| abstract |
The present invention relates to the methods for preparing Biaxially oriented multilayer film, the film includes that at least one includes the layer and at least one layer comprising daiamid composition of polyolefin composition, it the described method comprises the following steps: a) melting daiamid composition, the daiamid composition includes: i. semicrystalline polyamides Y, it includes: with the monomeric unit derived from caprolactam of at least amount of 75wt%；With the monomeric unit derived from aliphatic diamine of 2.5 to 12.5wt% amount；With the monomeric unit derived from aromatic diacid of 2.5 to 12.5wt% amount；Wherein weight percent is provided relative to the total weight of the polyamide Y；Ii. with the amorphous polyamides of 2.5 to 50wt% amount of the total weight relative to the daiamid composition；Wherein the amorphous polyamides include: with the monomeric unit derived from aliphatic diamine X of 30 to 70wt% amount；With the monomeric unit derived from aromatic diacid of 30 to 70wt% amount；Wherein weight percent is provided relative to the total weights of the amorphous polyamides；B) composition comprising polyolefin is melted；It c) will be at least from melt coextrusion a) and b) obtained to form the film at least two layers；D) while transmission the film along the direction for being referred to as machine direction, the film is cooled to 50 DEG C of highest of temperature；E) at a temperature of between the Tm of the Tg of polyamide Y and the polyolefin, with the film obtained at least 13 draw ratio stretching step d), wherein the draw ratio is defined as being parallel to the product of the draw ratio of machine direction and the draw ratio perpendicular to machine direction.The invention further relates to the Biaxially oriented multilayer films that can be obtained by the method. |