IMPROVEMENTS IN BUBBLE STABILITY

摘要

The invention includes a copolymer of vinylidene chloride with at least one monounsaturated comonomer and at least one branching monomer in an amount sufficient to increase molecular weight over that of a polymer prepared using the same process and same monomers in the same relative amounts except without the branching monomer, but preferably the branching monomer is present in a quantity not sufficient to result in measurable crosslinking as determined by solubility in tetrahydrofuran at up to 83 °C. The invention includes a process for making the polymer and processes for forming the copolymer or compositions thereof as well as articles comprising the copolymer and compositions thereof. The copolymer exhibits improved bubble stability and is particularly useful for processes in which the copolymer is at least partially oriented in formation such as blow molding, formation of monofilament fiber and film blowing.