Polyolefin bonding adhesive film

A polyolefin bonding adhesive film, comprising:

• a support base layer being a cast polypropylene film;
• and
• a bonding adhesive layer being formed on a side surface of the support base layer by co-extrusion;
• wherein the bonding adhesive layer is formed of a first polyolefin copolymer modified by maleic anhydride;
• wherein the first polyolefin copolymer is formed by copolymerization of propylene and 1-butene, a first graft ratio of the maleic anhydride grafted onto the first polyolefin copolymer is between 0.5% and 5%, and a first melt index of the first polyolefin copolymer is between 3 g/10 min and 5 g/10 min as measured according to ASTM D1238 at 190° C. and 2.16 kg;
• wherein, based on the total weight of the support base layer being 100 wt %, a material composition of the support base layer includes:
• 60 wt % to 80 wt % of a propylene block polymer, 15 wt % to 25 wt % of a vinyl elastomer, and 5 wt % to 15 wt % of a second polyolefin copolymer;
• wherein, in the support base layer, the propylene block polymer includes blocks consist of ethylene propylene elastic rubber, and a weight percentage of the ethylene propylene elastic rubber in the propylene block polymer ranges from 18% to 30%;
• wherein the vinyl elastomer is an ethylene-butylene elastomer, and a weight percentage of ethylene in the vinyl elastomer ranges from 30% to 60%;
• wherein the second polyolefin copolymer is modified by maleic anhydride, the second polyolefin copolymer is formed by copolymerization of propylene and 1-butene, a second graft ratio of the maleic anhydride grafted onto the second polyolefin copolymer is between 0.5% and 5%, and a second melt index of the second polyolefin copolymer is between 3 g/10 min and 5 g/10 min as measured according to ASTM D1238 at 190° C. and 2.16 kg;
• and
• wherein the support base layer further comprises 1.000 ppm to 4.000 ppm of a slip agent selected from silicon dioxide and talc.