TH28085A - A biaxially rotating, uniaxially shrinking polypropylene film with an HDPE surface. - Google Patents

Abstract

DC60 (21/04/40) A biaxially rotated and uniaxially heated multilayer film will have a core layer consisting of at least 70% by weight of the multilayer film, and a surface layer consisting of at least one polyolefin closely attached to the core layer, prepared by biaxially rotated co-extrusion and then co-extrusion with 10 to 40% stretching in the machining direction. The core layer consists of isotactic polypropylene and modifiers that reduce the crystallinity of the polypropylene by increasing chain imperfections or decreasing the isotactic properties of the polypropylene core. Examples of modifiers can be selected from groups comprising atactic polypropylene, syndiotactic polypropylene, ethylene-propylene copolymer, propylene-butene-1 copolymer, ethylene-propylene-butene-1 terpolymer, and low-density polyethylene straight chain. The surface layer can be high-density polyethylene on both sides or high-density polyethylene on one side and isotactic polypropylene on the other. A biaxially rotated and uniaxially heat-shrinkable multilayer film will have a core layer consisting of at least 70% by weight of the multilayer film, and a surface layer consisting of at least one polyolefin closely attached to the core layer, prepared by biaxially rotated co-extrusion and then co-rotated by 10 to 40% adhesion in the machining direction. The core layer consists of isotactic polypropylene and modifiers that reduce the crystallinity of the polypropylene by increasing chain imperfections or decreasing the isotactic properties of the core, which may consist of polypropylene syndiotactic polypropylene, ethylene-propylene-butene-1 terpolymer, and low-density linear polyethylene. The surface layer can be high-density polyethylene on both sides or high-density polyethylene on one side and isotactic polypropylene on the other.

Claims (10)

1. Multilayer films that rotate in two axes and contract uniaxially when heated consist of a core layer made of polypropylene and outer layers consisting of at least one high-density polyethylene component closely bonded to the core. The core layer consists of isotactic polypropylene and modifiers that reduce the crystallinity of the polypropylene by adding imperfections or reducing the isotactic properties of the polypropylene core. 2. A multilayer film of claim 1, whereby the surface layer consists of high-density polyethylene with an anti-blocking agent. 3. A multilayer film of claim 1, whereby an outer layer consisting of isotactic polypropylene is closely bonded to the aforementioned core layer. 4. A multilayer film of claim 3 whereby the surface layer consisting of such isotactic polypropylene contains an anti-blocking agent. 5. A multi-layer film of claim number 1, whereby a surface layer consisting of high-density polyethylene is placed on both sides of the said core layer. 6. A multilayer film of claim number 1, whereby the modifier is syndiotactic polypropylene. 7. A multilayer film of claim 1, whereby the core layer consists of polybutin-1 terepsalate (PBT) dispersed into particles with a diameter of 0.2 to 2.0 microns. 8. A multilayer film of claim I, whereby the core layer consists of a large number of lavaforms by cavitation relating to solid cavitation material. 9. A multilayer film of claim number 1, where the core layer consists of a polypropylene support layer containing 2 to 18% by weight of titanium oxide. 10. A multilayer film of claim I, whereby such film is subjected to shrinkage of more than 15% at 100°C to 145°C in the first direction with -/5% stability in a second direction perpendicular to the first direction. (10 claims, 2 pages, 0 images)