Patent ID: 6472077
Filing Date: 2002-10-29
Classification: B32B,C08L,Y10T

Abstract:
A block-resistant film, comprising:(a) a core layer of a thermoplastic polymer, the core layer having a first side and a second side, and the thermoplastic polymer of the core layer being selected from the group consisting of propylene homopolymer, butene-1, propylene-ethylene copolymer, and propylene-butene-1 copolymer; (b) a functional layer which is printable or sealable or treatable for printing or sealing on the first side of the core layer, the functional layer comprising a film-forming polymer selected from the group consisting of (i) a homopolymer of ethylene or propylene, (ii) a copolymer of ethylene, propylene, butylene, or an olefin having from 5 to 10 carbon atoms, (iii) a terpolymer of ethylene, propylene, butylene, or an olefin having from 5 to 10 carbon atoms, and (iv) a blend thereof; and (c) a block-resistant layer on the second side of the core layer comprising a thermoplastic polymer and an amount of from I to about 10 wt %, based upon the entire weight of the block-resistant layer, of a polydialkylsiloxane having a number average molecular weight greater than about 250,000, the amount of polydialkylsiloxane being sufficient to inhibit blocking of the block-resistant layer to the functional layer when they are in contact, and the thermoplastic polymer of the block-resistant layer being selected from the group consisting of propylene homopolymer, ethylene homopolymer, a copolymer of propylene and an olefin having either 2 carbon atoms or from 4 to 8 carbon atoms, a copolymer of ethylene and an olefin having from 3 to 8 carbon atoms, ethylene-propylene-butene-1 terpolymer, and blends thereof, wherein an external surface of said block-resistant layer is flame treated or corona treated.