SANDWICHED FILM AND BAG MADE THEREOF Russian patent published in 2015 - IPC B32B27/32 A61J1/10 B32B25/08 B65D30/02 B65D65/40 

FIELD: process engineering.

SUBSTANCE: invention relates to processing of polymer materials. Sandwiched film comprises top layer (A) and at least one mid layer (B) and bottom layer (C) laid in a definite order. Here, mid layer (B) contains composition (b1) or (b2) described below. Top layer (A) and bottom layer (C) includes, each and independently, a linear ethylene polymer and/or propylene polymer. The latter features fusion point of 140-165°C measured by differential scanning calorimetry and melt flow rate (MFR; ASTM D 1238, 230°C, 2.16 kg charge) on the range of 0.1-20 g/10 min or mix thereof with random copolymer of propylene and α-olefin with chain-length distribution in the range 1.0-3.5 defined by gel penetration chromatography (GPC) and fusion point of 90-125°C measured by differential scanning calorimetry. Composition (b1) contains propylene polymer (p1) that features fusion point of 140-165°C measured by differential scanning calorimetry and melt flow rate (MFR; ASTM D 1238, 230°C, 2.16 kg charge) on the range of 0.1-20 g/10 min. Besides, it contains random copolymer of propylene and·α-olefin (r1) with chain-length distribution in the range 1.0-3.5 defined by gel penetration chromatography (GPC) and fusion point of 90-125°C measured by differential scanning calorimetry and 30-60 wt % of ethylene-based elastomer (the sum of components of propylene polymer (p1), random copolymer of propylene and·α-olefin (r1) and ethylene-base elastomer makes 100 wt %) (in case mid layer (B) composed of composition (b1)). Content of propylene polymer in said sandwiched film relates to the sum of propylene polymer (p1), random copolymer of propylene and·α-olefin (r1) makes 0.1-0.35 in the entire film. Composition (b2) contains 20-55 wt % of random propylene copolymer and that features fusion point of 140-165°C measured by differential scanning calorimetry, 35-60 wt % of ethylene-based elastomer and 6-25 wt % of dielthylene polymer (e1) that features density in the range of 0.950-0.970 g/cm³ and melt flow rate (MFR; ASTM D 1238, 230°C, 2.16 kg charge) on the range of 0.1-20 g/10 min (where the sum of components of random copolymer of propylene and·α-olefin (r1) and ethylene-base elastomer (e1) makes 100 wt %).

EFFECT: higher heat resistance sufficient for sterilisation at 118-121°C, flexibility and transparency unchanged after sterilisation.

9 cl, 4 tbl