| 摘要 |
PURPOSE:To improve tear strength, impact punching strength, gelbo test strength, etc., by laminating specific multi-layered co-extruded film layers, both side faces of which consist of an ethylene copolymer resin and polyolefin resin in such a manner that the ethylene copolymer resin film layers make tight contact with each other. CONSTITUTION:Two sheets of the multi-layered co-extruded film layers 3, both side faces of which consist of the ethylene copolymer resin film layers 1 and the polyolefin resin film layers 2 and which have 20-150mum thickness and contain 0.5-50g/m<2> light shieldable material are so laminated that the respective ethylene copolymer resin film layers make tight contact with each other. The ethylene copolymer resin film layers are preferably made of a low melting point ethylene copolymer resin which is liable to generate blocking or a resin mixture contg. >=20% resin mixture composed thereof. Various PE resins or PP resins having 0.1-10g/10min melt index and 0.930-0.980g/cm<2> density are preferable as the polyolefin resin. The packaging bag having the high tear strength, impact punching strength and gelbo test strength and less curls is thereby obtd. |
