Retroreflective laminate comprising a tear resistant film

Abstract

The present invention relates to a laminate and an article comprising a retroreflective layer having a retroreflective viewing surface and an opposing surface and a tear resistant film disposed on the retroreflective layer. The finished article is preferably flexible and suitable for use as roll-up signs, flags, banners and other retroreflective articles requiring similar flexibility including other traffic warning and personal safety items.

What is claimed is:  
     
         1 . A laminate comprising a retroreflective layer having a retroreflective viewing surface and a tear resistant film disposed on the retroreflective layer; wherein the tear resistant film has a tensile modulus of at least 120 kpsi (828 MPa).  
     
     
         2 . The laminate of  claim 1  wherein the tear resistant film is a single film having a nominal thickness of x in microns and a Graves area in at least one direction of at least about 40+0.4(x) kpsi % (276+2.76(x) MPa %).  
     
     
         3 . The laminate of  claim 2  wherein the tear resistant film has a Graves elongation at break of at least 20%.  
     
     
         4 . The laminate of  claim 9  wherein the tear resistant film has a Graves elongation at break of at least 40%.  
     
     
         5 . The laminate of  claim 1  wherein the laminate is substantially free of fibrous scrim.  
     
     
         6 . The laminate of  claim 1  wherein the retroreflective layer and tear resistant film are bonded directly to each other or bonded by means of an intermediate layer, having a minimum 90 degree peel strength of at least 0.5 lbf/in (0.9 Newtons/cm).  
     
     
         7 . A retroreflective article comprising the laminate of  claim 1;  wherein the article can be wrapped by hand around a mandrel having a diameter of about ½ inch (1.3 cm) at 25° C. without cracking.  
     
     
         8 . The retroreflective article of  claim 7  wherein said article is selected from the group of roll-up signs, flags, banners, roll-up sheeting, cone wrap sheeting, post wrap sheeting, barrel wrap sheeting, license plate sheeting, barricade sheeting, sign sheeting vehicle marking sheeting, segmented vehicle marking sheeting, pavement marking tape, pavement marking sheeting, tape, decal and sew-on retroreflective articles.  
     
     
         9 . The laminate of  claim 1  wherein the tear resistant film is transparent.  
     
     
         10 . The laminate of  claim 6  wherein the tear resistant film is disposed on the retroreflective viewing surface of the retroreflective layer.  
     
     
         11 . The laminate of  claim 6  wherein the tear resistant film comprises a light stabilizing compound, ultraviolet light absorbing compound, and mixtures thereof.  
     
     
         12 . The laminate of  claim 1  wherein the tear resistant film is provided as at least two film layers, the laminate having a Graves area of at least 60 kg %.  
     
     
         13 . The laminate of  claim 1  wherein the tear resistant film has a tensile modulus of at least 175 kpsi (1,208 MPa) in at least one direction.  
     
     
         14 . The laminate of  claim 1  wherein the tear resistant film has a tensile modulus of at least 240 kpsi (1,656 MPa) in at least one direction.  
     
     
         15 . The laminate of  claim 1  wherein the tear resistant film has tensile modulus of at least 450 kpsi (3,105 MPa) in at least one direction.  
     
     
         16 . The laminate of  claim 1  wherein the tear resistant film is a multilayer film.  
     
     
         17 . The laminate of  claim 16  wherein the multilayer film comprises at least one surface comprising a thermoplastic polymeric material layer that is bonded directly to the retroreflective viewing surface of the retroreflective layer.  
     
     
         18 . The laminate of  claim 17  wherein the thermoplastic polymeric material layer comprises co-polyethylene terephthalate.  
     
     
         19 . The laminate of  claim 19  wherein the multilayer tear resistant film comprises alternate layers of a stiff polyester or copolyester and a ductile thermoplastic polymer wherein the polyester or copolyester has a tensile modulus greater than 200 kpsi (1380 MPa) and the ductile material has a tensile modulus of less than 200 kpsi and a tensile elongation of greater than 50%.  
     
     
         20 . The laminate of  claim 16  wherein the multilayer film comprises a total of more than five stiff and ductile layers situated one on the other in a parallel array, the stiff layer having an average nominal thickness of greater than about 1 micron.  
     
     
         21 . The laminate of  claim 1  further comprising at least one tie layer disposed between said retroreflective layer and said tear resistant film.  
     
     
         22 . The laminate of  claim 1  further comprising at least one backing layer.  
     
     
         23 . A laminate comprising a retroreflective layer and a tear resistant film disposed on the retroreflective layer; wherein the tear resistant film is a multilayer film.  
     
     
         24 . A laminate comprising a retroreflective layer and a tear resistant film, wherein said laminate is substantially free of fibrous scrim and wherein the Graves area of the laminate is at least 150 kg %.