) cellulose acetate butyrate.
An embedded lens retroreflective sheeting comprising
- (A) a monolayer of transparent microsphere lenses;
- (B) A polymeric spacing layer underlying and contacting the bottom surfaces of the lenses and having a back surface that is spaced from the bottom surfaces of the lenses;
- (C) a reflective layer having its top surface in contact with the back surface of the spacing layer;
- and
- (D) an aliphatic polyurethane topcoat layer overlying and conforming the top surface of the lenses and having a flat top surface, said topcoat being obtained from a film-forming mixture comprising
- (D-1) an aliphatic polyurethane derived from an aliphatic polyisocyanate and a polyester polyol prepared from a mixture of
- (D-1-a) a dicarboxylic acid component comprising at least 40 mole percent of isophthalic acid;
- and
- (D-1-b) a polyol component;
- and
- (D-2) cellulose acetate butyrate.
Dependencies are inferred from the claim text.