Multilayer white-opaque biaxially-oriented polyester film, which is matt on one side for packing goods and foods, has base layer, cover layer, amorphous surface layer, and further layer arranged between base layer and cover layer

摘要

The multilayer white-opaque biaxially-oriented polyester film, which is matt on one side for packing goods and foods, comprises a base layer (B), a cover layer (A), an amorphous surface layer (C), and a further layer arranged between the base layer and the cover layer or surface layer. The polyester film contains barium sulfate (17-23 wt.%) as white-coloring pigment in the base layer related to the total weight of the base layer. The cover layer contains polyester, which contains 10-26 mol.% of isophthalic acid derived units related to its total acid quantity. The multilayer white-opaque biaxially-oriented polyester film, which is matt on one side for packing goods and foods, comprises a base layer (B), a cover layer (A), an amorphous surface layer (C), and a further layer arranged between the base layer and the cover layer or surface layer. The polyester film contains barium sulfate as white-coloring pigment. The base layer contains barium sulfate in a concentration of 17-23 wt.% related to the total weight of the base layer. The cover layer contains polyester, which contains 10-26 mol.% of isophthalic acid derived units related to its total acid quantity and particles (PP(A)) in a concentration of 3.0-6.0 wt.% related to the total weight of the cover layer. The average diameter (d 50-value) of the polyester particles is 2.6-7.0 ~mm. The polyester film has a degree of whiteness of greater than 90% and a transparency of less than 40%. The average diameter of the barium sulfate particles is 0.2-3.0 ~mm. The concentration of the polyester particles consists of other materials as barium sulfate. The base layer is arranged between the cover layer and the surface layer. The surface layer has composition differing from the cover layer and contains barium sulfate in a concentration of 2-25 wt.% and additional particles (PP c) in a concentration of 0.001-4 wt.% related to the total weight of the surface layer. The average diameter of the additional particles is 2-8 ~mm. The surface of the cover layer is treated by corona or plasma and has a coating with antistatic agent, a friction coefficient of less than 0.36 and a roughness with R a-value of 200-900 nm. The cover layer and the surface layer have a thickness of 0.6-6.0 ~mm. The total thickness of the polyester film is 10-150 ~mm. The base layer is 50-95% of the total thickness. An independent claim is included for a method for producing a white biaxially-oriented polyester film, which is matt on one side with a base layer and a cover layer.