the sequential polymerization is not added until the monomer employed in the preceding stage has been at least substantially consumed thereby insuring that the concentration of the monomer remaining from that preceding stage is sufficiently low to prevent formation of an excessive proportion of soluble random copolymer the terpolymers ethylene propylene butene preferably butene 1 can be made by any convenient method known to the art e g ziegler natta catalysis and generally have an ethylene content of from about 0 5 to 8 preferably 3 6 wt and a butene content of from about 0 5 6 wt and preferably 1 5 4 5 the terpolymers can have a melt flow rate at 446 u00b0 f of from about 3 to 15 and preferably 5 to 10 layer c consists of highly surface active and high temperature stable polymer groups including polyamide polyethylene terephthalate pet and polycarbonate are prepared in general polycondensation processes pet is the product of a condensation reaction between ethylene glycol and ethylene terephthalic acid polycarbonate may be prepared from aliphatic and cycloaliphatic diols by transesterification with diethyl carbonate the polymer groups however may be prepared in any convenient manner known to the art these groups in particular have high surface tension so they can be coated printed laminated or metallized without corona discharge treatment these added benefits make the present invention more versatile in the flexible packaging applications in preparing the multilayer structure of the present invention the polypropylene.