Paper-based lidding for blister packaging
A paper-based lidding material includes a paper layer and a layer containing a cyclic olefin copolymer. The material is useful for blister packaging and particularly suitable for push-through pharmaceutical and food blister packaging. In one embodiment, the lidding material is formed by extrusion coating and includes at least one paper layer, at least one primer layer, at least one tie layer, at least one barrier layer containing one or more cyclic olefin copolymers, and at least one sealant layer in that order. In another embodiment, the paper-based lidding material includes a paper layer laminated to one or more barrier layers containing one or more cyclic olefin copolymers adjacent to one or more sealant layers. Embodiments of the invention can be sealed to a variety of blister films, including films that are chloride-free, to provide environmentally benign blister packages having good moisture properties.
1. A lidding material for blister packaging, wherein the lidding material consists of a first layer of paper and a second layer of a cyclic olefin copolymer; and a sealant layer adjacent to the second layer; wherein the lidding material is characterized by a Mullen burst strength of less than about 30 psi and a tear strength of less than about 50 g/in, and a moisture vapor transmission rate of less than about 0.3 g per 100 in 2 per day.
2. The lidding material of claim 1 wherein the lidding material is characterized by a Mullen burst strength of less than about 25 psi and a tear strength of less than about 30 g/in.
3. The lidding material of claim 1 wherein the lidding material is characterized by a Mullen burst strength of about 10 psi to about 30 psi and Machine Direction-tear strength of about 30 to about 100 grams-force.
4. The lidding material of claim 1 wherein the lidding material is characterized by a moisture vapor transmission rate of less than about 0.25 g per 100 in 2 per day.
5. The lidding material of claim 1 wherein the paper has a weight of about 10 to about 30 lbs/ream.
6. The lidding material of claim 1 wherein the cyclic olefin copolymer is a compound of Formula (I):
wherein, n and p independently represent integers and wherein n and p are chosen so that the melt temperature of the compound is greater than about 150° C.
7. The lidding material of claim 1 wherein the sealant layer is a polyolefin selected from the group consisting of:
a) polyethylene;
b) polypropylene;
c) ethylene acrylate copolymer;
d) ethylene acetate copolymer;
e) modified ethylene acrylate copolymer;
f) modified ethylene acetate copolymer;
g) ionomer; and
h) a mixture of two or more of a-g.
8. A lidding material for push-through blister packaging, wherein the lidding material consists of a first layer consisting of paper, one or more primer layers which consists of polyamine or polyacetate gravure coated on the first layer, one or more tie layers extrusion coated on the primer layer, one or more barrier layers extrusion coated on the tie layer, one or more sealant layers extrusion coated on the barrier layer, and provided a cyclic olefin is present in the at least one barrier layer and wherein the lidding material is characterized by a Mullen burst strength of less than about 30 psi and a tear strength of less than about 50 g/in, and a moisture vapor transmission rate of less than about 0.3 g per 100 in 2 per day.
9. The lidding material of claim 8 wherein an embrittling agent is mixed within at least one of the tie layer or the sealant layer wherein said embrittling agent constitutes an amount of about 5 to about 50% by weight.
10. The lidding material of claim 9 wherein the embrittling agent is a mineral.
11. The lidding material of claim 9 wherein the embrittling agent is one or more of:
a) calcium carbonate;
b) calcium sulfate;
c) glass fiber;
d) kaolin;
e) mica;
f) silica
g) talc
h) wollastonite; and
i) a mixture of two or more of a-h.
12. The lidding material of claim 9 wherein the embrittling agent is within the sealant layer.
13. The lidding material of claim 8 wherein the tie layer is selected from the group consisting of:
a) polyethylene;
b) ethylene acid copolymer;
c) ethylene acetate copolymer;
d) ethylene acrylate copolymer
e) ethylene anhydride copolymer
f) modified ethylene acrylate copolymer;
g) ionomer;
h) polypropylene;
i) anhydride-grafted polypropylene; and
j) a mixture of two or more of a-i.
14. A push-through blister packaging comprising a blister film heat sealed to the lidding material of claim 1 .
15. A push-through blister packaging Comprising a blister film heat sealed to the lidding material of claim 8 .
16. A lidding material for push-through blister packaging, wherein the lidding material consists of a first layer of paper, one or more primer layers which consists of polyamine or polyacetate gravure coated on the first layer, one or more tie layers extrusion coated on the primer layer, one or more barrier layers extrusion coated on the tie layer, one or more sealant layers extrusion coated on the barrier layer; and wherein at least one barrier layer consists of a cyclic olefin copolymer.