US 11,027,523 B2 · Polyester film incorporating silicone for release of canned meat products

Abstract

Embodiments herein relates to a Bisphenol A-free multi-layer biaxially oriented polyester (BOPET) film, for lamination on metal sheets, which could be used for food containers. The BOPET film has at least one outer release layer, which aids in the release of food, such as a high protein food source, when food is cooked and sterilized in direct contact with the outer release layer. The BOPET film can be laminated to metals used in the manufacture of food containers with the outer release layer being exposed to allow a direct food contact between the surface of the outer release layer and food. More particularly, the invention relates to a novel outer release layer resin composition comprising an ultra high molecular weight siloxane polymer and a polyethylene trephthalate resin; and an alkali-metal phosphate and a phosphoric acid compound added, during polymerization of the outer release layer resin composition, as a catalyst/additive package to the ingredients forming the outer release layer resin composition. A wax component can be added in the outer release layer, for more robust release performance.

Claims8

Dependent claims

A polyester film comprising an outer release layer (Layer A) and a core layer (Layer B);

the outer release layer comprising:
(a) about 93 wt. % to 99.9 wt. % of a polyethylene terephthalate resin P1, the polyethylene terephthalate resin P1 comprising (i) an alkali metal phosphate in an amount of 1.3 mol/ton of the polyester resin P1 to 3.0 mol/ton of the polyester resin P1, and (ii) phosphoric acid in an amount of from 0.4 to 1.5 times by mole that of the alkali metal phosphate, (b) 0.1-2 wt. % of a silicone resin comprising a polydimethylsiloxane resin, and (c) 0.1-3 wt. % silica;
and
the core layer comprising a polyester resin P2 and about 15 wt % to about 45 wt % of polybutylene terephthalate (PBT);
wherein the polyester film is free of Bisphenol A, and wherein weight percentages of said (a), said (b), and any optional one or more additional ingredients in the outer release layer total 100 wt. %, and
wherein the outer release layer is free of wax and has a food area coverage of about 5% or less as measured according to Food Release Test;
wherein the silicone resin has a kinematic viscosity ranging from 10-5×106 centistokes at room temperature.

4 more elements

Dependencies are inferred from the claim text.

Polyester film incorporating silicone for release of canned meat products

Life of this patent

Polyester film incorporating silicone for release of canned meat products

Life of this patent

Abstract

Claims8