Fluoropolymer compositions with improved gas impermeability
AssigneeDuPont-Mitsui Fluorochemicals Co., Ltd.
InventorShinichi Namura
Life of this patent
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Abstract
A composition of tetrafluoroethylene/perfluoro(alkyl vinyl ether) having at least 4 wt % perfluoro(alkyl vinyl ether) and a melt flow rate of no greater than 4 g/10 min, and 5 to 30 wt % low molecular weight PTFE, has improved gas impermeability and also mechanical strength.
Claims9
A melt-fabrication composition consisting essentially of a copolymer of tetrafluoroethylene and perfluoro(alkyl vinyl ether) (PFA) and about 5 to about 30 wt % of low molecular weight polytetrafluoroethylene (PTFE), based on the combined weight of the PFA and PTFE, wherein the low molecular weight PTFE is characterized by a heat of crystallization of at least about 50 J/g and wherein the perfluoro(alkyl vinyl ether) content of the PFA is at least about 4 wt %, based on the total weight of the copolymer, and the PFA has a melt flow rate (MFR) of no more than about 4 g/10 min.
An article for handling liquid consisting essentially of a copolymer of tetrafluoroethylene and perfluoro(alkyl vinyl ether) (PFA) and about 5 to about 30 wt % of low molecular weight polytetrafluoroethylene (PTFE), based on the combined weight of the PFA and PTFE, wherein the low molecular weight PTFE is characterized by a heat of crystallization of at least about 50 J/g and wherein the perfluoro(alkyl vinyl ether) content of the PFA is at least about 4 wt %, based on the total weight of the copolymer, and the PFA has a melt flow rate (MFR) of no more than about 4 g/10 min.
Dependencies are inferred from the claim text.