Patent ID: 7368165

Claim:
A heat-sealable polymeric film comprising an oriented substrate layer of polymeric material having on a surface thereof a heat-sealable coating layer which consists of a copolyester and, optionally, one or more additives; the copolyester consisting of repeat units of one or more aliphatic dicarboxylic acids, one or more aromatic dicarboxylic acids selected from the group consisting of terephthalic acid, isophthalic acid, and phthalic acid, and a stoichiometric amount of a glycol component consisting of one or more glycols selected from the group consisting of aliphatic glycols and cycloaliphatic glycols, wherein the coating layer is less than about 8 microns in thickness; and wherein the one or more additives are selected from the group consisting of cross-linking agents, dyes, pigments, lubricants, anti-oxidants, radical scavengers, UV absorbers, thermal stabilisers, anti-blocking agents, surface active agents, slip aids, optical brighteners, gloss improvers, prodegradents, viscosity modifiers, dispersion stabilizers, and particulate inorganic fillers; wherein said heat-sealable polymeric film is peelable and wherein the concentration of said one or more aromatic dicarboxylic acids in the copolyester is in the range from 40 to 70 mol % based on all the dicarboxylic acid components of the copolyester, and the concentration of said one or more aliphatic dicarboxylic acids in the copolyester is in the range from 30 to 60 mol % based on all the dicarboxylic acid components of the copolyester.