초록 ▼

A multilayer preform and container, and method of forming the same, having at least one layer including polyethylene naphthalate (PEN) to provide enhanced oxygen barrier performance and thermal stability. The PEN layer may be a homopolymer, copolymer, or blend of PEN. In a first high-PEN embodiment,

A multilayer preform and container, and method of forming the same, having at least one layer including polyethylene naphthalate (PEN) to provide enhanced oxygen barrier performance and thermal stability. The PEN layer may be a homopolymer, copolymer, or blend of PEN. In a first high-PEN embodiment, the exterior layer contains on the order of 80-100% PEN and 0-20% PET by total weight of the layer, and a core layer of a non-strain hardenable polyester such as PETG. In a second low-PEN embodiment, the exterior layer includes a strain hardenable low-PEN copolymer or blend including on the order of 1-20% PEN and 80-99% PET, and the core layer is a strain-hardenable polyester such as a low-copolymer PET. In a third mid-range PEN embodiment, the exterior wall includes a substantially amorphous PEN copolymer or blend containing on the order of 20-80% PEN and 80-20% of another polyester such as PET, and a strain-hardened core layer of polyester such as a low-copolymer PET. To further enhance the oxygen barrier and thermal stability properties, the core layer may further include a copolymer or blend of PEN. Alternatively, PEN may be provided in an interior layer only.

대표청구항 ▼

A method of forming a container having a substantially transparent multilayer sidewall comprising; forming at an elevated temperature a preform having a substantially amorphous and transparent multilayer sidewall-forming portion including first and third layers of a first polymeric material and a se

A method of forming a container having a substantially transparent multilayer sidewall comprising; forming at an elevated temperature a preform having a substantially amorphous and transparent multilayer sidewall-forming portion including first and third layers of a first polymeric material and a second core layer between the first and third layers of a second polymeric material; wherein the first polymeric material comprises on the order of 80-100% PEN and 0-20% PET by total weight of the layer, and the second polymeric material is a substantially nonstrain-crystallizable polyester which remains substantially transparent when stretched-within an orientation temperature range of the first polymeric material; cooling below the glass transition temperature of the first polymeric material and then reheating the preform within the orientation temperature range of the first polymeric material, wherein the preform is reheated from the exterior such that heat is transferred across the core layer; and expanding the sidewall-forming portion within the orientation temperature range of the first polymeric material to form a container having a substantially transparent multilayer sidewall with strain-crysttallized layers of the first polymeric material.