Multi-layer polyisophthalate and polyterephthalate articles and process therefor

Claim 1

A multi-layer packaging material, comprising: (a) at least a layer made from a polyterephthalate compound or copolymers thereof, said polyterephthalate compound made by the reaction of terephthalic acid or esters thereof with ethylene glycol and up to 30 mole percent of one or more glycols having from 3 to 12 carbon atoms, said polyterephthalate copolymer made by reacting terephthalic acid or esters thereof and up to 30 mole percent of a 4 to 40 carbon atom dicarboxylic compound with ethylene glycol and up to 30 mole percent of one or more of a 3 to 12 carbon atom glycol, said polyterephthalate copolymer made by the reaction of one or more different said dicarboxylic compounds or one or more different said glycols, said dicarboxylic compound being other than terephthalic acid or an ester thereof and selected from the group consisting of an alkyl dicarboxylic acid, an aryl dicarboxylic acid, an alkyl substituted aryl dicarboxylic acid, a dimer carboxylic acid, a diester of an alkyl dicarboxylic acid, a diester of an aryl or alkyl substituted aryl carboxylic acid, an alkali sulfo dialkyl isophthalate, and combinations thereof; wherein said polyterephthalate compound has an intrinsic viscosity of 0.6 dl/g or greater and a glass transition temperature of from about 60° C. to about 100° C.; and (b) at least a layer made from a polyisophthalate compound or copolymers thereof, said polyisophthalate being the reaction product of an isophthalic compound and a glycol having from 2 to 12 carbon atoms, said isophthalic compound selected from the group consisting of isophthalic acid, and an alkyl ester of isophthalic acid having from 10 to 20 carbon atoms, said diol being ethylene gycol and containing from 0 to 60 mole percent of one or more compounds selected from the group consisting of a glycol having from 3 to 12 carbon atoms, a glycol ether having from 4 to 12 carbon atoms, and combinations thereof; said copolymers of said polyisophthalate being the reaction product of said isophthalic compound, said diol, and up to 60 mole percent of a carboxylic compound having from 4 to 40 carbon atoms based upon said isophthalic compound and said dicarboxylic acid or said ester thereof, said dicarboxylic acid or ester thereof being other than said isophthalic compound wherein said polyisophthalate compound has an intrinsic viscosity of 0.5 dl/g or greater, a glass transition temperature of from about 35° C. to about 100° C., an oxygen permeability of 7 cc·mil/100 in 2 ·day·atm or less, and a CO 2 permeability of 30 cc·mil/100 in·day·atm or less; wherein the layer made from a polyisophthalate compound has a thickness which ranges from about 10 percent to about 90 percent of the total thickness of the packaging material.