CA2345502A1 - Stand-up polymeric bags - Google Patents
Stand-up polymeric bags Download PDFInfo
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- CA2345502A1 CA2345502A1 CA 2345502 CA2345502A CA2345502A1 CA 2345502 A1 CA2345502 A1 CA 2345502A1 CA 2345502 CA2345502 CA 2345502 CA 2345502 A CA2345502 A CA 2345502A CA 2345502 A1 CA2345502 A1 CA 2345502A1
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Abstract
A stand-up polymeric bag comprising first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portions of the bottom wall. At least one of the first opposing body panel, the second opposing body panel and the bottom wall comprises a layer of from about 5 to about 95 wt.% of a polyolefinic resin and from about 5 to about 95 wt.% of a cyclic olefin copolymer. The cyclic olefin copolymer has a glass transition temperature, T G, of greater than about 20°C as determined by ASTM D3418. The cyclic olefin copolymer may comprise from about 10 to about 90 mol.% norbornene.
Description
STAND-UP POLYMERIC BAGS
FIELD OF INVENTION
s The present invention relates generally to the packaging industry and, more particularly, to stand-up polymeric bags.
BACKGROUND OF THE INVENTION
The use of inexpensive food packaging bags has become very common, to especially in the food industry. These food packaging bags have been popular for a number of reasons including the fact that they can be conveniently stored.
Some of these packages are reclosable via the use of a reclosable feature such as a resealable adhesive seal or a reclosable zipper. The zippers can be opened and closed either by pressure or by the use of an auxiliary slider mechanism. Food packaging bags, is especially reclosable packages, are a great convenience to the consumer especially for storing various food products. Often, the stored food items are desired to be heated or re-heated before serving to consumers. Consumers typically heat the food products in heating apparatus such as a microwave or a conventional oven.
Existing food packaging bags are often undesirable for heating in the above-zo described heating apparatus for a variety of reasons. Some commonly used materials for forming food packaging bags include low density polyethylenes (LDPE) and linear low density polyethylenes (LLDPE). Food packaging bags~(2-5 mils thickness) made of LDPE or LLDPE bags often do not have the modulus, stiffness and/or mechanical strength to be stable and stand up when being heated. The loss of stiffness and stand zs up characteristics at higher temperatures is evident at the temperatures generated in microwaves and conventional ovens. A loss of stand-up nature in a food packaging bag may result in spillage of food or liquid. Moreover, this can lead to extreme customer dissatisfaction if the food or liquid contacts a hand, an arm or apparel of a customer. Even if the food or liquid does not contact a customer, it is not aesthetically 3o pleasing to observe food or liquid leaving the packaging bag.
Accordingly, a need exists for a food packing bag that overcomes the above-noted shortcomings.
CHICAGO 58902v1 47097-01003 SUMMARY OF THE INVENTION
According to one embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portions of the bottom wall. At least one of the first s opposing body panel, the second opposing body panel and the bottom wall comprises a layer of from about 5 to about 95 wt.% of a polyolefinic resin and from about 5 to about 95 wt.% of a cyclic olefin copolymer. The cyclic olefin copolymer has a glass transition temperature, TG, of greater than about 20°C as determined by ASTM
D3418.
to According to another embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portions of the bottom wall. At least one of the first opposing body panel, the second opposing body panel and the bottom wall includes a layer from about 5 to about 95 wt.% of a polyolefinic resin and from about is 5 to about 95 wt.% of a cyclic olefin copolymer. The cyclic olefin copolymer comprises from about 10 to about 90 mol.% of norbornene.
According to a further embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portio_~~ of the bottom wall. At least one of the 2o first opposing body panel, the second opposing body panel and the bottom wall includes a first layer comprising from about 5 to 100 wt.% of a cyclic olefin copolymer and a second layer comprising from about 5 to 100 wt.% of a polyolefinic resin. The cyclic olefin copolymer has a glass transition temperature, TG, of greater than about 20°C as determined by ASTM D3418.
2s According to yet embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portions of the bottom wall. At least one of the first opposing body panel, the second opposing body panel and the bottom wall comprises a first layer of from about 5 to i 00 wt.% of a cyclic olefin copolymer and a second layer 3o comprising from about 5 to 100 wt.% of a polyolefinic resin. The cyclic olefin copolymer comprises from about 10 to about 90 mol.% of norbornene.
CHICAGO 58902v1 47097-01003 BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings.
FIG. I is a perspective view of a bag according to one embodiment of the s present invention;
FIG. 2 is a cross-sectional view taken generally along the line 2-2 in FIG. I
;
FIG. 3 is a perspective view of a bag having body panels comprising two layers according to another embodiment of the present invention;
FIG. 4 is a cross-sectional view taken generally along the line 4-4 in FIG. 3;
to FIG. 5 is a cross-sectional view taken generally along the line 5-5 in FIG.
FIELD OF INVENTION
s The present invention relates generally to the packaging industry and, more particularly, to stand-up polymeric bags.
BACKGROUND OF THE INVENTION
The use of inexpensive food packaging bags has become very common, to especially in the food industry. These food packaging bags have been popular for a number of reasons including the fact that they can be conveniently stored.
Some of these packages are reclosable via the use of a reclosable feature such as a resealable adhesive seal or a reclosable zipper. The zippers can be opened and closed either by pressure or by the use of an auxiliary slider mechanism. Food packaging bags, is especially reclosable packages, are a great convenience to the consumer especially for storing various food products. Often, the stored food items are desired to be heated or re-heated before serving to consumers. Consumers typically heat the food products in heating apparatus such as a microwave or a conventional oven.
Existing food packaging bags are often undesirable for heating in the above-zo described heating apparatus for a variety of reasons. Some commonly used materials for forming food packaging bags include low density polyethylenes (LDPE) and linear low density polyethylenes (LLDPE). Food packaging bags~(2-5 mils thickness) made of LDPE or LLDPE bags often do not have the modulus, stiffness and/or mechanical strength to be stable and stand up when being heated. The loss of stiffness and stand zs up characteristics at higher temperatures is evident at the temperatures generated in microwaves and conventional ovens. A loss of stand-up nature in a food packaging bag may result in spillage of food or liquid. Moreover, this can lead to extreme customer dissatisfaction if the food or liquid contacts a hand, an arm or apparel of a customer. Even if the food or liquid does not contact a customer, it is not aesthetically 3o pleasing to observe food or liquid leaving the packaging bag.
Accordingly, a need exists for a food packing bag that overcomes the above-noted shortcomings.
CHICAGO 58902v1 47097-01003 SUMMARY OF THE INVENTION
According to one embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portions of the bottom wall. At least one of the first s opposing body panel, the second opposing body panel and the bottom wall comprises a layer of from about 5 to about 95 wt.% of a polyolefinic resin and from about 5 to about 95 wt.% of a cyclic olefin copolymer. The cyclic olefin copolymer has a glass transition temperature, TG, of greater than about 20°C as determined by ASTM
D3418.
to According to another embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portions of the bottom wall. At least one of the first opposing body panel, the second opposing body panel and the bottom wall includes a layer from about 5 to about 95 wt.% of a polyolefinic resin and from about is 5 to about 95 wt.% of a cyclic olefin copolymer. The cyclic olefin copolymer comprises from about 10 to about 90 mol.% of norbornene.
According to a further embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portio_~~ of the bottom wall. At least one of the 2o first opposing body panel, the second opposing body panel and the bottom wall includes a first layer comprising from about 5 to 100 wt.% of a cyclic olefin copolymer and a second layer comprising from about 5 to 100 wt.% of a polyolefinic resin. The cyclic olefin copolymer has a glass transition temperature, TG, of greater than about 20°C as determined by ASTM D3418.
2s According to yet embodiment, a stand-up polymeric bag comprises first and second opposing body panels and a bottom wall. The first and second opposing body panels are coupled to opposing portions of the bottom wall. At least one of the first opposing body panel, the second opposing body panel and the bottom wall comprises a first layer of from about 5 to i 00 wt.% of a cyclic olefin copolymer and a second layer 3o comprising from about 5 to 100 wt.% of a polyolefinic resin. The cyclic olefin copolymer comprises from about 10 to about 90 mol.% of norbornene.
CHICAGO 58902v1 47097-01003 BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings.
FIG. I is a perspective view of a bag according to one embodiment of the s present invention;
FIG. 2 is a cross-sectional view taken generally along the line 2-2 in FIG. I
;
FIG. 3 is a perspective view of a bag having body panels comprising two layers according to another embodiment of the present invention;
FIG. 4 is a cross-sectional view taken generally along the line 4-4 in FIG. 3;
to FIG. 5 is a cross-sectional view taken generally along the line 5-5 in FIG.
3;
FIG. 6 is a perspective view of a bag having body panels comprising three layers according to a further embodiment of the present invention;
FIG. 7 is a cross-sectional view taken generally along the line 7-7 in FIG. 6;
FIG. 8 is a perspective view of a bag portion of FIG. 1 including a fastener and Is slider according to yet another embodiment of the present invention;
FIG. 9 is a cross-sectional view taken generally along the line 9-9 in FIG. 8 that includes an enlarged perspective view of the fastener of FIG. 8;
FIG. 10 is a side view of a bag in a closed position according to yet another embodin.:.~~ of the present invention; and 2o FIG. 11 is a perspective view of the bag of FIG. 10 in an open position.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed but, on the 2s contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
According to one embodiment of the packaging bags or pouches shown in 3o FIGS. 1 and 2, is a stand-up polymeric bag 10. The stand-up polymeric bag comprises first and second body panels 12 and 14 and a bottom wall 16. The first and second opposing body panels 12 and 14 are coupled to opposing portions of the bottom wall 16. The first and second opposing body panels 12 and 14 are fixedly CHICAGO 58902v1 47097-01003 connected to each other along a pair of sides 18 and 20. The bottom wall 16 extends between the pair of sides 18 and 20. The bottom wall 16 of FIG. 1 is a gusseted bottom wall that comprises two gusseted portions 16a and 16b. It is contemplated that the bottom wall 16 may be comprised of other configurations than a gusseted bottom s wall, such as shown in FIG. 1. Another configuration of a bottom wall will be discussed later with respect to FIGS. 10 and 11.
The body panels 12 and 14 of the stand-up polymeric bag 10 comprise a cyclic olefin copolymer and a polyolefinic resin. The cyclic olefin copolymer and the polyolefinic resin may be blended to form the body panels (i.e., a monolayer).
This is to shown in the bag 10 of FIGS. 1 and 2, for example. The body panels generally comprise from about 5 wt.% to about 95 wt.% of the cyclic olefin copolymer and from about 5 wt.% to about 95 wt.% of the polyolefinic resin. The body panels typically comprise from about 5 wt.% to about 50 wt.% of the cyclic olefin copolymer and from about 50 wt.% to about 95 wt.% of the polyolefinic resin. More specifically, the body is panels comprise from about 5 wt.% to about 25 wt.%, from about 10 wt.% to about 20 wt.%, or from about 15 wt.% or about 20 wt.% of the cyclic olefin copolymer, and from about 75 wt.% to about 95 wt.%, from about 80 wt.% to about 90 wt.%, or from about 80 wt.% to about 85 wt.% of the polyolefinic resin.
20 ~clic olefin copol~rmers The cyclic olefin copolymers of the present invention generally have a molecular weight distribution, or polydispersity, (MW/M", "MWD") from about 2.0 to about 5.0, and preferably from about 2.0 to about 2.5.
The cyclic olefin copolymers generally have a density of from about 0.90 to 2s about 1.10 g/cm3, typically from about 0.95 to about 1.05 g/cm3 and more typically from about 1.00 to about 1.03 g/cm3. The heat deflection temperature (HDT, measured at 66 psi) of cyclic olefin copolymers generally is from about 50 to about 200°C, and typically from about 70 to about 170°C.
The melt flow index (MI) of the cyclic olefin copolymers is generally from 3o about 1 to about 100 g/10 min., and typically from about 4 to about 20 g/10 min. at 115°C (239°F) above its corresponding HDT as determined by ISO
1133.
The cyclic olefin copolymers may be made from copolymers of ethylene and norbornene. The mole % of ethylene and norbornene may vary with respect to each CHICAGO 58902v1 47097-01003 other For example, the amount of norbornene is generally from about 10 to about 90 mol.%, with the remainder being ethylene (from about 10 to about 90 mol.%).
The amount of norbornene is typically from about 20 to about 70 mol.% with the remainder being ethylene. The amount of norbornene is more typically from about 35 to about 60 s mol.% with the remainder being ethylene. The cyclic olefin copolymers may be made using metallocene catalysts.
The glass transition temperature (Tg) of the cyclic olefin copolymer is generally greater than about 20°C, typically greater than about 50°C, and preferably greater than about 75°C, as measured by ASTM D3418. The glass transition temperature of the to cyclic olefin copolymer may be greater than about 100°C or about 150°C as measured by ASTM D3418. The glass transition temperature (T~) of the cyclic olefin copolymers increases as the mole % of norbornene in the copolymer increases.
For example, the glass temperature transition (Tg) of a cyclic olefin copolymer comprising 20 mol.% norbornene and 80 mol.% ethylene is about 25°C, while the glass is temperature transition of a cyclic olefin copolymer comprising 70 mol.%
norbornene and 30 mol.% ethylene is about 210°C. The glass temperature transition (Tg) of a cyclic olefin copolymer comprising 30 mol.% norbornene and 70 mol.% ethylene is about 75°C, while a cyclic olefin copolymer comprising 60 mol.%
norbornene and 40 mol.% ethylene is about 180°C.
2o The flexural modulus of the cyclic olefin copolymer is generally from about 300,000 to about 600,000 psi, and more specifically from about 400,000 to about 500,000 psi as measured by ASTM D790. The tensile mbdulus of the cyclic olefin copolymers is generally from about 300,000 to about 600,000 psi, and more specifically from about 400,000 to about 500,000 psi, as determined by ISO
527.
is Useful cyclic olefin copolymers are available from several companies. For example, Ticona, a business of Celanese AG, in Summit N.J. has cyclic olefin copolymers available. Other companies that have cyclic olefin copolymers available include Nippon Zeon (Japan), Mitsui Chemical (Japan) and JSR (Japan), formerly know as Japan Synthetic Rubber. Ticona, a business of Celanese AG, has so commercially available cyclic olefin copolymers (COCs) under the designation TOPAS~. These cyclic olefin copolymers are believed to be prepared with feedstocks of norbornene and ethylene and the use of a metallocene catalyst. There are believed to be at least four grades of TOPAS~ resins available (TOPAS~ 8007, TOPAS~
CHICAGO 58902v1 47097-01003 6013, TOPAS~ 601 S and TOPAS~ 6017). The four grades of TOPAS~ resins available have glass transition temperatures, Tg, of 80, 140, 160 and 180°C, respectively. The corresponding norbornene levels of the four grades of TOPAS~
resins are believed to be about 3S, 48, SS and S9 mole %.
s Polyolefinic Resins The polyolefinic resins that may be used in the present invention include low density polyethylenes (LDPE), linear low density polyethylenes (LLDPE), high density polyethylenes (HI~PE), medium density polyethylenes (1VIDPE), polypropylenes, to plastomers, ethylene vinyl acetates (EVA), polymethylpentene copolymers and combinations thereof. It is contemplated that other polyolefinic resins may be used.
The preferred polyolefinic resins are low density polyethylenes and linear low density polyethylenes.
The polyolefinic resin may include a small amount of an alkenyl aromatic is polymer (e.g., polystyrene). For example, the alkenyl aromatic polymer may be added in an amount up to about 1 or about 2 wt. % of the polyethylene. Further details may be obtained from U.S. Patent Nos. 4,579,912, 4,716,201, 4,743,649 and 4,804,564.
In another embodiment of the present invention, the body panels comprise a first layer comprising a cyclic olefin cu~olymer and a second layer comprising a 2o polyolefinic resin. This is shown, for example, in FIGS. 3-5 with a bag having panels made from two layers. The stand-up polymeric bag 110 of FIG. 3 has a body panel 112 that comprises a first layer 112a and a second layer '112b. Similarly, stand-up polymeric bag 110 has a body panel 114 that comprises a first layer 114a and a second layer 114b.
zs The first layers 112a and 114a comprise a cyclic olefin copolymer, while the second layers 112b and 114b comprise a polyolefinic resin. The compositions of the first layers 112a and 114a do not necessary have to be made of identical materials.
Likewise, the second layers 112b and 114b may be comprised of independently selected polyolefinic resins.
3o The first layers 112a and I 14a may comprise a cyclic olefin copolymer and a polyolefinic resin. The first layers 112a and 114a generally comprise from about 5 wt.% to 100 wt.% of the cyclic olefin copolymer and from about 0 wt.% to about wt.% of the polyolefinic resin. The first layers 112a and 114a typically comprise from CHICAGO 58902v1 47097-01003 about 5 wt.% to about 50 wt.% of the cyclic olefin copolymer and from about 50 wt.%
to about 95 wt.% of the polyolefinic resin. The first layers 112a and 114a may comprise from about 5 wt.% to about 25 wt.%, from about 10 wt.% to about 20 wt.%, or from about 15 wt.% or about 20 wt.% of the cyclic olefin copolymer, and s from about 75 wt.% to about 95 wt.%, from about 80 wt.% to about 90 wt.%, or from about 80 wt.% to about 85 wt.% of the poiyolefinic resin.
It is preferred that the first layers 112a and 114a are located on the exterior of the bag, while the second layers 112b and 114b are located on the interior of the bag.
This is the embodiment depicted in FIGS. 3 and 4. It is contemplated, however, that at to least one of the first layers 112a and 114a may be located on the interior of the bag with at least one of the second layers 112b and 114b being located on the exterior of the bag.
Referring to FIG. 5, a cross-sectional view of line 5-5 of FIG. 3 is shown that depicts a two-layer bottom 116. The bottom wall 116 comprises a first layer I
16a and is a second layer 116b that is similar to that described above with respect to the first and second layers 112a, b and 114x, b of FIGS. 3 and 4. It is contemplated, however, that the first layer 116a may be located on the interior of the bag.
In another embodiment of the present invention shown in FIGS. 6 and 7, a stand-up polymeric bag 210 includes bocy panels 212 and 214, a bottom wall 216 and 2o a pair of sides 218 and 220. The body panel 212 includes a first layer 212a comprising a cyclic olefin copolymer, and second and third layers 212b and 212c comprising independently selected polyolefinic resins. The first layer 2~12a is located between the second layer 212b and the third layer 212c, with the second layer 212b being located on the exterior of the bag. The third layer 212c may comprise a polyolefinic resin such zs as those described above or may be a heat-sealable polyolefin, such as LLDPE or LDPE.
It is contemplated that other three layered body panels may be made, as well as body panels having four or more layers. The body panels may further include a barrier layer to prevent or inhibit oxygen, carbon dioxide or other gases from reaching the 3o contents in the interior of the bag. Alternatively, the body panel may include a breathable layer such as, e.g., polymethylpentene copolymer, to enhance the permeation of oxygen, carbon dioxide and other gases.
CHICAGO 58902v1 47097-01003 The body panels of the present invention have enhanced stiffness. This allows the body panels to have a desired stiffness at a downgauged thickness as compared to existing body panels. The enhanced stiffness at elevated temperatures is measured in increased tensile modulus and flexural modulus.
s The stand-up polymeric bags may further include a reclosable feature or fastener, such as a resealable adhesive seal or a reclosable zipper. The zipper can be opened and closed either by pressure or by the use of an auxiliary slider mechanism.
One example of a zipper is shown in FIGS. 8 and 9 in stand-up polymeric bag 300. The stand-up polymeric bag 300 of FIGS. 8 and 9 includes a zipper 352 to extending along a mouth formed opposite the bottom (not shown) of the bag 300. The zipper 352 includes a male track and a female track. The male track includes a male profile 3 54 and a first depending fin or flange 3 56 extending downward from the male profile 354. Likewise, the female track includes a female profile 358 and a second depending fin or flange 360 extending downward from the female profile 358.
The is flanges 356 and 360 are shown attached to opposing body panels 312 and 314.
Of course, the one-layered body panels 312 and 314 may be made of two or more layers, such as described above in body panels 112 and 212.
To assist in opening the bag 300, a slider 362 is slidably mounted to the zipper 352 for movement between a closed position and an open position. In the open 2o position of the slider 362, the male and female profiles 354 and 358 are disengaged from each other so that a user can gain access to the interior of the bag 300.
Movement of the slider 362 from the open position to the~closed position interlocks the male and female profiles 3 S4 and 3 58 so as to restrict access to the interior of the polymeric bag 300.
2s End termination clamps 364 are mounted to opposite ends of the zipper 352.
The end clamps 364 prevent the slider 362 from going past the ends of the zipper 352 and hold the male and female profiles 354 and 358 together to resist stresses applied to the profiles during normal use of the plastic bag 300. Further details concerning the construction and operation of the slider 362 and the end clamps 364 may be obtained 3o from United States Patent No. 5,067,208 to Herrington, Jr. et al., which is incorporated herein by reference in its entirety.
CHICAGO 58902v1 47097-01003 As discussed above, it is contemplated that the bags of the present invention may use other reclosable features such as a resealable adhesive seal or a reclosable fastener that does not include the use of a slider.
According to yet another embodiment, a packaging bag or pouch shown in s FIGS. 10 and 11 is a stand-up polymeric bag 400. The stand-up polymeric bag 400 is of a different configuration than shown in, for example, FIG. 1. The present invention, however, is not limited to the shown bags. It is contemplated that other bags may include the body panels of the present invention.
Referring to FIGS. 10 and 11, the stand-up polymeric bag 400 includes a body to panel 412, an opposing body panel 414, and a bottom 416. In FIG. 10, the bottom is located between the opposing body panels 412 and 414 and extends from a bottom edge 492 to a hidden line 480. As shown in FIG. 1 I , the bottom 416 includes three integrally connected portions 416a, 416b and 416c.
Lines of attachment 488, as shown in FIGS. 10 and 11, assist in forming the Is bottom 416. The lines of attachment 488 are depicted in FIGS. 10 and 11 as attaching a portion of the body panel 412 to the bottom 416. Similarly, lines of attachment 490 of FIG. 11 are shown that attach a portion of the body panel 414 to the bottom 416.
The lines of attachment 488 and 490 divide the bottom 416 into portions 416a, 416b and 416c. The lines of attachment 488 and 490 of FIGS. 10 and 11 are generally zo straight lines that extend from a bottom edge 492 of the bag to sides 418 or 420. The lines of attachment of 488 are at an angle B, as depicted in FIG. 10. The angle B is generally from about 30 to about 60 degrees as taken from tile bottom edge 492a. The lines of attachment 488 and 490 may be shaped differently and proceed at different angles B. The lines of attachment may be formed by heat-sealing.
zs The bottom edge 492 may include a sealed edge portion 492a that attaches the body panel 412 and the bottom portions 416b and 416c. Similarly, the bag 400 may include a second bottom edge 494 and a sealed edge portion 494a. The sealed edge portion 494a attaches the body panel 414 and the bottom portions 416b and 416c.
The stand-up polymeric bag 400 also includes a slider 462 and end termination 3o clips 464, such as those described above (slider 62 and end termination clip 64). It is, however, not necessary for the bag 400 to include a fastener.
According to another embodiment, the stand-up polymeric bags of the present invention may further include a vented option. A vented polymeric bag may provide CHICAGO 58902v1 47097-01003 faster and more uniform heating, as well as extending the preservation time of the heated food. In addition, a vented stand-up polymeric bag may further assist in avoiding a spill from the bag because the bag would not likely need to be opened during the heating process. The contents of the bags, however, may still leak through s the vented option. Leaks from the vented option are less likely when a more tortuous path is created for the contents of the bags to leak.
The vented option is preferably located near the mouth of the bag, but may be in other locations, such as the sides. The vented option may be a small hole, a plurality of small holes or a one-way valve. An example of a vented option is shown in U. S.
to Patent Nos. 6,010,244 and 4,532,652, which is hereby incorporated by reference in its entirety.
Processes The body panels of the present invention may be formed by extruding or is coextruding one or more layers using conventional techniques known to those skilled in the art. For example, a first layer comprising a cyclic olefin copolymer portion and a second layer comprising a polyolefinic resin may be coextruded. The polyolefinic resin of the second layer may be a polyethylene, such as LLDPE or LDPE. A third-layer body panel may be coextruded with an ~:,ater layer comprising a polyolefinic resin, a zo middle layer comprising a cyclic olefin copolymer, and an inner layer comprising a heat-sealable polyolefin, such as LLDPE or LDPE. Alternatively, the layers may be laminated in forming the three-layer structure.
The polyolefinic resin and the cyclic olefin copolymer may also be blended in forming the body panels. These resins may be extruded in forming the body panels of 2s the present invention. According to another process of the present invention, the body panels of the present invention may be formed from blown processes or cast film processes.
The overall thickness of the bags or pouches may vary, but is generally from about 1 to about 5 mils, and typically from about 2 to about 4 mils. The overall 3o thickness of the bags or pouches is more typically from about 3 to about 4 mils. In the embodiments that include body panels having more than one layer, the thickness of the layers may vary between the layers and are likely dependent on the end use of the bag.
One contemplated embodiment is a 4.0 mil three layer body panel that includes a 0.5 CHICAGO 58902v1 47097-01003 mil middle layer comprising a cyclic olefin copolymer and outer polyethylene layers (3.5 mils total).
The bags or pouches of the present invention may store items such as food products or liquids. This includes, but is not limited to, soups, pre-packaged foods, s lasagna, chicken, meats, vegetables, liquids and left-over products.
The bags or pouches of the present invention are preferably capable of being heated at higher temperatures, such as those generated in microwaves and conventional ovens.
to Examples Bag Testing The results of the bag testing appear in Table 1. The bags (Bags 1-6) were formed manually. Each of the bags had a width of 12 inches, a height of 7 inches and a is depth of 6 inches. The thickness of the film used in forming the bags were either 2 mils or 4 mils. Each of the bags had a track on which a slider opened/closed the bag.
The bags also included clips at opposing ends of the track.
All of the body panels used in forming Bags 1-6 of Table 1 were made of a single layer. Bags 1-6 were made of different materials, but all included at least one 20 linear low density polyethylene (LLDPE). Bags 3-6 further included a cyclic olefin copolymer. In Bags 3-6, the cyclic olefin copolymers and the LLDPE were blended and extruded as a monolayer film. The monolayer film was used in forming the body panels.
The LLDPE resin used in Bag 1 from Dow Chemical had a melt index of 1.0 2s g/10 min. as measured by ASTM D1238, and a density of about 0.926 g/cm3.
The other LLDPE resin used in Bags 2-6 was from Eastman Chemical Company. The Eastman resin had a melt index of 0.5 g/10 min. as measured by ASTM D1238, and a density of about 0.928 g/cm~. The Eastman LLDPE resin used in Table 1 fi.lrther contained an added 2.5 wt.% slip and antiblock polyethylene concentrate and 1.25 so wt.% of a process aid concentrate.
There were two different types of cyclic olefin copolymers that were used in making Bags 3-6 of Table 1. The first cyclic olefin copolymer was TOPAS ~ 6013 made by Ticona, a business of Celanese AG. The TOPAS ~ 6013 had a melt index of CHICAGO 58902v1 47097-01003 16 g/ 10 min. as measured by ISO 1 133, a temperature glass transition (Tg) of 140°C
and a density of 1.02 g/cm3. The second cyclic olefin copolymer was TOPAS ~
made by Ticona, a business of Celanese AG. The TOPAS ~ 6015 had a melt index of 16 g/ 10 min. as measured by ISO I 133, a temperature glass transition (T~) of 160 °C
s and a density of 1.02 g/cm3.
As shown in Table 1, Bag i was comprised of 100 wt.% LLDPE from Dow Chemical, while Bag 2 was comprised of 100 wt.% of LLDPE from Eastman. Bags 3-were made of Eastman LLDPE and TOPAS ~ 6013 in various weight percentages.
Bag 3 was made of 95 wt.% of Eastman LLDPE and 5 wt.% of TOPAS ~ 6013. Bag l0 4 was made of 90 wt.% of Eastman LLDPE and 10 wt.% of TOPAS ~ 6013, while Bag 5 was made of 80 wt.% of Eastman LLDPE and 20 wt.% of TOPAS ~ 6013.
Bag 6 was made of 90 wt.% of Eastman LLDPE and 10 wt.% of TOPAS ~ 6015.
Before water was added to the bags, the bags were visually inspected to determine if each of the bags stood up. The results of the visually inspection are Is shown in Table 1 in the "Stand Up" columns.
The bags were tested in a microwave and included the following tests: the boiling water test, the frozen chili test and the frozen pizza test. The "boiling water"
test was performed on all of the bags and consisted of adding 1.5 liter of water to each cf the bags. The water that was added to the bags was initially at room temperature.
zo The added water had a depth or fill of about 2 to 2.5 inches in the bag.
The bags were then heated in the microwave for about 7 minutes at high power until the water was at its boiling temperature (about 200PF). The bags were then qualitatively evaluated by visually inspecting the bag to determine if the bag was still standing up or if sagging occurred.
2s The "frozen chili" test consisted of placing the content of the two cans of Hormel~ Chili without beans (each can was I S ounces, 425 grams) in the bag.
The chili was placed in the freezer for at least 36 hours. The frozen chili was removed from the freezer and heated for about 7.5 minutes in the microwave at high power.
After being heated in the microwave for this duration, the chili was at a temperature of about 30 150 to about 165°F.
The "frozen pizza" test started with 3 pieces of cheese pizza in the bag being placed in the freezer for at least 36 hours. The frozen pizza slices were removed from the freezer and heated for about 3 minutes in the microwave at high power.
After CHICAGO 58902v1 47097-01003 being heated in the microwave for this duration, the cheese pizza was at a temperature of about 140 to about 195°F.
In Table 1, the boiling water test is referred to as the "water test", the frozen chili test is referred to as the "chili test", and the frozen pizza test is referred to as the "pizza test". The boiling water test was performed on Bags 1-6. The frozen chili test was performed on Bag 3, while the frozen pizza test was performed on Bags 4-5.
Table 1 ThicknessWater Chili Pizza Test Test Test Bag Composition (mil) Stand Sag Stand Sag Stand Sag Up (%) Up Up (~%) No.
1 100 wt.% 4 Yes 50% ~6 ~, -LLDPE~ g 2 100 wt.% 4 Yes 100%' NT NT
LLDPE
3 95 w2.% LLDPEZ~ Yes 10%,-'BYes 0% NT
FIG. 6 is a perspective view of a bag having body panels comprising three layers according to a further embodiment of the present invention;
FIG. 7 is a cross-sectional view taken generally along the line 7-7 in FIG. 6;
FIG. 8 is a perspective view of a bag portion of FIG. 1 including a fastener and Is slider according to yet another embodiment of the present invention;
FIG. 9 is a cross-sectional view taken generally along the line 9-9 in FIG. 8 that includes an enlarged perspective view of the fastener of FIG. 8;
FIG. 10 is a side view of a bag in a closed position according to yet another embodin.:.~~ of the present invention; and 2o FIG. 11 is a perspective view of the bag of FIG. 10 in an open position.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed but, on the 2s contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
According to one embodiment of the packaging bags or pouches shown in 3o FIGS. 1 and 2, is a stand-up polymeric bag 10. The stand-up polymeric bag comprises first and second body panels 12 and 14 and a bottom wall 16. The first and second opposing body panels 12 and 14 are coupled to opposing portions of the bottom wall 16. The first and second opposing body panels 12 and 14 are fixedly CHICAGO 58902v1 47097-01003 connected to each other along a pair of sides 18 and 20. The bottom wall 16 extends between the pair of sides 18 and 20. The bottom wall 16 of FIG. 1 is a gusseted bottom wall that comprises two gusseted portions 16a and 16b. It is contemplated that the bottom wall 16 may be comprised of other configurations than a gusseted bottom s wall, such as shown in FIG. 1. Another configuration of a bottom wall will be discussed later with respect to FIGS. 10 and 11.
The body panels 12 and 14 of the stand-up polymeric bag 10 comprise a cyclic olefin copolymer and a polyolefinic resin. The cyclic olefin copolymer and the polyolefinic resin may be blended to form the body panels (i.e., a monolayer).
This is to shown in the bag 10 of FIGS. 1 and 2, for example. The body panels generally comprise from about 5 wt.% to about 95 wt.% of the cyclic olefin copolymer and from about 5 wt.% to about 95 wt.% of the polyolefinic resin. The body panels typically comprise from about 5 wt.% to about 50 wt.% of the cyclic olefin copolymer and from about 50 wt.% to about 95 wt.% of the polyolefinic resin. More specifically, the body is panels comprise from about 5 wt.% to about 25 wt.%, from about 10 wt.% to about 20 wt.%, or from about 15 wt.% or about 20 wt.% of the cyclic olefin copolymer, and from about 75 wt.% to about 95 wt.%, from about 80 wt.% to about 90 wt.%, or from about 80 wt.% to about 85 wt.% of the polyolefinic resin.
20 ~clic olefin copol~rmers The cyclic olefin copolymers of the present invention generally have a molecular weight distribution, or polydispersity, (MW/M", "MWD") from about 2.0 to about 5.0, and preferably from about 2.0 to about 2.5.
The cyclic olefin copolymers generally have a density of from about 0.90 to 2s about 1.10 g/cm3, typically from about 0.95 to about 1.05 g/cm3 and more typically from about 1.00 to about 1.03 g/cm3. The heat deflection temperature (HDT, measured at 66 psi) of cyclic olefin copolymers generally is from about 50 to about 200°C, and typically from about 70 to about 170°C.
The melt flow index (MI) of the cyclic olefin copolymers is generally from 3o about 1 to about 100 g/10 min., and typically from about 4 to about 20 g/10 min. at 115°C (239°F) above its corresponding HDT as determined by ISO
1133.
The cyclic olefin copolymers may be made from copolymers of ethylene and norbornene. The mole % of ethylene and norbornene may vary with respect to each CHICAGO 58902v1 47097-01003 other For example, the amount of norbornene is generally from about 10 to about 90 mol.%, with the remainder being ethylene (from about 10 to about 90 mol.%).
The amount of norbornene is typically from about 20 to about 70 mol.% with the remainder being ethylene. The amount of norbornene is more typically from about 35 to about 60 s mol.% with the remainder being ethylene. The cyclic olefin copolymers may be made using metallocene catalysts.
The glass transition temperature (Tg) of the cyclic olefin copolymer is generally greater than about 20°C, typically greater than about 50°C, and preferably greater than about 75°C, as measured by ASTM D3418. The glass transition temperature of the to cyclic olefin copolymer may be greater than about 100°C or about 150°C as measured by ASTM D3418. The glass transition temperature (T~) of the cyclic olefin copolymers increases as the mole % of norbornene in the copolymer increases.
For example, the glass temperature transition (Tg) of a cyclic olefin copolymer comprising 20 mol.% norbornene and 80 mol.% ethylene is about 25°C, while the glass is temperature transition of a cyclic olefin copolymer comprising 70 mol.%
norbornene and 30 mol.% ethylene is about 210°C. The glass temperature transition (Tg) of a cyclic olefin copolymer comprising 30 mol.% norbornene and 70 mol.% ethylene is about 75°C, while a cyclic olefin copolymer comprising 60 mol.%
norbornene and 40 mol.% ethylene is about 180°C.
2o The flexural modulus of the cyclic olefin copolymer is generally from about 300,000 to about 600,000 psi, and more specifically from about 400,000 to about 500,000 psi as measured by ASTM D790. The tensile mbdulus of the cyclic olefin copolymers is generally from about 300,000 to about 600,000 psi, and more specifically from about 400,000 to about 500,000 psi, as determined by ISO
527.
is Useful cyclic olefin copolymers are available from several companies. For example, Ticona, a business of Celanese AG, in Summit N.J. has cyclic olefin copolymers available. Other companies that have cyclic olefin copolymers available include Nippon Zeon (Japan), Mitsui Chemical (Japan) and JSR (Japan), formerly know as Japan Synthetic Rubber. Ticona, a business of Celanese AG, has so commercially available cyclic olefin copolymers (COCs) under the designation TOPAS~. These cyclic olefin copolymers are believed to be prepared with feedstocks of norbornene and ethylene and the use of a metallocene catalyst. There are believed to be at least four grades of TOPAS~ resins available (TOPAS~ 8007, TOPAS~
CHICAGO 58902v1 47097-01003 6013, TOPAS~ 601 S and TOPAS~ 6017). The four grades of TOPAS~ resins available have glass transition temperatures, Tg, of 80, 140, 160 and 180°C, respectively. The corresponding norbornene levels of the four grades of TOPAS~
resins are believed to be about 3S, 48, SS and S9 mole %.
s Polyolefinic Resins The polyolefinic resins that may be used in the present invention include low density polyethylenes (LDPE), linear low density polyethylenes (LLDPE), high density polyethylenes (HI~PE), medium density polyethylenes (1VIDPE), polypropylenes, to plastomers, ethylene vinyl acetates (EVA), polymethylpentene copolymers and combinations thereof. It is contemplated that other polyolefinic resins may be used.
The preferred polyolefinic resins are low density polyethylenes and linear low density polyethylenes.
The polyolefinic resin may include a small amount of an alkenyl aromatic is polymer (e.g., polystyrene). For example, the alkenyl aromatic polymer may be added in an amount up to about 1 or about 2 wt. % of the polyethylene. Further details may be obtained from U.S. Patent Nos. 4,579,912, 4,716,201, 4,743,649 and 4,804,564.
In another embodiment of the present invention, the body panels comprise a first layer comprising a cyclic olefin cu~olymer and a second layer comprising a 2o polyolefinic resin. This is shown, for example, in FIGS. 3-5 with a bag having panels made from two layers. The stand-up polymeric bag 110 of FIG. 3 has a body panel 112 that comprises a first layer 112a and a second layer '112b. Similarly, stand-up polymeric bag 110 has a body panel 114 that comprises a first layer 114a and a second layer 114b.
zs The first layers 112a and 114a comprise a cyclic olefin copolymer, while the second layers 112b and 114b comprise a polyolefinic resin. The compositions of the first layers 112a and 114a do not necessary have to be made of identical materials.
Likewise, the second layers 112b and 114b may be comprised of independently selected polyolefinic resins.
3o The first layers 112a and I 14a may comprise a cyclic olefin copolymer and a polyolefinic resin. The first layers 112a and 114a generally comprise from about 5 wt.% to 100 wt.% of the cyclic olefin copolymer and from about 0 wt.% to about wt.% of the polyolefinic resin. The first layers 112a and 114a typically comprise from CHICAGO 58902v1 47097-01003 about 5 wt.% to about 50 wt.% of the cyclic olefin copolymer and from about 50 wt.%
to about 95 wt.% of the polyolefinic resin. The first layers 112a and 114a may comprise from about 5 wt.% to about 25 wt.%, from about 10 wt.% to about 20 wt.%, or from about 15 wt.% or about 20 wt.% of the cyclic olefin copolymer, and s from about 75 wt.% to about 95 wt.%, from about 80 wt.% to about 90 wt.%, or from about 80 wt.% to about 85 wt.% of the poiyolefinic resin.
It is preferred that the first layers 112a and 114a are located on the exterior of the bag, while the second layers 112b and 114b are located on the interior of the bag.
This is the embodiment depicted in FIGS. 3 and 4. It is contemplated, however, that at to least one of the first layers 112a and 114a may be located on the interior of the bag with at least one of the second layers 112b and 114b being located on the exterior of the bag.
Referring to FIG. 5, a cross-sectional view of line 5-5 of FIG. 3 is shown that depicts a two-layer bottom 116. The bottom wall 116 comprises a first layer I
16a and is a second layer 116b that is similar to that described above with respect to the first and second layers 112a, b and 114x, b of FIGS. 3 and 4. It is contemplated, however, that the first layer 116a may be located on the interior of the bag.
In another embodiment of the present invention shown in FIGS. 6 and 7, a stand-up polymeric bag 210 includes bocy panels 212 and 214, a bottom wall 216 and 2o a pair of sides 218 and 220. The body panel 212 includes a first layer 212a comprising a cyclic olefin copolymer, and second and third layers 212b and 212c comprising independently selected polyolefinic resins. The first layer 2~12a is located between the second layer 212b and the third layer 212c, with the second layer 212b being located on the exterior of the bag. The third layer 212c may comprise a polyolefinic resin such zs as those described above or may be a heat-sealable polyolefin, such as LLDPE or LDPE.
It is contemplated that other three layered body panels may be made, as well as body panels having four or more layers. The body panels may further include a barrier layer to prevent or inhibit oxygen, carbon dioxide or other gases from reaching the 3o contents in the interior of the bag. Alternatively, the body panel may include a breathable layer such as, e.g., polymethylpentene copolymer, to enhance the permeation of oxygen, carbon dioxide and other gases.
CHICAGO 58902v1 47097-01003 The body panels of the present invention have enhanced stiffness. This allows the body panels to have a desired stiffness at a downgauged thickness as compared to existing body panels. The enhanced stiffness at elevated temperatures is measured in increased tensile modulus and flexural modulus.
s The stand-up polymeric bags may further include a reclosable feature or fastener, such as a resealable adhesive seal or a reclosable zipper. The zipper can be opened and closed either by pressure or by the use of an auxiliary slider mechanism.
One example of a zipper is shown in FIGS. 8 and 9 in stand-up polymeric bag 300. The stand-up polymeric bag 300 of FIGS. 8 and 9 includes a zipper 352 to extending along a mouth formed opposite the bottom (not shown) of the bag 300. The zipper 352 includes a male track and a female track. The male track includes a male profile 3 54 and a first depending fin or flange 3 56 extending downward from the male profile 354. Likewise, the female track includes a female profile 358 and a second depending fin or flange 360 extending downward from the female profile 358.
The is flanges 356 and 360 are shown attached to opposing body panels 312 and 314.
Of course, the one-layered body panels 312 and 314 may be made of two or more layers, such as described above in body panels 112 and 212.
To assist in opening the bag 300, a slider 362 is slidably mounted to the zipper 352 for movement between a closed position and an open position. In the open 2o position of the slider 362, the male and female profiles 354 and 358 are disengaged from each other so that a user can gain access to the interior of the bag 300.
Movement of the slider 362 from the open position to the~closed position interlocks the male and female profiles 3 S4 and 3 58 so as to restrict access to the interior of the polymeric bag 300.
2s End termination clamps 364 are mounted to opposite ends of the zipper 352.
The end clamps 364 prevent the slider 362 from going past the ends of the zipper 352 and hold the male and female profiles 354 and 358 together to resist stresses applied to the profiles during normal use of the plastic bag 300. Further details concerning the construction and operation of the slider 362 and the end clamps 364 may be obtained 3o from United States Patent No. 5,067,208 to Herrington, Jr. et al., which is incorporated herein by reference in its entirety.
CHICAGO 58902v1 47097-01003 As discussed above, it is contemplated that the bags of the present invention may use other reclosable features such as a resealable adhesive seal or a reclosable fastener that does not include the use of a slider.
According to yet another embodiment, a packaging bag or pouch shown in s FIGS. 10 and 11 is a stand-up polymeric bag 400. The stand-up polymeric bag 400 is of a different configuration than shown in, for example, FIG. 1. The present invention, however, is not limited to the shown bags. It is contemplated that other bags may include the body panels of the present invention.
Referring to FIGS. 10 and 11, the stand-up polymeric bag 400 includes a body to panel 412, an opposing body panel 414, and a bottom 416. In FIG. 10, the bottom is located between the opposing body panels 412 and 414 and extends from a bottom edge 492 to a hidden line 480. As shown in FIG. 1 I , the bottom 416 includes three integrally connected portions 416a, 416b and 416c.
Lines of attachment 488, as shown in FIGS. 10 and 11, assist in forming the Is bottom 416. The lines of attachment 488 are depicted in FIGS. 10 and 11 as attaching a portion of the body panel 412 to the bottom 416. Similarly, lines of attachment 490 of FIG. 11 are shown that attach a portion of the body panel 414 to the bottom 416.
The lines of attachment 488 and 490 divide the bottom 416 into portions 416a, 416b and 416c. The lines of attachment 488 and 490 of FIGS. 10 and 11 are generally zo straight lines that extend from a bottom edge 492 of the bag to sides 418 or 420. The lines of attachment of 488 are at an angle B, as depicted in FIG. 10. The angle B is generally from about 30 to about 60 degrees as taken from tile bottom edge 492a. The lines of attachment 488 and 490 may be shaped differently and proceed at different angles B. The lines of attachment may be formed by heat-sealing.
zs The bottom edge 492 may include a sealed edge portion 492a that attaches the body panel 412 and the bottom portions 416b and 416c. Similarly, the bag 400 may include a second bottom edge 494 and a sealed edge portion 494a. The sealed edge portion 494a attaches the body panel 414 and the bottom portions 416b and 416c.
The stand-up polymeric bag 400 also includes a slider 462 and end termination 3o clips 464, such as those described above (slider 62 and end termination clip 64). It is, however, not necessary for the bag 400 to include a fastener.
According to another embodiment, the stand-up polymeric bags of the present invention may further include a vented option. A vented polymeric bag may provide CHICAGO 58902v1 47097-01003 faster and more uniform heating, as well as extending the preservation time of the heated food. In addition, a vented stand-up polymeric bag may further assist in avoiding a spill from the bag because the bag would not likely need to be opened during the heating process. The contents of the bags, however, may still leak through s the vented option. Leaks from the vented option are less likely when a more tortuous path is created for the contents of the bags to leak.
The vented option is preferably located near the mouth of the bag, but may be in other locations, such as the sides. The vented option may be a small hole, a plurality of small holes or a one-way valve. An example of a vented option is shown in U. S.
to Patent Nos. 6,010,244 and 4,532,652, which is hereby incorporated by reference in its entirety.
Processes The body panels of the present invention may be formed by extruding or is coextruding one or more layers using conventional techniques known to those skilled in the art. For example, a first layer comprising a cyclic olefin copolymer portion and a second layer comprising a polyolefinic resin may be coextruded. The polyolefinic resin of the second layer may be a polyethylene, such as LLDPE or LDPE. A third-layer body panel may be coextruded with an ~:,ater layer comprising a polyolefinic resin, a zo middle layer comprising a cyclic olefin copolymer, and an inner layer comprising a heat-sealable polyolefin, such as LLDPE or LDPE. Alternatively, the layers may be laminated in forming the three-layer structure.
The polyolefinic resin and the cyclic olefin copolymer may also be blended in forming the body panels. These resins may be extruded in forming the body panels of 2s the present invention. According to another process of the present invention, the body panels of the present invention may be formed from blown processes or cast film processes.
The overall thickness of the bags or pouches may vary, but is generally from about 1 to about 5 mils, and typically from about 2 to about 4 mils. The overall 3o thickness of the bags or pouches is more typically from about 3 to about 4 mils. In the embodiments that include body panels having more than one layer, the thickness of the layers may vary between the layers and are likely dependent on the end use of the bag.
One contemplated embodiment is a 4.0 mil three layer body panel that includes a 0.5 CHICAGO 58902v1 47097-01003 mil middle layer comprising a cyclic olefin copolymer and outer polyethylene layers (3.5 mils total).
The bags or pouches of the present invention may store items such as food products or liquids. This includes, but is not limited to, soups, pre-packaged foods, s lasagna, chicken, meats, vegetables, liquids and left-over products.
The bags or pouches of the present invention are preferably capable of being heated at higher temperatures, such as those generated in microwaves and conventional ovens.
to Examples Bag Testing The results of the bag testing appear in Table 1. The bags (Bags 1-6) were formed manually. Each of the bags had a width of 12 inches, a height of 7 inches and a is depth of 6 inches. The thickness of the film used in forming the bags were either 2 mils or 4 mils. Each of the bags had a track on which a slider opened/closed the bag.
The bags also included clips at opposing ends of the track.
All of the body panels used in forming Bags 1-6 of Table 1 were made of a single layer. Bags 1-6 were made of different materials, but all included at least one 20 linear low density polyethylene (LLDPE). Bags 3-6 further included a cyclic olefin copolymer. In Bags 3-6, the cyclic olefin copolymers and the LLDPE were blended and extruded as a monolayer film. The monolayer film was used in forming the body panels.
The LLDPE resin used in Bag 1 from Dow Chemical had a melt index of 1.0 2s g/10 min. as measured by ASTM D1238, and a density of about 0.926 g/cm3.
The other LLDPE resin used in Bags 2-6 was from Eastman Chemical Company. The Eastman resin had a melt index of 0.5 g/10 min. as measured by ASTM D1238, and a density of about 0.928 g/cm~. The Eastman LLDPE resin used in Table 1 fi.lrther contained an added 2.5 wt.% slip and antiblock polyethylene concentrate and 1.25 so wt.% of a process aid concentrate.
There were two different types of cyclic olefin copolymers that were used in making Bags 3-6 of Table 1. The first cyclic olefin copolymer was TOPAS ~ 6013 made by Ticona, a business of Celanese AG. The TOPAS ~ 6013 had a melt index of CHICAGO 58902v1 47097-01003 16 g/ 10 min. as measured by ISO 1 133, a temperature glass transition (Tg) of 140°C
and a density of 1.02 g/cm3. The second cyclic olefin copolymer was TOPAS ~
made by Ticona, a business of Celanese AG. The TOPAS ~ 6015 had a melt index of 16 g/ 10 min. as measured by ISO I 133, a temperature glass transition (T~) of 160 °C
s and a density of 1.02 g/cm3.
As shown in Table 1, Bag i was comprised of 100 wt.% LLDPE from Dow Chemical, while Bag 2 was comprised of 100 wt.% of LLDPE from Eastman. Bags 3-were made of Eastman LLDPE and TOPAS ~ 6013 in various weight percentages.
Bag 3 was made of 95 wt.% of Eastman LLDPE and 5 wt.% of TOPAS ~ 6013. Bag l0 4 was made of 90 wt.% of Eastman LLDPE and 10 wt.% of TOPAS ~ 6013, while Bag 5 was made of 80 wt.% of Eastman LLDPE and 20 wt.% of TOPAS ~ 6013.
Bag 6 was made of 90 wt.% of Eastman LLDPE and 10 wt.% of TOPAS ~ 6015.
Before water was added to the bags, the bags were visually inspected to determine if each of the bags stood up. The results of the visually inspection are Is shown in Table 1 in the "Stand Up" columns.
The bags were tested in a microwave and included the following tests: the boiling water test, the frozen chili test and the frozen pizza test. The "boiling water"
test was performed on all of the bags and consisted of adding 1.5 liter of water to each cf the bags. The water that was added to the bags was initially at room temperature.
zo The added water had a depth or fill of about 2 to 2.5 inches in the bag.
The bags were then heated in the microwave for about 7 minutes at high power until the water was at its boiling temperature (about 200PF). The bags were then qualitatively evaluated by visually inspecting the bag to determine if the bag was still standing up or if sagging occurred.
2s The "frozen chili" test consisted of placing the content of the two cans of Hormel~ Chili without beans (each can was I S ounces, 425 grams) in the bag.
The chili was placed in the freezer for at least 36 hours. The frozen chili was removed from the freezer and heated for about 7.5 minutes in the microwave at high power.
After being heated in the microwave for this duration, the chili was at a temperature of about 30 150 to about 165°F.
The "frozen pizza" test started with 3 pieces of cheese pizza in the bag being placed in the freezer for at least 36 hours. The frozen pizza slices were removed from the freezer and heated for about 3 minutes in the microwave at high power.
After CHICAGO 58902v1 47097-01003 being heated in the microwave for this duration, the cheese pizza was at a temperature of about 140 to about 195°F.
In Table 1, the boiling water test is referred to as the "water test", the frozen chili test is referred to as the "chili test", and the frozen pizza test is referred to as the "pizza test". The boiling water test was performed on Bags 1-6. The frozen chili test was performed on Bag 3, while the frozen pizza test was performed on Bags 4-5.
Table 1 ThicknessWater Chili Pizza Test Test Test Bag Composition (mil) Stand Sag Stand Sag Stand Sag Up (%) Up Up (~%) No.
1 100 wt.% 4 Yes 50% ~6 ~, -LLDPE~ g 2 100 wt.% 4 Yes 100%' NT NT
LLDPE
3 95 w2.% LLDPEZ~ Yes 10%,-'BYes 0% NT
5 wt.% COC3 d 90 wt.% LLDPE14 Yes 0%'v NT Yes 10/$
10 wt.% COC3 80 wt.% LLDPE24 Yes 10%5~8NT Yes X10/$
- -20 wt.% COC' 6 90 wt.% LLDPE'4 Yes 10%'~ NT NT
10 wt.% COC
1 The LLDPE from Dow Chemical had a melt index of 1.0 g/10 min. and a density of 0.926 g/cm'.
2 The LLDPE from Eastman Chemical with a melt index of 0.5 g/10 min. and a density of 0.928 g/cm'.
3 Cyclic olefin copolymer (COC}-TOPAS~ 6013 with a melt index of 16 g/10 min.
and a density of 1.02 g/cm'.
4 Cyclic olefin copolymer (COCA TOPA S~ 6015 with a melt index of 16 g/10 min.
and a density of 1.02 p~cm'.
5 After 7. S minutes 6 NT = not tested 7 After 6. S minutes 8 The sagging % was located near the clip of the bag As shown in Table 1, bags without the cyclic olefin copolymers (COC) showed significantly poorer results in the boiling water test. Specifically, Bags 1 and 2 had 2s 50% and 100% sag, respectively, as compared to Bags 3-6 (bags comprising a COC) that had 10% or less of sagging. Bag 3, 5 and 6 had 10% sag near the clip, while Bag 4 did not have any sagging in the boiling water test. The boiling water test reported in Table 1 tested at least two different bags of the same composition (Bags 1-6).
Bags 3-5 also showed great results in other tests performed. The frozen chili 3o test and the frozen pizza test was performed twice on the same bag.
Specifically, the bag that was tested in the frozen chili test (Bag 3) and the bags tested in the frozen pizza test (Bags 4 and 5) showed good results in that they all had 10% or less of sagging. In fact, Bag 3 did not show any sagging after being tested in the frozen chili CHICA(i0 58902v1 47097-01003 test. It was surprising 'that a small amount of a cyclic olefin copolymer would produce the results shown in the boiling test, frozen chili test and the frozen pizza test.
Example 2 The films as shown in Table 2 (Films 1-5) were tested for various mechanical s properties. Specifically, tensile, elongation and modulus properties of the films were determined in accordance with ASTM D882. The visual appearance of Films 1-5 is also shown in Table 2 below.
Film 1 comprised 100 wt.% of linear low density polyethylene from Dow Chemical Company having a melt index of 2.0 g/10 min. as determined by ASTM
to D1238 and a density of 0.926 g/cm3. Films 2-5 comprised either 80 or 95 wt.% of the Dow Chemical LLDPE resin with the remainder being either TOPAS~ 8007 or TOPAS~ 6013. The average thicknesses of the films was from 2.5 to 3 mils. The tested films were formed by a cast process.
F5lm LLDPE' COCi Tensile ElongationModulus Appearance No. (wt. %) (wt. (kpsi (% at (kpsi) %) at break) break) 1 100 0 4.38 661 26.4 Clear 2 95 5 6._' 794 46.6 Clear 3 85 15' 4.83 556 67.4 Clear 4 95 5 3.01 605 18.4 Hazy 5 85 15 4.25 646 ~ 52.0 Hazy 1 The LLDPE had a melt index of 2.0 g/10 min. and a density of 0.926 g/cm'.
2 COC = cyclic olefin copolymer.
3 The COC was TOPAS~ 8007 with a melt index of 4.5 ml/ l0 min and a density of 1.02 g/cm' 4 The COC was TOPAS~ 6013.
Films 2, 3 and 5, with the cyclic olefin copolymer showed excellent modulus as zs compared to Film 1. Each of the modulus of Films 2, 3 and 5 was almost twice as high as the modulus value of Film 1 (the film without a cyclic olefin copolymer).
Compare 46.6, 67.4 and 52.0 kpsi vs. 26.4 kpsi in Table 2. The amount of increased modulus in Films 2, 3 and 5 was surprising considered the amount of cyclic olefin copolymer added (either 5% or 15%). Film 4 showed a reduced modulus as compared to Film 1.
3o The modulus of Films 2, 3 and 5 were especially surprising because the elongation CHICAGO 58902v1 47097-01003 values of Films 2, 3 and 5 were not much lower than the elongation value of Film 1 (compare 794, 556 and 646% vs. 661% in Table 2). In fact, the elongation of Film 2 was actually higher than the elongation of Film 1.
The tensile values of Films 2 and 3 were higher than that of Film 1 (compare 6.25 and 4.83 vs. 4.38 kpsi in Table 2), while the tensile value of Film S was slightly lower than Film 1 (4.25 kpsi vs. 4.38 kpsi). The appearance of the film was clear for Films 1-3, but was hazy for Films 4 and 5 that included TOPAS~ 6013. It is believed that the greater amount of norbornene included in TOPAS~ 6013, as compared to TOPAS~ 8007, produces a film that is hazy.
Io Example 3 The films of Table 2 were used in forming Bags 1-5. Bags 1-5 were tested to determine if the bags were self standing or could be made to stand-up with the addition of 1. S liters of water. The average thicknesses of the films used to form Bags 1-5 was from 2.5 to 3 mils. The films used in forming the bags were cast mono-layer.
t 5 TABLE 3 Bag No.s LLDPEI COCZ Stand Up Test w2. % Wt.
1 l 00 0 No 2 95 5' Yes, but with water inside 3 85 15 Yes 4 95 _ 5 Yes, but with water inside 85 15' Yesb 1 The LLDPE had a melt index of 2.0 g/ 10 min. and a density of 0.926 g/cm'.
2 COC = cyclic olefin copolymer.
2o 3 The COC was TOPAS~ 8007 with a melt index of 4.5 g/10 min. and a density of 1.02 g/cm'.
4 The COC was TOPAS~ 6013.
5 Bags 1-5 had a width of 5.5 inches and a height of 7 inches.
6 In addition to standing-up on its own and with the addition of water, Bag 5 also was a stand-up bag after being heated in a microwave at high power temperature for 2 minutes with water.
Bags 3 and 5 with the cyclic olefin copolymer were self stand up bags without the addition of water. Bags 2 and 4 with the cyclic olefin copolymer were stand-up bags with the addition of water. Bag 1, however, without the cyclic olefin copolymer 3o did not stand up with or without the addition of the water.
While the present invention has been described with reference to particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention.
Each of these embodiments and obvious variations thereof is contemplated as falling within the 3s spirit and scope of the claimed invention, which is set forth in the following claims.
CHICAGO 58902v1 47097-01003
10 wt.% COC3 80 wt.% LLDPE24 Yes 10%5~8NT Yes X10/$
- -20 wt.% COC' 6 90 wt.% LLDPE'4 Yes 10%'~ NT NT
10 wt.% COC
1 The LLDPE from Dow Chemical had a melt index of 1.0 g/10 min. and a density of 0.926 g/cm'.
2 The LLDPE from Eastman Chemical with a melt index of 0.5 g/10 min. and a density of 0.928 g/cm'.
3 Cyclic olefin copolymer (COC}-TOPAS~ 6013 with a melt index of 16 g/10 min.
and a density of 1.02 g/cm'.
4 Cyclic olefin copolymer (COCA TOPA S~ 6015 with a melt index of 16 g/10 min.
and a density of 1.02 p~cm'.
5 After 7. S minutes 6 NT = not tested 7 After 6. S minutes 8 The sagging % was located near the clip of the bag As shown in Table 1, bags without the cyclic olefin copolymers (COC) showed significantly poorer results in the boiling water test. Specifically, Bags 1 and 2 had 2s 50% and 100% sag, respectively, as compared to Bags 3-6 (bags comprising a COC) that had 10% or less of sagging. Bag 3, 5 and 6 had 10% sag near the clip, while Bag 4 did not have any sagging in the boiling water test. The boiling water test reported in Table 1 tested at least two different bags of the same composition (Bags 1-6).
Bags 3-5 also showed great results in other tests performed. The frozen chili 3o test and the frozen pizza test was performed twice on the same bag.
Specifically, the bag that was tested in the frozen chili test (Bag 3) and the bags tested in the frozen pizza test (Bags 4 and 5) showed good results in that they all had 10% or less of sagging. In fact, Bag 3 did not show any sagging after being tested in the frozen chili CHICA(i0 58902v1 47097-01003 test. It was surprising 'that a small amount of a cyclic olefin copolymer would produce the results shown in the boiling test, frozen chili test and the frozen pizza test.
Example 2 The films as shown in Table 2 (Films 1-5) were tested for various mechanical s properties. Specifically, tensile, elongation and modulus properties of the films were determined in accordance with ASTM D882. The visual appearance of Films 1-5 is also shown in Table 2 below.
Film 1 comprised 100 wt.% of linear low density polyethylene from Dow Chemical Company having a melt index of 2.0 g/10 min. as determined by ASTM
to D1238 and a density of 0.926 g/cm3. Films 2-5 comprised either 80 or 95 wt.% of the Dow Chemical LLDPE resin with the remainder being either TOPAS~ 8007 or TOPAS~ 6013. The average thicknesses of the films was from 2.5 to 3 mils. The tested films were formed by a cast process.
F5lm LLDPE' COCi Tensile ElongationModulus Appearance No. (wt. %) (wt. (kpsi (% at (kpsi) %) at break) break) 1 100 0 4.38 661 26.4 Clear 2 95 5 6._' 794 46.6 Clear 3 85 15' 4.83 556 67.4 Clear 4 95 5 3.01 605 18.4 Hazy 5 85 15 4.25 646 ~ 52.0 Hazy 1 The LLDPE had a melt index of 2.0 g/10 min. and a density of 0.926 g/cm'.
2 COC = cyclic olefin copolymer.
3 The COC was TOPAS~ 8007 with a melt index of 4.5 ml/ l0 min and a density of 1.02 g/cm' 4 The COC was TOPAS~ 6013.
Films 2, 3 and 5, with the cyclic olefin copolymer showed excellent modulus as zs compared to Film 1. Each of the modulus of Films 2, 3 and 5 was almost twice as high as the modulus value of Film 1 (the film without a cyclic olefin copolymer).
Compare 46.6, 67.4 and 52.0 kpsi vs. 26.4 kpsi in Table 2. The amount of increased modulus in Films 2, 3 and 5 was surprising considered the amount of cyclic olefin copolymer added (either 5% or 15%). Film 4 showed a reduced modulus as compared to Film 1.
3o The modulus of Films 2, 3 and 5 were especially surprising because the elongation CHICAGO 58902v1 47097-01003 values of Films 2, 3 and 5 were not much lower than the elongation value of Film 1 (compare 794, 556 and 646% vs. 661% in Table 2). In fact, the elongation of Film 2 was actually higher than the elongation of Film 1.
The tensile values of Films 2 and 3 were higher than that of Film 1 (compare 6.25 and 4.83 vs. 4.38 kpsi in Table 2), while the tensile value of Film S was slightly lower than Film 1 (4.25 kpsi vs. 4.38 kpsi). The appearance of the film was clear for Films 1-3, but was hazy for Films 4 and 5 that included TOPAS~ 6013. It is believed that the greater amount of norbornene included in TOPAS~ 6013, as compared to TOPAS~ 8007, produces a film that is hazy.
Io Example 3 The films of Table 2 were used in forming Bags 1-5. Bags 1-5 were tested to determine if the bags were self standing or could be made to stand-up with the addition of 1. S liters of water. The average thicknesses of the films used to form Bags 1-5 was from 2.5 to 3 mils. The films used in forming the bags were cast mono-layer.
t 5 TABLE 3 Bag No.s LLDPEI COCZ Stand Up Test w2. % Wt.
1 l 00 0 No 2 95 5' Yes, but with water inside 3 85 15 Yes 4 95 _ 5 Yes, but with water inside 85 15' Yesb 1 The LLDPE had a melt index of 2.0 g/ 10 min. and a density of 0.926 g/cm'.
2 COC = cyclic olefin copolymer.
2o 3 The COC was TOPAS~ 8007 with a melt index of 4.5 g/10 min. and a density of 1.02 g/cm'.
4 The COC was TOPAS~ 6013.
5 Bags 1-5 had a width of 5.5 inches and a height of 7 inches.
6 In addition to standing-up on its own and with the addition of water, Bag 5 also was a stand-up bag after being heated in a microwave at high power temperature for 2 minutes with water.
Bags 3 and 5 with the cyclic olefin copolymer were self stand up bags without the addition of water. Bags 2 and 4 with the cyclic olefin copolymer were stand-up bags with the addition of water. Bag 1, however, without the cyclic olefin copolymer 3o did not stand up with or without the addition of the water.
While the present invention has been described with reference to particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention.
Each of these embodiments and obvious variations thereof is contemplated as falling within the 3s spirit and scope of the claimed invention, which is set forth in the following claims.
CHICAGO 58902v1 47097-01003
Claims (59)
- WHAT IS CLAIMED IS:
A stand-up polymeric bag comprising first and second opposing body panels and a bottom wall, the first and second opposing body panels being coupled to opposing portions of the bottom wall, at least one of the first opposing body panel, the second opposing body panel and the bottom wall comprising a layer of from about 5 to about 95 wt.% of a polyolefinic resin and from about 5 to about 95 wt.% of a cyclic olefin copolymer, the cyclic olefin copolymer having a glass transition temperature, T G, of greater than about 20°C as determined by ASTM D3418. - 2. The bag of claim 1, wherein the first opposing body panel, the second opposing body panel and the bottom wall include the layer comprising from about 5 to about 95 wt.% of a polyolefinic resin and from about 5 to about 95 wt.% of a cyclic olefin copolymer.
- 3. The bag of claim 1, wherein the cyclic olefin copolymer comprises from about 10 to about 90 mol.% of norbornene.
- 4. The bag of claim 3, wherein the cyclic olefin copolymer comprises from about 20 to about 70 mol.% of norbornene.
- 5. The bag of claim 4, wherein the cyclic olefin copolymer comprises from about 35 to about 65 mol.% of norbornene.
- 6. The bag of claim 1, wherein the glass transition temperature, T G, of the cyclic olefin copolymer is greater than about 70°C as determined by ASTM D3418.
- 7. The bag of claim 6, wherein the glass transition temperature, T G, of the cyclic olefin copolymer is greater than about 100°C as determined by ASTM D3418.
- 8. The bag of claim 7, wherein the glass transition temperature, T G, of the cyclic olefin copolymer is greater than about 150°C as determined by ASTM D3418.
- 9. The bag of claim 2, wherein the first opposing body panel, the second opposing body panel and the bottom wall include the layer comprising from about 50 to about 95 wt.% of the polyolefinic resin and from about 5 to about 50 wt.%
of the cyclic olefin copolymer. - 10. The bag of claim 9, wherein the first opposing body panel, the second opposing body panel and the bottom wall include the layer comprising from about 75 to about 95 wt.% of the polyolefinic resin and from about 5 to about 25 wt.%
of the cyclic olefin copolymer. - 11. The bag of claim 10, wherein the first opposing body panel, the second opposing body panel and the bottom wall include the layer comprising from about 80 to about 90 wt.% of the polyolefinic resin and from about 10 to about 20 wt.%
of the cyclic olefin copolymer. - 12. The bag of claim 1, wherein the bottom wall comprises gusseted portions.
- 13. The bag of claim 1, wherein the polyolefinic resin is selected from the group consisting of low density polyethylenes, linear low density polyethylenes, high density polyethylenes, medium density polyethylenes, polypropylenes, plastomers, ethylene vinyl acetates, polymethylpentene copolymers and combinations thereof.
- 14. The bag of claim 13, wherein the polyolefinic resin is a low density polyethylene, a linear low density polyethylene or combinations thereof.
- 15. The bag of claim 1, wherein the bag further comprises a fastener.
- 16. The bag of claim 15, wherein the bag further comprises a slider.
- 17. The bag of claim 1, wherein the bag further comprises a reclosable seal.
- 18. The bag of claim 1, wherein the thickness of the first and second opposing body panels is from about 1 to about 5 mils.
- 19. The bag of claim 18, wherein the thickness of the first and second opposing body panels is from about 2 to about 4 mils.
- 20. The bag of claim 1, wherein the bag further includes a food product or a liquid stored therein.
- 21. The bag of claim 1, wherein the bag further includes at least one vent.
- 22. The bag of claim 1, wherein the bag is microwavable.
- 23. A stand-up polymeric bag comprising first and second opposing body panels and a bottom wall, the first and second opposing body panels being coupled to opposing portions of the bottom wall, at least one of the first opposing body panel, the second opposing body panel and the bottom wall including a layer from about 5 to about 95 wt.% of a polyolefinic resin and from about 5 to about 95 wt.% of a cyclic olefin copolymer, wherein the cyclic olefin copolymer comprises from about 10 to about 90 mol.% of norbornene.
- 24. The bag of claim 23, wherein the cyclic olefin copolymer further comprises from about 10 to about 90 mol.% ethylene.
- 25. The bag of claim 23, wherein the cyclic olefin copolymer comprises from about 20 to about 70 mol.% of norbornene.
- 26. The bag of claim 25, wherein the cyclic olefin copolymer comprises from about 35 to about 65 mol.% of norbornene.
- 27. The bag of claim 23, wherein the cyclic olefin copolymer has a glass transition temperature, T G, of greater than about 20°C as determined by ASTM
D3418. - 28. The bag of claim 27, wherein the cyclic olefin copolymer has a glass transition temperature, T G, of greater than about 100°C as determined by ASTM
D3418. - 29. The bag of claim 23, wherein the first opposing body panel, the second opposing body panel and the bottom wall include the layer comprising from about 50 to about 95 wt.% of the polyolefinic resin and from about 5 to about 50 wt.%
of the cyclic olefin copolymer. - 30. The bag of claim 29, wherein the first opposing body panel, the second opposing body panel and the bottom wall include the layer comprising from about 75 to about 95 wt.% of the polyolefinic resin and from about 5 to about 25 wt.%
of the cyclic olefin copolymer. - 31. The bag of claim 30, wherein the first opposing body panel, the second opposing body panel and the bottom wall include the layer comprising from about 80 to about 90 wt.% of the polyolefinic resin and from about 10 to about 20 wt.%
of the cyclic olefin copolymer. - 32. The bag of claim 23, wherein the polyolefinic resin is selected from the group consisting of low density polyethylenes, linear low density polyethylenes, high density polyethylenes, medium density polyethylenes, polypropylenes, plastomers, ethylene vinyl acetates, polymethylpentene copolymers and combinations thereof.
- 33. The bag of claim 32, wherein the polyolefinic resin is a low density polyethylene, a linear low density polyethylene or combinations thereof.
- 34. The bag of claim 23, wherein the bag further comprises a fastener.
- 35. The bag of claim 34, wherein the bag further comprises a slider.
- 36. The bag of claim 23, wherein the thickness of the first and second opposing body panels is from about 1 to about 5 mils.
- 37. The bag of claim 23, wherein the bag further includes a food product or a liquid stored therein.
- 38. The bag of claim 23, wherein the bag further includes at least one vent.
- 39. The bag of claim 23, wherein the bag is microwavable.
- 40. A stand-up polymeric bag comprising first and second opposing body panels and a bottom wall, the first and second opposing body panels being coupled to opposing portions of the bottom wall, at least one of the first opposing body panel, the second opposing body panel and the bottom wall including a first layer comprising from about 5 to 100 wt.% of a cyclic olefin copolymer and a second layer comprising from about 5 to 100 wt.% of a polyolefinic resin, the cyclic olefin copolymer having a glass transition temperature, T G, of greater than about 20°C as determined by ASTM
D3418. - 41. The bag of claim 40, wherein the first opposing body panel and the second opposing body panel comprise the first layer and the second layer.
- 42. The bag of claim 40, wherein the first layer further comprises from about 5 to about 95 wt.% polyolefinic resin.
- 43. The bag of claim 42, wherein the first layer comprises from 5 to about 50 wt.% cyclic olefin copolymer and from about 50 wt.% to about 95 wt.%
polyolefinic resin. - 44. The bag of claim 40, wherein the cyclic olefin copolymer comprises from about 10 to about 90 mol.% of norbornene.
- 45. The bag of claim 40, wherein the glass transition temperature, T G, of the cyclic olefin copolymer is greater than about 100°C as determined by ASTM
D3418. - 46. The bag of claim 45, wherein the glass transition temperature, T G, of the cyclic olefin copolymer is greater than about 150°C as determined by ASTM
D3418. - 47. The bag of claim 41, wherein the first opposing body panel and the second opposing body panel further include a third layer, the third layer comprising a polyolefinic resin.
- 48. The bag of claim 47, wherein the second layer and the third layer independently comprise either a linear low density polyethylene, a low density polyethylene or combination thereof.
- 49. The bag of claim 40, wherein the bag is microwavable.
- 50. A stand-up polymeric bag comprising first and second opposing body panels and a bottom wall, the first and second opposing body panels being coupled to opposing portions of the bottom wall, at least one of the first opposing body panel, the second opposing body panel and the bottom wall comprising a first layer of from about 5 to 100 wt.% of a cyclic olefin copolymer and a second layer comprising from about 5 to 100 wt.% of a polyolefinic resin, the cyclic olefin copolymer comprising from about 10 to about 90 mol.% of norbornene.
- 51. The bag of claim 50, wherein the first opposing body panel and the second opposing body panel comprise the first layer and the second layer.
- 52. The bag of claim 50, wherein the first layer further comprises from about 5 to about 95 wt.% polyolefinic resin.
- 53. The bag of claim 52, wherein the first layer comprises from 5 to about 50 wt.% cyclic olefin copolymer and from about 50 wt.% to about 95 wt.%
polyolefinic resin. - 54. The bag of claim 50, wherein the glass transition temperature, T G, of the cyclic olefin copolymer is greater than about 70°C as determined by ASTM D3418.
- 55. The bag of claim 50, wherein the cyclic olefin copolymer comprises from about 20 to about 70 mol.% of norbornene.
- 56. The bag of claim 55, wherein the cyclic olefin copolymer comprises from about 35 to about 65 mol.% of norbornene.
- 57. The bag of claim 51, wherein the first opposing body panel and the second opposing body panel further include a third layer, the third layer comprising a polyolefinic resin.
- 58. The bag of claim 57, wherein the second layer and the third layer independently comprise either a linear low density polyethylene, a low density polyethylene or combination thereof.
- 59. The bag of claim 50, wherein the bag is microwavable.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US59190100A | 2000-06-12 | 2000-06-12 | |
| US09/591,901 | 2000-06-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2345502A1 true CA2345502A1 (en) | 2001-12-12 |
Family
ID=24368422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2345502 Abandoned CA2345502A1 (en) | 2000-06-12 | 2001-04-30 | Stand-up polymeric bags |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2345502A1 (en) |
-
2001
- 2001-04-30 CA CA 2345502 patent/CA2345502A1/en not_active Abandoned
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