Patent ID: 8852738

Claim:
An Intrusion resistant thermal laminating film comprising: (a) a self-supporting polymeric substrate having a glass transition temperature of not greater than about 95° C., the polymeric substrate being selected from the group consisting of a polycyclohexylenedimethylene terephthalate (PCTA), glycol-modified polycyclohexylenedimethylene terephthalate (PCTg), and combinations thereof; (b) a thermal adhesive system adhered to said polymeric substrate to form an intrusion resistant thermal laminating film, said adhesive system is a blend of 35 to 55 weight percent of low density polyethylene (LDPE), 35 to 55 weight percent of maleic anhydride modified linear low density polyethylene (MA-LLDPE), and greater than 5 and less than 15 weight percent of ethylene ethyl acrylate (EEA) copolymer based on the total weight of the thermal adhesive system; wherein said adhesive system having a Vicat softening point that is below the polymeric substrate glass transition temperature and between about 80° C. and 95° C. and said adhesive system having a melt flow index (MFI) of about 15 grams or less per ten minutes; wherein the intrusion resistant thermal laminating film maintains adhesion between the adhesive system and the polymeric substrate and achieves cohesive failure of the adhesive system upon subjecting the intrusion resistant thermal laminating film to an elevated temperature below the polymeric substrate glass transition temperature.