POLYAMIDE-BASED TUBULAR FILM Russian patent published in 1998 - IPC

FIELD: food industry. SUBSTANCE: invention relates to biaxially oriented tubular film utilized in production of pastelike and plastic-state products submitted to heat treatment at 70 to 125 C. Film material, including polyamide 6 (77-83 wt parts), alifatic copolyamide (7-13 wt parts), aromatic polyamide containing hexamethylenediamine and terephthalic acid units (3-7 wt parts), and a copolymer including olefin units (0.1-5 wt parts), additionally contains ion-exchange resin (3-6 wt parts) and has, as alifatic copolyamide, polycaprolactam /hexamethylenediamine/ adipic acid copolymer and, as copolymer including olefin units, mixture of graft copolymers based on carboxylic and polycarboxylic acids. Tubular film may be multilayer, at least one its layer being composed as indicated above. EFFECT: reduced water, vapor, and oxygen-permeability and increased strength under heat treatment conditions. 6 cl, 2 tbl