Matte finish biaxially oriented polypropylene film for cold seal release applications

DETAILED DESCRIPTION The present invention is based upon the discovery of a new packaging film formulation which provides both a matte finish surface and cold seal release properties.
The composite films of the present invention can be reverse printed and pattern cold seal coated on a cold seal receptive surface thereof and released from the opposing cold seal release surface without the need for a cold seal release overprint varnish or migratory slip additives.
The invention relates to single or dual web polypropylene films or multilayer packaging films which can be reverse printed and/or pattern cold seal coated on a cold seal receptive surface thereof yet be releasable from the opposing release surface without the need for a cold seal release overprint varnish and/or migratory slip agents which deaden the cold seal composition.
This eliminates a step in the converting process as well as reduces the overall production costs.
In another embodiment a packaging film comprises a polymeric film surface on one side of a core wherein the film surface has a matte finish and gives excellent cold seal release without relying on conventional migratory slip and antiblock additives.
The other side of the core is provided with a surface treated polymeric film layer which enables excellent adhesion of a cold seal cohesive composition.
The composite films and matte finish release layers of the present invention demonstrate: A.
Good to excellent cold seal release to commercially applied cold seals cohesives.
B.
Immediate and permanent cold seal release; no additive migration is required.
C.
High haze, low gloss, matte finish surface.
D.
Excellent and permanent coefficient of friction.
E.
Good antiblock to reverse printed inks.
F.
Good ink adhesion.
G.
Good lamination bond strengths.
H.
No cold seal deadening in finished lamination roll form.
The aforementioned properties and advantages are achieved by the present invention, for example, in one embodiment which provides a coextruded biaxially oriented polyolefin packaging film comprising a core layer having a matte-finish cold seal release layer formed on one side thereof and a cold seal receptive skin layer formed on the opposite side thereof