ENHANCED PVOH-BASED BARRIER LAYER COMPOSITION, BARRIER LAYER AND METHODS FOR ITS MANUFACTURE

摘要

There is provided a packaging material comprising a fibre based substrate and a gas barrier layer based on a polyvinyl alcohol (PVOH), wherein said gas barrier layer comprises an interpolymer complex forming agent (IPCFA), which IPCFA is a watersoluble polymer exhibiting functional groups capable of forming hydrogen bonds with -OH groups of the PVOH. Said PVOH has a weight average molecular weight (M_w) measured according to ASTM D4001 - 13 in the range of about 80 kg/mol to 135 kg/mol, the proportion of said IPCFA to PVOH in said gas barrier layer is in the range of 0.5 to 7.0 % (w/w) and said packaging material has an oxygen permeability (OP) below 14 ml μm/m² day atm, which OP is obtained by multiplying the oxygen transmission rate (OTR) of the packaging material measured according to ASTM F1927-7 at a relative humidity (RH) of 80% and 23 °C by the thickness of the gas barrier layer.