초록

A multilayer coextruded light-reflecting film is improved by utilizing a mixture of a polyolefin and ethylenevinyl acetate as one of the diverse resinous material which form the plurality of layers.

대표청구항 ▼

A transparent thermoplastic resinous film of at least 10 substantially uniformly thick layers comprising a core having a pair of generally parallel surface layers thereon, said core comprising a plurality of generally parallel layers, said surface and core layers being of transparent thermoplastic r

A transparent thermoplastic resinous film of at least 10 substantially uniformly thick layers comprising a core having a pair of generally parallel surface layers thereon, said core comprising a plurality of generally parallel layers, said surface and core layers being of transparent thermoplastic resinous material in which the contiguous adjacent layers are of diverse resinous material differing in refractive index by at least about 0.03, each surface layer being of greater thickness than any of the core layers and the combined thickness of the surface layers being at least 5% of the thickness of said core, wherein at least one of said diverse resinous materials is a mixture of polyolefin and ethylene vinyl acetate. In a process of forming a transparent thermoplastic resinous film of at least 10 generally parallel layers in which contiguous adjacent layers are of diverse resinous material differing in refractive index by at least 0.03, by coextrusion, the improvement which comprises forming each surface layer so as to be a greater thickness than any of the core layers and such that the combined thickness of the surface layers is at least 5% of the thickness of said core and forming at least one of said diverse resinous materials from a mixture of polyethylene and ethylene vinyl acetate, whereby a substantially uniform thickness of said layers is realized.