Symbol of the Government of Canada


Patent Document Number: 2716988

(54) English Title: EXTRUSION-COATED LIDDING FOIL FOR PUSH-THROUGH BLISTER PACKAGING

(54) French Title: FEUILLE OPERCULE REVETUE PAR EXTRUSION POUR EMBALLAGE-COQUE ENFONCABLE


Claims:

Note: Claims are shown in the official language in which they were submitted.


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CLAIMS


1. A push-through blister packaging, comprising:
a. a lidding foil comprising:

i. all aluminum foil; and

ii. one or more tie layer comprising ethylene acid copolymer
extrusion coated on said aluminum foil and one or more sealant layer
comprising
modified ethylene acrylate copolymer extrusion coated on said tie layer, one
or
both of said tie and sealant layers having an embrittling agent mixed therein
in
an amount of about 5 to about 50% by weight;

wherein said lidding foil is characterized by a Mullen burst strength of
about 50 kPa to about 250 kPa and a MD tear strength of about 0.25 N to about
1.0 N; and

b. a polymeric blister film,

wherein said lidding foil is heat sealed to said blister film to form said
push-through blister packaging containing a substance which may be retrieved
from said packaging by pushing the substance against and breaking said lidding

foil.


2. The lidding foil of claim 1 wherein said embrittling agent is mixed
in one or both of said tie and sealant layers in an amount of about 10 to
about
30% by weight.


3. The lidding foil of claim 1 wherein said embrittling agent is a
mineral.


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4. The lidding foil of claim 3 wherein said 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.


5. The lidding foil of claim 1 wherein said embrittling agent is equally
distributed within said sealant layer.


6. The lidding foil of claim 1 wherein said embrittling agent is non-equally
distributed within said sealant layer, said embrittling agent being more
concentrated within a portion of said sealant layer that is adjacent to said
tie
layer.


7. The lidding foil of claim 1 wherein said aluminum foil has a thickness of
about 20 Ám to about 25 Ám.


8. The lidding foil of claim 1 wherein said aluminum foil is hard tempered
(unannealed).


9. The lidding foil of claim 1 wherein said aluminum foil is soft tempered
(anncaled).


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10. The lidding foil of claim 1 wherein said one or more tie layer is coated
on
said foil in an amount of about 3 to about 8 g/m2, and said one or more
sealant
layer is coated on said tie layer in an amount of about 6 to about 16 g/m2.


11. A push-through blister packaging comprising:
a. a lidding foil comprising:

i. an aluminum foil;

ii. one or more tie layer comprising ethylene acid copolymer
extrusion coated on said aluminum foil and one or more sealant layer
comprising
modified ethylene acrylate copolymer extrusion coated on said tie layer, one
or
both of said tie and sealant layers having an embrittling agent mixed therein
in
an amount of about 5 to about 50% by weight;

wherein said tie layer is extrusion coated to a coatweight of about 3 to
about 8 g/m2 and said sealant layer is extrusion coated to a coatweight of
about 6
to about 16 g/m2. ; and

b. a polymeric blister film,

wherein said lidding foil is heat sealed to said blister film to form said
push-through blister packaging containing a substance which may be retrieved
from said packaging by pushing the substance against and breaking said lidding

foil.


12. The lidding foil of claim 11 wherein said lidding foil is
characterized by a Mullen burst strength of about 50 kPa to about 250 kPa and
a
MD teat strength of about 0,25 N to about 1.0 N.


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13. The lidding foil of claim 11 wherein said embrittling agent is

mixed in one or both of said tie and sealant layers in an mount of about 10 to

about 30% by weight.


14. The lidding foil of claim 1 1 wherein said embrittling agent is a
mineral.


15. The lidding foil of claim 14 wherein said 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.


16. The lidding foil of claim 11 wherein said embrittling agent is
equally distributed within said sealant layer.


17. The lidding foil of claim 11 wherein said embrittling agent is non-
equally distributed within said sealant layer, said embrittling agent being
more
concentrated within a portion of said sealant layer that is adjacent to said
tie
layer.


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18. The lidding foil of claim 11 Wherein said aluminum foil has a

thickness of about 20 Ám to about 25 Ám.


19. The lidding foil of claim 11 wherein said aluminum foil is hard
tempered (i.e, unannealed).


20. The lidding foil of claim 11 wherein said aluminum foil is soft
tempered (i.e, annealed).


21. A method of making a push-through blister packaging comprising the
steps of:

a. making a lidding foil comprising the steps of,

i. providing an extrusion coating machine;

ii. providing a roll of aluminum foil on the extrusion coating
machine;

iii. extrusion coating a tie layer comprising ethylene acid
copolymer having a coatweight of about 3 to about 8 g/m2 onto said aluminum
fail;
iv. extrusion coating a sealant layer comprising modified ethylene

acrylate copolymer having a coatweiglit of about 6 to about 16 g/m2 onto said
tie
resin, one or both of said tie and sealant layers having an embrittling agent
mixed
therein in an amount of about 5 to about 50% by weight;

b. providing a polymeric blister film: and

c. sealing said lidding foil to said blister film containing a consumable
substance and thereby forming said push-through blister packaging,


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whereby said consumable substance may be retrieved from said blister

packaging by pushing the consumable substance against and breaking said
lidding foil
open.


22. The method of claim 21 wherein said blister film comprises a
polymer selected from the group consisting of PVC, PVDC, PS, HIPS, PCTFE,
HDPE, LLDPE, LDPE, PP, PETG, SBC, COC, and combinations thereof.


23. The method of claim 22 wherein said blister film comprises
polychlorotrifluoroethylene (PCTFE)


24. The method of claim 22 wherein said blister film comprises a cyclic
olefin copolymer (COC).


25. The method of claim 21 further comprising the step of adding an
embrittling agent mixed into one or both of said tie and sealant layers hi an
amount of about 5 to about 50% by weight.


26. The method of claim 25 wherein said 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


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i. a mixture of two or more of a-h.


27. The method of claim 25 wherein said embrittling agent is equally
distributed within said sealant layer,


28. The method of claim 25 wherein said embrittling agent is non-
equally distributed within said sealant layer, said embrittling agent being
more
concentrated within a portion of said sealant layer that is adjacent to said
tie
layer.


29. The method of claim 21 wherein said tie layer and said sealant layer are
simultaneously co-extruded onto the aluminum foil.


30.The method of claim 21 wherein said tie layer and said sealant layer are
sequentially extrusion-coated onto the aluminum foil.


31. The method of claim 21 wherein said aluminum foil has a thickness of
about 20 Ám to about 25 Ám.