CPC C08J 5/18 (2013.01) [B29C 48/0017 (2019.02); B29C 48/022 (2019.02); B29C 48/08 (2019.02); B29K 2105/0085 (2013.01); B29L 2007/008 (2013.01); B29L 2031/712 (2013.01); C08J 2367/03 (2013.01)] | 3 Claims |
1. A sheet of polymeric material, capable of being thermoformed into a desired shape, comprising:
poly(ethylene terephthalate)-poly(ethylene naphthalate (PET-PEN) copolymer where the PEN is present at a level of 2.0% to 15.0% by weight and wherein said PET-PEN copolymer is present in said sheet at a level of at least 80.0% by weight and includes poly(ethylene terephthalate or poly(ethylene terephthalate glycol) at a level of up to 20.0% by weight, wherein said PET-PEN copolymer has an intrinsic viscosity of 0.64 dL/g to 0.90 dL/g, a glass transition temperature, measured according to ASTM D3418-15 of greater than 81.0° C., a heat distortion temperature at 66 psi, as measured by ASTM D648-18 of greater than or equal to 72.0° C., wherein said sheet, at at thickness of 0.01 inches to 0.06 inches indicates one or more of the following mechanical properties:
(a) tensile modulus in the machine direction of at least 260,000 psi and in the transverse direction of at least 248,000 psi;
(b) tensile strength in the machine direction of at least 8,300 psi and in the transverse direction of at least 7950 psi; or
(c) flexural modulus in the machine direction of at least 475,000 psi and in the transverse direction of at least 490,000 psi;
wherein said sheet is thermoformable at a temperature in the range of 245° F. to 315° F.; has a moisture absorption in the range of 0.20% (wt.) to 0.40% (wt.) and wherein after 2 cycles at a sterilization temperature of 35° C. to 65° C., in the presence of ethylene oxide (EO) in conjunction with gamma radiation, the values of flexural modulus in either the machine direction and/or transverse direction will not fall by more than 10%.
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