Hot-melt adhesive resin film and production method thereof
The present invention relates to a hot-melt adhesive resin film which does not cause peeling between respective layers, has an excellent adhesive force, and has strong adherability even in severe durability evaluation, to various planar or film-like adherends such as metal, glass, and plastic, and a production method thereof. More particularly, the present invention relates to a hot-melt adhesive resin film including a first adhesive layer, a first intermediate layer, a substrate layer having heat resistance, a second intermediate layer, and a second adhesive layer, which are laminated in this order, in which the first adhesive layer and the second adhesive layer comprise an acid-modified polyolefin resin, and a production method thereof.
1. A hot-melt adhesive resin film comprising a first adhesive layer, a first intermediate layer, a substrate layer having heat resistance, a second intermediate layer, and a second adhesive layer, which are laminated in this order,
wherein said first adhesive layer and said second adhesive layer include an acid-modified polyolefin resin (A) having a melting point of 140° C. to 180° C.,
said substrate layer is a layer formed of cyclic olefin polymer, and
said first intermediate layer and said second intermediate layer include acid-modified polypropylene, metallocene-based polyethylene, and metallocene-based polypropylene.
2. The hot-melt adhesive resin film according to claim 1 , wherein said first adhesive layer and said second adhesive layer further include an epoxy group-containing resin or an oxazoline group-containing resin.
3. The hot-melt adhesive resin film according to claim 1 , wherein said first adhesive layer and said second adhesive layer contain 80 parts by mass to 99.9 parts by mass of the acid-modified polyolefin resin (A), and 0.1 parts by mass to 20 parts by mass of an epoxy group-containing polyolefin-based resin (B) having a main chain which is obtained by copolymerizing an olefin compound and an epoxy group-containing vinyl monomer and a side chain bound to said main chain, and having a melting point of 80° C. to 120° C.
4. The hot-melt adhesive resin film according to claim 1 , wherein said first adhesive layer and said second adhesive layer contain 90 parts by mass to 99.9 parts by mass of the acid-modified polyolefin resin (A), and 0.1 parts by mass to 10 parts by mass of a phenol novolak-type epoxy resin (C) which is solid at an ambient temperature.
5. The hot-melt adhesive resin film according to claim 1 , wherein said first adhesive layer and said second adhesive layer contain 80 parts by mass to 99.9 parts by mass of the acid-modified polyolefin resin (A), and 0.1 parts by mass to 20 parts by mass of an oxazoline group-containing styrene-based resin (D) having a number average molecular weight of 50,000 to 250,000.
6. The hot-melt adhesive resin film according to claim 1 , wherein said substrate layer comprises an inorganic filler.
7. A method of producing the hot-melt adhesive resin film as defined in claim 1 , the method comprising producing the hot-melt adhesive resin film by a coextrusion so as to laminate the first adhesive layer, the first intermediate layer, the substrate layer having heat resistance, the second intermediate layer, and the second adhesive layer in this order.