U.S. patent application number 11/593462 was filed with the patent office on 2007-07-19 for paperboard substrate for blister packaging.
Invention is credited to Victor P. Holbert, David V. Reed.
Application Number | 20070166492 11/593462 |
Document ID | / |
Family ID | 27734268 |
Filed Date | 2007-07-19 |
United States Patent
Application |
20070166492 |
Kind Code |
A1 |
Holbert; Victor P. ; et
al. |
July 19, 2007 |
Paperboard substrate for blister packaging
Abstract
A packaging laminate comprising a paperboard substrate for
providing a base layer, a tear-resistant polymer layer applied to
said substrate, and a heat seal polymer layer applied to said
tear-resistant polymer. This laminate structure is particularity
useful for blister pack packaging.
Inventors: |
Holbert; Victor P.;
(Loveland, OH) ; Reed; David V.; (Blanchester,
OH) |
Correspondence
Address: |
INTERNATIONAL PAPER COMPANY
6285 TRI-RIDGE BOULEVARD
LOVELAND
OH
45140
US
|
Family ID: |
27734268 |
Appl. No.: |
11/593462 |
Filed: |
November 6, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10355038 |
Jan 31, 2003 |
7192640 |
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11593462 |
Nov 6, 2006 |
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60352853 |
Feb 1, 2002 |
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Current U.S.
Class: |
428/35.7 ;
206/531; 428/198; 428/349; 428/423.1; 428/474.4; 428/480;
428/537.5 |
Current CPC
Class: |
Y10T 428/31725 20150401;
Y10T 428/31547 20150401; Y10T 428/2813 20150115; Y10T 428/31906
20150401; Y10T 428/24826 20150115; Y10T 428/31924 20150401; Y10T
428/1352 20150115; B32B 27/08 20130101; Y10T 428/2839 20150115;
Y10T 428/31779 20150401; Y10T 428/31786 20150401; Y10T 428/31899
20150401; Y10T 428/31663 20150401; Y10T 428/31913 20150401; Y10T
428/31895 20150401; Y10T 428/31993 20150401; Y10T 428/31909
20150401; Y10T 428/31551 20150401; B32B 7/10 20130101; Y10T
428/31917 20150401; Y10T 428/3188 20150401; Y10T 428/2878 20150115;
Y10T 428/31902 20150401; Y10T 428/31743 20150401; Y10T 428/31938
20150401; A61J 1/035 20130101; Y10T 428/31775 20150401; Y10T
428/31935 20150401; Y10T 428/3179 20150401; Y10T 428/3175 20150401;
Y10T 428/2843 20150115; Y10T 428/31928 20150401; Y10T 428/31931
20150401; Y10T 428/2817 20150115; B32B 27/10 20130101; Y10T
428/31591 20150401; Y10T 428/31598 20150401; Y10T 428/2826
20150115; Y10T 428/31739 20150401; Y10T 428/2891 20150115; Y10T
428/31728 20150401 |
Class at
Publication: |
428/035.7 ;
428/537.5; 428/480; 428/423.1; 428/474.4; 428/349; 428/198;
206/531 |
International
Class: |
B32B 27/08 20060101
B32B027/08; B32B 7/12 20060101 B32B007/12; B32B 27/40 20060101
B32B027/40; B32B 27/34 20060101 B32B027/34; B32B 27/36 20060101
B32B027/36; B65D 83/04 20060101 B65D083/04 |
Claims
1-27. (canceled)
28. A blister pack laminate comprising: a substrate having inner
and outer surfaces; a tear-resistant polymer layer positioned
interior to the inner surface of the substrate; an adhesion
inhibitor positioned between the substrate and the tear-resistant
polymer layer wherein the adhesion inhibitor promotes disengagement
of the substrate from the tear-resistant layer to reduce stress
concentration, crack propagation or a combination thereof in the
tear resistance layer; and a heat seal polymer layer positioned
interior to the tear-resistant layer.
29. The laminate of claim 28, wherein the substrate is
paperboard.
30. The laminate of claim 28, wherein the tear resistant polymer
layer comprises cross laminated HDPE.
31. The laminate of claim 28, wherein the tear resistant polymer
layer comprises oriented or biaxially oriented polyamide and
oriented polyester.
32. The laminate of claim 28, wherein the heat seal polymer layer
is selected from the group consisting of EVA, EMA, ionomers,
acrylic copolymers, acrylate copolymers and combination of two or
more thereof.
33. The laminate of claim 28, wherein the heat seal polymer layer
has anti-blocking agents to reduce the tackiness of the heat seal
polymer layer.
34. The laminate of claim 28, wherein the anti-blocking agents
comprise calcium carbonate, talc or silica.
35. The laminate of claim 28, further comprising a coating layer
positioned exterior to the outer surface of the substrate.
36. The laminate of claim 28, further comprising a tie layer
between the substrate and the tear resistant polymer layer.
37. The laminate of claim 28, further comprising a tie layer
positioned between the tear-resistant polymer layer and the heat
seal polymer layer.
38. The laminate of claim 28, further comprising a layer of
adhesive primer positioned between the substrate and the
tear-resistant polymer layer.
39. The laminate of claim 28 wherein the adhesion inhibitor is a
layer.
40. A blister pack laminate, comprising: a substrate having inner
and outer surfaces; a coating layer positioned exterior to the
outer surface of the substrate; a tear-resistant polymer layer
positioned interior to the inner surface of the substrate; an
adhesion inhibitor disposed between the substrate and the
tear-resistant polymer layer wherein the adhesion inhibitor
promotes disengagement of the substrate from the tear-resistant
layer to reduce stress concentration, crack propagation or a
combination thereof in the tear resistance layer; and a heat seal
polymer layer positioned interior to the tear-resistant layer.
41. The laminate of claim 40, wherein the tear resistant polymer
layer is a cross laminated HDPE tear resistant layer.
42. The laminate of claim 40, wherein the heat seal polymer layer
is selected from the group consisting of EVA, EMA, ionomers,
acrylic copolymers, acrylate copolymers and combination of two or
more thereof.
43. A blister pack laminate comprising: a substrate having inner
and outer surfaces; a tear-resistant polymer layer positioned
interior to the inner surface of the substrate; an adhesion
inhibitor positioned between the substrate and the tear-resistant
polymer layer; and a heat seal polymer layer positioned interior to
the tear-resistant polymer layer.
44. The blister pack laminate of claim 43 further comprising a
coating layer positioned exterior to the outer surface of the
substrate.
45. The blister pack laminate of claim 43 further comprising a tie
layer between the substrate and the tear-resistant polymer
layer.
46. The blister pack laminate of claim 43 further comprising a tie
layer between the tear-resistant layer and the heat seal polymer
layer.
47. The blister pack laminate of claim 43 wherein the adhesion
inhibitor promotes disengagement of the substrate from the
tear-resistant layer so as to reduce stress concentration and crack
propagation in the tear resistance layer.
48. The blister pack laminate of claim 43 wherein the adhesion
inhibitor is a layer.
49. The blister pack laminate of claim 48 wherein the adhesion
inhibitor is a discontinuous layer.
50. The blister pack laminate of claim 49 wherein the adhesion
inhibitor is a continuous layer.
51. The blister pack laminate of claim 43 wherein the adhesion
inhibitor is layer which is applied with a nip roll.
52. The blister pack laminate of claim 43 wherein the tear
resistant polymer layer comprises cross laminated HDPE.
53. The blister pack laminate of claim 43 wherein the tear
resistant polymer layer comprises oriented or biaxially oriented
polyamide and oriented polyester.
Description
[0001] This application claims the benefit of provisional
application 60/352,853, filed Feb. 1, 2002.
BACKGROUND OF THE INVENTION
[0002] Blister packs are formed by a substrate, such as paperboard,
with a plastic layer sealed to the substrate. The plastic layer has
bubbles or carpartments conforming to the size and shape of the
product being packaged in blister packs with each tablet
individually held within a bubble.
[0003] As is a common problem with pharmaceuticals in any type of
packaging, the packaging must be accessible by the person using the
medication, but also be child-resistant. This poses problems,
particularly when the recipient of the medication is lacking manual
dexterity of strength.
[0004] It is an object of the invention to provide a laminated
paperboard substrate for packaging that is child-resistant, yet
easily opened by the intended consumer.
[0005] It is another object of the invention to provide a laminated
paperboard substrate for packaging that is child-resistant, yet
easily opened by the intended consumer.
[0006] It is another object of the invention to provide a laminated
paperboard substrate packaging wherein the strengten needed to open
the package can be controlled.
[0007] It is yet another object of the invention to provide a
laminated paperboard substrate for a blister material that does not
adhere to chill rolls during manufacture.
[0008] It is another object of the invention to provide a substrate
that easily bonds to blister material including PVC, Aclar, and
PET.
[0009] It is another object of the invention to provide a package
which is inexpensive to manufacture.
[0010] These and other objects of the invention will become
apparent after review the disclosure of the invention.
SUMMARY OF THE INVENTION
[0011] A packaging laminate is formed by a paperboard substrate
with a plastic blister layer sealed to the structure. The packaging
laminate comprises a paperboard substrate for providing a base
layer, a tear-resistant polymer layer applied to said substrate,
and a heat seal ploymer layer applied to said tear-resistant
polymer. This laminate structure is particularly useful for blister
pack packaging. A series of instructions must be followed in order
to access the contents of the blister package due to the presence
of the tear-resistant layer. The tear strength can be controlled by
modulating the levels of adhesion of the tear-resistant polymer to
the paperboard by one of several methods. A patterned coating of
adhesion primer can be applied to the paperboard. Also, a patterned
coating of an adhesion inhibitor may be applied to the paperboard.
Alternatively, the molten polymer stream forming the tear-resistant
layer may be applied to the paperboard from the extrusion die with
a patterned nip roll. The use of such modulated adhesion allows for
higher tear strength in the body of the package and a lower level
in specific areas defined by the package design and geometry. This
allows the intended consumer to easily access the contents of the
blister pack while still forming a child-resistant layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a view of the laminate comprising the blister pack
substrate;
[0013] FIG. 2 depicts the laminate with a tie layer between the
tear-resistant polymer layer and heat seal polymer layer;
[0014] FIG. 3 is a view of the laminate having a tie layer between
the paperboard and tear-resistant polymer;
[0015] FIG. 4 depicts the laminate having a tear layer between both
the paperboard and tear-resistant layer and the tear-resistant
layer and heat sealable polymer.
[0016] FIG. 5 depicts the substrate having an adhesion primer or
adhesion inhibitor;
[0017] FIG. 6 depicts the substrate having a discontinuous layer of
adhesive primer or adhesion inhibitor;
[0018] FIG. 7 shows the process for applying the adhesive primer or
adhesion inhibitor to the substrate;
[0019] FIG. 8 shows the process for forming the laminate of the
invention; and
[0020] FIG. 9 shows a laminate having a combined tear resistant and
heat seal polymer layer.
DETAILED DESCRIPTION OF THE INVENTION
[0021] A laminate used to make the substrate of a blister pack is
shown in FIG. 1. The packaging laminate comprises a paperboard
substrate for providing a base layer, a tear-resistant polymer
layer applied to said substrate and a heat seal polymer layer
applied to said tear resistant polymer. Paperboard layer 12
provides the base layer of the substrate and a tear-resistant
polymer layer 14 is applied to the paperboard to provide a
child-proof resistance to opening. Paperboard layer 12 is most
suitably high grade paperboard stock, for example, 100-300 lbs. or
higher sized carton board. A heat seal polymer layer 16 is applied
as the outer layer of the laminate and provides a good bonding
surface for the plastic blister layer.
[0022] The tear-resistant polymer layer 14 may be polyamides, such
as nylon 6, nylon(6,6), nylon(6,12) or other polyamides, polyester,
polyurethane, block copolymer, unsaturated block copolymers such as
styrene-butadiene-styrene, styrene-isoprene-styrene and the like;
saturated block copolymers such as
styrene-ethylene/butylene-styrene,
styrene-ethylene/propylene-styrene, and the like) or other material
possessing high tear-resistant properties. The polymer used to make
the tear-resistant layer may be blended with another polymer
selected from the group including ethylene copolymers such as
ionomers, vinyl acetate, methylacrylic or acrylic acid
copolymers.
[0023] Film weights for the tear-resistant polymer layer may be
from 2 to 50 pounds per 3000 ft.sup.2 with a preferred weight of 5
to 30 pounds per 3000 ft.sup.2.
[0024] Blends of tear resistant polymers including from 60 to 100
weight percent of polyamide, such as nylon 6, nylon(6,6),
nylon(6,12) or other polyamides, polyester, polyurethane, block
copolymer, unsaturated block copolymers such as
styrene-butadiene-styrene, styrene-isoprene-styrene and the like;
saturated block copolymers such as
styrene-ethylene/butylene-styrene,
styrene-ethylene/propylene-styrene, and other material possessing
high tear-resistant properties, and blended with 0 to 40 weight
percent of other polymers comprising ethylene copolymers such as
ionomers, vinyl acetate, methylacrylic or acrylic acid
copolymers.
[0025] The heat seal polymer layer 16 is formed by a material
exhibiting excellent heat seal properties to PVC, Aclar, PET and
other materials used to make the blister layer. The heat seal
polymer layer is chosen from a group consisting of EVA, EMA,
ionomers, acrylic copolymers, acrylate copolymers and modified
versions of the like.
[0026] Film weights for the heat seal polymer layer may be from 3
to 15 pounds per 3000 ft.sup.2 with a preferred weight of 8 pounds
per 3000 ft.sup.2.
[0027] The heat seal polymer can incorporate anti-blocking agents
to reduce the tackiness of the sealant layer. The anti-blocking
agents can be calcium carbonate, talc, silica or other suitable
materials.
[0028] FIG. 2 depicts the laminate with the use of a tie layer 18
between the tear-resistant polymer layer 14 and heat sealable
polymer layer 16 such as tie material coatings marketed under the
trademark TYMOR, or more specifically, TYMOR 1205 having a coating
weight on the order of 4 pounds per 3000 square foot ream. The tie
material coating marketed is a polyethylene backbone polymer with
functional groups grafted thereon, such as maleic anhydride
copolymer. Suitable tie layer are selected from the group of
materials including polymers grafted with species such as maleic
anhydride. Film weights are from 1 to 12 pounds per 3000 ft.sup.2,
preferably from 1 to 3 pounds per 3000 ft.sup.2.
[0029] FIG. 3 depicts a laminate using a tie layer 18 between the
paperboard layer 12 and tear-resistant polymer layer 14 . Likewise,
FIG. 4 depicts a laminate having a tie layer 18 between both the
paperboard layer 12 and tear-resistant polymer layer, and between
the tear-resistant polymer layer 14 and heat sealable polymer layer
16. A clay coating can be formed on the side of the paperboard
substrate opposite the tear-resistant and heat seal polymers to
improve print quality.
[0030] The laminate tear strength can be controlled by varying the
film weight of the tear-resistant polymer layer as an increase in
tear resistance results from an increase in film weight. Also,
during manufacturing, die cuts or perforations may be provided in
the tear-resistant polymer layer. This creates areas of controlled
weakness to direct the tearing of the package limiting the
direction the package can be opened.
[0031] Also, modulating levels of adhesion between the
tear-resistant polymer and the paperboard controls the amount of
tear resistance. This may be done by the addition of adhesion
promoting primer 22 between the paperboard 12 and tear-resistant
polymer 14. Suitable materials for the adhesion promoting primer
include polyethylene amine applied at between 1 and 6 pounds per
3000 ft.sup.2, preferably 1 pound per 3000 ft.sup.2. The adhesion
primer is applied to the paperboard 12 prior to the extrusion of
the tear-resistant polymer onto the substrate as is shown in FIG.
5.
[0032] The adhesion promotion primer 22 may be applied in a
non-continuous pattern to create differential adhesion between the
tear-resistant polymer to the paperboard. Such a discontinuous
pattern is shown in FIG. 6. The weaker adhesion areas created by
the non-continuous pattern would dictate the steps necessary to
open the package to access the contents.
[0033] Alternatively, an adhesion inhibitor may, be applied between
the paperboard and tear-resistant polymer. Suitable adhesion
inhibitors include silicone, lacquers, or varnishes applied at
between 1 and 6 pounds per 3000 ft.sup.2, preferably 1 to 2 pounds
per 3000 ft.sup.2. The adhesion inhibitor may also be applied in a
non-continuous patter to create the differential adhesion of the
tear-resistant polymer to the paperboard. The differential adhesion
again creates patterns that may be followed to access the
contents.
[0034] FIG. 7 depicts a method for coating the paperboard substrate
with either the adhesion primer or adhesion inhibitor. A paperboard
roll 30 feeds unprimed web 32 between a gravure roll 35 and backing
roll 36 where either the adhesion primer or an adhesion inhibitor
is applied. After application, the wet coated paperboard 38 passes
through a dryer 40 and the dried primed web 42 exits from the dryer
40. Differential adhesion may also be attained by the use of a
patterned nip roll on the extrusion line when the tear-resistant
polymer is applied to the paperboard. This process is depicted in
FIG. 8. The nip roll cooperates with the chill roll and a
non-uniform pattern is created to result in areas of variable
adhesion. A paperboard web 12 is fed between a chill roll 50 and a
nip roll 52. A extruder drive 48 provides molten tear-resistant
polymer. The resulting two layer structure is then fed between a
second chill roll 50 and nip roll 52 where an extruder die applies
molten heat seal polymer 16. Exiting from this second chill roll is
a completed laminate 10. The resultant laminate will bond easily as
board-to-board as well as board to blister under conditions having
a range in temperature of 250-400 degrees Fahrenheit and pressure
of 40-80 psi with a dwell times of 1 to 2 seconds. A low heat
exposure results from the decreased heat seal initiation
temperature and shorter dwell time. This is critical to products
such as pharmaceutical, nutraceuticals and cosmetics that can be
damaged by heat exposure. The bond strength of the laminate of the
invention to itself and common blister materials under various seal
conditions is summarized in the following table. TABLE-US-00001
TABLE 1 Heat seal data for standard and tear-resistant blister
constructions at various heat seal conditions. Tear- Tear- Tear-
Standard Resistant Resistant Resistant Temp: Dwell: Pressure:
Blister Bilster to Blister to Blister to F. S PSI to PVC PVC PET
Aclar 275 1 80 Avg in gf 1151 1612 1301 1448 300 1 80 Avg in gf
1380 1538 1188 1264 325 1 80 Avg in gf 1060 1244 1092 1515 350 1 80
Avg in gf 996 1545 1080 1424 Avg Avg in gf 1147 1485 1165 1413 of
All 275 2 80 Avg in gf 1200 1811 1214 1532 300 2 80 Avg in gf 1365
1392 1164 1407 325 2 80 Avg in gf 1331 1596 1196 1326 350 2 80 Avg
in gf 1522 1652 1213 1514 Avg Avg in gf 1355 1613 1197 1445 of
All
[0035] In an alternative embodiment of the invention, the
tear-resistant polymer may be blended with a polymer possessing
heat sealable qualities. In this instance, shown in FIG. 9, a
single layer 15 having both tear-resistance and the ability to heat
seal to the blister layer is achieved in a single layer.
[0036] In another embodiment of the invention, the tear resistant
polymer may be a tear resistant polymer film laminated to the
paperboard substrate. For extrusion lamination the film could be
attached by a tie layer 18. The heat seal polymer is then applied
to the external side of the tear resistant polymer film. In this
embodiment, the film could be an oriented film such as oriented or
biaxially oriented polyamide, oriented polyester and the like. A
preferred embodiment is a cross oriented HDPE film marketed under
the trade name Valeron with film thickness from 1 to 3 mils,
preferably from 1 to 1.5 mils. The film can be laminated by
adhesive or extrusion lamination. If adhesive lamination is used,
any suitable liquid adhesive could be used, such as ethylene vinyl
acetate, polyurethane, acrylic or acrylate polymers and the like,
in place of the tie layer. The tear resistant film comprising films
of polyamide, such as nylon 6, nylon(6,6), nylon(6,12) or films of
other polyamides, polyester, polyurethane, block copolymer
including, unsaturated block copolymers such as
styrene-butadiene-styrene, styrene-isoprene-styrene and the like;
saturated block copolymers such as
styrene-ethylene/butylene-styrene,
styrene-ethylene/propylene-styrene, and the like or other materials
possessing high tear-resistant properties. The polymer film used to
make the tear-resistant layer may be blended with another polymer
selected from the group consisting of ethylene copolymers such as
ionomers, vinyl acetate, methylacrylic or acrylic acid copolymers.
The film thickness could be between 0.0005 and 0.002 inches,
preferably 0.0005 inches.
[0037] Tear strengths of various preferred structures are detailed
in the following table. TABLE-US-00002 TABLE 2 Tear data for
various tear resistant materials utilized in tear-resistant blister
board construction. MD Elmendorf Tear TD Elmendorf Tear Material
Composition (grams) (grams) 100% Polyamide 183.36 203.6 75%
Polyamide/25% Ionomer 389.96 342.68 80% Polyamide/20% Ionomer
423.42 371.06 Tear Resistant Film 1050.7 684.4
[0038] While the invention has been described with reference to a
preferred embodiment, variations and modifications would be
apparent to one of ordinary skill in the art after reviewing the
disclosure of the invention. The invention encompasses such
variations and modifications.
* * * * *