Light stable fluorescent vinyl suitable for use as a highway retroreflective roll-up sign
AssigneeAvery Dennison Corporation
InventorDrew J. Buoni
Life of this patent
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Abstract
Polyvinyl chloride (“PVC”) compositions and articles are provided which are suitable for fabricating flexible, reflective roll-up roadway signs in which a fluorescent perylene imide dye is present in the PVC reflective layer. The compositions afford enhanced fluorescence durability of perylene imide fluorescent dyes in the articles through the combination of a polymeric hindered amine light stabilizing compound having molecular weight greater about 1500, and a benzophenone ultraviolet absorbing compound. The compositions and articles preferably further comprise a polymeric plasticizer having molecular weight in the range of about 2000 to about 8000 to provide enhanced retention of retroreflectivity in flexible PVC highway signs.
Claims29
A fluorescence-stabilized polymeric composition comprising:
- polyvinyl chloride resin;
- a fluorescent dye selected from the class consisting of perylene imide fluorescent dyes;
- an ultraviolet absorbing compound selected from the class consisting of benzophenone ultraviolet absorbers;
- and a light stabilizing compound selected from the class consisting of polymeric hindered amine light stabilizer compounds having molecular weight greater than about 1500.
A flexible road sign capable of being manually rolled and unrolled by a user, wherein the sign comprises a fluorescent, retroreflective polymeric sheet, said sheet comprising:
- a polyvinyl chloride resin having an intrinsic viscosity in the range of about 1.02 to about 1.14;
- a polymeric plasticizer having molecular weight in the range of about 2000 to about 5000;
- a fluorescent perylene imide dye;
- an ultraviolet absorbing benzophenone compound;
- a polymeric hindered amine light stabilizing compound having molecular weight greater than about 1500;
- and wherein said sheet comprises a plurality of retroreflective elements.
A flexible, rollable fluorescence-stabilized retroreflective road sign comprising a retroreflective, flourescent polymeric sheet, said sheet comprising;
- (i) polyvinyl chloride resin having an intrinsic viscosity in the range of about 1.08 to about 1.10;
- (ii) a plasticizer mixture comprising (a) a polymeric plasticizer selected from polyester glutarate, adipate or sebacate plasticizers having molecular weight in the range of about 2500 to about 4200, and (b) a monomeric phthalate plasticizer having molecular weight less than about 1000;
- wherein the polyester plasticizer constitutes about 25 to about 45 percent by weight of the plasticizer mixture;
- said plasticizer mixture being present in the polymeric sheet in an amount ranging from about 30 to about 35 parts per hundred parts by weight of said polyvinyl resin in the sheet;
- (iii) one or more perylene imide fluorescent dyes, said one or more dyes in combination constituting about 0.05 to about 0.5 percent by weight of the polymeric sheet;
- (it) an ultraviolet absorbing compound comprising 2-hydroxy4-n-octoxybenzophenone present in an amount constituting about 0.2 to about 4 percent by weight of the polymeric sheet;
- (v) a polymeric hindered amine light stabilizing compound comprising the polymerization product of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine and having molecular weight greater than about 2500 wherein the light stabilizing compound constitutes about 0.1 to about 3 percent by weight of the polymeric sheet;
- and
- (vi) a plurality of cube-corner retroreflective elements.
Dependencies are inferred from the claim text.